description
stringlengths 2.98k
3.35M
| abstract
stringlengths 94
10.6k
| cpc
int64 0
8
|
|---|---|---|
CROSS-REFERENCE TO RELATED APPLICATIONS.
Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT.
Not Applicable.
Reference to a “Microfiche appendix.”
Not Applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to within the wall supports for wall mounted fixtures such as lavatories, urinals, hospital and laboratory sinks, and drinking fountains.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
Eriksson in U.S. Pat. No. 2,716,757 discloses a lavabos with a support consisting of two parallel vertical rods which are clamped to a frame which holds the basin. The support is not enclosed within the wall.
Brady et al. in U.S. Pat. No. 3,932,899 disclose a support frame with security means, the support frame intended to be case into an associated concrete wall. The frame consists of two parallel vertical side frame elements and parallel top and bottom frame elements. The patent discloses the elements as secured by welding. The frame is case into concrete to provide a secure and impassable support for the fixture when it is embedded in concrete. The frame has a facility attached to the vertical side frame elements. A lavatory and water closet are attached to the facility.
Denhart in U.S. Pat. No. 4,158,898 discloses an adjustable support for the front of a wall mounted washstand to resist the weight of a person sitting or standing on the washstand. The support is mounted below the washstand and rests on the floor in an exposed position.
Morris et al. in U.S. Pat. No. 4,434,516 disclose a jig for a poured concrete wall consisting of a base and top member and two vertical members each with a web and flange along the wall. Multiple fixtures are permanently mounted on the jig and cross members prevent passage of objects from one fixture to another. The jig does not bear the load of the lavatory or that of a mounted water closet, which are supported by a box-like fixture which rests on the floor.
Klein et al. in U.S. Pat. No. 4,979,239 disclose a support structure for wall-mounted sanitary apparatus with legs and crossmembers which support a water closet above the floor. The structure consists of two parallel crossmembers which are connected by legs inclined in a V shape. Adjustable cramps on the ends of the lower crossmember support the structure on the floor. In another embodiment, uprights are pivotally attached to the cramps and are used to support the structure in a desired elevated position.
Wasek in U.S. Pat. No. 5,050,253 discloses an adjustable vanity assembly with a rail assembly made of two vertical side members, a top member, and a bottom traverse support which is not flush with the floor. Gas springs which are visible below the vanity permit vertical movement of the vanity and lock the vanity at a desired vertical height.
Kress et al. in U.S. Pat. No. 5,148,552 disclose an assembly space apron consisting of a metal reinforced plate which is substantially resistant to bending and is embedded in foam. The apron extends below the installation module to the floor and conceals the waste water draining pipe elbow and prevents access to the area below the module.
Zaccai et al. in U.S. Pat. No. 5,230,109 disclose a vertically adjustable lavatory assembly with an outer frame and a movable carrier frame. The outer frame consists of a preferably rectangular support carrier frame with vertical side walls with apertures, a top cross-member and a bottom cross-member positioned horizontally between the side walls. The outer frame does not support the lavatory directly, but supports a moveable carrier frame which in turn supports the lavatory.
Hall in U.S. Pat. No. 5,724,773 discloses a prefabricated building module of parallel frames which support a water closet on either side. Angle brackets at the bottom of the module are anchored to the floor by anchor bolts. A larger embodiment of the module is prefabricated preferably with a ceiling and is finished with drywall.
SMITH YELLOW PAGES, Jay R. Smith Mfg. Co., 1998, pages 0-22, 0-L1, 0-L3, 0-L5, 0-L7, 0-L9, discloses a variety of in wall supports for off-the floor urinals and lavatory and sink supports, drinking fountain, and electric water cooler supports. The supports consist of vertical uprights with sleeves or other adjustable arm supports attached to the uprights. No unitary supports are disclosed.
The prior art does not disclose in wall universal fixture supports of the present invention. The present invention has the advantages of being a prefabricated unitary support which is stronger than, requires less space for installation than, and is installed with less labor than conventional prior art supports.
BRIEF SUMMARY OF THE INVENTION.
The support of this invention is mounted in a wall and is rigidly attached to the floor. The support is used to hold universal fixtures which are mounted above the floor. The support is based on a rigid frame of two parallel side bars and an upper and a lower cross bar. The upper cross bar is permanently attached to one end of each side bar, the lower cross bar is permanently attached to the other end of each side bar, the side bars are perpendicular to the cross bars, and the frame defines a plane. Both cross bars have cut-outs to accommodate services and the lower cross bar has means for attaching the lower cross bar to the floor. A bracket is adjustably attached to each side arm, and each bracket has attached a connector for universal fixtures. A universal fixture connector is used to support and connect a universal fixture to the support. A universal fixture connector is attached to the bracket and the universal fixture extends approximately perpendicular to the plane of the frame. Brackets may be attached to both the front and the rear sides of the frame which allows one frame to serve to support universal fixtures on both sides of a wall.
The objective of this invention is to provide an in wall universal fixture support which transmits the weight of the universal fixture directly to the floor without transmitting substantial weight to the wall.
Another objective of this invention is to provide an in wall universal fixture support which is prefabricated with standard dimensions which accommodates a wide variety of universal fixtures.
Another objective of this invention is to provide an in wall universal fixture support in which the height of the universal fixture retention arms can be varied in order to comply with regulatory requirements.
Another objective of this invention is to provide an in wall universal fixture support with enhanced stability.
Another objective of this invention is to provide an in wall universal fixture support which can be installed with a minimum of time and labor.
Another objective of this invention is to provide an in wall universal fixture support with reduced space requirements.
Another objective of this invention is to provide an in wall universal fixture support with provisions for water, waste, and vent line pipe and electrical wiring installation without further drilling or tapping.
Another objective of this invention is to provide an in wall universal fixture support with enhanced strength which resists overloads placed on the universal fixture.
Another objective of this invention is to provide an in wall universal fixture support which can be shipped to the installation site in an assembled condition which requires only the adjustment of the height of the lavatory retaining arms during installation.
Another objective of this invention is to provide an in wall universal fixture support of universal application for supporting standardized universal fixtures produced by any commercial manufacturer.
Another objective of this invention is to provide an in wall universal fixture support which may be used to support a single universal fixture on one wall or may be used to support two universal fixtures, each mounted on the opposite sides of a wall.
A final objective of this invention is to provide an in wall universal fixture support which is inexpensive, easily manufactured, and which is manufactured and installed without adverse effect on the environment.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 is a plan view of the frame.
FIG. 2 is a cross section view of the frame taken along line 2 — 2 .
FIG. 3 is a cross section view of the frame taken along line 3 — 3 .
FIG. 4 is a plan view of the first embodiment bracket.
FIG. 5 is a cross section view of the bracket taken along line 5 — 5 .
FIG. 6 is a perspective view of the in wall support with the finish wall removed.
FIG. 7 is a side view of the in wall support showing the finish wall in cross-section.
FIG. 8 is a side view of the two sided in wall support used to support two universal fixtures with the finish walls in cross-section.
FIG. 9 is a plan view of a support for a drinking fountain.
FIG. 10 is a side view of the in wall support for a drinking fountain.
FIG. 11 is a plan view of a support for a urinal.
FIG. 12 is a side view of the in wall support for a urinal.
DETAILED DESCRIPTION OF THE INVENTION
In this patent application, the term “universal fixture” means a sink, fixed basin, urinal, drinking fountain, electric water cooler, and other similar structures, all of which have a structure which holds water, have a source of running water, have a drainpipe which removes water from the structure, and are mounted above the floor. The term “in wall” means the support is located in the space behind a finished wall. The term “services” means pipes or conduits for providing water to, removing waste water from, or venting a universal fixture, or providing wires for providing electricity to a universal fixture.
FIG. 1 shows the in wall support frame 20 . The frame is rectangular in shape with an elongated left side bar 30 and a right side bar 40 , both of which are permanently attached to the lower cross bar 60 and the upper cross bar 50 . The side bars 30 and 40 are parallel and each side bar is perpendicular to the upper cross bar 50 and the lower cross bar 60 . Although tubes rectangular in cross-section are used as side arms in this example, other cross-sectional shapes may be used for side arms, such as solid rectangular rods, circular rods or tubes, or other shapes with suitable strength and rigidity. Any suitable permanent and strong method of connecting the side bars and cross bars, such as securing with bolts, permanent adhesives, or welding. A preferred connecting method is robot welding in a precision locating fixture to assure consistent sizing, squareness and improved loading strength. In the preferred process, the finish weldments are cleaned and powder coated for environmental protection and ease of handling. Any suitable strong, rigid material resistant to deformation, such as steel, iron, aluminum, or fiberglass may be used in construction of the in wall support of this invention. A preferred material for the side bars and cross bars is 1010/1015 grade hot drawn steel.
In a preferred manufacturing process, the support is prefabricated in a factory.
The lower cross bar is firmly attached to the floor by suitable strong and rigid fastening means. All the weight of the support and the universal fixture, and all of the loading which might be placed on the fixture, is transmitted through the support directly to the floor. None of the weight is borne by the wall.
FIG. 2 is a cross-section view along line 2 — 2 of FIG. 1 . Fig two shows the underside of the upper cross bar 50 . The cross bar consists of a web 52 and a flange 54 which is at a right angle to the web 52 . Both the web 52 and flange 54 are of approximately the same width. A cut-out 56 in the web 52 accommodates services such as pipes which serve to provide water, drain water, or vent the universal fixture and electrical wires. Further circular cutouts 57 and 58 provide additional spaces for services to the universal fixture. Left side bar 30 is shown in FIG. 2 where it is welded to the upper cross bar 50 . The left side bar 30 front side 32 , inside side 38 , back side 36 , and outside side 34 are also shown. The left side bar back side 36 is flush with the flange 54 . Right side bar 40 is shown in FIG. 2 where it is welded to the upper cross bar 50 . The right side bar 40 front side 42 , inside side 48 , back side 46 , and outside side 44 are also shown. The right side bar back side 46 is flush with the flange 54 .
FIG. 3 is a cross-section view along line 3 — 3 of FIG. 1 . FIG. 3 shows the upper side of the lower cross bar 60 . The cross bar consists of a web 62 and a flange 64 which is at a right angle to the web 62 . Both the web 62 and flange 64 are of approximately the same width. A cut-out 66 in the web 62 accommodates services such as pipes which serve to provide water, drain water, or vent the universal fixture or electrical wires. Further holes 65 , 67 , 68 , and 69 are used to rigidly attach the lower cross bar 60 to the floor when the in wall support is installed. Two bolts or other suitable strong fasteners are used to make the connection with the floor. A variety of suitable means may be used to make a strong, rigid connection between the lower cross bar and the floor, such as bolts, brackets, mortar, or adhesive. Left side bar 30 is shown in FIG. 3 where it is welded to the upper cross bar 50 . The left side bar 30 front side 32 , inside side 38 , back side 36 , and outside side 34 are also shown. The left side bar back side 36 is flush with the flange 64 . Right side bar 40 is shown in FIG. 3 where it is welded to the upper cross bar 50 . The right side bar 40 front side 42 , inside side 48 , back side 46 , and outside side 44 are also shown. The right side bar back side 46 is flush with the flange 64 .
FIG. 4 is a plan view of the first embodiment bracket 70 . The bracket 70 is rectangular with parallel long sides 71 and 73 and parallel short sides 75 and 77 . An internally-threaded socket 76 is welded to the bracket. The socket 76 receives the threaded end of an universal fixture connector or extended lavatory retention arm ( 78 in FIG. 7) which supports and retains the universal fixture. Extended slots 72 and 74 are parallel with the long sides 71 and 73 . Bracket 70 is adjustably attached to the front side of a side arm by U-bolts which extend around the side arm and the ends of each U-bolt extends through the extended slots 72 and 74 . Nuts secure the bracket to the side arm. The bracket can be adjusted vertically on the side arm. A preferred material for the bracket is 1010/1015 hot drawn steel plate with a NPS conduit coupling welded to it. A preferred material for the U-bolts and straight bolts, nuts and washers is Grade 3 steel.
FIG. 5 is a cross section-view taken along line 5 of FIG. 4 . Bracket 70 is shown along with slots 72 and 74 and socket 76 . Also visible are the threads 81 on the inside of the socket. The socket 76 is mounted perpendicular to the flange.
FIG. 6 is a perspective view of an in wall support showing in dotted line a universal fixture, in FIG. 6, a sink 100 . FIG. 6 shows the upper side of the lower cross bar 60 . The cross bar consists of a web 62 and a flange 64 which is at a right angle to the web 62 . Both the web 62 and flange 64 are of approximately the same width. A cut-out 66 in the web 62 accommodates services such as pipes which serve to provide water, drain water, or vent the universal fixture or electrical wires. Further holes 65 , 67 , 68 , and 69 are used to rigidly attach the lower cross bar 60 to the floor when the in wall support is installed. Two bolts are used to make the connection with the floor. Other suitable strong fasteners may be used to make the connection with the floor. A variety of suitable means may be used to make a strong, rigid connection between the lower cross bar and the floor, such as bolts, brackets, mortar, or adhesive.
FIG. 6 shows the upper side of the upper cross bar 50 . The upper cross bar consists of a web 52 and a flange 54 which is at a right angle to the web 52 . Both the web 52 and flange 54 are of approximately the same width. A cut-out 56 in the web 52 accommodates services such as pipes which serve to provide water, drain water, or vent the universal fixture, or electrical wires. Further circular cutouts 57 and 58 provide additional spaces for services to the universal fixture. Left side bar 30 is shown in FIG. 6 where it is welded to the upper cross bar 50 and lower cross bar 60 . The left side bar 30 front side 32 and outside side 34 are also shown. Right side bar 40 is shown in FIG. 6 where it is welded to the upper cross bar 50 and lower cross bar 60 . The right side bar 40 front side 42 and inside side 48 are also shown.
A second embodiment flange is shown in FIG. 6 . The second embodiment flange 270 is identical to the first embodiment flange 70 of FIG. 4 except in the second embodiment the attachment for a lavatory retention arm consists of bolts 276 which extend through holes in the second embodiment flange 270 . The second embodiment flange 270 does not have a socket, 76 in FIG. 4. A second embodiment extended lavatory retention arm 278 is shown in FIG. 6 . The second embodiment arm differs from the first embodiment arm in the bracket attachment and in that the second embodiment arm is designed to support the universal fixture from below and to be visible while the first embodiment arm is designed to support the fixture through extension into a hole in the back of the fixture. The first embodiment universal fixture retention arm is not visible when the universal fixture is installed.
FIG. 6 shows the second embodiment bracket 270 and extended lavatory retention arm 278 attached to left side arm 30 , and an identical bracket and arm attached to right side arm 40 .
FIG. 7 is a side view of an installed in wall support. In room 94 the floor 90 and the finish wall 92 are shown in cross-section. The lower cross arm 60 is attached to the left side arm 30 . Visible in FIG. 7 is the lower cross arm web 62 and lower cross arm flange 64 . The lower cross arm flange 64 is attached to the floor 90 by bolts 82 . The upper cross arm 50 is shown along with the upper cross arm web 52 and upper cross arm flange 54 . Bracket 70 is attached to the front side 32 of the left arm 30 by U-bolts 71 and 73 which extend around the rear side 36 of the left arm 30 and are secured by nuts 75 and 77 . The socket 76 is attached to the bracket 70 and extends approximately perpendicular from the bracket 70 . The first embodiment extended lavatory retention bar 78 is attached by a threaded portion 79 to the socket 76 .
FIG. 8 shows a second embodiment in wall support in which one support is used to support two universal fixtures located in a first 94 and a second 194 back-to-back rooms which share a common wall. FIG. 8 is identical to FIG. 7, and the second embodiment identical to the first embodiment with respect to elements designated by a number less than 100 . The second finish wall 192 located in the second room 194 is shown in cross section. The bracket 170 is attached to the rear side 36 of the left arm 30 by bolts 171 and 173 and secured by nuts 175 and 177 . The socket connector 176 is attached to the bracket 170 and extends approximately perpendicular from the bracket 170 . The first embodiment extended lavatory retention bar 178 is attached by a thread 179 to the socket connector 176 .
FIG. 9 shows a plan view of a support for a drinking fountain. The in wall support frame is the same as that in FIG. 1 . The bracket 370 extends from the left side arm 30 to the right side arm 40 . Slots 372 and 374 , 376 and 378 are used to connect the bracket 370 to left side arm 30 and right side arm 40 , respectively. U-bolt which extend around the side arms are attached to the bracket by bolts 380 , 382 , 384 , 386 , 390 , 392 , 394 , and 396 . Holes 314 , 316 , 318 , and 320 are used to accommodate connector bolts which connect the drinking fountain to the bracket 370 . Hole 310 accommodates a water source for the drinking fountain and cut-out 312 accommodates the drain pipe.
FIG. 10 is a side view of an installed in wall support for a drinking fountain, indicated by dotted lines at 396 . The in wall support frame is the same as that in FIG. 7 . Bracket 370 is attached to the front side 32 of the left arm 30 by U-bolts 371 and 373 which extend around the rear side 36 of the left arm 30 and are secured by nuts 380 and 384 . Universal fixture connector bolts 391 and 393 are attached to bracket 370 and extend approximately perpendicular from bracket 370 . Bolts 391 and 393 support the drinking fountain 396 and are secured by nuts 395 and 397 , respectively.
FIG. 11 shows a plan view of a support for a urinal. The in wall support frame is the same as that in FIG. 1 . An upper bracket 570 and a lower bracket 470 support the urinal.
The lower bracket 470 extends from the left side arm 30 to the right side arm 40 . Slots 472 and 474 , 476 and 478 are used to connect the lower bracket 470 to left side arm 30 and right side arm 40 , respectively. U-bolts which extend around the side arms are attached to the bracket by bolts 480 , 482 , 484 , 486 , 490 , 492 , 494 , and 496 . Holes 481 and 483 are used to accommodate connector bolts which connect the urinal to the bracket 470 . Hole 410 accommodates services for the urinal.
The upper bracket 570 extends from the left side arm 30 to the right side arm 40 . Slots 572 and 574 , 576 and 578 are used to connect the upper bracket 570 to left side arm 30 and right side arm 40 , respectively. U-bolts which extend around the side arms are attached to the bracket by bolts 580 , 582 , 584 , 586 , 590 , 592 , 594 , and 596 . Holes 514 , 516 , 518 and 520 are used to accommodate connector bolts which connect the urinal to the upper bracket 570 . Hole 510 accommodates the drain for the urinal.
FIG. 12 is a side view of an installed in wall support for a urinal, indicated by dotted lines at 500 . The in wall support frame is the same as that in FIG. 7 . Upper bracket 570 is attached to the front side 32 of the left arm 30 by U-bolts 571 and 573 which extend around the rear side 36 of the left arm 30 and are secured by nuts 580 and 584 . Universal fixture connector bolts which connect the urinal to the upper bracket are not shown in FIG. 12. A horn 510 extends from the bracket and accommodates the waste water from the urinal 500 through the fixture support to a wastewater pipe (not shown in FIG. 12 ). A gasket 512 seals the connection between the horn 510 and the urinal 500 .
EXAMPLE 1
In a preferred example, the frame was constructed of side arms of rectangular tubes 1.50″×2.00″×0.125″ in thickness, and 42.00″ in length. The cross arms were of angle iron sections with the web and flange of 2.50″ in width, 0.25″ in thickness, and 20.00″ in length. Both the side arms and cross arms were of 1010/1015 grade hot drawn steel. The support bracket was rectangular 4.00″ by 6.00″, and 0.250″ in width. The support bracket was 1010/1015 hot drawn steel plate. A 1.00″ NPS conduit coupling was robot welded to the bracket. The side arms were robot welded to the cross arms and the conduit coupling was robot welded to the bracket using precision locating fixtures to assure consistent sizing, squareness and improved loading strength. The finish weldments were cleaned and power coated for environmental protection and ease of handling. The brackets were mounted to the side arms using ⅜″-16thd., Grade 3 steel “U” bolts, nuts and washers.
The in wall support is precision prefabricated to accommodate standard universal fixtures widely available from manufacturers for commercial and institutional applications. The dimensions may be altered to accommodate custom or non-standard universal fixtures. The in wall support for universal fixtures of this invention is structurally stronger under a radial load than conventional supports, and requires the use of only two bolts to fasten the support to the floor, as opposed to the six or eight bolts required by conventional methods. Conventional methods use two independent vertical upright beams to support the fixture, which requires bolting of two independent beams to the floor, and, importantly, requires careful measurement to insure that the horizontal dimensions between the beams are appropriate. After the in wall support of the present invention is bolted to the floor, the only adjustment required is the vertical adjustment of the brackets. A considerable saving in skilled tradesperson labor is obtained through the use of the in wall support of the present invention, and the finished installation allows more accurate and reproducible placement of the fixture than does conventional installations.
The in wall support of the present invention may be installed in a minimal space between finished walls because of the provisions for providing services to the universal fixture without further drilling, tapping, or adding additional components.
It will be apparent to those skilled in the art that the examples and embodiments described herein are by way of illustration and not of limitation, and that other examples may be used without departing from the spirit and scope of the present invention, as set forth in the appended claims.
|
This invention is a prefabricated very strong in wall support for universal fixtures mounted on a wall. Fixture support connectors or arms extend from the support and hold up the fixture. The in wall support is rigidly bolted to the floor so the support bears all the weight of the fixture and transmits the weight directly to the floor. The support is manufactured to accommodate standard fixtures. The height of the mounted fixture can be varied by moving the brackets which hold the fixture support connectors up and down. Brackets can be mounted on both the front and back of the support, thereby allowing the mounting of a fixture on both sides of a wall using a single support.
| 4
|
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a cutting tool of a cutting machine having a base element and a chisel holder, wherein the chisel holder has a plug-in shoulder which is retained in a plug-in receptacle of the base element, and wherein the plug-in receptacle is spatially connected with its surroundings via one or several openings.
[0003] 2. Discussion of Related Art
[0004] A cutting tool is known from German Patent Reference DE 43 22 401 C2. The cutting tool contains a chisel holder and a base element which is fastened to a cylinder-shaped cutting body of a cutting machine. For fastening the chisel holder on the base element, the base element has a plug-in receptacle with a V-guide, into which a plug-in shoulder of the chisel holder can be pushed. The chisel holder is fixed in place using a pressure screw. Thus the exact positioning of the chisel holder has particular importance, also in case of repeated assembly/disassembly and exchange.
[0005] For absorbing the forces occurring during the operation, the base element has a stop, on which the chisel holder is supported. So that the effects of the stop are maintained and stress on the plug-in shoulder and the plug-in receptacle is prevented to the greatest extent possible, the chisel holder is arranged offset by an adjusting space in the area around the plug-in receptacle.
[0006] It is disadvantageous in connection with such cutting tools which are employed, for example, in road construction, that the pulverized rock and water penetrate the area of the plug-in shoulder and the plug-in receptacle. Pulverized rock and water can cause the plug-in shoulder, as well as the pressure screw, to become caught in the plug-in receptacle. Thus, the chisel holder can only be released from the base element with increased effort. Often the parts are damaged during forcible separation, which results in a more cost-intensive replacement. Also, the pulverized rock results in increased wear in this area, which leads to reduced service life and therefore to higher operating costs. While releasing the pressure screw, dirt which becomes caught on the pressure screw from the interior, is worked into the threaded receptacle of the base element and damages it. A repair or replacement of the base element which must occur then can only be performed with added outlay, because customarily the base element is welded to the cutting cylinder tube and the adjacent base elements.
[0007] Dirt on the plug-in shoulder of the chisel holder and in the area of the plug-in receptacle of the base element is particularly disadvantageous. The particles adhering there are shattered during subsequent operation of the machine. Play is then created between the plug-in shoulder and the plug-in receptacle. The exactly fitted positioning of the chisel holder is then no longer assured. This has a negative effect, in particular during so-called fine milling. This method, which is gaining importance in actual use, is used to mill road surfaces to their final quality in one processing step. A prerequisite for this is that the chisel holders are exactly positioned. If one chisel holder does not meet these criteria, it causes a wrong spot in the milling pattern, which has an effect on the total result. Thus, a chisel holder which is seated loosely in the base element can decisively worsen the milling quality. Also, the loosely seated chisel can become completely separated from the base element and seriously damage the tool.
SUMMARY OF THE INVENTION
[0008] It is one object of this invention to provide a cutting tool of the type mentioned above but wherein the service life of the tool, in particular of the base element, is improved.
[0009] This object is achieved if at least one of the openings is at least partially closed by a sealing element.
[0010] The sealing element protects the transition area of the plug-in receptacle formed between the plug-in shoulder and the base element. It prevents the penetration of the plug-in receptacle by removed material and water in a simple and effective way. Once the chisel holder reaches its worn state, it can be pulled out of the plug-in receptacle. The reception chamber formed by the plug-in receptacle remains clean and substantially free of dirt. It is possible to position and fasten a fresh chisel holder with little loss of time. Thus, the sealing element forms a simple component, which permits a more effective tool change, and at the same time substantially increases the service life of the base element. The sealing element can also be formed by a grease layer.
[0011] Depending on the shape and arrangement of the sealing element, a reproducible and exactly fitting position of the chisel holder is possible.
[0012] In accordance with a preferred embodiment of this invention, the sealing element is arranged around the plug-in receptacle, at least in some areas between the chisel holder and the base element. With this an area is protected through which often massive amounts of dirt can enter.
[0013] Particularly effective sealing is achieved if the sealing element is embodied as a molded element having the contour of the circumference of the plug-in shoulder of the chisel holder. The design is particularly installation-friendly, because the sealing element can be placed on the plug-in shoulder of the chisel holder for mounting and can then be installed in the base element together with the chisel holder.
[0014] Because the base element has a circumferential bezel around the plug-in receptacle, which is used as a seat for the sealing element, the sealing element is immovably seated during operations. Also, the bezel provides the space into which the sealing element is definitely pressed when mounting without a possibility of being destroyed. An optimal sealing effect is thus achieved.
[0015] Permanent sealing of the area to be protected is achieved if the sealing element is made of a permanently elastic material, preferably of silicon, or of a thermoplastic elastomer.
[0016] In one embodiment, the chisel holder rests with its stop against the stop of the base element, the base element has a shoulder extending at an angle relative to the stop, a clearance acting as an adjusting space is formed between the shoulder of the base element and the side of the chisel holder facing the shoulder, and the sealing element is shaped so that it bridges this clearance. With this arrangement, pulverized rock and water cannot penetrate the plug-in receptacle through the adjustment space.
[0017] A particularly easy assembly and assured sealing effects are achieved if the sealing element is angled in a manner corresponding to the angle between the shoulder and the stop of the base element.
[0018] Good sealing of the different gap widths in the area of the stop and the adjustment space can be achieved if the sealing element has a section of an O-shaped cross section, which rests at least in part against the stop of the base element and has a section which is angled off relative to the base element, which rests against the shoulder of the base element and has a thickened cross section which bridges the clearance, at least partially.
[0019] In one embodiment, the angled-off section has a wedge-shaped sealing lip, which is matched to the shape of the adjustment space. Unevenness and production tolerances of the chisel holder and the base element are thus compensated.
[0020] A cost-effective manufacture, even in large numbers, as well as narrow tolerance and a design matched to the production process, are made possible if the sealing element is embodied as an injection-molded element, and the sprue nose is arranged in an area of or near the cross section which is thickened corresponding to the clearance. With this arrangement, the sprue nose does not hamper the sealing effect of the sealing element.
[0021] A simple and exactly fitting mounting of the chisel holder on the base element is achieved if the sealing element is drawn as a separate plastic component on the plug-in shoulder, or if the sealing element is injection-molded on the plug-in shoulder as a plastic component.
[0022] In one embodiment of this invention, the chisel holder of the cutting tool has a plug-in shoulder formed on a base body and the plug-in shoulder has a sealing element extending around the plug-in shoulder in at least partial areas of its outer circumference. Thus it is possible to preform the chisel holder with the plug-in shoulder and the sealing element as a structural unit, to stock it as a unit and to install it quickly and cost-effectively as a replacement part.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] This invention is explained in greater detail in view of exemplary embodiments represented in the drawings, wherein:
[0024] FIG. 1 is a lateral sectional view of a cutting tool with an exchangeable chisel holder in a partially assembled state;
[0025] FIG. 2 is a lateral sectional view of the cutting tool in accordance with FIG. 1 but with the chisel holder inserted;
[0026] FIG. 3 a is a sealing element in a top view; and
[0027] FIG. 3 b shows the sealing element in accordance with FIG. 3 a , in a lateral view.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0028] The cutting tool ( 1 ) in FIG. 1 comprises a base element ( 20 ), into which an exchangeable chisel holder ( 10 ) can be inserted. The cutting tool ( 1 ) has a sealing element ( 30 ) and a pressure screw ( 40 ), which is used for fixing the chisel holder ( 10 ) in place in the base element ( 20 ).
[0029] The chisel holder ( 10 ) includes a base body ( 17 ) and on its lower end has a plug-in shoulder ( 15 ), which can be inserted into a corresponding plug-in receptacle ( 22 ) at the base element ( 20 ). The insertion movement of the chisel holder ( 10 ) into the base element ( 20 ) is limited in its rear area by a stop ( 11 ) at the chisel holder ( 10 ) and by a stop ( 24 ) on the base element ( 20 ) located opposite it. On its front edge, the plug-in shoulder ( 15 ) has at least one guide face ( 15 . 1 ), which is guided during insertion of the chisel holder ( 10 ) by a corresponding V-guide ( 22 . 1 ) in the plug-in receptacle ( 22 ).
[0030] Also, the chisel holder ( 10 ) has a chisel receptacle ( 12 ), into which a turning chisel, which is also easy to exchange, can be inserted. The longitudinal axis of the chisel receptacle ( 12 ) forms an acute angle with respect to the axis of the plug-in shoulder ( 15 ).
[0031] A sealing element ( 30 ) is drawn on the plug-in shoulder ( 15 ) which contour is matched to the prism-shaped cross-section of the plug-in receptacle ( 22 ) with its guide faces ( 15 . 1 ). The sealing element ( 30 ) can be angled, relative to the angle between the shoulder ( 21 ) and the stop ( 24 ) of the base element ( 20 ). Here, the sealing ( 30 ) has an 0 -shaped cross section ( 31 ) in the area of or near the stop ( 24 ) and a cross section, which is thickened in comparison with it, in the area of the shoulder ( 21 ). Here, this area is preferably formed as a wedge-shaped sealing lip ( 34 ).
[0032] In the area of or near the plug-in receptacle ( 22 ), the base element has a bezel ( 23 ) extending around the plug-in receptacle ( 22 ), which is used as a seating for the sealing element ( 30 ).
[0033] FIG. 2 shows the same cutting tool as shown in FIG. 1 in section with the chisel holder ( 10 ) completely inserted into the base element ( 20 ). Here, the pressure screw ( 40 ), which is preferably embodied as a stud screw and has a screw thread ( 41 ) and a flattened shaft ( 42 ), acts with its shaft ( 42 ) on a pressure face ( 14 ) formed by a V-shaped recess ( 13 ) on the side of the plug-in shoulder ( 15 ) located opposite the guide face ( 15 . 1 ).
[0034] When the pressure screw ( 40 ) is tightened, forces result which push the chisel holder ( 10 ) against the base element ( 20 ). During this, the stop ( 11 ) of the chisel holder ( 10 ) is supported on the stop ( 24 ) of the base element. During this, the sealing element ( 30 ) is seated with its area ( 31 ) of O-shaped cross section in the bezel ( 23 ) of the base element ( 20 ) designed as the sealing seat. The originally O-shaped cross section is pressed during this so that an optimum sealing effect is generated.
[0035] A clearance ( 16 ), acting as an adjustment space, is formed between the shoulder ( 21 ) in the front part of the base element ( 20 ) and the face of the chisel holder ( 10 ) located opposite the shoulder ( 21 ). With its cross section, which is thickened in this area, and the simultaneous embodiment as a wedge-shaped sealing lip ( 34 ), the sealing element ( 30 ) bridges the clearance ( 16 ), so that an optimal sealing effect is also thus achieved. With this arrangement, no waste material particles can penetrate into the area of the plug-in receptacle. This makes the exchange of the chisel holders ( 10 ) easier. At the same time, with this arrangement no water with waste material particles can penetrate the area of the shaft ( 42 ) and the pressure face ( 14 ) of the plug-in shoulder ( 15 ).
[0036] FIGS. 3 a and 3 b represent an embodiment of the sealing element ( 30 ) in a top view and in a lateral view, respectively.
[0037] The sealing element ( 30 ) is embodied as a molded part, having the contour of the circumference of the plug-in shoulder ( 15 ) of the chisel holder ( 10 ). The sealing element ( 30 ) is angled corresponding to the angle between the shoulder ( 21 ) and the stop ( 24 ) of the base element ( 20 ), wherein the sealing element ( 30 ) has at least one section of an O-shaped cross section, which rests against the stop ( 24 ) of the base element ( 20 ). The angled section ( 32 ) resting against the shoulder ( 21 ) of the base element ( 20 ) has a cross section which is thickened corresponding to the clearance ( 16 ). An angled section ( 32 ) embodied as a wedge-shaped sealing lip ( 34 ) increases the sealing effect.
[0038] In this case, the sealing element ( 30 ) is made of a permanently elastic material and is preferably designed as an injection-molded element. Silicons are used as the materials. Examples of this are so-called liquid silicon rubbers (LSR), for example SILOPREN(R) made by GE BAYER Silicones, which can be produced by the so-called liquid injector molding (LIM) process. Also suitable are thermoplastic elastomers, for example SANTOPRENE®, made by ADVANCED ELASTOMER SYSTEMS, which can be worked by the normal injection-molding process. The sprue, which is customary in connection with injection-molding processes, is displaced into the thickened area of the clearance ( 16 ), so that the sprue nose ( 33 ) does not hamper the sealing effect of the sealing element ( 30 ).
[0039] The sealing element ( 30 ) can be directly formed on the formed-on plug-in shoulder ( 15 ) of the chisel holder ( 10 ), and thus enclosing the exterior circumference of the plug-in shoulder ( 15 ) at least partially. In the same way, the sealing element ( 30 ) can be directly formed on the base element ( 20 ) in the area around or near the plug-in receptacle ( 22 ) and can enclose the exterior circumference of the plug-in receptacle ( 22 ), at least partially.
[0040] This invention is not limited to the cross-sectional shape of a plug-in shoulder ( 15 ) represented above and any arbitrary different cross-sectional variants are possible, such as round cross sections or plug-in shoulders of a conical shape, for example.
[0041] As shown in the drawings, the plug-in receptacle ( 22 ) in the base element ( 20 ) facing away from the chisel holder ( 10 ) is open. This opening is closed, together with the connected cutting cylinder tube, not represented in the drawings, by a weld seam connection.
|
A cutting tool of a cutting machine having a base part and a bit holder. According to this invention, the bit holder has a plug-in attachment, retained in a socket of the base part that has a stop against which the bit holder rests. To prevent the penetration of water and stone dust and to allow the bit holder to be easily detached from the base part, a sealing element is located between the bit holder and the base part, surrounding at least sections of the socket.
| 4
|
CROSS-REFERENCE TO RELATED APPLICATIONS
The following Application is related to U.S. patent application Ser. No. 10/136,684 filed on the same day with the same inventors.
BACKGROUND
MicroElectroMechanical systems (MEMS) routinely use suspended micromechanical moveable electrode structures as electrostatically actuated mechanical members for both sensor and actuator based devices. Different methods exist for creating a support structure to suspend a moveable electrode structure. One method for suspending such a moveable electrode uses cantilevered members that are fixed to a substrate on one end and fixed to the movable electrode structure on the other end. In an alternate embodiment, the cantilever is made of, or coated with a conducting material and the cantilever itself serves as the moving electrode. The mechanical flexibility of the cantilever (e.g. bending) and/or motion at the fixed end(s) (e.g. hinge or flexible connection) allows for the motion of the suspended electrode. In some cases, the sensor or actuator device is based on motion of cantilever as such without an additional movable structure at the end of the cantilever. Such cantilevers are typically fixed-free or fixed-simply supported cantilevers.
A second method of suspending one or more moveable electrodes utilizes a plurality of cantilevers that support a moveable member which either serves as a moveable electrode or has mounted upon it moveable electrodes. A fixed electrode serves as an actuator to control movement of the moveable electrode structure through the application of an electric potential difference between the fixed electrode and the moveable electrode structure. The fixed electrode is typically positioned beneath the suspended moveable electrode to form a parallel plate capacitor like structure, with the fixed electrode acting as a first plate and the suspended moveable electrode acting as a second plate. The electric potential applied to the electrodes generates electrostatic forces that move or deform the support mechanism supporting the moveable electrode or the moveable electrode itself. Such support mechanisms may include bendable or otherwise deformable cantilevers.
Typical cantilever applications include micro sized relays, antennas, force sensors, pressure sensors, acceleration sensors and electrical probes. Recently, considerable attention has been focused on using cantilever arrays to develop low power, finely tunable micro-mirror arrays to redirect light in optical switching applications. Such a structure is described in U.S. Pat. No. 6,300,665 B1 entitled “Structure for an Optical Switch on a Silicon on Insulator Substrate” hereby incorporated by reference.
One problem with such cantilever structures is the limited amount of controllable motion that can be achieved with traditional arrangements of the cantilever and electrode. When a voltage difference is applied between two electrically conducting bodies separated by an insulating medium (for example air), the electrostatic force between the two bodies is inversely proportional to the square of the distance between the bodies. Thus when the moveable electrode is moved in closer proximity to the fixed electrode, as often occurs when a greater range of motion is attempted, strong electrostatic forces between the fixed electrode and the moveable electrode results in a “pull-in” or “snap-down” effect that causes the two electrodes to contact. The problem is particularly acute in D.C. (direct current) systems compared to A.C. (alternating current) systems.
In moving the electrodes, instability theoretically occurs in parallel plate capacitor structures when the movably suspended plate has traveled one third of the potential range of motion (typ. equal to the height of the air gap) In stressed metal systems, as described in the previously cited patent application, the cantilevers are typically ‘curled’—as opposed to more typical ‘straight’ cantilevers. However, such instability usually occurs when the actuation electrode is placed underneath the cantilever and the cantilever moves approximately beyond one-third of its potential range of motion.
Various solutions have been proposed to correct the potential for suspended electrodes and the corresponding supports structures to “snap-down”. These solutions include the following: using charge drives (see Seeger, et. al, “Dynamics and control of parallel-plate actuators beyond the electrostatic instability”, Proc. Transducers '99, Sendai), adding capacitive elements in series (Seeger, et. al, “Stabilization of Electrostatically Actuated Mechanical Devices”, Proc. Transducers '97, Chicago) or creating closed-loop feedback systems using capacitive, piezoresistive or optical detectors (Fujita “MEMS: Application to Optical Communication”, Proc. of SPIE, '01, San Francisco). These methods extend the stable range of motion to varying degrees. However all these methods complicate fabrication of the cantilever and actuator mechanism thereby increasing fabrication costs and reducing reliability. Thus an improved method of moving a cantilever through a wide range of motion while avoiding instabilities is needed.
SUMMARY OF THE INVENTION
An improved system for controlling electrostatic deflection of a support mechanism associated with a moving electrode is described. In the system, a fixed electrode formed on a substrate uses electrostatic forces to control the motion of a moveable electrode coupled to a support structure. In order to avoid the strong electrostatic attractions that occur when the moveable electrode comes in close proximity to the fixed electrode on the substrate, the electrodes are offset such that a substantial portion of the fixed electrode is adjacent to, rather than directly in the path of the moveable electrode's range of motion.
BRIEF SUMMARY OF THE DRAWINGS
FIG. 1 shows a side view of a moveable electrode and a fixed electrode.
FIG. 2 shows a side and top view of a second support structure used to suspend a moveable electrode over a fixed electrode.
FIG. 3 is a flow chart showing one example method of forming a cantilever in a MEMS structure.
FIG. 4 shows a top view of a traditional placement of electrodes with respect to the cantilever.
FIG. 5 shows a top view of one possible placement of rectangular electrodes with respect to the cantilever.
FIG. 6 shows a top view of one possible placement of triangular electrodes with respect to the cantilever.
FIG. 7 shows a top view of a possible placement of a triangular or rectangular electrode with respect to a cantilever with a cutout area.
FIG. 8 is a graph showing a theoretical plot of cantilever height with respect to applied voltage for various electrode and cantilever structures.
FIG. 9 shows a cantilever used in a optical switching system.
FIG. 10 shows a plurality of cantilevers coupled to a mirror to redirect an optical beam across a two dimensional area.
FIG. 11 shows a top view of one possible placement of triangular electrodes with respect to the cantilever.
DETAILED DESCRIPTION
FIGS. 1 and 2 show two examples of MEMS cantilevered actuator structures. FIG. 1 shows a side view of a simple fixed end—free end cantilever-electrode structure. The example of the cantilever shown in FIG. 1 is a flexible cantilever that flexes upward and may be formed using techniques for forming stressy metal structures as described in U.S. patent application Ser. No. 5,613,861 entitled “Photolithographically Patterned Spring Contact” which is hereby incorporated by reference. In FIG. 1 , a flexible cantilever 104 is affixed to a substrate 108 at a fixed point 112 . Typically, the cantilever is composed of or coated with an electrically conducting material to form a suspended moveable electrode 114 that facilitates the generation of electrostatic forces between moveable electrode 114 and a fixed electrode actuator. Examples of suitable materials for forming the cantilever include metal, silicon and polysilicon. In an alternate embodiment, the cantilever is a stressed metal to create the curve structure illustrated. Such stressy metal cantilevers may be formed from a refractory metal such as molybdenum, zirconium and/or tungsten (Mo, Zr, W).
Fixed electrode 116 deposited on substrate 108 controls movement of moveable electrode 114 and thereby cantilever 104 . Moving electrode 114 moves in an arc in a motion plane 110 , which in the illustrated example, is oriented perpendicular to the substrate surface (in the illustrated embodiment, the paper in which the drawing is drawn represents motion plane 110 ). When a voltage difference is applied between fixed electrode 116 and moving electrode 114 , cantilever 104 moves towards fixed electrode 116 . When moving electrode 114 is maximally displaced along a trajectory of motion in motion plane 110 such that moving electrode 114 is in the lateral plane of substrate 108 , the position of the moving electrode is shown by outline 120 . In FIG. 1 , cantilever 104 flexes although in an alternate embodiment, a rigid cantilever may pivot around fixed point 112 .
Cantilever 104 may be made of a variety of materials such as metal, silicon, polysilicon or other electrically conductive materials to serve as a moveable electrode. Alternatively, the cantilever may be made of an insulating material such as polymers, ceramics and the like, and subsequently coated with a conductive material such as a metal film, the conductive material coating serving as the moveable electrode. Appropriate dimensions of the cantilever are a length 118 of less than 5000 micrometers (less than 500 typical) and a width of less than 1000 micrometers (less than 100 typical) although alternate embodiments may use larger cantilevers.
In order to maintain control over the moving electrode and its associated support structure through a large range of motion, the fixed electrode is positioned such that it is laterally adjacent to, rather than directly underneath the cantilever. For purposes of discussion, “laterally adjacent” is defined as a position adjacent to the trajectory of the moving electrode such that even when the moving electrode is maximally displaced such that the moving electrode, in this case the cantilever, is in the lateral plane of the substrate, the two electrodes are adjacent in the plane of the substrate. In most cases, even when the moving electrode moves in an arc, the arc radiuses are small such that the moving in a trajectory is practically equivalent to translating the suspended electrode along a line perpendicular to the surface of the substrate supporting the fixed electrode. Once the two electrodes are in the plane of the substrate, “laterally adjacent” does not require or imply that the moving electrode and the fixed electrode are in contact, merely that the electrodes are close, typically separated by less than approximately 50 micrometers (e.g. 5 μm) when the moving electrode is in the lateral plane of the substrate. It is contemplated however, that the system may still operate when the electrodes are not entirely laterally adjacent, thus when small amounts of overlap result, typically less than 10 percent of the electrode surface are, fringe electric fields are the dominant source of attraction between the moving electrode and the fixed electrode and stability may still be archived.
Even when the cantilever is not displaced from its resting position, the distance from the fixed electrode to the moving electrode should be kept relatively small, for example less than 10 micrometers to allow the effects of electrostatic attraction to control movement of the cantilever in a reasonable voltage range (typically less than 200 volts). When the entire surface area of the electrode is laterally adjacent to rather than underneath the cantilever; direct contact between the cantilever and the electrode when the cantilever is at a maximum displacement is avoided thereby making an insulating layer over the fixed electrode unnecessary.
A side view of an alternative mechanism for suspending a moving electrode is shown in FIG. 2 . The structure of FIG. 2 is a slight variation on what is typically called a Lucent mirror, Lucent mirrors have traditionally been used to redirect light in optical systems. In FIG. 2 , a straight, torsionally flexible cantilever 204 is affixed to a substrate 208 at a fixed point 212 and affixed to a movably suspended member 216 . Together, the elements represent a support structure for a moving electrode. In one embodiment of the invention, member 216 is composed of or coated with an electrically conducting material and thus also serves as the moveable electrode. The conducting material aids the generation of electrostatic forces between the moveable electrode and a fixed electrode 220 that serves as an electrode actuator. Examples of suitable materials from which to form the moveably suspended member include metal, silicon and polysilicon. Fixed Electrode 220 on substrate 208 controls movement of member 216 . In the illustrated embodiment, member 216 rotates about an axis 224 . Axis 224 is oriented parallel with the substrate surface. When a voltage difference is applied between fixed electrode 220 and a moving electrode associated with member 216 , member 216 rotates towards the fixed electrode. In the illustrated embodiment, cantilever 204 flexes torsionally although in alternate embodiments the tortional flexing may be replaced by a rigid cantilever that pivots around fixed point 228 .
Flexing cantilever 204 may be made of a variety of flexible materials such as metal, silicon, polysilicon. Appropriate dimensions of the cantilever are a length 232 of less than 5000 micrometers (less than 500 typical) and a width of less than 1000 micrometers (less than 100 typical) although alternate embodiments may use larger cantilevers. In order to maintain control over movements through a large range of motion, the fixed electrode is positioned such that it is laterally adjacent to, rather than directly underneath the moving electrode, in the illustrated example, suspended member 216 is formed from a conducting material and serves as the moving electrode. Even when the suspended member is not displaced from its resting position, the distance to the fixed electrode should be kept relatively small, for example less than 10-100 micrometers to allow the effects of electrostatic attraction to control movement of the cantilever in a reasonable voltage range (typically less than 200 volts). When the entire surface area of the electrode is laterally adjacent to rather than underneath the suspended member; direct contact between the cantilever and the electrode when the cantilever is at a maximum displacement is avoided thereby making an insulating layer over either electrode unnecessary.
In yet another variation of the structure shown in FIG. 2 , voltage differences may be simultaneously applied between suspended member 216 and multiple fixed electrodes such as fixed electrode 220 , thereby causing suspended member 105 ′ to translate downward, towards the plane of the fixed electrodes. By keeping the forces approximately equal across the suspended member, rotational motion may be avoided. In this translational case, instability occurs at one third of the potential travel range when fixed electrodes 220 are placed directly underneath suspended the moving electrode represented by suspended member 216 . Laterally offsetting the electrodes as shown in FIG. 2 substantially extends the stable range of motion beyond one third of the potential range, approaching the full potential travel range.
A number of methods exist to fabricate cantilever and actuator MEMS structures. FIG. 3 illustrates one method of fabricating the cantilever electrode structure using a three step semiconductor masking process. Although the process is described to enable one of ordinary skill in the art to fabricate a semiconductor cantilever, the invention should not be limited to the particular type of cantilever described nor the particular method used to fabricate the cantilever and electrode structures.
In operation 304 of FIG. 3 , an electrode material is deposited on a substrate such as glass or quartz. The electrode material may be made from a number of conducting materials or metals such as chromium. After deposition, a pattern masking and wet etch is done in operation 308 to define the electrode and tracks or wires that couple the electrode to controlling circuitry. The controlling circuitry controls the charge and discharge of the electrode thereby controlling the motion of the cantilever. The thickness of the electrode may be tuned to obtain a sheet resistance suitable for resistive sensing. Chromium has a resistivity of about 130×10 9 Ohms/M, thus a thin film of 25 nm results in about 5 ohms/square.
In operation 312 , a release layer, such as an amorphous silicon release layer is deposited. Typically, the release layer thickness determines the spacing between the cantilever and the substrate surface. The release layer is often slightly thicker than the electrode layer. The release layer serves as a buffer layer to prevent the entire subsequent cantilever layer from adhering to the substrate. A cantilever layer, such as a Molybdenum chromium (MoCr) layer is deposited in a blanket coat over the release layer in operation 316 . A typical cantilever thickness is approximately 1 micrometer. When a stressed metal cantilever is desired, a stressed metal deposition is used to deposit the cantilever layer.
In operation 320 , a second mask layer is used to define the cantilever shape by etching away the excess MoCr. In operation 324 , the release layer is etched to release the cantilever leaving only one end of the cantilever affixed directly to the substrate. A typical method for etching a silicon release layer utilizes a dry etch of XeF 2 as the etchant. When using other release layer materials, such as for example silicon oxide, a wet etch (e.g hydrofluoric acid) is typically used to remove the sacrificial layer.
FIGS. 4 , 5 , 6 and 7 are top views of the fixed electrode and a moving electrode cantilever structure that show alternate positions of the electrodes with respect to the cantilever. FIG. 4 shows a top view of a traditional cantilever over electrode structure. At contact area 404 , the cantilever is fixed to an underlying substrate, either directly or through an intermediate layer. The flexing region 408 of the cantilever rests directly over an electrode underneath which controls movement of the cantilever. The close proximity and direct application of force by electrodes positioned underneath the cantilever minimizes the operational voltage needed to move the cantilever. However, the reduced power requirements come at the expense of great instability. Voltages greater than a critical voltage results in the cantilever “snapping” down towards the substrate.
FIG. 5 shows one embodiment of the invention that utilizes rectangular strip electrodes 504 oriented with a length that runs parallel to the length of cantilever 508 . Because electrodes 504 are not positioned directly underneath the cantilever, the laterally displaced rectangular strip electrodes depend on fringe electric fields to pull the cantilever downward. As the cantilever moves downward towards the substrate, the force vector of the electric field between the cantilever and the electrode increasingly points in a lateral direction (in the plane of the substrate) rather than in a downward direction towards the substrate. Thus, although the intensity or absolute value of the electric field increases as the cantilever moves toward the substrate, a greater percentage of the force is applied in a lateral direction reducing the rapid increase in electric field strength downward. A symmetrical arrangement of electrodes around the cantilever causes the lateral force components to cancel thereby minimizing displacement of the cantilever in a lateral direction.
To further increase the stable range of motion, triangular electrodes 604 , 608 may be substituted for the rectangular electrodes as shown in FIG. 6 . In this embodiment, the distance between the cantilever and the fixed electrodes increases along the length of the cantilever. The increasing distance between the cantilever and the fixed electrode further reduces the force for a given voltage along the length of the cantilever further increasing the stable range of motion. The embodiment of FIG. 6 requires the highest voltages compared to the structures shown in FIG. 5 and FIG. 6 to achieve an equivalent displacement of the cantilever, although the actual voltage required depends on many factors including cantilever and electrode geometries, dimensions of the cantilever, material properties, etc. A typical voltage to achieve a large displacement of cantilever 612 may be approximately 150 volts. Because the triangular electrodes also provide a fairly constant balance between applied force on the cantilever and cantilever flexibility across the length of the cantilever, the configuration illustrated in FIG. 6 provides the most stable configuration.
The triangular electrodes shown in FIG. 6 results in a spacing between the cantilever and the edge of the electrode remaining fairly linear with respect to voltage applied to the electrodes. In general, stability of the system is increased when the moving and/or fixed electrode is shaped such that the distance between the closest point on the fixed electrode and the closest point on the moving electrode increases with distance from the point at which the support structure supporting the moving electrode is coupled to the substrate. Various ways of accomplishing the gradually increasing distance include forming triangular fixed electrodes, forming triangular moving electrodes, or angularly orienting rectangular fixed and moving electrodes such that the space between the edges of the electrodes form a triangle. Other embodiments of the invention may also use electrodes with other tapered geometries (e.g. curved as opposed to straight). These different configurations may be used to linearize or otherwise tailor the displacement versus voltage curve.
FIG. 11 shows repositioning of the fixed electrodes 604 in FIG. 6 such that a small portion of the fixed electrodes is overlapped by moving electrode 612 . The overlap portion is preferably less than 10% leaving 90% of the fixed electrode 604 extending beyond moving electrode 612 was opposed to having no overlap and 100% of the fixed electrode 604 extending beyond moving electrode 612 as shown in FIG. 6 . It may be theoretically possible to have up to a 50% overlap and still have proper control of the moving electrode.
FIG. 7 shows an embodiment of the invention in which a tapered (or straight) fixed electrode 704 is formed underneath a cutout area 708 of cantilever 712 . This and other types of ‘cutout’ cantilevers with ‘internally adjacent’ electrodes are based on the same concept as other laterally offset actuation electrodes, but may offer additional advantages. For example, the embodiment shown in FIG. 7 offers the advantages of adjacent electrodes while utilizing a minimum of area.
FIG. 8 is a graph that shows the vertical height of a cantilever tip in micro-meters as a function of a direct current (D.C.) voltage applied to the electrode for different electrode geometries and positions based on a simple numerical model. Each line 804 , 808 and 812 can be divided into two regions: (1) an actuation region in which an air gap exists between the cantilever and the substrate resulting in a nonzero cantilever tip height and (2) a critical voltage at which the cantilever “snaps” down to the substrate eliminating the gap between cantilever and substrate.
Line 804 shows the cantilever tip position as a function of electrode voltage for a traditional positioning of an electrode under the cantilever. In the model, the cantilever can only be controlled at a height displacement above approximately 110 micrometers. At approximately 20 volts, snap-down occurs after which manipulation of the cantilever over small displacements cannot be well controlled. When the electrode is placed under the cantilever, typically, the entire cantilever snaps down.
Line 808 shows a modeling of the cantilever height as a function of voltage for two rectangular parallel electrodes positioned adjacent to the cantilever as shown in the top view of FIG. 4 . From line 808 , it can be observed that the displacement of the cantilever can be well controlled for cantilever heights above 100 micro-meters. The cantilever snaps down at a critical voltage of approximately 55 volts
Line 812 plots cantilever height as a function of voltage for two electrodes positioned laterally adjacent to the cantilever, the two electrodes shaped such that the electrode edges closest to the cantilever increases in distance from the cantilever edge as one moves along the length of the cantilever. Such a structure may be achieved by using triangular electrodes as was shown in FIG. 6 , or by orienting straight lines electrodes such that they point slightly away from the cantilever edges. Comparing line 812 to lines 804 and 808 , it can be seen that the actuation region for the laterally adjacent triangular electrodes is substantially larger than the actuation region for the electrode positioned underneath the cantilever and the rectangular electrodes positioned laterally adjacent to the cantilever Thus the cantilever has a large actuation region allowing for control of the cantilever over a wide range of voltages and tip heights.
It should be understood that the foregoing described cantilevers may be used for a variety of structures, systems and applications, including but not limited to optical switching. FIG. 9 shows a simple cantilever used in a simplified optical switching system. In FIG. 9 , an optical fiber 904 in an array of optical fiber acts as a light source that outputs a ray of light 908 . The ray 908 is focused by a lens 912 and directed to a mirror 916 . The position of mirror 916 is controlled by electrode 920 positioned laterally adjacent to cantilever 924 . The orientation of mirror 916 determines which lens in receiving lens array 928 receives light. The receiving lens focuses the received light on a corresponding fiber in receiving fiber array 932 .
In the illustrated embodiment of FIG. 9 , mirror 916 positioned at the end of cantilever 924 offers movement in only one plane along an arc that represents the motion of a single cantilever. However, in array switching operations, it may be desirable to redirect light to various points in a two dimensional array.
FIG. 10 shows a mirror region 1004 affixed to the end of a plurality of cantilevers 1008 , 1012 , 1016 , 1020 . Each cantilever, such as cantilever 1008 , includes a fixed end, such as fixed end 1024 affixed to an underlying substrate. Fixed electrodes, such as electrodes 1028 and electrode 1032 typically are formed on the underlying substrate and run along the perimeter of a corresponding cantilever. Each electrode, such as electrode 1028 can be considered laterally adjacent to the corresponding cantilever and may be used to deflect the corresponding cantilever. An end of cantilever 1008 opposite fixed end 1024 is coupled to mirror region 1004 , thus as the cantilever moves up or down, the edge of the mirror coupled to the cantilever also moves up or down accordingly. The portion of the electrode near the fixed end such as fixed end 1024 serves mainly to couple the different sections of the electrode and keep the entire electrode at a fixed potential.
Other configurations of cantilevers and mirrors are also available as described in patent application Ser. Nos. 09/672,381 and 09/675,045 entitled “Method for an Optical Switch on a Silicon Substrate” and “Structure for an Optical Switch on a Substrate” respectively, both patent applications are hereby incorporated by reference. Control of the various mirror and cantilever configurations described in the references can be improved by placement of electrodes adjacent to the cantilevers.
The foregoing description includes a number of details that are provided to provide a clear understanding of the technology and the invention as well as to provide examples of different ways of using and/or implementing the technology. Details in the description such as dimensions, materials used to fabricate the device, and particular geometries should not be used to limit the invention. Likewise, it should be appreciated by those skilled in the art that other geometries and combinations are possible for suspension cantilevers and suspended structures, as well as for mechanical motions. It will also be appreciated by those skilled in the art that the presence of laterally offset electrodes does not preclude the presence of other, additional electrodes in any position or orientation, for any additional purpose (such as linearizing the deflection vs. voltage curve and the like). Thus, the invention should only be limited by the restrictions recited in the claims which follow.
|
A MEMS system including a fixed electrode and a suspended moveable electrode that is controllable over a wide range of motion. In traditional systems where an fixed electrode is positioned under the moveable electrode, the range of motion is limited because the support structure supporting the moveable electrode becomes unstable when the moveable electrode moves too close to the fixed electrode. By repositioning the fixed electrode from being directly underneath the moving electrode, a much wider range of controllable motion is achievable. Wide ranges of controllable motion are particularly important in optical switching applications.
| 1
|
This application is a continuation and claims the benefit under 35 U.S.C. §120 to U.S. patent application Ser. No. 09/663,372, filed on Sep. 12, 2000, now U.S. Pat. No. 6,389,890 issued on May 21, 2002, which is a continuation of U.S. patent application Ser. No. 09/267,498, filed on Mar. 12, 1999, which became abandoned on Oct. 27, 2000.
BACKGROUND OF THE INVENTION
1. Technical Field
The invention relates generally to electrical downhole tools which are employed for various downhole oil-field applications, e.g., firing shaped charges through a casing and setting a packer in a wellbore. More particularly, the invention relates to a pressure-actuated downhole tool and a method and an apparatus for generating pressure signals which may be interpreted as command signals for actuating the downhole tool.
2. Background Art
Electrical downhole tools which are used to perform one or more operations in a wellbore may receive power and command signals through conductive logging cables which run from the surface to the downhole tools. Alternatively, the downhole tool may be powered by batteries, and commands may be preprogrammed into the tool and executed in a predetermined order over a fixed time interval, or command signals may be sent to the tool by manipulating the pressure exerted on the tool. The downhole pressure exerted on the tool is recorded using a pressure gage, and downhole electronics and software interpret the pressure signals from the pressure gage as executable commands. Typically, the downhole pressure exerted on the tool is manipulated by surface wellhead controls or by moving the tool over set vertical distances and at specified speeds in a column of fluid. However, generating pressure signals using these typical approaches can be difficult, take excessively long periods of time to produce, or require too much or unavailable equipment. Thus, it would be desirable to have a means of quickly and efficiently generating pressure signals.
SUMMARY OF THE INVENTION
In general, in one aspect, a hydraulic strain sensor for use with a downhole tool comprises a housing having two chambers with a pressure differential between the two chambers. A mandrel disposed in the housing is adapted to be coupled to the tool such that the weight of the tool is supported by the pressure differential between the two chambers. A pressure-responsive member in communication with one of the chambers is arranged to sense pressure changes in the one of the chambers as the tool is accelerated or decelerated and to generate signals representative of the pressure changes.
Other aspects and advantages of the invention will be apparent from the following description and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of a downhole assembly for use in performing a downhole operation in a wellbore.
FIG. 2 is a detailed view of the hydraulic strain sensor shown in FIG. 1 .
DETAILED DESCRIPTION
Referring to the drawings wherein like characters are used for like parts throughout the several views, FIG. 1 depicts a downhole assembly 10 which is suspended in a wellbore 12 on the end of a conveyance device 14 . The conveyance device 14 may be a slickline, wireline, coiled tubing, or drill pipe. Although running the downhole assembly into the wellbore on a slickline or wireline is considerably faster and more economical than running on a coiled tubing or drill pipe. The downhole assembly 10 includes a hydraulic strain sensor 16 and a downhole tool 18 which may be operated to perform one or more downhole operations in response to pressure signals generated by the hydraulic strain sensor 16 . For example, the downhole tool 18 may be a perforating gun which may be operated to fire shaped charges through a casing 19 in the wellbore 12 .
The hydraulic strain sensor 16 includes a sealed chamber (not shown) which experiences pressure changes when the downhole tool 18 is accelerated or decelerated and a pressure-responsive sensor, e.g., a pressure transducer (not shown), which detects the pressure changes and converts them to electrical signals. The hydraulic strain sensor 16 communicates with the downhole tool 18 through an electronics cartridge 20 . The electronics cartridge 20 includes electronic circuitry, e.g., microprocessors (not shown), which interprets the electrical signals generated by the pressure transducer as commands for operating the downhole tool 18 . The electronics cartridge 20 may also include an electrical power source, e.g., a battery pack (not shown), which supplies power to the electrical components in the downhole assembly 10 . Power may also be supplied to the downhole assembly 10 from the surface, e.g., through a wireline, or from a downhole autonomous power source.
Referring to FIG. 2, the hydraulic strain sensor 16 comprises a hydraulic power section 22 and a sensor section 24 . The hydraulic power section 22 includes a cylinder 26 . A fishing neck 28 is mounted at the upper end of the cylinder 26 and adapted to be coupled to the conveyance device 14 (shown in FIG. 1) so that the hydraulic strain sensor 16 can be lowered into and retrieved from the wellbore on the conveyance device. With the fishing neck 28 coupled to the conveyance device 14 , the hydraulic strain sensor 16 and other attached components can be accelerated or decelerated by jerking the conveyance device. The fishing neck 28 may also be coupled to other tools. For example, if the conveyance device 14 is inadvertently disconnected from the fishing neck 28 so that the hydraulic strain sensor 16 drops to the bottom of the wellbore, a fishing tool, e.g., an overshot, may be lowered into the wellbore to engage the fishing neck 28 and retrieve the hydraulic strain sensor 16 . The fishing neck 28 may be provided with magnetic markers (not shown) which allow it to be easily located downhole.
A mandrel 30 is disposed in and axially movable within a bore 32 in the cylinder 26 . The mandrel 30 has a piston portion 34 and a shaft portion 36 . An upper chamber 38 is defined above the piston portion 34 , and a lower chamber 40 is defined below the piston portion 34 and around the shaft portion 36 . The upper chamber 38 is exposed to the pressure outside the cylinder 26 through a port 42 in the cylinder 26 . A sliding seal 44 between the piston portion 34 and the cylinder 26 isolates the upper chamber 38 from the lower chamber 40 , and a sliding seal 46 between the shaft portion 34 and the cylinder 26 isolates the lower chamber 40 from the exterior of the cylinder 26 . The sliding seal 44 is retained on the piston portion 34 by a seal retaining plug 48 , and the sliding seal 46 is secured to a lower end of the cylinder 26 by a seal retaining ring 50 .
The sensor section 24 comprises a first sleeve 52 which encloses and supports a pressure transducer 54 and a second sleeve 56 which includes an electrical connector 58 . The first sleeve 52 is attached to the lower end of a connecting body 62 with a portion of the pressure transducer 54 protruding into a bore 64 in the connecting body 62 . An end 66 of the shaft portion 36 extends out of the cylinder 26 into the bore 64 in the connecting body 62 . The end 66 of the shaft portion 26 is secured to the connecting body 62 so as to allow the connecting body 62 to move with the mandrel 30 . Static seals, e.g., o-ring seals 76 and 78 , are arranged between the connecting body 62 and the shaft portion 36 and pressure transducer 54 to contain fluid within the bore 64 .
The second sleeve 56 is mounted on the first sleeve 52 and includes slots 80 which are adapted to ride on projecting members 82 on the first sleeve 52 . When the slots 80 ride on the projecting members 82 , the hydraulic strain sensor 16 moves relative to the downhole tool 18 (shown in FIG. 1 ). A spring 82 connects and normally biases an upper end 84 of the second sleeve 56 to an outer shoulder 86 on the first sleeve 52 . The electrical connector 58 on the second sleeve 52 is connected to the pressure transducer 54 by electrical wires 88 . When the hydraulic strain sensor 16 is coupled to the electronics cartridge 20 (shown in FIG. 1 ), the electrical connector 58 forms a power and communications interface between the pressure transducer 54 and the electronic circuitry and electrical power source in the electronics cartridge.
The shaft portion 36 has a fluid channel 90 which is in communication with the bore 64 in the connecting body 62 . The fluid channel 90 opens to a bore 92 in the piston portion 34 , and the bore 92 in turn communicates with the lower chamber 40 through ports 94 in the piston portion 34 . The bore 92 and ports 94 in the piston portion 34 , the fluid channel 90 in the shaft portion 36 , and the bore 64 in the connecting body 62 define a pressure path from the lower chamber 40 to the pressure transducer 54 . The lower chamber 40 and the pressure path are filled with a pressure-transmitting medium, e.g., oil or other incompressible fluid, through fill ports 96 and 98 in the seal retaining plug 48 and the connecting body 62 , respectively. By using both fill ports 96 and 98 to fill the lower chamber 40 and the pressure path, the volume of air trapped in the lower chamber and the pressure path can be minimized. Plugs 100 and 102 are provided in the fill ports 96 and 98 to contain fluid in the pressure path and the lower chamber 40 .
When the hydraulic strain sensor 16 is coupled to the downhole tool 18 , as illustrated in FIG. 1, the net force, F net , resulting from the pressure differential across the piston portion 34 supports the weight of the downhole tool 18 . The net force resulting from the pressure differential across the piston portion 34 can be expressed as:
F net =( P lc −P uc )·A lc (1)
where P lc is the pressure in the lower chamber 40 , P uc is the pressure in the upper chamber 38 or the wellbore pressure outside the cylinder 26 , A lc is the cross-sectional area of the lower chamber 40 .
The total force, F total , that is applied to the piston portion 34 by the downhole tool 18 can be expressed as:
F total =m tool ( g−a )+ F drag (2)
where m tool is the mass of the downhole tool 18 , g is the acceleration due to gravity, a is the acceleration of the downhole tool 18 , and F drag is the drag force acting on the downhole tool 18 . Drag force and acceleration are considered to be positive when acting in the same direction as gravity.
Assuming that the weight of the sensor section 24 and the weight of the connecting body 62 is negligibly small compared to the weight of the downhole tool 18 , then the net force, F net , resulting from the pressure differential across the piston portion 34 can be equated to the total force, F total , applied to the piston portion 34 by the downhole tool 18 , and the pressure, P lc , in the lower chamber 40 can then be expressed as: P l c = 1 A l c [ m t o o l · ( g - a ) + F d r a g + P u c · A l c ] ( 3 )
From the expression above, it is clear that the pressure, P lc , in the lower chamber 40 changes as the downhole tool 18 is accelerated or decelerated. These pressure changes are transmitted to the pressure transducer 54 through the fluid in the lower chamber 40 and the pressure path. The pressure transducer 54 responds to the pressure changes in the lower chamber 40 and converts them to electrical signals. For a given acceleration or deceleration, the size of a pressure change or pulse can be increased by reducing the cross-sectional area, A lc , of the lower chamber 40 .
In operation, the downhole assembly 10 is lowered into the wellbore 12 with the lower chamber 40 and pressure path filled with a pressure-transmitting medium. When the downhole assembly 10 is accelerated in the upward direction, the total force, F total , which is applied to the piston portion 34 by the downhole tool 18 increases and results in a corresponding increase in the pressure, P lc , in the lower chamber 40 . When the downhole tool 18 is accelerated in the downward direction, the force, F total , which is applied to the piston portion 34 by the downhole tool 18 decreases and results in a corresponding decrease in the pressure, P lc , in the lower chamber 40 . The downhole assembly 10 may also be decelerated in either the upward or downward direction to effect similar pressure changes in the lower chamber 40 . The pressure changes in the lower chamber 40 are detected by the pressure transducer 54 as pressure pulses. Moving the downhole assembly 10 in prescribed patterns will produce pressure pulses which can be converted to electrical signals that can be interpreted by the electronics cartridge 20 in the downhole tool 18 as command signals.
If the downhole assembly 10 becomes stuck and jars are used to try and free the assembly, the pressure differential across the piston portion 34 can become very high. If the bottom-hole pressure, i.e., the wellbore pressure at the exterior of the downhole assembly 10 , is close to the pressure rating of the downhole assembly 10 , then the pressure transducer 54 can potentially be subjected to pressures that are well over its rated operating value. To prevent damage to the pressure transducer 54 , the fill plug 100 may be provided with a rupture disc 108 which bursts when the pressure in the lower chamber 40 is above the pressure rating of the pressure transducer 54 . When the rupture disc 108 bursts, fluid will drain out of the lower chamber 40 and the pressure path, through the fill port 96 , and out of the cylinder 26 . As the fluid drains out of the lower chamber 40 and the pressure path, the piston portion 34 will move to the lower end of the cylinder 26 until it reaches the end of travel, at which time the hydraulic strain sensor 16 becomes solid and the highest pressure the pressure transducer 54 will be subjected to is the bottom-hole pressure. Instead of using a rupture disc, a check valve or other pressure responsive member may also be arranged in the fill port 96 to allow fluid to drain out of the lower chamber 40 when necessary.
If the downhole assembly 10 becomes unstuck, commands can no longer be generated using acceleration or deceleration of the downhole assembly 10 . However, traditional methods such as manipulation of surface wellhead controls or movement of the downhole assembly 10 over fixed vertical distances in a column of liquid can still be used. When traditional methods are used, the pressure transducer 54 , which is now in communication with the wellbore, will detect changes in wellbore or bottom-hole pressure around the hydraulic strain sensor 16 and transmit signals that are representative of the pressure changes to the electronics cartridge 20 . It should be noted that while the downhole assembly 10 is stuck, pressure signals can still be sent to the downhole tool 18 by alternately pulling and releasing on the conveyance device 14 .
The invention is advantageous in that pressure signals can be generated by simply accelerating or decelerating the downhole tool. The pressure signals are generated at the downhole tool and received by the downhole tool in real-time. The invention can be used with traditional methods of pressure-signal transmission, i.e., manipulation of surface wellhead controls or movement of the downhole tool over fixed vertical distances in a column of liquid.
While the invention has been described with respect to a limited number of embodiments, those skilled in the art will appreciate numerous variations therefrom
without departing from the spirit and scope of the invention.
|
A hydraulic strain sensor for use with a downhole tool includes a housing having two chambers with a pressure differential between the two chambers. A mandrel is disposed in the housing. The mandrel is adapted to be coupled to the tool such that the weight of the tool is supported by the pressure differential between the two chambers. A pressure-responsive sensor in communication with the one of the chambers is provided to sense pressure changes in the chamber as the tool is accelerated or decelerated and to generate signals representative of the pressure changes.
| 4
|
BACKGROUND OF THE INVENTION
1. Reservation of Copyright
A claim of copyright protection is made on portions of the description in this patent document. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but reserves all other rights.
2. Field of the Invention
The present invention relates to a graphical user interface (GUI) operative on a workstation or computer system. More specifically, the present invention relates to a GUI system and method for entering or updating an element of a table.
DESCRIPTION OF THE RELATED ART
Present-day computerized business systems typically include a number of computers or workstations connected in a network configuration and tied to a database. One of the tasks of the computerized business system is to supply information from the database to multiple system users so that the users can organize information from the database into a useful form. A substantial amount of planning is necessary to successfully market a product. Information from the database supplies the foundation for this planning. Planning has become highly efficient through the usage of computerized systems for arranging database information in a useful format. Various procedures and techniques have continually improved the efficiency of planning.
Computer display systems have been developed to represent data to a user and facilitate understanding of the data through graphic representations of the data. Many types of data representations have been developed including text and numbers, graphs and pictorial views. The development of data representations has been facilitated through the usage of object-oriented user interfaces which define display objects, called icons, for symbolically defining display characteristics of a graphic element on a display screen. The usage and definition of icons replaces the usage of a large number of program code commands and greatly reduces the length of graphic display programs and the complexity of graphic program coding. The development of data representations has also been facilitated through the definition and usage of "windows" which are displayed concurrently with other windows on a display screen. A graphic window typically includes a plurality of objects which may overlap one another within the window screen. A user may call for the display of a window, cancel the display of a window, redefine the information illustrated in a window, delete information from a window, copy or move data from one window to another and the like. The user operates on a window in the manner that a worker operates on a file folder in an office. The user may operate on the window contents and manipulate the window contents and the window, as if the image in the window were an actual object.
One type of useful data format is a tabular format in which various related data structures are displayed in columns and rows. Tables are advantageously used to compactly display large amounts of information in the limited space of a display screen. The data in a table may be entered, modified or deleted by selecting an element within the table array and editing the information within the selected element. However, often the tabular format does not convey sufficient information to allow a user to understand what data is appropriate for the table entry since only a few columns can be accommodated in the visible region of the screen. Accordingly, a "form" format is advantageously used to present a greater amount of detailed information than is possible using a table format. A user can update either the table or the detailed form.
Unfortunately, if a screen which is separate from the table screen is used to display the detailed form several problems arise. First, data inconsistencies occur if a user updates both the table screen and the form screen simultaneously, since both windows are active in the system simultaneously. Second, the detailed form does not automatically display all portions of the screen that are selected in the table when the detailed window is open. Third, for a screen with multiple information type groups, multiple separate windows are displayed, causing confusion about which window corresponds to a particular portion of the table. Fourth, only one window should exist for a particular information type.
What is needed is an apparatus and technique for displaying a table and a detailed form relating to table entries that does not allow inconsistent definition of a particular data entry.
SUMMARY OF THE INVENTION
In accordance with the present invention, a graphic screen including data in a table format is displayed in a window. The window implements a Zoom-In function using a Zoom-In button function. A user "Zooms-In" to any row in the table by selecting a row and activating the Zoom-In button function. While displaying the same window, activation of the Zoom-In button function hides the table and displays detailed information in a form format for updating the selected row of the table. The table is hidden and the form format is presented until the user activates a "Zoom-Out" button function, terminating the detailed information form format display and leaving the table display exposed. In the form format, the user performs functions including modifying data relating to a table entry, saving the modified or entered data, proceeding to the next row item, or regressing to the previous row.
Many advantages are achieved by the described method and apparatus. One advantage is that only a single window is displayed so that the data entered in the form and data entered in the table are written to the same data structures, thereby preventing inconsistencies in the data. A further advantage is that a plurality of information types are displayed in the same window preventing confusion relating to which window is open.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the described embodiments believed to be novel are specifically set forth in the appended claims. However, embodiments of the invention relating to both structure and method of operation, may best be understood by referring to the following description and accompanying drawings.
FIG. 1 is a block diagram which depicts a workstation or computer system hardware upon which is implemented a graphical user interface for navigating a database in accordance with one embodiment of the present invention.
FIG. 2 is a primary storage map illustrating an arrangement of primary storage for usage in the computer system shown in FIG. 1.
FIGS. 3A and 3B illustrate a schematic block diagram and a corresponding pictorial example of a screen presentation which show the contents of a screen implementing a Zoom-In function.
FIGS. 4A and 4B illustrate a schematic block diagram and a corresponding pictorial example of a screen presentation which show the contents of a column list display screen invoked through the screen shown in FIGS. 3A and 3B.
FIGS. 5A and 5B illustrate a schematic block diagram and a corresponding pictorial example of a screen presentation which show the contents of a Zoom-In screen which is evoked by the selection of a Zoom-In button function.
FIGS. 6A and 6B illustrate a second example of a schematic block diagram and a corresponding pictorial example of a screen presentation which show the contents of a Zoom-In screen which is evoked by the selection of a Zoom-In button function.
FIG. 7 is a flow chart which illustrates the operation of the Zoom-In function.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a block diagram shows an example of a computer system 100, such as a personal computer, a desktop computer, a laptop computer, a workstation and the like, which operates a graphical user interface (GUI). The computer system 100 includes a central processing unit (processor) 102 connected to a primary storage 104, and an input/output (I/O) circuit 106. In one embodiment, the computer system 100 is a computer such as a Sun Microsystems workstation running a Solaris™ operating system version 2.4 or higher where Sun, Sun Microsystems, Solaris, and the Sun Logo are trademarks or registered trademarks of Sun Microsystems, Inc. in the United States and other countries. The processor 102 may include a plurality of processors. The primary storage 104 supplies storage for program code that is run on the processor 102 and data utilized in conjunction with the program code. The primary storage 104 is embodied in various forms including dynamic RAM, static RAM, various types of read-only memory, flash memories and the like. The I/O circuit 106 communicates information between the processor 102 and other devices in the computer system 100 including a input device 108, a secondary storage 110, a graphic display monitor 112, and a cursor control device 114, all of which are connected to the processor 102 via the I/O circuit 106. The input device 108 receives commands and inputs data from a user and communicates the commands and input data to the processor 102. The secondary storage 110 supplies storage, such as long-term storage of program code and data to the computer system 100. The secondary storage 110 may be embodied in various devices such as magnetic disk drives, hard disk drives, floppy disk drives, CD ROM drives, magnetic tape drives, cassette drives and the like. The graphic display monitor 112 displays images generated by the computer system 100. The cursor control device 114 is used in conjunction with a graphic display such as the graphic display monitor 112 and is manipulated by the user to select various command modes, input data, and position a cursor on a desired location of the graphic display monitor 112. The list of devices connected to the I/O circuit 106 is nonexclusive and may be extended in various embodiment to include a myriad of devices such as magnetic tape players and recorders, CD ROM players and recorders, printers, interface controllers (SCSI, PCI and others), network controllers and the like.
The cursor control device 114 is most typically a "mouse" but may also take the form of trackballs, joysticks, thumbwheels, and other manipulation devices. The cursor control device 114 includes a plurality of switches 116, 117 and 118. The cursor control device 114 is manipulated by the user to position a cursor 120 at a desired location on the graphic display monitor 112 by movement of the cursor control device 114 over a surface 122. The cursor control device 114 generally uses an optical method for signaling the processor 102 of position changes of the cursor 120 by movement of the cursor control device 114 over a grid on the surface 122.
Referring to FIG. 2, a primary storage map illustrates an arrangement of primary storage 104 for usage in the computer system 100. The primary storage 104 is arranged having a frame buffer 210, a program storage 212 and a data storage 214. This arrangement of the primary storage 104 is illustrative of a simple, useful configuration. Actual configurations will depend on the many programs and data structures that a user may use on the computer system 100. The a frame buffer 210 corresponds to a bitmap of the graphic display monitor 112 and represents the video storage of the graphic display monitor 112 so that each storage location of the a frame buffer 210 corresponds to a pixel on the graphic display monitor 112. In this manner, the a frame buffer 210 is a two dimensional array of points having known coordinates which correspond to pixels of the graphic display monitor 112. Most simply, the a frame buffer 210 is a continuous block in the primary storage 104 allocated so that each storage location is mapped onto a corresponding pixel on the graphic display monitor 112. The program storage 212 includes program code for a variety of programs operating on the processor 102 including graphic display programs, control programs, and calculation programs, for example. The data storage 214 includes data structures for usage by the operating programs contained in the program storage 212.
The computer system 100 commonly display a plurality of "windows" on the graphic display monitor 112, which may be displayed over the entire face of the graphic display monitor 112 or in only a portion of the graphic display monitor 112. A window is typically defined as a portion of a display surface in which display images pertaining to a particular application can be presented. Different applications can be displayed simultaneously in different windows. A representative window commonly includes multiple forms of data in the form of graphics, text and symbols. Referring to FIGS. 3A and 3B, a schematic block diagram and a corresponding pictorial example of a screen presentation show the contents of a screen implementing a Zoom-In function. In this example, the screen is a Parts Screen for displaying "Parts" data of a product in a "Table" format. However, the Zoom-In function is applicable for many other types of display screens and generally is applicable to any display screens that display information in a table format. The screen is termed an "invoking" screen 300 to make reference to the usage of the invoking screen 300 to activate the Zoom-In function while both the invoking screen 300 and an invoked screen remain in the same window. The invoking screen 300 includes a title field 302, a control field 304, a name field 306, a command field 307, a type field 308, a status box 310, a table 312, and a horizontal scroll bar 314.
The title field 302 is a text display showing the title of the invoking screen 300, in the present example, "Part Screen".
The control field 304 displays a plurality of button stacks including a File button stack 318, an Edit button stack 320, an Options button stack 322, a View button stack 324, and a Help button stack 326. A button function is a button for actuating a single function or for executing a single command on the processor 102. A button stack is used to display a group of commands in a logical set on a menu which is displayed when the button stack is selected by the user. The button stacks of the control field 304 are shown displayed in a horizontal arrangement, although the button stacks may alternatively be displayed in other arrangements such as a vertical arrangement or an arrangement of multiple rows and columns. A user activates a button stack, including the File button stack 318, the Edit button stack 320, the Options button stack 322, the View button stack 324, and the Help button stack 326 by manipulating the cursor control device 114 and activating a switch on the cursor control device 114, causing the processor 102 to generate and display a menu (not shown) below the corresponding button stack. The menu includes a plurality of single button functions which may be selected by the user by placing the cursor 120 over the selected single button function and actuating a selected switch of the switches 116, 117 or 118, causing the immediate execution of the selected command by the processor 102.
The name field 306 displays text identifying a selected row in the table 312. In particular, the name field 306 displays an identifier field 328 and a selected name field 330. In the illustrative example, the identifier field 328 corresponds to a "Product ID" and the a selected name field 330 corresponds to a "Product Name" of a product selected from a row in the table 312. The name field 306 also includes an information function button 332 which is actuated by the user to command the display of a predetermined information screen. The user activates the columns button 336 to display a list of all columns in the table 312 for all types displayed in the table 312. The user activates the Zoom-In button 338 to activate the Zoom-In function.
The command field 307 allows the user to perform a command which operates in some manner to change the invoking screen 300. In the illustrative example, the command field 307 includes three button functions including a row duplication button 334, a columns button 336 and a Zoom-In button 338. The user activates the row duplication button 334 to duplicate a row in the table 312. In particular, the user selects a row in the table 312 by placing the cursor 120 over a selected row and actuating a switch of switches 116, 117 and 118. The user then actuates the row duplication button 334, causing the selected row to be duplicated in the table 312.
The type field 308 lists different types of items that are listed in the table 312. A particular list of table entries corresponds to each of the types so that selection of a particular type causes the table entries corresponding to the selected type to be displayed in the table 312. The column description is determined for each of the types. In the illustrative example, the type field 308 lists various product types of the products listed in the table 312. The type field 308 includes a plurality of selection buttons 340, each of which is labeled by text. The user selects a selection button 340 by placing the cursor 120 over the selection button 340 and actuating a switch of switches 116, 117 and 118, causing the table 312 to list entries of the selected type. In the illustrative example, the part types include a system configuration maintenance type, a system configuration specification type, a hardware maintenance type, a hardware specification type, a software maintenance type, a software specification type, a document maintenance type, and a diagnostic maintenance type.
The status box 310 displays the status of the table 312 for the selected table type. The current status is shown by illumination of a status indicator corresponding to a status class. In the illustrative example, the status classes include a complete class indicating that the list of table entries has been designated as complete, and a not available (NA) class indicative that no entries are available for a particular class.
The table 312 is a table of information entries arranged in rows with the information entries including a plurality of information items that are shown in columns. The user places the cursor 120 over a selected row and activates a switch of switches 116, 117 and 118 to select a particular information entry. In the illustrative example, the information entries correspond to particular products. A first column is a "delete row" column which is a button function for commanding the deletion of a row. The user places the cursor 120 over the delete row button function of a selected row and activates a switch of switches 116, 117 and 118 to delete the row from the table 312. The user may update or change a selected row in a selected column by placing the cursor 120 over a particular row and column entry and entering replacement data using the input device 108. Data may alternatively be entered or replaced in the table 312 by evoking a Form-type display of the selected entry using the Zoom-In function button 338.
The illustrative example of the invoking screen 300 is a system configuration maintenance screen for a product list which includes columns including the delete row column, a manufacturing number column, a "not available" column, a marketing number column, a description column, an available date column, cost columns including an estimated cost and an actual cost, price columns including an estimated cost and an actual cost, and other columns. A complete list of columns is accessed by selecting the columns button 336 of the command field 307. An example of a columns screen 400 is shown in FIGS. 4A and 4B. The user invokes the columns screen 400 to select the columns to be displayed in the table 312 of the invoking screen 300. Upon activating the columns button 336, the same window is displayed but a plurality of fields of the invoking screen 300 are hidden by the columns screen 400 display. Specifically, the entire invoking screen 300 is hidden including the title field 302, the control field 304, the name field 306, the command field 307, the type field 308, the status box 310, the table 312, and the horizontal scroll bar 314 are hidden and the columns screen 400 is displayed.
The columns screen 400 includes a title field 402 and a plurality of selection buttons for selecting a particular column heading for display which may be organized into groups. In the illustrative example, a several of the different types of items are combined into groups that include the same column headings. For example, groupings are made including one group 404 of the system configuration maintenance type and the system configuration specification type, a second group 406 of the hardware maintenance type and the hardware specification type, and a third group 408 of the software maintenance type and the software specification type. These groupings are made on the basis of similarity or equivalence of the column types for particular groups. Each of the column identifiers includes a selection button 410 for designating whether a particular column of the plurality of columns is to be made visible in the invoking screen 300. The columns screen 400 has two button functions including an accept button function 412 for accepting the selection of designated visible columns and a cancel button function 414 for returning from the columns screen 400 to the invoking screen 300 without changing the selection of visible columns.
Referring again to FIGS. 3A and 3B, the horizontal scroll bar 314 is an image with arrows 316 on two sides which permits the text and graphics within the table 312 to be scrolled in the direction in which the horizontal scroll bar 314 is pulled. In particular, the horizontal scroll bar 314 is moved by placing the cursor 120 over one of the arrows 316 of the horizontal scroll bar 314 and activated a selected switch 116, 117 or 118 on the cursor control device 114, or alternatively, by placing the cursor 120 on the horizontal scroll bar 314, depressing a preselected switch 116, 117 or 118 on the cursor control device 114 and moving the cursor control device 114 in the direction the table 312 is to be scrolled. The horizontal scroll bar 314 is useful for displaying all columns of the table 312 particularly in a case, such as the illustrative case, in which the number of columns is too large to be displayed in a single screen width.
Referring to FIGS. 5A and 5B, a schematic block diagram and a corresponding pictorial example of a screen presentation show the contents of a Zoom-In screen 500 which is evoked by the selection of a Zoom-In button function he invoking screen 300. Specifically, the Zoom-In screen 500 is evoked from the invoking screen 300 by selecting a row in the table 312 by placing the cursor 120 over the row and activating a switch of switches 116, 117 and 118. Upon activating the Zoom-In button 338, the same window is displayed but a plurality of fields of the invoking screen 300 are hidden by the Zoom-In screen 500 display. Specifically, portions of the entire invoking screen 300 are displayed including the title field 302, the control field 304, and the name field 306. Other portions of the invoking screen 300 are hidden including the command field 307, the type field 308, the status box 310, the table 312, and the horizontal scroll bar 314 and new portions of the Zoom-In screen 500 are displayed. The Zoom-In screen 500 displays a Form-type presentation for entering information relating to a particular entry or row of the table 312 of the invoking screen 300. The Form format includes a plurality of entry boxes 510 for entering text information corresponding to the selected row of the table 312 in the invoking screen 300. All information in the Zoom-In screen 500 relates to a particular selected row of the table 312 in the invoking screen 300. An entry box of the plurality of entry boxes 510 is entered to define information in a column or columns in the table 312 in the invoking screen 300. In particular, information entered into an entry box may be placed in one or more columns of the table 312 or may be used to derive information in a column of the table 312.
In the illustrative example, the Zoom-In screen 500 is a Parts Screen for displaying information relating to a particular product in a "Form" format. However, the Zoom-In function is applicable for many other types of display screens and generally is applicable to any display screens that are invoked by a first screen and display information in a form format for accepting data to fill a table in a table format in the first screen. The Zoom-In screen 500 is termed an "invoked" screen making reference to the usage of the invoking screen 300 to activate the Zoom-In function in the invoked Zoom-In screen 500. The Zoom-In screen 500 includes the title field 302, the control field 304, and the name field 306 which are retained from the invoking screen 300. The Zoom-In screen 500 hides the remainder of the invoking screen 300 with a new command field 507, a form field 508, and a descriptive text field 509.
The command field 507 is operated by the user to perform a command operating to modify the data designated by the Zoom-In screen 500 or to control the screen presentation of the Zoom-In screen 500. In the illustrative example, the command field 507 has five button functions including delete row button 512, a previous row button 514, a next row button 516, a Zoom-Cancel button 518, and a Zoom-Out button 520.
The user activates the delete row button 512 to remove a row from the table 312. In particular, the user selects the delete row button 512 by placing the cursor 120 over the delete row button 512 and actuating a switch of switches 116, 117 and 118, causing the entry to be invalidated in the primary storage 104, removing the row from display in the table 312, and displaying the next row in the table 312 by changing the Zoom-In screen 500 so that the information in the form field 508 is replaced by the information relating to the next sequential row in the table 312 of the invoking screen 300 shown in FIGS. 3A and 3B.
The user activates the previous row button 514 by placing the cursor 120 over the previous row button 514 and actuating a switch of switches 116, 117 and 118, causing the display of the immediately previous row in the table 312 by changing the Zoom-In screen 500 so that the information in the form field 508 is replaced by the information relating to the immediately previous row in the table 312 of the invoking screen 300.
The user activates next row button 516 by placing the cursor 120 over the next row button 516 and actuating a switch of switches 116, 117 and 118, causing the display of the next sequential row in the table 312 by changing the Zoom-In screen 500 so that the information in the form field 508 is replaced by the information relating to the next sequential row in the table 312 of the invoking screen 300.
The user activates the Zoom-Cancel button 518 by placing the cursor 120 over the Zoom-Cancel button 518 and actuating a switch of switches 116, 117 and 118, canceling any changes made to the information during a current accessing of the Zoom-In screen 500 and returning the display to the invoking screen 300.
The user activates the Zoom-Out button 520 by placing the cursor 120 over the Zoom-Out button 520 and actuating a switch of switches 116, 117 and 118, accepting and making permanent any changes made to the information during a current accessing of the Zoom-In screen 500 and returning the display to the invoking screen 300.
The user modifies entries in the form field 508 by placing the cursor 120 over an entry box of the plurality of entry boxes 510 and entering desired data in the form of text and numbers into the entry box, typically using entry via the input device 108. In the illustrative example, the user has accessed a product of the system configuration maintenance type using the invoking screen 300 and activated the Zoom-In button 338 to display the illustrative Zoom-In screen 500. The entry boxes 510 generally correspond to the columns defined under the system configuration maintenance type in the columns screen 400 shown in FIGS. 4A and 4B although information entered into an entry box may be placed in one or more columns of the table 312 or may be used to derive information in one or more columns of the table 312. The form field 508 may include one or more selection buttons 511 in addition to entry boxes 510 to enter TRUE/FALSE type information as well as text information and numbers.
The descriptive text field 509 describes to the user the operation that is performed during accessing of the Zoom-In button 338. In the illustrative example, the operation performed is the loading of a currently selected row of a system maintenance configuration type into a form accessed using the Zoom-In function.
FIGS. 6A and 6B illustrate an example of a Zoom-In screen 600 which is similar to the Zoom-In screen 500 shown in FIGS. 5A and 5B, but refer to parts of the system configuration specification type rather than the system configuration maintenance type. The Zoom-In screen 600 includes specification-type entry boxes 610.
In an illustrative embodiment, the computer system 100 is implemented using a standard Motif interface in which Motif library functions are implemented according to OSF/Motif style Guide, Version 1.0. 1989. Cambridge, Mass.: Open Software. The Motif interface is used for performing most display functions including display widgets. A widget is an interface element such as a menu, a scroll bar, or a push button. In addition, the computer system 100 uses the X Window System (Scheifler R. and Gettys J., ACM Transactions on Graphics, V63, 1986) including the Xlib graphics library for multiple purposes including the drawing of status lines, error lines, background and text.
Referring to FIG. 7 in accordance with FIGS. 1, 3A and 3B, a flow chart illustrates a method 700 for controlling a graphic display of a computer system such as the computer system 100. The processor 102 generates and displays the invoking screen 300 in a window in step 702. The invoking screen 300 includes the Zoom-In button 338 and the table 312 for displaying data stored in the primary storage 104 in a tabular format including a plurality of data elements addressed in a plurality of rows columns. The processor 102 receives signals from the cursor control device 114 and controls the operation the cursor 120 in accordance with these signals to enable the user to select a particular row of the plurality of rows in the table 312 in step 704. Similarly, the processor 102 receives signals from the switches 116, 117 and 118 of the cursor control device 114 to enable the user to activate the Zoom-In button 338 in step 706. In this manner, a user "zooms in" to any row of the table 312 and selects, or clicks, the Zoom-In button 338 to access the data in the defined row. With respect to the illustrative embodiment, the "Parts List" display includes a plurality of parts, each part defining a row of the table 312. Each part has a plurality of attributes, which are displayed as columns of the rows shown in the table 312. The user selects a particular part by manipulating the cursor control device 114 so that the cursor 120 overlies a selected row. The user operates a switch on the cursor control device 114 to select the row.
In response to the activation of the Zoom-In button 338, the processor 102 "hides" the table 312 showing the data display in the tabular format in step 708 and, in step 710, displays a data in a detailed "form" format shown as the Zoom-In screen 500, including the form field 508 and the delete row button 512, the previous row button 514, the next row button 516, the Zoom-Cancel button 518, and the Zoom-Out button 520 shown in FIGS. 5A and 5B. Although the table 312 is hidden, the processor 102 continues to operate from the same window, accessing the same data structures. In this manner, when a data element of the display in the form field 508 is altered, the corresponding element in the display of the table 312 is altered simultaneously.
While the invention has been described with reference to various embodiments, it will be understood that these embodiments are illustrative and that the scope of the invention is not limited to them. Many variations, modifications, additions and improvements of the embodiments described are possible. For example, the embodiments are described as systems which utilize Xlib and Motif to implement the product navigation system. In other embodiments, other graphics libraries and systems may be used or the computer system may be constructed without using a graphics library.
|
A graphic screen including data in a table format is displayed in a window. The window implements a Zoom-In function using a Zoom-In display element. A user "Zooms-In" to any row in the table by selecting a row and activating the Zoom-In display element. While displaying the same window, activation of the Zoom-In display element hides the table and displays detailed information in a form format for updating the selected row of the table. The table is hidden and the form format is presented until the user activates a "Zoom-Out" display element, terminating the detailed information form format display and leaving the table display exposed. In the form format, the user performs functions including modifying data relating to a table entry, saving the modified or entered data, proceeding to the next row item, or regressing to the previous row.
| 6
|
BACKGROUND OF THE INVENTION
[0001] The field of invention relates generally to imprint lithography. More particularly, the present invention is directed to producing templates having a moat system surrounding alignment marks.
[0002] Micro-fabrication involves the fabrication of very small structures, e.g., having features on the order of micro-meters or smaller. One area in which micro-fabrication has a sizeable impact is in the processing of integrated circuits. As the semiconductor processing industry continues to strive for larger production yields while increasing the circuits per unit area formed on a substrate, micro-fabrication becomes increasingly important. Micro-fabrication provides greater process control while allowing increased reduction of the minimum feature dimension of the structures formed. Other areas of development in which micro-fabrication has been employed include biotechnology, optical technology, mechanical systems and the like.
[0003] An exemplary micro-fabrication technique is commonly referred to as imprint lithography and is described in detail in numerous publications, such as U.S. published patent applications 2004/0065976, entitled METHOD AND A MOLD TO ARRANGE FEATURES ON A SUBSTRATE TO REPLICATE FEATURES HAVING MINIMAL DIMENSIONAL VARIABILITY; 2004/0065252, entitled METHOD OF FORMING A LAYER ON A SUBSTRATE TO FACILITATE FABRICATION OF METROLOGY STANDARDS; 2004/0046271, entitled METHOD AND A MOLD TO ARRANGE FEATURES ON A SUBSTRATE TO REPLICATE FEATURES HAVING MINIMAL DIMENSIONAL VARIABILITY, all of which are assigned to the assignee of the present invention. The fundamental imprint lithography technique as shown in each of the aforementioned published patent applications includes formation of a relief pattern in a polymerizable layer and transferring a pattern corresponding to the relief pattern into an underlying substrate. To that end, a template is employed spaced-apart from the substrate with a formable liquid present between the template and the substrate. The liquid is solidified to form a solidified layer that has a pattern recorded therein that is conforming to a shape of the surface of the template in contact with the liquid. The substrate and the solidified layer are then subjected to processes to transfer, into the substrate, a relief image that corresponds to the pattern in the solidified layer.
[0004] One manner in which to locate the polymerizable liquid between the template and the substrate is by depositing a plurality of droplets of the liquid on the substrate. Thereafter, the polymerizable liquid is concurrently contacted by both the template and the substrate to spread the polymerizable liquid over the surface of the substrate. It is desirable to properly align the template with the substrate so that the proper orientation between the substrate and template may be obtained. To that end, both the template and substrate include alignment marks.
[0005] Thus, a need exists to provide alignment techniques for use in imprint lithographic processes.
SUMMARY OF THE INVENTION
[0006] The present invention is directed to a body having a first area and a second area separated by a recess. The recess is dimensioned to reduce, if not prevent, a liquid moving along a surface of the body from traveling between the first and second areas. One or more alignment marks may be positioned within one of the first and second areas. In this manner, the recess functions as a moat by reducing, if not preventing, a quantity of the liquid from being in superimposition with the alignment marks. These and other embodiments are discussed more fully below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a perspective view of a lithographic system in accordance with the present invention;
[0008] FIG. 2 is a simplified plan view of the lithographic system showing a mold included on a template shown in FIG. 1 ;
[0009] FIG. 3 is a simplified elevation view of a mold spaced-apart from the imprinting layer, shown in FIG. 2 , after patterning of the imprinting layer;
[0010] FIG. 4 is a simplified elevation view of an additional imprinting layer positioned atop of the substrate after etching of a pattern into the substrate that corresponds to the pattern in the first imprinting layer, shown in FIG. 3 ;
[0011] FIG. 5 is a plan view of an imaging system employed to sense alignment marks included on the template of FIG. 1 ;
[0012] FIG. 6 is a plan view of exemplary alignment marks utilized in the present invention;
[0013] FIG. 7 is a bottom-up view of the template shown in FIG. 1 , in accordance with a first embodiment of the present invention;
[0014] FIG. 8 is a cross-sectional view of the template shown in FIG. 7 taken along lines 8 - 8 ;
[0015] FIG. 9 is a bottom-up view of the template shown in FIG. 7 , in accordance with a second embodiment of the present invention;
[0016] FIG. 10 is a bottom-up view of the template shown in FIG. 7 , in accordance with a second embodiment of the present invention;
[0017] FIG. 11 is a bottom-up view of the template shown in FIG. 7 , in accordance with a third embodiment of the present invention; and
[0018] FIG. 12 is a plan view of a template having alignment marks and a moat system disposed along an edge of the template in accordance with a fourth embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0019] FIG. 1 depicts a lithographic system 10 in accordance with one embodiment of the present invention that includes a pair of spaced-apart bridge supports 12 having a bridge 14 and a stage support 16 extending therebetween. Bridge 14 and stage support 16 are spaced-apart. Coupled to bridge 14 is an imprint head 18 , which extends from bridge 14 toward stage support 16 and provides movement along the Z-axis. Disposed upon stage support 16 to face imprint head 18 is a motion stage 20 . Motion stage 20 is configured to move with respect to stage support 16 along X- and Y-axes. It should be understood that imprint head 18 may provide movement along the X- and Y-axes, as well as the Z-axis, and motion stage 20 may provide movement in the Z-axis, as well as the X- and Y-axes. An exemplary motion stage device is disclosed in U.S. patent application Ser. No. 10/194,414, filed Jul. 11, 2002, entitled “Step and Repeat Imprint Lithography Systems,” assigned to the assignee of the present invention, and which is incorporated by reference herein in its entirety. A radiation source 22 is coupled to lithographic system 10 to impinge actinic radiation upon motion stage 20 . As shown, radiation source 22 is coupled to bridge 14 and includes a power generator 23 connected to radiation source 22 . Operation of lithographic system 10 is typically controlled by a processor 25 that is in data communication therewith. An exemplary lithographic system is available under the trade name IMPRIO 100™ from Molecular Imprints, Inc. having a place of business at 1807-C Braker Lane, Suite 100, Austin, Tex. 78758. The system description for the IMPRIO 100™ is available at www.molecularimprints.com and is incorporated herein by reference.
[0020] Referring to both FIGS. 1 and 2 , connected to imprint head 18 is a template 26 having a mold 28 thereon. Mold 28 includes a plurality of features defined by a plurality of spaced-apart recessions 28 a and protrusions 28 b . The plurality of features defines an original pattern that is to be transferred into a substrate 30 positioned on motion stage 20 . To that end, imprint head 18 and/or motion stage 20 may vary a distance “d” between mold 28 and substrate 30 . In this manner, the features on mold 28 may be imprinted into a flowable region of substrate 30 , discussed more fully below. Radiation source 22 is located so that mold 28 is positioned between radiation source 22 and substrate 30 . As a result, mold 28 is fabricated from a material that allows it to be substantially transparent to the radiation produced by radiation source 22 .
[0021] Referring to FIG. 2 , a flowable region, such as an imprinting layer 34 , is disposed on a portion of a surface 32 that presents a substantially planar profile. A flowable region may be formed using any known technique, such as a hot embossing process disclosed in U.S. Pat. No. 5,772,905, which is incorporated by reference in its entirety herein, or a laser assisted direct imprinting (LADI) process of the type described by Chou et al. in Ultrafast and Direct Imprint of Nanostructures in Silicon, Nature , Col. 417, pp. 835-837, June 2002. In the present embodiment, however, a flowable region consists of imprinting layer 34 being deposited as a plurality of spaced-apart discrete droplets 36 of a material on substrate 30 , discussed more fully below. An exemplary system for depositing droplets 36 is disclosed in U.S. patent application Ser. No. 10/191,749, filed Jul. 9, 2002, entitled SYSTEM AND METHOD FOR DISPENSING LIQUIDS, and which is assigned to the assignee of the present invention, and which is incorporated by reference in its entirety herein. Imprinting layer 34 is formed from the material that may be polymerized and cross-linked to record the original pattern therein, defining a recorded pattern. An exemplary composition for the material is disclosed in U.S. patent application Ser. No. 10/463,396, filed Jun. 16, 2003 and entitled METHOD TO REDUCE ADHESION BETWEEN A CONFORMABLE REGION AND A PATTERN OF A MOLD, which is incorporated by reference in its entirety herein.
[0022] Referring to FIGS. 2 and 3 , the pattern recorded in imprinting layer 34 is produced, in part, by mechanical contact with mold 28 . To that end, distance “d” is reduced to allow imprinting droplets 36 to come into mechanical contact with mold 28 , spreading droplets 36 so as to form imprinting layer 34 with a contiguous formation of the material over surface 32 . In one embodiment, distance “d” is reduced to allow sub-portions 34 a of imprinting layer 34 to ingress into and fill recessions 28 a.
[0023] To facilitate filling of recessions 28 a , the material is provided with the requisite properties to completely fill recessions 28 a , while covering surface 32 with a contiguous formation of the material. In the present embodiment, sub-portions 34 b of imprinting layer 34 in superimposition with protrusions 28 b remain after the desired, usually minimum, distance “d”, has been reached, leaving sub-portions 34 a with a thickness “t 1 ,” and sub-portions 34 b with a thickness “t 2 .” Thicknesses “t 1 ,” and “t 2 ” may be any thickness desired, dependent upon the application.
[0024] Referring again to FIG. 2 , after a desired distance “d” has been reached, radiation source 22 produces actinic radiation that polymerizes and cross-links the material, forming a cross-linked polymer material. As a result, the composition of imprinting layer 34 transforms from the material to the cross-linked polymer material, which is a solid. Specifically, the cross-linked polymer material is solidified to provide side 34 c of imprinting layer 34 with a shape conforming to a shape of a surface 28 c of mold 28 , shown more clearly in FIG. 5 . After imprinting layer 34 is transformed to consist of the cross-linked polymer material, the distance “d” is increased so that mold 28 and imprinting layer 34 are spaced-apart.
[0025] Referring to FIG. 3 , additional processing may be employed to complete the patterning of substrate 30 . For example, substrate 30 and imprinting layer 34 may be etched to transfer the pattern of imprinting layer 34 into substrate 30 , providing a patterned surface 32 a , shown in FIG. 6 . To facilitate etching, the material from which imprinting layer 34 is formed from may be varied to define a relative etch rate with respect to substrate 30 , as desired. The relative etch rate of imprinting layer 34 to substrate 30 may be in a range of about 1.5:1 to about 100:1.
[0026] Alternatively, or in addition to, imprinting layer 34 may be provided with an etch differential with respect to photo-resist material (not shown) selectively disposed thereon. The photo-resist material (not shown) may be provided to further pattern imprinting layer 34 , using known techniques. Any etch process may be employed, dependent upon the etch rate desired and the underlying constituents that form substrate 30 and imprinting layer 34 . Exemplary etch processes may include plasma etching, reactive ion etching, chemical wet etching and the like. The sub portions 34 b are typically referred to as the residual layer.
[0027] Additionally, it has been found beneficial to deposit a primer layer (not shown) when forming imprinting layer 34 upon substrate 32 which may or may not include any previously disposed patterned/unpatterned layer present on substrate 32 . The primer layer (not shown) may function, inter alia, to provide a standard interface with imprinting layer 34 , thereby reducing the need to customize each process to the material upon which imprinting layer 34 is to be deposited. In addition, the primer layer (not shown) may be formed from an organic material with the same etch characteristics as imprinting layer 34 . The primer layer is fabricated in such a manner so as to possess a continuous, smooth, if not planar, relatively defect-free surface that may exhibit excellent adhesion to imprinting layer 34 . The magnitude of a thickness of the primer layer (not shown) should be such that the same is able comprise the above-mentioned characteristics, but also allow the same to be substantially transparent such that underlying alignment marks, described further below, may be detected by have an optical sensor, mentioned further below. An exemplary material from which to form the primer layer (not shown) is available from Brewer Science, Inc. of Rolla Missouri under the trade name DUV30J-6. The primer layer (not shown) may be deposited using any know technique, include spin-on deposition and drop-dispense deposition.
[0028] Referring to FIGS. 3 and 4 , to form an additional imprinting layer, such as a layer 31 atop of surface 32 a , or a primer layer (not shown) correct placement of mold 28 with respect to substrate 30 is important. To that end, overlay alignment schemes may include alignment error measurement and/or alignment error compensation and/or placement error measurement and correction. Placement error, as used herein, generally refers to X-Y positioning errors between a template and a substrate (that is, translation along the X- and/or Y-axis). Placement errors, in one embodiment, are determined and corrected for by using an optical imaging system 40 , shown in FIG. 5 , to sense alignment marks discussed below with respect to FIG. 6 .
[0029] Referring to FIG. 5 , optical imaging system 40 includes a light source 42 and an optical train 44 to focus light upon substrate 30 . Optical imaging system 40 is configured to focus alignment marks lying in differing focal planes onto a single focal plane, P, wherein an optical sensor 46 may be positioned. As a result, optical train 44 is configured to provide wavelength-dependent focal lengths. Differing wavelengths of light may be produced in any manner known in the art. For example, light source 42 may comprise a single broadband source of light that may produce wavelengths, shown as light 48 , which impinges impinge upon optical train 44 . Optical band-pass filters (not shown) may be disposed between the broadband source and the alignment marks (not shown). Alternatively, a plurality of sources of light (not shown) may be employed, each one of which produces distinct wavelengths of light. Light 48 is focused by optical train 44 to impinge upon alignment marks (not shown) at one or more regions, shown as region R 1 and region R 2 . Light reflects from regions R 1 and R 2 , shown as a reflected light 50 , and is collected by a collector lens 52 . Collector lens 52 focuses all wavelengths of reflected light 50 onto plane P so that optical sensor 46 detects reflected light 50 .
[0030] Referring to FIGS. 1 and 6 , alignment marks may be of many configurations and are arranged in pairs with one of the alignment marks of the pair being disposed on template 26 . The remaining alignment mark being positioned on substrate 30 , e.g., in a previously deposited imprinting layer or etched into substrate 30 or a previously deposited layer disposed thereon. For example, alignment marks may include first and second polygonal marks 54 and 56 , depicted as squares, but may be any polygonal shape desired. Another configuration for alignment marks are shown as crosses, shown as 58 and 60 . Also additional alignment marks may be employed, such as vernier marks 62 and 64 , as well as Moiré gratings, shown as 66 and 68 .
[0031] Referring to FIGS. 2, 7 , and 8 , wavelengths are selected to obtain a desired focal length, depending upon the gap between mold 28 and substrate 30 or an imprinting layer disposed on substrate 30 . Under each wavelength of light used, each alignment mark may produce two images on the imaging plane. First polygonal alignment mark 54 , using a specific wavelength of light, presents as a focused image on sensor 46 . Second polygonal alignment mark 56 , using the same wavelength of light, presents as an out-of-focus image on sensor 46 . In order to eliminate each out-of-focus image, several methods may be used.
[0032] Another concern with overlay alignment for imprint lithography processes that employ UV curable liquid materials may be the visibility of the alignment marks. For the overlay placement error measurement, two overlay marks, such as the marks discussed above with respect to FIG. 8 , are employed, referred to collectively as alignment marks 84 . However, since it is desirable for template 26 to be transparent to a curing agent, the template overlay marks, in some embodiments, are not opaque lines. Rather, the template overlay marks are topographical features of the template surface. In some embodiments, the overlay marks are made of the same material as the template. In addition, UV curable liquids may have a refractive index that is similar to the refractive index of the template materials, e.g., quartz or fused silica. Therefore, when the UV curable liquid fills the gap between template 26 and substrate 30 , template overlay marks may become very difficult to recognize. If the template overlay marks are made with an opaque material, e.g., chromium or nickel, the UV curable liquid below the overlay marks may not be properly exposed to the UV light, e.g., having wavelengths in a range of 310 to 365 nm. This frustrates patterning an underlying surface to include alignment mark for subsequent processing, were it desired to form alignment marks in substrate 30 by imprinting the pattern corresponding to the alignment marks into imprinting layer 34 with mold 28 and subsequently etching the alignment marks into substrate. Therefore, several reasons exist to prevent imprinting material from being in superimposition with alignment marks.
[0033] Referring to FIG. 7 , the present invention reduces, if not prevents, material in imprinting layer 34 from entering a region of substrate 30 in superimposition with alignment marks 84 . To that end, alignment marks 84 are surrounded by a moat system 100 . Segments 102 , 104 , 106 , and 108 of moat system 100 separate molds 92 , 94 , 96 , and 98 . Specifically, segments 102 , 104 , 106 , and 108 have a depth associated therewith, e.g., 30 microns, to minimize the egression of the material in imprinting layer 34 therein from adjacent active molds 92 , 94 , 96 , and 98 due to capillary forces. Additionally, moat system 100 may include a segment 109 that surrounds molds 92 , 94 , 96 , and 98 . As mentioned previously, when the desired gap defined between molds 92 , 94 , 96 and 98 and substrate 30 , or a layer previously deposited on substrate 30 occurs, the material in imprinting layer 34 forms a contiguous region of material therebetween. As a result of capillary attraction of the material of imprinting layer 34 to both mold 28 and substrate 30 , the material of imprinting layer 34 does not typically extend to regions of substrate 30 in superimposition with moat system 100 . Rather, the material of imprinting layer typically remains confined within a region of substrate 30 that is in superimposition with one of the molds 92 , 94 , 96 and 98 .
[0034] Referring to FIG. 8 , the material of imprinting layer 34 forms a meniscus 105 at the periphery of mold 94 due to the surface tension of the material in imprinting layer 34 and the same is substantially absent from segment 104 . The surface tension associated with the material in meniscus 105 substantially reduces the probability that the material extends through into segment 104 . It was determined, however, that the probability that the material of imprinting layer 34 ingressing into moat system 100 , such as segment 104 would be substantially minimized by minimizing surface discontinuities in the surfaces defining moat system 100 . Specifically, it was determined that surface discontinuities, such as sharp edges, right angles and the like, might cause the material of imprinting layer 34 to ingress into moat system 100 and be located in regions of substrate 30 in superimposition with alignment marks 84 , shown in FIG. 7 , which is undesirable.
[0035] Referring to FIGS. 7, 8 and 9 , therefore, to minimize, if not prevent, material of the imprinting layer 34 from being disposed upon a region of substrate 30 in superimposition with alignment marks 84 , moat system 100 abrogates most, if not all sharp corners by including portions 110 , 112 , 114 , and 116 defined by arcuate boundaries. Portions 110 , 112 , 114 , and 116 surround alignment marks 84 . Specifically, portion 110 is disposed between segments 104 and 106 ; portion 112 is disposed between segments 106 and 108 ; portion 114 is disposed between segments 102 and 108 ; and portion 116 is disposed between segments 102 and 104 .
[0036] The arcuate junctions/boundaries of portions 110 , 112 , 114 , and 116 minimize surface discontinuities in the surfaces the define moat system 100 , thereby minimizing imprinting material, such as imprinting material in meniscus 105 , from crossing moat system 100 when meniscus coming into contact therewith. This, it is believed, reduces the probability of, if not prevent, the material in imprinting layer 34 from becoming disposed upon a region of substrate 30 in superimposition with alignment marks 84 .
[0037] In a further embodiment, moat system 100 comprises a plurality of non-linear segments surrounding molds 92 , 94 , 96 , and 98 to further minimize, if not prevent, the material in imprinting layer 34 becoming disposed upon a region of substrate 30 , shown in FIG. 8 , in superimposition with alignment marks 84 . Specifically, connecting any two linear segments of moat system 100 is a non-linear segment, i.e., an arcuate segment. An example of a non-linear segment connecting two linear segments of moat system 100 is shown in FIG. 7 . More specifically, disposed between a linear segment 120 and a linear segment 122 is a non-linear segment 124 , wherein non-linear segment 124 comprises arcuate portions 126 and 128 , i.e., portions with a smooth contour lacking corners. In another example, disposed between linear segment 120 and a linear segment 130 is a non-linear segment 132 , wherein non-linear segment 132 comprises an arcuate portion 134 , i.e. a portion with a smooth contour lacking corners. Non-linear segments 124 and 132 may be described analogously to the arcuate boundaries of portions 120 , 112 , 114 , and 116 , as mentioned above, and thus, non-linear segments 124 and 132 reduce the probability of, if not prevent, the material in imprinting layer 34 from becoming disposed upon a region of substrate 30 in superimposition with alignment marks 84 .
[0038] Referring to FIG. 10 , in another embodiment, an additional set of alignment marks 136 may be placed within a mold, shown as a mold 138 , of template 90 . However, the region of mold 138 in which alignment marks 136 are positioned does not include any patterned features. Alignment marks 136 are surrounded by a moat system 140 so as to prevent the material in imprinting layer 34 from coming into contact therewith for the reasons discussed above with respect to FIGS. 7 and 8 . Moat system 140 comprises a plurality of linear segments, with two linear segments of the plurality being connected by a non-linear segment. An example of a non-linear segment connecting two linear segments of moat system 140 is shown as a linear segment 142 and a linear segment 144 having a non-linear segment 146 disposed therebetween. Non-linear segment 146 is analogous to non-linear segments 124 and 132 , mentioned above, and thus non-linear segment 146 reduces the probability, if not prevent, the imprinting material from becoming disposed upon a region of substrate 30 , shown in FIG. 8 , in superimposition with alignment marks 136 . Alignment marks 136 may be in addition to alignment marks 84 , wherein alignment marks 84 are surrounded by moat system 100 .
[0039] Alternatively, referring to FIG. 11 , alignment marks 136 may not be surrounded by a moat system, with alignment marks 136 being disposed within mold 138 . However, alignment marks 84 may be surrounded by moat system 100 . It has been found desirable to have at least one of alignment marks 84 and 136 not surrounded by a moat system and not formed from opaque material.
[0040] In a further embodiment, referring to FIG. 12 , alignment marks 148 may be disposed along an edge 150 of template 90 located between molds 238 and 239 . A moat system 152 , analogous to moat system 100 described above, surrounds alignment marks 148 and comprises arcuate portions 154 and 156 , which are analogous to arcuate portions 110 , 112 , 114 , and 116 , and thus arcuate portions 154 and 156 reduce the probability of, if not prevent, the imprinting material from becoming disposed upon a region of substrate 30 , shown in FIG. 13 , in superimposition with alignment marks 148 .
[0041] Alignment marks may be located at an edge of molds 438 and 538 , shown as alignment marks 448 and 548 , respectively. A moat system 452 , analogous to moat system 100 described above, surrounds alignment mark 448 and comprises arcuate portions 454 , 455 , 456 and 457 , which are analogous in function to the arcuate boundaries of portions 110 , 112 , 114 , and 116 . Specifically, each of arcuate portions 454 , 455 , 456 and 457 reduce the probability of, if not prevent, the material in imprinting layer 34 from becoming disposed upon a region of substrate 30 , shown in FIG. 13 , in superimposition with alignment marks 448 .
[0042] It should be understood that it is not necessary for an arcuate segment to couple transversely extending linear segments. For example, moat system 552 includes a first linear segments 560 and a second linear segments 562 coupled together via a corner segment, which in this case is shown as a right angle 563 , but may be formed from an acute angle or an obtuse angle. It was found that the presence of corner segments positioned at the boundary of mold 538 did not greatly undermine the problem solved by the present invention, i.e., deminimus amounts of the material in imprinting layer 34 extend into moat system 552 .
[0043] The embodiments of the present invention described above are exemplary. Many changes and modifications may be made to the disclosure recited above, while remaining within the scope of the invention. Therefore, the scope of the invention should not be limited by the above description, but instead should be determined with reference to the appended claims along with their full scope of equivalents.
|
The present invention is directed to a body having a first area and a second area separated by a recess. The recess is dimensioned to reduce, if not prevent, a liquid moving along a surface of the body from traveling between the first and second areas. One or more alignment marks may be positioned within one of the first and second areas. In this manner, the recess functions as a moat by reducing, if not preventing, a quantity of the liquid from being in superimposition with the alignment marks.
| 6
|
BACKGROUND OF THE INVENTION
The present invention relates to an improved wick-lubricated spinning and twisting ring construction and system.
By way of background, wick-lubricated spinning and twisting ring constructions and systems are well known. However, existing systems are subject to certain shortcomings. First of all, in existing systems the wick may lose contact with the lubricant and therefore the lubrication of the ring may be interrupted. Furthermore, in existing systems there are an excess number of fittings and points at which leakage of lubricant may occur and since most systems are series-connected, a leak in any part of the system will disrupt lubricant flow to the remainder of the system. Furthermore, in existing systems flow of lubricant is usually effected through a plurality of narrow conduits, which, if clogged, can result in the cessation of lubricant flow. It is with overcoming the foregoing deficiencies of prior art wick-lubricating systems that the present invention is concerned.
SUMMARY OF THE INVENTION
It is accordingly one object of the present invention to provide an improved wick-lubricated spinning and twisting ring construction in which immersion of the wicks is assured, thereby obviating the possibility of the wicks losing contact with the lubricant.
Another object of the present invention is to provide an improved wick-lubricated spinning and twisting ring construction wherein a plurality of rings are supplied with lubricant from a common lubricant manifold, thereby obviating the numerous conduits and connections which could provide sources of leakage.
A futher object of the present invention is to provide an improved wick-lubricating spinning and twisting ring, holder and block construction wherein the wicks are threaded through aligned conduits in the ring, holder and block in such a manner that pinching or kinking of the wicks is obviated, thereby assuring proper lubricant flow to the rings. Other objects and attendant advantages of the present invention will readily be perceived hereafter.
The present invention relates to a spinning and twisting ring construction comprising a holder, a ring in said holder, an annular conduit in said ring, a first wick-receiving bore in said ring extending transversely to said annular conduit, a second wick-receiving bore in said holder in alignment with said first wick-receiving bore, a wick adapter block connected to said holder, a third wick-receiving bore in said wick adapter block in alignment with said second wick-receiving bore, and a wick-receiving conduit extending outwardly from said wick adapter block.
The present invention also relates to a wick adapter block for attachment to a holder of a spinning and twisting ring comprising a wick-receiving bore in said block extending in a first direction, a wick-receiving conduit in communication with said wick-receiving bore and extending outwardly beyond said block in a second direction which is transverse to said first direction.
The present invention also relates to a wick adapter block and manifold construction for attachment to the holder of a spinning and twisting ring comprising a wick-receiving bore in said block extending in a first direction, a wick-receiving conduit in communication with said wick-receiving bore and extending outwardly beyond said block in a second direction which is transverse to said first direction, a lubricant manifold, a bore in said lubricant manifold for receiving the portion of said wick-receiving conduit which extends beyond said block, and a fluid tight seal between said block and said manifold.
The present invention also relates to a spinning and twisting ring system comprising a plurality of holders, a ring in each of said holders, an annular conduit in each ring, a first wick-receiving bore in each ring extending transversely to said annular conduit, a second wick-receiving bore in each holder in alignment with each first wick-receiving bore, a wick adapter block connected to each holder, a third wick-receiving bore in each wick adapter block in alignment with each second wick-receiving bore, a wick-receiving conduit extending downwardly and outwardly from each wick adapter block, a lubricant manifold, a plurality of spaced bores in said manifold for receiving wick-receiving conduits, means for securing said manifold to each of said wick adapter blocks, each of said wick-receiving conduits extending into said lubricant manifold through one of said spaced bores, a lubricant seal between each of said blocks and said manifold, each of said wick-receiving conduits including a lower portion and said lubricant manifold including a lower portion for receiving said lower portions of said wick-receiving conduits, and a wick extending through said first, second, and third wick-receiving bores and said wick-receiving conduit and extending beyond said wick-receiving conduit into said lower portion of said manifold.
The various aspects of the present invention will be more fully understood when the following portions of the specification are read in conjunction with the accompanying drawings wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary side elevational view of a spinning and twisting ring installation including the improved construction mounted on the rail of a frame;
FIG. 2 is an enlarged fragmentary plan view of a portion of FIG. 1 taken substantially in the direction of arrows 2--2 of FIG. 1;
FIG. 3 is a fragmentary side elevational view taken substantially in the direction of arrows 3--3 of FIG. 1 and showing the mounting structure for adjusting the level of the lubricant float tank;
FIG. 4 is a fragmentary view taken substantially in the direction of arrows 4--4 of FIG. 2 and showing the lubricant level gauge associated with the manifold;
FIG. 5 is a fragmentary enlarged plan view of a holder mounted on the rail and mounting the manifold by means of the wick adapter block;
FIG. 6 is an enlarged fragmentary cross sectional view taken substantially along line 6--6 of FIG. 5;
FIG. 7 is a fragmentary cross sectional view taken substantially along line 7--7 of FIG. 6; and
FIG. 8 is a fragmentary plan view of a ring and holder mounted on a flat rail and mounting the block and manifold of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The improved lubrication system of the present invention which contains the improved wick adapter blocks 10 and the associated lubricant manifolds 11 is shown in the drawings. A lubricant gravity feed arrangement is provided wherein a lubricant reservoir or tank 12 feeds an automatic lubricant level tank 13 through conduit 14. Tank 13 essentially contains a float valve which terminates flow to conduit 15 when there is a predetermined level of lubricant in float tank 13. Conduit 15 is in communication with the lubricant manifold 11 to the left of FIG. 1, which is in communication with an adjacent lubricant manifold 11 through conduit 16, which in turn is in communication with an adjacent lubricant manifold 11 through conduit 17. A bracket 18 of tank mounting structure 19 is secured to rail 20 by means of screws 21. Tank mounting structure 19 includes an adjustable bracket 22 attached to bracket 19, and bracket 22 may be adjusted in elevation by moving it in a vertical direction and thereafter tightening it in its adjusted position by screw 23. In this manner the level of lubricant in float tank 13 may be adjusted relative to manifolds 11, to thereby adjust the level of lubricant in the latter.
A plurality of spinning and twisting ring holders 24 are cantilever-mounted on rail 20 by means of screws 25 passing through enlarged slots 26 in holder portions 27, screws 25 bearing downwardly on washers 29. The enlarged slots permit adjustment of the holders relative to rail 20. Leveling screws 28 thread into each holder 24 and bear on rail 20.
Each holder 24 mounts a spinning and twisting ring 30 and clamps it tightly by means of screw 31' which extends through ear 32' of the holder and connects to holder portion 27. Each ring 30 may be of the type shown in U.S. Pat. Nos. 4,098,067 or 3,831,367, or 3,872,662, and these patents are incorporated herein by reference.
In accordance with the present invention, a precise positive flow of lubricant is assured to each ring 30 through wick adapter blocks 10. In this respect, each block 10 includes a bore 31 which extends substantially horizontally and has an enlarged counterbore portion 32 in communication therewith. A connector member 33 is provided having cylindrical conduit ends 42 and 43 and a central enlarged annular portion 34 which is received in bore 32. O-rings 35 are located on opposite sides of enlarged portion 34. One O-ring 35 is located on conduit end 42 between annular portion 34 and shoulder 36 and the other O-ring 35 is located on conduit end 43 between annular portion 34 and edge 37 of holder 24. Block 10 is secured to holder 24 by means of screws 39 which are received in portion 40 of holder 24, with the heads of screws 39 being received in counterbores 41. As can be seen from FIG. 7, one end 42 of member 33 is received in bore 31 and the other end 43 is received in bore 44 of holder portion 40. Thus, member 33 is in alignment with bores 31 and 44, which are in alignment with each other.
A bore 45 in holder portion 40 is in communication with bore 44 and the end portion 46 of bore 45 is in alignment with a bore 47 in ring 30 which is in communication with annular conduit 49 in ring 30. A bore 50 is in line with bore 47. A wick 51 passes through bore 31, bore 52 in member 33, bores 44, 45 and 46 in the holder, and bores 47 and 50 in ring 30. The wick 51 also passes through wick-receiving conduit 53 which has its upper portion press-fitted into block 10 and the wick 51 has lower portions 54 which extend out from the lower portion of wick-receiving conduit 53.
Manifold 11 includes a plurality of spaced bores 55 through which each of the wick-carrying conduits 53 extend. An O-ring 56 is located in recessed portion 57 of block 10 surrounding each conduit 53. Each block 10 supports manifold 11 by means of a pair of screws 59 which extend through bores 60 in block 10 and are received in tapped bores 61 in manifold 11. O-rings 62 are provided in recesses 63 surrounding screws 59 so that when screws 59 are tightened, a fluid tight seal is provided between block 10 and the upper wall 64 of manifold 11, which is substantially rectangular in cross section and includes side walls 65 and bottom wall 66, and end walls 58 and 68 which mount fluid-tight connectors for the conduits, such as 15, 16 and 17.
The function of each wick-receiving conduit 53 is to cause the wick ends 54, which extend through the bottom portion 66' thereof, to be maintained in the lower portion of manifold 11 so that they will always be immersed in lubricant 67. In other words, conduit 53 prevents wick ends 54 from floating on top of the lubricant. In addition, the level of lubricant in manifold 11 is adjusted to be above the lower portion 66' of conduit 53 so that there will always be lubricant within conduit 53 and thus there will be not portion of the wick 54 adjacent conduit 53 which is exposed to the air, thereby enhancing the capillary action or feeding of lubricant to the ring 30.
Because of the foregoing construction, there is a relatively straight run of wick from the lowermost portion 66' of conduit 53 to bore 50 in ring 30. This being the case, pinching or kinking of wick 51 is virtually obviated, thereby assuring proper flow of lubricant therethrough. Furthermore, because the lower portion 66' of conduit 53 is in the lower portion of manifold 11, the constant immersion of wick portion 54 is assured.
While the wick is shown in FIG. 7 as ending in bore 50 of ring 30, it will be appreciated that the wick may be caused to pass throughout the annular conduit 49 in the manner fully described in U.S. Pat. No. 4,098,067, which is incorporated herein by reference.
The block and manifold construction described above is especially of interest in that it permits modification of lubricating systems in the field by placing existing rings into new holders, such as 24, having blocks, such as 10, which can be attached between them and manifold 11.
It is to be especially noted that since each manifold 11 is essentially a continuous sump which is associated with six rings, the number of potential leak points between rings is lessened. This can be readily appreciated with the manifold construction of the present invention is compared to the construction shown in U.S. Pat. No. 4,098,067 wherein conduits, such as 18, 18a and 18b, are positioned between blocks 21 and which require fittings for attaching the conduits to the blocks. The present manifold construction eliminates the conduits and the fittings and the potential leak points resulting from their use. Furthermore, the fact that the ends 54 of the wicks are submerged in the lubricant in manifold 11 practically assures a constant oil flow which was not assured in the prior art because the oil had to flow through narrow tubes.
The tubes 16 and 17 between adjacent manifolds are flexible so as to allow for variations in elevation between adjacent rails 20 if separate rails are used or to allow for flexing of the rail if a single rail is used.
Each manifold 11 is provided with a vent 69 in the form of a screw-in type of plug. This vent includes as filtering element therein which permits the air to pass into and out of manifold 11 so as to equalize the pressure therein with the atmosphere. If desired, vent plugs 69 may be screwed out of manifold 11 and the hole may be used for filling the manifold with an initial charge of lubricant.
In order to check the level of oil in manifolds 11, a sight gauge 70 is attached to the manifold 11 at the right of FIG. 1 and the sight gauge is in communication with the inside of manifold 11 through fitting 71.
The wick 51 may be two-ply 8's wool yarn or any other type of wick which is suitable for the intended purpose. Furthermore, if desired, a second lubricant tank 12 and float tank 13 may be located at the right end of a plurality of manifolds 11, in addition to these members at the left end, so that the manifolds 11 will be supplied from both lubricant tanks.
In FIG. 8, the improved wick adapter block 10 and manifold 11 are mounted on a holder 80 which is secured to a flat rail 81 by means of a plurality of screws 82, and ring 83 is mounted within holder 80. The only differences between the embodiment of FIG. 8 and those shown in the preceding figures is in the configuration of the holder 80 and the fact that the mounting of the holder is on flat rail 81 rather than rail 20 which provides a cantilever type of mounting. In other words, except for the configuration of the holder and the type of rail which is used, the ring 83, wick adapter block 10 and manifold 11 are identical to that described above in the preceding figures. The significance of FIG. 8 is to show that the wick adapter block 10 and manifold 11 can be used with any type of holder and rail.
While preferred embodiments of the present invention have been disclosed, it will be appreciated that the present invention is not limited thereto, but may be otherwise embodied within the scope of the following claims.
|
A spinning and twisting ring system including a plurality of holders, a ring in each of the holders, an annular conduit in each ring, a wick adapter block connected to each holder, a plurality of aligned bores in the ring, holder, and adapter block for containing a wick, a lubricant manifold, a plurality of spaced bores in the manifold, a lubricant conduit extending externally from each block and received in each of the bores in the manifold with the wick extending downwardly through the lubricant conduit and into lubricant in the manifold, with the lower end of each wick-receiving conduit being located in the lower portion of the manifold to assure contact between the wick and the lubricant.
| 3
|
This application is a division of application Ser. No. 801,640 filed Nov. 25, 1985, now U.S. Pat. No. 4,682,609.
BACKGROUND OF THE INVENTION
The present invention is directed to devices for measuring cervical dilation.
In the early stages of labor, the doctor monitors cervical dilation to determine how far labor has advanced. Dilation monitoring is typically performed by inserting two fingers and noting how far they can be extended laterally.
Needless to say, this type of measurement is far from repeatable. Even if a given doctor comes to recognize different degrees of dilation by feel, he cannot reliably communicate that degree of dilation to another doctor without some objective scale. To overcome this shortcoming--i.e., to provide a way to assess dilation by means of an objective scale--devices for measuring cervical dilation have been proposed, but they have not attracted widespread use. The reason seems to be that the patient finds insertion of foreign objects more objectionable than insertion of the doctor's fingers.
It is accordingly an object of the present invention to permit an objective dilation measurement without the objectionable insertion of foreign objects.
SUMMARY OF THE INVENTION
The foregoing and related objects are achieved through the use of a dilation meter that comprises a pair of pivot arms pivotably mounted to each other. On one end of each arm is a ring adapted to fit around the bases of two adjacent fingers of a doctor. On the other end of one arm is a scale on which are provided indicia indicating meter pivot angle, while an indicating element such as a pointer is on the other end of the other arm to point to indicia on the scale. The scale is positioned with respect to the rings so that it fits in the palm of the doctor's hand when the rings are on the bases, rather than on the tips, of his fingers.
Dilation is determined from the angle measurement by means of a function, keyed to the sizes (lengths and thicknesses) of the doctor's fingers, that converts pivot angle to dilation. The doctor makes an initial determination of the size range for his fingers to determine which of several such conversion functions to use. The function may be provided on a separate table, or multiple functions may be provided on the device itself, and the functions are based on placement of the rings at the bases of the doctor's fingers rather than at their tips. In this way, an objective, repeatable dilation determination can be made without the need to have the meter touch the patient.
BRIEF DESCRIPTION OF THE DRAWINGS
These and further features and advantages are described in connection with the accompanying drawings, in which:
FIG. 1 is a front elevational view of the dilation meter of the present invention shown in position on the doctor's fingers;
FIG. 2 is an exploded view of the meter of FIG. 1;
FIG. 3 is an isometric view of a container for dilation meters of the type shown in FIG. 1;
FIG. 4 is a cross-sectional view of a part of the container of FIG. 3;
FIG. 5 is a detailed view of the table provided on the container of FIG. 3;
FIG. 6 is a perspective view of an alternate embodiment of the meter of the present invention;
FIG. 7 is an isometric view of an alternate embodiment of the container;
FIG. 8 is an isometric view of another alternate embodiment of the meter of the present invention.
FIG. 9 is an isometric view of another alternate embodiment of the meter of the present invention.
FIG. 10 is a front elevational view of another alternate embodiment of the meter of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a dilation meter 10 of the present invention in place on a doctor's hand 12. It includes two pivot arms 14 and 16 mounted together for pivoting about a pivot axis 18. At the distal ends of the arms 14 and 16 are mounted two rings 20 and 22, respectively. Rings 20 and 22 are adjustable in diameter and enclose the bases of the two adjacent fingers 24 and 26 that the doctor uses to perform the dilation measurement. At the proximal end of one pivot arm 14 is a scale 28 on which indicia are inscribed at different angular positions. At the proximal end of the other pivot arm 16 is an indicating element in the form of an elongated extension with a window 30 through which the doctor can see an indicium and thereby note the pivot angle--typically in arbitrary units--when his fingers are at their maximum lateral extension in the cervix. All parts of the meter are made of a plastic that will not be adversely affected by irradiation or other ordinary sterilization procedures.
As FIG. 2 shows, arm 14 is snap fit to arm 16. A resilient flanged boss 34 provided on arm 14 at its pivot axis extends through a registering aperture 36 at the pivot axis of arm 16 and thereby holds the two arms together.
Since the dilation for a given meter angle depends on the size of the doctor's fingers, the box 38 (FIGS. 3 and 4) in which the meters are delivered is provided with a calibration device. Perforations on the side of the box 38 define a tab 39 whose removal reveals an opening 40 in which a slide 42 is slidably mounted by any appropriate means such as track-defining internal rails 44 and 46 secured by spacers 48 and 50 to one wall 52 of the box 38. Complementary edges 54 and 56 on the wall and the slide define the opening 40, so the size of the opening 40 varies with the position of the slide 42.
Length indicia 54 are printed on the box wall 52 adjacent the slide 42, and a pointing indicium 57 is printed on the slide 42 to point to them. The size indicia in the illustrated embodiment are different colors, say, red, blue, green, and yellow.
Before a doctor uses a meter for the first time, he fits the rings 20 and 22 on the bases of his fingers and places his fingers in the opening 40 with the slide 42 disposed in a position somewhat to the left in FIG. 3. He opens his fingers until the meter reaches a predetermined reading, sliding the slide to the right as he does so. He then observes the size indicium 54 to which the pointing indicium 56 points when the meter reaches the predetermined reading, and this is an indication of the relative size of his fingers. Best calibration is obtained when the doctor's fingers are crooked in the manner in which they are crooked when he takes a dilation measurement.
When the doctor then uses the meter 10 to take an actual dilation measurement, he notes the angle indicium on the meter and consults a table 58 on container wall 52 to find the entry under the angle reading for his color. This is the dilation measurement. FIG. 5 shows the table in detail.
In practice, the doctor may rely for his own purposes on the angle measurement alone, converting to the dilation measurement only in communicating his measurements to others.
To avoid the need to consult a table on a separate box to determine dilation, the dilation-meter scale may be arranged to provide a dilation reading directly. Such a meter 59 is depicted in FIG. 6. The scale 60 on meter 59 provides indicia in four parallel ranges 62, 64, 66, and 68. Each range corresponds to a different finger size, and the doctor makes the dilation measurement by simply observing the indicium pointed to by the indicating element, in this case, a pointer 70.
The meter 59 shown in FIG. 6 may come in a container like box 72 of FIG. 7. Removal of a tab (not shown) reveals two holes 74 and 76 representing a predetermined cervical dilation. The initial calibration for the type of meter shown in FIG. 6 is performed by placing the tips of the doctor's fingers in the two holes and observing the range in which the pointer 70 points to an indicium representing the predetermined dilation.
FIG. 8 depicts a meter in which the indicating element includes a magnifying "glass" 78, typically made of transparent plastic, that magnifies the images of the indicia so that the doctor can read them more easily.
To further simplify the dilation determination, the disposable part of the meter can be provided without an integral scale. Instead, it could be adapted to be mechanically attached to a position encoder included in an electronic scale 80 (FIG. 9). With this type of an arrangement, the doctor simply presses a button when his fingers are in holes 74 and 76. The scale 80 is thereby automatically calibrated and displays dilation on an LCD display 84.
To increase measurement resolution in a strictly mechanical embodiment of the present invention, angle-multiplying arrangements can be used. An example is illustrated in FIG. 10, which shows rings 20 and 22 on arms 14 and 16 that are pivotably secured to each other for pivoting about a pivot axis 18. Instead of being attached directly to a pointer and scale, however, the arms 14 and 16 in the FIG. 10 embodiment are pivotably secured to auxiliary, angle-multiplying arms 86 and 88, respectively, for pivoting with respect to them about pivot points 90 and 92. The auxiliary arms 86 and 88 are in turn pivotably secured to each other at pivot point 94. A scale 98 and indicating element 98 are provided on the ends of auxiliary arms 86 and 88, respectively, and it becomes apparent upon reflection that a small change in the angle between the main arms 14 and 16 results in a much larger change in the angle between the auxiliary arms 86 and 88. The FIG. 10 embodiment thus affords greater resolution in the dilation measurement.
In light of the foregoing description, it can be appreciated that the present invention can be practiced in a wide variety of embodiments. It permits a doctor to make an objective dilation measurement without touching the patient with an objectional foreign object. The present invention therefore constitutes a significant advance in the art.
|
A meter (10) for measuring cervical dilation during labor includes rings (20 and 22) that fit at the bases of the user's fingers (24 and 26). Pivot arms (14 and 16) mount the rings (20 and 22) at one end and a scale and indicator (30) at the other end. Scale indicia indicate the separation of the rings. Ring separation can be translated into the separation of the finger tips and thus into cervical dilation.
| 0
|
FIELD OF THE INVENTION
This invention relates to the drying and restoration of wet books and other documents made from paper products. More specifically, the present invention relates to an apparatus and method for drying and/or restoring wet books, pamphlets, and other bound and unbound materials.
DESCRIPTION OF THE PRIOR ART
Paper products such as books, pamphlets and other bound or unbound materials are particularly susceptible to fire and/or water damage. Fire damage, of course, generally results in the destruction of the book or document. Water damage, on the other hand, may render the book or document or the like unsuitable for use, but generally does not result in total destruction of the object. There is also a relatively higher likelihood of water damage to books and the like, either because of the operation of a sprinkler system, the occurrence of a flood, burst pipes or other event. Accordingly, in order to place such water-damaged objects in condition to make them suitable for use, various drying techniques have been devised in the prior art.
Two methods have been primarily used in the prior art to dry water-damaged books and the like. In both methods the water soaked materials are placed in a chamber and subjected to vacuum or freeze drying (sublimination during the drying cycle) and require a 10-15 day drying cycle for heavily water soaked materials. One method involves the use of refrigeration cold traps or coils, in which water vapor is condensed on cooling coils and removed either by defrosting or condensing; and another method subjects the books to repeated cycles of elevated temperature, low humidity air or high temperature inert gas, such as dry nitrogen, wherein the moist atmosphere is cycled through dehumidifiers and recycled back into the chamber to absorb moisture.
One problem which occurs with books and other similar materials which have been water soaked is that the pages become distorted. This problem is especially acute with books, which, due to the unsymmetrical binding and board coverings have a natural affinity for distortion when wet. Neither of the prior art processes have any provision for restoring the distorted materials to at or near their original condition. In fact, the problem of distortion may even be exacerbated by the application of air drying or drying by other techniques, particularly the high temperature cycling used by one prior art method. Applicant is not aware of any prior art method or apparatus for restoring such distorted materials to an undistorted condition, whether they have been previously dried or not.
SUMMARY OF THE INVENTION
Accordingly, it is an object of this invention to provide an apparatus and method for drying books, pamphlets, and other bound and unbound materials, wherein the drying is accomplished more quickly than with prior art methods and apparatus.
Another object of the invention is to provide a method and apparatus for drying books, pamphlets and other bound and unbound materials, wherein the materials are restored to an undistorted condition during the drying process.
A further object of the invention is to provide a method and apparatus for restoring books, pamphlets and other bound and unbound materials which have been water soaked.
These objects are accomplished by a simple and effective apparatus and method, in which the wet materials are placed in shallow trays made of thermally conductive material, with separator plates of like or similar thermally conductive material inserted between selected numbers of pages of the material. Pressure applying means is then associated with the thus arranged materials to exert a compressive force on the materials in a direction perpendicular to the plane of the pages. These packages or trays of compressed materials are then placed on heated shelves which apply a substantially uniform low temperature to the thermally conductive trays and separator plates, and thus to the wetted materials. The entire assembly is then placed in a vacuum chamber for application of a vacuum to the materials to enhance removal of moisture therefrom. The water vapor partial pressure differential between the wet materials and the vacuum environment causes the water vapor to exit the materials and form a "fog" inside the chamber. This water vapor or "fog" is then extracted from the chamber via a vacuum pump.
It has been discovered by applicant that when the materials are permitted to reach equilibrium just above the freezing temperature, the materials "anneal" and, under the compressive force being exerted thereon, return to their original condition much more efficiently and in a shorter period of time than would otherwise be accomplished, thus reducing internal stresses on the materials during the drying and restoration process.
The heat and chamber pressure can be regulated to either maintain vacuum drying (above freezing) or freeze drying (below freezing) temperature in the materials. In either case, the addition of heat to the material accelerates the drying process. Best results have been obtained by maintaining the pressure above the triple point (freezing) of water with maximum heat of the materials maintained below 120° F. This results in the shortest drying cycle time with a concommitant maximum time to permit restoration of distorted material. A key feature of the invention is the gradual and uniform application of heat by conductivity such that the materials do not exceed 120° F. at any time during the cycle.
The invention is equally suitable for drying and restoring either large or small quantities of materials. For example, 10-15 books per day could be treated in accordance with the invention, or 10,000 books per day could be treated. The process is the same in either event.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing as well as other objects and advantages of the invention will become apparent from the following detailed description when considered with the accompanying drawings, in which like reference characters designate like parts throughout the several views, and wherein:
FIG. 1 is a schematic view of a system for practising the method of the invention;
FIG. 2 is a top perspective view of one form of thermally conductive tray and separator plate which may be used in the invention;
FIG. 3 is a top perspective view of another form of tray construction;
FIGS. 4, 5 and 6 are perspective views of some possible variations in the structure of the separator plates and/or tray end plates;
FIG. 7 is an isometric view of a plurality of wet materials, such as books, placed in alternating relationship with a plurality of separator plates on a thermally conductive tray;
FIG. 8 is an isometric view of the materials of FIG. 7, with compression means applied to the components;
FIG. 9 is a perspective view of a plurality of books assembled with separator plates in a tray, as they might appear after having been dried and restored;
FIG. 10 is an isometric view of a pair of books assembled with a plurality of plates and then wrapped with compression means and spacers to form an assembly for drying small quantities of materials;
FIGS. 11, 12, 13 and 14 are schematic views in side elevation of various types of compression means which may be applied to the wet materials and separator plates assembled on a tray;
FIG. 15 is a bottom perspective view of a heated shelf or platform on which the tray assemblies may be supported while in the vacuum chamber for drying and restoration;
FIGS. 16, 17, 18, 19, 20 and 21 are fragmentary sectional views showing various types of heating element means which may be used in association with the shelf of FIG. 15;
FIG. 22 is a perspective view of a movable cart having a plurality of heating platforms or shelves on which the tray assemblies may be placed;
FIG. 23 is a schematic view of one possible arrangement of heated support shelves and tray assemblies in a vacuum chamber; and
FIG. 24 is a schematic view of a variation in which the vacuum chamber is formed in a mobile unit, such as a truck or the like.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring more specifically to the drawings, a first form of apparatus in accordance with the invention is represented schematically at 10 in FIG. 1. In this form of the invention a plurality of water soaked materials, such as books 11, are placed spine down on a thermally conductive tray 12, with separator plates 13 of thermally conductive material placed in alternating relationship with the books. The tray and separator plates conduct thermal energy to the books, and preferably are made of a highly thermally conductive material such as aluminum. This material not only has good thermal conductivity, but also is rigid, lightweight, and resists surface oxidation.
Compression means, such as elastic cords 14, are placed around the assembled books and separator plates to apply a substantially constant compressive force in a direction perpendicular to the plane of the pages of the books. Thus, as the books dry, shrinkage occurs (approximately 10-20%) and the constant force applied thereto gradually straightens the materials. The thus-assembled tray, books and separator plates are placed on a heated shelf 15 in a vacuum chamber 16, and a vacuum is applied to the chamber to promote evaporation of moisture from the books and to remove the water vapor from the chamber. The shelves, trays, plates and books eventually reach an equilibrium temperature, depending upon the degree of dryness of the books. Generally, even at very low residual humidity in the books (0-4%), there is a constant temperature differential between the water and the books or other materials.
The shelf may be heated in a variety of ways, including the use of circulating hot water or other fluid, caused to flow through a serpentine conduit arrangement 20 (see FIG. 15) by suitable pump means 21 connected to an inlet 22 and outlet 23 leading to and from, respectively, the conduit 20. The heat exchange fluid is heated by a heat source 25 associated with a fluid reservoir 26 located outside the vacuum chamber. Whatever method of heating is applied to the shelves, it is preferred that the temperature be substantially uniform over the shelf area, and that it be carefully maintained below about 120° F. to avoid excessive heating of the materials. This heat is conducted through the shelf, tray and separator plates into the wet materials. Use of the separator plates between adjacent books, and even between the pages of larger books, insures that an elevated temperature is applied to essentially all of the wet materials. Use of circulating water at a controlled temperature through the conduit 20 provides maximum temperature regulation without danger of overheating the materials. This mode of heating also enables the gradual and uniform application of heat to the materials by conductivity, such that the temperature of the materials does not exceed approximately 120° F. at any time during the drying/restoration cycle.
Regulation of the pressure in the vacuum chamber is accomplished with a vacuum pump 30 connected to the chamber through a conduit 31. The vacuum pump may be of any suitable type, but in a particular embodiment comprises a liquid ring vacuum pump which operates to extract the water vapor from the chamber and mix it with the recirculating oil medium of the pump. This mixture is passed through a separator tank 32, at a temperature in excess of 212° F., whereby the water vapor is driven off as steam. The oil is then recycled through the vacuum pump system. Various other control devices, not shown, may be used to provide pressure and temperature control.
The trays may have a variety of shapes, but preferably are essentially U-shaped, with a bottom wall 35 and opposed fixed end walls 36 and 37 at opposite ends, as shown in FIG. 2, or one fixed end wall 38 and one movable end wall 39, as shown in FIG. 3. The trays may also be of any desireable size, although a tray assembly 17-19 inches long will accommodate 10-15 books and can easily be handled by one person. Further, the tray itself, and/or the separator plates may be perforated, as shown at 40 in FIG. 4, for better or more efficient evaporation of moisture from the wet materials; or the end walls and/or plates may have stiffened edges as shown at 41 in FIG. 5; or the plates may be plain rectangular plates as shown at 42 in FIG. 6. Additionally, aluminum alloys having a thickness between 0.090 and 0.125 inches have been found to be particularly suitable for the trays and plates.
As shown in FIG. 8, the assembly of books, tray and separator plates need not comprise uniformly sized books or other materials. For instance, as shown in this figure, some of the books may be substantially thicker than others, with separator plates preferably placed between the pages of the book, and other books may have a greater width or height dimension, with one or more additional flexible cords placed around these differently sized books to exert pressure uniformly over the entire width of the book.
In some instances involving small numbers of books, as shown at 50 in FIG. 10, it may be desireable to simply use a plurality of separator plates in alternating relationship with one, two or more books, and to wrap the assembly with elastic cords and spacers 51, rather than using the tray.
Various types of compression means may be used, as shown in FIGS. 11-14. In FIG. 11, for example, the compression means comprises a hydraulic or pneumatic press or ram 60 having one part 61 engaged against an end wall of the tray, and another arm or part 61a engaged against a movable plate positioned against the stack of books and plates mounted on the tray. The pressure on the ram is maintained substantially constant as the books shrink during the drying process. An alternate arrangement is shown in FIG. 12, wherein an inflated bladder 62 is engaged between an end wall of the tray and a movable plate adjacent the stack of books. As the pressure in the chamber drops, the bladder expands, maintaining a pressure on the books to straighten them during the drying process. In FIG. 13, one or more springs 63 are used to exert the compressive force on the books, and in FIG. 14 the preferred apparatus comprises the elastic cords previously described. The cords are easier to place and provide greater flexibility in positioning, adaptability to different book sizes and degree of compression. For instance, the cords enable use of plates and books without a tray, as shown in FIG. 10, and can be used in different multiples, depending upon the initial distortion of the materials. The elastic cords also exhibit almost constant force throughout the range of movement.
The conduit or tubing 20 for distributing heat over the area of the shelf may comprise any one of several different forms, as shown in FIGS. 16-21, for example. In FIG. 16, separate tubing 20a is welded to the underside of the shelf. In FIG. 17, tubing 20b is held captive between two spaced plates 70 and 71, making up the shelf. A plurality of brackets 72 welded to the underside of the plate support the tubing 20c in FIG. 18, and U-shaped brackets 73 extended through the shelf support the tubing 20d in FIG. 19. In FIG. 20, the conduit 20e is formed by an extruded channel 74 welded to the underside of the shelf. As shown in FIG. 21, electrical resistance heating means 75 supported on the underside of the shelf may be used instead of the circulating fluid systems described previously.
As shown in FIG. 22, one or more shelves 15 may be incorporated in a movable cart 80 having casters or wheels 81 so that the cart may be moved about. In addition, the cart preferably has open or wire mesh sides 82 for thorough circulation of air around the books or other materials. Conduits 83 interconnect the tubing under the respective shelves for circulation of heated fluid. When a cart has been loaded with books or other materials to be dried and/or restored, it may be easily moved into a vacuum chamber and hooked up with a source of heated fluid. If necessary or desired, a fork lift or other piece of equipment may be used to transfer the loaded cart.
An alternate arrangement is shown at 90 in FIG. 23. In this form of the invention, the heated shelves 91 are built into the vacuum chamber and interconnected by conduits 92 for circulation of heated fluid. Trays 12 containing alternating books 11 and separator plates 13 are placed on the shelves for drying and/or restoration of the books.
Yet another variation of the invention is shown at 100 in FIG. 24. In this form of the invention a mobile vacuum chamber 101 is provided in a truck T or other movable structure. Carts 80 containing trays of books 11 or other materials and separator plates are placed in the vacuum chamber and may rest on tracks 102 to facilitate placement of the carts into the chamber and removal therefrom. Power means for producing a vacuum and heated medium may be included on the mobile device.
The invention according to any of the forms described above can be used for drying wet books or other materials in a substantially shorter amount of time than is possible with prior art methods and apparatus. For instance, whereas it takes from 10-15 days to dry thoroughly wetted books in accordance with prior art methods, the present invention requires only 4-8 days. Additionally, the gradual application to the wet materials of a uniform low temperature via conduction, in conjunction with vacuum, results in much less stress on the materials being dried and yields a higher quality of dried materials. The use of compression to the materials through rigid plates during the drying process eliminates the distortion usually produced in books and the like which have become wet. The invention can also be used to recondition books and other materials which exhibit heavy distortion from air drying or drying by other prior art techniques.
In carrying out the invention, best results are obtained when the pressure is maintained above the triple point (freezing) of water, with the maximum temperature of the materials maintained below about 120° F. The books are allowed to reach equilibrium just above the freezing temperature, whereby the book materials anneal and, when supported by the rigid compression plates, return to their original condition.
Although the invention has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the application of the principles of the invention. Numerous modifications may be made therein and other arrangements may be devised without departing from the spirit and scope of the invention.
|
This invention relates to an apparatus and method for drying and/or restoring books and other materials which have been wet, wherein the wet and/or distorted materials are placed in a vacuum chamber and subjected to vacuum while being gradually and uniformly heated through the use of heat conductive supports. A compressive force is applied to the materials while they are being heated to straighten and restore the distorted materials.
| 5
|
This is a division of application Ser. No. 23,114, filed Mar. 23, 1979, which is a division of application Ser. No. 935,197, filed Aug. 21, 1978, now U.S. Pat. No. 4,158,007, issued June 12, 1979.
BRIEF SUMMARY OF THE INVENTION
The invention relates to a process for the preparation of a compound of the formula ##STR1## wherein R 2 is hydrogen, halogen, trifluoromethyl, hydroxy, lower alkyl, hydroxy-lower alkyl, lower alkylthio, amino, mono-lower alkylamino, or di-lower alkylamino; and R 3 is halogen, trifluoromethyl, lower alkyl, hydroxy-lower alkyl, lower alkoxy, lower alkylthio, hydroxy, amino, mono-lower alkylamino or di-lower alkylamino, or R 2 , taken together with an adjacent R 3 , is also lower alkylenedioxy, which comprises treating an α-methyl-3-oxocyclohexane malonic acid di-lower alkyl ester with a phenylhydrazine of the formula ##STR2## wherein R 2 and R 3 are as previously described, to yield a compound of the formula ##STR3## wherein R 1 is lower alkyl, and R 2 and R 3 are as previously described, treating the compound of formula IV with an oxidizing agent such as chloranil, to yield a compound of the formula ##STR4## wherein R 1 , R 2 and R 3 are as previously described, and treating the resulting compound of formula V to obtain the desired α-methylcarbazole-2-acetic acid of formula I.
DETAILED DESCRIPTION OF THE INVENTION
As used herein, the term "lower alkyl" denotes a straight or branched chain hydrocarbon group containing 1-7 carbon atoms, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tertiary butyl, neopentyl, pentyl, heptyl, and the like. The term "lower alkoxy" denotes an alkyloxy group in which the alkyl group is as described above, for example, methoxy, ethoxy, propoxy, isopropoxy, butoxy, pentoxy, and the like. The term "lower alkylthio" denotes an alkyl thioether group in which the alkyl group is as described above, for example, methylthio, ethylthio, propylthio, isopropylthio, butylthio, pentylthio, and the like. The term "halogen" denotes all the halogens, that is, bromine, chlorine, fluorine and iodine; bromine and chlorine are preferred. The term "lower alkylene" denotes a straight or branched chain alkylene of 1-7 carbon atoms, for example, methylene, ethylene, propylene, butylene, methylmethylene and the like. The term "lower alkylenedioxy" preferably denotes methylenedioxy and the like.
Exemplary of mono-lower alkylamino are methylamino, ethylamino and the like. Exemplary of di-lower alkylamino are dimethylamino, diethylamino and the like. Exemplary of amino-lower alkoxy are aminomethoxy, aminoethoxy and the like.
The compounds of the formula ##STR5## wherein R 2 is hydrogen, halogen, trifluoromethyl, hydroxy, lower alkyl, hydroxy-lower alkyl, lower alkylthio, amino, mono-lower alkylamino, or di-lower alkylamino; and R 3 is halogen, trifluoromethyl, lower alkyl, hydroxy-lower alkyl, lower alkoxy, lower alkylthio, hydroxy, amino, mono-lower alkylamino or di-lower alkylamino, or R 2 , taken together with an adjacent R 3 is also lower alkylenedioxy, are useful as anti-inflammatory, analgesic and anti-rheumatic agents.
The process of the invention comprises the preparation of the compounds of formula I. More specifically, an α-methyl-3-oxocyclohexane malonic acid di-lower alkyl ester of the formula ##STR6## wherein R 1 is lower alkyl, is treated with a phenylhydrazine of the formula ##STR7## wherein R 2 and R 3 are as previously described.
This reaction is carried out in the presence of an inert organic solvent, for example, an alkanol such as methanol, ethanol, propanol, or the like. The reaction yields a compound of the formula ##STR8## wherein R 1 , R 2 and R 3 are as previously described. The foregoing reaction can be conveniently carried out at room temperature or above, for example, at a temperature in the range of 25° to about 100° C. The compound of formula IV can be recovered, if desired, utilizing conventional methods. However, it is also possible to utilize the reaction product in situ in the next step of the process of the invention.
Exemplary of the compounds of formula IV are:
dimethyl-[6-chloro-1,2,3,4-tetrahydro-2-carbazolyl]-methyl malonate;
diethyl-[6-chloro-1,2,3,4-tetrahydro-2-carbazolyl]-methyl malonate;
dipropyl-[6-chloro-1,2,3,4-tetrahydro-2-carbazolyl]-methyl malonate;
dibutyl-[6-chloro-1,2,3,4-tetrahydro-2-carbazolyl]-methyl malonate;
diethyl-[6-methyl-1,2,3,4-tetrahydro-2-carbazolyl]-methyl malonate;
diethyl-[6-trifluoromethyl-1,2,3,4-tetrahydro-2-carbazolyl]-methyl malonate;
diethyl-[6-hydroxy-1,2,3,4-tetrahydro-2-carbazolyl]-methyl malonate;
diethyl-[6-ethyl-1,2,3,4-tetrahydro-2-carbazolyl]-methyl malonate;
diethyl-[6-propyl-1,2,3,4-tetrahydro-2-carbazolyl]-methyl malonate;
diethyl-[6-hydroxymethyl-1,2,3,4-tetrahydro-2-carbazolyl]-methyl malonate;
diethyl-[6-methylthio-1,2,3,4-tetrahydro-2-carbazolyl]-methyl malonate;
diethyl-[6-amino-1,2,3,4-tetrahydro-2-carbazolyl]-methyl malonate;
diethyl-[6-methylamino-1,2,3,4-tetrahydro-2-carbazolyl]-methyl malonate;
diethyl-[6-dimethylamino-1,2,3,4-tetrahydro-2-carbazolyl]-methyl malonate;
diethyl-[5-chloro-1,2,3,4-tetrahydro-2-carbazolyl]-methyl malonate;
diethyl-[7-chloro-1,2,3,4-tetrahydro-2-carbazolyl]-methyl malonate; and
diethyl-[8-chloro-1,2,3,4-tetrahydro-2-carbazolyl]-methyl malonate;
Exemplary of the compounds of formula II are:
α-methyl-3-oxocyclohexane malonic acid dimethyl ester;
α-methyl-3-oxocyclohexane malonic acid diethyl ester;
α-methyl-3-oxocyclohexane malonic acid dipropyl ester;
α-methyl-3-oxocyclohexane malonic acid dibutyl ester;
α-methyl-3-oxocyclohexane malonic acid dipentyl ester; and the like.
Exemplary of the substituted phenylhydrazines of formula III are:
p-chlorophenylhydrazine;
p-trifluoromethylphenylhydrazine;
p-hydroxyphenylhydrazine;
p-methylphenylhydrazine;
p-ethylphenylhydrazine;
p-hydroxymethylphenylhydrazine;
p-methylthiophenylhydrazine;
p-aminophenylhydrazine;
p-mono-methylaminophenylhydrazine;
p-dimethylaminophenylhydrazine;
m-chlorophenylhydrazine;
m-trifluoromethylphenylhydrazine;
m-hydroxyphenylhydrazine;
m-methylphenylhydrazine;
m-ethylphenylhydrazine;
m-hydroxymethylphenylhydrazine;
m-methylthiophenylhydrazine;
m-aminophenylhydrazine;
m-mono-methylaminophenylhydrazine; and
m-dimethylaminophenylhydrazine.
The reaction product of formula IV is treated with an oxidizing agent in a hydrocarbon solvent such as benzene, toluene, xylene, and the like, to yield a compound of the formula ##STR9## wherein R 1 , R 2 and R 3 are as previously described.
Exemplary of the oxidizing agents are paraquinones such as paraquinone, chloranil (tetramethyl-p-quinone), dichloroparaquinone, and dicyanoparaquinone. The reaction can be carried out at room temperature to the reflux temperature of the reaction mixture. Preferably, the reaction is carried out at the reflux temperature of the reaction mixture.
The compound of formula V can be recovered utilizing conventional methods, for example, crystallization or the like. Exemplary of the reaction products of formula V are:
dimethyl-[6-chloro-2-carbazolyl]-methyl malonate;
diethyl-[6-chloro-2-carbazolyl]-methyl malonate;
dipropyl-[6-chloro-2-carbazolyl]-methyl malonate;
dibutyl-[6-chloro-2-carbazolyl]-methyl malonate;
diethyl-[6-methyl-2-carbazolyl]-methyl malonate;
diethyl-[6-trifluoromethyl-2-carbazolyl]-methyl malonate;
diethyl-[6-hydroxy-2-carbazolyl]-methyl malonate;
diethyl-[6-ethyl-2-carbazolyl]-methyl malonate;
diethyl-[6-propyl-2-carbazolyl]-methyl malonate;
diethyl-[6-hydroxymethyl-2-carbazolyl]-methyl malonate;
diethyl-[6-methylthio-2-carbazolyl]-methyl malonate;
diethyl-[6-amino-2-carbazolyl]-methyl malonate;
diethyl-[6-methylamino-2-carbazolyl]-methyl malonate;
diethyl-[6-dimethylamino-2-carbazolyl]-methyl malonate;
diethyl-[5-chloro-2-carbazolyl]-methyl malonate;
diethyl-[7-chloro-2-carbazolyl]-methyl malonate; and
diethyl-[8-chloro-2-carbazolyl]-methyl malonate.
The compounds of formula V are then hydrolyzed to yield α-methylcarbazole-2-acetic acids of formula I. The hydrolysis can be carried out, for example, utilizing glacial acetic acid in the presence of a hydrohalic acid such as hydrochloric acid. The resulting end product of formula I is recovered utilizing conventional methods. As already mentioned, the compounds of formula I are useful as analgesic, anti-inflammatory and anti-rheumatic agents.
The following Examples further illustrate the invention. All temperatures are in degrees Centigrade, unless otherwise mentioned.
EXAMPLE 1
Preparation of α-methyl-3-oxocyclohexane malonic acid diethyl ester
Into a 2 l. 3-neck flask equipped with stirrer, condenser, thermometer, dropping funnel, and under a nitrogen atmosphere is placed 325 ml. of ethanol, and 2.5 g. of freshly cut sodium is added. When solution of the sodium is effected, 200 g. of diethyl methyl malonate is added in 5 minutes, and the mixture is stirred at room temperature for 1 hour. At the end of this period a solution of 100 g. of 2-cyclohexen-1-one in 130 ml. of ethanol is added through the dropping funnel over a period of 1 hour. The ensuing mild exothermic reaction causes the temperature to rise to 42°. Stirring is continued overnight at room temperature, after which 20 ml. of acetic acid is added, and the mixture is evaporated at reduced pressure. The residual oil is dissolved in 1.31 l. of ether, transferred to a separatory funnel and washed with three 230 ml. portions of water. The ether solution is dried over anhydrous sodium sulfate, filtered, and dried over anhydrous calcium sulfate. The ether is removed at reduced pressure and the residual oil distilled under high vacuum using a 6-inch Vigreux column. After removal of a forerun of 22.5 g., bp 49°-129°/0.14-0.21 mm, α-methyl-3-oxocyclohexane malonic acid diethyl ester distills at 129°-130°/0.2 mm; 211.5 g, 75.4% of theory.
EXAMPLE 2
Preparation of diethyl-[6-chloro-1,2,3,4-tetrahydro-2-carbazolyl]methyl malonate
Into a 1 l. 3-neck flask equipped with stirrer, condenser, thermometer, and under nitrogen atmosphere is placed 100 g. of α-methyl-3-oxocyclohexane malonic acid diethyl ester, 66.3 g. of p-chlorophenylhydrazine hydrochloride and 300 ml. of ethanol. The suspension is stirred at room temperature for 1.5 hours, and is then refluxed for 1.5 hours. The hot reaction mixture containing some insolubles is allowed to cool to room temperature overnight without stirring. It is then cooled in an ice bath, and the crystals filtered. Residual material in the flask is washed onto the funnel with the mother liquor, the presscake sucked dry, washed with three 50 ml. portions of ice cold ethanol, then with 50 ml. of 1:1 hexane-ethanol, and dried at 40°-50° at reduced pressure. The resultant 97.1 g. of bluish-white solid is placed in a 1 l. 3-neck flask equipped with stirrer, under nitrogen atmosphere, surrounded by an ice bath, and is stirred 15 minutes with 500 ml. of cold water, filtered, washed with three 100 ml. portions of cold water and dried at 40° at reduced pressure to give 78.8 g. of diethyl-[6-chloro-1,2,3,4-tetrahydro-2-carbazolyl]methyl malonate, mp 129°-130°, 56.5% of theory.
Anal. Calcd. for C 20 H 24 ClNO 4 : C, 63.57; H, 6.40; N, 3.71. Found: C, 63.59; H, 6.58; N, 3.84.
EXAMPLE 3
Preparation of diethyl-[6-chloro-2-carbazolyl]methyl malonate
Into a 3 l. 3-neck flask wrapped with aluminum foil, equipped with stirrer, condenser, thermometer, and under nitrogen atmosphere are placed 161.2 g. of diethyl-[6-chloro-1,2,3,4-tetrahydro-2-carbazolyl]methyl malonate, 251.0 g. of chloranil and 1.65 l. of xylene. The mixture is refluxed 6 hours and allowed to cool overnight. The supernatant liquid is decanted and filtered. The residue is triturated three times, each with 650 ml. of warm (45°-50°) benzene, and the supernatants are decanted and filtered. 2 L. of ether is added to the combined filtrates and the mixture extracted with four 650 ml. portions of 2 N sodium hydroxide. The organic phase is washed with water until the washings are neutral and is then dried over anhydrous magnesium sulfate. The organic phase is then evaporated at reduced pressure using a water aspirator. The residue is then dried at high vacuum. The resulting 156.3 g. of brown solid is dissolved in 300 ml. of boiling carbon tetrachloride, treated with 3.0 g. of charcoal, filtered hot, diluted with 600 ml. of hexane, heated to the boil, seeded immediately upon cessation of heating with crystals of diethyl-[6-chloro-2-carbazolyl]methyl malonate, allowed to cool overnight while stirring under a nitrogen atmosphere and then cooled in an ice bath. The crystalline material is filtered, and washed with three 100 ml. portions of 2:1 hexane-carbon tetrachloride. The solid, when dried at reduced pressure, yields 119.4 g. of diethyl-[6-chloro-2-carbazolyl]methyl malonate, mp 134°-135°, 75.2% of theory.
Anal. Calcd. for C 20 H 20 ClNO 4 : C, 64.26; H, 5.39; N, 3.75. Found: C, 64.41; H, 5.49; N, 3.72.
EXAMPLE 4
Preparation of 6-chloro-α-methylcarbazole-2-acetic acid
Into a 5 l. 3-neck flask equipped with a stirrer, thermometer, condenser and nitrogen atmosphere is placed 247 g. of diethyl-[6-chloro-2-carbazolyl]methyl malonate, 1.9 l. of glacial acetic acid and 1.9 l. of 6 N hydrochloric acid. The mixture is stirred and refluxed overnight and the resulting black solution allowed to cool to room temperature. The solid formed is filtered, washed with three 200 ml. portions of 1:1 acetic acid-water, followed by four 300 ml. portions of water, and dried at reduced pressure. The crude 6-chloro-α-methylcarbazole-2-acetic acid (approximately 192 g.) is dissolved in 1.2 l. of cold (10°) 1 N potassium hydroxide, and the solution is extracted with four 300 ml. portions of ether, and then while cooling in an ice bath, under nitrogen, is acidified by the addition of 100 ml. of concentrated hydrochloric acid. Stirring is continued for 15 minutes, the precipitated solid is filtered, washed with three 100 ml. portions of water, and dried at reduced pressure to give 167.7 g. Final purification is achieved by crystallization from 4.7 l. of boiling 1,2-dichloroethane with 8.0 g. of charcoal. The amber solution is allowed to cool overnight. The crystals are filtered, washed with two 200 ml. portions of cold dichloroethane and dried at reduced pressure. The yield of almost white 6-chloro-α-methylcarbazole-2-acetic acid is 103.8 g., mp 198.5°-201°, 57.3% of theory.
|
A process for the preparation of α-methyl-carbazole-2-acetic acids, which comprises reacting an α-methyl-3-oxocyclohexane malonic acid di-lower alkyl ester with a substituted phenylhydrazine, and thereafter sequentially oxidizing and hydrolyzing the reaction product to obtain the desired acid, is described.
| 2
|
CROSS REFERENCE TO RELATED APPLICATION
This application claims priority to U.S. Provisional Patent Application Ser. No. 61/150,093 entitled “Direct Drive System with Booster Compressor,” filed on Feb. 5, 2009. The content of this application is incorporated herein by reference in its entirety.
TECHNICAL FIELD
This invention relates generally to transport refrigeration systems and, more particularly, to the temporary boosting of capacity for the direct drive compressor during periods in which the effective displacement is insufficient to deliver desired capacity such as during idling and low speed operation of the drive vehicle.
BACKGROUND OF THE INVENTION
Refrigerated vehicles have long been employed in a wide variety of applications including storage and transportation of perishable commodities, particularly produce such as fruit and vegetables, as well as other perishable foods, including processed and frozen or chilled products such as ice cream or the like. The refrigerated vehicles contemplated by the present invention include, for example, trucks, truck trailers, and refrigerated vans.
In such vehicles, it has been common to drive the refrigeration compressor by way of direct drive arrangement with the vehicle engine. While operating at higher speeds as when on the highway, for example, the compressor speed is normally sufficient to provide adequate capacity to the refrigeration system. However, when idling or operating at low speed city delivery conditions, the engine speed, and thus the compressor speed, is sufficiently reduced so as to provide insufficient capacity for the system. In addition, the combination of selectable box temperatures, wide ranging ambient temperatures, and wide engine speed variations, often produce a mismatch between the desired compressor capacity and the actual compressor capacity.
One approach to solving this problem is that of substituting a direct drive compressor with an electrically driven variable speed compressor which, in turn, is operatively connected to an engine driven generator. Although effective, this approach is expensive since the cost of the generator is relatively high. Further, such an approach requires a high electrical demand, and the ac current must be converted to dc current and then back to ac current. There is therefore a substantial cost penalty using such an approach.
Other problems associated with a direct drive compressor during pulldown include those of overloading the compressor especially during periods in which the box is hot. That is, at the start of a pull down condition when the box is 100° F., for example, the direct drive compressor can easily be overloaded and result in clutch failure or otherwise be caused to shut down unless the load is limited. This is normally accomplished by way of a compressor pressure regulator, which is a throttling valve to reduce the flow of refrigerant from the evaporator to the compressor Thus, under the typical pull down operating cycle, during the initial stages when the box is hot, it is necessary to limit the suction pressure and the compressor pressure regulator needs to be in operation. During the later stages of pull down, when the temperature in the box has been reduced to a temperature such as, for example, −20° F., then the density of the suction gas is low, resulting in the direct drive compressor having insufficient capacity to meet the demands.
DISCLOSURE OF THE INVENTION
In accordance with one aspect of the invention, an electrically powered variable speed booster compressor is made to operate in series with the direct drive compressor so as to boost the suction pressure of the direct drive compressor when needed. It should be noted that in the context of this invention the direct drive compressor can be connected to the engine via a coupling, belts, gearbox or by some other mechanical means.
By another aspect of the invention, the booster compressor is used as a pressure limiter to the direct drive compressor when needed such that the compressor pressure regulator can be eliminated.
In the drawings as hereinafter described, a preferred embodiment is depicted; however, various other modifications and alternate constructions can be made thereto without departing from the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of a direct drive compressor circuit in accordance with the prior art.
FIG. 2 is a schematic illustration of a direct drive compressor circuitry in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Shown in FIG. 1 is a typical transport refrigeration circuit 11 which includes, in serial flow relationship, a direct drive compressor 12 , a condenser 13 , an expansion device 14 , and an evaporator 16 . The transport vehicle (not shown) is driven by a drive engine 17 having a drive shaft 18 . The drive shaft 18 is connected by a pulley 18 and a belt 21 to drive the direct drive compressor 12 . A similar pulley and belt 24 is connected to drive the generator 23 for producing electrical power to various components on the vehicle such as the lights, battery, gauges, etc.
As may be understood, when the drive engine is driving the vehicle at normal operating speeds such as when on the highway, the drive shaft 18 , and thus the direct drive compressor 12 , will also be operating at relatively higher speeds. Thus, under those conditions, the refrigerant flow through the refrigerant circuit 11 is sufficient to meet the cooling requirements. However, when the drive engine 17 is idling or otherwise operating at low speeds, the cooling requirements may exceed the cooling capacity delivered by refrigerant circuit 11 . In such a case the box temperature will rise above desired level, and, depending on the thermal inertia and duration, may result in product spoilage.
During periods in which the demands for higher capacity are made on the system, such as during pulldown conditions when the box is just loaded or is about to be loaded, and the temperature therein is relatively hot, the direct drive compressor 12 may be overloaded and thereby result in damage to the compressor, clutch, or belt. This can occur even at higher speeds of the drive engine 17 . During these conditions, it is necessary to limit the flow of refrigerant to the direct drive compressor 12 and this has traditionally been accomplished by way of a compressor pressure regulator 24 . Such regulating valves have been found to be inaccurate and unreliable in practice and often must be field adjusted at the risk of causing a compressor, clutch or belt failure.
In accordance with the present invention, a refrigeration circuit 26 includes the direct drive compressor 12 , the condenser 13 , the expansion device 14 and the evaporator 16 . Further, the direct drive compressor 12 is driven by the drive engine 17 in a manner similar as that described hereinabove. However, in order to meet the demands for higher capacities, a variable speed booster compressor 27 , driven by a variable speed motor 28 is provided in the circuit 26 as shown. As will be seen, the booster compressor 27 takes its suction from line 29 from the evaporator 16 , and discharges to line 31 which leads to the suction of the direct drive compressor 12 . In this manner, the booster compressor 27 operates in series flow relationship with the direct drive compressor 12 in order to regulate capacity of the system 26 .
The variable speed drive motor 28 receives its electrical power from the generator 23 and is controlled by the control 32 to operate at the appropriate speed to match the system requirements. In this way, the booster compressor speed can be increased during periods of high capacity demands increasing the pressure rise across this compressor. When the high capacities are no longer required, the control can operate to turn the drive motor 28 off and allow the booster compressor to “free wheel” in accordance with the gas flow and allow the direct drive compressor 12 to operate by itself. In this regard, it should be recognized that a screw compression or a centrifugal compressor will “free wheel”, whereas a rotary, scroll or reciprocating compressor will not, in which case it may be necessary to provide a bypass around the compressor during these periods of operation. This configuration needs to be shown on the drawing and indicated in the claims.
In addition to the advantages of the booster compressor 27 as described hereinabove, it should be recognized that the pressure regulator 24 can be eliminated from the refrigeration circuit. That is, the booster compressor 27 will not only provide the function of boosting the capacity of the direct drive compressor 12 but will also act to regulate the flow of refrigerant to the direct drive compressor 12 such that it does not become overloaded. Such regulation would be effected by powered operation of the booster compressor at a speed that would provide a pressure drop across the booster compressor which would in turn reduce the pressure from the evaporator to the direct drive compressor. In this way, the pressure to the direct drive compressor can be limited to a predetermined desirable level.
Although the present invention has been particularly shown and described with reference to one embodiment as illustrated by the drawings, it will be understood by one skilled in the art that various changes in detail may be made thereto without departing from the scope of the invention as defined by the claims.
|
A transport refrigeration system with a direct drive compressor arrangement is provided with a variable speed electrically driven booster compressor that operates in series with the direct drive compressor. The speed of the booster compressor is controlled to either boost or decrease the system capacity. The booster compressor also acts to regulate the flow of refrigerant from the evaporator during periods of operation in which the direct drive compressor might otherwise become overloaded.
| 8
|
This application is a division of application Ser. No. 08/538,653, filed Oct. 4, 1995, abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a punched plate material carrying-out system, and more specifically to a system for carrying out a plate material punched by a processing machine (e.g., a punch press machine, laser processing machine, etc.) onto a punched product supporting unit (e.g., table).
2. Description of the Prior Art
A conventional punched plate material carrying-out system will be first explained hereinbelow. The system is provided with a punch press machine (as an example of the hole-forming machines). The punch press machine has a punching section for punching at least one punch hole at any desired portion in a plate material (work) to manufacture a punched product, and a plate material locating mechanism for locating the plate material at a correct punching position.
Further, after the plate material has been punched out as a punched product, the punched plated material (i.e., punched product) must be carried out from the punch press machine to the outside (e.g., a punched product supporting table). For this purpose, a guide member extending in an X-axis direction (e.g., a longitudinal direction of the plate material (work)) is provided near the punch press machine in such a way that a part of the guide member reaches the vertical portion of the punch press machine. A slider is usually mounted on the guide member so as to be movable in the X-axis direction, and further a lift frame is attached to this slider movably up and down. Further, a number of vacuum pads are arranged at regular intervals along the bottom surface of the, lift frame to suck all over the upper surface of the punched plate material (punched product). These vacuum pads can be switched from a suction status to a non-suction status or vice versa, respectively. In the prior art punched plate material carrying-out system, however, in order to uniformly suck all over the upper surfaces of the punched products of various sizes, a plurality of vacuum pads are arranged in the lift frame at roughly regular intervals both in the X- and Y-axis directions. Here, the number of the vacuum pads is determined large so that the punched products of the maximum sizes can be sucked for lifting.
In operation, first a plate material is shifted and located at the plate material punching position by moving it in both X- and Y-axis directions by the plate material locating mechanism, and then the located plate material is punched out at any desired portion of the plate material to manufacture a plate punched product.
After or when the punching is accomplished, the slider is moved to over the punching position; the lift frame is lowered to bring a number of the vacuum pads (determined according to the maximum product size) attached to the lift frame into contact with the upper surface of the punched products at roughly regular intervals; the vacuum pads are switched from the non-suction status to the suction status to suck all over the upper surface of the punched product. After that, the lift frame (i.e., a number of the vacuum pads) is lifted to move the punched product upward. After the punched product has been moved upward, the slider is moved in the X-axis direction away from the punch press machine, and then mounted on an appropriate product support table. Thereafter, the vacuum pads are switched to the non-suction status to release the sucked punched product onto the product support table.
In the conventional punched plate material carrying-out system as described above, however, since a great number of vacuum pads are arranged in both X- and Y-axis directions roughly at regular intervals on the lift frame so that the punched product of the maximum size can be sucked, that is, in order to suck all over the surfaces of various products of different sizes, there exists a problem in that the number of vacuum pads increases. As a result, the mechanism of the punched plate material carrying-out system is complicated with increasing number of vacuum pads, thus causing a problem in that the manufacturing cost of the punched plate material carrying-out system is relatively high. In addition, since the sizes of the slider, the guide members, etc. increase with increasing number of the vacuum pads, another problem arises in that the system size is excessively large.
SUMMARY OF THE INVENTION
With these problems in mind, therefore, it is the object of the present invention to provide a punched plate material carrying-out system, which can reduce the number of vacuum pads to simplify the punched plate material carrying-out system and thereby to reduce the total size and the total manufacturing cost of the system.
To achieve the above-mentioned object, the present invention provides a punched plate material carrying-out system, comprising: a punching machine (3) having a punching section (15) for punching a plate material (W) and a plate material locating mechanism (23) for shifting the plate material in both horizontal X- and Y-axis directions; and punched plate material carrying-out means (7) including: a guide member (45) extending in the X-axis direction from over the punching section of said punching machine; a slider (51) attached to said guide member slidably in the X-axis direction along said guide member; first and second actuation cylinders (67, 71) attached to said slider; a lift arm (59) extending in the X-axis direction and supported by said first and second actuation cylinders, said lift arm being moved up and down by said said first and second actuation cylinders, respectively; a plurality of punched plate material holding members (79) arranged at regular intervals on a bottom surface of said lift arm to hold the punched plate material (WA); a gravity center calculating section (91) for calculating a gravity center of the punched plate material on the basis of manufacturing data; and a location control section (93) for controlling the plate material locating mechanism (23) in both horizontal X- and Y-axis directions on the basis of the calculated gravity center, so that the gravity center of the punched plate material can be located Just under some of said punched plate material holding members attached to said lift arm (59), the punched plate material (WA) being held by some of said actuated punched plate material holding members (79) and further carried out from said punching machine by said slider along said guide member.
Further, it is preferable that the system further comprises: a shape recognition section (95) for recognizing a shape of the punched plate material (WA) on the basis of the manufacturing data; a holding member or pad discriminating section (97) for discriminating which plate material holding members are located over the punched plate material on the basis of the recognized shape of the punched plate material; and a holding members or pad control control section (99) for actuating only the holding members discriminated as locating over the punched plate material, to hold the punched plate material (WA), before or after said holding members arranged on said lift arm are lowered into contact with the punched plate material by said first and second cylinders.
Further, the gravity center of the punched plate material is located under some of said punched plate material holding members in such a way that at least one of the outermost holding member (79 1 ) can hold an outermost end of the punched plate material (WA) when seen along the X-axis direction.
Further, said holding members (79) are a plurality of vacuum pads arranged at regular interval on the bottom surface of said lift arm in the X-axis direction, each vacuum pad being switched from a suction status to a non-suction status or vice versa by an air supply circuit composed of an air source (83), an air switch valve (85) and an air ejector (87).
Further, a plurality of said holding members (79) are arranged in a single line or a plurality of lines along a longitudinal direction of said lift arm.
Further, said lift arm (59) is composed of a horizontal lift arm (61) and a pivotal lift arm (65) pivotal relative to said first lift arm, said horizontal lift arm being lifted upward in horizontal status relative to the punched plate material and said second lift arm being pivoted upward in oblique status relative to the punched plate material, to facilitate separation of the punched plate material (WA) from the plate material (W).
Further, it is preferable that the system further comprises a punched plate material supporting unit (5) arranged in the vicinity of said punching machine, for supporting the carried-out punched plate material thereof, said guide member (45) being extending between said punching machine (3) and said punched plate material supporting unit (5).
Further, said punching machine is a punch press machine having a punching section composed of an upper turret and a lower turret, and the punched plate material is a punched product punched out from the plate material. And said punched plate material holding members are electromagnets.
Further, the present invention provides a method of carrying-out a product punched out by a punch press machine, which comprises the steps of: punching out a plate material to manufacture a punched product; moving a slider (51) provided with a lift arm (59) vertically movably supported by first and second cylinders (67, 71) and further having a plurality of vacuum pads (79), from a punched product support position to a punched product carry-out position near the punch press machine; calculating a gravity center of a punched product on the basis of product manufacturing data; recognizing a shape of the punched product on the basis of the product manufacturing data; moving the punched product in both X- and Y-axis direction by an X- and Y-axis locating mechanism of the punch press machine, so that the gravity center of the punched product can be located just under some of the vacuum pads arranged on a bottom surface of the lift arm (59); discriminating which vacuum pads are located over the punched product; actuating the first and second actuation cylinders to lower the lift arm so that the vacuum pads are brought into contact to an upper surface of the punched product; actuating only the vacuum pads located Just over the punched product to hold the punched product; actuating the first and second actuation cylinders to move the lift arm upward away from the plate material; and moving the slider away from the punched product carry-out position to the punched product support position.
Further, the gravity center of the punched plate material is located under some of the vacuum pads in such a way that at least one of the outermost vacuum pad (79 1 ) can hold an outermost end of the punched product (WA) when seen along the X-axis direction.
Further, after vacuum pads located over the punched product are discriminated, the punched product can be moved in both X- and Y-axis direction by the X- and Y-axis locating mechanism of the punch press machine, so that the gravity center of the punched product can be located Just under some of the vacuum pads arranged on the bottom surface of the lift arm.
Further, after the slider (51) has been moved from a punched product support position to the punched product carry-out position, the plate material can be punched out to manufacture the punched product.
Further, after only the vacuum pads located just over the punched product have been actuated so as to hold the punched product, the first and second actuation cylinders can be actuated to lower the lift arm so that the vacuum pads are brought into contact to an upper surface of the punched product.
Further, in the step of moving the lift arm upward away from the plate material, only the second actuation cylinder (71) is actuated by a larger stroke to bend one end of the punched product upward relative to the plate material for easy separation of the punched product from the remaining flat plate material.
Further, it is preferable that the method further comprises the steps of: moving the slider which holds the punched product by the vacuum pads via the lift arm, to a punched product support unit installed at the punched product support position; and deactuating the vacuum pads to release the carried punched product onto the punched product support unit.
In the punched plate material carrying-out system and method according to the present invention, before or after a plate material is punched out into a punched product by a punch press machine, the slider of the punch carry out unit is moved in the X-axis direction to near a punching section of the punch press machine. At the same time, a gravity center and a shape of the punched product are calculated and recognized on the basis of the manufacturing data. On the basis of these obtained gravity center and the shape of the punched product, the gravity center of the punched product is moved under the lift arm by the X- and Y-axis locating mechanism of the punch press. Further, the vacuum pads located just over the punched product are selected or discriminated. After that, the lift arm is lowered and further the punched product is held by actuating only the discriminated vacuum pads. In this lift motion, it is preferable to bend one end of the punched product slightly upward to separate the punched product easily from the remaining flat plate material. After the punched product has been lifted, the punched product is moved in horizontally away from the punch press machine, and then lowered on the punched product supporting unit by releasing only the actuated vacuum pads.
As described above, in the punched plate material carrying-out system according to the present invention, since the vacuum pads can suck only the vicinity of the punched product, irrespective of the shape and the size of the punched product WA, it is unnecessary to arrange a great number of vacuum pads both in the X- and Y-axis directions in a wide range so as cover all over the upper surface of the product WA of the maximum size. As a result, it is possible to reduce the number of vacuum pads and simplify the punched product carrying-out unit, thus reducing the cost thereof. In particular, since the slider and the guide member, etc. can be compacted, it is possible to reduce the size of the entire punched plate material (product) carrying-out system, thus economizing the installation space required for the system in a factory.
In addition, after the upper surface of the punched product has been sucked in the vicinity of the gravity center thereof, the left side of the punched product is further bent or curved upward, the punched product can be separated from the plate material W easily, so that It is possible to improve the working efficiency of the punched product carrying-out work for the plate material processing machine.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view showing a punched plate material carrying-out system according to the present invention, taken along the line I--I in FIG. 2;
FIG. 2 is a plane view showing the punched plate material carrying-out system according to the present invention shown in FIG. 1;
FIG. 3 is a schematic block diagram showing an NC control system used with the punched plate material carrying-out system according to the present invention;
FIG. 4 is an air circuit diagram for actuating a plurality vacuum pads, separately;
FIG. 5A is an illustration for assistance in explaining an example of the positional relationship between the arrangement of the vacuum pads and a punched product;
FIG. 5B is an illustration for assistance in explaining another example of the positional relationship between the arrangement of the vacuum pads and another punched product; and
FIGS. 6A to 6F are illustrations for assistance in explaining the operation sequence of the punched plate material carrying-out system according to the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
The punched plate material carrying-out system according to the present invention will be explained hereinbelow, by taking the case where a plate material (work) is punched out to a punched plate material (referred to as a punched product) by a punch press machine. However, a plate material can be punched off by user of a laser processing machine.
With reference to FIGS. 1 and 2, the punched plate material carrying-out system according to the present invention is roughly composed of a punch press machine 3 for punching a plate material (work) W into a punched product WA, a product support unit 5 arranged in the vicinity (on the left side in FIGS. 1 and 2) of the punch press machine 3, and a product carry-out unit 7 interposed between the punch press machine 3 and the product support unit 5. The product support unit 5 can support a plurality of punched products WA, and the product carry-out unit 7 can take out the punched product WA from the punch press machine 3 and further carries and mounts the punched product WA onto the product support unit 5.
The punch press machine 3 will be briefly explained hereinbelow. The punch press machine 3 has a base frame 9 (shown in FIG. 2) having an upper frame 11 and a lower frame 13 so as to be opposed to each other in the vertical direction (in the perpendicular direction to the paper in FIG. 2).
On the front side of the body frame 9, there is arranged a punching section 15 for punching any desired portion of a plate material W into a punched product WA. The punching section 15 is provided with an upper turret 17 for supporting a plurality of punches (not shown), a lower turret 19 for supporting a plurality of dies (not shown), and a ram 21 for striking any desired punch located at the punching position 15 from above. Here, the constructions of the upper turret 17, the lower turret 19, and the ram 21 are all well known, so that any detailed description thereof is omitted herein.
On the lower frame 13, a plate material locating section mechanism 23 is provided to shift and locate the plate material W to the punching position in both X- and Y-axis directions. In more detail, the lower frame 13 is provided with a Y-axis carriage 25 extending in the X-axis direction and moved in the Y-axis direction by a Y-axis servomotor 27. Further, the Y-axis carriage 25 is provided with an X-axis carriage 29 also extending in the X-axis direction and moved in the X-axis direction by an X-axis servomotor 31. Further, a plurality of clamps 33 for clamping the plate material W are provided for the X-axis carriage 29.
Further, on front side of the Y-axis carriage 25 (on the lower side in FIG. 2), a pair of right and left movable tables 35 and 37 are provided integral with each other, and a fixed table 39 (fixed to the lower frame 13) is interposed between the two movable tables 35 and 37.
The product support unit (table) 5 is composed of a product support base 41 for supporting a plurality of punched products WA and a link mechanism 43 for moving up and down the product support base 41. Further, when the link mechanism 43 is moved up and down by means of any appropriate drive mechanism (motor, hydraulic pump, etc.), it is possible to keep the outermost punched product WA mounted on the product support base 41 always at a constant height.
The punched product carry-out unit 7 will be described in detail hereinbelow, which is interposed between the punch press machine 3 and the product support unit 5. The punched product carry-out unit 7 is mainly composed of a guide member 45, a slider 51 slidable along the guide member 45, a lift arm 59 supported by the slider 51 via a first actuation cylinder 69 and a second actuation cylinder 71 and a plurality of vacuum pads 79. In more detail, the guide member 45 extending in the X-axis direction is supported by a plurality of support frames 47 (shown in FIG. 2) between the punch press machine 3 and the product support unit 5. The right end portion of the guide member 45 extends over the punch press 3 and the left end portion of the guide member 45 extends over the product support unit 5. The slider 51 is mounted on a rail portion 49 formed in the guide member 45. Accordingly, this slider 51 can be moved in the X-axis direction between over the product carry-out position (shown by solid lines in FIG. 2) of the punch press machine 3 and over the product support position (shown by dashed lines in FIG. 2) of the product support unit 5. To move the slider 51 in the X-axis direction, the guide member 45 is formed with a rack extending in the X-axis direction. On the other hand, a mobile motor 55 is mounted on the slider 51 and a pinion 57 driven by this mobile motor 55 is in mesh with this rack 53 of the guide rail 49. Therefore, when the mobile motor 55 is driven, the slider 51 can be moved in the X-axis direction along the guide member 45 via a mesh between the rack and pinion mechanism.
On the other hand, the lift arm 59 extending also in the X-axis direction is attached to the slider 51 so as to be moved up and down relative to the slider 51 via two actuation cylinders 67 and 71. This lift arm 59 is composed of a horizontal lift arm 61 and a pivotal lift arm 65 pivotal around a connection pin 63 provided on the left side end of the horizontal lift arm 61. Further, in order to keep the horizontal lift arm 61 roughly horizontally, a guide bar 75 extends downward from the lower surface of the slider 51, and further a lift sleeve 77 is attached on the upper surface of the horizontal lift arm 61 to support the guide bar 75 always in the vertical direction by the lift sleeve 77. Further, the first actuation cylinder 67 is provided on the right end of the slider 51 and the second actuation cylinder 71 is provided on the left end of the slider 51. A piston rod 69 of the first actuation cylinder 67 is linked with the right end of the horizontal lift arm 61, and a piston rod 13 of the second actuation cylinder 71 is linked with the left end of the pivotal lift arm 65.
A plurality of vacuum pads 79 1 , 79 2 , . . . , 79 n for sucking the upper surface of the punched product WA are attached on the bottom surface of the lift arm 59. As shown in FIGS. 5A and 5B and 6A-6F, a plurality of vacuum pads 79 1 , 79 2 , . . . , 79 n are arranged at appropriate intervals at two lines in the X-axis direction. However, it is possible to arrange these vacuum pads in a single line or three lines at regular intervals in the X-axis direction, without being limited only to the two lines as shown.
FIG. 4 shows an air circuit for switching these vacuum pads 79 1 , 79 2 , . . . , 79 n from the suction status to the non-suction status or vice versa. The air circuit comprises an air supply source 83. That is, each of the vacuum pads 79 1 , 79 2 , . . . , 79 n is connected to the air supply each of air pipes 81 1 , 81 2 , . . . , 81 n ; each of switch values 85 1 , 85 2 , . . . , 85 n ; and each of air ejector 87 1 , 87 2 , . . . , 87 n , independently. Therefore, when each switch value 85 is opened, since air is supplied from the air source 83 to the air vacuum pads 79 via the air ejector 87, respectively, the vacuum pads 79 can be actuated into the suction status in which the plate material WA can be sucked by the vacuum pads 79. Here, it is of course possible to use a vacuum pump as the air supply source 83,
With reference to FIG. 3, the punched product carrying-out system according to the present invention 1 is provided with an NC control system 89 for allowing a predetermined number of vacuum pads to suck the upper surface of the punched product WA only near a gravity center thereof. That is, the NC system 89 is composed of a gravity center calculate section 91, a locate control section 93, a shape recognize section 95, a pad discriminate section 97, and a pad control section 99. The gravity center calculate section 91 calculates coordinates of the center of gravity of the punched product WA on the basis of the product manufacturing data. The locate control section 93 controls the X- and Y-axis servomotors 27 and 31 on the basis of the calculated gravity center coordinates of the punched product WA in such a way that the gravity center of the punched product WA can be located Just under the lift arm 59, when the slider 51 is positioned at the punched material take-out position (on the right side (shown by solid lines) in FIG. 2).
The shape recognize section 95 recognizes the shape of the punched product WA on the basis of the product manufacturing data. The pad discriminate section 97 discriminates which vacuum pads 79 1 , 79 2 , . . . , 79 n are located over the product WA on the basis of the product shape whenever the gravity center of the punched product WA is located Just under the lift arm 59 (at the product carry-out position). In addition, the pad control section 99 controls a plurality of switch valves 85 1 , 85 2 , . . . , 85 n so that only the vacuum pads 79 located over the product WA can be switched from the non-suction status to the suction status.
Here, the product processing data imply the coordinates of a plurality of corners of the product WA in the case of a square product, center coordinates and a diameter (or a radius) of the product WA in the case of a circular product WA, etc. Further, the coordinates of the gravity center are determined on the basis of the origin of coordinate-axes of the plate material W. Further, the origin of coordinate-axes of the plate material W is determined on a predetermined corner (e.g., a rear left side corner) of the plate material W.
Further, in the above-mentioned description, the punched product WA is not limited to only a single punched product perfectly cut away from the plate material W, but includes a plurality of punched products still connected to each other via narrow connecting portions still connecting to the plate material W (without cut off away perfectly).
The operation of the above-mentioned punched product (punched plate material) carrying-out system according to the present invention will be explained hereinbelow.
First, the end portions of a plate material W are first clamped by a plurality of the clamps 33. The clamped work W is moved by the Y-axis carriage 25 together with the movable tables 35 and 37 in the Y-axis direction by activating the Y-axis servomotor 27, and further moved by the X-axis carriage 29 in the X-axis direction by activating the X-axis servomotor 31. That is, the plate material W is moved to the punching position correctly between the upper turret 17 and the lower turret 19 by moving the plate material w in both X- and Y-axis directions by the plate material locating mechanism 23. Further, the upper and lower turrets 17 and 19 are both indexed in synchronism with each other so that any desired pair of punch and die can be indexed just under the ram 21. Under these conditions, when the ram 21 is lowered, since the desired punch strikes the plate material W against the die at a predetermined punching position (e.g., a peripheral portion or portions in the plate material W), a punched hole can be formed or a punched product WA can be separated from the plate material W.
Before or after the plate material W is punched to manufacture a punched product WA, the mobile motor 55 mounted on the slider 51 is activated to move the slider 51 rightward in the X-axis direction from the product support unit 5 to the punch press machine 3. That is, the carrying-out unit 7 is moved from the product support position as shown in FIG. 6F to the product carry-out position (as shown in FIG. 6A).
After that,the gravity center calculate section 91 calculates the coordinates of the gravity center of the punched product WA on the basis of the product manufacturing data. Further, the shape recognize section 95 recognizes the product shape on the basis of the product manufacturing data. The pad discriminate section 97 discriminates (or selects) the vacuum pads 79 1 , 79 2 , . . . , 79 n locating over the punched product WA on the basis of the product shape on condition that the slider 51 is located at the product carry-out position and further that the gravity center of the punched product WA is located just under the lift arm 59. Here, in this embodiment, the location of the gravity center of the punched product WA just under the lift arm 59 implies that the gravity center of the punched product WA along the Y-axis direction roughly matches the gravity center of the lift arm 59 also along the Y-axis direction and in addition that the rightmost end of the punched product WA roughly matches the rightmost end of the lift arm 59, as shown in FIGS. 5A-6F, respectively. Further, here, the vacuum pads located just over the punched product WA are denoted by 79'.
After the plate material W has been punched and further after the slider 51 has been moved to the product carry-out position, the locate control section 93 controls the X- and Y-axis servomotors 31 and 27 so that the gravity center of the punched product WA can be located just under the lift arm 5 on the basis of the calculated gravity center of the punched product WA, as shown in FIG. 6A. After that, the first and second actuating cylinders 67 and 69 move a plurality of the vacuum pads 79 1 , 79 2 , . . . , 79 n downward, so that a plurality of the vacuum pads can be brought into contact with the punched products WA in the vicinity of the gravity center thereof, as shown in FIG. 6B. Further, the pad control section 99 switches only a plurality of the switch valves to switch only the vacuum pads 79' from the non-suction status to the suction status. As a result, a plurality of the vacuum pads 79' suck the upper surface of the punched product WA in the vicinity of the gravity center thereof. Further, it also possible to switch the vacuum pads 79' from the non-suction status to the suction status before being brought into contact with the upper surface of the punched product WA.
After the upper surface of the punched product WA has been sucked by the vacuum pads 79' in the vicinity of the gravity center thereof, only the second actuation cylinder 71 is actuated to move only the pivotal lift arm 65 upward so that the pivotal lift arm 65 can be pivoted clockwise to bend only the left side of the punched product WA upward, as shown in FIG. 6C.
After that, the punched product WA is separated upward from the plate material W perfectly by actuating both the first and second actuation cylinders 67 and 71 at the same time, as shown in FIG. 6D.
After the punched product WA has been lifted upward, the mobile motor 55 is driven to move the slider 51 in the X-axis direction from over the punch press machine 3 to over the product support unit 5, as shown in FIG. 6E.
Further, only the second actuation cylinder 71 is deactuated to lower only the left side of the punched product WA so that the punched product WA can be kept horizontally. Further, both the first and second actuation cylinder 71 are further deactuated to further lower the punched product WA, so that the punched product WA can be mounted on the punched product support unit 5. Under these conditions, the pad control section 99 releases the vacuum pads 79' into the non-suction status, and further the slider 51 is lifted by actuating the first and second cylinders 87 and 71 at the same time, as shown in FIG. 6F, so that the lift arm 63 or the vacuum pads 79 are moved upward away from the punched product WA mounted on the punched product support unit 5.
As described above, in the punched plate material carrying-out system according to the present invention, since the vacuum pads 79 can suck only the vicinity of the punched product WA, irrespective of the shape and the size of the punched product WA, it is unnecessary to arrange a great number of vacuum pads 79 1 , 79 2 , . . . , 79 n both in the X- and Y-axis directions in a wide range so as cover all over the upper surface of the product WA of the maximum size. As a result, it is possible to reduce the number of vacuum pads 79 and simplify the punched product carrying-out unit 7, thus reducing the cost thereof. In particular, since the slider 51 and the guide member 45, etc. can be compacted, it is possible to reduce the size of the entire punched plate material (product) carrying-out system, thus economizing the installation space required for the system in a factory.
In addition, after the upper surface of the punched product WA has been sucked in the vicinity of the gravity center thereof, the left side of the punched product WA is further bent or curved upward, the punched product WA can be separated from the plate material W easily, so that it is possible to improve the working efficiency of the punched product carrying-out work for the plate material processing machine.
|
A slider of the punch carry out unit is moved in the X-axis direction adjacent a punching section of the punch press machine before or after a plate material is punched into a punched product by a punch press machine. At the same time, a gravity center and a shape of the punched product are calculated and recognized on the basis of the manufacturing data. On the basis of the obtained gravity center and the shape of the punched product, the gravity center of the punched product is moved under the lift arm by the X- and Y-axis locating mechanism. Vacuum pads located just over the punched product are selected or discriminated. Then, the lift arm is lowered and the punched product is held by actuating only the discriminated vacuum pads. During this lift motion, it is preferable to bend one end of the punched product slightly upward to easily separate the punched product from the remaining flat plate material. After the punched product has been lifted, the punched product is moved horizontally away from the punch press, and is then lowered on the punched product supporting unit by releasing only the actuated vacuum pads. Since only the vicinity of the gravity center of the punched product is held by a minimum possible number of the vacuum pads, irrespective of the size and shape of the punched products, the number of the vacuum pads can be reduced.
| 8
|
CROSS REFERENCE TO RELATED APPLICATION
[0001] Reference is made to commonly-assigned U.S. patent application Ser. No.______ filed concurrently herewith, entitled “Correcting Defects In A Digital Image Caused ByA Pre-Existing Defect In A Pixel Of An Image Sensor” by John F. Hamilton, Jr., the disclosure of which is incorporated herein.
FIELD OF THE INVENTION
[0002] The present invention relates to correcting for corrupted data in a digital image caused by defective pixels in an image sensor.
BACKGROUND OF THE INVENTION
[0003] In certain types of image sensors, when there is a defect in two pixels of such sensor it causes two adjacent lines of pixels in a digital image to have corrupt data. This happens during the transfer of electrons corresponding to pixels when such electrons are transferred through the defective pixel. An example of this situation is a full frame image sensor. In a typical full frame image sensor after an image is captured, electrons stored in the pixels of such sensor are transferred a line at a time through the pixels of the image sensor. A defective pixel will corrupt data stored in the electrons of subsequent pixels which pass throught it. This causes a line of corrupted pixel data. In a full frame image sensor, a column defect is an anomaly in the structure of an image sensor that prevents the vertical transfer of pixel charge packets. As a consequence, none of the affected pixels in the adjacent columns of defective pixels can provide valid image information. If left untreated, this condition would produce a partial height or a full height adjacent vertical lines of artifacts running through the image. The current method of concealing a column defect is to average nearest horizontal neighbors of the same filter type. In a standard color filter array (CFA), for example, the Bayer CFA pattern shown in commonly-assigned U.S. Pat. No. 3,971,065, that means averaging the pixel two positions to the left with the pixel two positions to the right. While this method works well enough for the vast majority of pixels, it fails to properly handle corrupted pixels in certain image contexts, such as high contrast diagonal edges. In addition, when the current method fails, it doesn't fail gracefully, but rather with opposing vertical spikes of spurious color.
SUMMARY OF THE INVENTION
[0004] It is an object of the present invention to provide an improved method for correcting for two adjacent lines of corrupted data in a digital image formed by an image sensor with defective pixels.
[0005] It is another object of the present invention to provide a method which is particularly suited for correcting for adjacent column defects in a full frame image sensor and that works effectively for a variety of scene content including high contrast diagonal edges.
[0006] These objects are achieved in a method for correcting for defects in a digital image taken by an image sensor when there are pre-existing defects in two pixels in adjacent columns of the image sensor which causes two adjacent lines of pixels in the digital image to have corrupted data, comprising the steps of:
[0007] (a) providing a defect map which identifies the position of the defective pixels and specifies the two adjacent lines of pixels which during readout will be caused to have corrupted data;
[0008] (b) capturing the digital image in the image sensor and reading out such digital image to provide the digital image with the two adjacent lines of pixels in the digital image having corrupted data;
[0009] (c) computing classifiers based on adjacent non-corrupted pixel data which indicate that there is a horizontal edge or a diagonal edge feature which passes through the defective lines of pixels; and
[0010] (d) adaptively replacing the data in the corrupted image pixels by selecting an algorithm which correponds to the edge feature identified by the classifier and using the valid data in the neighboring non-corrupted pixels of the selected edge feature.
[0011] It is an advantage of the present invention to provide a concealment algorithm for correcting for corruption in two adjacent lines of pixel data caused by defective pixels in an image sensor such as a full frame image sensor. This algorithm significantly improves the efficacy of correcting for a line of corrupted pixel data over a wide range of scene content.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] [0012]FIG. 1 is a block diagram of an electronic still camera employing the defect correction algorithm according to the present invention;
[0013] [0013]FIG. 2 is a diagram of green pixels around a corrupted green pixel in a corrupted column;
[0014] [0014]FIG. 3 is a diagram of green pixels around a corrupted green pixel in one of two adjacent corrupted columns;
[0015] [0015]FIG. 4 is a diagram of red, green, and blue pixels around a corrupted red pixel in a corrupted column; and
[0016] [0016]FIG. 5 is a diagram of red, green, and blue pixels around a corrupted red pixel in one of two adjacent corrupted columns.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0017] Since single-sensor cameras employing color filter arrays are well known, the present description will be directed in particular to elements forming part of, or cooperating more directly with, apparatus and method in accordance with the present invention. Elements not specifically shown or described herein may be selected from those known in the art.
[0018] The present invention corrects for corrupted data in an output image caused by one or more defective pixels. Throughout the specification the terms “column” and “line” are used interchangeably. For example, a line of pixels of corrupted data could also be referred to as a column of corrupted data. Moreover, when referenced is made to a column or line of corrupted data as will become clearer hereinafter, the entire column or line or a portion thereof or part of a line of column of an output data image may be corrupted. In such a case the corrupted portion will be referred to a column or line of data.
[0019] Referring initially to FIG. 1, an electronic still camera is generally divided into an input section 2 and an interpolating and recording section 4 . The input section 2 includes an exposure section 10 for directing image light from a subject (not shown) toward an image sensor 12 . Although not shown, the exposure section 10 includes conventional optics for directing the image light through a diaphragm, which regulates the optical aperature, and a shutter, which regulates exposure time. The image sensor 12 , which includes a two-dimensional array of photosites corresponding to picture elements (pixels) of the image, is a conventional charge-couple device (CCD) using well-known interline transfer or full frame transfer techniques. The image sensor 12 is covered by a color filter array (CFA) 13 , known as a Bayer array (commonly-assigned U.S. Pat. No. 3,971,065), in which each pixel in the sensor is covered by a colored filter. In particular, chrominance colors (red and blue) are interspersed among a checkerboard pattern of luminance colors (green). The image sensor 12 is exposed to light so that analog image charge information is generated in respective photosites. The charge information is applied to an output diode 14 , which converts the charge information to analog image signals corresponding to respective picture elements. The analog image signals are applied to an A/D converter 16 , which generates a digital image signal from the analog input signal for each picture element. The digital signals are applied to an image buffer 18 , which may be a random access memory (RAM) with storage capacity for a plurality of still images.
[0020] A control processor 20 generally controls the input section 2 of the camera by initiating and controlling exposure (by opening the diaphragm and shutter (not shown) in the exposure section 10 ), by generating the horizontal and vertical clocks needed for driving the image sensor 12 and for clocking image information therefrom, and by enabling the A/D converter 16 in conjunction with the image buffer 18 for each signal segnebt relating to the picture element. (The control processor 20 would ordinarily include a microprocessor coupled with a system timing circuit.) Once a certain number of digital image signals have been accumulated in the image buffer 18 , the stored signals are applied to a digital signal processor 22 , which controls the throughput processing rate for the interpolation and recording section 4 of the camera. The digital signal processor 22 applies an interpolation algorithm to the digital image signals, and sends the interpolation signals to a conventional, removable memory card 24 via a connector 26 .
[0021] Since the interpolation and related processing ordinarily occurs over several steps, the intermediate products of the processing algorithm are stored in a processing buffer 28 . (The processing buffer 28 may also be configured as a part of the memory space of the image buffer 18 .) The number of image signals needed in the image buffer 18 before digital processing can begin depends on the type of processing, that is, for a neighborhood interpolation to begin, a block of signals including at least a portion of the image signals including a video frame must be available. Consequently, in most circumstances, the intepolation may commence as soon as the requisite block of picture elements is present in buffer 18 .
[0022] The input section 2 operates at a rate commensurate with normal operation of the camera while interpolation, which may consume more time, can be relatively divorced from the input rate. The exposure section 10 exposes the image sensor 12 to image light for a period of time dependent upon exposure requirements, for example, a time period between 1/1000 and several seconds. The image charge is then swept from the photosites in the image sensor 12 , converted to a digital format, and written into the image buffer 18 . The driving signals provided by the control processor 20 to the image sensor 12 , the A/D converter 16 and the buffer 18 are accordingly generated to achieve such a transfer. The processing throughput of the interpolation and recording section 4 is determined by the speed of the digital signal processor 22 .
[0023] One desirable consequence of this achitecture is that the processing algorithm employed in the interpolation and recording section may be selected for quality treatment of images rather than for throughput speed. This, of course, can put a delay between consecutive pictures which may affect the user, depending on the time between photographic events. This is a problem since it is well known and understood in the field of electronic imaging that a digital still camera should provide a continuous shooting capability for a successive sequence of images. For this reason, the buffer 18 shown in FIG. 1 provides for storage of a plurality of images, in effect permiting a series of images tp “stack up” at video rates The size of the buffer is established to hold enough consecutive images to cover most picture-taking situations.
[0024] An operational display panel 30 is connected to the control processor 20 for displaying information useful in the operation of the camera. Such information might include typical photographic data, such as shutter speed, aperature, exposure bias, color balance (auto, tungsten, fluorescent, daylight), field-frame, low battery, low light, exposure mode (aperature preferred, shutter preferred), and so on. Moreover, othe information unique to this type of camera is displayed. For instance, the removable memory card 24 would ordinarily include a directory signifying the beginning and ending of each stored image. This would show on the display panel 30 as either (or both0 the number of images stored or the number of image spaces remaining, or estimated to be remaining.
[0025] Referring to FIG. 1, the present invention can be applied to any digital camera sensor (block 12 ) producing partial columns or entire columns of corrupted image data. In addition to a single column corruption, the present invention also addresses the problem of double column corruption, in which two adjacent sensor columns produce corrupted data. The algorithm for replacing the corrupted image data can be implimented in the digital signal processing block 22 , although other arrangements are possible. The present invention addresses column defects for a Bayer pattern RGB sensor, although it is understood that the method can be applied to other filter combinations.
[0026] Referring to FIG. 2, when an entire column of data is corrupted, there are only three convenient directions for interpolation: slash (+1 slope) (line 42 ), horizontal (line 44 ), and backslash (−1 slope) (line 46 ). For green pixel repair in a single corrupted column, FIG. 2 shows the directions and the known surrounding green values. In the case of a double column corruption, the situation is similar but the problem is more difficult because valid data is now further away. In FIG. 3 are shown the three directions used for green pixel repair when two adjacent columns of data are corrupted. Correspondingly, the three directions are: slash (line 52 ), horizontal (line 54 ), and backslash (line 56 ).
[0027] Once the corrupted green values have been replaced, attention turns to the corrupted red or blue values. These values are found by interpolating the color differences (R−G) and (B−G). For a single corrupted column, FIG. 4 shows the three directions used for red, as an example. Correspondingly, the three directions are: slash (line 62 ), horizontal (line 64 ), and backslash (line 66 ). Because of the spacing of the red and blue pixels, FIG. 5 (depicting a double column corruption) shows that color difference interpolation may be handled the same way as shown in FIG. 4. Correspondingly, the three directions are: slash (line 72 ), horizontal (line 74 ), and backslash (line 76 ). Green values are shown in the shaded columns because the replaced green values are known at the time of color difference interpolation.
[0028] Following the pattern of FIG. 2, the diagram below shows the known green values in the case of a single column corruption. The corrupted column is column 5 and the question marks “???” at position 55 (i.e. col 5, row 5) locate the corrupted green value, G55, to be replaced. To illustrate a specific case, column 5 is assumed to be a green/blue column, so columns 4 and 6 are green/red columns.
col 3 4 5 6 7 row G33 R43 R63 G73 3 G44 G64 4 G35 R45 ??? R65 G75 5 G46 G66 6 G37 R47 R67 G77 7
[0029] First, two temporary green values, g45 and g65, are computed as follows:
g 45=(− R 43+3* G 44+2* R 45+3* G 46 −R 47+3)/6
g 65=(− R 63+3* G 64+2* R 65+3* G 66 −R 67+3)/6
[0030] The values g45 and g65 are temporary and are NOT the values G45 and G65 which appear later. Next, define some classifier values to assist in determining which is the preferred interpolation direction for replacing the corrupted green value. The directions are denoted as slash, horz, and back (“horz” for horizontal and “back” for backslash). Using “Abs” to denote the absolute value function, the classifiers as defined as follows:
Clas(Slash)=Abs( G 35 −G 44)+Abs( G 46 −G 64)+Abs( G 66 −G 75)+Abs( G 37 −G 46)+Abs( G 64 −G 73)
Clas(Horz)=Abs( G 44 −G 64)+Abs( g 45 −g 65)+Abs( G 46 −G 66)+Abs( G 35 −g 45)+Abs( g 65 −G 75)
Clas(Back)=Abs( G 35 −G 46)+Abs( G 44 −G 66)+Abs( G 64 −G 75)+Abs( G 33 −G 44)+Abs( G 66 −G 77)
[0031] and the auxiliary value:
Aux(Horz)=Abs( G 44 −G 46)+Abs(2* R 45 −R 43 −R 47)+Abs( G 64 −G 66)+Abs(2* R 65 −R 63 −R 67)
[0032] Accordingly, the following predictor values are defined:
Pred(Slash)=(4*( G 46 +G 64)−( G 37 +G 73)+3)/6
Pred(Horz_Hard)=( G 35 +G 75)/2
Pred(Horz_Soft)=(4*( g 45 +g 65)−( G 35 +G 75)+3)/6
Pred(Back)=(4*( G 44 +G 66)−( G 33 +G 77)+3)/6
Pred(Vert)=( g 45 +g 65)/2
[0033] As will become clear hereinafter, computed classifiers based on adjacent non-corrupted pixel data identify those cases in which there is a horizontal edge or a diagonal edge feature which passes through the defective column. Thereafter, the process adaptively replaces the data in the corrupted image pixels by selecting an algorithm which correponds to the edge feature identified by the classifier and using the valid data in the neighboring non-corrupted pixels of the selected edge feature.
[0034] The logic for utilizing the classifier values and selecting the proper predictor value, for example where corrupted green pixel G55 needs to be replaced.
IF Clas(Horz) < Min( Clas(Slash), Clas(Back)) THEN IF Threshold_1 < Aux(Horz) THEN IF Threshold_2 < Aux(Horz) THEN set G55 = Pred(Horz_Hard) ELSE set G55 = Pred(Horz_Soft) ENDIF ELSE set G55 = Pred(Vert) ENDIF ELSE IF Clas(Slash) < Clas(Back) THEN set G55 = Pred(Slash) ELSE set G55 = Pred(Back) ENDIF ENDIF
[0035] Typical values for Threshold — 1 and Threshold — 1 for an 8-bit image are 80 and 100 respectively.
[0036] Using the above algorithm the corrupted value for pixel G55 is now replaced. In a similar manner, the remaining corrupted green pixels are also replaced. Having replaced the corrupted green values, the corrupted red and blue values are now considered. To illustrate a specific case, the following account is done for replacing a corrupted red value. The very same action would be taken for blue. The diagram below follows the pattern shown in FIG. 4. As before, the pixel of interest is located in the 55 position, containing the question marks “???” . Because the corrupted green replacement has already been done, there are now valid green value defined above and below this position.
col 3 4 5 6 7 row R33 G43 G63 R73 3 G34 B44 G54 B64 G74 4 R35 G45 ??? G65 R75 5 G36 B46 G56 B66 G76 6 R37 G47 G67 R77 7
[0037] The process starts by summing the four central green values:
Green(Ctr)= G 54 +G 45 +G 56 +G 65
[0038] Next, three more green values are computed as follows:
Green(Slash)=(Green(Ctr)−( G 36 +G 47 +G 74 +G 63))/2
Green(Horz)=(Green(Ctr)−( G 34 +G 36 +G 76 +G 74))/2
Green(Back)=(Green(Ctr)−( G 43 +G 34 +G 67 +G 76))/2
[0039] These three green values are used in two ways. Their absolute values are used as classifiers, and they are also used as corrector terms in the corresponding predictor equations which follow:
Pred(Slash)=( R 37 +R 73+Green(Slash))/2
Pred(Horz)=( R 35 +R 75+Green(Horz))/2
Pred(Back)=( R 33 +R 77+Green(Back))/2
[0040] The logic for finding the restored red value (R55) is as follows:
IF Abs(Green(Horz)) < Min( Abs( Green(Slash) ), Abs( Green(Back))) THEN set R55 = Pred(Horz) ELSE IF Abs( Green(Slash)) < Abs( Green(Back)) THEN set R55 = Pred(Slash) ELSE set R55 = Pred(Back) ENDIF ENDIF
[0041] This completes the description of the algorithm for a single corrupted column. Now the algorithm for handling a double column corruption will be discussed. These two algorithms (for single and double column defects) may be applied as many times as there are single and double column corruptions in an image, and they may be applied in any order. The only requirement is that two valid columns must appear on each side of the corrupted column or columns. For example, these correspond to columns 3, 4, 6, and 7 in the pixel neighborhood shown above.
[0042] Following the pattern of FIG. 3, the diagram below shows the valid green values in the case of a double column corruption. The corrupted columns are columns 5 and 6 and the question marks “???” at position 55 locate the corrupted green value to be restored. As before, replacing the corrupted green values is the first order of business.
col 3 4 5 6 7 8 row G73 3 G44 --- G84 4 G35 ??? G75 5 G46 --- G86 6 G77 7
[0043] Although the pixel of interest has been chosen from the left hand corrupted column, the reasoning and the equations that follow may be applied to the right hand column as well. One would simply draw the mirror image of the above diagram so that columns 4 and 5 become the corrupted ones.
[0044] First the following classifier values are computed:
Clas(Slash)=Abs( G 35 −G 44)+Abs( G 46 −G 73)+Abs( G 77 −G 86)
Clas(Horz)=Abs( G 44 −G 84)+Abs( G 35 −G 75)+Abs( G 46 −G 86)
Clas(Back)=Abs( G 35 −G 46)+Abs( G 44 −G 77)+Abs( G 73 −G 84)
[0045] and the auxiliary value is computed:
Aux(Horz)=Abs( G 44 +G 84 −G 46 −G 86)
[0046] Next, the following predictor values are computed:
Pred(Slash)=(2* G 46 +G 73+1)/3
Pred(Horz)=( G 35 +G 75)/2
Pred(Back)=(2* G 44 +G 77+1)/3
Pred(Vert)=(Pred(Slash)+Pred(Back))/2
[0047] The logic for utilizing the classifier values and selecting the proper predictor value is similar to the logic used in the previous case of a single corrupted column.
IF Clas(Horz) < Min( Clas(Slash), Clas(Back)) THEN IF Threshold_3 < Aux(Horz) THEN set G55 = Pred(Horz) ELSE set G55 = Pred(Vert) ENDIF ELSE IF Clas(Slash) < Clas(Back) THEN set G55 = Pred(Slash) ELSE set G55 = Pred(Back) ENDIF
[0048] In this case, a typical value for Threshold — 3 for an 8-bit image is 24.
[0049] Having replaced corrupted green values, the corrupted red and blue values are now considered. As before, to illustrate a specific case, the following account is done for replacing a corrupted red value. The very same action would be taken for blue. The diagram below follows the pattern shown in FIG. 5. As before, the pixel of interest is located in the 55 position, containing the question marks “???”. In addition, all the surrounding green value are known to be valid. This diagram for the double column case is nearly identical to the corresponding diagram for the single column case. The only difference is that the blue values of column 6 are corrupted because columns 5 and 6 are the two corrupted columns in this scenario and the blue values haven't been replaced yet. However, the blue values played no part in the single column algorithm's replacment of the corrupted red pixels. Consequently, the single column algorithm for red replacement can be used in the double column case with no modification.
col 3 4 5 6 7 row R33 G43 G63 R73 3 G34 B44 G54 G74 4 R35 G45 ??? G65 R75 5 G36 B46 G56 G76 6 R37 G47 G67 R77 7
[0050] Since the replacement of corrupted red and blue pixels is the final step in column defect concealment, the description of the double column algorithm is now complete.
[0051] The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.
PARTS LIST 2 input section 4 interpolating and recording section 10 exposure section 12 image sensor 13 color filter array 14 output diode 16 A/D converter 18 image buffer 20 control processor 22 digital signal processor 24 removable memory card 26 connector 28 processing buffer 30 operational panel
|
A method for correcting for defects in a digital image taken by an image sensor when there are pre-existing defects in two pixels in adjacent columns of the image sensor which causes two adjacent lines of pixels in the digital image to have corrupted data.
| 7
|
FIELD OF THE INVENTION
[0001] The invention relates to a yarn withdrawal nozzle for an open-end rotor spinning machine and, more particularly, to a yarn withdrawal nozzle for an open-end rotor spinning machine comprising at least two ferromagnetic projections for magnetically coupling to permanent magnets arranged in depressions of a holder in the cover element of a rotor housing, wherein the ferromagnetic projections correspond in their arrangement and dimensions with the depressions in the holder.
BACKGROUND OF THE INVENTION
[0002] Yarn withdrawal nozzles can be secured replaceably for example in a so-called channel plate adapter of a cover element closing the open-end rotor spinning machine during the spinning operation. As the yarn withdrawal nozzles are subject to heavy wear from the running yarn, they usually consist of a funnel-like nozzle insert which is made from a very wear-resistant material, preferably a technical ceramic material, and is secured permanently in a nozzle fitting made from a metal material, for example by an adhesive or press-fitting connection.
[0003] The channel plate adapter consists essentially of a preferably circular basic body with a rear, conically designed bearing surface and an outlet part which projects during the spinning operation into the spinning rotor and the dimensions of which are adjusted to a specific spinning rotor diameter or diameter range.
[0004] The outlet area of a so-called fiber guiding channel is also formed in said outlet part of the channel plate adapter.
[0005] Such channel plate adapters have a central through bore, in which on the input side the yarn withdrawal nozzle is secured replaceably and in which on the outlet side a so-called yarn take-off tube engages.
[0006] The yarn withdrawal nozzle secured replaceably in the central through bore of a channel plate adapter generally consists, as shown for example in German Patent Publication DE 10 2008 019 214 A1, of a special nozzle fitting and a ceramic nozzle insert secured permanently onto the nozzle fitting.
[0007] The generally ferromagnetic nozzle setting corresponds with corresponding permanent magnets embedded in the channel plate adapter, which secure them in a force-fitting manner.
[0008] Such yarn withdrawal nozzles that have been known for a long time have proved effective in practice and make it possible to create optimal spinning conditions in open-end spinning devices.
[0009] The disadvantage of these yarn withdrawal nozzles is however that they are very expensive to manufacture and thus have a relatively high cost. For example the configuration of the transition from the nozzle insert to the nozzle setting is particularly complex to avoid the formation of any welt edges which would have a negative effect on the quality of the yarn because of the additional friction. Owing to the fit of the nozzle insert and nozzle setting in addition only small deviations are permissible in manufacturing which results in high production costs caused by rejects or the post-processing of parts.
[0010] Additional magnetically fixable yarn withdrawal nozzles are disclosed for example by German Patent Publications DE 27 45 195 A1, DE 37 29 425 A1 or DE 195 02 917 A1.
[0011] As shown in particular in German Patent Publication DE 27 45 195 A1, such a yarn withdrawal nozzle is made either of ferromagnetic material or a ceramic material with a ferromagnetic ring.
[0012] The yarn withdrawal nozzle according to German Patent Publication DE 37 29 425 A1 is also made of ceramic material and has a ferromagnetic disc which corresponds with a magnetic ring disc which is attached to the holder. In order that the fiber feed channel can be guided past the magnetic ring disc is missing a sector of about 60°.
[0013] The disadvantage of the yarn withdrawal nozzles according to German Patent Publications DE 27 45 195 A1 or DE 37 29 425 A1 is that no anti-rotation device is provided for the yarn withdrawal nozzle in the holder. This can mean, particularly with difficult yarns, that the magnetic fixing of the yarn withdrawal nozzle is not sufficient and the yarn withdrawal nozzle co-rotates in its holder which has a negative effect on the forming yarn.
[0014] From German Patent Publication DE 195 02 917 A1 therefore a yarn withdrawal nozzle is disclosed which in addition to the magnetic coupling ensures a desired installation position and also facilitates the release of the magnetic coupling.
[0015] In addition, the yarn withdrawal nozzle comprises a positioning means which in a different installation position of the yarn withdrawal nozzle than the one intended weakens the magnetic effect on the bearing surface at least. This is achieved in that the positioning means contains a cam-like catch securing the installation position which can be inserted into a recess of the holder.
[0016] To facilitate the release of the magnetic coupling, in addition a so-called uncoupling device is disclosed which is formed either by a recess provided in the bearing surface or by a support surface lifting the bearing surface from the holder. Said uncoupling devices have a lifting or weakening effect on the magnetism so that the yarn withdrawal nozzle can be disassembled more easily.
[0017] By using yarn withdrawal nozzles according to German Patent Publication DE 195 02 917 A1 an anti-rotational securing of the yarn withdrawal nozzle is ensured in its holder, but only with a very specific configuration of the yarn withdrawal nozzle and a very specific installation position. In addition, such yarn withdrawal nozzles are expensive to manufacture. A tool is generally necessary for the installation and disassembly in order to lock the yarn withdrawal nozzle to be used or in order to release the engaged yarn withdrawal nozzle.
SUMMARY OF THE INVENTION
[0018] The present invention therefore seeks to create a yarn withdrawal nozzle which is easy to assemble and during the spinning operation does not co-rotate in its holder. Furthermore, the yarn withdrawal nozzle should be easy and inexpensive to produce.
[0019] The yarn withdrawal nozzle of the invention is adapted for an open-end rotor spinning device with at least two ferromagnetic projections for magnetically coupling to permanent magnets arranged in depressions of a holder in the cover element of a rotor housing, wherein the ferromagnetic projections correspond in their arrangement and dimensions with the depressions in the holder. According to the invention, the ferromagnetic projections are formed directly in the yarn withdrawal nozzle ( 13 ) made from a non-magnetic material.
[0020] By means of the ferromagnetic projections, which are formed/pressed directly into the yarn withdrawal nozzle, a yarn withdrawal nozzle can be used which is itself not magnetic but is homogenous in its composition/assembly.
[0021] In this way not only is adequate fixing in the channel plate adapter ensured but also a simple positioning is made possible and the correct installation of the yarn withdrawal nozzle in the channel plate adapter is guaranteed. The yarn withdrawal nozzle according to the invention now only has to be held on the surface of the channel plate adapter and snaps independently of its angular position due to magnetism into the correct installation position in the channel plate adapter.
[0022] To take apart the yarn withdrawal nozzle it is sufficient if the yarn withdrawal nozzle is grasped by the fingers and removed from the holder in the channel plate adapter; it is not necessary to use a tool.
[0023] Furthermore, by means of the at least two ferromagnetic projections a functional form-fitting anti-rotational securing of the yarn withdrawal nozzle in the channel plate adapter is achieved.
[0024] The yarn withdrawal nozzle designed with ferromagnetic projections is simple and inexpensive to manufacture, as for example no tolerances have to be taken into account for the individual parts both for the manufacture and assembly. According to the invention there is no longer a welt on the two individual parts of the prior art which would have a negative effect on the quality of the yarn.
[0025] The configuration of the yarn withdrawal nozzle according to the invention provides a range of additional advantages.
[0026] As there is no longer a nozzle insert or nozzle setting the whole yarn guiding area is made from a non-magnetic material. This has a positive effect on the lifetime of the yarn withdrawal nozzle, which is subject to a high degree of wear.
[0027] Previously, a high requirement specification was defined for the selection of the material for the nozzle setting with respect to the hardness, absence of burr, surface quality and/or surface coating, so that the nozzle setting was as wear-resistant as the usually used nozzle insert. This is no longer necessary with the solution according to the invention.
[0028] A further advantage of the yarn withdrawal nozzle within the meaning of the invention is that the labelling or marking no longer has to be applied afterwards in an additional process onto a yarn withdrawal nozzle, but can be integrated into the latter directly during the production of the yarn withdrawal nozzle. This not only reduces the manufacturing costs again, but ensures a durable labelling/marking.
[0029] Overall it can be established that as well as the advantages relating to the production, assembly and handling of the yarn withdrawal nozzle according to the invention, the use of such a yarn withdrawal nozzle has a positive influence on the quality of the yarn to be produced.
[0030] Within the scope of this invention the term ferromagnetic material is defined as any material that either creates a static magnetic field itself or which is attracted by a pole of an external magnetic field, regardless of whether it is a north or south pole. For example iron has ferromagnetic properties, but also nickel, cobalt and ferromagnetic alloys. However, ferromagnetic materials do not have a permanently aligned south or north pole and their magnetic properties originate from external magnetic fields.
[0031] In particular, the projections are made from magnets which have a polarity which is opposite the polarity of the permanent magnets in the holder.
[0032] In this case the magnet used in the yarn withdrawal nozzle has to have an opposite polarity to the permanent magnet, which is attached in the cover element of the channel plate adapter.
[0033] In particular, the ferromagnetic projections are designed as cylinder pin-shaped bolts.
[0034] Bolts or pins are connecting elements which are simple and inexpensive to produce which can be inserted or pressed easily into the non-magnetic material of the yarn withdrawal nozzle.
[0035] Owing to the simple and inexpensive production of bolts, which are for example simply extruded and cut to size accordingly, such a configuration of the ferromagnetic projections reduces the production costs of the whole yarn withdrawal nozzle.
[0036] According to another feature of the invention, the yarn withdrawal nozzle is made from a ceramic material.
[0037] In a preferred configuration of the invention ceramic is the preferred material for the production of yarn withdrawal nozzles, as ceramic also has a high mechanical strength, good abrasion and wearing properties and has a high degree of hardness.
[0038] Of course, within the scope of this application yarn withdrawal nozzles are also possible which are not made from ceramic material, but alternatively are made of plastic or laminates.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] The invention is explained in more detail in the following with reference to an example embodiment shown in the drawings, wherein:
[0040] FIG. 1 shows schematically in side view, partly in cross-section, an open-end spinning device, in which the yarn withdrawal nozzle according to the invention is used;
[0041] FIG. 2 shows a spinning rotor with a yarn withdrawal nozzle according to the invention in the channel plate adapter;
[0042] FIG. 3 shows a yarn withdrawal nozzle according to the invention in side and plan view.
DETAILED DESCRIPTION OF THE INVENTION
[0043] FIG. 1 shows schematically an open-end rotor spinning device 1 . Such open-end-spinning devices 1 have, as already known, a rotor housing 2 , in which the spinning cup of a spinning rotor 3 rotates at high speed.
[0044] The spinning rotor 3 is thus supported for example by its rotor shaft 4 in the bearing gores of a so-called support disc bearing 5 and is driven frictionally by a machine-length tangential belt 6 , which is loaded by a pressing roller 7 .
[0045] The axial fixing of the rotor shaft 4 is performed for example by a permanent magnetic axial bearing 18 .
[0046] The rotor housing 2 open to the front is closed during the spinning operation by a pivotably mounted cover element 8 , in which a channel plate is formed which bears with a rotating lip seal 9 on the rotor housing 2 .
[0047] The rotor housing 2 is also connected by a corresponding negative pressure line 10 to a negative pressure source 11 , which produces the negative spinning pressure required in the rotor housing 2 .
[0048] In a mount of the channel plate (not shown in more detail) a channel plate adapter 12 is arranged replaceably, which comprises the outlet area of a fiber guiding channel 14 and a yarn withdrawal nozzle 13 according to the invention to which a yarn take-off tube 15 is connected.
[0049] Furthermore, a sliver opening device is integrated into the cover element 8 , which is mounted to be rotatable about a pivot axis 16 to a limited degree.
[0050] This means that the cover element 8 has an opening roller housing 17 and rear bearing consoles 19 , 20 for supporting an opening roller 21 or a sliver draw-in cylinder 22 .
[0051] The opening roller 21 is driven by a rotating machine-length tangential belt 24 , which loads a whorl 23 of the opening roller 21 , whereas the drive of the sliver draw-in cylinder 22 is preferably performed over a machine-length drive shaft 25 or a (not shown) worm wheel gear.
[0052] As shown in FIG. 2 on a larger scale, the yarn withdrawal nozzle 13 according to the invention is arranged in a central through bore of a channel plate adapter 12 and is positioned during the spinning process inside the spinning cup 26 of the spinning rotor 3 which is open towards the front.
[0053] The spinning cup 26 , which comprises a so-called rotor groove 27 , rotates, as already indicated above, at high speed inside the rotor housing 2 .
[0054] The individual fibers 28 opened by the opening roller 21 from a (not shown) feed sliver are fed via the fiber guiding channel 14 into the spinning rotor 3 and, as is usual in open-end rotor spinning devices, are firstly collected in the region of the rotor groove 27 of the spinning rotor 3 .
[0055] In a so-called binding area the individual fibers 28 are rotated onto a yarn 29 which is then drawn off via the yarn withdrawal nozzle 13 out of the spinning rotor 3 .
[0056] The yarn take-off speed, at which the new yarn 29 , which rolls or slides during take-off over the surface of the yarn withdrawal nozzle 13 , is drawn off in direction A from the open-end spinning device 1 , is dependent on various factors, such as for example the rotor speed, the desired yarn rotation etc., and can be adjusted in a defined manner by a yarn take-off device 35 .
[0057] The yarn withdrawal nozzle 13 is connected by magnetic connection 37 to the channel plate adapter 12 , if necessary so as to be easily detachable.
[0058] As shown in FIG. 3 , the yarn withdrawal nozzle 13 according to the invention comprises two ferromagnetic projections designed as bolts 32 in the form of cylindrical pins. The bolts 32 correspond with depressions 30 of the cover element 8 at the end of which a permanent magnet 31 is arranged respectively.
[0059] If a yarn withdrawal nozzle 13 is inserted into the channel plate adapter 12 it is thus sufficient to position the yarn withdrawal nozzle 13 on the surface of the channel plate adapter 12 . By means of the embodiment according to the invention the yarn withdrawal nozzle 13 is pulled by means of magnetism independently into the right installation position and snaps in.
[0060] If a yarn withdrawal nozzle 13 according to the invention is removed from the channel plate adapter 12 it is thus sufficient if the yarn withdrawal nozzle 13 is grasped by fingers and rotated out of the cover element 8 . It is not necessary to use a tool.
[0061] It will therefore be readily understood by those persons skilled in the art that the present invention is susceptible of a broad utility and application. Many embodiments and adaptations of the present invention other than those herein described, as well as many variations, modifications and equivalent arrangements will be apparent from or reasonably suggested by the present invention and the foregoing description thereof, without departing from the substance or scope of the present invention. Accordingly, while the present invention has been described herein in detail in relation to its preferred embodiment, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for purposes of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended or to be construed to limit the present invention or otherwise to exclude any such other embodiment, adaptations, variations, modifications and equivalent arrangements, the present invention being limited only by the claims appended hereto and the equivalents thereof.
|
A yarn withdrawal nozzle 13 for an open-end rotor spinning device 1 with at least two ferromagnetic projections for magnetically coupling to permanent magnets 31 arranged in depressions of a holder in the cover element 8 of a rotor housing 2, wherein the ferromagnetic projections correspond in their arrangement and dimensions to the depressions 30 in the holder. The ferromagnetic projections are formed directly in the yarn withdrawal nozzle 13 made from a non-magnetic material.
| 3
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is entitled to the benefit of Chinese Patent Application No. CN 200510023902.8 filed on Feb. 7, 2005 with the Chinese Patent Office.
FIELD OF THE INVENTION
[0002] The present invention relates to 3G (the 3rd Generation) wireless mobile communication field, particularly to method and system for scheduling of base station for HSUPA.
PRIOR ART
[0003] As an enhanced uplink technique of 3G, HSUPA is mainly used to enhance performance of uplink in a system and improve experience for users. In order to achieve the object, some new techniques are used in transmission of High Speed Uplink Packet Access (HSUPA), such as scheduling policy with Node B (Base Station) and etc., so that new processing and corresponding uplink and downlink signaling are introduced into the base station and the terminals to support the policy so as to achieve the object of enhancing uplink performance of system.
[0004] In HSUPA, a basic process for scheduling of base station is: the base station generating and transmitting a downlink signal to the terminal based on associated uplink information, and the terminal performing correct data transmission based on a downlink scheduling signaling.
[0005] In a HSUPA transmission process, the terminal reports its state to the base station according to a certain rule (e.g. in periodicity or event triggering mode), and transmits a happy bit for current occupied resources by the terminal on a signaling channel in each transmission period. Meanwhile, the base station makes measure for current interferences in each transmission period. Finally, the base station implements a scheduling process for resources among terminals based on the information.
[0006] Uplink signaling of HSUPA associated with the scheduling process mainly includes:
[0007] Scheduling Information (SI) transmitted in an Enhanced Dedicated Purpose Data Channel (E-DPDCH);
[0008] Happy bit transmitted in an Enhanced Dedicated Purpose Control Channel (E-DPCCH) discussed at present;
[0009] Downlink signaling associated with the scheduling process mainly includes:
[0010] Absolute Grant (AG) for indicating upper limit of available resources for a terminal user;
[0011] Relative Grant (RG) for adjusting user resources step by step.
[0012] For a HSUPA transmission process in a SHO (Soft Hand-Over) state, there are the following provisions in 3GPP:
[0013] SI is only transmitted to a serving base station;
[0014] Transmission mode of SI can be in periodicity or event triggering mode;
[0015] Scheduling grants generated by the serving base station include AG and RG;
[0016] Non-serving base station only generates RG;
[0017] AG is used for limiting upper limit of available resources for a terminal user;
[0018] RG is applied to actual used resources of a user;
[0019] RG of non-serving base station only relates to current interference
[0020] The effects of AG of serving base station and RG of non-serving base station are the same, i.e. to be applied to actual usage for resources of a user.
[0021] However, in order to implement a HSUPA transmission process, there exists the following important problems which can not be solved:
[0022] 1) How does the serving base station generate AG indicating upper limit of available resources for a user?
[0023] 2) How does the serving base station generate RG to be applied to actual usage for resources of a terminal user?
[0024] 3) How does the non-serving base station generate RG to be applied to actual usage for resources of a terminal user based on current interferences?
[0025] 4) What is relationship between scheduling process of base station and HARQ processing?
[0026] A proper solution directed to the above problems is significant for optimizing HSUPA transmission and is necessary for normalization process of 3GPP HSUPA, but it is a problem to be solved how a base station performs scheduling for resources among terminals based on uplink information.
[0027] The present invention is directed to corresponding solution to the above problems and has a significant effect on normalization process of HSUPA.
SUMMARY OF THE INVENTION
[0028] The object of the present invention is to provide method and system for scheduling of base station for HSUPA in order to enhance performance of uplink in a system and improve experience for users.
[0029] The present invention provides a method for scheduling of a serving base station for HSUPA, characterized in the base station generating a scheduling grant based on scheduling information SI and a happy bit transmitted from a terminal and based on a currently measured interference value, a configured threshold and associated resource information.
[0030] In the above method for scheduling of a serving base station for HSUPA, when the serving base station receives the SI and the configured associated resource information is that no E-RGCH is configured for a cell, the generated scheduling grant is an Absolute Grant (AG).
[0031] In the above method for scheduling of a serving base station for HSUPA, when the serving base station receives the SI and the configured associated resource information is that an E-RGCH is configured for a cell, the generated scheduling grant is one of an Absolute Grant (AG) and a Relative Grant (RG).
[0032] In the above method for scheduling of a serving base station for HSUPA, when |E t |≧E, the serving base station generates an AG; otherwise, the serving base station generates a RG; wherein E is the parameter of the base station configured threshold, Et is the dynamic control variable, E t =T current −T target , T target is the resources required for a user generated based on the SI, the interference, the happy bit of the terminal user, T current is the current-used resources of the terminal user obtained from transmission format information.
[0033] In the above method for scheduling of a serving base station for HSUPA, when the serving base station does not receive the SI and the configured associated resource information is that no E-RGCH is configured for a cell, the generated scheduling grant is an Absolute Grant (AG) or no scheduling grant is generated.
[0034] In the above method for scheduling of a serving base station for HSUPA, when the serving base station does not receive the SI and the configured associated resource information is that an E-RGCH is configured for a cell, the generated scheduling grant is a RG.
[0035] In the above method for scheduling of a serving base station for HSUPA, when information represented by the happy bit of the terminal user is inconsistent with the interference information of the serving base station, the priority of the interference information is higher than the information represented by the happy bit of the user.
[0036] The present invention further provides a method for scheduling of a serving base station for HSUPA, characterized in the base station generating a scheduling grant based on scheduling information SI transmitted from a terminal and based on a currently measured interference value, a configured threshold and associated resource information.
[0037] In the above method for scheduling of a serving base station for HSUPA, when the serving base station receives the SI and the configured associated resource information is that no E-RGCH is configured for a cell, the generated scheduling grant is an AG.
[0038] In the above method for scheduling of a serving base station for HSUPA, when the serving base station receives the SI and the configured associated resource information is that an E-RGCH is configured for a cell, the generated scheduling grant is one of an AG and a RG.
[0039] In the above method for scheduling of a serving base station for HSUPA, when |E t |≧E, the serving base station generates an AG; otherwise, the serving base station generates a RG; wherein E is the parameter of base station configured threshold, Et is the dynamic control variable, E t =T current −T target , T target is the resources required for a user generated based on the SI and the interference, T current is the current-used resources of the terminal user obtained from transmission format information.
[0040] In the above method for scheduling of a serving base station for HSUPA, when the serving base station does not receive the SI and the configured associated resource information is that an E-RGCH is configured for a cell, the generated scheduling grant is a RG.
[0041] The present invention further provides a method for scheduling of a non-serving base station for HSUPA, characterized in the base station generating a scheduling grant based on a currently measured interference value, a configured threshold and associated resource information.
[0042] In the above method for scheduling of a serving base station for HSUPA, when the configured associated resource information is that no E-RGCH is configured for a cell, no scheduling grant is generated.
[0043] In the above method for scheduling of a serving base station for HSUPA, when the configured associated resource information is that an E-RGCH is configured for a cell, the generated scheduling grant is a RG.
[0044] The present invention further provides a system for scheduling of a base station for HSUPA, characterized in that the system comprises a transmitting module in a terminal, a configuration module in a SRNC and a measurement module and a calculation module in a base station, wherein the calculation module is connected to the transmitting module, the configuration module and the measurement module respectively, the transmitting module is used by the terminal for transmitting information to the base station; the configuration module is used by the SRNC for configuring parameters of associated threshold to the base station; the measurement module is used by the base station for measuring current interference; the calculation module is used by the base station for performing scheduling based on the current-obtained information.
[0045] Using the above technical solution, i.e. by the method for generating Relative Grant RG S/N proposed by the present invention, the Serving Radio Network Controller (SRNC) configures parameters of associated threshold based on current network status, the serving base station generates RG S based on these parameters in combination with current interference and the happy bit of the terminal user, the non-serving base station generates RG N/S based on these parameters and current interference, so that scheduling for resources among the terminals is implemented to achieve the object of enhancing performance of uplink in a system and improving experience for users and to have an important effect on HSUPA normalization process.
BRIEF DESCRIPTION OF DRAWINGS
[0046] FIG. 1 is a structure schematic diagram of an apparatus for scheduling of base station of the present invention.
[0047] FIG. 2 is one of the present invention, i.e. a method for scheduling of a serving base station.
[0048] FIG. 3 is another one of the present invention, i.e. a method for scheduling of a non-serving base station.
DETAILED DESCRIPTION OF THE INVENTION
[0049] To facilitate the following discussion, symbols are defined and used as follows: AG: Absolute Grant generated by a serving base station; RG S : Relative Grant generated by a serving base station; RG N : Relative Grant generated by a non-serving base station; ROT: Rise Over Noise (interference); SI: Scheduling Information.
[0050] The present invention has proposed a complete solution of the existing base station scheduling for resources among terminal based on uplink information according to features of HSUPA and definitions to AG, RG S , RG N in combination with associated decisions of 3GPP.
[0051] I. For RG S
[0052] (1) SI represents requirements for resources of a user, and the serving base station shall respond to the user on the requirements based on SI, so SI is a first one of mechanisms for triggering generation of RG S .
[0053] (2) 3GPP has defined that RG S is generated based on a current ROT of the base station, in consideration that RG N and RG S have the same function: to be applied to actual used resources by a terminal user. Therefore, a second one of mechanisms for generation of RG S shall be based on a current ROT of the serving base station.
[0054] (3) 3GPP RAN2 conference is discussing that 1 bit of Happy bit is transmitted on an E-DPCCH as a simple representation of happy level for current transmission resources of the terminal user at present. This bit information is transmitted on the E-DPCCH, so both the serving base station and the non-serving base station can receive the bit information. However, the non-serving base station only makes corresponding instructions based on current ROT, and the Relative scheduling Grant (RG N ) can only have a negative effect on resources available to the terminal user (RG N =DOWN/Don't Care). Also, there are two cases for processing for Happy Bit: the user is satisfied with current resources; the user is not satisfied with current resources. Therefore, the non-serving base station does not respond to the bit information, but the scheduling for the terminal by the serving base station contains two aspects, negative and positive:
[0055] Positive response: transmitting a new AG to indicate a larger upper limit of resources or RG S =UP
[0056] Negative response: transmitting a new AG to indicate a smaller upper limit of resources or RG S =DOWN/HOLD
[0057] Therefore, if the Happy Bit is admitted by 3GPP, the serving base station responds to the bit information. Since information carried in 1 bit of Happy bit is limited, the serving base station can only generate a Relative Grant based on the bit information. That is, Happy Bit is a third one of mechanisms for generation of RG S .
[0058] In addition, it only has an effect on transmission quality of a single user whether the terminal user is satisfied with current resources, and ROT will have a significant effect on transmission quality of all terminal users controlled by Node B. Therefore, if information represented by the Happy Bit of the terminal user is inconsistent with ROT information of the serving Node B, the priority of ROT will higher than that of information represented by the Happy Bit of the user.
[0059] Summing up the above, three types of information shall be considered at the same time for generation of RG S :
[0060] SI;
[0061] ROT information of the serving base station;
[0062] Happy bit information of UE;
[0063] At the same time, it shall be considered that the transmission of SI is in periodically and event-triggered, i.e. Node B can not obtain SI information for all TTIs, and the ROT information and the Happy bit information exist for each TTI.
[0064] II. For AG:
[0065] 3GPP has prescribed that Scheduling Information SI is transmitted to a serving base station in MAC-e packet according to requirement so that the serving base station performs scheduling on resources available to a terminal user. Since the SI contains much information and the serving base station can properly allocate resources among different users, the serving base station can generate an AG based on SI, current-measured interference information, Happy bit information of the terminal and etc.
[0066] III. The Scheduling Process of Base Station is Divided into Scheduling Process of a Serving Base Station and Scheduling Process of a Non-Serving Base Station.
[0067] III(A). The Scheduling Process of a Serving Base Station: Generation of AG, RG S
[0068] 3a.1 The Scheduling Process of a Serving Base Station Which Receives SI from a Terminal
[0069] Referring to FIG. 2 , scheduling information from the terminal is transmitted according to requirement, and interference measurement information ROT and Happy bit information from the terminal are available in each transmission period. For this feature, if the serving base station receives scheduling information from the terminal at a certain scheduling time, it properly allocates resources among users using a certain rule based on the SI, current ROT measurement information from each user and Happy bit from the terminal user to enhance performance of uplink in a system and improve experience for users.
[0070] The serving base station generates different grants based on different configurations of cells.
[0071] 3a.11 The Case that no E-RGCH (Enhanced-Relative Grant Channel) is Configured for the Serving Cell
[0072] SRNC make a determination whether it assigns E-RGCH for transmitting RG grant to the cell based on results of network planning, so there are some cells having E-RGCH and some having no E-RGCH configured, but it is certain that E-AGCH is configured. For this feature, if no E-RGCH is configured for the cell, the serving base station only generates AG based on SI, current ROT information and Happy bit of each UE (if the Happy bit information is admitted by 3GPP, the information is considered, otherwise it is not considered), which is transmitted to each terminal by E-AGCH.
[0073] 3a.12 The Case that E-RGCH Channel is Configured for the Serving Cell
[0074] SRNC make a determination whether it assigns E-RGCH for transmitting RG grant to the cell based on results of network planning, so there are some cells having E-RGCH and some having no E-RGCH configured, but it is certain that E-AGCH is configured. For this feature, if an E-RGCH is configured for the cell, the serving base station switches between AG and RG S , generates and transmits one of AG and RG S to the terminal through a corresponding channel based on a certain rule and corresponding scheduling information:
[0075] if an AG is generated, it is transmitted to the terminal through an E-AGCH;
[0076] if an RG S is generated, it is transmitted to the terminal through an E-RGCH.
[0077] In order to implement selection between AG and RG S , the SRNC configures a parameter of threshold E for the base station. The serving base station generated resources required for the user T target based on the above SI, ROT, Happy bit information of the terminal user (if the Happy bit information is admitted by 3GPP, the information is considered, otherwise it is not considered) and etc, and obtains actual current-used resources of the terminal user by transmission format information. A dynamic control variable Et is defined as:
E t =T current −T target
and then selection decision algorithm is as follows:
[0078] if |E t |≧E then
[0079] the serving base station generated AG and transmits it to UE through E-AGCH, else
[0080] the serving base station generates RG and transmits it through E-RGCH end if
[0081] wherein the parameter of threshold E can be reconfigured by SRNC.
[0082] 3a.2 The Case that the Serving Base Station does not Receive SI from the Terminal
[0083] Referring to FIG. 2 , scheduling information from the terminal is transmitted according to requirement, and interference measurement information ROT and Happy bit information from the terminal are available in each transmission period. For this feature, if the serving base station does not receive scheduling information from the terminal at a certain scheduling time, it generates different grants based on different configurations of cells.
[0084] 3a.21 The Case that no E-RGCH is Configured for the Serving Cell
[0085] SRNC make a determination whether it assigns E-RGCH for transmitting RG grant to the cell based on results of network planning, so there are some cells having E-RGCH and some having no E-RGCH configured, but it is certain that E-AGCH is configured. For this feature, if no E-RGCH is configured for the cell and the scheduling process of the serving base station does not relate to the terminal, the serving base station does not generates any grants for the terminal, and if the scheduling process of the serving base station relates to the terminal, e.g. when resources for a certain terminal need to be decreased based on network status, the serving base station generates AG grant and transmits it to the terminal through the E-AGCH.
[0086] 3a.22 The Case that E-RGCH Channel is Configured for the Serving Cell
[0087] SRNC make a determination whether it assigns E-RGCH for transmitting RG grant to the cell based on results of network planning, so there are some cells having E-RGCH and some having no E-RGCH configured, but it is certain that E-AGCH is configured. For this feature, if an E-RGCH is configured for the cell, the serving base station only generates RG S based on ROT information and Happy bit information.
[0088] There are two cases for generation of RG S based on whether the Happy bit is admitted:
[0089] 3a.221; The Case without Happy Bit
[0090] Since Happy bit is being discussed by HSUPA Normalization Organization at present, it will be determined whether representation of Happy bit is used according to results of discussion. For this feature, if Happy bit is not admitted by the normalization organization, the present invention defines that RG S is generated based on current interference, according to function of the Relative Grant RG S of the serving base station and referring to definition of the Relative Grant RG N of the non-serving base station.
[0091] The SRNC configures parameters of threshold for the serving base station. The serving base station make corresponding decisions based on current-measured interference and threshold.
[0092] In n 1 successive transmission periods, if the interference measured by the serving base station is greater than Threshold 1 , the serving base station generates DOWN RG;
[0093] In n 2 successive transmission periods, if the interference measured by the serving base station is less than Threshold 2 , the serving base station generates UP RG;
[0094] In n 3 successive transmission periods, if the interference measured by the serving base station is between Threshold 1 and Threshold 2 , the serving base station generates HOLD RG;
[0095] wherein the thresholds and n 1 , n 2 , n 3 is configured according to current network status, and can be reconfigured in a service transmission process.
[0096] 3a.222 The Case with Happy Bit
[0097] Since Happy bit is being discussed by HSUPA Normalization Organization at present, it will be determined whether representation of Happy bit is used according to results of discussion. For this feature, if Happy bit is admitted by the normalization organization, since information carried in Happy bit is limited, it only has an effect on scheduling process of generating RG of the serving base station. Also, the Happy bit can only represent requirement for resources of a certain terminal user, and interference of the serving base station will have effects on transmission quality of all users controlled by the base station, so the priority of interference of the base station is higher than that of the Happy bit. Therefore, there is the following process of generating RG S :
[0098] If the terminal user is satisfied with current occupation of resources,
[0099] the serving base station generates RG scheduling grant according to process of 3a.221.
[0100] If the terminal user is not satisfied current occupation of resources, if the interference measured by the serving base station is greater than Threshold 1 in n 1 successive transmission periods, the serving base station generates DOWN RG;
[0101] if the interference measured by the serving base station is between Threshold 1 and Threshold 2 , the serving base station generates RG scheduling grant based on information represented by the Happy bit.
[0102] III(B). The scheduling process of a non-serving base station: generation of RGN
[0103] 3b.1 The Case that no E-RGCH is Configured
[0104] Referring to FIG. 3 , the non-serving base station can only generates RG scheduling grant based on current interference. SRNC configures parameters of threshold for the non-serving base station based on current network status. SRNC make a determination whether it assigns E-RGCH for transmitting RG grant to the cell based on results of network planning, so there are some cells having E-RGCH and some having no E-RGCH configured, but it is certain that E-AGCH is configured. For this feature, if no E-RGCH is configured for the cell, the non-serving base station does not perform any processing.
[0105] 3b.2 The Case that E-RGCH Channel is Configured
[0106] Referring to FIG. 3 , the non-serving base station can only generates RG scheduling grant based on current interference. SRNC configures parameters of threshold for the non-serving base station based on current network status. SRNC make a determination whether it assigns E-RGCH for transmitting RG grant to the cell based on results of network planning, so there are some cells having E-RGCH and some having no E-RGCH configured, but it is certain that E-AGCH is configured. For this feature, if an E-RGCH is configured for the cell, the non-serving base station generates RGN based on current interference and these thresholds:
[0107] in n 4 successive transmission periods, if the interference measured by the non-serving base station is greater than Threshold 4 , the non-serving base station generates DOWN RG;
[0108] in n 5 successive transmission periods, if the interference measured by the non-serving base station is less than Threshold 5 , the serving base station generates HOLD RG
[0109] These thresholds can be reconfigured in the transmission process.
[0110] As shown in FIG. 1 , the present invention provides a system for scheduling of a base station for HSUPA, comprising a transmitting module 10 in a terminal, a configuration module 20 in a SRNC and a measurement module 30 and a calculation module 40 in a base station, in which the calculation module 40 is connected to the transmitting module 10 , the configuration module 20 and the measurement module 30 respectively, the transmitting module 10 is used by the terminal for transmitting information to the base station; the configuration module 20 is used by the SRNC for configuring parameters of associated threshold to the base station; the measurement module 30 is used by the base station for measuring current interference; the calculation module 40 is used by the base station for performing scheduling based on the current-obtained information.
[0111] The present invention proposes the following for the first time:
[0112] The serving base station generates AG or RG S based on SI, ROT, and Happy bit from a terminal user.
[0113] If SI information is not received and Happy bit is not admitted, it is proposed that RG S is based on interference of a serving base station.
[0114] If SI information is not received and Happy bit is admitted by 3GPP, only the serving base station performs processing on the Happy bit, which only has a effect on RG S . That is, the serving base station generates a proper RG based on current interference and information carried in the Happy bit. If the current interference of the base station is inconsistent with information represented by the Happy bit, the priority of the interference is regarded as being higher, i.e. RG S is associated with the interference of the serving base station and the Happy bit information.
[0115] The present invention proposes a method for generating Relative Grant RG S/N : SRNC configures associated parameters of threshold, the serving base station generates RG S based on these parameters in combination with current interference and Happy bit information of a terminal user, and the non-serving base station generates RG N/S based on these parameters of threshold and current interference.
[0116] The above embodiments of the present invention have been presented by way of example only, and not limitation. It should be noted that various changes and modifications could be made by those skilled in the art herein without departing from the sprit and scope of the invention. Therefore, all equivalent technical solutions should belong to the scope of the present invention which should be limited by the attached claims.
|
Method and system for scheduling of a base station for HSUPA is provided. The method for scheduling of base station includes a method for scheduling of serving base station and a method for scheduling of non-serving base station, in which the method for scheduling of the serving base station comprises the base station generating a scheduling grant based on scheduling information SI and a happy bit transmitted from a terminal and based on a currently measured interference value, a configured threshold and associated resource information. The method for scheduling of the non serving base station comprises the base station generating a scheduling grant based on a currently measured interference value, a configured threshold and associated resource information. The system for scheduling of a base station comprises a transmitting module is used by the terminal for transmitting information to the base station; a configuration module is used by the SRNC for configuring parameters of associated threshold to the base station; a measurement module is used by the base station for measuring current interference; a calculation module is used by the base station for performing scheduling based on the current-obtained information. The present invention has solved the problem in scheduling of the base station for resources among terminals, which achieves the object of enhancing performance of uplink in a system and improving experience for users and has an important effect on HSUPA normalization process.
| 7
|
TECHNICAL FIELD
The present invention relates generally to an entry door for a building and, more specifically, to a building door having a door closer guide track formed as a portion of the firestop of the door.
BACKGROUND OF THE INVENTION
Installing doors into buildings under construction typically requires the assistance of various tradesmen. For example, for one opening, tradesmen such as carpenters, painters, glaziers, electricians and drywallers are required to complete the installation of a door. Other tradesmen may also be used for the installation of a door closer.
One problem associated with the use of tradesmen for completing the installation of a door is that alignment of the devices may have to be verified using several tradesmen. Tradesmen are expensive and therefore it is desirable to minimize adjustment and alignment procedures on the construction site.
Door closers are commonly used on commercial doors. Door closers may take many forms. Typically, door closers are mounted on the door and extend to the door frame. A spring, cam or other biasing members urges the door shut through the use of an arm.
Another type of door closer provides a slider mortised in the door frame that allows one end of the door closer arm to slide therein. One problem with mortising a track within the door frame is that further tradesmen are required on the construction site to mortise the closer track into the door frame. Such an operation is labor intensive and therefore costly.
Firestops are typically provided within a door frame. Many times the door frames are metal and have an integrally formed firestop therearound. The firestop is typically an extension of about five-eighths of an inch that extends into the door opening against which the door closes. The firestop along with weather stripping eliminates the air gap between the door and the door frame. The firestop may be integrally formed with the door frame or may be assembled as a separate add on piece.
It would therefore be desirable to provide a door assembly that reduces the cost of the installation of the door while incorporating features of the door closer assembly therein.
SUMMARY OF THE INVENTION
The present invention reduces the cost of assembly of the door by providing a firestop having a novel design which incorporates a slider channel therein for slidably receiving one end of the slider assembly.
In one aspect of the invention, a door assembly includes a door frame having a horizontal header along the top thereof. A firestop extends downwardly from the header, the firestop has a plurality of sides defining an open channel therein. The firestop has an at least partially open side to define the open channel. A door is rotatably mounted within the door frame. A door closer assembly is coupled to the door. The door closer assembly has a biasing assembly and an arm having a first end and a second end. The first end is rotatably coupled to the biasing assembly and is slidably coupled to the channel.
In a further aspect of the invention, a method of forming a door assembly comprises:
mounting a firestop to a header of a door frame, said firestop having an at least partially open side and a channel defined therein;
mounting a closer assembly having an arm extending therefrom to a door; and
slidably coupling the arm to the channel.
One advantage of the invention is that the cost of assembling the door by tradesmen is reduced because the door closer assembly may be mounted in a factory environment. This leads to another advantage in which the door assembly can be aligned and tested in the assembled position.
A further advantage of the invention is that doors without closer assemblies according to the present invention may be retrofitted to provide a door closer according to the present invention.
Other advantages and features of the present invention will become apparent when viewed in light of the detailed description of the preferred embodiment when taken in conjunction with the attached drawings and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view of a door frame defining an opening for use according to the present invention.
FIG. 2A is a cross-sectional view of a door in a closed position according to the present invention.
FIG. 2B is a cross-sectional view of a door in an open position according to the present invention.
FIG. 3 is a cross-sectional view of a firestop mounted to a door frame header according to the present invention.
FIG. 4 is a cross-sectional view of a door having a door closer in position with a firestop mounted to a header of a door frame according to the present invention.
FIGS. 5A, 5 B, and 5 C are elevational views of a slider used in the present invention.
FIG. 6 is a cross-sectional view of an assembled closer assembly according to the present invention.
FIG. 7 is a top view of a closer assembly having a closer arm.
FIG. 7A is a top view of a closer assembly similar to FIG. 7 using an alternative closer arm.
FIG. 8 is an elevational view of a door having an externally mounted closer according to the present invention.
FIG. 9 is a cross-sectional view of an alternative embodiment of a firestop according to the present invention.
FIG. 10 is a cross-sectional view of a retrofit door according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In the following figures, the same reference numerals will be used to illustrate the same components in the various views. The present invention is described with respect to commercial doors and has various geometrically shaped frame, track and other components. These shapes are illustrated but not meant to be limiting unless otherwise specified in the claims.
Referring now to FIG. 1, a door 10 is illustrated having a frame 12 around its perimeter. Frame 12 comprises a horizontal header 14 and vertical jambs 16 . Horizontal header 14 and vertical jambs 16 may be formed of a variety of materials including wood, metal or a composite material. Preferably in commercial door environments, horizontal header 14 and vertical jambs 16 are formed from metal.
Door 10 has a pair of faces 18 A and 18 B, which may be referred to as inner and outer, respectively. A portion of outer face 18 B is cut away to reveal the core of door 10 . A number of spacers 20 are typically incorporated to hold inner and outer faces 18 A, 18 B a predetermined distance apart. Spacers 20 are commonly used in the industry. Spacers 20 may be formed from various materials including cardboard, wood blocks, expanded polystyrene, metal, honeycomb, or fire resistant material. A void 22 is formed between spacers 20 and outer faces 18 A. Void 22 may be sized to receive an integrated door closer to urge the door into a closed position as will be further described below.
Door frame 12 has firestops 24 A and 24 B positioned to extend into the door opening. Firestop 24 A is positioned on horizontal header 14 . Firestops 24 B are positioned on jambs 16 . Firestops 24 A, 24 B closes the air gap between door 10 and frame 12 .
Referring now to FIGS. 2A and 2B, door 10 is shown in various positions. In FIG. 2A, door 10 is illustrated in a closed position while in FIG. 2B door 10 is illustrated in an open position. A hinge 26 is used to rotatably couple door 10 to jamb 16 . As illustrated, hinge 26 is a conventional pin-type hinge. However, those skilled in the art will recognize various alternative types of hinges may be employed. As shown best in FIG. 2A, outer face 18 B, which indicates the inside of the door, closes against or nearly against firestop 24 .
Referring now to FIG. 3, horizontal header 14 is illustrated with firestop 24 A coupled to header 14 . Firestop 24 A is coupled to header 14 with a screw or other type of fastener 28 . Firestop 24 A has a channel 30 defined therein. Channel 30 , as illustrated, is G-shaped and has an at least partially open wall 32 . As illustrated, wall 32 extends only about half the thickness of firestop 24 A. In addition to partially open wall 32 , firestop 24 A has a horizontal wall 34 extending in a plane parallel to horizontal header 14 . A vertical wall 36 extends between horizontal wall 34 and a second horizontal wall 38 positioned adjacent or against header 14 . A partial vertical wall 40 extending into channel 30 may be used to help secure and guide a slider therein as will be further described below.
Firestop 24 A may have a mounting portion 42 adjacent to channel portion 30 . Screw 28 may be mounted through mounting portion 42 .
Partially open wall 32 may include a weatherstrip channel 44 having a weatherstrip 46 therein. Weatherstrip 46 closes any gap between door 10 and firestop 24 A.
Referring now to FIG. 4, the relative position of door 10 and firestop 24 A is illustrated. Door 10 preferably has a closer 50 positioned between outer faces 18 A and 18 B. This configuration provides an aesthetically pleasing door in which assembly is only minimally visible.
Closer assembly 50 includes a biasing element 52 that has a pivot axis 54 extending therefrom. Pivot axis 54 may have a bushing 56 positioned thereon. Closer assembly 50 also includes an arm 58 having a first end 58 A and a second end 58 B. First end 58 A is coupled to bushing 56 so that arm 58 rotates therearound. Arm 58 is illustrated as a dash line for simplicity purposes and will be further illustrated below. The pivot axis 56 remains stationary relative to the door. The unit thus has a restoring force to close the door caused by the internal mechanism of the biasing element 52 about the pivot axis 56 .
A slider 60 is positioned within firestop 24 A. Slider 60 slides within channel 30 as the door moves from a closed position to an open position and back again. Slider 60 has an arm retainer 62 that is used to rotatably couple to second end 58 B of arm 58 .
Referring now to FIGS. 5A, 5 B, and 5 C, respective front, side and top views of slider 60 are illustrated. As mentioned above, slider 60 has arm retainer 62 extending from a main body 64 . With respect to the relative position of the door, retainer 62 extends upward from main body 64 . A retainer arm 66 also extends in upward direction from main body 64 . Retainer arm 66 in conjunction with wall 40 help retain slider 60 within channel 30 . Preferably, slider 60 is made from a resilient material such as plastic, Delrin® or nylon. Channel 30 may also include a lubricant (not illustrated) to assist in the smooth operation of slider 60 .
Preferably, arm 58 is placed over arm retainer 62 without the use of fasteners. Of course, as will be further described below, fasteners may be used to secure arm 58 to slider 60 depending on the geometric configuration.
Referring now to FIG. 6, another embodiment illustrates arm 58 coupled to slider 60 ′ through the use of a fastener 70 . As can be seen, retainer 62 , arm 58 , and pivot bushing 56 lie on a substantially horizontal pg, 10 plane. Also, the top edge 72 of door 10 also lies in the same substantially horizontal plane. To phrase it in another way, the thickness T of firestop 24 A if extended over to the door includes slider 60 , arm 58 , bushing 56 , and top portion of door 72 . That is, slider 60 , arm 58 , bushing 56 , and top portion of door 72 extend only a predetermined distance below the header 14 which corresponds to thickness T. Arm 58 in this embodiment is not entirely horizontal and thus has a slight elbow 74 to avoid partial wall 32 .
Referring now to FIG. 7, a door 10 is illustrated in a closed position and a partially open position (in dashed lines). As can be seen, bushing 56 remains fixed within door 10 while being rotatably coupled to arm 58 . Simultaneously, slider 60 moves within channel 30 as toward hinge 26 . As is illustrated, in a closed position, slider 60 is in the leftmost position while in a partially open position slider 60 moves to the right within channel 30 . The biasing element 50 provides a biasing effort to close the door as is known to those skilled in the art.
Arm 58 is illustrated having a slight angular or “dog-leg” configuration.
Referring now to FIG. 7A, arm 58 may also have a straight arm 58 ′ depending on the geometry of the closer, door and door opening.
Referring now to FIG. 8, a closer assembly 50 ′ may be coupled outside door 10 . That is, door closer assembly 50 ′ may be coupled to the push side door face 18 A or 18 B. In the exterior mounted configurations, slider 60 still slides within a similar firestop channel 30 as described above.
Referring now to FIG. 9, header 14 is illustrated with an alternative cross section of a firestop 24 A. In this embodiment, firestop 24 A′ is generally C-shaped and has a modified slider 60 ′ positioned therein. Horizontal wall 34 ′ has an opening 80 therein so that a fastener 82 may be used to secure firestop 24 ′ to horizontal header 14 . Slider 60 ′ has a groove 84 to prevent interference between slider 60 ′ and fastener 82 . A pin 86 may be used to couple arm 88 to slider 60 ′.
Referring now to FIG. 10, an embodiment similar to that of FIG. 9 is illustrated. Therefore, the same reference numerals are used to indicate the same components. The firestop 24 A′ and slider 60 ′ are the same as FIG. 9 . However, the firestop 24 A′ could also have other configurations such as those shown in FIGS. 3-5C. In this embodiment, horizontal header 14 ′ has been modified from that shown in the above figures. This embodiment is particularly useful for a pre-existing door frame. That is, the door frame 14 ′ is referred to in the industry as a rabbetted header that includes an integral firestop 90 . If, however, a door closer is desired to be employed according to the present invention, firestop 24 A′ is coupled to header 14 ′ on the previous firestop 90 . To align firestop 24 A′ with door 10 , door 10 is shortened in height. To provide a more finished surface, a filler 92 may be positioned on header 14 ′ to conceal that the door length has been reduced.
In operation, it is preferred that the door and door closer assembly are assembled in a factory environment rather than on the jobsite. However, the present invention applies to either situation. The conventional firestop of a door is replaced with a firestop configured according to the present invention having a channel 30 therein. The channel 30 allows the slide to move therein in a nearly concealed and aesthetically pleasing manner. In a retrofit configuration such as that described in FIG. 10 above, a new firestop is coupled to the door frame. The firestop has an at least partially open side so that the arm with the slider in channel 30 may move therein. The closer is mounted so that a biasing force on the arm allows the door to move to a closed position when opened.
When the present invention is used in a pre-existing door environment, the new firestop track with open channel 30 is coupled to the existing header. The door is then reduced in height and a closer assembly is coupled to the door. The slider assembly may be coupled externally or between the door panels. The slider is positioned within the channel which in turn is coupled to the closer arm for operation.
Advantageously, the present invention may be configured in a factory environment to allow testing and alignment of the door closer and door within the frame. This is one less operation that the trades are required to perform and therefore the overall cost of the installation of the door within the opening is reduced.
While particular embodiments of the invention have been shown and described, numerous variations and alternate embodiments will occur to those skilled in the art. Accordingly, it is intended that the invention be limited only in terms of the appended claims.
|
A door assembly includes a door frame having a horizontal header along the top thereof. A firestop extends downwardly from the header, the firestop has a plurality of sides defining a channel therein. The firestop has an at least partially open side to allow the channel to be open and receive a closer assembly. A door closer assembly is coupled to the door. The door closer assembly has a biasing assembly and an arm having a first end and a second end. The first end is rotatably coupled to the biasing assembly and is slidably coupled to the channel.
| 8
|
CROSS-REFERENCE TO RELATED APPLICATIONS
Copending U.S. patent application, Ser. No. 413,573, in the name of Dennis H. Hoskin and Kirk D. Schmitt, relates to methods for making 1,3-dihydrocarboxy-2-propoxypolyethoxypropane sulfonate surfactants.
Copending U.S. patent application, Ser. No. 373,550, filed Apr. 30, 1982, in the name of Catherine S. H. Chen and Albert L. Williams, describes (branched alkyl)-polyethoxypropane sulfonates and their use in enhanced oil recovery. This Chen et al application is a continuation-in-part of U.S. patent application Ser. No. 259,215 and Ser. No. 259,216, both filed Apr. 30, 1981, and both now abandoned.
Copending U.S. patent application, Ser. No. 259,218, filed Apr. 30, 1981, in the name of Kirk D. Schmitt, discloses a method for preparing alkylpolyethoxypropane sulfonates. This Schmitt application is, in turn, related to U.S. application, Ser. No. 96,947, filed Nov. 23, 1979, in the name of Catherine S. H. Chen, Kirk D. Schmitt and Albert L. Williams, entitled Method of Making Propane Sulfonates, now U.S. Pat. No. 4,267,123.
The above-mentioned U.S. patent applications and U.S. patent are expressly incorporated herein by reference.
BACKGROUND
This invention is directed to sulfonate and sulfate surfactants having 1,3-dihydrocarboxy-2-propyl hydrophobic tails, a process for their preparation and a process for their use in enhancing the secondary or tertiary recovery of oil from subterranean oil deposits or reservoirs, particularly from high salinity reservoirs. In particular, these sulfonates and sulfates are suitable as single component surfactants in continuous chemical flooding techniques.
In the recovery of oil from oil bearing deposits it is generally possible to recover only a portion of the original oil by so called "primary methods" which utilize only the natural forces present in the reservoir or deposit. Thus a variety of supplemental techniques have been employed in order to increase the recovery of oil from these subterranean reservoirs. The most widely used supplemental recovery technique is water flooding which involves injection of water into an oil bearing reservoir. However, there are problems associated with the water flooding technique and water soluble surfactants have generally been required to be used for this process to be completely successful. Thus the LTWF (Low Tension Water Flood) method using surfactants which function in low salinity (less then 3 percent) is well known. However, it has been found that preflushing the reservoirs with fresh or low salinity water to reduce the salinity so that the low salinity surfactants of the prior art may be used is not always effective, or, the preflushing is effective only for a short duration and the salinity of the fresh water increases over a period of time since it is in contact with reservoir rocks and clays. Either event renders the low salinity surfactants useless and therefore it is of vital importance to have a surfactant which functions at the salinity of the connant water to negate the necessity of preflushing.
Developments for using surfactants to enhance oil recovery may be categorized according to essentially two different concepts. In the first, a solution containing a low concentration of surfactants is injected into the reservoir. The surfactant is dissolved or dispersed in either water or oil. Large pore volumes (about 15-60% or more) of the liquid are injected into th reservoir to reduce interfacial tension between oil and water and thereby increase oil recovery. Specific relationships exist between interfacial tensions of the oil against the flooding media and the percentage recovery obtained by flooding, i.e., the efficiency of flooding increases as the interfacial tension decreases. Oil may be banked with the surfactant solution process but residual oil saturation at a given position in the reservoir will only approach zero after passage of large volumes of this flooding media.
In the second process, a relatively small pore volume (about 3-20%) of a higher concentration surfactant liquid is injected into the reservoir. The high concentration surfactant liquids displace both oil and water and readily displace all the oil contacted in the reservoir. As the high concentration slug moves in the reservoir, it is diluted by formation flood and the process reverts to a low concentration flood; Enhanced Oil Recovery, Van Poolen & Associates, 1980, Tulsa, Okla.
Aqueous surfactant liquids for injecting into reservoirs contain two essential components, namely, water and surfactant. An optional third component may be a hydrocarbon. Such three component mixtures of water, surfactant and hydrocarbon may be in the form of a water-external micellar dispersion as discussed in the Jones U.S. Pat. No. 3,506,071. A cosurfactant fourth component (usually alcohol) can be added. Electrolytes, normally inorganic salts, form a fifth component that may be used.
Work is still in progress in the laboratory and in the field to select the optimum method of injecting surfactant to improve oil recovery. The best process for a specific reservoir is the one which has the potential to provide the greatest efficiency and yield regardless of the concentration level of the surfactant. The chemical system, however, to be efficient must be tailored to the specific reservoir.
The prior art with respect to the use of surfactant polymer floods to recover oil from reservoirs has disclosed that for a given amount of surfactant, a small slug process with a high surfactant concentration is more efficient than a large slug process with a low surfactant concentration. The former produces oil earlier and takes a smaller number of pore volumes to complete oil production. This is a favorable condition. However, it has become evident that fluid dispersion and mixing take place in the reservoirs and the slug intake routine cannot be maintained. Deterioration of the surfactant and the mobility control slug can lead to process failure or at least a reduction in process efficiency. For heterogeneous reservoirs where fluid dispersion and mixing takes place to a greater extent it is desirable if not vital to have a continuous flooding process with a surfactant which can move oil even at very low concentrations.
There has now been discovered certain novel surfactants and their use in a continuous flooding process wherein low concentrations of the novel surfactant alone can be used to increase the oil production during secondary water flooding processes or to recover residual tertiary oil where the reservoirs already have been water flooded.
SUMMARY OF THE INVENTION
The present invention relates to novel sulfonate and sulfate surfactants having 1,3-dihydrocarboxy-2-propyl hydrophobic tails, processes for their preparation and processes for their use, particularly at low concentrations in enhanced oil recovery. The enhanced oil recovery process is especially adaptable to high salinity reservoirs, e.g., reservoirs having a salinity of from about 4 to 30%.
These sulfonate and sulfate surfactants, in amount effective for the intended purpose can be used as a single component surfactant without the addition of any other component or cosurfactant. However, it may be desirable to use mixtures of two or more of the branched surfactants described herein, or to use the surfactant in combination with a sacrificial agent such as lignin sulfonate.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-3 show graphs of interfacial tension of surfactants according to the present invention at different salinities.
FIG. 4 shows a graph of oil recovery from Berea sandpacks by a surfactant according to the present invention.
DETAILED DESCRIPTION
Surfactants of this invention may have the formula: ##STR1## where R 1 and R 2 are the same or different and are C 1 -C 15 hydrocarbyl, R 3 is C 0-5 alkyl, M is a cation and n is a rational number (e.g., including fractions) from 2 to 6. Preferably, R 1 and R 2 are C 1 -C 10 alkyl, especially, C 4 -C 10 alkyl. R 1 and R 2 together preferably contain at least 7 carbon atoms. Preferably, n is a rational number from 2 to 4.
In addition to alkyl groups, suitable hydrocarbyl groups for use as R 1 and R 2 include, e.g., aryl, arylalkyl, and alkylaryl.
It is noted that when R 3 is C o alkyl (i.e., R 3 is absent), the surfactant of formula (VI) is a sulfate. When R 3 is C 1-5 alkyl, the surfactant of formula (VI) is a sulfonate, preferably R 3 is CH 2 CH 2 CH 2 .
M is preferably a monovalent cation. Examples of such monovalent cations include ions of alkali metals and nitrogeneous bases. Where M is an alkali metal ion, it may be sodium or potassium. Various nitrogeneous bases, including ammonium or quaternary amines, may be employed. Representative alkylammonium ions include methylammonium, ethylammonium, and normal or isopropylammonium ions, and examples of alkanolammonium ions include monoethanolammonium and triethanolammonium ions.
The surfactants of the present invention produce ultralow interfacial tensions over a wide salinity range at low concentration on Berea sandpacks. A desired salinity window can, within limits, be achieved by varying the degree of ethoxylation of these to tune the hydrophobe/hydrophile ratio. The synthesis of these surfactants is accomplished from relatively inexpensive starting materials by conventional technology. An important feature of this synthesis is the utilization of epichlorohydrin as a low-cost method for achieving desirable two-tailed intermediates for further functionalization.
An example of this synthesis may be illustrated as follows: ##STR2##
The primary advantage of this route is that appropriately sized two-tailed alcohols (formula III) are made from inexpensive commercially available smaller alcohols. This procedure is generally described in the Blake U.S. Pat. No. 2,932,616, the entire disclosure of which is expressly incorporated herein by reference.
EXAMPLE 1
Following the above procedure, a two-tailed alcohol of formula III, where R 1 =R 2 =CH 2 CH(C 2 H 5 )C 4 H 9 , was made in 63% yield by the reaction of a sodium alkoxide (from 2-ethylhexanol and sodium metal) with epichlorohydrin. The alcohol of formula III was then partially metallized (less than or equal to 50%) with sodium metal and ethoxylated by sparging ethylene oxide into the hot (125°-150° C.) alcohol-alkoxide mixture. After the desired degree of ethoxylation was attained (as monitored by weight uptake), the intermediates were further functionalized to the surfactants of formula V by full metalization with Na followed by the addition of an approximately equimolar portion of propane sultone. Although other adducts have been synthesized and characterized (e.g., where R 1 =R 2 =n-hexyl) currently the best characterized member of this surfactant family is according to formula V, where R 1 =R 2 =CH 2 CH(C 2 H 5 )C 4 H 9 and n=3.2. This surfactant was isolated in 67% overall yield from the corresponding alcohol of formula III, including a rigorous preparative reverse phase HPLC purification step. During purification, the product where n=3.2 was collected in two cuts having differing average ethoxylation (n=2.4 and 3.6, respectively, by 13 C--NMR integration). Because this procedure gave products where n=2.4 and 3.6 of limited dispersity, these products were also mixed 1:1 (where n=3.0) for characterization purposes. The spinning drop method was used to determine interfacial tensions between West Burkburnett (WBB) oil and surfactant-brine mixtures. This spinning drop method is described by Wade in Adsorption at Interfaces, ACS Symp. #8, pp. 234-247 (1975).
The brine used contained Na + , Ca 2+ , and Mg 2+ in the ratio found in WBB brine. WBB brine has 16.6% by weight of total salt and was prepared by adding to water 13.2% by weight NaCl 2 , 3.47% by weight CaCl 2 .2H 2 O and 1.53% by weight MgCl 2 .6H 2 O. Interfacial tension data are summarized in Tables I-V and depicted in FIGS. 1-3. This data was obtained in the following manner.
A spinning drop Interfacial Tensiometer was used. Measurements, against a crude oil, were made after 30 minutes spinning at 10 to 14 msec., or longer, or until no more change in the drop took place. The width of the drop was then measured. The interfacial tension was calculated according to the below equation when the length of the drop was ≧4 times its diameter. ##EQU1## where IFT=Interfacial Tension, Dynes/cm
Δd=difference in density between oil and brine
Dm=diameter of oil drop (cm) measured from photograph
P=spinning speed, msec/revolution
TABLE I______________________________________INTERFACIAL TENSIONS AT DIFFERENT SALINITIES ##STR3## WBB Salinity, % IFT Against WBB Oil, dynes/cm______________________________________ Surf. Conc., % 0.1 0.01 0.0018 0.0565 -- --6 0.0116 0.0334 0.2974 0.0052 0.0071 0.01382 0.0058 0.0055 Too High1 0.0169 -- --______________________________________ Too High: Cannot be measured by the Spinning Drop method.
TABLE II______________________________________INTERFACIAL TENSIONS AT DIFFERENT SALINITIES ##STR4## WBB Salinity, % IFT Against WBB Oil, dynes/cm______________________________________ Surf. Conc., % 0.1 0.01 0.0014 0.0296 0.0406 0.0782 0.0064 0.011 Too High1 0.0017 0.0049 Too High0.5 0.0068 0.0017 Too High______________________________________ Too High: Cannot be measured by the Spinning Drop method.
TABLE III______________________________________INTERFACIAL TENSIONS ATDIFFERENT SALINITIES ##STR5## IFT Against WBB Oil,WBB Salinity, % dynes/cm______________________________________ Surf. Conc., % 0.1 0.01 0.00110 0.0188 -- --8 0.0126 0.0132 0.02096 0.0045 0.0023 Too High4 0.0071 0.0109 0.00722 0.0408 0.0287 Too High______________________________________ Too High: Cannot be measured by the Spinning Drop method.
TABLE IV______________________________________INTERFACIAL TENSIONS AT DIFFERENT SALINITIES ##STR6## WBB Salinity IFT Against WBB Oil, dynes/cm______________________________________ Surf. Conc., % 0.1 0.01 0.00120 0.0297 0.0663 Too High18 0.0088 0.025 "16.6 0.0041 0.0174 "14 0.0116 0.0038 "12 0.0226 0.0071 0.10610 0.0677 0.0174 Too High8 0.0904 0.0310 "6 0.151 -- --4 0.258 -- --______________________________________ Too High: Cannot be measured by the Spinning Drop method.
TABLE V______________________________________INTERFACIAL TENSIONS ATDIFFERENT SALINITIES OF 1:1 ##STR7## ##STR8## WBB Salinity, % IFT Against WBB Oil, dynes/cm______________________________________ Surf. Conc., % 0.1 0.01 0.00118 0.0607 -- --16.6 0.0411 0.107 Too High14 0.0227 0.0972 "12 0.0229 0.046 "10 0.0097 0.0416 "8 0.0072 0.0228 0.1066 0.0294 0.0061 0.09614 0.0534 0.0061 0.1382 0.0899 0.0142 Too High______________________________________ Too High: Cannot be measured by the Spinning Drop method.
These data indicate that compounds of the present invention produce ultralow IFT's in brine containing divalent cations and suggest that varying the hydrophobe/hydrophile ratio by means of ethoxylation tunes the brine tolerance of the resultant surfactant (see FIG. 1) with acceptable "windows". Mixing surfactants with different hydrophobic tails changes the location of the brine tolerant window as a 1:1 mixture of a surfactant where R 1 =R 2 =CH 2 CH(C 2 H 5 )C 4 H 9 and n=3.0 (tolerant to 2-6% WBB brine) and a surfactant where R 1 =R 2 =n-hexyl and n=2.2 (tolerant to 14-18% WBB brine) products ultralow IFT's at 8-12% WBB brine (0.1% concentration) (FIG. 3).
EXAMPLE 2
Berea sandpack tube runs were performed according to the following procedure.
A 6'×1/2" (o.d.) glass column was packed with Berea sand (40 to 325 mesh, typically 155 g). After evacuation the dry sandpack column was filled (ca. 35 ml) with West Burkburnett (WBB) brine of the appropriate salinity (that of the subsequent oil recovery experiment). The brine then was displaced by WBB crude oil until brine production ceased. Secondary oil recovery was simulated next by flushing with WBB brine of the appropriate salinity until oil production ended. The remaining oil (in a typical example 9.2 ml or 26.9 percent saturation) was the target of a tertiary oil recovery simulation experiment.
Tertiary oil recovery was effected by injecting 1 PV 0.3% sodium 1,3-bis[(2-ethylhexyl)oxy]-2-propoxypolyethyleneoxypropanesulfonate of limited polydispersity with 1% lignosulfonate sacrificial chemical and 500 ppm polysaccaride mobility control in either 2 or 4% WBB brine. This was followed by 0.3 PV of 500 ppm polysaccaride then 0.2 PV of 250 ppm polysaccaride in the appropriate brine and then continually with the same brine.
The results are summarized in FIG. 4. The limited dispersity surfactant where R 1 =R 2 =CH 2 CH(C 2 H 5 )C 4 H 9 and n=3.6 recovered 85% of the oil in 4% WBB brine.
The surfactants of this invention generally have their minimum interfacial tension at salinities of less than about 30%, typically at about 4 to 28%. Indeed, the surfactants can be tailored for use in particular salinity ranges by varying the overall chain length of the alkoxy radicals (defined as "R 1 O and R 2 O" above).
As indicated previously, the surfactants of this invention can be prepared by methods which in themselves are known in the art as illustrated in Example 1. One such method involves the reaction of an alkali metal salt of the branched alcohol of formula IV with propane sultone. This route provides a convenient laboratory synthesis and gives high yields but is not desirable on a large scale for several reasons. Foremost among them are the facts that (1) such a reaction requires multistep synthesis and purification of propane sultone (2) propane sultone is expensive to purify and its overall yield of 80-90% limits the yield in the preparation of propane sulfonates and (3) propane sultone is a known carcinogen. Therefore, processes involving the use of propane sultone must utilize expensive controls to minimize worker exposure but despite such controls its use will always engender some risk.
An alternative method of synthesis which has potential advantages on a commercial scale without the use of propane sultone can be conducted in accordance with the following reaction sequence. ##STR9## and R 1 , R 2 and n are as defined above and X is halogen or aryl sulfonates (e.g., tosylate).
Where R is such that the allyl ether product of reaction (I) has a solubility in water of less than 0.5% the process can be conducted in two steps in a single reactor without isolation of intermediates in almost 100% yield by control of reaction conditions in steps (I) and (II). Step (I) can be carried out in a completely aqueous system if about 50% NaOH is used as the base and if close contact between the water insoluble allyl halide and alcohol is brought about by inclusion of a certain minimum amount of desired sulfonate final product in the reaction vessel. At the end of the reaction any excess allyl chloride is easily distilled from the reactor. It needs not be dried but may be recycled directly, nor must it be separated from an organic solvent since no organic solvent is used.
The preparation of allyl ethers by the reaction of sodium or sodium methoxide with the alcohol followed by reaction with allyl chloride all in an organic solvent such as toluene or tetrahydrofuran (the Williamson ether synthesis) is well known and may be found in many standard textbooks on organic chemistry.
The reaction of NaHSO 3 with simple olefins, step (II), has been much studied. The literature teaches that for simple water-soluble olefins or olefins which can be made soluble by the addition of small amounts of alcohols, all that is required for high conversions to the desired products are conditions in which all reagents are dissolved in a single phase.
In the present method of preparation the corresponding ether intermediates do not behave this way. Conditions may be found in which all the reagents are dissolved in a single phase in alcohol and water and yet conversion will not exceed 40 or 50%. However, when a minor amount of propane sulfonate product is present in the reaction medium the conversion may be as high as 90% or more. Accordingly, it is advantageous to recycle part of the sulfonate final product of the reaction so that it is present during reaction. In general, the propane sulfonate product is present in a molar ratio of 1:1 to about 1:10 based on the allyl ether.
A convenient alternative to reaction of high molecular weight alcohols with metallic sodium is their reaction with sodium methoxide as exemplified by the following reaction sequence. ##STR10##
In this reaction sequence, the intermediate ##STR11## may be ethoxylated directly (i.e., omitting the final neutralization step with acid as depicted above) to give further intermediates in accordance with reaction sequences for preparing compounds of the present invention.
EXAMPLE 3
In accordance with the general procedure of the above reaction sequence, 13.3 g Na (0.578 mole) were dissolved in 20 min in 100 ml CH 3 OH and added to 75 g (0.577 mole) 2-ethylhexanol in 175 ml dry, refluxing xylene under N 2 . The mixture was fractionally distilled until the overhead reached 125°, the heat removed, and 25.9 g (0.280 mole) epichlorohydrin added over 15 min. A vigorous exothermic reaction was noted. The mixture was refluxed 20 min, cooled to room temperature, diluted with 500 ml ethyl ether, washed with water, saturated brine, the solvents evaporated in vacuo and the material distilled to give 70.4 g (61%) pale yellow oil, bp 110°-150°/0.05 mm whose gas chromatograph shows two peaks at 58 sec and 192 sec in ratio 4:96 on a 6'×1/8" 10% carbowax column at 230° C. C--13 NMR shows the expected peaks at 74.8, 72.4, 69.5, 39.8, 30.7, 29.2, 24.1, 23.1, 14.0, and 11.1 ppm relative to TMS. The presence of a small peak at 58.9 ppm probably indicates the 4% impurity (58 sec GC retention time) is: ##STR12##
In summary, advantages of the surfactants according to the present invention are as follows:
(a) They can be propane sulfonates which are hydrolytically stable.
(b) They are tolerant to high brine (including divalent cations).
(c) They have a wide window of brine tolerance.
(d) They can be made inexpensively by conventional technology.
(e) The hydrophobic portion of the molecule is easily made monoisomeric.
|
Novel sulfonate and sulfate surfactants which have low interfacial tension at high salinity, and their use in enhanced oil recovery are disclosed. These surfactants may be made from relatively inexpensive intermediates, such as monohydric alcohols and epichlorohydrin. These surfactants have 1,3-dihydrocarboxy-2-propyl hydrophobic tails linked by ethoxy linkages to sulfate or alkyl sulfonate moieties.
| 8
|
FIELD OF THE INVENTION
The present invention relates generally to providing multimedia content over a communications network, and more particularly, to an automated system for rating such multimedia content based on cues that are passively gathered from the user.
BACKGROUND OF THE INVENTION
The delivery of multimedia and other content over communications networks is well known in the art. Examples include, but are not limited to, web browsing, File Transfer Protocol (FTP), Internet Protocol (IP) services such as Voice-over-IP (VoIP), and even conventional Cable Television (CATV) over Hybrid Fiber Coax (HFC).
In the context of television programming, delivered either via HFC, IP or the like, current technology enables users to provide ratings for such programming (or other dynamic media such as radio, CD, audio books, etc.). However, the current state of the art requires that the users actively provide such feedback. This is often accomplished by the user manipulating a remote control or keyboard. For example, the well known TiVo® remote has data input controls for accepting such user input. However, the need for active user participation decreases the likelihood for the typical TV audience to provide any feedback.
It would therefore be desirable to provide a system and methodology whereby a viewer of multimedia content can provide feedback to a service provider or other entity in a transparent, non-invasive way that obviates the need for explicit viewer participation.
SUMMARY OF THE INVENTION
In accordance with aspects of the invention(s), methods and systems for capturing, transmitting and processing data for generating ratings relating to multimedia programming based on passively obtained user cues are disclosed herein.
An exemplary method, in the broadest sense, generally comprises the step of: receiving data over the communications network, the data comprising cues providing feedback regarding the multimedia content from at least one of the end users in a manner transparent to the user.
In accordance with another aspect of the invention, a system for gathering user feedback, that can be used for example, to rate multimedia content that is distributed to end users over a communications network, comprises: a network element adapted for receiving data over the communications network, the data comprising cues providing feedback regarding the multimedia content from at least one of the end users in a manner transparent to the user.
In accordance with still another aspect of the invention, a memory medium containing programmable machine readable instructions which, when executed by a processor, enable a network element to obtain rating data regarding multimedia content that is communicated to end users over a communications network, enable a system, device, network or other entity or apparatus to receive data over the communications network, where the data comprises cues providing feedback regarding the multimedia content from at least one of the end users in a manner transparent to the user.
These and further advantages will become apparent to those skilled in the art as the present invention is described with particular reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic of an illustrative network architecture embodying a Hybrid Fiber Coax (HFC) network serving a plurality of users;
FIG. 2 is a schematic of a user site that provides for multimedia content distribution to a user and a remote node communicating with the user site;
FIG. 3 is a flow chart describing a Ratings Method.
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the invention will be described with reference to the accompanying drawing figures wherein like numbers represent like elements throughout. Before embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of the examples set forth in the following description or illustrated in the figures. The invention is capable of other embodiments and of being practiced or carried out in a variety of applications and in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.
In accordance with a first aspect of the invention, a method and system for rating multimedia content is disclosed. With reference to FIG. 1 , an illustrative network architecture in the form a Hybrid Fiber Coax (HFC) delivery system is shown, which generally comprises an access network 100 that delivers communications services to a plurality of end users 102 1 , 102 2 , . . . , 102 N . The access network may comprise, in an exemplary expedient (shown here as an optical network) a Remote Node (RN) 104 coupled to a Central Office (CO) 106 or other entity. The RN 104 may be adapted to communicate with the end users 102 1 , 102 2 , . . . , 102 N via optical, electrical, electro-optical, or any other hereinafter developed network technology. The CO 106 and RN 104 communicate with each other in a conventional fashion and such communications and system architectures are not relevant to the present invention. In the context of multimedia content delivery, a content server 108 that generates or stores multimedia content is coupled to the access network via another network shown generally at 110 .
FIG. 2 is a schematic of a RN 204 coupled to an exemplary end user site 202 N (e.g., a residence or business). End user site 202 N may include a plurality of network access devices, such as, for example, a TV 206 , personal computer 208 , telephone 210 and/or the like. Multimedia content 212 is presented to an end user 214 in a conventional manner via the network access device. In accordance with the present invention, a passive feedback device 216 , which is either part of the network access device or a standalone apparatus, enables data comprising “user cues” to be transparently “received” from the viewer of the multimedia content. The “data” may be in the form of audio, visual or audio-visual “cues.” In this regard, the passive feedback device 216 may be a microphone, video camera or some like apparatus that is adapted to be coupled to the network.
With reference to FIG. 3 , a method in accordance with an aspect of the invention for rating multimedia content is disclosed. The method generally comprises the step 300 of receiving data over a communications network from an end user, where such data comprises cues that provide real-time (or almost real-time) user feedback concerning the multimedia content. In step 302 , a “system” (architecture is not relevant at this point) processes the data and extracts the user “feedback”, which may be in the form of a viewer laughing or otherwise reacting to something seen in the programming.
The cues, as previously discussed, may be aural, visual or audio-visual in nature and can be measured in terms of intensity and/or duration. Such cues may further be processed with specific regard to the multimedia content stream i to enable a service provider or other entity to generate “ratings” for the programming in step 304 . In this context, the cues may be temporally mapped against the content which could then be distributed in step 306 for multiple purposes, including but not limited to virtual audiences 308 , providing show recommendations 310 , enabling producers to understand which content is most likely to generate the best revenue 312 , advertisers 314 and service providers (e.g., TV networks) 316 .
For example, a particular “comedy” might cause a viewer to laugh, an interesting documentary might elicit a thought provoking discussion, or a horror “flick” might cause shock or fear. These aural, visual or audio-visual cues may be identified, captured and processed by the network access device in real or quasi real-time. A variety of acoustic models can be created to monitor different aural cues, such as a scream which, obviously, has different properties than laughter. In the case of conversation, the inventive method can identify dialog without the need for complicated speech recognition technology, or the need to even understand the content at all. Such mapping of user's audio or visual expressions for the purpose of authentication is known in the art.
In addition to monitoring the frequency and duration of such cues, in accordance with aspects of the invention, an interested entity or device can record when such viewer feedback is generated. For example, a set-top box (in the HFC context) knows what multimedia content (i.e., TV show) is being shown and the points in the show if and when, the viewer has which type of reactions thereto. This data, as described above, can be temporally correlated with the media content, thereby enabling the generation of a continuous ratings profile.
Another aspect of the invention comprises a memory medium storing machine readable instructions which, when executed by a processor enable a system, device or other entity/apparatus to generate the above-described ratings from passively obtained user cues. The memory medium may be part of the network access device described above, or disposed anywhere within the network or a separate entity responsible for generating ratings for multimedia programming. The memory medium and instructions may be embodied in software, hardware or firmware, as is well understood by those of ordinary skill in the art.
The foregoing detailed description is to be understood as being in every respect illustrative and exemplary, but not restrictive, and the scope of the invention disclosed herein is not to be determined from the description of the invention, but rather from the claims as interpreted according to the full breadth permitted by the patent laws. It is to be understood that various modifications will be implemented by those skilled in the art, without departing from the scope and spirit of the invention.
|
Methods and systems for capturing, transmitting and processing data for generating ratings relating to multimedia programming based on passively obtained user cues are disclosed herein.
| 7
|
CROSS-REFERENCE TO RELATED APPLICATION
This is a continuation-in-part of copending U.S. application Ser. No. 6,899, filed Jan. 26, 1979, now abandoned by Yves Jean Kemper, entitled "TRACTION SURFACE COOLING SYSTEM FOR TORQUE TRANSMISSIONS" and assigned to the assignee of the present invention.
BACKGROUND OF THE INVENTION
This invention relates to traction drive torque transmissions and, more particularly, it concerns improvements in traction surface cooling apparatus for such transmissions.
In traction drive transmissions, torque is transmitted by rolling friction between one or more pairs of traction surfaces on components arranged to be retained against one another in a manner to develop normal forces adequate to prevent slippage between the surfaces. Such transmissions are particularly useful in the transmission of power at continuously or infinitely variable speed ratios because of the facility offered by the smooth rolling surfaces of each traction surface pair for an infinitely variable radius ratio. Examples of such infinitely variable transmissions are disclosed in U.S. Pat. Nos. Re. 29,328, reissued Aug. 2, 1977, No. 4,112,779 and 4,112,780, both issued Sept. 12, 1978, and U.S. Application Ser. No. 706,291, filed July 19, 1976, now Pat. No. 4,152,946 all of which are owned by the assignee of the present invention.
Though seemingly inconsistent with transmission of torque by friction, the rolling or traction surfaces of the transmission exemplified by the disclosures of the aforementioned patents and application are lubricated and cooled by circulating a liquid lubricant through the transmission housing. Torque transfer is, in actuality, by viscous shear of a very thin film of lubricant between the traction surfaces which are of smooth tool steel. The lubricants used are synthetic oils developed specifically for traction drives and increase in viscosity under the pressures existing between the traction surfaces to a point of becoming almost glassy in character. Accordingly, high coefficients of traction are possible without abnormal deterioration of the contacting surfaces.
As indicated, the liquid lubricant functions also as a heat storage medium by which the heat developed at the traction surfaces is transferred to the exterior of the transmission housing by recirculation and cooling of the lubricant. Partially because of the relative motion between the traction surfaces and the recirculated lubricant, and also in part because of the viscosities reached by the lubricant, a boundary layer of lubricant tends to build on the surfaces to a point where the torque transmitting efficiencies of the lubricant is reduced and more critically, the transfer of heat to the recirculated lubricant is impeded. These problems created by the boundary layer of lubricant are, moreover, dichotomous in the sense that the reduction of torque transmitting efficiency can be avoided by circulating less lubricant over the surfaces whereas the removal of heat developed by the stresses imposed on the traction surfaces requires large quantities of the lubricant to be circulated over the same surfaces. Hence, the solution of these problems in the past have involved a trade-off or compromise between rated power transmission capacity and useful life of a particular transmission unit.
SUMMARY OF THE INVENTION
In accordance with the present invention, the removal of thermal energy or heat from the rolling friction surfaces of traction drive transmissions by recirculation of a liquid lubricant is enhanced without reduction in viscous film torque transmitting efficiency by mechanically wiping or scraping the traction surfaces to eliminate the boundary layer of lubricant on the surfaces. This operation is achieved very simply by providing wipers on a component which moves relative to the engaging surfaces of the respective traction surface pairs. The wipers are either elongated to be effective over the complete axial extent of the traction surfaces or in the form of a pattern of discrete wiping zones extending over a substantial portion of the traction surface area. Further, the wipers are preferably located in relation to porting or conduit openings through which the lubricant is passed to the traction surfaces so that localized heat developing at the points of traction surface engagement will pass immediately to freshly supplied lubricant and carried thereby to the exterior of the transmission.
Accordingly, among the objects of the present invention are: the provision of an improved cooling apparatus for traction drive torque transmissions; the provision of such a cooling apparatus which is very simply accommodated in an existing transmission design; and the provision of such a cooling system by which the deleterious effects of a boundary layer of lubricant are avoided to increase the transfer of heat from lubricant carrying traction surfaces to a liquid lubricant recirculated through the transmission without affecting the rheological characteristics of the lubricant needed to transmit torque by viscous shear.
Other objects and further scope of applicability of the present invention will become apparent from the detailed description to follow taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal cross-section illustration of a transmission incorporating the invention;
FIG. 2 is an enlarged fragmentary cross-section on line 2--2 of FIG. 1;
FIG. 3 is an enlarged fragmentary cross-section on line 3--3 of FIG. 1;
FIG. 4 is a plan view of a transmission component incorporating an alternative embodiment of the invention;
FIG. 5 is a cross-section on line 5--5 of FIG. 4;
FIG. 6 is a fragmentary cross-section on line 6--6 of FIG. 5;
FIG. 7 is a plan view like FIG. 4 but illustrating another alternative embodiment; and
FIG. 8 is a fragmentary cross-section on line 8--8 of FIG. 7.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 of the drawings, an exemplary embodiment of an infinitely variable traction drive transmission incorporating the present invention is shown in longitudinal cross section and designated generally by the reference numeral 10. Although the structure and operation of the transmission is fully described in the aforementioned U.S. Patents and Application, a summary description of the transmission 10 will facilitate a complete understanding of the present invention.
The plane of the cross-section in FIG. 1 includes a first or primary transmission axis 12 and a second or nutational axis 14 inclined with respect to the axis 12 and intersecting same at a point S of axes intersection. The orientation of the first axis 12 is established by a fixed frame 14 in the form of a cylindrical housing 16 closed at opposite ends by journalled end sections 18 and 20. Components located within the housing 16 include a crank-like alpha body 26 supported by bearings 28 and 30 in the frame end sections 18 and 20 for rotation about the primary or first axis 12. An input shaft 32 is connected directly to the alpha body 26 and is thus concentric with the axis 12. A nutatable beta body, generally designated by the reference numeral 34, is supported by bearings 36 and 38 in the alpha body 26 for rotation about the second axis 14. In the disclosed embodiment, the beta body 34 includes a central supporting shaft 42 on which a pair of oppositely convergent conical members 44 and 46 are supported for some measure of both axial and rotational movement relative to the shaft 42. A ball/ramp unit 48 is slidably keyed or splined on the shaft 42 between the cone members 44 and 46. While the unit 48 is fully disclosed in a commonly assigned copending U.S. Application Ser. No. 926,823, filed July 21, 1978, now abandoned, by Harvey N. Pouliot, to which reference may be made for structural detail, for a complete understanding of the present invention, it is necessary only to appreciate that the unit 48 functions to bias the cone members in opposite directions away from the point S in response to a torque differential between the shaft 42 and the cone members 44 and 46 and to couple the cone members rotatably with the shaft. It will be noted also that the conical surfaces of the members 44 and 46, also referred to herein as beta traction surfaces, are concentric with the second axis 14 and are of a variable radius R b with respect to that axis.
The axial bias of the cone members 44 and 46 by the ball/ramp unit 48 along the shaft 42, coupled with the angular relationship of the axis 14 as well as the configuration of the conical members, causes the conical beta surfaces on the members 44 and 46 to be urged into engagement with a pair of axially adjustable omega rings 50 and 52 defining interior omega rolling or traction surfaces 54 and 56 which are of revolution about the primary axis 12 and of a constant radius R w . The rings 50 and 52 are secured against rotation in the frame section 16 and are fixed at the inner ends of annular piston members 58 and 60 operably positioned respectively in annular chambers 62 and 64. The chambers 62 and 64 are ported to hydraulic fluid conduits (not shown) in such a manner that pressurized control fluid in the chambers 62 and 64 will cause the pistons and thus the rings 50 and 52 to move along the axis 12 toward or away from the point S of axes intersection.
In the operation of the transmission 10 to transmit torque originating at the input shaft 32, the alpha body 26 is rotated directly with the input shaft 32 causing the second axis 14 and thus the beta body 34 to nutate about the first axis 12 with the beta traction surfaces on the exterior of the cone members 44 and 46 in contact on opposite sides of the primary axis 12 with the omega traction surfaces 54 and 56 on the rings 50 and 52. The shaft 42, rotatable with the cone members 44 and 46 on the second axis 14 is coupled or linked to an output shaft 66 by an epicyclic gear set 68. Thus it will be seen that torque at the output shaft 66 will be the result of input torque driving the alpha body 26 in rotation about the first axis to cause planetary movement in the gear set 68 together with torque transmitted by friction between the omega surfaces 54 and 56 and the beta surfaces on the cone members 44 and 46 to cause rotation of the beta body 34 and the shaft 42 about the second axis 14. Further, the ball/ramp system 48 urges the cone members 44 into engagement with the omega rings 50 and 52 to develop a normal force proportional to torque transmitted by the shaft 42.
To lubricate and to cool the operating components of the transmission 10, a liquid lubricant is circulated from an external storage source such as a sump 70 to the interior of the housing 16 and returned to the sump by a gravity flow line 72. The lubricant is fed to the transmission by a pump 74 through a conduit 76 to a sealed gland or manifold 78 in the end frame 18 adjacent the bearing 28. The shaft 32 is internally bored to provide a lubricant passageway 80 which communicates with branch passages 84 in the alpha body 26. These latter passages communicate directly with discharge ports 86 in the body 26 as may be understood by reference to FIGS. 1 and 3.
In the embodiment of FIGS. 1-3, the alpha body 26 carries two sets of elongated blade-like scrapers 90 and 92, respectively. As shown in FIG. 1, the blades 90 are positioned to engage the omega traction surfaces 54 diametrically opposite from the point at which these surfaces are engaged by the beta traction surfaces on the conical members 44 and 46. These blades are elongated so that they will engage the surfaces 54 and 56 throughout axial movement of the rings 50 and 52 in the operation of the transmission 10 to vary the speed ratio thereof. As shown in FIG. 2, the blades 90 project from the surface of the alpha body 26 in a manner effective to scrape the traction surfaces 54 as a result of the direction of rotation of the alpha body 26. Though illustrated in FIG. 2 to have a tapered or knife-like edge, the blades may be of a variety of specific configuration appropriately secured to the body 26 such as by clamping wedges 94. Also, the material from which the blades are formed may include synthetic resinous materials or may be metallic.
Because of the relative rotation of the respective transmission bodies 26 and 34, the blades 92, which are identical in construction to the blades 90, project inwardly from the alpha body 26 in a manner to effectively remove lubricant from the surfaces of the members 44 and 46 as a result of relative rotation between the bodies 26 and 34. The blades 92 also extend in length through at least the axial distance of contact between the omega and beta surfaces.
Although the precise location of the blades 92 on the alpha body 26 is not critical, it will be noted that the oil discharge ports 86 from which oil is directed against the surfaces of the beta cone members 44 and 46 are positioned behind the blades 92 in terms of alpha-beta body rotation. As a result, residual lubricant on the surfaces of the cones, including lubricant resulting from a boundary layer phenomenon will be removed from these surfaces in advance of the application of newly recirculated lubricant from the ports 86. In this way the heat transfer from the surfaces 54 and 56 to the lubricant will be enhanced.
In the operation of the transmission 10, relatively cool lubricant will be pumped from the sump 70 through the passageways 80 and 84 in the alpha body 26 and be discharged through the ports 86 directly against the beta traction surfaces on the exterior of the cone members 44 and 46. Though not shown in the drawings, it is contemplated that the lubricant may be cooled by an appropriate heat exchanger associated with the sump 70 or with the passages 72 or 76 on the exterior of the transmission 10. Because of the location of the ports 86 relative to the blades 92, the fresh, cooled lubricant will engage the beta surfaces immediately after they have been wiped clean of any residual lubricant, thereby to enhance the passage of heat from the cone members 44 and 46 to the freshly supplied lubricant. The major portion of the lubricant will pass outwardly by centrifugal force to the omega rings 50 and 52 and other components inside the housing 16 from which it will pass back to the sump through the line 72. Although no direct porting is provided by which fresh lubricant is passed directly to the omega traction surfaces 54 and 56, the location of these rings about the exterior of the alpha body 26 and the beta body 34 enables a supply of lubricant to pass to these surfaces adequate to maintain lubrication of these surfaces as needed for the provention of wear or deterioration of the surfaces 54 and 56. Cooling of the surfaces 54 ad 56 will occur as a result of heat transfer from the surfaces 54 and 56 to the conical surfaces on the members 44 and 46 as well as by heat transfer to the lubricant recirculated to the sump 70. In this latter respect, although the temperature of the lubricant on reaching the rings 50 and 52 may be higher than it is at the surfaces on the cones 44 and 46, the removal of residual lubricant from the surfaces 54 and 56 by the blades 90 coupled with the relatively large ratio of total ring surface area to the area of working or traction surfaces 54 and 56 will prevent any excessive heat build up in the rings 50 and 52.
In FIGS. 4-6 of the drawings, an alternative embodiment of the invention is shown in which parts identical with those of FIGS. 1-3 are designated by the same reference numeral whereas parts having the same function but modified in structure are designated by the same reference numerals primed. Thus, in FIGS. 4 and 5 the alpha body 26 is shown by itself and in somewhat more detail than in FIG. 1. It will be seen more clearly in these figures, for example, that the body 26 is an integral or unitary member having a pair of symmetrical frusto-conical cavities 96 and 98 extending between a central cylindrical portion 100 to counterbores 102 in which the bearings 36 and 38 (see FIG. 1) are seated. The cavities 96 and 98 complement the exterior shape of the cone members 44 and 46 in a manner such that the cavity delimiting surfaces are normally spaced out of contact with the cone members. The cavities 96 are also sectors in the sense that they open at diametrically opposite windows 104 and 106 through which the cone members 44 and 46 contact the traction surfaces 54 and 56 on the omega rings 50 and 52. The arrangement of lubricant passages 84 and ports 86 is the same in FIGS. 4-6 as that of FIG. 1.
In the embodiment of FIGS. 4-6, a single wiper blade assembly 90' is again positioned on the exterior of the alpha body 26 to wipingly engage the traction surfaces 54 and 56. In this instance, the blades 90' are defined by spaced edges of flexible material retained by a central bar 94' is essentially the same manner as the blades 90 of the embodiment of FIGS. 1-3. In place of the single blades 92, however, a plurality of blade-like portions 92' are employed in this embodiment. As shown most clearly in FIGS. 5 and 6, the multiple blades 92' extend longitudinally to be effective over the full length of each of the cone members 44 and 46 and are provided as integral formations on a sheet-like molding 108 of a shape to conform with the frusto-conical configuration of the cavities 96 and 98. The sheet-like molding 108 may be secured by an appropriate adhesive or bonded within the cavities in the position illustrated.
To insure a complete distribution of lubricant between the blade portions 92' and thus against the exterior of the cone members 44 and 46, the blades 92' are interrupted along their respective lengths to establish lubricant passing openings or gaps 110. The openings 110 are preferably staggered or offset from each other axially in order that the wiping function of the blade portions 92' will be effective throughout the working length of the cone members 44 and 46.
In light of the provision of multiple blade portions 92' in the embodiment of FIGS. 4-6, a more complete removal of residual lubricant remaining on the cone members 44 and 46 will be effected. On the other hand, a complete distribution of fresh and cool lubricant over a substantial portion of the cone surfaces will enhance the removal of heat from and thus cool the working traction surfaces on the conical members 44 and 46.
In FIGS. 7 and 8, a still further embodiment of the invention is illustrated. In this embodiment, the function of the blades 92 and 92' of the previous embodiments is served by a plurality of discrete wiping plugs 111 arranged within the frusto-conical cavities of the alpha body 26 to be in a staggered again effective over the entire length of the conical surfaces on the members 44 and 46. As shown most clearly in FIG. 8, the wiping elements 110 are in the nature of plugs of felt-like material individually receivable in relatively shallow holes 112 bored into the surfaces of the cavities 96 and 98. The pattern of the plugs will in itself assure uniform distribution of fresh or cool lubricant fully over the surfaces of the cone members 44 and 46.
Thus it will be seen that as a result of the present invention, a highly effective apparatus is provided for cooling the frictionally engaged rolling surfaces of traction drive transmissions and by which the above-mentioned objectives are completely fulfilled. Also it will be appreciated that modifications may be made in the embodiments disclosed without departure from the invention concepts manifested by such embodiments. It is expressly intended, therefore, that the foregoing description is illustrative of a preferred embodiment, not limiting, and that the true spirit and scope of the present invention be determined by reference to the appended claims.
|
A traction drive torque transmission having a lubricant recirculating system by which a liquid lubricant is passed into and out of heat transfer contact with frictionally engaged rolling surfaces and in which transfer of thermal energy from the rolling surfaces to the lubricant is enhanced by removing a boundary layer of the lubricant which forms on the surfaces. Blade-like scrapers or wipers are mounted on a transmission component movable relative to the frictionally engaged rolling surfaces and are located in relation to ports through which lubricant is passed to the surfaces so that a supply of fresh and relatively cool lubricant is available at the surfaces as they are wiped.
| 5
|
TECHNICAL FIELD OF THE INVENTION
The invention relates to a method of applying a layer-form active ingredient depot with delayed release of active ingredients to plants or plant parts, having at least one pressure-sensitively adhering matrix layer (A) which comprises active ingredient and is in two-dimensional contact with the plant surface, and one back layer (B) which is essentially free from and impermeable to active ingredients and is on the side remote from the plant; the invention embraces a two-component or multicomponents preparation suitable for this method.
BACKGROUND OF THE INVENTION
For treating the wounds of cut surfaces on plants, especially trees, which come about as a result of cutting back or pollarding, pruning or thinning of budding or grafting, use has long been made of filler-comprising covering compositions which initially were formed essentially by natural materials, such as tar or tree wax, or--borrowed from the building sector--were based on mortarlike or paintlike compositions.
With the increasing development of synthetic resins, laminates and polymers, and also of active ingredients and pesticides, especially fungicides, more differentiated methods of plant treatment were developed.
For instance, as early as in DE-C 1 281 206, a composition for treating tissue-damaged plants was described which comprises an aqueous synthetic-resin dispersion which has cellulose as its filler, is intended for brush application and binds well to the plant.
DE-A 2 023 262 discloses a pesticidal pest control composition for forestry which is applied in mobile form and hardens in air to become viscous.
U.S. Pat. No. 4,456,587 provides a mixture which is intended for spray application to the leaves of the plants that are to be treated and which is based on polyvinyl alcohol/polyvinyl pyrrolidone in aqueous dispersion, in which an active ingredient (pheromone or insecticide), mixed with oil, is finely divided. The polymer mixture dries or "cures" on the plant and releases the active ingredient to the plant over a period of several weeks.
DE-A 35 07 008 emphasizes the positive effect of finely ground rock flour (<4μ) in a spreadable plant treatment composition based on polymers, synthetic resins or natural resins.
DD 272 219 describes treating tree wounds by brushing them with two coats of paint, which involves first of all coating the bark of the tree with a latex binder and, after it has set, carrying out treatment with a composition which comprises active ingredient, alkyd resin and phyllosilicate.
DD 273 573 A1 reveals a pastelike composition for controlling bark-breeding pests, such as bark beetles, which is spread onto the bark and which in addition to the active ingredient(s) comprises terpene hydrocarbons, such as α-pinene, or myrcene, and is suitable for the controlled, delayed release of active ingredient(s). Covering with plastic film is recommended as a means of avoiding environmental contamination.
Again, more recently, DE Patent Application P 44 30 449.8 has proposed a sprayable preparation of active ingredient which results in a water-insoluble, pressure-sensitively adhering film with controlled, delayed release of active ingredient.
U.S. Pat. No. 5,395,851, finally, describes a sprayable or spreadable composition comprising a fungicide in a mixture of natural and synthetic resin and metal salts of fatty acids.
None of these diverse efforts appears to be entirely satisfactory: the coverings produced in feasible technology, with more or less good adhesiveness, have the disadvantage that there may be losses of active ingredient into the surroundings, especially as a result of the effects of weathering, and that there is an increased risk to free-living animals. Layer application by spray technology is not without its problems for the user, and layers having good adhesiveness can result in adjacent plant parts becoming stuck.
An additional covering with plastic film is to start with complex and ackward and, moreover, is not always possible when there are spatial constraints.
SUMMARY OF THE INVENTION
The present invention is therefore based on the object of providing, for the administration of active ingredients to plants, systems which externally release active ingredients over a prolonged period without notable losses with the aim of a sustained therapeutic effect. These systems should be readily handleable with no hazard to the user and should be able to be applied with no spatial restriction (in other words, for example, to ground cover plants as well).
The achievement of this object is obtained in a surprisingly simple manner by the method according to the characterizing features of the main claim and with a corresponding active ingredient depot preparation which complies fully with the abovementioned requirements. Further embodiments, essential to the invention, of the active ingredient preparation are provided in accordance with the subclaims.
"Self-adhesive" or "pressure-sensitively adhering" means here "of permanent surface tackiness, both before and after application".
Although DE-C 39 22 366 has already disclosed ready-to-use active ingredient depot systems in the form of so-called plasters, which have an analogous layering and functionality at the site of application, such systems are complex and their use is limited for reasons of space.
In accordance with the invention, application results in a layer structure comprising an outer layer which is essentially impermeable to active ingredients and to water, and one or more pressure-sensitively adhering matrix layers which face the plant and comprise active ingredient. The simple mode of application makes it possible to treat plants of different morphologies without restriction. Essential to the invention is the presence of an inert, non-adhering back layer, which protects the active-ingredient-comprising matrix against the effects of weathering in that it entirely covers this matrix. In this way, the danger of environmental contamination and the danger of the unwanted sticking of other plant parts are avoided.
DETAILED DESCRIPTION
The systems presented below are applied by the painting method using brushes and applicator sponges. The individual layers are applied separately--that is, in terms of time--atop one another. The compositions to be used for this purpose can be supplied from containers or dispensers featuring a dual-chamber of multichamber system. In this arrangement the individual components are disposed such that the component which comprises active ingredient and has a pressure-sensitively adhering composition is coated first of all onto the plant surface in the form of a single-coat or multicoat covering. Not until the component has slightly dried is it covered over the whole of its area with the second layer, which is free from active ingredient.
The top layer here can also be produced by spraying (or foaming).
For this purpose the preparation to be sprayed is dispensed into a pump can which is free from propellant gas and has a press-down atomizer. In cases such as these the active-ingredient-free preparation will of course have a relatively low viscosity so as to ensure flawless spraying.
Important constituents of preparations according to the invention are polymers, which possess both the function of an active ingredient carrier (matrix) and that of the raw materials for the back layer.
For the pressure-sensitively adhering matrix layer of the plaster according to the invention use is made of homo- or copolymers of esters of acrylic acid, such as ethyl acrylate and n-butyl acrylate, and also methacrylic methyl ester. Further suitable polymers are ethylene-vinyl acetate or triblock polymers such as styrene-butadiene-styrene. They are processed on the basis of a solution in organic solvents or of an aqueous dispersion, aqueous systems being preferred on account of their favourable ecological properties.
In the case of polymers which do not adhere pressure-sensitively, appropriate auxiliaries must be added in order to achieve desired properties. This function is served principally by resinous substances, such as modified natural resins, especially rosin and its derivatives, polyterpene resins, and hydrocarbon resins. Particularly suitable such substances which may be emphasized here are rosin esters (such as Foral® 85 and Staybelite Ester® 10). The amount of the resin additive depends on the desired properties and is subject to an upper limit, since with too great a proportion of resin the cohesion of the resulting coverings becomes too low. The said amount can vary between 1.0 and 20.0% by weight and is usually in the range from 5 to 10% by weight, based on the solids content of the preparation.
The relative proportions of active ingredient and polymer in the matrix can vary over a wide range depending on the desired effect. The proportions can be in the range from 1% active ingredient and 99% active ingredient and 1% polymer. Proportions giving good results include 1 part of active ingredient to 10-30 parts of polymer.
If required, the active ingredient matrix may comprise penetration accelerants and mixtures thereof, normally in concentrations from 1 to 10% by weight. Examples of penetration accelerants which can be employed are long-chain alcohols, 2-pyrrolidone derivatives, mono-, di- and triglycerides, fatty acids, fatty acid esters, and many others.
The active ingredients present in plasters according to the invention can be in solution or dispersion in the polymer matrix. They may be present individually or in a mixture.
A particularly advantageous embodiment of the systems according to the invention are those in which active ingredients are subject to (diffusion-)controlled release. A prerequisite for this, however, is that the active-ingredient-comprising component is applied with an applicator which makes it possible to regulate both the overall surface area and the thickness of the layer that is to be applied. In this context, the overall area of active ingredient release that is to be achieved may be composed of a plurality of unit areas, which are preferably applied dotwise. The applicator can be of various configuration, such as, for example, in the form of a flexible stencil. A further option is that of dispenser systems, such as, for example, injection dispensers or a screen printing plate, which may additionally be integrated into the release container.
Among the active ingredients which can be released to plants by means of the preparations according to the invention, mention should be made primarily of systemic plant protection agents (fungicides, insecticides, acaricides, bactericides) and also growth regulators.
Examples, of systemic fungicides are benomyl, bromuconazole, bitertanol, etaconazole, flusilazole, furalaxyl, fosetyl-aluminium, imazalil, metalaxyl, propiconazole, thiabendazole, triadimefon and triticonazole.
Examples of systemic insecticides are butocarboxim, dimethbate, imidacloprid, fenoxycarb, methamyl, oxamyl, pirimicarb and propoxur.
Examples of systemic acaricides are clofentezine, fenbutatin oxide and hexythiazox.
Examples of systemic growth regulators are ethephon and β-indolylacetic acid (IAA).
Among the systemic bactericides mention may be made, for example, of flumequine.
In accordance with the protective function of the cover layer, the starting materials used to produce it on the plant should possess a relatively high diffusion resistance and have hydrophobic properties. Substances suitable for this purpose include polyvinyl acetate, cellulose derivatives, chitosan and others. Cellulose derivatives such as cellulose acetate or cellulose butyrate are particularly advantageous because they are biodegradable.
All of the said polymers are applied as fluid or pasty media to the previously applied active ingredient layer. For this purpose they are generally mixed with appropriate solvents. Suitable solvents which can be used for this purpose are ethyl acetate, acetone, ethanol, isopropanol or mixtures thereof. The amount of the solvent or solvent mixture must be chosen so that the overall preparation has a viscosity which enables it to be applied by spreading. With this application technique, good results can be achieved with compositions whose viscosity lies between 1.5 and 3.0 Pa.s. The polymer content of such compositions is judiciously about 25-80% by weight, preferably from 50 to 65% by weight.
The active ingredient release systems according to the invention can be used to provide controlled administration of bioactive substances to plants. A preferred field of use for these systems is the plant protection sector. The examples which follow serve to illustrate the invention. All amounts, proportions and percentages are based, unless specified otherwise, on the overall weight of the respective preparation of components.
EXAMPLE 1
29 parts by weight of the fungicide triticonazole were dispersed together with 2 parts by weight of the insecticide imidacloprid (both active ingredients suspended in 5 parts by weight of 1-methyl-2-pyrrolidone) in 65 parts by weight of an aqueous, polyacrylate-based adhesive dispersion (Collano® AGX-23; solids content 61%), with continual stirring. The resulting, active-ingredient-comprising dispersion, whose relative viscosity at 24° C. was 1.52 Pa.s (according to Brookfield LVF/measuring body), was applied with the aid of a brush to the main shoots of an infested rose tree (0.25 g of composition per shoot) and was spread out to form a stripe about 1 cm in width and 5 cm long. This pressure-sensitively adhering layer, comprising active ingredient, was subsequently covered with an approximately 0.1 mm thick layer of a polyvinyl acetate solution (33% strength solution of polyvinyl acetate in ethyl acetate), which was likewise applied by the painting method.
EXAMPLE 2
6 parts by weight of ethylcellulose (Ethylcellulose NF®50) were dissolved with stirring in 25 parts by weight of a solvent mixture of ethyl acetate and ethanol (ethyl acetate:ethanol=1:4). Following the addition of 15.0 parts by weight of a resin (Hercolyn®D) as tackifier, 3.5 parts by weight of the active ingredient imidacloprid and 42.5 parts by weight of the active ingredient triticonazole were added to the resulting, pressure-sensitively adhering composition, the active ingredients being in suspension in 8 parts by weight of 1-methyl-2-pyrrolidone. The added active ingredients were distributed uniformly in the composition with continual stirring. The resulting highly viscous (pasty), pressure-sensitively adhering composition comprising active ingredients was spread using a brush onto the main shoots of a rose tree (in the base region) (0.35 g of composition per shoot). A film of cellulose acetate butyrate was produced on the active-ingredient-comprising layer by spreading on 0.1 g of a 25% strength solution of cellulose acetate butyrate in acetone.
|
A method of applying a layer-form active ingredient depot with delayed release of active ingredients to plants or plant parts, having at least one pressure-sensitively adhering matrix layer (A) which comprises active ingredient and is in two-dimensional contact with the plant surface, and one back layer (B) which is essentially free from and impermeable to active ingredient and is on the side remote from the plant is characterized in that the layer (A) is produced by painting in the desired two-dimensional pattern at the site of application on the plant from a spreadable, pressure-sensitively adhering, polymer-based composition which comprises active ingredient and then on the said layer (A) the layer (B) is produced by painting or spraying.
| 8
|
RELATED APPLICATION
This is a continuation of application Ser. No. 10/708,722 filed Mar. 19, 2004, which was a continuation-in-part of application Ser. No. 10/250,110, which was a divisional application of application Ser. No. 09/799,210, filed Mar. 5, 2001, which issued as U.S. Pat. No. 6,703,469, the teachings and content of each of which are hereby incorporated by reference herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is broadly concerned with novel substantially biodegradable and substantially water soluble anionic polymers and derivatives thereof which have significant utility in agricultural applications, especially plant nutrition and related areas. More particularly, the invention is concerned with such polymers, as well as methods of synthesis and use thereof, wherein the preferred polymers have significant levels of anionic groups. The most preferred polymers of the invention include recurring polymeric subunits made up of dicarboxylic (e.g., maleic acid or anhydride, itaconic acid or anhydride, and other derivatives thereof) monomers. The polymers may be applied directly to the ground adjacent growing plants, complexed onto ions, applied directly to seeds, and/or mixed with or coated with phosphate-based fertilizers to provide improved plant nutrition products.
2. Description of the Prior Art
Lignosulfonates, polyacrylates, polyaspartates and related compounds have become known to the art of agriculture as materials that facilitate nutrient absorption. All of them suffer from significant disadvantages, which decrease their utility in comparison to the art discussed herein and limit performance.
Lignosulfonates are a byproduct of paper pulping; they are derived from highly variable sources. They are subject to large, unpredictable variations in color, physical properties, and performance in application areas of interest for this invention.
Polyacrylates and polymers containing appreciable levels thereof can be prepared with good control over their composition and performance. They are stable to pH variations. However, polyacrylates have just one carboxylate per repeat unit and they suffer from a very significant limitation in use, namely that they are not biodegradable. As a result, their utility for addressing the problems remedied by the instant invention is low.
Polyaspartates are biodegradable, but are very expensive, and are not stable outside a relatively small pH range of about 7 to about 10. They usually have very high color, and incorporate amide groups, which causes difficulties in formulating them. Additionally, polyaspartates have just one carboxylate per repeat unit and are therefore not a part of the present invention.
Preparation of itaconic Acid homopolymers has been known to the art of polymer chemistry for an extended period of time. Several approaches to making it exist. One approach is by the direct polymerization of itaconic acid and/or its salts in aqueous or organic solutions under a wide range of conditions. Such reactions are described in the Journal of Organic Chemistry , Vol. 24, pg. 599 (1959) the teachings of which are incorporated by reference herein. Another approach is to begin with esters of itaconic acid, polymerize them under suitable conditions, and then hydrolyze the ester groups off in order to liberate polyitaconic acid. This approach is described in U.S. Pat. No. 3,055,873, the teachings of which are hereby incorporated by reference. Additionally, a very good summary of many aspects of the prior art is found in U.S. Pat. No. 5,223,592, the teachings of which are hereby incorporated by reference.
It will thus be seen that the prior art fails to disclose or provide polymers which can be synthesized using a variety of monomers and techniques in order to yield end products which are substantially biodegradable, substantially water soluble, and have wide applicability for agricultural uses. Moreover, no prior art or combination of prior art discloses preparation of itaconic acid copolymers with one or more organic acids containing at least one olefinic bond and at least two carboxylic acid groups. Furthermore, while the prior art does disclose a variety of methods for making polyitaconic acid homopolymer, it fails to teach, disclose, or suggest the utility such materials unexpectedly have for a wide variety of agricultural uses.
SUMMARY OF THE INVENTION
The present invention overcomes the problems outlined above and provides a new class of anionic polymers having a variety of uses, e.g., for enhancing takeup of nutrient by plants or for mixture with conventional phosphate-based fertilizers to provide an improved fertilizer product. Advantageously, the polymers are biodegradable, in that they degrade to environmentally innocuous compounds within a relatively short time (up to about 1 year) after being in intimate contact with soil. That is to say, the degradation products are compounds such as CO 2 and H 2 O or the degradation products are absorbed as food or nutrients by soil microorganisms and plants. Similarly, derivatives of the polymers and/or salts of the polymers (e.g. ammonium salt forms of the polymer) also degrade within a relatively short time, during which significant fractions of the weight of the polymer are believed to be metabolized by soil organisms.
Broadly speaking, the anionic polymers of the invention include recurring polymeric subunits made up of at least two different moieties individually and respectively taken from the group consisting of what have been denominated for ease of reference as B and C moieties; alternately, the polymers may be formed from recurring C moieties. Thus, exemplary polymeric subunits may be BC, CB, CC, or any other combination of B, and C moieties; moreover, in a given polymer different polymeric subunits may include different types of moieties, e.g., in an BC recurring polymeric unit polymer, the B moiety may be different in different units.
In detail, moiety B is of the general formula
and moiety C is of the general formula
wherein each R 7 is individually and respectively selected from the group consisting of H, OH, C 1 -C 30 straight, branched chain and cyclic alkyl or aryl groups, C 1 -C 30 straight, branched chain and cyclic alkyl or aryl formate (C 0 ), acetate (C 1 ), propionate (C 2 ), butyrate (C 3 ), etc. up to C 30 based ester groups, R′CO 2 groups, OR′ groups and COOX groups, wherein R′ is selected from the group consisting of C 1 -C 30 straight, branched chain and cyclic alkyl or aryl groups and X is selected from the group consisting of H, the alkali metals, NH 4 and the C 1 -C 4 alkyl ammonium groups, R 3 and R 4 are individually and respectively selected from the group consisting of H, C 1 -C 30 straight, branched chain and cyclic alkyl or aryl groups, R 5 , R 6 , R 10 , and R 11 are individually and respectively selected from the group consisting of H, the alkali metals, NH 4 and the C 1 -C 4 alkyl ammonium groups, Y is selected from the group consisting of Fe, Mn, Mg, Zn, Cu, Ni, Co, Mo, V and Ca, and R 8 and R 9 are individually and respectively selected from the group consisting of nothing (i.e., the groups are non-existent), CH 2 , C 2 H 4 , and C 3 H 6 , each of said moieties having or being modified to have a total of two COO groups therein.
As can be appreciated, the polymers of the invention can have different sequences of recurring polymeric subunits as defined above (For example, a polymer comprising B and C subunits may include all three forms of B subunit and all three forms of C subunit. However, for reasons of cost and ease of synthesis, the most useful polymers include recurring polymeric subunits made up of B and C moieties. In the case of the polymer made up of B and C moieties, R 5 , R 6 , R 10 , and R 11 are individually and respectively selected from the group consisting of H, the alkali metals, NH 4 , and the C 1 -C 4 alkyl ammonium groups. This particular polymer is sometimes referred to as a butanedioic methylenesuccinic acid copolymer and can include various salts and derivatives thereof.
The most preferred polymers of the invention are composed of recurring polymeric subunits formed of B and C moieties and have the generalized formula
Preferred forms of this polymer have R 5 , R 6 , R 10 , and R 11 individually and respectively selected from the group consisting of H, the alkali metals, NH 4 , and the C 1 -C 4 alkyl ammonium groups. Other preferred forms of this polymer are capable of having a wide range of repeat unit concentrations in the polymer. For example, polymers having varying ratios of B:C (e.g., 10:90, 60:40, 50:50 and even 0:100) are contemplated and embraced by the present invention. Such polymers would be produced by varying monomer amounts in the reaction mixture from which the final product is eventually produced and the B and C type repeating units may be arranged in the polymer backbone in random order or in an alternating pattern.
The polymers of the invention may have a wide variety of molecular weights, ranging for example from 500-5,000,000, depending chiefly upon the desired end use. Additionally, n can range from about 1-10,000 and more preferably from about 1-5,000.
For purposes of the present invention, it is preferred to use dicarboxylic acids, precursors and derivatives thereof for the practice of the invention. For example, terpolymers containing mono and dicarboxylic acids with vinyl esters and vinyl alcohol are contemplated, however, polymers incorporating dicarboxylic acids were unexpectedly found to be significantly more useful for the purposes of this invention. This finding was in contrast to the conventional teachings that mixtures of mono and dicarboxylates were superior in applications previously suggested for mono-carboxylate polymers. Thus, the use of dicarboxylic acid derived polymers for agricultural applications is unprecedented and produced unexpected results. It is understood that when dicarboxylic acids are mentioned herein, various precursors and derivatives of such are contemplated and well within the scope of the present invention. Put another way, copolymers of the present invention are made up of monomers bearing at least two carboxylic groups or precursors and/or derivatives thereof. The polymers of the invention may have a wide variety of molecular weights, ranging for example from 500-5,000,000, more preferably from about 1,500-20,000, depending chiefly upon the desired end use.
In many applications, and especially for agricultural uses, the polymers of the invention may be mixed with or complexed with a metal or non-metal ion, and especially ions selected from the group consisting of Fe, Mn, Mg, Zn, Cu, Ni, Co, Mo, V, Cr, Si, B, and Ca. Alternatively, polymers containing, mixed with or complexed with such elements may be formulated using a wide variety of methods that are well known in the art of fertilizer formulation. Examples of such alternative methods include, forming an aqueous solution containing molybdate and the sodium salt of polymers in accordance with the invention, forming an aqueous solution which contains a zinc complex of polymers in accordance with the present invention and sodium molybdate, and combinations of such methods. In these examples, the presence of the polymer in soil adjacent growing plants would be expected to enhance the availability of these elements to these growing plants. In the case of Si and B, the element would merely be mixed with the polymer rather than having a coordinate metal complex formation. However, in these cases, the availability of these ions would be increased for uptake by growing plants and will be termed “complexed” for purposes of this application.
The polymers hereof (with or without complexed ions) may be used directly as plant growth enhancers. For example, such polymers may be dispersed in a liquid aqueous medium and applied foliarly to plant leaves or applied to the earth adjacent growing plants. It has been found that the polymers increase the plant's uptake of both polymer-borne metal nutrients and ambient non-polymer nutrients found in adjacent soil. In such uses, plant growth-enhancing amounts of compositions comprising the above-defined polymers are employed, either in liquid dispersions or in dried, granular form. Thus, application of polymer alone results in improved plant growth characteristics, presumably by increasing the availability of naturally occurring ambient nutrients. Typically, the polymers are applied at a level of from about 0.001 to about 100 lbs. polymer per acre of growing plants, and more preferably from about 0.005 to about 50 lbs. polymer per acre, and still more preferably from about 0.01 to about 2 lbs.
In other preferred uses, the polymers may be used to form composite products where the polymers are in intimate contact with fertilizer products including but not limited to phosphate-based fertilizers such as monoammonium phosphate (MAP), diammonium phosphate (DAP), any one of a number of well known N-P-K fertilizer products, and/or fertilizers containing nitrogen materials such as ammonia (anhydrous or aqueous), ammonium nitrate, ammonium sulfate, urea, ammonium phosphates, sodium nitrate, calcium nitrate, potassium nitrate, nitrate of soda, urea formaldehyde, metal (e.g. zinc, iron) ammonium phosphates; phosphorous materials such as calcium phosphates (normal phosphate and super phosphate), ammonium phosphate, ammoniated super phosphate, phosphoric acid, superphosphoric acid, basic slag, rock phosphate, colloidal phosphate, bone phosphate; potassium materials such as potassium chloride, potassium sulfate, potassium nitrate, potassium phosphate, potassium hydroxide, potassium carbonate; calcium materials, such as calcium sulfate, calcium carbonate, calcium nitrate; magnesium materials, such as magnesium carbonate, magnesium oxide, magnesium sulfate, magnesium hydroxide; sulfur materials such as ammonium sulfate, sulfates of other fertilizers discussed herein, ammonium thiosulfate, elemental sulfur (either alone or included with or coated on other fertilizers); micronutrients such as Zn, Mn, Cu, Fe, and other micronutrients discussed herein; oxides, sulfates, chlorides, and chelates of such micronutrients (e.g., zinc oxide, zinc sulfate and zinc chloride); such chelates sequestered onto other carriers such as EDTA; boron materials such as boric acid, sodium borate or calcium borate; organic wastes and waste waters such as manure, sewage, food processing industry by-products, and pulp and paper mill by-products; and molybdenum materials such as sodium molybdate. As known in the art, these fertilizer products can exist as dry powders/granules or as water solutions.
In such contexts, the polymers may be co-ground with the fertilizer products, applied as a surface coating to the fertilizer products, or otherwise thoroughly mixed with the fertilizer products. Preferably, in such combined fertilizer/polymer compositions, the fertilizer is in the form of particles having an average diameter of from about powder size (less than about 0.001 cm) to about 10 cm, more preferably from about 0.1 cm to about 2 cm, and still more preferably from about 0.15 cm to about 0.3 cm. The polymer is present in such combined products at a level of from about 0.001 g to about 20 g polymer per 100 g phosphate-based fertilizer, more preferably from about 0.1 g to about 10 g polymer per 100 g phosphate-based fertilizer, and still more preferably from about 0.5 g to about 2 g polymer per 100 g phosphate-based fertilizer. Again, the polymeric fraction of such combined products may include the polymers defined above, or such polymers complexed with the aforementioned ions. In the case of the combined fertilizer/polymer products, the combined product is applied at a level so that the polymer fraction is applied at a level of from about 0.001 to about 20 lbs. polymer per acre of growing plants, more preferably from about 0.01 to about 10 lbs polymer per acre of growing plants, and still more preferably from about 0.5 to about 2 lbs polymer per acre of growing plants. The combined products can likewise be applied as liquid dispersions or as dry granulated products, at the discretion of the user. When polymers in accordance with the present invention are used as a coating, the polymer comprises between about 0.005% and about 15% by weight of the coated fertilizer product, more preferably the polymer comprises between about 0.01% and about 10% by weight of the coated fertilizer product, and most preferably between 0.5% and about 1% by weight of the coated fertilizer product. It has been found that polymer-coated fertilizer products obtain highly desirable characteristics due to the alteration of mechanical and physical properties of the fertilizer.
Additionally, use of polymers in accordance with the present invention increases the availability of phosphorus and other common fertilizer ingredients and decreases nitrogen volatilization, thereby rendering ambient levels of such plant nutrient available for uptake by growing plants. In such cases, the polymer can be applied as a coating to fertilizer products prior to their introduction into the soil. In turn, plants grown in soil containing such polymers exhibit enhanced growth characteristics.
Another alternative use of polymers in accordance with the present invention includes using the polymer as a seed coating. In such cases, the polymer comprises at least about 0.005% and about 15% by weight of the coated seed, more preferably, the polymer comprises between about 0.01% and about 10% by weight of the coated seed, and most preferably between 0.5% and about 1% by weight of the coated seed. Use of the polymer as a seed coating provides polymer in close proximity to the seed when planted so that the polymer can exert its beneficial effects in the environment where it is most needed. That is to say that the polymer provides an environment conducive to enhanced plant growth in the area where the effects can be localized around the desired plant. In the case of seeds, the polymer coating provides an enhanced opportunity for seed germination and subsequent plant growth due to the decrease in nitrogen volatilization an increase in plant nutrient availability which is provided by the polymer.
In general, the polymers of the invention are made by free radical polymerization serving to convert selected monomers into the desired polymers with recurring polymeric subunits. Such polymers may be further modified to impart particular structures and/or properties. A variety of techniques can be used for generating free radicals, such as addition of peroxides, hydroperoxides, azo initiators, persulfates, percarbonates, per-acid, charge transfer complexes, irradiation (e.g., UV, electron beam, X-ray, gamma-radiation and other ionizing radiation types), and combinations of these techniques. Of course, an extensive variety of methods and techniques are well known in the art of polymer chemistry for initiating free-radical polymerizations. Those enumerated herein are but some of the more frequently used methods and techniques. Any suitable technique for performing free-radical polymerization is likely to be useful for the purposes of practicing the present invention
The polymerization reactions are carried out in a compatible solvent system, namely a system which does not unduly interfere with the desired polymerization, using essentially any desired monomer concentrations. A number of suitable aqueous or non-aqueous solvent systems can be employed, such as ketones, alcohols, esters, ethers, aromatic solvents, water and mixtures thereof. Water alone and the lower (C 1 -C 4 ) ketones and alcohols are especially preferred, and these may be mixed with water if desired. In some instances, the polymerization reactions are carried out with the substantial exclusion of oxygen, and most usually under an inert gas such as nitrogen or argon. There is no particular criticality in the type of equipment used in the synthesis of the polymers, i.e., stirred tank reactors, continuous stirred tank reactors, plug flow reactors, tube reactors and any combination of the foregoing arranged in series may be employed. A wide range of suitable reaction arrangements are well known to the art of polymerization.
In general, the initial polymerization step is carried out at a temperature of from about 0° C. to about 120° C. (more preferably from about 30° C. to about 95° C. for a period of from about 0.25 hours to about 24 hours and even more preferably from about 0.25 hours to about 5 hours). Usually, the reaction is carried out with continuous stirring.
Thereafter, the completed polymer may be recovered as a liquid dispersion or dried to a solid form. Additionally, in many cases it is preferred to react the polymer with an ion such as Fe, Mn, Mg, Zn, Cu, Ni, Co, Mo, V, Cr, and Ca to form a coordinate metal complex. Techniques for making metal-containing polymer compounds are well known to those skilled in the art. In some of these techniques, a metal's oxide, hydroxide, carbonate, salt, or other similar compound may be reacted with the polymer in acid form. These techniques also include reacting a finely divided free metal with a solution of an acid form of a polymer described or suggested herein. Additionally, the structures of complexes or salts of polymers with metals in general, and transition metals in particular, can be highly variable and difficult to precisely define. Thus, the depictions used herein are for illustrative purposes only and it is contemplated that desired metals or mixtures of such are bonded to the polymer backbone by chemical bonds. Alternatively, the metal may be bonded to other atoms in addition to those shown. For example, in the case of the structure shown herein for the second reactant, there may be additional atoms or functional groups bonded to the Y. These atoms include, but are not limited to, oxygen, sulfur, halogens, etc. and potential functional groups include (but are not limited to) sulfate, hydroxide, etc. It is understood by those skilled in the art of coordination compound chemistry that a broad range of structures may be formed depending upon the preparation protocol, the identity of the metal, the metal's oxidation state, the starting materials, etc. In the case of Si and B ions, the polymer is merely mixed with these ions and does not form a coordinate complex. However, the availability of these ions to growing plants is increased. It is also noted that it is possible to react the monomers used to form the polymer with ions in similar ways before polymerization. In other words, the monomers can be reacted with metals (including metals in their pure state, as oxides, carbonates, hydroxides, or other suitable metal-containing compounds) or ions in such a way as to result in the formation of a salt, a complex, or a similar molecule. It is also contemplated that reaction of monomers with a metal can be followed by their polymerization and subsequent reaction with a further portion of metal.
In more detail, the preferred method for polymer synthesis comprises the steps of providing a reaction mixture comprising at least two different reactants selected from the group consisting of first and second reactants. The first reactant is of the general formula
and the second reactant is of the general formula
With reference to the above formulae, each R 7 is individually and respectively selected from the group consisting of H, OH, C 1 -C 30 straight, branched chain and cyclic alkyl or aryl groups, C 1 -C 30 straight, branched chain and cyclic alkyl or aryl formate (C 0 ), acetate (C 1 ), propionate (C 2 ), butyrate (C 3 ), etc. up to C 30 based ester groups, R′CO 2 groups, OR′ groups and COOX groups, wherein R′ is selected from the group consisting of C 1 -C 30 straight, branched chain and cyclic alkyl or aryl groups and X is selected from the group consisting of H, the alkali metals, NH 4 and the C 1 -C 4 alkyl ammonium groups, R 3 and R 4 are individually and respectively selected from the group consisting of H, C 1 -C 30 straight, branched chain and cyclic alkyl or aryl groups, R 5 , R 6 , R 10 , and R 11 are individually and respectively selected from the group consisting of H, the alkali metals, NH 4 and the C 1 -C 4 alkyl ammonium groups, Y is selected from the group consisting of Fe, Mn, Mg, Zn, Cu, Ni, Co, Mo, V and Ca, and R 8 , and R 9 , are individually and respectively selected from the group consisting of nothing (i.e., the groups are non-existent), CH 2 , C 2 H 4 , and C 3 H 6 , each of said moieties having or being modified to have a total of two COO groups therein.
Selected monomers and reactants are dispersed in a suitable solvent system and placed in a reactor. The polymerization reaction is then carried out to obtain an initial polymerized product having the described recurring polymeric subunits. Put another way, the general reaction proceeds by dissolving monomers (e.g., maleic anhydride and itaconic acid) in acetone and/or water in either equimolar or non-equimolar amounts. A free radical initiator is then introduced and copolymerization takes place in solution. After the reaction is complete and a major fraction of the monomer has been reacted, the resulting solution for this particular example is a maleic acid-itaconic acid copolymer. Of course, if all monomers have not undergone polymerization, the resulting solution will contain a small portion of monomers which do not affect later use of the polymer.
Another important aspect of the present invention is the enhancement of dust control when a polymer in accordance with the present invention is applied as a coating to a fertilizer. It has been found that coating the fertilizer with a polymer in accordance with the present invention greatly decreases the generation of dust. Such a dust-controlling property of polymers in accordance with the present invention was entirely unexpected yet provides a distinct advance in the state of the art in that, typically, a separate dust-controlling substance is applied to fertilizers prior to their application in a field. Generally, the polymer will be applied as a coating to the surface of the fertilizer in order to form a substantially coated fertilizer product. As noted above, the polymer may comprise between about 0.005% to about 15% by weight of the coated fertilizer product, however, for dust control, it is preferred to have the coating level be up to about 0.5% w/w as it has been demonstrated that coating levels as low as 0.5% w/w completely inhibit the generation of dust. Of course, the coating level can be increased to levels greater than 0.5% w/w in order to enhance other beneficial properties of the polymer while still completely inhibiting dust generation. Thus, the present invention will eliminate the need for this separate dust-controlling substance while still contributing all of the beneficial properties described above.
Again, it is important to note that the aforementioned methods and procedures are merely preferred methods of practicing the present invention and those skilled in the art understand that a large number of variations and broadly analogous procedures can be carried out using the teachings contained herein. For example, polymers may be used as is (in the acid form) or further reacted with various materials to make salts and/or complexes. Furthermore, complexes or salts with various metals may be formed by reacting the acid form with various oxides, hydroxides, carbonates, and free metals under suitable conditions. Such reactions are well known in the art and include (but are not limited to) various techniques of reagent mixing, monomer and/or solvent feed, etc. One possible technique would be gradual or stepwise addition of an initiator to a reaction in progress. Other potential techniques include the addition of chain transfer agents, free radical initiator activators, molecular weight moderators/control agents, use of multiple initiators, initiator quenchers, inhibitors, etc. Of course, this list is not comprehensive but merely serves to demonstrate that there are a wide variety of techniques available to those skilled in the art and that all such techniques are embraced by the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph illustrating the percentage of nitrogen and ammonia lost from untreated urea over a sixteen day testing period; and
FIG. 2 is a graph illustrating the percentage of nitrogen and ammonia lost over a sixteen day testing period from urea coated with polymer.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following examples set forth techniques for the synthesis of polymers in accordance with the invention, and various uses thereof. It is to be understood that these examples are provided by way of illustration only and nothing therein should be taken as a limitation upon the overall scope of the invention.
Example 1
Acetone (803 g), maleic anhydride (140 g), itaconic acid (185 g) and benzoyl peroxide (11 g) were stirred together under inert gas in a reactor. The reactor provided included a suitably sized cylindrical jacketed glass reactor with mechanical agitator, a contents temperature measurement device in contact with the contents of the reactor, an inert gas inlet, and a removable reflux condenser. This mixture was heated by circulating heated oil in the reactor jacket and stirred vigorously at an internal temperature of about 65-70° C. This reaction was carried out over a period of about 5 hours. At this point, the contents of the reaction vessel were poured into 300 g water with vigorous mixing. This gave a clear solution. The solution was subjected to distillation at reduced pressure to drive off excess solvent and water. After sufficient solvent and water have been removed, the solid product of the reaction precipitates from the concentrated solution, and is recovered. The solids are subsequently dried in vacuo. A schematic representation of this reaction is shown below.
Example 2
This reaction was carried out in equipment similar to that used in Example 1 above. The following procedure was followed:
847 g purified water was placed into the reactor. Next, 172 g itaconic acid and 130 g maleic anhydride were added with vigorous stirring. This mixture was heated to about 85-90° C., at which temperature this mixture exists as a clear solution. When the mixture reached the desired temperature, 15 g of potassium persulfate was added to the solution. The reaction mixture was allowed to stir for 3 hours, and a second portion of persulfate, equal to the first, was added, and allowed to react for a further 3 hours. Product was isolated in the same manner as described for Example 1. A schematic representation of this reaction is shown below.
Example 3
The procedure of Example 2 was followed, but the product was not isolated. Instead, it was diluted with water to give a 10% w/w solution. Then, 6.62 g ZnO was added to 200 g of this solution. The oxide dissolved in the liquid with stirring. This solution was then dried to a white highly water-soluble powder.
Example 4
The procedure of Example 2 was followed, but the product was not isolated. Instead, it was diluted with water to give a 30% w/w solution. 6.66 g CuO was ten added to 260 g of this solution. The oxide dissolved in the liquid with stirring and heating to about 60 degrees C. This solution was then dried to a green-colored highly water-soluble powder.
Example 5
The procedure of Example 2 was followed, but the product was not isolated. Instead, it was diluted with water to give a 10% w/w solution. To 200 g of this solution, 5.76 g MnO 2 was added. The oxide dissolved in the liquid with stirring and heating to about 60 degrees C. This solution was then dried to a pink-colored, highly water-soluble powder.
Example 6
The procedure of Example 2 was followed, but the product was not isolated. Instead, it was diluted with water to give a 10% w/w solution. Next, 3.28 g MgO was added to 200 g of this solution. The oxide dissolved in the liquid with stirring. This solution was then dried to a white highly water-soluble powder.
Example 7
The procedure of Example 2 was followed, but the product was not isolated. Instead, it was diluted with water to give a 25% w/w solution. 2.96 g V 2 O 5 was then added to 240 g of this solution. The oxide dissolved in the liquid with stirring. This solution was then dried to a green highly water-soluble powder.
Example 8
The procedure of Example 2 was followed, but the product was not isolated. Instead, it was diluted with water to give a 10% w/w solution. To 200 g of this solution, 3.03 g metallic Fe in finely powdered form was added. The metal dissolved in the liquid with stirring. This solution was then dried to a yellow highly water-soluble powder.
Example 9
The procedure of Example 2 was followed, but the product was not isolated. Instead, it was diluted with water to give a 10% w/w solution. To 200 g of this solution, 8.14 g CaCO 3 was added. The carbonate dissolved in the liquid with stirring. This solution was then dried to a white highly water-soluble powder.
Example 10
The procedure of Example 2 was followed, but the product was not isolated. Instead, it was neutralized to a pH of 7 with aqueous NaOH (40% w/w). The resulting solution was dried to give a white highly water-soluble powder.
Example 11
The procedure of Example 2 was followed, but the product was not isolated. Instead, it was neutralized to a pH of 7 with aqueous KOH (30% w/w). The resulting solution was dried to give a white highly water-soluble powder.
Example 12
The procedure of Example 2 was followed, but the product was not isolated. Instead, it was neutralized to a pH of 3 with anhydrous ammonia gas that was introduced into the solution by means of a gas dispersion tube. The resulting solution was dried to give a white highly water-soluble powder.
Example 13
This example followed the procedure of Example 12. However, the anhydrous ammonia gas was introduced into the solution prior to the addition of the initiator. Again, the solution was neutralized to a pH of 3. Thus, the neutralization step partially neutralized the monomers rather than the polymer. The initiator used for this example was ammonium persulfate and the reaction scheme is depicted below.
In this scheme, the first three steps are just an extensive elaboration of the neutralization of the water-monomer mixture with anhydrous ammonia to a pH of 3. Such a reaction is equally describable by depicting a reaction scheme using starting materials including itaconic acid, maleic anhydride, anhydrous ammonia, and water which results in the product shown at the far right end in step 3. The salts as drawn are theoretical, however, this does show that the monomers are not completely neutralized nor are they completely un-neutralized. Of course, it is well within the scope of the present invention to have the monomers completely neutralized or completely un-neutralized by the addition of any suitable base as well as having a wide range of B:C monomer ratios.
Example 14
This reaction was carried out in equipment similar to that used in Example 1 above. The following procedure was followed:
1990 g purified water was placed into the reactor and 1260 g itaconic acid and 950 g maleic anhydride was added with vigorous stirring. This mixture was then heated to about 75 C, at which temperature this mixture exists as a clear solution. When the mixture reached the desired temperature, 270 g potassium persulfate was added stepwise to the solution. Persulfate addition was conducted at 1 hour intervals in amount of 30 g per addition. Product was isolated in the same manner as described in Example 1.
Example 15
This reaction was carried out in the same fashion as Example 14, but ammonium persulfate was used. The total amount of persulfate was 225 g.
Example 16
In this example, the effect of polymer upon volatilization of ammonia from urea was determined. A 100 g sample of granular urea was coated with the H polymer by adding 1% polymer and 3.5 ml liquid (H 2 O) to the urea and shaking the mixture to achieve a uniform coating on the urea. Clay (kaolanite clay) was then added to absorb the excess H 2 O. Polymer coated urea and uncoated urea were placed in chambers that were optimized for the volatilization of ammonia. The polymer coated urea and uncoated urea were then analyzed for content over a sixteen day period.
FIG. 1 illustrates the amount of nitrogen and ammonia lost from the urea over the sixteen day testing period. This loss totaled 37.4%. In comparison, FIG. 2 illustrates the amount of ammonia and nitrogen lost from the urea coated with the polymer. The polymer coated urea experienced a 54% reduction of nitrogen and ammonia loss in comparison to the uncoated urea. Thus, the polymer coating greatly decreased nitrogen volatilization. Such a decrease in volatilization would also result from the polymer and urea being co-ground together or by having the polymer in close proximity to the urea in soil.
Example 17
In this example the effects of liquid ammoniated phosphates and polymer-treated liquid ammoniated phosphates on acid soils having a high phosphorous fixation capacity period were compared. Untreated liquid ammoniated phosphate (10-34-0) and liquid ammoniated phosphate with 1% by weight polymer and liquid ammoniated phosphate with 2% by weight ammoniated polymer were applied in a band (2 inches below and 2 inches beneath) in the seed row. The polymer used for this experiment was the sodium form. Corn was grown to the six leaf stage and then harvested. The plants were dried, and the dry weight recorded. Results of this experiment are given below in Table 1.
The acid soil was very responsive to the 10-34-0 controlled and corn grown in this soil experienced a 151% increase in dry weight. In comparison, the addition of 1% polymer increased corn growth by an additional 19% and addition of the 2% polymer increased corn growth by 26% in comparison to the 10-34-0 control. Thus, addition of the polymer had advantageous effects on the growth of corn.
TABLE 1
Acid Soil
Dry Matter/grams
No P Control
1.67
10-34-0 Control (No Polymer)
4.20
10-34-0 1% Polymer
5.00
10-34-0 2% Polymer
5.30
Example 18
In this example the efficiency of different salts of the anionic polymer as a coating on phosphate fertilizer was evaluated. Polymer coatings were applied on a 1% by weight basis onto MAP. The test crop for this experiment was corn and the polymer used was a polymer formed by B and C monomers. All phosphorous treatments were banded 2 inches below and 2 inches away from the seed rows. The acid in calcareous soils used in this experiment are both known to fix phosphorous fertilizer, thereby limiting the growth of crops. The corn was harvested at the six leaf stage and dry weights were determined as an indication as the efficiency of the coatings on phosphorous uptake and resultant corn growth. Results of this experiment are given below in Table 2. Table 2 shows that both the hydrogen and ammonium salts of the polymer were effective at increasing corn growth when combined with MAP. The acid control (untreated MAP) produced 294% more dry matter than the control which did not include MAP. These results illustrate that the soil is very responsive to phosphorous. When the MAP was coated with the anionic polymer charged neutralized with hydrogen, dry matter yields were increased by 41.9%. The calcareous control (untreated MAP) produced 128% more dry matter than the control which did not include any MAP. The MAP treated with the anionic polymer charge neutralized with ammonium, produced 15.9% more dry matter than the MAP control.
TABLE 2
Acid Soil
Calcareous Soil
(Dry Matter/grams)
(Dry Matter/grams)
No P Control (no MAP)
4.72
12.4
MAP Control
18.6
28.3
1% Hydrogen Polymer
26.4
1% Ammonium Polymer
32.81
Example 19
In this example, the effect of a zinc polymer on corn seedling growth was determined. A 21% zinc-polymer was prepared and applied to corn seeds at a rate of eight ounces per 100 pounds of seed. The seeds were planted in six inch pots and allowed to grow until they reached the four leaf stage. The soil was calcareous and had low zinc availability. At the four leaf stage, plants were harvested and dried, then the dry weights were determined. Dry weights increased by 29% on the plants where the zinc-polymer was applied to the seed versus the control.
Example 20
This example tested the dust controlling effects of the polymer on fertilizer particles. The test used was an abrasion resistance test based on the rotary drum method. This tests the resistance to dust and fines formation resulting from granule-granule and granule-equipment contact. It is useful in determining material losses; handling, storage, and application properties; and pollution control equipment requirements. A sample was first screened manually to separate out a fraction containing approximately minus 3.35 mm to 1.00 mm granules. A representative 100 cm 3 portion of the minus 3.35-plus 1.00-mm fraction was then used in the test. A 20 g portion of this was then weighed out and placed in a 100 ml rectangular polyethylene bottle together with 10 stainless steel balls measuring 7.9 mm in diameter and having a total weight of 20.0 g. The bottle was then closed and manually shaken for five minutes. In order to ensure uniform shaking for all samples in an analytical run, all sample bottles were taped together into one block. At the end of the run, the balls were removed manually, and the bottle contents examined. Fines were separated manually and weighed. Results from this example are given below in Table 3 which clearly shows that the polymers of the present invention are highly useful as a coating for MAP fertilizer particles in order to enhance abrasion resistance and decrease dust generation. The reference to the “H” polymer form refers to the fact that the carboxylic acid groups are still intact.
TABLE 3
Coating Level,
% Dust
Fertilizer
Percent W/W,
after
Type
Coating
As-Is
Shaking
Granular MAP
None
N/A
0.43
Granular MAP
ARR-MAZ KGA500
0.52
0.29
Granular MAP
High charge polymer,
0.5
none
mostly H form, 60% solids
Granular MAP
High charge polymer,
1
none
mostly H form, 60% solids
Granular MAP
High charge polymer,
1.5
none
mostly H form, 60% solids
|
Biodegradable anionic polymers are disclosed which include recurring polymeric subunits preferably made up of dicarboxylic monomers such as maleic anhydride, itaconic anhydride or citraconic anhydride. Free radical polymerization is used in the synthesis of the polymers. The polymers may be complexed with ions and/or mixed with fertilizers or seeds to yield agriculturally useful compositions. The preferred products of the invention may be applied foliarly or to the earth adjacent growing plants in order to enhance nutrient uptake by the plants.
| 2
|
This application is the International Stage of PCT Application No. PCT/JP2010/064274 filed Aug. 24, 2010, which claims priority of Japan Patent Application No. 2009-193206 filed Aug. 24, 2009, Japan Patent Application No. 2010-179569 filed Aug. 10, 2010, Japan Patent Application No. 2010-069891 filed Mar. 25, 2010, and Japan Patent Application No. 2009-254651, filed Nov. 6, 2009.
TECHNICAL FIELD
The present invention relates to a flame retardant, a production method therefor, and a flame-retardant thermoplastic resin composition comprising the same.
BACKGROUND ART
Recently, a variety of synthetic resin materials have been used for production of housings and parts for OA devices and home appliances, connectors, auto parts, construction materials, household articles, fiber products and others. However, synthetic resin materials, which are inflammable, often need to have flame retardancy for assurance of fire safety, especially when used as home appliances, electric/electronic parts, and OA-related parts, and blending of various flame retardants is under study for that purpose.
A method of using a halogen-based flame retardant such as brominated polystyrene and an antimony-based flame retardant such as antimony trioxide in combination is known as the method to make a resin flameproofed, but such a flame retardant may generate toxic gas on combustion, and thus regulations on resin compositions containing halogen-based flame retardants got severer than before. For that reason, developments for non-halogen flame retardants are intensively in progress.
Methods of making a resin composition flameproofed without using a halogen-based flame retardant include, for example, those by using a metal hydroxide and by using a phosphorus compound. In the case of the method of using a metal hydroxide, it is possible to obtain desired flame retardancy only by using it in a large amount, but use of it in a large amount unfavorably causes a problem of deterioration of the properties inherent to the resin.
Methods of using an organic (condensed) phosphate ester compound and also by using red phosphorus were known as the methods of making a resin flameproofed by using a phosphorus compound. Relatively low-molecular-weight organic (condensed) phosphate esters are unsatisfactory from the points of volatility, sublimability, and heat resistance and have a problem that the flame retardants bleed out when the resin composition containing the same is used at high temperature for an extended period of time. Red phosphorus causes a problem that toxic phosphine gas is generated during drying and molding of the resin composition.
In addition, in the case of high-heat-resistance nylon resins demanding a processing temperature of 300° C. or higher, there is currently no phosphorus-based flame retardant that can withstand the processing temperature, and metal salts of dialkylphosphinic acid, only flame retardants that are considered sufficiently heat-resistant, had a problem that they cause corrosion of the metal regions of the extruders and injection molding machines such as cylinders and screws. Further, high-heat-resistance nylon resin compositions should be superior in heat resistance on reflow process, for example when used in connector application, but there is still no non-halogen flame retardant that has sufficient heat resistance on reflow process.
Patent Document 1 discloses a method of producing a flame-retardant triallyl isocyanurate prepolymer, characterized in that, in preparation of the prepolymer by polymerization of triallyl isocyanurate, as a controlling agent of polymerization, 6H-dibenz[c,e]-[1,2]-oxaphosphorin (molecular weight: 216.17) is added together with a polymerization initiator to the triallyl isocyanurate in an amount of 1 to 200% by weight.
Alternatively, Patent Document 2 describes a composition comprising a phosphorus-containing compound having a particular structure and an amorphous resin, which is improved in bleed-out resistance, but deterioration of the bleed-out resistance and the physical properties thereof under high-humidity high-heat condition is yet to be improved.
CITATION LIST
Patent Literature
Patent Document 1: JP-A No. 02-182707
Patent Document 2: WO 07/040,075
SUMMARY OF INVENTION
Technical Problem
The object of the present invention is to provide a thermoplastic resin composition superior in flame retardancy and also in bleed-out resistance and giving thermoplastic resin compositions superior in moldability and moldings superior in moist-heat resistance and chemical resistance, and a flame retardant for thermoplastic resins having high flame retardancy and showing heat resistance at a processing temperature of 300° C. or higher, giving moldings superior in heat resistance on reflow process and chemical resistance.
Solution to Problem
The inventors have studied intensively on the method of obtaining a flame retardant for thermoplastic resins, and consequently for thermoformable resin compositions, having favorable properties as additive, which is prepared from the raw materials identical with those for the triallyl isocyanurate-based flame-retardant prepolymer described in Patent Document 1 and has improved flame retardancy and consistent or improved moldability and gives moldings with non-deteriorated chemical resistance. The inventors have also studied intensively on the method of obtaining a flame retardant for thermoplastic resins, and consequently for thermoformable resin compositions, having favorable properties as additive, which is prepared from the raw materials identical with those for the triallyl isocyanurate-based flame-retardant prepolymer described in Patent Document 1 and designed to have a structure to show favorable flame retardancy as it is and to give favorable flame retardancy to a thermoplastic polymer when added thereto and gives a molding in the composition with non-deteriorated heat resistance on reflow process and chemical resistance.
As a result, the inventors have found that it is possible to obtain a more favorable flame retardant for thermoplastic resins superior in flame retardancy and also in chemical resistance, by making the flame retardant contain a particular phosphorus/nitrogen-containing flame-retardant compound obtained by the production method of the present invention and increasing the phosphorus atom content therein.
They have also found that it is possible to obtain a more favorable flame retardant for thermoplastic resins superior in flame retardancy and also in heat resistance on reflow process, and chemical resistance, by making the flame retardant contain a particular phosphorus/nitrogen-containing flame-retardant compound obtained by the production method of the present invention and have a crosslinked structure and increasing the phosphorus atom content therein.
Thus, the present invention relates to a flame retardant for thermoplastic resins, comprising a reaction product of a nitrogen-containing compound represented by structural formulae (1) and a phosphorus-containing compound represented by structural formula (2), wherein the flame retardant is insoluble in toluene and has a phosphorus atom content of 5 to 10 wt %.
(wherein, two or more of R 1 , R 2 , and R 3 are unsaturated bond-containing groups and the other is a hydrogen atom or an organic group other than unsaturated bond-containing groups).
(wherein, R 4 , R 5 , and R 6 each are independently a hydrogen atom or an alkyl, cycloalkyl, aryl or aralkyl group).
The flame retardant of the present invention having such a phosphorus content is superior in flame retardancy. On the other hand, the triallyl isocyanurate flame-retardant prepolymer described in Patent Document 1 contains a compound represented by structural formula (2) as a controlling agent of polymerization, but the phosphorus content is not designed to be as high as that in the present invention. In addition, since the polymerization method used is different from the polymerization method of the present invention described below, the phosphorus content is smaller than that of the present invention. Thus, the flame retardant prepolymer seems to show insufficient flame retardancy when added to a thermoplastic resin.
In addition, the flame retardant of the present invention is insoluble in toluene. Further, it is preferable that it is insoluble in tetrahydrofuran (THF) as well. The reason is that the flame retardant of the present invention should have preferable properties as an additive, to make the blended resin have consistent or improved moldability when added to a resin composition and giving moldings undeteriorated in chemical resistance, as described above. On the other hand, the triallyl isocyanurate flame-retardant prepolymer described in Patent Document 1 should have favorable solubility in solvent for that purpose and thus should be soluble in common solvents such as toluene, xylene, benzene, tetrahydrofuran, ethanol, isopropanol, and isobutanol.
In a favorable embodiment, the flame retardant above has a weight-average molecular weight (Mw) of 2,000 to 10,000. When the weight-average molecular weight is in the range above, the flame retardant is resistant to bleed out and also to transpiring during molding under heat.
In a more favorable embodiment, it is a flame retardant having a ratio (Mw/Mn) of the weight-average molecular weight (Mw) and the number-average molecular weight (Mn) at 1 to 1.5. When the ratio is in the range above, the advantageous effects of the present invention effect on flame retardancy, moldability, chemical resistance and others described above are amplified and it becomes a flame retardant with uniform properties. It gets thus possible to blend it to a base resin uniformly during melt blending, thus effectively preventing unfavorable molding caused by addition of a high-molecular weight compound and also preventing transpiring of low-molecular weight compounds during molding.
The present invention relates to a flame retardant for thermoplastic resins, comprising a polymer having the first to third repeating units respectively represented by structural formulae (3) to (5), characterized in that the flame retardant is insoluble in toluene and has a phosphorus atom content of 5 to 10 wt % and a weight-average molecular weight (Mw) of 2,000 to 10,000.
The present invention relates to the flame retardant, wherein a content of the crosslinked component in the flame retardant is 1 wt % or more.
Such a crosslinked component content leads to further improvement of heat resistance and improvement in heat resistance of the composition on reflow process.
The present invention also relates to a flame retardant for thermoplastic resins, comprising a polymer having the first to third repeating units respectively represented by structural formulae (3) to (5), wherein the a flame retardant is insoluble in toluene, a content of a crosslinked component insoluble in chloroform is 1 wt % or more, and a phosphorus atom content in the flame retardant is 5 to 10 wt %.
The present invention also relates to a flame-retardant thermoplastic resin composition, comprising 0.1 to 75 wt parts of the flame retardant of the present invention and 100 wt parts of a thermoplastic resin.
In a favorable embodiment, it is the flame-retardant thermoplastic resin composition, wherein the thermoplastic resin is one or more resins selected from the group consisting of polyethylene terephthalate resins, polybutylene terephthalate resins, aliphatic polyamide resins, semi-aromatic polyamide resins, polycarbonate resins, and modified polyphenyleneoxide-based resins.
The present invention also relates to a method of producing the flame retardant of the present invention, comprising a step of reacting the phosphorus-containing compound with the nitrogen-containing compound, and polymerizing the nitrogen-containing compound and the nitrogen-containing compound bonded with the phosphorus-containing compounds, by heating a mixture containing a nitrogen-containing compound and a phosphorus-containing compound at a molar ratio of 1:1.0 to 2.5 to 180-240° C. at a heating rate of 1-100° C./hour under nitrogen atmosphere.
The present invention is a method of producing a flame retardant, comprising a step of heating the mixture containing the particular raw materials at the particular molar ratio at the particular heating rate to the particular temperature, as described above, and it is thus possible to raise the content of the phosphorus/nitrogen-containing compound in the flame retardant of the present invention. Therefore, it is a production method for a flame retardant, having further advantageous effects of the present invention.
The present invention also relates to a method of producing the flame retardant of the present invention, comprising a step of adding the phosphorus-containing compound to the nitrogen-containing compound and the polymerized nitrogen-containing compound while polymerizing the nitrogen-containing compound, and a crosslinking step of reacting unreacted unsaturated bond-containing groups with each other directly or by using a crosslinking agent, by heating a mixture containing a nitrogen-containing compound and a phosphorus-containing compound at a molar ratio of 1:1.0 to 2.5 to 180-240° C. at a heating rate of 1° C.-100° C./hour under nitrogen atmosphere.
Thus, the production method for a flame retardant of the present invention, which includes particularly a crosslinking step, gives a flame retardant further improved in heat resistance, especially in heat resistance at a processing temperature of 300° C. or higher and the resin compositions obtained by using the flame retardant are superior in heat resistance on reflow process.
In a favorable embodiment, it is a production method for the flame retardant, wherein the crosslinking step includes a way using an extruder or batch kneader.
Advantageous Effects of Invention
The flame retardant for thermoplastic resins of the present invention has high flame retardancy and is resistant to bleed out. Thus, thermoplastic resin compositions containing the flame retardant are superior in moldability and the moldings show smaller deterioration in physical properties and also in chemical resistance after moist-heat resistance test.
In addition, the flame retardant for thermoplastic resins of the present invention has high flame retardancy and is tolerant to a processing temperature of 300° C. or higher. Thus, the thermoplastic resin composition containing the flame retardant is superior in heat resistance on reflow process and gives moldings superior in chemical resistance.
BRIEF DESCRIPTION OF DRAWING
FIG. 1 is a graph showing the temperature profile in accordance with the JEDEC Standards used in the heat-resistance test on reflow process of Example.
DESCRIPTION OF EMBODIMENTS
(Flame Retardant)
The flame retardant of the present invention is a flame retardant for thermoplastic resins, comprising a reaction product of a nitrogen-containing compound represented by one of structural formulae (1) and a phosphorus-containing compound represented by structural formula (2).
Such a flame retardant of the present invention should have a phosphorus atom content of 5 to 10 wt %, more preferably 6 to 9.5 wt %, more preferably 7 to 9 wt %, from the viewpoint of its flame retardancy.
For example, when triallyl isocyanurate used as the nitrogen-containing compound represented by one of the structural formulae (1) is reacted with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) used as the phosphorus-containing compound represented by the structural formula (2) at a nitrogen-containing compound: phosphorus-containing compound molar ratio of 1:1, the phosphorus atom content of the product is theoretically is 6.7%, and it is 9.1% in the case when the ratio is 1:2, and 9.8% in the case when the ratio is 1:2.5.
The flame retardant of the present invention is insoluble in toluene. Thus, the chemical resistance is further improved. It is preferable that it is insoluble also in tetrahydrofuran (THF). Thus, the chemical resistance is further improved. In the present invention, the phrase “insoluble in toluene” means that 80% or more of the sample remains undissolved based on the initial amount of the sample, when the solubility is examined by the test method (<Chemical resistance>) described below.
In addition, the flame retardant of the present invention preferably has a weight-average molecular weight (Mw) of 2,000 to 10,000, and more preferably 3,000 to 7,000, depending on the polymer structure, for sufficient expression of the advantageous effects of the present invention described above.
Further for expression of further advantageous effects of the present invention described above, when the weight-average molecular weight is in the particular range above, the flame retardant of the present invention, preferably has a ratio (Mw/Mn) of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn) at 1 to 1.5, and more preferably 1 to 1.3.
The flame retardant of the present invention preferably has a content of the crosslinked component, i.e., solvent (chloroform)-insoluble component, in the flame retardant at 1 wt % or more, more preferably 10 wt % or more, and still more preferably 15 wt % or more. It is possible in this way to improve the heat resistance further and the heat resistance on reflow process of the resin composition further, compared to the case when the crosslinked component content is not in the particular range above. In addition, the flame retardant at such a crosslinked component content has larger molecular weight (possibly converted to macromolecule) than flame retardants without it, and is improved apparently in hydrolysis resistance because of crosslinking. For that reason, it is considered to be resistant to bleed out.
The term “crosslinked component,” as used in the present invention, means a component having a crosslinked structure present in the reaction product, which is insoluble in chloroform. The content of the crosslinked component is to be determined in accordance with the measuring method described below.
The flame retardant of the present invention may contain polymers in various structure prepared by the production method described below. The polymer can be prepared, for example, by radical polymerization of ally groups in triallyl isocyanurate or the derivative thereof. Its typical example will be described below.
When triallyl isocyanurate 17-1 and triallyl cyanurate 17-2 are used as the nitrogen-containing compound and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) as the phosphorus-containing compound, monomer equivalents represented by structural formulae (8) would be formed in addition to the triallyl isocyanurate and the triallyl cyanurate.
Depending on the method of adding DOPO to triallyl isocyanurate and triallyl cyanurate, isomers represented by structural formulae (9) may also be formed.
A first example of the flame retardant of the present invention is, for example, a flame retardant containing a polymer having at least one repeating unit selected from the group consisting of the first to third repeating units represented by the structural formulae (3) to (5), prepared by polymerization of the monomers and the equivalents thereof and one or more of the monomer isomers. The polymer structure is, for example, that represented by the following chemical formula (10), wherein the units are bound to each other randomly to form a polymer (copolymer, random copolymer).
Although all bonds are shown in the head-to-tail configuration in the chemical formula (10) above, head-to-head bonds, as shown in structural formulae (11), may be formed, as in common polymerization reactions of allyl compounds.
In the structural formulae (11), Y 1 and Y 2 are any residues corresponding to those in chemical formula (10).
The flame retardant having the polymer structure above has a phosphorus atom content of 5 to 10 wt % and a weight-average molecular weight (Mw) of 2,000 to 10,000. Thus, for example in the case of the polymer structure represented by chemical formula (10), p, q, and r in chemical formula (10) are as follows, if the chain-transfer reaction described below is not taken into consideration. Specifically when the molecular weights of respective units are designated as M p , M q and M r , it is calculated approximately in accordance with the following Formula:
2000 ≦p×M p +q×M q +r×M r ≦1000
( q+ 2 r )×(atomic weight of phosphorus)/( p×M p +q×M q +r×M r )≧0.05
For example, in the case of the polymer represented by chemical formula (10), it is calculated approximately in accordance with the following Formulae:
p+ 1.87 q+ 2.73 r≧ 8.02
p+ 1.87 q+ 2.73 r≦ 40.11
( q+ 2 r )/( p+q+r )≧0.62
If the polymer consists only of the units above, p can be approximately 8 to 41; q can be 4 to 22; and r can be 2 to 15, from the viewpoint of the molecular weight of the polymer (flame retardant). However, the polymer containing the units arbitrarily may not contain one of the units, and if such a case is considered, p can be 0 to 41; q can be 0 to 22; and r can be 0 to 15. When the phosphorus atom content is taken into consideration, q and r are not 0 simultaneously.
Also from the viewpoint phosphorus atom content, when the molar ratio of the first repeating unit is designated as P(P=p/(p+q+r)), the molar ratio of the second repeating unit as Q (Q=q/(p+q+r)), and the molar ratio of the third repeating unit as R(R=r/(p+q+r)), p, q, and r are selected so that Q+2R is 0.62 or more, more preferably 0.82 or more, still more preferably 1.12 or more, yet still more preferably 1.46 or more, most preferably 1.96 or more.
When a nitrogen-containing compound represented by one of structural formulae (1) and the phosphorus-containing compound represented by structural formula (2) are reacted to each other, as will be described below, unsaturated bond-containing groups such as allyl group may be radically polymerized, and the polymer may have a terminal similar to that obtained in common radical polymerization. In the case of radical polymerization, it is generally considered that the start terminal is the residue of a polymerization initiator (e.g., azobisisobutylonitrile (AIBN)), a chain-transfer agent (e.g., DOPO), or a chain-transferred product (e.g., chain-transferred solvent molecule), while the end terminal is the residue formed by disproportionation (abstraction of hydrogen from the radical terminal, forming double bond once again), recombination (bonding to other radical group, leading to termination of polymerization), or hydrogen abstraction (abstraction of hydrogen for example from other polymer, chain-transfer agent (such as DOPO) or solvent molecule).
As for the chain-transfer agents above, sulfur-based compounds are commonly used as the chain-transfer agents, because thio radical is relatively stable and yet has sufficient activity for reaction with a monomer, initiating polymerization reaction. In the present invention, it is considered that the P—H bond in the phosphorus-containing compound represented by structural formula (2) forms a radical easily by abstraction of the hydrogen and has chain-transferring potential.
When the chain-transfer reaction is considered, p, q, and r in chemical formula (10) can be expressed as follows. Specifically, when the molecular weights of respective units are designated as M p , M q , and M r and the molecular weight of the DOPO residue as M z , it can be calculated approximately in accordance with the following formulae. The following Formula is a relationship when the start terminal is a DOPO residue and the end terminal is H (abstracted from DOPO).
2000 ≦p×M p +q×M q +r×M r +M z ≦10000
( q+ 2 r+ 1)×(atomic weight of phosphorus)/( p×M p +q×M q +r×M r +M z ≧0.05
For example in the case of the polymer represented by chemical formula (10), when both terminals are considered, it is defined approximately by the following Formula:
p+ 1.87 q+ 2.73 r≧ 7.16
p+ 1.87 q+ 2.73 r≦ 39.25
( q+ 2 r )/( p+q+r )≧0.42
From the viewpoint of the molecular weight of the polymer (flame retardant), when the polymer consists only of the units above, p can be approximately 7 to 40; q can be 4 to 22; and r can be 3 to 15. However, the polymer may not contain any one of the units above and, if such a case is taken into consideration, p can be 0 to 40; q can be 0 to 22; and r can be 0 to 15. When the phosphorus atom content is taken into consideration, q and 1′ are not 0 simultaneously.
From the viewpoint of phosphorus atom content, p, q, and r are determined so that Q+2R become preferably 0.42 or more, more preferably 0.61 or more, still more preferably 0.86 or more, yet still more preferably 1.18 or more, and most preferably 1.62 or more, similarly to above.
The chemical formula (10) used in the relationship above is an example when triallyl isocyanurate 17-1 and DOPO are used, but it also applies to the cases when triallyl cyanurate 17-2 and DOPO are used and when both triallyl isocyanurate 17-1 and triallyl cyanurate 17-2 are used.
In the present invention, at least one of the relationships of p, q, and r in the case when the chain-transfer reaction is not considered and in the case when it is considered will be satisfied.
A more typical example of the flame retardants of the present invention is the polymer represented by structural formula (12). It is a polymer having one of the third repeating units represented by the structural formulae (5) (p=q=0 and r=n in chemical formula (10)).
Another example is a polymer having the isomers represented by the following structural formulae (13), in addition to the polymer of the structural formula (12).
The phosphorus/nitrogen-containing compounds represented by the structural formulae (12) and (13) are linear polymers of a nitrogen-containing compound represented by one of structural formulae (1) that is bound to two molecules of the phosphorus-containing compound represented by structural formula (2).
The flame retardant of the present invention is considered to have, for example, a structure in which 3 to 14 pieces of a phosphorus/nitrogen-containing unit of a nitrogen-containing compound bound to two phosphorus-containing compounds are polymerized as the phosphorus/nitrogen-containing compound into straight chain. In such a case, the phosphorus/nitrogen-containing compound is likely to show very high flame-retardancy, as it has a high phosphorus atom content of 8.7 wt % and a high nitrogen atom content of 5.9 wt %, show excellent moldability, as it is dispersed in the resin matrix in the isolated island shape when added to a thermoplastic resin, and give a molding superior in bleed-out resistance and chemical resistance.
A second example is a flame retardant containing a polymer having the first to third repeating units represented respectively by the structural formulae (3) to (5) and containing a crosslinked component having the crosslinked structures represented by the structural formulae (6) and (7) at a particular rate. The polymer in the present example contains a crosslinked structure in which multiple polymers represented by the chemical formula (10) are bound to each other via the double bonds of the allyl groups.
In this example, the flame retardant containing the polymer has a phosphorus atom content of 5 to 10 wt %. When the molar ratio of the total amount of the first repeating unit represented by structural formula (3) and the components having a crosslinked structure represented by structural formulae (6) is designated as P′, the molar ratio of the total amount of the second repeating units represented by the structural formulae (4) and the components having crosslinked structure represented by structural formulae (7) is designated as Q′, and the molar ratio of the third repeating units represented by structural formulae (5) is designated as R′, Q′+2R′ is 0.62 or more, more preferably 0.82 or more, still more preferably 1.12 or more, yet still more preferably 1.46 or more, and most preferably 1.96 or more. Here, P′+Q′+R′=1.
Examples of other polymers having a crosslinked structure include polymers having the first to third repeating units represented by structural formulae (3) to (5) and additionally the crosslinked components having a crosslinked structure represented by structural formulae (14). The polymers in the present example are those in which, for example, multiple polymers represented by the chemical formula (10) are bound to each other via triallyl isocyanurate, as crosslinking agent, or other crosslinking agent.
(in structural formula (14), X represents a triallyl isocyanurate residue or a crosslinking agent residue).
The crosslinking agent for use may be a common bifunctional monomer used in normal radical polymerization. Examples thereof include non-methacrylic polyfunctional vinyl monomers such as divinylbenzene, polyfunctional methacrylate monomers such as ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, and allyl methacrylate and the like. Alternatively, one or more of these crosslinking agents may be used in combination.
The flame retardant in the present example is prepared by the production method of the present invention comprising a crosslinking step described below. For example, it is possible to obtain a phosphorus/nitrogen-containing compound having a crosslinked structure by reacting triallyl isocyanurate and DOPO with each other by using them at a molar ratio (T/H) of 1/2 or more, or by using reaction between unreacted allyl groups or by using a crosslinking agent even when it is less than 1/2. In this case, the flame retardant having a crosslinked structure is more thermally stabilized than non-crosslinked flame retardant. It has heat resistance as it is and it is thermally stable also as it is blended with a thermoplastic resin; it gives a blended resin, for example with nylon 46, nylon 9T, or nylon 6T, that shows consistent heat resistance on reflow process when used in application for lead-free SMT-compatible connectors. In addition, flame retardants containing such a crosslinked component are considered to be larger in molecular weight (possibly converted to macromolecule) than flame retardants without it, to have apparent hydrolysis resistance improved by crosslinking and to be resistant to bleed out.
The term reflow, as used herein, means a production method (step) of soldering an electronic part by connecting it onto a cream solder coated on a substrate and heating the entire substrate to a temperature higher than the solder melting point in a high-temperature oven. The heat resistance on reflow process is a property, in the case of a resin molding, of withstanding the temperature of the reflow process without fusion, deformation or blistering.
The flame retardant of the present invention does not need to have the structure of the structural formula (12) entirely as the backbone structure of flame retardant, if the advantageous effects of the present invention is obtained sufficiently, and, may contain partially, for example, the structure represented by structural formula (15) or (16), in which three molecules of a phosphorus-containing compound are connected to a nitrogen-containing compound.
(Nitrogen-Containing Compound)
As described above, the nitrogen-containing compound is represented by the structural formulae (1). The unsaturated bond-containing groups in the structural formulae (1) include methacryloyloxyethyl, vinylphenyl, vinylbenzyl, vinyl, allyl and the like. Nitrogen-containing compounds containing these unsaturated bond-containing group include tris(methacryloyloxyethyl) isocyanurate, tris(vinylphenyl) isocyanurate, tris(vinylbenzyl) isocyanurate, trivinyl isocyanurate, triallyl isocyanurate, triallyl cyanurate and the like. It is preferably one or more compounds selected from triallyl isocyanurate 17-1 and triallyl cyanurate 17-2 represented by structural formulae (17), and more preferably triallyl isocyanurate from the viewpoints of easiness of increasing phosphorus content in the reaction product and also availability.
(Phosphorus-Containing Compound)
The phosphorus-containing compound is represented by the structural formula (2), as described above. Typical examples of the compounds include 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), 8-methyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2,6,8-tri-t-butyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6,8-dicyclohexyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and the like. It is preferably DOPO from the viewpoints of high phosphorus content and availability.
(Thermoplastic Resin Composition)
The flame-retardant thermoplastic resin composition of the present invention should contain the flame retardant of the present invention in an amount of 0.1 to 75 wt parts and a thermoplastic resin in an amount of 100 wt parts. For obtaining sufficient flame retardancy, for favorable processability, and for preservation of the mechanical strength of the moldings, the flame retardant of the present invention is contained more preferably in an amount of 1 wt part or more, still more preferably 3 wt parts or more, particularly preferably 5 wt parts, and more preferably 70 wt parts or less, still more preferably 65 wt parts or less with respect to 100 wt parts of the thermoplastic resin.
Examples of the thermoplastic resins include polyester resins such as polyethylene terephthalate resins and polybutylene terephthalate resins; aliphatic polyamide resins such as nylon 6, nylon 66, and nylon 46; semi-aromatic polyamide resins such as modified nylon 6T and nylon 9T; polycarbonate resins, modified polyphenylene oxide resins, polyphenylene sulfide resins, polyacetal resins, polyolefin resins, polystyrene resins, ABS resins, polyacrylic resins and the like.
In particular, since favorable bleed-out resistance during use at high temperature and under humid heat, favorable heat resistance at a processing temperature of 300° C. or higher, prevention of deterioration in heat resistance on reflow process and mechanical strength, which are the advantageous effects of the flame retardant of the present invention, are demanded and these advantageous effects are obtained sufficiently, it is preferably one or more resins selected from polyethylene terephthalate resins, polybutylene terephthalate resins, aliphatic polyamide resins, semi-aromatic polyamide resins, polycarbonate resins, and modified polyphenyleneoxide-based resins. It is more preferably one or more resins selected from the group consisting of polyethylene terephthalate resins, polybutylene terephthalate, polycarbonate resins, modified nylon GT, and nylon 9T.
An inorganic filler may be added to the resin composition according to the present invention, as needed, for improvement in strength, rigidity, heat resistance and others. The inorganic filler is not particularly limited, if it is a fibrous and/or particulate inorganic filler, and two or more of them may be used in combination.
Typical examples of the inorganic fillers for use in the present invention include glass fibers, carbon fibers, metal fibers, aramide fibers, asbestos, potassium titanate whisker, wollastonite, glass flakes, glass beads, talc, mica, clay, calcium carbonate, barium sulfate, titanium oxide, aluminum oxide and the like.
A known glass fiber normally commonly used may be used as the glass fiber for use in the present invention, but use of chopped strand glass fiber treated with a sizing agent is preferable from the viewpoint of processability.
The glass fiber for use in the present invention is preferably a glass fiber treated with a coupling agent on the surface for improvement in adhesiveness between the resin and the glass fiber. It may be a glass fiber containing a binder. Favorable examples of the coupling agents include alkoxysilane compounds such as γ-aminopropyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane, and favorable examples of the binders for use include epoxy resins, urethane resins and the like, but are not limited thereto.
The content of the inorganic filler in the present invention is preferably at least 5 wt parts, more preferably at least 10 wt parts, still more preferably at least 15 wt parts with respect to 100 wt parts of the thermoplastic polyester. When the inorganic filler content is less than the lower limit value of 5 wt parts, improvement in heat resistance and rigidity may be insufficient. The maximum value of the inorganic filler content is preferably 120 wt parts, more preferably 100 wt parts, and still more preferably 80 wt parts. An inorganic filler content of more than the maximum value of 120 wt parts may lead to deterioration in flowability, deterioration in moldability of thin moldings, and also deterioration of the surface smoothness of the moldings obtained.
The resin composition of the present invention may contain, as needed, additives such as drip inhibitors, pigments, heat stabilizers, antioxidants, and lubricants.
The present invention also relates to the following fire-retardant resin composition: a fire-retardant resin composition, comprising 0.1 to 75 wt parts of a flame retardant containing the reaction product of a nitrogen-containing compound represented by structural formulae (1) and a phosphorus-containing compound represented by the structural formula (2) and having a phosphorus atom content of 5 to 10 wt %, and 100 wt parts of a resin. The flame retardant may be soluble or insoluble in toluene. The kinds and the contents of the components in the fire-retardant resin composition are the same as those explained above for the flame-retardant thermoplastic resin composition.
(Production Method for Flame Retardant)
A first favorable production method for the flame retardant of the present invention comprises a step of adding the phosphorus-containing compound to the nitrogen-containing compound and the polymerized nitrogen-containing compound while polymerizing the nitrogen-containing compound, by heating a mixture containing a nitrogen-containing compound and a phosphorus-containing compound at a molar ratio of 1:1.0 to 2.5 to 180-240° C. at a heating rate of 1° C.-100° C./hour under nitrogen atmosphere.
A radical initiator (polymerization initiator) may be added, as needed, in the step for acceleration of the addition or polymerization reaction and improvement of productivity. Addition of the radical initiator may also be effective for preparation of a flame retardant having a weight-average molecular weight in a particular range. However, for example for preparation of the flame retardant in the polymer structure represented by chemical formula (10) above, the addition amount thereof is preferably low for suppression of the crosslinking reaction as much as possible.
A second favorable production method for the flame retardant of the present invention comprises a step (1) of adding the phosphorus-containing compound to the nitrogen-containing compound and the polymerized nitrogen-containing compound while polymerizing the nitrogen-containing compound, and a crosslinking step (2) of reacting the unsaturated bond-containing groups such as unreacted allyl groups in the reaction precursor obtained in step (1) with each other directly or by using a crosslinking agent, by heating a mixture containing a nitrogen-containing compound and a phosphorus-containing compound at a molar ratio of 1:1.0 to 2.5 to 180-240° C. at a heating rate of 1° C.-100° C./hour under nitrogen atmosphere. The steps (1) and (2) may be carried out continuously.
For example, in a typical example of the step (2), the reaction among the unsaturated bond-containing groups such as allyl groups is promoted, as the polymerization period in step (1) is elongated; the unsaturated bond-containing groups are crosslinked by addition of a crosslinking agent; or the precursors obtained in step (1) are allowed to react by using a horizontal reactor such as extruder or a batch resin kneader such as kneader, Banbury mixer, two-roll or plastmill and additionally by addition of a radical initiator (polymerization initiator) or a crosslinking agent.
When a radical initiator is added in the second production method, the addition amount thereof is preferably 0.01 to 5 parts, more preferably, 0.05 to 1 part, with respect to 100 parts of the total amount of the nitrogen- and the phosphorus-containing compounds or of the reaction precursor. An organic peroxide or an other known initiator is preferably selected as the radical initiator, as the polymerization reaction time is taken into consideration. Examples thereof include dialkyl peroxides such as 1,3-di(t-butylperoxyisopropyl)benzene, 2,3-dimethyl-2,3-diphenylbutane.
The second production method is particularly favorable for production of a flame retardant containing a crosslinked component at a particular rate.
In any one of the production methods above, the molar ratio in the present invention is preferably 1:1.5 to 1:2, for reduction of the unreacted phosphorus-containing compounds which may cause gas generation and bleed-out during molding, i.e., during extrusion, and for improvement of the purity of the phosphorus/nitrogen-containing compound in the flame retardant.
Because the reactions for obtaining the phosphorus/nitrogen-containing compound in the present invention include addition of the phosphorus-containing compound to the unsaturated bonds in the nitrogen-containing compound and addition polymerization of the unsaturated bonds in the nitrogen-containing compound, two or more of R 1 , R 2 , and R 3 in the structural formulae (1) should be unsaturated bond-containing groups and the other should be a hydrogen atom or an organic group other than unsaturated bond-containing groups, as described above.
Progress of the reaction can be monitored by collecting samples of the reaction product during reaction periodically and analyzing it by using 1 H-NMR apparatus. The addition reaction in the reaction above occurs by addition of phosphorus in the phosphorus-containing compound to the C═C carbon unsaturated bonds of the nitrogen-containing compound, as described above, and thus, disappearance of the signals (8.80 and 7.08 ppm) of the P—H protons of the phosphorus-containing compound is observed on 1 H-NMR. Since the addition polymerization reaction in the reaction above is polymerization reaction of nitrogen compounds with each other, i.e., addition polymerization of allyl groups similar to the polymerization reaction of normal unsaturated bonds, decrease of the integrated value of the proton signals of unsaturated bonds (5.23 ppm to 5.33 ppm and 5.83 ppm to 5.93 ppm) and appearance of proton signals of the C—C single bonds newly formed are observed.
Although examples wherein the unsaturated bond-containing group is an allyl group were described, the progress of the reaction can be monitored similarly depending on the kind of the unsaturated bond.
EXAMPLES
Hereinafter, the composition of the present invention will be described more specifically with reference to typical examples, but it should be understood that the present invention is not limited thereby.
Hereinafter, the resins and raw materials used in Examples and Comparative Examples will be shown.
[Phosphorus-Containing Compound (A1)]
9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (product name: HCA, manufactured by SANKO CO., LTD) was used as a phosphorus-containing compound (A1) of the present invention.
[Phosphorus-Containing Compound (A2)]
The phosphorus-containing compound (A2) prepared by the preparative example 1 described below was used as a flame retardant of Comparative Example.
[Phosphorus-Containing Compound (A3)]
A condensed phosphate ester (product name: PX-200, manufactured by Daihachi Chemical Industry Co., Ltd.) was used as phosphorus-containing compound (A3) for a flame retardant of Comparative Example.
[Phosphorus-Containing Compound (A4)]
The phosphorus-containing compound (A4) prepared by the preparative example 7 described below was used as a flame retardant of Comparative Example.
[Phosphorus/Nitrogen-Containing Compounds (B1) to (B5)]
Phosphorus/nitrogen-containing compounds (B1) to (B5) respectively prepared by Preparative Examples 2 to 6 described below were used as the inventive flame retardants.
[Phosphorus/Nitrogen-Containing Compound (B6) to (B9)]
The phosphorus/nitrogen-containing compounds (B6) to (B9) respectively prepared by Preparative Examples 7 to 10 described below were used as inventive flame retardants.
[Nitrogen-Containing Compound (C1)]
Triallyl isocyanurate (product name: TAICROS, manufactured by Evonik Degussa) was used as an inventive nitrogen-containing compound (C1).
[Nitrogen-Containing Compound (C2)]
Triallyl cyanurate (product name: TAC, manufactured by Evonik Degussa) was uses as an inventive nitrogen-containing compound (C2).
[Resin (D1)]
A polyethylene terephthalate resin (product name: EFG-70, manufactured by Bell Polyester Products, Inc.) was used as an inventive thermoplastic resin (D1).
[Resin (D2)]
A polycarbonate resin (product name: Tarflon A2500, manufactured by Idemitsu Kosan Co., Ltd.) was used as an inventive thermoplastic resin (D2).
[Resin (D3)]
A nylon 9T resin (product name: Genestar N-1000A, manufactured by Kuraray Co., Ltd.), a semi-aromatic polyamide resin, was used as an inventive thermoplastic resin (D3).
[Resin (D4)]
A modified nylon 6T resin (product name: Amodel A-1006C, manufactured by Solvay Advanced Polymers, K.K), a semi-aromatic polyamide resin, was used as an inventive thermoplastic resin (D4).
[Inorganic Compound (E1)]
A glass fiber (product name: T-187H, manufactured by Nippon Electric Glass Co., Ltd.) was used as an inventive inorganic compound (E1).
[Inorganic Compound (E2)]
A glass fiber (product name: FT75GD, manufactured by Owens Corning) was used as an inventive inorganic compound (E2).
[Radical Initiator (F1)]
2,3-Dimethyl-2,3-diphenylbutane (product name: Nofiner BC, manufactured by NOF Corporation) was used as an inventive radical initiator (F1).
[Radical Initiator (F2)]
1,3-Di(t-butylperoxyisopropyl)benzene (product name: Perbutyl P, produce by NOF Corp.) was used as an inventive radical initiator (F2).
Evaluation methods used in Preparative Examples are as follows:
<Weight-Average Molecular Weight (Mw) and Mw/Mn>
Mw and Mw/Mn of the phosphorus/nitrogen-containing compound obtained were determined by GPC by using chloroform as the solvent, and the GPC measurement was performed by using polystyrene standards and a GPC apparatus (column: K-804 and K-802.5, manufactured by Showa Denko K.K.) at 35° C.
<Glass Transition Temperature (Tg)>
Tg of the phosphorus/nitrogen-containing compound obtained was determined by DSC, and the DSC analysis was performed by using DSC-220C manufactured by Seiko Instruments Inc. at a heating rate of 10° C./min under nitrogen stream.
<Phosphorus Content>
The phosphorus content of the phosphorus/nitrogen-containing compound obtained was determined by high-frequency plasma emission spectrophotometric analysis (ICP-AES). The ICP-AES was performed by decomposing the sample by microwave in ETHOS manufactured by Milestone in accordance with US EPA METHOD 3052 as pretreatment and analyzing the products by using ICPS-8100 manufactured by Shimadzu Corporation.
<Crosslinked Component Rate>
The phosphorus/nitrogen-containing compound obtained was crushed and the soluble component of the crushed product was extracted with chloroform in a Soxhlet extraction apparatus for 6 hours. The extraction residue was dried at 100° C. for 6 hours, the weight was measured, and the crosslinked component rate was calculated from the following calculation Formula:
[Crosslinked component rate (%)=[Weight of extraction residue]×100/[Weight of the phosphorus/nitrogen-containing compound initially supplied]
<Chemical Resistance>
5 mg of the phosphorus/nitrogen-containing compound obtained was dispersed in toluene (50 ml) or toluene and tetrahydrofuran (THF) (50 ml), left as it was at room temperature for 3 days, and the insoluble component was filtered and dried. The chemical resistance was evaluated by comparison of the weight thus determined with the initial weight.
A: Insoluble component content was 80% or more of the amount initially added.
B: Insoluble component content was less than 80% of the amount initially added.
Evaluation methods used in Examples are as follows.
<Flame Retardancy>
The pellets obtained in the following Examples were dried at 120° C. for 3 hours and injection-molded in an injection molding machine (JS36SS, clamp pressure: 35 tonnes) under the condition of a cylinder temperature setting of 250-280° C. and a mold temperature of 60° C., to give a test piece of 127 mm×12.7 mm× 1/16 inch (thickness). The combustibility thereof was evaluated in accordance with the V test specified in UL94 Standards by using the obtained bar-shaped test piece having a thickness of 1/16 inch.
<Tensile Strength>
The pellets obtained were dried at 120° C. for 3 hours and then injection-molded in an injection molding machine (clamp pressure: 75 tonnes) under the condition of a cylinder temperature setting of 250-280° C. and a mold temperature of 120° C. A dumbbell-shaped test piece was prepared in accordance with ASTM D-638. The tensile strength of the test piece obtained was determined in accordance with ASTM D-638 at 23° C.
<Evaluation of Bleed-Out Resistance>
The dumbbell used in the tensile test was heated in an oven at 140° C. for 1 hour and absorbent cotton was pressed on the molding after heating, to examine whether there is deposition of the absorbent cotton on the molding.
A: There was no bleed-out of the phosphorus-containing compound and not deposition of the absorbent cotton.
B: There was bleed-out of the phosphorus-containing compound and deposition of the absorbent cotton on the molding.
<Evaluation of Bleed-Out Resistance after Moist-Heat Resistance Test>
The dumbbell used in the tensile test was subjected to a moist-heat resistance test in a pressure cooker (PC-422R5E, manufactured by Hirayama Manufacturing Corporation) under the condition of 120° C. and 100% RH for 20 hours, and then absorbent cotton was pressed to the molding and deposition thereof on the mold was examined.
A: There was no bleed-out and no deposition of absorbent cotton on the molding.
B; There was bleed-out and deposition of absorbent cotton on the molding.
<Evaluation of Physical Properties after Moist-Heat Resistance Test>
After the moist-heat resistance was evaluated under the same condition as the bleed-out evaluation, a tensile test was performed by the method identical with that for the tensile strength above and the difference in tensile strength between before and after the test was calculated.
<Heat Resistance on Reflow Process>
The pellets obtained in the following Example were dried at 120° C. for 3 hours and injection-molded in an injection molding machine (JS36SS, clamp pressure: 35 tonnes) under the condition of a cylinder temperature setting of 280-310° C. and a mold temperature of 140° C., to give a test piece of 127 mm×6.3 mm× 1/32 inch (thickness). The test piece was dried at 125° C. for 24 hour, moisturized at level 2 (85° C.×60% RH×168 hours), as specified in IPC/JEDEC J-STD-020D.1, and placed on an alumina substrate having a thickness of 0.8 mm. A temperature sensor was additionally placed on the substrate and the profile was determined. A reflow test at the temperature profile shown in FIG. 1 was performed in accordance with JEDEC Standards by using an air/IR reflow apparatus (NRY-535 MB-7Z, manufactured by YAMATO WORKS Corporation), and the heat resistance on reflow process was evaluated in accordance with the following criteria:
A: There was no fusion, deformation or blistering in the test pieces used in the moisture-absorption test and absolutely dry test.
B: There was fusion, deformation or blistering only in the test piece used in the moisture-absorption test.
C: There was fusion, deformation or blistering both in the test pieces used in moisture-absorption test and absolutely dry test.
Preparative Example 1
A phosphorus-containing compound (A1), 60 wt parts (equimolar to (A1)) of itaconic acid, and 160 wt parts (two molars or more to itaconic acid) of ethylene glycol were placed in a vertical polymerization reactor equipped with a distillation column, a rectification column, a nitrogen-supplying tube, and a stirrer, and the mixture was heated gradually to 120-200° C. under nitrogen gas atmosphere and stirred approximately for 10 hours.
Antimony trioxide and zinc acetate each in an amount of 0.1 wt part were added thereto, and the mixture was kept at a temperature of 220° C. under a vacuum reduced pressure of less than 1 torr, allowing polycondensation reaction and distillation of ethylene glycol simultaneously. The reaction was considered complete approximately after 5 hours, when distillation of ethylene glycol subsided significantly. The properties of the phosphorus-containing compound (A2) obtained are shown in Table 1.
TABLE 1
Preparative Example
1
2
3
4
5
6
A2
B1
B2
B3
B4
B5
Blending
Phosphorus-containing compound (A1)
1
1
1.5
2
2
2
molar ratio
Nitrogen-containing compound (C1)
0
1
1
1
0
1
Nitrogen-containing compound (C2)
0
0
0
0
1
0
Properties
Mw × 10 −3
9.6
5.6
5.5
3.6
4.0
3.8
Mw/Mn
1.6
1.4
1.4
1.2
1.3
1.4
Tg (° C.)
81
128
135
126
100
131
Chemical resistance Toluene
A
A
A
A
A
A
Phosphorus content (wt %)
7.2
5.1
7.1
8.5
8.8
8.5
Preparative Examples 2 to 5
A phosphorus-containing compound and a nitrogen-containing compound were placed in a vertical polymerization reactor equipped with a rectification column, a nitrogen-supplying tube and a stirrer at the blending molar ratio shown in Table 1, and the mixture was heated gradually to 50-200° C. under nitrogen gas stream and stirred approximately for 12 hours. The samples of the phosphorus/nitrogen-containing compounds obtained were colorless glassy solids at room temperature and all samples were insoluble in toluene. The properties of the phosphorus/nitrogen-containing compounds are shown in Table 1.
Preparative Example 6
A phosphorus-containing compound and a nitrogen-containing compound were placed in a vertical polymerization reactor equipped with a rectification column, a nitrogen-supplying tube, and a stirrer at the blending molar ratio shown in Table 1; a radical initiator (F1) in an amount of 0.1 wt part with respect to 100 wt parts of the phosphorus- and nitrogen-containing compounds was added thereto; and the mixture was heated gradually to 50-200° C. under nitrogen gas stream and stirred approximately for 4 hours. The sample of the phosphorus/nitrogen-containing compound obtained was colorless glassy solid at room temperature and insoluble in toluene. The properties of the phosphorus/nitrogen-containing compound (B6) are shown in Table 1.
Preparative Example 7
A phosphorus-containing compound (A1), 60 wt parts (equimolar to (A1)) of itaconic acid, and 160 wt parts (two molars or more to itaconic acid) of ethylene glycol were placed in a vertical polymerization reactor equipped with a distillation column, a rectification column, a nitrogen-supplying tube, and a stirrer, and the mixture was heated gradually to 120-200° C. under nitrogen gas atmosphere and stirred approximately for 10 hours.
Antimony trioxide and zinc acetate each in an amount of 0.1 wt part were then added thereto, and the mixture was kept at a temperature of 220° C. under a vacuum reduced pressure of less than 1 torr allowing polycondensation reaction and distillation of ethylene glycol simultaneously. The reaction was considered complete approximately after 5 hours, when distillation of ethylene glycol subsided significantly. The properties of the phosphorus-containing compound (A4) obtained are shown in Table 2.
TABLE 2
Preparative Example
7
8
9
A4
B6
B7
Blending
Phosphorus-containing compound (A1)
1
2
1.9
molar ratio
Nitrogen-containing compound (C1)
0
1
1
Radical initiator (F1) ( * 1)
0
0
0.1
Properties
Content of crosslinked component (%)
0
0
27
Mw × 10 −3
9.6
3.6
—
Mw/Mn
1.6
1.2
—
Tg (° C.)
81
126
130
Chemical resistance
Toluene
A
A
A
THF
A
A
A
Phosphorus content (wt %)
7.2
8.5
8.3
( * 1) Addition amount with respect to 100 wt parts of A1 + C1
Preparative Examples 8 and 9
A phosphorus-containing compound and a nitrogen-containing compound are placed in a vertical polymerization reactor equipped with, a rectification column, a nitrogen-supplying tube, and a stirrer at the blending molar ratio shown in Table 2, and the mixtures were heated gradually to 50-200° C. under nitrogen gas stream and stirred approximately for 12 hours. The samples of the phosphorus/nitrogen-containing compounds obtained were colorless glassy solids at room temperature. All samples were insoluble in toluene and THF. The properties of the phosphorus/nitrogen-containing compounds are shown in Table 2.
Preparative Examples 10 and 11
The phosphorus/nitrogen-containing compound obtained in Preparative Example 8 and other additives were dry-blended at the blending composition shown in Table 3 (unit: wt parts), to give mixtures. Each of the mixtures was supplied to a 15 mmφ co-rotation twin-screw vent extruder (KZW15TWIN-45MG, manufactured by Technovel Corporation) through its hopper hole and extruded in a molten state at a cylinder temperature setting of 190-220° C. The obtained samples of the phosphorus/nitrogen-containing compounds were colorless glassy solids at room temperature and all samples were insoluble in toluene and THF. The properties of phosphorus/nitrogen-containing compounds are shown in Table 3.
TABLE 3
Preparative Example
10
11
B8
B9
Blending
Phosphorus/nitrogen-containing
100
100
composition
compound (B6)
(part)
Radical initiator (F2)
0.2
0.5
Properties
Content of crosslinked component (%)
69.2
64.9
Mw × 10 −3
—
—
Mw/Mn
—
—
Tg (° C.)
138
137
Chemical resistance
Toluene
A
A
THF
A
A
Phosphorus content (wt %)
8.5
8.5
Examples 1 to 10
The raw materials shown in Table 4 were dry-blended at the blending composition (unit: wt part) shown therein, to give mixtures. Each of the mixtures was supplied to a 44 mmφ co-rotation twin-screw vent extruder (TEX44, manufactured by Japan Steel Works, Ltd.) through its hopper hole and extruded in a molten state at a cylinder temperature setting of 250-280° C. into pellets. The pellets obtained were injection-molded under the condition described above, to give a test piece, which was evaluated by the evaluation methods described above.
The evaluation results in Examples 1 and 10 are shown in Table 4.
TABLE 4
Example
1
2
3
4
5
6
7
8
9
10
Blending
Thermoplastic resin (D1)
100
100
100
100
100
100
100
composition
Thermoplastic resin (D2)
100
(part)
Thermoplastic resin (D3)
100
Thermoplastic resin (D4)
100
Phosphorus-containing compound (A2)
Phosphorus-containing compound (A3)
Phosphorus/nitrogen-containing compound (B1)
20
Phosphorus/nitrogen-containing compound (B2)
20
Phosphorus/nitrogen-containing compound (B3)
20
5
40
10
60
40
Phosphorus/nitrogen-containing compound (B4)
20
Phosphorus/nitrogen-containing compound (B5)
20
Inorganic filler (E1)
51
60
Properties
Flame retardancy 1.6 mm thickness
V-2
V-0
V-0
V-0
V-0
V-2
V-0
V-0
V-0
V-0
Tensile strength (MPa)
68
61
56
50
65
70
47
60
150
170
Tensile strength retention rate
72
75
70
65
72
78
69
50
53
65
after moist-heat resistance test (%)
Evaluation of bleed-out resistance
A
A
A
A
A
A
A
A
A
A
Bleed-out after moist-heat resistance test
A
A
A
A
A
A
A
A
A
A
Comparative Examples 1 and 4
Pelletization and injection molding were carried out similarly to Examples 1 and 10 by using the raw materials at the blending composition (unit: wt part) shown in Table 5, to give test pieces, which were then evaluated by evaluation methods similar to those above. The evaluation results obtained in Comparative Examples 1 to 4 are shown in Table 5.
TABLE 5
Comparative Example
1
2
3
4
Blending
Thermoplastic resin (D1)
100
100
composition
Thermoplastic resin (D2)
100
100
(part)
Thermoplastic resin (D3)
Thermoplastic resin (D4)
Phosphorus-containing compound (A2)
20
10
Phosphorus-containing compound (A3)
20
10
Phosphorus/nitrogen-containing compound (B1)
Phosphorus/nitrogen-containing compound (B2)
Phosphorus/nitrogen-containing compound (B3)
Phosphorus/nitrogen-containing compound (B4)
Phosphorus/nitrogen-containing compound (B5)
Inorganic filler (E1)
Properties
Flame retardancy 1.6 mm thickness
V-0
V-2
V-2
V-0
Tensile strength (MPa)
43
61
66
50
Tensile strength retention rate
43
35
35
39
after moist-heat resistance test (%)
Evaluation of bleed-out resistance
A
A
B
B
Bleed-out after moist-heat resistance test
B
B
B
B
The results in Preparative Examples 1 to 6, Examples 1 to 10, and Comparative Examples 1 to 4 show that the inventive flame retardants are superior in flame retardancy and bleed-out resistance and also superior in moist-heat resistance and chemical resistance.
Examples 11 to 18
The raw materials shown in Table 6 were dry-blended at the blending composition (unit: wt parts) shown therein, to give mixtures. Each of the mixtures was supplied into a 44 mmφ co-rotation twin-screw vent extruder (TEX44, manufactured by Japan Steel Works, Ltd.) through its hopper hole and extruded in a molten state at a cylinder temperature setting of 290-320° C. into pellets. The pellets obtained were injection-molded under the condition above, to give a test piece, which was evaluated by the evaluation methods described above.
The evaluation results obtained in Examples 11 to 18 are shown in Table 6.
TABLE 6
Example
11
12
13
14
15
16
17
18
Blending
Thermoplastic resin (D3)
100
100
100
100
composition
Thermoplastic resin (D4)
100
100
100
100
(part)
Phosphorus/nitrogen-containing compound (B6)
40
56
Phosphorus/nitrogen-containing compound (B7)
40
56
Phosphorus/nitrogen-containing compound (B8)
40
56
Phosphorus/nitrogen-containing compound (B9)
40
56
Inorganic filler (E2)
60
60
60
67
67
67
60
67
Properties
Flame retardancy 1.6 mm thickness
V-0
V-0
V-0
V-0
V-0
V-0
V-0
V-0
Tensile strength (MPa)
179
180
182
155
156
160
170
150
Heat resistance on reflow process
A
A
A
A
A
A
B
B
Comparative Examples 5 to 8
Pelletization and injection molding were carried out similarly to Examples 11 and 18 by using the raw materials at the blending composition (unit: wt part) shown in Table 7, to give test pieces, which were then evaluated by evaluation methods similar to those above.
The evaluation results obtained in Comparative Examples 5 to 8 are shown in Table 7. The “poor feed defect” shown below Table 7 means that the mixture had low viscosity and was extruded less effectively in the molding machine.
TABLE 7
Comparative Example
5
6
7
8
Blending
Thermoplastic resin (D3)
100
100
composition
Thermoplastic resin (D4)
100
100
(part)
Phosphorus-containing compound (A3)
40
56
Phosphorus-containing compound (A4)
40
56
Inorganic filler (E2)
60
60
60
67
Properties
Flame retardancy 1.6 mm thickness
*
*
*
*
Tensile strength (MPa)
*
*
*
*
Heat resistance on reflow process
*
*
*
*
* The mixture was not extruded because of poor feed defect, permitting no evaluation.
The results obtained in Preparative Examples 7 to 11, Examples 11 to 18, and Comparative Examples 5 to 8 show that the inventive flame retardants were superior in flame retardancy, heat resistance, heat resistance on reflow process, and chemical resistance.
|
The aim is to provide a flame retardant for thermoplastic resins that has a high flame-retardant imparting effect, and that produces a thermoplastic resin composition with superior moldability and workability that does not easily bleed out and a molded body with superior resistance to heat-moisture and chemicals; and a flame retardant for thermoplastic resins that has a high flame-retardant imparting effect, and that produces a flame retardant with a heat resistance to working temperatures of 300° C. or higher and a molded body with superior resistance to reflow heat and chemicals. Disclosed is a flame retardant, which is a specific flame retardant for thermoplastic resins comprising the reaction product of a nitrogen-containing compound and a phosphorous-containing compound, that is insoluble in toluene and comprises in the range of 5 to 10 wt % of phosphorus atoms. The aforementioned flame retardant may have a weight average molecular weight (Mw) in the range of 2,000 to 10,000, or may have a ratio of at least 1 wt % of crosslinking components within the flame retardant components.
| 2
|
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of the following co-pending applications:
Application Ser. No. 08/677,811, Express Mail mailing number EM145280042US, filed Jul. 10, 1996, attorney docket number MOED-001; now U.S. Pat. No. 5,921,954.
Application Ser. No. 08/651,378, Express Mail mailing number EM214961542US, filed May 22, 1996, attorney docket number SOMN 1009-4; now U.S. Pat. No. 5,738,114.
Application Ser. No. 08/651,800, Express Mail mailing number EM214961556US, filed May 22, 1996, attorney docket number SOMN 1009-5; now U.S. Pat. No. 5,836,906.
Application Ser. No. 08/643,203, Express Mail mailing number TB84970533US, filed May 6, 1996, attorney docket number SOMN 1011-1; now U.S. Pat. No. 5,718,702.
Application Ser. No. 08,643,524, Express Mail mailing number TB849705582US, filed May 6, 1996, attorney docket number SOMN 1012-2; now U.S. Pat. No. 5,743,870.
Application Ser. No. 08/651,796, Express Mail mailing number EM214961525US, filed May 22, 1996, attorney docket number SOMN 2001; now ABN.
Application Ser. No. 08/651,798, Express Mail mailing number EM214961539US, filed May 22, 1996, attorney docket number SOMN 2002; now ABN.
Application Ser. No. 08/660,539, Express Mail mailing number EH522034424US, filed Jun. 7, 1996, attorney docket number SOMN 2003; and now U.S. Pat. No. 5,743,904.
Application Ser. No. 08/663,004, Express Mail mailing number EH522034441US, filed Jun. 7, 1996, attorney docket number SOMN 2004; now abandoned.
Each of these applications is hereby incorporated by reference as if fully set forth herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to ablation of rectal and other internal body structures.
2. Description of Related Art
Human beings are subject to a number of disorders in the area of the rectum and colon, including hemorrhoids (external and internal), prolapse of the rectal muscles, rectal muscle spasms, anal fissures, polyps, diverticulosus and diverticulitus, and pilonital cysts. Other internal disorders in nearby regions of the body include (in men) prostate cancer, (in women) incontinence, vaginal bleeding, vaginal cysts, vaginal fibroids, prolapse of the uterus, and related tumors or cancerous tissue.
Although there are treatments available for these disorders, such as surgery, systemic or topical medication, these treatments suffer from various drawbacks, including (for surgery) their relative invasiveness and expense, and (for medicinal approaches) their relative ineffectiveness and the causation of serious side-effects. Accordingly, it would be advantageous to provide methods and apparatus for treatment which are not subject to the drawbacks of surgery and medicinal approaches.
Although it is known to use RF energy to ablate tissue in the body (such as heart muscle tissue) to treat disorders, one problem which has arisen in the art is accounting for the flow of bodily fluids and gases while ablating tissue. Bodily fluids can dissipate, and can detrimentally absorb, energy to be applied to tissue.
Accordingly, it would be advantageous to provide improved techniques for treatment of disorders in the area of the rectum and colon, or (for women) in the area of the vagina. This advantage is achieved by a method and system according to the present invention in which a catheter is inserted into the rectum or vagina, and at least one electrode is disposed thereon for emitting energy to ablate body structures or other tissue in an ablation region in or near the rectum, such as the sphincter, rectum, colon, or prostate, or in or near the vagina.
SUMMARY OF THE INVENTION
The invention provides a method and system for ablation of body structures or tissue in an ablation region in or near the rectum (such as the sphincter, rectum, colon, or prostate), or in or near the vagina. A catheter is inserted into the rectum or vagina, and at least one electrode is disposed thereon for emitting energy to ablate body structures or other tissue, such as by cell death, dehydration, or denaturation. The environment for the ablation region is isolated or otherwise controlled, such as by blocking gas or fluid using a pair of inflatable balloons at upstream and downstream locations from the ablation region. In a preferred embodiment, inflatable balloons also serve to anchor the catheter in place and prevent the catheter from being expelled from the body.
In preferred embodiments, the catheter is flexible for reaching a selected internal organ or region, a plurality of electrodes are disposed on the catheter and at least one such electrode is selected and advanced out of the catheter to penetrate and ablate selected tissue inside the body in ablation region in or near the rectum, such as an individual cyst, hemorrhoid, polyp, tumor, or other selected lesion or tissue, or in or near the vagina, such as a fibroid tumor or other selected lesion or tissue. The electrodes are coupled to sensors to determine control parameters of the body structure or tissue, such as impedance or temperature, and which are used by feedback technique to control delivery of energy for ablation or fluids for cooling or hydration. In a preferred embodiment, the catheter includes an optical path disposed for coupling to an external view piece, so as to allow medical personnel to view or control positioning of the catheter and operation of the electrodes.
In further preferred embodiments, the catheter is disposed to deliver flowable substances for aiding in ablation, such as saline or antibiotics, or for aiding in repair of tissue (either before or after ablation), such as collagen or another substance for covering lesions or for filling fissures in or near the ablation region, or for other medicinal effects, such as anesthetic, anti-inflammatory, or antispasmodic substances, or other medication. The flowable substances are delivered using at least one lumen in the catheter, either from at least one hole in the catheter, from an area of the catheter covered by a microporous membrane, or from microporous balloons (either the same as or in addition to balloons used to anchor the catheter in place or to block gas or fluid).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a side view of a catheter and electrode assembly.
FIG. 2 shows a cut-away view of a catheter, taken along a line 2--2 in FIG. 1.
FIG. 3 shows a method of treatment of a hemorrhoid.
FIG. 4 shows a method of treatment of a prolapsed or spasmodic muscle.
FIG. 5 shows a method of treatment of an anal fissure.
FIG. 6 shows a method of treatment of a tumor in the prostate.
DESCRIPTION OF THE PREFERRED EMBODIMENT
CATHETER AND ELECTRODE ASSEMBLY
FIG. 1 shows a side view of a catheter and electrode assembly.
An assembly 100 for ablating rectal and other internal body structures includes a catheter 110, a control and delivery linkage 120, and a control element 130.
The catheter 110 is coupled to the control and delivery linkage 120 using a gearing element 121, which allows the catheter 110 to be rotated with respect to the control and delivery linkage 120 by an operator using the control element 130.
The catheter 110 includes a base 111, having a substantially cylindrical shape, coupled at a proximal end to the gearing element 121, and having a distal end. The catheter 110 is preferably disposed for insertion into the rectum at an angle to the control and delivery linkage 120, preferably an angle between about 30° and about 45° less than a right angle. The catheter 110 is between about 1 inch (2.54 cm) and about 2 inches (5.08 cm) in diameter, and between about 6 inches (15.24 cm) and about 8 inches (20.32 cm) in length.
In alternative embodiments in which the catheter 110 is disposed for insertion into another body structure, such as the vagina, the size of the cathether 110 and the angle to the control and delivery linkage 120 may be different. For example, in a preferred embodiment disposed for insertion into the vagina, the angle to the control and delivery linkage 120 may be less than about 10° different from a straight angle (i.e., more than about 80° less than a right angle).
The catheter 110 includes a plurality of holes 112, and a plurality of electrodes 113 which may be extended from at least some of the holes 112. The holes 112 are spaced regularly around the circumference and along the length of the catheter 110, having a spacing of about 0.25 inches (0.64 cm) between adjacent holes 112. The electrodes 113 are spaced regularly to occupy about one-half of the holes 112, and are between about 0.5 cm and about 1.0 cm in length.
The electrodes 113 each include a metallic tube 114 defining a hollow lumen 115, shaped similarly to an injection needle, so as to be disposed to deliver at least one flowable substance to a region 140 near the catheter 110. In a preferred embodiment, the deliverable flowable substance includes saline with a concentration of less than about 10% NaCl, which aids in both hydration of body structures and other tissue, and in delivery of RF energy to the region 140. However, in alternative embodiments, the deliverable flowable substance includes other substances, including saline with other concentrations, systemic or topical antibiotics, collagen or another hardenable substance, or other bioactive, chemoactive, or radioactive substances (including anesthetic, anti-inflammatory, or antispasmodic substances, or tracer materials).
The catheter 110 includes at least one balloon 116, disposed for inflation so as to block gas or fluid from the body from entering the region 140. In a preferred embodiment, there is a distal balloon 116 disposed at the distal end of the catheter 110 and there is a proximal balloon 116 disposed at the proximal end of the catheter 110. The distal balloon 116 and the proximal balloon 116 preferably each comprise ring-shaped balloons, disposed so that when inflated each surrounds the catheter 110 and makes a gas-tight or fluid-tight seal, both with the catheter 110 and with a wall 141 of the rectum or other body structure into which the catheter 110 is inserted. However, in alternative embodiments, the distal balloon 116 may comprise a spherical or ellipsoidal balloon disposed at the distal end of the catheter 110 in such manner that when inflated it surrounds the catheter 110 and makes a gas-tight or fluid-tight seal with the wall 141.
The catheter 110 also includes at least one balloon 116 disposed to anchor the catheter 110 at a selected location within the rectum or other body structure into which the catheter 110 is inserted. In a preferred embodiment, the balloon 116 used to anchor the catheter 110 is the proximal balloon 116, which when inflated prevents the catheter 110 from being expelled from the body in like manner as the operation of a Foley catheter. However, in alternative embodiments, the balloon 116 used to anchor the catheter 110 may comprise an additional or alternative balloon which is disposed solely or primarily for the purpose of anchoring the catheter 110 into its selected place, again in like manner as the operation of a Foley catheter.
The catheter 110 includes a fluid circulation system 117, including at least one fluid outlet port and at least one fluid inlet port. The fluid circulation system 117 is disposed for providing fluid in the region near the catheter 110, such as for delivering fluid for cooling the region 140 and for removing other fluid for aspirating the region 140.
The catheter 110 includes an optical view port 118, possibly including a lens or other transparent or translucent covering, disposed to allow inflow of light (visible or infrared) for transmission to an operator for viewing and control of the operation of the catheter 110.
The catheter 110 includes at least one sensor 119, such as a sensor 119 for impedance or temperature. In a preferred embodiment, the temperature sensor 119 includes a thermocouple, but in alternative embodiments, the temperature sensor 119 may include a thermistor or other device for sensing temperature and providing signals responsive to temperature near the catheter 110.
The control and delivery linkage 120 includes a metallic tube 223 defining a hollow lumen 224, and is further described with reference to FIG. 2.
In a preferred embodiment, the control and delivery linkage 120 is between about 1/2 inch (1.27 cm) and about 5/8 inches (1.59 cm) in diameter, and between about 6 inches (15.24 cm) and about 8 inches (20.32 cm) in length.
The control element 130 includes an electrode actuation element 131 for advancing the electrodes 113 out from the catheter 110, a electrode retraction element 132 for retracting the electrodes 113 into from the catheter 110, and an operation element 133 for controlling operation of the catheter 110, including delivery of flowable substances using the holes 112 and delivery of energy using the electrodes 113.
ADVANCING AND RETRACTING ELECTRODES
FIG. 2 shows a cut-away view of a catheter, taken along a line 2--2 in FIG. 1.
The catheter 110 comprises a rotatable element 210 which is disposed for rotation in a first direction 211 to advance the electrodes 113 out of the catheter 110 and in a second direction 212 opposite the first direction 211 to retract the electrodes 113 back into the catheter 110.
In a preferred embodiment, the rotatable element 210 is coupled to a spring (not shown) or other device which holds the rotatable element 210 in a steady state with the electrodes 113 retracted into the catheter 110.
The rotatable element 210 is coupled to the electrode actuation element 131, which forces the rotatable element 210 to rotate in the first direction 211 so as to advance the electrodes 113 out of the catheter 110. When the actuator element is not actuated, the spring causes the rotatable element 210 to rotate in the second direction 212 so as to retract the electrodes 113 back into the catheter 110.
Each electrode 113 is coupled to an electrode carrier 220. In a preferred embodiment, each electrode carrier 220 is substantially bar-shaped (but is shown end-on in the figure) and is coupled to a plurality of electrodes 113, such as about between about three and about six electrodes 113, so as to substantially simultaneously advance that plurality of electrodes 113 out of the catheter 110 and retract that plurality of electrodes 113 back into the catheter. A plurality of electrode carriers 220 are each disposed in a set of lines corresponding to lines of electrodes 113 disposed for advancement out of the catheter 110 and retraction back into the catheter 110.
In a preferred embodiment, the electrodes 113 may be disposed so that when advanced, the electrodes 113 extend to selected depths within the body structure to be ablated. These selected depths may be the same depth for all electrodes 113 which are advanced, or may include a first depth for a first set of electrodes 113 and a second depth for a second set of electrodes 113.
In a preferred embodiment, the electrode carriers 220 are coupled to a set of controls (not shown) in the control element 130 for selecting one or more electrode carriers 220 independently using one or more actuation levers 221, so as to be able to independently advance one or more sets of electrodes 113 coupled thereto out of the catheter 110 and to independently retract one or more sets of electrodes 113 back into the catheter 110.
Each electrode carrier 220 is coupled to the rotatable element 210 using a bearing 222, in such manner so as to translate rotation of the rotatable element 210 into linear radial movement of the electrodes 113. When the rotatable element 210 is rotated in the first direction 211, the electrodes are advanced in a first linear movement 223, while when the rotatable element 210 is rotated in the second direction 212, the electrodes are retracted in a second linear movement 224.
An interior 230 of the rotatable element 210 includes a lumen 225 through which fluids and other flowable substances are provided, and in which conductors providing control signals and sensor signals are disposed.
OPERATION OF THE CATHETER AND ELECTRODE ASSEMBLY
Operation of the catheter and electrode assembly 100 includes at least the following steps:
The catheter 110 is inserted into the body at an opening, such as the rectum.
In a preferred embodiment, the opening is the rectum. A region of the rectum is first infused with a lubricant, such as K-Y jelly, and with an anesthetic, such as lidocaine. An anti-inflammatory, antispasmodic, or other condign medication would also be applied as appropriate. Thereafter, the catheter 110 is inserted into the lubricated region of the rectum. Due to the potential pain induced by the presence of the catheter 110 or electrodes 113, during operation the catheter 110 infuses a mixture of saline and lidocaine into the region 140 to be ablated.
In alternative embodiments, the opening may be another opening into the body, such as a natural orifice such as the vagina or the urethra, or an opening which has been made surgically, such as an incision which allows the catheter 110 to be inserted into a blood vessel.
The preferred size of the catheter 110 will of course be responsive to the size of the opening if other than the rectum. The choice of medicinal elements to be infused prior to or coeval with the catheter 110 will of course be responsive to judgments by medical personnel, and may include lubricants, anesthetics, antispasmodics, anti-inflammatories, antibiotics, or other materials with bioactive, chemoactive, or radioactive effect.
The catheter 110 is positioned within the body at a selected orientation and location, such as a position near a hemorrhoid.
In one preferred embodiment, the catheter 110 is positioned in the rectum near an external or internal hemorrhoid, in a manner as shown in FIG. 3. In this preferred embodiment, the electrodes 113 are ultimately advanced into the hemorrhoid to ablate the hemorrhoid.
In another preferred embodiment, the catheter 110 1s positioned in the rectum near a prolapsed or spasmodic muscle, in a manner as shown in FIG. 4. In this preferred embodiment, the electrodes 113 are ultimately advanced into the prolapsed or spasmodic muscle to ablate selected portions of the prolapsed or spasmodic muscle.
In another preferred embodiment, the catheter 110 is positioned in the rectum near an anal fissure, in a manner as shown in FIG. 5. In this preferred embodiment, collagen is deposited into the fissure and the electrodes 113 are ultimately advanced into a region near the collagen to harden the collagen for filling the fissure.
In another preferred embodiment, the catheter 110 is positioned in the colon near a polyp, in a manner similar to that shown in FIG. 3. In this preferred embodiment, the electrodes 113 are ultimately advanced into the polyp to ablate the polyp.
In another preferred embodiment, the catheter 110 is positioned in the rectum near a pilonital cyst, in a manner similar to that shown in FIG. 3. In this preferred embodiment, the electrodes 113 are ultimately advanced into the cyst to ablate the cyst.
In another preferred embodiment, the catheter 110 is positioned in the rectum, colon, large intestine, or small intestine, near a cyst or tumor, in a manner similar to that shown in FIG. 3. In this preferred embodiment, the electrodes 113 are ultimately advanced into the cyst or tumor to ablate the cyst or tumor.
In another preferred embodiment, the catheter 110 is positioned in a male patient, in the rectum near the prostate, in a manner as shown in FIG. 6. In this preferred embodiment, the electrodes 113 are ultimately advanced into a tumor in the prostate to ablate the tumor.
In another preferred embodiment, the catheter 110 is positioned in a female patient, in the vagina, near a cyst or fibroid, in a manner similar to that shown in FIG. 3. In this preferred embodiment, the electrodes 113 are ultimately advanced into the cyst or fibroid to ablate the cyst or fibroid.
In another preferred embodiment, the catheter 110 is positioned in a female patient, in the vagina, near a prolapsed uterus, in a manner similar to that shown in FIG. 4. In this preferred embodiment, the electrodes 113 are ultimately advanced into the prolapsed uterus selected portions of the prolapsed uterus.
The catheter 110 is anchored into place at the selected orientation and location by inflating a balloon 116, such as the distal balloon 116 and the proximal balloon 116.
In embodiments where the catheter 110 is positioned in the rectum, the catheter 110 is anchored into place using the proximal balloon 116 and the proximal balloon 116 operates in similar manner as a Foley catheter.
In alternative embodiments, the catheter 110 includes a stop balloon 116, such as a ring balloon (as shown in FIG. 3), disposed outside the body so as to prevent the catheter 110 from being inserted "too far", i.e., beyond its selected location.
The region 140 near the catheter 110 is isolated from the rest of the body by inflating the distal balloon 116 and the proximal balloon 116. In a preferred embodiment, this step uses the same distal balloon 116 and the proximal balloon 116 as the step of anchoring the catheter 110 into place.
Isolation of the region 140 near the catheter 110 from the rest of the body need not be absolute. In a preferred embodiment, the distal balloon 116 and the proximal balloon 116 are microporous, are inflated using saline or water, and thus are disposed to provide saline or water into the region 140 near the catheter 110. However, in such an embodiment, gas and fluids from the rest of the body are allowed to leak into one or more of the balloons 116 and from there are allowed to leak into the region 140 near the catheter 110.
Moreover, while in a preferred embodiment the seal made with the wall 141 of the region 140 by the balloon 116 is gastight, in alternative embodiments, that seal is allowed to be simply fluid-tight, and might allow gas to leak from the rest of the body into the region 140 near the catheter 110.
One or more sets of electrodes 113 are selected for advancement into a selected mass of tissue in the region 140. The rotatable element 210 is rotated in the first direction 211, causing the selected sets of electrodes 113 to advance out of the catheter 110 and into the selected mass of tissue.
The selected set of electrodes 113 are just those electrodes 113 which are needed to penetrate the selected mass of tissue for ablation.
In a preferred embodiment where the selected mass of tissue for ablation is a hemorrhoid, the selected set of electrodes 113 are just those electrodes 113 which are needed to penetrate the hemorrhoid. If a plurality of hemorrhoids are selected for ablation, either (1) electrodes 113 needed to penetrate the plurality of hemorrhoids are selected, or (2) electrodes 113 needed to penetrate one of the hemorrhoids are selected, and the operation is repeated for each individual one of the hemorrhoids.
Similarly, in preferred embodiments where the selected body structure for ablation is an individual cyst, fibroid, polyp, or tumor, the selected set of electrodes 113 are just those electrodes 113 which are needed to penetrate the selected body structure. If there is more than one such selected body structure, either (1) more than one set of electrodes 113 may be selected, or (2) just one set of electrodes 113 may be selected and the operation is repeated for each individual such body structure.
Similarly, in preferred embodiments where the selected body structure for ablation is muscle tissue or other tissue which is part of a larger body structure, such as a prolapsed or spasmodic muscle, the selected set of electrodes 113 are just those one or more sets of electrodes 113 which are needed to penetrate the portion of the body structure which has been selected for ablation.
Flowable substances are provided using the holes 112, and energy is provided to the electrodes 113, so as to ablate the mass of tissue in the region 140.
In a preferred embodiment, the flowable substances are provided using the holes 112 to the region 140 near the catheter 110.
In alternative embodiments, the flowable substances may be provided, in addition or instead, (1) from an area of the catheter covered by a microporous membrane, or (2) from one or more microporous balloons. The microporous balloons may either be the same as or in addition to the balloons 116 used to anchor the catheter in place or to block gas or fluid.
In preferred embodiments, the flowable substances have one of the following functions: (1) to aid in ablation, such as by transmitting RF energy from the electrodes 113 to the body structure to be ablated, as is done by saline or other electrolytic solutions, (2) to rehydrate tissue, as in done by saline or water, or (3) to repair tissue, such as by flowing into cysts or fissures or voids, or by covering lesions, as is done by collagen in a soft form which can be hardened by RF energy.
In a preferred embodiment, the electrodes 113 deliver RF energy having a frequency between about 435 kilohertz and about 485 kilohertz, for a period between about 5 minutes and about 10 minutes. The RF energy is received by and heats tissue and other body structures near the electrodes 113, causing ablation by means of cell death, dehydration, or denaturation.
In alternative embodiments, the electrodes 113 may deliver other forms of energy, such as heat, microwaves, or infrared or visible laser energy.
The electrodes 113 are controlled by a feedback technique, using the at least one sensor 119. In embodiments where there is more than one sensor 119, the feedback technique may be responsive to each sensor 119.
In one preferred embodiment, the at least one sensor 119 includes a temperature sensor 119 and the feedback technique includes a microprocessor (not shown) disposed in or coupled to the control element 130 and operating under control of application software for maintaining the temperature of the body structure to be ablated at a selected temperature, such as a temperature exceeding between about 90° Celsius and about 120° Celsius. In this preferred embodiment, the microprocessor also controls delivery of fluids for cooling or hydration, so as to maintain the temperature of surrounding tissue (i.e., other than the tissue selected for ablation) at temperatures less than between about 90° Celsius and about 120° Celsius.
In another preferred embodiment, the at least one sensor 119 also includes an impedance sensor 119 and the feedback technique includes a microprocessor operating to terminate delivery of RF energy when a measured impedance of the body structure to be ablated undergoes a substantial change indicative of dehydration or denaturation.
One or more sets of electrodes 113 are selected for retraction back from the selected mass of tissue in the region 140. The rotatable element 210 is rotated in the second direction 211, causing the selected sets of electrodes 113 to retract out of the selected mass of tissue and back into the catheter 110.
The same electrodes 113 which were advanced out of the catheter 110 are retracted back into the catheter 110.
The catheter 110 is withdrawn from the body at the opening through which it was inserted.
Before removal, the balloons 116 are deflated so the catheter 110 is no longer anchored in place, all electrodes 113 are retracted back into the catheter 110, and the catheter 113 is configured to no longer provide flowable substances or energy for ablation.
PARTICULAR METHODS AND APPARATUS FOR TREATMENTS
In preferred embodiments, the catheter and electrode assembly 100 may also be used for treatments in addition to, or instead of, ablation of body structures or tissue.
In one preferred embodiment, operation of the catheter and electrode assembly 100 includes at least the following steps:
The catheter 110 is inserted into a natural body lumen, such as the urethra.
In a preferred embodiment, the natural body lumen comprises a normally tubular body structure which has prolapsed, is spasmodic, or is otherwise subject to blockage (partial or complete) or damage (such as to a wall of the natural body lumen).
The catheter 110 infuses a hardenable substance into the natural body lumen, so as to coat at least one selected section of the wall of the natural body lumen.
In a preferred embodiment, the hardenable substance includes a collagen which is capable of being flowed onto the wall of the natural body lumen and which is capable of being hardened by application of RF energy, heat, or another agent to be provided by the catheter and electrode assembly 100.
The electrodes 113 are advanced and deliver energy to the hardenable substance to harden it.
In a preferred embodiment, the holes 112 provide saline and the electrodes 113 deliver RF energy to the collagen to harden it, so as to form a hard covering to the wall of the natural body lumen. If appropriate, more than one layer of collagen is applied, so as to provide a hard covering having a thickness exceeding a selected threshold, such as 0.1 inch (0.25 cm). The particular selected threshold will of course depend on the preferred diameter of the natural body lumen.
In a preferred embodiment for treatment of a prolapsed or spasmodic muscle, (1) the catheter 110 is inserted and pushed through a region where the muscle has prolapsed or blocked the rectum, colon, large intestine, or small intestine, (2) the prolapsed or spasmodic muscle is partially ablated, and (3) collagen is infused and hardened to strengthen the muscle wall. In alternative embodiments, the collagen may be infused before ablation in one or more boluses deposited within the muscle (or on the muscle or near the muscle), so that the steps of muscle ablation and collagen hardening will occur substantially simultaneously.
In a preferred embodiment for treatment of an anal fissure, (1) the catheter 110 is inserted into a region where the fissure has occurred, (2) a suspension of collagen and saline is infused and fills the fissure, and (3) the collagen is hardened while the saline is removed from the suspension. In this preferred embodiment, the isolated region between the distal balloon 116 and the proximal balloon 116 is maintained at a positive differential pressure with respect to the rest of the rectum, so that the collagen infuses into the fissure; this procedure or a similar procedure is also followed for treatment of diverticulosus and diverticulitus.
In a preferred embodiment for treatment, in a female patient, of a prolapsed uterus, (1) the catheter 110 is inserted into a region where the uterus has prolapsed, (2) the prolapsed uterus is partially ablated, and (3) collagen is infused and hardened to strengthen the muscle wall. Similarly to treatment of a prolapsed muscle, in alternative embodiments, the collagen may be infused before ablation, so that the steps of muscle ablation and collagen hardening will occur substantially simultaneously.
ALTERNATIVE EMBODIMENTS
Although preferred embodiments are disclosed herein, many variations are possible which remain within the concept, scope, and spirit of the invention, and these variations would become clear to those skilled in the art after perusal of this application.
|
The invention provides an apparatus and system for ablation of body structures or tissue in the region of the rectum. A catheter is inserted into the rectum, and an electrode is disposed thereon for emitting energy. The environment for an ablation region is isolated or otherwise controlled by blocking gas or fluid using a pair of inflatable balloons at upstream and downstream locations. Inflatable balloons also serve to anchor the catheter in place. A plurality of electrodes are disposed on the catheter and at least one such electrode is selected and advanced out of the catheter to penetrate and ablate selected tissue inside the body in the region of the rectum. The electrodes are coupled to sensors to determine control parameters of the body structure or tissue, and which are used by feedback technique to control delivery of energy for ablation or fluids for cooling or hydration. The catheter includes an optical path disposed for coupling to an external view piece, so as to allow medical personnel to view or control positioning of the catheter and operation of the electrodes. The catheter is disposed to deliver flowable substances for aiding in ablation, or for aiding in repair of tissue, such as collagen or another substance for covering lesions or for filling fissures. The flowable substances are delivered using at least one lumen in the catheter, either from at least one hole in the catheter, from an area of the catheter covered by a microporous membrane, or from microporous balloons.
| 0
|
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is related to co-pending U.S. patent application Ser. No. ______ (IBM Docket No. AUS920010102US1) entitled “METHOD FOR PRESENTATION OF HTML IMAGE-MAP ELEMENTS IN NON VISUAL WEB BROWSERS” filed even date herewith. The content of the above mentioned commonly assigned, co-pending U.S. patent applications are hereby incorporated herein by reference for all purposes.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] The present invention relates to computer network environments and more specifically to non-visual presentation of electronic documents.
[0004] 2. Description of Related Art
[0005] Information on the World Wide Web is typically made available by structuring the information into a visual presentation. Hyper Text Markup Language (HTML) is used by web authors to define the visual structure. The end user is presented with this information by viewing the information on a computer display, after the information has been rendered into a visual format by a web browser (e.g. Netscape Navigator or MS Internet Explorer).
[0006] Web sites of well established businesses and organizations make extensive use of visual images. A HTML MAP defines a set of sub-regions over the image area. Each region is called an AREA, and is defined by an AREA element within the MAP definition. Each AREA can be associated with an Internet Uniform Resource Locator (URL). When the end user performs a mouse click within an area defined by the MAP, the web browser will navigate the associated URL. This process works well for a sighted user who is accessing the web using a visual browser. However, this process is not accessible by people with vision impairments, nor is it accessible by users who do not have a visual display device available (e.g. while driving a car).
[0007] A variety of software products are becoming available which enable non-visual access to HTML pages. These products capture the web page content and then present an audible rendering of the web page. This is generally accomplished by using a text-to-speech (TTS) technology to read the textual content.
[0008] HTML, which is used to provide a visual structure to a web page, also provides a semantic structure to the page. Well known techniques exist for parsing an HTML source file into a parse tree, also known as a Document Object Model (DOM). The various structural elements and relationships among the elements are then apparent from the topology of the parse tree. The DOM is accessible as a component, and this component provides the foundation needed to build a non-visual browser.
[0009] In an HTML page, a MAP-AREA definition is a non-visible element. Consequently, the web author is free to locate the MAP-AREA definition within the DOM wherever the author pleases. A cross referencing scheme is then used to associate the MAP-AREA definition with a corresponding IMAGE within the DOM. However, the physical separation of the IMAGE from the MAP-AREA definition introduces a fair amount of program complexity when the HTML page is being presented by a non-visual browser. Currently, non-visual browsers must maintain extensive internal records in order to keep track of the logical association between a MAP-AREA and an IMAGE in the DOM.
[0010] Therefore, it would be desirable to have a method for maintaining the logical association between corresponding IMAGE-AREAs and IMAGEs in a DOM, while reducing program complexity and the need for extensive record keeping.
SUMMARY OF THE INVENTION
[0011] The present invention provides a method, program and apparatus for the rendering an image area in an electronic document by means of a non-visual browser. The invention comprises parsing a web page and creating a document object model (DOM). The browser then determine if an image in the web page contains a “long description” attribute that names a URL address for a second web page. This second web page contains a long description of the image in the first web page. If the image does have this attribute, the browser creates a new subtree within the DOM of the first web page, and places the subtree adjacent to the image in the DOM. The subtree presents a visible and renderable hyperlink to the second web page containing the long description. The browser will then render the image and/or hyperlink. The image and hyperlink can be rendered audibly, tactilely, visually, or by a combination of these methods, depending on the needs of the user.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:
[0013] [0013]FIG. 1 depicts a pictorial representation of a network of data processing systems in which the present invention may be implemented;
[0014] [0014]FIG. 2 depicts a block diagram of a data processing system that may be implemented as a server in accordance with a preferred embodiment of the present invention;
[0015] [0015]FIG. 3 depicts a block diagram illustrating a data processing system in which the present invention may be implemented;
[0016] [0016]FIG. 4 depicts a block diagram of a browser program in accordance with a preferred embodiment of the present invention;
[0017] [0017]FIG. 5 depicts a diagram illustrating a Document Object Model in accordance with the prior art;
[0018] [0018]FIG. 6 depicts a diagram illustrating an edited DOM in accordance with the present invention;
[0019] [0019]FIG. 7 depicts a flowchart illustrating the process of editing a DOM in accordance with the present invention; and
[0020] [0020]FIG. 8 depicts a flowchart illustrating the process of creating a new subtree within a DOM in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0021] With reference now to the figures, FIG. 1 depicts a pictorial representation of a network of data processing systems in which the present invention may be implemented. Network data processing system 100 is a network of computers in which the present invention may be implemented. Network data processing system 100 contains a network 102 , which is the medium used to provide communications links between various devices and computers connected together within network data processing system 100 . Network 102 may include connections, such as wire, wireless communication links, or fiber optic cables.
[0022] In the depicted example, a server 104 is connected to network 102 along with storage unit 106 . In addition, clients 108 , 110 , and 112 also are connected to network 102 . These clients 108 , 110 , and 112 may be, for example, personal computers or network computers. In the depicted example, server 104 provides data, such as boot files, operating system images, and applications to clients 108 - 112 . Clients 108 , 110 , and 112 are clients to server 104 . Network data processing system 100 may include additional servers, clients, and other devices not shown.
[0023] In the depicted example, network data processing system 100 is the Internet with network 102 representing a worldwide collection of networks and gateways that use the TCP/IP suite of protocols to communicate with one another. At the heart of the Internet is a backbone of high-speed data communication lines between major nodes or host computers, consisting of thousands of commercial, government, educational and other computer systems that route data and messages. Of course, network data processing system 100 also may be implemented as a number of different types of networks, such as for example, an intranet, a local area network (LAN), or a wide area network (WAN). FIG. 1 is intended as an example, and not as an architectural limitation for the present invention.
[0024] Referring to FIG. 2, a block diagram of a data processing system that may be implemented as a server, such as server 104 in FIG. 1, is depicted in accordance with a preferred embodiment of the present invention. Data processing system 200 may be a symmetric multiprocessor (SMP) system including a plurality of processors 202 and 204 connected to system bus 206 . Alternatively, a single processor system may be employed. Also connected to system bus 206 is memory controller/cache 208 , which provides an interface to local memory 209 . I/O bus bridge 210 is connected to system bus 206 and provides an interface to I/O bus 212 . Memory controller/cache 208 and I/O bus bridge 210 may be integrated as depicted.
[0025] Peripheral component interconnect (PCI) bus bridge 214 connected to I/O bus 212 provides an interface to PCI local bus 216 . A number of modems may be connected to PCI bus 216 . Typical PCI bus implementations will support four PCI expansion slots or add-in connectors. Communications links to network computers 108 - 112 in FIG. 1 may be provided through modem 218 and network adapter 220 connected to PCI local bus 216 through add-in boards.
[0026] Additional PCI bus bridges 222 and 224 provide interfaces for additional PCI buses 226 and 228 , from which additional modems or network adapters may be supported. In this manner, data processing system 200 allows connections to multiple network computers. A memory-mapped graphics adapter 230 and hard disk 232 may also be connected to I/O bus 212 as depicted, either directly or indirectly.
[0027] Those of ordinary skill in the art will appreciate that the hardware depicted in FIG. 2 may vary. For example, other peripheral devices, such as optical disk drives and the like, also may be used in addition to or in place of the hardware depicted. The depicted example is not meant to imply architectural limitations with respect to the present invention.
[0028] The data processing system depicted in FIG. 2 may be, for example, an IBM RISC/System 6000 system, a product of International Business Machines Corporation in Armonk, N.Y., running the Advanced Interactive Executive (AIX) operating system.
[0029] With reference now to FIG. 3, a block diagram illustrating a data processing system is depicted in which the present invention may be implemented. Data processing system 300 is an example of a client computer. Data processing system 300 employs a peripheral component interconnect (PCI) local bus architecture. Although the depicted example employs a PCI bus, other bus architectures such as Accelerated Graphics Port (AGP) and Industry Standard Architecture (ISA) may be used. Processor 302 and main memory 304 are connected to PCI local bus 306 through PCI bridge 308 . PCI bridge 308 also may include an integrated memory controller and cache memory for processor 302 . Additional connections to PCI local bus 306 may be made through direct component interconnection or through add-in boards. In the depicted example, local area network (LAN) adapter 310 , SCSI host bus adapter 312 , and expansion bus interface 314 are connected to PCI local bus 306 by direct component connection. In contrast, audio adapter 316 , graphics adapter 318 , and audio/video adapter 319 are connected to PCI local bus 306 by add-in boards inserted into expansion slots. Expansion bus interface 314 provides a connection for a keyboard and mouse adapter 320 , modem 322 , and additional memory 324 . Small computer system interface (SCSI) host bus adapter 312 provides a connection for hard disk drive 326 , tape drive 328 , and CD-ROM drive 330 . Typical PCI local bus implementations will support three or four PCI expansion slots or add-in connectors.
[0030] An operating system runs on processor 302 and is used to coordinate and provide control of various components within data processing system 300 in FIG. 3. The operating system may be a commercially available operating system, such as Windows 2000, which is available from Microsoft Corporation. An object oriented programming system such as Java may run in conjunction with the operating system and provide calls to the operating system from Java programs or applications executing on data processing system 300 . “Java” is a trademark of Sun Microsystems, Inc. Instructions for the operating system, the object-oriented operating system, and applications or programs are located on storage devices, such as hard disk drive 326 , and may be loaded into main memory 304 for execution by processor 302 .
[0031] Those of ordinary skill in the art will appreciate that the hardware in FIG. 3 may vary depending on the implementation. Other internal hardware or peripheral devices, such as flash ROM (or equivalent nonvolatile memory) or optical disk drives and the like, may be used in addition to or in place of the hardware depicted in FIG. 3. Also, the processes of the present invention may be applied to a multiprocessor data processing system.
[0032] As another example, data processing system 300 may be a stand-alone system configured to be bootable without relying on some type of network communication interface, whether or not data processing system 300 comprises some type of network communication interface. As a further example, data processing system 300 may be a Personal Digital Assistant (PDA) device, which is configured with ROM and/or flash ROM in order to provide non-volatile memory for storing operating system files and/or user-generated data.
[0033] The depicted example in FIG. 3 and above-described examples are not meant to imply architectural limitations. For example, data processing system 300 also may be a notebook computer or hand held computer in addition to taking the form of a PDA. Data processing system 300 also may be a kiosk or a Web appliance.
[0034] Turning next to FIG. 4, a block diagram of a browser program is depicted in accordance with a preferred embodiment of the present invention. Browser 400 includes a user interface 402 , which is a graphical user interface (GUI) that allows the user to interface or communicate with browser 400 . This interface provides for selection of various functions through menus 404 and allows for navigation through the navigation input 410 . For example, menu 404 may allow a user to perform various functions, such as saving a file, opening a new window, displaying a history, and entering a URL. Navigation 410 allows for a user to navigate various pages and to select web sites for viewing. For example, navigation 410 may allow a user to see a previous page or a subsequent page relative to the present page. Navigation 410 may also have voice recognition capabilities. Preferences may be set through preferences 406 . Browser 400 also contains text-to-speech (TTS) 408 , which converts text data into auditory signals.
[0035] Communications 412 is the mechanism with which browser 400 receives documents and other resources from a network such as the Internet. Further, communications 412 is used to send or upload documents and resources onto a network. In the depicted example, communication 412 uses HTTP. However, other protocols are possible. Documents that are received by browser 400 are processed by language interpretation 414 , which includes an HTML unit 416 , and a parser 418 which is capable of generating a parse tree associated with an electronic document, as discussed below in reference to FIG. 6. Language interpretation 414 will process a document for presentation on graphical display 420 . In particular, HTML statements are processed by HTML unit 416 for presentation.
[0036] Graphical display 420 includes layout unit 422 , rendering unit 424 , and window management 426 . These units are involved in presenting web pages to a user based on results from language interpretation 414 .
[0037] Browser 400 is presented as an example of a browser program in which the present invention may be embodied. Browser 400 is not meant to imply architectural limitations to the present invention. Presently available browsers may include additional functions not shown or may omit functions shown in browser 400 . As used herein, the term “browser” encompasses any software application used to view or navigate for information or data (e.g. something that assists a user to browse) in a distributed data base where the distributed database is typically the internet or World Wide Web.
[0038] A variety of software products are becoming available which enable non-visual access to HTML pages. These products capture the web page content and then present an audible rendering of the web page. This is generally accomplished by using a text-to-speech (TTS) technology to read the textual content. However, TTS technology cannot directly render an image. Prior art approaches to the problem involve either ignoring the image or simply announcing the fact that there is an image that contains MAP-AREAs.
[0039] HTML, which is used to provide a visual structure to a web page, also provides a semantic structure to the page. Well known techniques exist for parsing an HTML source file into a parse tree. The various structural elements and relationships among the elements are then apparent from the topology of the parse tree. The parse tree is also called a Document Object Model (DOM). The present invention relies on information contained within the DOM to provide a non-visual rendering of web page images.
[0040] Referring to FIG. 5, a diagram illustrating a Document Object Model is depicted in accordance with the prior art. Current web browser component technology (i.e. MS IE 5.0+, or Mozilla) maintains a DOM for the web page currently displayed. The DOM is accessible as a component, and this component provides the foundation needed to build a non-visual browser.
[0041] The MAP-AREA elements 531 - 533 in DOM 500 describe the subregions of the IMAGE 511 , and the hyperlinks associated with each subregion. However, the MAP-AREA 525 is normally not shown in a HTML page. Since the MAP-AREA 525 is not visible, web authors frequently put it at the bottom of the page, where it would be completely out of context with the visible, informational content around it. Because the IMAGE 511 and MAP-AREA 525 are separated in the web page (and DOM), a cross referencing scheme, “IMAGE usemap=map 1 ” 511 and “MAP name=map 1 ” 525 , is used to associate the separate parts of the document.
[0042] However, the physical separation of the IMAGE 511 from the MAP-AREA definition 525 introduces a fair amount of program complexity when the HTML page is being presented by a web browser with non-visual capabilities. A non-visual browser must describe the map at the same time it describes the image. An object of the present invention is to provide an algorithm that makes this process easier to perform. Though prior art browsers can respect the logical association between a separated image and map by maintaining extensive internal records, the present invention provides a simpler approach.
[0043] Referring now to FIG. 6, a diagram illustrating an edited DOM is depicted in accordance with the present invention. The present invention comprises modifying the DOM to move the MAP-AREA definition 621 to be adjacent to the IMAGE 611 . Logically, this is the same as dynamically rewriting the web page to eliminate the problem with its topology.
[0044] Referring to FIG. 7, a flowchart illustrating the process of editing a DOM is depicted in accordance with the present invention. When a web page is first loaded, it is parsed, and a DOM is created which can be analyzed for IMAGE-MAPs (step 701 ). The browser then checks for any MAP-AREA references (step 702 ) and determines whether or not the MAP is adjacent to the IMAGE element (step 703 ). If the MAP is not adjacent to the IMAGE, a new subtree is created in the DOM which places the content of the MAP-AREA definition in proximity to the IMAGE (step 704 ). This provides a topology which requires no internal bookkeeping to deal with this issue of separated images and maps. The browser then checks if the MAP is referenced by more than one IMAGE (step 705 ). If the MAP is referenced by more than one IMAGE (which is unusual), duplicate copies of the MAP-AREA definition can be made so that the one MAP-AREA definition is directly adjacent to each IMAGE which references it (step 706 ).
[0045] An image on a web page can have a “longdesc” (long description) attribute. A “longdesc” names the URL where a long description of an image can be found. This attribute was added to HTML by the industry standards group (the w3c) precisely for Accessibility needs. For example, a web page may have a “Welcome” image. The longdesc attribute associated with the image might reference another web page which says “This is an image which welcomes customers to this page. There are three hyperlinks on the image.” Currently, the major commercial web browsers (IE, Netscape, Mozilla) all ignore this attribute.
[0046] Because non-visual technology cannot directly render a web page image, the present invention allows a user to access the longdesc attribute in order to obtain an indirect, non-visual rendering of image content. The present invention uses the long description associated with an image as a surrogate for the image itself.
[0047] Referring to FIG. 8, a flowchart illustrating the process of creating a new subtree within a DOM is depicted in accordance with the present invention. After the browser loads a web page and analyzes the DOM (step 801 ), the browser proceeds to the first DOM node (step 802 ). The browser then checks for Image elements with long description attributes (step 803 ). If there are no such Image elements, the process ends. If there are Image elements with long descriptions, the browser moves to the next one in the DOM (step 804 ).
[0048] A text node which reads “Image description” is created (step 805 ). Then, a new Anchor node is created and set up so that its hyperlink points to the long description URL (step 806 ). The new text node, which reads “Image description” is made a child of the new Anchor node, so that this text appears as the visible hyperlink (step 807 ). Finally, the new Anchor node is inserted into the DOM as the first sibling node following the Image element (step 808 ). From there, the browser returns to Step 803 to determine if there are any more Image elements in the DOM with long description attributes.
[0049] Rather than relying on the addition of special code for the longdesc attribute, the present invention transforms the DOM so that existing algorithms render the Accessibility information. The DOM transformation of the present invention makes the long description visible and renderable to anyone using today's current commercial web browsers (e.g. Mozilla or Internet Explorer). Currently, these browsers do not support the long description, and the information is lost.
[0050] After the DOM edits are performed, subsequent DOM traversal is much more straightforward. All navigation operations can be handled using simple tree walk order navigation algorithms. This process is the subject of typical undergraduate computer science education and such algorithms are available in most any computer science textbook on data structures. One such reference is Introduction to Algorithms, by Cormen, Leiserson, Rivest, 19th printing, ISBN 0-262-53091-0. See INORDER-TREE-WALK algorithm in section 13.1 on p. 245. The non-visual browser can now render the MAP-AREAS audibly with less extensive bookkeeping than that required by the prior art. In another embodiment, the non-visual browser renders the MAP-AREAs by means of a tactile feedback mechanism.
[0051] It should be pointed out that the non-visual rendering techniques of the present invention are not exclusive of traditional visual rendering. Both visual and non-visual rendering techniques may be used in conjunction with each other, depending on the needs of the user.
[0052] It is important to note that while the present invention has been described in the context of a fully functioning data processing system, those of ordinary skill in the art will appreciate that the processes of the present invention are capable of being distributed in the form of a computer readable medium of instructions in a variety of forms and that the present invention applies equally regardless of the particular type of signal bearing media actually used to carry out the distribution. Examples of computer readable media include recordable-type media, such as a floppy disk, a hard disk drive, a RAM, CD-ROMs, DVD-ROMs, and transmission-type media, such as digital and analog communications links, wired or wireless communications links using transmission forms, such as, for example, radio frequency and light wave transmissions. The computer readable media may take the form of coded formats that are decoded for actual use in a particular data processing system.
[0053] The description of the present invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to best explain the principles of the invention, the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.
|
A method, program and apparatus for rendering an image area in an electronic document are provided by means of a web browser having non-visual capabilities. The invention comprises parsing a web page and creating a document object model (DOM). The browser then determine if an image in the web page contains a “long description” attribute that names a URL address for a second web page. This second web page contains a long description of the image in the first web page. If the image does have this attribute, the browser creates a new subtree within the DOM of the first web page, and places the subtree adjacent to the image in the DOM. The subtree presents a visible and renderable hyperlink to the second web page containing the long description. The browser will then render the image and/or hyperlink. The image and hyperlink can be rendered audibly, tactilely, visually, or by a combination of these methods, depending on the needs of the user.
| 6
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a sound receiving microphone for a video camera which produces sounds corresponding to the image in the camera and, more particularly, to a sound receiving microphone which provides a sound quality similar to the natural sound by analog audio signal processing.
Korean Patent Application No. 93-1591 is incorporated herein by reference for all purposes.
2. Brief Description of the Prior Art
Generally, in the video camera and recorder (camcorder) purchased by the average consumer for simultaneously recording an image and a sound, the image part of the camcorder includes an optical lens with a zoom function, which lens selectively produces a life-like video image for recording. However, the audio section of the camcorder consists of a general purpose microphone which lacks the capability to produce a life-like sound level. Accordingly, the viewer's visual and aural perception become mis-matched since the visual distance from a camcorder to the subject changes for the image while the sound does not change in correspondence with a change in image size, i.e., with the change in apparent distance between the subject and the camcorder.
In order to overcome this problem, camcorders including a function wherein the audio amplitude changes in proportion to the change in magnification of the zoom lens, i.e., a sound receiving function having a unified image and sound qualities, have been proposed. FIG. 1 is a block diagram showing the sound-receiving microphone of the video camera employing conventional digital audio signal processing.
Referring to FIG. 1, the conventional microphone includes a central (C) microphone 10, a left (L) microphone 11, a right (R) microphone 12, a central amplifier 13, a left amplifier 14, a right amplifier 15, a central electronic volume control 16, a left electronic volume control 17, a right electronic volume control 18, a microcomputer 21, a left mixer 19, and a right mixer 20.
In an attempt to produce a life-like audio output, audio signals input from the left, right and center microphones 10, 11 and 12 are first amplified in C-, L- and R-amplifiers 13, 14 and 15, and the respective output signals are input to respective electronic volume controls 16, 17 and 18. It will be appreciated that the outputs of amplifiers 13, 14, and 15 are adjusted appropriately in C-, L- and R-electronic volume controls 16, 17 and 18 in accordance with a control signal produced by microcomputer 21 and the respective volume-controlled signals are, in turn, provided to L- and R- mixers 19 and 20. Left mixer 19 adds the output of C-electronic volume control 16 to that of L-electronic volume control 17, and amplifies the result. Right mixer 20 adds the output of C-electronic volume control 16 to that of R-electronic volume control 18, and amplifies the result.
It will be noted that microcomputer 21 receives a wide/tele signal, which signal changes depending on the position of the zoom lens in the camera section (not shown), and microcomputer 21 outputs the control signal according to wide/tele signal so as to represent the distance from the sound source. Therefore, the outputs of amplifiers 13, 14 and 15 are input to the relevant electronic volume controls 16, 17 and 18, and are adjusted according to the control signal. Thus, for a wide/tele signal corresponding to the position of the zoom lens in a video part (a camera section which is not shown) of the camcorder, the detected position is indicated by a direct current (DC) voltage and is applied from a camera section (not shown) to microcomputer 21, after being divided into eight steps, i.e., eight steps ranging from A1 to A8 volts.
FIG. 2 shows an embodiment of translating the wide/tele signal into eight steps according to the position of the conventional zoom lens. The output voltage, having one of eight steps and producing a change in the electronic volume associated with the recorded image, can be represented as shown in Table 1.
TABLE 1______________________________________Zoom Lens Voltage VOLUME (in dB)Position (Volts DC) Left Right Center______________________________________A0 0.0 0 0 + 1A1 0.6 - 2 - 2 + 3A2 1.1 - 4 - 4 + 5. . . . .. . . . .A8 3.2 - 20 - 20 + 15______________________________________
It will be noted that the zoom lens position is divided into eight steps from A1 to A8 depending on the distance, gradually increasing from A0, i.e., the reference and nearest point from the camera, to A8, as shown in FIG. 2. The corresponding wide/tele voltage varies in steps, e.g., 0, 0.6, 1.1 . . . 3.2 volts DC depending on the position of the zoom lens, which then results in the discontinuous change in L and R electronic volume controls 17 and 18, e.g., 0, -2, -4, . . . -20 dB and an attendant discontinuous change in C-electronic volume control 16, e.g., 1, 3, 5 . . . 15 dB. The central audio input signal is increased when the position of the zoom lens in FIG. 2 goes from "wide" to "tele" (which means that the distance received to the subject is shortened) while the level of central audio input signal is decreased when the position of the zoom lens in FIG. 2 goes from "tele" to "wide" (which means that the distance to the subject is decreased). For example, the human voice is loud when the position of the zoom lens goes from "wide" to "tele" and is soft when the position of the zoom lens goes from "tele" to "wide". Since the value of the electronic volume method is fixed to eight discrete steps, e.g., the sound feels discontinuous when the sound changes to match a change in lens position. In addition, since the microcomputer 21 is needed for control of the electronic volume operation, the manufacturing cost of the camcorder is high.
SUMMARY OF THE INVENTION
The principal purpose of the present invention is to provide a sound receiving microphone for a camcorder whose sound is varied smoothly in conjunction with operation of a zoom lens control.
Another object according to the present invention is to provide a sound receiving microphone system which smoothly varies an output sound characteristic proportional to zoom lens position. According to one aspect of the invention, the sound receiving microphone system employs analog audio processing circuits.
Still another object according to the present invention is to provide a sound receiving microphone system which smoothly varies an output sound characteristic proportional to zoom lens position wherein the system can be provided at low cost.
Yet another object of the present invention is to provide a sound receiving microphone system which smoothly varies an output sound characteristic proportional to zoom lens position wherein the system can be provided using low cost parts.
Another object of the present invention is to provide a camcorder including a sound receiving microphone system.
These and other objects, features and advantages according to the present invention are provided by a sound receiving microphone, which provides a life-like sound stereophonically in response to a wide/tele signal produced by a video camera, the wide/tele signal changing according to the position of a zoom lens. The sound receiving microphone advantageously includes a plurality of microphones converting received respective sounds from a subject into corresponding electrical signals permitting amplification, a plurality of sound receiving circuits which continuously change the respective amplified electrical signals output from the microphones in response to the wide/tele signal, using the dynamic resistance of respective transistors, and a plurality of sound mixers, each of which sums and amplifies selected outputs of selected ones of the sound receiving circuits.
These and other objects, features and advantages according to the present invention are provided by a camcorder including a camera section receiving a subject image subject through an optical lens, converting the subject image to a video signal and generating wide/tele signal representing position of the optical lens, an audio processing part including a plurality of microphones receiving input sounds from the subject and converting the input sounds into a recordable audio signal, wherein the audio processing part continuously amplifies the input audio signal according to the wide/tele signal using the dynamic resistance of the transistor, and outputs the recordable audio signal which corresponds to the distance of the received image and a recorder/reproducer which records and reproduces the video signal and the recordable audio signal onto video tape.
These and other objects, features and advantages of the invention are disclosed in or are apparent from the following description of preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
The above objects and other advantages of the present invention will become more apparent from the detailed description of preferred embodiments thereof taken with reference to the attached drawings, in which:
FIG. 1 is block diagram showing the sound receiving microphone according to the conventional digital method;
FIG. 2 is a schematic diagram illustrating detection of a wide/tele signal in eight steps according to the position of the conventional zoom lens;
FIG. 3 is a circuit diagram showing a sound receiving microphone according to analog signal processing of the present invention;
FIG. 4 is a detailed circuit diagram showing the left sound receiving circuit of FIG. 3;
FIG. 5 is a graphical representation showing the characteristic of the output according to the input current of the left sound receiving circuit of FIG. 4;
FIG. 6 is a detailed circuit diagram showing the central sound receiving circuit of FIG. 3;
FIG. 7 is a graphical representation showing the characteristic of the output according to the input current of the central sound receiving circuit of FIG. 6;
FIG. 8 is a graphical representation showing the combined input/output characteristic of the left and right sound receiving circuit of FIG. 5 and the central sound receiving circuit of FIG. 7; and
FIG. 9 is a schematic diagram showing the structure of the camcorder according to another embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will be described below in more detail with reference to the attached drawings.
FIG. 3 is a circuit diagram which schematically shows the sound receiving microphone of the present invention, wherein the device of the present invention comprises a microphone 30, an analog sound receiver 40 and a sound mixer 50. Microphone 30 is made up of a central microphone 34, a left microphone 32, a right microphone 36 and a microphone processor 38. Analog sound receiver 40 is made up of a left sound receiving circuit 42, a central sound receiving circuit 44 and a right sound receiving circuit 46. Sound mixer 50 is made up of a left sound mixing circuit 52 and a right sound mixing circuit 54.
Thus, the microphone consists of L microphone 32, R microphone 36 and C microphone 34, which enables the sound to be input and converted into an electrical sound signal (audio signal). Also, the audio signal which is input from microphones 32, 34 and 36 is amplified by microphone processor 38, which then is output to analog sound receiver 40. Sound receiving circuits 42, 44 and 46 of analog sound receiver 40 receive a wide/tele signal generated from a camera section (not shown) through a terminal 100.
The wide/tele signal is a DC voltage which continuously changes according to the position of the zoom lens of the camera section. That is, the DC voltage corresponding to the wide/tele signal is increased when the subject comes closer to the screen, i.e., when the position of the zoom lens goes from "wide" to "tele", while the DC voltage of wide/tele signal is decreased when the subject goes away from the screen, i.e., when the position of the zoom lens goes from "tele" to "wide". It will be appreciated that the continuously variable wide/tele signal advantageously can be generated, in an exemplary case, by a variable resistor, as illustrated in FIG. 3. Other circuitry and techniques for generating a suitable wide/tele signal will occur to those of ordinary skill in the art. Thus, modifications to the preferred embodiments may be made without departing from the spirit and scope of the invention.
The DC voltage of wide/tele signal is input to the respective bases of transistors TR L , TR R and TR C of sound receiving circuits 42, 44 and 46. Sound receiver 40 changes the amplitude of audio signals which are input from respective microphones according to wide/tele signal voltage and gives a life-like quality to the sound considering the image of the external environment. That is, the central audio output signal is increased as the position of the zoom lens of the camera section moves from "wide" to "tele" since the subject comes closer to the screen. On the contrary, the central audio input signal becomes small as the position of the zoom lens of the camera section moves from "tele" to "wide" since the subject goes far from the screen. For example, a voice of the person in front is loud when the position of the zoom lens goes from "wide" to "tele" and is soft when the position of the zoom lens goes from "tele" to "wide".
Left mixing circuit 52 sums the output of central sound receiving circuit 44 with the output of left sound receiving circuit 42, and amplifies and outputs this sum. Right mixing circuit 54 sums the output of central sound receiving circuit 44 with the output of right sound receiving circuit 46, and amplifies and outputs this sum.
FIG. 4 is a detailed circuit diagram showing the left sound receiving circuit of FIG. 3. Since the structure and operation of the left sound receiving circuit and the right sound receiving circuit are similar, only the left sound receiving circuit will be explained. Referring to FIG. 4, the left sound receiving circuit consists of transistor TR L , resistor R2, which is connected to the base of transistor TR L , and resistor R1, which is connected to the collector of transistor TR L . Referring to FIG. 4, r CE is the dynamic resistance between the collector and the emitter of the transistor. The wide/tele signal is input from a camera section to a first input terminal, which then is input to the base of transistor TR L through resistor R2. The wide/tele signal is a DC voltage signal which changes continuously according to the change of the position of the zoom lens.
When the DC voltage is input to the base of transistor TR L , a base input current i B is also changed according to the input DC voltage. Meanwhile, the audio signal is input to a second input terminal from microphone processor 38, which then is connected to the collector of transistor TR L through resistor R1. Accordingly, when the current i B , which is input to the base of transistor TR L increases, the output of transistor TR L decreases inversely proportional to the increase of the input current i B , since the resistance value r CE , i.e., TR L 's own dynamic resistance value, decreases. Here, the output voltage (V OL ) can be calculated according to the following expression: ##EQU1##
Here, r CE is a dynamic resistance of the transistor itself. Output voltage signal (V OL ) decreases as the dynamic resistance r CE decreases, as shown in expression (1). Accordingly, when the zoom lens goes from "wide" to "tele", the output voltage signal (V OL ) decreases because the input current i B increases in accordance with the increase of the DC voltage value of the wide/tele signal.
FIG. 5 is a graphical representation showing the relationship between the input current i B and output voltage signal (V OL ) according to the left sound receiving circuit of FIG. 4, wherein the traverse axis indicates an input current i B signal and the vertical axis indicates an output voltage signal (V OL ). Referring to the graph of FIG. 5, input current i B increases as the zoom lens goes from "wide" to "tele", while output voltage signal (V OL ) decreases as input current i B increases.
FIG. 6 is a detailed circuit diagram showing the central sound receiving circuit of FIG. 3. Referring to FIG. 6, the central sound receiving circuit is made of a transistor TR C , a resistor R4 connected to the base of transistor TR C , and a resistor R3 connected to the emitter of transistor TR C . The wide/tele signal is input from a camera section to a first input terminal, which then is input to the base of transistor TR C through resistor R4. The wide/tele signal is a DC voltage signal which changes continuously in accordance with the change of the position of the zoom lens. When the DC voltage is input to the base of transistor TR C , current i B input to the base is also changed. Meanwhile, the central audio signal is input to a second input terminal from microphone processor 38. Accordingly, when the current i B input to the base of transistor TR C increases, the output of transistor TR C increases in proportion to the increase of the input current i B , since the r CE value, i.e., transistor TR C ' s own dynamic resistance value, decreases. Here, the output voltage (V OC ) can be calculated as the following expression: ##EQU2##
As shown in expression (2), when input current i B increases, output voltage (V OC ) also increases while dynamic resistance r CE decreases. Accordingly, when the zoom lens goes from "wide" to "tele", the DC voltage of the wide/tele signal increases, thereby increasing input current i B and output voltage (V OC ).
FIG. 7 is a graphical representation showing the relationship between the output voltage (V OC ) according to the input current of the central sound receiving circuit of FIG. 6, wherein the traverse axis indicates input current i B signal and the vertical axis indicates the output voltage (V OC ) signal. Referring to the graph of FIG. 7, input current i B increases as the zoom lens goes from "wide" to "tele", while output voltage (V OC ) signal increases in proportion to the increase of input current i B .
FIG. 8, which combines FIG. 5 and FIG. 7 is a graphical representation showing the relationship wherein the left and right sound receiving and central sound receiving circuits change depending on input current i B .
Referring to FIG. 8, the traverse axis indicates input current i B while the vertical axis indicates output voltage signal. Input current i B increases as the zoom lens goes from "wide" to "tele". When input current i B increases, output of the left and right sound receiving circuits decreases as shown in graph `a`, while output of the central sound receiving circuit increases as shown in graph `b`. On the contrary, when the zoom lens goes from "tele" to "wide", input current i B decreases, and then output of the left and right sound receiving circuits increases as shown in graph `a`, while output of the central sound receiving circuit decreases as shown in graph `b`. Accordingly, when the zoom lens goes from "wide" to "tele" which means that the subject is coming closer, the voice input from the left and right microphones decreases while the voice input from the central microphone increases. As a result, the voice generated in the front is heard louder and louder while the voice generated from the side is heard softer and softer, which gives an effect of having a conformity with an image. Preferably, when the zoom lens goes from "tele" to "wide", which means that the subject gradually looks further away, the voice input from the left and right microphones is heard louder while the voice input from the central microphone is heard softer.
FIG. 9 is a schematic illustration showing the structure of the camcorder of another embodiment of the present invention, wherein a camera section 80, audio section 82 and a recorder/reproducer 84 are provided. Referring to FIG. 9, the camera section 80 and recorder/reproducer 84 are the same as those in the conventional device, and the audio section 82 is provided with a sound receiving microphone of the present invention as described in FIG. 3. That is, the camera section 80 picks up the subject through an optical lens and converts the picked-up subject into a video signal and generates the wide/tele signal in accordance with zoom lens position. The audio section 82 inputs the sound of the subject into a number of microphones and converts the input sound into an audio signal, and then performs an analog processing on the audio signal according to the wide/tele signal, and then outputs the audio signal that accords to the distance of the received image. The recorder/reproducer 84 inputs the video and audio signals and records and reproduces them on the video tape.
The device of the present invention uses the sound receiver of an analog method, which enables the natural connection of the change of the sound. Also, the construction of a simple circuit utilizing the dynamic resistance characteristic of the transistor enables lowering the number of parts and the cost.
Other modifications and variations to the invention will be apparent to those skilled in the art from the foregoing disclosure and teachings. Thus, while only certain embodiments of the invention have been specifically described herein, it will be apparent that numerous modifications may be made thereto without departing from the spirit and scope of the invention.
|
A camcorder includes a camera section receiving a subject image subject through a zoom lens, converting the subject image to a video signal and generating a corresponding wide/tele signal representing position of the zoom lens, an audio processing part including a plurality of microphones receiving input sounds from the subject and converting the input sounds into a recordable audio signal, and a recorder/reproducer which records and reproduces the video signal and the recordable audio signal onto video tape. The audio processing part includes a plurality of analog elements. The audio processing part continuously amplifies the input audio signal using the analog elements in response to the wide/tele signal and outputs the recordable audio signal which corresponds to perceived distance from the camcorder to the subject. The analog elements may be transistors, wherein the dynamic resistance of each transistor is continuously varied responsive to the wide/tele signal.
| 7
|
CROSS REFERENCE TO RELATED APPLICATION
This application discloses subject matter claimed in application Ser. No. 08/364,649 entitled THREE WIRE TELEVISION REMOTE CONTROL OPERABLE WITH KEY CLOSURES OR DATA PULSES filed of even data and assigned to Zenith Electronics Corporation.
BACKGROUND OF THE INVENTION AND PRIOR ART
This invention relates generally to wired television receiver remote control systems and specifically to such systems that are utilized in a hospital environment or the like.
Conventional hospital type television receivers are wired, i.e. connected by a multi wire cable, to a remotely located control unit that generally incorporates a small so-called pillow speaker. The most rudimentary systems involve three interconnecting wires and include a simple push button (key closure) for stepping the television receiver tuner sequentially through a plurality of television channels with one of the channel positions constituting an on/off position for the television receiver. The pillow speaker usually includes a simple variable resistor for controlling the volume of the sound produced. Such systems consist essentially of a push button switch and an audio volume control.
More elaborate systems may incorporate a greater number of wires, generally five, and may provide for channel up, channel down and separate on/off controls. They also have push button key closures for operating the channel controller and include a volume controllable pillow speaker.
The art has long recognized the need to provide a greater array of control functions that are accessible in the pillow speaker housing. Yet the need for a separate power supply to operate a multi function control signal generator, similar to conventional IR remote control encoders, as well as the need for the required additional wires to interconnect the pillow speaker and the television receiver have posed serious obstacles. One manufacturer used batteries in the pillow speaker unit in an effort to provide a variety of television control functions without using additional wires. Batteries pose their own problems, such as the need for periodic monitoring and replacement by hospital personnel and coupled with their cost, are not considered a viable solution. A further difficulty is that there are many existing installations with three and five wire interconnections and pillow speaker units. Consequently, any new or improved television receiver should ideally be retrofitable with existing Wired remote control units.
The present invention solves all of the above-mentioned problems by providing a pillow speaker remote control that requires a minimum number of wires, draws its operating power from the television receiver, is capable of providing multi function remote control signals to the television receiver over the existing wires and is compatible with existing three and five wire pillow speaker control units.
OBJECTS OF THE INVENTION
A principal object of the invention is to provide an improved wired remote control system for a television receiver.
Another object of the invention is to provide a pillow speaker remote control that provides full functional remote control over a three wire cable.
A further object of the invention is to provide a wired remote control television receiver that is capable of being controlled by a number of control units.
An important object of the invention is to provide a novel three wire multi function remote control pillow speaker that is powered from a television receiver.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and advantages of the invention will be apparent upon reading the following description in conjunction with the drawings, in which:
FIGS. 1A and 1B together are a schematic diagram of the portions of the television receiver and remote control constructed in accordance with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1A and 1B, a pillow speaker remote control device is generally designated by reference numeral 10. An encoder IC 12 is a multi function control signal generator for generating infrared (IR) pulses of 40 kilohertz frequency. Crystal 14 provides timing for encoder 12. A plurality of switches, appropriately labelled as to their respective functions, are connected to IC 12. A pair of jumpers B1 and B2, which may be used or omitted in accordance with which of two code patterns are to be transmitted by the pillow speaker remote control device to control a television receiver, are also shown. It will be appreciated that encoder IC 12 is well known in the prior art as are the various function switches, which generally comprise conductive rubber type switches in a keyboard array. The output of encoder 12 is supplied to a diode 16 and a filter capacitor 18 to remove the 40 kilohertz ultrasonic frequency. This results in an envelope of the data pulses being applied to a voltage divider comprising resistors 20 and 22, the junction of which is coupled to the base of a transistor 24. The emitter-collector circuit of transistor 24 is coupled through a resistor 26 to a pair of wires labelled DATA and COM (common) which is part of a three wire cable. As will be explained, power is supplied to encoder 12 from the television receiver over the DATA and COM lines. The DATA line is also connected through a series resistor 40 to a voltage divider, comprising resistors 36 and 38, which supplies the input of a Darlington connected pair of transistors 34 that function as a shunt regulator. A filter capacitor 32 is coupled across the output of the Darlington connected pair 34 and along with a resistor 28 and a capacitor 30 provides appropriate operating voltages to encoder 12. A potentiometer 44 is connected across an AUDIO line and the COM line and supplies a speaker 42. Potentiometer 44 controls the amount of audio signal supplied to the speaker 42 from the television receiver (shown in FIG. 1B).
Referring to the television receiver in FIG. 1B, the cable is indicated as having either three or five wires. It will be understood that installations that have a pillow speaker remote control that is constructed in accordance with FIG. 1A, only require three wires. The use of the additional wires is for the above-mentioned existing installations where the remote unit consists of one or two push buttons and a pillow speaker. In such installations, the push buttons are merely passive switches that are connectable between the various lines or wires. In a single switch installation the DATA/CH UP line and the COM line are bridged. In a five wire installation, that provides channel up, channel down and on and off control functions, the switches bridge the ON/OFF, the CH DN and the DATA/CH UP lines with the COM line, respectively. In all installations, the AUDIO and COM lines supply the potentiometer-controlled speaker.
For simplicity, only the pertinent control aspects of the television receiver are shown. An audio circuit 45 is coupled via an audio transformer 47 across the AUDIO and COM lines. A series of well known isolating opto couplers 50, 60 and 70 are shown. Each opto coupler consists of a light emitting diode (LED) that activates the base of a suitable output transistor. One or more of these opto couplers is used in the prior art receivers mentioned above. The output transistor of the opto coupler 70 is supplied to circuitry that enables it to be used for accepting either data signals, i.e. high frequency pulse trains, or key closures, i.e. channel up signals. The input LEDs of opto couplers 50, 60 and 70 are bridged by resistors 58, 68 and 78, respectively. The junctions of these resistors and the anodes of the LEDs are supplied with 12 volts DC from a power supply 90. Power supply 90 is conventional and oscillates at approximately 65 kilohertz to generate the 12 volt DC from a 5 volt DC input. The resistance capacitance network 92 between the power supply ground lead and the COM line precludes potentially dangerous charge buildup on the wires. The cathodes of the LEDs are coupled to respective wires in the cable via resistors 56, 66, and 76, respectively. The two leads labelled CH DN and ON/OFF are shown in dashed lines to indicate that they are not involved when utilizing the preferred embodiment of the remote control unit of FIG. 1A. The bases of the output transistors in opto couplers 50, 60 and 70 are connected, through respective resistors 52, 62 and 72, to a junction A which is shown as a ground. This potential is the lowest reference potential for the key scan circuits (94) and data processing circuits (88) of the television receiver.
The collector of the output transistor in opto coupler 70 is connected through a resistor 73 to a source of +5 volts DC, while its emitter is coupled through a resistor 74 to a junction A. A voltage divider consisting of resistors 75 and 77 is connected between +5 volts and junction A (ground). The tap on the voltage divider is coupled to the base of a transistor 80 whose collector is coupled through a resistor 81 to +5 volts. A storage capacitor 82 is connected across the collector-emitter junction of transistor 80. A resistor 83 is connected between the collector of transistor 80 and the base of a transistor 85 that has its collector connected to the commonly connected collectors of the output transistors in opto couplers 50 and 60 and its emitter connected through a resistor 87 to a microprocessor block 93 including a KEY SCAN & ID 94 (key scanning and identification). The emitter of the transistor in opto coupler 70 is also connected through a resistor 84 to the base of an IR data transistor 86 that has its collector connected through a resistor 89 to an IR data processing block 88 in microprocessor 93 and its emitter connected to junction A. As indicated, IR data may also be applied to IR data processor 88 from the television receiver circuitry. In a conventional (i.e, non hospital) type television receiver, this IR data would be received from an IR receiver that processes remotely transmitted IR control signals.
In operation, DC power is supplied to the pillow speaker device from power supply 90 via the DATA line and the COM line. A current source is defined through resistor 40 and must be sufficient to accommodate the worst case scenario of power requirements of encoder 12. The current requirement of encoder 12 ranges from a few microamperes during standby to about 1 milliampere (average) during data pulse times. Providing the voltage regulator (Darlington transistors 34) enables a constant current load to be seen by the television receiver whether the encoder IC is encoding data pulses or is in a standby condition. This precludes dangerous voltage conditions for encoder 12, because of the wide variation in current supplied during pulse times and standby, and makes the task of separating data from standby current simpler in the television receiver. The small amount of extra current during the data pulse on time (predominantly the base drive current for transistor 24) comes from capacitor 32 since the duty cycle is low. The data pulses are sent as a loop current increase during the periods that transistor 24 is on. The control loop current is 1 milliampere per speaker assembly (in standby) and rises to something on the order of 7 milliamperes during pulse time.
In FIG. 1B, transistor 80 effectively discriminates between relatively high frequency data pulses and key closures, which represent DC short circuits across the various lines. (The DC short circuit condition across the DATA and the COM lines generates a current that is close to 10 milliamperes.) Looking first at the data path, the 7 milliampere current pulses in the control loop pass through the emitter portion of opto coupler 70 which results in its output transistor being switched on and off by the optically coupled energy. This appears as a positive going signal of about 500 microamperes at pin 4 of opto coupler 70. The current is supplied to the base of transistor 86 which pulls the IR DATA line down during each pulse. This generally replicates the output of the IR receiver (not shown) in the television receiver and is sent to IR data processor 88. A DC short circuit, corresponding to a switch closure across the DATA and COM lines, results in a LOW on the IR DATA line for as long as the switch closure is maintained. This LOW is ignored by the logic in microprocessor 93 and no action takes place. Thus, in response to a data signal, transistor 86 passes the data signal to the IR data processor 88. In response to a key closure, however, transistor 86 simply, pulls the IR DATA line LOW which is ignored by microprocessor 93.
The response of the remainder of the circuitry to a key closure is as follows. When the output transistor of opto coupler 70 is on, the voltage at pin 5 of opto coupler 70 is reduced from +5 volts to approximately +1 volt. The voltage at pin 5 is divided by resistors 73, 75 and 77, with approximately 25% of the voltage at pin 5 appearing at the base of transistor 80. When pin 5 is high (+5 volts), the resulting current keeps transistor 80 turned on. When pin 5 is low (+1 volt), the resulting voltage at the base of transistor 80 is insufficient to keep it on and transistor 80 is turned off. This permits capacitor 82 to begin charging through resistor 81 from the +5 volt source. Since each data pulse is on the order of 500 microseconds in duration, only a small voltage appears on capacitor 82 before transistor 80 is again turned on, which rapidly reduces the voltage across capacitor 82 to zero. This timing circuit therefore maintains transistor 85 in the off state during data pulses. When opto coupler 70 is conductive for a sufficient time (about 10 milliseconds), capacitor 82 charges to a voltage sufficient to turn on transistor 85, which connects the appropriate lines on the keyboard scan matrix resulting in a channel up operation from the microprocessor. Therefore long term high currents in the control loop, i.e. currents greater than 10 milliseconds in duration, are passed to the microprocessor 93 as key scan inputs and short time high currents, i.e. about 500 microseconds in duration, are passed to the IR data processor 88. The small difference between the data pulse loop current and the DC short loop current is ignored by the system. The separation of the DC and data is accomplished solely based upon time. Inca five wire installation, opto couplers 50 and 60 will respond similarly to key closures across their respective input connections to activate their respective key scan inputs. Thus the inventive system functions with existing 3 wire and 5 wire remote pillow speakers as well as with the full function remote control pillow speaker of the invention.
What has been described is a novel pillow speaker wired remote control system for a television receiver. It is recognized that numerous changes in the described embodiment of the invention will be apparent to those skilled in the art without departing from its true spirit and scope. The invention is to limited only as defined in the following claims.
|
A full function remote control pillow speaker arrangement is coupled by three wires to a television receiver. The arrangement includes a standard IR control signal encoder, the output of which is filtered to remove the 40 kilohertz ultrasonic frequency, thus yielding an envelope corresponding to the data pulses. Operating power is supplied to the encoder from a DATA line and a common (COM) line with a shunt regulator being interposed to protect the encoder from over voltage conditions during standby operations. A speaker is supplied audio signals from the (COM) line and an audio line. The receiver is capable of functioning with other types of pillow speaker control units, i.e. those having a single key closure for channel and on/off control and those with extra key closures for channel directional control. A circuit is included that discriminates between data pulses and key closures for transmitting data pulses to the television receiver IR data processing circuitry and transmitting key closures to receiver key scan processing circuitry.
| 7
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Application Ser. No. 61/289,778, filed on Dec. 23, 2009, incorporated herein by reference.
BACKGROUND
[0002] This description relates to managing queries.
[0003] Some data storage systems (e.g., databases) store large amounts of data stored in a way that is mean to support processing a large number of queries. For example, some systems include parallel processing capabilities through the use of parallel storage devices, parallel query processing engines, or both.
SUMMARY
[0004] In one aspect, in general, a method for managing queries performed on one or more data sources includes: storing at least a first query in a storage medium; selecting the first query for processing; instructing a query engine to process the first query on a first portion of data in the one or more data sources for a first query interval; receiving result data from the query engine based on processing the first query on the first portion of data; saving a state of the first query in the storage medium after the first query interval; instructing the query engine to process a second query during a second query interval after the first query interval; and instructing the query engine to process the first query on a second portion of data in the one or more data sources during a third query interval after the second query interval.
[0005] Aspects can include one or more of the following features.
[0006] The method further includes: storing a priority associated with the first query in the storage medium; changing the priority associated with the first query prior to selecting the first query for processing; wherein selecting the first query for processing includes selecting the query based in part on the priority.
[0007] The first query interval is defined by a predetermined amount of time.
[0008] The priority of the first query affects how much of the data in the one or more data sources is included in the first portion of data on which the first query is executed for the first query interval.
[0009] Storing the first query includes storing a notification threshold of a quantity of result data to be available before a requester that provided the first query is notified.
[0010] The method further includes notifying the requester when the quantity of result data exceeds the notification threshold, wherein saving the state of the first query includes storing the quantity of result data received from the query engine.
[0011] The method further includes returning result data upon request from the requester; and storing the quantity of result data returned to the requester in the storage medium.
[0012] Selecting the query is based on the quantity of result data received from the query engine and the quantity of result data returned to the requester.
[0013] Saving the state of the first query includes: instructing the query engine to suspend the first query; and saving a state of the first query after the first query has been suspended.
[0014] Instructing the query engine to process the first query on the second portion of data includes: loading the saved state of the first query; and instructing the query engine to resume the first query.
[0015] Saving the state of the first query includes saving an offset into a secondary index.
[0016] The secondary index is a block compressed indexed file.
[0017] The method further includes dividing the first query into multiple subqueries, and instructing the query engine to process at least some of the subqueries concurrently.
[0018] The second query is received and stored in storage medium after the first query interval begins.
[0019] The second query is received and stored in storage medium before the first query interval begins.
[0020] In another aspect, in general, a computer-readable medium stores a computer program for managing queries performed on one or more data sources. The computer program includes instructions for causing a computer to: store at least a first query in a storage medium; select the first query for processing; instruct a query engine to process the first query on a first portion of data in the one or more data sources for a first query interval; receive result data from the query engine based on processing the first query on the first portion of data; save a state of the first query in the storage medium after the first query interval; instruct the query engine to process a second query during a second query interval after the first query interval; and instruct the query engine to process the first query on a second portion of data in the one or more data sources during a third query interval after the second query interval.
[0021] In another aspect, in general, a system for managing queries performed on one or more data sources. The system includes a storage medium storing at least a first query. The system includes a query engine configured to process queries on data in the one or more data sources. The system also includes a server configured to: select the first query for processing; instruct the query engine to process the first query on a first portion of data in the one or more data sources for a first query interval; receive result data from the query engine based on processing the first query on the first portion of data; save a state of the first query in the storage medium after the first query interval; instruct the query engine to process a second query during a second query interval after the first query interval; and instruct the query engine to process the first query on a second portion of data in the one or more data sources during a third query interval after the second query interval.
[0022] In another aspect, in general, a system for managing queries performed on one or more data sources. The system includes a storage medium storing at least a first query. The system includes a query engine configured to process queries on data in the one or more data sources. The system includes means for managing queries in the storage medium, the managing including: instructing the query engine to process the first query on a first portion of data in the one or more data sources for a first query interval; receiving result data from the query engine based on processing the first query on the first portion of data; saving the first query in the storage medium after the first query interval; instructing the query engine to process a second query during a second query interval after the first query interval; and instructing the query engine to process the first query on a second portion of data in the one or more data sources during a third query interval after the second query interval.
[0023] Aspects can include one or more of the following advantages.
[0024] Selecting queries based in part on the priority associated with the queries can enable efficient processing in a parallel query processing system. Slicing time into intervals in which portions of queries can be partially processed and then suspended allows some queries to be processed sooner and reduces some potential backlog in the system, in particular for high priority queries.
[0025] Other features and advantages of the invention will become apparent from the following description, and from the claims.
DESCRIPTION OF DRAWINGS
[0026] FIGS. 1 and 2 are schematic diagrams depicting query processing.
[0027] FIG. 3 is a block diagram of a data storage system.
[0028] FIG. 4 is a schematic diagram of an indexed compressed data storage.
[0029] FIGS. 5A-5B , 6 A- 6 B and 7 A- 7 D are plots showing intervals of time associated with processing queries.
[0030] FIG. 8 is a schematic diagram of sliced query processing.
[0031] FIG. 9 is a schematic diagram showing query processing of an indexed compressed data storage.
[0032] FIGS. 10 and 11 are flowcharts of processes for managing queries.
DESCRIPTION
1 Overview
[0033] Referring to FIG. 1 , several problems may arise in distributed query management. For example when queries are delivered to a query engine of a data storage system in a first in first out manner the system may become backlogged. In some cases, queries delivered may include short queries 102 , 104 , 108 , 112 , 118 which execute quickly with little need for resources, longer queries 110 , 114 , 116 which require a longer time to execute and utilize a great deal of system resources, and queries which fall somewhere in between short queries and long queries. It may not be practical to predetermine the amount of system resources a particular query will require before the query is executed. FIG. 1 shows an example of a system for processing queries using multiple query engines. Queries are asynchronously received and stored in a queue 101 waiting for an opportunity to be processed by a query engine executing on a query server 100 of a data storage system. In this example, initially a long query 116 is assigned to a first query engine 120 for processing and a short query 118 is assigned to a second query engine 122 for processing. Referring to FIG. 2 , a short time later the short query 118 may have been completed and the next query in line, a long query 114 is assigned to the free query engine 122 . At this point the remaining queries 102 , 104 , 108 , 110 , 112 wait until one of the long queries 116 , 114 completes processing and frees up processing resources in a query engine. This phenomenon increases the latency of shorter queries and may cause an unacceptable delay in queries for which a quick reply is expected.
[0034] Referring to FIG. 3 , a data storage system 300 is configured to provide a front-end service 302 , for example, a web service, to receive a request to execute a query. A mediation server 304 schedules query execution by multiple query engines 312 . Each query is permitted to execute for an allotted period, the period may be measured by time (e.g., as measured by the CPU clock), duration, numbers of rows processed, or number or rows retrieved, for example. The query engines 312 access data from one or more data sources 310 A, 310 B, 310 C to process the query to produce a result set 314 . Storage devices providing the data sources may be local to the system 300 , for example, being stored on a storage medium connected to a computer implementing the mediation server 304 (e.g., a hard drive), or may be remote to the mediation server 304 , for example, being hosted on a remote system (e.g., a mainframe) in communication over a remote connection.
[0035] The mediation server 304 manages the result set 314 . The mediation server 304 may store additional information about the query, for example, a priority of the query, the number of rows requested, the number of rows returned from the query, the number of rows returned to the requester, an indication of how the query is going to be used, how many rows are required at a time, the last time the query executed by a query engine, and a status indicator. The status indicator may indicate that the query is waiting, running, suspended, interrupted, or complete. In some arrangements, the query state may also indicate the presence of an error condition which occurred during query processing. Queries in the waiting state are eligible for execution but not currently running. Queries in the running state are currently being processed by the query engine. Queries in the suspended state are not eligible for execution because the mediation server has already returned the number of rows currently requested by a client. Queries in the interrupted state are not eligible for execution because they have been preempted by a higher priority query. Queries in the completed state have completed execution. In some arrangements, additional statuses are supported.
[0036] The mediation server 304 may also store information identifying when and how the requester should be notified that query results are ready for processing. In some arrangements, multiple query engines may independently operate on different portions of a single query. Each query engine independently updates the mediation database. A notification event will be triggered once when the triggering event occurs, for example, when the combined query engines have returned a requested number of rows.
[0037] In some implementations, mediation server includes a mediation logic module 306 and a mediation database 308 . In some implementations, the mediation logic module 306 may be incorporated into the individual query engines 312 , a front-end service 302 , or divided between multiple services. The query engines 312 may update the mediation database 308 as to the number of rows available in the result set 314 .
[0038] In some implementations, the data sources 310 include, referring to FIG. 4 , indexed compressed data storage 402 . An indexed compressed data storage includes multiple compressed data blocks 404 stored, for example, in a file. Each compressed data block is associated with at least one index 406 that enables location of data within that compressed data block. In some implementations, a primary index is provided that can be searched based on a first key (e.g., a primary key), and one or more secondary indexes are provided that can be searched based on other keys (e.g., a foreign key). Some of the indexes may be made up of a surrogate key where each key value is unique, other indexes based on a natural key where the values of the key may not be unique within the data set. In some implementations, the natural indexes may be combined to create a single consolidated index. Indexed compressed data storage techniques and systems are described in more detail in U.S. Patent Application Publication No. 2008/0104149 A1, incorporated herein by reference.
2 Query Slicing
[0039] Referring to FIG. 5A , a series of queries A 502 , B 504 , C 506 , and D 508 are shown in a plot showing intervals of time associated with different queries. If the queries are executed in the order in which they are delivered, query A is executed to completion over interval 502 , then query B is executed to completion over interval 504 , followed by queries C over interval 506 and D over interval 508 . Under these conditions, query A would not return results until it completes at time 510 , query B would not return results until it completes at time 512 , query C would not return results until it completes at time 514 , and query D would not return results until it completes at time 516 . Although query D is a short query, it takes a long time to return any results because it happened to be situated behind other longer queries.
[0040] In some implementations of the mediation server 304 , instead of necessarily running queries sequentially to completion, the mediation server divides a query into multiple different smaller portions. The query engine 304 is instructed to execute a query for a particular interval. This interval may be defined by a period of time, a number of rows to be returned, the number of rows processed, or based on some other criteria. Using this approach, referring to FIG. 5B , query A runs for an interval 528 , query B runs for an interval 530 , query C runs for an interval 532 , query D runs for an interval 534 (to completion), and then query A runs again for a second interval. In some cases, some results from a query may be returned to the process which submitted the query after each interval in which the query is processed. For example, some results from query A may be return after the time 520 , and some results from queries B, C, and D may be return after the times 522 , 524 , 526 , respectively. By dividing the queries into small execution intervals the system 300 can generate some results for more queries sooner than if the system had to wait for queries to complete before executing other queries. Additionally, some queries can be completed sooner than they would have been completed otherwise, with the trade-off of delaying other queries. In this example, query D is completed at time 526 , query C is completed at time 540 , query A is completed at time 542 , and query B is completed at time 544 . So in this example, the shorter queries C and D are completed sooner at the expense of delaying the longer queries A and B.
[0041] The determination of how to divide a query may depend on the operational characteristics desired for the system. For example, providing dividing a query based on time may guarantee that each query is allowed to do a specific amount of work, but there is no guarantee how long the work may take in calendar time nor is there a guarantee as to how many rows may be returned in an execution interval. In contrast, allowing a query to execute until a number of rows are returned determines how many execution intervals will be necessary to generate a number of results, but without a guarantee as to how long an interval may last. Allowing a query to run until a number of rows have been processed may allow the system to identify how many execution intervals will be necessary to complete a query but will not tell how many cycles are required to return a specific number of rows or specifically how long a particular execution cycle will take.
[0042] Time for processing queries can be divided into execution intervals (or “query intervals”) even if only a single query is being processed. At the end of a query interval, if a new query has arrived, then the query being processed is suspended and the next query interval is used to process the new query. Alternatively, if a new query has not arrived at the end of the query interval, then the query being processed can continue to be processed for an additional query interval. For example, in the example of FIG. 6A query B arrives at time 610 during the processing of query A, and in the example of FIG. 6B both queries A and B arrive before processing of either query A or query B has begun.
[0043] In the example of FIG. 6A , query A runs for an interval 602 and if query A has not completed at the end of the interval 602 , the system checks to determine whether query A should be processed for an additional query interval or whether there is another query waiting to be processed. Since query B has not yet arrived at the end of interval 602 , query A is processed during query interval 604 . Similarly, query A is also processed during the following query interval 606 . However, at the end of query interval 606 , the system determines that the query B, which arrived at time 610 , should be processed during interval 608 . Queries A and B are then processed in alternating intervals until each is completed (in this example, query A is completed at time 612 and query B is completed at time 614 ). In the example of FIG. 6B , query A runs for an interval 620 and if query A has not completed at the end of the interval 620 , the system checks to determine whether query A should be processed for an additional query interval or whether there is another query waiting to be processed. Since query B has arrived before the end of interval 620 , query B is processed during query interval 622 . Queries A and B are then processed in alternating intervals until each is completed.
[0044] Suspending a query at the end of a query interval includes saving the state of the query in the mediation database. In one arrangement, after an interval a query state may be updated in the mediation database to “suspended” or another state indicating the query is not eligible for execution. After a predetermined interval, the query's status may be updated to “waiting” to enable the query to run again. In other arrangements, the mediation server automatically schedules the query immediately after the predetermined interval.
3 Query Prioritization and Reprioritization
[0045] The mediation database may store a priority associated with individual queries. The priority may affect the frequency and manner in which a query is run. Referring to FIG. 7A , a high priority query A may be provided with larger execution intervals 702 than a query B (processed during intervals 704 ) or a low priority query C (processed during intervals 706 ). In this example, the high priority query A is provided larger execution intervals 702 than the execution intervals 704 provided to the query B, and the query B is provided with execution intervals 704 larger than the execution intervals 706 provided to the low priority query C. Alternatively, referring to FIG. 7B , a high priority query A may be provided with more frequent execution intervals 708 than a standard priority query B (processed during intervals 710 ), and the standard priority query B may be provided with more frequent execution intervals than a low priority query C (processed during intervals 712 ). Referring to FIG. 7C , In some circumstances a query A may be provided a priority high enough that processing of other queries B and C is suspended until the query A completes execution (after interval 714 ) at which point execution on the suspended queries B and C resumes, alternating between intervals 716 and 718 , respectively.
[0046] The mediation database also allows queries to reprioritize while the query executes. For example, referring to FIG. 7D , high priority query A is scheduled by the mediation database (during intervals 720 ) along with normal priority query B (during intervals 722 ) and low priority query C (during intervals 724 ). At a time 726 high priority query A is reprioritized to a normal priority level. At which point the mediation database adjusts the scheduling of queries based on the new prioritization. Going forward after reprioritization, now normal priority query A is provided with execution intervals 728 of similar size to the intervals 722 provided to normal priority query B.
[0047] The reprioritization may occur due to a determination made by the requesting process or may occur within the mediation server based on its own criteria. For example, the mediation server may be provided a deadline to complete a query, as the deadline approaches the server may boost the priority of the query to ensure timely completion. In some cases, a query may be provided with multiple smaller execution intervals, instead of a single larger execution interval in order to allow the mediation server to check for higher priority traffic. In other cases, the mediation server may be able to interrupt the execution interval of a running query to allow a higher priority query to execute.
[0048] In some cases, queries may be scheduled ahead of execution either before or during the execution of a previous query, with the new query entering in the next interval. In some cases, the next query to be scheduled for execution may be selected just before execution based on a selection criteria.
4 Parallel Query Processing
[0049] For many systems, it may be advantageous to execute multiple queries at once. For example, two queries running on a single system may experience improved performance over a single query running on a system. This may occur, for example, because one query may be utilizing one computing resource while the second query is utilizing a different resource. By running both queries at once throughput is improved. In some implementations, referring to FIG. 8 , a high priority query 802 is divided into query slices 804 , 806 , 808 , 810 , 812 . Each slice may be processed by a separate query engine 814 , 816 , 818 , 820 , 822 .
[0050] The high priority query 802 may be sliced based on a number of rows to process as described above. The partitioning information may be compared to a secondary index of an indexed compressed data storage that is the target of the query in order to determine how many execution intervals will be necessary to complete the query. This will also identify which parts of the index compressed data storage will be processed by each query slice. For example, referring to FIG. 9 , an indexed compressed file 902 includes multiple data blocks 904 , 906 , 908 , 910 each data block includes multiple data records. The indexed compressed file 902 is associated with an index 912 which references the data blocks. In some arrangements the index may include one index record 922 for each data block, and in other arrangements the index 912 may include fewer index records 922 than data blocks. In some arrangements each index record 922 references a data block 904 , 906 , 908 , 910 , and in other arrangements each index record 922 references the first data record of a data block. The mediation server reviews the index 912 and determines query execution intervals (or “query slices”) based on the index records. In this example, the query engine elects to create four query slices 914 , 916 , 918 , 920 based on the index 912 . One query slice 914 processes data records starting with block 1 904 and ends with the end of block 10 (not shown), query slice 916 processes data starting with block 11 906 and ends with the end of block 20 (not shown), query slice 918 starts processing with block 21 908 and ends with the end of block 30 (not shown), and finally query slice 920 starts processing with block 31 910 and ends processing at the end of the indexed compressed file 902 . In this example, the mediation server may elect to create any number of query slices, limited only by the number of index records 922 in the index 912 .
[0051] Referring to FIG. 8 , each slice of the query may be simultaneously processed by a different one of the query engines 814 , 816 , 818 , 820 , 822 . For example, query slice 804 may be processed by a query engine 814 while query slice 806 is substantially simultaneously processed by query engine 816 . At the same time query slice 808 is processed by query engine 818 ; query slice 810 , by query engine 820 ; and query slice 812 , by query engine 822 . Each query engine produces a result set for their query partition. Once all of the result sets are generated, the result sets may be combined together to form the complete result set for the entire query. Using this method, a high priority query can be completed in a fraction of the time it would normally take to complete the operation.
5 Callbacks
[0052] The system provides notification when a trigger defined by pre-designated criterion is met. Referring to FIG. 3 , when a new query is submitted to the front-end service 302 , the submission may include information requesting the mediation server 304 notify the requester (via the front-end service 302 ) when a condition is met. In some arrangements, the condition may be a notification when a particular number of result data elements are ready to be accessed by the requester. For example, a requester may be notified when one hundred result records are ready. In some cases, the requester may designate the number of result data elements that should be ready before notification. In other cases, the requester may provide other criteria which must be met before the requester is notified. For example, a requester may wish to be notified when the query is suspended or when all processing is complete. In some cases, the trigger criteria may be limited to state information tracked in the mediation database 308 . In other cases, the trigger criteria may be unlimited. The trigger may be provided to the mediation server 304 in a number of different ways. For example, the trigger may be provided as a script which the mediation server 304 executes after each query interval or a compiled class complying with a predetermined application programming interface (API). In some cases, the condition may occur only once, for example, a condition that one hundred result records had been discovered. In other arrangements the condition may be reoccurring, for example, a request for notification each time one hundred additional result records are discovered.
[0053] In some cases, the submission of the trigger condition may also include an action definition. This action may be stored in the mediation database 308 along with the trigger. The action defines how the mediation server 304 responds when the condition is met. The action may be one of a predetermined set of possible actions, for example, notify, summarize, etc. The action may be a script that is executed on the mediation server 304 . For example, one action may submit additional queries to the system using the returned results as a query parameter. The action may be provided as a compiled class which conforms to a pre-established API.
6 Query Suspension
[0054] In some implementations, the mediation server 304 is capable of suspending the processing of a query. The mediation server may mark the query as suspended and no processing will occur until the query is resumed. Along with suspending the query the query server may save a state of the query. This state is an indication of the process of the query. For example, the state may be an offset to an indexed compressed data store, or the state may include the last processed node in a b-tree.
[0055] In some cases, the mediation server may elect to suspend a query on its own initiative. This may occur, for example, when a query has produced a number of records in a result set and the number of rows in the result set waiting to be delivered to the requester exceeds a threshold.
[0056] For example, a requester who submits a query may later request the delivery of a fixed number of rows, for example, if a user interface may require a “page” of twenty-five rows of data to populate the screen the system may request twenty-five rows of data from the query. Later, if a user indicates that he wishes to see more query results the system may request the next “page” of query results, or results twenty-six to fifty. The mediation database tracks the number of results returned from the query and the number of results returned to the user. For example, the query may have returned 300 rows, but 25 rows may have been sent to the requester. If the number of rows returned from the query exceeds the number of rows sent to the requester by a margin (for example, 25, 50, 75, or 100 rows) then the mediation database may suspend processing of that query. This may be accomplished by either marking the query as suspended in the mediation database or via a check prior to scheduling the next execution of the query.
[0057] In some cases, the threshold may be defined by the system 300 , and in other cases the threshold may be defined individually for each query depending on how the query is going to be used. For example, a query whose results are going to be used to display lists of data on Web pages with a fixed number of items display may suspend when four pages of data are waiting. In contrast, a query whose results are going to be used to create a summary report of all of the data returned by the query, for example a month's end report, may not suspend at all. In some cases, the threshold may be inferred from the number of rows to collect before notifying the requester.
[0058] In some cases, a query may be explicitly suspended by updating the query's state information in the mediation database. For example, a query may be marked as suspended to allow higher priority queries to execute. In other cases, a query may be implicitly suspended because the mediation servers scheduling algorithm is such that a query with the state of the suspended query will not be scheduled. Suspending queries has the additional advantage of minimizing the waste of resources when a query is submitted and the calling program subsequently terminates before the query is complete. The mediation server may elect to delete a query and a result set if the requester has not accessed the results for a predefined period.
7 Mediation Server Processing
[0059] Referring to FIG. 10 , a flowchart 1000 represents an exemplary arrangement of operations of the mediation server 304 including a determination as whether to suspend processing of a query without an external request.
[0060] Operations include selecting a query for execution 1002 . In one example, the query may be selected as part of a pre-determined schedule established by the mediation server. In another example, the query may be selected based on some criteria which may include the priority of the query and the last time the query was run. In some arrangements, the mediation server iterates over the queries waiting execution (for example, in a waiting state). Each of the queries is schedule to run on the query engine. Once all queries which are waiting have been executed the mediation server repeats the process for the queries still waiting execution. In other arrangements, the mediation server selects the query which has been waiting for the longest interval for execution. In other arrangements, the mediation server selects the query with the highest priority for execution.
[0061] Operations also include running the query on a query engine 1004 . In one example, the selected query may be assigned to a query engine which executes the query against the data records, updates a result set, and notifies the mediation server of the number of rows returned.
[0062] Operations also include a check of the number of rows waiting to be delivered 1006 . If the number of rows waiting to be delivered exceeds the notification threshold then the mediation server performs a callback to the requester 1008 .
[0063] Operations also include a check 1010 if the number of rows waiting for the requester to access them exceeds the suspend threshold then the query is suspended 1012 . Whether the query is suspended or not, the mediation server moves on the select the next query to process.
[0064] Referring to FIG. 11 , a flowchart 1100 represents an exemplary arrangement of operations of the mediation server 304 in response to a requester accessing part of a result set returned by a query, for example, after a callback has notified the requester that the results are ready for access.
[0065] Operations include the requester requesting results from the query 1102 . In some arrangements, the requester may send an indication of the number of rows to be returned, for example a request to return twenty-five rows. In other arrangements, the requester may request a specific range of results to be returned. For example, the requester may request results fifty to one hundred twenty six to be returned. In still other arrangements, the requester may request that all collected results be returned.
[0066] Operations also include returning results and updating records 1104 . In response to the request, the mediation server may provide access to the rows requested. In some arrangements, the mediation server may also send an indication to the requester that the query is still processing additional results. In other arrangements, the mediation server may also provide an indication that additional results are available for immediate delivery.
[0067] Operations also include a check 1106 to determine if the query is currently suspended. If the query is suspended control passes to the next operation 1108 . Otherwise the process is complete.
[0068] Operations also include a check 1108 to determine if the number of rows waiting for delivery is less than the suspend threshold. If so then the query is resumed 1110 and may be scheduled for processing by the mediation server.
[0069] The query management approach described above can be implemented using software for execution on a computer. For instance, the software forms procedures in one or more computer programs that execute on one or more programmed or programmable computer systems (which may be of various architectures such as distributed, client/server, or grid) each including at least one processor, at least one data storage system (including volatile and non-volatile memory and/or storage elements), at least one input device or port, and at least one output device or port. The software may form one or more modules of a larger program, for example, that provides other services related to the design and configuration of computation graphs. The nodes and elements of the graph can be implemented as data structures stored in a computer readable medium or other organized data conforming to a data model stored in a data repository.
[0070] The software may be provided on a storage medium, such as a CD-ROM, readable by a general or special purpose programmable computer or delivered (encoded in a propagated signal) over a communication medium of a network to the computer where it is executed. All of the functions may be performed on a special purpose computer, or using special-purpose hardware, such as coprocessors. The software may be implemented in a distributed manner in which different parts of the computation specified by the software are performed by different computers. Each such computer program is preferably stored on or downloaded to a storage media or device (e.g., solid state memory or media, or magnetic or optical media) readable by a general or special purpose programmable computer, for configuring and operating the computer when the storage media or device is read by the computer system to perform the procedures described herein. The inventive system may also be considered to be implemented as a computer-readable storage medium, configured with a computer program, where the storage medium so configured causes a computer system to operate in a specific and predefined manner to perform the functions described herein.
[0071] A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, some of the steps described above may be order independent, and thus can be performed in an order different from that described.
[0072] It is to be understood that the foregoing description is intended to illustrate and not to limit the scope of the invention, which is defined by the scope of the appended claims. For example, a number of the function steps described above may be performed in a different order without substantially affecting overall processing. Other embodiments are within the scope of the following claims.
|
Managing queries performed on one or more data sources includes: storing at least a first query in a storage medium; selecting the first query for processing; instructing a query engine to process the first query on a first portion of data in the one or more data sources for a first query interval; receiving result data from the query engine based on processing the first query on the first portion of data; saving a state of the first query in the storage medium after the first query interval; instructing the query engine to process a second query during a second query interval after the first query interval; and instructing the query engine to process the first query on a second portion of data in the one or more data sources during a third query interval after the second query interval.
| 6
|
BACKGROUND OF THE INVENTION
The invention relates to a method and an arrangement for recognizing distribution information on mail items and can be used particularly advantageously for determining distribution information written in non-alphabetic language on mail items.
Systems for the automatic reading of distribution information, particularly addresses (OCR), are well known in the field of mail processing and are described, for example, in the DE 195 31 392. Modern OCR letter sorting equipment makes it possible to achieve processing rates of 10 letters per second, that is to say 36,000 letters per hour and more. However, the recognition reliability varies strongly based on the lettering style and total quality of the address information on the surfaces of the letters. In the case of a successful recognition, the respective letter can be provided with a machine-readable bar code. This bar code permits a further mechanical processing up to an optionally desired sorting arrangement. In particular, the use of bar codes makes it possible to sort the letters up to the sorting level of the mail carrier route, for which letters are sorted on the basis of the distribution sequence by the delivery person.
Economic trends and an increased mail volume in Asia have led to increased efforts in the automatic recognition of eastern writing styles, so as to limit costs and improve the delivery of mail. As compared to the situation in western countries where mail automation already represents an established technology, the recognition systems must meet new requirements, which stem from the fact that Chinese characters are used for local mail addresses in most countries of the Asiatic basin. Unlike the letters used in western alphabetic writing, Chinese characters are configured as ideograms. Each of these ideograms can represent a word. In place of an alphabet numbering thirty to sixty letters, 3000 to 6000 different Chinese characters are used daily, each with its own characteristic form. This practical non-perfectivity of the Chinese character system and the ideographic structure of the individual characters lead to a reduced effectiveness of OCR systems as compared to western alphabetical writing systems. In addition, problems are caused by the fact that the address on postal items appears to be oriented either in vertical or in horizontal direction and that frequently there is a mixture of Chinese and western writing.
Since the recognition rates for the automatic reading systems generally vary considerably for western as well as for Chinese characters, it is necessary to support these through various forms of manual intervention. Reverting to a manual sorting method is the simplest method of intervention in case of a rejection of letters that cannot be read automatically. However, the resulting costs are uneconomically high, owing to the increasing operating costs. Added to this is the fact that such hand-sorted mail cannot be further sorted mechanically at a later point in time, so that two separate flows of mail items are created, which must again be combined manually at a specific point in time.
Various methods for manually coding mail items have been developed to avoid the disadvantages of the manual sorting of OCR rejected mail items. All of these methods use operator intervention to apply bar codes to the mail items, in a manner that is consistent with the requirement for a mechanical sorting with the same equipment used to process the OCR read and bar-coded mail.
Another method for coding rejected mail items uses so-called manual coding stations. At these manual-coding stations, the mail items are physically moved sequentially past an operator, wherein the operator encodes as much information for each of these items, as is necessary to clearly identify the destination location. In the process, the input address is converted by means of a directory to a sorting bar code, which is then applied to the mail item. The coded mail items are then processed further with the aid of bar-code sorters (BCS), which are mechanically identical to OCR-suitable BCS. Such manual coding stations were initially introduced by the US Postal Service and the Royal Mail in the Seventies. The main disadvantages of such devices are the required removal of mail items from the OCR mail flow and the ergonomic difficulties, experienced by the operator during the recognition of the mail items that are moved past the operator.
The next advance in the treatment of mail items rejected in the OCR was the development of on-line video-coding systems (OVS). In an OVS, a video image of the item is presented to an operator for coding in place of the physical mail item that is present at manual coding stations. The video image is shown to the operator while the physical item is held in delay loops. In these delay loops, the item is normally held in motion for a period of time that is sufficient for the OVS operator to input the necessary sorting information for the respective image. The standard delay loops permit a delay of between 10 and 30 seconds. The longer the delay loop, the higher the costs as well as the requirements for maintenance and the physical size of the installation.
The main problem when using OVS is that the available time is sufficient only for a careful input of the zip code (ZIP) or the postal code (PC) unless long, impractical delay loops are used.
As long as a ZIP or PC exists, OVS can also be used effectively for items addressed with Chinese characters. However, the share of such mail items in many eastern countries is very low and probably will remain so in the foreseeable future.
For that reason, special coding methods were developed to keep the on-line delay time as low as possible.
In order to increase the coding productivity and/or make it possible to give all address elements, meaning the ZIP/PC, street/post office box, addressee/post office box, addressee/firm, various methods have been developed in prior art. Essentially, these include:
Preview Coding:
The preview coding involves a simultaneous display of images from two mail items, one above the other. The lower image in this case is the active one, meaning the one for which data are coded. Following a suitable training, operators can encode the information on the lower image while simultaneously visually recognizing the address information on the upper image. The upper image subsequently becomes active and the process is continued. The preview coding makes it possible to double the operator productivity through a complete overlapping of the cognitive and the motorized functions during the coding of sequential images.
Extraction Coding:
Owing to the fact that only the ZIP/PC address elements can be input reliably by the operator given the on-line delay times that can be achieved in practical operations, certain key components of the address components referring to the street are input during the extraction coding. The extraction coding normally is based on specially developed rules, for which a code with fixed length is used as access key to an address directory. For example, the Royal Mail uses an extraction formula that is based on the first three and the last two letters. For this, the operator must memorize special rules to avoid superfluous address information and to take into account specific, distinguishing characteristics, e.g. directions such as east, west or categories such as street, lane, road.
Despite being very effective, extraction coding has several considerable disadvantages, particularly complex extraction rules, which frequently require taking into account the end of a street name, even though these components normally are the least clear with hand-written addresses on mail items. In addition, there is a significantly high rate of unclear extractions, for which several entries in a directory correspond to the extraction code, so that it is not possible to make a definite sorting decision. It must also be considered that the input productivity of the operators is reduced as soon as the operators must make decisions instead of a simple repetitive keyboard entry.
Completion Coding
In contrast to the extraction coding, a variable input for each address to be coded must be made during the completion coding. Essentially, a comparison with the address directory takes place during the address input until a clear match has been found. An acceleration effect is achieved by displaying the remainder of the address as soon as a clear partial match has been identified. However, problems occur with this technique in that the operator must be supplied with an input-stop signal and that a display of the identified address remainder is required, which leads to reduced input productivity and makes a preview coding impossible.
Theoretically, all described video-coding techniques can also be used for mail items with Chinese characters, even though the lack of fast input techniques for Chinese characters continues to makes them only marginally usable.
Operator-assisted OCR Technique:
In order to increase the address information to be processed on-line, the US Postal Service has experimented with operator-assisted OCR techniques. For this, that portion of the address image for which the OCR recognition has failed is emphasized in order to increase the effectiveness. Since the operators are slow when deciphering missing letters and, in part, complex recognition errors such as segmenting problems occur as well, the operator productivity with this method is frequently lower than if the respective address is simply input once more.
Off-line Coding:
Since none of the aforementioned coding techniques make it possible to achieve a sufficiently high productivity for the pure on-line coding, an off-line coding system was recently introduced, e.g. as described in the US PS 49 92 649. In this system, mail items with unrecognized addresses are provided with an additional information, a tracking information (TID). The unrecognized mail items are stored externally, while the images of these mail items are presented to operators for coding, wherein time limitations in the range of seconds do not exist. The mail items are subsequently presented to TID reading devices. The TID is linked to the input address information. Based on this, a standard bar code sorting information can also be applied to the mail item, so that the respective mail item can be processed in the same way as mail items normally read with OCR. Even though the off-line video-coding method represents an effective method for coding all address components, additional capacities for the further processing of mail items with unread addresses and a correspondingly complex logic are required.
Basically, the operator-assisted OCR techniques are also suitable for processing mail items with Chinese characters, but they do not as yet permit a fast input of such characters.
This unsatisfactory situation is only made worse in that the operator faces relatively high requirements with respect to the necessary training and required knowledge.
SUMMARY OF THE INVENTION
The method and arrangement according to the invention are intended to solve the problem of quickly coding distribution information in the form of addresses, particularly non-alphabetic handwriting on mail items while making fewer demands on the personnel as compared to known solutions.
This is achieved by an arrangement for recognizing distribution information on mail items; which includes a device for obtaining images of mail items, an OCR unit for automatic evaluation of images of mail item surfaces that contains the distribution information, a video-coding device for recording the images of the mail item surfaces with at least one video-coding station; a processing unit that controls data flows between the input units and the output units of the video-coding device and the OCR, and a voice input unit with a microphone and a voice recognition module connected to each video-coding station where distribution information suggestions with the highest reliability are transmitted by means of the processing unit to a screen of a respective video-coding station for selection or confirmation, following a comparison with a dictionary.
The coding input by means of a speech input unit permits a very quick input of the address information, even for relatively untrained personnel and has particular advantages for the coding of hand-written addresses in Chinese characters without postal code (ZIP).
Advantageous embodiments of the invention follow from the dependent claims.
If keys of a keyboard are used in addition to the voice input for the coding input, especially for numerical distribution information components or frequently occurring higher target areas by means of control keys, an even more secure input is possible. The components of the distribution information, input with the aid of different input media, are then combined to form complete distribution data.
It is furthermore advantageous if a simultaneous address evaluation takes place in an OCR unit to increase the recognition safety and if the distribution information suggestions are combined with the suggestions obtained through the input procedure to form a complete list of distribution information suggestions with new reliabilities.
It is also advantageous if the distribution information suggestions of the OCR unit are correlated with the keyboard entry data to correct errors.
In another advantageous embodiment of the invention, implausible distribution information suggestions are removed from the complete list by means of statistically determined threshold values for reliability values so that a final selection of the distribution information suggestions can be made quicker and easier.
It is also advantageous if frequently addressed, larger target areas are assigned to a control key.
According to claim 6, it is also advantageous if frequently addressed, larger target areas are assigned to a control key.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained in further detail in the following with the aid of drawings, wherein the following is shown:
FIG. 1 A schematic representation of an arrangement according to the invention;
FIG. 2 A flow chart describing the coding of mail items according to the invention;
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a schematic representation of a letter distribution facility for realizing the method according to the invention. An OCR letter sorter 10 comprises a feeding device 11 , which pulls successive mail items from a magazine 12 and transports these at the rate of approximately 10 items per second to a high-resolution video scanner 17 , which serves as a device for obtaining images 18 of the mail items. The mail items are subsequently transported in a delay loop 13 . The mail items normally contain distribution information, particularly address information on their surfaces. The address information on the mail item images, obtained with the aid of video scanner 17 , is evaluated in an OCR unit 20 . In case of a complete evaluation, a bar code printer 14 is actuated and the mail item is provided with a respective bar code for the subsequent sorting into sorting compartments 16 . The OCR unit 20 consists of one or more microprocessors 21 with associated memory 22 for storing the images of the mail items. The OCR unit furthermore includes a dictionary 23 with ZIP codes, city names and street names and possibly additional address-related information. When evaluating the images containing the address information, a feature-controlled reduction of the entry obtained from the address listing preferably occurs, so that a type of partial dictionary is created. In that case, reliabilities are assigned to the individual entries, so that a number of data of addresses recognized as correct are created during the evaluation. The arrangement furthermore comprises a processing unit 30 , as well as a number of video-coding stations 40 , which are connected directly or via a local network (LAN) 31 to the processing unit. It is preferable if workstations are used as video-coding stations. If the OCR evaluation of an image was not completely successful, this image is transferred from the OCR unit 20 to the processing unit 30 , which controls among other things a TID bar code printer 15 and sends the corresponding image to one of the video-coding stations 40 . The TID bar code printer 15 affixes an identification code TID to the corresponding mail item, which makes it possible at a later point in time to link the evaluated address information with the physical mail item. The evaluation of the images in this case preferably occurs off-line, even though an on-line evaluation through video-coding is in principle also possible with a sufficiently long delay time. In the latter case, the TID can also be applied at a later point in time to the mail item, that is to say if the video-coding has not resulted in a complete evaluation during a specific, predetermined time interval.
As indicated schematically, a keyboard 50 for a keyboard input and a voice input unit, consisting of a microphone 60 and a voice recognition module 70 , are connected to each video-coding station 40 .
According to FIG. 2, the image (in 2 or more gray levels) of a mail item (e.g. a letter, mailing pouch, package) with additional information relating to the results of the previous processing (e.g. orientation, position of address block) is present for the input. A character string containing distribution information assigned to the mail item image is made available at the output.
The mail item image is displayed 100 on the screen of the video-coding station, wherein the possible address fields (ROIs) have a colored border and are marked with consecutive numbers starting with 1. The preferred ROI is emphasized relative to the other ROIs with a different color (e.g. red). The operator decides whether the mail item image contains a visible postal code (ZIP) 110 that is sufficient for the intended distribution. If so, the operator inputs this code via the keyboard 120 . At the completion of the input, the validity of the ZIP is checked with the aid of a list of reliable ZIP codes 130 , 140 . If the ZIP is not valid, a warning signal 150 is sounded (e.g. an acoustic signal) and a renewed input 120 is expected. If the ZIP is valid, it will be output as result, and the processing of this mail item is completed.
If the mail item image does not contain a sufficient ZIP, the operator depresses a warning key 121 (e.g. ESC) and checks whether the orientation and the selected address region (ROI) of the mail item image have been determined correctly 200 . If this is not the case, the operator selects the correct orientation with control keys and/or the correct ROI via number keys 210 .
The character recognition (OCR) is initiated by a decision on whether the preferred ROI contains handwriting or machine writing. This decision is prepared in a statistically adapted classifier 300 and is confirmed by the operator (with the space bar) or is corrected (for example with the keys “H” or “M”) 310 / 400 .
If a hand-written address is present, the multimedia recognition by means of voice input and manual input is actuated. For this, the preferred ROI are simultaneously processed with the manual OCR 320 . The operator inputs the name of the city (if defined) via a control key and the numerical components of the address (e.g. house numbers) via number keys 330 . At the same time, the operator speaks the name of the city (if not defined on the control key) or in another case the name of the street into the connected microphone 340 . The analog voice signal from the microphone is changed to digital data and is processed by the voice recognition module 341 , wherein a list of candidates is set up that is evaluated on the basis of reliability measures.
The result of the manual OCR 320 is correlated 350 with the input key codes 330 in such a way that if there is a city name, it is compared to the city name from the manual OCR and said name is corrected in case of a conflict, that the digit sequence representing the numerical address components is compared with respect to position and value to the OCR result and this result is corrected in case of a conflict. The result of the correlation is a list of reliability values, comprising one or several character chains that represent in each case a well-written address.
The result of the voice recognition 341 is composed 360 with the aid of the input key codes 330 in such a way that the address components (city name, street name, house number, etc) in a character chain are lined up in the correct sequence. A corresponding character chain is created from each candidate in the voice recognition 341 .
The character chains, produced in the steps 350 and 360 , are combined 370 with cumulative reliability measures for the same character chains to form a complete list with a uniform format. With the aid of statistically adapted threshold values for reliability measures, sufficiently implausible results are removed from the complete list 380 . A list of alternative addresses is then available as a result.
If a machine-written address exists, the preferred ROI is processed 410 in the traditional manner by an OCR with parameters adapted to machine writing.
The result of steps 380 or 410 are processed with a traditional address interpretation 500 , which checks for each address alternative to determine whether it is syntactically well-formed and exists in the dictionary, determines the respective ZIP from the dictionary and provides one or several result alternatives, respectively consisting of the ZIP and the complete or sufficiently unambiguous address character sequence as the result.
The result of the address interpretation is displayed on the screen 510 in the form of a selection menu (multiple choice), wherein the result alternative with the highest reliability appears as the first position. The operator then checks whether the result 520 , which corresponds to the mail item, is contained in the menu by comparing the mail item image 100 and the menu 500 . If this is the case, the operator marks the appropriate result 530 with a figure key (or the space bar, corresponding to the first alternative). The ZIP assigned to the selected alternative is output as result, and the processing of the mail item is completed.
If the correct result is not contained in the menu, the operator writes down the address via letter keys with shortened, phonetic or another coding 600 . The input character sequence is processed with another polling of the traditional address interpretation and the result is again displayed in the form of a menu 610 . As for step 530 , the operator selects the correct result from 630 or, if the correct result is not contained in the menu, the operator actuates the REJECT key 640 , which leads to a final rejection of the current item. This item must then be processed further in a manual distribution or the like.
|
The invention pertains to mail distribution information recognition technology, involving video-coding stations. According to the invention, the distribution information is fed into the screen of a video-coding unit by means of a speech input unit comprising a microphone ( 60 ), a speech recognition module ( 70 ) and, if need be, a key board ( 50 ). The input data are compiled to a list covering all possible proposals concerning the recognition of the distribution information, said proposals being assessed according to the plausibility criterion. After removal of the little plausible proposals, the selected ones are displayed.
| 6
|
[0001] This application is a Non-Provisional application which claims priority to and the benefit of Italian Application No. MI2012A000511 filed on Mar. 29, 2012, the content of which is incorporated herein by reference in its entirety.
SUMMARY OF THE INVENTION
[0002] The present invention relates to an advantageous process for the preparation of iloperidone, wherein the intermediate 1-[4-(3-chloropropoxy)-3-methoxyphenyl]-ethanone is not isolated but used in the next step with no need to conduct any work-up, isolation or purification step.
BACKGROUND TO THE INVENTION
[0003] Iloperidone (1-[4-[3-[4-(6-fluoro-1,2-benzisoxazole-3-yl)-1-piperidinyl]propoxy]-3-methoxyphenyl]ethanone) is an atypical new-generation antipsychotic medicament belonging to the class of piperidinyl-benzisoxazole derivatives, which is used to treat schizophrenia, bipolar disorder and other psychiatric conditions. Iloperidone acts as a serotonin/dopamine receptor antagonist (5-HT 2A /D 2 ).
[0004] The synthesis of iloperidone is described in USRE39198 (corresponding to EP 0 402 644 example 3) according to the following synthesis scheme:
[0000]
[0005] In agreement with said patent, the intermediate isolated, 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone, is reacted with 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole hydrochloride in N,N-dimethyl formamide at 90° C. for 16 hours. When the reaction is complete, the mixture is poured into water and extracted with ethyl acetate. The crude product thus obtained is crystallised twice from ethanol to give crystallised iloperidone with a total yield of 58%.
[0006] The yield of this process is very low; moreover, the process begins with two isolated intermediates, and requires an aqueous extractive work-up step with an increase in volumes and consequent reduction in the productivity and efficiency of the process. Said process also requires a double crystallisation step to obtain a beige product. The quality levels obtained are not described in the text of the example, but a beige color does not suggest a high-quality product, as iloperidone is a white substance.
[0007] The synthesis of intermediate 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone is disclosed in U.S. Pat. No. 4,366,162. Example 1 describes the preparation of said intermediate by reacting acetovanillone with 1-bromo-3-chloropropane in acetone with potassium carbonate. At the end of the reaction the resulting product is purified by distillation and obtained as an oily intermediate which is left to stand in order to obtain the solid intermediate.
[0008] The synthesis of intermediate 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone is also disclosed in U.S. Pat. No. 4,810,713. Preparation 12 describes the synthesis of said intermediate from acetovanillone and 1-bromo-3-chloropropane in sodium hydroxide alkalinized water. At the end of the reaction the product obtained is extracted in toluene, the organic phases are washed with basic aqueous solutions and finally, the intermediate 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone is crystallised with the aid of diisopropyl ether. The intermediate isolated is then recrystallised twice from cyclohexane and twice from petroleum ether.
[0009] An alternative process for the synthesis of iloperidone is reported in CN 102070626.
[0010] Scheme 2 shows the synthesis procedure:
[0000]
[0011] The decision to alkylate acetovanillone with 1-chloro-3-propanol requires an extra synthesis step (to convert the OH group to an OR leaving group) compared with the procedure reported by the combination of patents USRE39198 (EP402644) and U.S. Pat. No. 4,366,162/U.S. Pat. No. 4,810,713, making said process less efficient from the economic standpoint.
[0012] WO2011061750 discloses an alternative iloperidone synthesis process as reported in Scheme 3:
[0000]
[0013] Said process uses reagents such as methyl magnesium chloride to effect the Grignard reaction to convert the aldehyde group to a secondary alcohol group, which are much more complicated to manage on an industrial scale than the synthesis methods previously described. Moreover, the oxidation reaction of the next step uses reagents such as chromic acid or potassium permanganate, which have a very high environmental impact and very low industrial applicability.
[0014] WO2011055188 discloses a process for the synthesis of iloperidone comparable to the one reported in USRE39198 from two isolated intermediates 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone and 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole hydrochloride. The same patent application also gives preparation examples of the intermediate 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone isolated as crystalline solid by procedures similar to those known in the literature.
[0015] CN 101824030 reports an iloperidone synthesis method similar to that of CN 102070626 which involves the same problems of inefficiency due to the additional step of inserting the leaving group required for alkylation with 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole hydrochloride.
[0016] CN 101781243 discloses an alternative iloperidone synthesis process as reported in Scheme 4.
[0000]
[0017] Said process is not advantageous compared with the preceding processes as the intermediate with the oxime group, due to the nature of this functional group, is particularly liable to degradation due to the action of numerous factors such as the presence of metals, acid pHs and basic pHs.
[0018] CN101768154 discloses a process for the synthesis of iloperidone comparable to the one reported in USRE39198 from two isolated intermediates, 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone and 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole hydrochloride.
[0019] CN 101735208 describes a process for the synthesis of iloperidone comparable to the one reported in CN 101781243, namely through the intermediate with the functional oxime group.
[0020] IN 2007MU01980 discloses a process for the synthesis of iloperidone comparable to the one reported in USRE39198 from two isolated intermediates, 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone and 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole hydrochloride.
[0021] WO 2010031497 describes an alternative iloperidone synthesis process as reported in Scheme 5.
[0000]
[0022] The considerable economic disadvantage of the process reported in WO2010031497 is based on the fact that by reversing the order of alkylation and performing that of intermediate 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole hydrochloride first, a greater loss of yield is generated on this intermediate which, according to the literature, is more difficult to synthesise and consequently more expensive than the intermediate 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone, with a globally greater economic inefficiency of the iloperidone preparation process.
[0023] CN 102212063 discloses a process for the synthesis of iloperidone with the same arrangement of the synthesis steps as patent application WO 2010031497.
[0024] WO2011154860 describes a process for the synthesis of iloperidone wherein a phase transfer catalyst is used to prepare the intermediate 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone which, as in all the other preparation examples previously described, is crystallised, isolated and dried before use in the next step with 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole hydrochloride. Scheme 6 shows the synthesis scheme of the process of WO2011154860.
[0000]
[0025] On the basis of the information collected from the literature, there is an evident need to find a process for the synthesis of iloperidone with high purity which offers greater economic efficiency for implementation on an industrial scale; by “greater efficiency” is meant not only an increase in molar yield but also a reduction in the number of unit operations such as filtrations and isolations of process intermediates, and in particular of the intermediate 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone.
DESCRIPTION OF THE INVENTION
[0026] In the synthesis of 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone by alkylation of acetovanillone with 1-bromo-3-chloropropane, purification of said intermediate is mandatory when a significant molar excess of 1-bromo-3-chloropropane is used with respect to acetovanillone, as it is the case of the synthesis described in Example 1 of U.S. Pat. No. 4,366,162, wherein 1.32 molar equivalents of the latter reagent are used. This as in the subsequent step the excess of 1-bromo-3-chloropropane would react with 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole hydrochloride to give an iloperidone contaminated by impurities difficult to remove.
[0027] An advantageous process for the preparation of iloperidone has now been found wherein using a stoichiometric ratio between acetovanillone and 1-bromo-3-chloropropane close to 1.0 the intermediate 1-[4-(3-chloropropoxy)-3-methoxyphenyl]-ethanone is surprisingly not isolated but used in the next step with no need to conduct any work-up, isolation or purification step. The process according to the invention is exemplified in Scheme 7.
[0000]
[0028] The object of the present invention is a process for the preparation of iloperidone comprising the following steps:
[0029] i. alkylation of acetovanillone with 1-bromo-3-chloropropane to give the intermediate 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone in the presence of an inorganic base;
[0030] ii. alkylation of 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole hydrochloride by the intermediate 1-[4-(3-chloropropoxy)-3-methoxyphenyl]-ethanone obtained in the first step, in the presence of an inorganic base, to give a reaction mixture containing iloperidone;
[0031] iii. isolation of iloperidone from the reaction mixture obtained in the second step;
[0032] characterised in that in the first step 0.9-1.2 molar equivalents, preferably 1.0-1.16 molar equivalents, even more preferably 1.0 equivalents of 1-bromo-3-chloropropane with respect to acetovanillone are used;
[0033] and further characterised in that the intermediate 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone obtained in the first step is not isolated.
[0034] In a preferred embodiment of the invention, iloperidone is isolated from the reaction mixture obtained in the second step simply by filtering the reaction mixture to remove inorganic salts, followed by concentration of the reaction mixture, resulting in the separation of iloperidone with high yields and purity.
[0035] The first synthesis step, wherein the non-isolated intermediate 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone is produced, takes place in an organic solvent or mixtures of solvents selected from acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, preferably acetonitrile or mixtures of acetonitrile with N,N-dimethylformamide in the presence of an inorganic base, preferably potassium carbonate, potassium bicarbonate, sodium carbonate and sodium bicarbonate.
[0036] Preferably acetovanillone is added to a previously prepared solution of 1-bromo-3-chloropropane in acetonitrile or in a mixture of acetonitrile with N,N-dimethylformamide in the presence of an inorganic base.
[0037] The use in the first step of the present process of a stoichiometric ratio close to 1.0 as above defined between 1-bromo-3-chloropropane and acetovanillone, the reversal of the order of addition of acetovanillone and 1-bromo-3-chloropropane to the reaction mixture and the replacement of acetone with acetonitrile or acetonitrile/N,N,-dimethylformamide mixtures result in a significant improvement of the conversion of acetovanillone to 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone which can be converted in an one-pot process to an iloperidone characterized by an excellent purity profile.
[0038] The second synthesis step, wherein iloperidone is produced by alkylation of 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole hydrochloride by the non-isolated intermediate 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone, takes place in an organic solvent or a mixture of solvents selected from acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide and N-methylpyrrolidone, preferably acetonitrile or mixtures of acetonitrile with N,N-dimethylformamide in the presence of an inorganic base, preferably potassium carbonate, potassium bicarbonate, sodium carbonate and sodium bicarbonate.
[0039] Typically, the process according to the invention involves synthesising iloperidone by alkylation of 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole hydrochloride by the intermediate 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone directly from the reaction mixture originating from the first synthesis step, without any work-up, isolation or purification step, wherein an organic solvent selected from acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, an inorganic base, preferably potassium carbonate, potassium bicarbonate, sodium carbonate or sodium bicarbonate, and the raw material 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole hydrochloride, are added to the reaction mixture of the first synthesis step.
[0040] The order of addition of the organic solvent, the inorganic base and the raw material 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole hydrochloride can also be different from that reported above.
[0041] The iloperidone obtained is isolated directly from the reaction mixture of the second synthesis step by simple filtration of the reaction mixture to remove the inorganic salts, followed by concentration of the reaction mixture by evaporation of the solvent, resulting in the separation of iloperidone. The quality of the product obtained exceeds 99%.
[0042] According to a preferred embodiment of the invention, the process is performed as follows:
[0043] Typically, 1 molar equivalent of acetovanillone is added to an organic solution of 0.9-1.2 molar equivalents of 1-bromo-3-chloropropane, preferably 1.0-16 molar equivalents, even more preferably 1.0 equivalents, in the presence of an inorganic base, preferably potassium carbonate, in the amount of 0.9-2.0 molar equivalents, preferably 1.0-1.2 molar equivalents. The reaction is conducted in organic solvent or mixtures of solvents selected from acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, preferably acetonitrile or a mixture of acetonitrile and N,N-dimethylformamide in the temperature range between 45° C. and the reflux temperature of the reaction mixture, preferably at the temperature of 75°-85° C. 5-25 Volumes of solvent are used, preferably 10-20 volumes with respect to the amount of acetovanillone. The reaction is controlled by conventional analysis techniques, such as UPLC analysis using an ACQUITY BEH C18 column and water/acetonitrile/0.1% trifluoroacetic acid as eluent phase. After completion of the reaction, an inorganic base, preferably potassium carbonate, in an amount between 1.0 and 4.0 molar equivalents with respect to 1 molar equivalent of starting acetovanillone, preferably between 2.0 and 3.0 molar equivalents, is added to the reaction mixture containing the intermediate 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone. 6-Fluoro-3-(4-piperidinyl)-1,2-benzisoxazole hydrochloride is added to the reaction mixture in an amount between 0.85 and 1.20 molar equivalents with respect to 1 molar equivalent of starting acetovanillone, preferably between 0.90 and 1.00 molar equivalents. The resulting mixture is diluted with an organic solvent selected from acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide and N-methylpyrrolidone and heated to a temperature range between 70° C. and the reflux temperature of the reaction mixture, preferably to the temperature of 80-95° C. 1-10 Volumes of solvent are used, preferably 3-5 volumes with respect to the starting amount of acetovanillone. The reaction is controlled by conventional analysis techniques, such as UPLC analysis using an ACQUITY BEH C18 column and water/acetonitrile/0.1% trifluoroacetic acid as eluent phase. After completion of the reaction, the reaction mixture containing the iloperidone is cooled to the temperature of 40-60° C., preferably 45-55° C., and filtered; the solid filtrate is discarded as it consists mainly of inorganic salts. The clear filtered solution is concentrated under vacuum to a small volume and cooled to the temperature of 0-10° C. The resulting suspension is filtered to isolate the iloperidone. The solid filtrate is dried under vacuum at the temperature of 30-90° C., preferably 55-60° C., to obtain iloperidone with a purity exceeding 99%. The resulting solid can be further purified if necessary by recrystallisation from ethanol or other solvents known in the literature.
[0044] The process according to the invention is particularly advantageous in that, unlike the processes described in the literature, it is carried out without isolating the intermediate 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone, and also allows the product iloperidone to be obtained in high yields and a purity exceeding 99% directly from the reaction mixture by simple filtration of the reaction mixture followed by concentration thereof and filtration of the product, thus considerably simplifying the work-up steps described in the literature.
[0045] The invention is illustrated in detail in the following examples.
Example 1
Synthesis of Iloperidone
[0046] Acetovanillone (45 g, 0.27 mol) is added to a suspension of potassium carbonate (50 g, 0.36 mol), acetonitrile (860 ml) and 1-bromo-3-chloropropane (42.6 g, 0.27 mol). The mixture is heated at the temperature of 75-80° C. and monitored by UPLC. After completion of the reaction, potassium carbonate (70 g, 0.50 mol), 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole hydrochloride (72 g, 0.28 mol) and 250 ml of N,N-dimethylformamide are added. The mixture is heated at the temperature of 90-95° C. and monitored by UPLC. After completion of the reaction, the resulting mixture is cooled to 55° C. and the inorganic salts are filtered off. The clear solution obtained is concentrated under vacuum to a weight of 321 g, and cooled to 5° C. The resulting suspension is filtered. The solid isolated is dried under low pressure at 55° C. to obtain iloperidone (85 g, 0.20 mol) as a white solid with a purity exceeding 99%. Molar yield from acetovanillone to iloperidone: 74%.
[0047] UPLC-MS [M+H+]=427
[0048] 1H-NMR (in DMSO) (chemical shifts expressed in ppm with respect to the TMS signal): 2.06-1.78 (6H, m); 2.13 (2H, m); 2.49 (2H, t); 2.52 (2H, m); 2.97 (2H, m); 3.11 (1H, tt); 3.83 (3H, s); 4.12 (2H, t); 7.06 (1H, d); 7.22 (1H, m); 7.46 (1H, d); 7.61-7.58 (2H, m); 7.94 (1H, dd).
Example 2
Synthesis of Iloperidone
[0049] Acetovanillone (50 g, 0.30 mol) is added to a suspension of potassium carbonate (60 g, 0.43 mol), acetonitrile (800 ml), N,N-dimethylformamide (200 ml) and 1-bromo-3-chloropropane (55.2 g, 0.35 mol). The mixture is heated at the temperature of 75-80° C. and monitored by UPLC. After completion of the reaction, potassium carbonate (80 g, 0.58 mol), 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole hydrochloride (90 g, 0.35 mol) and 100 ml of N,N-dimethylformamide are added. The mixture is heated at the temperature of 90-95° C. and monitored by UPLC. After completion of the reaction, the resulting mixture is cooled to 55° C. and the inorganic salts are filtered off. The clear solution obtained is concentrated under vacuum to a weight of 370 g, and cooled to 5° C. The resulting suspension is filtered. The solid isolated is dried under low pressure at 55° C. to obtain iloperidone (97 g, 0.23 mol) as a white solid with a purity exceeding 99%. Molar yield from acetovanillone to iloperidone: 76%.
|
Disclosed is a process for the synthesis of iloperidone starting from 4-hydroxy-3-methoxy acetophenone (acetovanillone), 1-chloro-3-bromo propane and 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole hydrochloride, using a one-pot method.
Said process is performed without any intermediate isolation, and is particularly advantageous from the environmental standpoint and in terms of yields, productivity and the purity of the product obtained, both in the reaction mixture and in the crystal isolated.
| 2
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention concerns a method, device and computer program product for the purpose of filtering an EMG signal out of a raw signal, i.e., for extracting an EMG signal from a raw signal that contains the EMG signal, among other signal components.
2. Description of the Prior Art
Sensing of EMG-signals in a patient's diaphragm by placing a catheter with a number of electrodes in the esophagus is a known technique, which is described in, among others, U.S. Pat. No. 5,671,752. The EMG-signals received can be used in connection with mechanical ventilation of patients, which among others is described in U.S. Pat. No. 5,820,560 and WO 98/48877.
Sensing of EMG-signals from the diaphragm can even take place outside the body with electrodes placed on the patient, such as described in e.g. U.S. Pat. No. 4,248,240.
If a catheter with electrodes is guided down in the esophagus the electrodes lie on both sides of the diaphragm and at different distances therefrom. Each electrode's position relative to the diaphragm is normally not known and furthermore can vary when the patient breathes or moves in another way.
Since the EMG-signal from the diaphragm is relatively weak, in particular compared to interferences from EKG, a continuous desire is to in the best way attain the highest quality possible signal handling of the raw signal which the sensors detect. This is evident even in WO 01/03579. In WO 01/03579 it is assumed that the electrodes' location in relation to the center of the diaphragm is known. Then the electrodes are weighted based on location and symmetry, in which the EKG signal is taken into account in a conventional way.
Known methods for compensating for the EKG signal include, among others, using a band pass filter which filters out the frequencies where the EKG signal normally appears. It is also known to measure the EKG signal separately and then remove an equivalent signal from the measured EMG signal.
None of these methods takes into account the actual disturbance the EKG signal creates in a particular measuring situation in a particular patient. This disturbance also varies with time.
The known methods also fail to consider that the electrodes location relative to the diaphragm often varies during a single measurement.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a method and a device and a computer program product for measuring EMG signals that take into consideration that the location of the electrodes varies during a measurement.
The above object is achieved in accordance with the present invention by a method, device and a computer program product (i.e., a computer-readable medium encoded with computer program data) wherein a raw signal is obtained from a number of electrodes that are adapted for placement in a patient to capture signals from the patient's diaphragm, each electrode having an associated signal channel, wherein a signal-to-noise ratio is determined for each signal channel and a weighting factor is generated for each signal channel based on the signal-to-noise ratio, and the channels are summed dependent on the weighting factors.
By selectively estimating the signal-to-noise ratio for each signal channel and arranging significance factors depending upon the signal-to-noise ratio, the channels with the highest quality can be used more effectively for determining the EMG-signal.
Since EKG-signals constitute a primary disturbance source, the determination can in large part be done in relation to these signals. The signal-to-noise ratio can then be determined as the quotient between an estimated EKG-activity and an estimated EMG-activity. The quotient can be determined so that a high estimated EMG-activity is always awarded, e.g. by applying the equation
R 2 R + S
where R represents the EMG-activity and S represents the EKG-activity.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a device according to the invention connected to a patient who is undergoing respiratory therapy.
FIG. 2 shows a first example of electrode coupling for receiving a raw signal.
FIG. 3 shows a second example of electrode couplings for receiving a raw signal.
FIG. 4 is a flowchart describing the steps that are included in the signal treatment with the method according to the invention.
FIG. 5 is a flowchart showing how an ECG-activity is estimated with the method according to the invention.
FIG. 6 is a flowchart showing how an EMG-activity is estimated with the method according to the invention.
FIG. 7 and FIG. 8 are flowcharts showing, respectively, how an ECG activity and an EMG activity are estimated according to the method according to an alternative embodiment.
FIG. 9 is a flowchart showing how a weighing of signals on different signal channels can be obtained with the method according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The signal and raw signal are defined to encompass n-1 signals from the n electrodes/sensors, and for the n-1 signals there are n-1 channels.
FIG. 1 shows a device 2 for filtering and analysis of EMG-signals according to the invention. The device 2 can in a known way be connected to a patient 4 via a catheter 6 with a number of electrodes 8 A, 8 B, 8 C, 8 D in one end (four electrodes are shown, but the number can be larger or smaller). By placing the catheter 6 in the esophagus of the patient 4 , the electrodes 8 A, 8 B, 8 C, 8 D can be placed in different locations in the diaphragm 10 (the size of which has been exaggerated in FIG. 1 to indicate the relative placement of the electrodes 8 A, 8 B, 8 C, 8 D). In an analysis unit 12 in the device 2 , filtering and analysis of the raw signal from the catheter 6 is done to extract the highest quality EMG-signal possible.
In this connection, the raw signal can be received in many different ways. FIGS. 2 and 3 show two embodiments. From FIG. 2 it is evident that the electrodes 8 A, 8 B, 8 C, 8 D are coupled together in pairs via three couplers 14 A, 14 B, 14 C and in that way give rise to a three-channel raw signal (with e.g. nine electrodes, eight channels are received).
In FIG. 3 an example is shown where the respective electrodes 8 A, 8 B, 8 C, 8 D are connected to a reference electrode 16 (which e.g. can be grounded) via four couplers 14 D, 14 E, 14 F, 14 G. This results in a four-channel raw signal (for eight channels in this arrangement, eight electrodes and one reference are required).
Naturally an arbitrary number of electrodes can be used and for n electrodes, n-1 signals are allowed, and thereby n-1 channels.
More information regarding the catheter, the sensors and the entire process to capture raw signals from the diaphragm via esophagus can be found in e.g. U.S. Pat. No. 5,671,752 and WO 01/03579. As already noted, electrodes connected outside the body can even be used instead, for completely non-invasive reception of EMG-signals.
The patient 4 can also be connected in conventional ways to a ventilator system 18 , which in turn can be connected to the device 2 via a suitable connection 20 . The respiratory therapy given via the ventilator system 18 in that way can be influenced by the EMG-signal, which is extracted from the raw signal from the diaphragm 10 . This influence can be done in many different ways, of which some are described in U.S. Pat. No. 5,820,560 and WO 99/43374.
The present invention is directed to the device 2 and, to be precise, the analysis unit 12 . The analysis unit 12 filters EMG-signals out of the raw signal from the catheter 6 . The analysis unit can be operated by a computer program encoded on a computer-readable medium, such as a CD-ROM 13 . In that connection a number of signal channels are used, as noted above.
To receive the highest quality possible in the EMG-signals, the raw signal contains in addition to EMG even EKG, alternating current noise, noise, movement artifacts and other low frequency disturbances, filtering in the analysis unit 12 is done according to the method described below, which can be performed in an analog or digital manner, or as a combination thereof and can be realized in hardware, software or in a combination thereof.
The method is described in connection with the flowcharts in FIGS. 4 , 5 , 6 , 7 , 8 and 9 .
FIG. 4 shows a flowchart which describes the overall signal handling in the analysis unit 12 . The general handling is as follows.
The raw signals from the sensors are input by a (multi-channel) input 22 and first pass a first high pass filter 24 . The purpose of this is to filter away movement artifacts and other low-frequency interferences. The breaking frequency should be lower than 10 Hz.
In the next step, the signals are filtered in a non-linear low pass filter 26 . The purpose of this is to smooth the signal when it has a high amplitude, which typically happens with the existence of EKG-signals. The breaking frequency should lie within an interval of about 50-700 Hz. Where in the interval the breaking frequency lies depends on the energy or the amplitude of the signal. Higher amplitude results in lower breaking frequency. The non-linear low pass filter 26 should even have a dynamic component, namely that the breaking frequency changes with a time constant.
Subsequently, the signals pass a second high pass filter 28 . The purpose of the second high pass filter 28 is to select the frequency interval where the EMG-signal lies. The breaking frequency is therefore chosen to the lower regions of the bandwidth of the EMG-signal which is about 100 Hz.
The block 26 and 28 can be replaced with an adaptive band pass filter which is described in Swedish application 0303061-6 filed Nov. 19, 2003 and corresponding to Ser. No. 10/599,980 filed Mar. 26, 2007 and assigned to the same assignee as the present application, in connection with FIG. 6 in that application.
In the next step, nearby channels are differentiated from each other in a differentiator 30 . The purpose of this is to remove ringing in the filter and is based on the assumption that nearby channels are correlated with reference to common-mode interferences.
Subsequently, the energy content of the signal is determined in an RMS-former 32 (Root Mean Square). To reduce any remaining spikes in EKG-signals (foremost related to the QRS-complex in the EKG-signal), the derivative of the signal from the RMS-former 32 is limited in a rate limit block 34 .
In the next step, a summation is done in a summing unit 36 . The purpose of the summing unit 36 is to weigh together the channels. This is done by multiplying the signals in the respective channels by a weight factor (see below), summing and normalizing the signals. In this connection the weighting factor can be squared to more selectively promote the channels with good signal-to-noise ratio. In principle, the summing unit 36 can be seen as a channel selector in which the channels that have the highest weighting factor are selected for use while the channels with poorer SNR can be allocated the value 0 in extreme cases.
The weighting factor for the respective channels is determined as follows.
After the first high pass filter 24 , the signals in the channels are also passed to an EKG-detector 38 . The purpose of the EKG-detector 38 is to establish the presence of the EKG-signals in the channels. If a single channel indicates the presence of an EKG-signal, an estimated EKG-activity is calculated for all of the channels. The determination of the estimated EKG-activity is done in a first calculation block 40 . The output signal from the EKG-detector 38 is supplied to a second calculation block 42 .
In the manner described above, the presence of EMG-signals can also be established. This is done in an EMG-detector 44 , which is fed with the signal from the second high pass filter 28 .
The output signals from the EMG-detector 44 are led to the second calculation block 42 .
In addition to the signals mentioned above, the first calculation block 40 and the second calculation block 42 have a further input signal, namely the signal after the rate limit block 34 .
The EKG detector 38 and the EMG detector 44 can be designed in different ways. In one formulation the EKG detector 38 is designed for each channel and thus for each signal which is received from an electrode, to detect if the EKG signal exceeds a limit value which is defined for the EKG signals. To make this comparison the raw signal is filtered in a band pass filter to take away the relevant frequency band for an EKG signal and the output signal from the band pass filter is compared with the set threshold. If the output signal is higher than the threshold the EKG signal is considered present.
In an alternative embodiment both the detectors 38 , 44 are designed so that a first probability function P EKG is determined for each channel. P EKG indicates the probability that an EKG signal is present in the signal. A second probability function P EMG =1−P EKG indicates the probability that an EMG signal is present in the signal.
The probability functions are calculated from a frequency analysis for the respective EKG and EMG signals.
The function of the first calculation block 40 is evident from FIG. 5 . The signal from the EKG-detector 38 goes into a first decision block 46 . Here it is established whether an EKG-signal is present in one of the channels (output yes) or not (output no). If there is no EKG-activity, the activity level is set to 0 in block 48 (estimated EKG-activity=0). If an EKG-signal is present in one of the channels, the estimated EKG-activity S is calculated for all the channels, which is done via a low pass filter 50 , which also receives the filtered signal from the rate limit block 34 . In the low pass filter 50 , the D.C. voltage level for each channel is in principle determined, the filtered signal from rate limit block 34 , (a breaking frequency of a few Hz can be accepted), which in that connection represents the estimated EKG-activity S.
The function of the second calculation block 42 is explained in FIG. 6 . The signal from the EKG-detector 38 goes into a second decision block 52 . If an EKG-signal exists (output yes), the estimated EMG-activity is set to 0 in block 54 . If no EKG-signal exists (output no), it is investigated whether there exists some EMG-signal (from the EMG-detector 44 ) in a third decision block 56 . If no EMG-signal exists (output no), the activity is set to 0 in the block 54 . If EMG-signals exist, the estimated EMG-activity R is calculated by passing the signal, the filtered signal from Rate limit block 34 , through a low pass filter 58 .
Another embodiment of the blocks 40 and 42 are shown in FIGS. 7 and 8 , respectively.
FIG. 7 shows an alternative embodiment of the first calculation block 40 for estimating the EKG signal. From the rate limit block 34 a low pass filter 50 in the first calculation block 40 receives the filtered raw signal. From the EKG detector 38 it receives as previously the estimation of the presence of EKG signal. In contrast to the above-described embodiment the value which is received from the EKG detector is a probability function P ECG with a value between 0 and 1. The output signal from the calculation block 40 is an estimation of the effect contents in the EKG signal, which depends on the probability function.
FIG. 8 shows an alternative embodiment of the second calculation block 42 for estimating the EMG signal. The output signal from the EKG detector 38 , P ECG is fed to a second calculation block 42 where the probability 1−P ECG is fed to a low pass filter 58 . The low pass filter 58 receives the filtered signal from the rate limit block 34 . Before the filtered signal is fed to the low pass filter 58 the noise level in the signal is estimated in an estimating block 59 and cancelled from the signal. The output signal from the calculation block 42 is an estimation of the effect contents in the EMG signal, which depends on the mentioned probability function.
As shown, the embodiments shown in FIGS. 5 and 6 can be seen as a special case of that shown in FIGS. 7 and 8 , where the probability P ECG can assume the value 0 or 1.
The estimated EMG-activity R and the estimated EKG-activity S are transferred to a SN-block 60 for determining a signal-to-noise ratio for each channel between the estimated EMG-activity R and the estimated EKG-activity S. The signal-to-noise ratio can be determined in different ways. One way to determine a signal-to-noise ratio T is by the quotient
T = R R + S
where R is the estimated EMG-activity and S is the estimated EKG-activity.
To promote channels with high estimated EMG-activity (regardless of interferences), it is advantageous to instead use the quotient
T
=
R
2
R
+
S
Instead of R 2 , R n can naturally be used, where n suitably is considerably larger or equal to 1.
The signal-to-noise ratio is transferred to a weighting factor block 62 , where a weighing is determined for each channel. The determinations in the weighting factor block 62 are shown in FIG. 9 . A time block 64 counts time interval t, for example for a few seconds. In the example of FIG. 9 , t must be longer than 2.5 seconds. During the respective time interval t, the maximum signal T 1 is determined for the signal-to-noise ratio T from the SN-block 60 in a maximizing block 66 . This maximum signal T 1 is then filtered in a low pass filter 68 . The filtered signal T 2 then represents the base for the determination of a weighting factor for each channel in a calculation block 70 . In this example, the weighting factor is set to
T 2 max T 2
where maxT 2 is the maximum T 2 for all the channels. In other words, the channels are normalized to the strongest signal-to-noise ratio of all the channels, such that the weighting factor for the respective channel receives a value between 0 and 1.
The determined weighting factors are then transferred to the summing unit 36 ( FIG. 4 ), where handling is done as previously described. Finally, the signal can be smoothed in a low pass filter 72 and put out as a ready EMG-signal.
Preferably, a computer program is arranged in the analysis unit 12 , which directs the function of the different blocks in the analysis unit according to the above.
In the method according to the present invention, the determination of weighting factors for the respective signal channels plays a major role. The numerical values given above, e.g. breaking frequencies and multiplication factors, are only examples and in no way exclude other values. Similarly, certain portions of the signal handling can be obtained in other ways without deviating from the invention.
Although modifications and changes may be suggested by those skilled in the art, it is the invention of the inventors to embody within the patent warranted heron all changes and modifications as reasonably and properly come within the scope of their contribution to the art.
|
In a method, device and computer program product for extracting an EMG signal out of a raw signal obtained with a number of electrodes, the electrodes being adapted to interact with a patient to obtain signals from the patient's diaphragm on respective channels associated with the electrodes, a signal-to-noise-ratio is determined for the raw signal in each channel, and a weighting factor is automatically determined dependent on the signal-to-noise ratio. The respective raw signals from the channels are weighted according to the weighting factors, and are summed in order to generate a sum signal that represents the total EMG signal contained in all of the raw signals.
| 0
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of application Ser. No. 09/214,836 filed Oct. 4, 1999, which was the National Stage of International Application No. PCT/EP97/03712 filed Jul. 8, 1997 and having a priority date of Jul. 11, 1996. The disclosure of each of these related applications is incorporated herein in their entireties.
BACKGROUND OF THE INVENTION
[0002] The present invention is concerned with cancer treatment and diagnosis, especially with melanoma associated peptide analogues, epitopes thereof, vaccines against and diagnostics for the detection of melanoma and for the monitoring of vaccination.
[0003] During the stepwise changes from normal to tumor tissue, tumor-associated antigens appear. The characteristics of tumor-associated antigens are very much dependent on the origin of the tumor carrying them. The existence of antigens associated with animal tumors was documented in the last century, and the antigenic character of human cancers has been well established, primarily through recent studies with monoclonal antibodies.
[0004] Attempts to isolate and chemically characterize these antigens have encountered serious difficulties, many having to do with a lack of reagents suitable for precipitation of the antigen-bearing molecules from a solution.
[0005] Like many other stimuli, the tumor-associated antigens activate not one but a whole set of defense mechanisms—both specific and unspecific, humoral and cellular. The dominant role in in vivo resistance to tumor growth is played by T lymphocytes. These cells recognize tumor-associated antigens presented to them by antigen presenting cells (APCs), and will be activated by this recognition, and upon activation and differentiation, attack and kill the tumor cells.
[0006] Cytotoxic T lymphocytes (CTL) recognize short peptide fragments of 9-11 amino acids in length, which are presented in the antigen-binding groove of Major Histocompatibility Complex (MHC) class 1 molecules (Townsend et al., 1986 , Cell 44.959; Bjorkman et al., 1987 , Nature 329:512). These peptides are usually derived from intracellular protein pools and associate in the lumen of the endoplasmic reticulum with MHC class I heavy chain and 132-microglobulin molecules, followed by transportation of the MHC-peptide complex to the cell surface. Despite the presence of many putative antigenic peptides within the same antigen, only a few peptides are selected for recognition by CTL.
[0007] MHC Class I/II antigens are often down regulated in solid tumors. This may affect all class I/II antigens, or only part of them. Viral and cellular peptides that can sensitize appropriate target cells for cytotoxic T lymphocyte mediated lysis may fail to do so when produced in cells with a low level of expression of MHC class I antigen. Cytotoxic sensitivity may be induced, at least in some cases by raising the level of MHC class I/II antigen expression by interferon γ and tumor necrosis factor α.
[0008] The MHC class I binding-affinity of an epitope is an important parameter determining the immunogenicity of the peptide-MHC complex. Analysis of Human histocompatibility antigen (HLA-A *0201)-restricted epitopes recognized by anti-viral CTL demonstrated that several peptides bind to HLA-A *0201 with high affinity. Furthermore, immunogenicity analysis of motif containing potential epitopes using HLA-A *0201 transgenic mice revealed that a threshold MHC class I affinity was required for a peptide in order to elicit a CTL response (Ressing et al., 1995 , J. Immunol. 154:5934; Sette et al., 1994 , J. Immunol. 153:5586). In addition to the MHC class I-binding affinity, stability of peptide-MHC complexes at the cell surface contributes to the immunogenicity of a CTL epitope. Consequently, MHC class I binding-affinity and stability of peptide-MHC complexes are important criteria in the selection of specific peptide determinants for development of CTL-epitope based therapeutic vaccines.
[0009] Recently, a number of antigens have been identified as target antigens for anti-melanoma CTL. Using a genetic approach, the tumor specific antigens MAGE-1 and -3, as well as the melanocyte-lineage specific antigen tyrosinase, were identified (van der Bruggen et al., 1991 , Science 254:1643; Gaugler et al., 1994 , J. Exp. Med. 179:921; Brichard et al., 1993 , J. Exp. Med. 178:489).
[0010] In the co-owned and co-pending patent-application (EP 0 668 350), the gp100 melanocyte-specific protein was identified as a target antigen for melanoma tumor infiltrating lymphocytes.
[0011] Recently, two other melanocyte differentiation antigens, Melan-A/MART-1 and gp75, were identified as target antigens for anti-melanoma CTL (Coulie et al., 1994 , J. Exp. Med. 180:35; Kawakami et al., 1994 , Proc. Natl. Acad. Sci. USA. 91:3515; Wang et al., 1995, (vol 181, pg 799, 1995). J. Exp. Med. 181:1261. 10-12). Eight HLA-A *0201 restricted epitopes derived from these antigens have now been characterized, displaying varying affinities for HLA-A *0201 (Wolfel et al., 1994 , Eur. J. Immunol. 24:759; Cox et al, 1994 , Science 264:716; Kawakami et al. 1995. J. Immunol. 154:3961; Bakker et al., 1995 , Int. J. Cancer 62:97; Kawakami et al., 1994 , J. Exp. Med. 180:347; Castelli et al., 1995 , J. Exp. Med. 181:363).
DISCLOSURE OF THE INVENTION
[0012] In an attempt to improve the immunogenicity of two HLA-A *0201 presented epitopes derived from the melanocyte differentiation antigens gp 100 and Melan-A/MART-1, amino acid substitutions within the epitopes to improve HLA-A *0201-binding affinity were performed.
[0013] Surprisingly, it was found that these epitope-analogues have an improved immunogenicity in view of the original epitope. Furthermore, in the present invention it is demonstrated that the epitope-analogues allow the induction of peptide-specific CTL displaying cross-reactivity with target cells endogenously processing and presenting the native epitope.
[0014] Usage of these epitope-analogues according to the present invention with improved immunogenicity may contribute to the development of CTL-epitope based vaccines in chronic viral disease and cancer.
[0015] In more detail, since MHC class I-affinity and peptide-MHC complex-stability are important parameters determining the immunogenicity of an MHC class I presented epitope, the possibility to improve the capacity of two melanocyte differentiation antigen-derived epitopes to bind to HLA-A *0201 without affecting interactions with the T-cell receptor (TCR) is explored. Detailed analysis of the Melan-AIMART-1 27-35 and gp100 154-162 epitopes using alanine substitutions revealed that amino acids at positions 4 to 7 (Melan-A/MART-1 27-35) or 5 to 7 (gp100 154-162) are critical residues for TCR recognition. These data are in line with X-ray crystallography studies of the HLA-A *0201 molecule (Saper et al., 1991 , J. Mol. Biol. 219:277; Latron et al., 1992, Science 257:964); implying a role for the more permissive residues at position 4 and 5 of the peptide oriented towards the outside of the MHC molecule, as prominent TCR contact sites. It is demonstrated that for HLA-A *0201 the amino acids at positions 6 and 7 of the Melan-A/MART-1 27-35 and gp100 154-162 epitopes do not only interact with secondary pockets in the MHC peptide-binding cleft, but that they are also critical residues for TCR interaction (Ruppert et al., 1993, Cell 74:929; Madden et al., 1993, Cell 75:693).
[0016] Surprisingly, the alanine substitution at position 8 in the gp100 154-162 epitope, KTWGQYW A V (SEQ ID NO: 1), resulted in a peptide that displayed increased HLA-A *0201 affinity. Moreover, this epitope-analogue was recognized by gp100-reactive CTL at tenfold lower concentrations compared to the native epitope. These data demonstrate that amino acid substitutions at a non-anchor position can result in increased MHC class I affinity and T cell recognition.
[0017] By N-terminal anchor replacements with V, L, M or I towards the HLA-A *0201 binding-motifs were set out to identify epitope-analogues for both epitopes with improved affinity for HLA-A *0201 that were still recognized by wild type epitope-reactive CTL. For the Melan-A/MART-1 epitope, epitope-analogues were obtained with comparable (M) or improved (V, L and I) affinity for HLA-A *0201. However, all N-terminal anchor replacements resulted in decreased T cell reactivity. Apparently, in case of this epitope, the N-terminal anchoring residue affects the positioning of the side chains in the center of the peptide, thereby abrogating TCR interactions. Recently, a similar observation has been described involving an HLA-B*3501 restricted epitope of the influenza A matrix protein (Dong et al., 1996, Eur. J. Immunol. 26:335). Substitution of a serine residue at position 2 of the peptide for the more common HLA-B*3501 N-terminal anchor proline, considerably enhanced binding to HLA-B*3501, but the epitope-analogue was not recognized by CTL reactive with the native epitope. Moreover, this peptide behaved as a peptide-antagonist as was demonstrated for T cell recognition of both MEC class II and class I-presented peptides (Dong et al., 1996, Eur. J. Immunol. 26:335; De Magistris et al., 1992, Cell 68:625; Klenerman et al., 1994 , Nature 369:403). These findings illustrate that anchor residue substitutions not only affect MHC class I binding, but in some cases they may also result in a conformational change of the peptide-MHC complex, leading to an altered interaction with the TCR.
[0018] However, in case of the gp100 154-162 epitope, in addition to the alanine substituted analogue KTWGQYW A V (SEQ ID NO: 1), three anchor substituted epitope-analogues K V WGQYWQV (SEQ ID NO: 2), K L WGQYWQV (SEQ ID NO: 3), and K I WGQYWQV (SEQ ID NO: 4), with improved HLA-A*0201-affinity that were recognized by anti-gp100 CTL at tenfold lower concentrations compared to the wild type epitope were obtained. In vivo immunization experiments using HLA-A*0201/K b transgenic mice demonstrated that these epitope-analogues were immunogenic, resulting in the induction of murine CTL reactive with both the epitope-analogues and the native epitope. The immunogenicity of the epitope-analogues was expected since the peptide-MHC complex stability of both the epitope-analogues and the native epitope was comparably high.
[0019] In vitro CTL induction experiments using donor derived PBL demonstrated that epitope-analogue specific CTL could be obtained displaying cross-reactivity with tumor cells endogenously presenting the wild type epitope. In addition to T lymphocytes reactive with the wild type epitope, the T cell repertoire of healthy donors apparently also contains T cells reactive with the gp100 154-162 epitope-analogues. Analysis of TCR usage of cloned CTL reactive with the different gp100 154-162 epitope-analogues and with, wild type gp100 154-162 will be informative of the spectrum of the T cell repertoire that can be used to induce CTL reactivity towards the wild type epitope. With respect to immunotherapy of cancer, activation of multiple specificities in the T cell repertoire against an antigenic tumor epitope using epitope-analogues may increase the possibility of a patient to mount a successful anti-tumor response upon immunization. In addition, modified epitopes might still elicit immune responses if tolerance against the wild-type epitope is observed.
[0020] Employment of “improved” epitopes in immunotherapy protocols increases the amount of peptide-MHC complexes at the cell surface of antigen presenting cells in vivo, and will result in enhanced priming of antigen-specific CTL. Apart from their potential in cancer immunotherapy, usage of epitope-analogues with improved immunogenicity may contribute to the development of CTL-epitope based vaccines in chronic viral disease.
[0021] Therefore, the present invention includes peptides, immunogenic with lymphocytes directed against metastatic melanomas, characterized in that it comprises at least part of the amino-acid sequence of SEQ ID NO: 9 wherein the amino-acid at position 2 or 8 is substituted.
[0022] A preferred embodiment of the present invention are peptides, wherein at position 2 Threonine is substituted by Isoleucine, Leucine or Valine.
[0023] Another preferred embodiment of the present invention are peptides, wherein at position 8 Glutamine is substituted by Alanine.
[0024] A specific preferred embodiment of the present invention are peptides, characterized in that it comprises the amino-acid sequence of any of SEQ ID NOS: 1-4 or 32-34.
[0025] The term “peptide” refers to a molecular chain of amino acids, does not refer to a specific length of the product and if required can be modified in vivo or in vitro, for example by manosylation, glycosylation, amidation, carboxylation or phosphorylation: thus inter alia polypeptides, oligopeptides and proteins are included within the definition of peptide. In addition, peptides can be part of a (chimeric) protein or can be (part of) an RNA or DNA sequence encoding the peptide or protein.
[0026] Of course, functional derivatives as well as fragments of the peptide according to the invention are also included in the present invention. Functional derivatives are meant to include peptides which differ in one or more amino acids in the overall sequence, which have deletions, substitutions, inversions or additions. Amino acid substitutions which can be expected not to essentially alter biological and immunological activities have been described. Amino acid replacements between related amino acids or replacements which have occurred frequently in evolution are, inter alia Ser/Ala, Ser/Gly, Asp/Gly, Asp/Asn, Ile/Val (see Dayhof, M.D., Atlas of protein sequence and structure, Nat. Biomed. Res. Found., Washington D.C., 1978, vol. 5, suppl. 3). Based on this information, Lipman and Pearson developed a method for rapid and sensitive protein comparison (Science 227, 1435-1441, 1985) and determining the functional similarity between homologous polypeptides.
[0027] Furthermore, as functional derivatives of these peptides are also meant to include other peptide-analogues derived from gp100 (or Melan) that are able to induce target cell lysis by tumor infiltrating lymphocytes.
[0028] In addition, with functional derivatives of these peptides are also meant addition salts of the peptides, amides of the peptides and specifically the C-terminal amides, esters and specifically the C-terminal esters and N-acyl derivatives specifically N-terminal acyl derivatives and N-acetyl derivatives.
[0029] The peptides according to the invention can be produced synthetically, by recombinant DNA technology or by viruses, if the amino acid sequence of the peptide is encoded by a DNA sequence which is part of the virus DNA. Methods for producing synthetic peptides are well known in the art.
[0030] The organic chemical methods for peptide synthesis are considered to include the coupling of the required amino acids by means of a condensation reaction, either in homogenous phase or with the aid of a so-called solid phase. The condensation reaction can be carried out as follows:
[0031] condensation of a compound (amino acid, peptide) with a free carboxyl group and protected other reactive groups with a compound (amino acid, peptide) with a free amino group and protected other reactive groups, in the presence of a condensation agent;
[0032] condensation of a compound (amino acid, peptide) with an activated carboxyl group and free or protected other reaction groups with a compound (amino acid, peptide) with a free amino group and free or protected other reactive groups.
[0033] Activation of the carboxyl group can take place, inter alia, by converting the carboxyl group to an acid halide, azide, anhydride, imidazolide or an activated ester, such as the N-hydroxy-succinimide, N-hydroxy-benzotriazole or p-nitrophenyl ester.
[0034] The most common methods for the above condensation reactions are: the carbodiimide method, the azide method, the mixed anhydride method and the method using activated esters, such as described in The Peptides, Analysis, Synthesis, Biology Vol. 1-3 (Ed. Gross, E. and Meienhofer, J.) 1979, 1980, 1981 (Academic Press, Inc.).
[0035] Production of peptides by recombinant DNA techniques is a general method which is known, but which has a lot of possibilities all leading to somewhat different results. The polypeptide to be expressed is coded for by a DNA sequence or more accurately by a nucleic acid sequence.
[0036] Also part of the invention is the nucleic acid sequence comprising the sequence encoding the peptides according to the present invention.
[0037] Preferably, the sequence encoding the peptides according to the present invention are the sequences shown in SEQ ID NOS: 1-4 and 32-34.
[0038] As is well known in the art, the degeneracy of the genetic code permits substitution of bases in a codon to result in another codon still coding for the same amino acid, e.g., the codon for the amino acid glutamic acid is both GAT and GAA. Consequently, it is clear that for the expression of a polypeptide with an amino acid sequence as shown in SEQ ID NO: 1-4, 9 or 32-34 use can be made of a derivate nucleic acid sequence with such an alternative codon composition thereby different nucleic acid sequences can be found.
[0039] “Nucleotide sequence” as used herein refers to a polymeric form of nucleotides of any length, both to ribonucleic acid (RNA) sequences and to deoxyribonucleic acid (DNA) sequences. In principle, this term refers to the primary structure of the molecule. Thus, this term includes double and single stranded DNA, as well as double and single stranded RNA, and modifications thereof.
[0040] A further part of the invention are peptides, which are immunogenic fragments of the peptide-analogues.
[0041] Immunogenic fragments are fragments which still have the ability to induce an immunogenic response, i.e., that it is either possible to evoke antibodies recognizing the fragments specifically, or that it is possible to find T lymphocytes which have been activated by the fragments. Another possibility is a DNA vaccine.
[0042] As has been said above, it has been known that the immunogenic action of tumor associated antigens is often elicited through a T cell activating mechanism (Townsend et al., 1989 , H., Ann. Rev. Immunol. 1601-624). Cytotoxic T lymphocytes (CTLs) recognizing melanoma cells in a T-cell receptor (TCR)-dependent and MHC-restricted manner have been isolated from tumor-bearing patients (Knuth et al., 1992, Cancer surveys, 39-52). It has been shown that a peptide derived from tyrosinase, another melanocyte-specific antigen, is recognized by a CTL clone (Brichard et al., 1993, J. Exp. Med., 178, 489-495).
[0043] It is known that the activation of T cells through the MHC molecule necessitates processing of the antigen of which short pieces (for example 8-12 mers) are presented to the T lymphocyte.
[0044] Preferably, the peptides according to the present invention are flanked by non-related sequences, i.e., sequences with which they are not connected in nature, because it has been found that such flanking enhances the immunogenic properties of these peptides, probably through a better processing and presentation by APCs.
[0045] Another part of the invention is formed by nucleotide sequences comprising the nucleotide sequences coding for the above mentioned peptides or an array of peptides.
[0046] Next to the use of these sequences for the production of the peptides with recombinant DNA techniques, which will be exemplified further, the sequence information disclosed in the sequence listings for the peptides according to the present invention can be used for diagnostic purposes.
[0047] From these sequences primers can be derived as basis for a diagnostic test to detect gp100 or gp100-like proteins by a nucleic acid amplification technique for instance the polymerase chain reaction (PCR) or the nucleic acid sequence based amplification (NASBA) as described in U.S. Pat. No. 4,683,202 and EP 329,822, respectively.
[0048] These nucleotide sequences can be used for the production of the peptides according to the present invention with recombinant DNA techniques. For this, the nucleotide sequence must be comprised in a cloning vehicle which can be used to transform or transfect a suitable host cell.
[0049] A wide variety of host cell and cloning vehicle combinations may be usefully employed in cloning the nucleic acid sequence. For example, useful cloning vehicles may include chromosomal, non-chromosomal and synthetic DNA sequences such as various known bacterial plasmids, and wider host range plasmids such as pBR 322, the various pUC, pGEM and pBluescript plasmids, bacteriophages, e.g. lambda-gt-Wes, Charon 28 and the M13 derived phages and vectors derived from combinations of plasmids and phage or virus DNA, such as SV40, adenovirus or polyoma virus DNA (Rodriquez et al., 1988, ed. Vectors, Butterworths; Lenstra et al., 1990, Arch. Vivol., 110, 1-24).
[0050] Useful hosts may include bacterial hosts, yeasts and other fungi, plant or animal hosts, such as Chinese Hamster Ovary (CHO) cells, melanoma cells, dendritic cells, monkey cells and other hosts.
[0051] Vehicles for use in expression of the peptides may further comprise control sequences operably linked to the nucleic acid sequence coding for the peptide. Such control sequences generally comprise a promoter sequence and sequences which regulate and/or enhance expression levels. Furthermore, an origin of replication and/or a dominant selection marker are often present in such vehicles. Of course, control and other sequences can vary depending on the host cell selected.
[0052] Techniques for transforming or transfecting host cells are quite known in the art (for instance, Maniatis et al., 1982/1989 , Molecular cloning: A laboratory Manual , Cold Spring Harbor Lab.).
[0053] It is extremely practical if, next to the information for the peptide, also the host cell is co-transformed or co-transfected with a vector which carries the information for an MHC molecule to which said peptide is known to bind. Preferably, the MHC molecule is HLA-A2.1, HLA-A1 or HLA-A3.1, or any other HLA allele which is known to be present in melanoma patients. HLA-A2.1 is especially preferred because it has been established (Anichini et al., 1993 , J. Exp. Med., 177, 989-998) that melanoma cells carry antigens recognized by HLA-A2.1 restricted cytotoxic T cell clones from melanoma patients.
[0054] Host cells especially suited for the expression of the peptides according to the present invention are the murine EL4 and P8.15 cells. For expression of said peptides human BLM cells (Katano et al., 1984 , J. Cancer Res. Clin. Oncol. 108, 197) are especially suited because they already are able to express the MHC molecule HLA-A2.1.
[0055] The peptides according to the present invention can be used in a vaccine for the treatment of melanoma.
[0056] In addition to an immunogenically effective amount of the active peptide, the vaccine may contain a pharmaceutically acceptable carrier or diluent.
[0057] The immunogenicity of the peptides of the invention, especially the oligopeptides, can be enhanced by cross-linking or by coupling to an immunogenic carrier molecule (i.e., a macromolecule having the property of independently eliciting an immunological response in a patient, to which the peptides of the invention can be covalently linked) or if part of a protein.
[0058] Covalent coupling to the carrier molecule can be carried out using methods well known in the art, the exact choice of which will be dictated by the nature of the carrier molecule used. When the immunogenic carrier molecule is a protein, the peptides of the invention can be coupled, e.g., using water soluble carbodiimides such as dicyclohexylcarbodiimide, or glutaraldehyde.
[0059] Coupling agents such as these can also be used to cross-link the peptides to themselves without the use of a separate carrier molecule. Such cross-linking into polypeptides or peptide aggregates can also increase immunogenicity.
[0060] Examples of pharmaceutically acceptable carriers or diluents useful in the present invention include stabilizers such as SPGA, carbohydrates (e.g., mannose, sorbitol, mannitol, starch, sucrose, glucose, dextran), proteins such as albumin or casein, protein containing agents such as bovine serum or skimmed milk and buffers (e.g., phosphate buffer).
[0061] Optionally, one or more compounds having adjuvant activity may be added to the vaccine. Suitable adjuvants are for example aluminium hydroxide, phosphate or oxide, oil-emulsions (e.g. of Bayol F® or Marcol 52®), saponins or vitamin-E solubilisate.
[0062] Dendritic cells are professional APC that express mannose receptor used to take up antigen thus facilitating antigen processing.
[0063] The vaccine according to the present invention can be given inter alia intravenously, intraperitoneally, intranasally, intradermally, subcutaneously or intramuscularly.
[0064] The useful effective amount to be administered will vary depending on the age and weight of the patient and mode of administration of the vaccine.
[0065] The vaccine can be employed to specifically obtain a T cell response, but it is also possible that a B cell response is elicited after vaccination. If so, the B cell response leads to the formation of antibodies against the peptide of the vaccine, which antibodies will be directed to the source of the antigen production, i.e., the tumor cells. This is an advantageous feature, because in this way the tumor cells are combated by responses of both the immunological systems.
[0066] Both immunological systems will even be more effectively triggered when the vaccine comprises the peptides as presented in an MHC molecule by an antigen presenting cell (APC). Antigen presentation can be achieved by using monocytes, macrophages, interdigitating cells, Langerhans cells and especially dendritic cells, loaded with one of the peptides of the invention or loading with protein including peptide or manosylated protein. Loading of the APCs can be accomplished by bringing the peptides of the invention into or in the neighborhood of the APC, but it is more preferable to let the APC process the complete gp100 antigen. In this way a presentation is achieved which mimics the in vivo situation most realistically. Furthermore, the MHC used by the cell is of the type which is suited to present the epitope.
[0067] An overall advantage of using APCs for the presentation of the epitopes is the choice of APC cell that is used in this respect. It is known from different types of APCs that there are stimulating APCs and inhibiting APCs.
[0068] Preferred APCs include, but are not limited to, the listed cell types, which are so-called “professional” antigen presenting cells, characterized in that they have co-stimulating molecules, which have an important function in the process of antigen presentation. Such co-stimulating molecules are, for example, B7, CD25, CD40, CD70, CTLA-4 or heat stable antigen (Schwartz, 1992 , Cell 71, 1065-1068).
[0069] Fibroblasts, which have also been shown to be able to act as an antigen presenting cell, lack these co-stimulating molecules.
[0070] It is also possible to use cells already transfected with a cloning vehicle harboring the information for the melanocyte peptide analogues and which are cotransfected with a cloning vehicle which comprises the nucleotide sequence for an MHC class I molecule, for instance the sequence coding for HLA A2.1, HLA A1 or HLA A3.1. These cells will act as an antigen presenting cell and will present peptide analogues in the MHC class I molecules which are expressed on their surface. It is envisaged that this presentation will be enhanced, when the cell is also capable of expressing one of the above-mentioned co-stimulating molecules (in particular B7 (B7.1, B7.2), CD40), or a molecule with a similar function (e.g., cytokines transfected in cell line). This expression can be the result of transformation or transfection of the cell with a third cloning vehicle having the sequence information coding for such a co-stimulating molecule, but it can also be that the cell already was capable of production of co-stimulating molecules.
[0071] Instead of a vaccine with these cells, which next to the desired expression products, also harbor many elements which are also expressed and which can negatively affect the desired immunogenic reaction of the cell, it is also possible that a vaccine is composed with liposomes which expose MHC molecules loaded with peptides, and which, for instance, are filled with lymphokines. Such liposomes will trigger an immunologic T cell reaction.
[0072] By presenting the peptide in the same way as it is also presented in vivo, an enhanced T cell response will be evoked. Furthermore, by the natural adjuvant working of the relatively large, antigen presenting cells also a B cell response is triggered. This B cell response will also lead to the formation of antibodies directed to the peptide-MHC complex. This complex is especially found in tumor cells, where it has been shown that in the patient epitopes of gp100 are presented naturally, which are thus able to elicit a T cell response. It is this naturally occurring phenomenon which is enlarged by the vaccination of APCs already presenting the peptides of the invention. By enlarging not only an enlarged T cell response will be evoked, but also a B cell response which leads to antibodies directed to the MHC-peptide complex will be initiated.
[0073] The vaccines according to the invention can be enriched by numerous compounds which have an enhancing effect on the initiation and the maintenance of both the T cell and the B cell response after vaccination.
[0074] In this way, addition of cytokines to the vaccine will enhance the T cell response. Suitable cytokines are for instance interleukins, such as IL-2, IL-4, IL-7, or IL-12, GM-CSF, RANTES, MIP-α, and tumor necrosis factor, and interferons, such as IFN- or the chemokins.
[0075] In a similar way, antibodies against T cell surface antigens, such as CD2, CD3, CD27 and CD28 will enhance the immunogenic reaction.
[0076] Also, the addition of helper epitopes to stimulate CD4 + helper cells or CD8 + killer cells augments the immunogenic reaction. Alternatively, also helper epitopes from other antigens can be used, for instance from heat shock derived proteins or cholera toxin.
[0077] Another part of the invention is formed by using reactive tumor infiltrating lymphocytes (TILs) directed against the peptides according to the present invention. In this method, the first step is taking a sample from a patient. This is usually done by resection of a tumor deposit under local anesthesia. The TILs present in this specimen are then expanded in culture for four to eight weeks, according to known methods (Topalian et al., 1987 , J. Immunol. Meth. 102, 127-141). During this culture, the TILs are then checked for reactivity with the peptides according to the present invention or gp100-protein. The TILs which recognize the antigen are isolated and cultured further.
[0078] The reactive tumor infiltrating lymphocytes which are obtained through this method, also form part of the invention. An example of such TIL cell line, designated TIL 1200, has been found which specifically reacts with gp100 and its epitopes. This TIL 1200 cell line also expresses the MHC molecule HLA-A2.1. Furthermore, expression of TCR α/β, CD3 and CD8 by this cell line has been demonstrated. Furthermore, TIL 1200 recognizes transfectants expressing both HLA-A2.1 and gp100.
[0079] TIL 1200 and other TILs recognizing gp100 are suited for treatment of melanoma patients. For such treatment, TILs may be cultured as stated above, and they are given back to the patients by an intravenous infusion. The success of treatment can be enhanced by pre-treatment of the tumor bearing host with either total body radiation or treatment with cyclophosphamide and by the simultaneous administration of interleukin-2 (Rosenberg et al., 1986 , Science 223, 1318-1321).
[0080] The TILs infused back to the patient are preferably autologous TILs (i.e., derived from the patient's own tumor) but also infusion with allogenic TILs can be imagined.
[0081] A further use of the TILs obtained by the method as described above is for in vivo diagnosis. Labeling of the TILs, for instance with 111 In (Fisher et al., 1989 , J. Clin. Oncol. 7, 250-261) or any other suitable diagnostic marker, renders them suited for identification of tumor deposits in melanoma patients.
[0082] Another part of the invention is formed by the T cell receptor (TCR) expressed by reactive CTLs directed against the peptides according to this invention or the gp100-protein. As is well known in the art, the TCR determines the specificity of a CTL. Therefore, the cDNA encoding the TCR, especially its variable region, can be isolated and introduced into T cells, thereby transferring anti-tumor activity to any T cell. Especially introduction of such a TCR into autologous T cells and subsequent expansion of these T cells will result in large numbers of CTL suitable for adoptive transfer into the autologous patient.
[0083] Cells harboring this T cell receptor can also be used for vaccination purposes.
[0084] A vaccine can also be composed from melanoma cells capable of expression of the peptides according to the present invention. It is possible to isolate these cells from a patient, using specific antibodies, such as NKI-beteb (directed against gp100), but is also possible to produce such melanoma cells from cultured melanoma cell lines, which either are natural gp100-producers or have been manipulated genetically to produce the peptides according to the present invention. These cells can be irradiated to be non-tumorogenic and infused (back) into the patient. To enhance the immunologic effect of these melanoma cells it is preferred to alter them genetically to produce a lymphokine, preferably interleukin-2 (IL-2) or granulocyte-macrophage colony stimulation factor (GM-CSF). Peptide + /gp100 + melanoma cells can be transfected with a cloning vehicle having the sequence coding for the production of IL-2 or GM-CSF.
[0085] Infusion of such a vaccine into a patient will stimulate the formation of CTLs.
[0086] Another type of vaccination having a similar effect is vaccination with pure DNA, for instance the DNA of a vector or a vector virus having the DNA sequence encoding the peptides according the present invention (both homologues and heterologues (chimeric protein) or repetitive). Once injected, the virus will infect or the DNA will be transformed to cells which express the antigen or the peptide(s).
[0087] Antibodies directed against the peptides according to the present invention are also part of the invention.
[0088] Monospecific antibodies to these peptides can be obtained by affinity purification from polyspecific antisera by a modification of the method of Hall et al. (1984 , Nature 311, 379-387). Polyspecific antisera can be obtained by immunizing rabbits according to standard immunization schemes.
[0089] Monospecific antibody as used herein is defined as a single antibody species or multiple antibody species with homogeneous binding characteristics for the relevant antigen. Homogeneous binding as used herein refers to the ability of the antibody species to bind to ligand binding domain of the invention.
[0090] The antibody is preferably a monoclonal antibody, more preferably a humanized monoclonal antibody.
[0091] Monoclonal antibodies can be prepared by immunizing inbred mice, preferably Balb/c with the appropriate protein by techniques known in the art (Köhler, G. and Milstein C., 1975 , Nature 256, 495-497). Hybridoma cells are subsequently selected by growth in hypoxanthine, thymidine and aminopterin in an appropriate cell culture medium such as Dulbecco's modified Eagle's medium (DMEM). Antibody producing hybridomas are cloned, preferably using the soft agar technique of MacPherson (1973, Tissue Culture Methods and Applications , Kruse and Paterson, eds., Academic Press). Discrete colonies are transferred into individual wells of culture plates for cultivation in an appropriate culture medium. Antibody producing cells are identified by screening with the appropriate immunogen. Immunogen positive hybridoma cells are maintained by techniques known in the art. Specific anti-monoclonal antibodies are produced by cultivating the hybridomas in vitro or preparing ascites fluid in mice following hybridoma injection by procedures known in the art.
[0092] It may be preferred to use humanized antibodies. Methods for humanizing antibodies, such as CDR-grafting, are known (Jones et al., 1986, Nature 321, 522-525). Another possibility to avoid antigenic response to antibodies reactive with polypeptides according to the invention is the use of human antibodies or fragments or derivatives thereof.
[0093] Human antibodies can be produced by in vitro stimulation of isolated B-lymphocytes, or they can be isolated from (immortalized) B-lymphocytes which have been harvested from a human being immunized with at least one ligand binding domain according to the invention.
[0094] Antibodies as described above can be used for the passive vaccination of melanoma patients. A preferred type of antibodies for this kind of vaccine are antibodies directed against the above-mentioned peptides presented in connection with the MHC molecule. To produce these kind of antibodies immunization of peptides presented by APCs is required. Such an immunization can be performed as described above. Alternatively, human antibodies to peptide-MHC complexes can be isolated from patients treated with a vaccine consisting of APCs loaded with one of said peptides.
[0095] The antibodies, which are formed after treatment with one of the vaccines of the invention can also be used for the monitoring of said vaccination. For such a method, serum of the patients is obtained and the antibodies directed to the peptide with which has been vaccinated are detected. Knowing the antibody titre from this detection, it can be judged if there is need for a boost vaccination.
[0096] Specific detection of said antibodies in the serum can be achieved by labeled peptides. The label can be any diagnostic marker known in the field of in vitro diagnosis, but most preferred (and widely used) are enzymes, dyes, metals and radionuclides, such as 67 Ga, 99m Tc, 111 In, 113m In, 123 I, 125 I, or 131 I.
[0097] The radiodiagnostic markers can be coupled directly to the peptides of the invention or through chelating moieties which have been coupled to the peptide directly or through linker or spacer molecules. The technique of coupling of radionuclides to peptides or peptide-like structures is already known in the field of (tumor) diagnostics from the numerous applications of labeled antibodies used both in in vivo and in in vitro tests.
[0098] Direct labeling of peptides can, for instance, be performed as described in the one-vial method (Haisma et al., 1986, J. Nucl. Med. 27, 1890). A general method for labeling of peptides through chelators, with or without linker or spacer molecules, has, for instance, been described in U.S. Pat. Nos. 4,472,509 and 4,485,086. Chelators using a bicyclic anhydride of DTPA have been disclosed in Hnatowich et al. (1983 , J. Immunol. Meth. 65, 147-157). Coupling through diamide dimercaptide compounds has been disclosed in EP 188,256.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0099] The present invention is further described by way of examples with reference to the accompanying figures, in which:
[0100] FIG. 1 . Target cell sensitization of alanine replacement epitopes. (A) Chromium labeled T2 target cells were preincubated for 1 hour with various amounts of the indicated alanine-substituted epitope-analogues. Melan-A/MART-1 27-35-reactive TIL 1235 lymphocytes were added at an effector to target ratio of 20. (B) Target cell sensitization of alanine-substituted gp100 154-162-analogues was analyzed using gp100-reactive TIL 1200 lymphocytes at an effector to target ratio of 20.
[0101] FIG. 2 . Target cell sensitization of N-terminal anchor-replacement epitopes. Chromium release experiments were performed as in FIG. 1 . (A) Melan-A/MART-1 27-35-reactive TIL 1235 lymphocytes were used to assay target cell sensitization by the Melan-A/MART-1 27-35 analogues. (B) Gp100 154-162-reactive TIL 1200 lymphocytes were used to assay target cell sensitization by the gp100 154-162-analogues.
[0102] FIG. 3 . Immunogenicity of gp100 154-162 epitope-analogues in HLA-A*0201/K b transgenic mice. Bulk CTL obtained from immunized mice were tested for lytic activity using chromium labeled Jurkat A2/K b target cells that were preincubated with no peptide, 10 mM wild type gp100 154-162 or 10 mM of the epitope-analogue used to immunize the mice. For each peptide the mean specific lysis of bulk CTL of the responding mice is shown. Standard deviations never exceeded 15% of the mean value. One representative experiment out of two is shown.
[0103] FIG. 4 . Peptide specific reactivity of in vitro induced epitope-analogue specific CTL cultures. Chromium-labeled HLA-A*0201 + T2 target cells were pre-incubated with 10 mM of an irrelevant HLA-A*0201-binding peptide, 10 mM wild type gp100 154-162 or 10 mM of the epitope-analogue used for CTL induction. The different CTL cultures were added at an effector to target ratio of 20:1. One representative experiment out of two is shown.
[0104] FIG. 5 . Epitope-analogue induced CTL cultures specifically lyse melanoma cells endogenously presenting the wild type epitope. Chromium-labeled HLA-A2.1 + BLM and Mel 624 melanoma cells were used as target cells. BLM cells lack expression of gp100. The different CTL cultures were added at an effector to target ratio of 20:1. One representative experiment out of two is shown.
DETAILED DESCRIPTION OF THE INVENTION
Materials and Methods
Cell Culture.
[0105] The HLA-A*0201 + melanoma line BLM was cultured as described previously (Bakker et al, 1994, J. Exp. Med. 179:1005). TIL 1200 and TIL 1235 lymphocytes were cultured as was reported previously (Kawakami et al., 1992 , J. Immunol. 148:638). T2 cells (Salter et al., 1985 , Immunogenetics. 21:235) and HLA-A*0201 + B lymphoblastoid JY cells were maintained in Iscoves medium (Gibco, Paisley, Scotland UK) supplemented with 5% FCS (BioWhittaker, Verviers, Belgium). Jurkat A*0201/K b cells (Irwin et al., 1989, J. Exp. Med. 170:1091) expressing the HLA-A*0201/K b chimeric molecule were cultured in Iscoves medium with 5% FCS supplemented with 0.8 mg/ml G418 (Gibco, Paisley, Scotland UK).
HLA-A*0201 + Lymphocytes.
[0106] Healthy caucasian volunteers were phenotyped HLA-A2 by flow cytometry using mAbs BB7.2 (Parham et al., 1981, Hum. Immunol. 3:277) and MA2.1 (Parham et al., 1978 , Nature 276:397). The donors underwent leukapheresis and PBMC were isolated by Ficoll/Hypaque density gradient centrifugation. The cells were cryopreserved in aliquots of 4×10 7 PBMC.
Transgenic Mice
[0107] HLA-A*0201/K b transgenic mice were used (animal distributor Harlan Sprague Dawley, Inc., Indianapolis, USA). Mice were held under clean conventional conditions. The transgenic mice express the product of the HLA-A*0201/K b chimeric gene in which the α3 domain of the heavy chain is replaced by the corresponding murine H-2 K b domain while leaving the HLA-A*0201 at and a2 domains unaffected (Vitiello et al., 1991, J. Exp. Med. 1007). This allows the murine CD8 molecule on the murine CD8 + T lymphocytes to interact with the syngeneic α3 domain of the hybrid MHC class I molecule.
Peptides.
[0108] For induction of CTL and chromium-release assays, peptides were synthesized with a free carboxy-terminus by Fmoc peptide chemistry using an ABIMED multiple synthesizer. All peptides were >90% pure as indicated by analytical HPLC. Peptides were dissolved in DMSO and stored at −20° C.
HLA-A*0201 Upregulation on T2 Cells.
[0109] Peptide-induced HLA-A*0201 upregulation on T2 cells was performed as described previously (Nijman et al., 1993, Eur. J. Immunol. 23:1215). Briefly, peptides were diluted from DMSO stocks to various concentrations (final DMSO concentration 0.5%) and were incubated together with 10 5 T2 cells for 14 hours at 37° C., 5% C0 2 in serum-free Iscoves medium in a volume of 100 ml in the presence of 3 mg/ml human β2-microglobulin (Sigma, St Louis, Mo.). Stabilization of HLA-A*0201 molecules at the cell surface of T2 cells was analyzed by flow cytometry using anti-HLA-A2 mAb BB7.2 (Parham et al., 1981, Hum. Immunol. 3:277). The Fluorescence Index is expressed as: (experimental mean fluorescence÷ background mean fluorescence)−1. The background mean fluorescence values were obtained by incubating T2 cells with a HLA-A*0201 non-binding peptide at similar concentrations.
Competition Based HLA-A*0201 Peptide-Binding Assay.
[0110] Peptide-binding to HLA-A*0201 was analyzed using HLA-A*0201 + JY cells as was described previously (van der Burg et al., 1995, Hum. Immunol. 44:189). Briefly, mild-acid treated JY cells were incubated with 150 nM Fluorescein (FL)-labeled reference peptide (FLPSDC(-FL)FPSV) and with several concentrations of competitor peptide for 24 hours at 4° in the presence of 1.0 mg/ml β2-microglobulin (Sigma, St. Louis, Mo.). Subsequently, the cells were washed, fixed with paraformaldehyde and analyzed by flow cytometry. The mean-fluorescence (MF) obtained in the absence of competitor peptide was regarded as maximal binding and equated to 0%; the MF obtained without reference peptide was equated to 100% inhibition. % inhibition of binding was calculated using the formula: (1-(MF 150 nM reference & competitor peptide−MF no reference peptide)÷(MF 150 nM reference peptide-MF no reference peptide))×100%. The binding capacity of competitor peptides is expressed as the concentration needed to inhibit 50% of binding of the FL-labeled reference peptide (IC 50 .
Measurement of MHC-Peptide Complex Stability at 37° C.
[0111] Measurement of MHC-peptide complex stability was performed. HLA-A*0201 + homozygous JY cells were treated with 10 4 M emetine (Sigma, St. Louis, USA) for 1 hour at 37° C. to stop de novo synthesis of MHC class I molecules. The cells were then mild-acid treated and subsequently loaded with 200 mM of peptide for 1 hour at room temperature. Thereafter, the cells were washed twice to remove free peptide and were incubated at 37° C. for 0, 2, 4 and 6 hours. Subsequently, the cells were stained using mAb BB7.2 (Parham et al., 1981 , Hum. Immunol. 3:277), fixed with paraformaldehyde and analyzed by flow cytometry.
[0000] CTL Induction in HLA-A*0201/K b Transgenic Mice. Groups of 3 HLA-A*0201/K b transgenic mice were injected subcutaneously in the base of the tail vein with 100 mg peptide emulsified in WA in the presence of 140 mg of the H-2 I-A b -restricted HBV core antigen-derived T helper epitope (128-140; sequence TPPAYRPPNAPIL) (Milich et al., 1988, Proc. Natl. Acad. Sci. U.S.A. 85:1610). After 11 days, mice were sacrificed and spleen cells (30×10 6 cells in 10 ml) were restimulated in vitro with peptide-loaded syngeneic irradiated LPS-stimulated B cell lymphoblasts (ratio 4:1). At day 6 of culture, the bulk responder populations were tested for specific lytic activity.
HLA-A*0201 + Donor Derived CTL Induction In Vitro
[0112] Using thawed PBMC, dendritic cells were generated according the procedure of Romani et al. (Romani et al., 1994, J. Exp. Med. 180:83) as was described previously (Bakker et al., 1995 , Cancer Res. 55:5330). Before the onset of culture, dendritic cells were loaded with 50 mM of peptide. Autologous CM + enriched responder T lymphocytes were prepared by adhering thawed PBMC for 2 hours and by subsequent partial depletion of the non-adherent fraction of CD4 + T cells using the anti-CD4 mAb RIV-7 (Leerling et al., 1990 , Dev. Biol. Stand. 71:191) and Sheep-anti-Mouse-IgG coated magnetic beads (Dynal, Oslo, Sweden). At the onset of stimulation, 2×10 5 peptide-loaded DC and 2×10 6 responder cells were co-cultured per well of a 24-well tissue culture plate (Costar, Badhoevedorp, The Netherlands) in 2 ml of Iscoves medium containing 5% pooled human AB + serum, 10 3 U/ml IL-6 (Sandoz, Basel, Switzerland) and 5 ng/ml IL-12.
[0113] On day 8 and day 15, the responder populations were restimulated using peptide-pulsed dendritic cells as stimulator cells. The cultures were propagated in medium containing IL-2 (Cetus Corp., Emeryville, Calif.) and IL-7 (Genzyme, Cambridge, Mass.) at final concentrations of 10 U/ml and 5 ng/ml respectively. Weekly hereafter the cultures were restimulated using adherent peptide-pulsed PBMC as was described previously (Bakker et al., 1995 , Cancer Res. 55:5330). Responder populations were tested for specific lytic activity after at least 4 rounds of restimulation.
Chromium-Release Assay.
[0114] Chromium release assays were performed as described previously (Bakker et al., 1994, J. Exp. Med. 179:1005). Briefly, 10 6 target cells were incubated with 100 mCi Na 2 51 CrO 4 (Amersham, Bucks, UK) for 1 hour. Various amounts of effector cells were then added to the target cells in triplicate wells of U bottomed microliter plates (Costar, Badhoevedorp, The Netherlands) in a final volume of 150 ml. In peptide recognition assays, target cells were pre-incubated with various concentrations of peptide for 30 or 60 min at 37° C. in a volume of 100 ml prior to the addition of effector cells. After 5 h of incubation, part of the supernatant was harvested and its radioactive content was measured. The mean percentage specific lysis of triplicate wells was calculated using the formula: % specific lysis=((experimental release−spontaneous release)÷(maximal release−spontaneous release))×100.
Example 1
Identification of Amino Acid Residues Engaged in HLA-A*0201 Binding and/or TCR Interactions for the Melan-A/MART-1 27-35 and the gp100 154-162 Epitopes
[0115] The Melan-A/MART-1 27-35 and the gp100 154-162 epitopes have been identified using HLA-A*0201 restricted TIL lines derived from metastatic melanomas. The Melan-A/MART-1 27-35 epitope was found to be the nominal epitope capable of triggering the Melan-A/MART-1 specific TIL 1235 line when presented on HLA-A*0201 + target cells (Kawakami et al., 1994 . J. Exp. Med. 180:347). Among a panel of peptides ranging from 8-mers to 11-mers located around gp100 amino acids 155-161, we identified the 9-mer 154-162 as the peptide most efficient in sensitizing HLA-A*0201 + target cells for lysis by the gp100 reactive TIL 1200 line (Bakker et al., 1995 , Int. J. Cancer 62:97). Both the Melan-A/MART-1 27-35 9-mer and the gp100 154-162 9-mer have now been eluted from the cell surface of HLA-A*0201 + melanoma cells, and were identified by tandem mass-spectroscopy, indicating that they are indeed the nominal epitopes endogenously presented in HLA-A*0201. To identify amino acid residues in both epitopes engaged in HLA-A*0201 binding and/or TCR interactions, epitope-analogues were synthesized in which the native amino acid was replaced by an alanine residue. In case alanine residues were present in the wild type epitope, they were substituted for the amino acid glycine. The substituted peptides were assayed for binding to HLA-A*0201 by means of an indirect binding assay using the processing defective cell line T2 (Nijman et al., 1993 , Eur. J. Immunol. 23:1215). All substitutions in the Melan-A/MART-1 epitope resulted in a nearly complete loss in the capability to stabilize HLA-A*0201 molecules at the cell surface of T2 cells (Table I). When the Melan-A/MART-1 27-35 analogues were used at micromolar concentrations to sensitize HLA-A*0201 + target cells for lysis by Melan-A/MART-1-specific CTL, we observed a decrease in target cell lysis for the alanine replacements at positions 4 to 7 of the epitope (Table I). In addition, the glycine substitution at position 2 resulted in decreased CTL reactivity. The amino acids at these positions in the Melan-A/MART-1 27-35 epitope are therefore most likely involved in TCR interactions.
[0116] In case of the gp100 154-162 epitope decreased HLA-A*0201 affinity of epitope-analogues was only observed for the alanine substitutions at position 3 and 9 (Table 1). With respect to T cell recognition, alanine substitutions at positions 5, 6 and 7 of the epitope were not allowed, indicating that amino acids at these positions are critical contact residues within this epitope for the TCR.
[0117] Subsequently, the epitope-analogues that induced reactivity at micromolar concentrations were titrated to evaluate their relative ability to sensitize T2 target cells for lysis by the relevant CTL ( FIG. 1 ). In all cases the epitope-analogues were similar or inferior compared to the wild type epitope in their sensitizing capacity, except for the alanine substitution at position 8 of the gp100 154-162 epitope. Surprisingly, this peptide was able to induce target cell lysis by gp100-reactive CTL even at a tenfold lower concentration.
Example 2
N-Terminal Anchor Residue Replacements in Both the gp100 154-162 and the Melan-A/MART-1 27-35 Epitopes Result in Improved Affinity for HLA-A*0201
[0118] Since both the Melan-A/MART-1 27-35 and the gp100 154-162 epitopes have non-conventional N-terminal anchoring residues, we replaced these residues for the common HLA-A*0201 anchoring residues V, L, I or M (Drijthout et al., 1995 , Hum. Immunol. 43:1). Subsequently, we tested these peptides for HLA-A*0201 binding and their ability to sensitize target cells for lysis by the relevant CTL. Apart from the methionine substitution, all anchor residue replacements in the Melan-A/MART-1 epitope resulted in significantly improved binding to HLA-A*0201 (Table II). HLA-A*0201 + target cells loaded with these peptides at a concentration of 1 mM were recognized by the Melan-A/MART-1 reactive CTL, except for the methionine substituted epitope (Table II). Although this peptide did bind to HLA-A*0201 at a level comparable to the wild type epitope, it failed to induce CTL reactivity. Titration experiments using the Melan-A/MART-1 anchor replacement peptides demonstrated that these epitope-analogues were inferior to wild type in sensitizing target cells for lysis by TIL 1235 ( FIG. 2 ).
[0119] Using the T2 assay all gp100 154-162 anchor replacement peptides except the methionine substituted epitope showed HLA-A*0201 binding comparable to the wild type epitope (Table II). Interestingly, these peptides were recognized by TIL 1200 when loaded on target cells at tenfold lower concentrations compared to the wild type peptide ( FIG. 2 ), while the methionine substituted peptide showed no difference. These findings demonstrate that amino acid substitutions within the native epitope can result in improved T cell recognition.
Example 3
Improved Target Cell Sensitization by gp100 154-162 Epitope Analogues Correlates with Increased Affinity for HLA-A*0201
[0120] To assess whether the augmented CTL recognition of the substituted gp100 154-162 epitopes could be attributed to improved HLA-A*0201 affinity, the HLA-A*0201 binding capacity of these peptides was tested now using a more sensitive cell-bound HLA-A*0201 binding assay based on competition of a labeled reference peptide with the peptides of interest (van der Burg et al., 1995 , Hum. Immunol. 44:189). HLA-A*0201 binding-affinities obtained with this assay demonstrated that all peptides that were able to sensitize target cells for lysis by TIL 1200 at tenfold lower concentrations compared to wild type, also bound with higher affinity to HLA-A*0201 (Table III). In addition to the N-terminal anchor substitutions, replacement of a polar residue for a hydrophobic residue adjacent to the C-terminal anchoring position also resulted in an epitope-analogue with improved HLA-A*0201 affinity (KTWGQYW A V (SEQ ID NO: 1)), apparently without affecting TCR recognition. Measurement of MHC class I-peptide complex dissociation rates demonstrated that the epitope-analogues tested are at least equally stable when compared to wild type (Table III). All peptides tested showed a DT 50 (the time required for 50% of the complexes to decay) longer than 4 hours. Peptides with DT 50 values of ≧3 hours were immunogenic in HLA-A*0201/K b transgenic mice. Taken together, these data indicate that the gp100 154-162 epitope-analogues may have similar or increased immunogenicity compared to wild type gp100 154-162.
Example 4
Immunogenicity of gp100 154-162 Epitope-Analogues in HLA-A*0201/K b Transgenic Mice
[0121] In order to determine the in vivo immunogenicity of the gp100 154-162 epitope-analogues of which the MHC class I binding-affinity and dissociation rate was measured. HLA-A*0201/K b transgenic mice were vaccinated with the gp100 154-162 wild type epitope, with the epitope-analogues KTWGQYW A V (SEQ ID NO: 1), K V WGQYWQV (SEQ ID NO: 2), K L WGQYWQV (SEQ ID NO: 3) or K I WGQYWQV (SEQ ID NO: 4), or with a control peptide (HBV core 18-27: FLPSDDFPSV (SEQ ID NO: 6)). The generation of these transgenic mice (Vitiello et al., 1991 . J. Exp. Med. 173:1007) and their use to analyze in vivo immunogenicity have been described previously (Ressing et al., 1995 , J. Immunol. 154:5934; Sette et al., 1994 , J. Immunol. 153:5586). As shown in FIG. 3 , the gp100 154-162 epitope-analogues KTWGQYW A V (SEQ ID NO: 1), K V WGQYWQV (SEQ ID NO: 2), and K L WGQYWQV (SEQ ID NO: 3), very efficiently induced a CTL response. To a lesser extent also the epitope-analogue K I WGQYWQV (SEQ ID NO: 4) and the wild type gp100 154-162 were able to elicit a CTL response. Bulk CTL derived from mice vaccinated with the gp100 154-162 epitope-analogues specifically lysed Jurkat A*0201/K b cells loaded with both the peptide used for vaccination and the wild type epitope. Interestingly, CTL bulk cultures raised against the epitope-analogues all recognized target cells pulsed with the wild type epitope equally well or better compared to target cells pulsed with epitope-analogues used for vaccination. Thus, all gp100 154-162 epitope-analogues tested were immunogenic in HLA-A*0201/K b transgenic mice, and elicited CTL displaying cross-reactivity with the native gp100 154-162 epitope.
Example 5
In Vitro Induction of gp100 154-162 Epitope-Analogue Specific Human CTL Displaying Cross-Reactivity with Endogenously HLA-A*9201 Presented Wild Type gp100 154-162
[0122] Next, we performed in vitro CTL induction assays to assess whether within the T cell repertoire of HLA-A*0201 + healthy donors precursor T lymphocytes were present capable of recognizing gp100 154-162 epitope-analogues. In order to achieve this, we initiated cultures of peptide-loaded dendritic cells together with autologous responder T lymphocytes as described previously (Bakker et al., 1995, Cancer Res. 55:5330). After several rounds of restimulation, responder T cells were tested for cytotoxic activity ( FIG. 4 ). All bulk CTL populations raised against the gp100 154-162 epitope-analogues, KTWGQYW A V (SEQ ID NO: 1), K V WGQYWQV (SEQ ID NO: 2), K L WGQYWQV (SEQ ID NO: 3) and K I WGQYWQV (SEQ ID NO: 4), efficiently lysed HLA-A*0201 + T2 target cells incubated with the peptides used for CTL induction. Only low background lysis was observed in the presence of an irrelevant peptide. In addition, these gp100 154-162 epitope-analogue reactive CTL efficiently lysed T2 target cells incubated with wild type gp100 154-162. To address the question whether these CTL responder populations could also recognize endogenously processed and presented wild type epitope, we performed chromium-release experiments using HLA-A*0201 + melanoma cell lines BLM and MeI 624 as targets. BLM cells have lost expression of the gp100 antigen, both at the protein and at the mRNA level (Adema et al., 1993 , Am. J. Pathol. 143:1579). As shown in FIG. 5 , all peptide-induced CTL cultures lysed the antigen expressing MeI 624 cells, whereas no or background lysis was observed against antigen negative BLM cells. TNF release by the anti-gp100 154-162 analogue CTL further demonstrated the reactivity of these CTL with endogenously presented wild type gp100 154-162 (data not shown). These data show that the four different CTL cultures induced using gp100 154-162 epitope-analogue loaded dendritic cells, all recognized the native gp100 154-162 epitope endogenously processed and presented by HLA-A*0201 + Mel 624 cells.
[0000]
TABLE I
HLA-A*0201-binding and target cell sensitization of alanine-replacement epitopes.
target cell
target
HLA-A*0201
lysis by
HLA-A*0201
cell
stabilization a
TIL
stabilization
lysis by
Melan A/MART-1 27-35
50 μM
25 μM
1235 b
gp100 154-162
50 μM
25 μM
TIL 1200
YLEPGPVTA c (SEQ ID NO: 7)
2.26
2.12
−3
YLEPGPVTA (SEQ ID NO: 7)
3
AAGIGILTV (SEQ ID NO: 8)
1.20
1.11
40
KTWGQYWQV (SEQ ID NO: 6)
2.06
1.40
67
G AGIGILTV (SEQ ID NO: 10)
1.07
1.11
52
ATWGQYWQV (SEQ ID NO: 11)
1.94
1.42
75
A G GIGILTV (SEQ ID NO: 12)
0.96
1.05
6
KAWGQYWQV (SEQ ID NO: 13)
1.57
1.20
64
AA AI GILTV (SEQ ID NO: 14)
0.98
0.99
13
KTAGQYWQV (SEQ ID NO: 15)
1.17
1.02
58
AAG A GILTV (SEQ ID NO: 16)
0.93
0.97
0
KTWAQYWQV (SEQ ID NO: 17)
1.45
1.13
63
AAG IA ILTV (SEQ ID NO: 18)
1.01
1.01
4
KTWGAYWQV (SEQ ID NO: 19)
1.59
1.25
9
AAGIG A LTV (SEQ ID NO: 20)
0.93
1.00
2
KTWGQAWQV (SEQ ID NO: 21)
1.42
1.15
7
AAGIGI A TV (SEQ ID NO: 22)
1.10
1.13
6
KTWGQYAQV (SEQ ID NO: 23)
1.31
1.14
−2
AAGIGIL A V (SEQ ID NO: 24)
1.05
1.01
11
KTWGQYWAV (SEQ ID NO: 1)
1.72
1.35
73
AAGIGILT A (SEQ ID NO: 25)
1.00
1.03
26
KTWGQYWQA (SEQ ID NO: 26)
1.08
1.02
76
a Binding of peptides to HLA-A2.1 was analyzed using the processing-defective T2 cell line at the indicated peptide concentrations. Numbers indicate Fluorescence Index: experimental mean fluorescence divided by the mean fluorescence that is obtained when T2 cells are incubated with an HLA-A2.1 non-binding peptide at a similar concentration.
b Numbers indicate % specific lysis by the relevant TIL lines at an E:T ratio of 20:1. Chromium-labeled T2 target cells were preincubated for 90 min with 1 μM of peptide. Chromium release was measured after 5 hours of incubation.
c gp100 280-288.
[0000]
TABLE II
HLA-A*0201-binding and target cell sensitization of N-terminal anchor-replacement epitopes.
HLA-A*0201
HLA-A*0201
stabilization a
target cell
stabilization
target cell
50
25
lysis by
50
25
lysis by
Melan A/MART-1 27-35
μM
μM
TIL 1235 b
gp100 154-162
μM
μM
TIL 1200
YLEPGPVTA c (SEQ ID NO: 7)
2.26
2.12
−1
YLEPGPVTA (SEQ ID NO: 7)
3
AAGIGILTV (SEQ ID NO: 8)
1.20
1.11
40
KTWGQYWQV (SEQ ID NO: 9)
2.06
1.40
67
AVGIGILTV (SEQ ID NO: 27)
1.62
1.36
27
KVWGQYWQV (SEQ ID NO: 2)
2.13
1.57
69
ALGIGILTV (SEQ ID NO: 28)
2.21
1.93
16
KLWGQYWQV (SEQ ID NO: 3)
2.19
1.55
65
AMGIGILTV (SEQ ID NO: 29)
1.18
1.05
6
KMWGQYWQV (SEQ ID NO: 35)
1.73
1.28
57
AIGIGLTV (SEQ ID NO: 30)
1.58
1.29
27
KIWGQYWQV (SEQ ID NO: 4)
2.00
1.43
68
a Binding of peptides to HLA-A2.1 was analyzed using the processing-defective T2 cell line at the indicated peptide concentrations. Numbers indicate Fluorescence Index: experimental mean fluorescence divided by the mean fluorescence that is obtained when T2 cells are incubated with an HLA-A2.1 non-binding peptide at a similar concentration.
b Numbers indicate % specific lysis by the relevant TIL lines at an E:T ratio of 20:1. Chromium-labeled T2 target cells were preincubated for 90 min with 1 μM of peptide. Chromium release was measured after 5 hours of incubation.
c gp100 280-288.
[0000]
TABLE III
HLA-A*0201 binding and complex stability of gp100
154-162 epitope-analogues
Affinity
Stability
peptide
IC50 (μM) a
(DT 50%) b
FLPSDFFPSV C (SEQ ID NO: 31)
0.5
>4 hr
KTWGQYWQV (SEQ ID NO: 9)
1.4
>4 hr
KTWGQYWAV (SEQ ID NO: 1)
0.5
>4 hr
KVWGQYWQV (SEQ ID NO: 2)
0.8
>4 hr
KTWGQYWQV (SEQ ID NO: 3)
0.4
>4 hr
KIWGQYWQV (SEQ ID NO: 4)
0.6
>4 hr
a Binding of peptides to HLA-A*0201 was analyzed in a competition away at 4° C. using mild acid treated HLA-A*0201 + B-LCL. The binding capacity of the peptides is shown as the concentration of peptide needed to inhibit 50% of binding of the Fluorescein labeled reference peptide.
b The dissociation rate of HLA-A*0201-peptide complexes was measured using emetine pretreated HLA-A*0201 + B-LCL. After mild acid treatment, empty cell surface HLA-A*0201 molecules were loaded with peptide at room temperature and B-LCL were then put at 37° C. The decay of cell surface HLA-A*0201 molecules was analyzed by flow cytometry. The dissociation rate is depicted as the time required for 50% of the MHC class I-peptide complexes to decay at 37° C.
c HBC 18-27, unlabeled reference peptide.
|
The present invention is concerned with cancer treatment and diagnosis, especially with melanoma associated peptide analogues with improved immunogenicity, epitopes thereof; vaccines against melanoma, tumor infiltrating T lymphocytes recognizing the antigen and diagnostics for the detection of melanoma and for the monitoring of vaccination. The peptides according to the invention can be exploited to elicit native epitope-reactive Cm. Usage of the peptides with improved immunogenicity may contribute to the development of CTL-epitope based vaccines in viral disease and cancer.
| 0
|
FIELD OF THE INVENTION
[0001] This invention relates to 4-aza-steroids, processes for their preparation, and their pharmaceutical applications. More specifically, the invention relates to novel 4-aza-steroids useful both as pharmaceutical agents in the inhibition of the enzyme steroid 5-α-reductase, as intermediates in the preparation of other, novel, pharmaceutically active 4-aza-steroid compounds, and the novel, pharmaceutically active 4-aza-steroids preparable therefrom.
BACKGROUND OF THE INVENTION AND PRIOR ART
[0002] The enzyme testosterone 5-α-reductase is known to cause reduction of testosterone in the body, to form dihydrotestosterone, DHT. DHT has been implicated in causing enlargement of the prostate, benign prostatic hyperplasia (BHP), leading to malignant conditions namely prostate cancer. Accordingly, it is desirable to inhibit the action of testosterone 5-α-reductase, and a number of 4-aza-steroids have been reported to be active in this respect. The best known of these is (5α, 17β)-(1,1-dimethyl-ethyl)-3-oxo-4-aza-androst-1-ene-17-carboxamide, commonly known as finasteride, of chemical structure:
[0003] Finasteride has, since its original introduction, been reported to be less effective in treating BPH than originally expected (R. S. Rittmaster, N. Engl. J. Med., 1994, 330, 120-125). According to reports, there is room for further improvement in the level of residual circulating DHT (20-40%) in patients undergoing treatment with finasteride (G. J. Gormley et. al., J. Clin. Endocrinol. Metab., 1990, 70, 1136-1141).
[0004] It is now known that there are two isozymes of steroid reductase. The isozyme that principally interacts in skin tissue is conventionally designated as 5-α-reductase type I (present in rat ventral prostate), while the isozyme that interacts within the prostatic tissue is designated as 5-α-reductase type II (present in human prostate tissue and rat epididymus). It would be highly desirable to have one drug showing selectivity towards inhibiting 5-α-reductase type II isozyme, associated with benign prostatic hyperplasia and prostate cancer. It also would be highly desirable to have another drug showing selectivity towards 5-α-reductase type I isozyme associated with the scalp for use in treatment of male pattern baldness and hirsutism in females.
[0005] It is an object of the present invention to provide novel 4-aza-steroids having activity against testosterone 5-α-reductase.
SUMMARY OF THE INVENTION
[0006] The present invention provides hydroxylated and other 4-aza-steroid compounds, said compounds having hydroxyl groups or other functional groups at one or both of the 7 and 15-positions. The novel compounds of the invention are active as inhibitors of testosterone 5-α-reductase type I and/or type II, and/or useful as chemical intermediates in preparing such active finasteride derivatives. They include both finasteride-type compounds and 1,2-dihydro-finasteride compounds.
[0007] The present invention also provides a novel microbiological process for preparing hydroxylated compounds of finasteride and 1,2-dihydro-finasteride, which comprises regio- and stereo-specific enzymatic oxidation reaction using a microorganism selected from the group consisting of Mortierella isabellina ATCC-42613, Bacillus megaterium ATCC-13368, Cunninghamella elegans ATCC-9244 and Cunninghamella elegans ATCC-9245, in a fermentation medium which supports the growth of the selected microorganism.
[0008] The present invention further provides a process of preparing novel finasteride and 1,2-dihydro-finasteride compounds having functional groups at one or more of positions 7-β, 11-α and 15-β, which comprises chemical reaction of the corresponding hydroxylated finasteride or 1,2-dihydro-finasteride compound with an appropriately chosen hydroxy-reactive chemical reagent capable of chemical conversion of the hydroxy group to the desired functional group.
[0009] Thus according to the present invention, there are provided novel finasteride derivatives corresponding to the general formula:
[0010] wherein solid bonds to substituents denote optional α or β stereo configurations and dotted lines in the nucleus denote optional unsaturation;
[0011] R and R 2 are independently selected from hydrogen; hydroxyl; halogen (F, Cl, Br, I); ester of formula —O—CO—R 3 where R 3 is hydrocarbyl selected from aliphatic (C 1 -C 12 ), cycloalkyl (C 3 -C 12 ), aromatic and aromatic-aliphatic such as benzyl, or heterocyclic (N, O or S), any of which are optionally unsaturated, optionally polybasic and optionally substituted with one or more substituents selected from alkyl, hydroxy, alkoxy, oxo, amino and halogen; sulphonic ester of formula —O—SO 2 —R 4 where R 4 is hydrocarbyl aliphatic or aromatic of up to 12 carbon atoms; azide; amino; substituted amino of formula NR 3 R 5 where R 3 is as defined above and R 5 is H or is independently selected from the radicals comprising R 3 ; and amino acyl of formula —NH—CO—R 6 or —NH—COOR 6 where R 6 is H or is independently selected from radicals comprising R 3 ;
[0012] R 1 is independently selected from the same group of radicals as R and R 2 but omitting hydroxy;
[0013] R 7 represent H or lower alkyl; with the proviso that R, R 1 and R 2 cannot all be hydrogen;
[0014] and R 8 is independently selected from hydrogen; hydroxyl; azide; oxo; halogen (F, Cl, Br, I); amino; substituted amino of formula NR 3 R 5 where R 3 and R 5 are as defined above; amino acyl of formula —NH—CO—R 6 or —NH.CO.OR 6 where R 6 is H or is independently selected from the groups comprising R 3 ; —CO—R 9 or —CO—OR 9 or CO—NH—R 9 where R 9 is H or is independently selected from the groups comprising R 3 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] The preferred choice for group R 8 in formula I above is —CO—NH—R 9 where R 9 represents lower alkyl, especially t.butyl.
[0016] One preferred group of compounds according to the invention is that corresponding to the general formula:
[0017] wherein at least one of the groups R, R 1 and R 2 represents a functional group chemically derivable from hydroxyl, and selected from halogen (F, Cl, Br, I); ester of formula —O—OC—R 3 where R 3 is aliphatic, cycloalkyl, aromatic, aromatic-aliphatic such as benzyl, or heterocyclic series (N, O or S atoms), any of which can be unsaturated and/or polybasic and/or conventionally substituted with substituents such as alkyl, hydroxy, alkoxy, oxo, amino, or halogen (F, Cl, Br, I); sulphonic ester of formula —O—O 2 S—R 4 where R 4 is aliphatic or aromatic of 1-12 carbon atoms; azide-N 3 ; amino; substituted amino of formula —NR 3 R 5 where R 3 is as shown above and R 5 ═R 3 , H; amino acyl of formula —NH—CO—R 6 where R 6 ═R 3 , OR 3 .
[0018] One specific preferred compound according to the invention is 15-β-hydroxy-finasteride, of chemical structure:
[0019] Conventional knowledge in organic chemistry can be utilized by those skilled in the art in converting the 15-β-hydroxy group of finasteride into its various novel 15-substituted compounds. Thus, 15-β-hydroxy-finasteride can be converted to various 15-substituted esters by the reaction of suitable acid halides or anhydrides in presence of esterifying agents such as trifluoroacetic anhydride (J. Org. Chem., 30, 927, 1965), dicyclohexylcarbodiimide (J. Org. Chem., 27, 4675, 1962), and acid catalysts such as sulphuric acid, hydrogen chloride, p-toluene sulphonic acid, methane sulphonic acid (Org. Synth. Coll. Vol. IV, 610, 1955). Esterification can also be performed on the hydroxyl group in the presence of suitable esterifying agents catalysed by a base. Suitable base catalysts are preferably tertiary amines such as pyridine, collidine triethylamine, 4-dimethylaminopyridine. Displacement of the halogen of any halogen ester with a suitable amine such as morpholine, piperidine, piperazine, N-methyl piperazine, dimethylamine, pyrrolidine, can form novel 15-substituted aminoesters of finasteride.
[0020] The 15-β-hydroxy-finasteride compound can be converted to 15-halo (F, Cl, Br, I) finasteride by reacting with appropriate halogenating reagents such as HCl, HBr, SOCl 2 , PCl 3 , PBr 3 , PCl 5 , POCl 3 , an organic acid chloride or by reacting the 15-halo derivative (Cl, Br) with NaI. Those skilled in the art can use 15-halo- and/or 15-hydroxy-finasteride as an intermediate to synthesize various 15-substituted compounds, such as oxo, amino, amide, azido analogues and as well as Δ-14(15)-4-azasteroid, by known methods. Treatment of a 15-halo azasteroid with sodium azide to produce the 15-azido compound is an example of such chemical conversion. These azido compounds are themselves potent 5-alpha reductase enzyme inhibitors and serve as intermediates for synthesis of various 15-substituted amino azasteroids.
[0021] A second specific, preferred compound is 7-β-hydroxy-finasteride, of structure:
[0022] This is similarly convertible to halo, ester, azido, oxo, amino and amido derivatives, and to a Δ-7(8)-azasteroid.
[0023] Particularly preferred according to the present invention is the compound 7-α-chloro-finasteride, which can be prepared by reacting 7-β-hydroxy-finasteride with a chlorinating agent such as thionyl chloride in solution, followed by extraction and chromatographic purification. The 7-βchloro analog may be prepared in the same way. 7-α-chloro-finasteride has been found to have an activity against 5-α-reductase type II which is considerably higher than that of finasteride itself.
[0024] Similarly, the novel 7-α-azido-finasteride, prepared from 7-β-hydroxy-finasteride as shown in the following synthetic scheme, has also shown a very high specific inhibitory activity against 5-α-reductase type II.
[0025] The process of the present invention, using as the microorganism Bacillus megaterium ATCC-13368, produces along with 15-β-hydroxy-finasteride, the compound 11-α-hydroxy-finasteride, of formula:
[0026] This compound can be similarly chemically converted at its 11-position to the corresponding halo, ester, amino, substituted amino, azido and Δ-9, 11 unsaturated derivatives which also form an aspect of the present invention.
[0027] One of the fungal microorganisms used in the process of the present invention, Mortierella isabellina ATCC-42613, is known to be capable of biochemical oxidation of organic compounds. It is commercially available. Suitable fermentation media for its growth are also known. However, its previous uses have been in oxidizing methyl groups —CH 3 to hydroxymethyl groups —CH 2 OH in the side chains of organic compounds, such as oxidation of ethylbenzene to benzyl alcohol. Since finasteride possesses three terminal methyl groups on a side chain, it would have been expected that, if this microorganism had any action on finasteride at all, it would have been oxidation of one or more of these terminal methyl groups. Experimental work to date has shown that a small amount of such a product is indeed produced. It is most surprising and unexpected to find, in addition, that in its predominant reaction, Mortierella isabellina ATCC-42613 oxidizes C—H groups on the aza-steroid nucleus to C—OH.
[0028] Culturing the microorganism Mortierella isabellina ATCC-42613 in a fermentation broth in the presence of finasteride in fact leads to the production of a mixture of 4 different hydroxylated derivatives of finasteride, namely 11-α-hydroxy-finasteride, 15-β-hydroxy-finasteride (the major product) and 7-β-hydroxy-finasteride, of structural formulae given above, along with a small amount of ω-hydroxy finasteride.
[0029] Similarly, 1,2-dihydro-finasteride, a precursor of finasteride, as microbial biotransformation with Mortierella isabellina ATCC 42613 produced a mixture of different hydroxylated compounds of 1,2-dihydro-finasteride, namely 15-β-hydroxy-1,2-dihydro-finasteride and 7-β-hydroxy-1,2-dihydro-finasteride.
[0030] The microorganisms Cunninghamella elegans strains ATCC-9245 and ATCC-9244 used in the process of the present invention are more specific in their action. In a suitable growth medium, they convert finasteride in high yield to 15-β-hydroxy-finasteride, substantially selectively, without production of significant amounts of other finasteride derivatives. This microorganism is known and commercially available. Suitable fermentation media for its growth are also known. It has previously been proposed for use in dehydrogenation and oxidation of saturated aza-steroid compounds, see international patent application PCT/EP95/03992 (WO 96/12034) Poli et al.
[0031] The microorganism Bacillus megaterium ATCC-13368 used in the process of the present invention is also known and is commercially available, along with suitable growth media for its cultivation. It has previously been proposed for use in biochemical conversion of cyproterone acetate, another steroid, to 15-β-cyproterone acetate-see U.S. Pat. No. 4,337,311 Schering. In a suitable growth medium, Bacillus megaterium ATCC-13368 converts finasteride into the known 11-α-hydroxy-finasteride (see U.S. Pat. No. 5,215,894 Merck) and the novel 15-β-hydroxy-finasteride of the present invention, in an approximately 1:2 ratio.
[0032] The above described hydroxylation processes can also be carried out using the above-mentioned micro-organisms immobilized or using crude homogenates isolated from these organisms or purified enzymes isolated from these organisms or using them as biocatalysts. These experimental techniques are well known in the literature and can be carried out by those skilled in the art, see international patent application PCT/EP95/03992 (WO96/12034) Poli et al.
[0033] Pharmaceutical compositions, dosage forms and methods of administration, and dosage rates, for the compounds of the present invention are essentially similar to those for finasteride itself, and suitable such formulations and dosage rates can be determined by consulting the relevant published literature concerning finasteride.
[0034] The invention is further described, for illustrative purposes, in the following specific examples.
EXAMPLE 1
[0035] Bioconversion of Finasteride using Mortierella isabellina, ATCC 42613
[0036] Nine 1 liter Erlenmeyer flasks each containing 200 ml of a nutrient solution of 4.0% dextrose, 0.5% yeast extract, 0.5% soytone, 0.5% sodium chloride, and 0.5% potassium phosphate dibasic, sterilized in an autoclave for 20 minutes at 121° C. were inoculated with a slope of culture of Mortierella isabellina ATCC 42613 kept on Malt Agar and kept shaking on an incubator shaker at 28° C. at 230 RPM for 3 days (68 hours). The combined fungal cells from all the flasks were filtered on a buchner funnel and washed with water. The resting cells were distributed among nine 1 liter Erlenmeyer flasks, each containing 150 ml of distilled water. A solution of finasteride (0.9 g) in 95% ethyl alcohol (9 ml) was distributed equally among the nine flasks and they were kept shaking at 28° C. at 230 RPM for 44 hours. The fungal biotransformation reaction was then worked up by filtering the fungal broth and extracting the medium with chloroform. The chloroform extract was dried over sodium sulfate and evaporated to dryness to afford the crude product which on TLC analysis showed the presence of four products and no starting material. Purification of crude product by column chromatography over silica by gradient elution with chloroform and methanol (90:10) afforded the desired novel fungal metabolites.
[0037] 1) 15-β-hydroxy-finasteride (˜300 mg). 1 H-NMR (500 MHz; CDCl 3 ) δ: 0.96 s, 3H (CH 3 at 18); 0.99, s, 3H (CH 3 at 19); 1.33, s, 9H(t-butyl group); 3.32-3.35, m, 1H (CH-5; α-H); 4.25-4.28, m, 1H; 5.06, bs, 1H; 5.51, bs, 1H; 5.78-5.81, dd, 1H; 6.76-6.78, d, 1H.
[0038] MS(m/z): 389 (M+H); 388 (M +° ); 370 (M-H 2 O); 355 (7.5%); 270.
[0039] 2) 7-β-hydroxy-finasteride (˜200 mg). 1 H-NMR (500 MHz; CDCl 3 ; diagnostic signals) δ: 0.70 s, 3H (CH 3 at 18); 0.97, s, 3H (CH 3 at 19); 1.33, s, 9H(t-butyl group); 3.30-3.33, m, 1H (CH-5;α-H); 3.45-3.50, m, 1H; 5.07, bs, 1H; 5.66, bs, 1H; 5.79-5.81, dd, 1H; 6.75, d, 1H.
[0040] MS(m/z): 389 (M+H); 388 (m +° ); 370 (M-H 2 O); 355; 270.
[0041] In addition to the above products, the purification yielded 20 mg. of ω-hydroxy-finasteride, the plasma metabolite and 70 mg. of 11-α-hydroxy-finasteride.
EXAMPLE 2
[0042] Bioconversion of Finasteride using Cunninghamella elegans, ATCC 9245
[0043] Fourteen 1 liter Erlenmeyer flasks each containing 200 ml of a nutrient solution of 3% sabouraud dextrose broth, sterilized in an autoclave for 20 minutes at 121° C. were inoculated with a slope of culture of Cunninghamella eleqans ATCC 9245 kept on potato dextrose agar and kept shaking on an incubator shaker at 19-24° C. at 200 RPM for 71 hours. The combined fungal cells from all the flasks were filtered on a buchner funnel and washed with water. The resting cells were distributed among fourteen 1 liter Erlenmeyer flasks, each containing 150 ml of distilled water. A solution of finasteride (2.1 g) in 95% ethyl alcohol (14 ml) was distributed equally among the fourteen flasks and they were kept for shaking at 19-23° C. at 200 RPM for 73 hours. The fungal biotransformation reaction was then worked up by filtering the fungal broth and extracting the medium with chloroform. The chloroform extract was dried over sodium sulfate and evaporated to dryness to afford the crude product which on TLC analysis showed the presence of a single product. Purification of crude product by column chromatography over silica by gradient elution with chloroform and methanol (90:10) afforded 1.4 g of the desired 15-β-hydroxy-finasteride. The identity was confirmed by comparing on TLC with an authentic sample of 15-β-hydroxy-finasteride obtained from biotransformation of finasteride with Mortierella isabellina, ATCC 42613.
EXAMPLE 3
[0044] Bioconversion of Finasteride using Cunninghamella elegans ATCC-9244
[0045] Nine 1 liter Erlenmeyer flasks each containing 200 ml of a nutrient solution of 3% sabouraud dextrose broth, sterilized in an autoclave for 20 minutes at 121° C. were inoculated with a slope of culture of Cunninghamella elegans ATCC 9244 kept on potato dextrose agar and kept shaking on an incubator shaker at 28° C. at 200 RPM for 90 hours. The combined fungal cells from all the flasks were filtered on a buchner funnel and washed with water. The resting cells were distributed among nine 1 liter Erlenmeyer flasks, each containing 150 ml of distilled water. A solution of finasteride (1.35 g) in 95% ethyl alcohol (9 ml) was distributed equally among the nine flasks and they were kept shaking at 28° C. at 200 RPM for 74 hours. The fungal biotransformation reaction was then worked up by filtering the fungal broth and extracting the medium with chloroform. The chloroform extract was dried over sodium sulfate and evaporated to dryness to afford the crude product by column chromatography over silica by gradient elution with chloroform and methanol (90:10) afforded 1.1 g of the desired 15-β-hydroxy-finasteride. The identity was confirmed by comparing on TLC with an authentic sample of 15-β-hydroxy-finasteride obtained from biotransformation of finasteride with Mortierella isabellina, ATCC 42613.
EXAMPLE 4
[0046] Bioconversion of Finasteride using Bacillus Megaterium, ATCC 13368
[0047] Nine 1 liter Erlenmeyer flasks each containing 200 ml of a nutrient solution (pH adjusted to 7.24 with 1N. sodium hydroxide) of 4% yeast extract and 1.5% soytone, sterilized in an autoclave for 20 minutes at 121° C. were inoculated with a slope of culture of Bacillus megaterium, ATCC 13368 kept on nutrient agar and kept shaking on an incubator shaker at 28° C. at 200 RPM for 72 hours. A solution of finasteride (1.35 g) in 95% ethyl alcohol (9 ml) was distributed equally among the nine Erlenmeyer flasks containing the bacterial suspension and they were kept shaking at 28° C. at 200 RPM for 24.5 hours. The bacterial biotransformation reaction was then worked up by combining the bacterial broth and extracting it with chloroform. The chloroform extract was dried over sodium sulfate and evaporated to dryness to afford a crude product which on comparative TLC analysis showed the presence of two products, 11-α-hydroxy and 15-β-hydroxy compounds of finasteride. Purification of crude product by column chromatography over silica by gradient elution with chloroform and methanol (95:5) afforded 0.49 g of 11-α-hydroxy-finasteride and 0.85 g of 15-β-hydroxy-finasteride. The identity was confirmed by comparing on TLC with the authentic samples of 11-α-hydroxy-finasteride and 15-β-hydroxy-finasteride, obtained from biotransformation of finasteride with Mortierella isabellina ATCC 42613.
EXAMPLE 5
[0048] Preparation of 15-β-acetoxy-finasteride
[0049] 15-β-hydroxy-finasteride (150 mg), taken in tetrahydrofuran (7 ml) and chloroform (3 ml), was allowed to react with acetyl chloride (82 μl) and pyridine (0.28 ml) at room temperature overnight. The reaction mixture was mixed with water and extracted with chloroform. Evaporation of the dried solvent followed by chromatographic purification with chloroform and methanol (95:5) afforded 15-β-acetoxy-finasteride (130 mg) as a colourless solid.
[0050] [0050] 1 H-NMR (500 MHz; CDCl 3 ; diagnostic signals) δ: 0.91 s, 3H (CH 3 at 18); 1.00, s, 3H (CH 3 at 19); 1.33, s, 9H (t-butyl group); 2.00, s, 3H(—OCOCH 3 ); 3.30-3.34, t. 1H; 5.04, s, 1H; 5.09-5.12, m, 1H; 5.51, s, 1H; 5.79-5.81, dd, 1H; 6.75-6.77, d, 1H.
[0051] MS(m/z): 430 (M + ); 370 (M-CH 3 COOH); 270; 110.
EXAMPLE 6
[0052] Preparation of 7-β-acetoxy-finasteride
[0053] 7-β-hydroxy-finasteride (150 mg), taken in chloroform (5 ml), was allowed to react with acetyl chloride (82 μl) with pyridine (0.281 ml) at room temperature overnight. The reaction mixture was mixed with water and extracted with chloroform, washed with 1N HCl, water, saturated sodium bicarbonate solution and dried over sodium sulfate. Evaporation of the dried solvent followed by chromatographic purification with chloroform and methanol (97:3) and crystallization from chloroform and hexane afforded a colourless solid (61 mg).
[0054] [0054] 1 H-NMR (500 MHz; CDCl 3 ; diagnostic signals)δ: 0.71 s, 3H (CH 3 at 18); 0.99, s, 3H (CH 3 at 19); 1.33, s, 9H (t-butyl group); 2.01, s, 3H (—OCOCH 3 ); 3.35-3.38, m, 1H (C-5; α-H); 4.59-4.65, m, 1H (7-α-H); 5.06, s, 1H (NH); 5.59, s, 1H (NH); 5.81-5.83, d, 1H (CH at 2); 6.73-6.75, d, 1H (CH at 1).
[0055] MS (m/z): 430 (M + ); 370 m-CH 3 COOH) +
EXAMPLE 7
[0056] Preparation of 7-α-chloro-finasteride
[0057] A mixture of 7-β-hydroxy-finasteride (208 mg), benzene (15 ml) and thionyl chloride (0.4) was stirred at room temperature overnight. The reaction mixture was mixed with water, the pH was adjusted to 10 and extracted with chloroform, washed with 1N HCl, water, saturated sodium bicarbonate solution and dried over sodium sulfate. Evaporation of the dried solvent followed by chromatographic purification of the resultant crude product with chloroform and methanol (95:5) and crystallization from chloroform and hexane afforded 7-α-chloro-finasteride as a colorless solid (47 mg).
[0058] [0058] 1 H-NMR (500 MHz; CDCl 3 ; diagnostic signals)δ; 0.69, s, 3H (CH 3 at 18); 0.97, s, 3H (CH 3 at 19); 1.33, s, 9H (t-butyl group); 3.95-3.98, m, 1H (CH-5; α-H; 0.63 ppm deshielded suggests Cl is in 7-α-position); 4.31, d, 1H (7-β-H); 5.06, s, 1H; 5.60, s, 1H; 5.81-5.83, dd, 1H; 6.75-6.67, d, 1H.
[0059] MS (m/z): 406 (M + ); 371 (M-Cl); 270-110
EXAMPLE 8
[0060] Preparation of 7-β-tosyloxy-finasteride
[0061] To a solution of 7-β-hydroxy-finasteride (200 mg) in pyridine (5 ml) at 0-5° C. was added p-toluene sulphonyl chloride (215 mg). The resultant mixture was kept in the refrigerator. TLC analysis suggested that there was still unreacted starting material. Another 220 mg of p-toluene sulphonyl chloride was added and kept in the refrigerator. Reaction mixture was poured into ice cold water, pH was adjusted to 3 with 5N HCl and it was extracted with chloroform, washed with water dried over sodium sulfate. Evaporation of the solvent followed by chromatographic purification of the crude product with chloroform and methanol (92:8) and crystallization afforded 7-β-tosyloxy-finasteride as a colorless solid (90 mg).
[0062] [0062] 1 H-NMR (500 MHz; CDCl 3 ; diagnostic signals)δ: 0.66, s, 3H (CH 3 at 18); 0.93, s, 3H (CH 3 at 19); 1.31, s, 9H (t-butyl group); 2.44, s, 3H; 3.24-3.27, dd, 1H; 4.48-4,54, m 1H; 5.07, s, 1H; 5.18, s, 1H; 5.78-5.80, d, 1H; 6.70-6.72, d, 1H; 7.31-7.33, d, 2H; 7.75-7.77, d, 2H.
[0063] MS (m/z): 543 (M+H) +
EXAMPLE 9
[0064] Preparation of 7-α-azido-finasteride
[0065] A mixture of 7-β-tosyloxy-finasteride (50 mg), sodium azide (55 mg) in DMF (3 ml) was stirred at RT overnight. TLC analysis suggested that there was still unreacted starting material. Another 10 mg of sodium azide was added and kept stirring overnight. Reaction mixture was poured into water, extracted with ether, washed with water, dried over magnesium sulfate and evaporation of the solvent afforded 7-α-azido-finasteride, a colorless solid.
[0066] [0066] 1 H-NMR (500 MHz; CDCl 3 ; diagnostic signals)δ: 0.68, s, 3H (CH 3 at 18); 0.95, s, 3H (CH 3 at 19); 1.33, s, 9H (t-butyl) 3.71-3.75, dd, 1H (7-β-H; equatorial); 3.80, s, 1H (CH-5; α-H; 0.5 ppm deshielded suggests N 3 is in 7-α-position); 5.05, s, 1H; 5.80-5.82, d, 1H; 6.72-6.74, d, 1H.
[0067] MS (m/z): 414 (M+H) +
EXAMPLE 10
[0068] Preparation of 14,15-dehydro-finasteride
[0069] To a mixture of 15-β-hydroxy-finasteride (206 mg) in benzene (10 ml), was added a solution of thionyl chloride (1.0 ml) in benzene (5 ml), and the resultant mixture was stirred at room temperature overnight. TLC indicated that the starting material has disappeared. The reaction mixture was added with water, pH was adjusted to 10, extracted with chloroform, the solvent extract was washed with 1N HCl and saturated sodium bicarbonate solution and dried over sodium sulfate. The resultant crude product, after purification by column chromatography (chloroform: MeOH; 95:5) and crystallization from chloroform and hexane, afforded a colorless solid (108 mg), expected to be the intermediate, 15-chloro-finasteride. A mixture of the intermediate (50 mg) and sodium hydroxide (8 mg) were stirred in methanol (3 ml) at room temperature overnight. Water (3 ml) was added to the reaction mixture and was extracted with chloroform (2×10 ml) after the pH was adjusted to 3 with 1N HCl. The organic extract was washed with saturated sodium bicarbonate and dried over sodium sulfate. Evaporation of the solvent followed by chromatographic purification of the crude product with chloroform and methanol (95:5) and crystallization from ether afforded 14,15-dehydro-finasteride as a colorless solid (27 mg).
[0070] [0070] 1 H-NMR (500 MHz; CDCl 3 ; diagnostic signals)δ: 0.94, 0.97, 2 siglets, 6H (2 CH 3 at 18 and 19); 1.35, s, 9H (t-butyl); 3.28-3.31, m, 1H (CH-5); 5.11, s, 1H; 5.17, s, 1H; 5.24, s, 1H; 5.79-5.82, dd, 1H; 6.73-6.75, d, 1H.
[0071] MS (m/z: 370 (M + ).
EXAMPLE 11
[0072] Preparation of 1,2-dihydro-15β-hydroxy-finasteride
[0073] 15-β-hydroxy-finasteride (70 mg) was hydrogenated over 10% Pd/C (7 mg) in absolute ethanol (10 ml) at room temperature under atmospheric pressure with stirring for five days. The reaction mixture was filtered, solids washed with ethanol, the combined alcohol extracts were evaporated off to give a residue. Crystallization of the resultant crude product from chloroform and hexane afforded 1,2-dihydro-15-β-hydroxy-finasteride as a colorless solid (41 mg).
[0074] [0074] 1 H-NMR (500 MHz; CDCl 3 ; diagnostic signals)δ: 0.92, s, 3H (CH 3 at 18); 0.95, s, 3H (CH 3 at 19); 1.33, s, 9H (t-butyl group); 3.04-3.07, dd, 1H (CH-5; α-H); 4.27, s, 1H (15-α-H); 5.06, s, 1H, 5.65, s, 1H.
[0075] MS (m/z): 391 (M+H) +
EXAMPLE 12
[0076] Preparation of 1,2-dihydro-7-β-hydroxy-finasteride
[0077] 7-β-hydroxy-finasteride (50 mg) was hydrogenated over 5 10% Pd/C (7 mg) in absolute ethanol (10 ml) at room temperature under atmospheric pressure with stirring for five days. The reaction mixture was filtered, solids were washed with ethanol. The combined ethanol extract was concentrated to afford 1,2-dihydro-7-β-hydroxy-finasteride as a colorless solid (22 mg).
[0078] [0078] 1 H-NMR (500 MHz; CDCl 3 ; diagnostic signals)δ: 0.70, s, 3H (CH 3 at 18); 0.92, s, 3H (CH 3 at 19); 1.33, s, 9H (t-butyl); 3.05-3.08, dd, 1H (CH-5; α-H); 3.42-3.45, m, 1H (7-α-H); 3.69, s, 1H, 5.07, s, 1H; 5.50, s, 1H.
[0079] MS (m/z): 391 (M+H) +
EXAMPLE 13
[0080] Bioconversion of 1,2-dihydro-finasteride using Mortierella isabellina ATCC 42613
[0081] Following the procedure as described in Example 1, the microbial biotransformation was carried out on 1,2-dihydro-finasteride using Mortierella isabellina, ATCC 42613. Thus, fungal broth, obtained from biotransformation reaction of 1,2-dihydro-finasteride (3.0 g) for 69 hours, was extracted with chloroform. The chloroform extract was dried over sodium sulfate and evaporated to dryness to afford a crude product (4.29 g) which on purification by column chromatography over silica by gradient elution with chloroform, and methanol (95:5) afforded the desired novel fungal metabolites.
[0082] 1) 1,2-Dihydro-15-β-hydroxy-finasteride (1.2 g). NMR and M/S are identical to that of Example 11.
[0083] 2) 1,2-Dihydro-7-β-hydroxy-finasteride 1.2 g). NMR and M/S are identical to that of Example 12.
EXAMPLE 14
[0084] Preparation of 1,2-dihydro-7-α-chloro-finasteride
[0085] A mixture of 1,2-dihydro-7-β-hydroxy-finasteride (50 mg), benzene (5 ml) and thionyl chloride (0.5 ml) was stirred at room temperature for five days. Reaction mixture was mixed with chloroform (40 ml) and water (20 ml) and stirred for 10 minutes. The aqueous extract was washed with water, saturated sodium bicarbonate solution and dried over sodium sulfate.
[0086] Evaporation of the dried solvent followed by chromatographic purification of the resultant crude product with chloroform and crystallization from chloroform and hexane afforded 1,2-dihydro-7-α-chloro-finasteride as a colorless solid (30 mg).
[0087] [0087] 1 H-NMR (500 MHZ; CDCl 3 ; diagnostic signals)δ: 0.68, s, 3H (CH 3 at 18); 0.91, s, 3H (CH 3 at 19); 1.33, s, 9H (t-butyl group); 3.67-3.70, t, 1H (CH-5; α-H; 0.63 ppm deshielded suggests Cl is in a 7-α-position); 4.31, d, 1H (7-β-H); 5.04, s, 1H; 5.46, s, 1H.
[0088] MS (m/z): 408 (M + ).
EXAMPLE 15
[0089] Biochemical Assays
[0090] Biochemical Assays were carried out to determine the inhibitory activities of various compounds of the previous examples on 5-α-reductase I enzyme isolated from male rate prostate and 5-α-reductase II enzyme isolated from rat epididymus and human prostate. These procedures were carried out following published literature procedures (H. Takami et al., J. Med. Chem., 39, pp 5047-5052; Tehming Liang, Margaret A. Cascieri et al., Endocrinology, 117, pp 571-579). Brief descriptions are as follows:
[0091] Rat 5-α-reductase I enzyme assay. Prostates, removed from 16 young male Sprague dawley rats (each weighing about 300-400 g), were minced and homogenized at 0-4° C. in 3 tissue volumes of buffer (0.32 M sucrose, 1 mM dithiothreitol, and 20 mM phosphate buffer, pH 6.5) using a polytron homogenizer. The homogenate was centrifuged at 4° C. at 140,000 g for 1 hour. The resultant pellet, after washing with the homogenizing buffer was suspended in the same buffer and stored at −70° C. The assay was carried out in a final volume of 0.5 ml containing 20 mM phosphate buffer (pH 6.5), 1 mM dithiothreitol, 150 μM NADPH, 2 μM 14 C testosterone and the enzyme concentration (500 μg-1 mg) For conducting the inhibitory studies on a 5-α-reductase I, finasteride and other test compounds were added in 10 μl of ethanol to a concentration 10 −9 to 10 −5 with five to six points including control using duplicate for each point to the above reaction mixture. The incubations were done for 20 minutes at 37° C. The reactions were stopped by adding 2.0 ml of ethyl acetate containing testosterone, 5-α-dihydrotestosterone, and androstenedione (10 μg each). After centrifugation at 1000 g for 5 minutes, the upper ethyl acetate extract was transferred to a tube and then evaporated under nitrogen to dryness. The compounds were taken up in 50 μl of ethyl acetate and chromatographed on Whatman LK5DF silica GF TLC plates using ethyl acetate-cyclohexane (1:1). The respective TLC spots corresponding to testosterone and dihydrotestosterone (Rf value same as that of androstenedione) were scraped from the plate and taken in respective scintillation vials. They were counted in the Beckman scintillation counter model No. LS 6500 with counting efficiency of 95% for 14 C carbon. Finasteride was used as a known standard during all screening. The range of IC 50 values for different test compounds obtained from different experiments is shown in Table 1 under the column, Rat Prostate Enzyme I IC 50 .
[0092] Rat 5-α-reductase II enzyme assay: Epididymus, taken out during the isolation of the rat prostates during rat enzyme I assay, was stored at −70° C. Isolation of the enzyme and the assay were carried out following the procedure described above, except the reaction buffer used was 40 mM Tris-citrate, pH 4.5. The range of IC 50 values for different test compounds obtained from different experiments is shown in Table 1 under the column, Rat Epididymus Enzyme II IC 50 .
[0093] Human 5-α-reductase II enzyme assay: Specimens of human prostates were quickly frozen in dry ice after collection and kept at −70° C. before isolation of the enzyme. Isolation of the enzyme and the assay were carried out following a similar procedure as for the isolation of rat 5-α-reductase II enzyme with some modifications. During the isolation of the enzyme, 50 μM NADPH was added to the homogenizing buffer as a stabilizer. The enzyme was stored in the homogenizing buffer containing 20% glycerol. The enzyme reaction buffer used as 40 mM Tris-citrate buffer, pH 5.0. The range of IC 50 values for different test compounds obtained from different experiments is shown in Table 1 under the column, Human Prostate Enzyme II IC 50 .
TABLE 1 BIOCHEMICAL ASSAYS Rat Human Compound Rat Prostate Epididymus Prostate of Enzyme I Enzyme II Enzyme II Example Compound IC 50 IC 50 IC 50 Finasteride 13-30 ˜2.9-11.8 3.3-7 nM nM nM Finasteride I 11.0-38 5.1-14.8 2.7-10.6 given as a blind nM nM nM compound to test the assay results 1,2,3,4 15-β-hydroxy- 805-853 640 nM- 50-59 finasteride nM 1.01 nM nM 1 7-β-hydroxy- 811-1800 106 62-64 finasteride nM nM nM 5 15-β-Acetoxy- 4.2-5.7 1.6-2.7 2.01 finasteride μm μM μM 6 7-β-Acetoxy- 385-697 135-357 175-362 finasteride nM nM nM 7 7-α-Chloro- 306-350 1.92-3.1 0.9-3.6 finasteride nM nM nM 8 7-β-Tosyloxy- 1.5-4.3 incomplete 213-570 finasteride μM nM 9 7-α-Azido- 577-1.1 incomplete 19-32 finasteride μM nM 10 14,15-Dehydro- 50-67 45 39-49.6 finasteride nM nM nM 11,13 1,2-Dihydro-15- 351-468 incom- incom- β-hydroxy- nM plete plete finasteride 12,13 1,2-Dihydro-7-β- 453-492 567-891 536-755 hydroxy- nM nM nM finasteride 14 1,2-Dihydro-7-α- 53-99 2.9-8.6 11.5-44 chloro- nM nM nM finasteride
|
4-Aza-steroid compounds are provided, which have functional groups at one or more of positions 7, 11 and 15, such as hydroxyl or hydroxyl derivative groups. The compounds are active against 5-α-reductase giving indications of utility in combating prostate cancer. The compounds can be prepared by chemo-enzymatic synthesis from easily available 4-aza-steroids.
| 2
|
TECHNICAL FIELD
[0001] The present invention relates to a chair and the structure for stretching a mesh over the backrest, a seat, a headrest etc. of the chair.
BACKGROUND OF THE INVENTION
[0002] U.S. Pat. No. 6,386,634B1 discloses the backrest structure of a chair and the stretching structure of a mesh in the backrest in which edge material is mounted by molding around the mesh to which tension is already applied, the edge material engaging in grooves in a front surface of a back frame to apply mesh over the front surface of the back frame.
[0003] JP2004-49685A discloses that an engagement piece mounted to the periphery of a mesh engages on a peripheral groove on the rear surface of a back frame, said engagement piece being pressed into the groove by the binding frame mounted to the rear surface of the back frame to apply tension to the mesh over the upper surface of the back frame.
[0004] A hanger for having clothes of a sitting person is mounted to the backrest of a chair in JP6-45553U, JP2004-159745A, JP9-10189U, JP11-155690A and JP5-7179U.
Problems to be Solved by the Invention
[0005] However, U.S. Pat. No. 6,386,634B1 discloses that it is necessary to take the width of the back frame to prevent flexure of the back frame by force applied to the mesh when the user sits down, a groove which engages with the edge material around the mesh being formed on the front surface of the back frame so that the periphery of the back frame is exposed from the mesh. The back frame greatly occupying the appearance of the chair causes bad appearance in design.
[0006] In JP2004-49685A, when a user sits down on the chair, flexing of the back frame against the force applied to the mesh is prevented by both the back frame and binding frame. Thus, the back frame covered with the mesh and binding frame not covered with the mesh are overlapped and exposed to the outside, which does not produce good appearance in design as well as heavy weight, a lot of the parts, a lot of time for assembling and high cost.
[0007] In JP6-45553U and JP2004-159745A, the support rod for supporting the hanger body is directly mounted in the middle of the rear surface of the backrest. It cannot be applied to a chair in which mesh is applied to the back frame. And a special device is required so that the mounting parts do not project from the front surface of the backrest when the support rod is directly attached to the middle of the rear surface of the backrest.
[0008] In JP9-10189U, JP11-155690A and JP5-7179U, the support rod is mounted to the transverse rod at the lower part of the rear of the backrest or support post standing from the lower part thereby increasing the length of the support rod. When the chair is pulled with the hunger body, the hanger is likely to be broken.
[0009] In view of the above disadvantages in the prior art, it is objects of the present invention to solve the problems below:
[0010] (A) To provide a chair with the backrest structure in which the ratio of the back frame is small with respect to the appearance of the chair, having good design, light weight, reduction in the number of parts and improvement in assembling.
[0011] (B) To provide a chair with a hanger in which the hanger is easily mounted to the backrest to allow parts for mounting the hanger not to project from the front surface of the backrest, preventing the hanger from being damaged and providing good appearance.
[0012] (C) To provide the structure for a mesh over the backrest of a chair in which the ratio of a frame to appearance of the chair is small to provide good appearance, light weight, reduction in the number of parts and improvement in assembling.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a front elevational view of the first embodiment of a chair according to the present invention;
[0014] FIG. 2 is a side elevational view thereof;
[0015] FIG. 3 is a rear perspective view thereof;
[0016] FIG. 4 is a front perspective view of the backrest;
[0017] FIG. 5 is a sectional view taken along the line V-V in FIG. 4 ;
[0018] FIG. 6 is a sectional view taken along the line VI-VI in FIG. 4 ;
[0019] FIG. 7 is an enlarged perspective view of the part VII in FIG. 4 ;
[0020] FIG. 8 is a side view of the second embodiment of a chair with a hanger according to the present invention;
[0021] FIG. 9 is an enlarged rear perspective view of main part of the chair in FIG. 8 ;
[0022] FIG. 10 is a rear enlarged exploded perspective view of the chair in FIG. 8 ;
[0023] FIG. 11 is a front enlarged exploded perspective view thereof;
[0024] FIG. 12 is an enlarged sectional view taken along the line XII-XII in FIG. 9 ; and
[0025] FIG. 13 is an enlarged sectional view taken along the line XIII-XIII in FIG. 9 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0026] FIGS. 1-7 show the first embodiment of the present invention.
[0027] The present application is applied to the structure of the backrest of the chair and the structure of mesh in the backrest.
[0028] As shown in FIGS. 1 and 2 , a reclining chair 1 comprises a leg 4 comprising five leg rods 3 each of which has a caster 2 at the end. At the center of the leg 4 , a telescopic leg post 6 which comprises a gas spring 5 stands. At the upper end of the leg post 6 , a rear part of a support base 7 is fixed.
[0029] The support base 7 comprises a hollow rhombus-like box which opens at an upper front part, and arms 8 , 8 are integrally formed from each side of the front part of the support base 7 .
[0030] A hexagonal pivot 9 passes through the support base 7 in the middle. At each end of the pivot 9 extending from the support base 7 , a tubular portion 11 a fits. The tubular portions 11 a are provided at the lower front ends of a pair of backrest support rods 11 , 11 that support a backrest 10 . The backrest 10 , the backrest support rods 11 , 11 and the backrest 10 are rotated around the pivot 9 with respect to the support base 7 .
[0031] Inside the support base 7 , there are provided a rubber torsion unit for promoting the pivot 8 in an anticlockwise direction and a promoting-force adjusting device (not shown). In the middle of the front lower surface of the support base 7 , there is a gas spring unit 13 for assisting promoting force of the rubber torsion unit in connection with the rubber torsion unit to form a force-promoting unit to stand the backrest 10 .
[0032] Short arms 12 , 12 project from the backrest support rods 11 , 11 at the back of the pivot 9 . At the upper ends of the arms 12 , 12 , a pair of seat-supporting frames 15 , 15 which support each side of a seat 14 are connected at the rear ends with a shaft 16 .
[0033] The backrest 10 will be described with respect to FIGS. 3-7 .
[0034] In FIG. 3 , a back frame 17 of the backrest 10 comprises a rectangular synthetic-resin front face frame 18 . The front face frame 18 comprises an upper frame rod 18 a , a lower frame rod 18 b , a left-side frame rod 18 c and a right-side frame rod 18 d . The rods 18 b , 18 d are wider than the rods 18 a , 18 b . A mesh is held on the rods 18 a , 18 b , 18 c , 18 d.
[0035] In FIGS. 4 and 5 , a pair of grooves 19 , 20 is formed longitudinally on the outer side surfaces of the right and left side frame rods 18 c , 18 d.
[0036] In FIG. 6 , a groove 21 is horizontally formed along the lower edge of the front surface of the upper frame rod 18 a , and a groove 22 is horizontally formed along the upper edge of the front surface of the lower frame rod 18 b.
[0037] A surface 21 a between the lower edge of the front surface of the upper frame rod 18 a and the groove 21 and a surface 22 a between the upper edge of the front surface of the lower frame rod 18 b and the groove 22 are grooved by thickness of an outward portion 25 b of an edge piece 25 . When the edge piece 25 engages with a corner between the lower surface and the front surface of the upper frame rod 18 a and the front surface and with a corner between the upper surface and the front surface of the lower frame rod 18 b , the end face of each of the edge piece 25 is coplanar with the front surfaces of the upper frame rod 18 a and the lower frame rod 18 b.
[0038] A mesh 23 may be preferably net-like or mesh-like material knitted or woven from high-tension plastic or other elastic fibers, or may be woven fabric, synthetic resin sheet or porous sheet. Synthetic resin edge pieces 24 , 24 which engage in a pair of grooves 19 , 20 are fixed in the left and right side edges of the mesh 23 by molding. The synthetic-resin edge pieces 25 , 25 which has a hook-like portions 25 d , 25 d and engage in the grooves 21 , 22 are fixed in the upper and lower edges by molding.
[0039] The edge piece 25 comprises a base 25 a , the outward portion 25 b , and a turning portion 25 c which turns in parallel with the base 25 a from the end of the outward portion 25 b . The base 25 a and the outward portion 25 b constitute the hook-like portion 25 d.
[0040] The size of the mesh 23 mounted to the edge pieces 24 , 24 , 25 , 25 is formerly determined to apply a suitable tension to the mesh 23 when the edge pieces 24 , 24 , 25 , 25 engage in the grooves 19 , 20 or the grooves 21 , 22 .
[0041] In FIGS. 4-7 , the right and left edge pieces 24 , 24 of the mesh 23 engage in the grooves 19 , 20 of the right and left side frame rods 18 c , 18 d . The upper and lower ends of the mesh 23 are wound from the front surface to the rear surface around the upper and lower surfaces of the upper and lower frame rods 18 a , 18 b . The hook-like portions 25 d , 25 d of the upper and lower edge pieces 25 , 25 engage on the corner between the lower surface and the front surface, and the corner between the upper surface and the front surface. The turning portions 25 c , 25 c of the upper and lower edge pieces 25 , 25 engage in the upper and lower grooves 21 , 22 , so that the mesh 23 is stretched over the entire front surface of the front face frame 18 tensionally.
[0042] Thus, the front surface of the front face frame 18 or the front surface of the back frame 17 is entirely covered with the mesh 23 . So the back frame 17 is not so occupied in the appearance of the chair, so that good impression is given in design.
[0043] In FIGS. 3 and 6 , to each side end of the upper frame rod 18 a of the front face frame 18 , an arcuate upper reinforcement rod 26 is joined so that the middle of the rod 26 is spaced apart from the upper frame rod 18 a . The upper reinforcement rod 26 and the upper frame rod 18 a is like crescent.
[0044] The upper reinforcement rod 26 keeps strength of the upper part of the back frame 17 together with the back frame 17 . When a user is reclined on the backrest 10 , it is allowed for the upper frame rod 18 a to be slightly flexed elastically.
[0045] The upper reinforcement rod 26 is spaced apart from the upper frame rod 18 a . Thus, without hindering attachment of the mesh 23 , a headrest 27 as shown by dotted lines in FIG. 4 and an optional member such as a hanger for clothes in FIG. 8 and so on are detachably mounted.
[0046] The upper reinforcement rod 26 is also used with a hand when the chair is moved.
[0047] In FIGS. 3 , 6 and 7 , to the lower ends of the right and left side frame rods 18 c , 18 d of the front face frame 18 , both ends of the lower reinforcement rod 28 are coupled. The middle of the lower frame rod 18 b is spaced forward of the lower reinforcement rod 28 , but each end thereof is fastened to each end of the lower reinforcement rod 28 with a screw 29 .
[0048] The lower end of the mesh 23 is wound around the lower frame rod 18 b after the lower frame rod 18 b is fastened to the front surface of the lower reinforcement rod 28 . A folding portion 25 c of the lower edge piece 25 is engaged in the groove 22 of the lower frame rod 18 b , so that the mesh 23 is mounted to the lower frame rod 18 b.
[0049] When the chair is scrapped, a tool such as a screwdriver (not shown) is stuck through the mesh 23 and engaged with a head of the screw 29 which is loosened, so that the lower frame rod 18 b is removed from the lower reinforcement rod 28 . Thereafter, the upper edge of the mesh 23 and the right and left side edges are removed from the upper frame rod 18 a and the right and left side frame rods 18 c , 18 d with the edge members 25 , 24 , 24 . The mesh 23 is separately removed from the back frame 17 and replaced with a new one.
[0050] When the chair is moved and hit with another chair, the lower frame rod 18 b is protected by the lower reinforcement rod 28 , so that the lower ends of the lower frame rod 18 b and the mesh 23 are prevented from being damaged.
[0051] FIGS. 8-13 show the second embodiment in which a hanger is mounted to the chair in the first embodiment of the present invention. The basic structure of the chair is similar to the first embodiment, and the same numerals are allotted to the same members. Description thereof is omitted.
[0052] A chair 30 with a hanger in the second embodiment of the invention comprises a hanger 31 that moves up and down behind the backrest 10 .
[0053] The hanger 31 comprises a hanger body 32 on which a suit can be hung; and a pair of support rods 33 , 34 which support the body 32 . The support rods 33 , 34 are mounted on the backrest 10 with a mounting member 35 and a screw seat piece 36 by a screws 37 .
[0054] The backrest 10 comprises the back frame 17 in which the mesh 23 in FIGS. 1-7 is stretched over the front face frame 18 . The middle of the hanger 31 is spaced apart from the upper frame rod 18 a of the front face frame 18 , and each end of the hanger 31 is mounted to the middle of the upper reinforcement rod 26 connected to the upper frame rod 18 a.
[0055] A pair of support rods 33 , 34 comprises parallel vertical rod portions 33 a , 34 a ; extending rod portions 33 b , 34 b inclined upward of the vertical rod portions 33 a , 34 a ; and connecting portions 33 c , 34 c curved downward of the vertical rod portions 33 a , 34 a . The support rods 33 , 34 are connected at inner ends of the connecting portions 33 c , 34 c.
[0056] The upper ends of the extending rod portions 33 b , 34 b are plain. The extending rod portions 33 b , 34 b are mounted to the right and left ends of the hanger body 32 with screws (not shown), so that the support rods 33 , 34 are fixed to the hanger body 32 .
[0057] The extending rod portions 33 b , 34 b of the support rods 33 , 34 are curved forward. So the hanger body 32 is positioned in front of the rear end of the upper reinforcement rod 26 .
[0058] FIGS. 12 and 13 are enlarged sectional views taken along the line XII-XII and XIII-XIII in FIG. 9 .
[0059] In FIGS. 9-12 , plain portions 40 , 41 are formed on opposite surfaces 38 , 39 of the vertical rod portions 33 a , 34 a of the right and left support rods 33 , 34 .
[0060] A mounting member 35 comprises a thick rectangular plate. The right and left ends 42 , 42 are formed in size such that the mounting member 35 can engage in the plain portions 40 , 41 of the vertical rod portions 33 a , 34 a of the right and left support rods 33 , 34 .
[0061] On the inner side edges of the plain portions 40 , 41 , vertical projections 43 , 44 are provided in parallel with each other.
[0062] The projections 43 , 44 engage in engagement grooves 45 , 45 on the front surface of the mounting member 35 so that the support rods 33 , 34 slidably move with respect to the mounting member 35 .
[0063] In FIGS. 11 and 12 , vertical forward projections 46 , 46 are provided on the front surface of the vertical rod portions 33 a , 34 a of the right and left support rods 33 , 34 . On the rear surface of the upper reinforcement rod 26 of the backrest 10 , vertical engagement grooves 47 , 47 are provided to engage with the forward projections 46 , 46 .
[0064] Through holes 48 , 48 are formed in the mounting member 35 , and through holes 49 , 49 are formed in the upper reinforcement rod 26 . Blind bores 50 , 50 are formed in the rear surface of a screw seat piece 36 at a position corresponding to the through holes 48 , 48 .
[0065] The hanger 31 will be mounted to the upper reinforcement rod 26 below.
[0066] The right and left support rods 33 , 34 having the hanger body 32 at the upper end contacts the upper reinforcement rod 26 to allow the forward projections 46 , 46 of the vertical rods 33 a , 34 a of the support rods 33 , 34 to engage in the engagement grooves 47 , 47 on the rear surface of the screw seat piece 26 , thereby positioning the support rods 33 , 34 .
[0067] Then, the right and left ends of the mounting member 35 engage in the plain portions 40 , 41 of the vertical rod portions 33 a , 34 a of the right and left support rods 33 , 34 . In the engagement grooves 45 , 45 on the front surface of the mounting member 35 , the projections 43 , 44 of the plain portions 40 , 41 of the vertical rod portions 33 a , 34 a engage, and the mounting member 35 is positioned between the right and left vertical rod portions 33 a and 34 a.
[0068] Then, the screw seat piece 36 contacts the front surface of the upper reinforcement rod 26 . While the support rods 33 , 34 are put between the upper reinforcement rod 26 and the mounting member 35 , the upper reinforcement rod 26 is held between the mounting member 35 and the screw seat piece 36 . The screws 37 , 37 pass into the blind bores 50 of the screw seat piece 36 through the through holes 48 , 49 , so that the hanger 31 is mounted to move up and down with suitable resistance behind the backrest.
[0069] An engagement bore 52 for mounting a cover member 51 is formed in the middle of the mounting member 35 . An inward projection 53 is provided on a rear edge of the engagement bore 52 . The cover member 51 comprises a thin elongate plate and has in the middle an engagement claw 54 which is engagable with the inward projection 53 of the engagement bore 52 .
[0070] On the rear surface of the mounting member 35 , there is formed a recess 55 which engages with the cover member 51 . The engagement claw 54 of the cover member 51 is put in the engagement bore 52 of the mounting member 35 to allow the claw 54 to engage on the inward projection 53 . The entire cover member 51 engages in the recess 55 , so that the cover member 51 is mounted to the mounting member 35 .
[0071] The cover member 51 is also used as nameplate.
[0072] The hanger 31 is slidable up and down. When a suit is hung at an upper limit where the hanger slides, the hanger 31 moves down owing to the weight of the suit and the lower end of the suit contacts a floor, so that the suit is likely to become dirty.
[0073] For prevention, in FIGS. 10 and 12 , a plurality of small rearward projections 56 a , 56 b are provided on the vertical rod portions 33 a , 34 a . and an engagement groove 57 which is elastically engagable with the small projections 56 a , 56 b are provided in FIGS. 11 and 12 . Thus, at a plurality of vertical positions where the small projections 56 a , 56 b elastically engage in the engagement groove 57 , the hanger can be held against a certain load.
[0074] By tightening the screw 37 , the support rods 33 , 34 may be held between the upper reinforcement rod 26 and the mounting member 35 . To change a height of the hanger 31 , the screw 37 is loosened to allow the support rods 33 , 34 to move up and down. Thereafter, the screw 37 is tightened again to allow the hanger 31 to be held at a desired height.
[0075] Various modifications of the present invention may be possible without departing from the scope of claims.
[0076] For example, in the foregoing embodiment, the upper reinforcement rod 26 and the lower reinforcement rod 28 are mounted on the rear surface of the upper and lower frame rods 18 a , 18 b . But the upper reinforcement rod 26 or the lower reinforcement rod 28 may be omitted.
[0077] In the foregoing embodiments, the present invention is applied to the stretching structure of the mesh 23 of the backrest 10 of the chair, but may be applied to a seat of a chair or a headrest.
[0078] The edge member 25 is made like a letter L and may engage to a corner between the lower surface and front surface of the upper frame rod 18 a or lower frame rod 18 b.
|
A stretching structure of a stretching material in a chair in which the ratio of the rear frame of a backrest to the outline of the chair is small, design is smart, weight is reduced, the number of parts is reduced, and assemblability is improved and the backrest of the chair. In the chair having the backrest formed by stretching the stretching material on the front surface of the rear frame, the rear frame comprises a front frame to which the peripheral edge part of the stretching material is fixed and an upper reinforcement frame rod. The laterally facing upper reinforcement frame rod is connected at its both ends to both ends of the laterally facing upper frame rod at the top of the front frame with the center part of the upper reinforcement frame rod separated backward from the upper frame rod.
| 0
|
Related Application
[0001] This application is related to a U.S. provisional application titled “Closed-Loop Drawdown Apparatus and Method for In-Situ Analysis for Formation Fluids” filed on Jan. 2, 2001, Ser. No. 60/219,741, and from which priority is claimed for the present application.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to the testing of underground formations or reservoirs. More particularly, this invention relates to a method and apparatus for isolating a downhole reservoir and testing the reservoir fluid.
[0004] 2. Description of the Related Art
[0005] To obtain hydrocarbons such as oil and gas, boreholes are drilled by rotating a drill bit attached at a drill string end. A large proportion of the current drilling activity involves directional drilling, i.e., drilling deviated and horizontal boreholes to increase the hydrocarbon production and/or to withdraw additional hydrocarbons from the earth's formations. Modern directional drilling systems generally employ a drill string having a bottomhole assembly (BHA) and a drill bit at an end thereof that is rotated by a drill motor (mud motor) and/or by rotating the drill string. A number of downhole devices placed in close proximity to the drill bit measure certain downhole operating parameters associated with the drill string. Such devices typically include sensors for measuring downhole temperature and pressure, azimuth and inclination measuring devices and a resistivity-measuring device to determine the presence of hydrocarbons and water. Additional down-hole instruments, known as logging-while-drilling (LWD) tools, are frequently attached to the drill string to determine the formation geology and formation fluid conditions during the drilling operations.
[0006] Drilling fluid (commonly known as the “mud” or “drilling mud”) is pumped into the drill pipe to rotate the drill motor, provide lubrication to various members of the drill string including the drill bit and to remove cuttings produced by the drill bit. The drill pipe is rotated by a prime mover, such as a motor, to facilitate directional drilling and to drill vertical boreholes. The drill bit is typically coupled to a bearing assembly having a drive shaft, which in turn rotates the drill bit attached thereto. Radial and axial bearings in the bearing assembly provide support to the radial and axial forces of the drill bit.
[0007] Boreholes are usually drilled along predetermined paths and the drilling of a typical borehole proceeds through various formations. The drilling operator typically controls the surface-controlled drilling parameters, such as the weight on bit, drilling fluid flow through the drill pipe, the drill string rotational speed and the density and viscosity of the drilling fluid to optimize the drilling operations. The downhole operating conditions continually change and the operator must react to such changes and adjust the surface-controlled parameters to optimize the drilling operations. For drilling a borehole in a virgin region, the operator typically has seismic survey plots which provide a macro picture of the subsurface formations and a pre-planned borehole path. For drilling multiple boreholes in the same formation, the operator also has information about the previously drilled boreholes in the same formation.
[0008] Typically, the information provided to the operator during drilling includes borehole pressure and temperature and drilling parameters, such as Weight-On-Bit (WOB), rotational speed of the drill bit and/or the drill string, and the drilling fluid flow rate. In some cases, the drilling operator also is provided selected information about the bottom hole assembly condition (parameters), such as torque, mud motor differential pressure, torque, bit bounce and whirl etc.
[0009] Downhole sensor data are typically processed downhole to some extent and telemetered uphole by sending a signal through the drill string, or by mud-pulse telemetry which is transmitting pressure pulses through the circulating drilling fluid. Although mud-pulse telemetry is more commonly used, such a system is capable of transmitting only a few (1-4) bits of information per second. Due to such a low transmission rate, the trend in the industry has been to attempt to process greater amounts of data downhole and transmit selected computed results or “answers” uphole for use by the driller for controlling the drilling operations.
[0010] Commercial development of hydrocarbon fields requires significant amounts of capital. Before field development begins, operators desire to have as much data as possible in order to evaluate the reservoir for commercial viability. Despite the advances in data acquisition during drilling using the MWD systems, it is often necessary to conduct further testing of the hydrocarbon reservoirs in order to obtain additional data. Therefore, after the well has been drilled, the hydrocarbon zones are often tested with other test equipment.
[0011] One type of post-drilling test involves producing fluid from the reservoir, shutting-in the well, collecting samples with a probe or dual packers, reducing pressure in a test volume and allowing the pressure to build-up to a static level. This sequence may be repeated several times at several different depths or point within a single reservoir and/or at several different reservoirs within a given borehole. One of the important aspects of the data collected during such a test is the pressure build-up information gathered after drawing the pressure down. From these data, information can be derived as to permeability, and size of the reservoir. Further, actual samples of the reservoir fluid must be obtained, and these samples must be tested to gather Pressure-Volume-Temperature and fluid properties such as density, viscosity and composition.
[0012] In order to perform these important tests, some systems require retrieval of the drill string from the borehole. Thereafter, a different tool, designed for the testing, is run into the borehole. A wireline is often used to lower the test tool into the borehole. The test tool sometimes utilizes packers for isolating the reservoir. Numerous communication devices have been designed which provide for manipulation of the test assembly, or alternatively, provide for data transmission from the test assembly. Some of those designs include mud-pulse telemetry to or from a downhole microprocessor located within, or associated with the test assembly. Alternatively, a wire line can be lowered from the surface, into a landing receptacle located within a test assembly, establishing electrical signal communication between the surface and the test assembly. Regardless of the type of test equipment currently used, and regardless of the type of communication system used, the amount of time and money required for retrieving the drill string and running a second test rig into the hole is significant. Further, if the hole is highly deviated, a wire line can not be used to perform the testing, because to test tool may not enter the hole deep enough to reach the desired formation.
[0013] A more recent system is desclosed in U.S. Pat. No. 5,803,186 to Berger et al. The '186 patent provides a MWD system that includes use of pressure and resistivity sensors with the MWD system, to allow for reat time data transmission of those measurements. The '186 device allows obtaining static pressures, pressure build-ups, and pressure draws-downs with the work string, such as a drill string, in place. Also, computation of permeability and other reservoir parameters based on the pressure measurements can be accomplished without pulling the drill string.
[0014] The system described in the '186 patent decreases the time required to take a test when compared to using a wireline. However, the '186 patent does not provide an apparatus for improved efficiency when wireline applications are desirable. A pressure gradient test is one such test wherein multiple pressure tests are taken as a wireline conveys a test apparatus downward through a borehole. The purpose of the test is to determine fluid density in-situ and the interface or contact points between gas, oil and water when these fluids are present in a single reservoir.
[0015] Another apparatus method for measuring formation pressure and permeability is described in U.S. Pat. No. 5,233,866 issued to Robert Desbrandes, hereinafter the '866 patent. FIG. 1 is a reproduction of a figure from the '866 patent that shows a drawdown test method for determining formation pressure and permeability.
[0016] Referring to FIG. 1, the method includes reducing pressure in a flow line that is in fluid communication with a borehole wall. In Step 2 , a piston is used to increase the flow line volume thereby decreasing the flow line pressure. The rate of pressure decrease is such that formation fluid entering the flow line combines with fluid leaving the flow line to create a substantially linear pressure decrease. A “best straight line fit” is used to define a straight-line reference for a predetermined acceptable deviation determination. The acceptable deviation shown is 2π from the straight line. Once the straight-line reference is determined, the volume increase is maintained at a steady rate. At a time t 1 , the pressure exceeds the 2π limit and it is assumed that the flow line pressure being below the formation pressure causes the deviation. At t 1 , the drawdown is discontinued and the pressure is allowed to stabilize in Step 3 . At t 2 , another drawdown cycle is started which may include using a new straight-line reference. The drawdown cycle is repeated until the flow line stabilizes at a pressure twice. Step 5 starts at t 4 and shows a final drawdown cycle for determining permeability of the formation. Step 5 ends at t 5 when the flow line pressure builds up to the borehole pressure Pm. With the flow line pressure equalized to the borehole pressure, the chance of sticking the tool is reduced. The tool can then be moved to a new test location or removed from the borehole.
[0017] A drawback of the '866 patent is that the time required for testing is too long due to stabilization time during the “mini-buildup cycles.” In the case of a low permeability formation, the stabilization may take from tens of minutes to even days before stabilization occurs. One or more cycles following the first cycle only compound the time problem.
[0018] Still another known method for measuring permeability and other parameters of a formation and fluid is described in U.S. Pat. No. 5,708,204 issued to Ekrem Kasap, and assigned Western Atlas, hereinafter the '204 patent and incorporated herein by reference. The '204 patent describes a wireline method using a closed-loop system. One drawback to the '204 patent is that it is only useful in wireline applications. A significant advantage of the present invention apparatus and method is the use of a MWD tool. Another improvement of over the '204 patent is the use of varying draw-rates during a test as will be described in detail later.
[0019] Whether using wireline or MWD, the formation pressure and permeability measurement systems discussed above measure pressure by drawing down the pressure of a portion of the borehole to a point below the expected formation pressure in one step to a predetermined point well below the expected formation pressure or continuing the drawdown at an established rate until the formation fluid entering the tool stabilizes the tool pressure. Then the pressure is allowed to rise and stabilize by stopping the drawdown. The drawdown cycle may be repeated to ensure a valid formation pressure is being measured, and in some cases lost or corrupted data require retest. This is a time-consuming measurement process.
SUMMARY OF THE INVENTION
[0020] The present invention addresses some of the drawbacks described above by utilizing a closed-loop apparatus and method to perform formation pressure and permeability tests more quickly than the devices and methods described above. With quicker formation testing, more tests providing actual pressures and permeability may be provided to enhance well operation efficiency and safety.
[0021] The present invention provides an apparatus and method capable of creating a test volume within a borehole, and incrementally decreasing the pressure within the test volume at a variable rate to allow periodic measurements of pressure as the test volume pressure decreases. Adjustments to the rate of decrease are made before the pressure stabilizes thereby eliminating the need for multiple cycles. This incremental drawdown apparatus and method will significantly reduce overall measurement time, thereby increasing drilling efficiency and safety.
[0022] Further, an apparatus is provided for testing an underground formation parameter of interest such as a pressure during drilling operations. The apparatus has a drill string for drilling a well borehole. At least one extendable member is mounted on the drill string, and the at least one extendable member is selectively extendable into sealing engagement with the wall of the bore hole for isolating a portion of the annular space between the drill string and the borehole. A port in the drill string is exposable to formation fluid in the isolated annular space, and a fluid volume control device mounted within the drill string is in fluid communication with the port for incrementally reducing a pressure within the isolated portion. A sensor is operatively associated with the fluid volume control device for sensing at least one characteristic of the fluid.
[0023] In addition to the apparatus provided, a method is provided for testing an underground formation during drilling operations. The method comprises drilling a borehole with a drill string, isolating a portion of the annular space between the drill string and the borehole with at least one extendable member mounted on the drill string. The extendable member is brought into sealing engagement with the wall of the borehole, then a port disposed in the drill string is exposed to formation fluid in the isolated annular space. The method also included incrementally reducing pressure within the isolated portion of the annulus with a fluid volume control device mounted within the drill string, and sensing at least one characteristic of the fluid with a sensor.
[0024] A wireline apparatus is provided for determining an underground formation parameter of interest such as contact points. The apparatus has a tool disposed on a wireline used to lower the tool into a well borehole. At least one extendable member is mounted on the tool, and the at least one extendable member is selectively extendable into sealing engagement with the wall of the borehole for isolating a portion of the annular space between the tool and the borehole. A port in the tool is exposable to formation fluid in the isolated annular space, and a fluid volume control device mounted within the tool is in fluid communication with the port for incrementally reducing a pressure within the isolated portion. A sensor is operatively associated with the fluid volume control device for sensing at least one characteristic of the fluid.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The novel features of this invention, as well as the invention itself, will be best understood from the attached drawings, taken along with the following description, in which similar reference characters refer to similar parts, and in which:
[0026] [0026]FIG. 1 is a graphical qualitative representation a formation pressure test using a particular prior art method.
[0027] [0027]FIG. 2 is an elevation view of an offshore drilling system according to one embodiment of the present invention.
[0028] [0028]FIG. 3 shows a portion of drill string incorporating the present invention.
[0029] [0029]FIG. 4 is a system schematic of the present invention.
[0030] [0030]FIG. 5 is an elevation view of a wireline embodiment according to the present invention.
[0031] [0031]FIG. 6 is a plot graph of pressure vs. time and pump volume showing predicted drawdown behavior using specific parameters for calculation.
[0032] [0032]FIG. 7 is a plot graph of pressure vs. time showing the early portion of a pressure buildup curve for a moderately low permeability formation.
[0033] [0033]FIG. 8 is a plot graph of a method using iterative guesses for determining formation pressure.
[0034] [0034]FIG. 9 is a plot graph of a method for finding formation pressure using incomplete pressure buildup data.
[0035] [0035]FIG. 10 is a plot graph of pressure vs. draw rate illustrating a computation technique used in a method according to the present invention to determine formation pressure.
[0036] [0036]FIG. 11 is a graphical representation illustrating a method according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0037] [0037]FIG. 2 is a drilling apparatus according to one embodiment of the present invention. A typical drilling rig 202 with a borehole 204 extending therefrom is illustrated, as is well understood by those of ordinary skill in the art. The drilling rig 202 has a work string 206 , which in the embodiment shown is a drill string. The drill string 206 has attached thereto a drill bit 208 for drilling the borehole 204 . The present invention is also useful in other types of work strings, and it is useful with a wireline, jointed tubing, coiled tubing, or other small diameter work string such as snubbing pipe. The drilling rig 202 is shown positioned on a drilling ship 222 with a riser 224 extending from the drilling ship 222 to the sea floor 220 . However, any drilling rig configuration such as a land-based rig may be adapted to implement the present invention.
[0038] If applicable, the drill string 206 can have downhole drill motor 210 . Incorporated in the drill string 206 above the drill bit 208 is a typical testing unit, which can have at least one sensor 214 to sense downhole characteristics of the borehole, the bit, and the reservoir, with such sensors being well known in the art. A useful application of the sensor 214 is to determine direction, azimuth and orientation of the drill string 206 using an accelerometer or similar sensor. The BHA also contains the formation test apparatus 216 of the present invention, which will be described in greater detail hereinafter. A telemetry system 212 is located in a suitable location on the work string 206 such as above the test apparatus 216 . The telemetry system 212 is used for command and data communication between the surface and the test apparatus 216 .
[0039] [0039]FIG. 3 is a section of drill string 206 incorporating the present invention. The tool section is preferably located in a BHA close to the drill bit (not shown). The tool includes communication unit and power supply 320 for two-way communication to the surface and supplying power to the downhole components. In the preferred embodiment, the tool requires a signal from the surface only for test initiation. A downhole controller and processor (not shown) carry out all subsequent control. The power supply may be a generator driven by a mud motor (not shown) or it may be any other suitable power source. Also included are multiple stabilizers 308 and 310 for stabilizing the tool section of the drill string 206 and packers 304 and 306 for sealing a portion of the annulus. A circulation valve disposed preferably above the upper packer 304 is used to allow continued circulation of drilling mud above the packers 304 and 306 while rotation of the drill bit is stopped. A separate vent or equalization valve (not shown) is used to vent fluid from the test volume between the packers 304 and 306 to the upper annulus. This venting reduces the test volume pressure, which is required for a drawdown test. It is also contemplated that the pressure between the packers 304 and 306 could be reduced by drawing fluid into the system or venting fluid to the lower annulus, but in any case some method of increasing the volume of the intermediate annulus to decrease the pressure will be required.
[0040] In one embodiment of the present invention an extendable pad-sealing element 302 for engaging the well wall 4 (FIG. 1) is disposed between the packers 304 and 306 on the test apparatus 216 . The pad-sealing element 302 could be used without the packers 304 and 306 , because a sufficient seal with the well wall can be maintained with the pad 302 alone. If packers 304 and 306 are not used, a counterforce is required so pad 302 can maintain sealing engagement with the wall of the borehole 204 . The seal creates a test volume at the pad seal and extending only within the tool to the pump rather than also using the volume between packer elements.
[0041] One way to ensure the seal is maintained is to ensure greater stability of the drill string 206 . Selectively extendable gripper elements 312 and 314 could be incorporated into the drill string 206 to anchor the drill string 206 during the test. The grippers 312 and 314 are shown incorporated into the stabilizers 308 and 310 in this embodiment. The grippers 312 and 314 , which would have a roughened end surface for engaging the well wall, would protect soft components such as the pad-sealing element 302 and packers 304 and 306 from damage due to tool movement. The grippers 312 would be especially desirable in offshore systems such as the one shown in FIG. 2, because movement caused by heave can cause premature wear out of sealing components.
[0042] [0042]FIG. 4 shows the tool of FIG. 3 schematically with internal downhole and surface components. Selectively extendable gripper elements 312 engage the borehole wall 204 to anchor the drill string 206 . Packer elements 304 and 306 well known in the art extend to engage the borehole wall 204 . The extended packers separate the well annulus into three sections, and upper annulus 402 , an intermediate annulus 404 and a lower annulus 406 . The sealed annular section (or simply sealed section) 404 is adjacent a formation 218 . Mounted on the drill string 206 and extendable into the sealed section 404 is the selectively extendable pad sealing element 302 . A fluid line providing fluid communication between pristine formation fluid 408 and tool sensors such as pressure sensor 424 is shown extending through the pad member 302 to provide a port 420 in the sealed annulus 404 . The preferable configuration to ensure pristine fluid is tested or sampled is to have packers 304 and 306 sealingly urged against the wall 204 , and to have a sealed relationship between the wall and extendable element 302 . Reducing the pressure in sealed section 404 prior to engaging the pad 302 will initiate fluid flow from the formation into the sealed section 404 . With formation flowing when the extendable element 302 engages the wall, the port 420 extending through the pad 320 will be exposed to pristine fluid 408 . Control of the orientation of the extendable element 302 is highly desirable when drilling deviated or horizontal wells. The preferred orientation is toward an upper portion of the borehole wall. A sensor 214 , such as an accelerometer, can be used to sense the orientation of the extendable element 302 . The extendable element can then be oriented to the desired direction using methods and not-shown components well known in the art such as directional drilling with a bend-sub. For example, the drilling apparatus may include a drill string 206 rotated by a surface rotary drive (not shown). A downhole mud motor (see FIG. 2 at 210 ) may be used to independently rotate the drill bit. The drill string can thus be rotated until the extendable element is oriented to the desired direction as indicated by the sensor 214 . The surface rotary drive is halted to stop rotation of the drill string 206 during a test, while rotation of the drill bit may be continued using the mud motor of desired.
[0043] A downhole controller 418 preferably controls the test. The controller 418 is connected to at least one system volume control device (pump) 426 . The pump 426 is a preferably small piston driven by a ball screw and stepper motor or other variable control motor, because of the ability to iteratively change the volume of the system. The pump 426 may also be a progressive cavity pump. When using other types of pumps, a flow meter should also be included. A valve 430 for controlling fluid flow to the pump 426 is disposed in the fluid line 422 between a pressure sensor 424 and the pump 426 . A test volume 405 is the volume below the retracting piston of the pump 426 and includes the fluid line 422 . The pressure sensor is used to sense the pressure within the test volume 404 . It should be noted here that the test could be equally valuable if performed with the pad member 302 in a retracted position. In this case, the text volume includes the volume of the intermediate annulus 404 . This allows for a “quick” test, meaning that no time for pad extension and retraction would be required. The sensor 424 is connected to the controller 418 to provide the feed back data required for a closed loop control system. The feedback is used to adjust parameter settings such as a pressure limit for subsequent volume changes. The downhole controller should incorporate a processor (not separately shown) for further reducing test time, and an optional database and storage system could be incorporated to save data for future analysis and for providing default settings.
[0044] When drawing down the sealed section 404 , fluid is vented to the upper annulus 402 via an equalization valve 419 . A conduit 427 connecting the pump 426 to the equalization valve 419 includes a selectable internal valve 432 . If fluid sampling is desired, the fluid may be diverted to optional sample reservoirs 428 by using the internal valves 432 , 433 a , and 433 b rather than venting through the equalization valve 419 . For typical fluid sampling, the fluid contained in the reservoirs 428 is retrieved from the well for analysis.
[0045] A preferred embodiment for testing low mobility (tight) formations includes at least one pump (not separately shown) in addition to the pump 426 shown. The second pump should have an internal volume much less than the internal volume of the primary pump 426 . A suggested volume of the second pump is {fraction (1/100)} the volume of the primary pump. A typical “T” connector having selection valve controlled by the downhole controller 418 may be used to connect the two pumps to the fluid line 422 .
[0046] In a tight formation, the primary pump is used for the initial draw down. The controller switches to the second pump for operations below the formation pressure. An advantage of the second pump with a small internal volume is that build-up times are faster than with a pump having a larger volume.
[0047] Results of data processed downhole may be sent to the surface in order to provide downhole conditions to a drilling operator or to validate test results. The controller passes processed data to a two-way data communication system 416 disposed downhole. The downhole system 416 transmits a data signal to a surface communication system 412 . There are several methods and apparatus known in the art suitable for transmitting data. Any suitable system would suffice for the purposes of this invention. Once the signal is received at the surface, a surface controller and a processor 410 converts and transfers the data to a suitable output or storage device 414 . As described earlier, the surface controller 410 and surface communication system 412 is also used to send the test initiation command.
[0048] [0048]FIG. 5 is a wireline embodiment according to the present invention. A well 502 is shown traversing a formation 504 containing a reservoir having gas 506 , oil 508 and water 510 layers. A wireline tool 512 supported by an armored cable 514 is disposed in the well 502 adjacent the formation 504 . Extending from the tool 512 are optional grippers 312 for stabilizing the tool 512 . Two expandable packers 304 and 306 are disposed on the tool 512 are capable of separating the annulus of the borehole 502 into an upper annulus 402 , a sealed intermediate annulus 404 and a lower annulus 406 . A selectively extendable pad member 302 is disposed on the tool 512 . The grippers 312 , packers 304 and 306 , and extendable pad element 302 are essentially the same as those described in FIG. 3 and 4 , therefore the detailed descriptions are not repeated here.
[0049] Telemetry for the wireline embodiment is a downhole two-way communication unit 516 connected to a surface two-way communication unit 518 by one or more conductors 520 within the armored cable 514 . The surface communication unit 518 is housed within a surface controller that includes a processor 412 and output device 414 as described in FIG. 4. A typical cable sheave 522 is used to guide the armored cable 514 into the borehole 502 . The tool 512 includes a downhole processor 418 for controlling formation tests in accordance with methods to be described in detail later.
[0050] The embodiment shown in FIG. 5 is desirable for determining contact points 538 and 540 between the gas 506 and oil 508 and between the oil 508 and water 510 . To illustrate this application a plot 542 of pressure vs. depth is shown superimposed on the formation 504 . The downhole tool 512 includes a pump 426 , a plurality of sensors 424 and optional sample tanks 428 as described above for the embodiment shown in FIG. 4. These components are used to measure formation pressure at varying depths within the borehole 502 . The pressures plotted as shown are indicative of fluid or gas density, which varies distinctly from one fluid to the next. Therefore, having multiple pressure measurements M 1 -M n provides data necessary to determine the contact points 538 and 540 .
[0051] Measurement strategies and calculation procedures for determining effective mobility (k/μ) in a reservoir according to the present invention are described below. Measurement times are fairly short, and calculations are robust for a large range of mobility values. The initial pressure drawdown employs a much lower pump withdrawal rate, 0.1 to 0.2 cm 3 /s, than rates typically used currently. Using lower rates reduces the probability of formation damage due to fines migration, reduces temperature changes related to fluid expansion, reduces inertial flow resistance, which can be substantial in probe permeability measurements, and permits rapid attainment of steady-state flow into the probe for all but very low mobilities.
[0052] Steady state flow is not required for low mobility values (less than about 2 md/cp). For these measurements, fluid compressibility is determined form the initial part of the drawdown when pressure in the probe is greater than formation pressure. Effective mobility and distant formation pressure, p*, are determined from the early portion of the pressure buildup, by methods presented, thus eliminating the need for the lengthy final portion of the buildup in which pressure gradually reaches a constant value.
[0053] For higher mobilities, where steady-state flow is reached fairly quickly during the drawdown, the pump is stopped to initiate the rapid pressure buildup. For a mobility of 10 md/cp, and the conditions used for the sample calculations later herein (including a pump rate of 0.2 cm 3 /s), steady-state flow occurs at a drawdown of about 54 psi below formation pressure. The following buildup (to within 0.01 psi of formation pressure) requires only about 6 seconds. The drawdown is smaller and the buildup time is shorter (both inversely proportional) for higher mobilities. Mobility can be calculated from the steady-state flowrate and the difference between formation and drawdown pressures. Different pump rates can be used to check for inertial flow resistance. Instrument modifications may be required to accommodate the lower pumps rates and smaller pressure differences.
[0054] Referring to FIG. 4, after the packers 304 and 306 are set and the pump piston is in its initial position with a full withdrawal stroke remaining, the pump 426 is started preferably using a constant rate (q pump ). The probe and connecting lines to the pressure gauge and pump comprise the “system volume,” V sys which is assumed to be filled with a uniform fluid, e.g., drilling mud. As long as pressure in the probe is greater than the formation pressure, and the formation face at the periphery of the borehole is sealed by a mud cake, no fluid should flow into the probe. Assuming no leaks past the packer and no work-related expansional temperature decreases, pressure in the “system,” at the datum of the pressure gauge, is governed by fluid expansion, equal to the pump withdrawal volume. Where A p is the cross sectional area of a pump piston, x is the travel distance of the piston, C is fluid compressibility, and p is system pressure, the rate of pressure decline depends on the volumetric expansion rate as shown in equation 1:
q pump = A p ( x t ) = V p t = - CV sys ( p t ) ( 1 )
[0055] Equation 2 shows the system volume increases as the pump piston is withdrawn:
V sys [t]=V 0 +( x[t]−x 0 ) A p =V 0 +V p [t], (2)
[0056] and differentiation of Eq. 2 shows that:
V sys t = V p t ( 3 )
[0057] Therefore, substituting the results of Eq. 3 into Eq. 1 and rearranging:
- V sys CV sys ≡ - ln V sys C = p ( 4 )
[0058] For constant compressibility, Eq. 4 can be integrated to yield pressure in the probe as a function of system volume:
P n = P n - 1 + 1 C ln [ V sys n - 1 V sys n ] . ( 5 )
[0059] Pressure in the probe can be related to time by calculating the system volume as a function of time from Eq. 2. Conversely, if compressibility is not constant, its average value between any two system volume is:
C avg . = ln [ V sys n - 1 V sys n ] P 2 - P 1 ( 6 )
[0060] where subscripts 1 and 2 are not restricted to being consecutive pairs of readings. Note that if temperature decreases during the drawdown, the apparent compressibility will be too low. A sudden increase in compressibility may indicate the evolution of gas or a leak past the packer. The calculation of compressibility, under any circumstances, is invalid whenever pressure in the probe is less than formation pressure: fluid can flow into the probe giving the appearance of a marked increase in compressibility. Note, however, that compressibility of real fluids almost invariably increases slightly with decreasing pressure.
[0061] [0061]FIG. 6 shows an example of drawdown from an initial hydrostatic borehole pressure of 5000 psia to (and below) a reservoir pressure (p*) 608 of 4626.168 psia, calculated using the following conditions as an example:
[0062] Effective probe radius, r i , of 1.27 cm;
[0063] Dimensionless geometric factor, G 0 , of 4.30;
[0064] Initial system volume, V 0 , of 267.0 cm 3 ;
[0065] Constant pump volumetric withdrawal rate q pump of 0.2 cm 3 /s; and
[0066] Constant compressibility, C, of I×10 −5 psi −1 .
[0067] The calculation assumes no temperature change and no leakage into the probe. The pressure drawdown is shown as a function of time or as a function of pump withdrawal volume, shown at the bottom and top of the figure respectively. The initial portion 610 of the drawdown (above p*) is calculated from Eq. 5 using V sys calculated from Eq. 2. Continuing the drawdown below reservoir pressure for no flow into the probe is shown as the “zero” mobility curve 612 . Note that the entire “no flow” drawdown is slightly curved, due to the progressively increasing system volume.
[0068] Normally, when pressure falls below p* and permeability is greater than zero, fluid from the formation starts to flow into the probe. When p=p* the flow rate is zero, but gradually increases as p decreases. In actual practice, a finite difference may be required before the mud cake starts to slough off the portion of the borehole surface beneath the interior radius of the probe packer seal. In this case, a discontinuity would be observed in the time-pressure curve, rather than the smooth departure from the “no flow” curve as shown in FIG. 6. As long as the rate of system-volume-increase (from the pump withdrawal rate) exceeds the rate of fluid flow into the probe, pressure in the probe will continue to decline. Fluid contained in V sys expands to fill the flow rate deficit. As long as flow from the formation obeys Darcy's law, it will continue to increase, proportionally to (p*−p). Eventually, flow from the formation becomes equal to the pump rate, and pressure in the probe thereafter remains constant. This is known as “steady state” flow. The equation governing steady state flow is:
k μ = 14 , 696 q pump G 0 r i ( p * - p ss ) ( 7 )
[0069] For the conditions given for FIG. 6, the steady state drawdown pressure difference, p*−p ss , is 0.5384 psi for k/μ=1000 md/cp, 5.384 psi for 100 md/cp, 53.84 psi for 10 md/cp, etc. For a pump rate of 0.1 cm 3 /s, these pressure differences would be halved; and they would be doubled for a pump rate of 0.4 cm 3 /s, etc.
[0070] As will be shown later, these high mobility drawdowns have very fast pressure buildups after the pump-piston withdrawal is stopped. The value of p* can be found from the stabilized buildup pressure after a few seconds. In the case of high mobilities (k/μ>50 md/cp), the pump rate may have to be increased in subsequent drawdown(s) to obtain an adequate drawdown pressure difference (p*−p). For lower mobilities, it should be reduced to ascertain that inertial flow resistance (non-Darcy flow) is not significant. A total of three different pump rates would be desirable in these cases.
[0071] Steady-state calculations are very desirable for the higher mobilities because compressibility drops out of the calculation, and mobility calculations are straight forward. However, instrument demands are high: 1) pump rates should be constant and easy to change, and 2) pressure differences (p*−p ss ) are small. It would be desirable to have a small piston driven by a ball screw and stepper motor to control pressure decline during the approach to steady state flow for low mobilities
[0072] [0072]FIG. 6 shows that within the time period illustrated, the drawdown for the 1.0 md/cp curve 614 and lower mobilities did not reach steady state. Furthermore, the departures from the zero mobility curve for 0.1 md/cp 616 and below, are barely observable. For example, at a total time of 10 seconds, the drawdown pressure difference for 0.01 md/cp is only 1.286 psi less than that for no flow. Much greater pressure upsets than this, due to nonisothermal conditions or to small changes in fluid compressibility, are anticipated. Drawdowns greater than 200-400 psi below p* are not recommended: significant inertial flow resistance (non-Darcy flow) is almost guaranteed, formation damage due to fines migration is likely, thermal upsets are more significantly unavoidable, gas evolution is likely, and pump power requirements are increased.
[0073] During the period when p<p*, and before steady state flow is attained, three rates are operative: 1) the pump rate, which increases the system volume with time, 2) fluid flow rate from the formation into the probe, and 3) the rate of expansion of fluid within the system volume, which is equal to the difference between the first two rates. Assuming isothermal conditions, Darcy flow in the formation, no permeability damage near the probe face, and constant viscosity, drawdown curves for 10, 1, and 0.1 md/cp mobilities 618 , 614 and 616 , shown for FIG. 6, are calculated from an equation based on the relationship of these three rates as discussed above:
p n = p n - 1 + q f n ( t n - t n - 1 ) - ( V pump n - V pump n - 1 ) C [ V 0 + 1 2 ( V pump n + V pump n - 1 ) ] ( 8 )
[0074] wherein, the flow rate into the probe from the formation at time step n, is calculated from:
q f n = k G 0 r i [ p * - 1 2 ( p n - 1 + p n ) ] 14,696μ ( 9 )
[0075] Because p n is required for the calculation of q f n in Eq. 9, which is required for the solution of Eq. 8, an iterative procedure was used. For the lower mobilities, convergence was rapid when using P n−1 as the first guess for p. However, for the 10 md/cp curve, many more iterations were required for each time step, and this procedure became unstable for the 100 md/cp and higher mobility cases. Smaller time steps, and/or much greater damping (or a solver technique, rather than an iterative procedure) is required.
[0076] The pump piston is stopped (or slowed) to initiate the pressure buildup. When the piston is stopped, the system volume remains constant, and flow into the probe from the formation causes compression of fluid contained in the system volume and the consequent rise in pressure. For high mobility measurements, for which only steady-state calculations are performed, determination of fluid compressibility is not required. The buildup is used only to determine p*, so the pump is completely stopped for buildup. For the conditions given for FIG. 6, the buildup time, to reach within 0.01 psi of p* is about 6, 0.6, and 0.06 seconds for mobilities of 10, 100 and 1000 md/cp 618 , 620 and 622 , respectively.
[0077] For low mobility measurements, in which steady state was not reached during the drawdown, the buildup is used to determine both p* and k/μ. However, it is not necessary to measure the entire buildup. This takes an unreasonable length of time because at the tail of the buildup curve, the driving force to reach p* approaches zero. A technique for avoiding this lengthy portion of the measurement will be presented in the next section.
[0078] The equation governing the pressure buildup, assuming constant temperature, permeability, viscosity, and compressibility, is:
k G 0 r i ( p * - p ) 14,696μ = - CV sys ( p t ) . ( 10 )
[0079] Rearranging and integrating yields:
t - t 0 = 14,696μ CV sys k G 0 r i ln ( p * - p 0 p * - p ) . ( 11 )
[0080] where t 0 and p 0 , are the time and pressure in the probe, respectively, at the start of the buildup, or at any arbitrary point in the buildup curve.
[0081] [0081]FIG. 7 is a plot of the early portion of a buildup curve 630 for a 1 md/cp mobility, which starts at 4200 psia, and if run to completion, would end at a p* of 4600. This is calculated from Eq. 11. In addition to the other parameters shown on this figure, p 0 =4200 psia.
[0082] Determining p* from an incomplete buildup curve can be described by way of an example. Table 2 represents hypothetical experimental data, and may be the only data available. The challenge is to determine accurately the value of p*, which would not otherwise be available. To obtain p* experimentally would have taken at least 60 s, instead of the 15 s shown. The only information known in the hypothetical are the system values for FIG. 6 and V sys of 269.0 cm 3 . The compressibility, C, is determined from the initial drawdown data starting at the hydrostatic borehole pressure, using Eq. 6.
TABLE 2 Hypothetical Pressure Buildup Data From A Moderately Low Permeability Reservoir t-t 0 , s p, psia t-t 0 , s p, psia 0.0000 4200 7.1002 4450 0.9666 4250 8.4201 4475 2.0825 4300 10.0354 4500 3.4024 4350 12.1179 4525 5.0177 4400 15.0531 4550 5.9843 4425
[0083] The first group on the right side of Eq. 11 and preceding the logarithmic group can be considered the time constant, τ, for the pressure buildup. Thus, using this definition, and rearranging Eq. 11 yields:
ln ( p * - p 0 p * - p ) = ( 1 τ ) ( t - t 0 ) , ( 12 )
[0084] A plot of the left side of Eq. 12 vs. (t−t 0 ) is a straight line with slope equal to (1/τ), and intercept equal to zero. FIG. 8 is a plot of data from Table 2, using Eq. 12 with various guesses for the value of p*. We can see that only the correct value, 4600 psia, yields the required straight line 640 . Furthermore, for guesses that are lower than the correct p*, the slope of the early-time portion of a curve 646 is smaller than the slope at later times. Conversely, for guesses that are too high, the early-time slope is larger than late-time slopes for the curves 642 and 644 .
[0085] These observations can be used to construct a fast method for finding the correct p*. First, calculate the average slope from an arbitrary early-time portion of the data shown in Table 2. This slope calculation starts at t 1 , and p 1 , and ends at t 2 and p 2 . Next calculate the average late-time slope from a later portion of the table. The subscripts for beginning and end of this calculation would be 3 and 4, respectively. Next divide the early-time slope by the late-time slope for a ratio R:
R = ln ( p * - p 1 p * - p 2 ) ( t 4 - t 3 ) ln ( p * - p 3 p * - p 4 ) ( t 2 - t 1 ) ( 13 )
[0086] Suppose we choose the second set of data points from Table 2: 2.0825 s and 4300 psia for the beginning of the early-time slope. Suppose further that we select data from sets 5, 9, and 11 as the end of the early time slope, and beginning and end of the late-time slope, respectively, with corresponding subscripts 2, 3, and 4. If we now guess that p* is 4700 psia, then insert these numbers into Eq. 13, the calculated value of R is 1.5270. Because this is greater than 1, the guess was too high. Results of this and other guesses for p* while using the same data above are shown as a curve plot 650 in FIG. 9. The correct value of p*, 4600 psia, occurs at R=1. These calculations can easily be incorporated into a solver routine, which converges rapidly to the correct p* without plots. Mobility, having found the correct p*, is calculated from a rearrangement of Eq. 11, using the compressibility obtained from the initial hydrostatic drawdown.
[0087] In general, for real data, the very early portion of the buildup data should be avoided for the calculations of p*, then k/μ. This fastest portion of the buildup, with high pressure differences, has the greatest thermal distortion due to compressive heating, and has the highest probability of non-Darcy flow. After p* has been determined as described above, the entire data set should be plotted per FIG. 7. Whenever the initial portion of the plot displays an increasing slope with increasing time, followed by a progressively more linear curve, this may be a strong indication of non-Darcy flow at the higher pressure differences.
[0088] Another method according to the present invention can be described with reference to FIG. 10. FIG. 10 shows a relationship between tool pressure 602 and formation flow rate q fn 604 along with the effect of rates below and above certain limits. Darcy's Law teaches that pressure is directly proportional to fluid flow rate in the formation. Thus, plotting pressure against a drawdown piston draw rate will form a straight line when the pressure in the tool is constant while the piston is moving at a given rate. Likewise, the plot of flow rates and stabilized pressures will form a straight line, typically with a negative slope (m) 606 , between a lower and an upper rate limit. The slope is used to determine mobility (k/μ) of fluid in the formation. Equation 8 can be rearranged for the formation flow rate:
q fn = ( V pump n - V pump n - 1 ) - C [ V 0 + 1 2 ( V pump n + V pump n - 1 ) ] ( p n - 1 - p n ) ( t n - t n - 1 ) ( 14 )
[0089] Equation 14 is valid for non-steady-state conditions as well as steady-state conditions. Formation flow rate q fn can be calculated using Eq. 14 for non-steady-state conditions when C is known reasonably accurately to determine points along the plot of FIG. 10.
[0090] Steady-state conditions will simplify Eq. 14 because (p n−1 −p n )=0. Under steady state conditions, and only steady-state conditions, known tool parameters and measured values may be used to determine points along the straight line region of FIG. 10. In this region, the pump rate q pump can be substituted. Then using q pump in equation 9 yields:
k μ = - 14696 m G 0 r i ( 15 )
[0091] In Eq. 15 , m=(p*−p ss )/q pump . The units for k/μ are in md/cp, p n and p* are in psia, r i is in cm, q fn is in cm 3 /s, V pump and V 0 are in cm 3 , C is in psi −1 , and t is in s. Each pressure on the straight line is a steady state pressure at the given flow rate (or draw rate).
[0092] In practice, a deviation from a straight line near zero formation flow rate (filtrate) may be an indicator of drilling mud leakage into the tool (flow rate approximately zero). The deviation at high flow rates is typically a non-Darcy effect. However, the formation pressure can be determined by extending the straight line to an intercept with zero draw rate. The calculated formation pressure p* should equal a measured formation pressure within a negligible margin of error.
[0093] The purpose of a pressure test is to determine the pressure in the reservoir and determine the mobility of fluid in that reservoir. A procedure adjusting the piston draw rate until the pressure reading is constant (zero slope) provides the necessary information to determine pressure and mobility independently of a “stable” pressure build up using a constant volume.
[0094] Some advantages of this procedure are quality assurance through self-validation of a test where a stable build up pressure is observed, and quality assurance through comparison of drawdown mobility with build up mobility. Also, when a build up portion of a test is not available (in the cases of lost probe seal or excessive build up time), p* provides the formation pressure.
[0095] [0095]FIG. 11 is an exemplary plot of tool pressure vs. time using another method according to the present invention. The plot illustrates a method that involves changing the drawdown piston draw rate based on the slope of the pressure-time curve. Sensor data acquired at any point can be used with Eq. 14 to develop a plot as in FIG. 10 or used in automated solver routines controlled by a computer. Data points defining steady state pressures at various flow rates can be used to validate tests.
[0096] The procedure begins by using a MWD tool as described in FIG. 4 or a wireline tool as described in FIG. 5. A tool probe 420 is initially sealed against the borehole and the test volume 405 contains essentially only drilling fluid at the hydrostatic pressure of the annulus. Phase I 702 of the test is initiated by a command transmitted from the surface. A downhole controller 418 preferably controls subsequent actions. Using the controller to control a drawdown pump 426 that includes a drawdown piston, the pressure within the test volume is decreased at a constant rate by setting the draw rate of the drawdown piston to a predetermined rate. Sensors 424 are used to measure at least the pressure of the fluid in the tool at predetermined time intervals. The predetermined time intervals are adjusted to ensure at least two measurements can be made during each phase of the procedure. Additional advantages are gained by measuring the system volume, temperature and/or the rate of system volume change with suitable sensors. Compressibility of the fluid in the tool is determined during Phase 1 using the calculations discussed above.
[0097] Phase II of the test 704 begins when the tool pressure drops below the formation pressure p*. The slope of the pressure curve changes due to formation fluid beginning to enter the test volume. The change in slope is determined by using a downhole processor to calculate a slope from the measurements taken at two time intervals within the Phase. If the draw rate were held constant, the tool pressure would tend to stabilize at a pressure below p*.
[0098] The draw rate is increased at a predetermined time 706 to begin Phase 3 of the test. The increased draw rate reduces the pressure in the tool. As the pressure decreases, the flow rate of formation fluid into the tool increases. The tool pressure would tend to stabilize at a tool pressure lower than the pressure experienced during Phase II, because the draw rate is greater in Phase III than in Phase II. The draw rate is decreased again at a time 708 beginning Phase IV of the test when interval measurements indicate that pressure in the tool is approaching stabilization.
[0099] The draw rate may then be slowed or stopped so that pressure in the tool begins building. The curve slope changes sign when pressure begins to increase, and the change initiates Phase V 710 where the draw rate is then increased to stabilize the pressure. The stabilized pressure is indicated when pressure measurements yield zero slope. The drawdown piston rate is then decreased for Phase VI 712 to allow buildup until the pressure again stabilizes. When the pressure is stabilized, the drawdown piston is stopped at Phase VII 714 , and the pressure within the tool is allowed to build until the tool pressure stabilizes at the formation pressure p f . The test is then complete and the controller equalizes the test volume 716 to the hydrostatic pressure of the annulus. The tool can then be retracted and moved to a new location or removed from the borehole.
[0100] Stabilized pressures determined during Phase V 710 and Phase VI, 712 along with the corresponding piston rates, are used by the downhole processor to determine a curve as in FIG. 10. The processor calculates formation pressure p* from the measured data points. The calculated value p* is then compared to measured formation pressure p f obtained by the tool during Phase VII 714 of the test. The comparison serves to validate the measured formation pressure p f thereby eliminating the need to perform a separate validation test.
[0101] Other embodiments using one or more of the method elements discussed above are also considered within the scope of this invention. Still referring to FIG. 11, another embodiment includes Phase I through Phase IV and then Phase VII. This method is desirable with moderately permeable formations when it is desired to measure formation pressure. Typically, there would be a slight variation in the profile for Phase IV in this embodiment. Phase VII would be initiated when measurements show a substantially zero slope on the pressure curve 709 . The equalizing procedure 716 would also be necessary before moving the tool.
[0102] Another embodiment of the present invention includes Phase I 702 , Phase II 704 , Phase VI 712 , Phase VII 714 and the equalization procedure 716 . This method is used in very low permeability formations or when the probe seal is lost. Phase II would not be as distinct a deviation as shown, so the straight line portion 703 of Phase I would seem to extend well below the formation pressure p f .
[0103] While the particular embodiments as herein shown and disclosed in detail are fully capable of providing the advantages hereinbefore stated, it is to be understood that this disclosure is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended other than as described in the appended claims.
|
An apparatus and method capable of incrementally decreasing the borehole pressure at a variable rate by controlling a test volume within the borehole. The system includes an incrementally controllable pump, closed loop feedback and a controller for drawing down the pressure of a test volume to a level just below formation pressure. This incremental drawdown system will significantly reduce the overall measurement time, thereby increasing drilling efficiency and safety.
| 4
|
FIELD OF THE INVENTION
The present invention relates to a device for use in the analysis of absorbed gases in liquids and, in particular, is concerned with a flexible intravascular probe for use in the analysis of absorbed gases in the blood of man (or other mammals), e.g. by mass spectroscopy.
BACKGROUND OF THE INVENTION
In a known method for the continuous measurement of blood gases in vivo, use is made of an intravascular probe in the form of a flexible catheter having its distal end closed by a gas-permeable membrane. The said end of the probe is inserted into the blood vessel in question and its other end is connected to the inlet of a mass spectrometer whereby the device is evacuated. Gases absorbed in the blood diffuse through the membrane and pass along the catheter to the mass spectrometer wherein they are analysed.
U.S. Pat. No. 3,658,053 describes a blood catheter for use in the determination of the amount and type of dissolved gas in blood, which catheter includes a cannula of plastics material closed at one end. The cannula has an aperture in its wall towards said closed end, the exterior surface of at least that portion of the tube which includes the aperture being sheathed by a layer of gas-permeable material such as silicone rubber. Gases diffuse through the silicone rubber membrane and into the cannula via the aperture.
A constraint which has hitherto limited the practicability of known probes used in this procedure has been the need to manufacture the gas-permeable membrane from a bio-compatible material. Thus one known form of probe employs a flexible nylon catheter with a membrane of silicone rubber while another employs a malleable stainless steel catheter with a membrane of polytetrafluorethylene (PTFE). However, a disadvantage of silicone rubber as a membrane material is its inherently high gas permeability (typically in the region of 200×10 -10 cm 2 s -1 (cm Hg) -1 for oxygen at 20° C.) and the problem with a high permeability membrane is the tendency for the sampling region to become depleted of absorbed gas if the rate of transport of gas to the probe tip is not sufficiently high.
In other words the signal obtained from a probe of this type is undesirably dependent upon blood flow velocity. PTFE, on the other hand, is a virtually ideal membrane material from the standpoint of its inherent permeability. However, the problem with this material is the high temperature required for it to be worked, which precludes its use with flexible polymeric catheters. Thus, a PTFE membrane is limited to use with a catheter made from a material such as stainless steel, which does not however exhibit the same degree of flexibility as nylon for example. In particular the flexibility of stainless steel catheters is not sufficient to permit the safe monitoring of blood gas levels in infants.
Accordingly it is an aim of the invention to provide a form of construction for an intravascular probe or like device for use in the analysis of absorbed gases in liquids, whereby the above-discussed problems can be avoided.
SUMMARY OF THE INVENTION
According to one aspect of the present invention, a device for use in the analysis of absorbed gases in liquids comprises a flexible tube at or towards one end of which is provided a membrane across which gas can diffuse into the tube, in which the membrane comprises a first layer of gas-permeable material and a second layer of gas-permeable material in intimate contact with, and supported by, the first layer, and wherein the inherent gas permeability of the second layer is significantly less than the inherent gas-permeability of the first layer and, in use, defines the passage of gas across the membrane.
The device as defined above is particularly useful in the analysis of absorbed gases in blood, for example for in vivo measurements of oxygen and carbon dioxide gas tension in arterial and venous blood, but may be used in the analysis of absorbed gases in any liquid, eg, by mass spectroscopy or gas chromatography.
As advantage of the composite membrane construction of the device as hereinbefore defined is that the aforesaid second layer can be selected to provide a desired permeability for the membrane, in particular so that problems of gas-depletion and flow dependence are avoided, while the first layer can be selected to provide the desired mechanical compatibility and other properties of the membrane. The mechanical support afforded to the first layer by the second layer means that the second layer may itself be made thinner than known single-layer membranes with the result that an improved response time for the device may be achieved (response time being a function of the permeability of, and the square of the thickness of, the flow-defining level).
When the device is in the form of an intravascular probe the aforesaid first layer will generally constitute the outer layer of the membrane and be made of a recognised bio-compatible material, although this need not necessarily be so for the inner layer.
For use in the measurement of blood gas levels the permeability of the second layer of the membrane is preferably in the range (0.001-0.01)×10 -10 cm 2 s -1 (cm Hg) -1 for oxygen at 20° C.
In a preferred embodiment, the flexible tube is made from plastics material and closed at one end, the tube having an aperture in its wall towards said closed end, the exterior surface of at least that portion of the tube which includes the aperture being sheathed by a layer of bio-compatible gas-permeable material and the interior surface of that area of said sheathing layer which overlies said aperture being coated with a layer of gas-permeable material, the permeability of which is significantly less than that of the sheathing layer.
In this form of construction the gas-permeable membrane of the device is constituted by that portion of the sheathing material which overlies the tube aperture (ie, the said first layer of the membrane) together with that portion of the coating material supported thereby (ie, the said second layer of the membrane).
According to a second aspect of the present invention a method of manufacturing a device for use in the analysis of absorbed gases in liquids as hereinbefore defined, comprises the steps of: taking a flexible plastics material tube with an aperture in its wall; sheathing the exterior surface of at least that portion of the tube which includes said aperture with a layer of bio-compatible gas-permeable material; and coating the interior surface of that area of said sheathing layer which overlies said aperture with a layer of gas-permeable material, the permeability of which is significantly less than that of the sheathing layer.
It is a preferred feature of this form of construction that substantially the entire interior surface of the tube receives the aforesaid coating of low permeability material. Such a coating helps to reduce the incidence of ambient gases diffusing through the walls of the tube and thereby increases the signal-to-background ratio achievable with the device. The coating can also act to reduce the ingress of water vapour from the walls of tubes made from hydrophilic materials (of which nylon is an example).
A further example of this coating is that an acceptable signal-to-background ratio can be achieved even with tubes made from materials of relatively high gas permeability which hitherto have been considered unsuitable for use as intravascular probes. In other words the tube material can be selected on considerations of its flexibility, bio-compatibility, durability or other characteristics; its inherent gas permeability need no longer be the principal criterion of selection.
A preferred material for the coating is polyvinylidene chloride propolymer (PVDC). An alternative is crystalline polytrifluorochloro-ethylene (kel-F).
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention will now be described, by way of example, reference being made to the Figures of the accompanying diagrammatic drawings in which:
FIG. 1 is a longitudinal cross-section through a device for use in the analysis of absorbed gases in liquids; and
FIG. 2 is a longitudinal cross-section through a different device for use in the analysis of absorbed gases in liquids.
DESCRIPTION OF PREFERRED EMBODIMENT
Referring to FIGS. 1 and 2, each device is in the form of an intravascular probe and comprises a flexible bilumen catheter 1 made, for example, of nylon 6, the outside diameter of which may typically be 1.43 mm. A first lumen 2 is used as the gas sampling tube while the other lumen 3 is used as a blood (liquid) sampling tube.
As shown in the Figures, the outside wall of lumen 2 is somewhat thicker than that of lumen 3, and its cross sectional area is somewhat less than that of lumen 3. To manufacture the illustrated probes the following procedures are performed.
In each cas, a 50 cm length of the bilumen tubing is taken out at about 10 cm from one end an aperture 4 is cut in the outside wall of lumen 2. In prototype form the aperture is cut by means of a scalpel and guide. The guide consists of a short length of stainless steel tube having an aperture in its side such that when the bilumen tubing is placed into the guide the required size aperture can be cut in the tubing by following round the edge of the guide aperture with the scalpel. The aperture 4 typically measures 3 mm along the lumen axis by 0.52 mm, the lumen diameter.
Next an outer sheath 5 of medical grad silastic tubing is applied over the length of the bilumen tubing, using Analar grade Xylene to swell and lubricate the silastic. The Xylene is driven off using a hot air blower, causing the silastic to shrink onto the inner tubing. It is also ensured that any Xylene which may have entered the lumens is flushed out. The wall thickness of the sheath 5 is typically 25 microns.
The whole inner surface of the gas sampling lumen 2, including the area of the sheath 5 overlying aperture 4, is then given several coats of PVDC, to build up a layer 6 typically 6 microns thick. The PVDC coating is used in two forms--an organic solution and an aqueous latex. The latter is available ready to use, called IXAN (Registered Trade Mark) WA50, and marketed by LAPORTE Industries Limited. The organic solution is made by dissolving IXAN (Registered Trade Mark) WN 91 PVDC resin in tetrahydrofuran (THF) to a concentration of 200 g per kg of solution. The catheter tube is mounted vertically and 0.3 ml of the organic solution is injected into the top of the gas sampling lumen 2. Air is then passed through the lumen to flush out excess solution and drive off the solvent THF. The uniformity of the layer and to some extent the thickness is determined by the flow of air passing through the lumen. It has been found that a small flow rate, in the region of 1 ml s -1 , produces the best results. With air still passing through the lumen a hot air blower is used to heat the tubing to about 80° C. This procedure is then repeated three times using the aqueous base IXAN WA 50 latex.
Excess tubing is cut off each end leaving 1 cm before the aperture 4 and 25 cm after it. The distal end is then sealed by either of two methods. Firstly, as shown in FIG. 1, by drawing up in to both lumens 2 and 3 a quantity of medical grade silastic adhesive 7A, the plug so-formed then being fashioned into a hemisphere to ease the introduction of the probe into a blood vessel. Alternatively, as shown in FIG. 2, the end of the tubing may be heat sealed, followed by a dip coat 7B of medical grade silastomer. The latter method has proved to be the more acceptable in terms of smoothness of finish and ease of manufacture. The apparatus used for heat sealing may comprise a small block of PTFE heated with electrical resistance wire to about 90° C. A blind 1.5 mm diameter well is made in the PTFE block with a depth of approximately 3 mm by using a drill ground to obtain smooth surfaces and a hemispherical well bottom. The distal end of the bilumen tubing is placed into the heated well and by applying slight pressure the end is sealed.
Finally, an aperture 8 is cut in the outside wall and sheathing layer of lumen 3, for the taking of blood samples, and its edge painted with silastic elastomer 9 to prevent any possible gas leakage under the silastic sheath 5. The finished catheter is then put in a warm ventilated place for about 24 hours to allow the adhesives and elastomer to cure.
In use, the proximal end of the catheter (not shown) is provided with a bilumen adapter whereby the gas sampling lumen 2 can be connected to the inlet of a mass spectrometer or other analysis instrument, and blood sampling lumen 3 to a syringe.
In the construction of the probes shown in the Figures the gas-permeable membrane 10 is constituted by that portion of the silastic sheath 5 which overlies aperture 4 together with that portion of the PVDC layer 6 supported thereby. The silastic sheath 5 has a relatively high gas-permeability typically in the region of 200×10 -10 cm 2 s -1 (cm Hg) -1 for oxygen, and serves essentially for the support and protection of the thin PVDC layer 6, having no significant effect on the rate of gas flow across the membrane. Rather it is the PVDC layer, typically having a gas permeability in the region of 0.005×10 -10 cm 2 s -1 (cm Hg) -1 for oxygen, which defines the passage of gas across the membrane when the lumen 2 is evacuated by the analysis instrument.
The particular advantages possessed by the probes of the illustrated type can be summarised as follows:
1. The effective gas permeability of the membrane 10, as defined by its inner layer 6, is low, and the probe thereby avoids the problems of gas-depletion and flow dependence.
2. The inner layer 6 of the membrane 10 is itself significantly thinner than the single-layer membranes of known intravascular probes and confers on the device a very rapid response time.
3. The mechanical support afforded to the membrane layer 6 by the corresponding portion of sheath 5 is sufficient in itself without the need to resort to additional stiffening wires, a sintered metal substrate or a special aperture geometry, all of which feature in prior probe designs.
4. The application of the layer 6 to the entire interior surface of the gas sampling lumen cuts down the passage of ambient gases and water vapour through the walls of the lumen and confers on the device a high signal-to-background ratio.
5. The bio-compatible sheathing 5 and the low-permeability coating 6 permit the catheter 1 to be selected essentially on considerations of its mechanical properties, eg, its flexibility. In particular the illustrated probes are flexible enough to allow the continuous monitoring of gas levels in sick infants.
6. The bilumen construction permits both blood gas sampling and the taking of discreet samples of the blood itself with one and the same probe.
It will be appreciated however that although the invention has been described above in terms of a bilumen probe this need not be the case. Single lumen probes for use in blood gas analysis can be constructed in accordance with the invention to enjoy all of the advantages listed above save number 6.
|
A device in the form of a flexible intravascular probe for use in analyzing absorbed blood gases includes a gas-permeable membrane 10 comprising two layers in intimate contact and supporting each other. The permeability of the second layer 6 is significantly less than that of the first 5, and provides the desired permeability of the membrane 10 as a whole. The first layer 5 provides the desired mechanical compatibility and other properties of the membrane 10.
| 1
|
BACKGROUND OF THE INVENTION
The present invention pertains to the reduction of pollutants into the atmosphere by vehicles. Due to increasing government regulations many different approaches have been taken to comply with the same and these include various treatments of both the fuel and the air and their mixture to provide a more complete combustion to reduce the discharge of nitrous oxides, hydrocarbons and other impurities into the atmosphere.
The known devices attempting to effect these changes include the atomization of the gasoline into fine particles, the heating and cooling of the same, the treatment of the exhaust before its discharge and combinations of the same. Any, and all of the above require the addition of components to the vehicle which, in turn, require more expense and care without, in many instances, any significant change in the quality of exhaust discharged.
SUMMARY OF THE INVENTION
This invention relates to apparatus added to a vehicle which draws atmospheric air into an intake, and sequentially subjects it to ultraviolet rays, heats it to a temperature which removes the moisture therefrom and conducts it to a housing, which supplants the conventional air filter whereat it is additionally subjected to heat and ultraviolet rays before being induced into the carburetor.
The apparatus for effecting the above includes a main conduit means having one end secured to an opening in the vehicle body and having its other end secured to the housing mentioned above. The conduit includes a fan housing and fan for drawing the air therein, an ultraviolet ray treating section, a moisture removing section comprised of a plurality of individual tubes which are effective for breaking the air into separate streams which can be more effectively worked upon, controlled heating means for the tubes, a smaller tube including a normally closed valve which permits the addition of air when needed, and a housing which includes a plurality of sealed glass tubes conforming in shape to that of the housing, and which include different inert gases electrically connected generators which cause the same to produce ultraviolet light and heat. Thus, the air is treated to remove the moisture therefrom, if any, and is converted to a vapor which is expanding due to its lightness to facilitate its mixing with the fuel to thereby enhance the charge fed to the cylinders to produce a combustible explosion having its exhaust free from pollutants. It is seen, then, that this end result is obtained in a very simple and efficient manner which includes the addition of a minimum amount of parts which do not appreciably increase the overall weight of the vehicle nor does it increase the maintenance thereof since there are no moving parts. The device can be readily installed and maintained with a minimum amount of care.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of a vehicle engine showing the device installed and its relationship with respect to the same,
FIG. 2 is a view showing the details of the air induction means,
FIG. 3 shows the device and its detailed connection to the power generators,
FIG. 4 shows the details of the housing and the glass envelopes disposed therein.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to FIGS. 1 and 2, the component parts A, B, C and D of the present invention are seen to be mounted within the vehicle engine housing 10 which includes an engine block 11, fan 13 and radiator 14. The component parts of the system include the air induction and preliminary treating means A, the main conduit B, the additional air conduit C, and the main air treatment housing D. The main treatment station D comprises a housing 15 having an air inlet 16 communicating at one end to the interior thereof and at the other end with a V-shaped connector 17 having conduits 18, 19, parts C and B, extending from each leg thereof. Conduits 18, 19 are joined at their other ends to form a single coupling 20 housing a blower 21 connected by a flexible hose 21' to an atmospheric air entrance means 22. As seen in FIG. 3, air entrance means 22 comprises a housing having its opening disposed in a plug-like member which facilitates its insertion into an aperture formed in the vehicle body. Conduit 19 forms the main passageway for the conducting of air to the housing D and is formed in the shape of a "U" with one leg 23 thereof disposed and secured adjacent the interior vehicle wall 24 and the other leg 25 secured adjacent to the engine block 12. As seen, conduit 18 is of a shorter length and directly connects couplings 17,20.
Further details of the conduits B, C are seen in FIG. 2 and as seen, main conduit 19 is formed of a plurality of individual copper or aluminum small diametered tubes 26 banded together by a plurality of spaced straps 26' (only 3 being shown) extending between the couplings 17 and 20. Heating elements 27, 28, 29 are disposed adjacent to or within the tubes 26 and are controlled by a thermostat 30. Thermostatic control means 30 automatically control the heaters 27, 28, 29 to regulate the temperature thereof in response to the temperature of the outside air, that is, when the outside air is cooler, the heating means will heat for a longer period of time as compared to when the outside temperature is warmer. Conduit 18 comprises a short tube joining the other legs of the couplings 17 and 20 and has a normally closed bypass valve 31 disposed medially thereof which is effective to open automatically in response to the temperature of the engine air to permit the addition of atmospheric air to assist in cooling to avoid overheating, if needed. Also, in extremely hot, dry air conditions, the main conduit 19 is assisted by air conducted directly to treatment station D via short conduit 18 which valve is opened in response to the thermostat.
Immediately preceding the tubes 26 is a pre-treatment station comprised of a pair of sealed glass tubes or envelopes 26', 26' having a charge of inert gas therein. These envelopes 26', 26' are electrically connected to a generator power source and serves to condition the air prior to its being dispersed into the individual tubes 26.
It is therefore seen that the function of the component parts A, B and C is to draw atmospheric air into the conduit, passing it by the sealed envelopes 26', 26' which initially treats it, then introducing it into the plurality of individual tubes 26 whereat it is heated to remove moisture by vaporizing it prior to its further treatment at station D which will be explained hereinafter. The optimum temperature of the air is controlled both by the heaters associated with the conduit means which are associated with sensors indicating the temperature of the atmospheric air, the exhaust gas, the engine temperature, etc., to thereby determine the amount of heat that has to be added to the incoming air to effect vaporization of the moisture. The elongated length of conduit 19 and therefore, the individual tubes 26, causes the air to travel over a longer path before it reaches the treatment station D to effectively control the heating and the vaporization of the moisture therein.
The details of the main treatment station D are seen in the exploded view of FIG. 4 and includes a generally circular cup-shaped housing 15 having stepped interior recesses 32, 33 disposed therearound, an open top 34, and a small discharge opening 35 in the base thereof. The housing 15 is secured to the top of the carburetor, not seen, with the opening 35 leading directly into the interior thereof, or alternatively, can be connected thereto by any suitably shaped adapter such as shown at 35, 35'. These adapters can take any shape to effect the joining of the housing 15 to the carburetor. The open end 34 is closed by a cover 34' snapped thereon or secured in any desirable fashion. A plurality of sealed tubes or envelopes 36 are positioned in the respective recesses 32, 33.
In one preferred arrangement, the tubes 36 are bunched or nested together as shown at 37 and stacked one on top of the other as seen at 38, and secured to the housing 15 in any convenient manner. This disposition provides a surface area substantially covering the interior of the housing 15 to insure that all the air is expanded and treated.
The tubes 36 contain charges of inert gas which can be selected from one or more of helium, neon, argon, krypton and xenon. Mercury is also selectively utilized in combination with these gases. By choosing specific types of glass to form the tubes or envelopes and charging these with selected gases, either ultra-violet rays or heat will be caused to be discharged by the same when electrically connected to a power source.
The purpose of the charged tubes is to emit rays and heat to cause the previously dried air to become chemically unstable whereby the same will co-act with the unburned gas particles emanating from the manifold and being introduced into the inlet 16 from the tube 16' leading from the exhaust manifold as seen in FIG. 1. As the air cascades downwardly over the tubes, the rays and heat causes the oxygen molecules to disperse thereby increasing the available oxygen which enhances and facilitates the burning of the fuel as it passes downwardly into the carburetor. In other words, the expanding and continuous motion of the oxygen molecules lengthen the burning time of the mixture due to the availability thereof to cause a more complete burning of the mixture which, in turn, will reduce the amount of pollutants discharged into the atmopshere, and, since the combustion is that much more complete the engine's demand for fuel will be reduced to increase the miles per gallon.
Therefore, with these desirous end results in mind, tubes 40, 41 of the bunched tubes 37 contain neon gas with tube 40 being made from lime glass and tube 41 from unleaded glass such as Vycor 7913TM made by Corning Glass. The function of each of these tubes is to generate heat which changes the weight of the air by expanding it by further reducing the humidity, if any, contained therein. Tubes 43, 44 of the stacked tubes contain neon gas and function in the same manner as tubes 40, 41. Tubes 42 and 45 are made from lime glass and each contain argon gas with mercury and are effective to emit ultraviolet rays which cause the movement of the oxygen molecules referred to hereinabove. As mentioned before, other inert gases could be used, such as krypton, and the selection in many cases is dependent on the cost and availability of the same. Also, various combinations and numbers of tubes can be utilized with the prime considerations being the size of the engine; and the general nature of the air where the vehicle is being used, that is, is the air dry or moist. In this regard, the sealed tubes 26', 26' immediately preceding the air conducting tubes 26 also contain charges of the inert gases described above to cause the emission of ultraviolet rays and heat to initially treat the air.
As further seen in FIG. 2, the tubes 40, 41, 42 are interconnected by a plurality of spaced sets 46 of individual wide braided wires which are threaded over and under these tubes in a FIG. 8 configuration so that each tube is contacted by the wire as it passes therearound. One end 47 of the wire 46 is anchored back on itself and the other end 48 is connected to one end of a power generator. When the wire is heated, it will be seen that by wrapping the tubes in this fashion there will be a feed back effect which will cause each of the tubes to be additionally heated due to its contact with the wire 46 as the primary tube is being heated. The wire braid also inherently serves to cushion the tubes within the housing 15.
With continuing reference to FIG. 3, the electrical connection of the envelopes to the power generator is seen to consist of a plurality of circuits, with only one being described, as they are all basically the same. As seen, end 48 of the braided wire extends to a power generator, shown generally at 49 which is a conventional feed back transistorized circuit including a transformer 50, transistor 51, series resistors 52, 53, ground 54, fuse 55, indicator lamp 56 and return lead 57 extending to the wire connecting the ends of tube 42.
These circuits are in turn electrically connected to the vehicles ignition system and are energized upon actuation of the ignition key and once the same are fired the telltale lights 56 will burn indicating to the driver the on condition of each of the generators.
The above circuitry can be placed in a single box using one common ground and a single positive connection to facilitate installation and removal for repair and maintenance thereof.
|
Exhaust pollutants of a vehicle are reduced by providing dry, substantilly moisture-free air which is mixed with the fuel. The conventional air filter is removed and replaced by a housing containing a plurality of sealed glass tubes having inert gas therein which treats the air by subjecting it to ultraviolet rays and additional heat. The air has been initially heated to remove the moisture and subjected to an ultraviolet treatment before it reaches the housing.
| 8
|
CROSS-REFERENCE TO RELATED APPLICATIONS
The present disclosure is a continuation of U.S. patent application Ser. No. 11/725,397 (now U.S. Pat. No. 8,768,274), filed on Mar. 19, 2007, which is a continuation of U.S. patent application Ser. No. 11/704,885 (now U.S. Pat. No. 8,457,576), filed Feb. 9, 2007. This application claims the benefit of U.S. Provisional Application No. 60/785,116, filed on Mar. 19, 2007. The above referenced applications are related to U.S. patent application Ser. No. 11/725,426 (now U.S. Pat. No. 8,457,577), filed Mar. 19, 2007 and U.S. patent application Ser. No. 11/725,248 (now Abandoned), filed Jul. 23, 2013. The entire disclosures of the applications referenced above are incorporated herein by reference.
FIELD
The present disclosure relates to cellular phones, and more particularly to cellular phones with integrated FM radio receivers.
BACKGROUND
Consumers increasing want to purchase smaller cellular phones. At the same time, consumers also expect their cellular phones to have increased functionality. These two trends may pose problems for cellular phone manufacturers since the demand for increased functionality tends to increase the size of the cellular phones.
Cellular phones may include MP3 players, personal digital assistants (PDAs), WiFi or other network interfaces, cameras, Bluetooth interfaces and/or other devices. Some new cell phones also incorporate FM radio receivers to allow users to receive analog and/or digital FM broadcasts.
Multi-function cellular phones usually require multiple antennas for receiving analog cellular signals, digital cellular signals, Bluetooth signals, WiFi signals and/or other types of wireless signals. If the cellular phone has an FM receiver, another antenna having suitable dimensions is required to allow reception of the FM signals. Because of the compact dimensions of cellular phones, it is not feasible to integrate a suitable FM antenna within the form factor of the cellular phone. Rather, antennas having larger dimensions are typically required and are externally connected to the cellular phone. For example, the antenna may be combined with and/or run adjacent to wires that connect the FM receiver to earphones such as earbuds.
There are multiple ways of implementing an FM receiver. For purposes of illustration, simplified block diagrams of super-heterodyne and direct conversion transmitter and receiver architectures will be discussed, although other architectures may be used. Referring now to FIG. 1A , an exemplary super-heterodyne receiver 14 - 1 is shown. The receiver 14 - 1 includes an antenna 19 that is coupled to an optional RF filter 20 and a low noise amplifier 22 . An output of the amplifier 22 is coupled to a first input of a mixer 24 . A second input of the mixer 24 is connected to an oscillator 25 , which provides a reference frequency. The mixer 24 converts radio frequency (RF) signals to intermediate frequency (IF) signals.
An output of the mixer 24 is connected to an optional IF filter 26 , which has an output that is coupled to an automatic gain control amplifier (AGCA) 32 . An output of the AGCA 32 is coupled to first inputs of mixers 40 and 41 . A second input of the mixer 41 is coupled to an oscillator 42 , which provides a reference frequency. A second input of the mixer 40 is connected to the oscillator 42 through a −90° phase shifter 43 .
The mixers 40 and 41 convert the IF signals to baseband (BB) signals. Outputs of the mixers 40 and 41 are coupled to BB circuits 44 - 1 and 44 - 2 , respectively. The BB circuits 44 - 1 and 44 - 2 may include low pass filters (LPF) 45 - 1 and 45 - 2 and gain blocks 46 - 1 and 46 - 2 , respectively, although other BB circuits may be used. Mixer 40 generates an in-phase (I) signal, which is output to a BB processor 47 . The mixer 41 generates a quadrature-phase (Q) signal, which is output to the BB processor 47 .
Referring now to FIG. 1B , an exemplary direct conversion receiver 14 - 2 is shown. The receiver 14 - 2 includes the antenna 19 that is coupled to the optional RF filter 20 and to the low noise amplifier 22 . An output of the low noise amplifier 22 is coupled to first inputs of RF to BB mixers 48 and 50 . A second input of the mixer 50 is connected to oscillator 51 , which provides a reference frequency. A second input of the mixer 48 is connected to the oscillator 51 through a −90° phase shifter 52 . The mixer 48 outputs the I-signal to the BB circuit 44 - 1 , which may include the LPF 45 - 1 and the gain block 46 - 1 . An output of the BB circuit 44 - 1 is input to the BB processor 47 . Similarly, the mixer 50 outputs the Q signal to the BB circuit 44 - 2 , which may include the LPF 45 - 2 and the gain block 46 - 2 . An output of the BB circuit 44 - 2 is output to the BB processor 47 .
SUMMARY
In one feature of the present disclosure, a cellular phone is provided that includes a first wireless transceiver that receives intermediate frequency (IF) signals. The IF signals are based on frequency modulated (FM) signals that have been tuned and down-converted from a radio frequency (RF) to an IF by a remote device. An FM processing module receives the IF signals, converts the IF signals to baseband signals, and generates processed FM signals.
In another feature, the cellular phone further includes a cellular phone processing module that performs cellular phone signal processing. One of the first wireless transceiver and the FM processing module is integrated with the cellular phone processing module in an integrated circuit.
In another feature, the first wireless transceiver transmits the processed FM signals to the remote device.
In yet another feature, the cellular phone further includes a user interface that generates FM station selection data. The first wireless transceiver transmits the FM station selection data to the remote device.
In another feature, a system includes the cellular phone and further includes the remote device. The remote device generates an audio signal based on the processed FM signals.
In still another feature, a system includes the cellular phone and further includes the remote device. The remote device further includes an antenna and a tuner. The tuner communicates with the antenna and tunes an RF frequency. In an additional feature, the remote device further includes an amplifier that amplifies RF signals at the RF frequency. In a further feature, the remote device further includes a mixer that mixes the RF signals to generate the IF signals. In another feature, the remote device further comprises a second wireless transceiver that transmits the IF signals to the cellular phone. In another feature, the remote device includes a user interface that communicates with the tuner to select an FM station.
In another feature, the first wireless transceiver and the FM processing module are implemented as an integrated circuit.
In yet another feature, a communication method is provided and includes receiving intermediate frequency (IF) signals via a first wireless transceiver. The IF signals are based on frequency modulated (FM) signals that have been tuned and down-converted from a radio frequency (RF) to an IF by a remote device. The IF signals are received via an FM processing module. The FM processing module converts the IF signals to baseband signals and generates processed FM signals.
In another feature, the communication method includes transmitting the processed FM signals to the remote device.
In still another feature, the communication method further includes generating FM station selection data and transmitting the FM station selection data to the remote device.
In an additional feature, the communication method further includes generating an audio signal based on the processed FM signals.
In another feature, the communication method further includes communicating with an antenna via a tuner. An RF frequency is tuned. In another feature, the communication method further includes amplifying RF signals at the RF frequency. In another feature, the communication method further includes mixing the RF signals to generate the IF signals. In another feature, the communication method includes transmitting the IF signals to a cellular phone.
In another feature, the communication method further includes communicating with a tuner to select an FM station.
In yet another feature, a cellular phone is provided that includes first wireless transceiver means for receiving intermediate frequency (IF) signals, which are based on frequency modulated (FM) signals. The FM signals have been tuned and down-converted from a radio frequency (RF) to an IF by a remote device. FM processing means is included for receiving the IF signals, converts the IF signals to baseband signals, and generates processed FM signals.
In another feature, the cellular phone further includes a cellular phone processing means for performing cellular phone signal processing, at least one of the first wireless transceiver means and the FM processing means is integrated with the cellular phone processing means in an integrated circuit.
In a further feature, the first wireless transceiver means transmits the processed FM signals to the remote device.
In another feature, the cellular phone further includes user interface means for generating FM station selection data, the first wireless transceiver means transmits the FM station selection data to the remote device.
In another feature, a system includes the cellular phone and further includes the remote device, the remote means generates an audio signal based on the processed FM signals.
In still another feature, a system includes the cellular phone and further includes the remote device. The remote device further includes an antenna, and tuner means for communicating with the antenna and tuning an RF frequency. In another feature, the remote device further includes amplifier means for amplifying RF signals at the RF frequency. In an additional feature, the remote device further includes mixer means for mixing the RF signals to generate the IF signals. In another feature, the remote device further includes second wireless transceiver means for transmitting the IF signals to the cellular phone. In another feature, the remote device includes user interface means for communicating with the tuner means to select an FM station.
In another feature, the first wireless transceiver means and the FM processing means are implemented as an integrated circuit.
In a further feature, a cellular phone is provided that includes a first wireless transceiver that receives radio frequency (RF) signals. The RF signals include frequency modulated (FM) signals that have been tuned by a remote device. An FM processing module receives the RF signals, converts the RF signals to baseband signals, and generates processed FM signals.
In another feature, the cellular phone further includes a cellular phone processing module that performs cellular phone signal processing. One or more of the first wireless transceiver and the FM processing module are integrated with the cellular phone processing module in an integrated circuit.
In still another feature, the first wireless transceiver transmits the processed signals to the remote device.
In another feature, the cellular phone further includes a user interface that generates FM station selection data. The first wireless transceiver transmits the FM station selection data to the remote device.
In yet another feature, a system includes the cellular phone and further includes the remote device. The remote device generates an audio signal based on the processed FM signals.
In another feature, a system includes the cellular phone and further includes the remote device. The remote device further includes an antenna and a tuner that communicates with the antenna and that tunes an RF frequency. In another feature, the remote device further includes an amplifier that amplifies signals at the tuned RF frequency. In another feature, the remote device further includes a second wireless transceiver that transmits the IF signals to the cellular phone.
In an additional feature, the first wireless transceiver and the FM processing module are implemented as an integrated circuit.
In another feature, the FM processing module includes an intermediate frequency (IF) mixer that converts the RF signals to IF signals. A BB mixer converts the IF signals to BB signals.
In yet another feature, a communication method is provided that includes receiving radio frequency (RF) signals. The RF signals include frequency modulated (FM) signals that have been tuned by a remote device via a first wireless transceiver. The RF signals are received. The RF signals are converted to baseband signals. Processed FM signals are generated via an FM processing module.
In yet another feature, the communication method further includes transmitting the processed signals to the remote device. In another feature, the communication method further includes generating and transmitting FM station selection data to the remote device.
In another feature, the communication method further includes generating an audio signal based on the processed FM signals. In another feature, the communication method further includes communicating with an antenna and tuning an RF frequency. In still another feature, the communication method further includes amplifying signals at the tuned RF frequency. In another feature, the communication method further includes transmitting the IF signals to the cellular phone.
In an additional feature, the communication method further includes converting the RF signals to IF signals. The IF signals are converted to BB signals.
In another feature, a cellular phone is provided and includes first wireless transceiver means for receiving radio frequency (RF) signals. The RF signals include frequency modulated (FM) signals that have been tuned by a remote device. FM processing means for receiving the RF signals is included. The FM processing means converts the RF signals to baseband signals and generates processed FM signals.
In a further feature, the cellular phone further includes cellular phone processing means for performing cellular phone signal processing. One or more of the first wireless transceiver means and the FM processing means are integrated with the cellular phone processing means in an integrated circuit.
In another feature, the first wireless transceiver means transmits the processed signals to the remote device.
In yet another feature, the cellular phone further includes user interface means for generating FM station selection data. The first wireless transceiver means transmits the FM station selection data to the remote device.
In another feature, a system includes the cellular phone and further includes the remote device. The remote device generates an audio signal based on the processed FM signals.
In still another feature, a system includes the cellular phone and further includes the remote device. The remote device further includes antenna means and tuner means for communicating with the antenna means and for tuning an RF frequency. In another feature, the remote device further includes an amplifier means for amplifying signals at the tuned RF frequency. In another feature, the remote device further includes a second wireless transceiver means that transmits the IF signals to the cellular phone.
In another feature, the first wireless transceiver means and the FM processing means are implemented as an integrated circuit.
In a further feature, the FM processing means includes intermediate frequency (IF) mixer means for converting the RF signals to IF signals. BB mixer means for converting the IF signals to BB signals is also included.
In another feature, a cellular phone is provided and includes a first wireless transceiver that receives baseband (BB) signals. The BB signals are based on frequency modulated (FM) signals that have been tuned and down-converted from a radio frequency (RF) to the BB by a remote device. An FM processing module receives the BB signals and generates processed FM signals based on the BB signals.
In still another feature, the cellular phone further includes a cellular phone processing module that performs cellular phone signal processing. One or more of the first wireless transceiver and the FM processing module are integrated with the cellular phone processing module in an integrated circuit.
In another feature, the first wireless transceiver transmits the processed FM signals to the remote device.
In yet another feature, the cellular phone further includes a user interface that generates FM station selection data. The first wireless transceiver transmits the FM station selection data to the remote device.
In another feature, a system includes the cellular phone and further includes the remote device. The remote device further generates an audio signal based on the processed FM signals.
In an additional feature, a system includes the cellular phone and further includes the remote device. The remote device further includes an antenna and a tuner that communicates with the antenna and that tunes an RF frequency. In another feature, the remote device further includes an amplifier that amplifies RF signals at the tuned RF frequency. In another feature, the remote device further includes an intermediate frequency (IF) mixer that mixes the RF signals to IF signals. In yet another feature, the remote device further includes a BB mixer that mixes the IF signals to BB signals. In another feature, the remote device further includes a second wireless transceiver that transmits the BB signals to the cellular phone.
In another feature, the first wireless transceiver and the FM processing module is implemented as an integrated circuit.
In a further feature, a communication method is provided and includes receiving baseband (BB) signals, which are based on frequency modulated (FM) signals that have been tuned and down-converted from a radio frequency (RF) to the BB by a remote device via a first wireless transceiver. The BB signals are received via an FM processing module. Processed FM signals are generated based on the BB signals.
In another feature, the communication method further includes transmitting the processed FM signals to the remote device.
In still another feature, the communication method further includes generating FM station selection data and transmitting the FM station selection data to the remote device.
In another feature, the communication method further includes generating an audio signal based on the processed FM signals.
In an additional feature, the communication method further includes communicating with an antenna via a tuner and tunings an RF frequency. In another feature, the communication method further includes amplifying RF signals at the tuned RF frequency. In yet another feature, the communication method further includes mixing the RF signals to generate IF signals. In another feature, the communication method further includes mixing the IF signals to generate BB signals. In another feature, the communication method further includes transmitting the BB signals to a cellular phone.
In still another feature, a cellular phone is provided and includes first wireless transceiver means for receiving baseband (BB) signals. The BB signals are based on frequency modulated (FM) signals that have been tuned and down-converted from a radio frequency (RF) to the BB by a remote device. FM processing means for receiving the BB signals is also included. The FM processing means generates processed FM signals based on the BB signals.
In another feature, the cellular phone further includes cellular phone processing means for performing cellular phone signal processing. One or more of the first wireless transceiver means and the FM processing means is integrated with the cellular phone processing means in an integrated circuit.
In a further feature, the first wireless transceiver means transmits the processed FM signals to the remote device.
In another feature, the cellular phone further includes user interface means for generating FM station selection data. The first wireless transceiver means transmits the FM station selection data to the remote device.
In still another feature, a system includes the cellular phone and further includes the remote device. The remote device further generates an audio signal based on the processed FM signals.
In another feature, a system includes the cellular phone and further includes the remote device. The remote device further includes an antenna and tuner means for communicating with the antenna and for tuning an RF frequency. In another feature, the remote device further includes amplifier means for amplifying RF signals at the tuned RF frequency. In a further feature, the remote device further includes intermediate frequency (IF) mixer means for mixing the RF signals to generate IF signals. In another feature, the remote device further includes a BB mixer means for mixing the IF signals to generate BB signals. In yet another feature, the remote device further includes a second wireless transceiver means for transmitting the BB signals to the cellular phone.
In another feature, the first wireless transceiver means and the FM processing means are implemented as an integrated circuit.
In still another feature, a remote device is provided and includes a frequency modulated (FM) tuner that communicates with an antenna and that tunes an FM frequency. A wireless transceiver transmits wireless signals to a remote cellular phone based on FM signals received at the FM frequency.
In another feature, the first wireless transceiver receives FM tuning data from the remote cellular phone and adjusts the FM tuner based on the FM tuning data.
In another feature, the remote device further includes a first antenna that communicates with the FM tuner and receives the RF signals. A second antenna communicates with the first wireless transceiver and transmits the wireless signals.
In an additional feature, the first wireless transceiver includes a Bluetooth interface.
In another feature, the remote device further includes an amplifier that amplifies signals at the tuned RF frequency. A mixer mixes the signals to the IF signals. The first wireless transceiver transmits the IF signals to the remote cellular phone and receives processed FM signals from the remote cellular phone. An amplifier generates amplified audio signals based on the processed FM signals.
In a further feature, a headset includes the remote device and further includes speakers that output the amplified audio signals. In another feature, the headset further includes a conductor that connects the remote device to the speakers. The antenna extends adjacent to the conductor.
In another feature, an article of clothing includes the remote device and further includes a speaker that outputs the amplified audio signals. In another feature, a system includes the remote device and further includes speakers that output the amplified audio signals. In another feature, the system further includes a conductor that connects the remote device to the speakers. The antenna extends adjacent to the conductor.
In yet another feature, the remote device further includes a first amplifier that amplifies RF signals at the tuned RF frequency. An intermediate frequency (IF) mixer mixes the RF signals to IF signals. A BB mixer mixes the IF signals to BB signals. The wireless transceiver transmits the BB signals to the remote cellular phone and receives processed FM signals from the remote cellular phone. A second amplifier generates amplified audio signals based on the processed FM signals.
In another feature, a headset includes the remote device and further includes speakers that output the amplified audio signals. In another feature, the headset further includes a conductor that connects the remote device to the speakers, wherein the antenna extends adjacent to the conductor.
In still another feature, an article of clothing includes the remote device and further includes a speaker that outputs the amplified audio signals.
In another feature, a system includes the remote device of claim 6 and further includes earbuds that output the amplified audio signals. In another feature, the system further includes a conductor that connects the remote device to the earbuds. The antenna extends adjacent to the conductor.
In another feature, the remote device further includes a tuner that tunes an RF frequency. A first amplifier amplifies signals at the tuned RF frequency. The wireless transceiver transmits the RF signals to the remote cellular phone and receives processed FM signals from the remote cellular phone. A second amplifier generates amplified audio signals based on the processed FM signals.
In yet another feature, a headset includes the remote device further includes speakers that output the amplified audio signals. In another feature, the headset further includes a conductor that connects the remote device to the speakers. The antenna extends adjacent to the conductor.
In another feature, an article of clothing includes the remote device and further includes a speaker that outputs the amplified audio signals. In another feature, a system includes the remote device and further includes earbuds that output the amplified audio signals. In another feature, the system further includes a conductor that connects the remote device to the earbuds. The antenna extends adjacent to the conductor.
In another feature, a communication method is provided and includes communicating with an antenna and tuning an FM frequency via a frequency modulated (FM) tuner. Wireless signals are transmitted to a remote cellular phone based on FM signals received at the FM frequency via a wireless transceiver.
In another feature, the communication method includes receiving FM tuning data from the remote cellular phone and adjusting the FM tuner based on the FM tuning data.
In still another feature, the communication method further includes communicating with the FM tuner and receiving the RF signals via a first antenna. The first wireless transceiver is communicated with and the wireless signals are transmitted via a second antenna.
In another feature, the communication method further includes amplifying signals at the tuned RF frequency. The amplified signals are mixed to generate the IF signals. The IF signals are transmitted to the remote cellular phone. Processed FM signals are received from the remote cellular phone. The amplified audio signals are generated based on the processed FM signals.
In a further feature, the communication method further includes amplifying RF signals at the tuned RF frequency. The RF signals are mixed to generate IF signals. The IF signals are mixed to generate BB signals. The BB signals are transmitted to the remote cellular phone. Processed FM signals are received from the remote cellular phone. Amplified audio signals are generated based on the processed FM signals.
In another feature, the communication method further includes tuning an RF frequency. Amplifying signals are tuned at the RF frequency. The RF signals are transmitted to the remote cellular phone. Processed FM signals are received from the remote cellular phone. Amplified audio signals are generated based on the processed FM signals.
In another feature, the communication method further includes outputting the amplified audio signals. In another feature, the communication method further includes outputting the amplified audio signals. In another feature, the communication method further includes outputting the amplified audio signals.
In an additional feature, a remote device is provided and includes frequency modulated (FM) tuner means for communicating with an antenna and for tuning an FM frequency. Wireless transceiver means for transmitting wireless signals to a remote cellular phone based on FM signals received at the FM frequency is also included.
In another feature, the first wireless transceiver means receives FM tuning data from the remote cellular phone and adjusts the FM tuner based on the FM tuning data.
In another feature, the remote device further includes first antenna means for communicating with the FM tuner and receiving the RF signals. Second antenna means for communicating with the first wireless transceiver means and transmitting the wireless signals is included.
In another feature, the first wireless transceiver means includes a Bluetooth interface means.
In yet another feature, the remote device further includes amplifier means for amplifying signals at the tuned RF frequency. Mixer means for mixing the signals to generate the IF signals. First wireless transceiver means for transmitting the IF signals to the remote cellular phone and for receiving processed FM signals from the remote cellular phone is included. Amplifier means for generating amplified audio signals based on the processed FM signals is also included.
In another feature, a headset includes the remote device and further includes audio means for outputting the amplified audio signals. In another feature, the headset further includes a conductor means for connecting the remote means to the audio means. The antenna extends adjacent to the conductor means.
In still another feature, an article of clothing includes the remote device and further includes audio means for outputting the amplified audio signals. In another feature, a system includes the remote device and further includes audio means for outputting the amplified audio signals. In another feature, the system further includes conductor means for connecting the remote means to the audio means. The antenna extends adjacent to the conductor means.
In another feature, the remote device further includes first amplifier means for amplifying RF signals at the tuned RF frequency. Intermediate frequency (IF) mixer means for mixing the RF signals to generate IF signals is included. BB mixer means for mixing the IF signals to generate BB signals is also included. The wireless transceiver means transmits the BB signals to the remote cellular phone and receives processed FM signals from the remote cellular phone. Second amplifier means for generating amplified audio signals based on the processed FM signals is further included.
In another feature, a headset includes the remote device and further includes audio means for outputting the amplified audio signals. In another feature, the headset further includes conductor means for connecting the remote means to the audio means. The antenna extends adjacent to the conductor means.
In a further feature, an article of clothing includes the remote means and further includes audio means for outputting the amplified audio signals. In another feature, a system includes the remote means and further includes audio means for outputting the amplified audio signals. In another feature, the system further includes conductor means for connecting the remote means to the audio means. The antenna extends adjacent to the conductor means.
In another feature, the remote device further includes tuner means for tuning an RF frequency. First amplifier means for amplifying signals at the tuned RF frequency is included. The wireless transceiver means transmits the RF signals to the remote cellular phone and receives processed FM signals from the remote cellular phone. Second amplifier means for generating amplified audio signals based on the processed FM signals is further included.
In another feature, a headset includes the remote device and further includes audio means for outputting the amplified audio signals. In another feature, the headset further includes conductor means for connecting the remote device to the audio means. The antenna extends adjacent to the conductor means.
In an additional feature, an article of clothing includes the remote device and further includes audio means for outputting the amplified audio signals. In another feature, a system includes the remote device and further includes audio means for outputting the amplified audio signals. In another feature, the system further includes conductor means for connecting the remote device to the audio means. The antenna extends adjacent to the conductor means.
In still other features, the systems and methods described above are implemented by a computer program executed by one or more processors. The computer program can reside on a computer readable medium such as but not limited to memory, non-volatile data storage and/or other suitable tangible storage mediums.
Further areas of applicability of the present disclosure 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 disclosure, are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:
FIG. 1A is a functional block diagram of an exemplary FM receiver according to the prior art;
FIG. 1B is a functional block diagram of a second exemplary FM receiver according to the prior art;
FIG. 2 is a functional block diagram of a cellular phone system including an exemplary remote device and an exemplary cellular phone according to the present disclosure;
FIG. 3A is a functional block diagram of a headset according to the present disclosure;
FIG. 3B is a functional block diagram of earbuds according to the present disclosure;
FIGS. 4A and 4B illustrate articles of clothing that incorporate the remote device according to the present disclosure;
FIG. 5 is a more detailed functional block diagram of the cellular phone system of FIG. 2 ;
FIG. 6 is a functional block diagram of an alternate cellular phone system;
FIG. 7 is a functional block diagram of another alternate cellular phone system; and
FIG. 8 is a logic flow diagram illustrating a method of operating a cellular phone system.
DETAILED DESCRIPTION
The following description is merely exemplary in nature and is in no way intended to limit the disclosure, its application, or uses. For purposes of clarity, the same reference numbers will be used in the drawings to identify similar elements. As used herein, the term module refers to an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A or B or C), using a non-exclusive logical or. It should be understood that steps within a method may be executed sequentially, simultaneously or in different order without altering the principles of the present disclosure.
A cellular phone FM receiver typically has multiple associated components, such as tuners, low noise amplifiers (LNAs), oscillators, amplifiers, filters, converters, etc. The cellular phone system according to the present invention separates one or more of such components from a cellular phone. As a result, a potion of the FM signal processing is performed remotely from the cellular phone. The cellular phone continues and completes the FM signal processing as described in further detail below.
Referring now to FIG. 2 , a cellular phone system 100 is shown and includes a remote device 110 and a cellular phone 120 . The cellular phone system 100 , the remote device 110 , and the cellular phone 120 are shown as and each considered a cellular phone circuit. The remote device 110 includes a tuning module 124 that tunes to one or more selected frequencies, such as one or more FM radio stations. The tuning module 124 communicates with one or more FM antennas 126 that receive FM signals as input signals. A low noise amplifier (LNA) module 128 amplifies the selected FM signals and outputs amplified signals to an analog to digital (A/D) converter module 130 . The A/D converter 130 outputs digital signals to a wireless interface module 132 of the remote device 110 . The wireless interface module 132 transmits wireless signals to the cellular phone 120 via an antenna 133 . One or more components of the remote device 110 can be integrated into a system on a chip (SOC).
The user may select a particular FM station using inputs on the cellular phone 120 and/or on the remote device 110 . If the user employs inputs of the cellular phone 120 to select an FM station, the wireless interface 132 also may receive tuning data such as frequency data from the cellular phone 120 , which is output to the tuner 124 . Alternately, the remote device 110 may include a user input 136 that allows a user to select a station, adjust volume, and/or perform other radio-based functions such as selecting preset stations, setting preset stations, scanning, etc. The user input of the cellular phone 120 may also allow the user to adjust volume, and/or perform other radio-based functions such as selecting preset stations, setting preset stations, scanning, etc.
The wireless interface 132 also receives the processed FM radio signal from the cellular phone 120 . The received signal is output to a digital to analog (D/A) converter 142 , which outputs analog audio signals. The D/A converter 142 outputs the audio signal to an amplifier 144 , which amplifies the audio signal and outputs the signal to an output 146 , such as an output jack, speakers, etc.
An exemplary embodiment of the cellular phone 120 is shown in FIG. 2 . Still other types of cellular phones may be used. The cellular phone 120 includes a modified FM receiver or FM processing module 200 , which communicates with a wireless interface module 168 of the cellular phone 120 . The FM module 200 continues processing of the FM signals as will be described further below. When the processing is completed, the FM module 200 outputs the processed FM signals to the signal processing and/or control module 152 and/or to the wireless interface module 168 . From the control module 152 , the processed FM signals may be sent to the wireless interface 168 and/or to an audio out 158 . The wireless interface module 168 , in turn, transmits the wireless signals to the wireless interface module 132 via an antenna 167 . The remote device 110 receives the wireless signals and outputs the signals as described above.
The cellular phone 120 in addition to the audio output 158 , which may be a speaker and/or audio output jack, may include a microphone 156 , a display 160 and/or an input device 162 such as a keypad, pointing device, voice actuation and/or other input device. The control module 152 and/or other circuits (not shown) in the cellular phone 120 may process data, perform coding and/or encryption, perform calculations, format data and/or perform other cellular phone functions. The cellular phone in addition to the antenna 167 may have a cellular designated antenna 170 .
The cellular phone 120 may communicate with mass data storage 164 that stores data in a nonvolatile manner such as optical and/or magnetic storage devices for example hard disk drives HDD. The HDD may be a mini HDD that includes one or more platters having a diameter that is smaller than approximately 1.8″.
The cellular phone 120 may be connected to memory 166 such as RAM, ROM, low latency nonvolatile memory such as flash memory and/or other suitable electronic data storage. The cellular phone 120 also may support connections with a WLAN via the wireless interface 168 and/or via an additional wireless interface (not shown). The wireless interfaces may be compliant with one or more of the following IEEE standards 802.11, 802.11a, 802.11b, 802.11g, 802.11h, 802.11n, 802.16, 802.20, and/or Bluetooth. The control module 152 may be integrated with the FM module 200 , the memory 166 into a system on-chip (SOC).
Referring now to FIG. 3A , the remote device 110 may be packaged with a headset 220 , that includes first and second housings 224 and 226 . The first and second housings 224 and 226 enclose speakers 230 and 232 , respectively. The remote device 110 may be packaged with the first and/or second housings 224 and 226 . The housings 224 and 226 may be connected by a “C”-shaped portion 230 , which supports the headset 220 on a user's head. The antenna 126 may be routed through the “C”-shaped portion 230 . The housings 224 and/or 226 may also house batteries 240 , which power the remote device 110 .
Referring now to FIG. 3B , the remote device 110 may be integrated with a headset 250 , which is shown to include first and second earbuds 244 and 246 , respectively. The first and second earbuds 244 and 246 include speakers 230 and 232 , respectively. The earbuds 244 and 246 may include a device (not shown) that physically attaches to attach the earbuds 244 and 246 to the user's ears. The remote device 110 may be integrated with one or both of the earbuds 244 and/or 246 . The earbuds 244 and 246 may be connected by wire 260 . The antenna 126 may be integrated with and/or routed adjacent to the wire 260 . The earbuds 244 and/or 246 may also house batteries 240 , which power the remote device 110 .
Referring now to FIGS. 4A and 4B , the remote device 110 may be attached to and/or inserted in an article of clothing 260 . In FIG. 4A , the article of clothing 260 also includes a speaker 270 and a battery 272 . In FIG. 4B , the earbuds 244 and 246 are connected by wire 260 to the remote device 110 via an output jack thereof. The antenna 126 may be located adjacent to the wire 260 . Still other variations are contemplated.
Referring now to FIGS. 5-7 , several variations relating to the relative arrangement and location of FM receiver components associated with the remote device 110 and/or the cellular phone 120 are shown. In FIG. 5 , a more detailed drawing of the remote device 110 of FIG. 2 is shown. The LNA is located in the remote device 110 . In FIG. 6 , an intermediate frequency (IF) mixer is also located in the remote device 110 in addition to the LNA. In FIG. 7 , the IF mixer and a baseband (BB) mixer are located in the remote device 110 in addition to the LNA.
In FIG. 5 , the antenna 126 receives a RF signal including FM signals. The LNA 128 amplifies the signals and outputs the signals to the A/D converter 130 . Optional filters 300 may be used at the input and/or output of the LNA 128 . The digital signal output by the A/D converter 130 is output to the wireless network interface 132 , which transmits the digital signal to the wireless network interface 168 . The wireless network interface 168 outputs the signal to intermediate frequency (IF) mixers 304 - 1 and 304 - 2 , which also receive a reference signal outputs from an oscillator 308 . Intermediate signal outputs of the IF mixers 304 - 1 and 304 - 2 are optionally filtered by filters 310 and 312 and input to BB mixers 312 - 1 and 312 - 2 , respectively. The BB mixers 312 - 1 and 312 - 2 also receive reference signal outputs from an oscillator 316 . Baseband signal outputs of the BB mixers 312 - 1 and 312 - 2 are optionally filtered by filters 320 and 322 and input to a signal processor 330 , which processes the baseband FM signals.
The processed FM signals are output by the signal processor 330 to the wireless network interface 168 . The wireless network interface 168 transmits the processed signal to the wireless network interface 132 . The wireless network interface 132 outputs the received processed signal to a digital to analog (D/A) converter 142 . The D/A converter 142 outputs the analog signals to an amplifier 144 as described above.
In FIG. 6 , an analog IF mixer 400 is integrated with the remote device 110 . The mixer 400 includes first and second mixers 410 - 1 and 410 - 2 . An analog oscillator 414 outputs oscillator signals to the mixers 410 - 1 and 410 - 2 . Outputs of the mixers 410 - 1 and 410 - 2 are optionally filtered by filters 414 and 416 , respectively and output to the A/D converter 130 .
In FIG. 7 , the analog IF mixer 400 is integrated with the remote device 110 . In addition, an analog BB mixer 430 is integrated with the remote device 110 . The mixer 430 includes first and second mixers 432 - 1 and 432 - 2 . An analog oscillator 434 outputs oscillator signals to the mixers 432 - 1 and 432 - 2 . Outputs of the mixers 432 - 1 and 432 - 2 are optionally filtered (not shown) and output to the A/D converter 130 . As can be appreciated, one or both of the mixers 400 , 430 can be implemented in the digital domain by adjusting the location of the A/D converter 130 in the remote device 110 .
Referring to FIG. 8 , a logic flow diagram illustrating a method of operating a cellular phone system is shown. Although the following steps are primarily described with respect to the embodiment of FIG. 2 , the steps may be easily modified to encompass other embodiments of the present invention, some of which are described above.
In step 500 , a remote device receives FM station data. The FM station data may be received from a user input of the remote device or may be wirelessly received from a cellular phone using wireless interfaces, such as the interfaces 132 , 168 . In step 502 , a tuner of the remote device tunes to a FM station based on the FM station data. In step 504 , FM radio signals are received via a first antenna, such as the antenna 126 . In step 506 , the FM signals are amplified to generate amplified signals. The FM signals may be amplified by a LNA, such the LNA 128 .
In step 508 , the amplified signals are converted into digital signals or preprocessed FM signals. The amplified signals may be converter using an A/D converter, such as the A/D converter 130 . In step 510 , the preprocessed FM signals are wirelessly transmitted as wireless signals to the cellular phone via a second antenna, such as the antenna 133 .
Note that additional steps may be incorporated in between steps 504 - 510 to perform addition FM signal processing as described above and below. For example, additional steps may be incorporated to include the generation of intermediate frequency signals and baseband signals, as well the filtration of such signals.
In step 512 , the preprocessed FM signals are received by the cellular phone as input signals via an antenna, such as the antenna 167 . In step 514 , the preprocessed FM signals are passed through a wireless interface to a FM processing module, such as the FM processing module 200 . In step 516 , the FM processing module or some other cellular phone processor or control module completes the processing of the originally received FM signals. The preprocessed FM signals are converted into processed FM signals.
In step 518 , the processed FM signals from step 116 are transmitted to the remote device for audio output thereof or to an audio output of the cellular phone. Of course, the processed FM signals or data related thereto may be stored in a memory of the cellular phone or in a memory of the remote device.
The above-described method eliminates some of the disadvantages that are associated with the need for a long FM antenna to be directly connected to a cellular phone.
Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, the specification and the following claims.
|
A cellular phone including a transceiver and a processing module. The transceiver receives, from a device separate from the cellular phone, a radio or intermediate frequency signal. The radio frequency signal has been tuned by the device to a selected frequency. The intermediate frequency signal is a downconverted version of the radio frequency signal. Each of the radio and intermediate frequency signals includes the content. The content has been frequency modulated and broadcast at the selected frequency prior to the transceiver receiving the radio or intermediate frequency signal. A processing module downconverts the radio or intermediate frequency signal to a baseband signal and converts the baseband signal to a digital signal. The processing module either forwards the digital signal for audio play out of the content at the cellular phone or forwards the digital signal to the transceiver for transmission of the digital signal back to the device.
| 7
|
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to cosmetic compositions which normally contain purified or distilled water wherein the water has been at least partially replaced by a distillate of a green plant juice. More particularly, the present invention is directed to cosmetic compositions containing at least one cosmetically effective ingredient and a distillate of a green plant juice; and methods of producing the same.
[0003] 2. Description of the Prior Art
[0004] Fresh raw edible green plants are very important foodstuffs for the maintenance of health, but they involve problems concerning edibility, e.g., in that they are tough and hard to digest. In order to solve these problems, various foodstuffs comprising green plant juice squeezed from a fresh raw edible green plant or its dry powder have been proposed in the prior art.
[0005] In the preparation of such dry powders, a large amount of liquid is removed from the green plant juice and then discarded as a waste material.
[0006] The present invention provides a use for this by-product liquid.
BRIEF SUMMARY OF THE INVENTION
[0007] It is an object of the present invention to utilize an otherwise discarded by-product of the manufacture of a dry powder of green plant juice.
[0008] It is a further object of the present invention to provide a cosmetic composition having reduced requirements for preservative materials.
[0009] It is a still further object of the present invention to provide a process for producing a cosmetic composition having reduced requirements for preservative materials.
[0010] These objects of the invention, and others that will become apparent upon reading the disclosure of this invention, are achieved by the provision of an improved cosmetic composition comprising at least one cosmetically effective ingredient and water, wherein the improvement is the replacement of at least a portion of the water by a distillate of a green plant juice.
[0011] Additionally, the present invention provides an improved process for producing a cosmetic composition comprising mixing at least one cosmetically effective ingredient and water, wherein the improvement is the replacement of at least a portion of the water by a distillate of a green plant juice.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] [0012]FIG. 1 is a graph illustrating the antioxidant activity of the distillate of green plant juice as tested in Example 2.
DETAILED DESCRIPTION OF THE INVENTION
[0013] The presently contemplated distillate of a green plant juice is obtained as a by-product of the production of dry powder of green plant juice squeezed from a fresh raw edible green plant.
[0014] In this production process, the leaves and/or stems, preferably leaves and stems, of young green plants are harvested; the harvested materials are washed with water; the washed materials are squeezed to collect a green plant juice; the green plant juice is concentrated (producing the distillate of a green plant juice used in this invention and a concentrate); the concentrate is spray-dried into a powder; and the powder is granulated and packed into jars.
[0015] The green plants which are used as starting materials in the present invention are preferably edible green plants and these include not only cultivated edible plants having green leaves or stems, but also edible wild grasses and herbs having green leaves and stems; plants having green leaves and stems which are not usually eaten, such as fruit, vegetables, root crops, cereals and fruit trees; green edible algae; and the like. Specific examples thereof include green leaves of barley and wheat, spinach, lettuce, cabbage, Chinese cabbage, Japanese cabbage, cucumber, bitter melon, pimento, carrot leaves, radish leaves, parsley, celery, “ashitaba” (Angelica keiskei (Miq.) koidz.), comfrey leaves, green leaves of grasses, (e.g., alfalfa, clover and kale), striped bamboo leaves, persimmon leaves, pine needles, spirulina, chlorella, “wakame seaweed” (Undaria pinnatifida (Harvey) Suringar) and green laver. These plants may be used alone or in combination of two or more.
[0016] Among the foregoing green plants, cereals such as barley, wheat, rye, oats, pearl barley, corn, millet and Italian ryegrass are preferred. Of these, barley (in particular, its leaves and stems before maturation) is most preferred.
[0017] It is desirable to treat these green plants while they are as fresh as possible. Where stored plants are used, it is preferable that they have been subjected to proper measures for the prevention of discoloration and deterioration, such as inert gas storage, cold storage, deaerated and dehydrated storage, or treatment with sulfur dioxide or a sulfite salt. A green plant used as the starting material is thoroughly washed to remove all of the matter adhering thereto, preferably such washing is effected using room temperature water (with no detergents being involved); sterilized with a germicide (e.g., hypochlorous acid), as desired; further washed thoroughly with water; and, optionally, cut to pieces of appropriate size. When cut to pieces, the plant may be soaked in a dilute aqueous solution of sodium chloride (e.g., a 0.1-2% aqueous solution of sodium chloride) and cut therein. Moreover, at any stage of this pretreatment, the plant may be subjected to a blanching treatment at a temperature of 100° C. to 140° C. under atmospheric pressure (or under sub-atmospheric or super-atmospheric pressure in some cases) for about 2 to 10 seconds and then cooled rapidly. This treatment serves to inactivate enzymes which may cause undesirable discoloration or deterioration of green plants (e.g., chlorophyllase, peroxidases and polyphenol oxidase).
[0018] After the green plant is pre-treated in the above-described manner, juice is squeezed therefrom. The squeezing can readily be carried out according to any conventionally known method, for example, by the combined use of a mechanical disintegration means (such as a mixer or juicer) and a solid-liquid separation means (such as a centrifuge or a filter apparatus). Water may be added to the green plant material prior to the squeezing in order to facilitate handling of the green plant material. After the squeezing, the pH of the resulting green juice may be adjusted to a pH of 6.2 to 9.5, preferably 6.5 to 8.5, more preferably, about 6.5 to 7.5, by use of a base.
[0019] Bases which can be used for the above-described pH adjustment include hydroxides, carbonates and bicarbonates of alkali metals and alkaline earth metals, such as sodium hydroxide, calcium hydroxide, magnesium hydroxide, sodium carbonate, potassium carbonate, calcium carbonate and sodium bicarbonate; ammonium hydroxide; glutamic acid salts such as calcium glutamate; and kelp extract.
[0020] At any stage following the separation of the green juice and preceding the drying treatment, the green plant juice may be subjected to a flash heating treatment for decomposing or inactivating undesirable enzymes which will participate in discoloration or deterioration, and also destroying bacteria which may be present therein. This treatment may be carried out under atmospheric, sub-atmospheric or super-atmospheric pressure, using a heating temperature of 90° C. to 150° C. and a treating time of about 180 to 2 seconds. After such a treatment, it is desirable to cool the juice rapidly, particularly to a temperature of 10° C. or below.
[0021] As described previously, the green plant juice having undergone the pH adjustment is spray-dried or freeze-dried, preferably spray-dried, as soon as possible. The spray-drying or freeze-drying may be carried out according to any conventionally known method.
[0022] For example, in the case of spray drying, hot spray drying using hot air at about 120° C. to 200° C., preferably 140° C. to 170° C., or cold spray drying using air dried with a suitable desiccant, e.g., lithium chloride, may be employed. In the case of freeze drying, treating conditions such as drying plate temperature of 40° C. to 50° C. and a vacuum of the order of 1.0 to 0.01 mmHg are usually employed.
[0023] The concentration of the green plant juice (i.e. solids content) used in the drying step should be in the range of about 1.5 to 30% and preferably as high as possible within those limits. In order to concentrate the green juice to this end, a continuous thin-film concentrator or a vacuum distillation apparatus or the like may be used, preferably, a centrifugal-flow, thin-film vacuum evaporator wherein, most preferably, the atmospheric pressure is reduced so as to allow evaporation of water at a temperature of about 40° C. It is the distillate of the green plant juice produced in this concentration step, a by-product normally disposed of as waste, that is utilized in the present invention.
[0024] In the course of the above-described procedures, various means, such as the replacement of air by an inert gas (e.g., nitrogen or argon), the inclusion of an oxygen absorber (e.g., glucose oxidase), maintenance at low temperatures and protection from light, may be used, alone or in any combination, to prevent the green plant juice from being discolored or deteriorated during transfer and storage preceding the drying step.
[0025] The distillate of the green plant juice produced in the concentration step may be utilized in the formulation of cosmetic compositions because of its strong antioxidant and antiseptic properties.
[0026] Cosmetic compositions are preparations applied to the surface of the body for the purpose of enhancing its appearance. These compositions can be make-up preparations, applied to bring about temporary effects, lasting only so long as the preparations remain on the body surface, or treatment preparations, which effect no immediately noticeable change but which, after repeated use, are expected to have a beautifying effect.
[0027] The present distillate of the green plant juice finds particular use in cosmetic compositions containing water, i.e. as a substitute for at least a portion of the pure water or distilled water normally compounded in such compositions. Generally, at least about 25% of the water should be replaced, in order to take advantage of the antioxidant and antiseptic properties of the distillate of the green plant juice, preferably at least about 50%, more preferably at least about 75%, and most preferably 100%.
[0028] The cosmetic compositions of the present invention may be skin care products such as lotions, creams, cleansers, etc. The compositions of the invention may be emulsions of liquid or semi-liquid consistency of the milk type, obtained by dispersion of an oil phase in an aqueous phase or vice versa; or suspensions or emulsions of soft consistency of the cream type.
[0029] All oils used in the production of cosmetic compositions are suited for use in the compositions of the present invention. There may be mentioned hydrocarbons such as mineral oils, petrolatum and squalane; animal and vegetable triglycerides such as almond oil, peanut oil, wheat germ oil, linseed oil, jojoba oil, oil of apricot pits, oil of walnuts, oil of palm nuts, oil of pistachio nuts, oil of sesame seeds, oil of rapeseed, cade oil, corn oil, peach pit oil, poppyseed oil, pine oil, castor oil, soybean oil, avocado oil, safflower oil, coconut oil, hazelnut oil, olive oil, grapeseed oil, and sunflower seed oil; hydroxy-substituted C 8 -C 50 unsaturated fatty acids and esters thereof; C 1 -C 24 esters of C 8 -C 30 saturated fatty acids such as isopropyl myristate, cetyl palmitate and octyldodecylmyristate (Wickenol 142); beeswax; saturated and unsaturated fatty alcohols such as behenyl alcohol and cetyl alcohol; fatty sorbitan esters; lanolin and lanolin derivatives; C 1 -C 24 esters of dimer and trimer acids such as diisopropyl dimerate, diisostearylmalate, diisostearyldimerate and triisostearyltrimerate; and silicones such as water-insoluble silicones inclusive of non-volatile polyalkyl and polyaryl siloxane gums and fluids, volatile cyclic and linear polyalkylsiloxanes, polyalkoxylated silicones, amino and quaternary ammonium modified silicones, rigid cross-linked and reinforced silicones and mixtures thereof.
[0030] While the distillate of the green plant juice of the present invention has antioxidant properties which may allow the preparation of compositions without the addition of other antioxidants, it is possible to use standard antioxidants such as t-butyl hydroquinone, butylated hydroxytoluene and α-tocopherol and its derivatives in the cosmetic compositions of the present invention, preferably, in amounts less than would normally be utilized.
[0031] Similarly, while the distillate of the green plant juice of the present invention has antiseptic properties, which may allow the preparation of compositions without the addition of other preservatives, it is possible to use standard preservatives such as methyl, ethyl, propyl, butyl and isobutyl p-hydroxybenzoate (parabems), 2-phenoxyethanol, sorbic acid, potassium sorbate, hexamidine diisothionate, imidazolidinylurea (Germall 115) or preservatives marketed under the names Kathon and Tridssan.
[0032] A wide variety of optional ingredients such as non-occlusive moisturizers, humectants, gelling agents, neutralizing agents, perfumes, coloring agents and surfactants can be added to the presently contemplated cosmetic compositions.
[0033] A humectant may be present in an amount of from about 0.1% to about 20%, preferably from about 1% to about 10% and especially from about 2% to about 5% by weight of the total composition. Suitable humectants include sorbitol, propylene glycol, butylene glycol, hexylene glycol, ethoxylated glucose derivatives, hexanetriol, glycerine, water-soluble polyglycerylmethacrylate lubricants (e.g., compositions available under the trademark Lubrajel) and panthenols (e.g. D-panthenol).
[0034] A hydrophilic gelling agent may be present in an amount of from about 0.01% to about 10%, preferably from about 0.02% to about 2% and especially from about 0.02% to about 0.5% by weight of the total composition. Suitable hydrophilic gelling agents include cellulose ethers (e.g., hydroxyethyl cellulose, hydroxypropylmethyl cellulose), polyvinylalcohol, guar gum, hydroxypropyl guar gum and xantham gum, as well as the acrylic acid/ethyl acrylate copolymers and the carboxyvinyl polymers sold under the trademark Carbopol.
[0035] Neutralizing agents, suitable for use in neutralizing acidic group containing hydrophilic gelling agents, include sodium hydroxide, potassium hydroxide, ammonium hydroxide, monoethanolamine, diethanolamine and triethanolamine.
[0036] Other optional materials include keratolytic agents such as salicylic acid; proteins and polypeptides and derivatives thereof; soluble or colloidally-soluble moisturizing agents such as hylaronic acid and starch-grafted sodium polyacrylates; coloring agents; perfumes and perfume solubilizers; surfactants/emulsifiers such as fatty alcohol ethoxylates and ethoxylated polyol fatty acid esters; and pigments which can be organic or inorganic and which include materials having a low color or lustre, such as matte finishing agents, and also light scattering agents.
[0037] The compositions of the present invention may be prepared by any conventional technique for preparing a cosmetic composition by merely substituting the distillate of green plant juice for the water normally incorporated into the composition.
[0038] The following examples are illustrative and are not intended to limit the invention in any way.
EXAMPLE 1
[0039] Young green leaves of barley (i.e., leaves and stems of barley before maturation) are thoroughly washed with water, disintegrated with a mixer, and squeezed. A green juice is obtained by filtering off fibrous residue. The green juice is vacuum distilled (pressure=about 55 mm Hg) in a centrifugal-flow-thin-film vacuum evaporator (EVAPOR®, Model No. CEP-305, made by Okawara Mfg. Co., Ltd. Shizuoka, Japan), the juice being poured on to the conical evaporating surface, rotating at 300 to 500 RPM, to form a thin film of about 0.1 mm thickness, with a residence time on the evaporating surface of only about one second. The outside of the rotating conical evaporating surface is jacketed and heated evenly by steam (inlet temp.=130° C., outlet temp.=80° C.). A tube at the edge of the rotating evaporating surface collects concentrate.
[0040] The distillate is a clear watery liquid with a very slightly greenish color and a refreshing grassy odor.
[0041] An analysis was conducted according to an internal standard method as described by L. S. Ettre in The Practice of Gas Chromatography , Ettre, L. S., Zlatkis, A., Eds., Interscience Publishers: New York, 1967, p. 402. A Hewlett-Packard model HP5890 Series II gas chromatograph equipped with a 60 m×0.25 mm i.d. (d γ =1 μm) DB-WAX bonded-phase fused silica capillary column (J&W Scientific, Folsom, Calif.) was used and interfaced to an HP5791A mass selective detector for mass spectral identification of the components. The linear velocity of the helium carrier gas was 30 cm/sec, the oven temperature was programmed from 50° C. to 200° C. at 3° C./min and held for 40 minutes, and the ionization voltage for mass spectral identification was 70 eV.
[0042] An analysis is shown in Table A.
TABLE A No. R. TIME R. Index CONC COMPOUNDS 1 2.762 0 0.01 2 2.860 0 0.00 3-methyl-1-butene 3 2.908 0 0.00 4 2.962 0 0.01 5 3.060 600 0.00 6 3.317 702 0.01 acetaldehyde 7 3.950 792 0.18 propanal 8 4.291 820 0.01 9 4.486 833 0.01 10 4.603 841 0.00 11 5.458 900 0.02 12 5.560 904 0.02 butanal 13 6.362 933 0.01 14 6.511 939 0.00 15 6.701 945 0.08 2-ethylfuran 16 7.022 957 0.00 17 7.428 972 0.54 3-pentanone 18 7.548 977 0.01 19 7.638 980 0.01 20 7.824 987 0.02 2-methyl-3-buten-2-one 21 8.101 997 0.02 22 8.557 1009 0.01 2-methyl-2-butanol 23 8.992 1019 7.42 1-penten-3-one 24 9.280 1025 0.00 25 9.430 1029 0.00 26 9.573 1032 0.02 (E)-2-butenal 27 9.780 1037 0.00 28 9.850 1039 0.00 29 10.023 1043 0.00 30 10.423 1052 0.03 2,3-pentanedione 31 10.751 1059 0.00 32 11.279 1072 0.01 33 11.465 1076 0.42 hexanal 34 11.749 1083 0.01 35 12.594 1102 0.02 36 12.850 1106 0.00 37 13.013 1109 0.04 3-pentanol 38 t 2-pentanol 39 13.769 1123 0.82 (E)-2-pentenal 40 14.287 1132 0.10 (E)-3-hexenal 41 14.585 1137 0.22 (Z)-3-hexenal 42 16.226 1166 22.12 1-penten-3-ol 43 16.540 1172 0.00 44 16.939 1179 0.02 3-penten-2-ol 45 17.565 1190 0.01 46 17.930 1196 0.21 (Z)-2-hexenal 47 19.341 1219 14.55 (E)-2-hexenal 48 20.369 1235 0.05 49 21.431 1252 0.17 pentanol 50 22.560 1269 0.01 51 23.141 1279 0.08 3-hydroxybutan-2-one 52 23.720 1288 0.01 53 24.040 1293 0.00 54 24.280 1296 0.00 55 25.430 1314 0.42 (E)-2-pentenol 56 26.564 1332 34.67 (Z)-2-pentenol 57 27.160 1341 0.07 58 27.480 1346 0.05 59 28.176 1356 0.37 hexanol 60 28.176 1356 0.05 2-hydroxypentan-3-one 61 28.757 1365 0.15 (E)-3-hexenol 62 63 30.263 1388 4.27 (Z)-3-hexanol 64 30.708 1395 0.14 (E,E)-2,4-hexadienal 65 31.200 1403 0.02 66 31.578 1408 0.82 (E)-2-hexanol 67 32.330 1420 0.03 (E)-2-octenal 68 34.345 1451 0.03 1-octen-3-ol 69 34.776 1458 0.21 (E,Z)-2,4-heptadienal 70 36.537 1485 0.11 (E,E)-2,4-heptadienal 71 36.537 1485 0.01 (Z)-1,5-octadlen-3-ol 72 36.920 1491 0.01 2-ethylhexanol 73 38.418 1515 0.18 74 38.920 1523 0.17 75 t propanoic acid 76 39.669 1535 0.12 4-oxohexanal 77 40.000 1540 0.06 78 41.251 1560 0.56 octanol 79 42.080 1574 0.02 80 42.386 1579 0.04 (E,Z)-2,6-nonadienal 81 42.897 1587 0.19 82 43.389 1595 0.12 2-hydroxy-2,6,6- trimethylcyclohexanone 83 43.800 1601 0.02 84 44.215 1608 0.39 85 44.720 1617 0.09 beta-cyclocitral 86 45.445 1629 0.12 87 46.160 1641 0.03 3-hydroxyoctan-2-one 88 46.649 1649 0.28 89 47.640 1666 0.00 90 48.123 1674 0.07 5-methyl-2(5H)-furanone 91 49.006 1689 1.62 92 49.923 1704 0.43 93 51.000 1723 0.00 94 51.440 1731 0.02 95 51.920 1739 0.01 96 52.533 1750 0.38 5-ethyl-2(5H)- furanone (T) 97 52.799 1755 0.14 98 53.314 1764 0.24 99 54.303 1781 0.04 100 54.678 1788 0.14 101 55.197 1797 0.03 102 55.921 1810 0.10 103 56.440 1819 0.06 104 57.130 1832 0.13 105 57.517 1839 0.10 106 58.040 1849 0.03 hexanoic acid 107 58.640 1860 0.00 108 58.910 1864 0.04 109 59.375 1873 0.05 110 59.375 1873 0.11 111 59.960 1884 0.01 (E,E,E)-2,4,6-nonatrienal 112 60.400 1892 0.02 113 60.734 1898 0.02 114 61.250 1908 0.09 phenylethyl alcohol 115 61.720 1917 0.06 116 62.414 1930 0.26 117 62.829 1938 0.15 beta-ionone 118 63.429 1949 0.07 119 63.884 1958 0.08 120 64.246 1965 0.61 121 64.906 1978 0.40 122 65.312 1985 0.15 5,6-epoxy-beta-ionone 123 65.920 1997 0.24 124 66.895 2016 0.07 125 67.461 2028 0.17 126 68.800 2055 0.02 127 69.135 2061 0.04 128 69.480 2068 0.01 129 70.035 2079 0.03 130 70.413 2087 0.06 131 70.966 2098 0.04 2,6-di-tert-butyl-4- hydroxy-4-methyl-2,5- cyclohexadlen-1-one (T) 132 71.600 2111 0.29 133 72.179 2123 0.07 134 72.763 2135 0.05 135 73.245 2145 0.04 136 74.000 2161 0.03 137 74.400 2169 0.02 138 75.257 2187 0.40 139 75.610 2195 0.14 140 76.782 2220 0.09 141 77.497 2235 0.01 142 77.920 2244 0.01 143 78.342 2254 0.04 144 78.778 2263 0.03 145 79.347 2275 0.02 146 79.680 2283 0.01 147 80.026 2290 0.02 148 81.920 2331 0.03 dihydroactinidiolide 149 81.920 2331 0.03 150 82.664 2347 0.04 151 83.417 2363 0.01 diethyl phthalate 152 84.629 2389 0.02 153 85.118 2400 0.04 tetracosane 154 85.587 2408 0.07 155 86.787 2429 0.03 156 87.360 2439 0.01 157 87.677 2445 0.05 158 88.980 2468 0.02 159 90.141 2489 0.05 160 91.346 2508 0.02 pentacosane 161 92.293 2521 0.03 phytyl acetate 162 93.018 2531 0.02 diisobutyl phthalate 163 93.491 2538 0.01 164 93.791 2542 0.01 165 94.411 2551 0.01 vanillin 166 94.960 2559 0.01 167 95.497 2566 0.01 168 95.987 2573 0.01 169 96.586 2581 0.01 170 97.234 2590 0.10 octadecanol 171 97.880 2599 0.01 hexacosane 172 98.820 2610 0.07 phytol 173 100.251 2625 0.01 4-hydroxy-3- methoxyacetophenone 174 101.071 2634 0.03 175 102.299 2647 0.05 176 103.240 2657 0.01 177 105.148 2677 0.01 178 105.790 2684 0.04 179 106.463 2691 0.15 dibutyl phthalate 180 107.278 2700 0.01 heptacosane 181 109.078 2714 0.01 182 114.139 2755 0.02 183 118.800 2793 0.17 bis(2-ethylhexyl) adipate
EXAMPLE 2
[0043] 250 ml of the distillate produced by the technique of Example 1 is extracted with 50 ml of dichloromethane using a liquid-liquid continuous extractor for 6 hours. The solvent is separated from the extract by using a rotary evaporator and further condensation is achieved under a purified nitrogen stream.
[0044] The extract is examined for antioxidative activity using an aldehyde/acid oxidation system. The method used is based on the auto-oxidation of aldehydes to carboxylic acids with active oxygen species such as hydroxy radical as discussed in Autoxidation of various organic substances , Horner, L., Autoxidation and Antioxidants , Lundberg, W. O., Ed., John Wiley & Sons, New York, 1961, pp. 197-202. The results, illustrated in FIG. 1, show that the extract inhibited oxidation of hexanol more than two weeks at the level of 50 ppm. This activity is almost equal to that of the well-known antioxidant, α-tocopherol.
[0045] A gas chromatogram of the extract shows more than 100 peaks, suggesting that the distillate contains many volatile chemicals some of which possess a potent antioxidant activity.
EXAMPLE 3
[0046] The distillate produced by the technique of Example 1 is passed through a 0.45 μm membrane filter to remove any barley juice residues.
[0047] Apples are peeled and immersed in regular tap water, filtered distillate or tap water containing salt for five minutes. The apples are then taken out and allowed to sit for 1 hour, whereupon their color is determined. The results are set forth in Table 1.
TABLE 1 IMMERSION LIQUID COLOR Tap Water 80% of the surface becomes brown or tan Filtered Distillate less than 5% of the surface becomes brown Tap Water Containing Salt less than 5% of the surface becomes brown
EXAMPLE 4
[0048] Cut tulips are kept in tap water or the filtered distillate as in Example 3. The water and the filtered distillate are changed every other day. The result is shown in Table 2.
TABLE 2 Number of Days That Liquid Tulips Lasted Tap Water 5 Filtered Distillate 10
[0049] The tulips in filtered distillate last longer and are in better condition than those in tap water.
EXAMPLE 5
[0050] Two facial toners are prepared as set forth in Table 3.
TABLE 3 TONER INGREDIENT A (1) B Butylene glycol 60 g 60 g Sorbitol 20 g 20 g Glycerin 20 g 20 g Methylparaben 0.6 g 0.3 g Phenoxyethanol 0.5 g 0.5 g Sodium citrate 0.1 g 0.1 g Butylparaben 0.1 g 0.05 g Propylparaben 0.1 g 0.05 g Citric acid 0.02 g 0.02 g Distilled H 2 O balance — Filtered Distillate (Ex. 3) — balance Total 1,000 g 1,000 g
[0051] 18 ml. of toner A, 18 ml of toner B and 18 ml of a toner having the same formulation as toner A except for being devoid of preservatives are each inoculated with 2 ml of Staphylococcus aureus solution (Staphylococcus aureus in sterile diluent (pepton, lecithin, distilled water) at a concentration between 1×10 6 and 1×10 7 ) to make sample solutions A, B and C, respectively. Sample A, B and C are allowed to stand at room temperature and sampled at day 0, day 1, day 3, day 7, day 14 and day 21. Each time 1 ml of solution is taken and general bacteria plate count tests are performed. In the plate count tests, 1 ml. of sample solution and 20 ml of media are placed in a Petri dish, cultivated at 36° C. for 48 hours, and the number of colonies reported. Serial dilutions, such as 1/10, 1/100, 1/1000, etc., are done if the colonies number more than 200 and the test procedures are repeated. The results are set forth in Table 4.
TABLE 4 SAMPLE A B C Day 0 2.7 × 10 5 1.5 × 10 5 1.5 × 10 5 Day 1 6.8 5.5 2.5 × 10 4 Day 3 0 0.5 5.9 × 10 7 Day 7 0 0 3.3 × 10 7 Day 14 0 0 4.9 × 10 7 Day 21 0 0 2.4 × 10 7
[0052] Samples A and B have similar antibacterial activities. Therefore, filtered distillate may be used in a cosmetic product to reduce the required amount of preservatives.
EXAMPLE 6
[0053] A toner having the following composition is prepared using the filtered distillate as in Example 3.
95% Ethanol 100 g Methyl p-hydroxybenzoate 0.05 g Perfume 0.5 g Colorant 0.005 g Filtered distillate Balance 1,000 g
[0054] This toner is used everyday after washing the face in the morning and before sleeping to examine the effect on spots and freckles. Evaluation was effected by comparing spots and freckles before and after a 6-week application period. The results obtained on a panel of 20 women are shown in Table 5.
TABLE 5 EFFECT COLOR (1) BOUNDARY (2) Effective 5 7 Slightly effective 7 8 No effect 8 5
[0055] (2) boundary between snot or freckle and other regular skin areas
[0056] Boundary apparent No effect
[0057] Boundary unclear Slightly effective
[0058] Boundary almost undiscernible Effective
|
An improved cosmetic composition comprises at least one cosmetically effective ingredient and water, where at least a potion of the water has been replaced by a distillate of a green plant juice. The distillate is obtained from a green plant juice, produced by squeezing green plants, by evaporation of the green plant juice to cause a concentration increase of the green plant juice.
| 0
|
CROSS REFERENCES TO RELATED APPLICATIONS
The present application is a continuation of U.S. patent application Ser. No. 14/713,090, filed on May 15, 2015, and issued on May 31, 2016, as U.S. Pat. No. 9,352,199, which is a continuation of U.S. patent application Ser. No. 14/159,262, filed on Jan. 20, 2014, and issued on Jun. 30, 2015, as U.S. Pat. No. 9,067,110, which claims priority to U.S. Provisional Patent Application No. 61/886,473, filed on Oct. 3, 2013, and is a continuation-in-part of U.S. patent application Ser. No. 14/039,102, filed on Sep. 27, 2013, and issued on Sep. 16, 2014, as U.S. Pat. No. 8,834,294, which is a continuation of U.S. patent application Ser. No. 13/797,404, filed on Mar. 12, 2013, now abandoned, which claims priority to U.S. Provisional Patent Application No. 61/657,247, filed on Jun. 8, 2012, U.S. Provisional Patent Application No. 61/665,203 filed on Jun. 27, 2012, and U.S. Provisional Patent Application No. 61/684,079 filed on Aug. 16, 2012, the disclosure of each of which is hereby incorporated by reference in its entirety herein. U.S. patent application Ser. No. 14/159,262 also is a continuation in part of U.S. patent application Ser. No. 13/906,572, filed on May 31, 2013, and issued on Feb. 17, 2015, as U.S. Pat. No. 8,956,244, the disclosure of which is also hereby incorporated by reference in its entirety herein.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to a golf club head comprising a center of gravity height adjustability assembly.
Description of the Related Art
The prior art discloses various designs with center of gravity adjustments to improve golf club performance, but fails to provide designs that efficiently alter center of gravity parameters while at the same time contributing to an improved impact event with the golf ball.
The United States Golf Association (USGA) has increasingly limited the performance innovations of golf clubs, particularly drivers. Recently, the USGA has limited the volume, dimensions of the head, such as length, width, and height, face compliance, inertia of driver heads and overall club length. Current methods previously used to improve the performance of a driver have been curtailed by limitations on design parameters set by the USGA. An area of driver performance improvement that exists, as of this date, is the potential to adjust the height of the center of gravity. A change in height of the center of gravity changes the amount of backspin provided with a given impact. A higher center of gravity increases spin, while a lower center of gravity decreases spin.
The recent past has shown that driver designs have trended to include characteristics to increase the driver's inertia values to help off-center hits go farther and straighter. Driver designs have also recently included larger faces, which may help the driver deliver better feeling shots as well as shots that have higher ball speeds if hit away from the face center. However, these recent trends may also be detrimental to the driver's performance due to the head speed reductions that these design features introduce due to the larger geometries. The design of the present invention allows for the higher inertias and robust face design of current drivers while at the same time providing center of gravity is adjustability.
BRIEF SUMMARY OF THE INVENTION
One purpose of this invention is to effectively incorporate several design features in the golf club head that will enable both adjustment and optimization of the height of the center of gravity. Another object of the present invention is an adjustable weighting feature for vertical center of gravity control which is entirely concealed from view at address. To improve achieve these goals, a golf club head with an internal center of gravity height adjustment assembly is provided, which affects the moment of inertia and ultimately the forgiveness of the golf club head.
One aspect of the golf club head of the present invention comprises a body having a crown, a sole, a face and a hosel, wherein the body defines a hollow interior, and a center of gravity height adjustment assembly that is positioned within the hollow interior of the body. Preferably, the location of the center of gravity of the golf club head can be adjusted by 0.050-0.100 inch along any axis, but preferably along a vertical Z axis.
Another aspect of the present invention is a golf club head comprising a face, a crown, a sole, a hollow tube, a cap screw, and a cartridge comprising a first material having a first specific gravity and a second material having a second specific gravity that is at least three times the value of the first specific gravity, wherein the tube is disposed within a hollow interior of the golf club head and extends from the crown to the sole, wherein the cartridge is sized to fit within the tube, wherein the tube is accessible via an opening in one of the crown and the sole, and wherein changing the orientation of the carrier within the tube changes the location of the golf club head's center of gravity along a vertical Z axis. In some embodiments, the first material may be selected from the group consisting of a glass filled epoxy, a glass filled polyester, and a glass-filled nylon, and the second material may be tungsten. In another embodiment, the cap screw may comprise external threads, the opening may comprise internal threads, and the cap screw may be sized to fit within the opening such that the external threads engage with the internal threads. In another embodiment, the cap screw may comprise a plurality of cutouts.
In other embodiments, the cartridge may comprise a first end and a second end, and each of the first and second ends may have a shape selected from the group consisting of conically tapered, rounded tapered, and circular. In some further embodiments, the second material may be disposed at the first end, such that the first end is heavier than the second end. In another embodiment, the first end may comprise a first color, and the second end may comprise a second, different color. In another embodiment, the cap screw may comprise a plurality of cutouts, and a portion of the first end or the second end of the cartridge may be visible through the cutouts.
In still other embodiments, the crown may comprise an edge support structure sized to receive an end of the hollow tube. In another embodiment, the face may have a frequency of 3000 to 4010 Hz, and the sole may have a frequency of 2500 to 3100 Hz. In another embodiment, the cartridge may be compressed between the crown and the sole, and the tube may be in tension between the crown and the sole. In a further embodiment, the cap screw may place a compression load on the cartridge that exceeds 50 lbs. In another embodiment, the golf club head may further comprise a first cartridge cap comprising a first color and a second cartridge cap comprising a second color, the first cartridge cap may be affixed to the first end of the cartridge, the second cartridge cap may be affixed to the second end of the cartridge, and the first color may be different from the second color. In a further embodiment, the cap screw may comprise a plurality of cutouts, and a portion of the first cartridge cap or the second cartridge cap may be visible through the cutouts.
Another aspect of the present invention is a golf club head comprising a body comprising a face, a sole, a rear portion, and a hollow interior, and a hollow tube, wherein the hollow tube is disposed within the hollow interior, and wherein the golf club exhibits one distinguished sound peak that has a frequency of at least 3000 Hz and an amplitude that is at least 8 decibels greater than any other sound peak. In some embodiments, the hollow tube may be disposed closer to the face than to the rear portion. In other embodiments, the face may have a frequency of 3000 to 4010 Hz, and the sole may have a frequency of 2500 to 3100 Hz. In another embodiment, the hollow tube may not extend between the crown and the sole.
Yet another aspect of the present invention is a driver-type golf club head comprising a metal body comprising a face and a sole, a composite crown, a hollow tube, a cap screw, and a cartridge comprising a first material having a first specific gravity and a second material having a second specific gravity that is at least three times the value of the first specific gravity, wherein the tube is disposed within a hollow interior of the golf club head, wherein the cartridge is sized to fit within the tube, wherein the cap screw places a compression load on the cartridge that exceeds 50 lbs, and wherein changing the orientation of the carrier within the tube changes the location of the golf club head's center of gravity by at least 0.050 inch.
Another aspect of the present invention is a golf club head comprising a body comprising a face, a sole, and an interior cavity, and an adjustable cartridge that can be removably affixed in the interior cavity in more than one orientation, wherein a distance between a center of gravity of the cartridge and a geometric centroid of the cartridge is defined as ½D, wherein a weight of the cartridge is defined as M T , wherein the combined weight of the body and the cartridge is defined as M, and wherein D≧0.065(1+M/M T ).
Having briefly described the present 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
FIG. 1 is a top perspective view of a golf club head according to the present invention.
FIG. 2A is a cross sectional view of the golf club head shown in FIG. 1 along lines 2 - 2 , without a cartridge in the tube.
FIG. 2B is a cross sectional view of the golf club head shown in FIG. 1 along lines 2 - 2 , with a cartridge in the tube.
FIGS. 3A, 3B, and 3C are cross sectional views of different cartridges that may be used with the golf club head of the present invention.
FIG. 4 is a cross-sectional view of another cartridge engaged with the golf club of the present invention that illustrates the forces placed on the tube and cartridge.
FIG. 5 is an enlarged view of the circled portion in FIG. 2B .
FIG. 6 is a top plan view of a screw cap according to one embodiment of the present invention.
FIG. 7 is a cross-sectional view of the screw cap shown in FIG. 6 along lines 7 - 7 .
FIGS. 8A and 8B are rear and front perspective views of the screw cap shown in FIG. 6 .
FIGS. 9A, 9B, and 9C are side plan, top plan, and cross-sectional views of a cartridge cap according to one embodiment of the present invention.
FIG. 10 is a top plan view of the screw cap shown in FIG. 6 engaged with the cartridge cap shown in FIG. 9A .
FIG. 11 is a cross sectional view of the screw cap and cartridge cap shown in FIG. 10 along lines 11 - 11 .
FIG. 12 is a sole perspective view of the golf club head shown in FIG. 1 .
FIG. 13 is a top perspective view of the golf club head shown in FIG. 1 without its crown.
FIG. 14 is a side perspective view of the center of gravity height adjustment assembly of the present invention comprising a tube and a cartridge wherein the distance from the midpoint of the tube to the center of gravity is shown.
FIG. 15 is a plan view of an inner surface of the crown of the golf club head shown in FIG. 1 .
FIG. 16 is a chart comparing sound results of the preferred embodiment of the present invention with two other adjustable weight drivers that do not include the center of gravity adjustment assembly of the present invention.
FIG. 17 is a transparent, top perspective view of an alternative embodiment of the golf club head of the present invention.
FIG. 18 is a transparent, top perspective view of an alternative embodiment of the golf club head of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
A preferred embodiment of the golf club head 10 of the present invention is shown in FIGS. 1-2A, 2B, 12, and 13 . The golf club head 10 includes a crown 30 , sole 40 , face 50 , adjustable hosel 60 , and interior cavity 70 , and a center of gravity height adjustment assembly 100 positioned within the interior cavity 70 and completely obscured from view when the golf club head 10 is viewed from above and at address. As shown in FIGS. 2A and 2B , the center of gravity height adjustment assembly 100 comprises a hollow tube 110 and a removable cartridge 120 . The tube 110 preferably is composed of a carbon composite material, but in alternative embodiments may be composed of Kevlar, fiberglass, plastic, and/or glass-filled plastic (including glass-filled nylon and polycarbonate), and has an extremely low weight, preferably under 5 grams, and more preferably approximately 2 grams. The tube 110 extends from the crown 30 to the sole 40 , has a length of less than 3.8 inches, and preferably is accessed via an opening 45 in the sole 40 , but in alternative embodiments may be accessible via the crown 30 as well as, or instead of, the sole 40 . The center of gravity height adjustment assembly 100 is disposed closer to the face 50 than the rearmost portion 55 of the golf club head 10 .
The cartridge 120 is sized to fit snugly within the tube 110 , and is composed of at least two different materials. The first material 122 preferably is a polymer material, such as urethane, or more preferably a glass-filled plastic, nylon, or epoxy, while the second material 124 , which preferably is a tungsten alloy, has a specific gravity that is at least three times greater than the specific gravity of the first material 122 . As shown in FIG. 2B , the second material 124 preferably is provided in the form of a slug 124 , which is disposed at a first end 121 of the cartridge 120 such that the cartridge 120 has a heavy side 128 and a light side 129 . The slug 124 includes a tapered end 125 that has the same dimensions as the second end 123 of the cartridge 120 , which is also tapered. The tapering on the second end 123 of the cartridge 120 can be provided by a separate cartridge cover 126 , as shown in FIG. 4 , but is preferably integrally formed with the first material of the cartridge 120 . While the slug 124 and cartridge 120 ends 125 , 123 are preferably sharply conically tapered as shown in FIGS. 2B and 3A , they may have rounded tapering as shown in FIG. 3B , or be circular as shown in FIG. 3C .
When the cartridge 120 is fully inserted into the tube 110 , it is retained therein with a cap screw 130 . The opening 45 in the sole 40 comprises internal threads 46 , and the cap screw 130 comprises external threads 132 that mate with the internal threads 46 of the opening 45 in the sole 40 . When the cap screw 130 is fully screwed into the opening, the inner surface 134 of the cap screw 130 abuts whichever end 123 , 125 of the cartridge 120 is proximate the sole 40 and presses the cartridge 120 against the interior surface 32 of the crown 30 . Therefore, the cartridge 120 is placed in compression when it is properly disposed in the tube 110 and when the cap screw 130 is torqued with a wrench or other such tool. The cap screw 130 preferably places a compression load on the cartridge 120 that exceeds 50 lbs. In contrast, the tube 110 preferably is slightly shorter in length than the distance between the crown 30 and the sole 40 , such that the tube 110 is in tension, as shown in FIG. 4 .
In addition to providing the function of trapping and compressing the cartridge 120 within the tube 110 , the cap screw 130 of the preferred embodiment also includes a window feature that allows a user to view the orientation of the cartridge 120 within the tube 110 without having to remove the cap screw 130 and the cartridge 120 from the golf club head 10 . As shown in FIGS. 5-8B , the cap screw 130 includes cutouts 131 , 133 , 135 in the cap screw 130 that may be filled in with a translucent material such as glass or plastic or, in the preferred embodiment, be left open to reduce the overall weight of the golf club head 10 . The cartridge ends 123 , 125 preferably are painted different colors or are marked to indicate orientation, such that when a user looks at the cap screw 130 , he or she can see the colors or markings through one or more of the cutouts 131 , 133 , 135 and infer the orientation of the cartridge 120 within the tube 110 .
In another embodiment, an additional cartridge cap 140 , an example of which is shown in FIGS. 9A-9C , may be affixed to both ends 123 , 125 of the cartridge 120 . This cartridge cap 140 includes a cavity 145 to receive the ends 123 , 125 of the cartridge 120 , and projections 141 , 142 , 142 that extend into the cutouts 131 , 133 , 135 of the cap screw 130 when these two parts 130 , 140 are engaged with one another, as shown in FIGS. 10 and 11 , thus closing the cutouts 131 , 133 , 135 off and preventing debris from entering the cap screw 130 when the golf club head 10 is in use. Each cartridge cap 140 preferably is painted a different color so that a user can immediately determine, upon looking at the cap screw/cartridge cap 130 , 140 combination, how the cartridge 120 is oriented within the tube 110 .
In another embodiment, shown in FIG. 12 , the cap screw 130 is encircled by a separate sole plate 150 , which preferably is attached to the sole 40 of the golf club head 10 beneath the center of gravity height adjustment assembly 100 . In some embodiments, this sole plate 150 includes an uneven surface for the purpose of adjusting the face angle of the golf club head 10 .
As shown in FIGS. 12 and 13 , the preferred embodiment of the present invention includes at least two weight ports 160 , 170 , one on each side of the center of gravity adjustment assembly 100 , which are sized to receive removable weights 165 , 175 . Alternative embodiments may include additional weight ports disposed in the crown 30 , sole 40 , or ribbon/skirt area (not shown) of the golf club head.
In the preferred embodiment, the golf club head 10 and cartridge 120 have a mass M, the cartridge 120 has a length L and a mass M T , the distance from the midpoint of the length L to a center of gravity 200 of the cartridge when the cartridge 120 is disposed within a club head 10 is defined as ½D as shown in FIG. 14 , and the golf club head 10 satisfies the equation D≧0.065(1+M/M T ). In other embodiments, the cartridge 120 can be placed or affixed to the golf club head 10 at more than one orientation and has a distance between its geometric centroid and its center of gravity 200 of ½D, and when combined with a golf club head 10 satisfies the equation D≧0.065(1+M/M T ) in which the M is mass of the golf club head 10 and cartridge 120 and M T is the mass of the cartridge 120 .
In the preferred embodiment disclosed herein, the interior surface 32 of the crown 30 includes a ring-shaped edge support structure 35 to hold the weighting system. This edge support structure 35 preferably is integrally molded from the crown 30 parent material, which preferably is a composite, but may in alternative embodiments be secondarily bonded to the crown 30 . The edge support structure 35 preferably includes two ribs 37 , 38 with a width of approximately 0.090 inch, a length of 0.407 inch, and a height of 0.236 inch, and serves to increase stiffness of the crown 30 to counteract the mass effect of the center of gravity height adjustment assembly 100 , thus mitigating effects on vibrational behavior. In this manner the edge support structures 35 serve two functional roles; stiffener and tube 110 holder.
The edge support structure 35 also affects the sound of the golf club head 10 when it impacts a golf ball, as do other weights that are affixed to the golf club head 10 . In particular, varying the amount of weight in the crown 30 and sole 40 has an effect on driver sound at impact. A relatively flexible weight will mass load the crown, thus affecting vibration modes with significant crown participation. This effect can be mitigated by the use of the edge support structure 35 and matching the stiffness of the center of gravity height adjustment assembly 100 to the local crown 30 structure.
The center of gravity adjustment height assembly 100 beneficially affects the sound of the golf club head 10 . The presence of the center of gravity adjustment assembly 100 , and particularly the tube 110 , has a positive effect on the sound and feel of the golf club head 10 during performance. The tube 110 also increases the stiffness of the sole 40 , and thus reduces the sound made by the sole 40 when the golf club head 10 strikes a golf ball, particularly when the tube 110 is disposed proximate the face 50 of the golf club head 10 like in the preferred embodiment. The sole 40 has a sound mode that is split into a higher frequency mode and a lower frequency mode, both of which have lower amplitudes when a tube 110 is located closer to the face 50 than to the rearmost portion 55 of the golf club head 10 as shown in FIGS. 2A and 2B . Tables 1 and 2 show sound measurements taken at three points on a traditional golf club head and the preferred embodiment of the golf club head 10 .
TABLE 1
MODE
sole
face
Traditional
Golf Club
Head
frequency (Hz)
A
2810
B
3940 (baseline)
Amplitude (dB)
109
104 (baseline)
Preferred
Embodiment
frequency (Hz)
1
2520
2
3100
3
4010
Amplitude (dB)
96.1
97.9
102
TABLE 2
MODE
sole
face
Traditional
Golf Club
Head
frequency (Hz)
A
71%
B
100% (baseline)
Amplitude (dB)
105%
100% (baseline)
Preferred
Embodiment
frequency (Hz)
1
64%
2
79%
3
102%
Amplitude (dB)
92%
94%
98%
As shown in Tables 1 and 2, the center of gravity height adjustment assembly 100 included in the preferred embodiment minimizes amplitude (dB) of the sole 40 compared to the traditional golf club head construction, while keeping the face 50 amplitude within a desired range of approximately 3000 to 4000 Hz, and while remaining at the highest amplitude in the system. The presence of the tube 110 thus improves the overall sound quality and durability of the golf club head 10 , which allows for the use of cheaper metals and cheaper manufacturing processes. The tube 110 also creates a peak that is more than 8 dB higher than all other peak frequencies of the preferred embodiment, and which is greater than 3000 Hz, as shown in FIG. 16 . As shown in FIG. 16 , this type of peak is not present in equivalent golf club heads having adjustable weighting but lacking the tube 110 of the present invention. The preferred sound of a driver-type golf club is in the 3000-6000 Hz range, and it is preferable to have only one peak with an amplitude of 8-20 db greater than other peaks.
As shown in FIGS. 2A, 2B, 13, and 14 , the center of gravity height adjustment assembly 100 preferably is located within the interior cavity 70 of the golf club head 10 in a crown 30 to sole 40 direction, running parallel to the tangent vector of the face 50 , and the center of gravity height adjustment preferably occurs in the vertical Z-axis plane. In alternative embodiments, shown in FIGS. 17 and 18 , the center of gravity height adjustment assembly 100 can be disposed anywhere within the interior cavity 70 of the golf club head 10 , and can extend diagonally or horizontally from different locations within the golf club head 10 .
The design approach described herein is based on the construction used in the Callaway Golf Company RAZR Fit driver head, characterized by a composite crown adhesively bonded to a cast titanium body, which includes a face, sole, and adjustable hosel. However, this center of gravity adjustment assembly may be used with other golf club head constructions, including all titanium, all composite, and a composite body with a metal face cup. It may also be used with other type of golf club heads, including fairway woods, hybrids, and utility irons. It is also intended to work in conjunction with at least one adjustable weight port disposed anywhere on the club head, including the crown and sole, and a slidable weight.
The disclosure of each of U.S. Pat. Nos. 7,147,573, 7,163,468, 7,163,470, 7,166,038, 7,214,143, 7,252,600, 7,258,626, 7,258,631, 7,273,419, 8,337,328, 8,317,636, and 8,262,506 is hereby incorporated by reference herein in its entirety.
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.
|
The present invention comprises a golf club head comprising a body having a crown, a sole, a front wall and a hosel, wherein the body defines a hollow interior. The golf club head further comprises a center of gravity adjustment assembly wherein the center of gravity adjustment assembly is positioned within the hollow interior of the body, and allows the center of gravity of the golf club head to be adjusted by at least 0.050 inch, preferably along a vertical axis.
| 0
|
FIELD OF THE INVENTION
The invention relates to a device for measuring the light scattering properties of a suspension which is fed through a sample cell and is illuminated by a collimated light beam, as well as to a method for measuring the light scattered on molecules present in a suspension.
BACKGROUND OF THE INVENTION
The measurement of the static light scattering is used for the characterisation (size, mass, form and structure) of molecules or colloidal substances. This is an absolute quantification which manages without any previous calibration or use of standard samples. A sample is illuminated with a collimated light beam, and the scattered light is measured at different scattering angles.
The principle of light scattering is widespread in nature. It can be observed, e.g. at sunset or when dust particles become visible. Light beams strike a strongly scattering medium, and are deflected from their geometrically prescribed path by particles. The intensity of the light beams is weakened here by absorption and scattering. The scattering is the basis for different physical phenomena such as e.g. deflection, refraction and reflection.
Scattering can be sub-divided into non-elastic, quasi-elastic and elastic scattering which differ in their frequency shift. With non-elastic scattering a frequency shift of approximately 10 11 to 10 13 Hz occurs. With quasi-elastic scattering, with which light additionally interacts with translation and rotation quanta of a molecule, a frequency shift of 10 to 10 6 Hz occurs. With elastic light scattering (e.g. static light scattering) there is no change to the wavelength (also called coherent scattered radiation). The underlying principle of light scattering can be demonstrated with a very small, optically isotropic gas molecule. The electrons of the molecule are caused to vibrate through the incidence of the electromagnetic wave with the frequency of the stimulating light source. The oscillating dipole thus produced in turn emits electromagnetic radiation of the same frequency, the intensity of the radiation depending on the strength of the induced dipole, i.e. the more polarisable the molecule, the stronger the dipole and the greater the intensity of the emitted radiation.
If a sample, for example a suspension, in which a number of macromolecules are located, is illuminated with a collimated light beam, every macromolecule emits radiation. The sum of the intensities of the emitted radiation is in proportion to the concentration of the macromolecules in the suspension and of the molar mass of the molecules. Furthermore, the size of the molecules contained in the colloid can be calculated from the angle dependency of the scattered light intensities since the light scattered at the different scattering centres in the macromolecule interferes and produces an angle-dependent scattering pattern. The average values of the particles located in the cell are respectively determined here. In the prior art measuring instruments are described which measure the scattering properties of colloidal liquids and use them for the characterisation of the material properties. EP 0 182 618 B1 discloses a device which describes the measurement of the static light scattering by means of a sample cell. The sample cell can be coupled to a chromatographic construction so that the particles, separated according to size, flow through the sample cell. For this a round glass cell is provided with a longitudinal bore hole through which a flow of liquid with the contained particles is fed and is illuminated with a laser beam. Detectors, which collect the scattered light, are arranged around the round glass cell at different angles. In order to determine the angle dependency every detector may only collect a small angle range. Therefore, with this instrument it is necessary to reduce the detected range in the bore hole to a few nanoliters by means of apertures, and this increases noise and interference. This inevitably leads to a reduction in sensitivity.
This technology was described first of all in U.S. Pat. No. 4,616,927 and in EP 0 182 618. However, they only disclose the measurement of the scattered light at a number of different angles. The scattering range observed is limited to a few nanoliters by means of apertures. EP 0 626 064 is a further development where measurements are taken at 2 angles, the light scattered at 15 degrees being collected by means of a lens and aperture system.
In U.S. Pat. No. 6,052,184 the scattered light is collected by means of fibre optics, the latter also only observing a very small liquid range however. The flow of liquid is guided here perpendicularly to the incident light beam. In EP 1 515 131 it is described how the volume of liquid can be minimized by using a second flow of liquid, the volume of liquid observed also being limited, however.
It is a disadvantage with the devices disclosed in the prior art that the volume of liquid observed is extremely limited by aperture systems or the use of fibre optics which are brought close to the scattering centre in order to obtain a good angle resolution and to keep scattered light away from air/glass/medium interfaces. Therefore the sensitivity of the method is reduced.
SUMMARY OF THE INVENTION
The problem underlying the invention is to provide a measuring device which does not have the disadvantages given in the prior art and which achieves improvement of the measuring sensitivity.
The problem is solved by the independent claims. Advantageous embodiments of the invention are given by the sub-claims.
Accordingly, the invention comprises a device for measuring the light scattering properties of a suspension which is fed through a sample cell and is illuminated by a monochrome collimated light beam, the sample cell having a channel which permits the feed and discharge of the suspension, and which allows a monochrome collimated light beam to pass in, pass through and pass out in the direction of its length, wherein the cell geometry of the sample cell has a curved surface, and the sample cell is formed from transparent material and focuses scattered light by the curved surface of the sample cell, and wherein light-sensitive detectors are arranged so that they collect the light scattered by a suspension and which passes through the channel and the transparent material of the sample cell.
It was totally surprising that the deficiencies of the prior art could be eliminated by the device according to the invention. The invention relates to a device which serves to measure the light scattering properties of a suspension which is fed through a sample cell and is illuminated by a monochrome collimated light beam. The coherence length of the light beam can preferably be greater than the maximum size of the molecules to be measured, molecules with a size of 10 nm to 1000 nm and a molecular mass of 1000 Da to 1×10 9 Da being preferably characterized. The cell geometry of the sample cell has a curved surface. The sample cell surrounds a channel which permits the feed and discharge of the suspension. Furthermore, the channel allows a collimated light beam to pass in, pass through and pass out in the direction of its length. The light scattered by the molecules present in the suspension passes through the transparent material of the sample cell and is focused by the curved surface of the sample cell according to the invention such that light-sensitive detectors arranged around the sample cell collect the light which passes through the channel and the transparent material of the sample cell. The irradiated molecules scatter the light in all directions, the scattering intensity at different angles depending upon the size of the molecules.
In a preferred embodiment a device for measuring the light scattering properties of a suspension which is fed through a sample cell and is irradiated by a monochrome collimated light beam is provided, the sample cell formed from transparent material having a channel which includes at least two openings, and the sample cell being formed as a segment preferably of an ellipsoid, a hyperbolic shape, a parabolic shape or of a circle, and having a curved surface, light-sensitive detectors being arranged around the sample cell, preferably around the curved surface. It was totally surprising that the preferred shape of the sample cell improves in particular the measurement of colloidal substances and reduces background noise. Within the framework of the invention a segment here preferably denotes a partial area which preferably has a curved surface and a flat surface lying opposite the curved surface. Within the framework of the invention a curved surface or side preferably denotes a curvature which has a change in direction for each unit of length, i.e. an outwardly quadratically increasing deviation of the surface from its tangential plane preferably occurs. This preferred embodiment of the sample cell makes in particular a compact and inexpensive design possible. An advantageous sample cell of this type is shown as an example in FIG. 1 .
Within the framework of the invention a suspension denotes a heterogeneous mixture in which solids (molecules) are distributed within a fluid.
Within the framework of the invention a channel denotes a recess in the cell body through which the medium being investigated flows and in which it is illuminated by a monochrome collimated light beam which preferably consists of light beams running in parallel and is monochrome. The coherence length of the light is preferably greater than the diameter of the macromolecules being investigated.
Advantages are gained by the device according to the invention in comparison to the prior art. The device thus makes it possible to collect all of the scattered light which passes from the colloidal suspension through the sample cell and is collected by the detectors. The scattered light of substantially all of the suspension present within the sample cell is thus collected, by means of which a scattered volume in the microliter range can be measured. Sample cells described in the prior art only have a scattered volume in the nanoliter range.
It is a further advantage of the device according to the invention that due to the increased scattered volume the intensity of the scattered light is increased because the intensity is in proportion to the scattered volume. An increase in intensity results in a strengthening of the signal and leads to improved sensitivity and enables measurement of colloidal suspensions in low concentrations.
A further advantage of the device according to the invention is the reduction of the background noise. The particles in the suspension move in reciprocal dependency upon their size in random directions. This movement results in a measuring error when measuring a colloidal suspension which is called noise and can distort the measurement result. The smaller the volume of the sample cell being observed, the less molecules are contained in the suspension, and the stronger is the temporal fluctuation of the scattered radiation. This results in an increase in noise. With an increase in the volume to be measured, the number of molecules in the sample cell is increased, and the effect of the noise is reduced because more scattered beams pass to the detectors, and so the signals can be averaged.
The invention thus resolves a long-standing problem of the prior art and makes it possible to collect all of the scattered light and so leads to improved sensitivity.
It is preferred if the geometry of the sample cell preferably has a segment of a curved surface, in particular of an ellipsoid, a hyperbolic, a parabolic shape or the form of a circle.
One advantageous embodiment of the subject matter of the invention makes provision such that the sample cell is produced from glass, polymer or a combination of both or a liquid which has a higher refractive index than the suspension or air being measured. A polymer denotes a chemical compound which consists of chains or branched molecules which are made up of identical or similar units. Examples of these are polymers made of polyethylene, polypropylene, polyvinyl chloride, polymethyl methacrylate, polyester or polyurethane. The refractive index, previously the index of refraction or the refractivity, is a material constant and describes the propagation of the light, i.e. electromagnetic waves, in an optically dense medium. It can be determined from the ratio between the phase velocity of the light in a vacuum and its phase velocity in the respective medium. Therefore e.g. the refractive index for visible light in a vacuum is exactly 1, for air at sea level 1.000292, for quartz glass 1.46 and for polymers approximately 1.5. The embodiment according to invention makes it possible for the scattered beams to be refracted such that they are focused in a point at which light-sensitive detectors are installed. Therefore the scattered radiation scattered away from the detectors can also be focused into the latter. Consequently it is made possible by the advantageous embodiment for the light-sensitive detectors to collect substantially all of the scattered beams coming from the sample cell.
Provision is advantageously made such that the sample cell has an optically polished surface and a cross-section of the sample cell is curved in the plane of the channel and the channel extends along an axis, the channel being shorter than the smallest diameter of the curved surface. The curved surface, through which the light passes out, is to be polished using standard methods in order to minimize angular distortions or scattering on the optical interfaces. A circle axis is defined as a stretch which is produced by connecting two points located on a circle. A polished surface is achieved by conventional polishing methods. The surface of e.g. quartz glass can thus be processed by flame polishing and mechanical polishing Polishing by means of laser beams is also possible.
By means of the preferred configuration of the sample cell it is possible for the light scattered by the molecules to be refracted towards the axis of incidence at the suspension/sample cell interface because the refractive index of the sample cell is preferably greater than the refractive index of the medium. In other words, light beams which have been scattered at a specific angle within the channel run parallel to one another through the sample cell. By means of the preferred embodiment the light beams scattered (horizontally) in the plane of the channel are focused onto a point outside of the sample cell at the sample cell/surrounding medium interface where the light-sensitive detectors are arranged. In this way it is possible to collect all of the light scattered in the horizontal plane, by means of which the sensitivity of the device is significantly increased. Furthermore, by means of the embodiment it is also possible for scattered beams, which are scattered away from the detectors, to be focused into the latter. Substantially more scattered light can thus be collected by the light-sensitive detectors.
In one preferred embodiment the sample cell has a polished surface, and a cross-section of the sample cell is curved in the plane perpendicular to the plane of the channel. Since the sample cell has a curve not only in the plane of the channel (horizontal), but also in the plane perpendicular to the plane of the channel (vertical) the beams running in parallel through the sample cell are focused in a point outside of the sample cell upon reaching the outside of the sample cell. Therefore vertical and horizontal focusing of the scattered beams preferably takes place, and all of the beams scattered below an angle are focused in a point outside of the sample cell. By means of the preferred embodiment all of the scattered light of the sample cell is collected and the scattered volume measured is increased, and this leads to improved sensitivity.
In a further preferred embodiment light-sensitive detectors are arranged over the curved surface or side in a plane with the channel (horizontal) in order to collect the light scattered by the irradiated suspension and focused by means of the sample cell. A detector is a device described in the prior art which converts an incident light intensity into electric signals which takes place e.g. by means of light-sensitive diodes or photomultipliers and forwards them to processing equipment which converts the measured signals into the desired units. By means of the arrangement of the detectors over the curved surface it is possible for scattered light, which has not been generated by the suspension but was produced e.g. on the side edges of the channel, to not pass into the detectors. The inflow of disruptive scattered light into the measurement is thus prevented and measuring errors reduced. Furthermore, by means of the preferred embodiment a compact and material-saving construction can be realized since light-sensitive detectors are only arranged on one side, namely the curved side.
Furthermore, it is preferred if light is focussed on the curved surface or side in a plane perpendicular to the plane of the channel, preferably by means of the curved side of the surface or by means of Fresnel lenses and/or cylindrical lenses, and is collected by light-sensitive detectors. The focusing of the scattered light beams at the sample cell/surrounding medium interface is preferably achieved by the curvature of the surface. The sample cell is produced from a material with a higher refractive index than air by means of which the light beams passing out are focused. The focusing can also be implemented with the aid of Fresnel lenses and/or cylindrical lenses. Fresnel lenses are compact optical lenses which are characterized by a division into annular steps. By means of the steps a constant focal width is achieved, i.e. the distance of the focal point or the focus does not change. The characteristic shape of the Fresnel lenses makes it possible to save weight due to which they are used in applications where the weight is crucial. Cylindrical lenses have different curvatures in two directions perpendicular to one another, i.e. cylindrical lenses are preferably sections of a cylinder. As a further embodiment, both lens types can execute the focussing of the light beams scattered by the suspension and focus the latter into the detectors. By means of the weight-saving shape of the lenses a compact embodiment is realized, and additionally the maintenance of the preferred embodiment is simplified by the lenses since the latter can easily be changed by the person skilled in the art. The preferred embodiments lead to the scattered beams being focussed in detectors at the sample cell/surrounding medium interface. By means of this arrangement it is possible to collect all of the scattered light and no scattered light is lost. Improved sensitivity is the result.
In a further preferred embodiment of the invention the light-sensitive detectors, which collect the scattered light, have an aperture system which defines the angle range to be observed provided the focus lies within the aperture. An aperture system describes a device fitted to the detectors which only allows collection of specific beams. Thus, beams reaching the detectors at an angle which is not to be used for the measurement are excluded by the aperture system. The range of the beams to be measured (the angle range) is set by the aperture system. Preferably the aperture is fitted in front of the detector exactly in the focus of the scattered light and serves to minimize the detected angle range. Furthermore, beams which are not exactly in the focus are masked by the apertures. By means of this arrangement all of the scattered light which is produced in the channel by the irradiation of the suspension is collected, and so the sensitivity of the further embodiment of the invention is improved. In addition the use of an aperture system enables adaptation to properties of the suspension being measured, such as e.g. highly concentrated suspensions, suspensions with large or small molecules, since this can easily be set by the person skilled in the art.
In a preferred embodiment there are no detectors arranged on the side lying opposite the curved surface or side, but a light-absorbing device is installed which absorbs light which is not to be collected by the detectors. Thus e.g. by means of the light-absorbing device scattered light which is produced on the feeds and discharges of the channel should not pass into the light-sensitive detectors. This scattered light would distort the measurement of the scattered beams which have been generated by the suspension being measured because one can no longer differentiate between scattered light to be measured and the scattered light not to be measured. Consequently the characterisation of the colloidal suspension would be based upon incorrect measurement data. For this reason the detectors are not arranged all the way round the sample cell. It is preferable for the detectors only to be arranged on one side of the sample cell, in particular on the side which is in the form of a curved surface, preferably a curved surface of a segment. By means of the preferred embodiment it is guaranteed that substantially all of the light scattered by the suspension is collected by the detectors, and in addition light, which does not derive from the light scattering of the suspension, is not collected by the detectors. A trap aperture is given as an example of this type of light-absorbing device which removes light not to be measured and so prevents distortion of the measurement result. Furthermore, coating the sample cell with an absorbent coloring can be advantageous.
In a further preferred embodiment the monochrome collimated light beam has a cross-sectional dimension that is smaller than that of the channel. A monochrome collimated light beam describes a monochrome light beam running in parallel. By means of the preferred embodiment it is guaranteed that no reflections are produced when the monochrome light beams running in parallel pass through the channel.
Furthermore, by using a monochrome collimated light beam it is guaranteed that no interference occurs and the scattered light beams do not affect one another.
The invention also relates to a method for measuring the light scattered on molecules present in a suspension, wherein
a) a suspension is fed though a channel that extends along a circle axis through a sample cell, b) a collimated, monochrome light beam runs along this channel, c) the scattered light beams running in parallel pass the curved shape of the sample cell, d) are focussed by the polished, curved shape of the sample cell, e) and the detectors arranged horizontally and vertically to the channel collect the focussed light.
The method makes it possible to measure the scattered light which is produced by irradiating a colloidal suspension. For this purpose a colloidal suspension is fed through a channel that extends along a circle axis through a sample cell. A monochrome, collimated light beam runs along this channel and irradiates the suspension by means of which light is scattered by the colloidal components. The light beams scattered at a specific angle are refracted towards the axis of incidence at the suspension/sample cell interface and run in parallel through the sample cell. At the sample cell/surrounding medium interface the scattered beams running in parallel are focussed by the polished, curved shape of the sample cell. Light-sensitive detectors, which receive the focussed light, are arranged around the round or curved side of the sample cell. The detectors are located in the horizontal and the vertical plane, i.e. in a plane with the channel running through the sample cell and in a plane perpendicular to the plane of the channel. Therefore, substantially all of the light which is scattered by the suspension can be collected by the detectors. The light received by the detectors is preferably converted into electric signals and forwarded to processing equipment in order to calculate the desired properties, such as e.g. size and concentration. The method makes it possible to measure a large scattered volume which is directly in proportion to the intensity of the beams. A higher intensity correlates to a higher sensitivity because the scattered radiation of molecules, which are, for example, present in the suspension in a low concentration, is amplified and can be collected by the detectors. Furthermore, by increasing the scattered volume reduction of the noise is achieved. The noise is produced by random movements of the molecules in the suspension and the resulting temporal displacement of the scattered beams due to which interference occurs which makes it difficult to measure the scattered beams because light beams affect one another, i.e. they can be amplified or deleted. The method reduces the noise by increasing the scattered volume, by means of which more molecules are collected in the suspension and averaging of the scattered beams reduces the effect of the movement. Therefore, by means of the method a long-standing problem in the prior art is resolved. The sensitivity of the measurement is improved by collecting a larger scattered volume, and substantially all of the scattered light of the suspension being measured is collected by means of light-sensitive detectors. This is a simple and inexpensive method which determines properties of a colloidal suspension.
A preferred embodiment of the method is characterized in that the sample cell in the plane of the channel and in the plane perpendicular to the plane of the channel displays a curved surface. By means of this shape of the sample cell it is possible for the light beams scattered at an angle to be diffracted towards the axis of incidence at the suspension/sample cell interface and to run in parallel through the sample cell, and to be focussed in a point outside of the sample cell at the sample cell/surrounding medium interface. Detectors fitted at this point collect the scattered light. Therefore the preferred embodiment allows substantially all of the scattered light to be collected, by means of which sensitivity is increased.
A further embodiment of the method is characterized in that the light-sensitive detectors are arranged over the round side of the sample cell. The arrangement of the light-sensitive detectors over the curved side of the sample cell causes substantially the scattered light which is focussed by the sample cell to fall into the detectors and enables it to be used in order to calculate the properties of the colloidal suspension. Light beams which are produced at the feeds and discharges of the channel or reflections may not be collected by the detectors because the measurement result is distorted by these light beams and the colloidal suspension can not be determined correctly. In order to exclude light beams or reflections which are not to be measured from the measurement a light-absorbing device, such as e.g. a trap aperture or a light-absorbing coating, is advantageously installed on the side lying opposite the round side of the sample cell. Furthermore, the light-sensitive detectors are preferably equipped with an aperture system which defines the angle range to be measured. In this way accurate measurement of the light scattering is possible because substantially all of the scattered light coming from the sample cell is collected and used for the calculation of the properties of the colloidal suspension.
Further advantageous measures are described in the other sub-claims.
DESCRIPTION OF THE DRAWINGS
The invention will now be described as an example by means of figures, without, however, being restricted to the latter; these show as follows:
FIG. 1 A horizontal section through the cell geometry
FIG. 2 A vertical section through the cell geometry.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows diagrammatically a horizontal section through the cell geometry. The sample cell 1 is preferably made of glass, polymer or a combination of both or a liquid which has a higher refractive index than air. A channel 2 is made in the sample cell 1 which has a curved surface 7 , and the channel 2 extends along an axis through the sample cell 1 . A cross-section of the sample cell 1 in the plane of the channel 2 and a cross-section in the plane perpendicular to the plane of the channel 2 displays a curved surface 7 . There is fed through the channel 2 a colloidal suspension which is irradiated by a monochrome collimated laser beam 3 . The laser beam 3 runs along the channel 2 , the cross-section of the laser beam 3 being smaller than that of the channel 2 . At the incidence of the light beams 3 onto the molecules of the suspension, the light is scattered in all directions depending on the size of the molecules. The scattered beams 4 are refracted towards the axis of incidence at the suspension/sample cell interface and run in parallel through the sample cell 1 . When the scattered beams 4 reach the curved, polished surface in the horizontal plane, i.e. in the plane of the channel, the beams are focused on a point where light-sensitive detectors 5 are fitted. Accordingly all of the beams 4 scattered at a specific angle are focussed by the curved surface 7 so that substantially all of the scattered light 4 of the suspension is collected by the light-sensitive detectors 5 . Scattered beams 4 , which are scattered away from the detectors 5 , are also focussed into the latter by the round surface. The light-sensitive detectors 5 process the incoming signals, convert the latter into electric signals, and forward the latter to corresponding processing equipment. An aperture system 6 is installed on the light-sensitive detectors 5 . The aperture system 6 makes it possible to restrict the scattered beams 4 to be collected by means of an aperture which only allows light beams which have been scattered at a defined angle to pass into the light-sensitive detectors 5 . Reflections or scattered light which occurs to the side from the feeds and discharges of the channel 2 . 1 can thus be prevented from being collected by the light-sensitive detectors 5 and being used for the calculation. The measurement result would be distorted by this disruptive scattered light. The sample cell 1 is advantageously in the form of a segment, i.e. a non-curved surface 8 is preferably arranged opposite the curved surface or side 7 .
FIG. 2 is a diagrammatic illustration of a vertical section through the cell geometry. A colloidal suspension, which is irradiated by a light beam 3 , flows through the channel 2 made in the sample cell 1 . In the plane perpendicular to the plane of the channel the sample cell 1 has a curved surface, and the channel 2 extends along an axis. Therefore the sample cell 1 displays a curved surface in the plane of the channel 2 (horizontal) in the plane perpendicular to the plane of the channel 2 (vertical). Therefore the sample cell 1 has a curved side. There is arranged on the side lying opposite the curved side a light-absorbing device, such as e.g. a trap aperture, which absorbs reflective beams or beams which pass through the feeds and discharges of the channel 2 . 1 out of the sample cell 1 . These light beams are not to be taken into account for the measurement and distort the measurement result if they are collected by the light-sensitive detectors 5 . The light beam 3 running along the channel 2 irradiates the colloidal suspension, and light is scattered by the molecules in all directions. The light beams 4 scattered at a specific angle are refracted towards the axis of incidence at the suspension/sample cell interface, and run in parallel through the sample cell 1 . The light beams 4 scattered in a plane with the channel 2 (horizontal) are focused into the light-sensitive detectors 5 by the polished, round side of the sample cell 1 at the sample cell/surrounding medium interface, an aperture system 6 determining the angle range to be measured. The light beams 4 scattered in a plane perpendicular to the plane of the channel 2 (vertical) are also focussed by the polished, round side of the sample cell 1 so that the focussed beams 4 are collected by the light-sensitive detectors 5 . The focusing can additionally be implemented by Fresnel lenses and/or cylindrical lenses. Fresnel lenses are compact optical lenses which are characterized by a division into annular steps. By means of the steps a constant focal width is achieved, i.e. the distance of the focal point or focus does not change. The characteristic shape of the Fresnel lenses makes it possible to save weight, due to which they are used in applications where weight is crucial. Cylinder lenses have different curvatures in two directions perpendicular to one another, i.e. in a narrower sense cylindrical lenses are sections of a cylinder. As a further embodiment, both types of lens can execute the focussing of the light beams scattered by the suspension and focus the latter into the detectors 5 . Light beams which are produced by reflection and/or light scattering on the feed and discharge of the channel 2 . 1 are prevented from passing into the detectors by the aperture system 6 fitted to the light-sensitive detectors 5 . The angle range to be measured is thus defined. By means of the vertical and horizontal focussing substantially all of the scattered light 4 which is produced by the irradiation of the colloidal suspension is fed into the light-sensitive detectors 5 . The scattered volume to be measured is thus increased and the sensitivity improved.
LIST OF REFERENCE NUMBERS
1 Sample cell
2 Channel
2 . 1 Feed and discharge of the channel
3 Light beam
4 Light scattered by the suspension
5 Light-sensitive detectors
6 Aperture system
7 Curved surface/side
8 Non-curved surface/side
|
The invention relates to a device and to a method for measuring the scattered light about molecules present in a suspension, wherein the suspension is fed through a measurement cell. The measurement cell is produced as a segment of a curved surface, particularly an ellipsoid, a hyperbolic shape, a parabolic shape, or a circle, and comprises a curved and a flat surface. Light-sensitive detectors are disposed about the curved surface and capture the scattered light.
| 6
|
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a divisional application of application U.S. patent application Ser. No. 10/564,827 filed May 22, 2006 now U.S. Pat. No. 8,157,210, which is a National Stage application for Patent Cooperation Treaty (PCT) Application No. PCT/EP2004/007922 filed Jul. 15, 2004 entitled, “FLOOR FOR AN AIRCRAFT CARGO COMPARTMENT AND A METHOD FOR THE ASSEMBLY THEREOF,” which claims priority to: German Patent Application No. 103 32 798.3, filed Jul. 18, 2003; German Patent Application 103 39 507.5, filed Aug. 27, 2003; German Patent Application No. 103 39 508.3, filed Aug. 27, 2003; German Patent Application No. 10 2004 011 163.4, filed Mar. 8, 2004; and German Patent Application No. 10 2004 011 164.2, filed Mar. 8, 2004; all of the above disclosures are herein incorporated by reference in their entirety.
FIELD OF THE INVENTION
The invention relates to a floor for an aircraft cargo compartment as well as to a method of assembling said floor.
BACKGROUND OF THE INVENTION
From the documents DE 19627846A1 (U.S. Pat. No. 5,927,650), DE 19720224A1 (U.S. Pat. No. 6,125,984), EP 0649802A1, U.S. Pat. No. 4,807,735 or U.S. Pat. No. 3,612,316 floors for aircraft cargo compartments are known in which panels or similar flat floor elements are provided for the fixation of roller elements, ball elements, latches, PDUs or similar functional units; these panels are mounted on a flat floor of an aircraft or on floor beams or similar supporting elements that support the panels and are themselves connected to a body or skin of the aircraft. In order to assemble the known cargo-compartment floors, initially the body or skin of the aircraft, i.e. the fuselage, is constructed together with the supporting elements, and subsequently the floor elements are mounted on the supporting elements in the aircraft cargo compartment. As a final step the functional units are installed and connecting leads (control lines, hydraulic conduits, drainage conduits etc.) are attached. This involves a major expenditure of effort, in that the assembly work is very intricate and furthermore must be carried out within the restricted space of the cargo compartment. Because of this complicated procedure and the limited possibilities for manipulation during the work, there is the added problem that errors can easily be made.
BRIEF SUMMARY OF THE INVENTION
It is the objective of the invention to disclose a cargo-compartment floor as well as a method for its assembly in which the work is facilitated and a reduction of the possibilities for errors during assembly is ensured.
This objective is achieved, in the case of a floor for an aircraft cargo space that comprises panels or similar flat floor elements to which are attached roller elements, ball elements, latch elements, PDUs or similar functional units, as well as floor beams or similar supporting elements to support the floor elements and to be connected to a body or a skin of the aircraft, in that the floor elements are fixedly connected to the supporting elements so as to form prefabricated floor modules and the floor modules can be installed in the aircraft.
Regarding the method, the objective is achieved by a method for assembling an aircraft cargo-compartment floor that comprises the following steps:
The panels, or similar flat floor elements for the fixation of roller elements, ball elements, latch elements, PDUs or similar functional units, are attached to floor beams or similar supporting elements that support the floor elements and are to be connected to a body or skin of the aircraft, so that the panels together with the supporting elements constitute prefabricated floor modules that can be manipulated as a unit,
A floor module is lifted into the cargo compartment, and
The supporting elements are fastened to the body or skin of the aircraft.
Hence an essential point of the invention resides in the fact that the supporting elements, in particular floor beams, are no longer considered as parts of the aircraft fuselage to which the floor elements are to be fastened while inside the aircraft. Instead, the supporting elements or floor beams are considered to be elements of the cargo-compartment floor, which together with the floor elements form floor modules and which then, as a whole, can be installed in the aircraft or cargo compartment in the prefabricated state. In this way the installation is not only made very much simpler, but also the floor modules can be set up outside the constricting cargo compartment, where they are readily accessible, and assembled to the desired level of construction, so that errors can be avoided and in many cases it is even possible to employ completely different assembly methods (e.g., automated and performed by robots) that could not be used inside the cargo space. Furthermore, sites below the floor elements are made accessible that could not be reached at all in the case of cargo-compartment floors constructed in the conventional manner or with conventional assembly methods.
Preferably the functional units are mounted on the floor element of the floor modules, so that a subsequent mounting inside the cargo compartment is no longer necessary. In particular electrical and/or mechanical control devices are provided, e.g. data-bus devices to control the functional units, in particular the PDUs, and are connected to the functional units, which is particularly simple to achieve outside the cargo compartment because accessibility from below is guaranteed at all times.
Preferably transmission sockets or similar transmission connecting devices are provided and attached to the floor modules in such a way that they can be connected to correspondingly shaped transmission devices on an adjacent floor module. Thus each floor module constitutes a self-contained functional unit, which after it has been lifted into the cargo compartment can be connected or coupled to the floor module already present there.
Preferably sections of cable channels, hydraulic conduits, water conduits, electrical leads or similar types of conductors are provided in the floor modules so that, together with conductors of the same kind that are provided in adjacent floor modules, they form overall conduction systems once the floor modules have been installed in the aircraft. In this way the floor modules simultaneously also constitute sections of the conduction devices, in which branches are provided to enable any desired connections to prespecified parts of the panels and/or the functional units. As a result, the construction of conduction systems is made considerably easier. As a whole, therefore, the floor modules should not only contain the complete cabling and drainage etc. for the organs of the cargo-loading system, but are preferably intended to comprise all the “ducting” needed for the entire aircraft—e.g., conduits for the air-conditioning system or other cable arrangements that are normally arranged separately so as to pass through this region of the aircraft. This achieves a considerably more efficient operation during construction of the aircraft as a whole.
Preferably the floor elements are provided with assembly elements to enable a mechanically stable connection to adjacent floor elements during or after installation in the aircraft. This measure makes it possible to connect the floor elements so as to form a firm, stable and rigid surface, which endows the entire aircraft with increased stability and considerably reinforces the cargo-compartment floor.
Preferably there are provided in the floor elements inspection or installation openings, by way of which a bilge space below the floor elements is accessible. To close these openings special floor-element sections are provided. As a result it is possible to carry out assembly work within the bilge space even after installation. The floor-element sections for closing the openings are preferably fixed to the floor elements by means of quick-acting closures, so that they can be opened very easily and rapidly.
The floor elements preferably comprise sealing means for sealing off a space above the floor elements against a space (e.g., the bilge space) below the floor elements. This sealing is intended on one hand for the containment of fluids such as water that may be carried into the cargo compartment as the containers are being loaded, and on the other hand to prevent leakage of gases such as are used to extinguish fires, so that the cargo compartment (in some cases also the bilge space) can be filled with an inert gas in order to put a fire out. These sealing means are especially simple to apply (e.g., in the form of a sprayed-on coating), because the floor modules are assembled outside the cargo space and hence are accessible from below.
Preferably leakproof connecting elements are provided, to create a sealed connection between a floor element and adjacent floor elements and/or the skin of the aircraft. These connecting elements are in particular so constructed that after installation of a floor module, the floor element in this module is tightly sealed to the adjacent floor element as well as the cargo compartment, so that there is no need for a separate, subsequent sealing process.
Preferably drainage devices are provided to carry fluids away from the cargo compartment (the water that is brought in as described above) and to transfer the fluid into corresponding drainage devices in neighboring floor modules, so that a separate installation of conduits for removing water is not required.
Preferably the floor modules in addition comprise floor panels or similar surfaces on which it is convenient to walk, so that each floor module constitutes a complete section of a cargo-compartment floor.
The floor modules are additionally provided with insulation devices for insulation from a lower half of the fuselage. As a result, the insulation (which is always necessary) need not be added at a later stage, but can be fitted to the modules while they are still outside the aircraft. These insulation devices can be attached either under the floor elements, which is especially simple to accomplish outside the aircraft, or alternatively (in some cases additionally) in the region of the supporting elements, where they will be near the aircraft's skin, if desired. Hence there is no need to work in the constricted region of the aircraft that is below the cargo-compartment floor.
The floor modules can also be constructed so as to comprise bulkheads or similar partitions, or alternatively fixation devices with which to attach partitions such as are ordinarily attached after installation in certain parts of the cargo compartment. The floor module designed in accordance with the invention, however, is very much simpler to install. The partitions preferably consist at least partially of ballistically resistant material, so that a high degree of reliability is ensured.
The floor modules can additionally comprise devices for mounting electronic equipment (EE racks) and similar components, or fixation devices for such components. This again offers the advantage that extremely simple construction is possible outside the aircraft, and is both economical and efficient.
The floor modules further comprise water and/or waste-water tanks or devices for fixing such tanks in position, as well as devices for connecting pipelines, so that the floor modules simultaneously represent “water-supply—modules”. Where appropriate, it is also possible to provide supplementary fuel tanks on the floor modules, including the necessary pipeline connections; in this case exchangeable units are especially advantageous, so that aircraft can be equipped with larger or smaller supplementary tanks (or none at all), as required.
The floor modules are also provided with coverings for walls and/or ceilings or similar covering elements, or devices for installing such coverings, in order to provide the cargo compartment with a lining. Then the floor modules amount to compact “cells” of which the cargo compartment is composed, which can be pushed into the aircraft fuselage. The floor modules are preferably constructed and fixed to the skin of the aircraft in such a way that after installation in the aircraft, they can be taken out again in any arbitrary sequence. This makes maintenance and/or repair of the cargo-compartment floor considerably easier.
In order to assemble a floor for the cargo-compartment of an aircraft, the following steps are carried out:
First the flat floor elements are fixedly connected to the supporting elements. Then the floor modules thus produced are lifted into the cargo compartment. Finally the supporting elements are attached to the body or the skin of the aircraft. The functional units are preferably fixed to the floor elements before the latter are lifted into the cargo compartment, which can be done considerably more easily than installing them when inside the aircraft.
After the floor modules have been lifted in, the control devices for controlling the functional units—cable channels, hydraulic conduits, water conduits, electrical leads or similar conducting devices, as well as drainage devices for removing fluids from the cargo compartment, if present—are connected to the respective counterparts (control devices, conducting devices etc.) associated with an adjacent floor module that has already been fixed in position within the cargo compartment. This kind of procedure also makes it possible to test parts of the “growing” overall system, which considerably facilitates the localization of any defects that may be present. In particular, at least parts of the said connection steps take place before the supporting elements are attached to the body or skin of the aircraft, so that if mistakes occur during connection and/or defects are discovered within a module, the module can be lifted back out of the cargo compartment and replaced by another, correctly constructed module.
Preferred embodiments will be apparent from the subordinate claims as well as the following description of an exemplary embodiment of the invention, which is explained in detail with reference to figures, wherein
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective drawing of part of a floor module prior to installation,
FIG. 2 is a drawing similar to that in FIG. 1 but with the floor module installed,
FIG. 3 is a schematic perspective drawing of a floor module as viewed from below,
FIG. 4 is a partial perspective drawing of a detail of a floor element,
FIG. 5 shows another embodiment of a floor module with partition and surface on which to walk
FIG. 6 shows an embodiment of a floor module with tank and EE rack, and
FIG. 7 shows an embodiment of a floor module with wall and ceiling lining.
DETAILED DESCRIPTION OF THE INVENTION
In the following description, the same reference numerals are used for identical parts or parts with identical actions.
As shown in FIG. 1 , a body or an (outer) skin 1 of an aircraft encloses in the lower half 6 of the fuselage a cargo compartment 2 , in which floor elements 51 form a cargo-compartment floor, below which is a bilge space 4 . The floor elements 51 are fixed to supporting elements, so-called floor beams 16 , which in turn are fixed to the skin 1 of the aircraft.
On or at the floor elements 51 there are attached surfaces on which to walk, called floorboards, as well as functional units for transporting and securing loads, namely roller elements 11 , ball elements 12 , latches 13 and roller-drive units, so-called PDUs 14 , as is known from the printed documents cited at the outset.
The floor elements 51 for producing the cargo-compartment floor are attached to the floor beams 16 while outside the aircraft, so as to produce floor modules 50 that will occupy either part of the width, or preferably the entire width of the final cargo-compartment floor.
Also mounted on the floor modules 50 are the partitions 54 that will be needed in the cargo compartment; the fixation devices 55 provided for this purpose can also be constructed so that installation and/or removal of the partitions 54 can be done inside the aircraft. The partitions 54 , as indicated in FIG. 1 , are provided with sealing devices 64 so that after they have been installed, the seating of the partitions 54 in the cargo compartment 2 is sufficiently gas-tight that the compartment can be filled with halon in order to extinguish fires.
As can be seen in FIG. 3 , when assembly occurs outside the aircraft the floor elements 51 , which are attached to the floor beams 16 (or conversely), are provided with control devices 20 that by way of branches 28 are connected to functional elements mounted on a floor element 51 , in particular PDUs 14 , so as to control the function of the functional elements.
The floor elements 51 further comprise inspection openings 34 that can be closed by means of floor-element sections that form flaps 35 . To close them fast-acting closures 38 are provided.
The floor elements 51 are additionally equipped with leakproof connecting elements 43 and 44 , e.g. sealing lips made of elastomer, so that a tight seal is ensured on one hand against the skin 1 of the aircraft (by means of the leakproof connecting elements 43 ) and on the other hand against the floor elements 51 ′ (see FIG. 1 ) that will occupy adjacent positions after installation.
In addition—as indicated in FIG. 3 —insulators 53 are disposed on the modules 50 in such a way that they are in relatively close contact with the outer skin 1 when the modules 50 have been installed. In addition (or alternatively) corresponding insulation devices can also be mounted below the floor elements 51 , or an insulating coating can be sprayed onto their lower surfaces, so that the cargo compartment is thermally isolated from the outer skin.
As can be seen in FIG. 4 , the floor elements 51 and/or floor modules 50 are also provided with electrical leads 27 , which by way of transmission sockets 21 can be connected to corresponding leads of adjacent floor elements 51 ′ and/or floor modules 50 ′, so as to form continuous strands.
In addition, cable channels 23 , hydraulic conduits 25 , water conduits 26 and electrical leads 27 are provided so that various operations customarily required in aircraft can be accomplished. Here, again, it is preferable for transmission sockets or similar connecting elements to be provided so that these conducting channels can be connected to their counterparts in adjacent floor modules 50 ′. The same applies to the drainage conduits 46 , which are known per se and serve to carry away water that penetrates into the cargo compartment or is carried in along with the cargo. It should be emphasized at this point that the conduits, channels and similar conducting means that are installed in the modules can be employed not only to assist the functions of the elements installed in the cargo compartment, but can also incorporate the entire “infrastructure” of the aircraft, i.e. other systems that are normally housed in this region of the aircraft.
The floor elements 51 are preferably sealed on their undersurface, by means of sprayed-on coatings, films or similar sealing devices 40 , so as to produce a preferably gas-tight seal between the upper surface and the lower surface of the floor elements 51 , so that fire-extinguishing gas introduced to the cargo compartment 2 cannot escape through the bilge space 4 . The floor modules 50 are thus substantially pre-assembled, so that after this pre-assembly it is even possible (while they are still outside the aircraft) to conduct trials intended, e.g., to test in individual sections whether the conduits are correctly connected and the functional elements, in particular the PDUs, are functioning properly. It is also possible to incorporate into the modules electronic control components that are “responsible” for the controllable functional elements, in particular the PDUs. This facilitates the construction and also the test procedures outside the cargo compartment.
The floor modules 50 thus previously assembled are then, as shown in FIG. 2 , set into the aircraft and connected by way of the floor beams 16 to the body 1 of the aircraft. In this way the entire cargo-compartment floor is produced, one section after another.
It is of course also possible to operate in smaller or larger structural units, depending on how large the units are and how easy or difficult it is to handle them. Preferably, however, modules 50 are provided that constitute a complete floor in the direction across the cargo space, so that the floor beams 16 can be constructed as a single piece and hence are extremely stable.
FIG. 5 again illustrates the basic appearance of a floor module to which a partition 54 has been fixed. Mounted adjacent to this partition 4 , in the embodiment of a floor module 50 shown in FIG. 6 , are an EE rack 56 attached by means of fixation devices 57 , as well as a water tank 58 with its fixation devices 60 and a waste-water tank 59 with water connection 61 . The EE rack contains the electronics ordinarily mounted (behind a partition) in the cargo compartment; thus the major advantage of the embodiment illustrated here is that it is extremely simple to install it in the floor module while the latter is outside the aircraft, so that the risk of errors is reduced. The connections of the EE rack and/or of the electronic components it contains can also be completed outside the aircraft, in which case the electronic components are incorporated into the overall system by way of the conduits and channels described above, as well as the devices for connecting to adjacent modules. It should be pointed out here that this “incorporation” into the overall system naturally also applies to the water tank 58 and the waste-water tank 59 , and that such tanks can also serve as extra tanks for fuel. The important thing here is that a simplified assembly outside the aircraft, to form a unitary module which in some cases includes an associated partition 54 , is thereby made possible.
The floor modules thus constitute, firstly, “functional subassemblies” that comprise special equipment for transporting and securing freight or electronic components (EE rack) or tanks. On the other hand, the floor modules also constitute “passageways”, which serve only to provide a passage for, e.g., air-conditioning conduits 29 ( FIG. 6 ) that has no special direct function in this section of the cargo compartment.
Furthermore it is also possible, as shown in FIG. 7 , to mount lining elements 62 on the floor modules 50 by way of mounting devices 63 , in which case preferably additional guide rails or similar guide means are fastened to the outer skin of the aircraft within the cargo compartment in such a way that the floor modules can be transported into the cargo compartment together with the lining elements.
It will be evident from the above that it is an essential basic idea of the invention for the cargo-compartment floor to incorporate its carrying structures and as many as possible of the other functional elements and sections of leads, which must ordinarily be installed separately and subsequently, while the floor is within the aircraft. Such a modular construction not only facilitates the assembly of an aircraft as a whole, but also enhances its quality. Furthermore, various construction methods and materials can be used that could not be employed if the assembly were to be done in the interior of the aircraft fuselage.
|
In conventional aircraft cargo compartments panels or similar flat floor elements are fastened to floor beams or similar supporting elements that are installed in the body of the aircraft. Subsequently functional units such as roller elements, latches or PDUs are mounted and connected to one another by way of appropriate control conductors. It is proposed to fasten the floor elements permanently to the supporting beams so as to form prefabricated floor modules and to install these floor modules in the aircraft.
| 1
|
BACKGROUND/SUMMARY
[0001] Turbocharged and supercharged engines pressurize air entering an engine so that engine power can be increased. The pressurized air provides for an increased cylinder air charge during a cycle of the engine as compared to a naturally aspirated engine. Further, the cylinder fuel charge can be increased as the cylinder air charge is increased to increase the amount of energy produced when the fuel is combusted with the air during a cycle of the cylinder. However, during periods of valve overlap where both intake and exhaust valves of a cylinder are simultaneously open, it is possible for air to pass directly from the engine intake manifold to the engine exhaust manifold without participating in combustion within a cylinder. Air passing directly from the intake manifold to the exhaust manifold without participating in combustion may be referred to as blow-through.
[0002] Fresh air or blow-through passing through the intake manifold to the exhaust manifold may have beneficial as well as undesirable characteristics. For example, blow-through can evacuate internal exhaust residuals from engine cylinders so that the fresh charge in the cylinder increases, thereby increasing engine power output. However, blow-through may also upset a delicate balance between oxygen, hydrocarbons, and CO in a catalyst in the engine exhaust path. If blow-through provides excess oxygen to the catalyst, it may be possible for NOx conversion efficiency to decrease.
[0003] One way to mitigate engine emissions that may result from blow-through is to account for blow-through gases. In one example, engine air-fuel ratio may be richened so that on average a stoichiometric air-fuel ratio mixture passes through engine cylinders. For example, for a direct injection engine where fuel is injected after exhaust valve closing, fresh air can flow from the intake manifold to the exhaust manifold during intake and exhaust overlap. Further, an increased amount of fuel may be supplied to an engine cylinder so that the cylinder combusts a rich air-fuel mixture. The contents of the cylinder may be subsequently combined with the blow-through air stored in the catalyst to provide near stoichiometric ratios of gases to the catalyst so that the catalyst can efficiently oxidize and reduce undesirable exhaust gas constituents. However, it is difficult to keep the catalyst balanced and adjust air-fuel ratio of a cylinder without knowing the amount of blow-through for speed-density control systems.
[0004] The inventors herein have recognized the above-mentioned disadvantages and have developed a method for accounting for cylinder blow-through of an engine, comprising: adjusting an engine actuator controlling supply of a constituent for combustion to a cylinder of the engine in response to a difference between a total cylinder air mass flow curve and a volumetric efficiency curve.
[0005] A mass of oxygen that reaches an exhaust after treatment device resulting from cylinder blow-through may be determined from two curves that characterize engine breathing. In particular, cylinder blow-through may be determined as a difference between a first curve that represents volumetric efficiency for a theoretical maximum cylinder air charge and second curve that represents total air flow through the cylinder. Both curves may be described according to slopes of lines so that cylinder blow-through may be determined without having to perform a significant number of calculations and without having to determine a cylinder air-fuel ratio.
[0006] In another example, the amount of blow-through can be adjusted to increase engine output and to provide a desired amount of oxygen to the exhaust system to promote regeneration of an exhaust gas emissions device. For example, blow-through may be used during regeneration of a particulate filter to oxidize stored carbonaceous soot. The amount of blow though can affect the temperature rise of the oxidizing carbonaceous shoot during regeneration. Therefore, it may be desirable to determine the amount of blow though so that a desired level of blow-though may be provided to the emissions device without supplying excess blow-through.
[0007] The present description may provide several advantages. In particular, the approach can reduce vehicle emissions by providing an accurate blow-through estimate so that an amount of air reaching an exhaust gas after treatment device may be determined. Further, an engine actuator may be adjusted so as to control the amount of blow-through supplied to the exhaust gas after treatment device. Further still, the method provides for determining an engine operating condition where blow-through begins so that blow-though can be controlled during conditions where increased engine power is desired or when exhaust gas constituents entering a catalyst may be balanced so as to improve conversion efficiency of engine exhaust emissions.
[0008] The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
[0009] It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.
BRIEF DESCRIPTION OF THE FIGURES
[0010] FIG. 1 shows a schematic depiction of an engine;
[0011] FIG. 2 shows a volumetric efficiency characterization of cylinder air charge;
[0012] FIG. 3 shows a high level flowchart of a method for determining cylinder blow-through and making adjustments to compensate for cylinder blow-through.
DETAILED DESCRIPTION
[0013] The present description is directed to determining blow-through of a cylinder of an engine. FIG. 1 shows one example system for determining blow-through of a cylinder. The system includes a turbocharger operated with a spark ignited mixture of air and gasoline, alcohol, or a mixture of gasoline and alcohol. However, in other examples the engine may be a compression ignition engine, such as a diesel engine. FIG. 2 shows a simulated example plot of curves that are the basis for determining cylinder blow-through. FIG. 3 shows an example method for determining and adjusting cylinder blow-through.
[0014] Referring to FIG. 1 , internal combustion engine 10 , comprising a plurality of cylinders, one cylinder of which is shown in FIG. 1 , is controlled by electronic engine controller 12 . Engine 10 includes combustion chamber 30 and cylinder walls 32 with piston 36 positioned therein and connected to crankshaft 40 . Combustion chamber 30 is shown communicating with intake manifold 44 and exhaust manifold 48 via respective intake valve 52 and exhaust valve 54 . Each intake and exhaust valve may be operated by an intake cam 51 and an exhaust cam 53 . Alternatively, one or more of the intake and exhaust valves may be operated by an electromechanically controlled valve coil and armature assembly. The position of intake cam 51 may be determined by intake cam sensor 55 . The position of exhaust cam 53 may be determined by exhaust cam sensor 57 .
[0015] Fuel injector 66 is shown positioned to inject fuel directly into cylinder 30 , which is known to those skilled in the art as direct injection. Alternatively, fuel may be injected to an intake port, which is known to those skilled in the art as port injection. Fuel injector 66 delivers liquid fuel in proportion to the pulse width of signal FPW from controller 12 . Fuel is delivered to fuel injector 66 by a fuel system (not shown) including a fuel tank, fuel pump, and fuel rail (not shown). Fuel injector 66 is supplied operating current from driver 68 which responds to controller 12 . In addition, intake manifold 44 is shown communicating with optional electronic throttle 62 which adjusts a position of throttle plate 64 to control air flow from intake boost chamber 46 .
[0016] Exhaust gases spin turbocharger turbine 164 which is coupled to turbocharger compressor 162 via shaft 161 . Compressor 162 draws air from air intake 42 to supply boost chamber 46 . Thus, air pressure in intake manifold 44 may be elevated to a pressure greater than atmospheric pressure. Consequently, engine 10 may output more power than a normally aspirated engine. In other examples, compressor 162 may be a supercharger driven by the engine where turbine 164 is omitted.
[0017] Distributorless ignition system 88 provides an ignition spark to combustion chamber 30 via spark plug 92 in response to controller 12 . Ignition system 88 may provide a single or multiple sparks to each cylinder during each cylinder cycle. Further, the timing of spark provided via ignition system 88 may be advanced or retarded relative to crankshaft timing in response to engine operating conditions.
[0018] Universal Exhaust Gas Oxygen (UEGO) sensor 126 is shown coupled to exhaust manifold 48 upstream of exhaust gas after treatment device 70 . Alternatively, a two-state exhaust gas oxygen sensor may be substituted for UEGO sensor 126 . In some examples, exhaust gas after treatment device 70 is a particulate filter and/or a three-way catalyst. In other examples, exhaust gas after treatment device 70 is solely a three-way catalyst.
[0019] Controller 12 is shown in FIG. 1 as a conventional microcomputer including: microprocessor unit 102 , input/output ports 104 , read-only memory 106 , random access memory 108 , keep alive memory 110 , and a conventional data bus. Controller 12 is shown receiving various signals from sensors coupled to engine 10 , in addition to those signals previously discussed, including: engine coolant temperature (ECT) from temperature sensor 112 coupled to cooling sleeve 114 ; a position sensor 134 coupled to an accelerator pedal 130 for sensing accelerator position adjusted by foot 132 ; a knock sensor for determining ignition of end gases (not shown); a measurement of engine manifold pressure (MAP) from pressure sensor 121 coupled to intake manifold 44 ; a measurement of boost pressure from pressure sensor 122 coupled to boost chamber 46 ; an engine position sensor from a Hall effect sensor 118 sensing crankshaft 40 position; a measurement of air mass entering the engine from sensor 120 (e.g., a hot wire air flow meter); and a measurement of throttle position from sensor 58 . Barometric pressure may also be sensed (sensor not shown) for processing by controller 12 . In a preferred aspect of the present description, engine position sensor 118 produces a predetermined number of equally spaced pulses every revolution of the crankshaft from which engine speed (RPM) can be determined.
[0020] In some embodiments, the engine may be coupled to an electric motor/battery system in a hybrid vehicle. The hybrid vehicle may have a parallel configuration, series configuration, or variation or combinations thereof. Further, in some embodiments, other engine configurations may be employed, for example a diesel engine.
[0021] During operation, each cylinder within engine 10 typically undergoes a four stroke cycle: the cycle includes the intake stroke, compression stroke, expansion stroke, and exhaust stroke. During the intake stroke, generally, the exhaust valve 54 closes and intake valve 52 opens. Air is introduced into combustion chamber 30 via intake manifold 44 , and piston 36 moves to the bottom of the cylinder so as to increase the volume within combustion chamber 30 . The position at which piston 36 is near the bottom of the cylinder and at the end of its stroke (e.g. when combustion chamber 30 is at its largest volume) is typically referred to by those of skill in the art as bottom dead center (BDC). During the compression stroke, intake valve 52 and exhaust valve 54 are closed. Piston 36 moves toward the cylinder head so as to compress the air within combustion chamber 30 . The point at which piston 36 is at the end of its stroke and closest to the cylinder head (e.g. when combustion chamber 30 is at its smallest volume) is typically referred to by those of skill in the art as top dead center (TDC). In a process hereinafter referred to as injection, fuel is introduced into the combustion chamber. In a process hereinafter referred to as ignition, the injected fuel is ignited by known ignition means such as spark plug 92 resulting in combustion. During the expansion stroke, the expanding gases push piston 36 back to BDC. Crankshaft 40 converts piston movement into a rotational torque of the rotary shaft. Finally, during the exhaust stroke, the exhaust valve 54 opens to release the combusted air-fuel mixture to exhaust manifold 48 and the piston returns to TDC. Note that the above is described merely as an example, and that intake and exhaust valve opening and/or closing timings may vary, such as to provide positive or negative valve overlap, late intake valve closing, or various other examples.
[0022] Referring now to FIG. 2 , a simulated plot of volumetric efficiency characterization of cylinder air charge is shown. The X axis of plot 200 represents air mass charge of a cylinder per cylinder intake event or cylinder cycle. Air mass charge increases from the left side of the plot to the right side of the plot. The Y axis of plot 200 represents engine intake manifold absolute pressure (MAP) and MAP increase from the bottom of the origin of the plot in a direction of the Y axis.
[0023] Curve 202 represents the theoretical maximum air charge that the cylinder can hold at a given pressure at intake valve closing (IVC). Thus, the cylinder mass charge increases linearly as the cylinder pressure increases. In one example, the maximum air charge that the cylinder can hold may be characterized as a slope of a line where the slope is described as:
[0000]
Slope
=
1
(
1
-
r
pb
)
c
norm
[0000] where variable c norm accounts for physical properties of air, intake manifold temperature, and cylinder displacement. Variable r pb is an effective pushback ratio characterizing a portion of a cylinder mixture that may be pushed into the engine intake manifold from the cylinder as the piston moves in a direction toward the cylinder head while the intake valve is open. The pushback ratio may be determined as the greater of a constant multiplied by the physical ratio of cylinder volume displaced by the piston moving from the bottom dead center (BDC) to the intake valve closing (IVC) point, to the total cylinder displacement volume of the cylinder and the pushback ratio computed from engine mapping as:
[0000]
1
-
1
c
norm
*
air_slope
[0000] where air_slope is the least-squares linear fit of the manifold pressure vs. trapped air charge data excluding blow-through data points.
[0024] Curve 204 represents a conventional non-blow-through (e.g., conditions where blow-through is not present) volumetric regression curve in which both x and y axes have been scaled by ExhMAP/ExhMAP_nom. Where ExhMAP is exhaust manifold absolute pressure and where ExhMAP_nom is a nominal exhaust manifold absolute pressure (e.g. at sea level). Instead of the cycle average exhaust manifold absolute pressure, an average over the valve-overlap window, or some other related quantity, could be used for scaling. In engines having variable cam timing, curve 204 may be regressed from data points such as 220 into a quadratic curve.
[0025] Intersection 208 represents the point where the conventional non-blow-through curve 204 and the theoretical maximum air charge curve 202 intersect. Thus, when MAP is greater than the level of MAP where intersection 208 takes place, air blows through the cylinder. In some examples, the engine may be operated at a MAP up to where intersection 208 occurs but not higher so that cylinder blow-through may be prevented. In other examples, when MAP is higher than MAP where intersection 208 takes place, blow-through may be determined so that an actuator may compensate for the amount of blow-through.
[0026] Curve 210 represents a total amount of air flowing through the cylinder during the blow through operation. The total amount of air includes air in the cylinder as well as blow-through air. In one example, curve 210 may be described by a slope that extends from intersection 208 . The slope may be found via regressing empirically determined data. For example, a least-squares or other regression may be the basis for determining the equation of a line describing total air flow through a cylinder during blow-through conditions.
[0027] Given the cylinder air charge m air cyl , the inferred pressure in the intake manifold as shown in FIG. 2 may be described as:
[0000] m air x ( k ) = m air cyl ( k ) vol_eff _cor ( ACT , ECT ) * 30 [ in - Hg ] P exh ( k ) if m air x (k) > m c (k) P inf ( k ) =
P exh ( k ) 30 [ in - Hg ] max { 1 c norm * m c ( k ) , [ 1 c norm * m c ( k ) + slp * ( m air x ( k ) - m c ( k ) ] } else P inf ( k ) =
P exh ( k ) 30 [ in - Hg ] ( air_offset + air_slope × m air x ( k ) + air_quad × m air x ( k ) 2 ) end
Where k is a k th sample interval, m air cyl (k) is mass of air in cylinder, m c (k) is mass of air in cylinder at the point blow-through begins (e.g., 208 ), slp is the slope of the line describing total amount of air flowing through the cylinder (e.g., 210 ), P exh (k) is exhaust pressure, vol_eff_cor (ACT, ECT) is a volumetric correction for air charge temperature ACT and engine temperature ECT, and m air x is the scaled cylinder air charge. The parameters air_offset, air_slope, and air_quad represent the conventional non-blow-through curve 204 and can be calibrated by a least squares fit of the engine data.
[0028] To compute the trapped cylinder air charge and the mass of blow-through air for a given manifold absolute pressure MAP, a recursive calculation can be used. At time k, the cylinder air charge is computed from the current measurement of MAP and one of the previously computed estimates of the mass of dilution:
[0000] m air cyl ( k )=(1 −r pb )* chd norm *MAP( k )− m d ( k−b 1 )
[0000] where an d is the estimated mass of dilution in the cylinder “l” events before (l is equal to 1 for an I4 engine, 1.5 for a V6, and 2 for a V8). Next, the inferred manifold absolute pressure is computed as above while assuming operation in the non-blow-through condition:
[0000]
m
air
x
(
k
)
=
m
air
cyl
(
k
)
vol_eff
_cor
(
ACT
,
ECT
)
*
30
[
in
-
Hg
]
P
exh
(
k
)
P
inf
(
k
)
=
P
exh
(
k
)
30
[
in
-
Hg
]
(
air_offset
+
air_slope
×
m
air
x
(
k
)
+
air_quad
×
m
air
x
(
k
)
2
)
[0000] The current estimate of the mass of dilution in the cylinder is:
[0000] m d ( k )=max {0 , c norm *(1 −r pb )* P inf ( k )− m air cyl ( k )}
[0000] If the computed mass of dilution is 0, the air charge computed above is higher than the critical value m c , which means the engine is operating in blow-through. In this case the in-cylinder air charge is clipped to:
[0000] m air cyl ( k )=(1 −r pb )* c norm *MAP( k )
[0029] The amount or mass of blow-through may be determined for a desired or given MAP via taking a difference between curve 210 and curve 202 as represented by the distance 250 . Thus, blow-through may be determined according to volumetric efficiency characterization of an engine:
[0000]
m
air
bt
(
k
)
=
max
{
0
,
(
1
/
c
norm
-
slp
bt
)
×
[
m
air
x
(
k
)
-
m
c
(
k
)
]
slp
bt
}
×
P
exh
(
k
)
30
[
inHg
]
×
560
ACT
+
460
[0030] Finally the total amount of air is equal to the sum of the in-cylinder air-charge m air cyl and the mass of blow through m air bt .
[0031] Referring now to FIG. 3 , a high level flowchart of a method for determining cylinder blow-through and compensating for cylinder blow-through is shown. The method of FIG. 3 is executable via instructions of a controller as shown in the system of FIG. 1 .
[0032] At 302 , method 300 determines engine operating conditions. Engine operating conditions may include but are not limited to engine temperature, ambient air temperature, MAP, engine air flow, throttle position, engine torque demand, and cam positions. Method 300 proceeds to 304 after engine operating conditions are determined.
[0033] At 304 , method 300 characterizes a non-blow-through curve of an engine in a MAP/Air charge plane as shown via curve 204 of FIG. 2 . In one example, values of MAP and cylinder air charge are determined at steady state (e.g., steady engine speed and torque demand) engine operating conditions. An equation of a curve is identified from the MAP and cylinder air charge data points via a least-squares or other type of regression. The curve may also be scaled via a ratio of exhaust pressure versus nominal exhaust pressure. The equation of the curve may be stored in controller memory such that cylinder air charge or MAP may be determined when the equation of the curve is indexed or multiplied by a present value of MAP or cylinder air charge. Method 300 proceeds to 308 after non-blow-through volumetric efficiency is characterized.
[0034] At 308 , method 300 determines a maximum volumetric efficiency of the cylinder or maximum air charge that the cylinder can hold at a give pressure. In one example, the maximum volumetric efficiency is determined at IVC. The maximum air charge that the cylinder can hold as described above may be characterized as a slope of a line where the slope is described as:
[0000]
Slope
=
1
(
1
-
r
pb
)
c
norm
[0000] The slope may be stored in controller memory and indexed at a later time to determine MAP or cylinder air charge. For example, when the slope is multiplied by a desired cylinder air charge, an intake manifold pressure that provides the desired cylinder air charge is output. Similarly, cylinder air charge may be determined via multiplying 1/slope by MAP to determine cylinder air charge. Method 300 proceeds to 310 after maximum volumetric efficiency of the engine is determined.
[0035] At 310 , method 300 determines a total mass of air through the engine during blow-through conditions. In one example as described above, the total amount of air passing through an engine cylinder and MAP may be empirically determined via monitoring MAP and mass air flow through an engine after the blow-through point 208 is determined. The blow-through point 208 may be determined as the intersection of the non-blow-through volumetric efficiency curve and the maximum volumetric efficiency curves as is described above. The blow-through point may be determined and stored in memory so that engine blow-through may be easily determined during engine operation, or it may be computed on-line while the engine is running. Method 300 proceeds to 312 after the total mass of air through the engine is determined. One possible way to calculate trapped cylinder air amount and the blow-through air mass is described above.
[0036] At 312 , cylinder air charge is determined. In one example, cylinder air charge may be determined via selecting the lower value of cylinder air charge from the non-blow-through curve (e.g., curve 204 of FIG. 2 ) and the cylinder air charge from the theoretical maximum air charge that the cylinder can hold (e.g., curve 202 of FIG. 2 ) at a given MAP. Alternatively, a MAP where a desired cylinder air charge is provided may be determined via selecting the higher value of MAP from the non-blow-through curve and the theoretical maximum air charge curve. In this way, depending on the sensor set available and the objectives, either MAP or cylinder air charge may be determined. Method 300 proceeds to 314 after cylinder air charge is determined.
[0037] At 314 , method 300 determines blow-through via the total mass flow through the cylinder and the maximum volumetric efficiency curves. In one example, the flow at the maximum volumetric efficiency of the cylinder is subtracted from the total mass flow through the cylinder to provide an amount of cylinder blow-through. An amount of engine blow-through may be determined via summing blow-through amounts of each engine cylinder over one or more engine cycles. In one example, as shown in FIG. 2 , the blow-through may be visually represented as shown at 250 of FIG. 2 . Method 300 proceeds to 316 after blow-through is determined.
[0038] At 316 , total cylinder air charge may be determined via adding cylinder air charge from 312 and blow-through from 314 . Alternatively, total cylinder air charge may be determined via simply indexing the total air mass curve as described at 310 and FIG. 2 . Method 300 proceeds to 318 after the total cylinder air charge is determined.
[0039] At 318 , method 300 adjusts engine operation based on cylinder air charge, blow-through, and total cylinder air flow. Spark timing and air-fuel ratio for a cylinder may be determined via indexing a spark map via the present cylinder air charge. For example, if cylinder air charge is X lbm/stroke engine spark may be determined to be 30 crankshaft degrees before top dead center compression stroke. Further, injector and cam timing may be adjusted based on cylinder air charge via similarly indexing tables of empirically determined injector timings and cam timing using the present cylinder air charge. Further, in some examples, MAP, throttle position, compressor or supercharger controls and/or variable valve timing controls may be adjusted to provide a desired cylinder air charge via indexing tables of empirically determined values that are indexed via cylinder air charge.
[0040] Injector timing and pulse width may also be adjusted for blow-through. In one example, an injected fuel amount can be adjusted proportionately with blow-through via adjusting fuel injector pulse width. For example, if blow through is X lbm/event a fuel pulse width may be adjusted so that X*1/14.6 lbm/event of fuel is added to each cylinder during a cylinder cycle so as to balance air and fuel reaching the catalyst.
[0041] In another example, a position of a throttle can be adjusted based on the pressure drop across the throttle and the desired cylinder air flow rate to provide a MAP that provides the cylinder flow rate.
[0042] In another example, throttle position and turbocharger vane or waste gate position can be adjusted to adjust boost and MAP so that a desired amount of blow-through is provided. For example, if a predetermined amount of blow-through is desired, the predetermined amount of blow-through may be determined via subtracting the maximum volumetric efficiency curve from the total amount of air flowing through the cylinder at MAP values greater than a point where blow-through begins (e.g., 208 of FIG. 2 ). Engine boost may be increased along with adjusting throttle position such that the lowest value of MAP where the desired level of blow-through is present is provided. In one example, the waste gate may be closed to increase boost pressure and the throttle opened to increase MAP to a level where a desired amount of blow-through is present. Alternatively, if MAP is higher than where a desired blow-through is provided (e.g., blow-through is greater than is desired), then the throttle may be closed and the boost reduced via opening a turbocharger waste gate. In some cases, the amount of blow-through can be lowered by opening the compressor bypass valve or increased by engaging a supercharger, if the engine is so equipped. Further, in some examples intake and exhaust valve opening time overlap may be increased to provide a desired level of blow-through. Thus, blow-through can be adjusted to increase or decrease an amount of energy, oxygen, or other exhaust gas constituents supplied to an emissions device in an exhaust system.
[0043] Some engine actuators may also be adjusted based on the total cylinder flow. For example, the amount of fuel injected to the engine may be adjusted based on the total flow of air through engine cylinders. Thus, different engine actuators may be adjusted for cylinder air charge, blow-through, and total cylinder flow.
[0044] As will be appreciated by one of ordinary skill in the art, the method described in FIG. 3 may represent one or more of any number of processing strategies such as event-driven, interrupt-driven, multi-tasking, multi-threading, and the like. As such, various steps or functions illustrated may be performed in the sequence illustrated, in parallel, or in some cases omitted. Likewise, the order of processing is not necessarily required to achieve the objects, features, and advantages described herein, but is provided for ease of illustration and description. Although not explicitly illustrated, one of ordinary skill in the art will recognize that one or more of the illustrated steps or functions may be repeatedly performed depending on the particular strategy being used.
[0045] This concludes the description. The reading of it by those skilled in the art would bring to mind many alterations and modifications without departing from the spirit and the scope of the description. For example, single cylinder, 12, 13, 14, 15, V6, V8, V10, V12 and V16 engines operating in natural gas, gasoline, diesel, or alternative fuel configurations could use the present description to advantage.
|
A method for determining cylinder blow-through air via engine volumetric efficiency is disclosed. In one example, the method provides a way to adjust cylinder blow-through to promote and control a reaction in an exhaust after treatment device. The approach may simplify cylinder blow-through calculations and improve engine emissions via providing improved control of constituents reaching an exhaust after treatment device.
| 5
|
TECHNICAL FIELD
The invention concerns a method for treating or manufacturing a paper to provide at least a part of it with anisotropic electric conductivity as well as a paper so produced.
BACKGROUND OF THE INVENTION
Electrically conductive cellulose containing materials can be based on the mixture of cellulose containing matrix and conductive particles (fillers) embedded into this matrix. In the former case the matrix can also contain organic or inorganic additives and the electrically conductive particles be either carbon particles, metal particles or metal oxide particles. The materials can also be directionally conductive.
Conductive papers are proposed for applications in energy storage.
In PNAS 2009 106 21490 is described how conductive paper is prepared by using commercially available paper and conductive carbon and silver particles. This paper act as a capacitor with very high capacitance (200 F/g) and specific energy (7.5 Wh/kg). This stems from the fact that the material is significantly lighter than corresponding capacitors with metal framework.
Conductive papers are proposed for applications in electromagnetic interference (EMI) shielding.
In Compos. Sci. Tech. 2010 70 1564 is described how carbon nanotube/cellulose composites incorporated into the paper making lead to a paper with EMI shielding properties. Typically 10 wt-% carbon content is required to achieve a composite paper with sufficient 20 dB far-field EMI shielding effectiveness.
Conductive papers contain typically large amount of conductive particles.
In U.S. Pat. No. 3,367,851 is described how electrically conductive paper can be prepared from electrically conductive carbonaceous fibers and wood pulp. The fraction of conductive component varied from 2 to 35 wt-%.
In U.S. Pat. No 4,347,104 is described the electrically conductive paper with the fraction of conductive carbonaceous component from 1 to 35 wt-%.
In U.S. Pat. No. 3,998,689 is described a carbon fiber paper where the ratio of carbon fibers falls in the range of 40-90 wt-%.
One problem with these techniques is that one has to use lots of conductive fillers like carbon. These relatively high fractions of conductive fillers are problematic for a variety of reasons. Another problem is that the sizes of the conductive fibers are limited. Long conductive carbon fibers would be beneficial for applications seeking to reduce electromagnetic interference. However, if the fibers are too long one can have problem getting the fibers dispersed.
OBJECTIVES
It is an object of the present invention to provide a conductive paper with significantly lower filler fraction.
It is also an object of the present invention to provide a paper which exhibits, at least in parts thereof, anisotropic electric conductivity.
It is furthermore an object to provide a method for treating a paper to provide at least a part of it with anisotropic electric conductivity and/or a method for forming a paper with anisotropic electric conductivity.
It is a still further object to provide such paper with means that are inexpensive and reliable in industrial scale manufacturing or preparations.
DESCRIPTION OF THE INVENTION
The above mentioned objects are achieved by the present invention which in a first aspect has the form of a method for treating already manufactured paper.
According to a second aspect the invention concerns a method for forming paper with anisotropic electric conductivity from a cellulose dispersion.
According to a third aspect the present invention concerns a paper.
Preferred embodiments of the invention are disclosed.
It should be emphasized that the term “paper” as used herein is not restricted with respect to its thickness, only with respect to the material as such.
In conducting the process of producing paper from a cellulose dispersion, a person skilled in the art will understand that any mechanical or other treatment which the cellulose dispersion is typically subjected to under such a process, may also be included in the present process without being specifically mentioned here.
The steps will typically be performed in sequence, but some variations may occur. For instance, the step of applying an electric field will usually not be terminated when the next step is initiated, and may, but need not, continue until a mainly dry paper product is obtained.
In a preferred embodiment of the first aspect of the invention, the paper is, as the first characterizing step, soaked in the non-aqueous, liquid dispersion.
In a preferred embodiment of the second aspect of the invention, the cellulose dispersion is an industrial paper pulp and the cellulose dispersion may contain organic or inorganic additives which are common in the paper manufacturing industry.
While typically the entire paper treated or produced is provided with that the anisotropic electric conductivity, in some cases the anisotropic electric conductivity is restricted to one or more areas smaller than the paper treated or produced.
It is important that the concentration of conductive particles in the liquid dispersion thereof can be comparatively low and for many applications well below the percolation threshold of the corresponding isotropic dispersion.
This makes paper less expensive and in some cases its preparation is easier.
When the electric field is applied to the liquid dispersion, be it applied to a manufactured paper or to a cellulose dispersion, the conductive particles start to align with the electric field. If an AC source is used, the particles are generally aligned symmetrically from both sides of the “matrix” in which the particles are confined, forming long strings parallel to the electric field. According to one embodiment these mainly mutually parallel conductive pathways are directed perpendicular to the two largest dimensions of the paper. In another embodiment, however, dependent upon the application and the positioning of the electrodes, the mainly mutually parallel conductive pathways are parallel to a plane formed by the two largest dimensions of the paper.
A special effect may be obtained by using a DC current. In this case strings of conductive particles will start growing from just one side, i.e. shorter strings that will eventually build a conductive network mainly sideways at the surface from which the strings started to grow. In this case the strings thus assume the shape of a branched structure that extends mainly transverse to that of the electric field applied and the obtained conductivity becomes two-dimensional and mainly perpendicular to the direction of the applied electric field. Its direction or directions are still determined by that of the electric field but not coinciding with the electric field.
Such dispersion may contain small amount of water but it should be a minority component to avoid hydrolysis by electric field. Alternatively the field should be very low.
The step of eliminating the dispersion agent is typically conducted by mechanically removing part of it and thereafter evaporating the remaining parts. It is also feasible that the dispersion agent may be a monomer which is eliminated by its polymerization to a solid material.
If the solvent is volatile enough, it is also possible to rely only on evaporation process.
The conductive particles are infusible particles such as carbon particles, metal oxide particles, metal coated particles, or metal particles. It is preferred that the particles generally have a low aspect ratio, i.e. they are not fibre-like or extremely elongate in one direction. The particles may be spherical but are more typically irregular of any random shape. Particles of more regular shape, other than spherical, may also be used, e.g. disc shaped particles having to dimensions more or less equal and a third dimension which is smaller. The term “low aspect ratio” as used herein refers to aspect ratios lower than 20, preferably lower than 10 and more preferably lower than 5, the aspect ratio defined as the largest linear dimension of a particle divided by the largest linear dimension perpendicular to said largest dimension
The cellulose dispersion according to the second aspect of the present invention can contain one or several optional components, typically components commonly used in paper manufacturing, provided such components do not negatively interact with the system, e.g. make the conductive particles settle or agglomerate. Such components may be added at any stage of the process, before or after the addition of conductive particles or together with the conductive particles. The cellulose system is characteristically lyotropic which means that the cellulose/paper can be plasticised by solvent and solidified by evaporating this solvent partly or fully. A person skilled in the art will understand that minor amounts of fibres other than cellulose fibres can also be included as long as their properties are compatible with cellulose. Even carbon nano-fibres may be added to the cellulose dispersion in limited concentrations.
The electric field can be created between one or more pairs of electrodes that can be placed either in direct contact with one or both sides of the cellulose dispersion or paper or outside additional insulating layers, where the insulating layers are placed in contact with the cellulose dispersion or paper; or that may not be in direct contact with the cellulose dispersion or paper. Typically, at least one electrode, and preferably all of the electrodes, has/have the shape of an open grid to allow fluid to pass therethrough.
The direction of the electric field can be predetermined by the electrode arrangement and thereby the direction of the electric connections formed by the aligned conductive particles can be controlled.
The electric field applied can be in the order of 0.05 to 10 kV/cm, or more specifically 0.1 to 5 kV/cm. This means that for a typical alignment distance in the range of 10 □m to 1 mm, the voltage applied can be in the range of 0.1 to 100 V. The field is typically an alternating (AC) field, but can also, for specific purposes, be a direct (DC) electric field. A typical field is an AC field having a frequency of 10 Hz to 10 MHz. Very low frequencies <10 Hz or DC fields lead to asymmetric chain formation and build up. The low voltage needed for applying the method is simple to handle in a production line and does not need the specific arrangements necessary when handling high voltages.
Thus, the present invention is based on the finding that it possible to align conductive particles in lyotropic cellulose matrices using an electric field to form particle pathways. The pathways are able to enhance the macroscopic conductivity of the material. In particular, the formation of conductive pathways allows the material to become conductive also when it contains a lower amount of conductive particles than is otherwise necessary for creating electrical contact for the material having randomly distributed particles. The amount of conductive particles in the cellulose matrix could thereby be reduced and be up to 10 times lower than the isotropic percolation threshold or even lower.
Moreover, this procedure renders anisotropic material and directional conductivity that is higher along the alignment direction(s) than perpendicular to same. The anisotropic conductive properties may be exhibited by the entire paper or to one or more limited areas thereof. The conductivity may be unidirectional or assume the form of a layer restricted to one side of the paper. More typical the conductivity is unidirectional and aligned across the paper thickness.
The method can be used to produce electric conductive paper which has a wide range of applications. One of these applications is preventing or reducing electromagnetic interference (EMI) by using the paper as shielding. Another application is to use the paper for electric shielding, electrostatic discharge (ESD) material, in batteries, capacitors and as high-performance energy storage devices such as super-capacitors. Frequency identification tags may also be a possible application in the future as well as for providing watermarks in paper or even “intelligent” functionality” in papers of different kinds, such as security control mechanisms for bank notes. Many other future applications may be feasible and the present invention is not restricted to certain uses or applications.
If significant amounts of conductive particles are used in a paper, negative effects on the paper properties may occur, such as the paper becoming more stiff and brittle. A particular advantage of the present invention is that the anisotropic electric conductivity is obtainable at such low particle concentration that negative effects on the cellulose structure by the presence of particles, is neglectable.
LIST OF DRAWINGS
FIG. 1 shows schematics of the employed alignment procedures for in-plane alignment. This displays orientation electrodes, a, lyotropic mixture, b, evaporation of solvent, c, by alternating electric field, d, and thus obtaining aligned conducting pathways in the solid material, e.
FIG. 2 shows schematics of the employed alignment procedures for out-of-plane alignment. This displays lyotropic mixture, a, on the bottom electrode, top-electrode electrode with holes, b, evaporation of solvent, c, by alternating electric field, d, and thus obtaining aligned conducting pathways in the solid material, e, that can be free-standing, f, after removal of one or both electrodes.
FIG. 3 shows transmitted light optical micrograph of aligned material for a filler fraction at or above the corresponding isotropic percolation threshold.
FIG. 4 shows transmitted light optical micrograph of aligned material for a filler fraction an order of magnitude below the corresponding isotropic percolation threshold.
FIG. 5 shows optical micrograph of aligned material as seen in reflected light. The electrode configuration is as in FIG. 4 .
DETAILED DESCRIPTION OF THE INVENTION
In all embodiments, the method comprising the mixing of infusible conductive particles and fluid matrix that contains at least cellulose and solvent, the electric field alignment of conductive particles mixed in this fluid and the control of the viscosity of this mixture by evaporating solvent off. This procedure can be done using opposite electrodes for example in in-plane geometry or out-of-plane geometry, illustrated in FIGS. 1 and 2 , respectively.
The resultant aligned material retains anisotropic properties such as directional electrical conductivity. In this way, aligned conductive microstructures of originally infusible particles which do not allow alignment as such are formed.
The invention will be further described by the following examples. These are intended to embody the invention but not to limit its scope.
Example 1
This example is referred to FIG. 1 and FIG. 3 . The example concerns the preparation of a mixture of conductive particles that in this example are carbon particles and cellulose containing matrix that in this example contains solvent being thus lyotropic dispersion; as well as alignment of these particles so that the aligned particles form conductive paths resulting in a conductive material, whose conductivity is directional; and subsequent evaporation of solvent so that the aligned material is stabilized and the conductivity maintained.
In this procedure 2.78 wt-% (or ˜ 0.7 vol-%) microcrystalline cellulose powder with a particle size of 20 μm (Sigma-Aldrich) was mixed with graphene platelets with the lateral size of less than 5 μm (Angstron Materials). These two components were first mixed with 1-propanol, 1 part of cellulose and graphene in 6 parts alcohol. The cellulose powder and the graphene were uniformly dispersed in the alcohol.
The lyotropic mixture was spread on top of interdigitated electrodes with a spacing of 100 μm and area of 0.5 cm 2 .
A voltage of 19 V with a frequency of 1 kHz, thus corresponding to electric field of 1.9 kV/cm, was applied for about 3 minutes.
Most of the solvent was evaporated in about 30 seconds. The graphene platelets aligned into chain-like formations over this period. FIG. 3 shows optical micrograph of the aligned platelets in cellulose in the end of period.
The resistance before alignment is in the order of MΩ's, the resistance was about 200Ω after the alignment. The latter resistance corresponds to the DC conductivity of ˜ 5·10 −3 S/m.
Example 2
This example concerns scalability of particle fraction and its influence on the resultant conductivity.
The procedure was otherwise similar to that in Example 1, cf. FIG. 1 , but graphene concentration of ˜ 0.4 vol-% was employed. The material behaved similarly as in Example 1. The resistance was MΩ's before alignment and 10 kΩ after alignment.
FIG. 4 shows alignment of ˜ 0.4 vol-% (black) graphene platelets in (white) cellulose as taken by transmitted light.
FIG. 5 shows micrograph of the surface showing a good dispersion of the graphene platelets.
Example 3
This example concerns addition of inorganic additive to the mixture without adverse effect on the alignment.
Following the same procedure as in Example 1 and 2 but now clay was mixed with the microcrystalline cellulose powder and graphene platelets. The clay used was Laponite RD (Rockwood). The overall mixture contained 62.5 wt-% ( ˜ 90 vol %) cellulose 35 wt-% ( ˜ 9.6 vol %) clay and 2.5 wt-% ( ˜ 0.4 vol %) graphene. This solution was mixed as 1 part in 4 parts 1-propanol.
The resistance was 2 MΩ before alignment and 170 kΩ after in-plane alignment and evaporation.
This result shows that the cellulose and graphene solution was still conducting after mixing it with an inorganic material like clay.
Example 4
This exemplifies alignment of metal particles.
The materials were prepared and the alignment was performed as in Examples 1, 2, 3 and 4 but silver particles (Sigma-Aldrich) with the size of 10 μm were used instead of graphene platelets.
The alignment occurred as in Examples 1, 2, 3, and 4 but the obtained conductivity was higher, typically 100 times higher.
Example 5
This exemplifies alignment on existent paper or a cellulose containing sheet, cf. FIG. 1 .
The alignment was performed as in Examples 1, 2, 3 and 4 but the lyotropic mixture was poured on to the paper sheet that was put on the interdigitated alignment electrodes. To ensure fairly uniform field on top of the sheet, the electrode spacing was selected to be larger than the sheet thickness. For instance 200 μm and 80 μm were used for spacing and sheet thickness, respectively.
Alignment occurred as described in Examples 1, 2, 3 and 4 and the paper was conductive in-plane.
Example 6
This example shows alignment through existent paper or a cellulose containing sheet.
The alignment was performed as in Examples 1, 2, 3 and 4 but the lyotropic mixture was poured on to the paper sheet that was on a flat sheet-like bottom electrode. A sheet-like top electrode was then placed on the sample
Alignment occurred as described in Examples 1, 2, 3 and 4, the particle pathways were formed through the porous structure and the paper was conductive out-of-plane.
In order to achieve efficient evaporation the electrodes can also contain holes or they can be mesh-like and the solvent can get evaporated via these holes.
|
A method for treating a paper to provide at least a part of it with anisotropic electric conductivity, by i) applying to the paper a dispersion comprising a non-aqueous, liquid dispersing agent and conductive particles, ii) applying an electric field over at least part of the paper, so that a number of the conductive particles are aligned with the field, thus creating conductive pathways, and wholly or partially eliminating the dispersing agent and allowing the paper to dry thereby stabilizing and preserving the conductive pathways in the paper as well as paper so produced. The paper may alternatively be prepared from a cellulose dispersion comprising conductive particles and subjecting the dispersion for similar aligning of the conductive particles.
| 3
|
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is divisional of U.S. Ser. No. 10/599,092, now U.S. Pat. No. 7,887,671, which was a U.S. national phase application based on International Application No. PCT/SE2005/000350, filed Mar. 9, 2005, claiming priority from Swedish Patent Application No. 0400940-3, filed Apr. 7, 2004.
The present invention concerns a device for the dilution of dewatered cellulose pulp, and, more specifically, a device for diluting shredded cellulosic particles/chips.
THE PRIOR ART
In association with either one of the bleaching and the delignification of cellulose pulp in bleaching lines, the pulp passes between different treatment steps in which the pulp is subjected to bleaching or the delignifying effect of various treatment chemicals. The treatment typically alternates between alkaline and acidic treatment steps in which typical sequences may be of ECF type (elemental chlorine-free, Cl, in which chlorine dioxide may be used) such as O-D-E-D-E-D, O-D-PO or sequences of TCF-type (totally chlorine-free) such as O-Z-E-P. Other bleaching steps, such as Pa steps and H steps may be used.
The treatment steps may take place either at medium consistency (8-16%) or at high consistency (≧20-30%), but it is vitally important to wash out after each treatment step degradation products and lignin precipitated during the treatment step and to reduce to a minimum the remaining fraction of fluid, since the latter will otherwise lead to an increased requirement for pH-adjusting chemicals for the subsequent treatment steps and transfer of precipitated lignin and other degradation products, which subsequent step generally takes place at a completely different pH.
Simple vacuum filters with dewatering drums that are partially (typically 20%-40% of the drum) immersed in the pulp suspension that is to be dewatered were used in certain older types of washing step after a bleaching step or a delignification step. In these vacuum filters, a bed of pulp forms spontaneously against the outer surface of the drum under the influence of a negative pressure in the interior of the drum, and the pulp bed is drawn up from the pulp suspension by the rotation of the drum and is scraped off with a scraper on the side of the drum that is moving downwards. A consistency higher than 8-14% is generally never achieved for the pulp bed that has been dewatered, due to the limited degree of dewatering that is achieved, and the dewatered pulp that is scraped of can be readily formed to a slurry with a low consistency again in a subsequent collecting trough. The technique used here is a lower degree of dewatering followed by slurry formation with a cleaner filtrate, and this takes place in a series of vacuum filters in order to achieve the required washing effect. For this reason, it is attempted to achieve as high a degree of dewatering as possible before the dewatered pulp is again formed to a slurry with cleaner filtrate before the subsequent treatment stage.
A dominating washing machine on the market for bleaching lines is the conventional dewatering press, or thickening press, in which pulp is applied to at least one outer surface of the dewatering drum and subsequently passes a nip between the drums and acquires a consistency of 20-30% or greater after the nip. A practical upper limit lies at 35-40%, where a higher degree of dryness cannot be achieved without affecting the strength properties of the fibres negatively. A representative washing press of this type is disclosed in the U.S. Pat. No. 6,521,094.
The dewatered mat of cellulose pulp that is fed out from the washing machine's nip must first be shredded due to the high degree of dewatering, which shredding takes place in a shredder screw.
The purpose of the shredder screw has been exclusively to break up the mat of dewatered cellulose pulp and feed it onwards to equipment in which the cellulose pulp is rediluted to a consistency that makes it possible to pump it onwards to the next treatment step.
The redilution thus preferably takes place in association with adjustment of the pH, which after an alkaline wash normally involves the addition of powerful acidifiers, or the addition of acidic return water/filtrate from subsequent process steps, before the subsequent acidic treatment step. These acidic conditions have involved the dilution in general being held well separated from the previous alkaline wash as well as the associated shredder screw, since the alkaline wash can be built from simpler material than that which is normally required for washing machines that resist acidic conditions. Acidic conditions require material that can resist acids, and this is significantly more expensive that other material.
The pulp on exit from the shredder screw has a very high level of dryness, a consistency of 20-30% or greater, and this means that redilution has been carried out in all installed plants in at least one separate dilution screw arranged after the shredder screw, where the dilution fluid is added during intensive agitation from the dilution screw in order to achieve a suitable homogenous consistency that makes pumping onwards to the next treatment stage possible. The diluted pulp that is achieved after the dilution screw is fed to a stand pipe in the bottom of which a pump is arranged.
A second alternative for washing is the use of a dewatering screw, in which the cellulose pulp is first diluted and subsequently dewatered in a dewatering screw (of the Thune type or Sudor press type) to a level of dryness that considerably exceeds 20-30%. In this way, what is known as “wash-by-dilution” is achieved. A compacted and well-consolidated dewatered pulp is obtained at the exit from the dewatering screw also in this case. A redilution has been used also in this case after the dewatering screw, with the addition of dilution fluid during intensive agitation from a dilution screw.
The very high consistency of the pulp after the dewatering press or the dewatering screw has given rise to the belief that dilution to a homogenous medium consistency cannot be achieved unless dilution occurs under the influence of intensive agitation from the dilution screw. A consistency of the pulp of 20-30% or greater is experienced as dry and compacted. It can be mentioned for the sake of comparison that medium-consistency pulp is so compact that it is just about possible to walk on this pulp, when it is at the upper part of the consistency range.
The use of a dilution screw at this position, however, increases the requirement for energy, it increases investment costs, it raises the requirement for maintenance and it involves a further mechanical treatment of the pulp which has a negative influence on the strength properties of the pulp.
AIM AND PURPOSE OF THE INVENTION
The present invention is intended to remove the above-mentioned disadvantages and is based on the surprising insight that even if the pulp has been dewatered to give a very high consistency, 20-30% or more, no mechanical agitation at all is required during the dilution provided that the pulp bed has been shredded to give small granules of a suitable size, and provided that the dilution fluid is added evenly over a flow of the freely falling granulated pulp.
It has surprisingly turned out to be the case that the granulated pulp demonstrates the properties of a sponge, despite its high consistency, and that, provided the dilution fluid is added evenly to a flow of non-tightly packed granulated pulp in freefall, a primary homogenised dilution of the pulp takes place that is fully adequate such that it can subsequently be pumped or led onwards to the following bleaching stage or treatment stage.
It is sufficient in laboratory experiments with small quantities of well-granulated pulp with a consistency around 30-35% to pour the required amount of fluid to obtain the required consistency into a container with granulated and non-compressed pulp, and the complete mixture has been homogenised to an even consistency after the addition of the fluid totally without mechanical agitation. Observation of the granulated pulp has shown that there lie cavities between the granules, and the fluid rapidly penetrates between the granules through the complete volume of the granules, after which the granules absorb the fluid as sponges.
This primarily homogenised pulp is fully adequate to be pumped with a subsequent pump, in which a secondary or complementary homogenisation takes place, and these together ensure that the same degree of homogenisation of the pulp can be achieved for the subsequent treatment stage completely without mechanical agitation from a dilution screw. The principal aim of the invention is thus to redilute pulp from a high consistency of 20-30% or higher without the use of a dilution screw and without intensive mechanical agitation, which reduces losses in the strength of the pulp.
A second aim is to reduce operating costs and maintenance costs for the process equipment in the redilution, since no operation of dilution screw is necessary.
A further aim is to reduce the investment cost of the process equipment. A reduction of both operating costs and investment costs in the process equipment entails a reduction in the cost of manufacturing bleached pulp to an equivalent degree, and this saving is multiplied by the number of washing machines that are used in the bleaching line. No less than six washing machines are included in an O-D-E-D-E-D sequence, and thus the reduction in costs can be significant.
Approximately 50 kW is required solely for the operation of one dilution screw, and the investment cost is approximately SEK 500,000 (depending to a certain extent on requirements on materials, i.e. whether it needs to be acid-resistant or not).
The operating costs per year in an O-D-E-D-E-D bleaching line will be: 6*50 kW*SEK 0.20 (the price for an operator in Sweden)*24 hours*350 days (the number of operating days per year, excluding stoppages)=SEK 500,000 SEK per year;
and the investment cost will be: 6*SEK 500,000=SEK 3,000,000.
This investment cost at an interest rate of 5% corresponds to an annual expense of SEK 150,000.
In summary, implementation of the invention involves a total annual saving that approaches SEK 650,000-1,000,000 SEK including maintenance costs and building space (frameworks, etc.) in a bleaching line with a capacity of 1,000 tonnes per day.
Furthermore, availability of the mill increases since six machines can be removed, each of which has an MTBF (mean time between failure).
A further aim is to remove a treatment step between the washing machine and the subsequent pumping, which makes possible a more compact mill and opportunities to place the washing machines at a lower height over the ground in the mill. The washing machines are normally placed at a great height over the ground, and the pulp falls downwards after being washed in the washing machine while it passes through various conditioning steps. If one of these conditioning steps (such as the dilution screw) becomes unnecessary, the building height can be reduced, which In turn gives a saving.
DESCRIPTION OF DRAWINGS
FIG. 1 shows a typical treatment step for the pulp in a reactor with a subsequent washing press according to the prior art;
FIG. 2 shows part of the system in FIG. 1 (prior art);
FIG. 3 shows a dilution system according to the invention;
FIG. 4 shows a detail of FIG. 3 ; and
FIG. 5 shows a view seen from underneath in FIG. 4 , seen at the level of the section A-A.
FIG. 6 shows an alternative dilution system according to the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 shows a conventional treatment step for cellulose pulp, hereafter denoted “pulp”. The pulp is fed by the pump 1 to a mixer 2 in which necessary treatment chemicals are added. These treatment chemicals can be, for example, oxygen gas, ozone, chlorine dioxide, chlorine, peroxide, pure acid or a suitable alkali for an extraction step, or a mixture of these, and possibly other chemical or additives such as a chelating agent. The pulp is transported after the addition of the necessary chemicals by the mixer 2 to a reactor system 3 , here shown in the form of a single-vessel tower 3 of upwards flow. The reactor system can, however, be constituted by simple pipes or by one or several reactors in series, and possibly with the batchwise addition of chemicals between the towers in those cases In which the bleaching processes are compatible and do not require washing between the towers.
The treated pulp is fed after treatment in the reactor system 3 to a pulp chute/stand pipe 4 , which establishes the buffer volume and static pressure required, to a pump 5 arranged at the bottom of the pulp chute. The pulp is fed from the pump 5 to a washing machine 7 , shown here in the form of a washing press with two drums 7 a , 7 b . The pulp is applied to the drums, here at the 12 o'clock position, and is led by convergent pulp collectors during the addition of washing fluid (not shown in the drawing) to a final dewatering nip between the drums, from where a mat of dewatered pulp is fed upwards to a shredder screw 8 .
The drums in FIG. 1 rotate in opposite directions and the pulp mat is dewatered through the outer surface of the drum while the pulp is lead approximately 270 Degrees around the circumference of the drum to the nip. The washing press may be preferably equivalent to that revealed by the patent U.S. Pat. No. 6,521,094. Any other type of dewatering press or washing press, however, having a drum or drums, may be used, in which a consistency of 20-30% or higher is achieved, for example a washing press with a single dewatering drum and an opposing roller, or other types of washing press with two dewatering drums.
The pulp is fed upwards from the nip in the form of a dewatered and compressed mat 20 of cellulose pulp that has been consolidated into large pieces to a shredder screw 8 , the shredding axis of which is arranged to be essentially parallel to the axes of rotation of the drums. A small oblique mounting of a maximum of 5-10 Degrees may, for example, be present if a conical shredder screw is used, where the mat is fed to an inlet slit in the outer casing of a conical shredder screw, where the inlet slit lies parallel with the axes of the drums. The fragmented pulp is led after this shredder screw 8 out from an outlet in the casing of the shredder screw in the flow 21 to a dilution screw 30 that is driven by a motor 31 . The dilution screw exposes the pulp to continuous tumbling during the addition of dilution fluid Liq2, and the pulp is subsequently fed to a stand pipe 40 at its finally conditioned consistency. The pulp can subsequently be pumped from the stand pipe 40 to the next treatment step of similar type in the bleaching line.
FIG. 2 shows another view of a part of the same process in which the shredder screw 8 is oriented in the same direction as the dilution screw 30 . It can be seen more clearly here how the dewatered and compressed mat 20 of pulp that has been consolidated into large pieces is fed into the shredder screw 8 . The shredder screw contains a threaded screw 8 a that is driven by a motor 8 c , and that may also be equipped with a number of beaters 8 b at its outlet, which beaters further whip and break up the shredded pulp. The purpose of the shredder screw is primarily to break into smaller pieces the dewatered and compressed mat 20 of pulp that has been consolidated into large pieces, and it may sometimes be sufficient with one such shredder screw. The beaters 8 b may be arranged on the same shaft as the shredder screw and they provide an extra fragmentation effect, but they are primarily used to hold the outlet from the shredder screw free from the formation of blockages.
The fragmented flow 21 of pulp particles is fed thereafter to fall under its own weight to the subsequent dilution screw 30 .
FIG. 3 shows the dilution system according to the invention in a treatment step that is otherwise equivalent to that shown in FIG. 1 . The dewatered web of pulp, which has a consistency of 20-30% or greater, is fed in this case in to the shredder screw 8 in the same way as shown in FIGS. 1 and 2 . However, dilution occurs in the outlet from the shredder screw according to the invention in a significantly simplified manner. It is important that the web or mat 20 of pulp, which maintains a consistency of 20-30% or higher, is first fragmented by the shredder screw such that the mat 20 is granulated to a particle size that is normally distributed around a mean size that lies in the interval 5-40 mm. This is taken to denote that the fragmented pulp has a particle size that is normally distributed around a maximum size that is less than 40 mm, preferably less than 30 mm, and even more preferably less than 20 mm. It is appropriate that the normal distribution is distributed such that 90-95% of the fragmented pulp lies within +− 5 mm of the maximum size, 40-30 or 20 mm, of the fragmented pulp.
The granulated pulp is then fed out from the outlet of the shredder screw in free fall into a stand pipe 22 connected to the outer casing of the shredder screw at its outlet. The dilution fluid Liq DIL is subsequently added under pressure into the stand pipe through a number of fluid jets preferably arranged around the periphery of the stand pipe and above a level Liq LEV of diluted cellulose pulp established in the stand pipe. Alternatively, some or all of the fluid jets may originate from a central pipe that is located in the flow of the fragmented pieces of pulp that are standing in free fall, and where the fluid jets are directed essentially radially outwards. A certain oblique adjustment may be established, but it is preferable that the jets are directed towards the freely falling flow with an angle of attack of 90 Degrees, or within the interval 90 Degrees+−60 Degrees (=30 Degrees−155 Degrees), such that a certain minimum angle of attack is established. There may be so many fluid jets that an essentially continuous “fluid curtain” is established, or the dilution fluid may be injected into the flow of freely falling fragmented pulp through one or several slits. The important fact is that the dilution fluid is added to the flow at several points and at points at which the granulate is falling freely before it reaches the underlying surface of pulp that has been diluted to its final degree.
In the embodiment shown in FIG. 3 , the upper connection 22 of the stand pipe to the outer casing of the shredder screw has a smaller diameter than the lower part 40 ′ that lies below. The principle is that the pulp falls under the influence of gravity down through the parts 22 , 40 ′ of the stand pipe, and its lower part 40 ′ is given a larger diameter in order to be able to establish a suitable buffer volume before the pumping with the pump 41 ′ at a given level of pulp LiqLEV in the stand pipe 22 , 40 ′.
The amount of dilution fluid Liq DIL added establishes a consistency of the cellulose pulp within the range of medium consistency 8-16%, which is a consistency that allows the pulp to be sent onwards using an MC pump. The amount of dilution fluid that is required in order to establish the consistency at which the pulp is subsequently pumped is constituted to more than 75-90% of the fluid that is added at the said nozzles arranged above the level/surface that has been established in the stand pipe. A certain amount of chemicals such as acidifiers/alkali or chelating agents may be added at the bottom of the stand pipe 22 / 40 ′, but the principal dilution takes place with the dilution fluid above the pulp level established in the stand pipe.
The cellulose pulp at this medium consistency is fed by the pump 41 onwards from the lower end of the stand pipe to subsequent treatment steps for the cellulose pulp.
The dilution of the pulp from high consistency of 20-30% or greater at the upper part of the stand pipe to a medium consistency of 8-16% before the pumping from the lower part of the stand pipe takes place in this manner exclusively under the influence of the hydrodynamic effect from the addition of the dilution fluid through the said nozzles.
FIG. 3 and FIG. 4 show an embodiment of the manner in which addition of the dilution fluid can be realized. The dilution fluid is added by a pump to a distribution chamber 60 that is arranged concentrically around the stand pipe 22 . The pump pressurizes the fluid to a suitable level, an excess pressure of approximately 0.1-0.8 bar. Alternatively, high-pressure nozzles can be used, which finely distribute the dilution fluid in the form of fanned plumes of fluid, oriented at a suitable angle relative to the vertical, a suitable angle being 30-90 Degrees.
A number of nozzles 62 are arranged at the bottom of the distribution chamber oriented obliquely downwards, in the direction of flow of the granulate, and inwards towards the center of the flow. The amount of obliqueness in the mounting is appropriately 45+−15 Degrees relative to the vertical. The oblique orientation downwards is favorable for achieving an ejecting influence on the granulate flow, and for avoiding the risk that the dilution fluid splashes upwards in the stand pipe.
A number of nozzles, at least four, are arranged around the stand pipe 22 / 40 ′, preferably with equal distances between them. With a stand pipe 22 having a diameter of 800-1,500 mm, it is appropriate that 10-40 nozzles are arranged around the periphery of the stand pipe. It is appropriate that the distance between adjacent nozzles be less than 50-300 mm. If high-pressure nozzles with fanned plumes of fluid are used, the nozzles may be arranged with a greater distance between neighbouring nozzles. It is important that the dilution fluid is added evenly around the complete circumference of the flow of granulate and at a sufficiently high pressure in order to penetrate to the centre of the granulate flow. The pressure setting is an engineering adaptation that is based on the nozzles being used, the diameter of the pipe and the rate of flow of fragmented pulp.
FIG. 6 shows an alternative embodiment of the invention. The difference between the embodiment shown in FIG. 3 and this embodiment is that the dewatering arrangement in this case is a deewatering screw (of Thune type or Sudor type) in which a conical screw 80 a compresses an incoming flow 20 of pulp during dewatering against a surrounding space through a screwed surrounding perforated housing, and in which filtrate 80 b is led away from this space. The driving force for the screw is normally located at its inlet, but the motor 8 c is here shown connected to the outlet of the screw.
The dewatered and compressed pulp that has been consolidated into large pieces is also in this case fed from the outlet of the screw to a simpler fragmentation arrangement in the form of a number of beaters 8 b that may be located on the same shaft as the conical screw while being located at its outlet. These beaters 8 b whip and break up the pulp that is fed out from the dewatering screw in the form of dewatered and compressed pulp that has been consolidated into large pieces. It Is preferable that these beaters have their own source of power, and that they are driven at a rate of revolution that considerably exceeds the rate of revolution of the screw.
The fragmented flow 21 of pulp particles is subsequently fed by falling under its own weight to the fall 40 , in the same manner as that shown in FIG. 3 . Furthermore, a second dewatering screw 90 is arranged to receive the diluted pulp suspension at the bottom of the fall 40 . The dewatering screw 90 may be another transport arrangement or another distribution arrangement, such as, for example, a distribution screw in the inlet arrangement to a dewatering press.
The dilution otherwise functions in the same manner as in the embodiment shown in FIG. 3 , and those parts that are the same have the same reference numerals.
The invention can be modified in a number of ways within the scope of the claims. The nozzle 62 for the addition of dilution fluid may, for example, be constituted by a simple drilled hole in a thick corrugated sheet, with a minimum thickness of 8-10 mm. However, specially adapted nozzles are preferred, which preferably generate a fan-shaped plume of fluid, in order to ensure optimal penetration of the granulate flow and an even distribution over the complete circumference of the flow. Addition of dilution fluid can also take place at a sufficiently high pressure that the dilution fluid more forms a very finely divided mist in the region that the granulated pulp passes.
Addition of dilution fluid takes place in the preferred embodiment in association with an increase in the area of the stand pipe 22 to a lower part 40 ′ of the stand pipe having a larger diameter, but it is not necessary that the addition takes place in association with an increase in area. A small amount may also be added at the outlet end of the shredder screw, with the addition flow directed down towards the stand pipe. But the dilution is to take place principally through the hydrodynamic mixing effect from the addition of the dilution fluid into the flow of granulate.
|
The device is for the dilution of dewatered cellulose pulp that maintains a consistency of 20-30% or greater. By shredding of the pulp to a finely divided dry-granulate, dilution to a homogeneous consistency in the medium consistency range can take place exclusively through hydrodynamic effects from the addition of dilution fluid. The dilution fluid is added to granulate at a position at which granulate is in free fall in a standpipe and above a level Liq lev of diluted pulp in the standpipe. A number of nozzles are arranged around the periphery of the stand pipe, directed in towards the center of the stand pipe, obliquely downwards in the direction of fall of the granulate. It is possible through this simplified procedure to avoid completely the conventional dilution screws, and this reduces the investment costs and operating costs, while at the same time unnecessary mechanical influence of the pulp fibers can be avoided.
| 3
|
FIELD OF THE INVENTION
The present invention relates in general to a suction member and more particularly to a suction roll or suction cylinder which comprises a roll mantle, end flanges connected to ends of the mantle and roll axle journals connected to the end flanges and on whose support the suction roll/suction cylinder revolves. The roll mantle comprises numerous perforations, holes or equivalent openings passing therethrough. The suction roll/suction cylinder is connected to a suction duct that passes into the interior of the roll mantle and transfers a vacuum force or negative pressure into the roll mantle. Air is thus drawn or sucked through the perforations into the interior of the roll mantle to press the paper web toward the outer face of the roll mantle and from the interior of the roll mantle through the suction duct.
The present invention also relates to a method for removing air from a roll or cylinder such as suction roll or suction cylinder.
BACKGROUND OF THE INVENTION
In the following description, in order to simplify the description, the designation "suction roll" will be used instead of suction member. This does not, however, restrict the invention in any way whatsoever, but rather the term suction roll refers to various suction rolls, suction cylinders, and equivalent suction members.
With respect to the prior art, reference is first made to the current assignee's Finnish Patent No. 83,680 (corresponding to U.S. Pat. No. 5,022,163, which is incorporated by reference herein), which describes a suction roll for supporting the paper web which does not comprise a suction box in the interior of the roll. Rather, the suction roll is constructed such that it comprises perforations in the roll mantle and, at the ends of the perforations, a separate recess, preferably a groove, through which the vacuum is distributed over a wider area on the roll face so as to produce a suitable suction force across the paper web. In this manner, with a favorable dimensioning of the perforations, an adequate holding force to hold the web is obtained without the need to place a suction box or an equivalent arrangement in the interior of the suction roll mantle.
When air is removed out of a revolving roll whose mantle is perforated and whose interior is empty, through a hollow centrally-located shaft or suction pipe in the shaft, in the suction pipe in the shaft a vortex is formed, which produces a high flow resistance and, thus, makes the removal of air from the roll mantle interior more difficult. With respect to the prior art related to this concept, reference is also made to the current assignee's Finnish Pat. No. 82,849 (corresponding to U.S. Pat. No. 5,024,729, which is incorporated by reference herein), which describes an embodiment related to the problems described above. In the suction roll in accordance with FI Pat. No. 82,849, it is considered a novelty that the suction roll comprises at least a vortex prevention equipment placed at the vicinity of the suction pipe of the suction roll. This vortex prevention equipment comprises at least one plate part which has a face substantially parallel to the radius of the roll, i.e., transverse to the axial direction of the roll, and which vortex prevention equipment is arranged in such a way in relation to the end of the suction pipe that, in an operative suction situation, increasing vortex formation in the sucked air is prevented and, thus, the vacuum level/negative pressure force is kept at a desired, substantially invariable value on the inside face of the roll mantle across the entire width of the roll. Also, the flow rate of suction air through the perforations in the roll mantle is kept at a desired, substantially invariable value. However, in this prior art construction, problems have still been caused by the pressure loss produced by the centrifugal force arising from the speed of rotation.
OBJECTS AND SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to suggest a novel solution for the problem described above which arises from the fact that, during its rotation, the suction roll produces a resistance against the air to be sucked, which air resistance increases when the speed of rotation increases and thus makes removal of air out of the roll more difficult. Also, in this case, the centrally-arranged suction force must also overcome the resistance arising from rotation. When the suction takes place from the hole in the shaft of the roll, the negative pressure dependent on the speed of rotation of the roll center, i.e., the difference in pressure arising from the centrifugal force, is about 300 Pa to about 500 Pa even if the suction effect has not yet been switched on. Thus, an object of the present invention is also to overcome this negative pressure and, at the same time, to provide a solution thereto in which the dynamic pressure produced by the rotation of the roll (about 200 Pa to about 300 Pa) in the air is utilized.
It is another object of the present invention to provide a new and improved suction apparatus in which the same suction air flow is produced in the air duct with a clearly lower vacuum, compared with the prior art suction apparatus.
It is a further object of the present invention to provide a suction member such as a suction roll in which a vacuum source is not connected with the suction duct at all.
It is yet another object of the present invention to provide a new and improved suction apparatus such as a suction roll by whose means it is effectively possible to remove a large quantity of air through perforations in the suction roll without a pressure loss arising from centrifugal force.
It is another object of the present invention to provide a new and improved method for removing air from an interior of a roll or cylinder such as a suction roll or suction cylinder.
In view of achieving the objects stated above, those that will come out later and others, the suction member in accordance with the invention, which may be a suction roll or suction cylinder, comprises a system of suction pipes connected with a centrally arranged suction duct, i.e., a suction duct extending through or defined within one or both of the axle journals of the roll. The system of suction pipes includes at least one suction pipe arranged in the interior of the roll to which air is guided and/or sucked from the vicinity of an inner face of the roll mantle of the roll/cylinder.
In a suction roll in accordance with the present invention, the lowering of the vacuum level in the duct is achieved so that a stationary system of suction pipes has been installed in the interior of the roll through the suction opening of the suction roll, and the suction openings in the system of suction pipes are directed against the rotational movement of the roll and are placed in the vicinity of, i.e., proximate to, the outer circumference of the roll near the inner face of the roll mantle. The air to be sucked is thus drawn or taken from the outer circumference of the layer of air revolving inside the roll from the lowest vacuum and, at the same time, the dynamic motive energy of the revolving air is also utilized. In this manner, a lower vacuum is achieved in the system of suction ducts with the same quantity of air, compared with a prior art suction roll in whose interior there is no system of suction pipes. In this way, economies are obtained in the consumption of energy.
In the arrangement in accordance with the invention, when the speed of rotation of the roll increases, the requirement of vacuum in the suction duct of the suction roll also becomes lower, which also reduces the consumption of energy of the apparatus used for the generation of vacuum, such as, for example, blowers. In the arrangement of the present invention, the flow of suction air in the suction duct can also be produced completely without a source of vacuum by utilizing the centrifugal air flows.
The invention is particularly well suitable for use in suction rolls in which there is no inside suction box, such as, for example, the current assignee's suction rolls of the "VAC ROLL"™ type, whose construction is described in detail, e.g., in the current assignee's Finnish Pat. No. 83,680 mentioned above.
In its most general embodiment, the suction member in accordance with the invention includes a roll mantle defining an interior, end flanges arranged at ends of the roll mantle and axle journals connected to the end flanges for rotatingly supporting the roll mantle. At least one of the axle journals defines a suction duct in flow communication with an interior of the roll. The roll mantle has an outer face, an inner face and plurality of apertures extending from the outer face to the inner face. Suction means are provided for drawing air into the interior of the roll through the apertures and from the interior of the roll through the suction duct. The suction means comprise a suction pipe system arranged in flow communication with the suction duct and which includes at least one suction pipe extending within the interior of the roll to a location proximate the inner face of the roll mantle such that air is guided and/or sucked from the location proximate the inner face of the roll mantle through the suction pipe system into the suction duct. The suction pipe(s) can extend from a centrally arranged flange part in a radial direction toward the inner face of the roll mantle. Also, if more than one suction pipe is provided, the suction pipes are preferably placed substantially in a common plane in a direction transverse to an axial direction of the suction member and extend from the flange part in opposite directions in relation to one another. The suction pipe(s) can also be elongate and have a first end connected to the flange part and a second end opposed to the first end opening at the location proximate to the inner face of the roll mantle, the pipe(s being sealed between the first and second ends.
The method in accordance with invention for removing air from an interior of a suction roll is applicable for a suction roll including a roll mantle, end flanges arranged at ends of the roll mantle and axle journals connected to the end flanges for rotatingly supporting the roll mantle, and whereby at least one of the axle journals defines a suction duct and the roll mantle has an inner face. The method comprises the steps of directing air from a location proximate the inner face of the roll mantle into and through at least one suction pipe extending within the interior of the roll to the location proximate the inner face of the roll mantle, fluidly coupling the suction pipe(s) to the suction duct, and applying negative pressure through the suction duct.
In other embodiments of the method, there are a pair of elongate suction pipes, each of which has an end having a suction opening adjacent to the inner face of the roll mantle. The suction openings of the suction pipes are oriented in a direction substantially perpendicular to a direction of air flow rotating in the interior of the roll during rotation of the roll. The suction pipe(s) may be mounted in a stationary position during operative rotation of the roll. Also, the roll can be rotated at a first speed, and the suction pipe(s) rotated at a second speed substantially slower than the first speed of rotation of the roll. The roll may also be rotated in a first direction of rotation whereby the suction pipe(s) is/are rotated in a second direction of rotation opposite to the first direction of rotation of the roll.
In the following, the invention will be described in more detail with reference to the figures in the accompanying drawing. However, the invention is not in any way strictly confined to the details of the illustrated embodiments alone.
BRIEF DESCRIPTION OF THE DRAWINGS
The following drawings are illustrative of embodiments of the invention and are not meant to limit the scope of the invention as encompassed by the claims.
FIGS. 1A and 1B are schematic sectional views of a prior art suction roll.
FIGS. 2A and 2B illustrate an arrangement in accordance with the invention for lowering the vacuum level in the suction duct of a suction roll, and which may be used in the method in accordance with the invention.
FIG. 3 is a schematic illustration of test results of the static pressure in the suction duct as a function of the air quantity in a prior art suction roll as compared with a suction roll provided with an arrangement in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1A and lB show a prior art suction roll 10. The suction roll 10 comprises a roll mantle 11 revolvingly mounted on axle journals 13A and 13B coupled to the roll mantle 11 by means of end flanges 12A and 12B, respectively. The roll mantle 11 includes perforations 15 which comprise a large number of holes 15 passing through the roll mantle 11 from its outer face to its inner face. In this manner, upon the application of a vacuum in an interior 16 of the suction roll 10, air is operatively drawn or sucked through the holes 15 in the roll mantle 11 into the interior 16 of the suction roll 10 (in the direction of arrows A), and a paper web W is thus drawn by means of the thus-generated vacuum into contact with the felt F or equivalent on which it is being carried over the suction roll 10 (FIG. 1B). A suction duct 21 is defined in, or connected to and extending through, the axle journal 13A, i.e., the axle journal 13A may be a hollow shaft alone acting as a duct or a separate duct member may be placed within the hollow shaft. The suction duct 21 can also be provided at both ends of the roll 10, i.e., one arranged in connection with each axle journal. The other end of the suction duct 21 is connected to a blower or to some other, equivalent source of vacuum/negative pressure (not shown). In this manner, the hold of the web against the felt F as they pass over the suction roll 10 is achieved by means of the suction roll 10, which has no stationary air sector. The perforations 15 are dimensioned so that the air flow rate through the perforations remains within controlled limits in all positions of the face of the roll mantle. In the assignee's suction roll of the VAC-ROLL™ type, there are additionally grooves 17 on the outer face of the roll mantle, which grooves equalize the vacuum. Such a roll is described in more detail in FI Pat. No. 83,680 mentioned above.
Referring now to FIGS. 2A and 2B wherein the same reference numerals refer to the same or similar elements, and the same nomenclature used above is also used in pertinent part, FIGS. 2A and 2B show an arrangement in accordance with the present invention in which a system of suction pipes 20 is placed inside a suction roll 10 at the side of an axle journal 13A of the suction roll 10. Air is drawn or sucked through the system 20 of pipes and through a suction duct 21 in flow communication therewith as an air flow C. Suction duct 21 is situated in a hollow central space of axle journal 13A. If a suction duct 21 is provided in connection with each of the axle journals 13A, 13B, a system of suction pipes 20 can then, of course, be fitted in connection with each of the axle journals. The suction duct 21 is placed in a hole 14 passing through the axle journal 13A. A connecting flange or flange part 22 is arranged at the end of the suction duct 21 inside the roll 10 and in the interior of the roll 10. The system of suction pipes 20 comprises at least one and preferably a pair of suction pipes 23,24, as shown in the illustrated embodiment, which are connected to the connecting flange 22 and extend from the connecting flange 22 outward, but within the roll interior, the connecting flange 22 being placed on or substantially close to a central axis X of the roll 10 (FIG. 1). The suction pipes 23,24 thus extend radially toward an inner face of a roll mantle 11 of the suction roll 10 and open at a location displaced from the central axis of the roll 10. The suction pipes 23,24 are preferably stationary while the suction roll 10 revolves, which is achieved by appropriate mounting components. The suction pipes 23,24 may also revolve at a speed substantially slower than the suction roll 10 or in the opposite direction of rotation than the direction of rotation of the suction roll 10.
The suction pipes 23 and 24 are placed so that their respective suction openings 25,26, at an end opposite to an end attached to the connecting flange 22, are placed in the vicinity of, i.e, proximate to, the inner face of the roll mantle 11 of the suction roll 10. More precisely, the suction openings 25,26 should be positioned so that when the roll 10 revolves, they are situated on the outer circumference of the inside revolving air flow (or in fact, anywhere within the revolving air flow). In this connection, when the suction roll 10 revolves in the direction of rotation S, air is sucked into the interior of the roll 10 through the holes 15 passing through the mantle 11 as the air flows A. Air flow A turns, by the effect of the rotation of the roll 10, in the way indicated by the arrow A, into the direction of rotation S of the roll 10. The ends of the suction pipes 23,24 are preferably bent or shaped so that the suction openings 25,26 are oriented in a direction substantially perpendicular to direction of the air flow B revolving along with the circumference, in which case the air is guided into the suction pipes 23,24 and drawn therethrough. From the suction pipes 23,24, the air is carried further through the connecting flange 22 into the suction duct 21 into the suction flow C.
When the suction pipes 23,24 are stationary or revolve at a speed substantially slower than the speed of the roll 10 mantle, by means of the described arrangement it is possible to eliminate the pressure loss, which is produced by centrifugal force, which depends on the speed, and which can be typically from about 300 Pa to about 500 Pa in a high-speed paper machine. At the same time, it is also possible to take advantage of the dynamic pressure of the air revolving along with the roll, which pressure is, in a high-speed paper machine, from about 200 Pa to about 300 Pa. In this manner, in the system of suction ducts, a lower vacuum of from about 500 Pa to about 800 Pa is produced with the same quantity of air, compared with the situation in a roll which is not provided with the arrangement in accordance with the invention, but the holding effect on the web remains the same.
It is an interesting aspect that with an increasing speed of rotation, the effect of the arrangement in accordance with the invention is increased, and so, along with the reduction of the pressure of the air quantity to be sucked, the consumption of energy can be reduced, because the level of vacuum in the system of suction ducts can be made lower. By means of the arrangement in accordance with the invention, it is also possible to subject the roll face to a reasonable suction effect without a source of vacuum, because in such an embodiment, when the roll revolves, air is discharged out of the open air duct by the effect of the rotation of the roll.
In FIGS. 2A and 2B, an embodiment is shown in which there are two suction pipes 23,24, but the scope of the invention, of course, also includes constructions in which there is just one suction pipe or in which there are more than two suction pipes.
FIG. 3 is a schematic illustration of test results concerning the static pressure in the suction duct of a suction roll (the y-axis coordinate) as a function of the air quantity (the x-axis coordinate)in a prior art suction roll as compared with a suction roll provided with an arrangement in accordance with the present invention. The curves 31,32,33 illustrate the test results of a suction roll provided with an arrangement in accordance with the invention, and the curves 34,35,36 illustrate the test results of the prior art arrangement. The vertical axis Y represents the pressure in the suction duct, and the horizontal axis X represents the air quantity that is sucked into the suction roll. The curves 31 and 34 illustrate the operative situation at a speed of rotation of about 1800 meters per minute (m/min), the curves 32 and 35 illustrate the operative situation at a speed of rotation of about at 1500 m/min, and the curves 33,36 illustrate the operative situation at a speed of rotation of about at 1200 m/min.
In FIG. 3, in the curves 31,32,33, which illustrate the arrangement in accordance with the invention, it is seen that the pressure level rises above the 0-pressure level at low air flow rates. In this portion, the flow is directed outward from the suction opening of the roll without an outside source of vacuum. From the curves 31,32,33; 34,35,36 it can also be seen that the relative sequence of the curves is changed, compare, for example, the curves 31;34. In other words, by means of the arrangement in accordance with the invention, a certain amount of air can be removed out of the roll more easily at higher speeds of rotation. In the prior art construction, the situation is the opposite, in which case the suction must be intensified to produce the same effect.
The examples provided above are not meant to be exclusive. Many other variations of the present invention would be obvious to those skilled in the art, and are contemplated to be within the scope of the appended claims.
|
A method for removing air from a suction roll/suction cylinder and a suction roll/suction cylinder including a roll mantle, end flanges connected to the roll mantle and axle journals for revolvingly supported the roll mantle. The mantle has numerous perforations, holes or equivalent openings passing therethrough. The suction roll/suction cylinder is connected to a suction duct that passes onto the interior of the roll/cylinder and transfers a vacuum force therein. Air is drawn or sucked through the perforations into the interior of the roll mantle so as to press a paper web toward an outer face of the roll mantle. The suction roll/suction cylinder has a system of suction pipes connected with the suction duct and including at least one suction pipe into which air is guided and/or sucked from the vicinity of the inner face of the roll mantle of the roll/cylinder.
| 3
|
[0001] This application is a continuation of, and claims priority to, U.S. Provisional Application Ser. No. 60/459,763, filed on Apr. 2, 2003, the disclosures of which are herein incorporated by reference in their entireties.
BACKGROUND
[0002] Vaccines enable the body to fight infection. In the developed world, most vaccines are delivered by injection. Some research is currently ongoing to develop vaccines and antigens for transdermal delivery in an effort to confer improved immunity as well as improved patient compliance. There are several advantages to delivering antigens transdermally. Transdermal administration may improve patient compliance because it eliminates the discomfort of injections and other problems associated with needle exchange. By pulsing the antigen one can realize a further advantage by reducing the irritation caused by long-term contact of the transdermal adhesive, which tends to be very irritating. Pulsatile delivery also improves the driving force of the antigen across the skin and creates a higher probability that the antigen will make contact with the correct recipient cell (Langerhans cells).
[0003] Numerous companies have focused on the delivery of vaccines in an effort to meet significant unmet clinical needs. For example IOMAI, Gaithersburg, Md., Cygnus, Vyteris, and others.
[0004] It is well known in the art that the Langerhans cells, located in the upper spinosum layer of the skin, are dendritic cells. Langerhans cells were described in 1868, and they play an important role in contact allergies, the rejection of skin transplants, and other immunological processes of the skin. It is also well known in the art that these cells are the outermost post of the immune system.
[0005] The method for improving an immune response is preferably one that induces improved resistance to infection post administration of the antigen, such as by inducing or elevating a T cell response to the pulsatile transdermal administered antigen. Pulsatile transdermal delivery has been well documented by Wong, et al WO 96/00111. The pulsatile transdermal administration of the antigen and adjuvant can be delivered in a pulsatile fashion making contact with the Langerhans cells. This in turn triggers the dormant T-helper cells and thus initiates a primary T-cell dependent immune response.
[0006] Often times an adjuvant must be delivered with the antigen concomitantly in order to elicit an immune response. In order to produce such an immune response the adjuvant is required to stimulate the Langerhans cells so that they recognize the antigen and are stimulated to mature into dendritic cells. Pulsatile delivery of the adjuvant prior to and throughout the transdermal delivery of the antigen would give a more complete immune response.
[0007] The pulsatile delivery of the adjuvant to the dendritic cells, or Langerhans cells, provides substantial advantages over traditional sustained style delivery of transdermal or patch technology. The benefit of dosing an adjuvant concomitantly with an immune response producing material in a pulsatile fashion is three fold. First, multiple dosage units or spacing the dosing of the agent should allow for improved absorption since the skin would not reach saturation during pulsatile delivery. Secondly, studies demonstrate that an increased frequency of a lower dose yields better results than bolus dosing. And thirdly, by pulsing the adjuvant into the skin there would be less local toxicity due not only to the adjuvants, but also the active agent used in the transdermal administration of the antigen.
[0008] Pulsatile transdermal dosing can be effected through the use of externally regulated mechanisms such as those listed, but are not limited to: mechanical means such as electrophoresis, phonophoresis, iontophoresis, gene gun, and others; and chemical means such as pH sensitive gels, swelling mechanisms, solubility dependent control and temperature. In fact, many of these mechanisms are listed in WO 96/00111 by Wong et al.
[0009] The distinct difference between the prior art of Wong and the applicant's invention is that the material is not delivered through the tissue, which in effect gives biologically significant levels of the material in the systemic circulation, but is rather just delivered to the Langerhans cells, which then carry the antigenic material to elicit an immunological response.
Definitions
[0010] As used herein the term “antigenic material” shall mean any material which confers an immunologic response either in vitro or in vivo
[0011] As used herein the term “immunogen” shall mean any antigenic material
[0012] As used herein the terms “pulsatile” or “pulasatile fashion” shall describe the delivery of antigenic material such that a portion of the dose of the product is released, followed by a second portion of the dose of product, followed by a third portion of the dose of product, and so on.
DESCRIPTION
[0013] Antigens of interest
[0014] The types of infections that may be prevented by vaccination are numerous. Included in this application is just a short list of example diseases treatable by pulsatile transdermal vaccine treatment. Possibilities include, but are not limited to: staph, fungal infections that arise from psoriasis, other topical bacterial infections, melanoma, salmonella, influenza, travelers' diarrhea, tetanus, and H. Pylori. In addition, various autoimmune diseases, allergies, and multiple cancers are also subject to pulsatile transdermal vaccine treatment.
[0015] The present invention covers therapeutic proteins which include but are not limited to allergenic proteins and digested fragments thereof. These include pollen allergens from ragweek, rye, June grass, orchard grass, sweet vernal grass, red top grass, timothy grass, yellow dock, wheat, corn, sagebrush, blue grass, California annual grass, pigweek, Bermuda grass, Russian thistle, mountain cedar, oak, box elder, sycamore, maple, elm, etc. dust and mites, bee venom, food allergens, animal dander, and other insect venoms.
[0016] Therapeutic proteins include microbial vaccines which include viral, bacterial and protozoal vaccines and their various components such as surface antigens. These include vaccines which contain glycoproteins, proteins or peptides derived from these proteins. Such vaccines are prepared from Staphylococcus aureus, Streptococcus pyogenes, Streptococcus pneumoniae, Neisseria meningitides, Neisseria gonorrhoeae, Salmonellae, Shigellae, Eschrichia coli, Klebsiellae, Proteus species, Vibrio cholerae, Helicobacterpylori, Pseudomonas aeruginosa, Haemophilus influenzae, Bordetella pertussis, Branhamella catarrhalis, Mycobacterium tuberculosis, Legionella pneumophila, Pneumocystis carinii, Treponema pallidum, Chlamydia, Telanus loxoid, Diphtheria toxoid, Influenza viruses, adenoviruses, paramyxo viruses rubella viruses, polioviruses, hepatitis viruses, herpes viruses, rabies viruses, HIV-1 viruses, HIV-2 viruses, and papilloma viruses. Other therapeutic proteins include those used for the treatment of autoimmune disease and to prevent transplant rejection. Yet other therapeutic proteins include those used for the treatment of cancer and influenza.
[0017] The present invention can also be utilized with Synagis®, Respigam, Synagis: CHD, CAOV-T (FluMist Liquid), HPV Cervical cancer vaccine; Epstein Barr Virus vaccine, CMV vaccine, Pneumococcal vaccine, hMPV/PIV-3/RSV vaccine, and Human metapneumovirus Mab.
[0018] In obtaining bacteria preparations, it is preferable to employ lyophilized bacteria which can be purchased. Alternatively, the bacteria can be grown, killed, washed and thereafter lyophilized.
[0019] Autoimmune disease is a disease in which the body produces an immunogenic response to some constituent of its own tissue. An autoimmune disease can be classified into those which predominantly affect one organ, such as hemolytic anemia and chronic thyroiditis, and those in which the autoimmune disease process is diffused through many tissues, such as multiple sclerosis, systemic lupus erythematosus, and arthritis. Exemplary autoimmune diseases and corresponding auto antigens include:
Autoimmune Disease Therapeutic Protein Multiple Sclerosis Myclin basic protein Myasthemia Gravis Acetyl choline receptor Rheumatoid Arthritis Type II collagen Diabetes Mellitus Insulin Juvenile Diabetes Mellitus Insulin Autoimmune Thyroiditis Thyroid proteins
[0020] A second component which can be added to the therapeutic protein is a stabilizing agent. Stabilizing agents provide physical protection for the protein. Generally these stabilizing agents are therapeutically inactive water soluble sugars such as lactose, mannitol, and trehalose. These act to protect the therapeutic antigen during the coating process and the passage through the gastrointestinal tract.
[0021] The stabilizing medium ingredients can be present in a range of from about 1-10%, preferably at about 5%.
[0022] The antigen can be present in the range from about 0.5-10%, preferably at about 1%.
[0023] Antigen and Adjuvant can be present in a 1:2 ratio.
[0024] Adjuvant
[0025] The formulation also contains an adjuvant, although a single molecule may contain both adjuvant and antigen properties (e.g., cholera toxin) (Elson and Dertzbaugh, 1994). Adjuvants are substances that are used to specifically or non-specifically potentiate an antigen-specific immune response. Usually, the adjuvant and the formulation are mixed prior to presentation of the antigen but, alternatively, they may be separately presented within a short interval of time. For example the adjuvant can be pulsed once, twice or several times prior to antigen delivery or alternatively, the adjuvant can be pulsed in a variety of ways after the antigen is introduced.
[0026] Adjuvants include, for example, an oil emulsion (e.g., complete or incomplete Freund's adjuvant), a chemokine (e.g., defensins 1 or 2, RANTES, MIP1-.alpha., MIP-2, interleukin-8) or a cytokine (e.g., interleukin-1.beta., -2, -6, -10 or -12; gamma.-interferon; tumor necrosis factor-.alpha.; or granulocyte-monocyte-colony stimulating factor) (reviewed in Nohria and Rubin, 1994), a muramyl dipeptide derivative (e.g., murabutide, threonyl-MDP or muramyl tripeptide), a heat shock protein or a derivative thereof, a derivative of Leishmania major LeIF (Skeiky et al., 1995), cholera toxin or cholera toxin B, a lipopolysaccharide (LPS) derivative (e.g., lipid A or monophosphoryl lipid A), or superantigen (Saloga et al., 1996). Also, see Richards et al. (1995) for adjuvants useful in immunization.
[0027] An adjuvant may be chosen to preferentially induce antibody or cellular effectors, specific antibody isotypes (e.g., IgM, IgD, IgA1, IgA2, secretory IgA, IgE, IgG1, IgG2, IgG3, and/or IgG4), or specific T-cell subsets (e.g., CTL, Th1, Th2 and/or T.sub.DTH) (Glenn et al., 1995).
[0028] Cholera toxin is a bacterial exotoxin from the family of ADP-ribsoylating exotoxins (referred to as bAREs). Most bAREs are organized as A:B dimer with a binding B subunit and an A subunit containing the ADP-ribosyltransferase. Such toxins include diphtheria, Pseudomonas exotoxin A, cholera toxin (CT), E. coli heat-labile enterotoxin (LT), pertussis toxin, C. botulinum toxin C2, C. botulinum toxin C3, C. limosum exoenzyme, B. cereus exoenzyme, Pseudomonas exotoxin S, Staphylococcus aureus EDIN, and B. sphaericus toxin.
[0029] Cholera toxin is an example of a bARE that is organized with A and B subunits. The B subunit is the binding subunit and consists of a B-subunit pentamer which is non-covalently bound to the A subunit. The B-subunit pentamer is arranged in a symmetrical doughnut-shaped structure that binds to GM.sub.1-ganglioside on the target cell. The A subunit serves to ADP ribosylate the alpha subunit of a subset of the hetero trimeric GTP proteins (G proteins) including the Gs protein which results in the elevated intracellular levels of cyclic AMP. This stimulates release of ions and fluid from intestinal cells in the case of cholera.
[0030] Cholera toxin (CT) and its B subunit (CTB) have adjuvant properties when used as either an intramuscular or oral immunogen (Elson and Dertzbaugh, 1994; Trach et al., 1997). Another antigen, heat-labile enterotoxin from E. coli (LT) is 80% homologous at the amino acid level with CT and possesses similar binding properties; it also appears to bind the GM.sub.1-ganglioside receptor in the gut and has similar ADP-ribosylating exotoxin activities. Another bARE, Pseudomonas exotoxin A (ETA), binds to the .alpha..sub.2-macroglobulin receptor-low density lipoprotein receptor-related protein (Kounnas et al., 1992). bAREs are reviewed by Krueger and Barbieri (1995).
[0031] It is known in the art that cholera toxin (CT), its B subunit (CTB), E. coli heat-labile enterotoxin (LT), and pertussis toxin are potent adjuvants for transcutaneous immunization, inducing high levels of IgG antibodies but not IgE antibodies. It is also known that CTB without CT can also induce high levels of IgG antibodies. Thus, both bAREs and a derivative thereof can effectively immunize when epicutaneouly applied to the skin in a simple solution. As part of this invention it is apparent that pulsing the adjuvant would offer an advantage over static delivery so as to avoid possible toxic side effects elicited by the adjuvant.
[0032] When an adjuvant such as CT is mixed with BSA, a protein not usually immunogenic when applied to the skin, anti-BSA antibodies are induced. An immune response to diphtheria toxoid was induced using pertussis toxin as adjuvant, but not with diphtheria toxoid alone. Thus, bAREs can act as adjuvants for non-immunogenic proteins in an transcutaneous immunization system.
[0033] Protection against the life-threatening infections diphtheria, pertussis, and tetanus (DPT) can be achieved by inducing high levels of circulating anti-toxin antibodies. Pertussis may be an exception in that some investigators feel that antibodies directed to other portions of the invading organism are necessary for protection, although this is controversial (see Schneerson et al., 1996) and most new generation acellular pertussis vaccines have PT as a component of the vaccine (Krueger and Barbieri, 1995). The pathologies in the diseases caused by DPT are directly related to the effects of their toxins, and anti-toxin antibodies most certainly play a role in protection (Schneerson et al., 1996).
[0034] In general, toxins can be chemically inactivated to form toxoids which are less toxic but remain immunogenic. We envision that the transcutaneous immunization system using toxin-based immunogens and adjuvants can achieve anti-toxin levels adequate for protection against these diseases. The anti-toxin antibodies may be induced through immunization with the toxins, or genetically-detoxified toxoids themselves, or with toxoids and adjuvants such as CT. Genetically toxoided toxins which have altered ADP-ribosylating exotoxin activity, but not binding activity, are envisioned to be especially useful as non-toxic activators of antigen presenting cells used in transcutaneous immunization.
[0035] We envision that CT can also act as an adjuvant to induce antigen-specific CTLs through transcutaneous immunization (see Bowen et al., 1994; Porgador et al., 1997 for the use of CT as an adjuvant in oral immunization).
[0036] The bARE adjuvant may be chemically conjugated to other antigens including, for example, carbohydrates, polypeptides, glycolipids, and glycoprotein antigens. Chemical conjugation with toxins, their subunits, or toxoids with these antigens would be expected to enhance the immune response to these antigens when applied epicutaneously.
[0037] To overcome the problem of the toxicity of the toxins, (e.g., diphtheria toxin is known to be so toxic that one molecule can kill a cell) and to overcome the difficulty of working with such potent toxins as tetanus, several workers have taken a recombinant approach to producing genetically produced toxoids. This is based on inactivating the catalytic activity of the ADP-ribosyl transferase by genetic deletion. These toxins retain the binding capabilities, but lack the toxicity, of the natural toxins. This approach is described by Burnette et al. (1994), Rappuoli et al. (1995), and Rappuoli et al. (1996). Such genetically toxoided exotoxins could be useful for transcutaneous immunization system in that they would not create a safety concern as the toxoids would not be considered toxic. Additionally, several techniques exist to chemically toxoid toxins which can address the same problem (Schneerson et al., 1996). These techniques could be important for certain applications, especially pediatric applications, in which ingested toxins (e.g., diphtheria toxin) might possibly create adverse reactions.
[0038] Optionally, an activator of Langerhans cells may be used as an adjuvant. Examples of such activators include: inducers of heat shock protein; contact sensitizers (e.g., trinitrochlorobenzene, dinitrofluorobenzene, nitrogen mustard, pentadecylcatechol); toxins (e.g, Shiga toxin, Staph enterotoxin B); lipopolysaccharides, lipid A, or derivatives thereof; bacterial DNA (Stacey et al., 1996); cytokines (e.g., tumor necrosis factor-.alpha., interleukin-1.beta., -10, -12); and chemokines (e.g., defensins 1 or 2, RANTES, MIP-1.alpha., MIP-2, interleukin-8).
[0039] If an immunizing antigen has sufficient Langerhans cell activating capabilities then a separate adjuvant may not be required, as in the case of CT which is both antigen and adjuvant. It is envisioned that whole cell preparations, live viruses, attenuated viruses, DNA plasmids, and bacterial DNA could be sufficient to immunize transcutaneously. It may be possible to use low concentrations of contact sensitizers or other activators of Langerhans cells to induce an immune response without inducing skin lesions.
[0040] Adjuvant
[0041] The formulation of liposomes and antigen may also contain an adjuvant. Adjuvants are substances that are used to specifically or nonspecifically potentiate an antigen-specific immune response. Usually, the adjuvant and the formulation are mixed prior to presentation of the antigen but, alternatively, they may be separately presented within a short interval of time. Suitable adjuvants include, for example, an oil emulsion (e.g., complete or incomplete Freund's adjuvant), a chemokine (e.g., defensins 1 or 2, RANTES, interleukin-8) or a cytokine (e.g., interleukin-1, -2, -6, or -12; .gamma.-interferon; tumor necrosis factor; or granulocyte-monocyte-colony stimulating factor) (reviewed in Nohria and Rubin, 1994), a muramyl dipeptide derivative (e.g., murabutide, threonyl-MDP or muramyl tripeptide), a heat shock protein or a derivative, a derivative of Leishmania major LeIF (Skeiky et al., 1995), cholera toxin or cholera toxin B, or a lipopolysaccharide (LPS) derivative (e.g., lipid A or monophosphoryl lipid A). An adjuvant may be chosen to preferentially induce antibody or cellular effectors, specific antibody isotypes (e.g., IgM, IgD, IgA1, IgA2, secretory IgA, IgE, IgG1, IgG2, IgG3, and/or IgG4), or specific T-cell subsets (e.g., CTL, Th1, Th2 and/or T.sub.DTH) (Glenn et al., 1995).
[0042] Lipid A is derived from the lipopolysaccharide (LPS) of gram-negative bacterial endotoxin. It is an outstanding adjuvant that can be incorporated into the liposome bilayer to induce an immune response to a liposome-associated antigen (Alving, 1993). Lipid A is actually a heterogeneous mixture of compounds having similar structures (Banerji and Alving, 1979). The methods ordinarily used to obtain lipid A can produce a crude fraction, which is then purified by ethylenediamine tetraacetic acid and chloroform extraction to give a purified lipid A that is chloroform soluble (Banerji and Alving, 1979).
[0043] Other non-toxic adjuvants also fall into the type like aluminum hydroxide. (allergenics example).
[0044] The addition of bile salts in the form of bilosomes to oral vaccines has been reported to stimulate the potency of the immune response when added to synthetic measles peptide antigen-influenza vaccine combination therapy. (By Sharp, Acurian web site www.acurian.com) Similar penetration enhancers known to one skilled in the art of transdermal delivery may act as adjuvants. Those penetration enhancers known to disrupt the statum corneum, such as surfactants that may also be compatible with the antigen being delivered could be considered for this type of application.
[0045] Pulsing Schemes
[0046] Pulsatile delivery of the antigen/adjuvant combination can occur via various patterns of delivery. The following table outlines possible patterns of pulsing used to achieve optimum antigenic response. The table outlines the first several pulses in a system, but is not meant to indicate that the system is limited to 4 pulses. The pulsing patterns described are repeated until an appropriate therapeutic effect is attained either by titre or by previous experimentation and determination.
Patch Constant Type Pulse 1 Pulse 2 Pulse 3 Pulse 4 Delivery I Antigen Adjuvant Antigen Adjuvant II Adjuvant Antigen Adjuvant Antigen III Adjuvant Adjuvant Antigen Adjuvant Antigen IV Adjuvant Adjuvant Adjuvant Adjuvant Antigen V Antigen Antigen Antigen Antigen Adjuvant
[0047] While not required for use with the transdermal method of the invention, permeability enhancers conventionally known in the art can also be present. Suitable permeability enhancers are listed but are not limited to fatty acid esters or fatty alcohol ethers of C 2-4 alkanediols, alcohols, such as ethanol, dimethyl sulfoxide, dimethyl lauramide, polyethylene glycol monolaurate and the like.
[0048] The dose and frequency of transdermal administration of a substance by the method of the invention depends on a number of factors, including the antigen/adjuvant combination being used, the intended use, potential skin irritation side effects, the lifetime of the substance, the tissue to which it is being administered, the age, weight and sex of any subject or patient. One skilled in the art will know how to evaluate these factors to determine a suitable dose and frequency of administration. A prior art rate control delivery device is designed to release an antigen/adjuvant at rates lower than that obtainable through skin of average permeability and to contain sufficient antigen/adjuvant such that unit activity is maintained throughout the desired rate of delivery.
[0049] Transdermal Delivery Devices and Mechanisms:
[0050] Numerous examples of transdermal delivery systems are know in the art and are currently on the market world wide. There are currently two types of transdermal drug delivery systems: “passive” and “active”. Passive systems deliver drug through the skin of the user unaided, which is the most popular type of transdermal system on the market. For specific indications though, Active systems are employed, which deliver the drug to or through the skin by use of an external mechanical device such as electricity, light, sonic force, heat or other herein unnamed method.
[0051] Possible ways to enable the technology in the scope of this invention would be through the use of iontophoresis, electrophoresis, electroosmosis, phonophoresis, sonophoresis, or otherwise un-named method of transdermal delivery method, such as silicon microneedle arrays (Remington: The science and practice of pharmacy, 20 th edition, 2002). In iontophoresis, electrical current is used to deliver ionic medicament to/through the skin. Iontophoretic devices are described in U.S. Pat. No. 4,820,263 (Spevak et al.), U.S. Pat. No. 4,927,408 ( Haak et al.), U.S. Pat. No. 5,084,008 (Phipps) and U.S. Pat. No. 6,377,847 (Keusch, et al.). The types of devices described in the references range from pastes, porous pads, cross-linked polymer supported devices, etc. Any of these types of devices can be adapted to pulse the antigen and adjuvant combination as described in the present invention.
[0052] Iontophoresis equipment is available from ISOKINETIcS, Inc. Therapy Equipment and Supplies. IOMED'S iontphoresis devices are easy to use, refillable and offer a reservoir system. Specific devices go by the trade name: TransQE, with Sur-Seal adhesive. Electrodes are also available from IOMED, and are compatible with Empi and Life-Tech units.
[0053] If one skilled in the art were determined to build their own reservoir units, numerous components for such devices can be obtained from various suppliers. The two suppliers for such materials listed here are not meant to be limiting in any way. The two suppliers are 3M, Minneapolis, Minn. and Berlex, Burlington, Vt. Specifically, 3M supplies CoTran backing, membranes and nonwoven backings. In addition 3M also offers a variety of foam tapes, Scotchpak Backings and Scotchpak Liners.
[0054] One can use emulsions as a medium or reservoir material to transdermally deliver the active agent, which protects the antigens until they reach the antigen presenting cells in the skin. This embodiment is particularly useful for delivery of active peptide fragments that require protection from degradation or additional assistance in traversing the layers of the skin. An emulsion is a dispersed system containing at least two immiscible liquid phases, a hydrophobic phase and a hydrophilic phase. The emulsion comprises the dispersed phase, the dispersion phase and an emulsifying agent or surfactant agent, except when the hydrophobic material is a “self-emulsifying” ester, whereby it is possible to produce an emulsion without a separate emulsifying agent. Usually one of the two immiscible liquids is an oil while the other is aqueous. Which phase becomes the dispersed phase depends on the relative amounts of the two liquid phases and which emulsifying agent is selected. Therefore, an emulsion in which the aqueous phase in the discontinuous phase is called a water-in-oil (w/o) emulsion and vice versa. The term “colloidal” refers to emulsions in which the dispersed phase is of very fine particles, usually less than about 1 mm in size. A “microcolloid” is an emulsion wherein the dispersed particles are usually about 300 .mu.m or less in size. Cosurfactants are also common components of microcolloids and are simply surfactants included in addition to the primary surfactant.
[0055] A “microemulsion” is an optically clear, isotropic and thermodynamically stable liquid. Microemulsions are composed of an oily phase, an aqueous phase, a surfactant, and sometimes, a cosurfactant. A homogenous mixture forms when components of the microemulsion are mixed together in any order. The resulting composition is thermodynamically stable with either a water continuous phase, an oily continuous phase, or a bicontinuous combination of the phases. Specifically, the microemulsion of the invention is a water-in-oil microemulsion, with the oil as the continuous phase.
[0056] Microemulsions are ideal for delivery of peptide fragment systems since they are homogenous, thermodynamically stable, have uniform droplet sizes of approximately 200-400 micrometers and are optically clear. A water-in-oil microemulsion, in particular, has small aqueous phase droplets, uniformly dispersed in a continuous oil phase. Therefore, the peptide is protected from proteolytic enzymes that may be present in the tissue. In general, the chemical structure of a peptide dictates that it will be at least somewhat, if not mostly, water soluble, and thus will be located inside the water droplet or very near the surface of the droplet of the water-in-oil microemulsion system. Thus, the outer oily phase of the microemulsion prohibits migration of proteolytic enzymes through the delivery system. The outer oily phase of the microemulsion is also able to incorporate into the intestinal cell matrix, thus creating membrane channels through which the peptide can pass. One general preparation procedure that maximizes peptide solubility is as follows: first, the peptide is prepared as a slurry in the aqueous phase at pH 2; second, the surfactant is added and mixed thoroughly; third, the oily phase is added and mixed to form the microemulsion.
[0057] The ingredients of the microemulsion can include any of the below named surfactants, oily phases or aqueous phases. The emulsions can either be macro- or microemulsions. Ordinary materials that are used to make emulsified hydrophobic and hydrophilic phases are contemplated. These materials include, but are not limited to, surfactants, aqueous and nonaqueous hydrophilic materials and numerous hydrophobic materials. Non-limiting examples of surfactants are polyoxyethylene sorbitan esters, ethyleneoxide propylene oxide block copolymers, polyglycolized glycerides, sucrose esters, polyoxyethylene laurel esters, and others. Non-limiting examples of hydrophilic materials are various aqueous buffered systems, polyethylene glycols, diethylene glycol monoethyl ether, and others. Non-limiting examples of hydrophobic materials are carboxylic acid esters, fatty acids, glyceryl derivatives such as glyceryl behenate, short, medium and long chain triglycerides and others.
[0058] Macro or gross emulsions can be made by conventional emulsion methods. In large scale manufacture, these steps can be accomplished using standard mixing equipment employed in the production of ointments, creams and lotions. Specifically, mixing tanks made by Lee Industries (New Cumberland, Pa.) can be readily used. Regardless of the equipment employed, mixing needs to be accomplished using as low a shear rate as practical, in order to maintain the physical integrity of the peptide. The bioactive agent can be added to the cooled mixture at a suitable temperature for stability and activity purposes. Microemulsions, which are spontaneously formed, isotopically clear liquids are formed with mechanical mixing of the ingredients. The bioactive agent can be added either to the hydrophilic phase prior to mixing with the surfactant and hydrophobic phases or after the microemulsion is formed, depending on stability and activity of the bioactive agent. The emulsions can be filled into hard or soft gelatin capsules and optionally coated with enteric polymers.
[0059] The incorporated peptide/protein is further protected from peptidases and proteases with the addition of a hydrophobic thickening agent in the oily phase. An additional hydrophobic ingredient, when added to the microemulsion, forms a paste-like composition that becomes liquefied at about 37.degree. C.
[0060] Monitoring Antigenic Activity:
[0061] It is understood that individuals receiving immunization may also be receiving additional preventative treatment for bacterial or viral infection, such as strepto pneumonococus or influenza.
[0062] It will be appreciated that unit content of active ingredient(s), whole plasma proteins or their active fragment(s) or analog(s), contained in an individual dose of each dosage form need not in itself constitute an effective amount, since the necessary effective amount can be reached by administration of a plurality of dosage units (such as by repeated pulsing). Administration of an effective dosage may be in a single dose form or in multiple dosage forms and it may be provided with an enteric coating and/or a sustained release mechanism, such as a reservoir.
[0063] As is typical from the traditional means of antigen delivery, and from the newer transdermal method, the antigenic activity resulting from the delivery of antigen with and without an adjuvant is typically monitored by measuring the antibody level in plasma initially and 2-4 weeks subsequent to the application of the antigen. As expected, several applications of the antigen may be necessary to confer immunity. U.S. Pat. No. 5,980,898 (Glenn et al.) and U.S. Pat. No. 5,910,306 (Alving et al.) have described monitoring the results of immunization and boosting immunization in the examples, those patents are hereby incorporated by reference in their entireties. It would be understood that this type of work is both customary and necessary in order to determine an effective application of the antigen.
EXAMPLES
[0064] The following examples are provided to illustrate the invention and should not be regarded as limiting the invention in any way.
Example 1
[0065] Allergenic protein such as oak pollen
[0066] Adjuvant such as aluminium hydroxide
[0067] Aqueous medium with stabilizing agent
[0068] Package in a transdermal device with an appropriate mechanism, such as an IOMED complete iontophoresis set up containing the Trans QE delivery system to which the dosage form is added to allow the contents to come in contact with the skin. The patch will be equipped with leads to which electrodes can be attached to effect electrotransport. In the case that the medicament to be delivered to the skin is a cation, the reservoir is connected to the electrode which acts as an anode. The return electrode would act as a cathode. If the medicament is an anion, then the drug containing reservoir would be connected to the cathode and the return reservoir would be connected to the anode. The reservoir containing the adjuvant would also be connected to electrodes in a similar manner, with an independent pulsing device.
[0069] To accomplish the delivery of antigen/adjuvant to the skin, a sequence of electrical pulses (between 20 and 200V peak to peak, preferably, and between 10 and 15,000 Hz is preferably provided to the electrodes that are placed in contact with the delivery device.
[0070] Specifically, an electrical burst of pulses at 2,200 Hz are provided to the skin at a burst ON/OFF frequency e.g., 50 Hz by way of an electrode array. Electrical pulses are provided by a pulse generator, in which a transformer is used as an element of the pulse generator. Several iontophoresis electrical generators are currently available in the market, either D.C. or D.C. pulsed.
Example 2
[0071] [0071] streptococcus pneumonae vaccine
[0072] Adjuvant
[0073] Administer pulse transdermal system, as in Example 1, at time 0, 1 year, and thereafter as determined by necessary by titre.
Example 3
[0074] herpes vaccine
[0075] Adjuvant
[0076] Administer pulse transdermal system, as in Example 1, at time 0, and monthly, or once daily following periods of high stress or sun exposure.
Example 4
[0077] HIV
[0078] Adjuvant
[0079] Administer pulse transdermal system, as in Example 1, on a weekly or monthly basis as determined by healthcare professional.
Example 5
[0080] Influenza
[0081] Adjuvant
[0082] Administer pulse transdermal system, as in Example 1, prior to flu season
Example 6
[0083] [0083] H. Pylori
[0084] Adjuvant
[0085] Administer pulse transdermal system, as in Example 1, weekly until breath test is negative.
Example 7
[0086] Therapeutic protein such as human papillomavirus vaccine (or other cancer vaccine)
[0087] Adjuvant such as Aluminum
[0088] Stabilizing medium
[0089] Apply to skin using a reservoir system known to one skilled in the art of transdermal delivery. Transdermal delivery device can be single or double compartment. In the case of a single compartment, then only one set of electrophoresis leads is present. In the case of a double compartment device, then two sets of electrophoresis leads are present and one can affect the desired pattern of pulsing as described in Example 1.
Example 8
[0090] Autoimmune disease antigen
[0091] Adjuvant such as Aluminum
[0092] Stabilizing medium
[0093] Apply to skin using a reservoir system known to one skilled in the art of transdermal delivery. Transdermal delivery device can be single or double compartment. In the case of a single compartment, then only one set of electrophoresis leads is present. In the case of a double compartment device, then two sets of electrophoresis leads are present and one can affect the desired pattern of pulsing as described in Example 1.
|
Methods for triggering immunogenic responses and for eliciting improved immunogenic responses to immunogens in humans or animals through pulsatile transdermal delivery of antigens and adjuvants to the Langerhans cells of the skin, are disclosed.
| 0
|
CROSS-REFERENCE OF RELATED APPLICATION
The present invention claims the priority under 35 U.S.C. §119 of German Patent Application No. 196 31 056.3 filed on Aug. 1, 1996, the disclosure of which is expressly incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a calender with a roll stack that has two end rolls and at least one intermediary roll, wherein the end rolls each have a deflection compensation device that acts in the direction of the intermediary roll.
2. Discussion of Background Information
In the current state of the art, calenders are frequently embodied as supercalenders. Supercalenders have a large number of rolls, as a rule 10 or 12, that are disposed vertically one above another. The end rolls are disposed in the highest and lowest positions. The end rolls may also be called the top roll and the bottom roll, respectively.
Calenders of this kind are used, for example, for satinating a paper web, i.e., the paper web is conducted through the nips between neighboring rolls. Through suitable means, the rolls are placed against one another with pressure. This treatment on the one hand compresses the paper web and on the other, gives it an improved surface quality, e.g., higher gloss or better smoothness. The pressing can take place in either of two ways: in the first, one of the two end rolls rotates at a fixed location and the other roll is pressed by a pressing means, e.g., a hydraulic cylinder, in the direction of the fixed end roll; in the second, the top roll and the bottom roll have pressing means that act in opposite directions. The deflections thus produced can be compensated for by deflection compensation devices so that all nips assume a straight course.
At this point, paper manufacturers often like to carry out a matte satination. The process of matte satination may be carried out by a soft calender. Soft calenders, however, are often not available as a result of cost or space requirements, so that the supercalender has to additionally take care of this function.
To carry out matte satination in conventional supercalenders, one of the rolls that is supported in vertically movable supports is fastened in its position in the roll stack using a suitable mechanical locking means. As a rule, the roll fastened in its position is one of the intermediary rolls. All the vertically movable rolls disposed beneath it, including the bottom roll, which is embodied as a deflection compensation roll, are pressed upward against the locked roller by means of a hydraulic cylinder. The deflection of the rolls is in turn compensated for by a deflection compensation device of the bottom roll.
This process has some disadvantages. Frequently, the roll disposed directly above the bottom roll cannot be locked so that a number of rolls, which do not contribute directly to the satination process, have to be driven and correspondingly undergo wear and tear. More importantly, the satination pressure is not adjustable as a practical matter. The satination pressure can only be so great that the deflection of the individual rolls is corrected. In other words, the pressing force of the currently functioning rolls can only be as great as is permitted by the compensation of the individual load deflection of the locked center roll. The pressing force is therefore determined by the weight, the width, and the rigidity of the locked center roll. The pressing force in the working nip cannot be changed because this would lead to an asymmetry of the pressure on the roll width and result in a distortion of the rolled material. If the pressure is too great, the locked roll deflects upward. However, if the pressure is too small, then the locked roll deflects downward.
SUMMARY OF THE INVENTION
An object of the present invention is to carry out a matte satination operation with the aid of a calender with the roll-specific pressures being adjustable, i.e., without the roll-specific pressures having to be fixed.
This object may be attained by a calender having a roll stack that has two end rolls and at least one intermediary roll. The end rolls each have a deflection compensation device that acts in a direction toward the intermediary roll. At least one end roll has an additional compensation device acting in a direction away from the intermediary roll and a supplementary deflection compensation roll disposed on a side of the at least one end roll which is remote from the intermediary roll.
Thus, this object may be attained by a calender having a roll stack. The calender includes at least one intermediary roll. The calender also includes two end rolls which each have a deflection compensation device that acts in a direction toward the intermediary roll, wherein at least one end roll has an additional deflection compensation device acting in a direction away from the intermediary roll. The calender further includes a supplementary roll disposed on a side of the at least one end roll which is remote from the intermediary roll.
Therefore, in comparison with conventional calenders, an additional roll suited for matte satination operation is added to the calender. In the present invention, the supplementary roll has a construction similar to end rolls used in conventional calenders. Therefore, practically no additional space is required, with the exception of a slight increase in the height of the new calender. Also, the additional cost stays within limits because no additional floor space is required. The additional expense involves providing a second deflection compensation device to an end roll and providing an additional deflection compensation roll. In other words, in comparison with conventional supercalenders, the end roll embodied as a deflection adjusting roll is shifted over by one position and a bi-directionally acting deflection adjusting roller is added. The additional expenditure is acceptable since the new calender can carry out the matte satination operation practically and allows adjustment of the pressures that are determined by the roll or rolls.
In the present invention, pressures can be adjusted within wide ranges. Operation can take place with relatively low pressures because the deflection compensation devices of the end roll and the supplementary roll can cooperate and can assure that the nip remains straight. If one seeks to operate at a pressure that goes beyond the pressures necessary for the compensation of the individual deflection, then the deflection compensation devices of both the end roll and the supplementary roll, which devices work in opposition to each other, cooperate. If one seeks to operate at a lower pressure, then the deflection compensation device of the end roll is used, which device acts in the direction of the intermediary roll or rolls. Thus, if only the compensation device of the end roll is used, a pressure release of the nip in the direction of the supplementary roll occurs.
In a preferred embodiment, the supplementary roll and the associated end roll have a common bearing device on the machine frame. The machine frame can, for example, be the seating of the calender or the calender stanchion. This embodiment permits the operational behavior of the calender to otherwise only be changed in a nonessential manner. In particular, with the installation of the supplementary roll in the region of the bottom roll, this embodiment even has advantages because the bottom roll is provided with additional weight which accelerates the lowering of the bottom roll when the rolls of the calender must be separated.
Preferably, at least one of the rolls on the common bearing device can be shifted in relation to the other roll of the common bearing device. By means of this shifting, the nip between the two rolls can be opened so that the supplementary roll is actually used only when the matte satination operation is carried out.
In preferred embodiments, the supplementary roll has a carrier that is supported on the bearing device via a hydraulic cylinder. This embodiment has two advantages. First, the end roll is disposed to rotate at a fixed location on the bearing device so that in controlling the rolls, practically no changes have to be made in relation to a conventional calender. Second, the supplementary roll can be moved as a unit, i.e., not just its jacket. As a result, the construction is simple.
Preferably at least one of the supplementary roll and the end roll has a separate rotary drive. Thus, the matte satination operation can then be carried out without external drives.
In preferred embodiments, the rotary drive is disposed on the bearing device and is connected to the roll disposed to rotate at fixed a location on the bearing device. A rigid connection between the rotary drive and the roll can then be provided because the positions of the roll and the rotary drive do not change in relation to each other.
Advantageously, the bearing device is disposed so that it can be moved on the machine frame. This disposition is particularly advantageous when the supplementary roll is provided in the region of the bottom roll. When the matte satination operation is carried out, the end roll can be separated from the intermediary rolls so that the wear and tear of the intermediary rolls remains low.
It is also preferable that either the supplementary roll or the end roll has a soft surface and the other roll has a hard surface. Then, with the aid of the supplementary roll, a soft calender can be formed, which has proven its worth both intrinsically and for matte satination.
Further embodiments and advantages can be seen from the detailed description of the present invention and the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is further described in the detailed description which follows, in reference to the noted drawings by way of non-limiting examples of preferred embodiments of the present invention, wherein same reference numerals represent similar parts throughout the several views of the drawings, and
FIG. 1 shows a calender in normal operation;
FIG. 2 shows the calender in matte satination;
FIG. 3 shows a modified form of the calender with the supplementary roll in the top position;
FIG. 4 shows a detail of the lower end of the calender in the mode of operation according to FIG. 1; and
FIG. 5 shows the detail of the calender in the mode of operation according to FIG. 2.
DETAILED DESCRIPTION
The particulars shown herein 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 the 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.
A calender 1 has a frame 2 in which a roll stack 3 is disposed. The roll stack has a top roll 4, a bottom roll 5, and a number of intermediary rolls 6. A number of guide rolls 7 are provided for web guidance. The top roll 4 and the bottom roll 5 are both also referred to as end rolls.
The top roll 4 and the bottom roll 5 are embodied as deflection compensation rolls. They each have deflection compensation devices 8 and 9, that act in the direction of the intermediary rolls 6.
The intermediary rolls 6 and the bottom roll 5 can be moved in relation to the frame 2. The top roll 4 is affixed to the frame. For this purpose, the intermediary rolls are fastened to the frame 2 via bearings, not shown. The bottom roll 5 is disposed in a bearing device 10, which can be moved upward with the aid of a hydraulic cylinder 11. As soon as all the nips between the intermediary rolls 6 and the bottom roll 5 or the top roll 4 are closed, the hydraulic cylinder 11 can also be used to increase the pressure in the nips. A deflection of the rolls 4, 5, 6 is compensated for by the deflection compensation devices 8, 9.
Furthermore, a supplementary roll 12 is disposed on the bearing device 10, is likewise embodied as a deflection compensation roll, and correspondingly has a deflection compensation device 13. This deflection compensation device 13 acts in the direction of the bottom roll 5.
The bottom roll 5 additionally has a second deflection compensation device 14, which acts in the direction of the supplementary roll 12.
All of the deflection compensation devices 8, 9, 13, 14 can be embodied, for example, by hydrostatically acting sliding shoes, which are supported on a carrier, not shown, which passes axially through the rolls 4, 5, 12.
The supplementary roll 12 can be moved in the vertical direction on the bearing device 10. It can therefore be moved in relation to the bottom roll 5. In the position shown in FIG. 1, the supplementary roll 12 permits a nip 15 to open in the direction of the bottom roll 5. The bearing device 10, though, has been moved so far in the direction of the top roll 4 that all of the other nips are closed. The paper web 16 to be treated can then be calendered in the normal operation.
FIG. 2 now shows another mode of operation in which all the nips are open, in particular a nip 17 between the bottom roll 5 and the subsequent intermediary roll 6. For this purpose, the nip 15 is closed, i.e., the supplementary roll 12 rests against the bottom roll 5 with the interposition of the paper web 16. In this case, the hydraulic cylinder 11 can be retracted. As will be explained in connection with FIGS. 4 and 5, a separate hydraulic cylinder is provided on the bearing device 10, which cylinder is used for shifting the supplementary roll 12 on the bearing device.
In the mode of operation shown in FIG. 2, the paper web 16 is guided only through the nip to matte satinate the paper web 16. For this purpose, either the bottom roll 5 or the supplementary roll 12 is provided with a soft surface while the other roll has a hard surface.
The pressures that prevail in the nip 15 can now be arbitrarily set within wide limits.
On the one hand, as was previously also possible, a pressure can be set that compensates for the individual deflection of the bottom roll 5. In this instance, only the deflection compensation devices 13 of the supplementary roll 12 are actuated. If the production of a higher pressure is desired, then both the deflection compensation device 13 and the deflection compensation device 14 are placed in operation. Besides the function of straightening the nip, they have the function of producing the necessary pressures.
However, if the production of lower pressures is desired, then the deflection compensation device 13 and the deflection compensation device 9 are placed in operation. The deflection compensation device 9 prevents the bottom roll 5 from deflecting downward when the supplementary roll 12 no longer exerts the necessary counter pressure.
FIG. 3 shows the possibility of allowing the supplementary roll 12 to also cooperate with the top roll 4. In this instance, the top roll 2 has deflection compensation devices 8 and 14, wherein compensation device 14 acts in the direction away from the intermediary rolls 6, but this time in an upward direction. In the same manner, the deflection compensation device 13 of the supplementary roll 12 acts in a downward direction, i.e., in the direction toward the intermediary rolls 6.
FIGS. 4 and 5 show the bearing device 10 with the bottom roll 5 and the supplementary roll 12 in more detail.
The bearing device 10 includes a slide 18, which is disposed so that it can move vertically on the frame 2. The slide 18 is driven by hydraulic cylinder 11, which is shown under pressure in FIG. 4 and is shown discharged in FIG. 5.
A roll carrier 19 is disposed on the slide 18 in a stationary manner. The roll carrier 19 carries the bottom roll 5. The roll carrier 19 also has a roll rotating drive 20 that is rigidly connected to the bottom roll 5.
Another hydraulic cylinder 21 is provided on the slide 18, which cylinder is shown discharged in FIG. 4 and is shown under pressure in FIG. 5. A roll carrier 22 is disposed on the piston of this hydraulic cylinder, which roll carrier passes axially through the supplementary roll 12. The elements of the deflection compensation device 13 are supported on the roll carrier. The nip 15 between the bottom roll 5 and the supplementary roll 12 can be opened or closed by using the hydraulic cylinder 21.
The hydraulic cylinder 21 can be smaller than the hydraulic cylinder 11 since it only has to shift the supplementary roll 12 in relation to the bottom roll 5. The hydraulic cylinder 11, though, must be able to lift the bottom roll 5 and all of the intermediary rolls 6.
It is noted that the foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present invention. While the invention has been described with reference to a preferred embodiment, it is understood that the words which have been used herein are words of description and illustration, rather than words of limitation. Changes may be made, within the purview of the appended claims, as presently stated and as amended, without departing from the scope and the spirit of the invention in its aspects. Although the invention has been described herein with reference to particular means, materials and embodiments, the invention is not intended to be limited to the particulars disclosed herein; rather, the invention extends to all functionally equivalent structures, methods and uses, such as are within the scope of the appended claims.
|
A calender includes a roll stack that has two end rolls and at least one intermediary roll, wherein the end rolls each have a deflection compensation device that acts in the direction of the intermediary roll. At least one end roll has an additional deflection compensation device that acts in the direction away from the intermediary roll. On the side of the at least one end roll which is remote from the intermediary roll is disposed a supplementary roll. This calender is able to carry out a matte satination operation without being fixed as to roll-specific pressures, which pressures must be of a precise magnitude so as to compensate for the deflection of the intermediary rolls.
| 3
|
CROSS-REFERENCE TO RELATED PATENT APPLICATION
This application is a continuation application of patent application Ser. No. 10/217,109, filed Aug. 9, 2002, now U.S Pat. No. 6,527,873, which is a divisional of patent application, Ser. No. 09/710,187, filed Nov. 10, 2000, now U.S Pat. No. 6,576,346, which claimed the benefit of the filing date of divisional patent application, Ser. No. 09/317,304, filed May 24, 1999, now U.S Pat. No. 6,309,476.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the formation of a hybrid chemical conversion coating on ferrous metal substrates, consisting of an iron/oxygen rich intermediate coating and a top layer of magnetite. This invention also relates to ferrous metal substrates coated according to the presently disclosed process. This invention further includes the oxidation solution used in oxidizing the iron/oxygen rich intermediate coating to the final magnetite containing top layer. This invention also includes a seven-step procedure for preparing a ferrous metal substrate with a magnetite containing coating.
2. Description of the Related Art
The established art of coloring ferrous metals has revolved principally around methods for producing black coatings. Since the 1950's, the most commonly used commercial method for blackening ferrous metals has been the caustic black oxidizing process. This method will be examined, along with the ferrous oxalate conversion coating on ferrous metal substrate and the iron phosphatizing process.
Caustic black oxidizing: This process uses sodium hydroxide, sodium nitrate and sodium nitrite as oxidizing agents, operating at about pH 14, at temperatures of about 285-305° F. A black coating is formed during exposures of about 10-30 minutes. This process forms a magnetite (Fe 3 O 4 ) deposit, approximately 1 micron thick, by reacting with the metallic iron substrate in situ. Although the process produces high quality black finishes when operated properly, it has the disadvantage of requiring high temperatures and highly concentrated solutions (700-1000 grams per liter) to carry out the reaction.
During the course of operation, this reaction consumes oxidizing salts and the solution boils off significant quantities of water. These materials must be added back to the solution to maintain proper operating conditions. However, adding sodium hydroxide to water, being a highly exothermic reaction, is quite hazardous because the operating solution is already boiling. Likewise, adding make-up water to a solution which is already at 285-305° F. causes the water to instantly boil if not added very slowly and carefully. Consequently, the operation of the process poses severe safety hazards for personnel, due to the dangers involved in normal system operation and maintenance. These hazardous conditions may be difficult to justify in the manufacturing environments of modem industry. In addition, normal operating conditions typically entail heavy sludge formation in the process tank, difficulty in disposal of the spent solutions (due to extremely high concentrations), and variable quality on certain metals, including tool steel alloys, sintered iron articles or other porous substrates. Unless highly skilled operators are employed, this process may result in poor quality finishes. It is common to see undesirable red/brown finishes on certain alloys or salt leaching on porous substrates. As a result, the process is largely relegated to use by professional metal finishers who possess specialized knowledge and experience in dealing with hazardous materials.
Ferrous oxalate conversion coating: This coating was originally developed for use as a metal forming lubricant and anti-galling coating for mating parts. The finish is generally applied at about ambient temperatures, is about 1 micron thick and opaque gray in color. When sealed with a rust preventative topcoat, the oxalate offers some degree of corrosion protection. Used more commonly in the 1950's, the oxalate process is rarely used today, having given way to the several phosphate processes on the market, which offer more beneficial properties in terms of lubrication and/or paint adhesion.
Iron phosphate conversion coating: These coatings are widely used in the metal finishing industry as pretreatments to enhance paint adhesion and corrosion resistance on ferrous metal substrates. With a coating thickness of about 1 micron, the amorphous deposit is formed at temperatures of about 70-130° F. by a mildly acid solution which may also contain cleaning agents. The iron phosphate process has proven to be a very versatile and effective option in paint lines and other metal finishing process lines.
There have been several patents issued over the years which relate to blackening processes. For purposes of this invention, however, reference is made to prior patents which are directly related to oxalate and phosphate conversion coatings on ferrous metal substrates and to the caustic black oxidizing of ferrous metal substrates:
U.S. Pat.
No.
Date
Subject
2,774,696
Dec. 18, 1956
Oxalate Coatings on Chromium Alloy
Substrates
2,791,525
May 7, 1957
Chlorate Accelerated Oxalate Coatings on
Ferrous Metals for Forming Lubricity and
Paint Adhesion
2,805,696
Sep. 10, 1957
Molybdenum Accelerated Oxalate Coatings
2,835,616
May 20, 1958
Method of Processing Ferrous Metals to
Form Oxalate Coatings
2,850,417
Sep. 2, 1958
m-Nitrobenzene Sulfonate Accelerated
Oxalates on Ferrous Metals
2,960,420
Nov. 15, 1960
Composition and Process For Black Oxidi-
zing of Ferrous Metals Using Mercapto-
Based Accelerators and naphthalene based
Wetting Agents
3,121,033
Feb. 11, 1964
Oxalates on Stainless Steels
3,481,762
Dec. 2, 1969
Manganous Oxalates Sealed with Graphite
and Oil for Forming Lubricity
3,632,452
Sep. 17, 1958
Stannous Accelerated Oxalates on Stainless
Steels
3,649,371
Mar. 14, 1972
Fluoride Modified Oxalates
3,806,375
Apr. 23, 1975
Hexamine/SO 2 Accelerated Oxalates
3,879,237
Apr. 22, 1975
Manganese, Fluoride, Sulfide Accelerated
Oxalates
3,899,367
Aug. 12, 1975
Composition and Process For Black Oxidi-
zing Of Ferrous Metals Using Molybdic
Acids On Tool Steels
4,017,335
Apr. 12, 1977
pH Stabilized Composition and Method For
Iron Phosphatizing Of Ferrous Metal
Surfaces
5,104,463
Apr. 14, 1992
Composition and Process For Caustic
Oxidizing Of Stainless Steels Using
Chromate Accelerators
All but one of these oxalate patents pertain to the formation of a ferrous oxalate conversion coating on ferrous metal substrates using various accelerators. These oxalates are intended for use as functional coatings to aid in assembly or provide forming lubricity, etc. These coatings serve as deformable or crushable boundary layers at the metal surface, thereby protecting the base metal during contact with another surface. The caustic black oxidizing patents focus on compositions and processes which oxidize the metallic iron substrate to a magnetite, Fe 3 O 4 , as described in U.S. Pat. No. 2,960,420. Actually, when examining the stoichiometry of the Fe 3 O 4 , one can see that the iron is not in either a purely ferrous (II) or ferric (III) oxidation state. Perhaps a more precise description of the material is that of a mixed salt, ferrosoferric oxide, or FeO.Fe 2 O 3 , which exhibits both ferrous and ferric iron. The conventional caustic oxidizing processes all depend on the ability of the operating solution to oxidize metallic iron to both ferrous (II) and ferric (III) oxidation states to form the mixed oxide FeO.Fe 2 O 3 .
The process described in U.S. Pat. No. 4,017,335 is representative of the state of the art, focusing on the primary phosphatizing mechanism which is well known to those skilled in the art. In addition, this same patent illustrates incorporation of a cleaning agent and pH stabilizer into the oxidizing solution to effectively clean lightly soiled ferrous articles and iron phosphatize them in a single step.
SUMMARY OF THE INVENTION
This invention provides an alternative method and composition for forming aesthetically pleasing and protective, as well as functionally useful, magnetite coatings on ferrous metal substrates. The mechanism involves a first oxidation to provide an intermediate coating on the metallic iron substrate, such as a ferrous oxalate (or other dicarboxylate) or an iron phosphate coating, whose primary purpose is to act as a precursor to the magnetite. By providing a surface abundant in both molecular iron and molecular oxygen, the intermediate coating facilitates the formation of the magnetite (in a second oxidation), thereby requiring a blackening solution with much less oxidizing potential than is necessary with conventional oxidizing solutions in terms of concentration, operating temperatures and contact times. It is important to note that the oxidizing solution used in the second oxidation of this invention is not able to blacken the metal substrate without the intermediate coating (from the first oxidation) in place. The overall oxidizing potential of the second oxidizing solution in this invention is so much lower than that of conventional solutions that no reaction will take place unless the intermediate coating (from the first oxidation) has been applied first. After the second oxidation, the coating may be topcoated with a lubricant, rust preventative compound or polymer-based topcoat appropriate to the end use of the article.
A process according to this invention for forming a hybrid conversion coating on a ferrous metal substrate, encompasses applying to the substrate an intermediate coating rich in molecular iron and oxygen, and then contacting the intermediate coated substrate with an aqueous solution of oxidizing agents to form a magnetite containing surface. The substrate is coated with a water insoluble molecular oxygen and iron enriched intermediate coating by a first oxidation which comprises contacting the substrate with an aqueous solution of a dicarboxylic acid, or of a reagent selected from phosphoric acid, pyrophosphoric acid and salts thereof, or mixtures thereof, at an appropriate concentration, pH, temperature and time to achieve a desired water insoluble molecular oxygen and iron enriched intermediate coating. The intermediate coated substrate is then subjected to a second oxidation by contacting with an aqueous solution of an oxidizing agent at a concentration, pH, temperature and time to form the desired amount of magnetite. The coated substrate may then be sealed with a topcoat.
A coated colored ferrous metal article according to this invention has a surface formed by two treatments, wherein the first treatment is an iron/oxygen-enriched intermediate oxidized coating applied to a ferrous substrate, and the second treatment is a further oxidation of the first coating to magnetite.
An oxidation solution for oxidizing at least a portion of an iron/oxygen enriched intermediate coating on a ferrous substrate to magnetite according to this invention comprises an aqueous solution of oxidizing agents selected from alkali metal compounds of hydroxide, nitrate, and nitrite and mixtures thereof, and optionally further including an additional component selected from an accelerator, a metal chelator, a surface tension reducer and mixtures thereof.
This invention also provides a seven-step procedure for forming a hybrid conversion coating on a ferrous metal substrate, comprising the steps of:
(1) subjecting the ferrous metal substrate to treatment selected from cleaning, degreasing, descaling, and mixtures thereof;
(2) rinsing the substrate from step (1) with water;
(3) subjecting the substrate from step (2) to a first oxidation to form a molecular iron/oxygen enriched intermediate coating;
(4) rinsing the substrate from step (3) with water;
(5) subjecting the substrate from step (4) to a second oxidation to form a surface which is predominantly magnetite, Fe 3 O 4 ;
(6) rinsing the substrate from step (5) with water; and
(7) sealing the substrate with an appropriate topcoat.
DETAILED DESCRIPTION OF THE INVENTION
A ferrous metal substrate is defined herein as any metallic substrate whose composition is primarily iron. This may include steel, stainless steel, cast iron, gray and ductile iron, and sintered iron of all alloys.
The iron/oxygen rich intermediate coating applied to the substrate in the first oxidation can be formed using any of the water soluble dicarboxylic acids, especially aliphatic dicarboxylic acids generally of up to about five carbon atoms, such as oxalic, malonic, succinic, tartaric acids, and others and mixtures thereof. There are advantages and disadvantages to each dicarboxylic acid. For example, oxalic acid is generally available at the lowest cost and is the most reactive. However, oxalic acid tends to form intermediate coatings of relatively coarse grain, with large crystals and the intermediate coating usually benefits from the addition of a grain refiner to the first oxidation, such as alkali metal compounds of tartrate, tripolyphosphate, molybdate, citrate, polyphosphate and thiocyanate, including sodium potassium tartrate, sodium citrate, sodium molybdate, sodium polyphosphate and sodium thiocyanate. An intermediate coating with a denser crystal structure is considered preferable because it tends to produce a resultant black finish (after the second oxidation) that is cleaner, with less ruboff, and also thinner, which is desirable for most machine/tool applications. A mixture of two or more dicarboxylic acids tends to favor the formation of a denser microcrystalline structure on the metal surface, perhaps obviating the need for a grain refiner. However, the costs of many of the commercial grades of other dicarboxylic acids are significantly higher than that of oxalic acid, the solubilities are lower and the reaction rates significantly lower as well. In fact, these other longer chain aliphatic dicarboxylic acids may actually require the use of accelerators instead of or in addition to grain refiners in order to be workable in a practical sense. Suitable accelerators for use in the first oxidation include organic and inorganic nitro compounds, and alkali-metal compounds of citrate, molybdate, polyphosphate, thiocyanate, chlorate, and sulfide, such as sodium chlorate, sodium molybdate, and organic nitro compounds.
Alternatively, the iron/oxygen rich intermediate coating can consist of other coatings such as iron phosphate. The iron phosphate coating does not appear to be quite as effective as the dicarboxylate coatings, because the iron phosphate deposit tends to be amorphous rather than crystalline. Though the adhesion of iron phosphate to the substrate is generally satisfactory, the amorphous iron phosphate deposit tends to be less durable and less resistant to rubbing and/or wear factors, thus appearing to have more sooty ruboff in the final prepared article. The advantages of the phosphate coating, however, include the lower commercial cost of the chemicals and the ability to operate at higher (less acidic) pH levels. These advantages improve worker safety aspects of the process line. Appropriate reagents for deposition of the water insoluble phosphate-based coating include phosphoric acid, as well as alkali metal acid phosphates, alkali metal pyrophosphates, primary alkanol amine phosphates and mixtures thereof. Typically, the iron phosphate solutions are able to operate at about pH 3.0-5.0 (dicarboxylates operate at about pH 1.0-2.0), at temperatures of about 70-130° F., and contact times of 1 -3 minutes.
An intermediate coating with a more densely formed crystal structure tends to concentrate or increase the availability of iron and oxygen and thus tends to favor the formation of the magnetite in the second oxidation. A more densely formed crystal structure tends to facilitate the blackening of certain ferrous alloys of lower reactivity, such as heat-treated steels or more highly alloyed steels. Typically, these types of steels tend to be less reactive because the concentration of metallic iron at the surface is lower than that encountered with cast irons or softer steels. Consequently, it is considered preferable to design the composition of the iron/oxygen rich intermediate coating solution to maximize the crystal structure density of the intermediate coating, thereby overcoming any low initial reactivity of iron substrate.
The operating temperature of the intermediate coating solution also has an effect on the reaction rate—higher temperatures tend to increase the reaction rate. Experimental evidence indicates that, although many iron alloys can be successfully processed at ambient temperatures, certain less reactive alloys benefit from application of the intermediate coating at temperatures of about 100-150° F. to overcome any low initial reactivity of the metal surface.
At suitable grain refiner for the first oxidation has been found to be an alkali metal tartrate, typically at a concentration of about 0.1-1.0 gram per liter. the accelerator is selected from organic and inorganic nitro compounds, alkali metal salts of citrate, molybdate, polyphosphate, thiocyanate, chlorate and sulfide at concentrations of about 0.5-5.0 grams per liter. A suitable accelerator for the first oxidation may be selected from organic and inorganic nitro compounds, typically at concentrations of about 0.1-5.0 grams per liter.
In summary, then, the composition of the intermediate coating solution (the first oxidation) may take many forms, depending on the cost, solubility and activity level of the chemicals used, the pH of the solution and coarseness of the crystal structure, as well as the initial reactivity of the iron metal alloy, the value or intended use of the article and other factors deemed pertinent to each application.
After coating the article with the iron/oxygen rich intermediate coating, the article is blackened by contacting it with a second oxidation solution at elevated temperatures to form the magnetite. Experimental evidence indicates that most of the intermediate coating remains intact on the article surface after the second oxidation, with only a small portion of the coating reacting to form magnetite. Although the exact reaction mechanism of the second oxidation is not clearly understood, it is believed that portions of the intermediate coating react with the second oxidation solution to form magnetite interspersed within the crystal structure of the coating. Some magnetite may be chemically bonded to molecules of the intermediate coating.
The first oxidation is believed to convert metallic iron, to Fe(II), when the coating is a ferrous dicarboxylate, or to a mixture of Fe(II) and Fe(III) when the coating is an iron phosphate. Accordingly, in this specification the dicarboxylate coating is designated as “ferrous,” because the iron is in the ferrous or Fe(II) oxidation state, while the phosphate coating is designated more broadly as “iron,” because the iron is in both the ferrous, Fe(II), and ferric, Fe(III), oxidation states. It is reasonable to believe that the primary iron oxide formed is Fe 3 O 4 , although it is possible that other iron oxides are formed, such as FeO and Fe 2 O 3 , and other compounds, such as FeS, SnS and SnO (due to the possible presence of sulfur and tin in the reagent solutions), all of which can be gray/black in color. The oxides of iron tend to be non-stoichiometric, and readily interconvertible with each other. The tendency of each of the iron oxides to be nonstoichiometric is due to some extent to the intimate relationship between their structures. The structure of each oxide may be visualized as a cubic close-packed array of oxide ions with a certain number of Fe(II) and/or Fe(III) ions distributed among octahedral and tetrahedral holes. Each of the iron oxides can alter its composition in the direction of one or two of the others without there being any major structural change, only a redistribution of ions among the tetrahedral and octahedral interstices. This accounts for their ready interconvertibility, their tendency to be nonstoichiometric, and, in general, the complexity of the Fe—O system. For further discussion of the oxides of iron, see, for example, Cotton and Wilkinson, Advanced Inorganic Chemisty , Interscience Publishers, 1966, 2nd edition, pages 847-862.
The second oxidation then converts at least a portion of the intermediate coating to magnetite. The exact reaction mechanism for the second oxidation has not been determined. However, the non-stoichiometric nature and easy interconvertibility of these iron compounds, as recognized by the art and as discussed in Cotton and Wilkinson, makes it reasonable to believe that the resultant black coating is composed of a mixture of iron and oxygen which only loosely resembles precise, or discrete, compounds.
The composition of the second oxidation solution can vary, depending on the type, thickness and grain structure of the prepared intermediate coating. Generally, it is considered preferable to add at least one, two or even three oxidizers and an accelerator to the second oxidation solution. The primary oxidizers may be alkali metal compounds of hydroxide, nitrate, and nitrite and mixtures thereof Specific examples of suitable primary oxidizers include sodium hydroxide, sodium nitrate and sodium nitrite in varying concentrations. In every case, however, the overall concentration of oxidizers according to this invention is significantly lower than that seen in the conventional oxidizing processes as described in the U.S. patents cited earlier. For example, U.S. Pat. No. 3,899,367 suggests the following concentrations in the oxidizing solutions:
sodium hydroxide
200-1000
grams per liter
sodium nitrate
12-60
grams per liter
sodium nitrite
30-150
grams per liter.
along with minor concentrations of such additives as accelerators and wetting agents.
Actual practice in the metal finishing industry indicates that only the upper end of the concentration range shown in the above example from U.S. Pat. No. 3,899,367 is effective in producing a satisfactory black magnetite coating. Solutions of lower concentrations tend to boil at lower temperatures, leading to formation of undesirable red and brown coatings with less than satisfactory results.
According to the present invention, the optimal concentrations used for the second oxidation solution to produce satisfactory final black magnetite coatings may be as follows:
sodium hydroxide
25-200 grams per liter
sodium nitrate
9-70 grams per liter
sodium nitrite
1-10 grams per liter
Additional components which may be added to the second oxidation solution include accelerators, metal chelators and surface tension reducers. Appropriate accelerators for the second oxidation include organic and inorganic nitro compounds, alkali metal compounds of citrate, molybdate, polyphosphate, vanadate, chlorate, tungstate, thiocyanate, dichromate, stannate, sulfide and thiosulfate, and stannous chloride and stannic chloride. Suitable accelerators are chosen according to such considerations as cost and solubility. Appropriate metal chelators include alkali metal compounds of thiosulfate, sulfide, ethylene diamine tetraacetate, thiocyanate, gluconate, citrate, and tartrate. Suitable chelators are chosen according to such considerations as cost, solubility and reactivity. Appropriate surface tension reducers include alkylnaphthalene sulfonate and related compounds which are stable in high pH environments.
A suitable accelerator for the second oxidation is selected from alkali metal salts of molybdate, vanadate, tungstate, thiocyanate, dichromate, stannate, thiosulfate, stannous chloride, and stannic chloride, preferably at concentrations of about 0.05-0.5 grams per liter. A suitable metal chelator for the second oxidation is selected from alkali metal salts of thiosulfate, sulfide, ethylene diamine tetraacetate, thiocyanate, gluconate, citrate or tartrate, preferably at concentrations of about 1.0-10.0 grams per liter. A suitable surface tension reducer for the second oxidation is selected from alkylnaphthalene sulfonate, typically at concentrations of about 0.025-0.2 grains per liter.
Suitable reaction parameters for the second oxidation are as follows: pH range: about 12.0-14.0, typically about 13.0-14.0; operating temperature range: about 120-220° F., typically about 160-200° F.; contact time range: about 0.5-10 min., typically about 2-5Temperatures as low as about 70-80 ° F. at reaction times of 30 min. or more have successfully been used.
The iron/oxygen rich intermediate coating (from the first oxidation) is responsible for reducing the minimum oxidizing potential necessary for satisfactory coatings. Since the substrate metal has already been oxidized by the intermediate coating solution (the first oxidation), it is easier for a less powerful oxidation solution to finish the oxidation to the black magnetite level (the second oxidation). The second oxidation solution is unable to react with metallic iron; the second oxidation solution reacts only with the pre-existing, easily accessible iron and oxygen contained in the intermediate coating. Because the intermediate coating (from the first oxidation) facilitates the second oxidation reaction, a much less powerful second oxidation solution is required than has been typically used in conventional blackening processes.
In like manner, the operating temperature and contact time for the second oxidation is significantly reduced from similar parameters for conventional oxidizing solutions. Again, U.S. Pat. No. 3,899,367 suggests an operating temperature of 255-325° F. and contact times of 10-25 minutes. In actual practice, the optimal operating temperature for the process of U.S. Pat. No. 3,899,367 has been found to be about 285-295° F. with 10-25 minute contact time. According to the present invention, the optimal temperature range for the second oxidation is about 190-220° F. for black coatings and about 160-190° F. for brown coatings. Optimal contact times are about 2-10 minutes. Both of these parameters are significantly lower than for the conventional oxidizing solutions employed in U.S. Pat. No. 3,899,367.
Among the important advantages of the process of this invention are the suprisingly low temperatures at which this second oxidation may successfully operate. Reactions at temperatures as low as about 70-80° F. produce products with highly acceptable colored surface finish, generally by increasing the contact time, for example, up to about 30 min. or more. The ability to successfully operate at such suprisingly low temperatures offers substantial advantages in providing a process which may be safely and effectively carried out by an end user. Such ‘ low temperature—longer time’ procedures produce attractive finishes for less demanding final products, including such decorative and artistic products as ornamental wrought iron work, finish hardware, sculptural works, craft and artisan handworks, and similar enhancements. These finishes from the ‘ low temperature—longer time’ procedures may evidence colors in the black to dark black-brown range. Further embellishment of the colored product may involve removal of some of the colored finish to reveal the bright underlying metal, achieving a patina or antique effect. Although it is of course known in reaction kinetics that lowering an operating temperature may call for increasing reaction times, the ability to operate at such surprisingly low temperatures has nowhere been reported in this industry, to the knowledge of the present inventors.
Along with the primary oxidizing agents mentioned, the second oxidation solution may preferably contain an accelerator. In the present invention, the accelerators for the second oxidation solution may be alkali metal compounds of molybdate, vanadate, tungstate, thiocyanate, dichromate, stannate or thiosulfate, or stannous or stannic chloride, or mixtures thereof. Suitable accelerators include stannous chloride, stannic chloride, sodium stannate, sodium thiosulfate, sodium molybdate and ethylene thiourea, and mixtures thereof. Other accelerators which have been mentioned in prior related literature, including sodium dichromate, sodium tungstate, sodium vanadate, sodium thiocyanate and benzothiazyl disulfide, all show varying degrees of effectiveness in the second oxidation of this invention. In addition, surface tension reducing agents tend to improve rinsability and reduce dragout from the solution. Effective surface tension reducing agents include alkyl naphthalene sodium sulfonate, such as manufactured by the Witco Corporation under the trademark Petro AA, and similar surface tension reducing agents.
It is important to note that, in the second oxidation of this invention, the overall concentrations of the primary oxidizers and the relative concentrations of each oxidizer in the second oxidation solution are factors critical to success. It has been stated that the second oxidation solution of this invention is not able to react with metallic iron, because the oxidizing potential of the solution is too low. Similarly, treating a ferrous substrate, as defined above, with a conventional oxidizing solution and merely reducing the concentration, temperature and contact time will not result in satisfactory finishes. In general, the finishes obtained by treating a ferrous substrate with a conventional oxidizing solution at reduced concentration, temperature and contact time is a loosely adherent coating with an undesirable brown color. For example, the oxidizing solution described in U.S. Pat. No. 2,960,420, when operated at reduced concentrations, contact times and temperatures (at about 190-200° F.) reacts poorly with the intermediate coating, producing finishes which are brown and very loosely adherent. In like manner, the oxidizing solutions described in U.S. Pat. No. 3,899,367 under similar operating conditions also produce undesirable thin, loosely adherent brownish coatings.
The primary benefits derived from the process according to the present invention are not related to the quality of the black finish itself, but rather to processing advantages. These improved advantages include lower operating temperatures, shorter process times, and lower solution concentrations, which lead to enhanced worker safety and lower operating costs. The resultant black finish itself is very comparable to that of conventional blackening processes in terms of corrosion resistance, wear resistance, appearance, thickness, and applications in which the finished article is used.
The present inventive process entails the deposition of an intermediate conversion coating, which is rich in iron and oxygen and represents a first oxidation of the metallic iron of the substrate. This first oxidation (forming the intermediate conversion coating) is followed by a second oxidation, which forms a magnetite compound by reacting with the intermediate coating. The precise chemical composition of the resultant black finish has not been identified. The chemical literature, as discussed above, suggests that there are three oxides of iron, all of which are likely present in the intermediate conversion coating: FeO, Fe 2 O 3 and Fe 3 O 4 with Fe 3 O 4 being a mixed salt of FeO and Fe 2 O 3 . Besides these iron oxides, it is likely that other salts are formed on the surface, including FeS, SnS, SnO in minor quantities, due to the presence of sulfur and tin-based additives in the solution.
The first oxidation and the intermediate conversion coating formed by this invention, which may be a dicarboxylate, a phosphate, mixtures thereof, or some other iron/oxygen rich material, depending on the oxidation solution used, are not per se novel. The first oxidation and the intermediate conversion coating are in fact based on known chemistry. The novelty of the present invention is the use of these coatings (and the processes forming them) in the context of a blackening process. The novelty of the process, and the key to its success, lies in the second oxidation solution and its reaction with the intermediate coating. The concept of an initial oxidation of the metallic iron, to form an intermediate dicarboxylate, phosphate or other iron/oxygen enriched coating, followed by a further oxidation of the intermediate coating is a novel concept in this industry and depends on the composition and operating parameters of the second oxidization solution.
Our research to date does not indicate that the entire dicarboxylate, phosphate or other iron/oxygen-enriched intermediate coating from the first oxidation is converted to iron magnetite, Fe 3 O 4 , in the second oxidation. Rather, our experimental work suggests that the second oxidation solution is reacting with molecular iron and oxygen of the intermediate coating. Although the entire intermediate coating is rich in molecular iron and oxygen, it is reasonable to assume that the area in which these materials are most accessible is at the top surfaces of the intermediate coating crystal structure. Indeed, our tests have indicated that the black finish formed by the entire process (the first and the second oxidations) of this invention can be stripped off a steel article with hydrochloric acid, leaving a gray-looking finish behind. This gray-looking finish is the intermediate coating. The article can then be immediately re-blackened by immersion in the second oxidation solution. We have determined experimentally that the second oxidation solution has no effect on metallic iron. The stripping and re-blackening experiment reasonably suggests that only the top surface of the intermediate coating is turning black. If the entire intermediate coating were being converted to black iron magnetite, the hydrochloric acid stripping operation would remove all of the coating, down to the metallic iron, and it would be impossible to re-blacken the article without first re-coating it with the intermediate coating.
The invention will now be further illustrated by the description of certain specific examples of its practice which are intended to be illustrative only and not limiting in any sense.
EXAMPLE 1
First Oxidation: A 1018 steel article is cleaned by conventional means. The cleaned article is then immersed for 1 minute at room temperature in an aqueous solution containing:
Oxalic Acid
14 g/l
Phosphoric Acid
1.2 g/l
Sodium m-Nitroberizene Sulfonate
6 g/l
Sodium Potassium Tartrate
0.4 g/l
The above immersion produces an opaque gray intermediate coating on the steel surface. Second Oxidation: After rinsing, the intermediate coated article is immersed for 4-5 minutes at 200° F. in an aqueous solution containing:
Sodium Hydroxide
100
g/l
Sodium Nitrate
35
g/l
Sodium Nitrite
5
g/l
Sodium Thiosulfate
5
g/l
Sodium Molybdate
5
g/l
Stannous Chloride
0.2
g/l
Petro AA
0.1
g/l
During this second immersion, the article gradually takes on a black color due to the formation of magnetite on the surface. The article is then rinsed in water and sealed in a water-displacing oil topcoat which serves as a rust preventative. The resultant coating is opaque black in color, tightly adherent, with corrosion resistance equal to that provided by the topcoat oil sealant.
EXAMPLE 2
First Oxidation: A 4140 heat-treated steel cutting tool is cleaned and descaled by conventional means. The tool is then immersed for 90 seconds at 120° F. in an aqueous solution containing:
Oxalic Acid
14 g/l
Phosphoric Acid
1.2 g/l
Sodium m-Nitrobenzene Sulfonate
6 g/l
The above immersion produces an opaque gray coating on the steel surface. Because the 4140 steel is less reactive than the 1018 steel used in Example 1, the above oxidation solution has been modified from the first oxidation solution of Example 1 to eliminate the grain refiner (Sodium Potassium Tartrate), and to raise the operating temperature to make the reaction more aggressive.
Second Oxidation: After rinsing in water, the tool is immersed for 8 minutes at 200° F. in an aqueous solution containing:
Sodium Hydroxide
100
g/l
Sodium Nitrate
35
g/l
Sodium Nitrite
5
g/l
Sodium Thiosulfate
5
g/l
Sodium Molybdate
5
g/l
Stannic Chloride
0.2
g/l
Petro AA
0.1
g/l
During the second immersion, the tool gradually takes on an opaque black color. The tool is then rinsed in water and sealed with a water-displacing rust preventative oil.
EXAMPLE 3
First Oxidation: A mild steel decorative article is cleaned by conventional means and immersed for 1 minute at room temperature in an aqueous solution containing:
Oxalic Acid
14 g/l
Phosphoric Acid
1.2 g/l
Sodium m-Nitrobenzene Sulfonate
6 g/l
Sodium Potassium Tartrate
0.4 g/l
The above immersion will produce an opaque gray intermediate coating on the article surface after rinsing.
Second Oxidation: The article is then immersed for 6 minutes at 180° F. in an aqueous solution containing:
Sodium Hydroxide
100
g/l
Sodium Nitrate
27
g/l
Ethylene Thiourea
0.6
g/l
Tin (IV) Chloride
2
g/l
Sodium Dichromate
0.3
g/l
Petro AA
0.1
g/l
During the second immersion above, the article gradually takes on an opaque brown color. The article is then rinsed in clear water and sealed in a clear acrylic polymer-based topcoat. The resultant coating may serve as an aesthetic finish for decorative hardware, etc.
EXAMPLE 4
First Oxidation: A sintered iron metal article is cleaned by conventional means and immersed for 3 minutes at 120° F. in an aqueous solution containing:
Phosphoric Acid
28
g/l
Hydrofluosilicic Acid
8
g/l
Xylene Sulfonic Acid
3
g/l
Dodecylbenzene Sulfonic Acid
2
g/l
Monoethanolamine
17
g/l
Sodium m-Nitrobenzene Sulfonate
1
g/l
Molybdenum Trioxide
0.2
g/l
After this immersion, the article has an intermediate coating of an opaque gray iron phosphate deposit.
Second Oxidation: After rinsing in water, the article is immersed for 5 minutes at 200° F.
Sodium Hydroxide
100
g/l
Sodium Nitrate
35
g/l
Sodium Nitrite
5
g/l
Sodium Thiosulfate
5
g/l
Sodium Tungstate
5
g/l
Sodium Stannate
0.2
g/l
Petro AA
0.1
g/l
During the above immersion, the article gradually takes on a black color. After rinsing in water, the article is sealed in a water-displacing rust preventative oil. The resultant finish is somewhat more fragile than that deposited in Examples 1 and 2, but may be considered preferable for certain applications because of the expected lower operating cost. In addition, the extremely porous substrate produced by this process may tend to make the fragile nature unimportant, depending on the end use of the article.
Because of the potentially dangerous nature of the prior known metal blackening processes, many manufacturers have found it more convenient to send parts to an outside vendor for application of a black finish. This, of course, is inefficient and adds to the overall cost of production. A particular feature of this invention is a seven-step process which may be provided in a set-up of seven baths or containers, so that a metal manufacturer may safely and conveniently carry out in-house metal blackening without the risk to employees posed by such previous blackening procedures. The inventive process may be commercially carried out as a seven step process as follows:
Step 1: The article is cleaned, degreased and descaled (if necessary) to remove foreign materials such as fabricating oils, coolants, extraneous lubricants, rust, millscale, heat treat scale, etc. The aim here is to generate a metal surface which is free of oils and oxides, exposing a uniform and reactive metal surface. Any method of providing such a surface known to the metal finishing industry is suitable. Acceptable methods include conventional cleaning in an alkaline detergent soak cleaner, solvent degreasing or electrocleaning. Descaling can be accomplished by acid or caustic descaling methods. Abrasive cleaning methods such as bead blasting, shot peening and vapor honing may be used with good results. All these methods are well known to the metal finishing industry. Step 2: The article is rinsed in clean water to remove any cleaning residues from the surface. Step 3 (First Oxidation): The article is then subjected to a first oxidation to provide an intermediate coating on the metallic iron substrate. The oxidation reagent is an aqueous solution of either a dicarboxylate or a phosphate or mixtures thereof, optionally with a grain refiner, to provide a water insoluble dicarboxylate-based deposit or a water insoluble phosphate-based deposit, or mixtures thereof. Appropriate dicarboxylic acids include aliphatic dicarboyxlic acids, generally of up to about five carbon atoms, such as oxalic, malonic, succinic, glutaric, adipic, pimelic, maleic, malic, tartaric, or citric acid, and mixtures thereof. When the intermediate coating is a ferrous oxalate, suitable reaction parameters are as follows: pH range: about 0.5-2.5, typically about 1.6; operating temperature range: about 50-150° F., typically about 75° F.; contact time range: about 0.5-5.0 min., typically about 2 min.
Appropriate reagents for deposition of the water insoluble phosphate-based coating include phosphoric acid, as well as alkali metal acid phosphates, alkali metal pyrophosphates or primary alkanol amine phosphates. When the intermediate coating is a iron phosphate, suitable reaction parameters are as follows: pH range: about 3.0-5.5, typically about 4.0-5.0; operating temperature range: about 60-180° F., typically about 120-130° F.; contact time range: about 1-10 min., typically about 3-5 min.
Appropriate grain refiners include alkali metal compounds of tartrate, tripolyphosphate, molybdate, citrate, polyphosphate and thiocyanate, such as sodium potassium tartrate. A suitable grain refiner is sodium potassium tartrate.
A suitable first oxidation solution according to this invention is prepared as follows:
Component
Concentration
Acceptable Range
Oxalic acid
14 g/l
3-35
g/l
Phosphoric acid
1.2 g/l
0.5-3.0
g/l
Sodium m-Nitrobenzene sulfonate
6 g/l
1-15
g/l
Sodium Potassium Tartrate
0.4 g/l
0.1-2.0
g/l
Contact time in this solution is usually about 1-3 minutes at about 50-150° F. The resulting deposition is an opaque, gray dicarboxylate intermediate coating.
Alternatively, an iron phosphating solution can be used to deposit an intermediate coating which is also effective. A suitable composition and acceptable range of concentrations for this option are shown below:
Component
Concentration
Acceptable Range
Phosphoric acid
28 g/l
7-70
g/l
Hydrofluosilicic acid
8 g/l
2-20
g/l
Xylene Sulfonic acid
3 g/l
1-7.5
g/l
Dodecylbenzene sulfonic acid
2 g/l
1-5.0
g/l
Monoethanolamine
17 g/l
4-43.0
g/l
Sodium m-Nitrobenzene sulfonate
1 g/l
0.25-2.5
g/l
Molybdenum trioxide
0.2 g/l
0.05-0.5
g/l
Contact time in this solution is usually about 1-13 minutes at about 80-150° F., resulting in the deposition of an opaque, gray iron phosphate intermediate coating.
Step 4: The article is rinsed in clean water to remove any acid solution residues from the surface.
Step 5 (Second Oxidation): The article is then oxidized to a colored surface by a second oxidation with an aqueous solution of oxidizing agents for a time sufficient to achieve the desired surface color. The composition of this second oxidation solution may include primary oxidizers along with such additional components as accelerators, metal chelators and surface tension reducers. Appropriate oxidizers include alkali metal compounds of hydroxide, nitrate, and nitrite. The oxidizing solution for the blackening reaction (the second oxidation) preferably contains three oxidizers, sodium hydroxide, sodium nitrate and sodium nitrite. If one of these oxidizers is omitted, the blackening reaction has been found to proceed less efficiently.
Appropriate accelerators for the second oxidation include organic and inorganic nitro compounds, alkali metal compounds of citrate, molybdate, polyphosphate, vanadate, chlorate, tungstate, thiocyanate, dichromate, stannate, sulfide and thiosulfate, and stannous chloride and stannic chloride. Suitable accelerators are chosen according to such considerations as cost and solubility. Appropriate metal chelators include alkali metal compounds of thiosulfate, sulfide, ethylene diamine tetraacetate, thiocyanate, gluconate, citrate, and tartrate. Suitable chelators are chosen according to such considerations as cost, solubility and reactivity. Appropriate surface tension reducers include alkylnaphthalene sulfonate and related compounds which are stable in high pH environments.
Suitable reaction parameters for the second oxidation are as follows: pH range: about 2.0-14.0, typically about 13.0-14.0; operating temperature range: about 120-220° F., typically about 160-200° F.; contact time range: about 0.5-10 min., typically about 2-5 min.
A typical composition and range of concentrations for the process solution for Step 5 are shown below:
Component
Concentration
Acceptable Range
Sodium hydroxide
100
g/l
25-200
g/l
Sodium nitrate
35
g/l
8.75-70
g/l
Sodium nitrite
5
g/l
1-10
g/l
Sodium thiosulfate
5
g/l
1-10
g/l
Sodium molybdate
5
g/l
1-10
g/l
Tin (IV) Chloride
0.2
g/l
.05-0.4
g/l
Petro AA
0.1
g/l
.025-0.2
g/l
Normal contact time for the second oxidation is about 2-10 minutes at about 160-220° F. The resulting coating may be black or brown in color, depending on exposure time, temperature and composition of the oxidizing solution.
Step 6: The article is rinsed in clean water to remove any oxidizing solution residues from the surface.
Step 7: The article is then sealed with a topcoat appropriate to the end use of the product, such as a lubricant, a rust preventative compound or a polymer-based topcoat.
Cleaning and rinsing techniques, such as those described above for Steps 1, 2, 4 and 6, may vary widely and are well-known to the metal finishing industry. Many different such techniques can be used, depending on the condition of the metal surface prior to blackening, the volume of work to be done, the finish requirements for the final finish, etc. Consequently, alternate cleaning and rinsing techniques, as recognized within the metal finishing industry may be used and can be determined by the operator of the process. The specific cleaning and rinsing techniques described above should be considered merely illustrative. Following is a description of parameters of a seven-step sequence as described above used to produce a black finish on a substrate of 1018 low carbon steel panel, which exemplifies operation of the process of this invention at the extraordinarily low temperature of 80° F.:
Step 1: The panel is cleaned as above described.
Step 2: The panel is rinsed as above described.
Step 3(First Oxidation): A dicarboxylate coating is provided.
Step 4: The panel is rinsed as above described.
Step 5(Second Oxidation): The panel is oxidized to a produce a black finish.
Suitable reaction parameters for the second oxidation are as follows: pH range: about 12.0-14.0, typically about 13.0-14.0; operating temperature range: about 80° F.; contact time range: about 30 min.
The composition and concentrations for this process solution are shown below:
Component
Concentration
Sodium hydroxide
175
g/l
Sodium nitrate
60
g/l
Sodium nitrite
10
g/l
Sodium thiosulfate
10
g/l
Sodium molybdate
8
g/l
Tin (IV) Chloride
0.5
g/l
Petro AA
0.2
g/l
Step 6: The panel is rinsed as above described.
Step 7: The panel is then sealed with a topcoat appropriate to its end use as above described, such as with a lubricant, a rust preventative compound or a polymer-based topcoat.
|
This invention is a method for forming a chemical conversion coating on ferrous metal substrates, the chemical solutions used in the coating and the articles coated thereby. By modifying and combining the features of two existing, but heretofore unrelated, coating technologies, a hybrid conversion coating is formed. Specifically, a molecular iron/oxygen-enriched intermediate coating, such as a dicarboxylate or phosphate, is applied to a ferrous substrate by a first oxidation. The intermediate coating pre-conditions the substrate to form a surface rich in molecular iron and oxygen in a form easily accessible for further reaction. This oxidation procedure is followed by a coloring procedure using a heated (about 120-220° F.) oxidizing solution containing alkali metal hydroxide, alkali metal nitrate, alkali metal nitrite or mixtures thereof, which reacts with the iron and oxygen enriched intermediate coating to form magnetite (Fe 3 O 4 ). The result is the formation of a brown or black finish under much more favorable, milder and safer conditions than previously seen with conventional caustic blackening processes, by virtue of the chemical reaction between the intermediate coating and the second oxidation solution. When sealed with an appropriate rust preventative topcoat, the final result is an ultra-thin, attractive and protective finish applied through simple immersion techniques. The finish is a final protective coating on a fabricated metal article and also affords a degree of lubricity to aid assembly, break-in of sliding surfaces or provide anti-galling protection. The finish also provides an adherent base for paint finishes.
| 2
|
RELATED APPLICATION
[0001] This application claims priority to and the benefit of U.S. Provisional Patent Application Ser. No. 60/716,168, filed Sep. 12, 2005, entitled “High Speed Sailing Craft,” attorney docket number XYP-002PR, incorporated herein by reference.
FIELD
[0002] The present invention is directed generally to the field of water craft.
BACKGROUND AND OBJECTIVES OF THE INVENTION
[0003] Generally, the force of the wind on a sail can be resolved into a force that drives a boat forward and, a force that causes the boat to slide sideways and heel (tip to the side). In a typical sailboat, the boat is restrained from sliding sideways by one or more foil(s) in the water (e.g., keel(s), centerboard(s), rudder(s)), and the tipping moment is counteracted by such things as a heavy weight on the bottom of a keel, the weight of the crew leaning out to windward, or for example, in the case of a catamaran, the weight of the windward hull and the buoyancy of the leeward hull.
[0004] The speed of a sailboat typically is constrained by drag, particularly drag due to dynamic displacement of water by (a) the hull, steering foils (e.g., a rudder) and tracking foils (e.g., keel, centerboard), and (b) skin friction on the hull and foils. Displacement drag results from the energy required to move water out of the way of the moving hull. Friction drag results from the water sticking to the hull as a result of molecular attraction. The loss of energy through drag decreases the energy available to push the boat forward. Generally, the amount of force needed to overcome these drags increases as the square of the speed, which tends to put a practical limit on possible speed.
[0005] To increase forward driving force, techniques such as increasing sail area are needed, but increasing the sail area can result in a variety of problems such as decreased control and increased tipping moment, which causes the boat to heel over too far. Also, as the speed of a sailboat increases, it becomes more difficult to balance the large driving forces and large drags so constant adjustment of sails and boat direction is required.
[0006] Recent advances in sailboat design have resulted in the development and construction of sailboats which can travel at much higher speeds than sailboats many years ago. For example, it is now common for high-speed sailboats to go faster than the wind, in some cases twice or as much as almost three times as fast. Such increase in performance has been largely due to changes in design which use better sails, reduce weight, make use of planing hulls that raise the boat out of the water, hydrofoils, novel sail configurations, or some combination of these.
[0007] Some of the advances in boat design are described in the books “The Physics of Sailing Explained” by Bryon Anderson, Sheridan House, 2003, ISBN 1-57409-170-0 and “Aero-hydrodyanmics of Sailing” by C. A. Marchaj, Dodd, Mead & Company, 1979, ISBN 0-396-07739-0.
[0008] With such technologies, some modem high speed sailboats can occasionally achieve high speeds, but their maximum speeds have been limited to somewhat less than 50 knots (approx. 57 mph). In 2004, for example, the speed sailing record for water borne-sailing craft was set at 46.85 knots (53.95 mph) by a windsurfer. Prior to that it was held for eleven years by an Australian boat, the Yellow Pages Endeavour (YPE), (http://innovoile.free.fr/YPE_e.html); at 46.52 knots (53.57 mph). This modest increase in recent years illustrates the difficulties of increasing speed.
[0009] One of the early contributions to increased speed was the refinement of the planing board, which is designed to lift water craft up out of the water. Water skis, surf boards and windsurfers are examples of water craft which use planing boards. Also some modem high speed sailboats such as the Hobie Trifoiler (http://www.hobiecat.com/sailing/models_trifoiler.html ) use planing boards which are similar to water skis.
[0010] In addition, very wide sailboats with multiple hulls, such as the YPE, have improved balancing of the tipping moment of the sail with the righting moment of the weight of the crew, allowing larger sail areas. Also, improvements have been made with such innovations as stiff sails, which avoid driving force loss due to sail twist; solid sails similar to airplane wings which are more aerodynamically efficient than soft sails; steering and tracking foils having shapes that result in reduced drag; and taller sails for better wind attack angles. Nevertheless, significant limitations due to displacement drag and skin friction drag have remained. In addition, with current designs, at very high speeds, cavitation on the steering, tracking foils and hydrofoils, if employed, reduce control because the cavitating foils lose contact with the water. Moreover, many high-speed sailboats are designed so they can only operate with the wind coming from one side of the boat, and are therefore not suitable for purely recreational use.
[0011] Jean Margail of France, the leader of the Water.Resist speed sailing team (http://foxxaero.com/indsail — 013.html), has noted that “everybody knows that for speed sailing the craft should be out of the water . . . hydrofoils generate too much drag—max speed 45 knots.” He published a design on his web site that appears to use airfoils (e.g., wings) to lift the boat up from the water, but the fixed steering and tracking foils that he proposes remain submerged, which still limit the speed at which his proposed sailboat can travel because of the displacement and skin friction drags on those vertical foils.
[0012] One of the objectives of the technology described here is to reduce displacement and skin friction drags described above. A further objective is to provide more stable control of a boat that is lifted out of the water, by reducing cavitation, which results in loss of control. A further objective is to enable high speed sailboats to operate more like conventional sailboats so a larger part of the sailing public can enjoy high-speed sailing.
SUMMARY
[0013] In general, in one aspect, the disclosed technology relates to high-speed sailing craft. In one aspect the high-speed sailing craft has one or more airfoils. The airfoil may be shaped, for example like a wing, such as an airplane wing. The airfoil may extend from the craft or be integral to the craft, for example, may be designed into a deck, or used to connect portions of the craft. The airfoil is preferably approximately (and relative to vertical foils) horizontal, although generally at a slight angle, and is configured for lifting the craft up from the water, such that in operation of a portion of, and in some cases, much of, the craft can be out of the water.
[0014] The craft also has one or more rotating foils. Just as one example, the rotating foils can be, or can be mounted on, wheels, that are configured to rotate according to the direction of travel of the boat. In one embodiment, a rotating foil(s) typically is partially submerged in the water for providing tracking and/or steering. The rotating foil is preferably approximately (and relative to horizontal foils) vertical. For tracking, the top of the rotating foil preferably rotates in line with the direction of travel, such that the rotation of the bottom of the rotating foil is approximately stationary with respect to the water as the boat travels. To provide steering, one or more rotating foils can also be configured to pivot, such that the foil rotates in a direction that is at an angle from the direction from the front to the back of the craft, thereby providing a force that will direct other than straight ahead. This is analogous to the pivot of a rudder or the wheels of a car that are controlled by a steering wheel.
[0015] By lifting the craft up from the water, the airfoil allows the craft to travel faster by reducing the displacement drag and friction drag of the water on hull(s) and/or float(s). The rotating action of tracking and/or steering foil(s) reduces the friction on them, also resulting in reduced drag and reduced cavitation. In combination, one or more airfoils and one or more rotating tracking and/or steering foils have the combined effect of significantly reducing the forces holding back and impeding control of a water craft, thereby improving speed and performance.
[0016] In general, in another aspect, the disclosed technology relates to a sailing craft that can attain high speeds by using one or more airfoils alone or in combination with one or more planing boards to lift the board and boards out of the water. Rotating foils are used in combination with the boards. In increased-speed operation, the craft is lifted almost entirely out of the water. As the boards and foils for steering and tracking rise, displacement and skin friction drags are greatly reduced. In addition, the steering and tracking foils needed for control are free to turn, further reducing skin friction.
[0017] In some such embodiments, at rest and at very low speeds, planing board buoyancy is the primary source of lift, but at higher speeds, the boards plane (lift up in the water), and at yet higher speeds, aerodynamic lift from the airfoils provides lift, and the planing boards lift out of the water.
[0018] The rotating steering and tracking foils can be implemented as wheels. One exemplary implementation, for example, uses three varieties of wheels. Wheels near the front of the boat include a body, a tread and a peripherally mounted foil for tracking. These wheels protrude through planing boards such that their bottoms are below the boards' bottom surfaces. At top speed, only the foils and a small part of the wheel body of the wheels are submerged.
[0019] In one implementation, these wheels are spring-loaded such that the wheels descend downward as the airfoils lift the boat and raise it from the water. The descending motion also is coordinated with control of an aileron on the adjacent foils such that lift is reduced. This action prevents the boat from becoming airborne and keeps the tracking foil submerged so it can perform its function.
[0020] For example, in one embodiment, the wheel is attached to an arm that activates a mechanism to adjust aileron position. When enough lift has been provided to lift the wheel bodies mostly out of the water, leaving the bottoms of the foils submerged, any further lift causes ailerons to reduce lift and prevent the boat from becoming airborne. Other embodiments use electronic sensors and aileron position motors to accomplish this function. In other embodiments, wind speed is sensed, and when the wind exceeds the level at which the boat would become airborne, the ailerons are raised to reduce lift. In another embodiment, a water level sensor is used, alone or in combination with the above, to control the ailerons.
[0021] In one embodiment, the wheel(s) in the aft section of the boat have only the wheel body and tread, with no foil, but are connected to a lift-reducing apparatus which is configured to coordinate with the nearby aileron.
[0022] In one embodiment, in a third type of wheel, only the foil portion is used, the body and tread are omitted, and the wheel is used as a rudder. The foils on the aft wheels can be omitted so that they do not interfere with rudder function.
[0023] In one embodiment, the craft includes a combination of a planing board, an airfoil and a rotating wheel at one or more locations. The wheel and planing board comprise an assembly referred to as a pod.
[0024] In one embodiment, the boat is designed generally as a rectangle, similar to a catamaran. However, instead of a starboard and a port hull, at each corner of the catamaran, is a pod, such that there are two pods on the starboard side of the boat that replace the right hull of a traditional catamaran, and likewise two pods on the port side replace the left hull of a traditional catamaran. Airfoils are attached to the center of the boat and extend out to the pods. Wheels are mounted in the planing boards and their foils, if any, protrude below the bottoms of the boards.
[0025] In one embodiment, planing hulls are not used, and the boat floats on its buoyant wheels.
[0026] In one embodiment, the boat is in the form of a trimaran with two pods to starboard of a center hull and two to port. In such a configuration, the planing boards in the pods may be omitted with a planing board added to the center of the boat. This embodiment can result in a boat which is lighter and simpler to construct since the boat is not held up at the ends of the airfoils while at rest or in light winds since the pods at the ends of the airfoils contribute little to floatation.
[0027] In some embodiments, the pods and/or wheels are spring loaded to adjust to waves. This reduces the drag experienced by the planing hull plowing into a wave.
[0028] In some embodiments, there are multiple wheels in each pod.
[0029] In some embodiments, the tread of the wheels are honeycomb structures bonded to the wheel on one side and open to the water on the other. As the wheel revolves, the honeycomb pockets become submerged, trapping air in each one. At rest or at low speeds, the buoyancy of the boat is enhanced by these air pockets, and the wetted surface of the boat is reduced, and the tread has less tendency to contribute to loss of energy caused by throwing water into the air at the back of the wheel. Essentially the honeycomb decouples the boat from the water.
[0030] In some embodiments, a water level sensor is mounted in each pod to determine how much the pod has been lifted by its associated planing board, air foil and wheel. This sensor is used to adjust the position of an aileron on one or more the associated airfoils to control the amount of lift provided by the airfoil and to prevent the foil from coming completely out of the water. The adjustment can be automatic so that at high speeds the planing board is above the water surface and only a small portion of the wheel tread and body is submerged, leaving only the foil portion of the steering/tracking foil completely submerged. The adjustment could also (or instead) be controlled by the crew.
[0031] In some embodiments, a trampoline deck is used and configured so that the crew can move out toward or beyond the windward pods countering the tipping moment of the sail. In other embodiments, the leeward airfoils are adjusted to increase lift to balance sail tipping moment and in still further embodiments the windward foils are adjusted to decrease lift or produce reverse lift to balance sail tipping moment. In some embodiments, the deck is a net so that its interference with air circulation necessary to produce lift is minimized.
[0032] In some embodiments, the aft and forward airfoils are separately controlled to keep the boat level fore to aft. This is particularly useful when the boat is on a run (with the wind behind it). In this situation, some boats can be prone to tip over bow first. Control of the boat angle can prevent such a forward pitch.
[0033] In some embodiments a wind shield is mounted on each pod to reduce drag due to wind similar to aerodynamic designs used in land vehicles (e.g., cars).
[0034] In one embodiment, in which there are no ailerons on the airfoils, the boat is prevented from becoming airborne by adjusting the trim of the sail so that as the lift-off speed is approached, the pulling force of the sail is reduced. The trim may be automatically adjusted in response to a water level sensor or may be adjusted by the crew. In other embodiments in which there are no ailerons on airfoils, the angle of the airfoils may be adjusted to control lift.
[0035] In one embodiment, the boat is operated by a single skipper and in others by a crew of two of more.
[0036] In one embodiment, the boat is small, similar in size to a windsurfer, and the skipper operates the boat in a standing position and trims the sail by rocking the sail forward and aft as in a windsurfer. In this embodiment there is no rudder.
[0037] The boat can be any sort of sailing craft, with any sort of configuration of sails and propulsion. In some embodiments there are multiple masts and sails. In some embodiments, the boat is equipped with a jib and/or a spinnaker.
[0038] In one embodiment, an engine or other propulsion is used to accelerate the boat to the speed necessary for the airfoils to lift all but the wheel foils out of the water, thereby taking advantage of the resulting reduced displacement and skin friction drags. Once the necessary lift has been achieved, the engine is turned off.
[0039] In some embodiments, the mast is taller than would typically be found in a similar-sized sailboat, reducing leakage of air off the top of the sail and decreasing the angle of attack of the boat to the apparent wind. The taller mast is facilitated by the availability of using the airfoils to counteract tipping moment. Masts twice the length of the boat or more are possible.
[0040] In one embodiment, steering is controlled by a tail fin, like an airplane's. The tail fin can be used instead or in combination with a rudder.
[0041] In one embodiment, the pods are arranged in a triangular configuration rather than a rectangle. Preferably, in such embodiment, the frame of the craft may be triangular. Generally in such embodiments the rudder will be at the point of the triangle, either forward or aft, and the wheel at that location will have a body and tread as well as a rudder foil.
[0042] In some embodiments one or more pods pivot, or turn, like the wheels of a car, to provide a steering function. In some embodiments, just the wheels, not the pods, are configured to pivot, or turn, to provide steering. In a further embodiments, only forward pods or wheels pivot, only aft pods or wheels pivot, or pods or wheels in forward and aft positions pivot.
[0043] In one embodiment, the pods are wide and are in the form of airfoils. In such an embodiment, the pods act both as planing boards at low speeds and airfoils at high speeds.
[0044] In one embodiment the airfoil is designed to produce a stalling action at a desired maximum speed to assist in preventing the boat from becoming completely airborne. For example, as wind speed increases, airfoils with large lift angles will produce turbulence in the air flow pattern, which reduces lift. The angle of airfoils also may be adjustable to control lift.
[0045] In various embodiments, commercially available boats may be modified, or designs for commercially available boats may be modified to include embodiments of the invention. In one exemplary embodiment, an A Class catamaran is modified to provide a lower cost version of the invention. An A Class catamaran is a light (e.g., 165 pound), fast catamaran, typically with a 30 foot mast, which can be sailed single or double-handed. In one embodiment, the hulls of such a boat are separated further than normal, the trampoline is tilted back, and in some configurations it is cambered to provide greater lift. In addition, airfoils may be placed in front of the mast to provide lift. In some such embodiments, the usual daggerboards and rudders may be replaced by rotating foils. The result is a boat that may lift substantially off the water in true wind speeds as low as 10-15 knots and may reach very high forward speeds in high winds. It should be understood that this embodiment is exemplary, and other boats may be modified in an analogous manner.
[0046] In various embodiments, two or more airfoils may be used, e.g., a port-side airfoil or set of airfoils and a starboard-side airfoil or set of airfoils. The lift generated by each of the airfoils may be adjusted during operation, for example but not limited to by using ailerons, adjusting the airfoil angle, or by another technique, so that the airfoils can be used help control the angle of the boat to avoid tip-over. In this way, a boat may travel at speeds that might otherwise cause tip-over. For example, in a boat in which a skipper is hiking out, airfoils (and/or ailerons) on one or both sides may be adjusted to help hold the windward side down, and so control tipping. The adjustment of airfoils (and/or ailerons) may be automatic, for example but not limited to based on distance from water surface and/or boat angle and/or based on the weight distribution within the boat. Adjustments may be made manually instead of or in addition to automatic adjustment.
[0047] In some embodiments, a sailing craft may include a frame, a sail connected to the frame, a port side airfoil for providing lift, and a starboard side airfoil for providing lift. The lift provided by the port side airfoil and the lift provided by the starboard side airfoil may be adjusted automatically to control tipping. The lift may be adjusted for example but not limited to by adjusting airfoil angle, adjusting ailerons, or some other method. In some implementations, there may be a set of two, three or more port side airfoils and/or a set of two, three or more starboard side airfoils. There may be additional airfoils not associated with one side or the other.
[0048] As mentioned, the principles described here can be used in any suitable craft or configuration. For example, in one embodiment, a craft has a proa configuration in which the mast is on either the starboard or port side of the boat rather than in the middle. As another example, another embodiment has catamaran hulls instead of or in combination with the pods described above. In yet another embodiment, the craft is a trimaran, and all three·hulls lift out of the water at high speeds, and one or more of the hulls have rotating foils built-in or affixed thereto.
[0049] In general, in one aspect, the invention uses the teachings of co-pending International PCT Application No. PCT/US2004/012241, entitled “Sailing Craft with Wheels,” which is incorporated herein by reference in its entirety. The technology described here, such as the use of airfoils and planing boards can be used effectively with the foils and crafts described therein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0050] FIG. 1 shows a three dimensional view of an illustrative embodiment of the invention.
[0051] FIG. 2 a shows a wheel with a peripheral foil such as might be used in the embodiment illustrated in FIG. 1 in the forward two pods.
[0052] FIG. 2 b is a side view of a tracking wheel and FIG. 2 c is a cross section of a this wheel.
[0053] FIG. 2 d is an isometric view of a wheel such as would be used in the aft portion of the illustrative embodiment. Here the foil is omitted as it might interfere with the operation of the rudder.
[0054] FIG. 2 e shows a rotating foil used for steering.
[0055] FIG. 3 a shows the forward airfoil of the illustrative embodiment.
[0056] FIG. 3 b shows a top view of the forward airfoil illustrative embodiment with its associated pods while FIG. 3 c is the side view with the wheel in its lifted and unlifted positions.
[0057] FIG. 3 d is a top view of a forward airfoil for an ultra high speed embodiment in which the planing board is on the bottom of the central torsion box and the planing boards are omitted from the pods. FIG. 4 e is the side view.
[0058] FIG. 3 f illustrated a forward airfoil with the wings swept forward.
[0059] FIG. 4 a is a top view of a pod.
[0060] FIG. 4 b shows a side view when the airfoil has lifted the boat to the level which leaves only the wheel's foil submerged as would occur at top speed.
[0061] FIG. 4 e shows the position of the wheel in the pod and the position of the aileron with the boat as rest or a very low speed.
[0062] FIG. 4 c and 4 d are the end views corresponding to 4 b and 4 e .
[0063] FIG. 5 a is a top view of the rudder assembly of the illustrative embodiment while 5 b is the side view with the boat at rest or at low speed.
[0064] FIGS. 6 a , 6 b , 6 c and 6 d are vector diagrams showing motion of the boat for various true wind directions.
[0065] FIG. 7 a and 7 b illustrate a pod in which the planing board can pivot to accommodate waves.
[0066] FIG. 8 shows the action of spring loaded airfoils to accommodate waves.
[0067] FIG. 9 describes the velocities of points on the rotating foil relative to the water.
[0068] FIG. 10 shows an example of a commercially available boat modified to include embodiments of the invention.
DETAILED DESCRIPTION
[0069] Referring to FIG. 1 , in one illustrative embodiment, a boat 100 has four pods 101 , a sail 102 and associated equipment, and a frame 103 with its associated equipment.
[0070] In this embodiment, the sail 102 is attached to a mast 104 by conventional means. The mast 104 is held in place by a fore stay 105 , a starboard shroud 106 and a port shroud (mostly hidden behind the sail). The skipper controls the trim of the sail 102 using the main sheet 117 which is attached to the boom 118 and passes through the block 119 . This may be a conventional sail 102 and rigging, or may be a sail that is specially configured for operation of this boat.
[0071] The skipper controls the boat from the deck, which in this embodiment is a trampoline 112 . The skipper steers the boat using a tiller extension 1 13 attached to a tiller 114 which in turn is attached to a tiller post 1 5 . This can be a conventional tiller and assembly. As in a conventional craft, the boat is steered by tiller operation that results in turning the rudder 121 . In this boat, however, the rudder is a freely rotating disk, such as a wheel as described below with reference to FIG. 2 e.
[0072] Forward and aft airfoils 109 , 110 are attached to the frame 103 . These are equipped with ailerons 111 , which are adjusted to control the amount of lift provided by the airfoils.
[0073] Each pod 101 includes a freely rotating wheel 107 , also with reference to FIGS. 2 a and 2 d , and a planing board 108 . The pods are covered by shields 122 to reduce aerodynamic drag. The pods are attached to the airfoils 109 , 110 by posts 120 .
[0074] A central structural member 116 of the frame runs fore to aft, and in this embodiment is in the form of a torsion box so that the pressure on the sail results in minimal twist to the boat, keeping the pods at approximately the same level with respect to the frame each other. In the preferred embodiment, this structure is approximately one foot square in cross section. It is fabricated from aluminum extrusions, but could instead be manufactured as a tube of composite material. Torsion boxes, for example, were widely used in early biplanes to prevent the wings from twisting. The supports used in them can be made from struts and cables.
[0075] In the absence of wind, the boat floats on the planing boards 108 , such that the outer portions of the wheels 414 ( FIG. 4 ) protrude below the bottoms of the boards. In light winds, the boat operates in a similar manner to an ordinary sailboat. The wind generates forces which cause the boat to move forward, and the drag holding the boat back comes primarily from the energy taken to displace water as the planing boards move through it. This is referred to as a displacement mode of operation.
[0076] In moderate winds the planing boards 108 will move more rapidly, and it becomes more difficult to move the water out of the way fast enough, so drag increases. This is called the forced mode. As the wind increases further, the planing boards 108 will begin to plane, i.e., rise up, and the boat enters a planing mode. In this mode the drag continues to increase with increased velocity by not at the same rate as in the forced mode because less and less water is displaced. For most boats, the displacement drag generally increases as the square of velocity in the displacement and planing modes and as the cube of velocity or higher in the forced mode. A second form of drag, skin friction drag, begins to significantly add to drag as the boat accelerates. This drag also generally increases as the square of velocity. Since the wetted surface area of the boat in the planing mode is less than in the displacement or forced modes, planing somewhat mitigates the increase in skin friction drag.
[0077] As the boat continues to go faster, the airfoils provide lift, which raises the boat with its planing boards out of the water, thereby dramatically reducing both displacement drag, because less volume of water needs to be displaced, and skin friction drag because (i) the planing board is out of the water (ii)the bottom of the wheel is almost stationary relative to the surface of the water and (iii) the tread 205 ( FIG. 2 c ) is decoupled from the water by air trapped in the honeycomb pattern when the wheel is partially submerged.
[0078] The lift of an airfoil varies as the square of wind velocity. Since displacement drag varies as the volume of water displaced by the hull which varies with depth of immersion, and skin friction varies as the wetted area which also varies as the depth of immersion, the lift of the airfoils counters some of the typical drag increases that result from increased velocity. This decrease in drag due to the airfoils will greatly facilitate the boat's acceleration compared to ordinary boats.
[0079] As speed increases, the boat will lift until only portions of the wheels and the rudder wheel are immersed, and drag from the water is reduced to its minimum. This is the ideal running elevation. If the airfoils were to continue to increase lift, the boat might become completely airborne, and the wind will push it sideways and backwards, allowing the boat to descend back into the water but at a lower velocity.
[0080] In one embodiment control of the airfoils is provided by a mechanism which senses the depth of the tread in the water. In this embodiment the tread does not fully lift out of the water as described below and illustrated in FIGS. 4 b and 4 c . However, since almost all the tread is above the water surface, wheel displacement drag and skin friction drag are extremely low compared to conventional boats.
[0081] As wind speed increases, drag due to the airfoils increases. However, due to the lower density and viscosity of air compared to water, this drag increases at a much slower rate than the decreases in drag due to the planing board and wheel treads being lifted out of the water.
Wheels and Rotating Foils
[0082] Referring to FIG. 2 a , a three-dimensional view of a design of an exemplary wheel depicts an axle 201 , a body 202 with a tread 205 ( FIG. 2 c ) and a foil 203 . The body includes the core 204 ( FIG. 2 c ), tread 205 ( FIG. 2 c ) and axle 201 . In the illustrative embodiment, the foil 203 is not included on the aft wheels, as shown in FIG. 2 d. In FIG. 1 the foil is shown 107 as protruding through the top of a forward pod aerodynamic shell, but as there is no foil used in the aft pods, no foil is shown.
[0083] Referring briefly to FIG. 2 c , in one embodiment, the tread 205 is attached to the outside of each cylinder of the body and consists of a honeycomb or other suitable structure bonded to a cylinder on one side and open to the water on the other. The core 204 of the wheel body is made from foam or other light weight material. In other embodiments the core may be hollow.
[0084] Referring again to FIG. 2 a , in an illustrative embodiment, the diameter of the foil 203 is about 36 inches and its thickness is approximately ⅛ inch. Any suitable material, for example, a composite material such as fiberglass re-enforced resin or stainless steel can be used. The foil protrudes six inches beyond the diameter of the body 202 . It must be sufficiently strong and stiff to withstand the sideways pressure exerted when the boat is underway.
[0085] The core of the wheel may be formed using lightweight foam such as polystyrene or polystyrene foam sheets, such as those manufactured by the Owens Corning Company of Midland Michigan, available in standard two inch thickness, and which can be purchased in lumber supply stores. The sheets may be cut to the needed diameters and bonded together using Resorcinol glue, which can be obtained from Allerd & Associates 2 South St., Auburn N.Y. 13021. In one embodiment, on the periphery of each cylindrical section of the wheel a layer of honeycomb 205 such as that shown in FIG. 2 c is bonded to the foam body using epoxy resin such as can be obtained from West System Inc. of Bay City, Mich. Honeycomb is available, for example, from Plascore Inc. of Zeeland Mich. The unbonded side of the core is left open so that air pockets are formed when the wheel is immersed and the amount of wetted surface area on the tread is kept low. Other suitable structures can also be used.
[0086] The axle 201 can be made from any suitable material, and in the illustrative implementation is made from stainless steel. Preferably, in general, the metal materials used are preferably corrosion resistant or plated to prevent attack by salt water. Aluminum boat parts, for example, can be anodized.
Wheel Mounts and Planing Boards
[0087] Referring to FIGS. 4 a , 4 b , 4 c , 4 d and 4 e , the assembly of the wheel in the pod is shown with the pod's wind shield removed so that the inside of the pod can be seen. FIG. 4 a is a top view, FIG. 4 b a side view and FIG. 4 c a view from the back. These are two dimensional drawings using standard mechanical drawing protocols.
[0088] Referring now to both FIGS. 2 a and 4 a , the axle 201 of a wheel is held by mounting brackets 411 at each end. Each bracket contains a set of ball bearings to allow smooth rotation of the wheel and a set of thrust bearings to accommodate sidewise thrust. The bearings can be commercially available standard stainless steel bearings, available, for example, from AFC Bearings, 11 E. 44 th St., Suite 700, NY, N.Y. 10017. The mounting brackets 411 ride on shafts 412 which are attached to long L-brackets 405 which are bonded or bolted to the planing board 402 . The L-brackets 405 can be anodized aluminum or a composite material such as fiberglass and epoxy resin.
[0089] In an illustrative embodiment, the L-brackets 405 are attached to the airfoil 406 by posts 408 . The wheel mounting is strengthened by braces 409 that form a torsion box to enhance the stability of the assembly. Referring to FIG. 4 b , L-brackets 405 are mounted on the airfoil to provide anchors for the posts 408 . The posts 408 can be extruded aluminum tubing, available from Speed D Metals located in Willoughby Ohio or other commercial sources of extrusions, or can be pultrusion extruded composites from Ten Com LTD, Holland, Ohio or other commercial sources. Stainless steel may also be used for braces and brackets.
[0090] An aerodynamic shell 122 ( FIG. 1 ), omitted from FIG. 4 drawings for clarity, can be made from composite sheet material and can be formed using standard molding techniques such as described in the book “Fiberglass Composite Materials” by Forbes Aird, HP Books,1996, ISBN-1-55788-239-8. Flexible composite sheet stock cut and bent into shape can also be used. The aerodynamic shell is mounted to the planing board around its periphery using epoxy resin or rivets. In some embodiments the aerodynamic shell is omitted because it adds weight. It might not reduce aerodynamic drag by a substantial amount but may improve the appearance of the boat in commercial applications.
Planing Board
[0091] Referring to FIG. 4 a, an exemplary planing board 402 is constructed of plastic foam. Its shape, density and thickness are similar to surf board and windsurfer boards. These boards can be custom manufactured. Custom surf board suppliers, such as Johnny Rice Custom Surfboards, Santa Cruz Calif., produce boards 402 of this type. In an illustrative embodiment, the planing boards are approximately 3 inches thick, 28 inches wide and 76 inches long at the bottom. A cutout is made in the middle of the hull for the wheel to protrude down into the water. Grooves toward the stem can allow water thrown off by the wheels to exit the pod.
[0092] Information on hydrodynamic planing can be found in the book “High Performance Sailing” by Frank Bethwaite, International Marine,1993, ISBN 0-07-05799-0.
Airfoil
[0093] Referring to FIG. 3 a, an airfoil follows conventional design practices for wings on light aircraft. These techniques are described, for example, in the book “Understanding Aircraft Composite Construction ” by Zeke Smith, Aeronaut Press, 1996, ISBN 0-9642828-1-X or “Composite Construction for Homebuilt Aircraft: The Basic Handbook of Composite Aircraft Aerodynamics, Construction, Maintenance and Repair Plus, How-to and Design Information” by Jack Lambie, 1996. In addition information on airfoil design can be found in “Foundations of Aerodynamics Bases of Aerodynamic Design” by Arnold Kuethe and Chuen-Yan Chow, John Wiley & Sons, 1998, ISBN 0-471012919-4 and “Theory of Wind Sections” by Ira Abbott and Albert Doenhoff, Dover Publications, 1949, Standard Book Number 486-60586-8. Also software on airfoil design is available from DaVinci Technologies, LLC, in Laurel, Md. The basics of aerodynamic design can be found in “Introduction to Aerodynamics” by Gale Craig, Regenerative Press, 2002, ISBN 0-9646806-3-7.
[0094] It sometimes comes as a surprise to some people that a boat can go faster than the wind because often people view a boat as being pushed from behind by the wind. In reality, a boat is propelled by the difference in air pressure between the air on the front of the sail and on the back of the sail. As the pressure in front of the sail is less than that behind it, the boat will move forward.
[0095] If the wind is coming directed from the front of a sailboat, the sailboat will be driven backwards. However, if the wind is coming largely from the front, e.g., at an angle of 45 degrees from the front, if the flow of air along the front of the sail is faster then than behind it, the air pressure in front of the sail will be less than behind it, and the boat will be pushed forward. The keel and rudder are needed to prevent the boat from going sideways. This situation by itself places no limit on how fast the boat can go. Ice boats, for example, have been known to go as much as five times as fast as the wind.
[0096] The direction of the wind experienced by the sail, called the apparent wind, is combination of the true wind, i.e., the direction sensed by a person standing on the shore and the wind generated by the motion of the boat, i.e., the wind experienced by the skipper of a motor boat traveling on a windless day. In technical terms this combination is the vector sum of the two winds, the true wind and the boat speed wind. For instance if the true wind is coming directly from the side of a sailboat, and the boat is traveling forward at same speed as the true wind, the two winds will have equal speeds but will be a right angles to each other and the apparent wind, i.e., the wind experienced by the sail will be coming at an angle of 45 degrees to the forward direction of the boat. This is the direction of the apparent wind. The angle of the sail with respect to the boat, normally called the trim of the sail, is adjusted to apparent wind to maximize the boat speed. (For a conventional boat a typical relationship between boat speed and wind speed as a function of the angle between the boat direction and the wind is illustrated on page 71 of the book by Marchaj previously mentioned.)
[0097] For high speed sailboats, the relationships between the true wind, the boat speed wind and the apparent wind and the significance of these relationships to the performance of the airfoil can be better understood by referring to FIGS. 6 a , 6 b , 6 c, and 6 d.
[0098] Referring to FIGS. 6 a , 6 b , 6 c , and 6 d, the dark arrows 601 a , 601 b , 601 c ,and 601 d represent vectors for the true wind. The arrow's length represents the speed of the wind, and its angle its direction. The arrows with long dashes 602 a , 602 b , 602 c , and 602 d represent the vectors for the wind generated by the forward motion of the boat, while the arrows representing the vectors for the apparent wind 603 a , 603 b , 603 c and 603 d have shorter dashes. The apparent wind is the wind which operates the sail. For each true wind example in each of FIGS. 6 a , 6 b , 6 c , and 6 d, diagrams of boats 604 a , 604 b , 604 c , and 604 d are shown along with their sails 605 a , 605 b , 605 c , and 605 d and direction of travel 606 a , 606 b , 606 c , and 606 d. The angles between the apparent wind and the boat direction 607 a and 607 b are also shown, and for the illustrative examples in FIG. 6 a and FIG. 6 b are both 20 degrees.
[0099] The FIGS. 6 a - 6 d are illustrative of a boat with a tall sail. A boat equipped with a tall sail can sail closer to the wind, i.e., more nearly into the wind, than conventional boats, for example as described on page 199 of Bethwaite's book, previously mentioned.
[0100] In the example of FIG. 6 a , a boat is driven by the true wind 601 a coming from behind and to starboard. With this geometry, the boat speed is shown as 2.3 times the true wind speed. Note that the angle between the apparent wind 603 a and the boat direction 607 a is 20 degrees.
[0101] In the example of FIG. 6 b the true wind 601 b is coming from the front of the boat. The apparent wind is still 20 degrees off the boat direction, but the boat speed is slower. As shown, the boat speed is 12% faster than the wind.
[0102] In the example of FIG. 6 c, when the true wind 601 c comes directly toward the boat, the boat will go backward 606 c. This is an undesirable situation which occasionally occurs with amateur sailors.
[0103] In the example of FIG. 6 d, the true wind 601 d comes from directly behind. In this situation, the boat goes more slowly than the wind.
[0104] As illustrated in these figures, for a large variety of true wind angles, for example in 601 a and 601 b, the angle that the apparent wind makes with the sail is the same if the skipper uses ideal sail trim.
[0105] Then airfoil responds best to wind coming head on to the boat, but a 20 degree angle such as that shown in FIGS. 6 a and 6 b is acceptable to obtain lift. If the true wind is coming largely from the side, the airfoil still can provide substantial lift since the apparent wind is from the front. But when the wind is directly from the back, the apparent wind direction is from the back of the boat so an airfoil is ineffective. Likewise, if the apparent wind is from the side, an airfoil will not generate lift. Very high speed sailboats cause the apparent wind to normally approach the boat mostly from the front, so for most true wind directions, the airfoils will generate lift.
[0106] Referring to FIG. 3 a , in the illustrative embodiment, the airfoil 301 is 18′ 4″ tip to tip and 5′ 1¾″ wide. In this embodiment, if the boat travels at twice the rate of the actual wind speed, the sum of the lifts of both the forward and aft airfoils will be approximately 130 lbs at an actual wind of 7.5 mph. Using for this example an approximate boat weight of 500 lbs, this will not be enough wind to raise the planing boards completely out of the water. But, at an apparent wind speed of 15 mph, the total lift is approximately 500 pounds, which can cause the boat to ride with primarily only the wheel foils submerged. As wind speed increases, the ailerons 302 are raised to reduce lift so that the boat does not become completely airborne.
[0107] When the boat is moving in very light winds, the skipper would operate the boat from the center of the trampoline. As wind increases, he may move out to windward to counter the tipping moment of the sail and keep the boat level. Eventually, as wind continues to increase, he cannot go any further out, and the ailerons on the windward side can be raised to decrease lift and assist in countering the tipping moment. In one embodiment, this happens automatically: when the windward pods are lifted out of the water leaving only the foils submerged, this initiates an automatic aileron-raising mechanism, such as that described with reference to FIG. 4 .
[0108] In this embodiment, the trailing edge of the airfoil 301 with the aileron in its normal position is aimed about 12 degrees downward. Other embodiments with larger and smaller angles are possible, and since lift is directly proportional to the sine of the angle, larger angles can facilitate narrower airfoils. Lift is also directly proportional to airfoil length and width, and is proportional to the square of wind velocity.
[0109] FIG. 3 b shows a top view of the forward airfoil 301 for the illustrative embodiment, and depicts a torsion box 303 , pods 304 and the location of the wheels 305 .
[0110] FIG. 3 c is a side view of this assembly which shows the position of the wheels for the highest 306 and lowest 307 lift positions and their associated water levels 308 , 309 .
[0111] Wind impinging on the boat is rarely directly from the front of the boat because such a wind would merely drive the boat backwards. As previously described, under ideal operating conditions, the wind is about 20 degrees off the direction of the boat. Thus, unlike the airfoils of an airplane, the wind does not come head-on. The wind directions 310 , 311 for starboard and port tacks are shown in FIG. 3 b.
[0112] In the illustrative embodiment the torsion box may interfere with air flow. This latter effect can be mitigated by using an embodiment such as shown in FIG. 3 d. Here the torsion box 313 is nearer the water, leaving a gap between it and the airfoil. A planing board 314 is mounted on the bottom of the torsion box and the planing boards may be omitted from the pods. As a result, the weight of the boat is reduced, and the boat is no longer held at the end of the wings which simplifies the design of the airfoils. As illustrated in FIG. 3 e, the wheel which operates the automatic lift mechanism is the same as for the illustrative embodiment. FIG. 3 e also shows the airfoil tipped slightly upward in front to enhance lift due to higher a angle of attack.
[0113] In general, the airfoils are positioned as low as convenient to the water so that the airfoils operate in the ground effect region. In this mode of operation, speed is enhanced because induced drag from the vortices generated at the wingtips is less.
[0114] FIG. 3 f shows an airfoil configuration in which the wings sweep forward by the angle of best performance between wind direction and boat direction. If the wind is approaching somewhat from starboard, the leeward airfoil lift will be enhanced at the expense of the windward airfoil. Since it is desirable for the leeward lift to be larger in any case to counter tipping moment, the sweep wing approach can improve overall performance. In the figure, the direction of the wind 312 is shown for starboard tack.
Pod and Aileron Control Assemblies
[0115] Referring again to FIG. 4 a, the interior of a pod is shown from the top. In this view both the aerodynamic shell of the pod and the airfoil have been deleted to show the parts inside the pod. The bottom surface 401 of the planing hull is adhered to the buoyant part of the board 402 using epoxy resin which is available from Fibre Glast Developments Corporation in Brookville, Ohio. The bottom surface 401 is a fiberglass and resin sheet bent at the bow for appropriate entry into waves. The sheet can be formed using pre-preg fiberglass sheet which can be obtained from Adhesive Prepregs for Composites Manufacturers, Plainfield Conn., or it can be made in a mold using techniques which are described in the book, “Fiberglass and Composite Materials” by Forbes Aird referred to above. The buoyant part is a foam sheet, made, for example, of polystyrene foam, such as that manufactured by Owens-Coming Company of Toledo, Ohio.
[0116] A wheel 403 protrudes into the water through an opening 404 in the planing board.
[0117] The wheel 403 has an axle 410 , 201 ( FIG. 2 a ) that extends into bearing housings 411 that ride on rods 412 . Springs 413 press the bearing housings 411 down. The movement of the wheels 403 is illustrated in FIGS. 4 c and 4 d, which show the interior of the pod from the back. FIG. 4 c shows the wheel in its lowest position, which corresponds to a high wind situation in which the airfoils have lifted the boat so that only the foil 414 and a small part of the wheel body are in the water. The dotted line 415 delineates the level of the water.
[0118] In light air, the wheel can go up to the position shown in FIG. 4 d. These figures also show braces 409 used to strengthen the assembly and the mounted airfoil 406 .
[0119] The operation of the illustrative embodiment's automatic system used to reduce lift as wind reaches or exceeds an acceptable limit is shown in FIGS. 4 b and 4 e. As illustrated in 4 e, a rod 416 is attached to one of the bearing housings 411 . The rod can pivot at the bearing housing. The rod passes through a bushing 417 which is mounted on a brace 418 which in turn is mounted on a cross brace 419 ( FIG. 4 a ) between the aft two posts. The rod also passes through a bushing 420 on the tip the aileron 421 . As the boat lifts, and the water level gets further below the airfoil, the springs depresses the wheel, and the rod moves from the position shown in FIG. 4 e to that shown in FIG. 4 b . This moves the tip of the aileron upward, which reduces lift, since the amount of lift is dependent on the angle at which air leaves the tip of the aileron.
[0120] Using this arrangement, the skipper of the boat does not have to control the four ailerons. In other embodiments, the skipper can control the ailerons manually or in combination with an automatic system. For example, the height of the wheel can be measured using a displacement sensor that generates a signal that is used to control a motor that moves an aileron. Arrangements for moving ailerons are common in airplanes.
[0121] In some embodiments, the aileron can be raised far enough so that air leaving the aileron is aimed upward. This is useful if it is desired to use reverse lift on the windward side of the boat to compensate for the tipping moment of the sail. Again the action can be automatic, since the tipping action will cause the windward wheels to lift and the leeward wheels to lower. The aileron adjustment mechanism described above decreases and perhaps reverses the lift of the windward airfoils, while the lift of the leeward airfoils is increased. Thus the overall effect will be to keep the boat more level.
[0122] As an added benefit, if a lifted pod encounters a wave, its wheel will rise due to the buoyancy of the wheel, tipping the aileron down thereby increasing lift and assisting the boat to ride over the wave. Likewise at a wave trough, the lift will decrease forcing the boat down into the trough.
[0123] In embodiments which use airfoil/pod assemblies spring loaded at the central torsion box, the ability of the boat adjust to waves and ride at the appropriate height above the water is further enhanced. Such an embodiment is illustrated in FIGS. 8 . This embodiment uses the planing board under the torsion box as illustrated in FIG. 3 d and 3 e. These figures show the action of the forward airfoils. Aft airfoils operate similarly.
[0124] The airfoils mount on posts 804 and attached to hinges 805 which include a pivot point 806 . Springs 807 hold the airfoils in place.
[0125] In other embodiments accommodation to waves can be implemented as shown in FIG. 7 a and 7 b. These figures show a pivoting planing board in a pod. The pivoting action is provided so that the pod rides up and down waves more easily rather plowing through them. The airfoil 701 is held by struts 702 to the planing board pivot point 703 on which the wheel 704 is held. If the water level 705 angle changes as a wave is encountered the planing board 706 will tip to adjust to it.
Rudder and Tiller Assembly
[0126] FIG. 5 a shows a top view of the illustrative embodiment's rudder assembly. A side view is shown in FIG. 5 b. The rudder 501 is a rotating foil. The rudder 501 is attached to a small diameter rim 502 and hub assembly 503 , such as used in tricycles. The assembly 503 shown has a hub with ball bearings, spokes and a rim, and can be obtained from retail bicycle stores. The rudder is attached to the rim 502 using bolts and/or adhesives. The rudder is a thin composite disk made from fiberglass and resin. Alternatively, the disk may be fabricated from stainless steel. The rudder is held in place by a fork 504 similar to that used in a bicycle. The top part of the fork is a rod 505 as in a bicycle which passes through two braces 506 which are attached to the torsion box 507 with four braces 508 . The fork assembly operates like a bicycle's except that instead of handle bars a conventional pulley wheel 509 is mounted on the top. A cable 510 connects the pulley wheel 509 to a second pulley wheel 512 which is mounted on the torsion box 507 . Such cables and pulley wheels can be obtained from hardware and industrial suppliers.
[0127] The tiller 512 is attached to the second pulley 511 , and a tiller extension 513 is connected to the tiller. This assembly can be obtained from marine supply retailers such as Layline in Rayleigh N.C. The steering assembly thus operates as in normal sailboats such that as the tiller is pulled to starboard, the boat turns to port. As a rotating foil, this rudder has the advantage described above of decreased drag in the direction of travel.
Foil Skin Friction and Cavitation
[0128] The advantages of rotating foils are further illustrated with reference to FIG. 9 , which depicts a wheel 902 submerged up to the water line 904 . The boat is traveling to the right in the figure as shown by the arrow 905 . Since the boat is traveling with respect to the water, the axle 903 of the wheel 902 is traveling at the same speed and in the same direction as the boat. The parts of the foil 901 and wheel body 906 which are below the water line experience skin friction drag when the boat moves. Since the drag is at a distance from the hub and the axle and the axle rides on ball bearings, the wheel will turn much like a car's wheels rotate as a car moves forward on pavement. The rate of rotation will be constant if the boat's speed in constant. In this situation the periphery of the wheel 907 will be approximately stationary with respect to the water at its lowest point and will have a speed of twice the boat speed at its top 908 . At all other points it will have a forward component and vertical component either down or up depending on whether the point is ahead of the axle or behind it.
[0129] The speeds of various points on the wheel's foil are depicted using vectors. The vectors represent the velocity of the boat 905 a , 905 b , 905 c and 905 d as shown by the solid arrow at points a, b, c, and d in the vector diagrams. The vectors representing the velocities 909 a , 909 b , 909 c and 909 d due to rotation at points a, b, c, and d are the heavy dotted line with the small dashes. The resultant vectors representing the actual speeds and directions of the points are represented by the fine dotted lines 910 a , 910 c , 910 d with the long dashes.
[0130] At point b, the resultant vector has a value of zero, indicating that point is approximately stationary with respect to the water. At a and c, the result vector has speed about 90% of the boat speed for the embodiment shown. At d the speed is about 57% of boat speed. On average, the points on the submerged portion of the foil will be traveling at about half the boat speed. As a result, the onset of serious cavitation occurs at a much higher boat speed than if the foil were being dragged forward through the water, as happens in conventional boats. Furthermore the lowest part of foil, which performs most of the function of the foil, travels at the lowest speed relative to the water.
[0131] FIG. 9 assumes that the bottom of the foil is stationary with respect to the water. This is only an approximation because some water will adhere to the foil and will be thrown off by centrifugal force. The energy required for this may diminish wheel rotational speed, but only by a small amount.
[0132] Referring to FIG. 10 , embodiments of the invention may involve modifications to commercially available boats to add features described here, for example, components designed to provide lift, and rotating foils, to reduce surface friction, and allow a boat so modified to travel faster. It should be understood, however, that just the airfoils, or just the rotating foils may be used, alone, or in combination with other features described here.
[0133] An illustrative example boat shown in the figure is an A Class catamaran (“Acat”) that has been modified to include features of the invention. The figure shows the boat going up-wind (beating) on starboard tack in a high wind.
[0134] An Acat typically has hulls that are approximately 18 feet long, separated by 8 feet, and a mast which is 30 feet tall, with a total sail area of 150 square feet. A Class catamarans may be obtained, for example, from Performance Catamarans, 1800 East Boarchard Ave., Santa Ana Calif. 92705.
[0135] As shown in the figure, a modified Acat has hulls, 1001 and 1018 , that are separated by approximately 12 feet, four feet more than normal. Additional separation increases the sizes of the trampoline 1002 and airfoils 1003 , 1005 that may be used for lift and may allow the boat to become substantially airborne at lower wind speeds.
[0136] As is typical, a trampoline 1002 is mounted between the two hulls 1001 , 1018 . To provide lift in this modification, however, the trampoline 1002 is tilted upward in front and cambered (curved) in a manner that enhances lift (e.g., in the shape of an airplane wing, or other suitable shape). Thus, in this exemplary implementation, the trampoline also may be referred to as an airfoil, in that it serves both the functions of a trampoline and an airfoil. The trampoline also may be made of any other suitable material, for example but not limited to a solid material such as foam or sailcloth.
[0137] Two additional airfoils, 1003 and 1005 , are mounted in front of the mast 1004 . In some embodiments, these airfoils are made from sailcloth, but these also may be made of any suitable material, including but not limited to rubber or foam. If made of sailcloth, the airfoils 1002 , 1003 , and 1005 may be adjusted to control lift, for example manually and/or automatically, and it should be understood that various techniques may be used to control the angle of the airfoils 1002 , 1003 , and 1005 . It should be understood that various embodiments may include only the modified trampoline, additional airfoils, or both.
[0138] In this exemplary implementation, a rotating foil 1006 is in a position that may typically hold a dagger board in an Acat. In this exemplary implementation, a rotating foil is also used for rudder 1007 . As shown, the top portion of the foil may be covered by a shield 1017 to prevent a sailor from disturbing the foil. For example, the skipper of the boat may operate the boat from this area in strong winds. The rotating rudder 1007 is held by forked bracket 1008 , similar to that used to hold the front wheel of a bicycle. The forked bracket is held in place by a fixed bracket 1009 affixed to the hull 1001 . The rudder is turned by a tiller assembly 1010 .
[0139] The boat's sail 1011 is attached to the mast 1004 and the boom 1012 in a manner typical for sailboats. The trim of the sail is adjusted by a main sheet 1013 , also in typical fashion. The hulls are held in place by rods 1014 , 1015 and 1016 .
[0140] Each of the forward airfoils, 1003 and 1005 , is mounted on a rectangular frame 1018 . The sailcloth airfoils are loosely affixed to the forward and aft parts of the frames so they assume an upward camber if the frame is tilted up and a downward camber if it is tilted down. The fames are attached to brackets 1019 . The brackets contain a pivot point 1020 at the position in the airfoil representing the center of lift for the airfoil. At the front edge of an airfoil's frame a bracket 1021 is attached with a small water ski 1022 on its bottom. A spring at the pivot point 1020 of the bracket causes slight pressure on the frame to cause the ski to push down slightly into the water.
[0141] In the absence of wind both airfoils 1003 and 1005 assume a tilt shown by the port airfoil 1003 . As the wind increases, all three of the airfoils, 1002 , 1003 and 1004 contribute to lifting the boat out of the water thereby reducing displacement and frictional drag. As the boat rises the lowering skis cause the tilt of the airfoil frame to lessen, thereby reducing lift and diminishing the tendency of the boat to become airborne in a puff.
[0142] As wind speed continues to increase, the weight of the skipper hiking out on the windward hull may be insufficient to hold the windward hull down on the water. In this condition, the starboard hull 1001 is lifted out of the water sufficiently far that it is desirable to reduce the lift on the starboard side of the boat so that the boat does not tip over. The port hull 10018 is either at the surface of the water or its bottom is slightly submerged.
[0143] As shown in FIG. 10 when the windward hull 1001 lifts out of the water the windward ski 1022 descends downward staying on the surface of the water, and the windward airfoil 1005 assumes a downward tilt. The upward tilt of the leeward airfoil 1003 and the downward tilt of the windward airfoil 1005 act to right the boat assisting the hiking skipper to keep the boat at the desired angle.
[0144] In some embodiments adjustment of the tilts of the forward airfoils 1003 and 1005 could be done by the crew, but since the skipper needs to trim the sail and steer the boat, a second crew member would be needed and his extra weight would slow the boat down.
[0145] A boat as configured in this exemplary figure may not achieve the speeds of an embodiment such as that shown in FIG. 1 ; however, it may be less expensive to construct as many of the parts are used in boats already in production.
|
The invention relates to high-speed sailing craft, in particular, high-speed sailing craft that have one or more substantially horizontal airfoils for lifting the craft up from the water and one or more substantially vertical, rotating foils that are generally at least partially submerged in the water for providing tracking or steering. By lifting the craft out of the water, the airfoil allows the craft to travel faster, by reducing the friction of the water on the hull(s) and/or float(s). By rotating, the generally at least partially submerged portions of the vertical foils reduce the friction on the vertical foils. In combination, airfoils and rotating tracking/steering foils have the combined effect of reducing the friction of water on the craft, and improving the speed of the craft.
| 1
|
This invention concerns a sensor system for providing sensor information for a monitoring, control or other operating function of an apparatus, in particular a land, sea or air vehicle.
BACKGROUND OF THE INVENTION
It is well known in vehicles such as ships and aircraft to employ a plurality of sensors connected together and to a remote central control unit by means of wired connections for supplying sensor information for a monitoring, control or other operational function of the vehicle. Such sensor systems are complicated and expensive to install, in view of the need for complex wiring systems for supplying power to the sensors and for transmitting sensor information to the control unit from the sensors. Moreover, such systems are costly to maintain, in view of the need to monitor the integrity of the individual wired connections and/or to build in sufficient redundancy to allow for the failure of such connections without impairing the overall functioning of the system. Such systems furthermore require a substantial central power source, which may be costly to provide and may result in undesirable bulk in an environment where weight and space savings are at a premium.
SUMMARY OF THE INVENTION
It is an aim of the present invention to overcome these problems by providing localised power generation for a sensor system in such apparatus.
A further aim of the invention is to provide an effective and inexpensive sensor system having local power generators arranged to exploit the environmental characteristics at each sensing location for providing the small amounts of electrical power required.
Another aim of the invention is to employ the characteristics of a boundary layer of fluid flowing over a surface of the apparatus or vehicle in which the sensor system may be installed for generating the electrical power for operating the or each of the sensors.
A further aim of the present invention is to provide a sensor system in such an apparatus or vehicle with a remote communication arrangement for transmitting control information to and receiving detection information from the sensor system.
Still another aim of the present invention is to provide such a sensor system in a land, sea or air vehicle, particularly an aircraft.
In accordance with the invention there is provided an apparatus having a sensor system for providing detection information for a monitoring, control or other operating function of the apparatus, the sensor system comprising:
a transducer adapted to be responsive to a predetermined environmental characteristic of the apparatus for providing an electrical output, means being provided to accentuate the said characteristic adjacent to the transducer, at least one sensor arranged to be operated by power derived from the electrical output for generating a detection signal, and means arranged to be operated by power derived from the electrical output and responsive to the detection signal, for communicating sensor information to a processing unit remote from the sensor system and associated with the said function.
The transducer advantageously provides a localised power generator and is preferably a solid-state device, such as a piezo-electric or thermoelectric device.
The transducer may be arranged to be responsive to at least one of: a boundary layer characteristic of fluid flowing over a surface of the apparatus, a structural characteristic of the apparatus, vibration in the apparatus, electromagnetic radiation, and temperature or temperature difference within and/or adjacent to the apparatus.
Conveniently, the transducer may itself constitute a sensor for measuring one of these characteristics.
In a preferred form of the invention, the transducer is adapted to be responsive to pressure, temperature gradients or differences, flow or turbulence in a boundary layer of fluid, such as air or water, flowing past a surface of the apparatus. More particularly, the transducer is advantageously arranged to be responsive to variations in one of these characteristics.
Advantageously, in this event, a small formation, such as a protrusion, may be provided on or in a surface of the apparatus upstream of the transducer in order to accentuate fluctuations or variations in the fluid flow across the surface.
In another preferred form of the invention, the transducer is arranged to be responsive to structural vibrations of the apparatus. For example, such vibrations may be due to the turbulence of a boundary layer of fluid flowing past a surface of the apparatus or they may be due to vibrations of machinery associated with the apparatus or to frictional engagement of parts of the apparatus with contact surfaces in the environment.
The at least one sensor may measure external characteristics of the apparatus, such as turbulence, velocity and incident radiation, or internal characteristics such as vibration, strain, electrical resistance and temperature, or cross boundary characteristics.
In a preferred form of the invention described below, the transducer is provided on or embedded within a surface of the apparatus.
In this instance, the or each sensor may also be provided on or embedded within the same surface or an opposite surface of the apparatus.
Some or all of the parts of the sensor system, including electrical connections, may be formed on the surface(s) by surface deposition techniques, such as printing techniques.
Advantageously, the sensor system also includes means for communicating with a remote control unit, for example employing electromagnetic radiation. Such communication means may conveniently comprise short range wireless data links.
The invention in its preferred form described herein makes use of the characteristics of a boundary layer of fluid flowing past a surface of a vehicle for supplying sensor information. For example, the sensor system could be applied to the wing surface of an aircraft for providing sensor information for a monitoring or control function of the aircraft. Alternatively, the sensor system could be employed in a combustion cylinder of an engine of a vehicle in order to sense accurately the conditions in the combustion chamber, for controlling the supply of fuel for example.
Likewise, the invention could be applied to the monitoring of conditions within pipelines in the gas, water and oil industries by employing the characteristics of a boundary layer of fluid flowing along the internal surface of a pipe.
According to another aspect of the present invention, there is provided a sensor system for providing detection information for a monitoring, control or other operational system of an apparatus, comprising:
a transducer adapted to be responsive to a predetermined environmental characteristic of the apparatus, such as fluid flow over a surface of the apparatus, for providing an electrical output, and at least one sensor arranged to be operated by power derived from the electrical output for generating a detection signal, means being provided to accentuate the said characteristic adjacent to the transducer.
According to another aspect of the present invention, there is provided a device for generating electrical power, said device being associated in use with a surface subjected to fluid flow there-past, comprising:
a transducer adapted to be responsive to a predetermined characteristic of a boundary layer of the fluid for providing an electrical output, and means for supplying electrical power derived from the electrical output, means being provided to accentuate the said characteristic adjacent to the transducer.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic view illustrating the operation of a local power generator of a sensor system according to the present invention;
FIG. 2 is a diagrammatic view corresponding to FIG. 1 and showing a modification of the arrangement of FIG. 1 ;
FIG. 3 is a diagrammatic view of a first sensor system according to the present invention;
FIG. 4 is a diagrammatic view of a second sensor system according to the present invention; and
FIG. 5 is a block diagram of the sensor system of FIGS. 3 and 4 .
DETAILED DESCRIPTION OF THE INVENTION
Referring initially to FIG. 1 , a local power generator for use in the sensor system of the invention will first be described. As shown in FIG. 1 , a panel 10 of a vehicle, such as an aircraft, has an external surface 12 which is subject to a flow of fluid thereover in use due to the movement of the vehicle. For example, the panel 10 may comprise the skin of an aircraft wing, which is subject to a flow of air during manoeuvring on the ground, take off, flight and landing. As is well known, fluid flow past the panel 10 in these conditions will generate a boundary layer 14 of turbulence adjacent the panel 10 as illustrated.
Mounted on the surface 12 , or alternatively embedded within the panel 10 so as to be proximate to or flush with the surface 12 , is a solid state transducer 16 , which in the present instance is a piezo-electric device. This piezo-electric device 16 is subject in use to the turbulence of the air in the boundary layer 14 and is arranged to be responsive to such turbulence in order to generate an electrical output. As can be appreciated, the velocity of the air flow past the panel 10 will affect the level of turbulence in the boundary layer 14 and hence the level of the electrical output from the piezo-electric device 16 . In effect, the piezo-electric device 16 responds to pressure fluctuations in the boundary layer 14 and the energy of these is converted into relatively small amounts of electrical power.
It is possible to accentuate the turbulence in and hence the pressure fluctuations of the boundary layer 14 by an arrangement such as that illustrated in FIG. 2 , according to which a formation comprising a protrusion 18 is provided on or in the surface 12 of the panel 10 upstream of the piezo-electric device 16 so that the boundary layer 14 encounters an obstruction and is further disturbed in its flow. As illustrated, the protrusion 18 is in the form of a rib of rectangular section mounted on the surface 12 , but alternative formations of any shape may be employed so long as the effect is to increase turbulence in the vicinity of the device 16 .
Turning now to FIG. 3 , a sensor system employing a local power generator as shown in FIG. 1 or 2 will be described. As shown, a series of solid state sensors 20 are mounted on or in the surface 12 of the panel 10 adjacent the piezo-electric device 16 . The sensors 20 may, like the piezo-electric device 16 , be mounted on the surface of the panel 10 or at least partially embedded in the surface of the panel 10 . The sensors 20 may be arranged in a row or an array or randomly, but in each instance it is envisaged that a substantial number of them will be associated with the one piezo-electric device 16 .
The sensors 20 , the other circuit elements mounted on or in the surface 12 , and the piezo-electric device 16 may all be formed by what is known as a “direct write” process on the surface 12 . Such a process involves surface deposition techniques, such as ink jet printing, screen printing and maskless patterning, to apply layers of dissimilar materials to the surface. By the appropriate selection of such materials, and the interfaces between them, it is possible to form all of these electrical components, as well as the associated wiring, through such deposition techniques. Differing components simply require the selection of different material layers according to their function. Such components are cheap and easy to produce in relatively small volume and without the problems of added wiring and parasitic mass.
The piezo-electric device 16 may be cantilevered (not shown) above the surface 12 , or above a cavity (not shown) formed in the surface 12 , such that electrical energy is produced by the pressure and velocity of the boundary layer fluctuating and causing the piezo-electric cantilever to vibrate and so produce alternating electrical signals which can be extracted through an appropriate circuit. Whereas the devices described above are robust and simple to apply, this cantilever type of device produces more electrical power. It has been found that, in both cases, the incorporation of boundary flow disrupting elements such as protrusion 18 (see FIG. 2 ) increases local pressure and velocity fluctuations and thus enables significantly more electrical power to be generated. If the arrangement is such that the surface 12 adjacent to the device 16 is also able to vibrate under the fluid pressure and velocity fluctuations then this increases the electrical power generated—and this effect can be further increased by the use of appropriately shaped and located boundary flow disruption elements such as protrusion 18 .
In an aircraft application, for example, it is envisaged that the entire surface 12 , for example, the entire wing surface, might be covered with arrays of the sensors 20 each grouped around a respective piezo-electric device 16 .
It will be appreciated that it is equally possible as shown in FIG. 4 for the sensors 20 to be mounted instead on or in an internal surface 22 of the panel 10 facing the surface 12 on which the piezo-electric device 16 is provided. In this instance, a wire connection 24 will be provided through the interior of the panel 10 to connect the piezo-electric device 16 to the sensors 20 . Further connections (not shown) between the sensors 20 and other circuit elements are then provided as before on the panel 10 , on this occasion on the internal surface 22 .
Turning now to FIG. 5 , the electrical circuitry of the sensor system will be described. As shown in FIG. 5 , the piezo-electric device 16 acts not only as a power generator but also as a sensor in its own right, and is connected to a measuring circuit 30 for monitoring the amplitude of its electrical output. For example, the output of the device 16 may represent the amount of turbulence adjacent the wing of an aircraft and hence the velocity of the aircraft. The circuit 30 is connected to a circuit 32 such as a converter for converting the output received from the measuring circuit 30 into a form suitable for supply to a storage circuit 34 , such as an integrator or capacitor or small chargeable battery for storing the electrical power. A power supply 36 is arranged to supply power from the store 34 for operation of the various elements of the sensor system.
FIG. 5 shows only one sensor 20 but it will be appreciated that there will in practice be a plurality of such sensors, as mentioned above. As shown in FIG. 5 , each sensor 20 is arranged to receive power derived from the device 16 supplied from the power supply 36 . The output of the sensor 20 is supplied to a processing circuit 38 , which also receives the measuring output from the amplitude measuring circuit 30 and which is supplied with power from the power supply 36 .
The processing circuit 38 is arranged to extract sensor information from the sensor signal output from the sensor 20 and from the measuring signal output from the measuring circuit 38 to convert this information into a form suitable for transmission to a remote source, such as a control unit of a monitoring, control or other operational system of the vehicle. The output from the processing circuit 38 is supplied to a communication device 40 operable to transmit the information by electromagnetic radiation to the remote source. In the present instance, the communication device 40 comprises a radio transmitter and receiver. As shown, the communication device 40 is also supplied with power from the power supply 36 .
It will be understood that the entire sensor system is self contained and is mounted on the panel 10 of the vehicle, either on the external surface 12 which carries the piezo-electric device 16 or on the internal surface 22 opposite the surface 12 carrying the piezo-electric device 16 .
It will also be appreciated that a number of modifications are possible within the scope of the invention.
For example, the present sensor system has been described in relation to a vehicle such as an aircraft, for travelling through air with the transducer being responsive to fluctuations in the boundary layer of air associated with an external surface of the vehicle. However, the invention is equally applicable to a sea vehicle such as a ship or submarine in which the fluid flowing over or past the vehicle is water.
The invention could also be applied to the detection of conditions in a combustion chamber of an engine combustion cylinder of a vehicle in order to supply sensor information for control of the fuel supply, for example.
The invention could equally well be applied to a fluid supply system, for example, for gas, water or oil, in which the fluid is conveyed to its destination through pipelines. In this instance, the transducer will be associated with an internal surface of one of the pipes.
The invention has been described in relation to the use of a transducer responsive to the turbulence in a boundary layer of fluid flowing over a surface, in other words to pressure fluctuations in this layer. It is equally possible to employ a transducer which is responsive to temperature fluctuations (or temperature differences) in this layer, for example, a thermo-electric device.
In this instance, a formation, such as the formation 18 , could still be provided on the surface upstream of the thermoelectric device, this time in order to create a temperature difference by generating high and low pressure regions having correspondingly higher and lower temperatures respectively.
In the case of a transducer responsive to temperature fluctuations, a thermo-electric device may be employed comprising a thermo-couple or thermo-pile arranged on and/or within the panel 10 of the vehicle such that local hot and cold junctions respectively can be created due to variations in temperature either with time or with physical separation/distance. Such temperature variations may take place either in the fluid flowing over or past the vehicle or in the vehicle structure itself.
Other possibilities include the use of transducers responsive to vibrations in the panel on which they are mounted, for example, due to the fluid turbulence or to vibrations of machinery associated with the vehicle or to frictional engagement of parts of the vehicle with contact surfaces for example in the environment.
More especially, the device 16 may be responsive to a variety of external characteristics such as turbulence and incident radiation, a variety of internal characteristics such as vibration, strain and temperature, and equally a variety of cross-boundary characteristics such as differential temperature.
Likewise, the sensors 20 may be employed to measure external characteristics such as turbulence or incident radiation, and internal characteristics such as vibration, strain, electrical resistance and temperature.
The energy in such environmental fluctuations is generally relatively low but is more than adequate for generating the small amounts of power required by the present sensor system and communication device.
It will be understood that the electrical power generated from the transducer 16 may be employed directly and continuously, or it may be stored in the storage device 34 for intermittent use.
The communication means described with reference to FIG. 5 employs radio transmissions, but it could alternatively employ infrared transmissions or close coupling of electric or magnetic fields.
Whilst FIG. 5 shows only one device 16 and one sensor 20 , it is to be understood that in practice, there may be a number of the devices 16 , each supplying power to a group or array of the sensors 20 and to a respective communication device 40 .
In this way, a very complex sensor system may be built up for supplying a substantial amount of sensor information to a remote processing unit of the vehicle. It is even possible with a sufficient number of such devices to set up an artificial neural network (ANN) including the remote central processing unit, in order to provide an information processing system which is adaptive according to sensed environmental conditions and which achieves this adaptation by iteratively adjusting the response to the received sensor information in the central processing unit.
A highly sophisticated monitoring or control system capable of dealing with complex control situations can thereby be implemented. This may be especially advantageous for specialised applications within the aircraft industry.
The present invention has a number of advantages, not the least of which are that it offers a simple, reliable and robust system for providing sensor information to a remote source such as a central control unit. Furthermore, this simple basic system is capable of expansion into complex and sophisticated forms, according to the application. The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.
|
The invention provides apparatus having a sensor system for providing sensor information for a monitoring, control or other operating function of the apparatus. The sensor system comprises: a transducer ( 16 ) adapted to be responsive to a predetermined environmental characteristic of the apparatus for providing an electrical output, and means ( 18 ) adjacent to the transducer to accentuate the said characteristic. At least one sensor ( 20 ) is arranged to be operated by power derived from the electrical output for generating a detection signal, and means ( 38, 40 ) arranged to be operated by power derived from the electrical output and responsive to the detection signal are also provided for communicating sensor information to a processing unit remote from the sensor system and associated with the said function.
| 6
|
RELATED APPLICATIONS
This application is related to U.S. patent application Ser. No. 12/614,234, filed on Nov. 6, 2009, which is incorporated herein by reference for all purposes. This application is related to U.S. patent application Ser. No. 12/641,101, filed Dec. 17, 2009.
BACKGROUND OF THE INVENTION
High Definition (HD) displays are becoming increasingly and popular. Many uses are now accustomed to viewing high definition media. However, a lot of media, such as older movies, and shows were captured with in Standard Definition (SD). Since the actual the actual scene was captured by a video camera that only captured the scene in standard definition, even if the display is high definition, there are not enough pixels to take advantage of the display.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with some aspects of the present invention as set forth in the remainder of the present application with reference to the drawings.
BRIEF SUMMARY OF THE INVENTION
The present invention is directed to parallel processing for providing high resolution frames from low resolution frames, substantially as shown in and/or described in connection with at least one of the figures, as set forth more completely in the claims.
These and other advantages and novel features of the present invention, as well as illustrated embodiments thereof will be more fully understood from the following description and drawings.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a block diagram describing an exemplary video frame capturing a scene at a particular time in lower resolution;
FIG. 2 is a block diagram describing an exemplary video frame capturing the scene at the same time in higher resolution;
FIG. 3 is a block diagram describing upscaling lower resolution frames to higher resolution in accordance with an embodiment of the present invention;
FIG. 4 is a block diagram describing motion estimation in accordance with an embodiment of the present invention;
FIG. 5 is a block diagram describing motion estimation between non-adjacent frames in accordance with an embodiment of the present invention;
FIG. 6 is a block diagram describing motion compensated back projection in accordance with an embodiment of the present invention;
FIG. 7 is a block diagram describing motion free back projection in accordance with an embodiment of the present invention;
FIG. 8 is a block diagram of an integrated circuit and off-chip memory in accordance with an embodiment of the present invention;
FIG. 9 is a block diagram of a higher resolution frame partition into blocks in accordance with an embodiment of the present invention;
FIG. 10 is a block diagram of a destination domain in accordance with an embodiment of the present invention;
FIG. 11 is a block diagram of an exemplary source domain stripe in accordance with an embodiment of the present invention;
FIG. 12 is a block diagram describing an exemplary order of processing source domain stripes in accordance with an embodiment of the present invention;
FIG. 13 is a block diagram describing another exemplary order of processing source domain stripes in accordance with an embodiment of the present invention;
FIG. 14 is a block diagram describing a portion of a high resolution frames mapped to a buffer;
FIG. 15 is a block diagram describing pixel level parallel processing in accordance with an embodiment of the present invention; and
FIG. 16 is a block diagram describing another exemplary pixel level parallel processing in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to FIG. 1 , there is illustrated a block diagram describing an exemplary video frame capturing a scene in lower resolution. Video frames 120 are generated by a video camera and represent images captured by the camera at specific time intervals t. A frame 120 0 . . . t represents each image. The frames 120 comprise two-dimensional grids of pixels 125 ( x,y ), wherein each pixel in the grid corresponds to a particular spatial location of an image captured by the camera. Each pixel 125 stores a color value describing the spatial location corresponding thereto.
It is noted that position x,y are discrete variables, that actually correspond to a range xΔx−0.5Δx→xΔx+0.5Δx, yΔy−0.5Δy→yΔy+0.5Δy, in both the scene and the picture, where Δx*Δy are the dimensions of the pixel. An exemplary standard for frame dimensions is the ITU-R Recommendation Bt.656 which provides for 30 frames of 720×480 pixels per second. Additionally, the pixel value of 125 ( x, y ) is also a discrete value. For example, 24-bit color uses 256 red, 256 blue, and 256 green color values to represent the range of colors that are visible to the human eye.
While the video frames 120 comprise discrete pixels at discrete locations, a real-life scene that is captured is continuous in color and space. Thus, while the position in a scene corresponding to pixel 125 ( x, y ), xΔx−0.5Δx→xΔx+0.5Δx, yΔy−0.5Δy→yΔy+0.5Δy is within a range that may include several colors. The colors themselves may not necessarily match exactly with any one of the 24-bit colors.
However, the actual color that is recorded by the camera can be modeled as some type of statistical averaging of the colors that appear between xΔx−0.5Δx→xΔx+0.5Δx, yΔy−0.5Δy→yΔy+0.5Δy. The averaging can be a simple averaging of the colors or weighted averaging based on the distance of the point and color from the center x, y. A particular one of the 24-bit colors is selected that most closely approximates the actual color.
The differences between adjacent colors in 24-bit colors are indistinguishable to the human eye. Accordingly, adjacent colors appear continuous. An exemplary standard for display of the video sequence 105 is the ITU-R Recommendation Bt.656 which provides for 30 frames of 720×480 pixels per second. The foregoing picture appears spatially continuous to the viewer. However, although 720×480 pixels appear continuous to the user, information is lost from the original scene, resulting in a loss of detail. For example, fine texture in the scene may be lost.
Referring now to FIG. 2 , there is illustrated a block diagram describing an exemplary video frame capturing the scene 100 in higher resolution. The higher resolution is double the resolution in both the x and y directions, e.g., 960V×1440H pixels, in the present example, however it should be understood that other multiples, integer or non-integer, may be used. It should also be understood that the multiples in the x and y directions are not necessarily the same.
Thus pixels 225 ( x,y ) are discrete variables, that actually correspond to a range 0.5xΔx−0.25Δx→0.5xΔx+0.25Δx, 0.5yΔy−0.25Δy→0.5yΔy+0.25Δy, in both the scene and the picture, where 0.5Δx*0.5Δy are the dimensions of the pixel. As in the case of lower resolution, the pixel value of 225 ( x, y ) is also a discrete value. For example, 24-bit color uses 256 red, 256 blue, and 256 green color values to represent the range of colors that are visible to the human eye.
The position in a scene corresponding to pixel 1125 ( x, y ), 0.5xΔx−0.25Δx→0.5xΔx+0.25Δx, 0.5yΔy−0.25Δy→0.5yΔy+0.25Δy is also within a range that may include several colors. The colors themselves may not necessarily match exactly with any one of the 24-bit colors. The actual color that is recorded by the camera can be modeled as some type of statistical averaging of the colors that appear between 0.5xΔx−0.25Δx→0.5xΔx+0.25Δx, 0.5yΔy−0.25Δy→0.5yΔy+0.25Δy. The averaging can be a simple averaging of the colors or weighted averaging based on the distance of the point and color from the center x, y. A particular one of the 24-bit colors is selected that most closely approximates the actual color.
The foregoing higher resolution picture more accurately captures the scene and provides greater detail, including finer texture than the lower resolution picture. However, a lot of media, such as older movies, and shows were captured with in Standard Definition (SD), while high definition displays are becoming increasingly common.
When a scene is captured in lower resolution, although the continuous detail of the scene is not known, information about the scene as a series of ranges xΔx−0.5Δx→xΔx+0.5Δx, yΔy−0.5Δy→yΔy+0.5Δy is known. The image of FIG. 2 is the gold standard, higher resolution image. However, the gold standard higher resolution image includes information from the scene at 0.5xΔx−0.25Δx→0.5xΔx+0.25Δx, 0.5yΔy−0.25Δy→0.5yΔy+0.25Δy, which is not available.
Nevertheless, the foregoing information can be estimated by up-sampling the low resolution frame using any one of a variety of techniques such as spatial interpolation, or filtering. The foregoing results in an estimated higher resolution frame. Exemplary upsampled frames 320 that estimate the higher resolution frame are shown in FIG. 3 .
The foregoing can be done with each of the low resolution frames that are captured at other times, e.g., t−3, t−2, t−1, t, t+1, t+2, t+3 . . . , resulting in upsampled frames 320 t−3 , 320 t−2 , 320 t−1 , 320 t , 320 t+1 , 320 t+2 , 320 t+3 . However, it should be noted that with recursion, the processing for higher resolution frames prior to 320 t was completed prior to processing of frame 320 t . Accordingly, these frames are now designated 320 t−3 ′, 320 t−2 ′, 320 t−1 ′. Frames 320 t+1 , 320 t+2 , 320 t+3 are not yet completely processed.
Information from proximate time periods can be used to improve the quality of frame 320 t . To achieve this, the motion between proximate input frames may be required. The foregoing will now be described with reference to FIG. 4 . FIG. 4 is an illustration of an exemplary motion estimation process using stages. The purpose of the proposed method of motion estimation using staged procedures is to achieve a large effective search area by covering small actual search areas in each motion estimation stage. This is especially useful when a large number of low resolution frames are used to generate a high resolution frame, since in that case, the motion between two non-adjacent frames may be relatively substantial. For example, locating a best matching block in a frame that is substantially distant in time, may require the search of a large frame area.
ME stage 1 : In the first stage, details of which are shown in 410 , motion estimation is performed between pairs of neighboring frames 320 t−3 ′ and 320 t−2 ′, 320 t−2 ′, and 320 t−1 ′, 320 t−1 ′ and 320 t , 320 t and 320 t+1 , 320 t+2 , 320 t+2 and 320 t+3 . For each pair of neighboring frames, two motion estimations are performed.
In the first motion estimation, the earlier frame is the reference frame and divided into predetermined sized blocks, e.g., 320 t−1 ′. The later frame 320 t is the target frames and is searched for a block that matches 320 t−1 ′. In the second motion estimation, the later frame is the reference frame and divided into predetermined sized blocks, e.g., 320 t . The earlier frame 320 t−1 ′ is the target frame and is searched for a block that matches 320 t .
Motion estimation in this stage is based on full-search block matching, with (0, 0) as search center and a rectangular search area with horizontal dimension search_range_H and vertical dimension search_range_V. The reference frame is partitioned into non-overlapping blocks of size block_size_H×block_size_V. Next, for a block R in a reference frame with top-left pixel at (x, y), the corresponding search area is defined as the rectangular area in the target frame delimited by the top-left position (x−0.5*search_range_H, y−0.5*search_range_V) and its bottom-right position (x+0.5*search_range_H 1 / 2 , y+0.5*search_range_V 1 ), where search_range_H and search_range_V are programmable integers. Thereafter, in searching for the best-matching block in the target frame for the block R in the reference frame, R is compared with each of the blocks in the target frame whose top-left pixel is included in the search area. The matching metric used in the comparison is the sum of absolute differences (SAD) between the pixels of block R and the pixels of each candidate block in the target frame. If, among all the candidate blocks in the search area, the block at the position (x′, y′) has the minimal SAD, then the motion vector (MV) for the block R is given by (MVx, MVy) where MVx=x-x′, and MVy=y-y′.
As noted above, with recursion, the processing of frames 320 t−3 ′, 320 t−2 ′, 320 t−1 ′ is completed. While frames 320 t−3 ′ . . . 320 t+3 are a window for 320 t . During processing of 320 t−1 ′, the upsampling was performed for all of the time periods except t+3, and motion estimation would be performed for all of the foregoing pairs except for 320 t+2 and 320 t+2 . All the other motion estimation results are available from previous processing due to pipelined processing of consecutive images. Thus, only the foregoing motion estimation needs to be computed at this stage, provided the previous motion estimation results are properly buffered and ready to be used in the next two stages of motion estimation.
After the first stage of motion estimation, the next two stages are preferably performed in the following order at frame level: first, stages 2 and 3 for 320 t−2 ′ and 1320 t+2 , then stage 2 and 3 for 320 t−2 ′ and 320 t+2 .
ME stage 2 : In this stage, details of which are shown in 420 , the motion vectors between non-adjacent frames are predicted based on the available motion estimation results. The predicted motion vectors will be used as search centers in stage 3 . For example, the predicted motion vectors between 320 t+2 as the reference frame and 320 t as the target frame, can be represented as C_MV(t+2, t). To determine C_MV(t+2, t), MV(t+2, t+1) and MV(n+1, t) are combined, both being available from the previous stage of motion estimation processing.
For example, as shown in FIG. 5 , a block R at location (x, y) in 320 t+2 may have its best-matching block in 320 t+1 as block T, which is determined in the motion estimation between 320 t+2 as the reference frame and 320 t+1 as the target frame. Note that although R is aligned with the block grids, for example, x % block_size_H 1 =0 and y % block_size_V 1 =0, T may not be aligned with the block grid of its frame, and may be located anywhere in the search area. Block T may contain pixels from up to four grid-aligned blocks in 302 t+1 whose top-left pixels are at (x 0 , y 0 ), (x 1 , y 1 ), (x 2 , y 2 ), and (x 3 , y 3 ), respectively. In case of less than four grid-aligned blocks covered by T, some of the four top-left pixels overlap.
The predicted motion vector for R from 320 t+2 to 320 t may be set as the summation of the motion vectors for the block R from 320 t+2 to 320 t+1 and the median of the motion vectors for the block T from 320 t+1 to 320 t , as shown in Equation 1:
C _ MV ( t+ 2, t,x,y )= MV ( t+ 2, t+ 1, x,y )+median ( MV ( t+ 1, t,xi,yi ), i= 0,1,2,3) (1)
where the median of a set of motion vectors may be the motion vector with the lowest sum of distances to the other motion vectors in the set. For example, consider each motion vector in the set as a point in the two dimensional space, and calculate the distance between each pair of motion vectors in the set. The median of the set may then be the motion vector whose summation of the distances to other motion vectors is minimal among the motion vectors in the set. Note that in other embodiments, the distance between two motion vectors may be calculated as the Cartesian distance between the two points corresponding to the two motion vectors, or it may be approximated as the sum of the horizontal distance and the vertical distance between the two motion vectors to reduce computing complexity.
Similarly, the predicted motion vectors from 320 t+3 as the reference frame to 320 t as the target frame is obtained by cascading the motion vectors from 320 t+3 to 320 t+2 with the motion vectors from 320 t+2 and 320 t . The predicted motion vectors from 320 t−3 ′ and 320 t can be obtained in a similar manner.
In another embodiment of this invention, in predicting the motion vector for R from non-adjacent frames, the median operator in Equation 1 may be replaced with the arithmetic average of the four motion vectors. In another embodiment, in predicting the motion vector for R, the minimal SAD between the block T and each of the four blocks Si (i=1, 2, 3, 4) may be used in Equation 1 to replace the median of the four motion vectors. In yet another embodiment of this invention, in predicting the motion vector, one may calculate the SAD corresponding to each of the following four motion vectors: MV(t+2,t+1,x,y)+MV(t+1,t,xi,yi) (i=0,1,2,3), and choose the one with the minimal SAD.
ME stage 3 : In the last stage, 430 of FIG. 4 , of processing in the motion estimation block, the predicted motion vectors are refined to determine to determine motion vectors between 320 t+k , 320 t for (k=−3, −2, 2, 3), by searching around the corresponding predicted motion vectors. For example, to determine the motion vectors, a block-based motion estimation is performed with a search center at (x+C_MVx(t+k, t), y+C_MVy(t+k, t)) and a search areas (search_range_H 2 , search_range_V 2 ) and (search_range_H 3 , search_range_V 3 ), where the foregoing are programmable integers representing respectively the horizontal search range and vertical search range. The search range at this stage may be set to be smaller than that in the stage 1 of motion estimation to reduce the computational complexity of motion estimation.
Motion-Compensated Back Projection
Subsequent to motion estimation processing, the image 320 t ′ is subjected to processing for motion-compensated back projection (MCBP). The inputs to this block are the frames and motion estimation results from 320 t+k , (k=−3, −2, −1, 1, 2, 3), and frame 320 t .
MCBP favors frames that are temporally close to 320 t over frames further away. Temporally close frames are favored because motion estimation is generally more reliable for a pair of frames with a smaller temporal distance than that with a larger temporal distance. Also, this ordering favors the motion estimation results of prior frames over later frames. Thus, MCBP follows the order t−3, t+3, t−2, t+2, t−1, t+1.
Referring now to FIG. 6 , there is illustrated a block diagram describing motion compensated back projection between two frames in accordance with an embodiment of the present invention.
In a first step, for each block-grid-aligned block R in 320 t+3 , the corresponding motion-compensated block T in 320 t is found using the motion estimation results. For example, if block R is at the position (x, y) in 320 t+3 and its motion vector is (mvx, mvy), the corresponding motion compensated block T is the block at the position (x-mvx, y-mvy) in 320 t .
In a second step, for each pixel z in the low resolution frame LR(n+3) within the spatial location of block R, the corresponding pixels are identified in block R of 320 t+3 based on a pre-determined spatial window, for example, a 00 . . . a 55 , and consequently the corresponding pixels in block T of 320 t , for example, a′ 00 . . . a′ 55 . From the identified pixels in 320 t a simulated pixel z′ corresponding to z is generated. Note that the simulated pixel z′ may not necessarily co-site with an existing pixel of LR(n): the pixel z′ co-sites with an existing pixel of LR(n) if and only if both mvx and mvy are integers in terms of the resolution of LR(t). For example, in the case of using spatial interpolation to up-scale LR(t) by three both horizontally and vertically, the simulated pixel z′ co-sites with an existing pixel of LR(t) if and only mvx % 3=0 and mvy % 3=0.
In the second step above, to identify the pixels in 320 t corresponding to the pixel z in LR(t+3) and simulate the pixel z′ from these pixels, ideally, the point spread function (PSF) in the image acquisition process is required. Since PSF is generally not available to high-resolution processing and it often varies among video sources, an assumption may be made with regard to the PSF, considering both the required robustness and computational complexity.
For example, a poly-phase down-sampling filter may be used as PSF. The filter may consist, for example, of a 6-tap vertical poly-phase filter and a consequent 6-tap horizontal poly-phase filter. As shown in FIG. 6 , the pixel z in LR(n+3) corresponds to the pixels a 00 to a 55 in 1320 t+3 through the PSF; and the pixels a 00 to a 55 correspond to the pixels a′ 00 to a′ 55 in 1320 t through the motion vector (mvx, mvy); therefore, the pixels in 1320 t corresponding to z are a′ 00 to a′ 55 and the simulated pixel z′ is:
z ′ = ∑ i = 0 5 ∑ j = 0 5 PSF ij * a ij ′ ( 2 )
where PSF ij is the coefficient in the PSF corresponding to a′ ij . In another embodiment of this invention, a bi-cubic filter may be used as the PSF.
In a third step, the residue error between the simulated pixel z′ and the observed pixel z is computed, as residue_error=z-z′.
In a fourth step, the pixels in 320 t can be updated for example, from pixels a′ 00 . . . a′ 55 in 320 t to pixels a″ 00 . . . a″ 55 , according to the calculated residue error as shown at the bottom right in FIG. 6 .
In the fourth step above, the residue error is scaled by λ*PSF ij and added back to the pixel a′ ij in 320 t to generate the pixel a″ ij . The purpose of PSF ij is to distribute the residue error to the pixels a′ ij in 320 t according to their respective contributions to the pixel z′. As proposed herein, the purpose of the scaling factor λ is to increase the robustness of the algorithm to motion estimation inaccuracy and noise. λ may be determined according to the reliability of the motion estimation results for the block R. The motion estimation results can include (mvx, mvy, sad, nact). Among the eight immediate neighboring blocks of R in 320 t+3 , let sp be the number of blocks whose motion vectors are not different from (mvx, mvy) by 1 pixel (in terms of the high-resolution), both horizontally and vertically. In an embodiment of this invention, λ may be determined according to the following formula:
if sp ≥ 1 && sad < nact * 4 / 4 λ = 1 ; else if sp ≥ 2 && sad < nact * 6 / 4 λ = 1 / 2 ; else if sp ≥ 3 && sad < nact * 8 / 4 λ = 1 / 4 ; else if sp ≥ 4 && sad < nact * 10 / 4 λ = 1 / 8 ; else sp ≥ 5 && sad < nact * 12 / 4 λ = 1 / 16 ; else λ = 0 ; ( 3 )
conveying that the contribution from the residue error to updating the pixels in 320 t should be proportional to the reliability of the motion estimation results. This proportionality is measured in terms of motion field smoothness, represented by the variable sp in the neighborhood of R and how good the match is between R and T, for example, as represented by comparison of sad and nact.
Note that, in FIG. 6 , if the simulated pixel z′ co-sites with an existing pixel in LR(n), λ is reduced by half, which implies the updating back-projection strength from the residue error is reduced by half. A reason for this is that, in the case that z′ co-sites with an existing pixel in LR(n), the pixel z′ is a version of the pixel z that is simply shifted an integer number of pixels, and hence it does not provide much additional information in terms of resolution enhancement. However, it may be helpful in reducing noise.
In another embodiment of this invention, in calculating the scaling factor λ, the reliability of the motion estimation results may be measured using the pixels in 320 t and 320 t+3 corresponding to the pixel z, i.e., a 00 . . . a 55 in 320 t+3 and a′ 00 . . . a′ 55 in 320 t . For example, sad and nact may be computed from these pixels only instead from all the pixels in R and T.
For example, if the block size is 4×4 pixels, the sad between R and T may be defined as in Equation 4:
sad = ∑ i = - 1 4 ∑ j = - 1 4 R i , j - T i , j ( 4 )
and act of R may be defined as in Equation 5:
act = ∑ i = - 1 3 ∑ j = - 1 4 R i , j - R i + 1 , j + ∑ i = - 1 4 ∑ j = - 1 3 R i , j - R i , j + 1 ( 5 )
where R i,j refers to the i,j pixel of R, and likewise T i,j refers to the i,j pixel of T. Block R is a rectangular area with a top-left pixel of R 0,0 and a bottom right pixel of R 3,3 , likewise block T is a rectangular area with a top-left pixel of T 0,0 and a bottom right pixel of T 3,3 . Equations (4) and (5) are indicative of the fact that the pixels surrounding R and T may also be used in the computation of sad and act. The activity of a block may be used to evaluate the reliability of corresponding motion estimation results. To accurately reflect reliability, act may have to be normalized against the corresponding SAD in terms of the number of absolute pixel differences, as shown below in Equation 6:
nact = act * num_pixels _in _sad num_pixels _in _act ( 6 )
where num_pixels_in_sad is the number of absolute pixel differences in the calculation of sad, and num_pixels_in_act is that of act, respectively. The term nact is the normalized activity of the block. Note that the surrounding pixels of R and T may be used in calculating sad and act as well.
The foregoing can be repeated for the frames for each time period t−3, t−2, t−1, t+1, t+2, and t+3, resulting in a motion compensated back predicted higher resolution frame 320 t .
Motion Free Back Projection
Referring now to FIG. 7 , there is illustrated a block diagram describing motion-free back projection in accordance with an embodiment of the present invention. Subsequent to motion compensated back projection, the image 320 t ′ is subjected to processing for motion-free back projection (MCBP). The inputs to this block are the frame 320 t ′, and motion compensated back predicted higher resolution frame 320 t ″. The output from the MCBP processing block is the high resolution frame.
Motion-free back projection between frame 320 t ′ and frame 320 t ″ are performed similar to motion-compensated back projection, except that all motion vectors are set to zero and the weighting factor λ is a constant.
FIG. 8 is an illustration of an exemplary block diagram of a system in accordance with an embodiment of the present invention. The system comprises an integrated circuit 802 comprising high resolution image estimation module 820 that generates an initially estimated high resolution image by processing images. Also included are a motion estimation module 830 for motion estimation, a motion-compensated back projection module 840 , a direct memory access 885 , and a cache 890 for motion-compensated back projection, and a motion-free back projection module 850 for motion-free back projection.
The modules 820 - 840 can be implemented in software, firmware, hardware (such as processors or ASICs which may be manufactured from or using hardware description language coding that has been synthesized), or using any combination thereof. The embodiment may further include a processor 870 , and an input interface 810 through which the lower resolution images are received and an output interface 860 through which the higher resolved images are transmitted.
An off-chip memory 880 stores data after interpolation, after motion estimation 830 , and after the motion compensation back projection 840 . On-chip memory 851 stores portions of the higher resolution frames that are being updated. Program memory 852 stores instruction for execution by the processor 870 .
It is noted that the foregoing image processing involves the transfer and processing of large amounts of data. Storing larger amounts of the data within the integrated circuit 802 increases the cost and consumes more area on the integrated circuit 802 . Storing larger amounts of data in the off-chip memory 880 results in lower access times, and consequently, lower throughput.
In certain embodiments of the present invention, the pixels in the low-resolution frames are traversed according to a certain temporal and spatial order, and the motion-compensated back-projection processes for all the low-resolution pixels are serialized. The motion-compensation back-projection for a low-resolution pixel runs to its completion before the motion-compensation back-projection for the next low-resolution pixel begins. For each low-resolution pixel, the corresponding high-resolution pixels are read from memory, updated, and then written back to the memory. In a real-time system, the foregoing processes for all the low-resolution pixels may be completed in a fixed frame interval.
The foregoing may advantageously use very small, shared on-chip storage that is enough to hold the high-resolution pixels to be updated for a low-resolution pixel. Additional bandwidth can be allocated for reading/writing the high-resolution pixels to/from off-chip memory.
In another embodiments, each low-resolution frame may have its own high-resolution buffer for MCBP to work on. At any point of time, a portion of the pixels in a high-resolution buffer corresponding to a low-resolution frame may be retired from the MCBP if they are no longer impacted by the MCBP process for the remainder pixels in the low-resolution frame. The retired pixels from the high-resolution buffer may be conceptually moved to another high-resolution buffer corresponding to the next low-resolution frame, and the high-resolution pixels that are no longer impacted by any low-resolution pixels are output to HR(t). This approach may use a small amount of bandwidth for reading/writing the high-resolution frame to/from off-chip memory, and a low operating frequency since this approach may allow parallel processing of the multiple MCBP processes for the multiple low-resolution frames. Additionally, on-chip storage can be allocated to hold the multiple high-resolution buffers.
MCBP may require significant computation resources, such as bandwidth, storage, and computational cycles. This is especially true in a real-time, embedded environment. Therefore, methods of implementing MCBP are needed that are efficient in terms of computation resources and also can offer various trade-offs among these resources.
In certain embodiments of the invention, a patch of pixels in higher resolution frame 320 t is processed to completion in the MCBP processes using all the low-resolution frames LR.
Referring now to FIG. 9 , there is illustrated a block diagram of the higher resolution frame 320 t partitioned into non-overlapping blocks 905 , each block 905 having a size of dest_size_x*dest_size_y, which respectively represent the horizontal size and vertical size of the block. Shown on the left of FIG. 9 is such a partition. For a block 905 at the position (m*dest_size_x, n*dest_size_y) in the partition, define its corresponding back-projection patch as the rectangle delimited by its top-left pixel
( m * dest_size _x - patch_size _x - dest_size _x 2 , n * dest_size _y - patch_size _y - dest_size _y 2 )
and its bottom-right pixel
( ( m + 1 ) * dest_size _x - 1 + patch_size _x - dest_size _x 2 , ( n + 1 ) * dest_size _y - 1 + patch_size _y - dest_size _y 2 )
where patch_size_x and patch_size_y represent respectively the horizontal size and vertical size of the patch. Each block 905 has a corresponding back-projection patch 910 . Note that the two patches of two neighboring blocks in the partition may overlap each other.
Following a raster-scan order, each patch 910 is motion compensation back projected for the pixels in LR(n−k), . . . , LR(n+k) (or any other temporal order of them). After the MCBP processes are completed for the patch, the center block 905 in the patch and of size dest_size_x by dest_size_y is output.
It is noted that in the MCBP processes for the patch 910 , all the pixels in the patch may be updated, but only the pixels at the center block 905 are output. The boundary pixels, the pixels that are in the patch 910 but not in the block 905 may have impact on the inner pixels in the patch during the MCBP process. Additionally, the boundary pixels may be further impacted by the MCBP processes of the neighboring patches 910 .
Referring now to FIG. 10 , there is illustrated a block diagram of a patch 910 and an the area 1005 in a low-resolution frame LR(n+j) that potentially impacts the patch 910 in MCBP, with the area being defined as the set of the blocks 1010 (each of size block_size_x*block_size_y) in LR(n+j) that, after motion-compensation, may potentially back-project into the patch.
It is noted that the total number of blocks in the above defined area in LR(n+j) may increase with the motion range between LR(n+j) and LR(n), and this number may potentially become quite large. However, quite often, only a portion of the blocks in the area can actually be back-projected into the patch after considering their corresponding motion vectors, and this portion may become even smaller if some conditions on the motion vectors are imposed for a block to be used in MCBP. Therefore, to reduce the requirements on bandwidth for accessing low-resolution blocks, an upper-limit on the number of blocks that can be used in MCBP is imposed for a patch 910 . An example of such upper-limit is γ*(patch_size_x/block_size_x)*(patch_size_y/block_size_y), where γ is a constant parameter.
In one embodiment, all the blocks in the area can be scanned in the low-resolution frame corresponding to a patch 910 . Each qualified block is processed in the MCBP 840 until the upper-limit is reached. Note that in scanning the low-resolution area, in certain embodiments, different scan orders may be used instead of the conventional raster-scan; for example, in one embodiment, the center blocks in the area are used first, spiraling to the outer blocks in the area.
In another embodiment, the blocks can be scanned in the area in the low-resolution frame, and ranked according to a measurement of their corresponding motion quality. The blocks can be chosen from the top rank down until the limit is reached.
It is noted that the foregoing allows parallel processing of multiple patches in the destination domain, since a patch may be processed independently of other patches. Another advantage is the relatively lower requirement of on-chip storage, since only a number of patches are required for high-resolution storage.
Although some redundant operations may occur in the MCBP 840 due to the fact that the patch size is larger than the destination block size, this can be reduced by appropriately choosing the patch sizing and using cache.
In other embodiments, instead of using the destination domain, the source domain can be used. A stripe in the low resolution frames can be defined as a row of blocks, each block having a size of block_size_x*block_size_y, and all being aligned with the block grids in the low-resolution frame. Shown in FIG. 11 are a stripe in a low-resolution frame LR(n+j) and the area in SP(n) that may be potentially impacted by the stripe in MCBP.
Referring now to FIG. 11 , there is illustrated a block diagram describing an exemplary stripe 1105 in a lower resolution frame LR and the corresponding area 1110 in the higher resolution frame. The blocks of each stripe are back projected to the higher resolution frame following a certain order.
Referring now to FIG. 12 , there is illustrated a block diagram describing an exemplary order for the MCBP 840 in accordance with an embodiment of the present invention. The stripes are processed in the order 1201 , 1202 , 1203 , . . . , 1210 , 1211 .
In certain embodiments of the present invention, the blocks in the two co-located stripes in LR(n±j) may be processed in ping-pong fashion; i.e., process a first block in 1201 in the MCBP 840 , then process a first block in 1202 which may be co-located with the first block in 1201 , then a second block in 1201 , then a second block in 1202 which may be co-located with the second block in 1201 , and so on.
In certain embodiments of the present invention, the MCBP 840 may process in a stripe-based manner, top-to-bottom spatially and far-to-near (relative to LR(n)) temporally, but with some vertical offsets among the stripes at the low-resolution frames. Referring now to FIG. 13 , there is illustrated an exemplary order for the MCBP 840 . The MCBP 840 proceeds starting with stripe 1301 , and proceeds to 1302 . . . 1311 .
A high-resolution buffer in MCBP may still be shared among the MCBP processes for the low-resolution frames, since the motion ranges and thus the sizes of the MCBP support normally decrease as the temporal distance from LR(n+j) to LR(n) decreases.
In certain embodiments of the present invention, the blocks in the two co-located stripes in LR(n±j) may be processed in ping-pong fashion; i.e., process a first block in 1301 in the MCBP 840 , then process a first block in 1302 which may be co-located with the first block in 1301 , then a second block in 1301 , then a second block in 1302 which may be co-located with the second block in 1301 , and so on.
In certain embodiments of the present invention, the MCBP 840 can process the blocks in the multiple low-resolution frames in the following order. For each block in a low-resolution frame, a block-coordinate (bx, by) is assigned which specifies its block-column position and block-row position. The top-left block in a low-resolution frame has the coordinate of (0, 0). An example process order at any moment in MCBP is shown in the following, using the case of 9 low-resolution frames as an example:
(bx, by) in 1301 (bx, by) in 1302 (bx−offset 3 _H, by−offset 3 _V) in 1303 (bx−offset 3 _H, by−offset 3 _V in 1304 (bx−offset 2 _H, by−offset 2 _V) in 1305 (bx−offset 2 _H, by−offset 2 _V in 1306 (bx−offset 1 _H, by−offset 1 _V) in 1307 (bx−offset 1 _H, by−offset 1 _V in 1308 (bx−offset 0 _H, by−offset 0 _V) in 1309
In the above, offset 3 _H/V, offset 2 _H/V, offset 1 _H/V, and offset 0 _H/V are offsets in blocks in the horizontal and vertical directions, all relative to the position of the current block in LR(n±4). If the foregoing offsets are properly chosen, the MCBP 840 processes may potentially be performed in parallel within a shared high-resolution buffer.
Referring now to FIG. 14 , there is illustrated an exemplary higher resolution frame mapped to a shared buffer in accordance with an embodiment of the present invention. It is noted that the areas impacted 1415 by the current blocks in 1301 . . . 1309 do not overlap with each other.
Accordingly, a high-resolution buffer may be shared between the MCBP 840 processes for the multiple low-resolution frames. Additionally, the MCBP 840 can perform the foregoing processes in parallel. Additionally, bandwidth efficiency in accessing the blocks of the low-resolution frames is improved, as a result of the stripe based pattern.
Referring now to FIG. 15 , there is illustrated a block diagram describing a parallel processing at the pixel level in the MCBP 840 . A block of 8×8 pixels 1505 in a low-resolution frame share the same motion, and that 6×6 pixels 1510 in a higher resolution frame are used in simulating a low-resolution pixel 1515 . For the 8×8 pixels in each low-resolution block, a raster-scan order may be followed in the MCBP 840 . Note that MCBP 840 in this manner is essentially sequential in two senses:
(i) the high-resolution pixels updated in processing the current low-resolution pixel are subject to further updating in processing the subsequent low-resolution pixels in the block;
(ii) in simulating a low-resolution pixel, the previously updated high-resolution pixels are used.
Referring now to FIG. 16 , in certain embodiments of the present invention, the 8×8 pixels 1505 in a low-resolution block can be partitioned into 4 quadrants 1605 , and each of which contains 4×4 pixels with a top-left pixel 1610 . Shown also are the high-resolution areas 1615 that are impacted by the four pixels top-left pixels 1610 . Note that if 6×6 pixels in the higher resolution are used to simulate a low-resolution pixel and thus are impacted by the low-resolution pixel, the four high-resolution areas 1615 corresponding to these four pixels 1610 do not overlap each other. Therefore, in MCBP, these four low-resolution pixels 1610 may be processed in parallel, assuming sufficient hardware resources exist. After the four pixels 1610 are processed, the four pixels to the right of the four pixels 1610 in the four quadrants may be processed in parallel, and so on until all the pixels in the block are processed.
It is noted that in certain embodiments of the present invention, within the four quadrants in 1615 , other scan orders may be followed instead of the conventional raster scanning order. Additionally, in certain embodiments, different numbers of low-resolution pixels may be processed in parallel.
As well, if a measure of motion quality is available at pixel-level, the MCBP 840 behavior may be adapted accordingly. For example, the strength of MCBP 840 may be increased for a low-resolution pixel having a smaller local SAD and decrease the strength of MCBP 840 for a low-resolution pixel having a larger local SAD, where the local SAD of a low-resolution pixel z may be calculated as the sum-of-absolute-difference between a window of pixels in LR(n+j) surrounding z and the corresponding motion-compensated pixels in LR(n).
Note that this method does not require motion estimation at pixel-level but still offers pixel-level adaptive-ness in MCBP. An upper-limit may be be imposed on the number of pixels in a low-resolution block that are allowed to use in MCBP, for the potential benefit of reducing computation cycles for each low-resolution block. In such case, a fixed scan order of the low-resolution pixels in a block can be followed until the upper-limit is reached, or the pixels in the block can be ranked according to some pixel-level motion quality measurement the top-ranked pixels are chosen until the upper-limit is reached.
In certain embodiments of the present invention, the foregoing allows a lower operation frequency of the MCBP 840 hardware, due to the parallel processing at pixel level. Another advantage is that it may be superior to the conventional raster scanning order in terms of the resulting picture quality, since it allows the effects of MCBP to diffuse across the resultant high-resolution frame more evenly in all directions, rather than imposing a diffusion from top-left to bottom-right within, across the entire frame.
In certain embodiments of the present invention, the methods described in the above may be applied to both luma and chroma, or to luma only. In another embodiment, the pixel-level parallel MCBP may be used together with the destination-domain patch-based processing or the source-domain stripe-based processing.
Example embodiments of the present invention may include such systems as personal computers, personal digital assistants (PDAs), mobile devices (e.g., multimedia handheld or portable devices), digital televisions, set top boxes, video editing and displaying equipment and the like.
The embodiments described herein may be implemented as a board level product, as a single chip, application specific integrated circuit (ASIC), or with varying levels of the system integrated with other portions of the system as separate components. Alternatively, certain aspects of the present invention are implemented as firmware. The degree of integration may primarily be determined by the speed and cost considerations.
While the present invention has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the present invention.
Therefore, it is intended that the present invention not be limited to the particular embodiment disclosed, but that the present invention will include all embodiments falling within the scope of the appended claims and equivalents thereof.
|
Presented herein are caching structures and apparatus for use in block based video. In one embodiment, there is described a system receiving lower resolution frames and generating higher resolution frames. The system comprises an upsampling circuit, a first circuit, and a second circuit. The upsampling circuit upsamples a particular lower resolution frame, thereby resulting in an upsampled frame. The first circuit maps frames that are proximate to the particular frame, to the particular frame. The second circuit simultaneously updates the upsampled frame with two or more blocks from at least one of the frames that are proximate to the particular frame.
| 6
|
RELATED APPLICATIONS
This application is related to the inventions disclosed and claimed in concurrently filed, copending, commonly assigned applications entitled High Pressure Plasma Hydrogenation of Silicon Tetrachloride Ser. No. 148,094 and Polycrystalline Silicon Production Ser. No. 148,093.
BACKGROUND OF THE INVENTION
This invention relates in general to the deposition of polycrystalline silicon and more particularly to the deposition of silicon from a silicon-bearing compound in the presence of a high pressure plasma.
Large quantities of high quality silicon are used by the semiconductor industry for the fabrication of transistors, integrated circuits, solar cells, and the like. The silicon must be of high purity, containing only carefully controlled amounts of conductivity determining dopants. Silicon is typically produced by the hydrogen reduction of a chlorosilane. In the typical process the chlorosilane, usually trichlorosilane, and hydrogen are reacted in a reactor apparatus to deposit pure silicon on a heated filament. The filament can be, for example, either pure silicon or a refractory metal such as tungsten or molybdenum. It is usually about one-half centimeter in diameter and is heated to about 1100° C. by the passage of a heating current. Because the small diameter of the rod provides a heated reaction area of limited size the process starts slowly and is relatively inefficient. Large volumes of gases go unreacted and must be purified for subsequent reuse. Additional large volumes of gases react to form other silicon compounds without resulting in the deposition of silicon. Large quantities of energy are expended, contributing to the high cost of the silicon produced.
A further disadvantage of the prior art process relates to the shape of the outer diameter of the polycrystalline body formed. The rate of deposition and thus the outer shape of the deposited body is partly a function of the temperature of the deposition surface. Any nonuniformities in the deposition filament will result in non-uniformity in the temperature along that filament. This will in turn cause non-uniform deposition rates along the filament and a non-uniform outer diameter.
The filament can also be a source of contaminants. The refractory metal filament can contribute small amounts of unwanted dopants to the depositing silicon at the elevated temperatures used in the deposition process. The filament itself must be bored out of the center of the polycrystalline body before that polycrystalline silicon can be used in subsequent crystal growth processes. This of course entails an additional mechanical operation which is costly and time consuming and which can contribute further contaminants to the silicon.
If a silicon filament is used rather than a refractory metal filament, the silicon must be of extremely high purity, that is, of a purity equivalent to that of the silicon being deposited. Such high purity silicon is, however, very highly resistive and thus difficult to heat uniformly by forcing a current through the filament. The high resistance makes it difficult to force the thousands of Amperes of current through the filament that are required to achieve the deposition temperature.
There is a growing need for high quality, inexpensive polycrystalline silicon resulting from the tremendous present growth in the use of semiconductor products. The availability of low-cost silicon is a necessary prerequisite if silicon photovoltaic cells are to provide an appreciable amount of the country's energy needs. But present methods for producing polycrystalline silicon are expensive, inefficient in the use of both energy and reactants, and tend to yield impure and irregularly shaped silicon deposits. Accordingly a need existed for a silicon deposition process that overcomes these deficiences attendant with present methods.
It is therefore an object of this invention to provide an improved process for harvesting polycrystalline silicon by high pressure plasma deposition.
It is a further object of this invention to provide a process for the deposition of polycrystalline silicon having a high efficiency of input gas utilization.
It is another object of this invention to provide an improved process for the deposition of polycrystalline silicon which is characterized by lower energy consumption than are prior art processes.
It is still another object of this invention to provide a process for the deposition of high purity polycrystalline silicon in shapes having well controlled outer diameters.
SUMMARY OF THE INVENTION
The foregoing objects are achieved in the present invention through the use of a high pressure plasma deposition method. A chlorosilane or other silicon source gas is reduced by hydrogen in the presence of a high pressure plasma to deposit polycrystalline silicon on the interior wall of a heated substrate structure. The substrate material is selected to have a thermal expansion coefficient which permits separation of the polycrystalline silicon from the substrate by a thermal expansion shear separation process.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a high pressure plasma apparatus suitable for practice of the invention;
FIG. 2 illustrates a high pressure plasma module for impedance matching and for introduction of reactant gases;
FIG. 3 illustrates in exploded cross section a dual-flow nozzle for the high pressure plasma apparatus;
FIG. 4 illustrates a high pressure plasma deposition system suitable for practice of the invention;
FIG. 5 illustrates a gas seal geometry suitable for sealing the entrance and exit of the HPP deposition system; and
FIG. 6 illustrates a clam-shell substrate structure.
DETAILED DESCRIPTION OF THE INVENTION
A plasma can be defined as an approximately neutral cloud of charged particles, formed, for example, by an electric glow discharge. The types and characteristics of plasmas vary widely depending on conditions; two types commonly of interest are denoted as the low pressure and high pressure plasmas. The boundary line which distinguishes between the two types of plasma is a pressure of about 100 torr (1.33×10 4 pa), but for practical purposes the high pressure plasma (HPP) is typically produced at a pressure of about one atmosphere. An important distinction between low pressure and high pressure plasma relates to temperature: in a low pressure plasma the electron temperature can be much greater than the gas temperature; in contrast, the conditions found in a high pressure plasma lead to thermal equilibrium in which the electron and gas temperatures are nearly identical. The gas temperature in the high pressure plasma can typically reach 3000°-5000° K.
FIG. 1 illustrates an overall system for practice of the invention. The deposition reaction takes place within a reaction chamber 10 within which the atmosphere can be properly controlled. The reaction chamber is discussed in detail below. An output tube 18 terminates in a high pressure plasma (HPP) nozzle 20 from which a high pressure plasma 22 is directed. Tube 18 is the high voltage output from the impedance matching module 24. Energy from an RF generator 26 is conveyed to the impedance matching module by a coaxial cable 28. Also conveyed to the impedance matching module are two gas streams, an inner gas stream 30 and an outer gas stream 31. The gas streams are controlled by a gas control system 32. Piped to the gas control system are reactants including hydrogen 34 and a silicon source gas 36. This silicon source gas is preferably trichlorosilane but can also be selected from silicon tetrachloride, silicon tetrafluoride, other chlorosilanes, or other silicon bearing gases or mixtures thereof. An inert gas 38 such as helium is also piped to the gas control system.
FIG. 2 illustrates details of impedance matching module 24. The impedance matching module comprises a coil 42 and variable input and output capacitors 44, 46, respectively. RF power is conveyed to the module by coaxial cable 28. The coil is tuned to resonance by adjusting the input and output capacitors. At resonance, output tube 18 is tuned to a high voltage. Coil 42 is made of coaxial tubing and has an inner tube 48 to carry inner gas stream 30 and an outer tube 50 to carry outer gas stream 31 as shown in cross-section 2a. The inner and outer tubes are formed of a metal such as stainless steel which is chemically resistant to the silicon-bearing gas. The inner and outer gas streams are thus conveyed through the tuned coil to the high voltage output tube and then to the high pressure plasma nozzle 20. The high voltage present at output tube 18 and thus at nozzle 20 is sufficient to generate an RF discharge plasma at the nozzle tip.
A dual-flow high pressure plasma nozzle assembly is illustrated in more detail in FIG. 3. Output 18 of coil 42 with its concentric inner and outer tubes conveying two different gas streams is attached to nozzle 20. The nozzle is comprised of a metal shell 52 made of stainless steel or other chemically resistant metal. An inner electrode 54 is formed of a refractory metal such as molybdenum or tungsten. An insulator sheath 56 forms the end of the nozzle. The sheath is formed of an insulator such as boron nitride which has a high dielectric strength at the RF frequency and which is resistant to the chemical ambient. One of the reactant gases is conveyed through inner tube 48 to inner electrode 54. The second gas is conveyed through outer tube 50 and then through a plurality of ports 58 or openings which are bored through metal shell 52 and which are arranged concentrically about opening 60 into which inner tube 48 and inner electrode 54 are positioned. The nozzle thus permits the isolation of the two gas streams until they exit at the tip of the nozzle.
FIG. 4 schematically illustrates one embodiment of deposition reaction chamber 10. The chamber comprises a quartz enclosure 70, gas seals or curtains 80 at the reactor entrance and exit and an auxiliary resistance heated furnace 82. A finite length, thermal expansion, shear separation (TESS) substrate 40 is introduced into the reactor from the left through the gas seals and is withdrawn from the right along with deposited silicon 84. The HPP nozzle is positioned in the reactor through a high dielectric strength elastomer seal 86 which serves to center the nozzle in the chamber and to electrically isolate output tube 18 from the chamber and TESS substrate. Effluent gases from the reaction pass through an exhaust tube 88 to a chlorosilane and hydrogen recovery system (not shown) for subsequent separation and recycling.
The TESS substrate is maintained during deposition at a temperature greater than about 950° C. and preferably at about 1100° C. The enthalpy of the HPP gases provides about 25 to 50 percent of the required substrate heating. Substrate heater 82 supplies the remaining necessary heat energy and maintains the temperature at a constant selected deposition temperature.
FIG. 5 illustrates one embodiment of a gas seal for use with the deposition reactor chamber described above. An O-ring seal 90 provides an airtight seal between gas seal 80 and quartz enclosure 70. Gas seal 80 comprises three sections 91, 92, 93. Sections 91 and 93 provide pressurized inert gas curtains which impinge upon the moving TESS substrate. The inert gas curtains are separated by a vacuum curtain provided by section 92. Flexible wipers 94 minimize the gas flow through the curtains, a necessary condition for adequate sealing. The inert gas curtain is achieved by forcing an inert gas such as nitrogen or argon through an opening or series of orifices. In a similar manner, gases are expelled through an opening or series of orifices in the vacuum portion 92 and are pumped out by a vacuum pump (not shown).
FIG. 6 illustrates one preferred embodiment for the TESS substrate. The substrate is of finite length and comprises two half cyclinders 95, 96 which together form the total cylinder 40. The split cylinder facilitates separation of the substrate from the silicon deposit.
The deposition reaction is carried out generally as follows to form a hollow cylindrical silicon deposit. Initially the reactor is loaded with a finite length TESS substrate positioned to extend from the gas seals at the left to the gas seals at the right. The gas seals are activated by initiating the gas and vacuum curtains and the reactor is purged with an inert gas such as helium to remove all air from the system. For this purge step the helium is directed through both the inner and outer coaxial tubes of coil 42 and output tube 18. The reactor is flushed with the helium and any air or other contaminants present in the system are removed at 88.
Hydrogen is then introduced into both inner and outer gas streams through the gas control system. The RF generator is turned on and the power is increased to a level suitable for creating a plasma. The input and output capacitors of the impedance matching module are tuned to resonance. Creation of a plasma beam at the dual-flow nozzle and a low reflected power measured at the RF generator are indications of resonance.
After the plasma is created, furnace power is turned on to heat the TESS substrate. When the furnace temperature reaches the deposition temperature (about 1100° C.), trichlorosilane or other silicon bearing gas is gradually introduced into the inner gas stream while gradually reducing the hydrogen flow in that stream. A change in the gas stream from hydrogen to trichlorosilane affects the tuning of the network; it is therefore necessary to simultaneously retune the impedance matching network to sustain the plasma. The flow rates of the two gases are adjusted to obtain the desired flow rate and mole ratio of the reactants. At this time, the TESS substrate translation from left to right is initiated at a rate compatible with the thickness of the silicon tube desired. The two reactants exit the high pressure plasma nozzle and the trichlorosilane reacts with the hydrogen; the extremely high temperatures resulting from the high pressure plasma favor the endothermic reduction reaction to produce solid silicon.
The silicon deposit is in the form of a hollow tube having an outer shape conforming to the shape of the TESS substrate. The thickness of the silicon deposit, that is the thickness of the cylinder wall, is determined by a number of variables including the translational speed of the TESS substrate through the deposition chamber. As the deposition is initiated, it is necessary to change the inner portion of the gas seal at the exhaust side of the chamber until the silicon tube diameter reaches a steady state value. Once the steady state value is reached, no change in seal is needed.
As the TESS substrate moves through the deposition chamber, silicon is deposited on the substrate from the high pressure plasma reaction. The substrate exiting the exhaust side of the chamber has a silicon deposit upon it having a uniform thickness; the deposition rate non-uniformities along the length of the deposition system, such as non-uniformities in furnace temperature, become averaged out over the term of the deposition.
As the TESS substrate with the silicon deposited upon it exits the deposition chamber the substrate and silicon deposit are separated by utilizing the difference in thermal expansion coefficient between the substrate and the silicon. As each length of TESS substrate exits the furnace it is removed from the silicon. The silicon itself, however, exits the gas seals as a continuous tube and is sawed into predetermined lengths. During the sawing operation, the deposition system is switched to a purging mode in which reactant flows and substrate translation are stopped and inert gas is substituted for the reactant hydrogen and silicon source gas. After removing the cut silicon portion, the exhaust seal is reinserted in the remaining silicon and the deposition cycle is reinitiated.
Polycrystalline silicon tubes so produced are useful, for example, as starting material for single crystal silicon growth by methods such as the Czochralski or float-zone techniques. Only a slight surface cleaning or etching is required. The deposited silicon is dense and continuous. If the substrate deposition temperature is not maintained above about 950° C., silicon is still deposited but the deposit is brown, flaky and porous.
After separation of the deposit from the TESS substrate, the reusable substrate is recycled and is reintroduced into the deposition chamber. The TESS substrate shell material is selected to have a thermal expansion coefficient significantly different from that of silicon with the shell having the smaller expansion coefficient and to be relatively unreactive with silicon at the deposition temperature. Suitable materials include molybdenum and tungsten. The difference in expansion coefficient and the minimal amount of reaction between substrate and silicon permits the ready separation of the two materials.
Reactor input gas composition and flow rate are preferably optimized to obtain high silicon throughput (amount of silicon deposited per minute) and high per pass conversion (amount of silicon gas converted to solid deposited silicon). In general, low silicon bearing gas concentrations and low total reactant flow rates result in high per pass conversion efficiency at the expense of silicon deposition throughput. High silicon gas concentrations and higher reactant flow rate, conversely, result in high throughput and low per pass conversion efficiency. In preferred reactions using SiHCl 3 or SiCl 4 as the silicon source gas composition is adjusted to about 7% SiHCl 3 in H 2 , or about 5% SiCl 4 in H 2 . The optimum total reactant flow rate depends on the reactor dimensions. For a reactor having a diameter of about 5 cm and a length of about 60 cm, a silicon deposition throughput of about 1.4 gm/minute and a per pass conversation efficiency of about 35% is achieved under the following conditions: 45 liters per minute hydrogen and 3.15 liters per minute SiHCl.sub. 3, 3 kw rf power for the high pressure plasma beam, and a deposition substrate temperature of about 1100° C. In comparison, prior art processes yield about the same throughput with only a 14% per pass conversion using 90 liters per minute of hydrogen and 9 liters per minute of SiHCl 3 .
The higher per pass conversion efficiency for the process in accordance with the invention, apart from increasing the throughput of the HPP deposition system, also reduces expenses associated with the effluent recovery system. The HPP process achieves approximately 50% higher material utilization efficiency. For an identical amount of silicon produced, the HPP process requires approximately 20% less energy.
Thus there has been provided, in accordance with the invention, a process for the deposition of silicon in a high pressure plasma which fully meets the objects set forth above. While the invention has been described with regard to specific embodiments thereof, the invention is not to be so limited. Those skilled in the art will appreciate that modifications can be made, for example, in the deposition apparatus and the high pressure plasma nozzle design. Further, practice of the invention has been illustrated by the use of a cylindrical deposition surface. Other shapes can be used to achieve silicon bodies having ribbon-shapes, rectangular cross-section, or the like. Other similar variations and modifications will be apparent in light of the foregoing description. Accordingly, it is intended to embrace all such variations and modifications as fall within the scope of the appended claims.
|
Polycrystalline silicon is deposited on the interior surface of a shaped container. The silicon is deposited by reacting hydrogen and a silicon bearing gas in the presence of a high pressure plasma. The silicon body is separated from the shaped container by utilizing thermal expansion shear stress.
| 2
|
FIELD OF THE INVENTION
The invention relates generally to the field of photofinishing, and in particular to customized or specialized photofinishing. More specifically, the invention relates to a method and system utilizing a unique, affixed label on a camera to indicate to a photofinisher that specific specialty types of goods and/or services are requested.
BACKGROUND OF THE INVENTION
Photofinishing modifications are often made on the basis of film type. However, the details of modification are limited to specific treatments for specific film types. Specialty photofinishing is not encouraged since detection and execution of different processing features disrupts the photo processing environment.
What is needed is a simple and reliable means for delivering a request for specialty photofinishing to the photofinisher. The requested type of photofinishing must also be communicated to the consumer. Printing a data frame on film is well known. It is possible to simultaneously expose a data frame and print, by means of ink jet technology, on the camera label; however, labels are conventionally printed and applied in different operations in the manufacturing process. Also, the label has to be customized at a speed that is equal to the exposure rate of the data frame.
The APS film system reads a number from the label that will be applied to the film cassette and exposes that number to the film. However, that number is not read from a camera, and it is not used to make any determination of film processing.
A need exists for easily communicating to a photofinisher specialty type film processing as explicitly requested by the consumer or implicitly from the consumer's use of the camera.
SUMMARY OF THE INVENTION
The present invention is directed to overcoming one or more of the problems set forth above. Briefly summarized, according to one aspect of the present invention, a method for specialized photofinishing goods and/or services produced from a one-time-use camera, including providing a label on the one-time-use camera, with at least one area containing first instructional information, that identifies a particular photofinishing goods and/or services to be used with images captured by the one-time-use camera. Subsequently, displaying a second instructional information according to the first instructional information. Finally, recording a second instructional information onto a film residing in the one-time-use camera and resulting in a latent image, said second instructional information for use by a photofinisher for producing the specialized photofinishing goods and/or services from latent images on said film.
Another aspect of the present invention provides a method for obtaining photofinishing goods and/or services, including capturing an image of a public target associated with photofinishing goods an/or services and subsequently, forwarding the captured image of the public target to a photofinisher. Finally, the user obtains at least one photofinishing good and/or service according to information associated with the public target.
BRIEF DESCRIPTION OF THE DRAWINGS
The above aspects, features, and advantages of the present invention will become more apparent when taken in conjunction with the following description and drawings wherein identical reference numerals have been used, where possible, to designate identical features that are common to the figures, and wherein:
FIG. 1 is a perspective view of a one-time use camera with an external printed unique code;
FIG. 2 is a perspective view of a digital system for exposing the unique code obtained from the printed label to the film data frame within the one-time-use camera;
FIG. 3 is a front view of a section of an exposed and processed film strip including data and image frames;
FIG. 4 is a diagram of a system for obtaining the unique ID from the data frame;
FIG. 5 is a perspective view of an analog system for exposing the unique code obtained from the printed label to the film data frame within the one-time-use camera;
FIG. 6 is an exemplary label for a one-time use camera having a detachable receipt and externally printed unique code;
FIG. 7 is an exemplary system according to the present invention for creating targets;
FIG. 8 is an example of a pre-printed target for use in retail locations;
FIG. 9 is an exemplary billboard used for creating targets; and
FIG. 10 is an exemplary flowchart of capturing and displaying instructional information associated with specialized photofinishing goods and/or services.
To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a means for communicating the desired type of specialized photofinishing to both the consumer and the photofinisher.
Referring to FIG. 1 , a one-time-use camera 10 (herein after referred to as OTUC 10 ) with a pre-exposed image frame that includes an affixed label 20 that has written upon it a machine readable code 30 or a human readable code 40 to alert a photofinisher that the OTUC 10 requires a specialized photo finishing service. Machine readable code 30 and human readable code 40 may be combined such as in characters designed for optical character recognition and written upon label 20 . Label 20 may also include a detachable receipt 50 that has written upon it a URL internet address for receipt or ordering of photofinishing goods and/or services. These photofinishing goods and/or services may be accessed with a password that is included with detachable receipt 50 . Furthermore, label 20 may be an RF tag with a unique ID code capable of being linked to a database that includes other photofinishing ID codes.
Referring to FIG. 2 , a system 5 includes a OTUC 10 and a camera retaining fixture 60 with the ability to read label 20 via barcode reader 70 . In lieu of using barcode reader 70 , the camera may include an RF tag to automatically communicate information via an RF reader (not shown). In a preferred embodiment, this label is permanently affixed to the OTUC, but that need not be the case. The label may be temporary or detachable in the manufacturing process.
Diopter 80 is employed to reduce the distance from soft display 90 and OTUC 10 in camera retaining fixture 60 while maintaining good focus. A database is also employed to associate the unique ID to a specified photofinishing service such as “internet access.”
Label 20 with a specialized marking or other means of communication such as an RF tag is affixed to the OTUC. The case of the label will be described by way of example and not limitation. Label 20 alerts the purchaser that the film from this OTUC will be printed or otherwise acted upon by the digital photofinishing system to create the desired output. In a preferred embodiment, camera 10 is an OTUC capable of taking pictures underwater such as the Kodak's Max Water & Sport®. Label 20 on OTUC 10 contains instructional information such as machine readable code 30 and human readable code 40 . The instructional information alerts the digital photofinishing system that appropriate photofinishing such as Eastman Kodak's Sea Processing® is to be applied to the developed images.
FIG. 2 shows OTUC 10 in camera retaining fixture 60 . Barcode reader 70 reads machine readable code 30 and sends it to computer 110 by means of fixture/computer linkage 120 . Alternately, an electronic camera can be used in place of barcode reader 70 . In this example, linkage 120 is shown as a wire, but other means such as wireless transmission may be employed. Computer 110 uses machine readable code 30 to select a displayed image 100 for display on soft display 90 . Displayed image 100 may be an image of machine readable code 30 or some other image. OTUC 10 now opens its shutter and an exposure of displayed image 100 is made. Focusing the exposure of displayed image 100 is accomplished by use of an ancillary optical means for focusing, such as a close up diopter 80 . The film in OTUC 10 may be advanced so that the exposed frame is not double exposed, or it may be advanced by the user of OTUC 10 .
Referring to FIGS. 3 and 4 , the user obtains OTUC 10 in the traditional manner at retail and captures his desired images. When the photofinisher receives the OTUC 10 , exposed film 190 is extracted from OTUC 10 and processed in the film processor 200 . Processed film strip 130 is scanned in scanner 210 . Image server 220 identifies the scanned images as conventional images 180 or data frame 140 . Data frame 140 may have instructional information within it, and be in the form of a unique ID. Upon detecting data frame 140 , image server 220 reads machine readable unique ID 160 and applies the desired algorithm to the captured images. In this example, Sea Processing® from Eastman Kodak Company is applied to the images taken underwater so that their appearance is improved. Modified image files are sent to digital printer 230 where they are printed. Data frame 140 may not be printed.
When the film is processed in film processor 200 and scanned with scanner 210 , machine readable unique ID 160 in data frame 140 is read by the scanner 210 . Alternatively, the human readable unique ID 150 could be read by scanner 210 and interpreted by Optical Character Recognition (OCR) software. The unique ID number is now available to be used to access the database to provide the designated photofinishing service.
Alternatively, human readable unique ID 170 could be used by an operator to key the appropriate photofinishing. This human readable unique ID 170 may be used by a photofinisher who does not understand the meaning of the machine readable unique ID 160 to provide the appropriate photofinishing. This photofinisher may not have the algorithms indicated by the unique ID and can use the human readable unique ID 170 information to key photofinishing similar to the desired type.
Another method of exposing data frame 140 can be via a folded optical path as shown in FIG. 5 . Instead of reading a number and having OTUC 10 capture an image on a soft display, OTUC 10 can be used to provide an exposure of label 20 on the camera itself. Thus, the exposure of the data frame 140 is actually a captured image of the label 20 . Light source 240 illuminates label 20 . An image of label 20 is reflected by mirrors 250 and 260 . The close up diopter 80 provides appropriate focus and magnification for OTUC 10 to expose data frame 140 ′. Another optical path (not shown) may be provided to illuminate the label 20 with the light from a flash 15 on OTUC 10 .
The designated photofinishing service can be many different services depending on the unique ID. The aforementioned Sea Processing® is one example. The service could be as simple as backprinting the date or a logo on the back of the prints. The specialization of the service could go as far as a different specialized service for each camera.
If there is a means for detecting a switchable condition, such as in the well known APS system, during the time the consumer is taking images, the service could be requested for less than all the exposures for a single camera. Thus, the specialized service designated by data frame 140 can be selected for some pictures and not others.
FIG. 6 shows label 20 with detachable receipt 50 with a completely unique code. Label 20 has some unique identifier that distinguishes it from all others. In this case, detachable label 50 carries URL 52 or a number that corresponds to a URL. Additionally, the label 20 carries password 54 that is obscured from view by a scratch off coating. A database is also employed to associate the unique code to a specified photofinishing service such as “internet access.” This unique code is exposed to the film in the OTUC 10 , in this case a one-time-use camera, by the method described above. When the consumer has the film processed after capturing images, the code is read and the scanned images are posted to URL 52 on the detachable receipt 50 and the consumer can access the images on that site by using the password 54 . This demonstrates the potential of using the invention to control photofinishing via the unique exposure on the film.
The method allows a unique ID to be applied to film in each OTUC 10 . The unique ID allows the images from each OTUC 10 to be handled differently. In this case, the images from each individual OTUC 10 are posted to a different URL 52 and accessed only by a specific password 54 that may be different for each OTUC 10 . Note that if the database contains password 54 associated with URL 52 , password 54 may also be included in the exposure on data frame 140 . This allows the user to access images posted to URL 52 without the detachable receipt 50 if negatives are returned, or if the URL 52 and password 54 are printed along with any prints returned with the order. Additionally, password 54 may be printed with an ink only visible under special lighting conditions. The website corresponding to URL 52 may also provide a means for image storage and access to selecting alternative types of images, including, but not limited to: big prints, sentiments, greetings, multiple images, digital zoom instruction, panoramic instruction, DVD orders, CD orders, or large index print orders.
Data frame 140 may also include security information. Watermarks (not shown) or other security measures can be included to determine authenticity of the data frame 140 . This may be important if the purchase price includes an extra cost for the specialized photofinishing service. The photofinisher can detect the watermark and look up in a database provided by the camera manufacturer the validity of the service for the unique ID.
Referring to FIG. 7 , a system 700 is described for providing targets to control photofinishing. The system 700 includes a touch screen monitor 710 which provides a means for selecting photofinishing goods and/or services; a computer 720 ; a printer 725 ; and a target 730 used for providing photofinishing control codes. A user 705 selects photofinishing goods and/or services on monitor 710 and computer 720 directs printer 725 to print appropriate target 730 . Subsequently, the user 705 captures an image of target 730 . Alternatively, user 705 may capture an image of monitor 710 directly.
Similarly, the user 705 could be instructed to go to www.kodak.com\specials and see a myriad of options for ‘programming’ the OTUC 10 . The web interface would allow the user to print out an 8.5×11 sheet which would have instructions for exposing one frame from the camera (e.g. place printout on floor—place toes on edge of sheet—in standing position take picture of printout, etc.).
Referring to FIG. 8 , a target 730 is provided by a retailer for placement on photo retail counter 800 . A user 705 is encouraged by an explicit message 810 on target 730 to capture an image of target 730 . This image capture results in a creation of data frame 140 , as shown in FIG. 3 . The user 705 receives specialized photofinishing, such as a free second set of prints when the photofinisher reads data frame 140 .
Referring to FIG. 9 , another way to create the data frame 140 is to provide public targets for consumers in public places or theme locations, etc. A billboard 900 shows enticing instructions, such as, “Take a picture of this billboard and send your film to CVS and get a second set of B&W prints.” Another embodiment would have consumers at a sporting event capture at certain times a large outdoor display screen, such as a Jumbo-Tron™ screen, displaying a target label. (Not shown) The camera users would be encouraged to take a picture of the Jumbo-Tron™ and send their film to a specific photofinisher for a special service such as, a free 8×10 of a winning touchdown or bordered prints with a sporting events theme (e.g., football, baseball, soccer, etc.) Capture of the billboard or Jumbo-tron image can be accomplished with any camera, including film or digital, and is not limited to OTUC 10 .
Referring to FIG. 10 , a flowchart 1000 describing a series of operations for capture and display of instructional information associated with specialized photofinishing goods and/or services is shown. Operation 1010 requires image capture of instructional information on label 20 , the instructional information comprising machine readable code 30 or human readable code 40 . A determination of requested specialized photofinishing goods and/or services from a first instructional information source occurs in operation 1020 . Operation 1030 requires a display of second instructional information (second instructional information is based on first instructional information); whereupon, operation 1040 requires image capture of the second instructional information via OTUC 10 .
Also, the specialized service could be applied to only sections of the film order. The consumer could take a picture of target label 1 (B&W prints) and expose several pictures in that ‘mode’ then decide they would like color prints for the next several frames—so they would expose another frame with target label 2 (Color prints) and then decide for the remainder of the order they would like Cartoon prints (exposing another target label). So at the photofinishing system the targets would be valid until another target is detected or until the end of the order. This technique may also be used by digital cameras. The first image exposed with a target may alert a photofinisher or software receiving the digital images that the next images in sequence are desired to be handled in some special fashion. A second target or a second exposure of the first target may indicate that the user desires to return to normal image handling.
The invention has been described with reference to a preferred embodiment. However, it will be appreciated that variations and modifications can be effected by a person of ordinary skill in the art without departing from the scope of the invention.
PARTS LIST
5 system
10 one-time-use camera
15 flash
20 label
30 machine readable code
40 human readable code
50 detachable receipt
52 URL
54 password
60 camera retaining fixture
70 barcode reader
80 diopter
90 soft display
100 displayed image
110 computer
120 camera retaining fixture/computer linkage
130 processed film strip
140 data frame
150 human readable unique ID
160 machine readable unique ID
170 human readable unique ID
180 image frame
190 exposed film roll
200 film processor
210 film scanner
220 image server
230 digital printer
240 light source
250 mirror
260 mirror
Parts List—Continued
700 system
705 user
710 touch screen monitor
720 computer
725 printer
730 target
800 retail counter
810 message
900 billboard
1000 flowchart
1010 capture image of instructional information
1020 determinization of requested specialized photofinishing goods and/or services
1030 display second instructional information
1040 image capture of second instructional information
|
A method for specialized photofinishing goods and/or services produced from a one-time-use camera, including providing a label on the one-time-use camera, with at least one area containing first instructional information, that identifies particular photofinishing goods and/or services to be applied to images captured by the one-time-use camera. Subsequently, displaying a second instructional information according to the first instructional information. Finally, capturing a second instructional information onto a film residing in the one-time-use camera and resulting in a latent image, the second instructional information for use by a photofinisher for producing the specialized photofinishing goods and/or services from latent images on the film.
| 7
|
FIELD OF THE INVENTION
[0001] The invention relates to oxygen regulation with at least two saturation of peripheral oxygen (SPO 2 ) monitors with an automatic selection or recognition of a signal from one of at least two SPO 2 monitors.
BACKGROUND OF THE INVENTION
[0002] An SPO 2 monitor is required for the regulation of the oxygen saturation in a patient. Physiological closed loop systems must pass over into a fallback mode in care of any error that generates an unacceptable risk. The recognition of incorrect measured SPO 2 values may take place by checking the signal in the SPO 2 itself. The manufacturer Masimo provides an index of the signal quality of an SPO 2 monitor. If the signal quality drops below a threshold value or the time integral of the signal quality drops below a threshold value, the control system recognizes the need for the fall back mode. However, such SPO 2 control systems only send a warning or alarm during phases of unacceptable signal quality such that the oxygenation of the patient can be set manually. Such SPO 2 control systems do not provide for the oxygenation of the patient to be set automatically.
[0003] US 20100139659 A1 relates to a device and a process for controlling a respirator with inclusion of an oxygen saturation value for compensating a device-dependent time response, a physiological time response and a measuring method-dependent time response. The device-dependent time response, the physiological time response and the measuring method-dependent time response are determined in a continuous sequence and a run time of a change in the oxygen concentration from the metering means in the respirator to the patient is determined and taken into account in regulating the oxygen concentration. The device and process would benefit greatly from increased reliability of measured SPO 2 values.
SUMMARY OF THE INVENTION
[0004] An object of the present invention is to increase the reliability of an SPO 2 control system by providing a higher correlation between the measured value essential for the control and actual oxygenation of the blood during phases of acceptable signal quality. The deviation between the actual oxygenation and the target oxygenation is reduced so that the average quality of the control is improved over long periods of time.
[0005] The present invention allows for setting the saturation of a patient's blood during phases of poor signal quality. This provides a real improvement of patient therapy as it is not always ensured that a nursing staff is immediately available in clinical practice.
[0006] Another object of the present invention is to make possible an emergency operation during phases of unacceptable signal quality to reduce the deviation between the actual oxygenation of the blood and the target oxygenation.
[0007] Yet another object of the present invention is to increase the reliability of the closed loop of the SPO 2 monitor. The present invention reduces the percentage of time represented by phases of unacceptable signal quality.
[0008] The control system contains at least two independent SPO 2 monitors. The SPO 2 monitors may be placed at different points or locations on a patient's body. The SPO 2 monitors may preferably be provided on different extremities of the patient. The system optionally has a measured value of the pulse rate or heart rate by means of an electrocardiography (ECG). Both SPO 2 monitors send measured values on the pulse rate or heart rate, perfusion and signal quality as well as the oxygen saturation of the patient's blood.
[0009] The trustworthiness or reliability of the measurement values is rated by automatic comparison of the measured values of the first SPO 2 monitor with the measurement values of the second SPO 2 monitor. The pulse rates or heart rates of the monitors are optionally compared with the ECG-based pulse rate. The SPO 2 value that is used for the next control procedure is identified from the results of the comparison. The measured SPO 2 signal with the higher trustworthiness or reliability is used for the control. A mean value from the two measured SPO 2 values is sent to the control unit in case of comparable trustworthiness or reliability of the two measured values.
[0010] In addition to the features provided in US 20100139659 A1 (the entire contents of US 20100139659 A1 are incorporated herein by reference), the system of the present invention has another SPO 2 monitor and an ECG. A decision unit processes a measured value, which is sent to the control unit based on the criterion discussed below.
[0011] The first criteria is the oxygen saturation level. Above or equal to 80% oxygen saturation, SPO 2 monitors usually indicate less than the actual saturation when poor signal quality exists. However, the probability of excessively high measured values is low. The decision unit therefore rates the higher measured value as being more trustworthy or reliable.
[0012] The second criteria is the agreement of the heart rates measured by each SPO 2 monitor with another reference heart rate measurement. The ECG provides a reference measurement. The SPO 2 monitor that has a heart rate that shows better agreement with the reference measurement is rated as being more trustworthy.
[0013] The measured values of the SPO 2 monitor that has proved to be better, on average, is used for controlling the oxygen concentration delivered to the patient. The mean value of the two measured values is used in case of equal values.
[0014] According to the present invention, a process for controlling a respirator is provided. A first oxygen saturation monitor is provided. A second oxygen saturation monitor is provided. A first measurement signal is detected with the first oxygen saturation monitor. The first measurement signal comprises a first patient blood oxygen saturation measurement. A second measurement signal is detected with the second oxygen saturation monitor. The second measurement signal comprises a second patient blood oxygen saturation measurement. A measuring reliability rating is determined for each of the first measurement signal and the second measurement signal when the first patient blood oxygen saturation measurement and the second patient blood oxygen saturation measurement are greater than or equal to a predetermined oxygen saturation threshold. At least one of the first measurement signal associated with the first oxygen saturation monitor and the second measurement signal associated with said second oxygen saturation monitor is selected based on the measuring reliability rating associated with each of the first measurement signal and the second measurement signal to define at least one selected measurement signal. An oxygen concentration delivered to the patient is controlled based on the at least one selected oxygen saturation measurement.
[0015] The measuring reliability rating may be determined based on at least a comparison of the first patient blood oxygen saturation measurement and the second blood oxygen saturation measurement.
[0016] The measuring reliability rating associated with one of the first measurement and the second measurement may be increased when the one of the first patient blood oxygen saturation measurement and the second patient blood oxygen saturation measurement is greater than another one of the first patient blood oxygen saturation measurement and the second patient blood oxygen saturation measurement.
[0017] The predetermined oxygen saturation threshold may be eighty percent.
[0018] An alarm element may be provided. The alarm element may be activated when the first patient blood oxygen saturation measurement and the second patient blood oxygen saturation measurement are less than the predetermined oxygen saturation threshold.
[0019] An electrocardiography device may be provided. A patient may be measured with the electrocardiography device to provide a reference heart rate. A first patient heart rate signal may be detected with the first oxygen saturation monitor. The first patient heart rate signal may comprise a first patient heart rate measurement. A second patient heart rate signal may be detected with the second oxygen saturation monitor. The second patient heart rate signal may comprise a second patient heart rate measurement. The first patient heart rate measurement may be compared with the reference heart rate measurement. The second patient heart rate measurement may be compared with the reference heart rate. The measuring reliability rating may be determined based on the comparison of the first patient heart rate measurement with the reference heart rate and the comparison of the second patient heart rate measurement with the reference heart rate.
[0020] The measuring reliability rating associated with one of the first measurement signal and the second measurement signal may be increased when a difference between the reference heart rate and at least one of the first patient heart rate measurement and the second patient heart rate measurement is less than a difference between the reference heart rate and another one of the first patient heart measurement and the second patient heart rate measurement.
[0021] The measuring reliability rating associated with the first measurement signal may be compared with the measuring reliability rating associated with the second measurement signal. The measuring reliability rating associated with the one of the first measurement signal and the second measurement signal may be greater than the measuring reliability rating associated with the another one of the first measurement signal and the second measurement signal. The at least one selected measurement signal may correspond to the one of the first measurement signal and the second measurement signal with the greater measuring reliability rating.
[0022] The measuring reliability rating associated with the first measurement signal may be compared with the measuring reliability rating associated with the second measurement signal. The at least one selected measurement signal may comprise an average of the first patient blood oxygen saturation measurement and the second patient blood oxygen saturation measurement.
[0023] An oxygen saturation bedside monitor may be provided. The oxygen saturation beside monitor may provide the second patient blood oxygen saturation measurement as output. The second patient blood oxygen saturation measurement signal may be transferred to the second oxygen saturation monitor via a network.
[0024] According to the present invention, a device for controlling a respirator is provided. The device comprises a first oxygen saturation monitor detecting a first measurement signal. The first measurement signal comprises a first patient blood oxygen saturation measurement. A second oxygen saturation monitor detects a second measurement signal. The second measurement signal comprises a second patient blood oxygen saturation measurement. A measurement selection means is provided for determining a reliability rating for each of the first measurement signal and the second measurement signal and for selecting at least one of the first measurement signal and the second measurement signal based on the measuring reliability rating associated with each of the first measurement signal and the second measurement signal when the first patient blood oxygen saturation measurement and the second patient blood oxygen saturation measurement is greater than a predetermined oxygen saturation threshold to define at least one selected measurement signal. A means is provided for controlling an oxygen concentration delivered to a patient based on said at least one selected measurement signal.
[0025] The measuring reliability rating may be determined via the measurement selection means based on at least a comparison of the first patient blood oxygen saturation measurement and the second blood oxygen saturation measurement.
[0026] The measurement selection means may increase the reliability rating associated with one of the first measurement signal and the second measurement signal when one of the first patient blood oxygen saturation measurement and the second patient blood oxygen saturation measurement is greater than another one of the first patient blood oxygen saturation measurement and the second patient blood oxygen saturation measurement.
[0027] The device may comprise an alarm device. The predetermined oxygen saturation threshold may be eighty percent. The alarm device may generate an alarm signal as output when the first oxygen saturation measurement and the second oxygen saturation measurement is less than the predetermined oxygen saturation threshold.
[0028] The device may further comprise an electrocardiography device. The electrocardiography device may provide a patient reference heart rate. The first oxygen saturation monitor may provide a first patient heart rate as output. The second oxygen saturation monitor may provide a second patient heart rate as output. The measurement selection means may receive the patient reference heart rate, the first patient heart rate and the second patient heart rate as input. The measurement selection means may determine the measuring reliability rating based on a comparison of the first patient heart rate measurement with the reference heart rate and a comparison of the second patient heart rate measurement with the reference heart rate.
[0029] The measurement selection means may increase the measuring reliability rating associated with one of the first measurement signal and the second measurement signal when a difference between the reference heart rate and at least one of the first patient heart rate measurement and the second patient heart rate measurement is less than a difference between the reference heart rate and another one of the first patient heart measurement and the second patient heart rate measurement.
[0030] The measurement selection means may select the at least one of the first measurement signal and the second measurement signal based on a comparison of the measuring reliability rating associated with the first measurement signal with the measuring reliability rating associated with the second measurement signal. The measuring reliability rating associated with the one of the first measurement signal and the second measurement signal may be greater than the measuring reliability rating associated with the another one of the first measurement signal and the second measurement signal. The at least one selected measurement signal may correspond to the one of the first measurement signal and the second measurement signal with the greater measuring reliability rating.
[0031] The measurement selection means may select the at least one of the first measurement signal and the second measurement signal based on a comparison of the measuring reliability rating associated with the first measurement signal with the measuring reliability rating associated the second measurement signal. The at least one selected measurement signal may comprise an average of the first patient blood oxygen saturation measurement and the second patient blood oxygen saturation measurement.
[0032] The device may comprise an oxygen saturation bedside monitor that provides the second patient blood oxygen saturation measurement as output. The second patient blood oxygen saturation measurement signal may be transferred to the second oxygen saturation monitor via a network.
[0033] According to the present invention, a process is provided for controlling a respirator. The process comprises providing a first measuring device. The first measuring device provides a first measurement signal as output. The first measurement signal comprises a first patient oxygen saturation measurement. A first oxygen saturation monitor is provided and the first oxygen saturation monitor receives the first measurement signal. A second measuring device is provided. The second measuring device provides a second measurement signal as output. The second measurement signal comprises a second patient oxygen saturation measurement. A second oxygen saturation monitor receives the second measurement signal. The first patient oxygen saturation measurement and the second patient oxygen saturation measurement are compared with a predetermined saturation threshold. At least one measuring reliability rating criteria is provided. The at least one measuring reliability rating criteria comprises at least a comparison of the first patient oxygen saturation measurement with the second patient oxygen saturation measurement. At least one of the first measurement signal and the second measurement signal is selected based on the at least one measuring reliability rating criteria when the first patient oxygen saturation measurement and the second patient oxygen saturation measurement are greater than or equal to the predetermined saturation threshold to define at least one selected measurement signal. An oxygen concentration delivered to the patient is controlled based on the selected one of the first measurement signal and the second measurement signal. The selected one of the first measurement signal and the second measurement signal comprises one of the first patient oxygen saturation measurement, the second patient oxygen saturation measurement and an average of the first patient oxygen saturation measurement and the second patient oxygen saturation measurement.
[0034] 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 preferred embodiments of the invention are illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] In the drawings:
[0036] FIG. 1 is schematic view of a closed control loop;
[0037] FIG. 2 is a diagram of the steps taken to determine which measurement from one or more of the SPO 2 monitors should be used to control the concentration of oxygen supplied to a patient;
[0038] FIG. 3 is a view showing an algorithm used to determine which measurement from one or more of the SPO 2 monitors should be used to control the concentration of oxygen supplied to a patient; and
[0039] FIG. 4 is a schematic view of another embodiment of the closed control loop.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0040] Referring to the drawings in particular, FIG. 1 is a schematic view of a closed control loop with a first oxygen saturation-measuring means 25 , a second oxygen saturation-measuring means 27 , a patient 4 , an ECG unit 28 , a decision unit 170 , a pneumatic patient connection to the respirator and time function elements formed by models.
[0041] The closed control loop 70 comprises a controller element 101 , a controlled system 102 , a time modeling component 122 and measuring components 25 , 27 , 28 . Furthermore, a first summation point 104 and a first branching point 106 are arranged in series with controller 40 . The control loop 70 is preferably designed as a part of the control and regulating unit 7 , and controller 40 is designed in the digital form in another preferred manner.
[0042] An input data set 55 transmitted by an input unit with a set point 37 of the oxygen saturation is sent as a command variable to the controller 40 via the control and regulating unit 7 . Device parameters of the respirator, of a gas path 6 and of the humidifier 23 are made available by the control and regulating unit 7 by means of a data connection 116 . In addition, measured parameters of the measuring arrangement comprising the SPO 2 monitor 25 and SPO 2 monitor 27 are made available to decision unit 170 . The humidifying unit 23 is in connection with the control unit 7 via the data connection 116 . A state of the liquid feed to the humidifying unit 23 or of a filling level of the liquid reservoir of the humidifying unit 23 can be transmitted to the control unit 7 via the data connection 116 . Control unit 7 can thereupon correspondingly adjust the device parameters and make them available to the modeling component 122 by means of the data connection 115 .
[0043] The controlled system 102 comprises a patient 4 , the humidifying unit 23 , a gas-metering unit 9 , a gas-mixing unit 8 , an inspiration valve 2 , a breathing tube system as the gas path 6 and a Y-piece 22 for connecting the breathing tube system 6 to the patient 4 .
[0044] The first SPO 2 monitor 25 provides a first SPO 2 measurement 103 a as output. The second SPO 2 monitor 27 provides a second SPO 2 measurement 103 b as output. The first SPO 2 monitor 25 may detect the first SPO 2 measurement 103 a via an SPO 2 sensor 24 at one location, such as the finger 44 of patient 4 , with a sensor line 26 . The second SPO 2 27 may detect the second SPO 2 measurement 103 b via an SPO 2 sensor at another location of the patient 4 . Alternatively, a signal comprising the SPO 2 measurement may be also be transferred to at least one of the SPO 2 monitors from a bedside monitor 180 via a network 182 , which may be wirelessly connected to at least one of the SPO 2 monitors as shown in FIG. 4 . A reference patient heart rate 103 c is provided as output by ECG unit 27 . The first SPO 2 measurement 103 a , the second SPO 2 measurement 103 b and the patient heart rate 103 c are provided as input to the decision unit 170 . The decision unit 170 determines whether the first SPO 2 measurement 103 a , the second SPO 2 measurement 103 b or an average of the first SPO 2 measurement 103 a and the second SPO 2 measurement 103 b should be provided as an output signal based on criterion disclosed in the diagram or flow chart as shown in FIG. 2 . The output signal of the decision unit 170 is sent as a controlled variable as a set of measured values of the oxygen saturation 34 to the controller input 41 of controller 40 in the controller element 101 . Controller element 101 comprises a controller 40 , a controller input 41 , which is designed to form a difference value of the oxygen saturation 36 from the set point 37 and actual oxygen saturation value 34 , and the controller output 43 , which receives the difference value 36 and at which the response of the controller 40 is present corresponding to the control characteristic. One or more values of oxygen saturation 34 are also provided as input to the modeling component 122 via the decision unit 170 . The modeling component 122 includes a time lag element 19 . The time lag element 19 includes a first-order time function element 191 and a dead time component 192 . The controller output signal 43 and feedback signal 108 of the modeling component 122 are sent to the first summation point 104 . The feedback signal 108 of the modeling component 122 is likewise sent to the first summation point 104 . A first branching point 106 from which the summation signal 110 is sent to the gas-metering unit 9 , on the one hand, and additionally to the modeling component 122 as an input variable, is arranged in series with the first summation point 104 . The set value of the oxygen concentration 30 is corrected in the gas-metering unit 9 on the basis of the summation signal 110 .
[0045] FIG. 2 shows a flow chart of the steps taken by the decision unit 170 to determine the reliability rating of one or more measurements 103 a associated with the first SPO 2 monitor 25 and the reliability rating of one or more measurements 103 b associated with the second SPO 2 monitor 27 . The decision unit 170 is initiated in step 200 . The reliability ratings are set to zero in step 202 . The decision unit 170 acquires at least one oxygen saturation measurement associated with the first SPO 2 monitor 25 and at least one oxygen saturation measurement associated with the second SPO 2 monitor 27 in step 204 . The decision unit 170 determines whether the at least one oxygen saturation measurement associated with the first SPO 2 monitor 25 and the at least one oxygen saturation measurement associated with the second SPO 2 monitor 27 are greater than or equal to an oxygen concentration of 80%. If the oxygen saturation measurement associated with the first SPO 2 monitor 25 and the oxygen saturation measurement associated with the second SPO 2 monitor 27 are not greater than or equal to 80%, an alarm 208 is generated. The alarm 208 is of a therapeutical nature and alerts medical staff as to a dangerous level of patient oxygen saturation.
[0046] The decision unit 170 compares the oxygen saturation measurement associated with the first SPO 2 monitor 25 with the oxygen saturation measurement associated with the second SPO 2 monitor 27 . The SPO 2 monitor with the greater oxygen saturation measurement is determined by the decision unit 170 to correspond to a more reliable measurement reading. If the oxygen saturation measurement associated with the first SPO 2 monitor 25 and the oxygen saturation measurement associated with the second SPO 2 monitor 27 are greater than or equal to 80%, the oxygen saturation measurement associated with the first SPO 2 monitor 25 is compared with the oxygen saturation measurement associated with the second SPO 2 monitor 27 to determine which of the oxygen saturation measurements is greater in step 210 . If the oxygen saturation measurement associated with the first SPO 2 monitor 25 is greater than the oxygen saturation measurement associated with the SPO 2 monitor 27 , the measuring reliability rating associated with the oxygen saturation measurement associated with the first SPO 2 monitor 25 is increased in step 212 . If the oxygen saturation measurement associated with the first SPO 2 monitor 25 is not greater than the oxygen saturation measurement associated with the second SPO 2 monitor 27 , the decision unit 170 checks to determine if the oxygen saturation measurement associated with the second SPO 2 monitor 27 is greater than the oxygen saturation measurement associated with the first SPO 2 monitor 25 in step 214 . The measuring reliability rating associated with the oxygen saturation measurement associated with the second SPO 2 monitor 27 is increased in step 216 if the oxygen saturation measurement associated with the second SPO 2 monitor 27 is greater than the oxygen saturation measurement associated with the first SPO 2 monitor 25 .
[0047] After comparing the oxygen saturation measurements to determine which oxygen saturation measurement is greater and providing the higher reliability rating to the greater of the two oxygen saturation measurements or determining that one SPO 2 measurement is not greater than the other SPO 2 measurement, the decision unit 170 compares the pulse rate or heart rate associated with each SPO 2 monitor with a reference heart rate or pulse rate, which is measured by ECG unit 28 , in step 218 . If the heart rate or pulse rate measurement associated with the first SPO 2 monitor 25 is closer to the reference heart rate or pulse rate measurement than the heart rate or pulse rate measurement associated with the second SPO 2 monitor 27 , then reliability rating associated with the at least one measurement associated with the first SPO 2 monitor 25 is increased in step 220 . If the heart rate or pulse rate measurement associated with the first SPO 2 monitor 25 is not in agreement with the reference heart rate or pulse rate or closer to the reference heart rate or pulse rate measurement in step 218 than the heart rate or pulse rate associated with the second SPO 2 monitor, the decision unit 170 determines whether the heart rate or pulse rate measurement associated with the second SPO 2 monitor 27 is closer or more in agreement with the reference heart rate or pulse rate measurement than the heart rate or pulse rate measurement associated with the first SPO 2 monitor 25 in step 222 . If the heart rate or pulse rate measurement of the second SPO 2 monitor 27 is closer or more in agreement with the reference heart rate or pulse rate measurement than the heart rate or pulse rate measurement associated with the first SPO 2 monitor 25 , the measuring reliability rating associated with the at least one measurement associated with the second SPO 2 monitor 27 is increased in step 224 .
[0048] The decision unit 170 determines whether one or more of the at least one measurement associated with the first SPO 2 monitor 25 and the at least one measurement associated with the second SPO 2 monitor 27 should be selected based on one or more of the reliability ratings determined in steps 212 , 216 , 220 and 224 . Steps 212 and 216 determine that the higher oxygen saturation measurement is the more reliable measurement and steps 220 and 224 qualify the SPO 2 sensor providing a heart rate or pulse rate as output that is closer to the reference heart rate or pulse as the more reliable SPO 2 sensor. If one SPO 2 monitor and the measurements provided as output from the respective SPO 2 monitor receive more votings or weight based on the ratings 212 , 216 , 220 and 224 , the sensor signal associated with the SPO 2 monitor with the most votings or weight is used as a controlled variable that is provided as input to the controller input 41 of the controller element 101 and to the time modeling component 122 . Examples of an SPO 2 monitor receiving a greater amount of reliability ratings than another SPO 2 monitor occurs when an oxygen saturation measurement associated with a first SPO 2 is greater than the oxygen saturation measurement associated with a second SPO 2 monitor and a heart rate or pulse rate associated with the first SPO 2 monitor is closer to the reference heart rate or pulse rate than the pulse rate or heart rate associated with the second SPO 2 monitor. If both sensors have the same amount of reliability ratings, an average of the at least one oxygen saturation measurement associated with the first SPO 2 monitor 25 and the second SPO 2 monitor 27 is used as a controlled variable as input to the controller input 41 of the controller element 101 and to the time modeling component 122 . An example in which the amount of the reliability ratings of each SPO 2 monitor are the same is in a case in which the oxygen saturation measurement associated with each SPO 2 monitor is not greater than the other and the pulse rate or heart rate associated with each SPO 2 monitor is equally close to the reference pulse rate or heart rate. Another example of when the average of the at least one oxygen saturation measurement associated with the first SPO 2 monitor 25 and the second SPO 2 monitor 27 would be used is in a case in which the saturation oxygen measurement associated with one of the SPO 2 monitors is greater than the saturation oxygen measurement associated with the other one of the SPO 2 monitors and the heart rate or pulse rate associated with the other one of the SPO 2 monitors is closer to the reference heart rate or pulse rate than the heart rate or pulse rate associated with the one of the SPO 2 monitors.
[0049] The decision unit 170 determines in step 226 whether the reliability rating associated with the first SPO 2 monitor 25 is greater than the reliability rating associated with the second SPO 2 monitor 27 . The at least one measurement associated with the first SPO 2 monitor 25 is selected in step 228 if the reliability rating associated with the first SPO 2 monitor 25 is greater than the reliability rating associated with the second SPO 2 monitor 27 such that the at least one measurement associated with the first SPO 2 monitor 25 is sent as a controlled variable to the controller input 41 of controller 40 in the controller element 101 and to the time modeling component 122 .
[0050] If the reliability rating associated with the first SPO 2 monitor 25 is not greater than the reliability rating associated with the second SPO 2 monitor 27 in step 226 , the decision unit 170 determines whether the reliability rating associated with the second SPO 2 monitor 27 is greater than the reliability rating associated with the first SPO 2 monitor 25 in step 230 . The at least one measurement associated with the second SPO 2 monitor 27 is selected in step 232 if the reliability rating associated with the second SPO 2 monitor 27 is greater than the reliability rating associated with the first SPO 2 monitor 25 such that the at least one oxygen saturation measurement associated with the second SPO 2 monitor 27 is sent as a controlled variable to the controller input 41 of controller 40 in the controller element 101 and to the time modeling component 122 .
[0051] An average of the at least one measurement associated with the first SPO 2 monitor 25 and the at least one measurement associated with the second SPO 2 monitor 27 is selected in step 234 if the reliability rating associated with the first SPO 2 monitor 25 is comparable or substantially equal to the reliability rating associated with the second SPO 2 monitor 27 . The average of the at least one measurement associated with the first SPO 2 monitor 25 and the at least one measurement associated with the second SPO 2 monitor 27 is sent as a controlled variable to the controller input 41 of controller 40 in the controller element 101 and to the time modeling component 122 . The measurements associated with the first SPO 2 monitor 25 and the second SPO 2 monitor 27 are continuously compared to each other and each respective pulse rate or heart rate associated with one of the SPO 2 monitors 25 , 27 is continuously compared to the reference heart rate or pulse rate to determine which of the oxygen saturation measurements are more reliable. In one embodiment, the decision about which SPO 2 sensor is more reliable may be done in a specific period of time, such as every second.
[0052] FIG. 3 is a view showing an algorithm used to determine which oxygen saturation measurement from one or more of the SPO 2 monitors should be used to control the concentration of oxygen supplied to a patient. The algorithm shows the steps taken when the oxygen saturation measurement associated with the first SPO 2 monitor and the oxygen saturation measurement associated with the second SPO 2 monitor are greater than or equal to 80%, which are essentially the same as the steps shown in FIG. 2 .
[0053] FIG. 4 is a schematic view of another embodiment of the closed control loop. The closed control loop is identical to the closed control loop shown in FIG. 1 , except that one or more of the signals comprising the SPO 2 measurement is transferred to one or more of the SPO 2 monitors from a bedside monitor 180 via a network 182 . The network 182 may be wirelessly connected to one or more of the SPO 2 monitors.
[0054] 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 process and a device for oxygen regulation of a patient having at least two SPO 2 monitors and a control for automatic recognition of which measurements are more reliable. The measurement from one or more of the two SPO 2 is used to control the oxygen concentration delivered to a patient based on a comparison of the measurements from the at least two SPO 2 monitors.
| 0
|
This application is a continuation, of application Ser. No. 386,316, filed June 8, 1982, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to an extractor designed to increase and regulate natural ventilation in industrial and/or agricultural buildings, such as industrial machining sheds, livestock-breeding farms, greenhouses and the like.
It is known that such buildings produce heat and harmful gases or fumes which must be continuously eliminated by means of a suitable air changing system. For obvious economic reasons, this problem is normally solved using ventilation systems with natural air circulation, which are simply called "static extractors". Only in particularly difficult cases, or in the presence of poison gases, use is made of ventilation systems with forced air circulation, equipped with appropriate ventilating fans. It should however be remembered that such fans--even apart from the costs--always cause localized air draughts which are harmful in some cases (for instance, in greenhouses), and for the health of the environment.
The aforespecified static extractors are usually installed at the top of a building (either on the summit of the roof or on the highest part of the side walls) for sucking stale air from the same. The intake of fresh air is instead guaranteed by a number of flap doors, or other similar openings, installed in the lower part of the building.
These extractors must simultaneously satisfy two fundamental and contrasting requirements, that is, on one hand they must prevent external atmospheric agents from propagating inside the building and, on the other hand, they must guarantee the outlet of the air stream which is extreme even and the flow of which varies according to requirements.
For what concerns the first problem, while it is relatively simple to prevent the inlet of water and snow, it is instead very difficult to prevent the access of wind, unless greatly reducing the free outlet sections of the extractor, thereby reducing the flow of outgoing air. On the other hand, it is particularly important to prevent the incoming wind from causing a reversal of the flow of outgoing air, and a consequent inlet of cold air from the top of the building, rather than from the openings provided for this purpose in the lower part of the building itself. In fact--particularly in the winter season, when the flow of outgoing air is reduced to a minimum (as will be better explained hereinafter)--the cold air eventually coming in from the top draws along with it the masses of stale rising air, recycling them with no possibility of control and hampering the regular change thereof. Furthermore, it causes undesired air draughts and an uncontrollable increase of the amount of heat required for keeping the environment in the desired conditions of temperature.
For what concerns the second problem, namely the control of the flow of fresh air coming out of the extractor, it should be noted first of all that it must be possible to vary said flow between a minimum value, typical of the winter season, and a maximum value which is instead typical of the summer season.
The minimum winter value is determined by the requirement to remove the least possible amount of heat in order to maintain a high difference between the indoor and outdoor temperature, while guaranteeing the dilution of the polluting gases circulating in the air and, at the same time, ensuring healthy environmental conditions. The maximum summer value is instead determined by the need to remove as much as possible of the heat produced within the building, in order to ensure the smallest difference between indoor and outdoor temperature (for instance, 4° or 5° C.).
It should at once be noted that the ratio between maximum and minimum flow is quite considerable and it can reach values of fifty or more.
Different types of static extractors have been proposed up to date, which have given preference to the solution of either of the aforementioned problems, while only one extractor has been proposed, apt to successfully overcome both problems, but the spreading of which has been impeded by the exceedingly high cost thereof. We shall now briefly examine the main static extractors of known type.
Perhaps the most widely known and spread static extractor now on the market is the "Robertson" extractor. This is characterized by a metal device generally mounted on the summit of the roof, having an elliptical cross section, open on top, and being provided inside with an overturned V-shaped bent tile surface apt to prevent the inlet of inclement atmosheric agents and to discharge them sideways. This extractor, though being fairly economic, presents however a number of drawbacks, such as the following:
having fairly large free outflow surfaces for the stale air, it is extremely easy for cold air to enter from the leeward side and, furthermore, under particularly severe conditions, even with protection against weather inclemencies is unsatisfactory;
in the event of abundant snowfalls, when it is out-of-work, it easily tends to clog with snow, with consequent overloads on the building;
the extraction effect is acceptable when the wind blows perpendicularly to the axis of the extractor, whereas, when the wind blows along said axis, its efficiency drops to very low levels;
its dimensions are very large, both in width and in height, as compared to the width of the roof opening it fits onto, whereby the weight of the extractor and the mechanical action thereon of the wind are such as to require--in most applications--that the roofing structure be specially reinforced, which notably reduces the economical advantages of this device.
The original "Robertson" extractor has been the object of several modifications and improvements, which have given rise to a number of improved extractors, among which we can recall the extractors object of the U.S. Pat. Nos. 3,107,598 and 3,182,580 and of the German Pat. No. 2,156,189. In these extractors, an attempt has been made to eliminate the drawbacks present in the "Robertson" extractor, particularly for what concerns the inlet of wind in the extractor itself. This result has been achieved, both by dividing the free outflow section into several sub-sections and by providing closing means which should operate in the winter season. The partial results obtained with these extractors are however not compensated by the weight and bulk, still very high, as well as by the further complexity deriving from the provision of the new devices. Moreover, the operation of the closing means in reply to unforeseeable events, such as are determined by atmospheric agents (particularly wind), can only be done manually, with all the inconveniences deriving therefrom, both from the economical point of view and from the point of view of the results obtained.
The British Pat. No. 678,032 describes an extractor which has excellent characteristics for what concerns the impenetrability to atmospheric agents, particularly wind. This is obtained, however, thanks to a particularly tortuous and narrow path of the flow of outgoing air, whereby this apparatus is fit only for applications which require a scare flow of extraction air, or it has to be used in combination with motor driven ventilators.
Another type of extractor is described in the Swiss Pat. No. 371,879. In this case, the device has a fairly light and simple structure and its free sections are wide enough to allow even high outflow rates of the stale air. Nonetheless, the devices provided therein for preventing the inlet of rain are scarcely efficient and, furthermore, the access to winds blowing crosswise is prevented only closing all the openings, thereby renouncing to the extracting action.
It can finally be said that the heretofore considered extractors, though varying in their achievements which involve different structural problems and hence different costs, still have in common the following drawbacks:
they can be mounted only on the roof of the building to be ventilated, and not on the side walls thereof;
they are not apt to prevent the inlet of winds blowing crosswise, unless by closing the openings for the passage of the flow of outgoing air, thereby annulling the extracting action;
they are so formed as to pile up snow inside in case of abundant snowfalls. This drawback is particularly felt in the northern regions and it occurs when the plants are out-of-work, failing the heat produced inside the building.
As already mentioned, there is also a type of static extractor which has successfully solved the aforespecified problems. This extractor is commonly known as the "Mueller" or "Modified Mueller" extractor and it consists of a double layer of suitably shaped and spaced blades, as described in the Italian Pat. No. 883,144.
This last type of extractor has the characteristic of preventing the inlet of wind, no matter what direction it blows from, while it takes advantage of the depression caused by the wind--to a further extent in the leeward side of the building--in order to accomplish a particularly efficient extraction.
However, since this extractor (as, obviously, also all the previous ones) must clearly be dimensioned according to the maximum summer flow (the flow reduction in the winter season is in fact obtained by gradually closing the flap doors provided in the lower part of the building), and it is furthermore provided with a relatively low specific outflow surface, of relatively high unitary cost, it involves installation costs which are too heavy to allow its proper spreading on the market.
The object of the present invention is to overcome the aforespecified drawbacks by providing a device which--with a structure involving very limited costs and having characteristics of size and weight such as to present no problems of stability during installation--allows to adjustably increase the air flow during the summer season, as related to the minimal flow required in the winter season, while preventing the inlet of cold air in any weather conditions.
SUMMARY OF THE INVENTION
The invention thus relates to an extractor designed to increase and regulate natural ventilation in industrial buildings, of the type installed on the outside of openings provided in the roof or walls of such buildings, and being characterized in that it comprises, in combination: at least one controlled flow section and at least one free flow section, for the passage of stale air; blade means arranged within a line enveloping the extractor, ending onto said line and being positioned in the same quadrant thereof, in order to divide said free flow section into a plurality of smaller subsections; and means for closing and/or regulating the flow passing through the free flow section.
According to a main characteristic of the present invention, the controlled flow section is constituted by a "Mueller" or "Modified Mueller" extractor.
According to further characteristics of the invention, said dividing means consist of rectangular blades of fiberglass-reinforced plastic, and said closing and/or regulating means consist of the same blades pivoting on their own axis, or of flap doors pivoting on the edge of said openings and forming a rabbet against the ends of said free flow section.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will anyhow be described in detail, hereinafter, with reference to the accompanying drawings which illustrate some non-limiting embodiments thereof, and in which:
FIG. 1 is a schematic axonometric view of a portion of the extractor according to the present invention;
FIG. 2 is a schematic cross-section view of the same extractor;
FIG. 3 is a schematic cross-section view of an extractor of the "Robertson" type;
FIG. 4 is the same view of FIG. 2, showing the direction of the fluid stream of a wind blowing crosswise and hitting the extractor;
FIG. 5 is the same view of FIG. 3, showing the direction of the fluid stream of a wind blowing crosswise and hitting the extractor;
FIGS. 6, 7 and 8 are schematic section views of different embodiments of the extractor according to the present invention, installed on a roof, wherein the controlled flow section is constituted by an extractor of the "Mueller" type;
FIG. 9 is a schematic section view of the extractor according to the present invention, applied on a wall, wherein the controlled flow section is constituted by an extractor of the "Mueller" type;
FIGS. 10 and 11 are two graphs illustrating the operation of the extractor in two practical applications;
FIG. 12 is an edge view of a typical Mueller extractor;
FIG. 13 is a lateral view of the extractor of FIG. 12;
FIG. 14 is an edge view of another embodiment of a Mueller extractor; and
FIG. 15 is a planar view of the extractor of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIG. 1, the extractor according to the present invention is installed on the outside of an opening 1 provided on a roof 2, and it consists of two free flow sections 3 and of three controlled flow sections 4 and 4'. The area of the free flow sections 3, added to the product of the area of the controlled flow sections multiplied by the relative specific surface over which the air flows, is approximately equal to the area of the opening 1. Said controlled flow sections can be divided into:
no-flow sections, in which case they merely act as support and/or covering and are constituted by solid panelings (for instance, the sections 4');
positive flow sections, preferably constituted by static extractors of the "Mueller" type (for instance, section 4).
The free flow sections 3 are in turn divided into sub-sections 6 by a set of parallel rectangular blades 5, positioned longitudinally. These blades are arranged in such a way as to be included into a line enveloping the whole extractor, while ending onto said line, and they are positioned at an angle of between 45° and 80° in respect of the horizontal line. The blades 5 are fixed one to the other and to the sections 4 by any suitable means (not shown). It should be noted that sections 4' only rest to a slight extent with their lower edge onto the roof 2, to allow the drainage of rainwater which, through the sub-sections 6, falls onto that part of the roof 2' situated inside the extractor (see FIG. 2).
The air flow through the free flow sections 3 can be interrupted, in an adjustable way, by a pair of tilting flaps 7, pivoted onto the edge 8 of the roof portion 2' extending inside the extractor. The flaps 7 are dimensioned so as to form a rabbet against the ends of the controlled flow section 4.
Alternatively, the air flow through the free flow sections 3 may be regulated and/or interrupted by the same blades 5, pivoting on their own axis and caused to rotate, for example, simultaneously by interconnecting rod 5a.
FIGS. 2 and 3 compare the dimensions of a "Robertson" extractor with those of an extractor according to the present invention, showing the same width of the opening provided on the roof of the building to be ventilated (it should be here mentioned that the size of the opening must be in proportion to the maximum air flow required).
As clearly shown in said figures, for an opening of size "L", the "Robertson" extractor has a width of about 2.2 L and a height of about 1.3 L, while the extractor according to the present invention--while being slightly narrower than the "Robertson" extractor (2 L)--has a height ranging between L/2 and L/3, thus considerably lower. This makes the extractor according to the invention far superior to other known extractors, as to mechanical stability under the action of wind, and it allows, on one hand, to avoid costly operations of static reinforcement of the roof and, on the other hand, to make the whole device of plastic material, for instance fiberglass-reinforced plastic, with further reduction of costs and with great advantages as to the weight of the device and the easy mounting thereof.
FIGS. 4 and 5 show, respectively, the direction followed by the fluid stream over the extractor according to the invention and over a "Robertson" extractor. It can easily be seen that in the "Robertson" extractor, owing to the larger size of the openings, the wind is likely to penetrate in the leeward side, as largely demonstrated in practical applications where snowflakes were found to have actually enteres the building.
Whereas, in the extractor according to the present invention, the position of the blades 5--included into the line enveloping the whole extractor and variably inclined in respect of said line but positioned in the same quadrant thereof (the quadrant being formed by a horizontal line and by a vertical line)--favours the regular reforming of the fluid stream; furthermore, the possible turbulence caused by the limited dimensions of the sub-sections 6, occurs at the mouth of said sub-sections in the form of micro-whirls, which in turn determine an air pressure drop, such as to prevent almost entirely the inlet of wind. The extraction effect, as in the "Robertson" extractor, evidently takes place on the windward side, where a Venturi-effect depression is created.
FIGS. 6, 7, 8 and 9 show different embodiments of the extractor according to the present invention, wherein some of the controlled flow sections and/or part of the roofings or walls (FIG. 9) comprise "Mueller" extractors. These sectiona are marked in the figures with the letter "M".
Referring to FIGS. 12-15, a typical Mueller static extractor includes a plurality of slats L1 reciprocally set side by side at appropriate intervals and behind which a second series of slats L2 is disposed in which every individual element remains set in a position corresponding to the opening of slot A which exists between the contiguous slots L1.
In a first form of realization (FIGS. 12 and 13), the slats L1, L2 have a transversal section with an undulated profile having on the outside E of these slats a median convexity C.
The lateral extremities 11 contiguous to the adjacent slat L1 converge, among themselves, toward the outside thus creating the opening or slots A, with a transversal section substantially like an exhaust.
Of course, the interval between the adjacent slats L2 can also be like an exhaust, the extremities 12 of these slats L2 are bent toward the outside at a predetermined angle.
The slats L2 are supported by means of the bolts 13, from two braces 14 preferably L shaped, in the same manner the bolts 13 support two splines 15 on which the slats L1 are mounted in the appropriate manner by means of the bolts 16.
Filling bodies B, preferably semiround, prevent the deformation of the slats L1, L2 mounted in this manner.
In a second realization (FIG. 14), the slats L1, L2 have on their outside edge E1 a substantial concavity connected in the middle by a ridge 17.
The lateral extremities 18 contiguous to the adjacent slats L1 converge between themselves toward the outside, thus determining the appropriate configuration in exhaust of the opening A.
A framing element T supports the slats L1, L2.
The slats L1, L2, in couples, with the proper supporting elements, are examples of the aforementioned realizations, one or more panels P (FIG. 15) can constitute the Mueller static extractor.
In addition, the slats L1, L2 are made up, at least in part, of transparent and anti-corrosive material, preferably of suitable plastic material or of glass.
In all such embodiments, the surface covered by the "Mueller" extractor is related in size to a flow value ranging between the minimum (winter) value and a value twice to three times higher, while the flow required during the summer season (i.e. up to 50 or more times higher than the minimum flow value) is obtained through the free flow sections 3 of the extractor according to the invention, placed gradually in communication with the opening 1 thanks to the already seen adjustment means.
It is quite evident that the heretofore described and illustrated extractor ensures great economy of use, without reducing the quality of the ventilation. In fact, during the winter season when the difference in density between the outgoing hot air masses and the outdoor cold air masses is greatest, whereby the danger of any cold air draughts entering the building is higher owing to the strong disturbance which they create in the air circulation, the free flow sections 3 are completely cut off from the opening 1 via the flaps 7 or, alternatively, they are closed off by the blades 5, rotated up to overlapping. Thus only the "Mueller" extractor remains in operation, with its excellent heretofore specified characteristics.
As the outside temperature gradually increases and the need for a greater flow of fresh air thus grows, the flaps 7 will be gradually opened or, alternatively, the blades 5 rotated, giving rise to an additional flow through the free flow sections 3. It is worth while noting that, during the summer season, any reversals of the air flow or any cold air which may return from the freeflow sections 3, are far less dangerous due to the far smaller difference in density between hot and cold air and, moreover, due to the fact that any cold air draughts entering through the free flow sections 3, would be immediately re-expelled by the powerful flow going out from the adjacent section constituted by the "Mueller" extractor.
This means that in every season it is possible to keep the environment in the desired physical conditions, and the level of the polluting gases can be perfectly controlled, thanks to the fact that the system prevents them from being recycled.
It should finally be noted that, since the "Mueller" extractor can be made of materials which are at least partly transparent to light, the extractor according to the present invention can also act as skylight.
The last two figures of the drawings show two graphs relating to the fresh air flow (ordinates) in function of the outside temperature (abscisses). The abscisses also include the corresponding indoor temperature values (Ti) and the surface areas of the extractors used (Sex). The temperatures are in °C., the surface areas in m 2 and the flow rates in m 3 /h 10 -3 . The two cases refer to two typical applications, a livestock-breeding farm (FIG. 10) and a greenhouse (FIG. 11).
As can be seen from the graphs, only the "Mueller" extractors are used up to an outside temperature of approximately 10°-12° C. (X point); then, starting from this temperature value, the free flow sections 3 are gradually set to work. The maximum flow for which the "Mueller" extractors have to be dimensioned is, in this case, only twice or three times the minimum (winter) flow, instead of being up to 50 or more times greater, as would have been required using the previous technique.
It is understood that the invention should not be limited to the various heretofore described embodiments, but that its scope should extend to any variants or modifications thereof, within reach of the technicians skilled in the art.
|
An extractor to be used in the natural ventilation of industrial buildings, for increasing the air flow during the summer season. The extractor, installed on the outside of openings provided in the roof or walls of the buildings to be ventilated, essentially comprises at least one free flow section associated to at least one controlled flow section, such as a "Mueller" static extractor, and provides means for subdividing said free flow section, consisting of rotary blades, and adjustment means interposing between the free flow section and the openings.
| 4
|
BACKGROUND OF THE INVENTION
This invention relates to systems for storing large quantities of data in digital audio tape (DAT) or other format, and more particularly to such systems utilizing an automatic loader mechanism.
Magnetic tape storage devices are widely used for the storage of large amounts of digital data, because they provide an economical and reliable means for temporary and permanent storage. Because magnetic tape systems inherently rely on serial recording, access times are substantially longer than other modern storage devices, but at the same time the danger of catastrophic failure is virtually absent. Thus it has become common practice to utilize tape systems as data backup for floppy disk and hard disk files, typically by reading out the entire contents of a random access memory system at the end of the day or other operating period, and retaining this data in storage until the next backup date or time. Where the volume of data is limited, one tape system and tape reel or cartridge may suffice, but where the data base is much larger, many reels or cartridges may be needed. To utilize a backup system efficiently, it is preferred to record the backup data at a high data transfer rate during what would normally be down time for the system, e.g. the time between the close of business one evening and the start of business the next morning.
Tape drive systems have evolved over the recent past with technical improvements that have resulted in substantial increases in capacity accompanied by significant decreases in size. Large self-contained tape transports using parallel track recording techniques and relatively wide tape have been used, but these are incompatible in size, cost and power requirements with the compact and highly efficient central processor units and disk drives that are now employed. Threading of tape in reel-to-reel devices has always been a cumbersome task, so that efficient tape cassette and cartridge systems have been generated, using longitudinal scan recording techniques. By improvements in recording techniques and efficient cartridge configurations, these tape drives have been made in geometries and with sizes suitable for utilization with a standard peripheral equipment slot in a console, such as the full height slot for receiving a 51/4" floppy disk drive.
More recently, helical scan recording techniques originally devised for video recording have been adapted in compact systems to provide high density, high fidelity, digital audio tape recordings. The DAT format has in turn been adapted, under the so-called Sony/Hewlett-Packard standard, to digital data processing applications. The cassette (sometimes also called a cartridge) used for these applications is very small, the standard 4 mm digital audio cassette being 0.39" (10 mm) in height by 2.1" (54 mm) in depth, with a nominal tape width of 0.15" (3.81 mm). The recording technique used is group code encoding with error correcting codes, to the "DDS" specification X3B5/88-185A. "DDS" is a trademark of Hewlett-Packard/Sony. Using helical scan technology and 61K bpi linear density, each cassette has a data capacity of 1.3 Gbytes so that at a sustained transfer rate of 183 Kbytes/sec (burst transfer rate of 4.0 Mbytes/sec.) there is a capacity for receiving 2.2 hours of data, equivalent to the contents of two large 650 Mbyte disk drives. Large commercial organizations, however, may have many such drives, in a data base system. Consequently large main frame and parallel processors need to use many backup cassettes, even in the DAT format. It is preferable to utilize a single drive to prepare a number of tape records in sequence, rather than to employ a number of drives in parallel. This is not only more costly but less efficient. Thus stacker-type loaders have been considered that fit on the front of the console in which the tape drive is mounted, as add-on units, to provide a handler for the cassettes. This approach is unsatisfactory for aesthetic, safety and technical reasons, and is often unusable simply because of the location of the tape drive unit, since there is usually inadequate clearance available relative to other parts of the computer console.
SUMMARY OF THE INVENTION
A cassette loading system for tape drives comprises a tape drive unit having a flat broad surface on one side, typically the upper or lower side, and a cassette storage and circulating advance mechanism adjacent the flat broad side, together with a transporter for shifting cassettes between entry and exit level openings in the cassette storage mechanism and a loading door of the tape drive unit. The arrangement is preferably utilized with a tape storage system using cassettes and recording and reproducing in the DAT format, such as a streaming tape drive for backup of random access memories.
In a preferred example, the, space in a standard height enclosure, such as used for a 51/4" storage device, is occupied by a DAT drive unit of less than full height, and an adjacent magazine assembly in the space within the enclosure, to fully utilize the available form factor. The magazine assembly includes both a removable cassette tray and internal adjacent mechanisms which move the cassettes within the tray. The tray is a two level structure which comprises an exit level guideway superimposed above an entry level guideway, both disposed parallel to the front to rear axis of the tape drive. At the front of the unit, a vertical transporter, which includes means for shifting a single cassette laterally in the front-rear direction, is positioned to transfer cassettes received from the tape drive to the entry level of the magazine assembly, and to supply cassettes received from the exit level of the magazine assembly to the loading door of the tape drive. With this arrangement, a completely self-contained unit can be mounted within a standardized form factor of enclosure in a processor console, to enable many hours of high density storage in the DAT format. Furthermore, cassette trays can be inserted into and removed from the magazine assembly as desired. On a practical basis, this enables data transfer to take place substantially continuously with operator intervention required only slightly more than once a day to change the cassette trays.
In a more specific example of a mechanism in accordance with the invention, the vertical transporter for shifting cassettes is mounted to span from the front loading door region of the tape drive to the magazine assembly. The transporter includes a vertically movable cassette holder along with a lateral drive mechanism which can impel cassettes either into the tape drive or magazine assembly, and remove partially ejected cassettes. The magazine assembly is disposed within an enclosure and comprises a cassette holder into which a slidably removable cassette tray having a front-rear array of slidable at two levels. The cassette holder and tray include access apertures through which a rearwardly mounted lifter may shift cassettes from the a lower entry level to a higher exit level. The magazine assembly also comprises a separately actuable advancing mechanism insertable into the cartridge tray for advancing cassettes at the exit level toward the cassette holder on the transporter. The cassette holder about the tray includes a side-coupled rack engageable by an adjacent mechanism to draw the cassette tray into a fully inserted position.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the invention may be had by reference to the following description, taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a perspective view, partially broken away, of a tape drive system with automatic loader mechanism in accordance with the invention;
FIG. 2 is a perspective view, partially broken away, of a multicassette tray and cassette holder for use in the system of FIG. 1 showing cassettes in phantom;
FIG. 3 is a perspective view of a cassette tray as in FIG. 2;
FIG. 4 is a side sectional view of the system of FIG. 1;
FIG. 5 is a perspective view, partially broken away, of a vertical and lateral transporter mechanism used in the system of FIGS. 1 and 2;
FIG. 6 is a perspective fragmentary view of a cassette lifter mechanism utilized in the system of FIGS. 1 and 4;
FIG. 7 is a side fragmentary view of the lifter mechanism of FIG. 6 showing alternate positions of operation;
FIG. 8 is a perspective view, partially broken away, of a cassette advancing mechanism used in the system of FIGS. 1 and 4; and
FIG. 9 is a perspective fragmentary view of an automatic insertion mechanism for the cassette holder and cassette tray.
DETAILED DESCRIPTION OF THE INVENTION
A system in accordance with the invention is described as used in conjunction with a data processing system having a console 10, such as one which has a standard 5.25" full height enclosure 12. The standard 5.25" full height enclosure, for receiving tape drives, floppy disk drives and other peripheral equipment units, has a height of 3.25", a depth of 8" and a width of 5.75". The invention is described in conjunction with DAT drives, inasmuch as there is a particular need for an automatic loader in this environment, in order to enable very large quantities of data to be recorded without a need for operator attendance. However, the concepts of the invention are applicable, as will be apparent to those skilled in the art, in a number of other environments and applications.
A tape drive and loader housing 14 containing devices in accordance with the invention and having a front to rear axis is fitted into the standard height enclosure 12, filling the available volume and including a front extension 16 having a bezel 18. The bezel 18 includes a single cassette door 20 in an upper position and a magazine door 22 for receiving a multicassette magazine as described below. Hinging door covers and lock mechanisms may be of the usual form and are not shown for simplicity. An interlock system may be provided so that the doors cannot be opened when a cartridge is loaded and operating.
In FIGS. 1 and 4 a cassette 24 is shown at an intermediate position, not one of the operating positions, in order to show some of the operative structure more clearly. Within the housing 14, a tape drive unit 26 is disposed in the upper portion. The tape drive unit 26 is a DAT half-height unit, such as is available as the Model 1300 of WangDAT Inc. of Costa Mesa, Calif. A front door 28 on the tape drive unit 26 is in alignment with the single cassette door 20 in the bezel 18. The internal mechanism of the tape drive unit 26, which includes recording and reproducing circuits, servo drives, controller functions and cassette handling elements is not described inasmuch as these features are in the commercially available product. The principal items to note as far, as the storage and loader system is concerned, are that a partially inserted cassette 24 is thereafter drawn into operative position and, when data transfer is complete, the cassette is ejected sufficiently to be accessible to an exterior withdrawal mechanism.
The lower portion of the housing 14 is occupied by a magazine assembly 30, also of half-height relative to the standard height enclosure 12, and comprising a number of mechanisms adjacent a magazine frame 32 of rectangular form within the enclosure 12. As best seen in FIGS. 2 and 3 the magazine frame 32 is slidably movable on underlying rails (not shown) or other low friction support between limits in the front-rear direction. The magazine frame 32 includes an open front end, side cutouts 33 adjacent the rearward end, and a top slot 34 open to the rear end. A removable cassette tray 36 is insertable from the front via the magazine door 22 in the bezel 18, through the front extension 16 into the open front end of the magazine frame 32. The cassette tray 36 includes a swingable front door 38, which is open when the cassette tray 36 and magazine frame 32 are fully inserted, the open position being shown in FIG. 2 and the closed position in FIG. 3. The cassette tray 36 is divided into upper and lower internal storage areas for cassettes, by a central horizontal plate 39. In this example the cassette tray holds four cassettes in each level, this being determined by the depth of the enclosure 12. As seen in FIG. 4, the plate 39 extends rearwardly three cassette lengths from the front, and spring loaded detents 37 in the side walls hold the fourth (rearmost) cassette 24 in the upper level. A central web 35 or strip is used in the center of the bottom level, to hold the rearmost cassette while permitting lifters at the side to raise the cassette, as described below. The lower cassette level may be said to have an entry aperture 40 at the door end, while the upper level has an exit aperture 42, these levels being utilized in circulation of cassettes into and out of the cassette tray 36. The swing door 38 is operated by a slide rod 43 coupled to a pin 44 extending through a slot in the side of the holder 32. The pin 44 engages a fixed stop (not shown in detail) in the adjacent structure when the magazine frame 32 and cassette tray 36 are fully inserted, so that the door 38 is automatically opened. Further details are not shown inasmuch as a wide variety of other automatic door opening mechanisms are known in the cassette art and various ones may be used for this function.
The mechanisms for circulating cassettes within the magazine are also a part of the magazine assembly 30, but are mounted within the lower half of the standard height enclosure, external to the magazine frame 32, although they have access to the interior cassettes. These are described in greater detail hereafter.
A transporter mechanism 46, best seen in FIGS. 1 and 5, is disposed in the front extension 16 of the housing 14, so as to span the single cassette door 20 and cassette door 22. This mechanism 46 enables insertion of a single cassette directly into the tape drive 26, or alternatively a full cassette tray 36 containing multiple cassettes 24. It also transfers cassettes to and from the tape drive unit 26 and the cassette tray 36. The transporter mechanism 46 includes a pair of vertical lead screws 48, 49, one on each side of the loader housing 14, spaced so as to permit unrestricted passage of a cassette tray 36 between the lead screws 48, 49. The lead screws support and drive a transverse carriage 50 which includes a central rectangular cassette holder 52 that is in alignment with the single cassette door 20 and the front door 28 in the tape drive 26 when the holder is in the same horizontal plane as those doors. The cassette holder 52 has an open gap in its bottom region, a cassette 24 on the holder 52 thus being engageable from its underside for movement laterally in the front to rear direction. A position sensor 56 detecting the height of the cassette holder 52 on the lead screws 48, 49 provides signals to a sequencer 58, which controls this and other mechanisms in the system. The specific form of sensor used is not shown in detail, inasmuch as optical sensor elements, electromechanical sensor elements, a vertical scale, or an incremental motor with pulse counting may be used for this purpose. The sequencer 58 may be a microprocessor or a specialized control circuit for operating the various mechanisms in proper order and in various modes. A microprocessor system is preferred because stepper motors can then be incremented directly between limits of motion. Most of the movements are strictly repetitive, and only limited actions responsive to sensors are involved. The use of a microprocessor enables other functions to be added.
The transporter mechanism 46 incorporates a lateral shifter 60 for moving single cassettes into and out of the tape drive unit 26 and the cassette tray 36. The lateral shifter 60 is mounted, including its drive unit, on a bracket 62 on the cassette holder 52. A drive motor 64 for the shifter 60 is coupled via a drive pulley 66 and belt 67 to a driven pulley 68 which operates a worm gear 70 driving a toothed wheel 72. The wheel 72 controls a swing arm 74 that extends radially toward the cassette 24 on the cassette holder 52. The swing arm 74 is angularly movable in opposite senses of rotation between predetermined arcs, under control of the motor 64. An engagement pin 76 at the end of the swing arm registers against specific points on the cassette 24, to move the cassette in the frontward or rearward direction, as needed. When a cassette 24 is to be fed in the pin 76 registers against the front lower edge, and the spring arm 74 moves the cassette rearwardly for an appropriate distance. A cassette sensor system 75 detects the direction from which a cassette 24 enters the holder 52 and when the cartridge is centered. A number of expedients, such as an array of photosensitive elements, can be used for this purpose to provide signals to the sequencer 58. Thus a detailed example is not given, in the interest of brevity.
When the cassette 24 is to be moved out the engagement pin 76 (FIG. 5) engages a standard depending lip along the front edge of the cassette 24, to move the cassette out to a desired position.
The lead screws 48, 49 are driven by a means mounted in the upper portion of the front extension 16. A lead screw drive motor 80 along one wall of the front extension is coupled by a drive pulley 82, belt 83 and driven pulley 84 to an elevator drive pulley 86 which is positioned in the plane above the door 28 on the tape drive unit 26. Lead screw pulleys 88, 89 coupled to the lead screws 48, 49 respectively, lie in the same plane as to the elevator drive pulley 86 and are driven in common by an elevator drive belt 90 in response to actuation of the motor 80 by the sequencer 58.
At the rear of the fully inserted magazine frame 32, in line with and adjacent the cutouts 33, are separately disposed a pair of L angle lifter brackets 97, 98 respectively, with the bases of the L angles facing inwardly to fit under the magazine frame 32 in the rest position. In this position they are clear of the magazine frame 32 and cassette tray 36 as they are inserted. When raised, the lifter brackets 97, 98 engage the opposite edges of a cassette, as seen in FIGS. 6 and 7, to shift the cassette from the lower level to the upper level. For this purpose, the cassette lifter mechanism 100 is mounted in the enclosure outside the magazine frame 32 on each side thereof. A lifter motor 102 is coupled by a pulley drive 104 to a worm gear 106 that is rotatable about a vertical axis, and engages the periphery of a wheel gear 108, to which one end of a drive arm 110 is pivotally coupled. The drive arm 110 is pivotably coupled to a double arm 112, the other end of which rotates a transverse pivot shaft 113 rotating about a fixed axis. The shaft 113 extends across the width of, and underneath, the magazine frame 32. A lifter arm 114, which is coupled to and pivots with the shaft 113, extends rearwardly to the lifter bracket 97, being pivotally engaged thereto at a lower position. A substantially parallel rod 118 is mounted to pivot at its forward end about a fixed axis adjacent the pivot axis of the shaft 113. At its rearward end the rod 118 is coupled so as to pivot in an upper position on the lifter bracket 97. These elements complete a four bar linkage structure that maintains the lifter bracket 97 horizontal as it is raised or lowered by action of the lifter arm 114, as best seen in FIG. 7.
On the opposite side of the magazine frame 32, the transverse pivot shaft 113 actuates a second lifter arm 122, which together with a second parallel rod 124 controls the lifter bracket 98 on that side in similar fashion.
The lifter brackets 97, 98 are normally, during the wait period, at their lowermost position, until, when a cassette 24 is pushed in the entry aperture 40, the innermost cassette is fed toward the open rear end of the cassette tray 36, to rest above the lifter brackets 97, 98. After the cassette is raised to the upper level, a cassette advance mechanism 130 moves the row of cassettes at the upper level, forcing the frontmost cartridge out the exit aperture 42.
The cassette advance mechanism 130 (FIG. 8) is mounted in the housing 14 on the opposite side from the cassette lifter mechanism 100. The mechanism 130 includes a drive motor 132 having its axis of rotation parallel to the front to rear direction, and coupled by a pulley drive 134 to rotate a lead screw 136 that is rotatable within end mounts 138 in the enclosure. A slidable panel 140 having a lead screw seat 142 engaged with the lead screw 136, and therefore movable along the front-rear axis when the lead screw 136 rotates, includes an end tab 144 that is in alignment with the top slot 34 on the magazine frame 32. The slidable panel 140 is, in the wait position, located at the rear of the magazine frame 32. When the motor 132 is actuated, however, the panel 140 and end tab 144 are driven forwardly, to engage the rearmost cassette on the lifter mechanism 100, and thereby advance the circulation of the cassettes. Following this action, the sequencer returns the panel 140 and end tab 144 to the wait position.
A number of guide rails (not shown in detail) are disposed below the magazine frame 32, to provide easy movement on the front-rear axis.
To more readily insert and retrieve the cassette tray 36, the magazine frame 32 is driven both forwardly and rearwardly by a magazine frame drive mechanism 150 on one side of the magazine frame 32 structure, as seen in FIG. 9. A drive motor 152 is coupled by a pulley drive 154 to a vertically disposed worm gear 156, which engages the periphery of a gear wheel 157 that rotates about a horizontal axis. A pinion 158 concentric with the gear wheel 157 engages a horizontal rack 159 that is mounted on the exterior of the magazine frame 32. When the magazine frame 32 is empty, the rack 159 and coupled magazine frame 32 are driven to the forward limit by the drive motor 152. In this position, the open forward end of the magazine frame 32 is close to the magazine door 22 and the front bezel 18, so that the loaded cassette tray 36 may be fully inserted into the frame 32. Thereafter, the sequencer 58 drives the magazine frame 32 and the included tray 36 in the rearward direction until it is fully inserted, at which point the swing door 38 on the magazine is opened and the lifter brackets 97, 98 are in alignment with the cutouts 33 at the rear of the magazine frame 32.
In operation, the system circulates cassettes within the removable cassette tray 36, feeding them sequentially to and taking them from the tape drive unit 26. Each cassette 24 may thus be supplied for data transfer, received and used, then returned individually to the cassette tray 36 after which a new cassette is fed to the tape drive unit. At a sustained data transfer rate of 183 Kbytes/sec, and a capacity of 1.3 Gbytes, each cassette provides two hours of data transfer, so that nine cassettes in total give almost sixteen hours of operation. Furthermore, the mechanism enables single cassettes to be loaded into the tape drive unit individually, as well as via the cassette tray operation.
In operation, the transporter mechanism 46 is held in alignment with the upper doors 20 in the bezel 18 and tape drive unit 26 when awaiting insertion of one or more cartridges. If a single cassette is entered through the single cassette door 20, it moves into the cassette holder 52. The lateral shifter 60 is then actuated to move the cassette 24 into the tape drive unit 26 via the front door 28, to a distance sufficient for the tape drive unit to take command. Upon completion of operation the first cassette will be ejected from the tape drive 26 and returned to the cassette holder 52 for removal. At this point the lateral shifter 60 engages the standard lip on the underside of the front cartridge edcge to complete movement into the holder 52.
Alternatively, a cassette tray 36 loaded with eight cassettes 24 may be entered through the magazine door 22 into the magazine frame 32. In the wait mode, the magazine frame drive 150 has shifted the magazine frame 32 toward the magazine door 22, so that the cassette tray 36 can be fully engaged in the magazine frame 32. Upon automatic sensing of the presence of the cassette tray 36, as by a microswitch (not shown) or operator actuation of a start control, the magazine frame drive 150 moves the entire cassette tray and magazine frame assembly to the rearward position, opening the cassette tray door 38 at this position. Although automatic controls can be employed, the data processing system operator will typically know how much data is to be transferred and will simply arrange for shutdown after the completion of data transfer to a given number of cassettes, with a maximum of eight.
To start the sequence of successive insertions of cassettes 24 into the tape drive 26, the transporter mechanism 46 is first positioned in line with the exit level 42 of the cassette tray 36 (FIG. 2) while the cassette-associated mechanisms are in wait mode positions. In this mode the lifter brackets 97, 98 are in the lowered position and the end tab 144 and the cartridge advance mechanism 130 are at their rearward positions. When the height position sensor 56 (FIG. 1) indicates that the cassette holder 52 is in alignment with the exit aperture 42, the sequencer 58 operates the cassette advance mechanism 130 (FIG. 8) through a cycle. In this cycle the motor 132 and coupled lead screw 136 are first driven to shift the cassette 24 in the upper level forwardly by one cassette dimension in the front-rear direction. The rear cassette thus moves to leave a gap, as the forward cassette is moved into the cassette holder 52 in the transporter 46. The lateral shifter 60 may be used for final adjustment of cassette position, by engaging the lip or acting as a stop. The cassette advance mechanism 130 then returns to its wait position.
The available, empty, cassette position at the rear of the upper level is thus available to be filled by the rear cassette in the lower row. However, this can be done during the wait period, after the transporter 46 is vertically raised to align with the tape drive door 28, by use of the sequencer 58 and height position sensor 56. When this position is reached, the swing arm 74 is rotated so that the engagement pin 76 moves the cassette 24, via its front edge, into the tape drive 26 sufficiently for the tape drive to engage and position the cassette internally. Data transfer can thus begin, and be carried out for the full capacity of the tape. In the interim the carriage advance mechanism 130 is returned to its rearward, wait mode, position and the transporter 46 is left at the tape drive level. The rearmost lower level cassette is moved to the upper level, by movement of the lifter mechanism 100 of FIGS. 6 and 7, controlled by the sequencer 58. The rearmost cassette resting on the central web 35 is lifted at its edges by the angles 97, 98, which move forward slightly but are held horizontal by the parallel arm sets 114, 118 and 122, 124 respectively. The detents 37 (FIG. 4 only) in the sides of the cassette tray 36 hold the rear cassette at the upper level, leaving an opening at the rear position of the lower level. The lifter mechanism 100 is then returned to the lower position.
When the tape drive 26 finishes data transfer with the first cassette, it is ejected, positioned in the holder 52, and the transporter 46 is lowered to align the cartridge with the entry level aperture 40 in the cassette tray 36. The cassette is then moved into the lower level, shirting prior cassettes rearwardly to fill the open gap. The transporter 46 is moved up to the exit level, a new cassette is loaded in, and the transporter inserts it in the tape drive.
This sequence is repeated with each cassette in turn, until all cassettes are filled with data via the tape drive unit 26, at which point the transporter mechanism 46 can be stopped in the upper position. The magazine frame drive 150 is operated to bring the magazine frame 32 and cassette tray 36 forwardly, so that the cassette tray 36 may be manually removed and a new one inserted.
It will be recognized that the mechanism is extremely compact, and does not require small precision parts, such as would be needed if a circulating conveyor of the chain type were to be employed. However, where space or other requirements permit, such a conveyor would be feasible.
Because the arrangement permits the entire tape drive, removable cassette tray and transporter mechanism to be self contained behind a front panel, the danger of damage is greatly lessened and the aesthetics of the construction are preserved. It will be appreciated that if the tape drive unit can be shortened in length, and a smaller or lesser number of cartridges can be used, the front protrusion may be eliminated so that the entire unit may be flush with the console in which it is mounted. Conversely, where space permits a greater number of cassettes can be used in a line.
A number of other variants also suggest themselves. The self-contained unit can be used either with an enclosure in a console, as shown, or as a stand alone unit. In the latter event an interior or separate power supply is employed. The direction of movement of cassette in the cassette tray can be changed, so that the entry level is above and the exit level below, with appropriate change of the lifter and the cassette advance mechanism. The system is useful with any tape drive that employs cassettes, whether digital, audio or video. If it is desired to load a single cassette directly into the tape drive along with a cassette tray in the storage system, two open spaces are held at the rearward position and the sequence is slightly changed. Thus a cassette returned from the tape drive is entered into the cassette tray, shifting the entry line back so that the lifter mechanism can first raise the rear cassette up and the advance mechanism can then move the upper line forwardly. Also, the magazine frame system and tape drive can be inverted so that the tape drive is below, where this is advantageous.
While a number of forms and modifications in accordance with the invention have been shown, it should be appreciated that the invention is not limited thereto but encompasses all versions and variations within the scope of the appended claims.
|
A data transfer system using cassettes with a tape drive is configured with a number of removable cassettes stored in front to rear alignment adjacent one side (e.g. the bottom) of the tape drive. Cassettes in a removable cassette tray in a magazine are disposed in two levels, and shifted between entry and exit regions of the cassette tray after each successive cassette is derived from the tape drive and a new one is supplied. A transporter moves the individual cassette between the cassette tray and the tape drive. Advantageously, this system is configured to fit into the form factor of a standard height enclosure, with a high density DAT format tape drive occupying the upper half and the cassette tray and magazine occupying the lower half.
| 8
|
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to biology and medicine and might be applied for biological fluids purification and to normalize a condition of those to physiological standards.
[0003] 2. Discussion of Related Art
[0004] There is a known ferreed sorbent (FS), made of iron in the form of crystals with particle size of 10-15 nm, as taught by USSR Patent Reference 1589327, dated Apr. 14, 1988.
[0005] While exerting bactericidal effects, the known sorbent is limited in applicability because it can be used “in vitro” only.
[0006] The closest analogical prototype product is ferreed sorbent (FS), with the atomic centre or core as grading fraction with particle size of (0.1-1000) mc, made of iron, iron oxides, nickel, or iron-nickel alloy, and coated with a single or double layer coat of carbon, aluminum oxide, silicium dioxide, zirconium dioxide, dextrane, e.g. sephadex, gelatin, albumin, polysaccharide, e.g. amylum, or ion-exchange resins, e.g. cations or anions, where the coat upper layer is either conjugated with antibodies, or modified by pharmaceutical composition, e.g. antibiotics or phthalhydrazide salines, e.g. 5-amino-2,3-dihydro-1,4-dione salines, or else fermented e.g. with urease, such as taught by Russian Federation Patent 2178313, dated Aug. 29, 2000.
[0007] The above sorbent appears to be an effective remedy used for biological fluids extracorporal restoration to physiological standards, providing clearance of e.g. blood from low-molecular, medium-molecular and high-molecular exotoxines and endotoxines with distraction of its rheological properties, correction of biological fluids enzymatic and immune constitution, as well as antisepsis of viruses and retroviruses pathogenic microflora. However, as such sorbent turns up a very expensive product, and a great quantity of the above sorbent is needed for an appropriate course of treatment, and consequently the treatment is related with significant financial expenses.
[0008] There is a known method of ferreed sorbent preparation technique taught by USSR Patent Reference 1589327, dated Apr. 14, 1988, including an iron powder volatilization procedure at low temperature (10 4 ×(0.5-5)° K.) plasma in an argon atmosphere, and the derived volatile product is quenched and condensed in an argon gas flow. Then, the precipitated product in the form of crystals is transferred to a stabilizer containing dispersion medium, e.g. water at pH 7-9 or oil, and sustained there while being mixed, within (10-15) hours at the temperature (50-90)° C. and at residual pressure of (1-3) Mmhg until the end of gas liberation.
[0009] The known method provides the possibility to derivate sorbent in the form of iron particles (crystals) with particle size of (10-15) nm, however, due to small particle size the above sorbent has got low magnetic susceptibility values, consequently in order to withdraw sorbent out of the biological medium application of magnetic fields with intensity (1-3) tesla is required, which is unacceptable by medical norms, such as taught by Russian Federation Patent 2109522, dated Aug. 1, 1996.
[0010] One analogical prototype of ferreed sorbent preparation technique is taught by Russian Federation Patent 2109522, dated Aug. 1, 1996, and includes fractionating of high dispersed powder of Ferram reductum in inert gas flow with the velocity of (0.02-1.00) m/s under exposure of a magnetic field with an intensity of (10-10 3 ) A/u with subsequent thermal treatment of received iron particles at the temperature of (1000-1500)° C. in inert gas flow containing coal and/or silicon oxide and/or aluminium oxide microparticles, after which treatment the ferreed sorbent particles surface are covered by biologically active compounds, such as food proteins or dextrane, or pharmaceutical preparations, or antibodies.
[0011] Such method provides a possibility to receive ferreed sorbent of certain chemical composition, effective at recession <<in vivo>> and <<in vitro>> of low, medium and high molecular toxins, microflora and retroviruses. However, the above method is limited to receiving the ferreed sorbent with volumetrical particles, having predominantly proportionate dimensions with respect to both thickness of (0.5-2.5) mcm and those particles surface dimensions corresponding to that form.
SUMMARY OF THE INVENTION
[0012] One object of the “Ferreed Sorbent” invention is to develop the sorbent similar in performance to analogous sorbent having substantially larger particles surface without any significant increase in weight of the sorbent core.
[0013] Another object of the “Ferreed Sorbent” invention is to develop the procedure of receiving the sorbent with the core in a form of e.g. flake.
[0014] The above and other objects are achieved with the ferreed sorbent having a ferromagnetic core, with a single or double layer coat or no coat, and the core made in a form of a flake, with in-plane dimensions of (500-5000) mc, and thickness of (0.1-1000) mc. Here the core is made either of iron, nickel, iron-nickel alloy, iron or nickel alloy with titanium, iron or nickel alloy with tantalum, iron-nickel-titanium alloy, or iron-nickel-tantalum alloy.
[0015] Furthermore, the one layer coat is made either of carbon, aluminum oxides, silicon dioxide, zirconium dioxide, dextrane, e.g. from sephadex, gelatin or albumin, polysaccharide, e.g. amylum, or ion-exchange resins, e.g. cations or anions.
[0016] Here, in double layer coat the first closest to the core or inner layer is made either of carbon, aluminum oxides, silicon dioxide, zirconium dioxide, and the second or outer layer of the coat is made either of dextrane, e.g. from sephadex, or gelatin or albumin, polysaccharide, e.g. amylum, or ion-exchange resins, e.g. cations or anions.
[0017] Also, the outer layer of the coat is either conjugated with antibodies, or modified by pharmaceutical composition, e.g. antibiotics or phthalhydrazide salines, e.g. 5-amino-2,3-dihydro-1,4-dione salines, or else fermented e.g. with urease.
[0018] The above and other objects are achieved by the fact that in the ferreed sorbent generation method, iron, nickel, titanium and/or tantalum powder is volatilized or fused in a low-temperature plasma with the temperature of 10 4 ×(0.5-5)° K., and a received product of vaporous or fused particles of respective metals or respective metals alloys is quenched and condensed in a gas flow, e.g. an argon flow, and then the product settled as crystals or, correspondingly, as microbars of respective metals alloys, is transferred to a disperse medium containing stabilizer, e.g. water and/or oil, and while being mixed, sustained there within (5-15) hours at the temperature (50-90)° C. and at residual pressure of (1-5) Mmhg until gas liberation ends. Then, those crystals or microbars are treated by flattening e.g. through pressing e.g. in a ball mill, until flakes are of the specified thickness, and afterwards are repeatedly (up to 10 times) washed in distilled water, and then separated from weak parts of flakes, treating with e.g. ultrasound of e.g. (200-300) Vt/cm 2 capacity. Then, the received flakes are dried out e.g. in a hot air sterilizer at the temperature of (80-110)° C., and after that the dried flakes are fractionated in either an inert gas flow with the velocity of (0.02-1.00) m/s under exposure of magnetic field of 5×(10-10 3 ) A/m intensity, or by using e.g. centrifugation. Then, the specified size sorbent cores with a layer-by-layer formed coat are extracted, and the received end product is packed in light-protected and hermetically sealed containers and sterilized, by e.g. U-rays, where sorbent received right after fractionating can be used as the end product.
[0019] Here, the first or inner layer of the coat is formed by thermal treatment of fractionated flakes at the temperature of (1000-1500)° C. in an inert gas flow, e.g. a flow of argon, containing microparticles of either carbon, silicon oxide, aluminum oxide, or zirconium oxide.
[0020] Furthermore, the first layer of the coat is formed by blending with and using ultrasound exposure to fractionated flakes suspension within (1-10) minutes in heated to the temperature of (30-80)° C. aqueous solution of dextrane, gelatin or albumin, or amylum, with subsequent cooling of the above suspension down to the temperature of (4-10)° C., and the received precipitate is filled up with formalin, sustained there within (10-40) minutes, simultaneously being mixed, and after that dried out thoroughly at the temperature of (25-50)° C. and grinded, then the received sorbent capsules, the end product, are filtered in a magnetic field.
[0021] Furthermore, the first layer of the coat is formed through adding an ion-exchange resin, e.g. amberlite into a fractionated flakes suspension in distilled water, heated up to the temperature of (40-60)° C., with subsequent cooling of the above suspension down to the temperature of (15-30)° C., with adding nitrous acid (HN0 2 ) diluted in water, sustaining within (10-15) minutes, cooling down to the temperature of (4-10)° C. and elution of precipitate which is washed in a physiological solution and buffered in an aqueous solution of NH 4 OH foundation blend and NH4 C1 salt.
[0022] Here, the second layer of the coat is formed by blending with using ultrasound exposure within (1-10) minutes to a suspension of ferromagnetics covered with carbon or silicon oxide, aluminium oxide, zirconium oxide coat in aqueous solution of dextrane, gelatin, albumin, or amylum heated up to the temperature (30-80)° C. with subsequent cooling of the above suspension down to the temperature (4-10)° C. The received precipitate is filled up with formalin, sustained in there within (10-40) minutes of simultaneously being mixed, then dried out thoroughly at the temperature of (25-50)° C., grinded and the received sorbent capsules, of the end product, are filtered in a magnetic field.
[0023] Furthermore, the second layer of the coat is formed through adding an ion-exchange resin, e.g. amberlite into a heated, up to the temperature of (40-60)° C., suspension of ferromagnetics, covered with carbon or silicon oxide, aluminium oxide, or zirconium oxide coat, in distilled water, with subsequent cooling of the above suspension down to the temperature of (15-30)° C., and adding and immixturing albumin, e.g. in the form of serum, with subsequent adding of nitrous acid (HN0 2 ) diluted in water, sustaining within (10-15) minutes, cooling down to the temperature of (4-10)° C. and elution of precipitate which is activated by sustaining within (1.5-2) hours in a modifier solution, then washed in physiological solution and buffered in aqueous solution of NH 4 OH foundation blend and NH4 C1 salt.
[0024] Sodium periodate (NaI0 4 ) or glutaric dialdehyde in (3-10)% solution of Na 2 S0 4 in water can be used here as a modifier.
[0025] Furthermore, while forming the outer layer of the coat, it is conjugated with antibodies by adding the ferreed sorbent with a single or double layer coat into aqueous suspension; but it should be with the outer coat layer made of sephadex or albumin, modified e.g. with glutaric dialdehyde or sodium periodate, with serum, e.g. of blood, containing antibodies, specified to sorbed antigen, e.g. to systemic lupus erythematosus antigen, in buffered liquid with pH of 6.5-10, sustaining while being mixed of the above compound within (1-3) hours at the temperature of (15-25)° C., subsequent to adding to the compound of sodium borhydrate, cooling down to the temperature of (4-10)° C., and repeated sustaining while being mixed within (1-3) hours, precipitate extraction and its buffering and drying out.
[0026] Furthermore, while forming the outer layer of the coat, it is modified with pharmaceutical composition through heating the ferreed sorbent suspension with a single or double layer coat, but with the outer coat made of e.g. dextrane or gelatin, up to the temperature of (35-70)° C. in physiological solution, and adding into it a pharmaceutical composition in powder, e.g. antibiotic, e.g. oxaccillin, sustaining at thorough mixing at the above mentioned temperature within (0.5-2.5) hours, a subsequent cooling of the compound down to the temperature of (4-10)° C., decanting of a supernatant fluid in a magnetic field, and washing the precipitate in running distilled water and its subsequent drying out.
[0027] Furthermore, while forming the outer layer of the coat, it is modified through preliminary dissolution of urease crystals in polyether, e.g. dibenzo-18 crown 6, immixture of the above solution with the suspension in distilled water of ferreed sorbent with the coat made of e.g. sephadex, sustaining while being mixed at the temperature of (25-40)° C. within (2-5) hours and cooling down to the temperature of (4-10)° C., subsequently adding of formaldehyde and repeated sustaining within (1-3) hours, and draining out the supernatant fluid in the presence of a magnetic field and drying out the precipitate.
[0028] Furthermore, while forming the outer layer of the coat, it is modified through a heating up of an aqueous suspension of the ferreed sorbent with the coat made of e.g. dextrane, to the temperature of (40-70)° C., a subsequent immixture with zirconium saline powder, e.g. of respective phthalhydrazide saline, and (50-120) Vt/c M intensity ultrasound exposure to the above mixture within (1-10) minutes, a cooling of the received compound down to the temperature of (4-10)° C., adding formaldehyde, sustaining while being mixed within (1-3) hours, and draining out the supernatant fluid in the presence of a magnetic field and drying out the precipitate.
DETAILED DESCRIPTION OF THE INVENTION
[0029] Ferreed sorbent is made in the form of cores with a single or double layer coat surrounding the core, and with no coating.
[0030] To be used as cores for the ferreed sorbent powder is taken from ferromagnets, e.g. from iron (Fe), its oxides (Fe 2 0 3 or Fe 3 O 4 nickel (Ni), iron-nickel alloys, as well as from iron or nickel alloy with titanium (Ti), from iron or nickel alloy with tantalum (Ta), from iron-nickel-titanium alloy, or from iron-nickel-tantalum-titanium alloy and the like magnetic sensible materials.
[0031] For the subsequent use fractions in the form of flakes with the dimensions in plane of (500-5000) mc and with the thickness of (0.1-1000) mc are taken.
[0032] For getting cores for the ferreed sorbent, iron, nickel, titanium, and/or tantalum powder with particle size of (10 2 -10 5 ) nm is volatiled and/or fused in low-temperature plasma with the temperature of 10 4 ×(0.5-5)° K., and the received product volatized and/or fused in the form of respective metals or respective metals alloys with concentration of (0.1-0.5) volume % quenched down to the temperature of (50-80)° C. and condensed in a reactor, such as taught by USSR Patent Reference 1589327, in a gas flow, e.g. in an argon flow, and then the product settled in the form of crystals or, respectively, microbars of respective metals alloys, e.g. in the amount of (0.05-10) mg, is transferred to the disperse medium containing stabilizer, e.g. distilled water of (50-500) with pH of 7-9 and/or mineral, e.g. paraffin or vegetable oil e.g. olive or sea-buckthorn oil, with preliminarily added e.g. oleic acid in the amount of (2-20) volume %, and, while being mixed, sustained in there within (5-15) hours at the temperature of (50-90)° C. and at the residual pressure of (1-5) Mmhg until the end of gas liberation.
[0033] After that those crystals or microbars are treated by flattering, e.g. through pressing e.g. in a ball mill, until having flakes of the specified thickness, which then repeatedly (up to 10 times) are washed in distilled water, and then weak flake parts are removed by exposing to ultrasound of e.g. (200-300) V T /sm 2 intensity in e.g. water.
[0034] The received material, different size flakes and chip bits, is dried in whole e.g. in a hot air sterilizer at the temperature of (80-110)° C., and then the dried product or flakes is fractionated either in inert gas flow with velocity of (0.02-1.00) m/c under the exposure of magnetic field with intensity of 5×(10-10 3 ) A/ M or by using centrifugation. The sorbent or flakes of the specified size is excreted in the form of cores, on which coats are formed layer by layer, and the acquired end product is packed up in lightproof hermetically closed containers and sterilized through e.g. U-rays. Here, the sorbent received right after fractionating can be chosen as the end product as well. The output of conditioned sorbent cores after fractionating makes (60-75) %.
[0035] For getting or forming of the first, closest to the core, layer of the coat, the fractionated flakes are treated at the temperature of (1000-1500)° C. in a thermo oven in inert gas flow, e.g. in argon flow, containing microparticles of carbon (C), silicon oxide (Si0 2 ), aluminum oxide (Al 2 0 3 or Al 3 0 4 ), or zirconium oxide (Zr0 2 ). A flow velocity makes (0.02-1.2) m/s. Coating quality of cores depends on inert gas flow throughput rate, as well as on saturation of the gas with microparticles of coating material and the size of those particles. In the given examples, the thickness of the coat layer made with the above method makes (0.2-50) mc.
[0036] The efficient output of the sorbent is (70-85) %.
[0037] While forming the first layer of the coat through covering sorbent cores with such substances like either dextrane, gelatin, albumin, or amylum, a fractionated flakes suspension in the amount of (2-20) g in (10-50) ml of distilled water is mixed with (50-100) ml of a heated to the temperature of (30-80)° C. aqueous solution of either dextrane, gelatin, albumin, or amylum, with the blend ratio of (volume %): (50-95) % of the respective product, the rest is water; then is mixed within (1-10) minutes until it gets homogeneous structure under the exposure of e.g. ultrasound dispergator “ -2T”, such as taught by USSR Patent Reference 1684616, and ultrasound with an oscillation frequency (10-15) kHz and an intensity rate of (50-120) Wt/cm. Then the suspension is cooled e.g. in a refrigerator down to the temperature of (4-10)° C., then the precipitate received is filled up with formalin (aqueous solution HCHO), sustained in there within (10-40) minutes while simultaneously being mixed, and after that can be thoroughly dried up at the temperature of (25-50)° C., grinded and the received sorbent capsules, the end product, are filtered in magnetic field with the intensity of 5×(10-10 3 ) A/m, of e.g. constant magnet made of samarium (8t)-cobalt (Co) alloy.
[0038] A thickness of the coat layer made using the method above makes (0.5-3) mm.
[0039] The quantitative output of sorbent makes (85-95) % out of the initial.
[0040] While forming the first layer of the coat by using ion-exchange resin, e.g. (10-25) g of amberlite is added into the heated up to the temperature of (40-60)° C. fractionated flakes suspension of (2-5) g per (10-100) ml of distilled water, then the received compound is cooled down to the temperature of (15-30)° C., then added is nitrous acid (HN0 3 ) diluted in water (in the amount of (1-10) vol. %), sustained within (10-15) minutes, then cooled again down to the temperature of (4-10)° C. and then precipitate is excreted, which is washed in a physiological solution, and buffered until it gets pH 4.0±0.5 in the aqueous solution of foundation of NH 4 OH or NH 4 C1 saline.
[0041] A thickness of the coat layer made by the above method makes (0.2-1) mm.
[0042] The quantitative output of sorbent makes (90-92) % out of the initial.
[0043] While forming the second layer of the coat through covering the ferreed sorbent coated with either carbon or silicon oxide or aluminum oxide, or zirconium oxide with such substances like either dextrane, gelatin, albumin, or amylum, a suspension of ferromagnetics, in the amount of (2-20) g per (10-50) ml of distilled water, covered with a carbon, silicon oxide, aluminum oxide, or zirconium oxide coat, being mixed within (1-10) minutes under the exposure of ultrasound with intensity of (50-120) Vt/cm in (50-100) ml of heated to the temperature of (30-80)° C. (50-95) % solution of dextrane, gelatin, albumin, or amylum in distilled water with a subsequent cooling to the above suspension down to the temperature (4-10)° C. The precipitate is filled up with formalin, sustained in there within (10-40) minutes while simultaneously being mixed and after that it is thoroughly dried out at the temperature of (25-50)° C., grinded, and the acquired sorbent capsules or end product are filtered in magnetic field with the intensity of 5×(10-10 3 ) A/m.
[0044] The thickness of the coat layer made by the above method makes (0.5-3) mm.
[0045] The quantitative output of sorbent makes (85-95) % out of the initial.
[0046] While forming the second layer of the coat by using ion-exchange resin, a suspension of ferromagnetics, in the amount of (0.2-0.5) g per (10-100) ml of distilled water, covered with a carbon, silicon oxide, aluminum oxide, or zirconium oxide coat, is heated up to the temperature of (40-60)° C., then e.g (1-2) g of amberlite is added into there, and then the received compound is cooled down to the temperature of (15-30)° C. Then nitrous acid (HN0 3 ) diluted in water, in the amount of (1-10) vol. %, is added, sustained within (10-15) minutes, then cooled again down to the temperature (4-10)° C. and the precipitate is excreted, which is activated by sustaining within (1.5-2) hours in a modifier solution, then washed in a physiological solution and buffered until it gets to pH 4.0±0.5 in aqueous solution of NH 4 OH foundation and NH 4 C1 salt. Here, sodium periodate (NaI0 4 ) or glutaric dialdehyde in a (3-10)% solution of Na 2 S04 in water can be used as a modifier.
[0047] The thickness of the coat layer made by the above method makes (0.2-1) mm.
[0048] The quantitative output of sorbent makes (90-95)% out of the initial.
[0049] Moreover, while forming the outer layer of the coat, it is conjugated with antibodies through adding serum e.g. of blood, into an aqueous suspension of ferreed sorbent with a single or double coated, but with the outer coat made from sephadex or albumin, modified with e.g. glutaric dialdehyde or sodium periodate, in the amount of (1-50) ml of serum per (100-150) ml of suspension, containing antibodies specific to the antigen sorbed, e.g. to systemic lupus erythematosus antigen, in buffering liquid with pH of 6.5-10, sustaining while the compound being mixed within (1-3) hours at the temperature of (15-25)° C., with subsequent adding of sodium borhydrate into the compound, cooling down to the temperature of (4-10)° C., repeated sustaining with simultaneous mixing within (1-3) hours, and the precipitate extraction and its buffering and drying out.
[0050] Here the respective coat layer thickness is increased for (0.2-0.5) mm.
[0051] The quantitative output of sorbent makes (92-95)% out of the initial.
[0052] Furthermore, while forming the outer layer of the coat, it is modified with a pharmaceutical composition by heating up to the temperature of (35-70)° C. of aqueous suspension of ferreed sorbent, (10-20) g of sorbent per (50) ml of distilled water, with a single or double layer coat, but the outer coat made of e.g. dextrane, or gelatin, in physiological solution (0.9% solution of NaCl in distilled water), and adding a pharmaceutical preparation powder, in the amount of (1-5) Γ per (10-50) ml of suspension, e.g. antibiotic, e.g. oxaccillin, sustaining while simultaneous thorough mixing at the above mentioned temperature within (0.5-2.5) hours, subsequent cooling of the above compound down to the temperature of (4-10)° C., decanting of the supernatant fluid in magnetic field with the intensity of 5×(10-10 3 ) A/m, washing the precipitate in running distilled water and its subsequent drying out at the temperature of (25-40)° C.
[0053] Here the respective coat layer thickness is increased for (0.01-0.1) mm.
[0054] The quantitative output of sorbent makes (90-95)% out of the initial.
[0055] Furthermore, while forming of the outer layer of the coat, it is modified by preliminary dilution of e.g. (1-5) g of urease crystals in (10-15) ml of polyether, e.g. of dibenzo-18 crown 6, blending the above solution with ferreed sorbent suspension in distilled water ((10-15) hg of sorbent per (50-100) ml of water) with the coat made e.g. from sephadex-10, sustaining while mixed at the temperature of (25-40)° C. within (2-5) hours and cooling down to the temperature of (4-10)° C., and subsequent adding of formaldehyde ((25-30) ml per 100 ml of compound) and repeated sustaining while mixed within (1-3) hours, pouring out the supernatant fluid under the influence of magnetic field with the intensity of 5×(10-10 3 ) A/m and precipitate drying out e.g. in a hot air sterilizer at the temperature of (50-85)° C.
[0056] Here the respective coat layer thickness is increased for (0.5-1) mm.
[0057] The quantitative output of sorbent makes (90-95) % out of the initial.
[0058] Furthermore, while forming the outer layer of the coat, it is modified through heating of aqueous suspension of ferreed sorbent with e.g. dextrane coat up ((15-20) g of sorbent per 75-100 ml of distilled water) to the temperature of (40-70)° C., and subsequent blending with zirconium saline powder of e.g. respective phthalhydrazide saline, e.g. 5-amino-2,3-dihydro-1,4-dion, and treating the above compound within (1-10) minutes with ultrasound of (15-25) kHz oscillation frequency and (50-120) Vt/cm 2 intensity, cooling of the received compound down to the temperature (4-10)° C., adding formaldehyde ((25-30) ml per 100 ml of compound), sustaining in there while mixing within (1-3) hours, and pouring out of supernatant fluid in the presence of magnetic field with the intensity of 5×(10-10 3 ) A/m and precipitate drying out at the temperature of (25-45) C.
[0059] Here the respective coat layer thickness is increased for (0.01-0.1) mm.
[0060] The quantitative output of sorbent makes (90-95)% out of the initial.
INDUSTRIAL APPLICABILITY
[0061] Use of a ferreed sorbent having a substantially larger surface of the particles with no significant weight increase of its core, and the method of receiving such sorbent provides effective cleaning of biological fluids, e.g. blood, out of low-, medium- and high-molecular exotoxines and endotoxines without disorder of its rheological properties, provide possibility to correct ferment and immune structure of the biological fluids, as well as destruction of viruses and retroviruses pathogenic microflora while using appreciably low amount of the proposed ferreed sorbent, with respect to weight, relatively to the amount of the analogous sorbent known earlier and specified for the same purposes.
[0062] Thus, in view of the fact that biological fluid cleaning by using ferreed sorbent takes place by interaction of its surface with the fluid being corrected, one can show that the effective particle surface of the known sorbent, a size of which in terms of length, width and thickness are on average commensurable at mass conservation, is significantly smaller than the surface of the proposed sorbent.
[0063] For example, consider a spherical particle.
[0064] Using known mathematical formulas, we get the following as sphere volume value (V sphere ) which is equal to:
[0065] V sphere =4π r 3 /3, where r is sphere radius, and accordingly, the sphere surface area (S sphere ) is equal to
[0066] S sphere − 4π r 2 , then
[0067] S sphere − 3 V sphere /r
[0068] Considering that the particle mass is proportional to its volume, and assuming that after the above described procedure of acquiring sorbent particles in the form of flakes, a spherical sorbent particle will be reformed into a round flake/disk. Then as the flake volume is V flake =πR 2 δ, and the surface area S flake =πR 2 , where R—flake radius, and δ—its thickness, while δ=0.1 g (in accordance with the above said statement about some decrease of particle thickness), then S flake =V flake /0.1 g.
[0069] Considering that V flake = V sphere , then, as their masses are equal, we get the following:
S flake =10 V sphere /r
[0070] Taking into consideration that, there are two such surfaces on the flake, and putting the term (1) into the formula (2) we get the following:
S flake's full surface =20 S sphere /3
[0071] The results received justify the above hypothesis that in the case of using the sorbent being proposed, each particle surface interacting with a biological fluid is significantly enlarged, and, consequently, consumption of sorbent and respective treatment costs are decreased.
[0072] Feasibility of effective application of the proposed ferreed sorbent extracted using the above-described methods is confirmed by the following examples:
EXAMPLE 1
[0073] A non-pedigree dog weighing 12 kilos was injected (per os) 4.3 g of veronal. After 45 minutes amount of barbiturate in blood gets 118 mkg/ml.
[0074] Blood extracorporeal regeneration (correction) procedure was conducted using the expedient equipment ( -1). The animal's blood was retrieved in portions of 10 ml, being then blended in equal volume proportions with ferreed sorbent suspension in physiological solution, which contained (mass. %): ferreed sorbent (core—nickel flake, coat inner layer—carbon, coat outer layer—dextrane) −1.5; anticoagulant (heparin) −0.015; physiological solution as the balance; then the blood was sustained within 2-3 seconds and administered back into animal's organism.
[0075] About one liter of blood had been treated/processed during one session.
[0076] Indications before and after the correction session:
Creatinine (m mole/l) 1.45 1.10. Urea (m mole/l) 11.9 6.2. Bilirubin (total) (m mole/l) 25.0 14.4. Barbiturates (mkg/ml) 141.5 14.2.
[0077] Furthermore, gastric lavage was made during the session, the animal was injected intravenously 500 ml of solution of electrolytes and 2% glucose.
[0078] After the session, the animal was in the state of moderate severity, brisk reflexes.
[0079] The indications of sorbate effectiveness are shown in the following examples below, as well as effectiveness of selective and functional properties of know ferreed sorbents, described, e.g. in the specifications of Russian Federation 2178313, and the results received during the researches with ferreed sorbent being proposed in this invention.
EXAMPLE 2
[0080] 5 ml of carbofos solution was injected into the test-tube with 100 ml of a non-pedigree dog blood. Carbofos concentration in the blood was 0.015 mkg/ml.
[0081] The received blend was divided in two parts and each part was added 20 ml of ferreed sorbent suspension, where in one part was added the known ferreed sorbent suspension in physiological solution (cores as iron particles, coat layers as silicon oxide) in the amount of 1.0 g, while in the second part was added the proposed ferreed sorbent with the same material composition but with flake cores, in the amount of OD g.
[0082] After mixing of the received compositions within 1.5 minutes the supernatant fluid was decanted, and the precipitate was withhold using a magnet.
[0083] Carbofos concentration in the supernatant fluid received from the first blend made 0.002 mkg/ml, and the supernatant fluid received from the second blend made 0.012 mkg/ml.
EXAMPLE 3
[0084] Into two different test-tubes each containing 20 ml of blood serum of a dog with simulated nephratonia (urea concentration in the first test-tube was 26.4 m mole/l, and 30.2 m mole/l in the second), the following had been added: 200 mg of the known ferreed sorbent with the coating of sephadex-10 fermented with urease into the first test-tube; 30 mg of the ferreed sorbent being proposed with the cores in the form of titanium flakes with the coating analogous to the above specified, into the second test-tube.
[0085] After sustaining (while shaken) of the received compositions within seconds and removal of the supernatant fluid in magnetic field, the urea content concentration in supernatant fluid in the first test-tube got −10.7 m mole/l, and got 12.1 m mole/l in the second one.
EXAMPLE 4
[0086] In two different test-tubes each containing 20 ml of phosphoric acid sodium saline solution (NaH 2 P0 4 ) in water the following had been added: 100 mg of the known ferreed sorbent with cation-modified (COON group polysaccharides) ion-exchange resin coating into the first test-tube, and 10 mg of the ferreed sorbent being proposed in the form of tantalum flakes with the coating analogous to the above specified—into the second test-tube.
[0087] After mixing (while shaken) of the received compositions and removal of the supernatant fluid in magnetic field, the concentration of phosphates in the supernatant fluid received from the first test-tube had reduced for 57% comparatively to the initial, and the concentration of phosphates in the supernatant fluid from the second test-tube, correspondingly, had reduced for almost half (for 44.8%) from the initial point of phosphates concentration.
EXAMPLE 5
[0088] In two different test-tubes each containing 20 ml of sulphuric acid salines solution in water the following had been added: 100 M Γ of the known ferreed sorbent with anoinite-modified (NH 3 x″ group) ion-exchange resin coating into the first test-tube, and 20 mg of the ferreed sorbent being proposed in the form of iron-nickel flakes with the coating analogous to the above specified—into the second test-tube.
[0089] After mixing (while shaken) of the received compositions and removal of the supernatant fluid in magnetic field, the concentration of sulphuric acid salines in the supernatant fluids received from both of the test-tubes had reduced virtually for the same, i.e. for 72% comparatively to the initial concentration in the first test-tube, and for 73.4% comparatively to the initial concentration—in the second test-tube.
EXAMPLE 6
[0090] In two different test-tubes each containing 20 ml of blood of a patient with chronic renal-hepatic insufficiency disease the following had been added: 100 mg of the known ferreed sorbent with zirconium luminole saline-modified dextrane coating into the first test-tube; and 30 mg of the ferreed sorbent being proposed in the form of iron-titanium flakes with the coating analogous to the above-specified—into the second test-tube.
[0091] After mixing (while shaken) of the received compositions and removal of the supernatant fluid in magnetic field, the concentration of phosphoric acid salines (NaH 2 PO 4 ) in the supernatant fluid received from the first test-tube had got 0.07 mg/ml; and the concentration of phosphoric acid salines (NaHyPCˆ) in the supernatant fluid received from the second test-tube had got 0.021 mg/ml. The initial concentration of the saline was 0.61 mg/ml.
EXAMPLE 7
[0092] In two different test-tubes each containing 10 ml of blood serum of a patient with chronic renal-hepatic insufficiency disease the following had been added: 50 mg of the known ferreed sorbent with iron-nickel cores and urease-modified sephadex coating into the first test-tube; and 10 mg of the ferreed sorbent being proposed with iron-nickel cores with coating analogous to the above-specified—into the second test-tube.
[0093] After sustaining within 10 seconds and the supernatant fluid decanting (sorption) the urea concentration in the supernatant fluid received from the first test-tube had reduced for 23% comparatively to the initial urea concentration in blood serum, and the urea concentration in the supernatant fluid received from the second test-tube had reduced for 35% comparatively to the initial urea concentration in the blood serum.
EXAMPLE 8
[0094] In two different test-tubes each containing 20 ml of blood serum of a patient with sepsis the following had been added: 150 mg of the known ferreed sorbent with iron-nickel cores and oxaccillin-modified gelatin coating into the first test-tube; and 15 mg of the ferreed sorbent being proposed with iron-nickel-titanium-tantalum alloy flake cores with coating analogous to the above-specified—into the second test-tube.
[0095] After mixing while shaking of the test-tubes contents within 2 minutes, the supernatant fluid was decanted and the hard constituent was retained using a magnet field.
[0096] Inoculation was made both on the patient's blood agar-agar and the blood having been exposed to ferreed sorbent (the supernatant fluids) from the both test-tubes.
[0097] Growth of streptococcus and staphylococcus colonies was observed in the inoculation of the patients' blood; and no such growth was observed in the inoculation of the blood taken from the test-tubes.
EXAMPLE 9
[0098] In two different test-tubes each containing 10 ml of lymph plasma of a patient with sepsis the following had been added: 100 mg of the known ferreed sorbent with iron-nickel cores and dextrane coating into the first test-tube; and 15 mg of the ferreed sorbent being proposed with iron-nickel-titanium-tantalum alloy flake cores with coating analogous to the above-specified—into the second test-tube.
[0099] After mixing (while shaking) of the compositions received and removal of the supernatant fluid in magnetic field, inoculation was made both on the patient's lymph agar-agar and the lymph having been exposed to ferreed sorbent (the supernatant fluids) from the both test-tubes.
[0100] Growth of multiple staphylococcus colonies was observed in the inoculation of the lymph with no lymph-separation; virtually no such growth was observed in the inoculation of the supernatant fluids taken from the test-tubes.
EXAMPLE 10
[0101] In two different test-tubes each containing 5 ml of blood-tinted cerebrospinal fluid (a patient with craniocerebral injury) the following had been added: 50 mg of the known ferreed sorbent with iron cores and silicon oxide coating into the first test-tube; and 15 mg of the ferreed sorbent being proposed with iron-tantalum alloy flake cores with coating analogous to the above-specified—into the second test-tube.
[0102] After sedimentation the cerebrospinal fluid in the test-tubes had got light yellow color.
[0103] Effectiveness of the developed preparation application is confirmed by the experiments when doing the research on sorption capacity of the ferreed sorbent for each above-described variation for its performance, and at the same time the results are commensurable to the results of using analogous variations of the known ferreed sorbent were achieved at using significantly lower amounts of the ferreed sorbent being proposed.
|
Biology and medicine that can be used for cleaning biological fluids and for bringing the content to meet physiological standards. An absorbent includes a ferromagnetic nucleus with a one-layer or two-layer shell or devoid thereof and the nucleus is embodied in the form of a plate with a planar size that ranges from 500-5000 □m and the thickness is equal to 0.1-1000 □m. The method for producing the inventive magnetically-operated absorbent includes evaporating and/or melting a magnetic material powder in a low-temperature plasma, quenching and condensing the thus obtained vaporized and/or melt-particle product in a gas flux, and transferring the product precipitated in the form of crystals or micro slugs of corresponding metals, correspondingly to a stabilizer-containing dispersion medium and holding in the medium until a gas release is over. Then the crystals or micro slugs are processed by flatting, for example pressing so that the plates of a specified thickness are obtained. The plates are repeatedly (up to 10 times) washed with distilled water, the weak sections thereof are separated by exposing them in water, for example to the action of ultrasound with power ranges, for example from 200 to 300 W/cm 2 , and the thus produced plates are dried. The dried plates are broken up, the absorbent nucleuses of a required size are obtained and the shells are formed thereon layer-by-layer. The final product is packed in light-protected sealed containers and sterilized, for example by γ-radiation. The final product can be also selected in the form of an absorbent produced immediately after the fractionation thereof.
| 8
|
CROSS-REFERENCES TO RELATED APPLICATION
[0001] The present application claims priority under 35 U.S.C. §119(a) to Korean application number 10-2012-0056120 filed on May 25, 2012, in the Korean Intellectual Property Office, which is incorporated by reference in its entirety.
BACKGROUND
[0002] 1. Technical Field
[0003] The present invention relates to a semiconductor circuit, and more particularly, to a column repair circuit.
[0004] 2. Related Art
[0005] In general, a semiconductor memory apparatus includes a is plurality of mats, and each mat includes numerous memory cells. A failure in any one of the numerous memory cells may cause the semiconductor memory apparatus to malfunction, which may lead to the entire semiconductor memory apparatus to be discarded as a defective product. Therefore, a repair circuit is used to replace the failed memory cell with a cell included in a redundancy circuit. When a failure occurs in a memory cell, the repair circuit recognizes the failed memory cell in advance, and when access to the corresponding memory cell is requested, the repair circuit replaces the memory cell with the cell included in the redundancy circuit. Here, the redundancy circuit refers to a group of spare memory cells which are separately prepared.
[0006] A variety of methods may be used to replace a failed memory cell with a redundancy memory cell. Such methods may include replacing a memory cell by row, replacing a memory cell by column, and replacing a memory cell by memory cell.
[0007] The method for replacing a memory cell by column corresponding to bit lines is generally used. In this method, when a failure occurs in a memory cell of a mat, a fuse is cut to replace a column including the failed memory cell with a redundancy column.
[0008] The above-described column repair method is advantageous in that a memory cell may be repaired using column addresses of the mat. However, when failures uniformly occur in memory cells of a plurality of mats, fuses of all corresponding mats must be cut. Furthermore, even when memory cell failures occur in portions of the mats, fuses of all corresponding mats must be cut. Thus, unnecessary repair time may be required, and excessive fuse cutting may reduce the reliability of the semiconductor apparatus.
SUMMARY
[0009] In an embodiment of the present invention, a column repair circuit of a semiconductor memory apparatus which includes a plurality of mats performs a column repair operation to replace failed cells among a plurality of memory cells provided in the mats. The column repair circuit includes two or more fuse units configured to perform the column repair operation. Each of the fuse units includes a plurality of fuses, and is configured in such a manner that m mats correspond to one fuse and n mats correspond to another fuse, where m and n are natural numbers greater than or equal to 1 and differ from each other.
[0010] In an embodiment of the present invention, a column repair circuit includes a combined mat address generation unit and at least two fuse units. The combined mat address generation unit is configured to receive mat addresses, perform one or more combination steps according to a method of combining the received mat addresses by adjacent addresses and recombining the combination results by adjacent values, and outputs the received mat addresses and the combination results of the respective combination steps as combined mat addresses of the respective steps. The two or more fuse units each include a plurality of fuses corresponding to the is combined mat addresses based on respective bits of a column address, and are configured to replace a corresponding column of the inputted column address with a redundancy column depending on whether or not a fuse corresponding to a selected combined mat address is cut, wherein each of the fuse units receives the combined mat addresses outputted at any one step of the method described above.
[0011] In an embodiment of the present invention, a column repair circuit includes a combined mat address generation unit and at least two fuse units. The combined mat address generation unit is configured to receive x mat addresses, performs a plurality of combination steps according to a method of combining the received x mat addresses by adjacent addresses and recombining the combination results by adjacent values, and outputs the x mat addresses, x/2 combination results, x/4 combination results, and x/8 combination results as combined mat addresses of the respective steps. The two or more fuse units each include a plurality of fuses corresponding to the combined mat addresses based on respective bits of a column address, and are configured to replace a corresponding column of the inputted column address with a redundancy column depending on whether or not a fuse corresponding to a selected combined mat address is cut, wherein each of the fuse units receives the combined mat addresses outputted at any one of the steps of the method described above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Features, aspects, and embodiments are described in conjunction with the attached drawings, in which:
[0013] FIG. 1 is a block diagram of a column repair circuit according to an embodiment of the present invention,
[0014] FIG. 2 is a block diagram of a first fuse unit of FIG. 1 ,
[0015] FIG. 3 is a circuit diagram of a first fuse set of FIG. 2 ,
[0016] FIG. 4 illustrates a column repair operation according to an embodiment of the present invention,
[0017] FIG. 5 is a block diagram of a column repair circuit according to an embodiment of the present invention,
[0018] FIG. 6 is a circuit diagram of a combined mat address generation unit of FIG. 5 ,
[0019] FIG. 7 is a circuit diagram of a combined mat address selection unit which may be additionally included in the combined mat address generation unit of FIG. 5 ,
[0020] FIGS. 8A and 8B are block diagrams of first and second fuse units of FIG. 5 , respectively,
[0021] FIGS. 9A and 9B are circuit diagrams of first fuse sets of FIGS. 8A and 8B , respectively, and
[0022] FIG. 10 illustrates a column repair operation according to an embodiment of the present invention.
DETAILED DESCRIPTION
[0023] Hereinafter, a column repair circuit according to the present invention will be described below with reference to the accompanying drawings through various embodiments.
[0024] FIG. 1 is a block diagram of a column repair circuit according to an embodiment of the present invention.
[0025] The column repair circuit illustrated in FIG. 1 includes a combined mat address generation unit 1 and a fuse unit 2 .
[0026] The combined mat address generation unit 1 is configured to receive mat addresses MATADD< 0 ˜ 15 >, combine the received addresses by adjacent address, and output the combined addresses as combined mat addresses MAT< 0 ˜ 7 >. FIG. 1 illustrates a case in which the received mat addresses MATADD< 0 ˜ 15 > include 16 addresses where two adjacent addresses are combined to output eight combined mat addresses MAT< 0 ˜ 7 >. The combined mat address generation unit 1 is not limited to the embodiment of the present invention, but may receive various numbers of mat addresses MATADD and output various numbers of combined mat addresses MAT by combining the received mat addresses by a plurality of addresses.
[0027] The fuse unit 2 includes first to fourth fuse units 20 to 50 configured to receive the combined mat addresses MAT< 0 ˜ 7 > and a column address YADD< 2 : 9 > to generate redundancy column enable signals REN 1 to REN 4 , respectively. The column address YADD< 2 : 9 > is a code signal which is not decoded. The fuse unit 2 may include a fuse corresponding to each column address. In this embodiment of the present invention, the fuse unit 2 may include a fuse is corresponding to each bit of the column address, in order to perform a repair operation.
[0028] According to the embodiment of the present invention, fuse sets (not illustrated) corresponding to the respective bits of the 8-bit column address YADD< 2 : 9 >are provided to repair 256 columns. It is difficult to repair all the columns using only one fuse unit.
[0029] Accordingly, an efficient number of fuse units 20 to 50 may be included by taking into consideration factors such as available area for the fuse units as well as the repair yield.
[0030] The combined mat address generation unit 1 receives the mat addresses MATADD< 0 ˜ 15 >, combines the received mat addresses MATADD< 0 ˜ 15 > by adjacent address, and outputs the combination results as the mat addresses MAT< 0 ˜ 7 >. The received mat addresses MATADD< 0 ˜ 15 > are divided into a plurality of groups each including adjacent addresses. When any one of the addresses of one group is selected, a combined mat address corresponding to the selected address is selected and outputted to the fuse unit 2 .
[0031] Referring to FIG. 1 , the combined mat address generation unit 1 receives 16 mat addresses MATADD< 0 ˜ 15 >, and divides the received mat addresses MATADD< 0 ˜ 15 > into eight groups each including two adjacent addresses. For example, the mat addresses MATADD< 0 > and MATADD< 1 > may be combined and outputted, and the mat addresses MATADD< 2 > and MATADD< 3 > may be combined and outputted. In this way, eight combined mat addresses MAT< 0 ˜ 7 > are generated. When any one of the mat addresses MATADD< 0 > and MATADD< 1 > is selected, the corresponding combined mat address MAT< 0 > may be selected and outputted, and when any one of the mat addresses MATADD< 2 > and MATADD< 3 > is selected, the corresponding combined mat address MAT< 1 > may be selected and outputted. In this way, the selection for the eight combined mat addresses MAT< 0 ˜ 7 > is controlled. In this embodiment of the present invention, the combined mat addresses MAT are generated by combining the mat addresses by two adjacent addresses. However, the combined mat addresses MAT may be generated by combining the mat addresses by two or more addresses.
[0032] Each of the first to fourth fuse units 20 to 50 of the fuse unit 2 includes a fuse which is cut depending on whether or not a failure occurred in a corresponding memory cell. The fuse unit 2 determines whether or not to repair a column designated by the combined mat addresses MAT< 0 ˜ 7 > and the column address YADD< 2 : 9 > selected according to whether or not the fuse is cut.
[0033] FIG. 2 is a block diagram of the first fuse unit 20 . The detailed descriptions of the configuration of the first fuse unit 20 may also be applied to the second to fourth fuse units 30 to 50 .
[0034] The first fuse unit 20 includes first to eighth fuse sets 21 to 28 and a comparator 29 .
[0035] The number of the first to eighth fuse sets 21 to 28 corresponds to the bit number of the column address YADD< 2 : 9 >. Each of the fuse sets 21 to 28 includes a plurality of fuses corresponding to the number of the combined mat addresses MAT< 0 ˜ 7 >.
[0036] For example, referring to FIG. 3 , the first fuse set 21 includes a plurality of fuse FUSE 1 to FUSE 8 allocated to the first column address bit YADD< 2 >. The fuses FUSE 1 to FUSE 8 are connected to a plurality of transistors N 1 to N 8 to receive the combined mat addresses MAT< 0 ˜ 7 >, respectively. Depending on whether or not the fuses FUSE 1 to FUSE 8 are cut, the state of a first fuse signal YFUSE< 2 > is determined.
[0037] When none of the fuses are cut, a deactivated first fuse signal YFUSE< 2 > is outputted regardless of which one of the combined mat addresses MAT< 0 ˜ 7 > is selected. On the other hand, when any one of the combined mat addresses MAT< 0 ˜ 7 > is selected and a fuse corresponding to the selected address is cut, an activated first fuse signal YFUSE< 2 > is outputted.
[0038] The second to eighth fuse sets 22 to 28 include a plurality of fuses allocated to the second to eighth column address bits YADD< 3 : 9 >, respectively, and operate in a similar manner to the first fuse set 21 so as to output second to eighth fuse signals YFUSE< 3 ˜ 9 >.
[0039] The comparator 29 is configured to receive the column address YADD< 2 : 9 >, compare the received column address YADD< 2 : 9 > to the first to eighth fuse signals YFUSE< 2 ˜ 9 >, and output a first redundancy column enable signal REN 1 . When the first to eighth fuse signals YFUSE< 2 ˜ 9 > are matched with the inputted column address YADD< 2 : 9 >, the first redundancy column enable signal REN 1 is activated.
[0040] When the first redundancy column enable signal REN 1 is activated, columns of two mats corresponding to the selected combined mat address may be replaced with redundancy columns.
[0041] Similarly, when the second to fourth redundancy column enable signals REN 2 to REN 4 are activated according to the above-described manner, columns of two mats corresponding to the selected combined mat address may be replaced with redundancy columns.
[0042] FIG. 4 illustrates the column repair operation according to an embodiment of the present invention.
[0043] FIG. 4 illustrates a case in which failures occur in specific cells of first, third, fourth, and eighth mats in a main cell region. According to the embodiment of the present invention, two mat addresses are combined to perform a column repair operation. Although a failure occurs in a memory cell belonging to the first mat, corresponding columns of the first and second mats are replaced with redundancy columns. When failures occur in the same columns of the third and fourth mats, the repair operation may be performed more efficiently than when a repair operation is performed in one mat.
[0044] However, when column failures occur in the all mats due to reasons such as a tainted fabrication environment, all fuses corresponding to the mats must be cut, which is inefficient in terms of repair time and reliability. In order to remove the inefficiency, a repair operation may be set to be performed only by collectively is repairing a plurality of mats. Inefficienty would then be measured in terms of the repair operation.
[0045] FIG. 5 is a block diagram of a column repair circuit according to an embodiment of the present invention, illustrating a configuration for solving the above-described problems.
[0046] The repair circuit illustrated in FIG. 5 includes a combined mat address generation unit 1 _ 1 and a fuse unit 2 _ 1 .
[0047] The combined mat address generation unit 1 _ 1 is configured to receive mat addresses MATADD< 0 ˜ 15 > and to perform one or more combination steps according to a method of combining the received mat addresses MATADD< 0 ˜ 15 > by adjacent address and recombining the combination results by adjacent value. The combined mat address generation unit 1 _ 1 outputs the received mat addresses MATADD< 0 ˜ 15 > and the combination results of the aforementioned steps as first to fourth combined mat addresses MAT_ 16 < 0 ˜ 15 >, MAT_ 8 < 0 ˜ 7 >, MAT_ 4 < 0 ˜ 3 >, and MAT_ 2 < 0 ˜ 1 >, respectively. FIG. 5 illustrates a case in which the received mat addresses MATADD< 0 ˜ 15 > include 16 addresses, and each two adjacent addresses are combined at each step, but the present invention is not limited thereto. For example, the combined mat address generation unit 1 _ 1 may receive various numbers of mat addresses MATADD, combine the received mat addresses MATADD by a plurality of addresses, and output various combined mat addresses MAT.
[0048] The fuse unit 2 _ 1 includes first to fourth fuse units 200 to 500 . The first to fourth fuse units 200 to 500 are configured to receive a column address YADD< 2 : 9 > and the first to fourth combined mat addresses MAT_ 16 < 0 ˜ 15 >, MAT_ 8 < 0 ˜ 7 >, MAT_ 4 < 0 ˜ 3 >, and MAT_ 2 < 0 ˜ 1 >, to generate redundancy column enable signals REN 1 to REN 4 , respectively.
[0049] According to the embodiment of the present invention, the first fuse unit 200 receives the first combined mat addresses MAT_ 16 < 0 ˜ 15 > and performs a column repair operation for one mat. The second fuse unit 300 receives the second combined mat addresses MAT_ 8 < 0 ˜ 7 > and performs a column repair operation for two mats. The third fuse unit 400 receives the third combined mat addresses MAT_ 4 < 0 ˜ 3 > and performs a column repair operation for four mats. The fourth fuse unit 500 receives the fourth combined mat addresses MAT_ 2 < 0 ˜ 3 > and performs a column repair operation for eight mats.
[0050] FIG. 6 is a circuit diagram of the combined mat address generation unit 1 _ 1 .
[0051] In FIG. 6 , the combined mat address generation unit 1 _ 1 is divided into a first address combination unit 1 _ 11 and a second address combination unit 1 _ 12 , for convenience of description. The first and second address combination units 1 _ 11 and 1 _ 12 similar configuration, and the process of combining 16 mat addresses MATADD< 0 ˜ 15 > is divided into two parts. Hereafter, the detailed configuration of the first address combination unit 1 _ 11 will be described. The descriptions may be applied to the second address combination unit 1 _ 12 .
[0052] The first address combination unit 1 _ 11 includes eight buffer sections 1 A to 8 A, four first combination sections 1 B to 4 B, two second combination sections 1 C and 2 C, and one third combination section 1 D.
[0053] The buffer sections 1 A to 8 A are configured to buffer the eight mat addresses MATADD< 0 ˜ 7 > to output the buffered addresses as the first combined mat addresses MAT_ 16 < 0 ˜ 7 >. The buffer sections 1 A to 8 A include inverters IV 1 to IV 8 and buffer stages BUF 1 to BUF 8 , respectively, to buffer the eight mat addresses MATADD< 0 ˜ 7 >.
[0054] The first combination sections 1 B to 4 B are configured to divide the eight first combined mat addresses MAT_ 16 < 0 ˜ 7 > by two adjacent addresses, and to select a corresponding second combined mat address among the four second combined mat addresses MAT_ 8 < 0 ˜ 3 > when any one of each two adjacent addresses is selected. The first combination sections 1 B to 4 B include NAND gates ND 1 to ND 4 and buffer stages BUF 9 to BUF 12 , respectively. The NAND gates ND 1 to ND 4 are configured to receive two adjacent addresses among the inverted mat addresses MADADD< 0 ˜ 7 >, and the buffer stages BUF 9 to BUF 12 are configured to buffer outputs of the NAND gates ND 1 to ND 4 , respectively.
[0055] The second combination sections 1 C and 2 C are configured to divide the four second combined mat addresses MAT_ 8 < 0 ˜ 3 > by two adjacent addresses, to select a corresponding third mat address is between the two third combined mat addresses MAT_ 4 < 0 ˜ 1 >, when any one of each two adjacent addresses is selected. The second combination sections 1 C and 2 C include NOR gates NR 1 and NR 2 and buffer stages BUF 13 and BUF 14 , respectively. The NOR gates NR 1 and NR 2 are configured to receive two adjacent output signals among the output signals of the NAND gates ND 1 to ND 4 , and the buffer stages BUF 13 and BUF 14 are configured to buffer outputs of the NOR gates NR 1 and NR 2 , respectively.
[0056] The third combination section 1 D is configured to select and output the fourth combined mat address MAT_ 2 < 0 > when any one of the two third combined mat address MAT_ 4 < 0 ˜ 1 > is selected. The third combination section 1 D includes a NAND gate ND 5 configured to receive the output signals of the NOR gates NR 1 and NR 2 .
[0057] The first address combination unit 1 _ 11 receives the eight mat addresses MATADD< 0 ˜ 7 >, and generates the eight first combined mat addresses MAT_ 16 < 0 ˜ 7 >, the four second combined mat addresses MAT_ 8 < 0 ˜ 3 >, the two third combined mat addresses MAT_ 4 < 0 ˜ 1 >, and the one fourth combined mat address MAT_ 2 < 0 >.
[0058] Similarly, the second address combination unit 1 _ 12 receives the other eight mat addresses MADADD< 8 ˜ 15 >, and generates the other eight first combined mat addresses MAT_ 16 < 8 ˜ 15 >, the other four second combined mat addresses MAT_ 8 < 4 ˜ 7 >, the other two third combined mat addresses MAT_ 4 < 2 ˜ 3 >, and the other fourth combined mat address MAT_ 2 < 1 >.
[0059] The combined mat address generation unit may additionally include a combined mat address selection unit configured to output the third combined mat addresses MAT _ 4 < 0 ˜ 3 > instead of the fourth combined mat addresses MAT_ 2 < 0 ˜ 1 >, depending on the number of fuses which are to be included in a redundancy circuit. For example, the existing redundancy circuit includes 256 fuses. In this embodiment of the present invention, however, 240 fuses are needed when addresses are combined and outputted in the above-described manner. Therefore, when 256 fuses are to be used, the third combined mat addresses MAT_ 4 < 0 ˜ 3 > may be outputted instead of the fourth combined mat addresses MAT 2 < 0 ˜ 1 >.
[0060] FIG. 7 is a circuit diagram of a combined mat address selection unit 1 _ 13 which may be additionally included in the combined mat address generation unit.
[0061] The combined mat address selection unit 1 _ 13 includes a fuse FUSE 9 , a first selector 1 _ 13 a, and a second selector 1 _ 13 b.
[0062] Whether or not to cut the fuse FUSE 9 is determined according to an initial setting. Accordingly, a third combined mat address MAT_ 4 or a fourth combined mat address MAT_ 2 is selected.
[0063] A select signal SEL is determined according to whether or not the fuse FUSE 9 is cut. The selectors 1 _ 13 a and 1 _ 13 b are provided for the respective addresses, and each includes two pass gates PG 1 and PG 2 or PG 3 and PG 4 and one inverter IV 9 or IV 10 . The operation of the first selector 1 _ 13 a will be described as follows. When the select signal SEL is deactivated according to whether or not the fuse FUSE 9 is cut, the first pass gate PG 1 is turned on to output the third combined mat address MAT_ 4 < 0 >. On the other hand, when the select signal SEL is activated according to whether or not the fuse FUSE 9 is cut, the second pass gate PG 2 is turned on to output the fourth combined mat address MAT_ 2 < 0 >. The operation of the second selector 1 _ 13 b is performed in a similar manner.
[0064] FIGS. 8A and 8B are block diagrams of the first and second fuse units 200 and 300 , respectively. The third and fourth fuse units 400 and 500 may be configured in a similar manner as described with reference to FIGS. 8A and 8B .
[0065] The first and second fuse units 200 and 300 of FIGS. 8A and 8 B may be configured and operated in a similar manner to the first fuse unit 20 of FIG. 2 .
[0066] The first and second fuse units 200 and 300 include first to eighth fuse sets 210 to 280 and 310 to 380 and comparators 290 and 390 , respectively. The numbers of the first to eighth fuse sets 210 to 280 and 310 to 380 correspond to the bit number of the column address YADD< 2 : 9 >.
[0067] Each of the fuse sets 210 to 280 included in the first fuse unit 200 includes a plurality of fuses corresponding to the number of the first combined mat addresses MAT 16 < 0 ˜ 15 >.
[0068] For example, referring to FIG. 9A , the first fuse set 210 of the first fuse unit 200 includes a plurality of fuses FUSE 10 to FUSE 25 allocated for the first column address bit YADD< 2 >. The fuses FUSE 10 to FUSE 25 are connected to 16 transistors N 9 to N 24 to is receive the first combined mat addresses MAT_ 16 < 0 ˜ 15 >, respectively. The state of a first fuse signal YFUSE_ 16 < 2 > is determined according to whether or not the fuses FUSE 10 to FUSE 25 are cut.
[0069] When none of the fuses are cut, a deactivated first fuse signal YFUSE_ 16 < 2 > is outputted regardless of which one of the first combined mat addresses MAT 16 < 0 ˜ 15 > is selected. On the other hand, when any one of the first combined mat addresses MAT_ 16 < 0 ˜ 15 > is selected and a fuse corresponding to the selected address is cut, an activated first fuse signal YFUSE_ 16 < 2 > is outputted.
[0070] The second to eighth fuse sets 220 to 280 include a plurality of fuses allocated for the second to eighth column address bits YADD< 3 : 9 >, and operate in a similar manner to the first fuse set 210 so as to output second to eighth fuse signals YFUSE_ 16 < 3 ˜ 9 >, respectively.
[0071] The comparator 290 is configured to receive the column address YADD< 2 : 9 >, compare the column address YADD< 2 : 9 > to the first to eighth fuse signals YFUSE_ 16 < 3 ˜ 9 >, and output a first redundancy column enable signal REN 1 . When the first to eighth fuse signals YFUSE- 16 < 2 ˜ 9 > are matched with the inputted column address YADD< 2 : 9 >, the first redundancy column enable signal REN 1 is activated.
[0072] When the first redundancy column enable signal REN 1 is activated, a column of a mat corresponding to a selected first combined mat address may be replaced with a redundancy column.
[0073] Similarly, each of the fuse sets 310 to 380 included in the second fuse unit 300 includes a plurality of fuses corresponding to the number of the second combined mat addresses MAT 8 < 0 ˜ 7 >.
[0074] For example, referring to FIG. 9B , the first fuse set 310 of the second fuse unit 300 includes a plurality of fuses FUSE 26 to FUSE 33 allocated for the first column address bit YADD< 2 >. The fuses FUSE 26 to FUSE 33 are connected to eight transistors N 25 to N 32 to receive the second combined mat addresses MAT_ 8 < 0 ˜ 7 >, respectively. The state of a first fuse signal YFUSE_ 8 < 2 > is determined according to whether or not the fuses FUSE 26 to FUSE 33 are cut.
[0075] When none of the fuses are cut, a deactivated first fuse signal YFUSE_ 8 < 2 > is outputted regardless of which one of the second combined mat addresses MAT 8 < 0 ˜ 7 > is selected. On the other hand, when any one of the second combined mat addresses MAT_ 8 < 0 ˜ 7 > is selected and a fuse corresponding to the selected address is cut, the activated first fuse signal YFUSE_ 8 < 2 > is outputted.
[0076] The second to eighth fuse sets 320 to 380 include a plurality of fuses allocated for the second to eighth column address bits YADD< 3 : 9 > and operate in a similar manner to the first fuse set 310 so as to output second to eighth fuse signals YFUSE_ 8 < 3 ˜ 9 >.
[0077] The comparator 390 is configured to receive the column address YADD< 2 : 9 >, compare the column address YADD< 2 : 9 > to the first to eighth fuse signals YFUSE_ 8 < 3 ˜ 9 >, and output a second redundancy column enable signal REN 2 . When the first to eighth fuse signals YFUSE_ 8 < 21 9 > are matched with the inputted column address YADD< 2 : 9 >, the second redundancy column enable signal REN 2 is activated.
[0078] When the second redundancy column enable signal REN 2 is activated, columns of two mats corresponding to a selected second combined mat address may be replaced with redundancy columns.
[0079] Fuse sets (not illustrated) included in the third and fourth fuse units 400 and 500 may also include a plurality of fuses corresponding to the numbers of the third and fourth combined mat addresses MAT_ 4 < 0 ˜ 3 > and MAT_ 2 < 0 ˜ 1 >, respectively. According to the above-described operation, the third fuse unit 400 activates a third redundancy column enable signal REN 3 , and the fourth fuse unit 500 activates a fourth redundancy column enable signal REN 4 .
[0080] When the third redundancy column enable signal REN 3 is activated, columns of four mats corresponding to a selected third combined mat address may be replaced with redundancy columns.
[0081] When the fourth redundancy column enable signal REN 4 is activated, columns of eight mats corresponding to a selected fourth combined mat address may be replaced with redundancy columns.
[0082] FIG. 10 illustrates the column repair operation according to an embodiment of the present invention.
[0083] In a main cell region, a failure may occur in memory cells of individual columns, or a column failure may occur in the entire mats due to factors such as tainted process environments.
[0084] According to an embodiment of the present invention, when an individual memory cell failure occurs in a seventh mat, the first fuse unit 200 may activate the first redundancy column enable signal REN 1 to replace a single column with a redundancy column.
[0085] When a column failure occurs in first to eighth mats, the fourth fuse unit 500 may activate the fourth redundancy column enable signal REN 4 to replace columns of eight mats with redundancy columns.
[0086] When a column failure occurs in the fifth and sixth mats, the second fuse unit 300 may activate the second redundancy column enable signal REN 2 to replace columns of two mats with redundancy columns.
[0087] When a column failure occurs in the second and third mats, the third fuse unit 400 may activate the third redundancy column enable signal REN 3 to replace columns of four mats with redundancy columns.
[0088] While certain embodiments have been described above, it will be understood to those skilled in the art that the embodiments described are by way of example only. Accordingly, the column repair circuit described herein should not be limited based on the described embodiments. Rather, the column repair circuit described herein should only be limited in light of the claims that follow when taken in conjunction with the above description and accompanying drawings.
|
A column repair circuit of a semiconductor memory apparatus includes a plurality of mats and performs a column repair operation to replace failed cells among a plurality of memory cells provided in the mats. The column repair circuit includes two or more fuse units configured to perform the column repair operation. Each of the fuse units includes a plurality of fuses, and is configured in such a manner that m mats correspond to one fuse or n mats correspond to one fuse, where m and n are natural numbers equal to or more than 1 and different from each other.
| 6
|
BACKGROUND OF INVENTION
[0001] It is common for wells to include multiple zones. A completion string positioned in a well to produce fluids from one or more zones may include casing, production tubing, packers, valves, pumps, and other components. One or more well sections may be perforated using a perforating gun string to create openings in the casing and to extend perforations into corresponding zones. Fluid flows from the zones through the perforations and casing openings into the wellbore and up the production tubing to the surface.
[0002] In many wells, sand control has to be performed to prevent the production of sand along with hydrocarbons through the production string. Sand control is typically accomplished by use of sand face completion hardware, which typically includes a sand screen. In a well having multiple zones, the presence of certain completion hardware, such as sand face completion hardware, may complicate the placement of flow control conduits and flow control valves. The complexity of completion hardware associated with completing a well with multiple zones can lead to increased expenses associated with operating the well. Also, in some cases, the presence of completion hardware for multiple zones may prevent convenient intervention operations.
SUMMARY OF INVENTION
[0003] In general, enhanced methods and apparatus are provided to complete a well having multiple zones. For example, an apparatus for use in a well having at least three zones includes at least three sand control assemblies for positioning proximal respective zones. The apparatus further includes a flow assembly defining at least three flow conduits to respectively communicate with the at least three zones, where each of at least two of the flow conduits includes an annular path. At least three flow control devices respectively control flow in the at least three flow conduits.
[0004] Other or alternative features will become apparent from the following description, from the drawings, and from the claims.
BRIEF DESCRIPTION OF DRAWINGS
[0005] FIG. 1 illustrates a completion string incorporating an embodiment of the invention.
[0006] FIGS. 2A-2C are cross-sectional views of the completion string of FIG. 1 .
DETAILED DESCRIPTION
[0007] In the following description, numerous details are set forth to provide an understanding of the present invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these details and that numerous variations or modifications from the described embodiments are possible.
[0008] As used here, the terms “up” and “down”; “upper” and “lower”; “upwardly” and downwardly”; “upstream” and “downstream”; “above” and “below”; and other like terms indicating relative positions above or below a given point or element are used in this description to more clearly described some embodiments of the invention. However, when applied to equipment and methods for use in wells that are deviated or horizontal, such terms may refer to a left to right, right to left, or other relationship as appropriate.
[0009] FIG. 1 is a general view of a completion string positioned in a well 100 . Although the well 100 depicted in FIG. 1 has one wellbore, it is contemplated that a well can have multiple bores, such as multilateral or branch bores. The well 100 has at least three zones 102 , 104 , and 106 . In other implementations, the well 100 may have additional zones (such as four or more). The zones 102 , 104 , and 106 are stacked one above another generally along an axial direction of the wellbore 100 . In this stacked arrangement, particularly when sand control equipment is used, it is sometimes difficult to provide flow conduits through the completion string in an efficient manner.
[0010] In accordance with some embodiments of the invention, three flow conduits 108 , 110 , and 112 are provided by a flow assembly in the completion string. In the implementation of FIG. 1 , the first flow conduit 108 communicates with the zone 102 through a first sand control assembly 114 . The second flow conduit 110 communicates with the second zone 104 through a second sand control assembly 116 . The third flow conduit 112 communicates with the third zone 106 through a third sand control assembly 118 . Note that in the depiction of FIG. 1 , the zone 102 is the most distal zone of the well from the well earth surface, whereas the zone 106 is the most proximal zone to the well earth surface.
[0011] The first flow conduit 108 extends through the inner bore of a tube or pipe. As used here, the term “tube” or “pipe” refers to an elongated structure that defines an inner bore. The elongated structure can be formed of one segment or of plural segments that are attached or coupled to each other. Although some embodiments of a “tube” or “pipe” are generally cylindrical in shape, other embodiments of a “tube” or “pipe” do not have to be cylindrically shaped. The terms “tube” and “pipe” are used interchangeably.
[0012] The second flow conduit 110 is an annular path that is defined outside of the tube that defines the first flow conduit 108 . In some embodiments, the second flow conduit 110 is the annular path between a first tube containing the first flow conduit 108 and a second tube having a larger diameter than the first tube.
[0013] Similarly, the third flow conduit 112 is an annular path that is defined outside of the second tube. The third flow conduit 112 , in some embodiments, is defined between the second tube and a third tube having a larger diameter than the second tube. A portion of the third flow conduit 112 includes a wellbore annulus region 120 , according to one embodiment.
[0014] Also shown in FIG. 1 are several packers 122 , 124 , 126 , 128 , 130 , and 132 . In other implementations, the number of packers can vary. The packers are provided to provide isolation between zones. Thus, any number of packers that provide adequate isolation between zones can be employed.
[0015] Flow control devices are also part of the completion string to control fluid flow in the flow conduits 108 , 110 , and 112 . A first flow control device 134 controls fluid flow through the first flow conduit 108 . In one implementation, the first flow control device 134 is a ball valve that is actuatable between an open position and a closed position.
[0016] In other embodiments, other types of valves can be used in the flow control device 134 . Examples of other valves include flapper valves, sleeve valves, barrel valves, and so forth.
[0017] A second flow control device 136 controls fluid flow in the second flow conduit 110 . In one implementation, the second flow control device 136 includes a sleeve valve, although other types of valves can be used in other embodiments.
[0018] A third flow control device 138 controls fluid flow in the third flow conduit 112 . Again, the third flow control device 138 is implemented as a sleeve valve in one embodiment. In other embodiments, the flow control device 138 can be implemented with other types of valves.
[0019] Each of the flow control devices 134 , 136 , and 138 is remotely actuatable by use of signals transmitted from the well surface to the flow control devices 134 , 136 , and 138 . For example, the flow control devices 134 , 136 , and 138 can be electrically activated between open and closed positions. Electrical activation can be accomplished by using electrical lines run from the well surface to the flow control devices. Alternatively, hydraulic pressure can be used to control the flow control devices 134 , 136 , and 138 . The hydraulic pressure can be communicated through control lines that are run from the well surface. Pressure pulses can also be transmitted through fluids in the wellbore to perform actuation of the flow control devices. Also, fiber optic lines can be run from the well surface, with optical signals transmitted through the fiber optic lines to control the flow control devices. Remote mechanical actuation can also be performed by use of mechanical signals (such as by lifting and dropping a portion of the completion screen in a predetermined sequence to control activation of the flow control devices 134 , 136 , and 138 ). Wireless techniques, such as electromagnetic, seismic, and acoustic telemetry, may also be used to communicated with the flow control devices.
[0020] In other embodiments, the flow control devices 134 , 136 , and 138 are multi-position flow control device having at least one additional position between on and off.
[0021] Once activated, each of the flow control devices 134 , 136 , and 138 controls fluid communication between the flow conduits 108 , 110 , and 112 , respectively, and a flow path 140 that extends upwardly, such as to the well surface through a production tubing.
[0022] Although not shown, sensors (e.g., flow rate sensors, pressure sensors, temperature sensors, etc.) can also be provided in the flow conduits 108 , 110 , and 112 . The sensors are provided to measure characteristics associated with fluid flow from the zones 102 , 104 , and 106 .
[0023] FIGS. 2A-2C provide cross-sectional views of a portion of the completion string of FIG. 1 . The bottom part of FIG. 2C shows the lower-most packer 122 and sand control assembly 114 . The sand control assembly 114 includes two sand screens 200 and 202 stacked one on top of the other. In other implementations, one sand screen can be used in the sand control assembly 114 . Fluid flows from surrounding formation (of the first zone 102 ) through the sand screens 200 and 202 into an inner bore 204 defined by a first tube 206 . Note that the first tube 206 includes many segments as depicted in FIGS. 2A Rather than label each of these segments with a different reference number, the segments are referred to collectively as a “tube” 206 . The segments of the tube 206 include all segments that define the inner bore 204 , which is part of the first flow conduit 108 . An isolation sub 208 includes a ball valve 210 . During run-in of the completion string, the ball valve 210 is in a closed position. However, once the completion string is installed, the ball valve 210 is opened and kept open during production. The ball valve 210 has a bore through which intervention equipment can pass.
[0024] The inner bore 204 (and first flow conduit 108 ) extend through the packer 124 that is located above the isolation assembly 208 . The flow conduit 108 also extends through another packer 126 located above the packer 124 . The packer 126 is connected to the second sand control assembly 116 , which also includes a sand screen 212 . As shown at the top part of FIG. 2C , flow from the surrounding formation (in zone 104 ) passes through the sand screen 212 into an annular path 214 that is defined outside the tube 206 defining the first flow path 108 . The annular path is defined between the first tube 206 and a second tube 216 ( FIG. 2B ) that has a larger diameter than the first tube 206 . The second flow conduit 110 extends through the annular path between the first tube 206 and the second tube 216 . As with the first tube 206 , the second tube 216 also includes multiple segments, which are collectively referred to as “tube” 216 .
[0025] The first and second flow conduits 108 and 110 extend through the next upper packer 128 . The packer 128 is connected to the third sand control assembly 118 , which includes a sand screen 218 . Fluid flows through the sand screen 218 into an annular path 220 defined between the second tube 216 and a third tube 222 . The annular region 220 is part of the third flow conduit 112 . The first, second and third flow conduits extend through the next packer 130 .
[0026] In one embodiment, at least portions of the first, second, and third tubes have a common axis. In other words, these portions of the first, second, and third tubes are concentric.
[0027] The third flow conduit 112 extends into the well annulus 120 outside the second tube 216 . The ball valve 134 is located in the first flow conduit 108 (see the upper part of FIG. 2B ) to control fluid flow between the first flow conduit 108 and the flow path 140 in a production tubing. The ball valve 134 is remotely actuatable to rotate between open and closed positions. A sleeve valve 136 is provided slightly above the ball valve 134 to control fluid flow in the second flow conduit 110 . The sleeve valve 136 is slidable up and down (by remote actuation) to enable opening and closing of a port between the annular path 214 and the flow path 140 .
[0028] As depicted in FIG. 2A , the third flow conduit 112 extends through the well annulus 120 to the sleeve valve 138 , which is slidable up and down (by remote actuation) to open and close ports between the well annulus 120 and the flow path 140 .
[0029] In operation, depending on which of the zones 102 , 104 , and 106 are to be produced, one of the flow control devices 134 , 136 , and 138 is actuated to the open position, while the remaining two flow control devices are maintained in the closed position. Alternatively, if multiple zones are to be produced, then two or more of the flow control devices 134 , 136 , and 138 can be opened, with fluids from the multiple zones commingled for production in the flow path 140 to the well surface. In other implementations, instead of producing fluids from zones 102 , 104 , and 106 , injection can be performed in which fluid is injected into one or more of the zones 102 , 104 , and 106 . In similar fashion, the flow control devices 134 , 136 , and 138 control injection of fluids into respective zones 102 , 104 , and 106 .
[0030] Another valve can also be stacked in the lower completion (such as below sand control assembly 114 ) to incorporate flow from an additional zone, if desired. Such valve would provide selective fluid communication between the additional zone and the flow conduit 108 .
[0031] By using the flow assembly according to some embodiments of the invention, convenient placement of flow control devices in conjunction with sand control equipment can be accomplished. Also, by using the flow assembly according to some embodiments, intervention operations are made more convenient.
[0032] While the present invention has been described with respect to a limited number of embodiments, those skilled in the art, having the benefit of this disclosure, will appreciate numerous modifications and variations therefrom. For instance, the present invention may be installed in a land as well as a subsea wellbore. It is intended that the appended claims cover all such modifications and variations as fall within the true spirit and scope of this present invention.
|
An apparatus and method for use in a well having at least three zones includes at least three sand control assemblies for positioning proximal respective zones. A flow assembly defines at least three flow conduits to respectively communicate with the at least three zones, where each of at least two of the flow conduits includes an annular path. At least three flow control devices respectively control flow of the at least three flow conduits.
| 4
|
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is related to concurrently filed, co-pending, and commonly assigned U.S. application Ser. No. 12/553,846, entitled “SYSTEMS AND METHODS FOR ENHANCEMENT OF MEDICAL DEVICE TRACKING,” which filed on Sep. 3, 2009, is incorporated by reference in its entirety.
TECHNICAL FIELD
This disclosure is related to medical device controls and more specifically to systems and methods for controlling electronic medical devices in a sterile environment.
BACKGROUND OF THE INVENTION
The use of electronic medical devices of all types is now routine. Often these devices are used in environments where adjustments must be made during the course of a medical procedure. In many situations, these adjustments need to be made to a control, or set of controls that may be preferably remotely located from the operator.
By way of example, a sonographic procedure is performed by a sonographer holding a scan-head probe against a patient's body and moving the probe along the body's contours in order to facilitate obtaining the desired image. While the sonographer is moving the probe with one hand it is often necessary to make one or more adjustments with respect to controls located on a control panel located separately from the probe. Typically, the sonographer must stretch spread-eagle style to reach both the control panel and the patient at the same time.
In some situations, remote control buttons can be placed on the probe to avoid requiring the operator to reach one hand for controls mounted behind or off to the side of the location where the probe is being used. However, in the case of a sterile environment the operator must not touch any non-sterile controls. This then presents a problem when any adjustments must be made during the course of the procedure.
BRIEF SUMMARY OF THE INVENTION
If simple control of a key parameter is needed, by incorporating a presence detector at the top of a control unit and one at the bottom of the control unit, the operator need only waive a hand near one or the other of the embedded detectors to control an up or down setting of a medical device. In one embodiment, the longer the hand is held over a detector the more adjustment the system will make. In another embodiment, safety mechanisms protect against false readings, for example, by not reacting when both detectors concurrently sense a presence.
The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention, reference is made to the following descriptions taken in conjunction with the accompanying drawing, in which:
FIG. 1 shows one embodiment of a medical device employing the concepts of the invention;
FIG. 2 illustrates one embodiment of a control system for using proximity detectors for controlling a medical device; and
FIGS. 3 and 4 show embodiments of flow charts for controlling methods for utilization of proximity detectors.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows one embodiment of medical device 10 having control interface 11 and controlled system 100 employing the concepts of the invention. In the embodiment shown, the system is turned on by the operator pushing button 12 of control interface 11 . Control interface 11 is connected, usually by a cable, such as cable 101 or possibly via RF link, such as Bluetooth™, to a controlled system, such as system 100 . The control interface 11 may be attached to the controlled system 100 or physically separated therefrom as shown. Control interface 11 can be a remote control of a device or embedded in the device itself. Controlled system 100 , when used for sonographic procedures could be as shown in the '363 patent or any other sonographic control system. Note that these are only examples and the inventive concepts can be used with any type of system that requires an operator to change parameters without making physical contact with a control circuit.
By way of example; to control the level of some parameter, up or down, such as a light on the end of a catheter, auxiliary control button 13 can be used to turn on/off the light (or turn on/off other equipment). In such a situation the power (or other parameter) of the light (or other equipment) can be controlled by increase or decrease buttons 14 and 15 , respectively. If the operator desires to work in the hands-free mode then that mode is entered, for example, by operating both buttons 14 and 15 simultaneously.
Note that if the hand-free mode needed to be enabled without physically touching on/off switch 12 then proximity detectors 16 and 17 could be used, for example by moving an object, such as a hand or a sterile cloth, simultaneously or in some sequence into proximity with both of them for a period of time.
Once the hands-free mode is entered, the operator simply moves an object, such as a hand, into proximity with top sensor 17 when power is to be increased or into proximity with lower sensor 16 when power is to be decreased. Because the sensors are located top and bottom the direction of power change is intuitive for the operator. The length of time the object is maintained in proximity to the respective sensor determines the magnitude of the change. Alternatively, a wave of the hand could be used to signal the controller that a new incremental step up or down was requested.
In the embodiment illustrated, the actual sensors are within the housing of control interface 11 (as will be discussed with respect to FIG. 2 ) and their respective signals are presented to the operator via holes (labeled T and R in FIG. 1 ).
In order to prevent false readings, control logic verifies that both sensors 16 and 17 are not receiving presence signals simultaneously (except perhaps prior to hands-free operation when simultaneous reception for a certain length of time could equate to a turn on signal). Holes T and R are designed in this embodiment to have a relatively narrow “field of view” so that they will only sense within a defined area. The volume of the presence sensing space (cone of acceptance) is a combination of hole placement, hole opening size, signal power and distance the actual sensor is placed behind the aperture. If desired, one or more of these variables can be operator controllable. For example, one or both of the T, R apertures can be made variable so that the operator can change the shape of the cone of acceptance to adjust distance/sensitivity as desired. The sensors can be made to be selectively sensitive to only a narrow spectrum such as infrared. The apertures would advantageously have covers on them that are transparent to the infrared region of light. The covers could also be filters to prevent other signal sources from interfering in the operation. The light source T can also be modulated such that sensor R is selective to only that modulation thereby making the detector especially resistant to false readings.
In a preferred embodiment a narrow cone of acceptance is desired. Also, we contemplate that the timing for power increase will be a level change for each second of detected presence, but again that is controllable. Power level display 19 can be used to show the operator the current level by progressively changing the lighted ones of the dots or, if desired, a digital numerical display could be used.
Note that the system as illustrated is designed for binary operation such that the object (hand) is either being sensed or not sensed and the time of presence determines the magnitude of the change. However, the system could also be designed such that the magnitude of the parameter to change is a function of the closeness of the hand to the sensor. In that instance, only one sensor might be necessarily employed.
FIG. 2 illustrates one embodiment 20 of a control system for using proximity detectors for controlling the medical device shown in FIG. 1 . Sensors 16 and 17 can have analog or digital outputs. Analog output sensor would be used, for example, if closeness to the sensor is to be used in the calculation. If closeness to the sensor were to be used to determine a magnitude change, having a second sensor, is especially helpful to help prevent a false reading from persons moving in proximity to the control interface. False readings are also minimized by a narrowly focused cone of acceptance (as discussed above) by controller 22 . In the case of analog operation, the output is a numerical representation of the distance of the detected hand to the control interface. In the case of “digital”, the output is binary, i.e., detected or not detected. Thus, in the case of a digital detector, the output from sensors 16 and 17 would be either a “1” or a “0”.
Sensors 16 and 17 each send out a transmit signal which is preferably a modulated RF signal for more accurate presence detection. In the embodiment, the RF signal is transmitted using an infrared LED. When an object comes into the cone of acceptance, the modulated signal is reflected back to the respective R aperture (which need not be the same size as the transmit aperture) and sensor 16 or 17 . The returning reflected signal is detected by an infrared detector and demodulated to determine if an object is within the zone of acceptance or not. In the case of a digital detector, if a threshold is exceeded, it provides a digital signal, usually a “1” to controller 22 .
In one embodiment, sensors 16 and 17 can be GP2Y0A21YK (Analog type) or GP2Y0D21YK (Digital judgment type) obtained from Sharp Electronics Corporation. Note that the sensors can be any type of presence sensor, electromagnetic, ultrasound, unmodulated light, etc. Also note that while sensors 16 an 17 are paired on a single unit, there can be several different sensors and several different sensor types each controlling different functions or working in combination with each other to perform a single function with more accuracy.
As noted above, while the discussion centers on up/down control of a laser light, the system could also control up and down sensitivity or power or any other parameter of any type of medical device, including a power level (or formed beam direction control) of the probe itself.
The difference between analog and digital outputs from the sensor is that with digital the system need only detect presence or absence (1 or 0) and then make a decision about what one or the other means. In the case of the digital output, it is possible to set a detection threshold. Some sensors allow an iteratively adjustment and other devices are pre-set. Generally, close detection for a medical instrument is desired. For analog sensors the controller would interpret the actual voltage level in order to make the appropriate decisions.
FIG. 3 shows one embodiment 30 of a method for controlling the on/off of the hands-free operation for utilization of proximity detectors. The method illustrated in FIGS. 3 and 4 can be run on a processor, such as processor 22 - 1 , ( FIG. 2 ) in conjunction with memory 22 - 2 or it can be performed in hardware or in a combination of hardware and processor control.
Process 301 , working in conjunction with wait timer 306 , determines if the control interface is in the hand-free mode. If not, then the interface will not respond to the detection of presence at either sensor until the hand-free mode is activated. Activation can be by operation of a switch (such as switch 12 , FIG. 1 ) or as shown by process 302 if desired where simultaneous presence detection from the “up” and “down” sensors is determined. If process 301 had determined the system had already been in the hands-free mode, then upon process 304 determining that both detectors or both up and down switches are activated, the system would leave the hands-free mode via process 305 .
FIG. 4 shows one embodiment 40 of a method for controlling the up/down function of a controlled system by hands-free operation. Process 401 determines if the system is in the hands-free mode. If not, timer 407 waits for a period of time. When process 401 determines the system to be in the hands-free mode, process 402 determines if both sensors 16 and 17 are sending detection signals. If both detectors are doing so at the same time then this condition prevents both the up and down signals from being sent and timer 407 delays operation for a period of time, for example, two seconds.
Assuming now that an “up” presences has been detected alone, then process 403 , in conjunction with process 404 sends an output control signal indicating that power should be raised (or indicating that some other function should be increased).
Following a wait period determined by timer 408 (for example, one second), the process repeats. If the up presence is still being detected, another up control signal is sent. This continues until process 403 no longer detects a presence at the up presence detector.
The down presence detector works similar to the up detector only using processes 403 , 405 and 406 .
Note that if desired the operator can have an input to change the up and down times ( 408 , 406 , respectively). Note also that wait timer 407 and the up and down times need not be the same time intervals.
Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.
|
A medical device includes a control interface for operating the medical device in a hands-free mode. To control the medical device in a hands-free mode, the control interface includes multiple proximity sensors, each sensor associated with a level of adjustment. For example, a sensor located on a top portion of the medical device is used to increase the level of adjustment. And similarly, a sensor located on a bottom portion of the medical device is used to decrease the level of adjustment. The magnitude of the level of adjustment applied to a parameter of the medical device is controlled based at least in part on the length of time an object remains in proximity to a respective sensor. In one embodiment, the longer the object is held over a respective sensor the more adjustment the control interface will make to the parameter.
| 0
|
RELATED APPLICATIONS/PATENTS & INCORPORATION BY REFERENCE
The present application claims the benefit of Korean Patent Application No. 10-2006-0061741 filed Jul. 3, 2006 and U.S. Provisional Application No. 60/864,413 filed Nov. 6, 2006, the entire contents of which are hereby incorporated by reference.
Also, documents or references are cited in this text, either in a Reference List before the claims, or in the text itself; and, each of these documents or references (“herein cited references”), as well as each document or reference cited in each of the herein cited references (including any manufacturer's specifications, instructions, etc.), is hereby expressly incorporated herein by reference.
BACKGROUND
1. Technical Field
The present invention relates to novel diagnostic methods and kits for colorectal cancer (CRC). More specifically, the present invention relates to diagnostic methods, comprising the steps of; a) identifying recurrently altered regions (RAR) on chromosome; and (b) detecting genomic alterations in RAR.
Also the present invention relates to kits for prognosis assessment of colorectal cancer (CRC) and novel tumor suppressor genes for diagnosis of colorectal cancer (CRC).
2. Background Art
Colorectal cancer (CRC) accounted for about 1 million new cases in 2002 worldwide (9.4% of the world total). In terms of incidence, CRC ranks fourth in men and third in women. Mortality is about one half of incidence (about 529,000 deaths in 2002), while prevalence is second only to that of breast cancer worldwide, with an estimated 2.8 million persons alive with CRC diagnosed within 5 years of diagnosis. There is at least a 25-fold variation in occurrence of CRC worldwide. The incidence rates are highest in developed countries, while they tend to be low in Africa and Asia. In Korea, CRC cancer became the fourth leading cause of cancer death in 2004 and the age-standardized incidence rates of CRC in both sexes are higher than world average rates. These geographic differences are probably due to genetic background as well as environmental factors since CRC is one of multifactorial diseases; environmental and genetic factors interact and may work synergistically to develop a disease.
It is known that multiple mutations accumulate during the pathogenesis of CRC. Two major forms of genetic instability in CRC have been classified as either microsatellite instability (MIN) or chromosomal instability (CIN). In about 13% of CRC, mismatch repair deficiency leads to MIN, whereas in the remaining 87%, CIN appears to result in gains and losses of genetic materials. So, characterization of CIN may help to identify potential oncogenes and/or tumor suppressor genes and furthermore elucidate the pathogenesis of CRC.
To characterize CIN, conventional comparative genomic hybridization (CGH) has been used to identify multiple chromosomal imbalances in a sample from a single experiment. However, resolution of the conventional CGH is insufficient for precise identification of sub-microscopic changes. As accumulated evidence suggests that changes in genomic dosage contribute to tumorigenesis by altering the expression levels of cancer-related genes, more detailed analyses with high resolution are necessary.
There is thus a need for an improved diagnostic method.
The information disclosed in this Background section is only for enhancement of understanding of the background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art that is already known to a person skilled in the art.
SUMMARY OF THE INVENTION
The present invention has been made in an effort to provide a new diagnostic method and a kit for prognostic assessment of colorectal cancer. The present invention has been made based, at least in part, on the following discovery. To see genomic alterations and their clinicopatholigical implications in CRC, the present inventor applied genome-wide array CGH to the genomic DNAs extracted from microdissected tissues of 59 colorectal cancer cases. Using this strategy, various genomic copy number changes related to CRC including novel recurrently altered regions (RAR) were identified and associations between genetic alterations detected by array CGH and clinicopathological variables were examined.
As a result, twenty-seven RARs were identified in CRC and RAR-L1 and RAR-L20 found to be independent indicators of poor prognosis. Expression of CAMTA1, located in RAR-L1, was frequently reduced in CRCs and low CAMTA1 expression was significantly associated with poor prognosis, which indicates CAMTA1 plays as a tumor suppressor in CRC.
The present invention is broadly directed to a method for prognosis assessment of colorectal cancer (CRC) by identifying recurrently altered genomic regions (RAR) in colorectal cancer with high resolution (one Mb-resolution) microarray based comparative genomic hybridization (array CGH), and using the specific recurrently altered genomic regions in colorectal cancer as a prognostic marker for colorectal cancer progress.
In one aspect, the present invention provides a diagnostic method for prognostic assessment of colorectal cancer, comprising the steps of: (a) obtaining a nucleic acid sample from a subject; (b) identifying recurrently altered regions (RAR) on chromosome by array CGH; (C) detecting variation of expression of a specific gene in the RAR; and (d) performing prognostic assessment based on the detected variation.
In a preferred embodiment, the RAR in the step (b) may be one or more region selected from group consisting of RAR-L1 (loss of chromosome 1p36) and RAR-L20 (loss of chromosome 21q22). Preferably, the specific gene in the step (c) may be a cancer suppressor gene located in the RAR. More preferably, the cancer suppressor gene may be CAMTA1. When reduced gene expression level of CAMTA1 is detected, it may be assessed as poor prognosis.
In another aspect, the present invention provides a diagnostic kit for prognostic assessment of colorectal cancer, which comprises: (a) an array CGH instrument for identifying recurrently altered regions (RAR) on a chromosome; and (b) an image analysis device for detecting variation of expression of a specific gene in the RAR. The kit may further include a container for holding the instrument and device.
In still another aspect, the present invention provides a use of cancer suppressor gene CAMTA1 for prognostic assessment of colorectal cancer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an analysis result for genome of patients with colorectal cancer. A: Genome-wide profiles of patients with colorectal cancer, B: Frequencies of all significant gains and losses on chromosome
FIG. 2 shows an analysis result for verification of array-CGH copy number profiles. A: normal tissue DNA, B: tumor tissue DNA of CCRC80, C: tumor versus normal peak ratio plot
FIG. 3 shows an analysis result for examples of recurrently altered regions (RAR) and survival curves. A: Stage, B: RAR-L1 on 1p36, C: RAR-L4 on 1p31, D: RAR-L20 on 21q22, E: Graph of RAR-L1 (loss of chromosome 1p36), F: Graph of RAR-L20 (loss of chromosome 21q22).
FIG. 4 shows an analysis result for expression profiles of cancer suppressor genes. A: Plots of tumor/normal intensity ratios, B: Kaplan-Meier survival curves, C: Examples of missense mutation (SEQ ID NOS 35 and 36, respectively, in order of appearance).
DETAILED DESCRIPTION
Hereinafter, the present invention will be described in further detail with reference to examples. It is to be understood, however, that these examples are for illustrative purposes only and are not to be construed to limit the scope of the present invention.
Example 1
General Characteristics of Genomic Alterations in Colorectal Cancer
(1) Collection of Tissue Samples from Patients with Colorectal Cancer
Surgical specimens from 59 CRC patients, who underwent surgical resection during 1995 and 1997 at Dankook University Hospital, Cheonan, Korea, were examined in this invention. This examination was performed under the approval of Institutional Review Boards of Kangnam St. Mary's Hospital, The Catholic University of Korea, Korea. After surgical resection, tumor and adjacent normal tissues from each patient were collected separately and snap frozen in deep freezer. Frozen sections were prepared of 10 μm thickness on a gelatin coated slide using cryotom (Reighert-Jung, Germany). After H&E staining of frozen section, tumor cell rich area (more than 60% of tumor cells) and normal cell area were selected under the microscope and dissected manually. Microdissected tissues were transferred into the cell lysis buffer (1% proteinase-K in TE buffer) and genomic DNA was extracted by incubating at 50° C. for 12 hours. DNA from normal tissue was used as reference for array CGH. Extracted DNA was purified using a DNA purification Kit (Solgent, Daejon, Korea) and quantified using NanoDrop ND-1000 spectrophotometer (NanoDrop Technologies, Delaware USA). Histopathological review of the tumors was performed by experienced pathologist according to the standard TNM classification in the American Joint Committee on Cancer guidelines.
(2) Array Comparative Genomic Hybridization and Data Processing
We used human large-insert clone arrays with 1 Mb resolution across the whole genome printed by the Sanger Institute Microarray Facility (Fiegler et al, Genes Chromosomes Cancer 2003; 36:361-374; Kim T M et al, Clin Cancer Res 2005; 11:8235-8242.) Details of DNA labeling, pre-hybridization, hybridization, and post-hybridization processes are described below. Genomic DNA from cancer tissue was labeled with Cy3-dCTP and DNA from normal tissue of the same patient was labeled with Cy5-dCTP. Open-well hybridization was done as described previously. Arrays were scanned using GenePix 4100A scanner (Axon Instruments, USA) and the image was processed using GenePix Pro 6.0. Normalization and re-aligning of raw array CGH data were performed using the web-based array CGH analysis interface, ArrayCyGHt (URL: genomics.catholic.ac.kr/arrayCGH/). In brief, we used print-tip loess normalization method for analysis. Mapping of large insert clones was done according to the genomic location in the Ensembl and UCSC genome browser. In sum, 2,981 BAC clones out of initial 3,014 clones were processed. Information of whole clone set is available in the Ensembl human genome browser (URL: ensembl.org/Homo_sapiens/index.html).
(3) Data Analysis for Chromosomal Alterations
To set the cutoff value for chromosomal alterations of individual clones, we performed four independent series of normal hybridization (three self to self and one male to female hybridizations) as controls. Based on the control hybridizations, the cutoff value for copy number aberration was set to above or below 3-fold of standard deviation at individual data point. Regional copy number change was defined as DNA copy number alterations stretching across more than 2 consecutive BAC clones, but not across entire chromosomes. High-level amplification of clones was defined when their intensity ratios were higher than 1.0 in log 2 scale, and vice versa for homozygous deletion. The boundary of the copy number changes was assigned to the halfway between two neighboring clones. RAR was defined as regional copy number changes, which appear in at least 10 tumor samples.
(4) The Data of Genomic Alterations
The clinicopathological data of all 59 patients are summarized in Table 1. There were 39 men and 20 women and the mean patient age at the time of surgery was 58.7 years (range from 23 to 81). Among the 59 cases, 41 patients (69.5%) had rectosigmoid cancer. Thirty six cancers (61.0%) were categorized as early stage tumors. At the end of the follow up, 23 patients were dead.
TABLE 1
General characteristics of study subjects
Number of patients
59 (100%)
male
39 (66.1%)
female
20 (33.9%)
Age group
Male
59.2
Female
57.8
<60
31 (52.5%)
>=60
28 (47.5%)
Stage
Early (Satge I and II)
36 (61.0%)
Advanced (Stage III and IV)
23 (39.0%)
Tumor site
Rectosigmoid
41 (69.5%)
Other sites
18 (30.5%)
Note:
other sites denote ascending, transverse, descending colon and cecum
The overall genomic alterations detected in 59 colorectal cancers are illustrated in FIG. 1A . The frequency plot of the chromosomal changes shows that they are not randomly distributed, but clustered in several hot regions across the whole genome ( FIG. 1B ). The array CGH signal intensity ratio (log 2 scale) data of the 59 cases can be downloaded from our website (URL: lib.cuk.ac.kr/micro/CGH/colon.htm).
The mean number of altered clones per case was 764.8 out of total 2,981 clones (range from 58 to 1,540). The mean numbers of altered clones are significantly higher in males (832.6 vs. 632.6, p=0.04), advanced stage group (897.7 vs. 679.9, p=0.03), and rectosigmoid cancer (826.7 vs. 623.8, p=0.03). The most frequent changes of entire chromosomal arms were gains of 13q (31/59, 52.5%), 20q (30/59, 50.8%), 20p (23/59, 40.0%), 7p (21/59, 35.6%), 8q (20/59, 33.9%) as well as losses of 18q (29/59, 49.2%), 18p (27/59, 45.8%) and 17p (26/59, 44.1%).
Example 2
Verification of Copy Number Alterations
To verify the copy number changes identified, multiplex ligation-dependent probe amplification (MLPA) analysis was performed using MLPA-Aneuploidy test kit P095 (MRC Holland, Amsterdam, Netherlands) as described below. Briefly, genomic DNA (250 ng) was denatured for 10 minutes at 98° C. and 3 μl of probe-mix including buffer was added. Then the mixture was heated at 95° C. for 1 minute and incubated at 60° C. for 16 hours. Ligation reaction was performed using a heat stable ligase-65 enzyme at 54° C. for 15 minutes. Ten μl of ligation reaction was mixed with 40 μl of PCR reaction mix containing universal primers. One primer is unlabelled and the other is labeled with FAM [N-(3-fluoranthyl)maleimide]. The thermal cycling was as follows: 1 minute at 95° C. followed by 35 cycles of 30 sec at 95° C., 30 sec at 60° C., and 60 sec at 72° C. Analysis of the amplified fragments was performed using ABI PRISM 3730 XL DNA Analyzer (Applied Biosystems, Foster City, USA) with ROX-500 (ROX-500 Genescan, ABI, USA) as a size standard. The peak area of the PCR products was determined by Genotyper software (Applied Biosystems, Foster City, USA) and data analysis was performed using a simplified analysis method from Coffalyser macro (URL: mlpa.com).
To verify the copy number changes identified by array-CGH, we performed MLPA analysis with 13 primary CRCs showing copy number aberrations. Copy number alterations identified by array-CGH were generally consistent with MLPA results. FIG. 2 illustrates example of MLPA validation results. Twelve peaks (numbered at each peak) are the examples of copy number alterations on chromosome 13, 18, 21, and X.
Example 3
Recurrently Altered Regions
In addition to the entire chromosomal changes, a lot of regional copy number changes were identified. Among those regional changes, we defined the chromosomal region recurrently altered in at least 10 cases as RAR. In sum, 7 RAR gains (RAR-G) and 20 RAR losses (RAR-L) were detected. Table 2 lists the map position, size and cancer-related genes located in 27 RARs. Five RARs were detected in more than 40% of cases; RAR-G4 (28/59, 47.5%), RAR-L2 (27/59, 45.8%), RAR-L5 (25/59, 42.4%), RAR-L14 (28/59, 47.5%), and RAR-L17 (28/59, 47.5%) (Table 2).
TABLE 2
Recurrent genetic alteration regions in 59 colorectal cancers
Boundary
Size
Putative cancer
Alterations
BAC clone ID
Cytoband
(Mb)
(Mb)
Frequency
related genes
Gain
RAR-G1
RP11-440P5-RP11-373L24
2p16.1-p15
59.90-61.92
2.01
15/59
BCL11A, REL
RAR-G2
RP11-163H6-RP11-4S4D1S
3q26.2-q26.32
172.14-178.64
6.49
12/59
PLD1, ECT2,
RAR-G3
RP11-196O16-RP11-486P11
7p21.1
15.35-20.32
4.97
21/59
AGR2, TWIST1
RAR-G4
RP11-495D4-RP11-17E16
8q24.13-q24.21
126.22-131.11
4.88
28/59
MYC
RAR-G5
RP11-121C18-RP11-34N19
11p15.1-p14.3
20.97-23.47
2.49
11/59
RAR-G6
RP11-31I23-RP1-68D18
11p13
34.47-35.49
1.01
19/59
CD44
RAR-G7
RP3-404F18-RP3-394F12
Xq24-q25
117.92-125.02
7.10
21/59
BIRC4
Loss
RAR-L1
RP3-438L4-RP11-338N10
1p36.31-p36.23
6.52-8.43
1.90
15/59
CAMTA1
RAR-L2
RP11-428D12-RP1-86A18
1p33-p32.3
48.50-51.17
2.66
27/59
FAF1
RAR-L3
RP5-944F13-RP11-175G14
1p31.1
69.56-72.27
2.70
15/59
CTH, PTGER3
RAR-L4
RP5-963M5-RP4-739M21
1p31.1
76.26-77.47
1.20
23/59
RAR-L5
RP11-22A3-RP11-446J8
4p15.33-p15.32
12.05-17.17
5.11
25/59
RAR-L6
RP11-100N21-RP11-415L23
4p12
46.67-48.32
1.65
19/59
TEC
RAR-L7
RP11-87F15-RP11-347K3
4q34.1-q26.33
177.12-189.92
12.79
10/59
CLDN22, IRF2,
ING2, CASP3
RAR-L8
CTD-2011L22-RP11-20O13
5q14.3-q15
91.52-93.36
1.83
12/59
RAR-L9
RP11-391B7-CTC-279E3
5q33.3-q34
157.36-160.78
3.41
12/59
RAR-L10
RP3-365E2-RP1-13D10
6p23-p22.3
13.97-17.02
3.04
19/59
RAR-L11
RP11-338B22-RP11-16H11
8p23.3-p23.2
0.46-4.49
4.02
23/59
RAR-L12
RP11-325D15-RP11-619F23
10q22.2-q22.3
77.33-79.26
1.91
13/59
RAR-L13
RP11-381K7-RP11-426E5
10q25.2
112.7-114.46
1.75
12/59
ACSL5
RAR-L14
RP11-164H13-RP11-76E12
14q32.13-q32.2
95.15-97.53
2.40
28/59
RAR-L15
RP11-353B9-RP11-105D1
15q21.1-q21.2
47.35-49.35
1.99
17/59
RAR-L16
RP11-231A23-RP11-24N10
15q22.2-q22.31
57.44-61.74
4.29
21/59
ANXA2, RORA
RAR-L17
RP11-401O9-RP11-219A15
17p13.1-p11.2
9.83-17.02
7.18
28/59
SCO1
RAR-L18
RP5-836L9-RP11-121A13
17p11.2
19.88-22.24
0.35
23/59
RAR-L19
RP1-270M7-RP1-152M24
21q11.2-q21.1
15.21-16.83
1.61
18/59
RAR-L20
RP11-98O13-RP5-1031P17
21q22.13-q22.2
37.50-40.67
3.16
13/59
Note:
The frequency represents the number of samples with the corresponding genomic change out of 59 colorectal cancers.
Several cancer-related genes are included in the RARs. For example, known oncogenes such as MYC and REL as well as putative oncogens such as BLC11A, PLD1, ECT2, AGR2, TWIST1, and BIRC4 are included in the RAR-Gs. Also, a number of known or putative tumor suppressor genes such as CAMTA1, FAF1, CTH, PTGER3, TEC, CLDN22, ING2, IRF2, ACSL5, ANXA2, RORA, and SCO1 are located in the RAR-Ls.
Example 4
High Copy Number Changes
All high-level amplifications and homozygous deletions along with the putative cancer-related genes located in them are summarized in Table 3.
TABLE 3
Genomic segments representing high copy number changes in 59 colorectal cancers
Boundary
Size
Observed
Putative cancer-
Change
BAC clone ID
Cytoband
(Mb)
(Mb)
cases a
related genes
Amp
RP11-449G3-RP4-725G10
7p12.1-p11.2
53.47-56.26
2.78
CCRC93
EGFR
RP4-550A13-RP11-506M12
7q22.1
97.86-99.59
1.72
CCRC29
MCM7
RP11-90J7-RP11-20E23
10q22.3-q23.1
79.26-83.53
4.27
CCRC37
RP5-1096D14-RP11-319E16
12p13.33-p13.31
1.43-5.57
4.13
CCRC33
CCND2, FGF6, FGF23,
AKAP3
RP11-129M14-RP11-332E3
13q21.31-q22.2
64.90-75.98
11.07
CCRC59
KLF5
RP11-564N10-RP11-255P5
13q33.1
100.86-102.84
1.97
CCRC72
FGF14
RP11-265C7-RP11-245B11
13q34
112.49-113.85
1.35
CCRC19
CUL4A, TFDP1
RP11-390P24-RP11-94L15
17q12-q21.2
34.71-35.45
0.73
CCRC17,
PPARBP, PPP1R1B,
81
STARD3, TCAP, PNMT,
ERBB2, GRB7, CDC6,
RARA
RP11-13L22-RP11-28F1
18q21.33
57.72-59.73
2
CCRC80
RP3-324O17-RP4-633O20
20q11.21-q11.23
28.92-36.34
7.41
CCRC12,
ID1, BCL2L1, HCK,
90, 93
TPX2, MYLK2, PLAGL2,
TGIF2, SRC
RP5-1028D15-RP4-719C8
20q13.12-q13.33
41.66-58.31
16.64
CCRC 11,
MYBL2, RAB22A
43, 72, 90,
93
HD
RP11-350K6-RP11-520K18
18q21.31-q21.33
54.78-57.70
2.91
CCRC73
PMAIP1/NOXA
RP11-25L3-RPU-396D4
18q22.3-q23
69.26-71.83
2.56
CCRC73
—
Note:
Amp, amplification; HD, homozygous deletion.
a In case of more than two cases observed, the boundary of high copy number change was defined as the most extended set of clones, so they were not necessarily overlapping.
In sum, 11 genomic segments of high-level amplifications and 2 homozygous deletions were identified at least in one case. Although, most high copy number changes were identified in single case, amplifications on 17q12, 20q11 and 20q13 were observed in more than two cases. There are known oncogenes such as EGFR, CCND2, ERBB2, and MYBL2 in the amplified regions. Also, there are several putative cancer-related genes in the high copy number change regions (Table 3).
Example 5
Correlation Between Genomic Alterations
Pairwise correlation analysis between the RARs was done to investigate the significant co-occurrence of them. For comparison, all possible pairs of RARs located on different chromosomal arms were considered. Five pairs of RARs were found to be significantly correlated to each other after adjusting for multiple testing. The RAR-L5 on 4p15 correlates with the RAR-L2 on 1p33 (r=0.66; padj=0.0001) and the RAR-G7 on Xq24 (r=0.51; padj=0.042). The RAR-L17 on 17p13 correlates with the RAR-L5 on 4p15 (r=0.56; padj=0.0073) and the RAR-L14 on 14q32 (r=0.59; padj=0.0022). The RAR-L6 on 4p12 correlates with the RAR-L2 on 1p33 (r=0.53, padj=0.02).
We further investigated whether significantly correlated RARs share functionally related genes using public gene database, Gene Ontology (GO). We selected genes that have the same functional annotations (e.g. signal transduction) but are separately located on two correlated RARs. Three RAR pairs were found to share functionally related genes across 12 annotations.
TABLE 4
Functionally related genes shared by significantly co-occurred RARs
Pathway
RefSeq
Symbol
RAR-G7
RAR-L5
RAR-L17
RAR-L14
0.0428
adjusted p-value
0.0073
0.0022
Receptor activity
NM_000623
BDKRB2
1
NM_000676
ADORA2B
1
NM_000710
BDKRB1
1
NM_001775
CD38
1
NM_006667
PGRMC1
1
NM_012452
TNFRSF13B
1
Regulation of transcription, DNA-dependent
NM_001189
BAPX1
1
NM_006777
ZBTB33
1
NM_017544
NKRF
1
NM_020653
ZNF287
1
NM_020787
ZNF624
1
NM_032498
PEPP-2
1
NM_144680
ZNF18
1
NM_153604
MYOCD
1
Transcription factor activity
NM_001189
BAPX1
1
NM_006470
TRIM16
1
NM_020653
ZNF287
1
NM_032498
PEPP-2
1
NM_144680
ZNF18
1
Sensory perception
NM_000623
BDKRB2
1
NM_006017
PROM1
1
NM_016113
TRPV2
1
Signal transduction
NM_000676
ADORA2B
1
NM_000710
BDKRB1
1
NM_001775
CD38
1
NM_003010
MAP2K4
1
NM_005130
FGFBP1
1
NM_016084
RASD1
1
Development
NM_001290
LDB2
1
NM_004334
BST1
1
NM_006978
RNF113A
1
ATP binding
NM_002470
MYH3
1
NM_002472
MYH8
1
NM_003010
MAP2K4
1
NM_003384
VRK1
1
NM_003802
MYH13
1
NM_005963
MYH1
1
NM_017533
MYH4
1
NM_017534
MYH2
1
Generation of precursor metabolites and energy
NM_001775
CD38
1
NM_004541
NDUFA1
1
Hydrolase activity
NM_001775
CD38
1
NM_004278
PIGL
1
NM_004334
BST1
1
Protein amino acid phosphorylation
NM_003010
MAP2K4
1
NM_003384
VRK1
1
G-protein coupled receptor protein signaling pathway
NM_000623
BDKRB2
1
NM_000676
ADORA2B
1
NM_000710
BDKRB1
1
NM_016084
RASD1
1
Transcription
NM_020653
ZNF287
1
NM_032632
PAPOLA
1
Example 6
Differential Distribution of Genetic Alterations According to Clinicopathologic Parameters
Four types of clinical variables (age, stage, sex, tumor site) were analysed for their associations with the genomic alterations identified. The RAR-G7, RAR-L11, RAR-L12, RAR-L13, RAR-L16, RAR-L17, RAR-L18, gains of 8q, 19p, X, loss of 14q, 15q, Xq, and Y were associated with sex. The RAR-G3, RAR-L1, RAR-L2, RAR-L5, RAR-L6, RAR-L20, loss of 1p, and 4p were found to be associated with advanced tumor stage. The RAR-G7, RAR-L4, RAR-L9, RAR-L11, RAR-L12, gains of 13q, 20p, 20q, losses of 18p, and 18q were associated with rectosigmoid tumor site.
Example 7
Survival Analysis with Genomic Alterations
Survival analysis was performed to assess the prognostic values of the clinicopathological parameters and the RARs. In univariate analysis, advanced stage (p=0.001), RAR-L1 (p=0.000), RAR-L4 (p=0.026), and RAR-L20 (p=0.031) were significantly associated with poor survival ( FIG. 3 ). The statistically highest significance was observed for the existence of RAR-L1.
Multivariate analysis using all the significant genomic alterations identified in univariate analysis as well as clinical variables such as age, sex and stage of tumor revealed that two RARs (RAR-L1 and RAR-L20), age, and stage are independent predictors for poor outcome in CRC (Table 5). Representative diagrams of these two RARs showing significant association with patient survival are illustrated in FIGS. 3E and F.
TABLE 5
Result of Cox regression analysis
95% Confidence interval
Variable
Hazard ratio
Lower
Upper
p value
Age
9.979
2.688
37.050
0.001
Stage
5.073
1.880
13.689
0.001
RAR-L1
8.151
2.167
30.657
0.002
RAR-L20
3.528
1.098
11.339
0.034
Age
6.455
2.034
20.488
0.002
Stage
7.409
2.481
22.124
0.000
Low CAMTA1
7.089
2.121
23.688
0.001
Note:
upper table, Cox regression using all the significant genomic alterations identified in univariate analysis as well as clinical variables such as age, sex and stage; lower table, Cox regression using CAMTA1 expression status and clinical variables such as age, sex and stage.
Example 8
Expression of Putative Cancer-Related Gene in Survival-Associated RARs
(1) Real-Time Quantitative PCR Assay
The first-strand cDNA was synthesized from total RNA of 44 pairs of cancer/normal tissues and 3 cell lines (RKO, HT29 and HCT116) using M-MLV reverse transcriptase (Invitrogen, Carlsbad, Calif.). Real-time quantitative PCR for analyzing CAMTA1 expression profile was performed using Mx3000P qPCR system and MxPro Version 3.00 software (Stratagene, CA, USA). The real-time qPCR mixture of 20 μl contained 10 ng of cDNA, 1X SYBR® Green Tbr polymerase mixture (FINNZYMES, Finland), 0.5×ROX, and primers of 20 pmole. GAPDH was used as an internal control in each procedure. The thermal cycling was as follows: 10 min at 95° C. followed by 40 cycles of 10 sec at 94° C., 30 sec at 54° C. and 30 sec at 72° C. To verify specific amplification, melting curve analysis was performed (55-95° C., 0.5° C./sec). Relative quantification was performed by the ΔΔCT method. We defined 40% reduction of expression in cancer tissue as low CAMTA1 expression. All the experiments were repeated twice and mean value of intensity ratio with standard deviation was plotted for each case. Primer sequences for CAMTA1 real-time quantitative PCR were as follows: 5′-AGTGCAGAAAATGAAGAATGCG-3′ (SEQ ID NO: 1) and 5′-CAAAATTCTCCTGCTTGATTCG-3′ (SEQ ID NO: 2) for forward and reverse, respectively.
(2) CAMTA1 Mutation Analysis
Somatic mutation of CAMTA1 was screened by PCR-direct sequencing. Primer sets for amplification of specific exons were prepared as described previously with some modifications. All the amplification was performed using Phusion™ High-Fidelity DNA polymerase (FINNZYMES, Finland). PCR products were purified using MEGA-spin™ gel extraction kit (iNtRON, Korea).
TABLE 6
Primer sequences for CAMTA1 mutation analysis
(SEQ ID NOS 3-34,
respectively, in order of appearance)
Forward primer
Reverse primer
Exon1
CCACTAGGAAGCTTTGTTTAG
CTCTTACCTTCCGGCCTTGTT
GT
T
Exon2
TTGGCAGGAATATCACAGAAG
TTTTGCTACCCCAGAAGGATT
AG
A
Exon3
GGAGATTTTATCTATTATTTT
GGACTATGTGAAGCAACCTAA
CTCTA
Exon4
AACAGCAAAAACTTTCTTACC
CCAAATCAGGTAATCAATGCA
TCTC
Exon5
TTTCTTCTACTTGGTACTCTT
AATGACATTTGTGCACCAAGG
GGTA
Exon6
CCCTCTTTCCAACTGAATTCT
CCAGAGACAGAAGAAGAATCC
C
Exon7
AGTCTGCTAATATCCCACATG
TGGTTGATGCCAGCCTGGTTC
CGC
Exon9
CCAGCACCATGGCCTACATGC
CAGCGGCGGCAGCTTACCTCT
Exon10
AACTCTGTTCCCCTCTCTGTT
CAGGCCATCACACTCACCTTG
CTCT
Exon11
CATTAAGGAGAGCTGGACATT
ACGACCCAAGCACTGTTCTTA
A
Exon13
GTGGTATGCGAGAAGATGATG
CAGTGCTCAGGAAGAATGTGA
Exon14
TACCCAGTTGGGTTTCATCTT
ATGCCAGACTGGAAGAACAGC
GGTG
AAG
Exon15-1
GGTCTTGACCTCTGATTGAGA
CTCTGCTAATTTCACATGACC
Exon15-2
ATCTCGATTCCCGACTCTCTA
ATAACAGTGACTCCCTTGGGT
G
Exon19
AAGCTGACATTTCTGGTAGTT
TTTAGCCAAACCAGGATCTTC
AATC
Exon20
TTCTCTTCTTCCCTTCCCGGT
AAGTCAGAGTTCTCTTCCCTA
A
GGG
Among the coding genes in RAR-L1 and RAR-20, CAMTA1 was suggested as a putative tumor suppressor gene in neuronal tumor. Therefore, we examined the expression profile of this gene in three CRC cell lines and 44 pairs primary CRCs by real-time quantitative PCR. Ratio of gene expression values (cancer versus normal) was calculated. All three cell lines and 26 CRCs out of 44 (59.1%) showed low expression of CAMTA1 compared with normal tissue ( FIG. 4A ). Low CAMTA1 expression was significantly associated with poor survival than CAMTA1 intact cases (p=0.029) ( FIG. 4B ). After being adjusted for age, sex and stage by Cox regression, low CAMTA1 expression showed more significant association with poor survival as an independent predictor (HR=7.089, p=0.001) (Table 5).
Low CAMTA1 expression was observed more frequently in the CRCs with RAR-L1 (70%, 7/10) than those without RAR-L1 (55.9%, 19/34) and expression level was also lower in CRCs with RAR-L1 (mean ratio 0.74) than those without RAR-L1 (mean ratio 0.93), but not significantly. For further exploring putative mechanisms of low CAMTA1 expression, we screened somatic mutations (26 CRCs) and methylation status (38 CRCs). One missense mutation was found in a primary CRC (CCRC71), which showed low CAMTA1 expression but without RAR-L1 ( FIG. 4C ). However, no hypermethylation was observed in the promoter region of CAMTA1 (data not shown).
The invention has been described in detail with reference to preferred embodiments thereof. However, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
All patents and publications mentioned in this specification are herein incorporated by reference to the same extent as if each independent patent and publication was specifically and individually indicated to be incorporated by reference.
REFERENCES
1. Parkin D M, Bray F, Ferlay J, Pisani P. Global cancer statistics, 2002. CA Cancer J Clin 2005; 55:74-108.
2. National Statistical Office, Korea. Korean Statistical Information System. 2006. Available from: URL: ncc.re.kr.
3. Shin H R, Won Y J, Jung K W, Kong H J, Yim S H, Lee J K, Noh H I, Lee J K, Park J G. Nationwide Cancer Incidence in Korea, 1999-2001; First result using the National Cancer Incidence Database. Cancer Res Treat 2006; 37:in press.
4. Michor F, Iwasa Y, Lengauer C, Nowak M A. Dynamics of colorectal cancer. Semin Cancer Biol 2005; 15:484-493.
5. Yim S H, Chung Y J. Current Status and Future Clinical Applications of Array based Comparative Genomic Hybridization. Genomics & Informatics 2004; 2:113-120.
6. Pinkel D, Segraves R, Sudar D, Clark S, Poole I, Kowbel D, Collins C, Kuo W L, Chen C, Zhai Y, Dairkee S H, Ljung B M, Gray J W, Albertson D G. High resolution analysis of DNA copy number variation using comparative genomic hybridization to microarrays. Nat Genet 1998; 20:207-211.
7. Fiegler H, Carr P, Douglas E J, Burford D C, Hunt S, Scott C E, Smith J, Vetrie D, Gorman P, Tomlinson I P, Carter N P. DNA microarrays for comparative genomic hybridization based on DOP-PCR amplification of BAC and PAC clones. Genes Chromosomes Cancer 2003; 36:361-374.
8. Kim T M, Yim S H, Lee J S, Kwon M S, Ryu J W, Kang H M, Fiegler H, Carter N P, Chung Y J. Genome-wide screening of genomic alterations and their clinicopathologic implications in non-small cell lung cancers. Clin Cancer Res 2005; 11:8235-8242.
9. Chung Y J, Jonkers J, Kitson H, Fiegler H, Humphray S, Scott C, Hunt S, Yu Y, Nishijima I, Velds A, Holstege H, Carter N, Bradley A. A whole-genome mouse BAC microarray with 1-Mb resolution for analysis of DNA copy number changes by array comparative genomic hybridization. Genome Res 2004; 14:188-196.
10. Kim S Y, Nam S W, Lee S H, Park W S, Yoo N J, Lee J Y, Chung Y J. ArrayCyGHt: a web application for analysis and visualization of array-CGH data. Bioinformatics 2005; 21:2554-2555.
11. Livak K J, Schmittgen T D. Analysis of relative gene expression data using real-time quantitative PCR and the 2 (-Delta Delta C(T)) Method. Methods 2001; 25: 402-408.
12. Henrich K O, Fischer M, Mertens D, Benner A, Wiedemeyer R, Brors B, Oberthuer A, Berthold F, Wei J S, Khan J, Schwab M, Westermann F. Reduced expression of CAMTA1 correlates with adverse outcome in neuroblastoma patients. Clin Cancer Res 2006; 12:131-138.
13. Barbashina V, Salazar P, Holland E C, Rosenblum M K, Ladanyi M. Allelic losses at 1p36 and 19q13 in gliomas: correlation with histologic classification, definition of a 150-kb minimal deleted region on 1p36, and evaluation of CAMTA1 as a candidate tumor suppressor gene. Clin Cancer Res 2005; 11:1119-1128.
14. Schouten J P, McElgunn C J, Waaijer R, Zwijnenburg D, Diepvens F, Pals G. Relative quantification of 40 nucleic acid sequences by multiplex ligation-dependent probe amplification. Nucleic Acids Res 2002; 30:e57.
15. He Q J, Zeng W F, Sham J S, Xie D, Yang X W, Lin H L, Zhan W H, Lin F, Zeng S D, Nie D, Ma L F, Li C J, Lu S, Guan X Y. Recurrent genetic alterations in 26 colorectal carcinomas and 21 adenomas from Chinese patients. Cancer Genet Cytogenet 2003; 144:112-118.
16. Poeaim S, Rerkamnuaychoke B, Jesdapatarakul S, Campiranon A. Chromosome alterations in colorectal cancer in That patients. Cancer Genet Cytogenet 2005; 160:152-159.
17. Ried T, Knutzen R, Steinbeck R, Blegen H, Schrock E, Heselmeyer K, du Manoir S, Auer G. Comparative genomic hybridization reveals a specific pattern of chromosomal gains and losses during the genesis of colorectal tumors. Genes Chromosomes Cancer 1996; 15:234-245.
18. Nakao K, Mehta K R, Fridlyand J, Moore D H, Jain A N, Lafuente A, Wiencke J W, Terdiman J P, Waldman F M. High-resolution analysis of DNA copy number alterations in colorectal cancer by array-based comparative genomic hybridization. Carcinogenesis 2004; 25:1345-1357.
19. Knosel T, Petersen S, Schwabe H, Schluns K, Stein U, Schlag P M, Dietel M, Petersen I. Incidence of chromosomal imbalances in advanced colorectal carcinomas and their metastases. Virchows Arch 2002; 440:187-194.
20. Jones A M, Douglas E J, Halford S E, Fiegler H, Gorman P A, Roylance R R, Carter N P, Tomlinson I P. Array-CGH analysis of microsatellite-stable, near-diploid bowel cancers and comparison with other types of colorectal carcinoma. Oncogene 2005; 24:118-129.
21. Knosel T, Schluns K, Stein U, Schwabe H, Schlag P M, Dietel M, Petersen I. Genetic imbalances with impact on survival in colorectal cancer patients. Histopathology 2003; 43:323-331.
22. Aragane H, Sakakura C, Nakanishi M, Yasuoka R, Fujita Y, Taniguchi H, Hagiwara A, Yamaguchi T, Abe T, Inazawa J, Yamagishi H. Chromosomal aberrations in colorectal cancers and liver metastases analyzed by comparative genomic hybridization. Int J Cancer 2001; 94:623-629.
23. Douglas E J, Fiegler H, Rowan A, Halford S, Bicknell D C, Bodmer W, Tomlinson I P, Carter N P. Array comparative genomic hybridization analysis of colorectal cancer cell lines and primary carcinomas. Cancer Res 2004; 64:4817-4825.
24. De Angelis P M, Clausen O P, Schjolberg A, Stokke T. Chromosomal gains and losses in primary colorectal carcinomas detected by CGH and their associations with tumour DNA ploidy, genotypes and phenotypes. Br J Cancer 1999; 80:526-535.
25. Shivapurkar N, Maitra A, Milchgrub S, Gazdar A F. Deletions of chromosome 4 occur early during the pathogenesis of colorectal carcinoma. Hum Pathol 2001; 32:169-177.
26. Finch R, Moore H G, Lindor N, Jalal S M, Markowitz A, Suresh J, Offit K, Guillem J G. Familial adenomatous polyposis and mental retardation caused by a de novo chromosomal deletion at 5q15-q22: report of a case. Dis Colon Rectum 2005; 48:2148-2152.
27. Flanagan J M, Healey S, Young J, Whitehall V, Trott D A, Newbold R F, Chenevix-Trench G. Mapping of a candidate colorectal cancer tumor-suppressor gene to a 900-kilobase region on the short arm of chromosome 8. Genes Chromosomes Cancer 2004; 40:247-260.
28. Frayling I M, Bodmer W F, Tomlinson I P. Allele loss in colorectal cancer at the Cowden disease/juvenile polyposis locus on 10q. Cancer Genet Cytogenet 1997; 97:64-69.
29. Bando T, Kato Y, Ihara Y, Yamagishi F, Tsukada K, Isobe M. Loss of heterozygosity of 14q32 in colorectal carcinoma. Cancer Genet Cytogenet 1999; 111:161-165.
30. Park W S, Park J Y, Oh R R, Yoo N J, Lee S H, Shin M S, Lee H K, Han S, Yoon S K, Kim S Y, Choi C, Kim P J, Oh S T, Lee J Y. A distinct tumor suppressor gene locus on chromosome 15q21.1 in sporadic form of colorectal cancer. Cancer Res 2000; 60:70-73.
31. Risio M, Casorzo L, Chiecchio L, De Rosa G, Rossini F P. Deletions of 17p are associated with transition from early to advanced colorectal cancer. Cancer Genet Cytogenet 2003; 147:44-49.
32. Knosel T, Petersen S, Schwabe H, Schluns K, Stein U, Schlag P M, Dietel M, Petersen I. Incidence of chromosomal imbalances in advanced colorectal carcinomas and their metastases. Virchows Arch 2002; 440:187-194.
33. Donzelli M, Bernardi R, Negri C, Prosperi E, Padovan L, Lavialle C, Brison O, Scovassi A I. Apoptosis-prone phenotype of human colon carcinoma cells with a high level amplification of the c-myc gene. Oncogene 1999; 18:439-448.
34. Lakshman M, Subramaniam V, Rubenthiran U, Jothy S. CD44 promotes resistance to apoptosis in human colon cancer cells. Exp Mol Pathol 2004; 77:18-25.
35. Cummins J M, Kohli M, Rago C, Kinzler K W, Vogelstein B, Bunz F. X-linked inhibitor of apoptosis protein (XIAP) is a nonredundant modulator of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-mediated apoptosis in human cancer cells. Cancer Res 2004; 64:3006-3008.
36. Satterwhite E, Sonoki T, Willis T G, Harder L, Nowak R, Arriola E L, Liu H, Price H P, Gesk S, Steinemann D, Schlegelberger B, Oscier D G, Siebert R, Tucker P W, Dyer M J. The BCL11 gene family: involvement of BCL11A in lymphoid malignancies. Blood 2001; 98:3413-3420.
37. Ahn B H, Kim S Y, Kim E H, Choi K S, Kwon T K, Lee Y H, Chang J S, Kim M S, Jo Y H, Min D S. Transmodulation between phospholipase D and c-Src enhances cell proliferation. Mol Cell Biol 2003; 23:3103-3115.
38. Zhang J S, Gong A, Cheville J C, Smith D I, Young C Y. AGR2, an androgen-inducible secretory protein overexpressed in prostate cancer. Genes Chromosomes Cancer 2005; 43:249-259.
39. Shoji Y, Takahashi M, Kitamura T, Watanabe K, Kawamori T, Maruyama T, Sugimoto Y, Negishi M, Narumiya S, Sugimura T, Wakabayashi K. Downregulation of prostaglandin E receptor subtype EP3 during colon cancer development. Gut 2004; 53:1151-1158.
40. Bjorling-Poulsen M, Seitz G, Guerra B, Issinger O G. The pro-apoptotic FAS-associated factor 1 is specifically reduced in human gastric carcinomas. Int J Oncol 2003; 23:1015-1023.
41. Dunn J R, Risk J M, Langan J E, Marlee D, Ellis A, Campbell F, Watson A J, Field J K. Physical and transcript map of the minimally deleted region III on 17p implicated in the early development of Barrett's oesophageal adenocarcinoma. Oncogene 2003; 22:4134-4142.
42. Kuo T, Fisher G A. Current status of small-molecule tyrosine kinase inhibitors targeting epidermal growth factor receptor in colorectal cancer. Clin Colorectal Cancer 2005; Suppl 2:S62-70.
43. Gunther K, Leier J, Henning G, Dimmler A, Weissbach R, Hohenberger W, Forster R. Prediction of lymph node metastasis in colorectal carcinoma by expression of chemokine receptor CCR7. Int J Cancer 2005; 116:726-733.
44. Aligayer H, Boyd D D, Heiss M M, Abdalla E K, Curley S A, Gallick G E. Activation of Src kinase in primary colorectal carcinoma: an indicator of poor clinical prognosis. Cancer 2002; 94:344-351.
45. Villunger A, Michalak E M, Coultas L, Mullauer F, Bock G, Ausserlechner M J, Adams J M, Strasser A. p53- and drug-induced apoptotic responses mediated by BH3-only proteins puma and noxa. Science 2003; 302:1036-1038.
46. Ogunbiyi O A, Goodfellow P J, Gagliardi G, Swanson P E, Birnbaum E H, Fleshman J W, Kodner I J, Moley J F. Prognostic value of chromosome 1p allelic loss in colon cancer. Gastroenterology 1997; 113:761-766.
47. Ray R, Cabal-Manzano R, Moser A R, Waldman T, Zipper L M, Aigner A, Byers S W, Riegel A T, Wellstein A. Up-regulation of fibroblast growth factor-binding protein, by beta-catenin during colon carcinogenesis. Cancer Res 2003; 63:8085-8089.
|
The present application discloses a diagnostic method and a kit for prognosis assessment of colorectal cancer (CRC) and a novel tumor suppressor gene to be used for diagnosis of colorectal cancer (CRC), the method comprising the steps of: (a) identifying recurrently altered regions (RAR) on a chromosome; and (b) detecting genomic alterations in the RAR. The present method makes it possible to perform early diagnosis as well as prognosis assessment for various cancers and tumors including colorectal cancer (CRC).
| 2
|
This patent application is a continuation of my U.S. patent application, Ser. No. 781,900 filed Sept. 30, 1985 and now abandoned, for "Hydraulically Operated Elevator Door Mechanism".
The priot Art:
______________________________________Patents Inventor______________________________________1,530,9641,574,7171,632,5061,751,0581,845,9041,950,1502,579,0173,012,6363,738,4543,194,3453,231,0483,370,6773,535,8373,598,2023,605,9523,702,6453,739,0091,927,580 Wisner2,378,409 Joy2,480,527 Wachter3,327,428 Horton et al 89,252 Siemens (Austrian) 556,487 Hobrough (Canada)1,012,707 Nibaud (France)______________________________________
BACKGROUND OF THE INVENTION
This invention relates to elevator systems, and in particular to the opening and closing of elevator cab doors using a hydraulic drive unit to move the doors open and closed.
In a typical automatic elevation system, there is an automatic drive unit mounted on the cab that opens and closes the cab door. Typically, such system includes a DC motor with an assembly of various mechanical cams, used to operate electrical "slow-down" units. These systems, with many moving parts, are subject to frequent malfunction and are not easily or efficiently repaired.
SUMMARY OF THE INVENTION
A hydraulically operated elevator door mechanism is proposed having a housing and motor which drives a shaft connected to a first spur gear. A second spur gear meshes with the first spur gear to be turned thereby, the two spar gears situated in a housing chamber and acting as a pump, driving oil through the chamber in a direction which depends on rotation of the shaft. At both ends of the chamber are orifices in the housing, fluidly connecting a cylinder chamber in which a piston is located. Thus, rotation of the shaft in one direction cause oil to be pumpted into one side of the cylinder chamber, increasing pressure on one side of the piston. A corresponding decrease in pressure occurs on the opposite side of the piston, the pressure difference over the piston propelling the piston toward the pressure side. Valve pins are used to control oil flow through the orifices, and thus control piston speed relative to the stationary housing. A cable connects the housing over two pulleys to an elevator door which moves in response to the piston movement.
An object of this invention is to provide a means of moving the door using a reversible drive motor, a reversible pump, a movable piston and a 2:1 linkage system.
Another object of the invention is to provide a door operating mechanism that have few moving parts, is quickly and efficiently adjusted, and is easily installed.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 shows a hydraulic drive unit mounted on an elevator car top with a drive piston extended, and the door open.
FIG. 2 shows a hydraulic drive unit mounted on an elevator car top with a drive piston extended opposite that of FIG. 1, and the door closed.
FIG. 3 reveals a top view of the present invention.
FIG. 4 portrays a sectional side view of the present invention.
FIG. 5 presents a sectional end view of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a housing structure 1 mountcd to a wall surface, the remaining elements of the hydraulically operated door mechanism having been actuated to drive the door 2 left. The shaft like structure 3 comprises the rail which is guided through the housing structure 1 to pull the door 2 in the same direction as the rail 3 moves.
FIG. 2 shows the apparatus of the invention, however operated such that the door 2 is positioned to the right. Here, the rail 3 is shown after sliding through the housing structure 1. It is evident that the housing structure 1 is stationary with respect to the sliding door 2 and rail 3, but is merely positioned as such for purposes of illustration.
FIG. 3 shows a top view of a hydraulically operated elevator door mechanism, in accordance with the present invention. In addition to the elements of FIGS. 1 and 2, a driving means or motor 4 is shown attached to a wall surface, and having a shaft 5 connected to drive a gear-like means (not shown) located within the housing structure 1. The details of operation of the present invention are better understood with respect to FIGS. 4 and 5 below. Valve pins 6 and 7 may be adjusted from the top side of the housing structure 1, for controlling the flow of fluid (discussed below) within the housing structure 1, such that the open and closing speed of the door may be regulated.
FIG. 4 provides a side, sectional view of the mechanism, taken along line 4--4 of FIG. 3. Within the housing structure 1 is a means for containing a fluid 8, comprising orifices 9A and 9B which fluidly connect a reservoir chamber 10 to a cylinder chamber 11. As is evident, the orifices 9A and 9B, the reservoir chamber 10 and the cylinder chamber 11 form a closed loop in which the oil 8 or other hydraulic fluid flows. To the shaft 5 is mounted a spur gear 12 which is rotated in response to any turning of the shaft 5 by the motor 4 (see FIG. 3). A second spur gear 13 is meshed with the spur gear 12 and is driven thereby. Thus, if the shaft 5 is actuated in the clockwise direction, so is the spur gear 12, while the spur gear 13 turns in the counter-clockwise direction. Attached to the rail 3 is a piston and piston ring 14 coaxial with the rail 3. The piston ring 14 divides the cylinder chamber 11 into two portions which vary in size depending upon the position of the piston ring 14. Attached to either end of the rail 3 are pulleys 15. Anchors 16, at the housing structure 1, secure two lengths of cable 17 which extend over the respective pulleys 15 and are connected to the door 2.
The operation of the present invention is must easily seen with respect to FIG. 4. Actuation of the motor 4 may turn the shaft 5, and thus the spur gear, in a clockwise direction. Accordingly, the meshed spur gear 13 rotates counter-clockwise, the two spur gears 12, 13 driving fluid left as viewed in FIG. 4. Fluid 8 so forced, flows from the reservoir chamber 10 through the orifice 9A and into the left portion of the cylinder chamber 11. Thus, a high pressure is realized within the cylinder chamber to the left of the piston ring 14, and owing to the closed loop fluid path a corresponding low pressure is created in the cylinder chamber 11 portion which is right of the piston ring 14. The resultant differential pressure occurring across the piston ring 14 propels the piston right, towards the low-pressure side. The rail 3 being connected to the piston, also moves to the right carrying pulleys 15. Since the right cable length 17 is attached to the housing structure 1 at 16 and because the right pulley is moving right, the portion of the cable length 17 between the right pulley 15 and the door 2 "shortens", in a manner which causes the door 2 to slide right. In effect the cable pulls the door. Thus, for every inch of piston 14/rail 4 travel, the door travels two inches. It is readily apparent that turning the shaft 5 counter-clockwise will move the door left.
Also visible in FIG. 4 are threaded holes for reception of the valve pins 6 and 7. Turning of the valve pins 6, 7 into the threaded holes will close off any of the desired orifices 9A, 9B. Thus, the flow of fluid within the closed loop is regulated by adjusting the valve pins 6, 7 to an appropriate depth, which in turn regulates the speed at which the door opens and closes. Evident also, in the housing structure 1 where the rail 3 exits, are two sealing members which prevent leakage of the fluid 8 from the cylinder chamber 11.
FIG. 5 shows a sectional end view of the invention, wherein the piston ring 14 is shown closing off the cylinder chamber 11 into a front portion (the rear portion is not visible). Here, the coaxially relationship of the piston ring 14 and rail 3 are easily seen. The shaft 5 is directly coupled to the spur gear 12 to spin upon its associated bearing. The meshed spur gear 13 rotates freely upon its associated bearing, but being meshed with the spur gear 12 is driven in a direction opposite that of the rotating spur gear 12.
Modifications to the present invention are apparent to those skilled in the art, which do not depart from the spirit of the present invention, the scope being defined by the appended claims.
|
A hydraulically operated elevator door mechanism includes a motor-driven shaft connected to rotate gears within a fluid reservoir. Fluid is "pumped" as the gears rotate, to one side of a piston, propelling the piston. The piston is connected to two pulleys over which a cable length is attached to the elevator door. Piston movement causes the pulleys to effectively shorten the length of cable between the pulley and door, which in turn, causes the door to slide.
| 4
|
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to microscopy. More specifically, it relates to epifluorescence and the measurement of comet halos. Even more specifically, it relates to the automated measurement of the length of comet trails created by broken DNA strands under electrophoresis. The system includes a light source, lenses, a filter, mirrors, and a low-light sensitive camera.
[0003] 2. Description of the Prior Art
[0004] One of the ways to measure the toxicity of an agent in relation to certain tissue types is by means of a “comet assay”. In short, the cells are exposed to the agent in question and are then embedded in a gel and exposed to a current: i.e. electrophoresis. After a predetermined time, the cells are placed on a slide and are stained with a fluorescing material. The broken DNA strands have migrated out of the cell an under certain frequencies of light the “halo” that is created by the migrating strands can be seen and measured. At present this measurement has been done manually, and the present apparatus that are used in the test create large amounts of heat due to the intensity of the light required. The samples that are being measured thus degrade at a fast rate, adding to the pressure placed on the technician or researcher attempting to determine the level of damage in the nucleus. The present invention, due to its novel construction, prevents this rapid sample degeneration and allows the user to see the halos or trails for up to an hour with accuracy before the fluorescence starts to fade. Additionally, the low-level light source, the light filter, and the low-light camera of the present invention do not require a light intensity that creates the amount of heat that so rapidly degrades the sample as is common in the present art devices. Additionally, the present invention includes an automated algorithm and system that allows the user to place the samples to be tested in a light sealed box, and then allow the instant invention to do the assay independently in less than half an hour. Thus, the toxicity of various materials can be rapidly determined in relation to a variety of tissue types. For example, liver cells could be exposed to various additives that would pass the stomach lining and be present in the bloodstream after ingestion.
[0005] During a search at the U.S. Patent and Trademark Office, a number of relevant patents were uncovered and they will be discussed below.
[0006] In U.S. Pat. No. 4,695,548 issued to Charles R. Cantor et al. On Sep. 22, 1987 there are disclosed gel inserts for electrophoresis. This is unlike the present invention in that there are no optical components disclosed.
[0007] U.S. Pat. No. 4,870,004 issued to Thomas J. Conroy et al. On Sep. 26, 1989 discloses an apparatus and method of analyzing nucleic acids. This involves electrophoresis however radiation detectors are used to determine when specific groups pass a predetermined point. This is clearly dissimilar from the present invention.
[0008] In U.S. Pat. No. 5,852,4989 issued to Douglas C. Youvan et al. On Dec. 22, 1998 an optical instrument with a filter is disclosed. This is unlike the present invention in that no measuring of comet halos is discussed.
[0009] In U.S. Pat. No. 5,989,835 issued to R. Terry Dunlay et al. A system for cell based screening is disclosed. Fluorescing reporter molecules are provided and an optical system reports the activity thereof. Unlike the present invention, electrophoresis is not used.
[0010] Lastly, in U.S. Pat. No. 6,154,282 issued to Lothar Lilge et al. On Nov. 28, 200 discloses an illuminator for fluorescent or phosphorescent microscopy. Again, no electrophoresis to separate broke DNA fragments is disclosed.
[0011] Thus, while the foregoing overview of prior art indicates it to be well known to use the measurement of comet halos to ascertain the damage done to DNA in a certain tissue type, none of the inventions discussed above, either alone or in combination, describe the instant invention as claimed.
SUMMARY OF THE INVENTION
[0012] An automated comet assay system wherein light filtered to the excitation frequency of a fluorescing compound is directed onto the sample. A second filter isolates the emission frequency and the resulting image is directed at a low-light camera.
[0013] To achieve the foregoing and other advantages, the present invention, briefly described, provides an apparatus and method for microscopic comet assay that overcome the disadvantages of the prior art.
[0014] Thus it is a principal object of the invention to provide an apparatus and method for microscopic comet assay that is completely automated.
[0015] It is a further object of the invention to provide an apparatus and method for microscopic comet assay wherein low levels of light are used to prevent degradation of the sample and to allow a longer viewing time.
[0016] Still yet a further object of the invention is to provide an apparatus and method for microscopic comet assay wherein a sensitive CCD image sensor is used to transmit the comet trail to a computer.
[0017] Yet another object of the invention is to provide an apparatus and method for microscopic comet assay wherein a light filter is used to maximize the epifluorescence of the stained DNA fragments.
[0018] These together with still other objects of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be made to the accompanying drawings and descriptive matter in which there are illustrated preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The invention will be better understood and the above objects as well as objects other than those set forth above will become more apparent after a study of the following detailed description thereof. Such description makes reference to the annexed drawings wherein:
[0020] [0020]FIG. 1 is a perspective view of the present invention showing the sample stage, light source, lenses, mirrors, filters, and camera.
[0021] [0021]FIG. 2 is a diagrammatic view of the optical components of the invention.
[0022] [0022]FIG. 3 is a graph showing the excitation and emission wavelengths of the epifluorescing components
[0023] [0023]FIG. 4 is a graph showing the transmission percentage of the filter set used in the instant invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] Referring first to FIG. 1, the instant invention is indicated generally at 10 . It should be understood that the stage and lens portion (discussed below) are contained within a light-tight box (not shown).
[0025] The sample stage portion 12 is mounted on a base 14 . The sample stage base 14 includes a slide holding area 16 that, in the embodiment described herein, holds two slides. It should be emphasized that fewer or more slides could be held in the holding area 16 . Placed in these slides are cells that have been exposed to an environment that the researcher wishes to study. This could be exposure to a chemical, electromagnetic radiation, or the like. The cells which are placed in the environment are also chosen by the user: for example liver cells could be exposed to chemicals that would be present in the bloodstream of a person who had ingested an experimental drug. After a set period of exposure time, the cells are placed into an electrophoresis column or gel. Voltage is applied across the gel and the broken or fragmented strands of DNA (if any such exist) resulting from the environmental exposure will migrate from the nucleus of the cell. The cells are then placed on the slides and stained with a compound that will bind to the DNA and epifluoresce under certain frequencies of light.
[0026] The discussion now turns to the optical portion 20 of the present invention. This is best seen while referring to both FIGS. 1 and 2. The source of illumination is a light box 22 that is connected to the light-tight area (not shown) by a fiber optic conduit 24 . The light passes through a pair of lenses 26 , 28 as indicated by arrow A 1 , then the lens 30 as shown in arrow A 2 . Next, the light passes through a filter 32 (which the transmission percentage is seen in FIG. 4), and then is reflected off a 50-50 mirror 34 through the microscope's objective lens 36 . In one embodiment of the invention, the sample 38 to be studied is located above a first surface mirror 40 that reflects the light even further back through the sample. The light from the epifluorescence passes back through the 50-50 mirror 34 , through another filter 42 that blocks out the original light frequency (see FIG. 3) and then is reflected back off another first surface mirror 44 , into the camera focusing lens 46 and into the CCD image sensor 48 of the low-light camera 50 . Low-light camera 50 is a type used for security work where only a very small amount of light is necessary for the image to register. This feature allows the amount of light used overall in the instant invention to be very small, which cuts down on the heat produced during the imaging process, and the subsequent degradation of the sample. It has been noted by the inventor that in the common art devices used to measure the comet halos, the light used is so intense that the samples begin to degrade and the halos cease to be visible after only one minute or so. With the present invention, the halos are still visible after twenty minutes, albeit more dimly than originally after staining.
[0027] Note that because of the second filter 42 , that blocks out the excitation wavelength and passes the emission wavelength (again, see FIG. 3) adequate signal to noise ratios are achieved with relatively low intensities of light.
[0028] Referring back to FIG. 1, the stage of the unit is movable in that two stepper motors 60 running worm gears move the stage as desired by the computer 70 . This allows for the automated assay to take place as follows:
[0029] A typical assay is comprised of 20 sample areas contained on two slides each with two 14 mm diameter sample areas thereon. These areas are scanned until a total of approximately 1000 cells are located and measured. It has been observed with this system that each field of view will contain cells numbering up to 20 or more and that each field of view will take about five seconds to locate, measure, And define the geometry of the cell. The head area of the cell is calculated and then subtracted from the total cell area. The length is measured from the edge of the head to the furthermost end of the tail area. Then the tail moment is calculated by multiplying each tail pixel intensity by the distance from the edge of the cell head divided by the total head and tail intensity added together.
[0030] It should be emphasized that the instant invention is not in any way limited to the embodiments as they are described above but encompasses all embodiments as described in the scope of then following claims.
|
An automated cometary assay system is disclosed wherein light filtered to the excitation frequency of a fluorescing compound is directed onto the sample. A second filter isolates the emission frequency and the resulting image is directed at a low-light camera.
| 6
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation-in-Part of application Ser. No. 11/704,650, filed on Feb. 9, 2007, which application claims the benefit of Provisional Application Ser. No. 60/771,834, filed Feb. 9, 2006, which applications are each incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention broadly relates to means for modifying surfaces by deposition and etching, and more specifically, to means for creating structures and materials selectively on the inside surfaces of medical devices to render the devices biocompatible, to provide drug elution capability and/or to promote cell growth on and cell attachment to the modified surface.
BACKGROUND OF THE INVENTION
[0003] Many medical devices, such as stents and stent grafts, are designed and manufactured to be inserted into the wall or lumen of a blood vessel. When this is done, complications may arise from the body's natural reaction to a foreign object. For example, inserting a stent into a blood vessel may cause the growth of an undesirable thick layer of smooth muscle tissue, and this new growth may cause restenosis, or re-narrowing of the vessel. The effects of restenosis are often minimized through the use of drug eluting stents, in which a medicated coating on the stent prevents tissue growth for a period of time. Thrombus formation is another serious condition that may occur after insertion of a stent, and recent studies have shown that current drug eluting stents can not prevent, and may even promote, thrombosis formation. See, for example, Windecker, S. et al. Randomized Comparison of a Titanium - Nitride - Oxide - Coated Stent With a Stainless Steel Stent for Coronary Revascularization, Circulation, 111:2617-2622 (2005).
[0004] The inner surface of a healthy blood vessel is lined with endothelial cells, which play an important role in controlling thrombosis, inflammation and other factors. It has generally been found that endothelial cells do not readily attach to the smooth inner surfaces of electropolished metal stents or to the polymers typically used for drug eluting stents. U.S. Pat. No. 6,140,127 discusses the desirability of having endothelial cells attach to the inner walls of stents, and overcomes the previously described attachment issue by using an adhesion specific peptide. Similarly, U.S. Pat. No. 6,478,815 discusses means for overcoming the attachment issue, however in this instance a stent is made primarily of niobium which can be coated with iridium oxide or other materials to promote the growth of endothelial cells. Additionally, a roughened surface on a stent has been proposed as a further means for promoting cell growth on a stent. For example, U.S. Pat. No. 6,820,676 B2 and United States Patent Application Publication No. 2005/0232968 discuss the role of surface inhomogeneities and surface structures in promoting endothelial cell growth.
[0005] While the growth of endothelial cells on the inner surface of a stent is highly desirable, the growth of smooth muscle tissue at the inner wall of the blood vessel, i.e., the portion in contact with the outer surface of the stent, is undesirable. It has been found that stents coated entirely with a drug imbibed polymer layer designed to prevent growth of smooth muscle tissue have been highly successful in reducing in-stent restenosis. Unfortunately, the smooth polymer surface also inhibits endothelial cell growth on the inside of the stent. For example, the use of a drug eluting coating on the outer surface of stents is taught in United States Patent Application Publication No. 2006/0200231, however tailoring the properties of the inner surface for endothelial cell growth is not addressed. Stents having outer and inner surfaces which function differently would overcome the defects described supra.
[0006] Many references that discuss surfaces to control cell growth, i.e., to enhance cell growth in the case of endothelial cells or suppress cell growth in the case of smooth muscle cells, are based on plasma processing and physical vapor deposition. As stents have a generally open structure, when they are coated or treated in a plasma environment both inner and outer surfaces typically receive the same or very similar coatings or treatments. United States Patent Application Publication No. 2006/0200231 describes a well-know means of coating only the outside surface of an object like a stent. The stent is placed on a mandrel which prevents the inner surfaces from receiving a coating while the outer surface is coated. Heretofore, nothing in the prior art suggests a means for plasma treating or coating only the inner surface of a medical device such as a stent, while leaving the outer surface largely unaltered, or allowing the outer surface to receive a different coating or treatment.
[0007] As can be derived from the variety of devices and methods directed at coating and treating implantable medical devices, many means have been contemplated to accomplish the desired end, i.e., surface specific coatings wherein a first surface promotes cell growth thereon and a second surfaces prevents cell growth thereon. Heretofore, tradeoffs between preventing cell growth on one surface and promoting cell growth on another surface were required. Thus, there is a long-felt need for a method to treat or coat only the inner surfaces of medical devices such as shunts, stent-grafts and stents, as a means of preparing the inner and outer surfaces of such devices so that they function differently.
BRIEF SUMMARY OF THE INVENTION
[0008] The present invention broadly comprises a method of modifying a surface to produce surface structures, coatings and inhomogeneities in order to promote cell growth on and/or attachment to the surface for a variety of applications. Generally, the subject invention includes plasma deposition and removal processes to produce nanometer scale surface structures and coatings primarily on the inner surfaces of devices having both inner and outer wall surfaces, e.g., stents, stent-grafts and shunts. Specifically, the invention includes methods for producing plasma glow discharges on the inside of medical devices.
[0009] The present invention also broadly comprises a method of manufacturing a medical device having interior and exterior surfaces, the method includes the steps of: a) shielding the exterior surface; and, b) exposing the interior surface to a plasma, wherein the shielding of the exterior surface substantially prevents exposure of the exterior surface to the plasma. In some embodiments, the medical device further includes a first cross-sectional shape; while the step of shielding the exterior surface further includes the step of: contacting the exterior surface of the medical device with an inner surface of a hollow electrically conducting tube, the inner surface having a second cross-sectional shape substantially similar to the first cross-sectional shape; and, the step of exposing the interior surface to the plasma further includes the step of: igniting a hollow cathode discharge within the hollow electrically conducting tube. In other embodiments, the step of exposing the interior surface to the plasma further includes the step of: simultaneously sputtering the tube and the medical device. In some of these embodiments, the step of simultaneously sputtering the tube and the medical device modifies the interior surface of the medical device to include an inhomogeneous surface having at least two materials, while in some of these embodiments, the inhomogeneous surface includes a plurality of individual regions and each of the individual regions includes at least two materials and is separated from others of the individual regions by a material boundary. In still yet other embodiments, the step of exposing the interior surface to the plasma further includes the step of: cooling the hollow electrically conducting tube.
[0010] In further embodiments of the present invention, the medical device further includes a first cross-sectional shape; while the step of shielding the exterior surface further includes the step of: contacting the exterior surface of the medical device with an inner surface of a hollow electrically insulating tube, the inner surface having a second cross-sectional shape substantially similar to the first cross-sectional shape; and, the step of exposing the interior surface to the plasma further includes the step of: igniting a discharge within the hollow electrically insulating tube using a radio frequency power. In some of these embodiments, the radio frequency power includes a capacitively coupled radio frequency field, while in others of these embodiments, the radio frequency power includes an inductively coupled radio frequency field. In some embodiments, the step of exposing the interior surface to the plasma further includes the step of: cooling the hollow electrically insulating tube.
[0011] In yet further embodiments of the present invention, the medical device further includes a first cross-sectional shape; while the step of shielding the exterior surface further includes the step of: contacting the exterior surface of the medical device with an inner surface of a hollow electrically insulating tube, the inner surface having a second cross-sectional shape substantially similar to the first cross-sectional shape; and, the step of exposing the interior surface to the plasma further includes the step of: igniting a discharge within the hollow electrically insulating tube using a microwave power. In some embodiments, the step of exposing the interior surface to the plasma further includes the step of: cooling the hollow electrically insulating tube.
[0012] In still yet further embodiments, the step of exposing the interior surface to the plasma is performed in an inert gas, while in other embodiments, the step of exposing the interior surface to the plasma is performed in a reactive gas selected from the group consisting of: oxygen, nitrogen, methane and mixtures thereof. In still other embodiments, the step of exposing the interior surface to the plasma is performed in a precursor gas, and the precursor gas is selected to deposit a coating on the interior surface, and in some of these embodiments, the precursor gas is selected from the group consisting of: a hydrocarbon, a metal containing compound, oxygen, nitrogen and mixtures thereof. In some embodiments, the coating includes a plurality of clusters and each of the clusters includes a lateral dimension from about ten nanometers to about one thousand nanometers. In other embodiments, each of the clusters have a size and a distance from others of the clusters, and in some of these embodiments, the size of each of the clusters and the distance from others of the clusters are chosen to preferentially bind at least one biological structure having a specific size.
[0013] In yet further embodiments, the step of exposing the interior surface to the plasma removes material from the interior surface of the medical device, while in other embodiments, the present invention method further includes the step of: c) coating at least the interior surface of the medical device with a biodegradable polymer after the step of exposing the interior surface to the plasma. In some embodiments, a medical device is constructed according to the present invention method.
[0014] The present invention further broadly comprises a medical device having an interior surface, an exterior surface and means for exposing the interior surface to at least one plasma. In some embodiments, the at least one plasma includes a first plasma and a second plasma, the first plasma deposits a plurality of clusters on the interior surface and the second plasma etches the interior surface. In other embodiments, the first and second plasmas produce a plurality of surface structures on the medical device. In some of these embodiments, each of the surface structures includes a lateral dimension from about ten nanometers to about one thousand nanometers, while in others of these embodiments, each of the surface structures includes a height from about one hundred nanometers to about ten thousand nanometers. In some embodiments, each of said clusters includes a size and a distance from others of the clusters, and in other embodiments, the size of each of the clusters and the distance from others of the clusters are chosen to preferentially bind at least one biological structure having a specific size.
[0015] It is a general object of the present invention to provide a medical device including an interior surface having different characteristics than the device's exterior surface.
[0016] It is another general object of the present invention to provide a medical device having an interior surface which includes surface structures, coatings and/or inhomogeneities.
[0017] It is yet another object of the present invention to provide a method of producing a plasma glow discharge on the inside of a medical device while substantially shielding the outside of the device from such discharge.
[0018] These and other objects and advantages of the present invention will be readily appreciable from the following description of preferred embodiments of the invention and from the accompanying drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The nature and mode of operation of the present invention will now be more fully described in the following detailed description of the invention taken with the accompanying drawing figures, in which:
[0020] FIG. 1 is a cross sectional view of a portion of a typical stent taken generally along a plane parallel to the longitudinal axis of the stent;
[0021] FIG. 2 is a cross sectional view of a representation of a hollow cathode discharge system;
[0022] FIG. 3 is a cross sectional view of an embodiment of a present invention apparatus for coating and/or treating an inner surface of a stent;
[0023] FIG. 4 a is a cross sectional view of an arrangement for capacitively coupling RF power into a tube to produce a plasma;
[0024] FIG. 4 b is a cross sectional view of an arrangement for inductively coupling RF power into a tube to produce a plasma;
[0025] FIG. 5 is a cross sectional view of an arrangement having a tube inserted within a microwave cavity so that microwave radiation may reach an interior of the tube;
[0026] FIG. 6 is a cross sectional view of an array of short tubes used to coat or treat a number of devices, e.g., stents, together;
[0027] FIG. 7 is a cross sectional view of a substrate having a discontinuous coating of atoms;
[0028] FIG. 8 is a cross sectional view of the substrate of FIG. 1 after etching; and,
[0029] FIG. 9 is a cross sectional view of a medical device manufactured according to an embodiment of present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0030] At the outset, it should be appreciated that like drawing numbers on different drawing views identify identical, or functionally similar, structural elements of the invention. While the present invention is described with respect to what is presently considered to be the preferred aspects, it is to be understood that the invention as claimed is not limited to the disclosed aspects.
[0031] Furthermore, it is understood that this invention is not limited to the particular methodology, materials and modifications described and as such may, of course, vary. It is also understood that the terminology used herein is for the purpose of describing particular aspects only, and is not intended to limit the scope of the present invention, which is limited only by the appended claims.
[0032] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs. Although any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the invention, the preferred methods, devices, and materials are now described.
[0033] Adverting now to the figures, FIG. 1 shows a cross sectional view of a portion of a typical stent 10 taken generally along a plane parallel to longitudinal axis 12 of stent 10 . Stent 10 is constructed from a plurality of struts 14 , however for clarity, only two struts 14 are shown in FIG. 1 . Struts 14 form a cage or scaffold, which holds open the lumen of a blood vessel and define a generally cylindrical envelope having longitudinal axis 12 . Struts 14 have inner surfaces 16 and outer surfaces 18 , while portions 20 represent the cut ends of struts 14 . As discussed infra, the present invention method alters inner surfaces 16 through a coating or treatment without substantially altering outer surfaces 18 during the same processing. It should be appreciated that inner surface 16 of stent 10 , i.e., the interior surfaces of the medical device, refers to the portion of the medical device which may be viewed from longitudinal axis 12 . Therefore, outer surface 18 or exterior surfaces refer to the portion of the medical device which may not be viewed from longitudinal axis 12 .
[0034] It is well known in the art of plasmas and plasma deposition that it is possible to produce a glow discharge inside of a tube, even a tube with a diameter of 1 millimeter (mm) or less, for example, using hollow cathode discharges. As one of ordinary skill in the art appreciates, hollow cathode discharges are primarily used as sources of electrons for a variety of applications such as ion beam neutralization, plasma enhancement and electron beam evaporation. FIG. 2 shows a representation of hollow cathode discharge system 22 . Tube 24 has a source of gas 26 flowing through it and is held at a negative voltage with respect to a second electrode 28 by power supply 30 . It should be appreciated that gas 26 may be an inert gas, e.g., argon, a reactive gas, e.g., oxygen, nitrogen, methane or mixtures thereof, or a precursor gas, e.g., hydrocarbon, metal containing gases, oxygen, nitrogen or mixtures thereof. In the embodiment shown in FIG. 2 , tube 24 is a small tube. It should be appreciated that second electrode 28 could be a grounded surface which is part of a vacuum chamber, and need not be a discrete electrode as shown in FIG. 2 . Alternatively, tube 24 could be the grounded surface and electrode 28 could be raised to a positive potential with respect to tube 24 .
[0035] The general principal of operation of hollow cathode discharge system 22 is that electrons 32 emitted from inner surface 34 of tube 24 are confined by reflections at the opposite wall and effectively produce ions 36 in the gas flowing in tube 24 until electrons 32 exit end 38 of tube 24 and are collected by anode 28 . Systems similar to hollow cathode discharge system 22 have been used to deposit material and plasma treat surfaces. See, e.g., U.S. Pat. No. 5,716,500 which describes the use of a hollow cathode discharge system as a source of coating material. Systems similar to hollow cathode discharge system 22 are usually operated at sub-atmospheric pressures, but it is also possible to operate some hollow cathode discharge systems at atmospheric pressures. See, e.g., “Characterization of Hybrid Atmospheric Plasma in Air and Nitrogen,” 49 th Annual Technical Conference Proceedings of the Society of Vacuum Coaters, 2006. Known methods of using hollow cathode discharge systems include placing a substrate to be coated or modified outside of the hollow cathode tube, e.g., tube 24 . Contrarily, in the present invention, a substrate to be treated or coated lines the inside wall of the hollow cathode discharge system, i.e., inner surface 34 of tube 24 , making the substrate an electrode in the plasma discharge system. Although the extremely small discharge volume in typical hollow cathode discharge systems limits their usefulness for etching or depositing on most substrates, their very size and shape make them ideal for etching or depositing on the inner surface of small objects having generally cylindrical shapes, such as stents, grafts and shunts.
[0036] FIG. 3 shows a cross sectional view of an embodiment of a present invention apparatus for coating and/or treating inner surface 40 of stent 42 . Stent 42 is inserted into tube 44 so that stent struts 46 (shown in cross-section as in FIG. 1 ) are in contact with inner surface 48 of tube 44 . When hollow cathode discharge plasma 50 is created within tube 44 , as described above, primarily inner surface 40 of struts 46 will be exposed to plasma 50 while outer surface 52 of struts 46 , which are in contact with inner surface 48 of tube 44 , will not receive as much exposure to plasma 50 . In this way, inner surface 40 of stent 42 can be altered through a coating, a plasma etch treatment or a combination of both, while outer surface 52 of stent 42 is left almost unchanged, i.e., outer surface 52 is substantially shielded from exposure to plasma 50 .
[0037] Various methods exist for using the present invention to treat or coat inner surface 40 of stent 42 or other medical devices having inner and outer surfaces. For example, a precursor gas such as methane or acetylene could be used alone or in combination with other gases such as argon to produce a carbon containing coating on inner surface 40 . The formation of a coating by a plasma discharge in a precursor gas, or plasma enhanced chemical vapor deposition (PECVD) is well know in the art and many precursor gases, such as hexamethyldisiloxane, tetrafluoroethylene, and those containing metals such as titanium isopropoxide can be used.
[0038] Alternatively, the hollow discharge tube, e.g., tube 44 shown in FIG. 3 could be made of a material that is meant to be deposited on inner surface 40 of strut 46 . For example, if tube 44 were made of titanium, because a significant portion of inner wall 48 of tube 44 is exposed through openings 54 a and 54 b in stent 42 , i.e., the areas within and between struts 46 , the bombardment of inner surface 48 of tube 44 by energetic ions, e.g., ions 36 shown in FIG. 2 , will sputter titanium onto inner surface 40 of strut 46 . Because plasma 50 will also bombard inner surface 40 of strut 46 , not all of the titanium that is deposited will remain, however some will remain and mix with inner surface 40 . Alternatively, by choosing a tube material that has a significantly different sputter yield than the stent material, it has been found that two or more materials may be effectively co-deposited to create an inhomogeneous surface on the inside surface of a stent without the use of lithography. It is believed that such a surface is conducive to endothelial cell growth. See, e.g., U.S. Pat. No. 6,820,676. It should be appreciated that, as used herein, sputter and sputtering is intended to mean removal of material by ion bombardment, and in some embodiments, includes the subsequent deposit of the removed material onto another surface, e.g., ion bombardment of an inner surface of a hollow electrically conducting tube removes material therefrom which is subsequently deposited on a medical device held within the hollow tube.
[0039] If it is desired to simply expose the inner surface of a device such as a stent to the energetic ion bombardment, for example to roughen the device or plasma activate the device for further processing, the hollow cathode discharge system tube can be made of a biocompatible, low sputter yield material, e.g., carbon. Because the device is biased at a negative voltage with respect to the anode, it will be impacted by ions that have been accelerated to high energy. Therefore, the surface of the device can be aggressively plasma etched, a coating can be put down with PECVD, or both can be done simultaneously.
[0040] In addition to a hollow cathode discharge, it is possible to create a plasma on the inside surface of a medical device by other means. For example, an inductively or capacitively coupled radio frequency (RF) field can produce a glow discharge on the inside surface of an electrically insulating tube. The tube must have a low enough conductivity that the RF fields are not shielded from the interior portion. A gas, which can be inert or can contain a precursor for depositing a coating, can flow through the tube. In this case, because the stent or device may itself shield the interior of the tube from the RF fields, the treatment or deposition can take place remotely from where the power is coupled. FIG. 4 a shows a cross sectional view of an arrangement for capacitively coupling RF power into a tube to produce a plasma and FIG. 4 b shows a cross sectional view of an arrangement for inductively coupling RF power into a tube to produce a plasma. In FIG. 4 a , plasma discharge device 58 comprises electrically insulating tube 60 and has separate electrodes 62 placed on opposite sides of tube 60 in a manner well known in the art. Radio frequency power supply 64 is connected to electrodes 62 . Gas 66 is admitted into tube 60 and excited by power supply 64 . Gas 66 may include any of the gases discussed supra, e.g., inert, reactive or precursor. The medical device, e.g., stent 67 , is located remotely from the electrodes, as explained above, and is treated or coated in the flow of ionized and excited gas 68 downstream from the plasma generation portion, i.e., the area within tube 60 between electrodes 62 , of plasma discharge device 58 . FIG. 4 b shows an alternative form a plasma discharge device, i.e., device 70 , wherein electrodes 62 of device 58 are replaced by coil of wire 72 . Coil 72 inductively couples power from power supply 64 into ionized and excited gas 68 in a manner well-known to those skilled in the art.
[0041] Alternatively, microwave power can be used to produce a discharge. In this instance, the tube that holds the medical device can be inserted into a microwave cavity, also known as a waveguide, in a manner well known to those of ordinary skill in the art. FIG. 5 shows a cross sectional view of an arrangement of discharge device 73 having tube 74 inserted within microwave cavity 76 so that microwave radiation 78 may reach interior 80 of tube 74 . Gas 82 , which may include any of the gases described supra, can flow through tube 74 and the medical device to be treated or coated, e.g., stent 84 , can be placed in a portion of tube 74 outside of cavity 76 , e.g., portion 86 , where ionized gas 88 can reach interior surfaces 90 of medical device 84 . It should be appreciated that medical device 84 is placed outside of cavity 76 so that its conductivity does not interfere with the propagation of microwaves 78 . As discussed above, gas 82 can be an inert gas intended to modify the surface of medical device 84 through physical bombardment with ions, can be a reactive gas or can contain a precursor gas used to deposit a coating onto interior surface 90 of device 84 .
[0042] It should be appreciated that the present invention method may be used to produce large numbers of devices simultaneously. For example, a number of stents can line the inside of a long tube and be coated or treated at one time. Alternatively, an array of shorter tubes, as shown in the cross sectional view in FIG. 6 , can be used to simultaneously coat or treat a number of devices. In the embodiment shown in FIG. 6 , tubes 92 , each of which holds one or more medical devices, e.g., stents 94 , for treatment or coating, are arrayed in holder 96 . Holder 96 includes hollow gas manifold 98 which is connected to tubes 92 . Gas manifold 98 is fed by gas line 100 such that gas 102 flowing in line 100 is distributed substantially evenly to tubes 92 . Assembly 104 is electrically insulated by means such as insulators 106 and is connected electrically to power supply 108 . When power supply 108 applies a sufficient negative voltage to assembly 104 , simultaneous hollow cathode discharges exist in tubes 92 , which treat and/or coat inside surfaces 110 of medical devices 94 therein.
[0043] The inventive method of the present invention can be used in a variety of ways to alter the interior surfaces of medical devices. For example, it is possible to create an inhomogeneous surface by depositing a discontinuous coating of atoms of a first substance on a substrate comprising a second substance. In some embodiments, the substrate can then be etched via physical sputtering, while in other embodiments, the steps of depositing and etching are performed simultaneously. This deposition and etching sequence is described in U.S. Patent Application Nos. 60/771,834 and 11/704,650, which applications have been incorporated herein by reference and form the basis of priority for this application. In further embodiments, the discontinuous coating of atoms forms a plurality of clusters, each of the plurality of clusters having lateral dimensions from about ten nanometers to about one thousand nanometers. In yet further embodiments, the inhomogeneous surface includes a plurality of structures, each of the structures having heights from about ten nanometers to about ten thousand nanometers. The above described embodiments of the present invention are shown in FIGS. 7 and 8 . FIG. 7 is a cross sectional view of a substrate having a discontinuous coating of atoms, more specifically, a coating of aluminum oxide (Al 2 O 3 ) clusters 112 randomly spaced about titanium substrate 114 thereby forming coated substrate 116 , while FIG. 8 is a cross sectional view of coated substrate 116 after etching. The following discussion is perhaps best understood in view of both FIGS. 7 and 8 .
[0044] Ultra thin coatings deposited using physical vapor deposition, or in other words those layers having average thicknesses from less than a monolayer, i.e., a single atomic layer, to tens of monolayers, do not ordinarily condense as a uniform coating. Rather, the atoms nucleate as clusters whose size and spacing are determined by such factors as substrate temperature, chemical binding energy between the coating and substrate, energy of the arriving atoms, etc. Therefore, the average height of these clusters may be significantly greater than the average thickness of the overall coating, while the regions between the clusters are merely bare substrate material. The instant invention makes use of differences in etch rates that can exist between such clusters and the underlying substrate material, in order to produce structures that have dimensions of tens to hundreds of nanometers in breadth and height in and on the substrate.
[0045] In the embodiment shown in FIGS. 7 and 8 , Ti substrate 114 is used as a base layer upon which Al 2 O 3 clusters 112 are deposited. Al 2 O 3 clusters 112 are attached to Ti substrate 114 and approximately several nanometers in height and approximately several nanometers in diameter. Under ion bombardment, the sputter yield of Al 2 O 3 clusters 112 , i.e., the number of Al 2 O 3 atoms ejected from coated substrate 116 per incident ion, is approximately a few percent of that of the atoms ejected from Ti substrate 114 . Thus, after depositing clusters 112 on Ti substrate 114 , coated substrate 116 is subjected to ion bombardment to cause sputtering. Initially, coated substrate 116 will be etched only in those areas not covered by Al 2 O 3 clusters 112 . By continuing to etch coated substrate 116 until Al 2 O 3 clusters 112 are removed, the resulting etched substrate 118 will have high aspect ratio structures 120 with spacings that reflect the original spacing of the Al 2 O 3 clusters 112 . Thus, FIG. 8 shows the results of coating Al 2 O 3 clusters 112 on Ti substrate 114 to form coated substrate 116 , and the subsequent removal of Al 2 O 3 clusters 112 by ion bombardment. It has been found that even if the substrate material, e.g., Ti substrate 114 , has a low sputter yield surface, such as a native oxide, removing that surface will require the same length of time in all locations. Therefore, the difference in sputter rates for the deposited clusters 112 and substrate 114 will still dictate the vertical size of the resulting structures 120 . It should be noted that as used herein lateral dimension or diameter is used to refer to diameters 122 , while vertical size, height and depth are used to refer to height 124 .
[0046] Although coating a substrate with Al 2 O 3 is described in the foregoing embodiment, one of ordinary skill in the art will recognize that a wide variety of coating materials may be used, e.g., metals, oxides, nitrides and alloys, and such variations are within the spirit and scope of the claimed invention. However, it has been found that metal oxides such as Al 2 O 3 as well as oxides of Titanium (Ti), Molybdenum (Mo), Niobium (Nb), Chromium (Cr) and others have very low sputter yields and are, therefore, particularly advantageous when used for coating a substrate. Such materials are good candidates for producing randomly spaced clusters of atoms on a nanometer scale, such as Al 2 O 3 clusters 112 . Hereinafter, such nanometer scale coatings are referred to as a “nanomask.”
[0047] As those skilled in the art will appreciate, the nanomask, e.g., Al 2 O 3 clusters 112 may be deposited using a source of the mask material or may be deposited reactively by, for example, sputtering a metal in a chamber containing oxygen (O 2 ), nitrogen (N 2 ), or some other compound forming gas. Any number of well-known means, such as sputtering, cathodic arc evaporation, thermal evaporation and chemical vapor deposition can deposit discontinuous clusters 112 . As mentioned previously, the deposition conditions strongly affect clusters 112 size and spacing, and conditions are chosen which produce the desired results.
[0048] For the purposes of bone growth, nucleation characteristics resulting in a discontinuous coating of clusters 112 having diameters from about several nanometers to about several hundreds of nanometers, and heights from about several nanometers to about several hundreds of nanometers, have been found to be particularly advantageous. The dimensions of resulting structures 120 of course still depend on the ratio of the etch rate of substrate 114 to the etch rate of clusters 112 . Although the aforementioned embodiment is described in terms of preferentially bonding to bone, one of ordinary skill in the art will recognize that a substrate have clusters of different dimensions than previously set forth will preferentially bond to other types of cells, and such variations are within the spirit and scope of the claimed invention. In a preferred embodiment, resulting structures 120 have lateral dimensions, i.e., diameters 122 , from approximately ten (10) to several hundreds of nanometers across and heights 124 from approximately ten (10) to ten thousand (10,000) nanometers.
[0049] The height H of a given resulting structure 120 will be:
[0000]
H=R×h,
[0000] Where h is the height of the initial cluster 112 that produced structure 120 and R is the ratio of the etch rate of substrate 114 to the etch rate of cluster 112 . Of course, a given cluster 112 will not have a single height, but will be domed or otherwise irregular, and therefore, the resulting structure 120 may also be irregularly shaped. For example, as is well known from published sputter yields for Al 2 O 3 and Ti, an Al 2 O 3 nanomask deposited on a Ti substrate and sputtered using 500 electron volts (eV) under Argon (Ar) will result in a ratio R of approximately 17. Therefore, if a nanomask cluster of atoms had a height h of 10 nanometers, the height H of the resulting structure would be approximately 170 nanometers.
[0050] In order to control the nucleation characteristics of the nanomask coating, it is possible to change the chemical binding energy between substrate 114 and the coating material, e.g., Al 2 O 3 . For example, a very thin layer of a material having weak chemical bonding with the nanomask material, such as a hydrocarbon, may be deposited onto the substrate prior to the deposition of the coating material. Such a low energy coating, as it is known, will result in fewer, larger nuclei of the nanomask material, clusters 112 . Alternatively, it is possible to use plasma cleaning as an integral part of the coating process to change the nucleation characteristics. In that case, an initial high voltage can be applied to substrate 114 in order to clean substrate 114 and remove any residual contamination. This cleaning may be done with the deposition source off or it may be carried out during the initial stages of deposition. Times for such cleaning may range from less than a minute to several minutes.
[0051] For purposes of cell attachment, coated substrate 116 may not require etching in order to form preferred sites for cell growth. In certain cases, it is possible that material boundaries formed between substrate 114 and clusters 112 will produce enough of discontinuity in surface characteristics to stimulate the attachment of cells at the locations of clusters 112 and/or therebetween clusters 112 . It has been found, for example, that material boundaries on such scales may result in relatively large local electric fields, which may enhance the attachment of biological materials at those locations. For example, a discontinuous coating of Gold (Au) on Ti may result in large chemical potentials at the boundaries of the two materials that stimulate biological materials, such as proteins, to locate preferentially at those boundaries. As one of ordinary skill in the art will appreciate, other types of dissimilar materials are also candidates for such nanoscale coating clusters, and such variations are within the scope of the claimed invention.
[0052] Clusters 112 may be deposited on otherwise smooth portions of substrate 114 or it is also possible to form clusters 112 on the surfaces of a sintered powder, thereby creating a surface with two roughness scales. In addition, if clusters 112 are porous they may be infused with bioactive materials, such as superoxide dismutuse to inhibit inflammation or proteins to promote bone growth.
[0053] As described supra, once clusters 112 are deposited on substrate 114 , thereby forming coated substrate 116 , structures 118 can be produced by etching coated substrate 116 . Any etching known in the art may be used, such as reactive or non-reactive ion etching. For example, introducing an inert gas such as Argon at a pressure from approximately one (1) mTorr to one hundred (100) Torr, and applying a voltage to coated substrate 116 that is high enough to cause physical sputtering, typically between one hundred (100) and one thousand (1000) volts (V), will result in the desired etching. The sputtering voltage may be direct current (DC), pulsed DC, radio frequencies (RF) in the megahertz range, or an intermediate frequency, i.e., alternating current (AC), and such voltage should be applied under conditions that produce a glow discharge. The gas used may be inert, such as Ar, or can be chosen to accentuate the difference in sputtering rates between clusters 112 and substrate 114 . For example, if clusters 112 are a metal oxide and substrate 114 is a polymer, it is known in the art that a plasma containing O 2 will etch the polymer very quickly while etching the metal oxide slowly. Such a process is known as reactive ion etching and relies on chemical processes as well as physical bombardment to remove material.
[0054] The above described etching processes are common in the electronics industry, where etch masks are routinely used to produce specific desired patterns in integrated circuits, for example. However, in those cases the patterns that define the final structure are made using lithography, which is an expensive process. In the method of the instant invention, the patterns are formed on the surfaces of implantable devices by choosing deposition conditions that form a random pattern of clusters of atoms, and therefore is far more cost effective and simple to perform than lithography processes.
[0055] The deposition of clusters 112 and subsequent etching of coated substrate 116 may be done in one continuous operation, or may be performed sequentially. An example of a continuous operation is depositing Al 2 O 3 clusters 112 onto Ti substrate 114 using RF sputtering. During deposition of clusters 112 , a voltage may also be applied to substrate 114 . The voltage should be kept low enough that it will not cause clusters 112 to be removed faster than they are deposited. However, once clusters 112 are properly deposited on substrate 114 , the voltage may be increased to cause sputtering of both clusters 112 and substrate 114 in such a way that there is a net removal of material, and the formation of nanostructures 120 as described above. It has been found that using RF sputtering to deposit clusters 112 is a relatively inefficient deposition process. That is, a relatively intense RF plasma is needed to produce even a small deposition rate of a nanomask material such as Al 2 O 3 . However, because the nanomask material is so thin on average, a low deposition rate is often acceptable. The advantage of using RF sputtering arises once the nanomask is deposited. By leaving the RF power on and applying a DC voltage to coated substrate 116 , the intense RF plasma provides a dense source of ions which are available to etch coated substrate 116 . In other words, applying a DC voltage to coated substrate 116 in the presence of RF plasma will produce a far greater etch rate than applying the same voltage in the absence of RF plasma. Even though there are still sputtered atoms arriving at coated substrate 116 , they are removed as quickly as they arrived by the combined effect of the dense plasma and high substrate voltage.
[0056] Alternatively, the deposition and etching steps may be sequential. If both steps are accomplished using sputtering, this may be accomplished by simply turning off the power to the deposition source of clusters 112 and turning on the power to substrate 114 . Or alternatively, the deposition and etching steps may take place in separate chambers.
[0057] It should be appreciated the above described sputtering of the hollow tube and medical device contained therein may occur simultaneously, and an example of such is shown in FIG. 9 . FIG. 9 shows a cross sectional view of medical device 122 manufactured according to an embodiment of present invention. Simultaneously sputtering both the hollow tube and medical device 122 modifies interior surface 124 of medical device 122 to comprise inhomogeneous surface 126 , wherein inhomogeneous surface 126 comprises at least two materials, e.g., first and second materials 128 and 130 , respectively. Inhomogeneous surface 126 includes a plurality of individual regions 132 , and each of these regions 132 comprises at least two materials, e.g., first and second materials 128 and 130 , respectively. Individual regions 132 are separated from other individual regions by material boundary 134 .
[0058] Furthermore, the present invention method allows for the creation of different surfaces on the inside and outside of medical devices, e.g., stents, which serve different purposes. For example, it may be possible to first deposit a material only on the outside of the medical device that enhances the biocompatibility of that surface with respect to a lumen wall. This could be done using conventional deposition techniques such as sputtering, evaporation, spray coating, plasma polymerization or others while using a mandrel to prevent coating on the interior surface of the device. In a separate operation, the present invention method could be used to create another surface on the inside of the medical device that serves an alternative purpose, for example, biocompatibility with blood rather than tissue or promotion of endothelial cell growth via a rough surface or inhomogeneous surface.
[0059] In some instances, it may be useful to use a drug that prevents cell growth for a period of time in combination with a medical device whose inner surface has been altered so that it promotes endothelial cell growth. In these instances, the textured inner surface may cause platelet attachment, which is undesirable, during the period of time when the drug is preventing cell growth. It has been found that this issue can be addressed by coating at least the inner surface of the medical device with a biodegradable polymer. The smooth surface of the polymer suppresses platelet attachment while the drug acts to prevent cell growth. When the polymer is gone, i.e., has degraded, and the drug no longer acts to prevent cell growth, the surface of the medical device that promotes endothelial cell growth is then exposed and becomes effective.
[0060] A further advantage of the present invention relates to controlling the temperature of medical devices during their coating or treatment. For example, if the inside diameter of the hollow cathode or discharge tube is slightly smaller than the outside diameter of the device, the device will remain in intimate contact with the tube during processing. Therefore, if the tube is cooled, for example by a circulating liquid, the medical device can also be cooled during processing. This is particularly important for medical devices made of a nickel/titanium alloy known as Nitinol. Nitinol has the unusual properties of superelasticity and shape memory which result from the fact that Nitinol exists in a martensitic phase below a first transition temperature, known as M f , and an austenitic phase above a second transition temperature, known as A f . Both M f and A f can be manipulated by altering the ratio of nickel to titanium in the alloy as well as changing the thermal processing of the material. In the martensitic phase, Nitinol is very ductile and easily deformed, while in the austenitic phase Nitinol has a high elastic modulus. Applying stresses to materials at temperatures above A f produces some martensitic materials, however when the stresses are removed, the material returns to its original shape. This results in a very springy behavior for Nitinol, referred to as superelasticity or pseudoelasticity. Furthermore, if the temperature is lowered below M f and the Nitinol is deformed, raising the temperature above A f will cause the Nitinol to recover its original shape. This property is described as shape memory.
[0061] It is well known that if Nitinol is raised to too high a temperature for too long of a period of time, the A f value will rise. Additionally, sustained temperatures above 300-400 degrees Centigrade will adversely affect typical A f values used in medical devices. Likewise, if stainless steel is raised to too high a temperature, it can lose its temper, while other materials would also be adversely affected by exposure to such conditions. Therefore, the time-temperature history of a medical device during a coating operation is critical. In view of the foregoing, the present invention allows the temperature of a device to be controlled directly while uniformly treating or coating its interior surface.
[0062] It should also be appreciated that the present invention method can also be used to selectively remove material from the interior surfaces of medical devices. For example, many polymer deposition processes used to coat devices are conformal, i.e., a process of spraying a dielectric material onto a device to protect it from moisture, fungus, dust, corrosion, abrasion, and other environmental stresses. Parylene, which is widely used as a coating material, is deposited by polymerizing a monomer vapor, and thereby coating parylene on all exposed surfaces. As has been discussed above, it may be desirable to remove such a polymer coating from the interior surface while leaving it on the exterior surface. Thus, the present method can be used to plasma etch a polymer using an oxygen containing plasma, thereby removing it from the interior surface while leaving it on the exterior surface as desired.
[0063] Thus, it is seen that the objects of the present invention are efficiently obtained, although modifications and changes to the invention should be readily apparent to those having ordinary skill in the art, which modifications are intended to be within the spirit and scope of the invention as claimed. It also is understood that the foregoing description is illustrative of the present invention and should not be considered as limiting. Therefore, other embodiments of the present invention are possible without departing from the spirit and scope of the present invention.
|
A method of manufacturing a medical device having interior and exterior surfaces, the method including the steps of: a) shielding the exterior surface; and, b) exposing the interior surface to a plasma, wherein the shielding of the exterior surface substantially prevents exposure of the exterior surface to the plasma.
| 8
|
BACKGROUND OF THE INVENTION
This invention relates to compositions of matter classified in the art of chemistry as N-alkylacrylamides, to processes for their use and to radiation curable compositions containing them.
The use of a Ritter reaction between acrylonitrile and C 12 , C 14 , C 16 and C 18 α-olefins is disclosed by Clarke et al in Journal of the American Oil Chemists Society, Vol. 44, pp. 78 to 82 (1964). The products obtained are solid at room temperature.
U.S. Pat. No. 3,796,578 to Keizo Hosoi et al indicates the use of "N-hexylacrylamide" in radiation curable compositions for use on printing plates. The compositions are rather specialized in their requirements and it is nowhere suggested that other than linear 1-alkyl N-substituents of up to 6 carbon atoms would be suitable for use in said compositions. Copies of the publication and the patent accompany this application for the convenience of the Examiner.
SUMMARY OF THE INVENTION
The invention provides in a composition aspect, a compound of the Formula I: ##STR1## Wherein R is hydrogen or methyl; and R' is an α-methyl substituted straight chain alkyl radical of from 5 to 10 carbon atoms, or a poly-branched alkyl radical of about 6 to about 18 carbon atoms.
The tangible embodiments of this composition aspect of the invention possess the inherent physical properties of being liquids at normal room temperature, of being substantially insoluble in water, and soluble in common organic solvents such as aromatic hydrocarbons, e.g. benzene or toluene; lower alkanols, e.g., ethanol, methanol; dimethyl acetamide; acetonitrile and the like and being of low vapor pressure under normal use conditions.
The tangible embodiments of this composition aspect of the invention possess the inherent applied use characteristics of being reactive diluents for radiation curable polymer systems, of being colorant dispersants indicating usefulness in the formulation of radiation curable pigmented or dye containing inks and coatings, and of being radiation curable coatings and impregnants for fabrics including woven and non-woven textiles and paper, such impregnation or coating improving surface finish and feel, oil and water repellency and wearing properties. The compositions are also of low toxicity to experimental animals in standard irritation screening.
Preferred embodiments of this composition aspect of the invention are those compounds of Formula I wherein R' is a poly-branched alkyl radical of from 9 to about 18 carbon atoms. Special mention is made of those embodiments wherein R' is derived from propylene trimer, tetramer, or the trimer dimerized. Special mention is also made of those compositions wherein the alkyl radical is a mixture of at least 2 radicals of different carbon atom content.
The invention further provides a curable composition which comprises an acrylate substituted prepolymer; and a compound of Formula I.
The invention further provides a curable composition which comprises a colorant and a compound of Formula I.
The invention further provides an ultraviolet curable composition which comprises an ultraviolet radiation cure accelerator and a compound of Formula I.
The invention further provides an article of manufacture which comprises a substrate comprising a woven or non-woven textile or a non-woven web of cellulosic fibers coated or impregnated with a curable composition comprising a compound of Formula I.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The manner of making and using the compositions of the invention will now be illustrated with reference to a specific embodiment thereof and compositions containing same; namely, N-nonylacrylamide (Ia) prepared from propylene trimer (II).
II is a commercially available material prepared by the acid catalyzed random trimerization of propylene. To prepare Ia, II, acrylonitrile, and a free radical inhibitor, conveniently phenothiazine, may be warmed slightly above room temperature, conveniently at about 40° to 45° C. in concentrated sulfuric acid containing some water, conveniently about 85% acid, for a short period of time, conveniently about 4 to 24 hours. After cooling to room temperature, any unreacted II may be separated. Ia may, if desired, be recovered from the remaining reaction mixture by standard techniques, conveniently by pouring the reaction mixture into ice water, adding toluene, separating the 2 phases which form, washing the organic phase with water and sodium carbonate solution, drying and evaporating the organic phase in vacuo to give Ia as a liquid residue.
One skilled in the art will recognize that instead of the above described II and acrylonitrile, one may substitute either methacrylonitrile or other known α-olefins such as 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, propylene tetramer, propylene trimer dimerized by treatment with a Lewis acid such as BF 3 ,1,3,4,5,-tetramethyl-2-ethylheptene-1 and the like to prepare the other amides contemplated by Formula I. It will similarly be obvious to one skilled in the art that mixtures of olefins of the type contemplated as starting materials for the compounds of Formula I are also known and if subjected to a Ritter reaction under conditions analogous to those described herein above with either acrylonitrile or methacrylonitrile will produce compounds of Formula I wherein R' will be a mixture of alkyl residues. Such mixtures are contemplated by Formula I both in the specification and in the appended claims.
In the processes for the use of the compounds of Formula I their incorporation into standard radiation curable formulations as reactive diluents and/or as dye and pigment dispersants is contemplated.
For example, one may add Ia to an acrylated epoxidized vegetable oil, an ultraviolet light sensitizer, such as diethoxy acetophenone and any desired adjuvants, such as other reactive diluents, plasticizers, colorants, such as dyes or pigments and surfactants, coat the mixture onto a desired substrate and subject the coated substrate to ultraviolet light to produce a cured film on the substrate.
One skilled in the art will recognize that analogous compositions may be used for electron beam curing and that the presence of an ultraviolet light sensitizer will be unnecessary for such use.
For use as inks containing colorants, the standard colorants, either dyes or pigments, may be dispersed in compounds of Formula I together with any desired standard ink adjuvants such as adhesiveness or flow control agents, opaquing agents, and viscosity control agents and if the ink is to be cured by ultraviolet light, an ultraviolet cure accelerator.
Similarly for impregnating and coating fabrics and papers, compounds of Formula I, in addition to any standard adjuvants, may be applied to the material by standard methods followed by cure by electron beam or ultraviolet radiation.
Useful coatings and impregnants curable by ultraviolet radiation for use particularly in connection with non-woven cellulosic materials, such as paper and the like, may be obtained by the admixture of a compound of Formula I and an ultraviolet cure accelerator.
In the specification and the appended claims, the optional use of any and all standard adjuvants as mentioned herein above is comprehended by the invention.
As used herein and the appended claims the term α-methyl substituted straight chain alkyl of 5 to 10 carbon atoms comprehends an alkyl radical of the average formula ##STR2## wherein n is 3 to 8; the term poly-branched alkyl radical of about 6 to 18 carbon atoms comprehends alkyl radicals of the specified number of carbon atoms having at least 2 chain branching points in the molecule.
One skilled in the art will recognize that the propylene trimers and tetramers, the dimerized propylene trimer and dimerized and trimerized mixtures of olefins of varying chain length comprehended among the starting materials for compounds of Formula I will be mixtures of all possible modes of addition of the monomers and that amides of such mixtures as well as of any single branched chain isomer thereof which may be separable either before or after formation of the N-alkyl amide are comprehended as part of this invention.
One skilled in the art will also recognize that for amides of poly-branched alkyl radicals of greater than about 12 carbon atoms, it will be necessary to have mixtures of alkyl chains, particularly mixtures of at least 2 varying chain length alkyl radicals to insure liquidity.
The acrylic acid residue substituted prepolymers comprehended among the starting materials for the compositions of this invention are those liquid acrylic acid or methacrylic acid substituted prepolymers known in the art. The linkage of the acrylate moiety to the prepolymer chain may be by reaction of the carboxylic acid portion of the acrylate molecule or its equivalent with hydroxyl, epoxy, urethane or amino functions on the prepolymer chain, or by reaction of a hydroxyl substituted acrylate ester with an epoxy, carboxy or urethane function on the prepolymer molecule.
Ultraviolet radiation cure accelerators are those standard radiation cure accelerators or mixtures thereof well known in the art. Commonly, these are benzoins, benzophenones, and acetophenones, either unsubstituted or more commonly substituted so as to increase efficiency at selected wavelengths. Use of such compounds in standard fashion in standard concentration ranges is contemplated.
Woven or non-woven textiles suitable for use in preparing the coated or impregnated articles of manufacture which are amenable to radiation curing, as well as for use in preparing the radiation cured articles of manufacture, are those known textiles prepared from the common fibers of commerce both natural and synthetic. Included among these fibers are; for example, cotton, linen, rayon, wool, polyester fibers, polyether fibers, polyamide fibers, polyurethane fibers, carbon fibers, and the like.
Non-woven cellulosic fiber webs include the common papers and like products of commerce; such as, rag papers, ground wood pulp papers, kraft papers and the like.
The following examples further illustrate the best mode contemplated by the inventor for the practice of his invention.
EXAMPLE 1
N-Nonylacrylamide
To a mixture of propylene trimer (504 parts by weight (pbw)) acrylonitrile (232 pbw), and phenothiazine (0.4 pbw) is added 85% sulfuric acid (510 pbw) at 40°-45° C. over a period of one hour. The reaction is held at this temperature for an additional four hours, cooled and the upper layer (unreacted olefin, 95 pbw) separated. The lower aqueous layer is decanted into ice water (1500 pbw) and toluene (250 pbw) added. The upper organic layer is washed twice with 100 pbw portions of water, then with 20% sodium carbonate solution (35 pbw) dried over anhydrous sodium sulfate (40 pbw) and evaporated under vacuum to give the title product as a liquid residue (575 pbw).
Analysis for: C 12 H 23 NO:
Calculated: C,73.04; H,11.75; N,7.10%.
Found: C,73.27; H,11.64; N,7.10%.
EXAMPLE 2
N-Dodecylacrylamide
To acrylonitrile (212 pbw), propylene tetramer (673 pbw) and phenothiazine (0.4 pbw) is added 85% sulfuric acid (520 pbw) at 40° C. over a period of one hour. The mixture is held at 40° to 42° C. for 12 hours. After cooling the upper layer of unreacted olefin is separated and the lower layer poured into ice water (1600 pbw). This mixture is stirred overnight then partitioned with 2 portions (500 pbw) of toluene. The combined organic phase is worked with 3 portions of water totalling 300 pbw and then to neutrality with 20% sodium carbonate. After drying over sodium sulfate and the addition of p-methoxyphenol, the solution is concentrated in vacuo to obtain the title product as a viscous yellow liquid (572 pbw).
EXAMPLE 3
N-(α-methylpentyl)acrylamide
Following a procedure analogous to that of Examples 1 and 2 from 530 pbw of acrylonitrile, 841.6 pbw hexene-1, 1.0 pbw phenothiazine and 1300 pbw 83% sulfuric acid, there is obtained 1010 pbw of the title product.
EXAMPLE 4
Toxicity screening of N-Nonylacrylamide
N-nonyl-acrylamide was tested according to the protocol established for the Federal Hazardous Substances Act.
The material is fed to fasted male and female albino rats in a geometric progression series of doses ranging from 2.0 to 64.0 mg/Kg of body weight. Animals are observed for deaths over a period of 2 weeks. The oral LD 50 found was 7430 mg/Kg of body weight.
The material is applied to hair free partially abraded skin of albino rabbits and held in place by a polyethylene sleeve over the test area for 24 hours, the skin cleaned and examined, following which the animals are observed for 2 weeks. Among six male and female albino rabbits, there were no deaths indicating a lack of acute dermal toxicity.
The test substance was tested for acute inhalation toxicity by exposing 10 adult male and female albino rats to an aerosol of the substance in an inhalation chamber for one hour. The animals were observed for a 2 week period following exposure and then sacrificed. All animals survived the observation period and no gross abnormalities were observed on autopsy after sacrifice.
The test substance was examined for eye irritation potential by introducing the test substance into the conjunctival sacs of the unwashed eyes of 6 albino rabbits. Evaluations of the results were made at 24, 48 and 72 hours according to the standardized scoring scheme established for the test. In this test score results below 5.0 indicate negligible potential for eye irritation. The test substance scored 4.3.
EXAMPLE 5
Ultraviolet light curable formulations are prepared containing the ingredients shown in Table I. The viscosity of each finished formulation is as shown. Films are cast on release paper from each formulation. In this and the following examples, prepolymer A is a hydroxyl terminated ethylene propylene 80/20 adipate polyester of about 2800 molecular weight capped with toluene diisocyanate then end-capped with 2-hydroxyethyl acrylate. Prepolymer B is a hydroxyl terminated poly(ethylene adipate), of about 600 molecular weight capped with toluene diisocyanate then endcapped with 2-hydroxyethyl acrylate. Prepolymer C is a hydroxy terminated poly(ethylene adipate) of molecular weight about 600 capped with hydrogenated methylene dianiline then endcapped with 2-hydroxyethyl acrylate. Prepolymer D is a hydroxyl terminated poly(ethylene adipate) of molecular weight about 600 capped with isophorone diisocyanate then endcapped with 2-hydroxyethyl acrylate, Actomer X-80 is an acrylic acid adduct to epoxidized vegetable oil supplied by Union Carbide Corp., Melcril 5919 is the reaction product of hydroxyalkyl acrylate with melamine formaldehyde resin supplied by Daubert Chemical Co., Epocryl 370 is an adduct of bisphenol A diglycidyl ether and acrylic acid supplied by Shell Chemical Co.
TABLE I__________________________________________________________________________ Formulation No.Ingredient (pbw) 1 2 3 4 5 6__________________________________________________________________________Prepolymer C 60 60Prepolymer D 70Actomer X-80 70Melcril 5919 70Epocryl 370 70N-(α-methylpentyl)acrylamide (Ex 3) 25 20 30 30 15 30Ethoxyethoxyethyl acrylate 15 20 15V-Pyrol 14.4Dioctylphthalate 20Diethoxyacetophenone 2 2 2 2 2Benzophenone 2.5Dimethylaminoethanol 2.5Viscosity (centistokes) 5500 2500 >14,800 >14,800 12,000 240 810__________________________________________________________________________
TABLE II______________________________________After complete cure under ultraviolet light,properties of cast films are as shown in Table II. Formulation No. 1 2 3 4 5 6______________________________________Tensile (psi) 1800 1470 2925 2540 Shattered 3650Elongation (%) 35 55 5 <5 on <5Modulus (psi) 25% 1620 795 -- -- die -- 50% -- 1310 -- -- cut -- 100% -- -- -- -- --Yield (psi) -- -- 2900 -- --Tear (pli) 129 72 244 -- --______________________________________
TABLE III__________________________________________________________________________Ultraviolet curable compositions are prepared, their viscositiesdetermined, curedfilms prepared and the properties of said films determined as shown inTable III. Formulation No.Ingredient (pbw) 1 2 3 4 5 6__________________________________________________________________________Prepolymer C 60 60 60 60Prepolymer A 70 70N-(α-methylheptyl) acrylamide (Ex 16) 30 25 20 16.8N-nonylacrylamide (Ex 1) 25 17.2Ethoxyethoxyethyl acrylate 10 15 20 15V-Pyrol 13.2 12.8Diethoxyacetophenone 2 2 2 2 2 2Viscosity (centistokes) >14,800 >14,800 3,200 >14,800 8,100 >14,800Physical PropertiesTensile (psi) 1820 1430 865 255 2140 1790Elongation (%) 40 25 35 120 55 185Modulus (psi) 25% 1480 (1300) 595 90 1510 240 50% (2280) 100% 190 510Tear (pli) 124 85 67 43 113 138__________________________________________________________________________
TABLE IV__________________________________________________________________________Ultraviolet curable compositions are prepared, their viscositiesdetermined,films cast and cured and the properties of said films determined as shownin Table IV. Formulation No.Ingredient (pbw) 1 2 3 4 5__________________________________________________________________________Prepolymer C 70 60 60 60Prepolymer A 70N-(α-methylnonyl) acrylamide (Ex 17) 15 30 25 20 17.6Ethoxyethoxyethyl acrylate 15 10 15 20V-Pyrol 12.4Diethoxyacetophenone 2 2 2 2 2DC-11 (Dow Corning Silicone 1 1 1 1 Surfactant)UCC L-7602 (Union Carbide Corp. Silicone Surfactant) 1Viscosity (centistokes) >14,800 >14,800 >14,800 5500 >14,800Physical PropertiesTensile (psi) 1240 900 940 1165 85Elongation (%) 35 30 35 65 120Modulus (psi) 25% 995 765 725 330 100% 60Tear 80 99 69 42 12__________________________________________________________________________
TABLE V__________________________________________________________________________Ultraviolet curable compositins are prepared, their viscositiesdetermined, curedfilms prepared and the properties of said films determined as shown inTable V. Formulation No.Ingredient (pbw) 1 2 3 4 5 6 7__________________________________________________________________________Prepolymer C 70 60 60 60Prepolymer A 70Prepolymer B 70 60N-Dodecylacrylamide (Ex 2) 15 30 25 20 18.4 15 20Ethoxyethoxyethyl acrylate 15 10 15 20 15 20V-Pyrol 11.6Diethoxyacetophenone 2 2 2 2 2 2 2DC-11 1 1 1 1 1 1UCC L-7602 1Viscosity (centistokes) >14,800 22 14,800 >14,800 >14,800 >14,800 >14,800 8,100PropertiesTensile (psi) 1680 1680 1570 1110 480 1510 445Elongation (%) 35 20 30 35 130 45 30Modulus (psi) 25% 1440 1400 810 110 795 310 100% 285Tear (pli) 102 123 105 68 120 69 32__________________________________________________________________________
TABLE VI__________________________________________________________________________Ultraviolet curable compositions are prepared, their viscositiesdetermined, curedprepared and the properties of said films determined as shown in TableVI. Formulation No.Ingredient (pbw) 1 2 3 4 5 6 7 8__________________________________________________________________________Prepolymer C 60 60 60 60 60 60 60 60N-(αmethylheptyl 25 20 acrylamideN-Nonylacrylamide (Ex 1) 25 20N-(α-methylnonyl) (Ex 17) 25 20 acrylamideN-Dodecyclacrylamide (Ex 2) 25 20Phenoxyethyl acrylate 15 20 15 20 15 20 15 20Diethoxyacetophenone 2 2 2 2 2 2 2 2DC-11 1 1 1 1 1 1 1 1Viscosity (centistokes) >14,800 12,000 >14,800 8,100 >14,800 >14,800 >14,800 >14,800PropertiesTensile (psi) 1700 > 2160 2590 1130 1915 2030 1880Elongation (%) 50 50 40 55 25 50 25 25Modulus (psi) 25% 1245 1410 1910 1810 1210 (1965) 1830 50% 2000 2330 1820Tear (pli) 133 135 174 161 72 97 160 160__________________________________________________________________________
TABLE VII__________________________________________________________________________Ultraviolet curable compositions are prepared, their viscositiesdetermined, curedprepared and the properties of said films determined as shown in TableVII. Formulation No.Ingredient (pbw) 1 2 3 4 5 6 7__________________________________________________________________________Prepolymer C 60 60 60 60 70Prepolymer B 70 60N-Nonylacrylamide (Ex 1) 30 20 15 15 20N-Dodecylarylamide (Ex 2) 30 20Ethoxyethoxyethyl acrylate 10 20 10 20 15 15 20Diethoxyacetophenone 2 2 2 2 2 2 2DC-11 1 1 1 1 1 1 1Viscosity >14,800 2500 >14,800 4100 12,000 12,000 4100PropertiesTensile (psi) 2000 1400 1710 1460 2320 2180 1815Elongation (%) 5 35 15 40 45 35 65Modulus (psi) 25% (1030) 965 1510 1705 1150Tear (pli) 132 140 67__________________________________________________________________________
TABLE VIII__________________________________________________________________________Ultraviolet curable compositions are prepared, their viscositiesdetermined, curedfilms prepared and the properties of said films determined as shown inTable VIII. Formulation No.Ingredient (pbw) 1 2 3 4 5 6 7__________________________________________________________________________Prepolymer C 60 60Prepolymer D 70 70Acetomer X-80 70Melcril 5919 70Epocryl 370 70N-Nonylacrylamide (Ex 1) 20 30 15 30 30 30 30Ethoxyethoxyethyl acrylate 20 15 10Dipropylene Glycol dibenzoate 20Dioctylphthlate 20Diethoxyacetophenone 2 2 2 2 2 2Benzophenone/Dimethylamino- ethanol (II) 5.0DC-11 1 1 1 1 1 1UCC L-7602 1Viscosity 3200 >14,800 215 >14,800 >14,800 12,000 >14,800PropertiesTensile (psi) 1610 (2430) shattered 2490 1080 2780 1930Elongation (%) 55 (<5) on 15 50 <5 15Modulus (psi) die 25% 730 cut 590 50% 1240 950Tear (pli) 54__________________________________________________________________________
TABLE IX__________________________________________________________________________Ultraviolet curable compositions are prepared, their viscositiesdetermined, curedfilms prepared and the properties of said films determined as shown inTable IX. Formulation No.Ingredient (pbw) 1 2 3 4 5 6__________________________________________________________________________Prepolymer B 70Prepolymer C 70 60 60 60Prepolymer A 70N-(α-methylpentyl, α-methyl- 14.6 15 15 20hexyl) acrylamide (Ex 15)N-(α-methylpentyl) acrylamide (Ex 3) 30 25Ethoxyethoxyethyl acrylate 15 15 20 10 15V-Pyrol 15.4Diethoxyacetophenone 2 2 2 2 2 2DC-11 1 1 1 1 1DC-1180 (silicone surfactantDow Corning) 2Viscosity (centistokes) >14,800 8100 12,000 2000 8100 2500PropertiesTensile (psi) 600 2370 2340 1240 2250 2250Elongation (%) 140 50 35 50 45 55Modulus (psi) 25% 150 1260 1830 705 1760 1320 50% 1980 100% 375Tear (pli) 83 117 129 59 189 120__________________________________________________________________________
TABLE X__________________________________________________________________________Ultraviolet curable compositions are prepared, their viscositiesdetermined, curedfilms prepared and the properties of said films determined as shown inTable X. Formulation No.Ingredient (pbw) 1 2 3 4 5 6__________________________________________________________________________Prepolymer C 60 60 60 60Prepoloymer A 70 70N-(α-methylpentyl) acrylamide (Ex 3) 20 15.6N-(α-methylheptyl) acrylamide (Ex 16) 30 25 20 16.8Ethoxyethoxyethyl acrylate 20 10 15 20V-Pyrol 14.4 13.2Diethoxyacetophenone 2 2 2 2 2 2DC-11 1 1 1 1Viscosity (centistokes) 1500 >14,800 >14,800 4100 1500 >14,800PropertiesTensile (psi) 1565 1120 1190 1120 760 935Elongation (%) 55 165 40 55 50 160Modulus (psi) 25% 715 190 820 480 310 160 50% 1240 930 100% 435 350Tear (pli) 66 98 65 44 30 130__________________________________________________________________________
EXAMPLE 14
Ultraviolet Curable Colorant Dispersion
A dispersion of "Microlith" Blue 4G-T (an insoluble, dispersable organic pigment Ciba-Geigy) (20 weight %) and N-nonylacrylamide (Ex 1) (80 wt %) is prepared by ball milling. This dispersion is blended with trimethylol propane triacrylate at a number of weight ratios and the resulting compositions are painted on aluminum foil with a brush and cured in a PPG QC processor with 2 lamps, focused, in air, at a line speed of 20 feet per minute. At pigment dispersion/trimethylol propane triacrylate weight ratios of 1:1 and 2:1 the cured surfaces were tack free and no pigment could be rubbed off when wiped with a ball of cotton.
EXAMPLE 15
N-(α-methylpentyl,α-methyl-hexyl)acrylamide
Following a procedure analogous to that of Example 1, treat acrylonitrile with a mixture of 1-hexene and 1-heptene in the presence of 83% sulfuric acid and phenothiazine to obtain the title product.
EXAMPLE 16
N-(α-methylheptyl)acrylamide
Following a procedure analogous to that of Example 1, treat acrylonitrile with 1-octene in the presence of phenothiazene and 83% sulfuric acid to obtain the title product.
EXAMPLE 17
N-(α-methylnonyl)acrylamide
Following a procedure analogous to that of Example 1, treat acrylonitrile with 1-decene in the presence of phenothiazine and 83% sulfuric acid to obtain the title product.
|
Novel C6 to C18 liquid, branched-chain, N-α-alkylacrylamides, their use as reactive diluents and dye and pigment dispersants for radiation curable compositions, and radiation curable compositions containing them are disclosed.
| 2
|
BACKGROUND OF THE INVENTION
The present invention relates to a new and improved construction of a spinning device for open-end spinning.
In its more particular aspects, the present invention specifically relates to a spinning device for open-end spinning and which spinning device contains a spinning rotor which is rotatable about a predetermined rotational axis, and a withdrawal arrangement for withdrawing the spun yarn or the like obtained by the open-end spinning operation.
In a spinning device for open-end spinning such as known, for example, from German patent No. 3,220,402 there is provided a withdrawal nozzle of the currently common construction which is combined with a balloon guide. The thread or yarn to be withdrawn forms a balloon in the balloon guide and the diameter of this balloon is subjected to multiple variations during each revolution thereof. Elements interfering with the balloon are provided and the thread impacts against such elements in order to induce thread or yarn formation. However, this is disadvantageous for the thread or yarn which is unduly stressed due to the plucking actions exerted upon the thread or yarn during this operation.
A withdrawal funnel as known, for example, from Czechoslovakian patent No. 129,036, granted Sept. 15, 1968, contains a projection which extends along a spiral-shaped path in a conical portion of the withdrawal funnel and along a helical path in a tubular portion of the withdrawal funnel. In such arrangement the projection exerts practically no effect upon the thread or yarn in the tubular portion and the overall effect is inadequate.
A spinning device for open-end spinning as known, for example, from U.S. Pat. No. 4,258,541, granted Mar. 31, 1981, contains a bent-off tube in which a wire is pressed against the internal surface of the tube. The wire has a plurality of turns for the purpose of temporarily increasing the twist level or twist in the thread. The provision of the multi-turn wire requires that the wire is manufactured from an elastic metal. A ceramic material, for example, can not be provided at such location.
It is known that the yarn or the like formed during an open-end spinning operation has lower hairiness and possesses a harder or firmer handle than a yarn which is produced by a ring spinning operation. While these properties are desirable for many purposes, they are particularly undesirable for the manufacture of knitted goods, i.e. knitted fabrics.
Therefore, attempts have been made to further develop the open-end spinning operation and open-end spinning equipment such that yarn or the like possessing a soft handle also can be produced. Since such yarns must be less strongly twisted, there exists the difficulty that in many cases, the yarns do not satisfy the demands imposed upon such yarns when employing an open-end spinning operation. This can result in substantial disadvantages such as insufficient yarn tensile strength and insufficient yarn evenness or uniformity, an excessive number of thick and thin places or neps at the yarn, or an intolerably high yarn or thread break rate.
SUMMARY OF THE INVENTION
Therefore, with the foregoing in mind it is primary object of the present invention to provide a new and improved construction of a spinning device or apparatus for open-end spinning and which spinning device or apparatus is not afflicted with the drawbacks and limitations of the prior art constructions heretofore discussed.
A further significant object of the present invention is directed to providing a new and improved construction of a spinning device for open-end spinning and which spinning device permits increasing the stability or strength of softly twisted yarns produced by the open-end spinning operation.
It is yet a further important object of the present invention to provide a new and improved construction of a device for open-end spinning and which spinning device permits a reduction in the yarn or thread break rate and an increase in the rotational speed of the rotor of the spinning device and thereby an increase in the production rate of softly twisted yarns during the open-end spinning operation.
Another noteworthy object of the present invention is directed to the provision of a new and improved construction of a spinning device for open-end spinning and which spinning device is intended to render the yarn properties or characteristics less dependent upon the fiber material used in the open-end spinning operation and the type of yarn produced by such open-end spinning operation.
Still another significant object of the present invention aims at a new and improved construction of a spinning device for open-end spinning and which spinning device renders possible the manufacture of soft handle yarns at spinning rotor speeds which are higher than the spinning rotor speeds presently used in open-end spinning machines.
In order to implement these and still further objects of the invention which will become more readily apparent as the description proceeds, the spinning device for open-end spinning of the present development is manifested by the features that, the withdrawal arrangement comprises a substantially funnel-shaped withdrawal nozzle containing at least one bead or ridge which extends along a substantially spiral-shaped path about the rotational axis of the spinning rotor and which is arranged at a conical portion or section of the funnel-shaped withdrawal nozzle. Such conical portion or section of the funnel-shaped withdrawal nozzle is slidingly contacted by the revolving yarn or the like during the open-end spinning operation. The withdrawal arrangement further comprises a twist blocking element or twist trap containing a thread withdrawal passage or channel. At least one bead or ridge arranged at an inclination relative to the longitudinal axis of the thread withdrawal passage or channel is present within the thread withdrawal passage or channel. The at least one bead or ridge is located in an arcuately shaped passage or channel section on the length of that half of the withdrawal passage or channel which faces the center of curvature associated with the arcuately shaped withdrawal passage or channel section. The at least one substantially spiral-shaped bead or ridge which is located in the withdrawal nozzle, and the at least one bead or ridge which is present in the arcuately shaped withdrawal passage or channel section, have an inclination substantially in the same direction as the direction of the twist of the spun yarn.
When using the inventive spinning device, the initially mentioned disadvantages of the prior art constructions can be avoided or at least appreciably minimized. In addition, the combination of the at least one substantially spiral-shaped bead or ridge in the withdrawal nozzle and the at least one bead or ridge formed in the withdrawal passage or channel results in an improvement with respect to the tensile strength of the yarn, the number of thin places thereof, the number of thick places thereof and the number of neps thereof in comparison to the presently used open-end spinning operations. Variations in the yarn or thread tension and in the resistance to twisting are also reduced. The softness of the handle or the yarn or the like is markedly improved. Also, the provisions or facilities made in accordance with the present invention result in a construction possessing great durability and, at least in a particular embodiment containing a nozzle which is manufactured using a withdrawable core, in a construction which can be relatively simply fabricated.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and objects other than those set forth above, will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein throughout the various figures of the drawings there have been generally used the same reference characters to denote the same or analogous components and wherein:
FIG. 1 is a longitudinal section through an exemplary embodiment of the inventive spinning device for open-end spinning;
FIG. 2 is a bottom plan view of a withdrawal nozzle used in the spinning device for open-end spinning as shown in FIG. 1;
FIG. 3 is a longitudinal cross-section on an enlarged scale through the withdrawal nozzle shown in FIG. 2; and
FIG. 4 is a view looking in the direction of the arrow A in FIG. 1 of beads or ridges present in the withdrawal passage or channel of the spinning device for open-end spinning shown in FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Describing now the drawings, it is to be understood that only enough of the construction of the exemplary embodiment of open-end spinning device has been shown as needed for those skilled in the art to readily understand the underlying principles and concepts of the present development, while simplifying the showing of the drawings. Turning attention now specifically to FIG. 1 of the drawings, there has been shown therein a longitudinal section through an exemplary embodiment of the inventive spinning device 1 for open-end spinning. In such open-end spinning device 1 a spinning rotor 12 is fixedly secured to a shaft 11. The shaft 11 and thereby the spinning rotor 12 are conjointly rotatable about a rotational axis 13 by means of any suitable rotary drive means llA. Fiber material 10 is infed into the interior of the spinning rotor 11 by way of a feed passage 10A. A revolving yarn or thread 14A or the like--hereinafter simply usually referred to as yarn--is formed during the open-end spinning operation and is yarn withdrawn through a yarn withdrawal arrangement 15 in order to thereby form a spun yarn 14.
The yarn withdrawal arrangement 15 contains a substantially funnel-shaped withdrawal nozzle 16 containing a substantially conical portion 18. An elongated projection, bead or ridge 17 or equivalent is confined to the substantially conical portion 18 and extends in a substantially spiral shape about the rotational axis 13 at the internal surface of the substantially conical portion 18 of the funnel-shaped withdrawal nozzle 16. In the illustrated exemplary embodiment, the substantially spiral-shaped bead 17 or the like constitutes a single-lead spiral. However, more than one substantially spiral-shaped bead, specifically beads or equivalent structure formed by multiple-lead spirals can also be used.
The substantially funnel-shaped withdrawal nozzle 16 further contains a tubular portion 19 having an internal surface 19A and communicating with said substantially conical portion 18 on the side or end thereof located remote from the spinning rotor 12. The internal surface 19A defines an imaginary or virtual cylinder 24, at best seen by referring to FIG. 3, which axially extends through said funnel-shaped withdrawal nozzle 16 as an extension of the internal surface 19A of the tubular portion 19.
The substantially spiral-shaped bead or ridge 17 which is confined to substantially conical portion 18 of the funnel-shaped withdrawal nozzle 16, extends throughout this substantially conical section 18 in such a manner that the substantially spiral-shaped bead or ridge 17 is located outside the aforementioned imaginary or virtual cylinder 24. Specifically, the substantially spiral-shaped bead or ridge 17 defines a surface 17A and a partial surface region 17B which faces the tubular portion 19 and which is structured such as to narrow or converge in the direction towards such tubular portion 19 of the funnel-shaped withdrawal nozzle 16. Instead, the partial surface region 17B which faces the tubular section 19, may also be structured such as to extend, at the maximum, substantially parallel to the imaginary or virtual cylinder 24 which extends from the internal surface 19A of the tubular portion 19 through the funnel-shaped withdrawal nozzle 16.
The substantially funnel-shaped withdrawal nozzle 16 and the substantially spiral-shaped bead 17 confined to the substantially conical portion 18 of the funnel-shaped withdrawal nozzle 16, preferably are manufactured from a ceramic material.
The withdrawal arrangement 15 further contains a twist blocking element or twist trap 20 possessing a tubular thread withdrawal passage or channel 21 communicating with an end 16A of the funnel-shaped withdrawal nozzle 16 and which end 16A is remote from the spinning rotor 12. The withdrawal passage or channel 21 defines a lengthwise axis 23 and contains a curved or arcuately shaped withdrawal channel section 21A associated with a predetermined center of curvature. The arcuately shaped withdrawal channel section 21A contains a withdrawal channel section half 21B, as seen in the direction of the lengthwise axis 23, on the side facing the predetermined center of curvature.
Elongated beads or ridges 22 are provided at the interior surface of the withdrawal passage or channel 21. As shown in FIGS. 1 and 4, the beads or ridges 22 extend along the arcuately shaped withdrawal channel section half 21B which faces the center of curvature of the arcuately shaped withdrawal channel section 21A.
The substantially spiral-shaped bead or ridge 17 which is formed at the surface of the substantially conical section 18 of the funnel-shaped withdrawal nozzle 16, as well as the beads or ridges 22 which are formed at the withdrawal channel section half 21B which faces the center of curvature associated with the arcuately shaped withdrawal channel section 21A, respectively extend at an inclination relative to the rotational axis 13 defined by the spinning rotor 12 and the lengthwise axis 23 of the withdrawal passage or channel 21. In other words, the substantially spiral-shaped bead or ridge 17 of the funnel-shaped withdrawal nozzle 16 and the beads or ridges 22 of the withdrawal passage or channel 21 extend at a predetermined inclination relative to the spun yarn 14 which runs through the withdrawal nozzle 16 and the withdrawal passage or channel 21 during the open-end spinning operation.
During the performance of the open-end spinning operation with the inventive spinning device 1, the spinning rotor 12 is rotated at a high rotational speed using the rotary drive means llA. The spun yarn 14 formed thereby is withdrawn through the withdrawal arrangement 15. During this operation, the substantially spiral-shaped bead 17 at the substantially conical portion 18 is contacted by the revolving yarn 14A in a sliding manner.
During the open-end spinning operation and depending upon the rotational direction of the spinning rotor 12, the thread or spun yarn 14 or the like is twisted so as to possess a so-called S-twist or Z-twist. In the illustrations of the exemplary embodiment of the inventive spinning device 1, it is assumed that the spun yarn 14 is formed so as to have an S-twist. In such case, the thread or yarn is twisted in the direction indicated by the inclined lines designated by the reference character "B" on the spun yarn 14 as shown in FIGS. 1, 3 and 4. Consequently, the fibers on the side facing the observer, extend in a manner similar to an S-shape whereas such fibers would extend in a manner similar to a Z-shape in the opposite twisting mode. As explained hereinbefore, the substantially spiral-shaped bead or ridge 17 of the conical section 18 in the substantially funnel-shaped withdrawal nozzle 16 as well as the beads or ridges 22 in the withdrawal passage or channel 21 extend at the predetermined inclined disposition as illustrated in FIGS. 3 and 4. During the passage of the thread or yarn in the upward direction illustrated in the drawings, the inclined disposition of the beads or ridges 17 and 22 is such in relation to the fibers, that the beads or ridges 17 and 22 substantially extend in the same direction, i.e. substantially parallel to the twist direction B of the spun yarn 14.
Under these circumstances, the beads 17 and 22 produce an additional twist in the spun yarn 14 which is moving across such beads 17 and 22 in the longitudinal direction of the spun yarn 14. This has the beneficial effect that the spun yarn 14 possesses in the region of the beads or ridges 17 and 22 a higher S-shape twist level or degree of twist than the twist produced by the rotation of the spinning rotor 12. Accordingly, a twist block is formed in the region of the beads or ridges 17 and 22. This twist block disappears, however, after the spun yarn 14 has moved beyond the beads or ridges 17 and 22. Thus, the spun yarn 14 possesses an increased strength in the regions in which the spun yarn is deflected and in which regions the spun yarn 14 is exposed to greatest stresses during the open-end spinning operation.
The aforedescribed formation of a twist block or blockage by means of the inclined disposition of the beads or ridges 17 and 22 in substantially the same direction as the twist direction B of the spun yarn 14, is an essential characteristic or aspect of the present invention and of eminent significance for achieving the initially mentioned advantages of the inventive open-end spinning device 1.
In an advantageous embodiment, as already noted hereinbefore, the substantially funnel-shaped withdrawal nozzle 16 and the substantially spiral-shaped bead or ridge 17 are made of a ceramic material. Such funnel-shaped withdrawal nozzle 16 can be manufactured at low cost if the withdrawal nozzle 16 is formed in such a manner that the ceramic material to be baked is placed in a basic mold and the portion containing the bead or ridge 17 and tubular portion 19 are formed by inserting a correspondingly shaped covering core. When a withdrawal nozzle shape is selected of the type as shown in FIG. 3, the covering core can be readily withdrawn after the baking operation without damaging the withdrawal nozzle 16. Also, the withdrawal nozzle 16 can be readily removed from the basic mold which received the ceramic material prior to the baking step. The possibility of multiple re-use of the basic mold and the covering core is the reason for rendering possible the relatively low-cost production of the withdrawal nozzles 16.
In order that the covering core may be removed from the withdrawal nozzle after the baking step without having to destroy such covering core, two conditions must be fulfilled: Considering the imaginary or virtual cylinder 24 as illustrated in broken lines in FIG. 3, which cylinder 24 extends from the internal surface 19A of the tubular portion 19 of the funnel-shaped withdrawal nozzle 16, the substantially spiral-shaped bead or ridge 17 must be located completely outside this cylinder 24. Furthermore, the surface 17A of the substantially spiral-shaped bead or ridge 17 must contain the partial surface region 17B directed towards the tubular portion 19 such as to converge or narrow towards this tubular portion 19 or, at most, to extend substantially parallel to the imaginary or virtual cylinder 24.
In a further advantageous embodiment of the inventive spinning device 1, the substantially spiral-shaped bead or ridge 17 extends through a predetermined number, preferably in the range of one to three turns, in the form of a single-lead spiral.
A preferred embodiment of the beads or ridges 22 in the twist blocking element 20 is one in which two or three such beads or ridges 22 are provided.
In order to laterally guide the spun yarn 14 at the beads or ridges 22 which are provided at the surface of the arcuately shaped withdrawal passage or channel section half 21B of the twist blocking element 20, it is recommended that these beads or ridges 22 are provided with a concave indentation or recess, specifically such that the beads or ridges 22, as shown in FIG. 4, have their lowest point at the locations where they are covered by the thread or spun yarn 14.
It is also advantageous if the beads or ridges 22 of the twist blocking element 20 are made of ceramic material.
While there are shown and described present preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto, but may be otherwise variously embodied and practiced within the scope of the following claims. ACCORDINGLY,
|
The spinning device for open-end spinning contains a withdrawal nozzle with a substantially spiral-shaped bead or ridge as well as a twist blocking element or twist trap containing beads or ridges and provided in a thread withdrawal passage. The inclinations of the substantially spiral-shaped bead or ridge and of the beads or ridges in the withdrawal nozzle and in the withdrawal passage, respectively, substantially extend in the same direction or sense as the twist of the yarn. This device permits increasing the stability of the yarn, reducing the number of thread breakages and/or increasing the production rate. The yarn characteristics are less dependent upon the fiber material and the yarn type. In particular, the production of yarns with a soft handle is rendered possible at higher rotor speeds than heretofore possible.
| 3
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to Application No. 10 2005 053 088.5, filed in the Federal Republic of German on Nov. 4, 2005, claims priority to Application No. 10 2006 017 708.8, filed in the Federal Republic of German on Apr. 15, 2006 and claims the benefit of U.S. Provisional Application No. 60/737,079, filed on Nov. 15, 2005, each of which is expressly incorporated herein in its entirety by reference thereto.
FIELD OF THE INVENTION
[0002] The present invention relates to a method for attaching a scale to a carrier, a scale and a carrier having a scale.
BACKGROUND INFORMATION
[0003] To measure the relative position of two machine parts, a scale is attached to one of the machine parts, and a scanning unit is attached to the other of the machine parts movable relative to each other. During the position measuring, a graduation marking of the scale is scanned by the scanning unit.
[0004] A distinction is made between two basic principles when attaching a scale to a carrier. In the case of the first basic principle, the scale is attached to the carrier such that it is able to expand freely with respect to the carrier in response to temperature changes. In this case, fastening elements that are deflectable in the measuring direction, or an elastic adhesive layer are used for the attachment.
[0005] In the case of the second basic principle, the scale is rigidly attached to the carrier. In this instance, the carrier and the scale may be made of a material having the same expansion coefficient. If the carrier and the scale are made of different materials, the thermal characteristic of the carrier is forced on the scale. In the case of the second basic principle, the fastening is accomplished via thin, rigidly curing adhesive layers or by direct contact, such as optical contacting.
[0006] For highly accurate position measuring, scales made of glass or glass ceramic having a negligible expansion coefficient are used. These scales may be effectively machined, so that direct bonding on opposing surfaces is used, as described in German Published Patent Application No. 101 53 147.
[0007] The problem in direct bonding a scale is that the connection can easily be disturbed by impurities or the formation of air bubbles. Moreover, the joining surfaces must be very even, which requires great effort. These problems are amplified in the case of relatively large-area scales. For this reason, the direct bonding of scales has not gained acceptance.
SUMMARY
[0008] Example embodiments of the present invention may provide a method that eliminates the foregoing problems, and example embodiments of the present invention may provide a carrier having a scale firmly attached to it.
[0009] Example embodiments of the present invention utilize the attainable advantages of optically contacting, by applying surface forces as large as possible in the form of retaining forces but simultaneously may avoid the disadvantages of optically contacting bond, in that a plurality of optically contacting bond surfaces separate from one another are formed.
[0010] Local separation of the bond due to contamination or scratches is limited by the separation of the optically contacting bond surfaces. Generally, the separation does not propagate due to a broken bond.
[0011] In addition, satisfactory flatness of the scale may be achieved, since disruptive media may escape through the at least one channel leading to the outside.
[0012] According to example embodiment of the present invention, a method for attaching a scale to a carrier includes: producing an optically contacting bond between the scale and the carrier at a plurality of surface regions of the scale spaced apart from each other and separated from each other by at least one channel.
[0013] The optically contacting bond may be produced in the producing step by at least one of (a) direct bonding, (b) low-temperature bonding and (c) anodic bonding.
[0014] The optically contacting bond may be produced in the producing step at surface regions distributed in a two-dimensional grid and set apart from each other.
[0015] The surface regions may include projections having a mutual spacing of less than a thickness of the scale.
[0016] The method may include producing a further connection in addition to the optically contacting bond.
[0017] The further connection may include an adhesive joint, and the further connection producing step may include introducing an adhesive agent between the scale and the carrier.
[0018] According to an example embodiment of the present invention a device includes: a scale; and a carrier, the scale attached to the carrier by an optically contacting bond. The optically contacting bond is provided at a plurality of surface regions of the scale set apart from each other and separated from each other by at least one channel.
[0019] The surface regions may include projections provided on at least one of (a) the scale and (b) the carrier.
[0020] The projections may be positioned distributed in a two-dimensional grid.
[0021] The projections may have a mutual spacing of less than a thickness of the scale.
[0022] The scale and the carrier may be connected by a further connection in addition to the optically contacting bond.
[0023] The additional connection may include an adhesive joint, and an adhesive agent may be provided on adhesive surfaces between the scale and the carrier.
[0024] The adhesive surfaces may be separated from projections provided on at least one of (a) the scale and (b) the carrier by grooved depressions.
[0025] The carrier may directly contact the scale at the projections, the adhesive surfaces may be recessed with respect to the projections to provide a gap between the scale and the carrier adapted to receive the adhesive agent, and the grooved depressions may be recessed with respect to the adhesive surfaces.
[0026] The carrier may include at least one opening adapted for introduction of the adhesive agent onto the adhesive surface.
[0027] The adhesive surface may extend to an edge of at least one of (a) the scale and (b) the carrier and may be formed so that the adhesive agent travels by capillary force from the edge to adhesive surfaces arranged away from the edge.
[0028] The carrier may include a taper in a direction of an edge.
[0029] According to an example embodiment of the present invention, a scale includes: an attachment surface adapted for attachment to a carrier, the attachment surface including projections set apart from each other, each projection including an optically contactable surface adapted to produce an optically contacting bond to an opposing surface of the carrier.
[0030] The projections may be positioned distributed in a two-dimensional grid.
[0031] The projections may have a mutual spacing of less than a thickness of the scale.
[0032] Further aspects and features of example embodiments of the present invention are described in more detail below with reference to the appended Figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] FIG. 1 illustrates a first scale and a first carrier for attachment of the scale.
[0034] FIG. 2 illustrates the scale illustrated in FIG. 1 attached to the carrier.
[0035] FIG. 3 is a longitudinal cross-sectional view of the scale and the carrier illustrated in FIG. 2 .
[0036] FIG. 4 illustrates a second carrier and a second scale.
[0037] FIG. 5 illustrates the scale illustrated in FIG. 4 attached to the carrier.
[0038] FIG. 6 is a top view of a third carrier and a third scale.
[0039] FIG. 7 is a cross-sectional view of the scale illustrated in FIG. 6 attached to the carrier.
[0040] FIG. 8 is a cross-sectional view of two alternatives drawn side-by-side for forming the third scale.
[0041] FIG. 9 is a top view of the two alternatives illustrated in FIG. 8 .
[0042] FIG. 10 illustrates a fourth carrier and a fourth scale.
[0043] FIG. 11 is a top view of the fourth carrier and fourth scale.
[0044] FIG. 12 is a cross-sectional view taken along the line A-A illustrated in FIG. 11 .
[0045] FIG. 13 is an enlarged view of region B illustrated in FIG. 12 .
[0046] FIG. 14 is an enlarged view of region C illustrated in FIG. 11 .
[0047] FIG. 15 illustrates a fifth carrier and a fifth scale.
[0048] FIG. 16 is a top view of the fifth carrier and fifth scale.
[0049] FIG. 17 is a cross-sectional view taken along the line A-A illustrated in FIG. 16 .
[0050] FIG. 18 is an enlarged view of region B illustrated in FIG. 17 .
[0051] FIG. 19 is an enlarged view of region C illustrated in FIG. 16 .
DETAILED DESCRIPTION
[0052] Referring to FIGS. 1 through 3 , a glass or glass-ceramic (e.g., ZERODUR) scale 11 having a measuring graduation marking 21 is illustrated. Measuring graduation marking 21 is an incremental graduation marking able to be scanned for position measuring in measuring direction X. Measuring graduation marking 21 may be a reflecting amplitude or diffraction grating or a phase grating which is used, e.g., in a conventional manner, for highly accurate, interferential position measuring. In the region of its Bessel points, scale 11 has projections 31 which are used as supports for placement onto an opposing surface 41 of a carrier 51 . Carrier 51 may be made of glass or glass ceramic (e.g., ZERODUR), etc.
[0053] Surfaces 61 of projections 31 opposite to opposing surface 41 of carrier 51 , as well as opposing surface 41 , are clean surfaces polished to a high degree. The surface finish required is achieved by mechanical, abrasive polishing, chemical-mechanical polishing, etc.
[0054] Projections 31 on scale 11 may be produced by conventional patterning methods, by covering the regions of projections 31 and etching away the material around projections 31 . Projections 31 are thus formed in one piece on scale 11 .
[0055] Scale 11 is joined to carrier 51 by optically contacting the surfaces 61 of projections 31 to opposing surface 41 of carrier 51 . The basis of the optically contacting is adhesion, as clean, conformable, and polished surfaces adhere to one another when their spacing enters the range of atomic bonding forces. Optically contacting is also referred to as optical bonding, non-adhesive bonding or wringing. Surfaces 61 of the projections are therefore formed such that they have an optically contactable surface 61 for producing an optically contacting bond with opposing surface 41 of carrier 51 .
[0056] This optically contacting may be direct bonding (or direct contacting), which is also referred to as wringing and “Ansprengen” in German. In the case of direct bonding, the bonding action may be increased by the effect of heat, or by applying surface-active agents. Direct bonding using surface-active agents also achieves a good bonding strength at relatively low temperatures. A special type of surface-active agent is the introduction of crystallizing liquid. This optically contacting method is also referred to as low-temperature bonding technique (LTB) and is explained in a treatise from the firm SCHOTT, available over the Internet, having the title: “SCHOTT Low Temperature Bonding for Precision Optics” by Carol Click, Leo Gilroy and Dave Vanderpool, which is expressly incorporated herein in its entirety by reference thereto. When using the LTB method, scale 11 and carrier 51 are each made of glass ceramic having an expansion coefficient close to zero, e.g., ZERODUR.
[0057] The optically contacting may also be anodic bonding, in which on one of surfaces 61 , 41 of scale 11 or carrier 51 to be joined together, a metallic, electroconductive auxiliary layer, e.g., aluminum, is applied as an intermediate layer between projections 31 and opposing surface 41 . This auxiliary layer may be a vapor-deposited layer. In anodic bonding, a voltage is applied between the auxiliary layer and carrier 51 , so that ions from the auxiliary layer migrate into carrier 51 and/or ions from carrier 51 migrate into the auxiliary layer. The applied voltage generates an electrostatic attractive force which brings about an atomic contact between the scale and the carrier.
[0058] Scales 12 having a two-dimensional measuring graduation marking 22 are increasingly being used for multi-dimensional position measuring. In that case, relatively large-sized scales 12 (e.g., 40 cm×40 cm) are mounted on a surface 42 of a machine part 52 . Example embodiments hereof are suitable for lithographic devices, e.g., in which machine parts 52 on which scale 12 is to be mounted are made of glass ceramic (e.g., ZERODUR) having an expansion coefficient close to zero. Such a machine possessing a scale having a two-dimensional measuring graduation marking is described, for example, in U.S. Patent Application Publication No. 2004/0263846, which is expressly incorporated herein in its entirety by reference thereto.
[0059] It may be necessary to mount a plurality of scales 12 in two-dimensional fashion side-by-side like a mosaic on a machine surface 52 of 1 m×2 m, for example, in order to cover the requisite measuring region of approximately 1 m×2 m. This is because scales 12 having, for example, a measuring graduation marking 22 able to be scanned photoelectrically are only able to be produced with the necessary precision in sizes of, e.g., approximately 40 cm×40 cm. Each of these scales 12 may be attached to carrier 52 as illustrated in the Figures described below.
[0060] The optically contacting methods explained above are used for this attachment.
[0061] In FIGS. 4 and 5 , such a scale 12 having a two-dimensional measuring graduation marking 22 , also referred to as a cross grating, is illustrated as an example. Projections 32 having optically contactable surfaces 62 are formed on the surface of scale 12 facing carrier 52 . These projections 32 may be spatially distributed two-dimensionally, either in a geometrically uniform manner in a normal grid, or in a statistical distribution. Projections 32 may each be circular, having a diameter of, e.g., less than 30 mm, e.g., 200 μm to 4 mm, and having a mutual spacing, e.g., less than the thickness of scale 12 , the mutual spacing being the edge spacing, i.e., 4 mm in FIGS. 11 and 16 . The height of projections 32 may be greater than, e.g., 10 nm, for example, 20 nm to 50 μm. The flatness (waviness) of surfaces 62 of projection 32 may be in the range of less than, e.g., 500 nm on a diameter of approximately 10 mm, e.g., 30 nm per 0.10 mm. Surfaces 62 of projections 32 formed as optically contacting surfaces are arranged in a common plane. Typical values of the thickness of scale 12 are, e.g., 1 mm to 15 mm. The lower the diameter of projections 32 , and the lower the mutual spacing, the lower the height of projections 32 may also be.
[0062] The two-dimensional, spatial distribution of projections 32 may be implemented such that, between projections 32 , opening channels 200 are formed which extend, relative to the X-Y plane, to the edge of scale 12 . This measure permits surface-active agents to escape easily from the space between scale 12 and carrier 52 after the optically contacting process. In addition, trapped air over the entire surface of scale 12 is able to escape easily via opening channels 200 , thus increasing the bonding strength and providing good planarity of scale 12 .
[0063] Projections 32 constitute a type of nub and are formed so that the edges, which are transitions to the depressions next to them that form opening channels 200 , are rounded off. In this manner, surfaces 62 to be optically contacting may be more effectively cleaned and, if desired, surface-activated. An additional aspect is that contact points for separation may be prevented and the risk of material splintering off may be substantially reduced.
[0064] For maintenance, the optically contacting bond may be broken by introducing a medium, e.g., compressed air, through at least one bore in carrier 52 or in scale 12 , into the gap of scale 12 and carrier 52 , thereby generating a pressure that forces scale 12 and carrier 52 apart.
[0065] For example, for scales 13 jutting out past carrier 53 (illustrated, for example, in FIGS. 6 and 7 ), there is the risk that induced vibration may cause the edge regions of scale 13 to alternately peel off and come together again. This event leads to unpredictable change in the short-period variation in length of the projecting scale region. Additional measures may be provided for preventing this.
[0066] Thus, an additional safety mechanism may be provided for supporting scale 11 to 15 at carrier 51 to 55 . This additional safety mechanism may include retaining elements in the form of springs, retaining clips, magnetic retaining elements, electrostatic clamp circuit, vacuum holding devices, etc., or adhesive holding devices such as oil films, etc., or adhesive bonding methods, etc., may be used. This additional safety mechanism may be implemented at least at the edge region of the optically contacting joint, i.e., at the edge region of scale 13 and/or carrier 53 , e.g., at the edge region of the overlap of scale 13 and carrier 53 .
[0067] Particularly suitable adhesive joints for supplementing the optically contacting are explained below with reference to FIGS. 6 to 19 . In this context, the surface pressure between connection partners 13 and 53 is increased with the aid of adhesive agent 7 , by prestressing discrete optically contacting surfaces 63 , e.g., in the edge zone of the connection of scale 13 and carrier 53 .
[0068] Fastening with the aid of adhesive agent 7 prevents the breaking-off and loss of scales 13 , for example, from inadvertent contact by an installer.
[0069] In this context, the adhesive layer produces deformations of scale 13 , which are, at most, locally minimal. Position and flatness are still extremely precise and largely drift-free due to the optically contacting joint.
[0070] FIG. 6 illustrates a scale 13 protruding from carrier 53 at edge regions. Some of annular projections 33 of scale 13 are additionally provided with a cementing point, of which a cross-section of one is illustrated in FIG. 7 . To differentiate the projections 32 that are only optically contacted and the projections 33 that are additionally secured by adhesive agent 7 , these are provided with different reference numerals, and projections 33 secured by adhesive agent 7 are represented in black in FIG. 6 . For projections 33 additionally fastened by adhesive agent 7 , a circular adhesive surface 73 , which is separated from optically contacting surface 63 by a grooved depression 83 in the form of an adhesive stop, is arranged inside annular optically contacting surface 63 . This prevents adhesive agent 7 from reaching optically contacting surface 63 when it is introduced.
[0071] For clarity, the measuring graduation marking is no longer illustrated.
[0072] The regions lying deeper than optically contacting surface 63 , i.e., adhesive surfaces 73 and depressions 83 , are produced, for example, in a lithographic manner. Possible alternatives include mechanical machining, e.g., milling, or, for a suitable material, laser machining.
[0073] Adhesive surface 73 and the E-module of adhesive agent 7 should only kept as large as absolutely necessary, in order to keep the bending deformation of scale 13 due to tensile forces after the curing of the adhesive agent only as large as necessary, but as small as possible. Tensile forces are caused by shrinkage of adhesive agent 7 .
[0074] Given the same size of adhesive surface 73 , negligible, short-period deflection of scale 13 may also be attained using an oval shape of optically contacting surface 63 and adhesive surface 73 , illustrated, in each instance, on the right side. Regardless of the structural arrangement, the goal is to absorb the forces applied by adhesive agent 7 upon curing, as all-around as possible, and at a support distance as small as possible, which is provided by the projection or optically contacting surface 63 surrounding adhesive surface 73 .
[0075] A method for optically contacting and adhesive fastening includes: bringing scale 13 into contact with carrier 53 ; aligning scale 13 on carrier 53 , the alignment being able to be facilitated by, for example, introducing a gas, e.g., air, through bore 93 into the gap of scale 13 and carrier 53 in order to prevent optically contacting in this state; pressing scale 13 against carrier 53 , and therefore optically contacting scale 13 , in the aligned state, the pressing being able to be generated by producing a vacuum (evacuation) in the gap of scale 13 and carrier 53 ; and introducing adhesive agent 7 to adhesive surface 73 via bores 93 in carrier 53 .
[0076] In order to prevent deformation of scale 13 during measuring operation, due to shrinkage or swelling of adhesive agent 7 , e.g., caused by a change in air humidity, bore 93 may be sealed air-tight after introduction of adhesive agent 7 . As an alternative, after optically contacting has occurred, a gas having a defined humidity (e.g., nitrogen, helium, etc.) may be directed through bore 93 into the gap of scale 13 and carrier 53 , and therefore to adhesive surfaces 73 , in order to prevent deterioration of adhesive agent 7 .
[0077] When a suitable adhesive agent 7 is used, the adhesive-secured optically contacting joint may be separated, e.g., for maintenance, by, for example, heating the adhesive agent 7 or cracking it with the aid of light of a defined wavelength, or using chemical agents. For separation by heating, a heating rod may be inserted into bore 93 in order to locally heat adhesive surface 73 . For separation by use of a chemical solvent, this may also be introduced through bore 93 .
[0078] Alternatively, or in addition, a pressure may be generated in the gap of scale 13 and carrier 53 , via bore 93 , in order to separate the optically contacting joint.
[0079] The following examples described with reference to FIGS. 10 to 19 illustrate alternatives that facilitate the introduction of adhesive agent 7 .
[0080] As illustrated in FIGS. 10 to 14 , adhesive agent 7 is dosed from the edge of scale 14 and carrier 54 and is drawn to adhesive surface 74 by capillary forces. Grooved or groove-shaped depressions 84 between surfaces 64 of nub-shaped projections 34 and adhesive surfaces 74 prevent the adhesive agent from contacting optically contacting surface 64 .
[0081] Support is provided by optically contacting surfaces 64 in direct proximity to the dosing channel and inside the adhesive region, formed by adhesive surfaces 74 . Depressions 84 prevent adhesive agent 7 from contacting optically contacting surfaces 64 (detachment due to drawn-in adhesive agent 7 is prevented).
[0082] As illustrated in FIGS. 15 to 19 , a slot 95 , which is used for introducing adhesive agent 7 to adhesive surface 75 , is introduced into carrier 55 . Adhesive agent 7 is drawn by capillary action from slot 95 to adhesive surface 75 . In this manner, a shrinking adhesive point on the protruding region of scale 15 is prevented, and adhesive agent 7 cannot pull protruding scale 15 down.
[0083] Carrier 55 may have a taper 100 in the direction of the edge. This renders carrier 55 more flexible, and it undergoes the deformation of protruding scale 15 along with it. The risk of separation in the edge region may thereby be reduced. An exemplary embodiment is illustrated in FIG. 15 .
[0084] A taper 100 of the edge region of carrier 51 to 55 may be used, with or without adhesive fixing, for improving the optically contacting stability.
[0085] Contact surfaces 63 to 65 , which are formed by projections 33 to 35 and surround adhesive surface(s) 73 to 75 , may be positioned about adhesive surface 73 to 75 as symmetrically as possible. This keeps the deformation of the scale graduation marking surface small as well.
[0086] Channels 200 leading to the outside separate nub-shaped projections 31 to 35 from each other in an otherwise planar optically contacting surface (providing, e.g., escape of the air from the gap, improvement of the optically contacting behavior). Several combinations of surfaces/nubs/grooves having, or not having, adhesive-stop depressions 83 , 84 , 85 are possible.
[0087] In order to protect the optically contacting joints from external effects and creeping-under, the gap between scale 11 to 15 and carrier 51 to 55 may be sealed, after generation of the optically contacting joint, by sealing the edge at the periphery of scale 11 to 15 . Varnishes or adhesive agents may be used for this purpose. Protection may also be achieved by flooding the gap with a medium, for which purpose a gas having defined properties, for example, is introduced into the space between projections 31 to 35 , i.e., into channels 200 , and flows through it.
[0088] In the above-mentioned examples, projections 31 to 35 set apart from one another are formed in one piece on scale 11 to 15 in the form of nubs. Alternatively or additionally, projections 31 , 35 may also be formed on carrier 51 to 55 . Projections 31 to 35 may also be formed by a layer deposited on scale 11 to 15 or carrier 51 to 55 and patterned.
[0089] The form and arrangement of projections 31 , 35 are not limited to the arrangements shown.
[0090] When working with at least approximately square or round scales, the projections may form a kinematically determined support, in that only three projections are provided, distributed in one plane.
[0091] The optically contacting methods have in common that surfaces 61 to 65 , 41 to 45 to be joined are brought toward each other in close contact until they are a few interatomic distances apart, in order to either be able to be attracted due to the power of the van der Waals forces (direct bonding), or else to be able to produce an atomic bond by the formation of a few atomic layers in the form of an intermediate bond (LTB, anodic bonding).
[0092] The dimensions specified in the drawings are indicated in mm and only show the orders of magnitude schematically.
|
A scale is attached to a carrier by optically contacting. The optically contacting bonds are formed by raised surface regions of the scale set apart from each other. Additional measures, such as the provision of adhesive surfaces, provide a rigid and vibration-resistant joint.
| 6
|
CROSS-REFERENCE TO RELATED APPLICATIONS
none
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to tools for the installation of wire. More particularly, it relates to devices for unrolling wire (e.g., barbed wire) in the field.
2. Description of the Related Art
Wire, be it electrical wire or fence wire, is commonly supplied in the form of rolls which may be wound on a reel or drum. If the wire is of sufficient stiffness, it may hold the roll shape without being wound on a reel or drum. To avoid twisting the wire, it should be unwound from the reel or drum (as opposed to being spiraled off one end of the roll).
Most reels and drums have a central, axial opening through which a rod or shaft may be placed to allow the reel or drum to rotate freely. Perhaps the most simple wire dispenser is a dowel inserted through the center of the roll. Holding the dowel on either side of the roll while walking backwards allows the wire to pay out as the roll unwinds. Heavier rolls of wire may be unwound by two people, one on either side of the roll supporting the respective ends of a shaft inserted through the roll, reel or drum. Still heavier rolls may be carried on motorized vehicles—a common method being a shaft resting on the side walls of a pickup truck's bed.
Barbed wire is commonly manufactured in rolls 80 rods (1320 feet) in length, 70-90 lbs per roll depending on the gauge, number of strands, type and number of barbs. The rolls are typically wound on a wire frame having radial arms at either end for containing the roll (as shown in phantom in the drawing figures). Since it is both heavy and sharp, it is highly desirable to utilize a dispensing device of some sort when stringing barb wire.
One method of the prior art for the paying out of fencing wire and barbed wire is the wire spinner. An old plough disk can be used as a type of spinner by welding a piece of 25 mm water pipe into the centre of the disk with the disks edge resting on the ground. The reel of wire may be slipped onto the pipe and paying out the wire becomes a one person operation. However, if the spinner is stationary, the wire must be dragged across the ground. To move the spinner, a conveyance of some sort is required. An alternative to this is to slip the handle of a shovel through the eye of the reel and have two fencers then walk the barbed wire along the fence line having tied off one end.
Wire unrollers are available for mounting on the back of an All Terrain Vehicle (ATV). Such devices are said to permit one to quickly or slowly release a spool of wire when building fences. An adjustable drag brake prevents free wheeling. Hydraulically-powered wire winders are available for Cat. I, Cat. II or Cat. III tractor hitches. It is said that wire may be unwound from the device by putting the hydraulic control lever in the “float” position while the tractor is driven across the ground. The circulation of hydraulic fluid through the motor provides sufficient resistance to keep the reel from overspinning. However, such devices are relatively expensive and additional clearance along the fence line is needed to accommodate the vehicle. What is needed is a wire dispenser that can be loaded and operated by one person and is simple, reliable and easy to manufacture. The present invention solves this problem.
BRIEF SUMMARY OF THE INVENTION
A spool or roll of wire is held on a horizontal shaft or spindle mounted on a handcart. The shaft or spindle is offset from the wheel axle such that tipping the cart forward raises the spool off the ground and permits the wire to payout from the roll.
In one preferred embodiment, a portion of the frame of the handcart supporting the spindle is hinged to move between an open position and a closed position. In the open position, the frame can slide onto a roll of wire resting on the ground or other such surface. Once in position over the roll of wire, the frame may be closed thereby securing the roll of wire to the cart.
In an alternative embodiment, the horizontal shaft or spindle is removable. With the shaft removed, the cart may be positioned over a roll of wire resting on the ground. The shaft may then be inserted through the roll of wire and secured to the frame of the handcart.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
FIG. 1 is a perspective view of one embodiment of the invention.
FIG. 2 is an enlargement of latching mechanism employed in the embodiment of FIG. 1 .
FIG. 3 is an enlargement of the hinge mechanism employed in the embodiment of FIG. 1 .
FIG. 4 is a perspective view of the device illustrated in FIG. 1 in the open or loading position.
FIG. 5 is a rear view of the device shown in FIG. 1 in the open or loading position.
FIG. 6 is a perspective view showing the spindle and wheel assembly of the cart shown in FIG. 1 .
FIG. 7 is a perspective view of the wheel and spindle assembly of an alternative embodiment of the invention.
FIG. 8 is a partial cross-sectional view of the spindle-to-frame attachment used in the embodiment of FIG. 7 taken along line 8 - 8 in FIG. 7 .
DETAILED DESCRIPTION OF THE INVENTION
The invention may be best understood by reference to the drawing figures wherein two preferred embodiments are illustrated.
The first preferred embodiment is shown in perspective in FIG. 1 . Carrier 10 may comprise a welded steel tubular frame to which handle 12 is attached. The frame may include a fixed portion 14 and a moveable or hinged portion 16 .
Carrier 10 has a transverse shaft or spindle 30 for holding a roll of wire 34 which may be barbed wire 32 for fencing. The wire is supplied on wire reel 36 which has a central, transverse opening through which shaft 30 may be passed. Other wire may be supplied on drums or spools which may also be used with the present invention.
Carrier 10 is also equipped with wheels 38 on axles 40 supported in axle brackets 42 . The wheels 38 are preferably aligned, one with the other, in a coaxial arrangement. The axis of aligned wheel axes 40 is offset from the axis of spindle 30 such that tipping carrier 10 forward on wheels 38 lifts spindle 30 , raising roll 34 and allowing wire 32 to payout from roll 34 as carrier 10 is moved across the ground, floor, or other such generally horizontal surface. Carrier 10 may be either pushed or pulled depending on which side of roll 34 it is desired to have wire 32 payout. Most commonly, carrier 10 will be pulled by the user and wire roll 34 will be mounted such that wire 32 pays out from the bottom of roll 34 .
Carrier 10 may be equipped with bushings 24 , 26 each having flange 28 which act to center roll 34 on shaft 30 and prevent roll 34 or reel 36 from contacting frame 14 or axle bracket 42 as it revolves on spindle 30 .
When the user desires to stop, he or she may move handle 12 to an approximately vertical position such that the bottom of roll 34 or reel 36 contacts the ground or floor. Carrier 10 is then in a stable position, resting on wheels 38 and wire roll 34 or reel 36 , as the case may be. Conversely, if it is desired to pull wire from roll 34 with cart 10 stationary, handle 12 may be lowered to the ground or floor, thereby raising spindle 30 and roll 34 such that the roll 34 may rotate freely on shaft 30 . In this configuration cart 10 is resting on wheels 38 and handle 12 .
The embodiment illustrated in FIG. 1 includes a hinged or moveable frame section 16 which facilitates loading and unloading wire roll 34 . Frame hinge 18 is shown in detail in FIG. 3 . Fixed frame section 14 and moveable frame section 16 are joined by frame hinge 18 which may comprise two opposing, spaced-apart plates. Bolt 50 having unthreaded portion 51 may be passed through aligned holes in the opposing plates and a hole proximate the end of moveable frame section 16 . Bolt 50 may be secured with nut 52 which may be a lock nut. Unthreaded portion 51 acts as a bearing surface for frame section 16 . Bolt 50 may be tightened to provide the desired amount of friction between frame member 16 and hinge 18 . It may be desired to have sufficient friction to hold frame member 16 in the open position when under the influence of its own weight.
FIGS. 4 and 5 show carrier 10 in the open or loading position (with the closed position shown in phantom in FIG. 4 ). Frame locking rod 22 is held out of the way by rod retainer 54 which, in the illustrated embodiment, comprises a U-shaped section welded to fixed frame section 14 . As shown in FIG. 5 , wire roll 34 is held on reel 36 having diameter D. Hinged frame member 16 is moved outward sufficiently to provide clearance C between flange 28 and the ground or floor on which reel 36 rests such that distance C is greater than diameter D. In this condition, cart 10 may be slid sideways such that spindle 30 is inserted through the center of roll 34 and/or a central aperture in reel 36 . Frame member 16 may then be moved to the closed position and locked in place by securing locking rod 22 in lock bracket 44 .
Moveable frame member 16 may be held in the closed position by frame locking rod 22 which pivots in hole 23 through fixed frame member 14 on one end and is releaseably secured by frame lock 20 on the opposing end. Frame lock 20 is shown in detail in FIG. 20 and may comprise lock bracket 44 having slot 45 arranged such that when locking rod 22 swings downward it enters slot 45 . The end of rod 22 may have a threaded portion to which backing nut 46 and wing nut 48 may be attached. Locking rod 22 may be secured by tightening lock bracket 44 between wing nut 48 and backing nut 46 . The alignment of frame member 16 with frame member 14 may be adjusted by moving backing nut 46 along the threaded portion of rod 22 .
As may be best seen in FIG. 6 , one end of spindle 30 may be secured in bushing 26 with spindle bolt 56 . Bushing 26 and spindle bolt 56 are on fixed frame member 14 . The opposing end of spindle 30 is in sliding engagement with bushing 24 on hinged frame member 16 . It will be appreciated by those skilled in the art that the central opening in bushing 24 must be large enough to accommodate spindle free end 58 as bushing 24 moves in an arc when frame section 16 pivots on bolt 50 in hinge 18 . To further assist in aligning spindle free end 58 with bushing 24 during the closing process, it may be advantageous to allow spindle 30 to pivot on spindle bolt 56 within the confines of bushing 26 .
An alternative embodiment of the invention is shown in FIGS. 7 and 8 . In this embodiment, frame 114 is fixed—i.e., unhinged—and may comprise cross member 115 for additional rigidity.
Referring to FIG. 7 , it may be seen that spindle shaft 130 is adapted for sliding engagement in spindle support brackets 164 which may comprise bushings 124 and 126 and flanges 128 . Each spindle bracket 164 may comprise hole 165 having an internal diameter slightly larger than the diameter of spindle 130 so as to permit spindle 130 to slide through hole 165 . Spindle 130 may include threaded stud 160 on each end. Washer 161 has an outside diameter larger than the diameter of hole 165 such that when nut 162 is screwed onto threaded stud 160 over washer 161 , spindle 130 is secured in spindle bracket 164 and prevented from sliding in the direction toward the center of the cart. The left side and right side of spindle 130 being similarly secured prevents spindle 130 from sliding in either direction and locks it within frame 114 .
The embodiment of FIGS. 7 and 8 may be used by removing one each of nut 162 and washer 161 and then sliding shaft 130 out of the frame. Cart 10 may then be rolled to or lifted over a roll of wire and positioned such that the axis of bushing 124 is in line with the axis of the wire roll. Shaft 130 may then be re-inserted, passing it from the outside of spindle bracket 164 through hole 165 and secured with nut 162 and washer 161 .
One disadvantage of the embodiment shown in FIGS. 7 and 8 is that tools may be required to tighten and/or loosen nut 162 . In yet other embodiments, nut 162 may be replaced with a knurled knob, wing nut, or similar fastening device that can be operated solely by hand.
In yet other embodiments, handle 12 may be replaced with a hitch to permit cart 10 to be pulled by a vehicle.
Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of the invention as described and defined in the following claims.
|
A handcart for unrolling wire is disclosed. In a preferred embodiment, one leg of the handcart is hinged to permit a roll of wire to be loaded or unloaded onto a horizontal spindle on the cart without lifting the roll. The axles of the wheels of the cart are offset from the spindle such that tipping the cart lifts the roll of wire from the surface on which it is resting and permits the wire to payout from the roll as the cart is rolled across the ground.
| 1
|
This application claims benefit from U.S. Provisional Application No. 60/108,985 filed on Nov. 18, 1998, and from U.S. Provisional Application No. 60/125,618 filed on Mar. 22, 1999.
GOVERNMENT INTEREST
This invention was made with U.S. Federal government support under Grant Nos. NSF96-32526 and NSF97-32763 awarded by the National Science Foundation. The government has certain rights in the invention.
BACKGROUND OF THE INVENTION
Magnetoresistive (MR) materials experience changes in electrical resistivity when exposed to external magnetic fields. Such materials have a wide range of use because of their ability to detect and differentiate magnetic field strength. One of the more common uses of this technology is in magnetic data storage where data is stored on a magnetic media by varying the magnetic fields of small magnetic particles in the media. The media's magnetic field is made to fluctuate by a write head in proportion with the information to be stored on the media. The fluctuations contained in the media can subsequently be retrieved using a read head.
Standard magnetoresistive sensors, which may be used in read heads to detect the magnetic fields on the magnetic data storage media, use a detection element constructed of a magnetic material subjected to an electrical current. When placed in the presence of an external magnetic field, such as that generated by magnetic storage media, the sensor is able to measure the existence and strength of the external magnetic field through correlation with measurements of the resistivity experienced by the electrical current. The sensor becomes more or less resistive depending upon the magnetic field of the media. This allows, for example, information on magnetic media to be read by measurement of the current flow through the sensor.
Certain magnetoresistive sensors exhibit an increased sensitivity to external magnetic fields. Such sensors experience relatively larger changes in resistivity compared to normal magnetoresistive sensors. These sensors exhibit what is known as the giant magnetoresistive (GMR) effect. Magnetic multilayers, granular solids, and other materials with heterogeneous magnetic nanostructures exhibit GMR effects. Specifically, these structures exhibit a negative GMR effect in which the magnetoresistance decreases with an increase in the magnitude of an external magnetic field. Prototype GMR structures such as multilayers and granular solids require magnetic fields on the order of 10 kOe to fully realize the GMR effect.
The effectiveness of a giant magnetoresistive construction is often measured in terms of its maximum MR effect size denoted by a ratio or percentage figure dependent upon the change in electrical resistance of a material when exposed to an external magnetic field. Currently, most read heads in the magnetic recording industry utilize the anisotropic MR effect in permalloy which has an MR effect of about 2%, or a ratio of 0.02. Recently, most sophisticated read head made of spin-valve GMR structures have been commercialized with an effect size of about 5-10%, or a ratio of 0.05 to 0.10. Maximum MR effect size is dependent upon the resistance of the material at zero magnetic field and the resistance of the material at magnetic saturation. The strength of the saturation magnetic field (H S ) is determined by the composition of the material and is the field at which the largest MR effect is realized. The largest MR effect values ever reported have been 150% at low temperatures (e.g., 4 K) and 80% at room temperature at a saturation field of about 20 kOe. Most reported MR values, and particularly those in devices, are much smaller, i.e., in the range of 5% to 10% at room temperature.
Important characteristics for MR devices include the detection limit (i.e., the smallest magnetic field that can be detected), sensitivity (i.e., the percent change of MR per unit magnetic field), and the dynamic range (i.e., the range of magnetic field that can be detected). Not all MR devices value these characteristics in the same way. For example, in read head applications, the detection limit and sensitivity are important, whereas in current sensing applications, the detection limit, sensitivity, and dynamic range are all important. In general, a large MR effect size is always advantageous since it directly improves the detection limit and the sensitivity. In addition, a simple magnetic field dependence (e.g., non-saturable) of the MR and a large dynamic range are desired for field sensors.
Bismuth (Bi) is a semi-metallic element with unusual transport properties, including a large MR and Hall effect. The electronic properties of Bi, which are very different from those of common metals, are due to its highly anisotropic Fermi surface, low carrier concentration, small carrier effective masses, and long carrier mean free path. As a result, bulk single crystals of Bi are known to exhibit a very large MR effect.
Unfortunately, the fabrication of high quality Bi thin films, a necessary requirement for most device applications, is known in the art to be difficult. Deposition of MR thin films generally occurs through one or a combination of the following techniques: chemical vapor deposition (CVD), physical vapor deposition (PVD) (e.g., sputtering, evaporation, etc.), or electrochemical deposition. Bi thin films made by traditional vapor deposition such as sputtering and laser ablation are of very poor quality and exhibit a polycrystalline structure with small grains. As a result, those Bi films exhibit very small MR, on the order of 1-10% at 300 K under a field of 1 Telsa (T), which is unsuitable for applications. Previously, only Bi films made by molecular beam epitaxy, which is a prohibitively expensive method, yielded high quality Bi thin films with large MR.
Electrochemical deposition offers precise control over the microstructure and a process which can be performed economically and reliably. This translates into the possibility for mass production of high quality materials.
However, electrochemical deposition processes used to deposit bismuth directly onto a substrate have thus far been insufficient to produce MR effect levels above 150%. Processes involving the direct electrochemical deposition of bismuth onto substrates or a metallic underlayer have generally resulted in polycrystahine films with voids and other defects. One such process is described in U.S. Pat. No. 5,256,260 (Norton et al.). This process utilizes a constant-current molten salt electrocrystalization bath in which bismuth ions are complexed with a barium-based component and a bismuth-based component. Current electrochemical deposition techniques for bismuth onto a substrate result in polycrystalline films which do not allow for realization of very large MR effects.
SUMMARY OF THE INVENTION
The invention is directed to the use of electrochemical deposition to fabricate thin films of a material (e.g., bismuth) exhibiting a superior magnetoresistive effect. The process in accordance with a preferred embodiment produces a thin film of bismuth with reduced polycrystallinization and allows for the production of single crystalline thin films. Fabrication of a bismuth thin film in accordance with a preferred embodiment of the invention includes deposition of a bismuth layer onto a substrate using electrochemical deposition under relatively constant current density. Preferably, the resulting product is subsequently exposed to an annealing stage for the formation of a single crystal bismuth thin film. The inclusion of these two stages in the process produces a thin film exhibiting superior MR with a simple field dependence suitable for a variety of field sensing applications.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other advantages and features of the invention will become more apparent from the detailed description of the preferred embodiments of the invention given below with reference to the accompanying drawings in which:
FIG. 1 is a cross-sectional view of the electrochemical cell used to prepare a thin film in accordance with a preferred embodiment of the invention;
FIG. 2 is a cross-sectional view of the structure produced in accordance with a preferred embodiment of the invention; and
FIG. 3 is a cross-sectional view of another structure produced in accordance with a preferred embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The invention will be described in detail with reference to the preferred embodiments illustrated in FIGS. 1-3. The invention is described herein in its preferred application to the formation of bismuth thin films for magnetoresistive sensor devices. However, the invention may be applicable to any type or configuration of layered structure that encounters the same or similar problems overcome by the invention described herein.
FIG. 1 shows an electrochemical deposition cell constructed in accordance with a preferred embodiment of the invention. The novel deposition process occurs through use of the well-known three-electrode process, although it should be understood that a two-electrode or other known electrochemical process may similarly be utilized. In the preferred embodiment, the electrochemical cell is made up of a reference electrode 108 , a counter electrode 106 , a working electrode (discussed below), and the substrate 100 . The electrochemical bath 104 is housed in container 102 allowing the formation of thin film 120 (e.g., bismuth) through the application of a potential by control device 110 .
To deposit the exemplary bismuth film directly on the substrate 100 , a specific electrochemical or electroplating process is performed in accordance with a preferred embodiment of the invention, preferably using the electrochemical cell shown in FIG. 1 . Before a thin film layer made of bismuth can be formed, however, a suitable substrate 100 must be chosen. Any material may be chosen whose surface, which may be flat or otherwise shaped, is stable in the electrochemical deposition bath solution used. The substrate may consist of a single material or may be a layer or a coating of another material.
The choice of substrates will depend upon the end use of the thin film construct. For devices using the MR effect, insulating substrates are preferred over metallic substrates because the large MR effect is not diluted through current shunting, as with the metallic substrate. Some common insulating substrates include silicon (Si) (with or without the native SiO 2 layer on the surface), glass, mica, magnesium oxide (MgO), aluminum oxide (Al 2 O 3 ), etc. In accordance with a preferred embodiment of the invention, before a bismuth thin film is formed on a substrate made of an insulating material such as silicon, a boundary layer in the form of a thin metallic underlayer is preferably laid over the substrate. The metallic underlayer can be formed by using any known thin film deposition method such as sputtering, evaporation, laser ablation, etc. This metallic underlayer can be any metal (e.g., Au, Pt, Cr, etc.) that is stable in the electrodeposition solution used in this process. FIG. 2 shows an embodiment of the substrate 100 of the invention utilizing a metallic underlayer 118 deposited on an insulating subtrate 200 .
If the substrate 100 is metallic, as shown in FIG. 3, it is preferable to first deposit an insulating thin layer 202 on the metallic substrate 206 , followed by the metallic underlayer 118 . The insulating layer may be any known insulator such as SiO 2 , glass, MgO, and Al 2 O 3 . This procedure electrically isolates the Bi film and the thin metallic underlayer 118 from the metallic substrate 206 , making the electrical measurement on Bi possible. The insulator layer 202 can also protect the metallic substrate 206 from possible reaction with the electrodeposition solution. However, for the electrodeposition of Bi film alone, the creation of insulating layer between the metallic substrate and the bismuth thin film may not be necessary.
Referring to the substrate shown in FIG. 2, a typical substrate (insulating) that may be used is prepared from Au(100 Å)/Cr(10 Å)/SiO 2 (native oxide layer on top of Si with a thickness of about 100 Å)/Si (100 orientation), where Au(100 Å)/Cr(10 Å) is the metallic underlayer 118 (Cr is used to provide adhesion of Au to Si), and SiO 2 /Si is the insulating substrate 200 having a native oxide.
The electrolytic bath 104 used preferably contains bismuth ions in an electrolytic solution. The deposition is preferably performed in the temperature range from 15° C. to 60° C. The solution may be one of several kinds that contain bismuth ions with the appropriate pH. For example, the solution may be prepared from 75 grams/liter Bi(NO 3 ) 3 .5H 2 O, 65 grams/liter KOH, 125 grams/liter glycerol, 50 grams/liter tartaric acid, and nitric acid (HNO 3 ) to adjust the pH to 0.5. A second example of a solution for bismuth deposition is 75 grams/liter Bi(NO 3 ) 3 .5H 2 O, 120 grams/liter KNO 3 , 125 grams/liter glycerol, 50 grams/liter tartaric acid, and nitric acid (HNO 3 ) to lower the pH to 0.5. The pH of the bath is a factor in the formation of single crystalline films in accordance with the invention. For production of single crystal, c-axis (001—indexed in a hexagonal system) Bi films, for example, the electrochemical bath should have a pH value in the range of 0 to 0.6. Another factor in fabricating high quality c-axis oriented single crystalline Bi films is to avoid aging of the solution.
The electrochemical deposition of bismuth in accordance with a preferred embodiment of the invention is performed by placing the substrate as constructed above in the electrolyte solution shown in FIG. 1 as bath 104 . As is well known in the art, the bath may resemble the basic three electrode cell structure utilized to perform electrochemical depositions, as shown in FIG. 1 . The reference electrode 108 is preferably positioned so that its tip is directly over the region of interest on the planar surface of substrate 100 . Reference electrode 108 may be made of any known material (e.g., silver/silver chloride [Ag + /AgCl (3 M NaCl)]), and may be raised or lowered using a capillary (not shown) or like mechanism. The counter electrode, or current collector 106 , is preferably constructed of platinum gauze or mesh. Control device 110 may be a potentiostat-based control system (or like system) provided to control the voltage and current parameters of the electrochemical process in accordance with the invention.
To initiate electrodeposition, an electric potential is applied to the cell by control device 110 across the working electrode and the counter electrode 106 , under the constant feedback of the reference electrode 108 . The actual contact to the substrate 100 is made to the metallic underlayer 118 which functions as the working electrode and as the surface upon which deposition will occur. The actual potential varies with the surface condition and thickness of the metallic underlayer 118 , typically from 90 mV to 140 mV. The current density is preferably kept within the range of 5 mA/cm 2 to 8 mA/cm 2 , preferably 6.5 mA/cm 2 . The thickness of the Bi films can be controlled through variation of the deposition time. For example, in a bath having a pH value of 0.6, a current density of 6.5 mA/cm 2 , a charge to volume conversion ratio of 1.36×10 4 coulomb/cm 3 , the inventive process required 3.5 minutes to produce a 1 μm thick Bi film. The Bi 3+ ions in the solution 104 are typically reduced in accordance with the invention to Bi during electrodeposition with an approximately 100% deposition efficiency (i.e., the percentage of the total charge transfer corresponding to the reduction of Bi 3+ to Bi).
The Bi films produced in accordance with this process are polycrystalline with large grains. The films exhibit very large MR effects. The MR ratio at room temperature, for example, of the Bi thin films is about 1.5 to 2.5. In contrast, the MR ratio at room temperature for the best Co/Cu multilayers and granular solids is only about 0.8, a factor of 2 to 3 smaller. Moreover, the thickness of the Bi thin films fabricated in accordance with the invention becomes less important. From 1 μm to 10 μm, both the MR ratio and the resistivity at room temperature vary relatively little, whereas, at 5 K, the corresponding values vary a great deal. The Bi films formed in accordance with the invention also have a simple magnetic field dependence without saturation or hysteresis. Therefore, the higher the applied external field, the greater the magnetoresistive effect. These Bi thin films can therefore be used as high dynamic-range magnetic field sensors. For many applications using Bi thin films, the Bi films thus constructed require no additional processing.
In accordance with another preferred embodiment of the invention, a novel annealing sequence can be initiated to establish even higher quality Bi thin films through the use of high-temperature processing. At low temperatures, the MR ratios of the annealed Bi thin films are increased by one to two orders of magnitude higher than those of the Bi thin films produced using the deposition processes described above. This unique annealing process for the Bi films may be performed in any inert gas atmosphere, such as an argon (Ar) atmosphere, in a variable temperature environment (e.g., variable temperature oven with a temperature controlling accuracy of ±1° C.). In accordance with the invention, the temperature is increased gradually in ramp fashion, preferably at a rate of approximately 1° C./min from room temperature to 268° C., and held for several hours, depending on the thickness of the Bi film. For films ranging in thickness from 0.5 μm to 5 μm, for example, the annealing time should be approximately 4-6 hours. Annealing times for thicker films will increase. For example, a 10 μm film should be annealed for 10 hours. Afterwards, the temperature is lowered to room temperature at a rate of decline proportional to the rate used to raise the temperature (e.g., in the described example, a rate of decline of approximately 1° C./min would be used). The effect of annealing is that after the annealing process is completed, the films become single-crystalline and thus have a greatly improved MR effect percentage. In the example above utilizing the processes in accordance with preferred embodiments of the invention, the Bi thin films produced resulted in single-crystalline c-axis (001) Bi films. The Bi films exhibit very large MR effect sizes, over 153,000% in some cases. In addition, the resistivity value also decreases significantly because of the high perfection of the single-crystalline material.
The Bi thin films produced by the foregoing novel processes can easily be used as a magnetoresistive sensor for measuring the changes in resistivity in a field. This can be accomplished by running a current through the sensor such that it passes through the bismuth thin film layer 120 . In one embodiment, electrical contacts are supplied to bismuth layer 120 such that the contacts are connected to a current source. A non-magnetic conductive layer may be deposited on bismuth layer 120 to facilitate the contact. To sense magnetic fields, a current measuring device such as a potentiometer may be utilized to measure current fluctuations resulting from resistivity changes in the Bi thin film 120 . Many such devices are well known in the art and devices utilizing bismuth thin films constructed in accordance with the preferred embodiment of the invention may be implemented in numerous known systems.
In another preferred embodiment, the metallic underlayer may be patterned into any geometrical shape through known masking or deposition processes. This defines the shape of the Bi thin films because the subsequent electrodeposition can occur only on top of the metallic underlayer. More than one underlayer may also be used to promote the growth of material in a certain orientation.
In another preferred embodiment, the single crystalline Bi thin films formed according to the invention can be combined with a magnetic flux concentrator to realize large MR effects at small external magnetic fields. A magnetic flux concentrator consists of soft magnetic materials, which, because of their shape, can channel or concentrate the magnetic flux into a specified region and increase the local magnetic field within this region. When a small external magnetic field is applied, the local magnetic field, after the magnetic flux concentration, can be much larger. If the Bi film is strategically placed at the location where a strong local magnetic field is concentrated, then the Bi film can be made to respond to much smaller external magnetic fields. This would allow the huge MR effect of Bi thin films to be utilized in magnetic recorder read head applications.
While certain embodiments of the invention have been described and illustrated above, the invention is not limited to these specific embodiments as numerous modifications, changes and substitutions of equivalent elements can be made without departing from the spirit and scope of the invention. Accordingly, the scope of the present invention is not to be considered as limited by the specifics of the particular structures which have been described and illustrated, but is only limited by the scope of the appended claims.
|
The invention is directed to the use of electrochemical deposition to fabricate thin films of a material (e.g., bismuth) exhibiting a superior magnetoresistive effect. The process in accordance with a preferred embodiment produces a thin film of bismuth with reduced polycrystallinization and allows for the production of single crystalline thin films. Fabrication of a bismuth thin film in accordance with a preferred embodiment of the invention includes deposition of a bismuth layer onto a substrate using electrochemical deposition under relatively constant current density. Preferably, the resulting product is subsequently exposed to an annealing stage for the formation of a single crystal bismuth thin film. The inclusion of these two stages in the process produces a thin film exhibiting superior MR with a simple field dependence in the process suitable for a variety of field sensing applications.
| 8
|
FIELD OF APPLICATION
The present invention relates generally to the remediation of contaminated soil.
In particular, the invention relates to a method of remediating soil that has been contaminated with heavy metals.
BACKGROUND ART
Contamination of the soil with heavy metals has long been a major environmental concern. Contamination from heavy metals, especially cadmium, lead and mercury, may be caused by such industrial activities as metal-processing, tanning, chemical processes employing metal catalysts, etc.
There have been several proposals directed to solve the problem, but none that has proved entirely satisfactory.
One prior method consisted of treating the soil in situ with solutions of alkali sulfides, and percolating the solutions through the soil to cause the heavy metal cations to react with the sulfide anions and yield very low-soluble sulfides. (For example, the solubility products of cadmium, lead and mercury are 1.4×10 −28 , 1.0×10 −29 , and 3.0×10 −53 , respectively.)
The cations of the heavy metals are blocked, by virtue of the above compounds being insoluble, and are no longer in a condition to contaminate springs and crops.
With such a method, however, a conversion rate into insoluble sulfides of no more than 70% is obtained, even where the soil comprises a substantial proportion of sand, making for better contact of the alkali sulfide solution with the heavy metal compounds.
In an attempt at improving the above method, it has been proposed (DE 19547271) of treating the soil with an acid solution, specifically a hydrochloric acid solution, subsequently to the step of percolating the soil with the sulfide solution. In this way, a conversion rate of heavy metals to sulfides upward of 99% is reportedly obtained.
However, the last-mentioned method has a major limitation in that it is only successful where the soil mostly comprises sand, since in this case good contact can be ensured between the reactant (alkali sulfide) and the heavy metal cations. On the other hand, a soil that is rich in clay or other cohesive components would hinder that contact, and the conversion to insoluble sulfides becomes incomplete.
SUMMARY OF THE INVENTION
The problem underlying this invention is to provide a method of remediating soil that contains heavy metals, whereby the aforementioned deficiencies of prior methods can be overcome.
The problem is solved, according to the invention, by a method comprising the steps of:
removing and sieving a heavy metal-containing soil to remove stones and gravel; and
treating said sieved soil, arranged in a thin layer and maintained in a highly turbulent condition, with a solution of an alkali sulfide at a temperature of at least 50° C.
Preferably, the step of treating the sieved soil with an alkali sulfide solution is preceded by a step of adjusting the soil pH to a value equal to or lower than 6.
The method is implemented more advantageously in an apparatus known as a “turbo-reactor”.
In this case, the inventive method comprises the steps of:
removing and sieving a heavy metal-containing soil to remove stones and gravel;
feeding a continuous stream of said soil into a turbo-reactor, which reactor comprises a cylindrical tubular body being laid with its axis horizontal, closed by end walls at its opposite ends, and provided with inlet openings for the soil to be treated and for at least one reactant, as well as provided with at least one discharge opening, a bladed rotor rotatably mounted in the cylindrical tubular body and driven at a high rotational speed to produce a stream of finely divided soil particles, and a heating jacket for raising the temperature of the inner wall of the cylindrical tubular body to at least 110° C.;
feeding a continuous stream of a reactant in the form of an aqueous solution of an alkali sulfide into the turbo-reactor in cocurrent with the soil stream; centrifuging the soil particles and the alkali sulfide solution against the inner wall of the cylindrical tubular body to form a highly turbulent, tubular dynamic fluid layer wherein the soil particles and the alkali sulfide solution are urged mechanically in intimate mutual contact by the rotor blades; and
reacting the soil and the alkali sulfide in the thin layer while the latter is being urged, substantially in contact with the heated inner wall, toward said at least one discharge opening of the turbo-reactor, with simultaneous generation of steam.
Said step of feeding in a continuous stream of an aqueous solution of alkali sulfide is preferably preceded by a step of adjusting the soil pH to a value equal to or lower than 6.
This pH adjusting step is carried out conveniently by feeding into the turbo-reactor a continuous stream of an aqueous acid solution in cocurrent with the soil stream.
An aqueous solution of a strong acid selected from hydrochloric acid or sulfuric acid is preferred, at a concentration in the 0.01N to 1N range, advantageously equal to 0.1N.
An opening for exhausting any vapors released during the treatment may be provided conveniently, and the exhaust opening may be connected to a scrubber for removing any hydrogen sulfide formed when the soil is markedly acidic.
To enhance the heavy metal insolubilization process, a continuous stream of an alkali silicate, having complexating and agglomerating properties, may be fed into the turbo-reactor through an inlet opening provided downstream of the inlet opening for the alkali sulfide solution.
The alkali sulfide solution is preferably a sodium sulfide solution, with a concentration of 5 to 15%, preferably about 12%, w/v.
The temperature of the turbo-reactor inner wall is preferably 110° to 220° C.
The treated soil exits the turbo-reactor at a temperature of about 50° to 90° C.
The peripheral velocity of the bladed rotor is preferably 20 to 40 meters per second.
The average time of residence of the soil being processed in the turbo-reactor varies generally between 30 and 120 seconds.
The amount of alkali sulfide solution used in the method of this invention generally exceeds the stoichiometric amount demanded by the proportion of heavy metals in the soil, as evaluated by a preliminary analysis of the soil composition. This because other metals, such as iron, present in the soil would also react with the sulfide.
The application of the inventive method results in a practically quantitative formation of insoluble sulfides from the cations of heavy metals in the soil, irrespective of the soil characteristics and its content in clay or cohesive components.
This is achieved by the creation of the aforementioned turbulent thin dynamic layer, in which the soil is divided into very fine particles so that heavy metal cations become liable to an intimate contact with the reactant. The reaction by which the cations are converted into alkali sulfides is promoted and accelerated by the elevated temperature of the turbo-reactor inner wall, the thin dynamic layer comprised of soil particles and tiny droplets of the reactant solution being forced to flow along said inner wall.
The method of this invention will be described in greater detail with reference to the accompanying drawing and through some exemplary and non-limiting embodiments thereof.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a longitudinal section view showing schematically an apparatus on which the inventive method can be implemented.
DETAILED DESCRIPTION
With reference to FIG. 1, an apparatus used for implementing the method according to the invention includes a turbo-reactor, essentially comprising a cylindrical tubular body 1 closed at its opposite ends by end walls 2 , 3 and provided coaxially with a heating jacket 4 through which a fluid, e.g. a diathermic oil, is caused to flow such that the temperature of the inner wall of the cylindrical tubular body 1 can be maintained at no less than 110° C.
The cylindrical tubular body is formed with inlet openings 5 , 6 for the sieved soil containing heavy metals and the alkali sulfide solution, respectively, and with a processed-soil discharge opening 7 .
Mounted rotatably inside the cylindrical tubular body 1 is a bladed rotor 8 , whose blades 9 are laid into a helical pattern and oriented to centrifuge and simultaneously urge the soil and reactant toward the turbo-reactor outlet.
The bladed rotor 8 is driven by a motor M at a peripheral velocity varying from 20 to 40 meters per second.
Reactant inlet openings 10 are formed through the inner wall of the tubular body 1 .
In particular, when an alkali silicate solution is used in the inventive method along with the alkali sulfide solution, the latter is fed through the inlet opening 6 of the turbo-reactor and the alkali silicate solution is fed through the openings 10 in the inner wall.
On the other hand, when only the alkali sulfide solution is used in the inventive method, the solution may be fed through either the inlet opening 6 of the turbo-reactor, or the openings 10 in the inner wall, or both.
Finally, should the pH of the sieved soil require preliminary adjustment, the aqueous acid solution is fed through the inlet opening 6 of the turbo-reactor, and the alkali sulfide solution fed through the inner wall openings 10 . Where an alkali silicate solution is to be used additionally to the acid and alkali sulfide solutions, the alkali silicate solution is fed through one or more of the inner wall openings 10 located in the downstream area of the turbo-reactor, while the alkali sulfide solution is fed through one or more of the inner wall openings located in the upstream area of the turbo-reactor. In this case, the acid solution is fed through the inlet opening 6 of the turbo-reactor.
The turbo-reactor also has an opening 11 for exhausting internally released vapors, the exhaust opening 11 being connected, over a suction fan 12 , to a scrubber 13 , only shown schematically, for removing any hydrogen sulfide contained in the vapor by scrubbing with alkali solutions.
EXAMPLE 1
A continuous stream of soil containing heavy metals (in particular, chromium, mercury and lead), which soil had been previously relieved of stones and gravel by a sieving step, is fed, at a flow rate of 100 kg/h, into a turbo-reactor having a cylindrical tubular body 1 with an inside diameter of 300 mm, and having a bladed rotor 8 driven at 1000 RPM, the temperature of its inner wall being maintained at 200° C.
Simultaneously therewith, a stream of a solution of Na 2 S 12% w/v is fed through the inlet opening 6 and the inner wall openings 10 at a flow rate of 5 liters/hour.
From the very moment that the soil stream enters the turbo-reactor, it is shattered mechanically into minute particles that are at once centrifuged against the inner wall of the turbo-reactor, where they will form a thin tubular dynamic layer.
At the same time, the aqueous sodium sulfide solution introduced through the opening 6 is atomized by the blades 9 of the rotor 8 , which will also centrifuge the resulting droplets. Thus, the droplets are incorporated into the thin tubular dynamic layer of soil particles, which results in an intimate contact between the cations of the heavy metals contained in the soil particles and the reactant.
The sodium sulfide solution added in atomized form through the openings 10 further enhances the interaction of the reactant with the soil particles, thereby bringing to completion the insoluble sulfide-forming reaction, which proceeds from the cations of heavy metals in the soil particles.
After a residence time of about 60 seconds in the turbo-reactor, the soil reacted with the sodium sulfide solution is discharged through the opening 7 continuously. The soil temperature at the turbo-reactor outlet is approximately 90° C.
Vapors released inside the turbo-reactor are exhausted by the suction fan 12 through the opening 11 and conveyed to the scrubber 13 , where they are scrubbed with soda to separate any trace hydrogen sulfide.
An analysis of the soil discharged out of the turbo-reactor, directed to determine its content of soluble chromium, mercury and lead compounds, reveals that such compounds are virtually absent, or at least below the threshold of detectability (IRSA Method—acetic acid).
EXAMPLE 2
A continuous stream of soil containing heavy metals (in particular chromium, mercury and lead), which soil has a pH of about 5 to 6 and had been previously freed of stones and gravel by a sieving step, is fed, at a flow rate of 100 kg/h, into a turbo-reactor having a cylindrical tubular body 1 with an inside diameter of 300 mm, and having a bladed rotor 8 driven at 1000 RPM, the temperature of its inner wall being maintained at 220° C.
Simultaneously therewith, an atomized stream of a solution of Na 2 S 12% w/v is fed through the inlet opening 6 at a flow rate of 5 l/h, and a stream of a sodium silicate solution 10& w/v is fed through the inner wall openings 10 at a flow rate of 10 l/h.
As it enters the turbo-reactor, the soil stream is shattered mechanically into minute particles, which are at once centrifuged against the inner wall of the turbo-reactor, where they will form a thin tubular dynamic layer.
At the same time, the aqueous sodium sulfide solution introduced through the opening 6 is atomized by the blades 9 of the rotor 8 , which will also centrifuge the resulting droplets. The droplets are thus incorporated into the thin tubular dynamic layer of soil particles, which results in an intimate contact between the cations of the heavy metals contained in the soil particles and the reactant.
The sodium silicate solution added in atomized form through the openings 10 is also blended in droplets with the thin tubular dynamic layer that includes the soil particles and the atomized sodium sulfide solution.
After a residence time of about 60 seconds in the turbo-reactor, the soil reacted with the sodium sulfide and sodium silicate solutions is discharged through the opening 7 continuously. The soil temperature at the turbo-reactor outlet is approximately 95° C.
Vapors released inside the turbo-reactor are exhausted by the suction fan 12 through the opening 11 and conveyed to the scrubber 13 , where they are scrubbed with soda to remove any trace hydrogen sulfide.
An analysis of the soil discharged out of the turbo-reactor, directed to determine its content of soluble chromium, mercury and lead compounds, reveals that such compounds are virtually absent, or at least below the threshold of detectability (IRSA Method—acetic acid).
EXAMPLE 3
A continuous stream of soil containing heavy metals (in particular, chromium, mercury and lead), which soil has pH of about 5 to 6 and had been previously freed of stones and gravel by a sieving step, is fed, at a flow rate of 100 kg/h, into a turbo-reactor having a cylindrical tubular body 1 with an inside diameter of 300 mm and having a bladed rotor 8 driven at 1000 RPM, the temperature of its inner wall being maintained at 180° C.
Simultaneously therewith, an atomized stream of a 0.1 N HCl solution is fed through the inlet opening 6 at a flow rate of 5 l/h, and a stream of a solution of sodium sulfide 12&, w/v is fed through the inner wall openings 10 at a flow rate of 5 l/h.
After a residence time of about 60 seconds in the turbo-reactor, the soil reacted with the sodium sulfide solution is discharged through the opening 7 continuously. The soil temperature at the turbo-reactor outlet is approximately 85° C. and its pH about 5.5.
Vapors released inside the turbo-reactor are exhausted by the suction fan 12 through the opening 11 and conveyed to the scrubber 13 , where they are scrubbed with soda to remove any trace hydrogen sulfide.
An analysis of the soil discharged out of the turbo-reactor, directed to determine its content of soluble chromium, mercury and lead compounds, reveals that such compounds are virtually absent, or at least below the threshold of detectability (IRSA Method—acetic acid).
With the method of this invention, any soil that has been contaminated with heavy metals can be remediated more efficiently and reliably than with conventional methods.
Furthermore, the apparatus for implementing this method is relatively inexpensive to install and run; it is also quite compact, and can be transferred by road or another carrier to a site where the remediation can take place on the spot, thus avoiding the cost of transferring the soil to be processed.
In addition, the method provides a continuous form of processing, from which running costs are sure to benefit, is time-efficient, and can sustain a high hourly throughput.
Changes and modifications may be made unto the invention described hereinabove within the protection scope of the following claims.
|
A method of remediating soil that contains heavy metals comprises the steps of removing and sieving heavy metal-containing soil to separate stones and gravel, and treating the sieved soil, in a thin layer kept in a strongly turbulent state, with a solution of an alkali sulfide at a temperature of at least 50° C.
| 1
|
BACKGROUND OF THE INVENTION
This invention relates to the field of preparing accurate gaseous and/or vapor mixtures for analytical instrumentation. Gas mixtures are in widespread use as calibration or reference standards for analytical instrumentation and as feed stock for scaled down chemical reaction or processes particularly in research and development.
Commercial bottled gas and vapor mixtures are available from numerous suppliers for analytical instrumentation use. However, the occasion often arises when it is of advantage to the user to have apparatus capable of mixing gases and/or vapors accurately to predetermined proportions.
Examples of these occasions are as follows:
1. One lacks the time required to obtain a commercially prepared mixture (a minimum of twenty-four hours is generally required although one to two weeks is commonly accepted delivery time);
2. The chemical stability or reactiveness of components in the mixture dictates that it be utilized immediately after preparation;
3. The accuracy of commercial mixtures is in question;
4. Sufficiently accurate mixtures are not easily obtained;
5. The selection of a final mixture requires a "trial and error" procedure by the user;
6. Only small quantities are required; and
7. The components of a mixture tend to stratify (heating and extensive rolling of the vessel are presently the only means for maintaining a homogeneous mixture of components which are easily stratified).
Preparation of gaseous or vapor mixtures by the user is limited to a few devices utilizing mass flow and permeation techniques. These are dynamic devices with blending occurring only when components are flowing. These techniques are not accurate and lend themselves to applications requiring few components in the mixture. Some of the devices can only be applied for specific mixtures. An example of this technique is disclosed in U.S. Pat. No. 3,948,281.
Commercial preparation of gaseous or vapor mixtures falls in two general categories. One is a gravimetric technique in which the vessel and its contents are weighed and the other is a partial pressure technique. The accuracy of the gravimetric method is dependent to a large degree on the weight of each component relative to the total weight of the vessel and its contents. This results in lower accuracies being attained in low density mixtures, such as hydrogen and helium, and also in situations where the components of interest are in low concentration.
The partial pressure method has limited accuracy due to use of high pressures required to make the process commercially feasible, lack of suitable means for homogenizing the mixture, and absence of temperature control. High pressures produce large compressibility factors which are not predictable with any degree of accuracy, being dependent on the composition and state of intermediate and final mixtures.
Lack of homogenizing capability and temperature control results in large errors due to variations in temperature during the vessel filling process which are caused by decompression and compression of gases. The partial pressure technique, as has been practiced commercially and by end users, is not a suitable method for the preparation of accurate gas or vapor mixtures. It is best used for preparing "target" concentrations, followed by analysis, or for blending low grades of calibration gases. Reference is made to the 1975 copyrighted book Gas Mixtures -- Facts and Fables, by Frank Scarporoicer that is available from Matheson Gas Products Company, 932 Paterson Plank Road, P.O. Box 85, East Rutherford, New Jersey 07073 and which is hereby incorporated by reference for all purposes herein.
Very low concentrations of gaseous or vapor mixtures are also difficult to prepare accurately and often require elaborate procedures, some of which are suitable only for specific compounds. An example is gas permeation, which is a dynamic technique, requires precision temperature control, has a limit on active component life, and has a narrow range of applicability.
In general, both high and low gas or vapor mixtures have previously required both a preparation procedure followed by an analysis procedure to confirm composition of the mixture.
Widespread use of analytical instruments such as gas chromatography apparatus now exists in the chemical process industry as well as in other fields. For example, see U.S. Pat. No. 3,595,063 to Loew as well as U.S. Pat. No. 3,888,109 to Sharki for a support system increasing the capability of a gas chromatograph. Such gas chromatographs are capable of rapidly analysing and indicating the presence of the mixture components in a gas sample both qualitatively and quantitatively. Since gas chromatographs enables a process operator to quickly determine the composition of a sample, more frequent analyses of the various process stream are available for enhancing process efficiency.
One major drawback to the many advantages of the use of gas chromatographs apparatus has been the need for a reference or calibration sample by which the gas chromatograph apparatus is both calibrated and from time to time tested for accuracy. Such reference samples have previously been prepared by chemists working in the laboratory using the techniques set forth above.
Gas blenders are known as evidenced by U.S. Pat. No. 2,950,618 to Lewis. Furthermore, systems have been developed for determining the concentration of a gas in a mixture, such as disclosed in U.S. Pat. No. 2,817,350 to Bradner, et al. Also, as disclosed in U.S. Pat. No. 3,817,085, polarographic sensors or electrolytic sensors may be used to measure the partial pressure of a component in a mixture.
SUMMARY OF THE INVENTION
This invention relates to a new and improved method and apparatus for providing a calibration sample for analytical instrumentation.
The apparatus includes a mixing chamber in which the components are blended while an absolute pressure transducer monitors the absolute pressure in the chamber. Suitable inlet valving is provided as well as a vacuum system for exhausting the chamber as desired. A magnetic stirrer means is provided for homogenizing the mixture of gases in the chamber.
By controlling the pressure increase during the introduction of each component into the mixture the concentration of each gas component in the mixture is controlled.
This invention relates to a new and improved method and apparatus for the preparation of multicomponent gaseous and vapor mixtures in low and high concentrations with a degree of accuracy which negates the requirement for analysis to ascertain the composition of the final mixture. The apparatus also serves as a storage facility for the mixture produced and has provisions for transfer of its contents to a separate vessel or for direct use.
The invention will be used primarily in the area of analytical instrumentation which requires accurate gas and vapor mixtures for reference or calibration.
It is to be understood that the reference samples prepared by the method and apparatus of the present invention will be disclosed in the context of gas chromatographs, but such reference samples are equally well adapted for other purposes and other analytical instruments.
An object of the present invention is to provide a new and improved apparatus for preparing calibration samples for gas chromatography.
Another object of the present invention is to provide a new and improved method for preparing calibration samples for gas chromatography.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of the calibrated sample blender apparatus of the present invention; and
FIG. 2 is an exploded cut-away of the pressure vessel detailing the assembly of the magnetic mixer.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The gas blending apparatus of the present invention is schematically illustrated in FIG. 1. The gas mixture blending apparatus, generally designated A, is used to prepare reference or calibration samples for use with gas or vapor analyzers (i.e., gas chromatographs, spectrophotometers, etc.). The reference samples are used to both calibrate and to check the analyzers for accuracy.
The apparatus A includes a pressure vessel, generally designated V, having a body 10 that is preferably formed from a twelve inch length of schedule 10S or 5S stainless steel Type 304 pipe and being approximately twelve inches in diameter. The pressure vessel V further includes end caps 12 and 14. The end cap 12 is preferably secured to the vessel body 10 at the periphery by welding while end cap 14 is preferably attached with suitable bolting (not illustrated) to flange 10a of the vessel body 10 in the usual manner. The end caps 12 and 14 are preferably constructed of Type 304 stainless steel plate suitably cut and drilled. The mass of the vessel V will provide a sufficient heat sink to hold the gas temperature substantially stable during the gas blending process. With the preferred construction of the vessel V, a cylindrical mixing member 16 is formed by the pressure vessel V of approximately twenty liters, but other dimensions and shapes of mixing chambers may be utilized.
As best illustrated in FIG. 2, a mixing or stirring means is generally designated M. The mixer M includes a stirrer or paddle means 20 that is disposed within the mixing chamber 16 and rotatably supported on journal pins 22 and 24 which are in turn fixed to the end plates 12 and 14, respectively. The paddle means 20 is preferably formed with a longitudinally extending central shaft 26 which is concentrically rotationally mounted on the journal pins 22 and 24. Secured to the central shaft 26 are stirrer blades 28a and 28b and which are circumferentially spaced 180° apart on the shaft 26. While two paddle blades 28a and 28b are illustrated, it is to be understood that variations in the number and form of the blades 28a and 28b will be readily apparent to those skilled in the art. Also, the arrangement of the opening or perforations indicated at 30a and 30b in the plates 28a and 28b, respectively, as well as the number of the perforations will be apparent to those skilled in the art.
Mounted on the central shaft 26 adjacent the end cap 14 is a rod or bar 32 which is made of corrosion resistant magnetic material. The bar magnet 32 provides the magnetic field drive linkage for rotating the shaft 26 and the attached paddle blades 28a and 28b. The flange connection between the vessel body 10 and the end plate 14 permits access to the chamber 16 for installation and to perform maintenance work on the paddle means 20.
Secured to the end plate 14 on the opposite side from the pivot pin 24 is a mixer means motor housing 34. Disposed within the housing 34 is an electrical motor (not illustrated) producing a rotating shaft speed of approximately 40 to 50 revolutions per minute and which carries a magnet similar to the magnet bar 32 on the paddle 20. The motor magnet is disposed adjacent the end plate 14 when positioned in the housing 34 in order that the movement of the magnetic field of the motor driven magnet in the housing 34 will effect rotation of the magnet 32 located in the mixing chamber 16 to rotate the paddle means 20 to homogenize the gas mixture in the chamber 16.
A plurality of openings, referenced as 10b through 10h in FIG. 2, are preferably formed in the end cap 12 for the introduction of the component gases into the mixing chamber 16. Preferably, the openings 10b-10h are threaded in order that right angle inlet control valves for the individual component gases may be attached directly to the end plate 12 as illustrated in FIG. 1. The right angle type valves, generally designated 40a-40i, are preferred because they allow designing for a minimum of volume between the valve seat and the chamber 16 that is not agitated by the paddles 28a and 28b in homogenizing the gas mixture in the chamber 16. Each of the inlet control valves 40a-40i are provided with the usual rotating operating handle, designated 40a'-40i' respectively, for opening and closing each inlet valve in the usual manner. The valve 40a is also connected through conduit 41a with a source (not illustrated) of a particular desired gas component for the mixture. The supply of component gas are normally bottled gases of certified purity and the conduit 41a may be connected directly to the pressure regulator on the cylinder of the component gas as is well known. Frequently, for safety, a bulkhead is provided between the cylinders of bottled gases and the equipment utilizing the bottled gases. FIG. 1 illustrates such a bulkhead arrangement, but it is to be understood that the end of the conduit 41a to 41aa is to be connected in the usual manner with the pressure regulator of a high pressure cylinder of a desired component gas. Conduits 41b through 41h are connected in such manner also.
Mounted directly on the pressure vessel body 10 is an electrical absolute pressure transducer or other suitable means 50 for continuously monitoring the absolute pressure accurately within the mixing chamber 16. The transducer 50 is mounted directly with the pressure vessel body 10 to minimize the dead area between the pressure sensor of the transducer 50 and the mixing chamber 16. In the preferred embodiment, a Model 1332-A-6 transducer manufactured by Rosemount, Inc., P.O. Box 35129, Minneapolis, Minnesota 55435, is utilized. In addition, reference may be made to U.S. Pat. Nos. 3,195,028; 3,271,669; and 3,318,153 for additional disclosure on the operation of such pressure transducers and the aforementioned three patents are hereby incorporated by reference for all purposes. Preferably, the output of the transducer which in the preferred embodiment is a high level DC output voltage or current linear with pressure that is electrically communicated through wires 52 to a voltmeter 54 which preferably displays the output in the illustrated digital form.
Disposed within an opening similar to that of 10b in the end plate 12, is a vent opening (not illustrated) which preferably has threadedly mounted therein a right angle type vent or exhaust valve 60. The vent valve 60 is in turn connected to the vacuum conduit system or means 62 which in turn communicates with the vacuum pump means 64. The vacuum conduit means 62 further includes a branch or sample connection 66 having a sample valve 68 therein which controls flow through the branch connection 66. The sample connection 66 is provided with suitable means, such as the threaded connector indicated at 70, to which sample containers or bombs may be attached in order that the reference gas mixture blended in the chamber 16 may be transferred. It is to be understood that such sample container or bombs and their operation and use are well known to those skilled in the art. The pressure differential between the gas mixture in the chamber 16 and in the sample container will of course be sufficient to move a portion of the referenced mixture into the sample bomb which may be disconnected from the connector 70 and stored or taken directly to the gas analyzer for calibration or testing purposes.
Disposed in the vent conduit 62 between the branch connections 66 and the vacuum pump 64 is a block valve 72 for controlling flow through the vent conduit 62. Normally, the valve 72 is closed when transferring a sample from the mixing chamber 16 through the valve 68 into the sample bomb.
Disposed within an opening similar to that of 10b in the end plate 12 may be an opening (not illustrated) which preferably has threadedly mounted therein a septum inlet to accommodate the injection of gases, vapors, or liquids into the mixing chamber by means of a syringe (not illustrated). It is to be understood that such septum inlets and their use with injection syringes for introducing small, but critical components, in the sample are well known to those of ordinary skill in the art.
The vacuum pump means 64 may be of any suitable type but preferably the "Vac Torr" Model DD-20 vacuum pump manufactured by Fisher Scientific Company of 711 Fourth Avenue, Pittsburgh, Pennsylvania 15219, is employed. The preferred model has an integral electric motor 64a, but it is understood that separate motor pumps may be employed when suitably coupled. The output of the pump 64 is preferably communicated through discharge conduit 74 to the bulkhead or other remote location for safety reasons.
OPERATION
The apparatus and method are based on the application of partial pressure and "addition of specific volume" technique singularly or in combination. The partial pressure technique is employed by controlling the pressure increase during the introduction of each component into the mixture which determines its concentration. The "addition of specific volume" technique is the direct introduction of a known quantity of liquid, vapor, or gas into the mixing chamber by means of a syringe. The other major components of the mixture are introduced by appropriate valving which will be described further.
Since the invention is intended for use primarily by the user of gas or vapor mixtures it is not necessary to utilize high pressures. The apparatus is designed for low pressures (approximately 100 psia or less). At low pressures the error due to compressibility is minimal. The mixing chamber pressure is monitored with a device which provides an accurate indication of the relationship of component volumes on the basis of their partial pressure.
The apparatus includes a provision for homogenizing the gas mixture with a magnetic stirring device. This eliminates errors due to stratifying and also aids in rapid stabilizing of the gas temperature.
The temperature of the mixing chamber and its contents is stabilized by the use of a chamber mass which is large relative to the mass of its contents.
The chamber has multiple valving to facilitate the introduction of individual gaseous components without cross-contamination.
A septum inlet is mounted on the chamber to allow syringe injection for the "addition by specific volume" technique. This feature is utilized for the preparation of very low (parts per million range) concentrations of vapor or gas. The exact concentrations are calculated on the basis of the mixing chamber volume, the volume of gas or vapor introduced by syringe and the system temperature and pressure. When liquid is injected directly the vapor volume is calculated based on Avogadro's law and the concentration determined in a similar manner as for direct injection of gas or vapors.
The apparatus also includes a vacuum pump for exhausting the chamber or a separate storage vessel.
The partial pressure and/or "addition by specific volume" techniques may also be utilized to add components to an existing gaseous or vapor mixture, increase the concentration of any of its components, or dilute it to any degree.
In the use and operation of the present invention, the apparatus A is assembled in the manner illustrated and the inlet conduits 41aa-41hh are connected to the pressure regulators on the cylinders containing the desired gas components to be blended. The vent valve 60 is placed in the open position while all of the inlet valves 40a-40i are placed in the closed position. The vacuum conduit valve 72 is placed in the open position while the branch valve 68 is closed. The vacuum pump 64 is then turned on to reduce the pressure in the chamber 16.
With the vacuum pump 64 operating, each of the inlet valves is in turn opened to purge the corresponding inlet conduit of any impurities that may be present in that conduit. For example, the valve 40a is open for sufficient periods to purge the conduit 41a of air and other matter that may be present therein when the end 41aa is connected to the bottle of component gas. After this operation is complete, the flow of pure gases into the chamber 16 can be controlled with the valves 40a-40i at the pressure vessel V. The above operation needs only to be repeated whenever it is necessary to change out a cylinder of component gas or to change components.
PREPARATION OF A FINISHED MIXTURE
With the valves 40a-40i in the closed position, the vacuum pump 64 will exhaust the chamber 16 sufficiently to reduce the chamber pressure to substantially zero atmospheric pressure. It should be understood that there is always some residual absolute pressure in the mixing chamber 16 but it is to be minimized as much as possible.
With the magnetic stirrer 20 and the digital display volt meter 54 operating, the first component of the gas mixture is introduced into the mixing chamber 16 by opening the appropriate inlet valve, such as 40a. During such filling of the chamber 16, operation of the vacuum pump may be interrupted but it is not necessary to do so. When the pressure of the first component reaches the desired level as indicated on the volt meter 54, the inlet valve is closed and the vacuum pump is used to purge the chamber 16 back to substantially zero atmospheric pressure. This operation is repeated with the first component gas until it is reasonably certain that the mixing chamber 16 is free from any other gases except the first component gas. Component gases are then individually introduced in the chamber to obtain predetermined pressure levels that will be more fully explained. Preferably, there will be a delay time in introducing the various components into the chamber in order to compensate for temperature variations caused by the expansion or contraction of the gases during the filling process. The relatively large mass of the pressure vessel V aids in stabilizing the temperature and enhancing the accuracy of the blending process.
For simplicity of operation, the percent by volume concentration of the component sample can be made equal to the absolute pressure per square inch value by having the total pressure of the reference sample in the mixing chamber 16 equal to 100 p.s.i. absolute. Such total sample pressure simplifies and reduces the chance of error in the following calculations.
The concentration of each gas component of the gas mixture is determined by the following known formula: ##EQU1##
From the foregoing formula, the pressure required for each component addition may be determined by the following formula: ##EQU2## Where:
Component partial pressure equals difference in pressure (PSIA) before and after its introduction to the mixing chamber.
The total pressure is the final pressure (PSIA) obtained after all components have been introduced.
The required pressure is defined as the pressure (PSIA) level which must be obtained when introducing a component gas into the mixing chamber 16. It is equal to the existing chamber pressure plus the component partial pressure.
As noted previously, the percent volume concentration can be made equal to the PSIA by having total pressure of the reference sample made equal to 100 PSIA.
Using the foregoing formula, the various components of the gas mixture are introduced into the chamber 16 with the valves 72 and 68 closed. When preparation of the mixture is complete, it may be transferred by the branch connection 62 into a sample container which may be used to introduce the mixture directly into an analyzer or it may be stored for future use.
Preparation of a Mixture by Combined Partial Pressure and Addition of Specific Volume
The initial procedure for purging the mixing chamber of undesired components is the same as that for the general partial pressure technique. A known volume of the desired low concentration component gases, vapors, or liquids are introduced at any suitable interval by means of a syringe and the septum inlet port. The major components are introduced by partial pressure technique at any suitable interval by means of the appropriate inlet valves 40a-40i. Low concentrations (part per million levels) of components can be achieved by injection of microliter quantities. These concentrations can be further reduced to the "parts per billion range" by dilution. This is accomplished by venting to reduce the mixing chamber pressure followed by repressurization with an appropriate dilution gas. Combinations of direct injection and dilution can produce component concentrations of any desired level.
Concentrations of each gas or vapor component of the mixture are determined by the following formula: ##EQU3##
The following formula is used to calculate a new component concentration level following a dilution: ##EQU4##
Note that temperature corrections are not required when the mixing chamber and its contents are maintained at constant temperature during the blending process.
The foregoing disclosure and description of the present invention are illustrative and explanatory thereof and various changes in the size, shape and materials as well as in the details of the preferred embodiment may be made without departing from the spirit of the invention.
|
Apparatus for and method of preparing reference mixture gas samples for use with analytical instrumentation and small scale chemical reactions and processes, having a motor-driven magnetic stirrer with the motor and driving magnet mounted externally of the mixing chamber. Such structure together with the mass of the mixing chamber, which is large in comparison to the mass of the samples, helps to stabilize the temperature of the mixing chamber.
| 1
|
FIELD OF THE INVENTION
The present invention relates to an apparatus and system for controlling a sequential transmission using a control motor and sensors to shift gears.
BACKGROUND OF THE INVENTION
A transmission is used to transmit power from an engine to a drive mechanism. The transmission uses the principle of mechanical advantage to convert the rotational speed, direction, and torque of a driving element into a different rotational speed, direction, and torque of a driven element. Most transmissions use a combination of gears in differing ratios to achieve this speed-torque conversion.
Vehicle transmissions often include more than one set of gear ratios (typically called “gears”) to allow the vehicle to operate in a variety of conditions. When the vehicle is at rest or travelling at a low speed, a gear ratio may be selected to deliver relatively high torque from the engine to the driveline. When the vehicle is travelling at higher speeds, a different ratio may be used to deliver higher rotational speeds at lower torque to the driveline. Gear ratio may be selected to optimize the delivery of power to the driveline having regard to the characteristics of the engine, and in particular, to the engine's delivery of power as a function of the engine's rotational speed. Changing the gear ratio of a transmission is commonly known as shifting or changing gears, and typically requires a brief decoupling of the engine from the driveline using a clutch arrangement.
A typical vehicle transmission as exemplified in FIG. 1 may include an input shaft 101 which is driven by the engine through a clutching arrangement, and an output shaft 102 which may drive the driveline when a gear is selected. The input shaft 101 typically passes through a number of input gears 110 . The output shaft 102 in this arrangement may pass through a number of corresponding output gears 109 which mesh with the input gears 110 , each pair of meshed gears being a gear set. In each gear set, one of the gears is not directly affixed to the input or output shaft, and may spin independently of the shaft when not engaged, and the other is affixed to the input or output shaft. Adjacent to the each free spinning gear 111 , a sliding gear 108 may be mounted on the shaft passing through that free spinning gear 111 . Each sliding gear 108 may slide along the length of the shaft, but otherwise engage the shaft so that it rotates along with the shaft. Each free spinning gear 111 may have dog teeth which engage with the adjacent sliding gear 108 when the sliding gear 108 is slid along the shaft. The sliding gear 108 engages and rotates the free spinning gear 111 with the corresponding shaft, thereby selecting a gear. Once engaged, the output shaft 102 is driven by the input shaft 101 in a ratio determined by the selected gear.
Although this is a common implementation of a vehicle transmission, there are many variations which achieve the same function in a similar manner.
Some vehicles use a sequential transmission, which is a transmission having at least two sets of gears which must be selected in a predetermined order during shifting. If a vehicle has three gears, the sequential transmission cannot be shifted from any one gear set to any other gear set. It must be shifted in an order which is determined by the configuration of the gear changing mechanism.
In a sequential transmission implemented on the typical vehicle transmission described above as exemplified in FIG. 1 , the sliding gears 108 , are moved by selector forks 106 that slidably engage a selector fork shaft 107 which is aligned parallel to a selector drum 104 . Typically, there are grooves 105 , wedges or ridges on a selector drum 104 which engage the selector forks 106 and convert the rotation of the selector drum 104 into lateral movement of the selector forks 106 along the selector fork shaft 107 in a direction parallel to the input shaft 101 and output shaft 102 , thereby moving the sliding gears 108 along the input shaft 101 or output shaft 102 . The use of a selector drum 104 to select gears in this arrangement forces the operator to shift gears in order. Gear dog teeth 112 located on the side of sliding gears 108 are used to engage gear dog windows 113 located on the common side of the free spinning gear 111 . This engagement effectively locks the free spinning gear 111 to the shaft running through its hub and permits torque to be transmitted from the input shaft 101 to the output shaft 102 through the free spinning gear 111 and its meshing gear 119 .
Sequential transmissions are preferred in certain applications over other types of transmissions because of the relative simplicity of the apparatus. A typical sequential transmission has fewer moving parts and is generally more reliable than a comparable fully manual non-sequential transmission. They can often be made smaller and lighter than other comparable designs, and can be faster to complete gear shifts. They are often employed in automotive racing and motorcycle applications for these reasons.
Many sequential transmissions are driven manually by the operator using hand or foot levers that may rotate the selector drum 104 through a ratcheting arrangement 114 . This allows the operator to rotate the selector drum 104 enough to cause the shift, but helps prevent the operator from rotating the selector shaft too far. When implemented on a motorcycle, the sequential transmission may include an indexer arrangement, such as a cam indexer 116 . The indexing arrangement may include a cam sprocket 115 connected to the selector drum 104 in combination with a pawl or cam follower 118 that engages depressions in the cam sprocket 115 as the selector drum 104 is rotated. The cam follower 118 may have a wheel 117 at one end which may roll along the cam sprocket 115 , and may be biased so that the wheel 117 maintains contact with the cam sprocket 115 . When the cam follower 118 is seated in a depression, the selector drum 104 has been rotated to a position where a gear is engaged. By applying force to a shift lever attached to the ratcheting arrangement 114 , the operator may rotate the selector drum 104 if the force is sufficient to unseat the cam follower 118 from the depression and overcome friction forces. As the selector drum 104 rotates, the cam follower 118 will move into an adjacent depression on the cam sprocket 115 .
Automatic and Semiautomatic Configurations
Any sequential transmission systems known in the art may be operated by automatic or semi-automatic control means. These automatic or semi-automatic controllers typically include an electrical or electronic control system that may be programmable, and a control mechanism which may include buttons, levers or switches that may be operated by the vehicle operator. In a fully automatic configuration the shifting of the transmission is performed entirely by the controller in response to external conditions, engine speed, current gear in which the transmission is operating and other factors such as whether the operator is braking or accelerating. Such an automatic transmission will shift up and down through the gears as the operator attempts to accelerate or decelerate the vehicle.
There are a number of transmission systems for sequential controllers that include a control motor or other drive means directly connected to the selector drum allowing the controller to drive the selector shaft and thereby shift the transmission from one gear set to another gear set in response to its programming. Many configurations for such control motor driven sequential transmissions have been disclosed in the prior art. Some describe a motor coupled to a sequential transmission using a set of gears to increase the electrical motor torque and reduce the speed. Some prior art configurations show a selector shaft gear system being implemented as a worm gear arrangement.
Semi-automatic and automatic transmission systems may use one or a number of sensors in order to determine the status of the transmission, such as what gear it is in, the position of the control motor and/or the position of the selector drum. The control system for such systems initiates a shift or prevents a shift from occurring under certain circumstances in response to the sensory inputs. For example, a control system could be aware of the current gear of the transmission and how far and how long it needs to operate the control motor to shift the system into an adjacent gear.
One problem with such systems is that the system must be calibrated when assembled to pre-select the particular positions for each gear relative to the motor. Once the pre-selected gear positions are programmed into the system, the system will typically drive the control motor to the pre-selected gear position. This can pose difficulties in operation because the transmission wears over time and may expand or contract as a result of external temperature changes, and so the exact position to shift the transmission into an adjacent gear may change over time and with such external conditions.
Some existing sequential transmission systems incorporate mechanical means (such as springs or biasing means) to accommodate variances in shift position due to wear and temperature changes. The incorporation of a control motor and control system in such systems typically leads to further losses in precision as the motor system may load these dynamic elements while attempting to perform the shift, which may prevent the shift from completing or interfere with sensing when a shift has been completed.
Another difficulty with electronically controlled motor driven transmission systems is that such systems typically perform poorly when detecting and responding to interference between the gear dogs during shifting. Commonly known as gear jam, the problem occurs when the leading edge of a gear dog belonging to a sliding gear is brought against the leading edge of the gear dog belonging to the corresponding free spinning gear. Under these conditions the gears may not fully engage or may resist engaging and the shift attempt will fail. Many modern transmissions incorporate a synchronizer mechanism, commonly known as a synchromesh device, to enable gear engagement, however these devices add to the size, weight, and cost of the transmission. In the absence of a synchromesh device, if the control system does not sense such interference conditions, it will continue to drive the motor generating excessive strain on the elements of the system. Under those circumstances the transmission, the control motor, or both may be damaged. Since a shift of a sequential transmission may occur in a short period of time (e.g. less than one hundredth of a second), any control system would have to be equipped with sensors that detect interference conditions quickly and accurately.
There is a need for a semi-automatic or automatic sequential shift system that detects the in-gear position of the selector shaft and calibrates the controller to adjust for short term changes in temperature and long term changes due to wear and tear. There is a need for control systems for motor controlled sequential transmissions that can quickly detect gear jams and accurately react to permit gear engagement without risking damage to the engine.
SUMMARY OF THE INVENTION
The present invention relates to an apparatus for controlling a sequential transmission of a vehicle, the transmission comprising an input shaft, an output shaft, at least two sets of gears which are selectively engageable, and a selector drum that when rotated selects a set of gears which engage to drive the output shaft from the input shaft, the apparatus comprising a control motor which is mechanically connected to the selector drum to rotate the selector drum when actuated, a torque sensor which senses the torque applied to the selector drum by the control motor, and a controller which controls the motor based on signals received from the torque sensor.
The apparatus may also include the feature wherein the torque sensor comprises a current sensor that monitors the current drawn by the control motor, and the controller detects a change in the current draw of the control motor during operation of the control motor as an indication of gear jam and adjusts the control motor in response to the change in the current draw.
The apparatus may include a plurality of selector drums, each independently actuated by a control motor to selectively engage sets of gears.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention will be described by way of example and with reference to the drawings in which:
FIG. 1 is a top sectional view of a prior art sequential transmission for a motorcycle.
FIG. 2 is a top view of an embodiment of the invention depicting a control motor driving the selector drum through a geartrain.
FIG. 3A is a side view of an indexing means slightly out of ideal position according to an embodiment of the invention.
FIG. 3B is a side view of an indexing means in a settled position according to an embodiment of the invention.
FIG. 4 is a schematic view of the system depicting the controller and its connection to other elements according to an embodiment of the invention.
FIG. 5 is a schematic view of a DC brushed motor, its driving circuits, and current sensing circuit according to an embodiment of the invention.
FIG. 6 a is a diagram showing gear dogs prior to engagement.
FIG. 6 b is a diagram showing gear dogs in an interference state.
FIG. 6 c is a diagram showing gear dogs in an engaged state.
FIG. 7 is a flowchart showing controller logic according to an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 2 shows one embodiment of the invention comprising a control motor 201 driving the selector drum 104 . A cam indexer 116 having a series of impressions therein biases the selector drum 104 into a fixed number of gear positions using a biased pawl 118 . The control motor 201 may drive the selector shaft 203 through a series of selector shaft gears 202 . The control motor 201 may incorporate a position sensor, such as a Hall effect sensor, to determine the position of the control motor 201 .
The selector shaft gears 202 may include spur gears, bevel gears, helical gears and hypoid gears. In a preferred embodiment the selector shaft gears 202 would not include a worm drive arrangement, as worm gear arrangements are typically poor mechanical transmitters of reverse torque, and therefore may not provide good feedback to a torque sensor. Worm gears are helical gears having a helix angle that does not exceed 50 degrees.
The invention may also comprise a position sensor 206 in addition to or instead of the position sensor in the control motor 201 , which may incorporate a Hall effect sensor or other current sensing means that encompasses or encircles or is immediately adjacent to the selector shaft 203 or selector drum 104 . The position sensor 206 may be used to detect the position of the selector shaft 203 relative to a fixed point such as the motor mounting 204 or relative to the housing of the transmission 205 . The position sensor 206 may operate by use of a potentiometer, in which case the selector shaft 203 rotates relative to the potentiometer changing the current flow through the potentiometer. In the case of a Hall effect sensor, the selector shaft 203 may have mounted upon it permanent magnets or may comprise a portion which has been magnetized so that it generates a magnetic field which is detected by the Hall effect sensor. Changes in the magnetic field may be outputted by the Hall effect sensor as a digital signal or as an analog voltage.
The position sensor 206 may also be used to determine the torque experienced by the selector shaft 203 , when positioned on a portion of the selector shaft 203 that is subject to mechanical strain caused by torque. In one embodiment, the position sensor 206 is located between the driving gears and the selector drum, which is subject to mechanical strain caused by torque.
When the position sensing means are used in conjunction with mechanical biasing means of the system, it is possible for the system to adapt over time to account for wear, and also to adapt on the fly to address transient dangerous gear jam conditions. In an embodiment which includes a biasing means for mechanically biasing the selector drum 104 into one of a number of gear positions, when the controller has actuated the control motor 201 and driven the selector drum 104 into one of those desired positions, as perceived by the controller in accordance with a set of pre-programmed control positions, the control motor 201 has completed its actuation into the next shift position. If the pre-programmed control position is out of calibration, the cam indexer 116 will apply a correcting torque to the selector drum 104 bringing it to the mechanically correct position. By monitoring the position of the selector drum 104 via the position sensor 206 the controller can detect when the pre-programmed control positions have fallen out of calibration. The control system can therefore alter the stored motor control positions to approach the settled values of the mechanical system. It may accomplish this by calculating the difference between the motor position coordinates following a gear change and the stored motor position coordinates corresponding with that gear, and modifies the stored motor position coordinates if the difference is greater than a predefined threshold.
In operation, the control motor 201 drives the selector shaft gears 202 which in turn drive the selector shaft 203 to one of the pre-programmed positions, overcoming the resistance of friction and the indexer biasing means to shift the system into an adjacent gear.
FIGS. 3 a & 3 b depict a mechanical biasing means comprising a cam sprocket 115 having a series of indentations and a cam follower 118 hinged at one end and having a wheel or cam follower 117 at the other end and a spring 301 for biasing the cam follower 118 against the cam sprocket 115 . When in gear, the cam follower 118 will settle into one of the indentations. As previously mentioned, a control system can detect if it has driven the selector drum 104 into a position where the cam follower 118 is not quite settled into one of the impressions because the selector drum 104 will experience torque caused by the biased cam follower 118 against the surface of the cam sprocket 115 to settle it into position. This permits the system to continually calibrate itself relative to the mechanical environment, which is necessary because, as mentioned, the system may over time become imprecise as wear and sensor degradation occurs.
FIG. 4 depicts a schematic of the system showing a controller 401 interfaced with a number of elements. The controller 401 controls a motor 402 , preferably a brushless DC motor, the motor 402 may be a three phase motor permitting AC control of the motor 402 and may also in such an environment include a motor position sensor 412 , which may be inherent in the design of the motor 402 , or separate. The system may also comprise a gear position sensor 403 , separate and independent from any sensing capabilities in the motor 402 , the gear position sensor 403 will sense the position of the selector drum and measure the position of the selector drum directly. The system may also comprise a gear position display 405 to display the current gear based on inputs from the gear position sensor 403 or the motor 402 and is determined by the gear controller 401 .
The controller may comprise hardware, electronic or electrical circuitry and/or a processor and storage for executing software. Software is executable statements and instructions stored in a memory for execution by a processor. A memory may include any static, transient or dynamic memory or storage medium, including without limitation read-only memory (ROM) or programmable ROM, random access registers memory (RAM), transient storage in registers or electrical, magnetic, quantum, optical or electronic storage media. A processor includes any device or set of devices, howsoever embodied, whether distributed or operating in a single location, that is designed to or has the effect of carrying out a set of instructions, but excludes an individual or person. A system implemented in accordance with the present invention may comprise a computer system having memory and a processor to execute the software.
The system may also comprise some sort of user interface, such as a shift button array 404 in a semi-automatic embodiment, and it may also be used in conjunction with other controls known in the art.
The controller 401 may control an automatic or semi-automatic clutch 409 in conjunction with the system in a preferred embodiment. A semi-automatic or automatic clutch system 409 may be directly controlled by the gear controller 401 such that the controller 401 both actuates the clutch and shifts the gears in response to a single input from a rider or in response to an automatic control strategy programmed into the controller 401 , or other electronic control units (ECUs) 410 located on the vehicle.
The controller 401 may be directly connected with the vehicle's sensors, or may communicate with ECUs 410 or an onboard computer system through direct connection or a bus. A commonly used standard for vehicle communication is a bus implementing the CAN multi-master broadcast serial bus standard, but any electronic or electrical communication means may be used. Though such communication means, or directly using a separate bus or buses 411 , the controller 401 may access and use any of the information produced by the vehicle's sensors, including wheel speed, throttle position, ignition timing, etc. This information may be used to control the transmission to optimize shifting speed and timing, and to prevent damage.
For example, the controller 401 may sense the current wheel speed via a wheel speed sensor which permits it to control which gears may be shifted into by the rider, to prevent errors by the rider which may damage the transmission or engine.
The controller 401 may also receive inputs from the ignition system through the wiring harness, such as the position of the stop switch, the position of the throttle and the speed of the engine.
The system may also be adapted to connect to other control systems on the vehicle such as any existing control systems that deal with engine control, braking, traction control or similar automated or semi-automated systems to coordinate shifting with those systems. This coordination would have the benefit of preventing shifts that could lead to unsafe conditions.
In the preferred embodiment, if the shift attempt causes the gears to interfere or clash, the shift would not initially proceed. In such a circumstance, the torque sensor, in this case two Hall effect current sensors 408 placed adjacent to the motor power lines 413 , would measure significant torque, by way of increased current flow, and the controller 401 could change the speed, target position, or applied torque of the control motor 402 to allow the transient condition to clear so that the selector drum could proceed into the desired position. This mechanism allows detection of transient gear interference conditions and prevention of damage to the control motor 402 and/or the transmission that may be otherwise caused by driving the transmission into a position where it mechanically cannot go.
Under such conditions, the controller 401 may respond in a number of different ways to resolve the gear interference. The controller 401 may adopt a position control, speed control, or torque control strategy to overcome the interference.
In one embodiment, shown in FIG. 5 , the means used to sense torque involves detecting current in the motor power lines 503 . The torque sensor in controller 501 may comprise an in-line resistor 504 or one or more Hall effect sensors to detect changes in current on the transmission lines 503 as consumed or generated by the control motor 502 . Current sensing can be used to detect power and torque as experienced by the control motor 502 when the voltage applied to the control motor 502 is known, as it is in the case of an electrically controlled system. A controller 501 , upon measuring the changes in current as compared to the input voltage, can calculate the torque experienced by the control motor 502 and can adjust it appropriately to prevent damage to the transmission. In this embodiment, the control motor 502 is controlled by the controller 501 though a set of switches 505 implemented using MOSFET circuitry. Other current sensing means may also be used, such as a dynamic transformer affixed to either the control motor or the selector shaft. The control motor 502 control means may also include a power conditioning unit 506 for conditioning the electrical power delivered to the control motor 502 for voltage, polarity, reverse polarity protection, and switching noise suppression, and delivers the power within the optimum parameters for the control motor 502 . The torque sensing means may also comprise a control signal conditioning unit 507 for filtering control signal noise, and providing amplification or attenuation of the control signals to drive the control motor 502
As shown in FIGS. 6 a - 6 c , gear interference, or jams, typically arise when the sliding gear 601 is slid towards the free spinning gear 602 . If outward surfaces 605 of the dog teeth of the sliding gear 603 impact the outward surfaces 606 of the dog teeth of the free spinning gear 604 when slid together, the dog teeth 603 604 will not engage, causing a jam. This gear dog interference causes the lateral force being applied by the shift forks to quickly increase, which is converted to torque seen at the selector drum based on the cam profile of the grooves cut into the selector drum. Once the jam is cleared or under normal operation, the dog teeth 603 604 engage, driving the free spinning gear together with the sliding gear.
There is typically a specific set of selector drum positions where jams can occur. These positions are particular to the shape of the selector drum and transmission, and are typically where the drum is moving the dog teeth of the gears together but not overlapping or engaging. Outside of these particular set of drum positions, high current readings may be measured, but are associated with other transient loads that are not related to jamming, such as loads caused by starting up the vehicle and braking.
In FIG. 7 , an embodiment of the invention is shown depicting the logic of the controller during a shift to detect a jam event. The process starts by detecting whether the selector drum has entered one of the positions where a jam is possible (a “jam zone”) 701 . The system may detect whether the selector drum has entered a jam zone by using a position sensor. The position sensor may be coupled directly to the selector drum, or may be integrated into the control motor. In the latter case, the position of the selector drum may be inferred from the number of revolutions that the control motor has made since the shift started. The system may also deem the selector drum to be in a jam zone after a predetermined delay from the initiation of the shift.
If the gear selector is in a jam zone, the process measures whether the control motor is drawing current in excess of a predefined threshold 702 . The value of the predefined threshold 702 will depend on the system, and the current typically drawn by the control motor during a jam event, as determined by modeling or experimentation, or based on previous jam events recorded by the controller. The process sets a jam event flag 703 should the current threshold be exceeded at any time while the drum is in a jam zone 702 704 . Should the process detect that the jam event flag is on, the process may adopt a position control, speed control, or torque control strategy to resolve the interference dynamically during the shift. These control strategies are designed to shepherd the transmission out of the jam zone, either into the desired gear, or back out into the starting gear. A jam event flag status check 706 ensures the event is only flagged once. Once the drum has exited the jam zone, the process can set a gear engaged flag 705 to indicate that the gear is expected to engage successfully. Should the process detect that the gear engaged flag 705 is on the process may trigger external events such as clutch control or engine control. If the jam event flag 703 is set at the end of the process, the process may run a diagnostic routine to identify the cause of the jam, or adopting a position control, speed control, or torque control strategy to resolve the interference should it remain (for example, because the shift has failed entirely, and the drum has reverted to its starting position).
It will be appreciated that the above description relates to the preferred embodiments by way of example only. Many variations on the system and method for delivering the invention without departing from the spirit of same will be clear to those knowledgeable in the field, and such variations are within the scope of the invention as described and claimed, whether or not expressly described.
|
An apparatus for controlling a sequential transmission of a vehicle is provided comprising a control motor that drives a selector drum for shifting gears wherein the apparatus measures torque applied to or position of the selector drum and controls the control motor to engage the gears, to accommodate for wear and transient gear interference or jamming.
| 8
|
This is a divisional application of application Ser. No. 11/129,957 filed on May 16, 2005, now U.S. Pat. No. 7,221,036, issued on May 22, 2007.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to BJTs and, more particularly, to a method of forming a BIT with ESD self protection.
2. Description of the Related Art
A bipolar junction transistor (BJT) is a well-known element that is utilized in a variety of circuits. BJTs are commonly formed by sandwiching a region of a first conductivity type, known as a base, between two regions of a second conductivity type, known as an emitter and a collector.
FIG. 1 shows a cross-sectional view that illustrates a prior-art BIT 100 . As shown in FIG. 1 , BJT 100 includes a p− substrate 110 , and a buried layer 112 that is formed in p− substrate 110 . Buried layer 112 includes an inner n+ layer 112 A and an outer diffused n layer 112 B that extends out from inner n+ layer 112 A.
Further, BJT 100 includes an n− epitaxial layer 114 that is formed on buried layer 112 . BJT 100 is a high-voltage device which, when compared to a conventional low-voltage bipolar device, has a substantially thicker epitaxial layer. For example, n− epitaxial layer 114 can be approximately 15-17 um thick.
In addition, BJT 100 includes a p− base region 120 that is formed in n− epitaxial layer 114 , an n+ emitter region 122 that is formed in p− base region 120 , and a sinker down region 124 that is formed in n− epitaxial layer 114 . Sinker down region 124 includes an inner n+ region 124 A and an outer diffused n region 124 B that surrounds inner n+ region 124 A.
Sinker down region 124 , along with n-type buried layer 112 and n− epitaxial layer 114 , function as the collector. (N+ sinker down region 124 A can alternately extend down to contact n+buried layer 112 A, be combined with an n+ sinker up region that extends up from n+ buried layer 112 A, or be implemented in any conventional manner.)
As further shown in FIG. 1 , BJT 100 also includes a layer of isolation material 130 that is formed on the surface of n− epitaxial layer 114 , and a metal base contact 132 that is formed through isolation layer 130 to make an electrical connection with p− base region 120 . BJT 100 additionally includes a metal emitter contact 134 that is formed through isolation layer 130 to make an electrical connection with n+ emitter region 122 , and a metal collector contact 136 that is formed through isolation layer 130 to make an electrical connection with sinker down region 124 . Further, p− base region 120 is separated from collector contact 136 by a separation distance SD.
For normal operation, n+ emitter region 122 is commonly connected to ground, while n+ collector region 124 is connected to a positive voltage. Under these biasing conditions, BJT 100 is turned off when ground is placed on p− base region 120 . In this case, the voltage on p− base region 120 is equal to the voltage on n+ emitter region 122 , and less than the voltage on n+ collector region 124 , thereby reverse biasing the base-collector junction.
On the other hand, when the voltage on p− base region 120 rises to approximately 0.7V, BJT 100 turns on. In this case, the voltage on p− base region 120 forward biases the base-emitter junction. When the base-emitter junction becomes forward biased, p− base region 120 begins injecting holes into emitter region 122 , while n+ emitter region 122 begins injecting electrons into base region 120 . The electrons injected into p− base region 120 diffuse through the lightly-doped base region 120 , and are swept into n− epitaxial layer 114 by the electric field across the reverse-biased, base-collector junction.
Once swept into n− epitaxial layer 114 , the electrons follow the lowest resistance path to n+ collector region 124 . In this example, the lowest resistance path is illustrated by a current path P that moves vertically down, horizontally through n+ buried layer 112 A, and vertically up to sinker down region 124 . Normal operation continues as long as holes can continue to be supplied to p− base region 120 (for injection into n+ emitter region 122 ) via an external base current that flows into base region 120 .
In addition to normal operation, BJT 100 can also be utilized to provide the pads of a semiconductor device with electrostatic discharge (ESD) protection from voltage spikes. For example, n+ collector region 124 can be connected to an I/O pad to protect the I/O pad from voltage spikes.
During an ESD event, the voltage on n+ sinker down region 124 rises quickly, which causes the voltage on n-type buried layer 112 and n− epitaxial layer 114 to rise with respect to the voltage on p− base region 120 , thereby reverse biasing the pn junction between n− epitaxial layer 114 and p− base region 120 .
When the rising voltage on n− epitaxial layer 114 (the collector) exceeds a breakdown voltage of the pn junction, avalanche multiplication causes large numbers of holes to be injected into p− base region 120 , and large numbers of electrons to be injected into n− epitaxial layer 114 . Ideally, the electrons injected into n− epitaxial layer 114 follow the same low-resistance path P to sinker down region 124 as described above.
On the other hand, the holes injected into p− base region 120 flow out of p− base region 120 into a circuit which causes the potential on p− base region 120 to rise and forward bias the base-emitter junction. For example, when a BJT is utilized as an ESD protection device, the base of the BIT can be connected to ground via a resistor. In this case, when the hole current from p− base region 120 flows to ground via the resistor, the resistor causes the voltage on p− base region 120 to rise and forward bias the base-emitter junction.
When the base-emitter junction becomes forward biased, p− base region 120 begins injecting holes into n+ emitter region 122 , while n+ emitter 122 begins injecting electrons into p− base region 120 . The electrons injected into p− base region 120 from n+ emitter region 122 diffuse to the base-collector junction, where the electrons are swept into n− epitaxial layer 114 by the electric field across the reverse-biased junction. The electrons from n+ emitter region 122 join the avalanche-generated electrons flowing to sinker down region 124 , thereby significantly increasing the current sunk by BJT 100 .
As noted above, the electrons injected into n− epitaxial layer 114 ideally follow the low-resistance current path P to sinker down region 124 . However, due to the high electric field that is present during an ESD event, and the large number of electrons that are injected into the lightly-doped epitaxial layer 114 , the electrons can flow laterally just below the surface of epitaxial layer 114 from p− base 120 to sinker down region 124 .
As illustrated in FIG. 1 , one problem with a significant lateral electron flow at the surface of n− epitaxial layer 114 is that the electron flow causes the lattice temperature to rise significantly, and can cause a localized hot spot 140 to develop next to the interface between sinker down region 124 and collector contact 136 . Hot spot 140 can cause collector contact 136 to melt which, in turn, can lead to the electrical inoperability of BJT 100 . Thus, there is a need for a BJT which can be used as an ESD protection device without being melted by an ESD event.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view illustrating a prior-art bipolar junction transistor (BJT) 100 .
FIG. 2 is a plan view illustrating an example of a bipolar junction transistor (BJT) 200 in accordance with the present invention.
FIG. 3A is a cross-sectional view illustrating an example of an embodiment 300 of BJT 200 in accordance with the present invention.
FIG. 3B is a cross-sectional view illustrating an example of a method of forming embodiment 300 of BJT 200 in accordance with the present invention.
FIG. 4A is a cross-sectional view illustrating an example of an embodiment 400 of BJT 200 in accordance with the present invention.
FIG. 4B is a cross-sectional view illustrating an example of a method of forming embodiment 400 of BIT 200 in accordance with the present invention.
FIG. 5 is a plan view illustrating an example of an embodiment 500 of BIT 200 in accordance with the present invention.
FIG. 6 is a plan view illustrating an example of an embodiment 600 of BIT 200 in accordance with the present invention.
FIG. 7 is a schematic diagram illustrating an example of a circuit 700 in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 2 shows a plan view that illustrates an example of a bipolar junction transistor (BIT) 200 in accordance with the present invention. As described in greater detail below, BIT 200 relocates a hot spot away from the collector contact, thereby allowing BJT 200 to be used in electro-static discharge (ESD) applications without melting the collector contact.
BIT 200 is similar to BJT 100 and, as a result, utilizes the same reference numerals to designate the structures which are common to both BJTs. As shown in FIG. 2 , BIT 200 differs from BJT 100 in that BIT 200 includes a ballasting region 210 that contacts the surface of n− epitaxial layer 114 and lies between p− base region 120 and sinker down region 124 . In operation, ballasting region 210 relocates the hot spot away from collector contact 136 , thereby allowing BIT 200 to be used in ESD applications without destroying the collector contact.
FIG. 3A shows a cross-sectional view that illustrates an example of an embodiment 300 of BIT 200 in accordance with the present invention. As shown in FIG. 3A , ballasting region 210 of embodiment 300 includes an n+ protection region 310 that contacts the surface of n− epitaxial layer 114 .
In the FIG. 3A example, n+ protection region 310 has a depth, measured along a line normal to the surface of n− epitaxial layer 114 , which is significantly shallower than p− base region 120 and n+ sinker down region 124 A. In addition, n+ protection region 310 extends laterally from n+ sinker down region 124 A towards p− base region 120 , but remains spaced apart from p− base region 120 . Further, to accommodate n+ protection region 310 , a separation distance SD between p− base region 120 and collector contact 136 is increased.
In operation, in response to an ESD event (e.g., in response to 100 nS of a 2 kV human body model (HBM) stress), embodiment 300 of BIT 200 operates the same as BJT 100 except that n+ protection region 310 forces the hot spot that results from the lateral current flow away from the collector contact region.
As shown in FIG. 3A , n+ protection region 310 causes a localized hot spot 312 to develop at an end E of n+ protection region 310 that lies closest to p− base region 120 . Although the peak temperature lies at the end, substantially elevated temperatures also extend towards p− base region 120 and n+ sinker down region 124 A.
As a result, the distances between the elements must be adjusted to insure that the temperature on the metal contacts is insufficient to melt the contacts. Thus, the use of n+ protection region 310 relocates the hot spot away from collector contact 136 , thereby allowing embodiment 300 of BIT 200 to be used in ESD applications without destroying the collector contact.
FIG. 3B shows a cross-sectional view that illustrates an example of a method of forming embodiment 300 of BIT 200 in accordance with the present invention. As shown in FIG. 3B , a semiconductor device 350 is conventionally formed to have p− base region 120 formed in n− epitaxial layer 114 .
Following this, as further shown in FIG. 3B , a mask 352 is formed and patterned to expose a portion of p− base 120 , and a portion of n− epitaxial layer 114 that is spaced apart from p− base region 120 . Next, the exposed regions are implanted with an n-type dopant to form n+ emitter region 122 and n+ protection region 310 . Mask 352 is then removed.
After this, the method continues with conventional steps. In the FIG. 3B example, no additional masking steps are required to form n+ protection region 310 because n+ protection region 310 is formed at the same time as n+ emitter region 122 . Further, n-type sinker down region 124 can be formed before or after regions 122 and 310 are formed. Alternately, n+ protection region 310 can have a different depth or dopant concentration by utilizing separate masking and implant steps to form n+ emitter region 122 and n+ protection region 310 .
FIG. 4A shows a cross-sectional view that illustrates an example of an embodiment 400 of BIT 200 in accordance with the present invention. As shown in FIG. 4A , ballasting region 210 of embodiment 400 includes an electrically-floating p− protection region 410 that contacts the surface of n− epitaxial layer 114 . Further, to accommodate p− protection region 410 , a separation distance SD between p− base region 120 and collector contact 136 is increased.
In operation, in response to an ESD event (e.g., in response to 100 nS of a 2 kV HBM stress), embodiment 400 of BJT 200 operates the same as BJT 100 except that p− protection region 410 forces the electron flow vertically down and away from the surface of epitaxial layer 114 substantially along the current path P, thereby eliminating or substantially reducing the lateral surface flow of electrons.
As shown in FIG. 4A , p− protection region 410 causes a localized hot spot 412 to develop at the interface between buried layer 112 and n− epitaxial layer 114 . Thus, the use of p− region 410 relocates the hot spot away from collector contact 136 . As a result, embodiment 400 of BJT 200 can be used in ESD applications without destroying the collector contact.
FIG. 4B shows a cross-sectional view that illustrates an example of a method of forming embodiment 400 of BJT 200 in accordance with the present invention. As shown in FIG. 4B , the method utilizes a semiconductor device 450 that has been conventionally formed to have an n− epitaxial layer 114 .
Following this, as further shown in FIG. 4B , a mask 452 is formed and patterned to expose spaced-apart portions of n− epitaxial layer 114 . Next, the exposed regions are implanted with a p-type dopant to form p− base region 120 and p− protection region 410 . Mask 452 is then removed.
After this, the method continues with conventional masking and implanting steps to form n+ emitter region 122 in p− base region 120 and n-type sinker down region 124 in epitaxial layer 114 so that p− protection region 410 lies between p− base region and n+ sinker down region 124 A.
In the FIG. 4B example, no additional masking steps are required to form p− protection region 410 because p− protection region 410 is formed at the same time as p− base region 120 . Alternately, p− protection region 410 can have a different depth or dopant concentration by utilizing separate masking and implant steps to form p− base region 120 and p− protection region 410 .
FIG. 5 shows a plan view that illustrates an example of an embodiment 500 of BJT 200 in accordance with the present invention. As shown in FIG. 5 , ballasting region 210 of embodiment 500 includes an n+ sinker down extension 510 that has a finger shape. Further, to accommodate n+ sinker down extension 510 , a separation distance SD between p− base region 120 and collector contact 136 is increased.
In operation, in response to an ESD event (e.g., in response to 100 nS of a 2 kV human body model (HBM) stress), embodiment 500 of BIT 200 operates the same as BJT 100 except that n+ sinker down extension 510 forces the hot spot that results from the lateral current flow away from the collector contact region in a manner similar to embodiment 300 . As a result, embodiment 500 of BIT 200 can be used in ESD applications without destroying the collector contact.
Embodiment 500 can be formed in the same manner as embodiment 300 , except that mask 352 illustrated in FIG. 3B must be modified to have a finger shaped pattern as illustrated by n+ ballasting region 510 . Thus, n+ ballasting region 510 can be formed at the same time that n+ emitter 122 is formed.
FIG. 6 shows a plan view that illustrates an example of an embodiment 600 of BIT 200 in accordance with the present invention. As shown in FIG. 6 , ballasting region 210 of embodiment 600 includes a significantly larger, e.g., 2×, separation distance SD between p− base region 120 and collector contact 136 than would be found in a standard BIT, such as BJT 100 .
In operation, in response to an ESD event (e.g., in response to 100 nS of a 2 kV HBM stress), embodiment 600 of BIT 200 operates the same as BJT 100 except that the larger separation distance SD forces the electron flow vertically down and away from the surface of n− epitaxial layer 114 substantially along the current path P, thereby eliminating or substantially reducing the lateral surface flow of electrons.
The significantly larger separation distance SD causes a localized hot spot to develop at the interface between buried layer 112 and n− epitaxial layer 114 . Thus, the use of a significantly larger separation distance SD relocates the hot spot away from collector contact 136 . As a result, embodiment 600 of BIT 200 can be used in ESD applications without destroying the collector contact.
FIG. 7 shows a schematic diagram that illustrates an example of a circuit 700 in accordance with the present invention. As shown in FIG. 7 , circuit 700 includes a pad 710 , and an ESD BJT 712 that is connected between pad 710 and ground. In addition, circuit 700 includes a resistor R that is connected between ESD BJT 712 and ground, and a circuit BJT 714 that is connected between pad 710 and ground.
ESD BJT 712 can be implemented with embodiments 300 - 600 of BJT 200 , while circuit BJT 714 can be implemented with a conventional BJT, such as BJT 100 , that can be damaged by an ESD strike. In each case, the separation distance SD between p− base region 120 and collector contact 136 of BJT 712 is greater than the separation distance SD of BJT 714 . Further, when embodiment 600 is utilized, the separation distance SD of BJT 712 is substantially greater, e.g., 2×, than the separation distance SD of BJT 714 . In operation, when an ESD event occurs, ESD BJT 712 shunts the voltage strike to ground, thereby protecting circuit BJT 714 from damage.
Thus, the present invention provides a BJT that can be utilized as an ESD protection device without melting the collector contact. One of the advantages of the present invention is that ESD BJT 712 can be modeled or simulated in cases where other devices, such as a silicon controlled rectifier (SCR) structures, can not be modeled or simulated.
Further, the present invention provides a BJT that can function as both a conventional bipolar device (with greater resistance), and as an ESD protection device. Thus, in the present invention, circuit BJT 714 can optionally be eliminated (if the base of circuit BJT 714 is connected to a circuit which can forward bias the base-emitter junction during an ESD event) because ESD BJT 712 can function as a conventional bipolar device (with greater resistance) during normal circuit operation, and as an ESD protection device should an ESD event occur. As a result, the BJT of the present invention provides ESD self protection.
It should be understood that the above descriptions are examples of the present invention, and that various alternatives of the invention described herein may be employed in practicing the invention. For example, elements of the above embodiments can be combined together. Thus, it is intended that the following claims define the scope of the invention and that structures and methods within the scope of these claims and their equivalents be covered thereby.
|
A ballasting region is placed between the base region and the collector contact of a bipolar junction transistor to relocate a hot spot away from the collector contact of the transistor. Relocating the hot spot away from the collector contact prevents the collector contact from melting during an electrostatic discharge (ESD) pulse.
| 7
|
TECHNICAL FIELD OF THE INVENTION
The present invention is directed, in general, to integrated circuit fabrication and, more specifically, to a system and method for forming a uniform, ultrathin gate oxide layer on a semiconductor substrate.
BACKGROUND OF THE INVENTION
As metal-oxide-semiconductor ("MOS") technology continues to advance and the features of the MOS devices shrink, a scaling down in the vertical dimension of the devices typically occurs. Critical to the success of these devices is a reliable, high-quality gate dielectric with a low defect density ("D o ") and a high breakdown field strength ("F bd ") that retains its quality during advanced processing. As the overall size of the semiconductors get ultrathin (e.g., less than 7.5 nm), the quality of the oxide (e.g., SiO 2 ), even under the best possible external growth conditions, is limited by the natural viscoelastic compressive stress generated in the SiO 2 at temperatures below 1000° C. and by the thermal expansion mismatch between silicon substrate and SiO 2 . In present applications, a genuine lowering of the D o in the range of 0.05 to 0.5 cm -2 has been achieved. For example, oxide/nitride or oxide/nitride/oxide (ONO) structures can attain such low D o . The Si 3 N 4 --SiO 2 ("silicon nitride-silicon oxide") interface, however, is invariably associated with a high density of interface states ("Q it ") that cannot be annealed out easily because the Si 3 N 4 layer is impervious to diffusion of oxidizing species. These multi-layered dielectrics are unsuitable as gate dielectrics in advanced complementary metal-oxide-semiconductor ("CMOS") integrated circuits, because the interface states can cause charge-induced shift in the threshold voltage and can reduce the channel conductance during operation.
To overcome this problem, the concept of stacking thermally grown and chemical-vapor-deposited ("CVD") SiO 2 structures has been proposed in U.S. Pat. No. 4,851,370 ("the '370 patent"), which is incorporated herein by reference for all purposes. Here, the composite stack is synthesized by a 3-step grow-deposit-grow technique wherein the growing steps are conducted at pressures equal to or greater than one atmosphere. The interface between the grown and deposited SiO 2 layers serves the same purpose as the interface in SiO 2 --Si 3 N 4 structures (i.e., it reduces the D o by misaligning the defects across the interface) . Moreover, the interface traps in stacked oxide structures that can be removed easily by an oxidizing anneal, since the top deposited SiO 2 layer, unlike the Si 3 N 4 film, is transparent to oxidizing species (i.e., it transports them by diffusion). This stacking concept can be applied to any composite dielectric structure with similar results as long as the top deposited dielectric layer is transparent to the oxidizing species.
A few major factors contributing to defects in conventional thin-oxide gate dielectrics are growth-induced micropores and intrinsic stress within the oxide layer. The micropores are 1.0 nm to 2.5 nm in diameter, with an average separation of about 10.0 nm. The pores form at energetically favored sites such as heterogeneities created by localized contaminants, ion-damaged areas, dislocation pileups and other defect areas on the silicon surface resulting from retarded oxidation in these sites. The pores grow outward as oxidation continues to consume silicon around the pore. Thus, a network of micropores usually exists in SiO 2 . The micropore network forms potential short-circuit paths for diffusional mass transport and for current leakage.
In addition, the stress within a SiO 2 layer, often accentuated by complex device geometries and processing, usually increases both the size and density of the micropores. Therefore, in developing thin dielectrics with ultra-low D o , not only should the initial D o be reduced, but also the local stress-gradients near the Si--SiO 2 interface should be reduced by providing a stress-accommodating layer, such as an interface (between grown and deposited layers) within the dielectric that acts as a stress cushion and defect sink.
The above-mentioned problems become even more acute as the overall size of devices decrease to sub-micron size with ultrathin gate dielectrics (e.g., less than 7.5 nm). Unfortunately, however, the above-discussed conventional stacked-oxide process, which works extremely well in technologies where the semiconductor thickness is greater than 7.5 nm, is not as applicable in technologies having thicknesses less than 7.5 nm. The main reason for this is that in the conventional 3-step stacked process, the SiO 2 is grown in pressures of one atmosphere or greater. In semiconductor technologies where the gate oxide thickness is 10.0 nm or greater, this particular condition is most advantageous because under such atmospheric pressure, the SiO 2 can be grown quite rapidly and one can grow the first grown layer (typically 3.5-7.5 nm) with good uniformity. This rapid growth is highly desirable, for it cuts down in manufacturing time, and thus, overall production costs. This same rapid growth, which is so advantageous in technologies with gate oxide thickness of 10.0 nm or greater is less desirable in sub-0.5 micron semiconductor technologies because the oxides grow too quickly, which makes thicknesses harder to control. As such, the oxide layers are less uniform in thickness, which is unacceptable.
Accordingly, what is needed in the art is a stacked-oxide process that provides semiconductors having thicknesses of less than 10.0 nm and, more advantageously less than 7.5 nm, and yet provides a semiconductor that has a low defect density ("D o ") and a high breakdown field strength ("F bd ") that retains its quality during advanced processing. The present invention addresses this need.
SUMMARY OF THE INVENTION
To address the above-discussed deficiencies of the prior art, the present invention provides a semiconductor and systems and methods of manufacture thereof. One method includes the following grow-deposit-grow steps: (1) growing a first oxide layer on the semiconductor substrate in a zone of low pressure, (2) depositing a dielectric layer on the first oxide layer in the zone of low pressure and (3) growing a second oxide layer between the first oxide layer and the substrate in the zone of low pressure. The zone of low pressure is created to retard the oxidation rate at which the first and second oxide layers are grown.
The present invention therefore introduces the broad concept of growing the first and second oxide layers under low pressure oxidizing conditions to retard their growth. Such retardation of the growth rate is necessary given the thinness and uniformity desired in the dielectric sub-layers in sub-micron technologies.
In one embodiment of the present invention, the second grown oxide layer may have a thickness of less than 10 nm or between about 0.5 nm and about 0.8 nm and may be grown at a temperature exceeding 800° C.
In one embodiment of the present invention, the steps of growing, depositing and growing are performed in a single vapor deposition equipment. That the method of the present invention may be performed in a single "tool" or "furnace" allows high rates of production and greater process control, although, performance in a single tool is not required.
In one embodiment of the present invention, a pressure in the zone of low pressure ranges from about 200 milliTorr to about 950 milliTorr. In a more specific embodiment, the pressure is about 900 milliTorr during the step of growing the first and second oxide layers and about 400 milliTorr during the second step of depositing the dielectric layer.
In one embodiment of the present invention, a thickness of the first grown oxide layer is less than about 5.0 nm. In a more specific embodiment of the present invention, however, the thickness is about 3.0 nm.
In another embodiment of the present invention, the deposited dielectric layer is generated from the decomposition of tetraethyl orthosilicate ("TEOS") and has a thickness of about 1.5 nm. In a more specific embodiment of the present invention, the thickness ranges from about 1 nm to about 4.0 nm. The TEOS is preferably deposited at a flow rate of 50 cubic centimeters per minute.
In one embodiment of the present invention, the steps of growing and depositing are performed at a temperature that ranges from about 600° C. to about 750° C. In yet another embodiment, the step of growing the second oxide layer is performed at a temperature ranging from about 800° C. to about 1000° C.
In one embodiment of the present invention, the step of growing the first oxide layer is performed under a pressure of 900 milliTorr and the oxygen has a flow rate of 9 standard liters per minute. In yet another embodiment, the step of growing is performed under a nitrous oxide and nitrogen environment wherein the nitrous oxide has a flow rate of about 1.72 standard liters per minute and the nitrogen has a flow rate of about 0.75 standard liters per minute to attain light-nitridation, (1-5%) near the interface between the first and second grown oxide layers.
In another aspect of the present invention, a semiconductor comprised of a substrate and having a stress-accommodating layer formed therein is provided. The semiconductor has a thickness less than 7.5 nm and comprises: (1) a first grown oxide layer on the substrate that was formed on an exposed surface of the substrate in a zone of low pressure, (2) a deposited dielectric layer on the first grown oxide layer that was formed over the first grown oxide layer in the zone of low pressure and (3) a second grown oxide layer formed between the first oxide layer and the substrate that was formed in the zone of low pressure. The zone of low pressure is created to retard a rate at which the first and second oxide layers are grown. During this third-step of stacked oxide synthesis oxide growth occurs under a stress-modulating condition provided by the interface between the first grown and second deposited layer generating a planar and stress-free substrate Si/SiO 2 interface which can otherwise never be achieved by conventional 1-step oxide growth.
In one embodiment of this aspect of the present invention, the first grown oxide, the second deposited dielectric and the second grown oxide layers are formed on the substrate in a single low-pressure vapor deposition equipment. As previously stated, this offers the advantage of decrease production cycle time and thus production cost.
In one embodiment of this aspect of the present invention, the second grown oxide layer may be formed at a temperature exceeding about 800° C., and the first oxide layer and the dielectric layer may be grown in a temperature exceeding about 600° C. The second grown oxide layer may have thickness that ranges from about 0.5 nm to about 0.8 nm.
In one embodiment of this aspect of the present invention, the deposited dielectric layer is formed in a pressure of about 400 milliTorr in the zone of low pressure and may have a thickness of about 10.5 nm. In yet another aspect of this particular embodiment, the deposited dielectric layer is formed from the decomposition of TEOS, which preferably had a flow rate of 50 cubic centimeters per minute during its deposition.
In one embodiment of this aspect of the present invention, the first oxide layer may have a thickness of less than about 5.0 nm (preferably in the range of 1.0 nm to 3.0 nm).
The foregoing has outlined, rather broadly, preferred and alternative features of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiment as a basis for designing or modifying other structures for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the invention in its broadest form.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
FIG. 1 illustrates a schematic representation of a structure according to an advantageous embodiment of the present invention; and
FIG. 2 illustrates a schematic graph of the thermal, pressure and flow rate history for an oxidation scheme in accordance with an advantageous embodiment of the present invention.
DETAILED DESCRIPTION
Referring initially to FIG. 1, there is illustrated a schematic representation of a structure according to an advantageous embodiment of the present invention. In one such embodiment, a substrate 10 is used, and a 1 nm to 2.5 nm oxide layer 12 is formed on the substrate under a low pressure, for example, a pressure of less than 10 Torr. In more advantageous embodiments, the pressures are at less than about 2 Torr. In one advantageous embodiment, the substrate 10 may be silicon and the oxide layer 12 may be silicon dioxide (SiO 2 ) that is thermally grown from the substrate 10 to a thickness that may range from about 1 nm to about 2.5 nm. However, it will be appreciated by those skilled in the art that other materials presently used in the manufacturer of semiconductor devices may be used or materials later-determined to be useful for such manufacture may also be used. Moreover, it is within the scope of the present invention that the oxide layer 12 could also be deposited, as long as it has a different defect structure compared to the second deposited layer. However, as just mentioned above, it is desirable that the oxide layer 12 be thermally grown. Depending on the particular embodiment, the low pressure under which the oxide layer 12 is grown may range from about 0.4 Torr to about 10 Torr and the temperature may range from about 350° C. to about 1000° C. In one embodiment, the oxygen flow may be at a rate that ranges from about 5 standard liters per minute (slm) to about 25 slm. However, in an advantageous embodiment, the pressure under which the oxide layer 12 is grown under a pressure of about 900 milliTorr and the temperature may range from about 600° C. to about 750° C.
Forming the oxide layer 12 under low pressure is a radical departure from the conventional stacked oxide synthesis, in which the oxide layer is grown under a pressure of one atmosphere or greater. In conventional stacked oxides, pressures of one atmosphere or greater were necessary to grow the first oxide layer because the substrate and oxide layers had an overall thickness of 10.0 nm or greater. As such, higher pressures were very desirable to rapidly grow the first and second oxide layers to minimize production cycle time without sacrificing oxide uniformity and quality. In the present invention, however, such rapid growth is no longer desirable because the overall thickness of today's semiconductors has decreased to ultrathin size, i.e., less than about 7.5 nm. Furthermore, it has been surprisingly found that growing the oxide layer 12 under low pressure, typically 1.0 nm-2.5 nm, does not adversely affect the electrical or physical properties of the semiconductor. To the contrary, because of the low pressure grow-deposit-grow scheme provided by the present invention, the physical and electrical properties, as well as the overall quality, of the semiconductors manufactured in accordance with the present invention, are believed to be equal to those manufactured under the conventional stacked oxide synthesis discussed in the incorporated '370 patent. Furthermore, ultrathin, uniform oxide layers are now possible in a single furnace cluster step as provided by the present invention.
Under conventional processes, the oxide layer grows rapidly, making it extremely difficult to achieve a uniform, high quality, ultrathin semiconductor that has an overall thickness of less than about 7.5 nm. Moreover, the conventional grow-deposit-grow process were conducted in three different furnaces; two furnaces in which the pressure was kept at atmospheric pressure or greater to grow the thicker oxides and a third in which the pressure was sub-atmospheric to deposit the dielectric. In application of this conventional grow-deposit-grow process, the semiconductor was first placed in an atmospheric furnace, then transferred to a low pressure furnace and then transferred back to an atmospheric furnace. As well imagined, this three separate furnace operation increased cycle time and reduced throughput, which increased the overall cost of the semiconductor device.
In contrast, however, the present invention provides a process that allows the oxide layer 12 to be formed in a controlled manner to thicknesses well below the 3.0 nm required by today's sub-micron (e.g., 0.25 microns) technologies, which are particularly useful in CMOS and BiCMOS technologies and their enhancement modules. While, the controlled growth is somewhat dependent on the pressures at which the oxide is formed, flow concentration and growth temperatures also play a part in the oxide growth. Furthermore, the grow-deposit-grow scheme of the present invention can be conducted in a single low pressure cluster furnace since the oxide layer 12 can be formed under the same low pressure environment under which a dielectric layer is deposited. The controlled growth of the oxide layer 12 provides a semiconductor having a ultrathin, yet high quality and very uniform thickness, which is highly desirable in ultrathin stacked oxide gate formation.
Also shown in FIG. 1 is the dielectric layer 14 formed over the oxide layer 12. This deposited oxide layer is, preferably an oxygen permeable film that is transparent to O 2 species, and more preferably is silicon oxide (SiO 2 ). In one advantageous embodiment, the dielectric layer 14 is deposited by the low pressure chemical vapor deposition decomposition of tetraethyl orthosilicate ("TEOS") or the oxidation of silane SiH 4 in the presence of oxygen or nitrous oxide (N 2 O) . The flow rate of material, which may be TEOS, may range from about 10 to about 100 cc/min, with the flow rate of the O 2 or the N 2 O ranging from about 0.5 slm to about 5 slm. These conditions combine to form a preferred deposition rate of the dielectric layer that may range from about 0.01 nm to about 10.0 nm per minute. The interface between these layers 12 and 14 is shown by the horizontal line 16. The deposition temperatures for the dielectric layer 14 may be in the same range as those stated above for the first grown oxide layer 12. An exemplary pressure under which the dielectric layer 14 is deposited is about 400 milliTorr.
For reasons that are discussed below, not all combinations of dielectric materials are useful because the deposited dielectric 14 must have different defect structures from layer 12 to form the interface 16 and also 14 must be transparent to oxidizing species to anneal out the traps during the second growing step. For example, although the well known SiO 2 --Si 3 N 4 structure has a low defect density, it also has a high density of traps that cannot be reduced by annealing. This structure is, therefore, not useful in the present invention, unless the nitride layer is completely consumed to form silicon oxynitride to make the layer semitransparent to oxidizing species. However, the thermally grown/deposited oxide structure of the present invention provides a low defect density as well as a deposited layer 14 that is transparent to oxidant ambient and therefore, traps can be removed by annealing.
Continuing to refer to FIG. 1, there is also illustrated a second grown oxide layer 18 formed between the substrate 10 and the oxide layer 12 during the third-step of synthesis. In preferred embodiments, this third oxide layer 18 is also thermally grown. The manufacturing temperature used to grow the oxide layer 12 and deposit the dielectric layer 14 is increased from about 650° C. to between about 800° C.-1000° C. These temperatures provide a densification/annealing oxidizing step, which, as the term suggests, both densifies the existing oxide and deposited oxide dielectric layer 14. In addition, the new oxide layer 18 is grown under stress-modulated conditions provided by the interface 16, resulting in a planar and stress-free substrate/oxide (18) interface that is critical to device performance and reliability. In an advantageous embodiment, this anneal is conducted at a temperature that may range from about 800° C. to about 1000° C. and a pressure that may range from about 0.4 Torr to about 10 Torr, with a preferred pressure during this phase being 900 milliTorr. More preferably, the temperature is held at about 850° C. for approximately one hour. The growing oxidizing environment is a mixture of oxygen and nitrogen or nitrous oxide and nitrogen. The oxygen or nitrous oxide may have flow rates that range from about 0.5 slm to about 25 slm. In an exemplary embodiment, this procedure produces an oxide layer with a thickness ranging from about 0.5 nm to about 0.8 nm. The thermally grown second grown oxide layer 18 forms a planar and stress-free interface between the substrate 10 and the oxide layer 18 as it is grown under controlled stress modulation provided by the stress-accommodating interface 16 layer. The planar substrate/dielectric interface has desirable interfacial and electrical properties. Furthermore, the formation of the second grown oxide layer 18 provides an Si/SiO 2 interface with minimum roughness and stress gradient, both of which are highly desirable in sub-micron technologies for device performance and reliability.
During annealing, oxide growth occurs as the oxidizing species diffuses through the existing oxide and then reacts with silicon at the Si/SiO 2 interface. It has been found that the presence of defect within the oxides enhances the transport of the oxidant by diffusion; that is, the defects provide paths for the oxidant. The newly grown SiO 2 is structurally superior than any other oxides because the growth occurs under the stress accommodating conditions provided by the interface 16, which acts as a stress cushion. The interface 16 also acts as a defect sink and as a barrier for the diffusional transport of contaminant ions from the ambient environment to the Si/SiO 2 interface. The oxidation reaction during the densification anneal third step produces a reduction in the number of interface traps together with a simultaneous reduction in the Si/SiO 2 interface stress gradient, and roughness.
In contrast, in a conventional Si 3 N 4 /SiO 2 structure Si 3 N 4 is opaque to the diffusion of the oxidant. During the oxidizing anneal, the top of the Si 3 N 4 oxidizes to form silicon oxynitride without any oxidant transport to the interface. Thus, the density of interface states remains unchanged after an oxidizing anneal. Moreover, because the Si 3 N 4 layer is relatively impervious to the diffusional transport of the oxidizing species, there is very little reduction in the interfacial roughness and number of asperities as there is no interfacial oxidation reaction during the densification anneal.
This concept of stacking can be achieved through variations of the composition of the materials that form the oxidized dielectric layers and the way in which they are formed. For example, onto the grown SiO 2 layer a polysilicon layer may be deposited and oxidized or a thin nitride layer may be completely oxidized to deposit layer 14. Other variations will be readily apparent by those skilled in the art.
As illustrated in FIG. 1, each layer has a plurality of defects, i.e, first grown and second deposited SiO 2 layers have different defect structures, which are schematically represented by the substantially vertical wavy lines. The defects are misaligned with respect to each other, that is, the defects within each layer terminate at the interface of grown oxide layer 12 and deposited dielectric layer 14. Defects for amorphous SiO 2 structures may be micropores, sudden change of local order, boundaries, etc. As understood from the incorporated '370 patent, misaligning defects across the interface reduces the defect density (D o ) For thin oxide gate dielectrics, the major contributors to D o are the growth induced defect density and the intrinsic stress within the oxide layer. Defects form at energetically favored sites such as heterogeneities formed by localized contaminants, ion damaged areas and faulting on silicon nucleation surface because of retarded oxidation. The defects grow outward as oxidation consumes silicon around the defect and eventually a network of defects exists. The defects may be viewed as pipes for diffusional mass transport as well as potential current paths, which would have substantial impact on device performance and reliability. The misalignment of these defects, which is a direct result of the low pressure grow-deposit-grow scheme, greatly reduces the D o , and thereby provides a high quality gate oxide.
With respect to density defects, it is known that stress incorporation in SiO 2 films is due to incomplete relaxation of the viscoelastic compressive stress at oxidation temperatures less than 900° C., and the thermal expansion mismatch between SiO 2 and Si. Moreover, complex device geometry and processing frequently results in locally high stress level that induce the generation and propagation of defects thereby increasing both the size and density of defects. The interface made between two different dielectrics, such as two types of oxides, e.g., the thermally grown oxide layer 12 and the layer 14 and deposited oxide described with respect to FIG. 1. The interface effectively reduces the defect density by providing a discontinuity in the defect structure. The interface is not effective in reducing the effective defect density if the defects in the two dielectrics are aligned, i.e., if they are not misaligned and there is no discontinuity. Thus, it is highly advantageous that the defects be misaligned as in the present invention.
Turning now to FIG. 2, an advantageous embodiment of the generalized thermal schedule and gas flow sequence of the formation of the oxide layers will now be described, keeping in mind that exemplary broader ranges have been previously discussed. Time is plotted horizontally and temperature is plotted vertically. Both scales are in arbitrary units. The oxidation cycle begins with the growth of the first oxide layer 12 at t 1 with the insertion of the pre-gate cleaned silicon wafers under an atmosphere of O 2 at a temperature of about 650° C. into a low pressure furnace. The O 2 is preferably flowed over the silicon substrates at a rate that ranges from about 5 slm to about 25 slm. In a more advantageous embodiment, the flow rate is 9 slm. The pressure is maintained at 900 milliTorr, and the semiconductor (Si) is left under these conditions for about 1 hour to grow an oxide layer having a thickness of about 3.0 nm. At time t 2 The dielectric layer 14 is then formed by discontinuing the flow of O 2 and commencing a flow of N 2 O at the rate of 1.75 slm and a flow of N 2 at the rate of 0.75 slm. The temperature is maintained at 650° C., but the pressure is dropped to about 400 milliTorr. TEOS is introduced into the furnace at the rate of 50 cubic centimeters per minute (cc/min.).
The semiconductor is left under these conditions for 0.5 hours to deposit a SiO 2 layer with a thickness of about 1.5 nm. At time t 3 The densification/annealing oxidizing step is then performed to densify the composite oxide (layers 12 and 14) and to oxidize the substrate 10 and grow the second grown oxide layer 18. To accomplish this step, the temperature is increased to about 850° C., the flow of N 2 is discontinued and either a flow of O 2 or N 2 O is commenced at a rate of 9 slm under a pressure of 900 milliTorr. This step is continued for about one hour to grow the second grown oxide layer 18 to a thickness of about 0.5 nm to about 0.8 nm. During this step, three events occur: (1) densification of layer 14, (2) removal of interface traps from the interface 16 between layers 12 and 14 and (3) growth of a stress-free oxide layer 18 that generates a planar Si/SiO 2 interface. Following this phase of the procedure, the semiconductor is removed from the low pressure furnace at time t 4 .
From the foregoing, it is readily apparent that the present invention provides a semiconductor and method of manufacturer therefore that includes the steps of: (1) growing a first oxide layer on the semiconductor substrate in a zone of low pressure; (2) depositing a dielectric layer on the first oxide layer in the zone of low pressure; and (3) growing a second oxide layer between the first oxide layer and the substrate in the zone of low pressure. The zone of low pressure is created to retard oxidation rates so that ultrathin stacked oxide with high quality and robustness can be achieved.
The present invention therefore introduces the broad concept of low pressure stacked (grow-deposit-grow) oxide synthesis in a single thermal schedule. Such retardation of the growth rate is necessary, given the thinness and uniformity desired in the oxide sub-layers for sub-micron technologies. The resulting ultrathin stacked SiO 2 structure has superior electrical and substructural properties over the conventional oxidation scheme of the prior art. This novel synthesis is achieved through the low pressure growing-depositing-growing of SiO 2 layers on silicon substrates by thermal oxidation, low pressure chemical vapor deposition ("LPCVD"), and densification/oxidation, respectively. The resulting stacked oxides have ultra-low defect density with excellent breakdown and interfacial characteristics.
Such low defect density in sub-micron technologies is comparable to that previously believed possible only for dual-dielectric Si 3 N 4 --SiO 2 interfaces. Moreover, it is believed that these stacked oxides of the present invention should have better robustness to severe ULSI processing, resistant to hot-carrier aging, mobility degradation, and narrow channel degradation behavior, in addition to the other superior physical and electrical properties as found in the stacked oxide semiconductors provided in the incorporated '307 patent.
Based on the stu dies conducted and disclosed in the '307 patent, the lowering in defect density, which is an aspect of the present invention, results from misaligning the micropores and other interconnecting defects within the stacked oxide layer and from annihilation of defects during densification/oxidation by the defect sink provided by the interface between the thermally grown and LPCVD-deposited SiO 2 layers. The superior Si--SiO 2 interfacial characteristics of the stacked oxide are due to the excellent substructure of the SiO 2 grown during low pressure densification/oxidation annealing in near-equilibrium conditions in the presence of a stress-accommodating interface layer.
Although the present invention has been described in detail, those skilled in the art should understand that they can make various changes, substitutions and alterations herein without departing from the spirit and scope of the invention in its broadest form.
|
This invention includes a novel synthesis of a three-step process of growing, depositing and growing SiO 2 under low pressure, e.g., 0.2-10 Torr, to generate high quality, robust and reliable gate oxides for sub 0.5 micron technologies. The first layer, 1.0-3.0 nm is thermally grown for passivation of the Si-semiconductor surface. The second deposited layer 1.0-5.0 nm forms an interface to with the first grown layer. During the third step of the synthesis densification of the deposited oxide layers occurs with a simultaneous removal of the interface traps at the interface and growth of a stress-modulated SiO 2 occurs at the Si/first grown layer interface in the presence of a stress-accommodating interface layer resulting in a planar and stress-reduced Si/SiO 2 interface. The entire synthesis is done under low-pressure (e.g., 0.2-10 Torr) for slowing down the oxidation kinetics to achieve ultrathin sublayers and may be done in a single low-pressure furnace by clustering all three steps. For light nitrogen-incorporation (<5%) for certain devices, often required due to improved resistance to boron and other dopant diffusion and hot-carrier characteristics, N 2 O or NO in the oxidant are used during each steps of the stacked oxide synthesis. Planar and stress-reduced Si/SiO 2 interface characteristics is a unique signature of stacked oxide that improves robustness of the gate oxide to ULSI processing resulting in reduced scatter in device parameters (e.g., threshold voltage transconductance), mobility degradation and resistance to hot-carrier and Fowler-Nordheim stress.
| 7
|
This application is a continuation-in-part of U.S. Ser. No. 118301, filed Nov. 16, 1987, now abandoned, which is a continuation-in-part of U.S. Ser. No. 606,940, filed May 4, 1984, now U.S. Pat. No. 4,714,601.
FIELD OF THE INVENTION
The present invention relates to a high silica polymorph, designated as ECR-30, having a novel large pore structure and containing the organic ions methyl triethyl ammonium. It also relates to a process for preparation of the zeolite. It may be employed in catalytic, absorbent or separation applications, particularly in cracking and hydrocracking catalysts. It may further comprise an intergrowth structure comprising sheets or blocks of the "Breck 6" alternating with blocks or strips of the faujasite structure (see claim 9).
BACKGROUND OF THE INVENTION
Zeolites with high silica to alumina ratios, i.e., of at least six, are desirable because of their particular catalytic selectivity and their thermal stability; the latter is a property particularly important when the zeolite is used as catalyst or in adsorption procedures wherein exposure to high temperatures would be expected.
The use of quaternary ammonium salts as templates or reaction modifiers in the preparation of synthetic crystalline aluminosilicates (zeolites), first discovered by R. M. Barrer in 1961, has led to preparation of zeolites with high silica to alumina ratios which are not found in nature. For example, U.S. Pat. No. 4,086,859 discloses preparation of a crystalline zeolite thought to have the ferrierite structure (ZSM-21) using a hydroxyethyl-trimethyl sodium aluminosilicate gel. A review provided by Barrer in Zeolites, Vol. I, p. 136 (October, 1981) shows the zeolite types which are obtained using various ammonium organic bases as cation. In addition, Breck, Zeolite Molecular Sieves, John Wiley (New York, 1974), pp. 348-378, provides a basic review of zeolites obtained using such ammonium cations in the synthesis thereof, as does a review by Lok et al. (Zeolites, 3, p. 282, (1983)).
The use of tetramethyl ammonium cations (TMA) in the synthesis of zeolites A, Y and ZSM-4 (mazzite) is known, e.g., U.S. Pat. Nos. 3,306,922; 3,642,434; 4,241,036 and 3,923,639. In all these cases, the TMA is trapped in the smaller cavities in the structures (sodalite or gmelinite cages), and must be burned out at high temperatures, often leading to lattice disruption and collapse. In most of these syntheses, the SiO 2 /Al 2 O 3 ratio of the zeolites is less than about 6.
It is also known that even minor changes in the size or charge distribution of these large organic cations can induce the formation of different zeolite structures. U.S. Pat. No. 4,046,859 teaches that replacement of one of the methyl groups of the TMA compound with a hydroxy ethyl group causes the formation of a ferrierite-like phase (ZSM-21). Many such examples are enumerated by Barrer (Zeolites, 1981). The objective of the present invention is to develop preparation methods yielding new high silica large pore materials, where the organic templates are not locked into the small cavities in the structure, but are instead present in the large "super cages" from which they can be readily removed without disruption and degradation of the host lattice.
It is a further objective of this invention to prepare materials having the basic faujasite building block (sheets of interconnected sodalite cages) linked in different ways so as to form new materials having large pores and internal free volumes. In a discussion of possible theoretical and actual structures based on interlinked trunkated cubooctahedra (sodalite cages), Moore and Smith (Mineralogical Magazine, 33, p. 1009, (1963)) showed a known zeolite built from connected sheets of linked sodalite cages in an ABCABC stacking sequence (i.e. faujasite), together with a purely theoretical structure of ABAB stacked similar sheets (this has become known as "Breck 6" by some researchers after a similar tabulation by Breck ("Zeolite Molecular Sieves", by D. W. Breck, J. Wiley and Sons, p. 58 (1973)). The latter structure comprises a hexagonal unit cell having approximate dimensions a=17.5 Å and c=28.5 Å. These two forms may also be viewed as being analogous to cubic (cp) and hexagonally (hp) packed sodalite cages.
As these materials comprise the same sheet only stacked in different ways, it is clear that the cp (faujasite) and hp ("Breck 6") forms may randomly intergrow to give a mixed structural composite. Said intergrowths are now well known in mineralogy, and in zeolite mineralogy in particular, thanks to the increasing use of high resolution lattice imaging electron microscopy (Millward et al., Proc. Roy. Soc., A 399, p. 57 (1985); Rao and Thomas, Accounts of Chem. Res., 18, p. 113 (1985)).
In the high silica form, the faujasite end member of this group has been described as ECR-4, and is made in the presence of several "unbalanced" alkyl ammonium template cations. The similar high silica hp form is the subject ECR-30, made in the presence of only one "unbalanced" template--vis, methyl triethylammonium. We have further discovered that, depending upon specific compositions of template and Si/Al ratios, intergrowths and mixtures of ECR-4 and ECR-30 may be synthesized and controlled. The differences in connectivity of sodalite cages in the prior art cp (faujasite, X, Y) and new hp (ECR-30) forms are clearly shown in FIG. 1.
In addition to the prior theoretical studies of the hp form, various other faujasite modifications have been discussed in the literature. One such material is CSZ-1 (U.S. Patent 4,309,313) made in the presence of cesium cations, and having an x-ray diffraction pattern which was originally tentatively indexed on a hexagonal unit cell. However, CSZ-1 was recently shown to comprise a lightly distorted faujasite structure containing a twin plane in very thin crystals (Treacy et al., J.C.S. Chem. Comm., p. 1211 (1986)). The twin creates enough strain in the faujasite lattice to cause a rhombohedral distortion (Treacy et al, in Proc. Electron Microscopy Workshop (Hawaii), San Francisco Press (1987)). A faujasite crystal with an individual double twin plane has also been observed (Thomas et al., J.C.S. Chem. Comm., p. 1221 (1981)). Other claimed faujasite like materials are ZSM-20 (U.S. Pat. No. 3,972,983) made with tetraethylammonium cations and ZSM-3 (U.S. Pat. No. 3,415,736) made with lithium and sodium. Although having a hexagonal like unit cell similar to CSZ-1 and ECR-30, the inventor of ZSM-3 could not establish a "c" axis dimension for a hexagonal cell (Kokotailo and Ciric, Molecular Sieves Zeolites-1, A.C.S. Adv. Chem. Ser. 101, Ed. Flanigen and Sand., p. 109 (1971)), and proposed that it may be a random stacking of faujasite (ABC) and "Breck 6" (AB) i.e., a random mixture of the cp and hp forms.
Recent re-evaluation of ZSM-20 by Derouane et al (Applied Cat., 28, p. 285, (1986)) and Ernst et al (Zeolites, 7, p. 180, (1987)) describe essentially the same material as being faujasite like, and comprising spherical aggregates of twinned chunky crystals, having a unit cell that can be indexed on a hexagonal unit cell. Our own analysis of ZSM-20 shows that it is an intergrown mixture of the cp and hp structures with significant intergrown crystals of the cp faujasite.
An analysis of the available data indicates that the structures and relationships between these various preparations of cp and hp stacking and sodalite cages linked through double six rings are as follows:
______________________________________Designation Si/Al Range Structure U.S. Pat. No.______________________________________X 1 to 1.5 cp 2882243Y 1.5 to 3 cp 3130007ECR-4 3 to 10 cp pendingCSZ-1 1.5 to 3.5 distorted cp 43093313ZSM-3 1.4 to 2.25 random mix cp + hp 3415736ZSM-20 3.5 to ∞ random mix cp + hp 3972983ECR-30 3 to 10 hp pending______________________________________
Morphologically ZSM-3 and ZSM-20 are similar, in that they form crystals about 0.6μ diameter and 0.2μ thick and having a squashed octahdron shape that is almost hexagonal in outline, very similar to a twinned "platelet faujasite" (U.S. Pat No. 4175059). ECR-30 and CSZ-1 are also similar morphologically, and form thin plates up to 1μ diameter and less than 0.05μ thick, as shown in FIG. 3 (ECR-30) and Treacy et al (CSZ-1) (JCS Chem. Comm., p 1211, (1986)).
A theoretical x-ray diffraction pattern for the hp structure based on the space group P6 3 /mmc is shown in Table 1, assuming lattice constants of a=17.3 Å and c=28.78 Å, and excluding water and cations. The three strongest lines are the first three peaks, having an intensity relationship of 100>002>101. As the 002 of the hp structure is coincident with the 110 of the cp structure, excessive intensity in this line, reflected in a relatively high 002/100 ratio, is indicative of contributions from the cp structure. An important defining characteristic of ECR-30 is therefore that this latter peak intensity ratio is minimum, and always lower than seen in mixed cp+hp structures like ZSM-3 and ZSM-20. Comparison of the intensity relationships in FIG. 2 with those for published spectra for ZSM-20 previously mentioned, clearly confirm this observation.
TABLE 1______________________________________THEORETICAL X-RAY DIFFRACTRION PATTERN FORECR-30 (hp STRUCTURE) FOR CuK.sub.a RADIATION20 D hkl I/I.sub.O +cp______________________________________5.89 14.98 100 1006.14 14.39 002 43.2 *6.65 13.29 101 30.710.22 8.65 110 14.610.98 8.079 103 22.011.80 7.491 200 4.2 *11.93 7.413 112 9.812.20 7.249 201 1.313.31 6.664 202 0.513.64 6.486 104 2.114.99 5.904 203 0.815.64 5.662 210 8.0 *15.94 5.556 211 4.516.48 5.373 105 2.716.81 5.269 212 1.017.07 5.189 204 8.818.18 4.876 213 2.218.79 4.718 302 1.519.41 4.568 106 0.919.43 4.564 205 0.919.94 4.450 214 0.920.03 4.430 303 0.220.52 4.325 220 5.021.99 4.040 206 2.222.00 4.037 215 1.122.40 3.965 107 2.323.74 3.745 400 1.823.94 3.714 401 1.024.54 3.625 402 0.324.68 3.604 207 0.624.72 3.598 314 2.125.44 3.498 108 0.825.51 3.489 403 0.225.73 3.459 306 0.225.90 3.437 320 0.826.43 3.369 315 1.426.64 3.343 322 0.326.82 3.322 118 1.927.25 3.269 410 1.827.54 3.236 323 0.928.09 3.174 307 0.428.39 3.141 316 0.228.76 3.101 324 1.728.83 3.094 413 0.229.39 3.027 218 0.229.79 2.996 500 0.229.96 2.980 501 0.230.37 2.941 209 0.330.45 2.933 502 0.330.60 2.919 308 1.430.99 2.883 330 1.331.05 2.878 0010 1.931.25 2.860 503 3.531.62 2.287 1010 0.432.01 2.794 326 0.332.19 2.788 422 0.532.34 2.766 504/228 1.7/1.0______________________________________
SUMMARY OF THE INVENTION
According to the present invention, a high silica crystalline polymorph (zeolite), designated for convenience herein as ECR-30, having the hp sodalite cage structure and a SiO 2 /Al 2 O 3 mole ratio of at least six can be readily prepared which contains organic templates of methyl triethyl within the large cages of the aluminosilicate. The chemical composition for this zeolite, expressed in terms of mole ratios of oxides, is in the range: 0.2 to 0.8 T 2 O:0.2 to 0.8 Na 2 O:Al 2 O 3 :6 to 20 SiO 2 :xH 2 O wherein T represents an unbalanced organic template of methyl triethyl ammonium, and x represents 0 or an integer from 1 to 25, depending on composition and degree of hydration. A more preferred composition for the zeolite is in the range: 0.2 to 0.6 T 2 O:0.20 to 0.8 Na 2 O:Al 2 O 3 :6 to 15 SiO 2 :xH 2 O. A most preferred composition for the zeolite is in the range: 0.2 to 0.6 T 2 O:0.4 to 0.8 Na 2 O: Al 2 O 3 :6 to 12 5:SiO 2 .
The aluminosilicate herein may be used as a sorbent or as a catalyst, e.g., as a hydrocarbon conversion catalyst for, e.g., cracking, hydrocracking, reforming, paraffin isomerization, aromatization, and alkylation. When the product is used as a catalyst, it is first calcined to remove the alkylammonium ion then it may be exchanged with cations from Groups I through VIII of the Periodic Table and ammonium replaces the excess sodium ions which may be undesirable. Cations generally may be removed by calcination at temperatures usually between 300° and 600° C. in an oxygen containing gas.
Such a calcined material is an excellent starting point for further dealumination of the said ECR-30, by a variety of chemical methods well known in the art, to further increase the Si/Al ratio of the hp form, even to the point of preparing a pure silica analogue of ECR-30.
In another embodiment of this invention, the novel aluminosilicate may be prepared by a process comprising:
(a) preparing a reaction mixture comprising an oxide of sodium, the alkyl ammonium salt, water, a source of silica, a source of alumina, and sodium aluminosilicate nucleating seeds, said reaction mixture having a composition, in terms of mole ratios of oxides, within the following ranges: ##EQU1## where T represents an alkyl ammonium cation of the type methyl triethyl, and said seeds being present in an amount to yield 0.1 to 10 mole percent of the total final alumina content in said aluminosilicate;
(b) blending the reaction mixture sufficiently to form a substantially homogeneous mixture;
(c) maintaining the reaction mixture at a temperature between about 70° C. and 160° C. under autogenous pressure for a sufficient period of time to form crystals of the aluminosilicate; and
(d) recovering the aluminosilicate crystals.
It will be understood that the compositions herein may contain some waters of hydration (the x value above) which may be at least partially removed when the zeolites are employed as sorbents or catalysts.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a comparison of connectivity in cubic packed and hexagonal packed sodalite cages.
FIG. 2 shows x-ray diffraction pattern for Ex. 2 and is typical for ECR-30.
FIG. 3 shows an electron micrograph with the unique layer sequence of ECR-30.
FIG. 4 shows x-ray diffraction pattern for Ex. 2 and is typical for ECR-30.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The aluminosilicate herein generally will have the formula, in terms of mole ratios of oxides, in the range: 0.2 to 0.8 T 2 O:0.20 to 0.8 Na 2 O:Al 2 O 3 :6 to 20 SiO 2 :xH 2 O or preferably 0.2 to 0.6 T 2 O:0.20 to 0.8 Na 2 O:Al 2 O 3 :6 to 15 SiO 2 :H 2 O, or most preferably 0.2 to 0.6 T 2 O: 0.4 to 0.8 Na 2 O: Al 2 O 3 :6 to 12 SiO 2 , where x is 0-25 and T is a triethyl methyl ammonium group.
The methyl triethyl ammonium cations are relatively large ions which are not trapped within the sodalite cages of the aluminosilicate faujasite structure, but are present in the super cages of the structure.
Minor variations in the mole ratios of the oxides within the ranges given in the chemical formulas above do not substantially alter the structure or properties of the zeolite. In addition, the number of waters of hydration x in the formula will not be the same for each preparation and will depend mainly on the degree to which the aluminosilicate is dried, and the amount of template.
In order to convert the inventive high silica ECR-30 zeolites into catalysts, the organic ions in the "super cage" of the zeolite are first exchanged, desorbed or degraded by temperature. By comparison to other zeolites having alkyl ammonium ions trapped in their smaller cages, the temperature of calcination is significantly lower. As even large decomposition organic fragments may easily diffuse through the large pores of the zeolite ECR-30, bond breakage and lattice degradation usually associated with the escape of such fragments from the smaller cages at high temperature is not observed in ECR-30.
The exchangeable cations, which may partially or fully replace the sodium ions wherever they may be found, and the organic ammonium ions in the large cages of the ECR-30 structure, may be cations of metals from any one of Groups I through VIII of the Periodic Table including rare earth metals and ammonium, depending on the end use desired. Preferably, the cations will be mono-, di- and trivalent metal cations, particularly from Groups I, II or III of the Periodic Table, such as barium, calcium, cesium, lithium, magnesium, potassium, strontium, zinc, or the like, or hydrogen, rare earth metals, or ammonium. The presence of these exchangeable cations will generally not cause a substantial alteration of the basic crystal structure of the aluminosilicate. Any ion exchange technique may be employed such as those discussed, for example, in U.S. Pat. No. 3,216,789.
The aluminosilicate herein may be prepared by a process in which a reaction mixture, generally a slurry, is formed comprises of an oxide of sodium, water, the organic ammonium salt, a source of silica, a source of alumina, and sodium zeolitic (aluminosilicate) nucleating seeds. The oxide of sodium may be, e.g., sodium hydroxide, and the organic ammonium salt may be a sulfate, nitrate, hydroxide or halide salt, and is preferably a halide such as the chloride, iodide or bromide salt because of lower cost. The silica may be derived from sources such as, e.g., silica gels, silica acid, aqueous colloidal silica sols as described, for example, in U.S. Pat. No. 2,574,902, reactive amorphous solid silicas such as fume silicas and chemically precipitated silica sols, and potassium or sodium silicate. The pure silicas such as sols and gel are preferred. The alumina may be derived from sources such as, e.g., activated alumina, gamma alumina, alumina trihydrate, sodium aluminate, alum, kaolin, metakaolin or the like. It is noted that the sodium oxide may be provided not only directly by adding, e.g., sodium hyroxide to the mixture, but also indirectly from the source of silica and/or the source of alumina if, for example, sodium silicate and sodium aluminate (prepared by dissolving NaOH and Al 2 O 3 .3H 2 O in water) are respectively employed as at least one of the silica and alumina sources. The preferred sources of alumina are the aluminates or an aluminum salt selected from the chloride, sulfate and nitrate salts.
The aluminosilicate nucleating seeds for the reaction mixture, also known as zeolitic nucleation centers, comprise of a slurry of zeolitic solids having the following components: SiO 2 , Al 2 O 3 , Na 2 O and H 2 O. Generally, the seeds will have an average particle size less than 0.05 microns. The composition of the nucleating seeds in the slurry may be in the approximate ranges, in terms of mole ratios of oxides, as follows: 4 to 30 Na 2 O:1 to 9 Al 2 O 3 :3 to 30 SiO 2 :250 to 2000 H 2 O. Such slurries of nucleating seeds may be prepared by the process disclosed in U.S. Pat. Nos. 3,808,326 and 4,178,352, the disclosures of which are incorporated by reference. In general, the preparation procedure involves mixing of silica sol or gel, sodium aluminate and water together and aging the resulting slurry at about 0° to 90° C. for about 1 to 700 hours, with lower temperatures requiring a longer period of time. The seed slurry is aged at about 15° to 40° C. for about 20 to 400 hours and the zeolite nucleation centers have compositions in the range: 10 to 16 Na 2 O:1 to 9 Al 2 O 3 :10 to 15 SiO 2 :250 to 2000 H 2 O.
The amount of nucleating seeds present in the reaction mixture is expressed in terms of the percentage of the total molar alumina content in the aluminosilicate product which is ultimately recovered on crystallization. Thus, for example, if 5 molar percent of the nucleating seeds is added to the mixture, the seeds are contributing 5% of the total molar amount of alumina in the zeolite product recovered. In general, the seeds are present in an amount to yield 0.1 to 20 mole percent of the total final alumina content of the product, and preferably 0.1 to 5 mole percent.
Slurries comprising recycled products of the process disclosed herein will also serve as nucleation seeds.
The relative amounts of ingredients in the reaction mixture will be such that the mixture has a composition, in terms of mole ratios of oxides, within the following ranges:
______________________________________Oxide Constituents Ranges of Mole Ratios______________________________________(Na,T).sub.2 O:Al.sub.2 O.sub.3 1.6 to 10SiO.sub.2 :Al.sub.2 O.sub.3 14 to 50H.sub.2 O:Al.sub.2 O.sub.3 150 to 600______________________________________
where T represents an organic ammonium group as described above. Preferably, the mole ratio of H 2 O to Al 2 O 3 in the reaction mixture ranges from 100 to 400, and the mole ratio of SiO 2 to Al 2 O 3 from 20 to 46.
The order of mixing the ingredients is not essential, and all ingredients may be added simultaneously. In one preferred method of preparation, an aqueous silica sol solution, a slurry of nucleating seeds and an organic ammonium halide solution are added to a blender, followed by slow addition, with mixing, of a sodium aluminate solution and an alum solution. Additional water is added to the resulting slurry. The reaction mixture is ordinarily prepared in a container made of glass, TEFLON, or metal or the like which should be closed to prevent water loss. Experiments are run under autogenous pressure conditions.
After the reaction mixture is formed, it may be homogenized by thorough blending so as to be substantially homogeneous in texture. This step is to ensure that the aluminosilicate product ultimately obtained is not a mixture of products and thus impure. The mixing may take place in any vessel in which complete mixing, e.g., a blender.
The homogenized mixture is then placed in a reactor, ordinarily one which can withstand elevated pressures such as a tetrafluoroethylene-lined jar or an autoclave, where it is maintained at a temperature of between about 70° C. and 160° C., preferably 90° C. and 120° C., and, for commercial purposes, preferably no greater than 160° C. The exact temperature will determine at a given sodium oxide level the length of time employed for reaction. At temperatures of about 120° C., the zeolite ECR-30 is obtained in 3-5 days. When the homogenized mixture is heated, it is maintained at autogenous pressures which will depend on the temperature employed. At the higher temperatures, pressures of up to about 3 to 5 atm or higher may be achieved. The amount of time required for heating will depend mainly on the temperature employed, so that at 95° C. the heating may be carried out, e.g., for up to 70 days or more, whereas at, e.g., 120° C. or more the time period may be, e.g., 3 to 7 days. In any event, the heating is carried out until crystals are fully formed of the aluminosilicate zeolite product, i.e., ECR-30, having a the hp designated structure, a mole ratio of SiO 2 /Al 2 O 3 of at least four and the presence of organic ammonium templates removable below about 400° C. as shown by thermogravimetric analysis.
The crystallization time may be shortened, if desired, by seeding the slurry before or after the blending step with minor amounts of zeolite ECR-30 crystals of this invention which are preferably chopped at low temperatures and a size range less than about 0.05 before adding to the reaction slurry.
When the aluminosilicate crystals have been obtained in sufficient amount, they are recovered by centrifugation or filtration from the reaction mixture and are then washed, preferably with deionized water, to separate them from the mother liquor. The washing should continue, for best purity results, until the wash water, equilibrated with the product, has a pH of between about 9 and 12. After the washing step, the zeolite crystals may be dried then calcined.
The aluminosilicate ECR-30 of this invention may be used as a sorbent or as a catalyst, e.g., in a hydrocarbon conversion process such as in paraffin isomerization, aromatization, and alkylation and reforming, and in the hydrocracking and cracking of lube stocks, fuels and crude oils. To be employed for these applications, the aluminosilicate may be at least partially dehydrated by drying at temperatures of up to about 500° C. or more until most or all of the water of hydration is removed. ECR-30 is defined by a chemical composition and x-ray diffraction spectrum. The typical x-ray diffraction pattern in Table 2 and illustrated in FIG. 2 is the most important definitive characteristic, together with high resolution electron microscopy lattice images, which clearly show the predominance ABAB stacking of sheets of interconnected sodalite cages (FIG. 3).
TABLE 2______________________________________dÅ Relative Intensity______________________________________15.00 ± 0.2 V-S14.20 ± 0.2 S13.40 ± 0.2 M-W8.70 ± 0.2 M8.03 ± 0.15 M-W7.40 ± 0.15 M5.65 ± 0.15 M-S5.20 ± 0.10 M-W4.70 ± 0.10 W4.34 ± 0.10 M3.97 ± 0.08 M-W3.75 ± 0.08 M-W3.28 ± 0.08 M-W2.89 ± 0.05 M-W2.86 ± 0.05 M-W2.83 ± 0.05 M-W2.60 ± 0.05 W2.36 ± 0.05 W______________________________________ Strong (S) Very Strong (V-S) Medium Strong (M-S) Medium (M) Medium Weak (M-W) Weak (W)
EXAMPLES
The following examples demonstrate the efficacy of the invention.
EXAMPLE 1
A seed composition of:
13.33 Na.sub.2 O:Al.sub.2 O.sub.3 :12.5 SiO.sub.2 :267H.sub.2 O
was made of dissolving 12.02 g. of aluminum oxide trihydrate in a solution of 60 g. NaOH in 100 g. H 2 O at 100° C. After complete dissolution of alumina, the solution was cooled to room temperature and added, with vigorous mixing, to a solution of 201.5 g. sodium silicate (P.Q. Corp., "N" brand) and 126.3 of H 2 O. After homogenization, the solution was allowed to age at least 16 hours in a Teflon bottle prior to use as a nucleant slurry.
EXAMPLE 2
A slurry of stoichiometry:
6(E.sub.3 MN).sub.2 O: 1.8 Na.sub.2 O:Al.sub.2 O.sub.3 :30SiO.sub.2 350H.sub.2 O
was made by mixing together 54.56 gm. colloidal silica sol (Dupont HS-40), 8.2 gms. of the seeds described in Example 1 (equivalent to 10% seeding), 50.5 gms 40% aqueous solution of the triethyl methyl ammonium hydroxide, 4.83 gms. sodium aluminate (made by dissolving 27.6 gm. NaOH in 35 gms. H 2 O, adding 3.5 gms. Al 2 O 3 ·3H 2 O, heating to boiling until the solution is clear, then cooling to room temperature and adding water to a final weight of 121.5 gms.), 3.5 gms aluminum sulfate from a solution of 50 gm alum in solution, 59.6 gm alum, then adding water to a final weight of 125 gms. The product was heated in a Teflon (Dupont) bottle at 100° C. for 27 days, at which time it was cooled, filtered, washed with distilled water and dried at 115° C. X-ray diffraction analysis gave the pattern shown in Table 3 and FIG. 2. Chemical analysis by ICPES gave a product composition of 29.1 Si, 5.58 Al, 2.07 Na to yield an ECR-30 stoichiometry of:
.56R.sub.2 O: .44Na.sub.2 O: Al.sub.2 O.sub.3 :10.02 SiO.sub.2.
TABLE 3______________________________________X-RAY DIFFRACTION PATTERN FOR ECR-30 OFEXAMPLE 22 THETA D I/I.sub.o______________________________________5.896 14.9761 100.06.214 14.2106 75.16.583 13.4156 5.110.181 8.6813 14.411.012 8.0278 4.911.905 7.4273 15.015.668 5.6512 29.517.111 5.1776 20.518.236 4.8607 2.018.742 4.7305 15.120.458 4.3374 16.222.361 3.9724 13.323.307 3.8132 4.023.718 3.7482 25.725.859 3.4425 4.726.650 3.3420 3.027.178 3.2783 15.128.752 3.1023 5.129.790 2.9965 3.330.903 2.8911 4.531.251 2.8597 16.631.522 2.8358 6.232.602 2.7442 5.534.408 2.6042 9.838.066 2.3619 4.539.370 2.2867 1.341.616 2.1683 2.144.296 2.0431 5.047.428 1.9153 1.548.086 1.8906 1.549.693 1.8331 1.2______________________________________
EXAMPLE 3
A slurry stoichiometry of:
2.4(E.sub.3 MN).sub.2 O: 0.8Na.sub.2 O: Al.sub.2 O.sub.3 :15 SiO.sub.2 :185 H.sub.2 O
was made by homogenizing a mixture of 79.3 gms. colloidal silica (Dupont HS-40), 4.64 gm. seeds (Example 1), 57.2 gms. 40% triethylmethylammonium hydroxide (E 3 MN) solution, 13 gms. sodium aluminate solution (25 gms. Al 2 O 3 ·3H 2 O+30 gm H 2 O+19.8 gm NaOH), 11.7 gms aluminum sulfate solution (20 gms. Al 2 (SO 4 ) 3 MH 2 O+28.3 gms H 2 O), then adding sufficient water to give a total weight of 160 gms. This was reacted in a Teflon bottle for 67 days to give an ECR-30 product showing a characteristic X-ray diffraction pattern, a chemical stoichiometry of:
O·41(E.sub.3 MN).sub.2 O: 0.59Na.sub.2 O: Al.sub.2 O.sub.3 :10.28 SiO.sub.2
(33.4% Si, 6.24% Al, 3.16% Na)
High resolution electron microscopy gave a characteristic product shown in FIG. 3, in which the lattice image clearly shows ABAB, stacking except for one single stack of ABC. This is clearly ECR-30 as defined as equivalent to hp stacked sodalite units.
EXAMPLE 4
A gel having the stoichiometry:
8(E.sub.3 MN).sub.2 O: 2.6 Na.sub.2 O: Al.sub.2 O.sub.3 :40 SiO.sub.2 :425 H.sub.2 O
was prepared by mixing the following components in a manner similar to that described in examples 2 and 3 6.12 gm seeds of EX. 1; 59.2 gm HS-40 colloidal silica (DuPont Co.), 1.43 gm C-31 alumina trihydrate (Alcoa Co); 1.13 gm NaOH; 54 gm 40% aqueous solution of triethyl methyl ammonium hydroxide and 3 gms H 2 O. After homogenisation in a micro-blender, the gel was placed in a capped 25 ml Teflon bottle and placed in an air oven at 100° C. After 40 days the product was cooled, filtered on a vacuum filter, washed with distilled water and dried at 100° C. Chemical analysis gave a chemical composition of 5.47% Al, 27.4% Si, 2.01% Na, representing an ECR-30 stoichiometry of 0.57 (E 3 MN) 2 O: 0.43 Na 2 O: Al 2 O 3 :9.62 SiO 2 . X-ray diffraction analysis gave the results shown in Table 4 and FIG. 4, and characteristic of ECR-30.
TABLE 4______________________________________2-THETA dÅ I/I.sub.o______________________________________5.8786 15.0212 100.006.1787 14.2924 78.836.6188 13.3429 26.2810.1595 8.6993 21.5310.8396 8.1550 2.8911.8798 7.4432 23.6915.5801 5.6827 52.9815.8802 5.5760 13.2216.7202 5.2977 14.1418.2003 4.8701 13.2118.7203 4.7360 19.9920.4603 4.3370 46.5523.3002 3.8144 25.4123.6602 3.7572 18.9027.1599 3.2804 48.0530.8995 2.8914 26.9031.2194 2.8625 14.9531.4794 2.8395 11.2631.5994 2.8290 12.69______________________________________
|
A zeolite characterized by having an x-ray diffraction pattern as shown in Table 1, a silica to alumina mole ratio of at least six, and containing triethyl methyl ammonium, wherein said organic ammonium templates are within the super cages of said aluminosilicate, said zeolite having a hexagonal unit cell.
| 8
|
BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The present invention relates to a method of and an apparatus for changing colors of an injection molding hot runner die provided with a hot runner which serves as a passage for supplying a melted resin from an injection device to a molding die.
[0003] 2. Related Art
[0004] Heretofore, in an injection machine provided with a hot runner which serves as a passage for supplying a melted resin from an injection device to a molding die, there is known, as a device for changing colors for molding products, a hot runner changing apparatus which comprises a support means for supporting a plurality of hot runners in the state of being placed side by side, a rotation means for rotating a pivotal shaft of the support means, and a fore-and-aft movement means for moving front ends of the hot runners forward and backward (for example, see Japanese patent application publication 5-64828).
[0005] Also, there is known an injection molding machine for changing colors for molding products which has two or more plasticizing devices for melting a resin supplied from outside and injecting the melted resin into a molding die. In this injection molding machine, at least one of the plasticizing devices is maintained in an operative position in which it supplies the resin from outside into the molding die while other plasticizing devices are maintained in a stand-by position in which they stand away from the operative position, such that each of the plasticizing devices is capable of switching its position from the stand-by position to the operative position or from the operative position to the stand-by position (see Japanese patent application publication 2001-277283).
[0006] However, the hot runner changing apparatus as described in Japanese patent application publication 5-64828 requires the supporting means for supporting the plurality of hot runners in the state of being placed side by side and the rotation means for rotating the pivotal shaft, or the like, so that it becomes complicated in construction and large in scale.
[0007] Also, the injection molding machine as described in Japanese patent application publication 2001-277283 requires two or more plasticizing devices thereby incurring an increase in size of equipment.
[0008] The present invention is made in view of such disadvantages as seen in the conventional art of injection molding and has its object to provide a method of and an apparatus for changing colors of an injection molding hot runner die which are simple in construction and capable of easily performing a color change for molding products without removing and replacing a hot runner.
SUMMARY OF THE INVENTION
[0009] To achieve the above described object, according to one aspect of the present invention, there is provided a method of changing colors of an injection molding hot runner die which has a passage for supplying a melted resin to a molding die, comprising the steps of moving the molding die, which is united with a hot runner block having hot runners each provided for exclusive use of each of molding colors, along with the hot runner block, and positioning the molding die in a state where one of sprues of the hot runner block is moved by the step of moving the molding die to a position opposed to an injection nozzle which injects the melted resin. The molding die united with the hot runner block is moved along with the hot runner block and positioned such that the sprue for a desired color is in an opposed position to the injection nozzle which injects the melted resin, and the color change for the molding product can be easily performed merely through such processes.
[0010] According to another aspect of the present invention, there is provided an apparatus for changing colors of an injection molding hot runner die which has a passage for supplying a melted resin to a molding die, comprising a hot runner block which is provided with hot runners for exclusive use of each of molding colors, sprues and nozzles being in communication with the hot runners, a moving means for moving the molding die, which is united with the hot runner block, along with the hot runner block, and a positioning means for positioning the molding die in a state where one of the sprues of the hot runner block is moved by the moving means to a position opposed to an injection nozzle which injects the melted resin. The molding die united with the hot runner block is moved along with the hot runner block by the moving means and positioned by the positioning means such that the sprue for a desired color is in an opposed position to the injection nozzle which injects the melted resin, and thereby the color change for the molding product can be easily performed.
[0011] According to yet another aspect of the present invention, in the color changing apparatus of an injection molding hot runner die of the second aspect, the hot runner block is an integral type hot runner block which has a plurality of hot runners. Further, the hot runner block can be compact corresponding to the molding die.
[0012] According to a further aspect of the present invention, in the color changing apparatus of an injection molding hot runner die of the second aspect, the hot runner block is a divided type hot runner block in which hot runner blocks each having one hot runner are separately formed at a predetermined interval. The separately-formed hot runner blocks each having one hot runner are in parallel at a predetermined interval, so that the hot runner block that is not in operation can be kept away from the heat, and a scorched resin will not come out of the hot runner block that is not in operation.
[0013] According to another aspect of the present invention, in the color changing apparatus of an injection molding hot runner die of any one of the second, third, and fourth aspect, the sprues formed in the hot runner block are capable of being arranged at an optional interval from each other. The sprues formed in the hot runner block are capable of being arranged at an optional interval, whereby it is possible to shorten a working time for changing the position of the molding die.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a schematic elevational view of a color changing apparatus of an injection molding hot runner die according to the present invention;
[0015] FIG. 2 is a schematic sectional plan view of the color changing apparatus of the injection molding hot runner die according to the present invention;
[0016] FIG. 3 is an elevational view of a divided type hot runner block;
[0017] FIG. 4 is an elevational view of an integral type hot runner block;
[0018] FIG. 5 is a perspective view of a molding die which is united with the divided type hot runner block; and
[0019] FIG. 6 is an explanatory view of an operation.
DETAILED DESCRIPTION OF THE INVENTION
[0020] Hereinafter, the embodiments of the present invention will be explained with reference to the accompanying drawings, wherein FIG. 1 is a schematic elevational view of a color changing apparatus of an injection molding hot runner die according to the present invention, FIG. 2 is a schematic plan view partly in section of the same apparatus, FIG. 3 is an elevational view of a divided type hot runner block, FIG. 4 is an elevational view of an integral type hot runner block, FIG. 5 is a schematic perspective view of a molding die which is united with the divided type hot runner block, and FIG. 6 is an explanatory view for explaining the operation.
[0021] As shown in FIG. 1 and FIG. 2 , the color changing apparatus of the injection molding hot runner die according to the present invention comprises a horizontally-installed hot runner block 3 of a divided type provided with two independent runners 1 , 2 , a molding die 4 united with the divided type hot runner block 3 , a moving means 5 for moving the molding die 4 along with the divided type hot runner block 3 , and a positioning means 7 for positioning the molding die 4 in a state where either of sprues 11 a and 12 a of the divided type hot runner block 3 is moved by the moving means 5 to a position opposed to an injection nozzle 6 which injects a melted resin. The injection nozzle 6 is fixedly placed in its position.
[0022] The divided type hot runner block 3 , as shown in FIG. 3 , is comprised of two separately-formed hot runner blocks 11 and 12 which are in parallel at a predetermined interval D. In the hot runner block 11 , there are provided the afore-mentioned runner 1 , the afore-mentioned sprue 11 a which is in communication with the runner 1 so as to supply the melted resin thereto, two nozzles 11 b, 11 c for injecting the melted resin into the molding die 4 , and two heaters 11 d, 11 d extending along and being placed on both sides of the runner 1 . Also, in the other hot runner block 12 , there are provided the afore-mentioned runner 2 , the afore-mentioned sprue 12 a being in communication with the runner 2 to supply the melted resin thereto, two nozzles 12 b, 12 c for injecting the melted resin into the molding die 4 , and two heaters 12 d, 12 d extending along and being placed on both sides of the runner 2 . The hot runners 1 , 2 are formed by the runners 1 , 2 and the heaters 11 d, 12 d which heat the melted resin passing through the runners 1 , 2 .
[0023] An integral type hot runner block 33 as shown in FIG. 4 can be used instead of the divided type hot runner block 3 . The integral type hot runner block 33 is comprised of two hot runners 31 , 32 , and an integrally-formed block 41 . On a side of the block 41 , there are provided the afore-mentioned runner 31 , a sprue 41 a being in communication with the runner 31 to supply the melted resin thereto, two nozzles 41 b, 41 c for injecting the melted resin into the molding die 4 , and two heaters 41 d, 41 d extending along and being placed on both sides of the runner 31 . On the other side of the block 41 , there are provided the afore-mentioned runner 32 , a sprue 42 a being in communication with the runner 32 to supply the melted resin thereto, two nozzles 42 b, 42 c for injecting the melted resin into the molding die 4 , and two heaters 42 d, 42 d extending along and being placed on both sides of the runner 32 . The hot runners 31 , 32 are formed by the runners 31 , 32 and the heaters 41 d, 42 d which heat the melted resin passing through the runners 31 , 32 .
[0024] In these embodiments, each of the hot runners is provided for exclusive use of each of molding colors. Therefore, when the two hot runners 1 , 2 are used, it is possible to choose two greatly different colors such as red and black, whereby the loss by color changing may be reduced. Further, instead of the horizontally-installed hot runner block 3 of a divided type in which the hot runner blocks 11 , 12 are placed side by side in a horizontal direction and the sprues 11 a, 12 a are arranged in a horizontal direction, it is possible to use a vertically-installed hot runner block of a divided type in which the hot runner blocks 11 , 12 are placed in a vertical direction and the sprues 11 a, 12 a are arranged in a vertical direction.
[0025] Examples of the moving means 5 include a crane (not shown in the drawings). As shown in FIG. 1 and FIG. 5 , hooks 4 a provided on the molding die 4 are connected through wires 5 b with a hook 5 a of the crane 5 , and the molding die 4 is moved in a state of being hoisted with the crane 5 . Then, either of the sprues 11 a, 12 a provided in the divided type hot runner block 3 can be moved by the moving means 5 to a position opposed to the injection nozzle 6 .
[0026] The positioning means 7 , as shown in FIG. 1 , comprises two cutout portions 14 , 15 formed on the flanged edge of the molding die 4 , a positioning block 16 provided with a projection 16 a to be engaged with the cutout portions 14 , 15 , and a molding die fixing means (not shown in the drawings) for fixing the molding die 4 in position. The positioning block 16 is fixed on a base (not shown in the drawings). When the projection 16 a enters into engagement with the cutout portion 14 , a center of axis of the sprue 11 a is in alignment with a center of axis of the injection nozzle 6 . When the projection 16 a enters into engagement with the other cutout portion 15 , a center of axis of the sprue 12 a comes to be in alignment with the center of axis of the injection nozzle 6 .
[0027] In this way, in cooperation between either of the cutout portions 14 , 15 and the positioning block 16 provided with the projection 16 a, either of the sprues 11 a, 12 a provided in the divided type hot runner block 3 can be positioned so as to be opposed to the injection nozzle 6 . Further, the molding die 4 can be fixed by the molding die fixing means in a state where either of the sprues 11 a, 12 a is opposed to the injection nozzle 6 .
[0028] The operation of the above-described color changing apparatus of the injection molding hot runner die according to the present invention and a color changing method for the injection molding hot runner die according to the present invention will now be explained as for the case of employing the divided type hot runner block 3 . For example, in order to change the molding color from red to black, the injection nozzle 6 is required first to be removed from the sprue 11 a of the hot runner block 11 which supplies a red material (melted resin) to the molding die 4 and next to be inserted into the sprue 12 a of the hot runner block 12 which supplies a black material (melted resin).
[0029] Firstly, the injection nozzle 6 is moved backward to be pulled out of the sprue 11 a of the hot runner block 11 which supplies the red material into the molding die 4 . Secondly, by connecting the hooks 4 a of the molding die 4 with the hook 5 a of the crane using the wires 5 b, the molding die 4 is hoisted in a vertical direction with the crane. Then, the cutout portion 14 formed in the flanged edge of the molding die 4 is released from the engagement with the projection 16 a formed in the positioning block 16 .
[0030] Next, as shown in FIG. 6 , after moving the molding die 4 , which is united with the divided type hot runner block 3 , in a horizontal direction by operating the crane, the molding die 4 is further moved downward in a vertical direction so as to place the sprue 12 a of the hot runner block 12 in an opposed position to the injection nozzle 6 (step of moving molding die).
[0031] Then, as shown in FIG. 1 , the cutout portion 15 formed in the flanged edge of the molding die 4 enters into engagement with the projection 16 a of the positioning block 16 .
[0032] Next, the molding die 4 is fixed by the molding die fixing means in a state where the cutout portion 15 is engaged with the projection 16 a. With this, the molding die 4 is fixed in a state where the center of axis of the sprue 12 a provided in the hot runner block 12 is in alignment with the center of axis of the injection nozzle 6 (step of positioning molding die).
[0033] Then, the injection nozzle 6 is inserted into the sprue 12 a of the hot runner block 12 which supplies the black material to the molding die 4 , whereby the color changing operation from red to black in the injection molding hot runner die is completed.
[0034] As described above, the color changing method of the molding die is easily performed and the time is shortened merely through the processes of moving the molding die 4 united with the horizontally-arranged hot runner block 3 of a divided type in a horizontal direction and in a vertical direction, and positioning the molding die 4 such that the axial center of either of the sprues 11 a, 12 a provided in the divided type hot runner block 3 is aligned with the axial center of the injection nozzle 6 .
Industrial Applicability
[0035] According to the present invention, since the color change for the molding die can be easily performed merely by moving the molding die united with the hot runner block and positioning the molding die in a state where the axial center of one of the sprues provided in the hot runner block is in alignment with the axial center of the injection nozzle, it is possible to provide effective method of and apparatus for changing colors for the molding die in which the time of the color change can be reduced.
|
A color changing apparatus of an injection molding hot runner die which is simple in construction and easily capable of changing colors for molding products without removing and replacing a hot runner. In the apparatus, a passage for supplying a melted resin to a molding die, a divided type hot runner block is provided with hot runners each for exclusive use of each of molding colors, sprues and nozzles being in communication with the hot runners. A moving device is provided for moving the molding die, which is united with the divided type hot runner block, along with the divided type hot runner block. A positioning device is adapted to place the molding die in position in a state where either of the sprues of the divided type hot runner block is moved by the moving device to a position opposed to an injection nozzle for injecting the melted resin.
| 1
|
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates in general to an automatic detection device for a frame header and a method thereof, and in particular, to a detection device and method for a DMB-TH communication protocol or PN signal mode in TDS OFDM systems.
[0003] 2. Description of the Related Art
[0004] In DMB-TH systems, a data frame typically comprises a 4-layer structure, in which a basic frame is known as a signal frame, including a frame header and a frame body. In DMB-TH systems, the frame header comprises three modes: the frame header signal PN 420 with a length of 420 symbols; the frame header signal PN 595 with a length of 595 symbols; and the frame header signal PN 945 with a length of 945 symbols. During signal transmission, the receiver determines the mode of the frame header of the signal frame, to accordingly perform different processing.
[0005] Conventionally, the method of determining the frame header mode is based on distance between two peaks generated by the cross correlation of the frame header sequence when frequencies of the transmitter and the receiver are synchronous.
[0006] However when a specific frequency offset occurs between the transmitter and the receiver, for example, frequency offset exceeding 30 KHz in the PN 420 mode, and frequency offset exceeding 15 KHz in the PN 945 mode, combining multipath effect and low signal to noise ratio (SNR), disturbance to the signal peaks for determining frame header mode renders inaccurate determinations.
[0007] As shown in FIG. 1( a ), FIG. 1 a illustrates the peak generation when the signals at the transmitter and receiver are synchronized, where the distance between two adjacent peaks 10 a and 10 b can be used to determine the header mode. Please refer to FIG. 1 b , FIG. 1 b illustrates the peak generation when a frequency difference exists between the signal frequencies at the transmitter and receiver and the peaks are unclear ( 12 b ), resulting in difficulty of frame header mode determination.
[0008] Thus, a need exists for an amplifier amplifying an input signal without introducing noise to the amplified signal.
BRIEF SUMMARY OF THE INVENTION
[0009] A detailed description is given in the following embodiments with reference to the accompanying drawings.
[0010] A determination method for determining a frame header mode of a DMB-TH system data structure, comprising generating a signal when signal frequencies at a transmitting terminal and a receiving terminal are identical, providing a predetermined process to process the signal, such that the signal forms a peak when a frequency offset occurs, and determining a type of the frame header mode according to the predetermined process.
[0011] According to another embodiment of the invention, a determination method for determining a frame header mode of a DMB-TH system data structure is disclosed, comprising generating a signal when signal frequencies at a transmitting terminal and a receiving terminal are identical, providing a plurality of processing methods, from which one processes the signal, determining whether the signal comprises a peak upon an occurrence of a frequency offset, if not, processing the signal with another processing method, until the signal comprises a peak upon an occurrence of a frequency offset, and determining frame header mode according the processing method.
[0012] According to another embodiment of the invention, a determination apparatus capable of determining a frame header mode of a DMB-TH system data structure is provided, comprising a signal generation device, an amplification device, and a determination device. The signal generation device generates a signal when signal frequencies at a transmitting terminal and a receiving terminal are identical. The amplification device provides a predetermined process to process the signal, such that the signal forms a peak when a frequency offset occurs. The determination device determines a type of the frame header mode according to the predetermined process.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
[0014] FIG. 1 a illustrates the peak generation when the signals at the transmitter and receiver are synchronized.
[0015] FIG. 1 b illustrates the peak generation when a frequency difference exists between the signal frequencies at the transmitter and receiver.
[0016] FIG. 2 is a block diagram of an exemplary signal determination device according to the invention.
[0017] FIG. 3 is a block diagram of an exemplary amplification device according to the invention.
[0018] FIGS. 4 a , 4 b , and 4 c show amplified signal diagrams of PN 420 , PN 595 , and PN 945 according to the invention.
[0019] FIG. 5 is a flowchart of an exemplary determination method for header mode according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0020] The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims.
[0021] In a DMB-TH system or a TDS OFDM system, the header of a data frame has three modes, namely: header signal PN 420 with a length of 420 symbols, comprising a preamble, a PN 255 sequence, and a postamble; header signal PN 595 with a length of 595 symbols, comprising the first 595 symbols of a pseudorandom binary sequence with a length of 1023; and header signal PN 945 with a length of 945 symbols, comprising a preamble, a PN 511 sequence, and a postamble.
[0022] FIG. 2 is a block diagram of an exemplary signal determination device according to the invention. As shown in FIG. 2 , signal determination device 2 comprises peak generation device 21 , amplification device 22 , and determination device 23 . Peak generation device 21 provides a threshold, and determines a peak if the signal generated when the signals at the transmitter and receiver are identical exceeds the threshold. Amplification device 22 amplifies the peak generated by the header signal to identify the peak under a high frequency shift situation. Determination device 23 calculates the distance between two adjacent peaks following the amplification process by amplification device 22 , to determine the mode of the header signal.
[0023] FIG. 3 is a block diagram of an exemplary amplification device according to the invention, comprising delay device 31 , logic device 32 , multiplier 33 , first accumulation device 34 , second accumulation device 35 , first computation device 36 , second computation device 37 , and divider 38 . Delay device 31 performs delay processes on frame header signal 311 . The delay processes comprise 3 types, namely: delay 255 symbols; 511 symbols; and 4375 symbols, wherein each generates a predetermined waveform when processing a particular type of header mode. When determining the mode frame header signal 311 , each delay process is performed thereon to generate an accurate amplification result for a predetermined waveform result. After the delay process, frame header signal 311 is processed to provide delayed frame header signal 312 . Logic device 32 performs phase conjugate process on delayed frame header signal 312 . Multiplier 33 multiplies phase conjugated processed delayed frame header signal 312 by frame header signal 311 . First accumulation device 34 accumulates the results of the multiplication to provide first accumulation 313 . Second accumulation device 35 accumulates delayed frame header signal 312 to provide second accumulation 314 . First computation device 36 squares first accumulation 313 to generate first squared value 315 , second computation device 37 squares second accumulation 314 to generate second squared value 316 . Divider 38 divides first squared value 315 by second squared value 316 to obtain amplification signal 317 . Amplification device 22 utilizes a processing method known as a delayed correlation method.
[0024] FIG. 4 a shows an amplified signal diagram of signal PN 420 according to the invention, FIG. 4 b shows an amplified signal diagram of signal PN 595 according to the invention, FIG. 4 c shows an amplified signal diagram of signal PN 945 according to the invention. As shown in FIG. 4 , amplification device 22 processes frame header signal 311 to provide amplification signal 317 , and amplification signal 317 can be identified even when high frequency shift occurs. Amplification device 22 utilizes three methods to perform processing of frame header signal 311 , wherein each type of frame header signal 311 corresponds to one method. When processing frame header signal 311 to generate amplification signal 317 , the mode of frame header signal 311 is determined by the method amplification device 22 uses for processing frame header signal 311 . The processed frame header signal 311 is appropriate for determination device 23 to determine the distance between two adjacent amplification signals 317 , to further confirm the type of header mode.
[0025] FIG. 5 is a flowchart of an exemplary determination method for header mode according to the invention. Upon initialization (S 51 ), the determination method performs cross correlation when the frequencies of the signals at the transmitter and receiver are identical to generate a signal (S 52 ), utilizes amplification device 22 to select a process to perform thereon (S 53 ), determines whether a peak is identified during a severe frequency shift (S 54 ), if not, utilizes another method by amplification device 22 to process the peak, until the peak is identified clearly, determines header mode according to the method amplification device 22 used for processing the peak (S 55 ), confirms the header mode by calculating the distance between two adjacent peaks, and terminates the determination method (S 57 ).
[0026] While the invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.
|
A determination method for determining a frame header mode of a DMB-TH system data structure and a determination apparatus thereof. The determination method comprises generating a signal when signal frequencies at a transmitting terminal and a receiving terminal are identical, providing a predetermined process to process the signal, such that the signal forms a peak when a frequency offset occurs, and determining a type of the frame header mode according to the predetermined process.
| 7
|
BACKGROUND
[0001] 1. Field of the Invention
[0002] The present invention generally relates to removable memories, and more particularly to a multiple adapter for flash drives and an access method for reading data from or writing data to the flash drives through the multiple adapter.
[0003] 2. Description of Related Art
[0004] Universal serial bus (USB) flash drives are very popular because of its low cost, low power consumption, and small size. A USB flash drive is a flash memory integrated with a USB connector. Referring to FIG. 9 , a USB flash drive 3 is plugged into a computer 2 to load or upload data. The computer 2 includes a controller 21 and a female connector 23 . The USB flash drive 3 includes a controller 31 , a male connector 33 , and a memory 35 . The male connector 33 and the female connector 23 are configured together to establish a connection therebetween. In operation, the controller 31 detects the USB flash drive 3 , and supplies power to the USB flash drive 3 . The controller 31 allocates an address to the USB flash drive 3 , and then the controller 31 sends store information, such as memory capacity, spare capacity, and stored data, of the memory 35 to the computer 2 .
[0005] When the memory of the USB flash drive is full the user must swap or remove the USB flash drive and replace it with a USB drive with free memory. If the memory of this replacement USB drive is also full the user must swap this replacement USB drive and replace it with another USB drive with free memory. This process is inconvenient. Also, the replacement USB flash drive and the new USB flash drive cannot be incorporated together to be used at the same time.
[0006] Therefore, improvements for a multiple adapter for flash drives and an access method are needed in the industry to address the aforementioned deficiency.
SUMMARY
[0007] A multiple adapter is used for assembling a plurality of flash drives. The multiple adapter includes a multiple expansion port, a detector, a file manager, and a controller. The multiple expansion port coupled to the flash drives. The detector is coupled to the multiple expansion port for detecting store information of the flash drives. The file manager is coupled to the multiple expansion port and the detector for receiving the store information and calculating total memory capacity and total spare capacity of the flash drives. The controller is used for controlling the detector and the file manager. A writing procedure and a reading procedure of an access method are also provided.
[0008] Other advantages and novel features of the present invention will become more apparent from the following detailed description of preferred embodiment when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a schematic diagram showing a multiple adapter in accordance with an exemplary embodiment.
[0010] FIG. 2 is a schematic, block diagram showing the multiple adapter of FIG. 1 .
[0011] FIG. 3 shows a file management table stored in the multiple adapter.
[0012] FIG. 4 shows a file information table stored in the multiple adapter.
[0013] FIG. 5 shows an updated file management table after a writing operation of the multiple adapter.
[0014] FIG. 6 shows an updated file information table after the writing operation of the multiple adapter.
[0015] FIG. 7 is a flow chart showing a writing procedure of an access method in accordance with an exemplary embodiment.
[0016] FIG. 8 is a flow chart showing a reading procedure of an access method in accordance with an exemplary embodiment.
[0017] FIG. 9 shows a conventional connection between a computer and a USB flash drive.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0018] Reference will now be made to the drawings to describe a preferred embodiment of the present multiple adapter and a preferred embodiment of the present access method.
[0019] Referring to FIG. 1 , a multiple adapter 4 in accordance with an exemplary embodiment is used for attaching a plurality of USB flash drives 70 and electrically connecting the plurality of USB flash drives 70 to a computer 2 . In operation, the computer 2 supplies power to the multiple adapter 4 and the plurality of USB flash drives 70 . The multiple adapter 4 generates a management table for identifying each of the plurality of USB flash drives 70 .
[0020] When a write operation is being performed, the computer 2 sends a write command and the to-be-written data to the multiple adapter 4 . The multiple adapter 4 receives the write command, and selects one of the plurality of USB flash drives 70 to store the to-be-written data according to the management table. When a read operation is being performed, the computer 2 sends a read command to the multiple adapter 4 . The multiple adapter 4 receives the read command, and reads stored data from a destination drive of the USB flash drives 70 according to the management table, and sends the stored data to the computer 2 .
[0021] Referring to FIG. 2 , the multiple adapter 4 includes a connector 40 , a controller 41 , a memory 42 , a comparer 43 , a detector 44 , a file manager 45 , and a multiple expansion port 47 . The controller 41 is coupled to the connector 40 , the controller 41 , the memory 42 , the comparer 43 , the detector 44 , and the file manager 45 . The comparer 43 is coupled to the connector 40 , the detector 44 , and the file manager 45 . The file manager 45 is coupled to the connector 40 , the memory 42 , the detector 44 , and the multiple expansion port 47 . The multiple expansion port 47 is coupled to the detector 44 .
[0022] In the embodiment, a USB flash drive 73 and a USB flash drive 75 are coupled to the multiple expansion port 47 for exemplary purposes. When the multiple adapter 4 is coupled to the computer 2 , the computer 2 supplies power to the multiple adapter 4 and the USB flash drives 73 , 75 . The controller 41 controls the detector 44 to detect store information of the plurality USB flash drives 73 and 75 , and to send the store information to the file manager 45 . The store information includes identifiers, memory capacities, spare capacities, logical addresses to spare capacities, file names, and logical addresses to files. The file manager 45 calculates total memory capacity, total spare capacity of the USB flash drives 73 and 75 , and generates a file management table and a file information table. The memory 42 stores the total memory capacity, the total spare capacity, the file management table, and the file information table.
[0023] Before accessing the USB flash drives 73 and 75 through the multiple adapter 4 , the computer 2 sends an access signal to the controller 41 . The controller 41 controls the file manager 45 to generate the file management table and the file information table.
[0024] Referring to FIG. 3 , the file management table records the identifiers, the spare capacities, the file names, and the logical addresses to the spare capacities. Regarding the USB flash drive 73 , its identifier is akwgi123, spare capacity is 22 M, file names are A1 and A2, and logical address is Addr5. Regarding the USB flash drive 75 , its identifier is a2c45678, spare capacity is 6 M, file names are A1 and B2, and logical address is Addr 6 .
[0025] Referring to FIG. 4 , the file information table includes file sub-names, file names, identifiers, and logical addresses to the files. As mentioned above, there are four files stored in the USB flash drives 73 and 75 . Regarding the file A1 of the USB flash drive 73 , its file sub-name is Akwgi123.A1, file name is A1, identifier is akwgi123, and logical address is Addr1. Regarding the file A2 of the USB flash drive 73 , its file sub-name is Akwgi123.A2, file name is A2, identifier is akwgi123, and logical address is Addr2. Regarding the file A1 of the USB flash drive 75 , its file sub-name is A2c45678.A1, file name is A1, identifier is a2c45678, and logical address is Addr3. Regarding the file B2 of the USB flash drive 75 , its file sub-name is A2c45678.B2, file name is B2, identifier is a2c45678, and logical address is Addr4.
[0026] In writing operation, the computer 2 sends the write command and a size of the to-be-written data to the multiple adapter 4 . The controller 41 sends a command to the comparer 43 to compare the capacity of the to-be-written data with the total spare capacity of the USB flash drives 73 and 75 stored in the memory 42 . If the capacity of the to-be-written data is larger than the total spare capacity, the comparer 43 notifies the computer 2 that the total spare capacity of the USB flash drives 73 and 75 is not enough to store the to-be-written data. If the capacity of the to-be-written data is smaller than the total spare capacity, the comparer 3 sends a write command to the controller 41 . The controller 41 controls the file manager 45 to write the to-be-written data to the USB flash drives 73 and 75 sequentially.
[0027] After completing the write operation, the controller 41 controls the detector 44 to detect the newly store information of the USB flash drives 73 and 75 , and to send the newest store information to the file manager 45 . The file manager 45 updates the file management table and the file information table.
[0028] For example, referring to FIGS. 5 and 6 , to-be-written data of a file C has been written into the USB flash drives 73 and 75 and the file management table and the file information table has been updated. In the updated file management table, the spare capacity of the USB flash drive 73 is reduced to 0 M, and the spare capacity of the USB flash drive 75 is reduced to 2 M. Moreover, the logical address of the USB flash drive 73 is changed to Addr7, and the logical address of the USB flash drive 75 is changed to Addr8. In the updated file information table, a logical address of a first part of the file C stored in the USB flash drive 73 is Addr5, and a logical address of a second part of the file C stored in the USB flash drive 75 is Addr6.
[0029] Take the aforementioned for example to explain a reading operation, the computer 2 sends the read command to the multiple adapter 4 to read the file C. The controller 41 controls the file manager 45 to read the file C from the USB flash drives 73 and 75 in turn according to the logical addresses Addr5 and Addr6.
[0030] Therefore, the multiple adapter 4 can help the computer 2 to substantially utilize the USB flash drives 73 and 75 to do the writing and reading operation.
[0031] Referring to FIG. 7 , a writing procedure of an access method in accordance with an exemplary embodiment is used for writing to-be-written data to a plurality of USB flash drives 70 . The writing procedure includes the following blocks.
[0032] Block 802 , the access signal is sent to the controller 41 .
[0033] Block 804 , the store information of the USB flash drives 70 is detected by the detector 44 .
[0034] Block 806 , the total spare capacity of the USB flash drives 70 is calculated by the file manager 45 based on the store information.
[0035] Block 808 , the file management table and the file information table are generated by the file manager 45 based on the store information.
[0036] Block 810 , the write command and the capacity of the to-be-written data are sent to the multiple adapter 4 .
[0037] Block 812 , the capacity of the to-be-written data is compared with the total spare capacity of the USB flash drives. If the capacity of the to-be-written data is larger than the total spare capacity, the procedure goes to block 822 . If the capacity of the to-be-written data is smaller than the total spare capacity, the procedure goes to block 814 .
[0038] Block 814 , the write command is received by the controller 41 .
[0039] Block 816 , the to-be-written data is written into the USB flash drives 70 in turn by the file manager 45 .
[0040] Block 818 , the newest store information is detected by the detector 44 .
[0041] Block 820 , the file management table and the file information table are updated by the file manager 45 .
[0042] Block 822 , the computer 2 is notified that the total spare capacity is not enough to store the to-be-written data.
[0043] Referring to FIG. 8 , a reading procedure of an access method in accordance with an exemplary embodiment is used for reading stored data from a plurality of USB flash drives 70 . The reading procedure includes the following blocks.
[0044] Block 902 , the access signal is sent to the controller 41 .
[0045] Block 904 , the store information of the USB flash drives 70 is detected by the detector 44 .
[0046] Block 906 , the file management table and the file information table are generated by the file manager 45 based on the store information.
[0047] Block 908 , the read command is sent to the multiple adapter 4 .
[0048] Block 910 , the stored data is read from the USB flash drives 70 in turn according to the read command.
[0049] Block 912 , the newest store information is detected by the detector 44 .
[0050] Block 914 , the file management table and the file information table are updated by the file manager 45 .
[0051] It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
|
A multiple adapter is used for assembling a plurality of flash drives. The multiple adapter includes a multiple expansion port, a detector, a file manager, and a controller. The multiple expansion port coupled to the flash drives. The detector is coupled to the multiple expansion port for detecting store information of the flash drives. The file manager is coupled to the multiple expansion port and the detector for receiving the store information and calculating total memory capacity and total spare capacity of the flash drives. The controller is used for controlling the detector and the file manager. A writing procedure and a reading procedure of an access method are also provided.
| 6
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an exhaust gas recirculation control device wherein a control is performed in which a part of exhaust gas of an internal combustion engine is recirculated back to an intake air pipe of the internal combustion engine, and its failure diagnosis device.
2. Discussion of Background
Formerly, an exhaust gas recirculation control device (hereinafter, EGR control device) which performs a control of exhaust gas recirculation, (hereinafter, EGR) as a means decreasing NO x in the exhaust gas of the internal combustion engine, is widely utilized. This EGR control device controls EGR by an exhaust pressure control system using BPT (Back Pressure Transducer) valve.
That is to say, a passage area of an EGR valve (recirculation valve) is controlled by a BPT valve so that a flow quantity of EGR becomes a predetermined value. Furthermore, in a system using a VVT (Venturi Vacuum Transducer) and a system in which the EGR control pressure is controlled by using a solenoid, similar to the system using the BPT valve, the passage area of the EGR valve is controlled.
As a means of diagnosing a failure of such EGR control device, conventionally, a device is proposed which is shown in Japanese Unexamined Patent Publication No. 256546/1985. In this device, a pressure difference between pressure values of a place adjacent to an exit of the EGR valve and an intake pipe, a clogging of the EGR valve is determined from the condition of the pressure difference.
Since the above-mentioned conventional EGR control device is composed using a VVT valve or the like, an exhaust gas recirculation quantity, that is, an EGR flow quantity can not be detected directly. As a result, when the EGR flow quantity is increased due to a deterioration of the BPT valve or the like, worsening of the drivability is caused. When the EGR flow quantity is decreased, the temperature of the engine is elevated and the NO x composition in the exhaust gas is increased. When the internal combustion engine is started up by making an ignition key switch ON, the actual EGR ratio, (first exhaust gas recirculation ratio) does not agree with a target EGR ratio (second exhaust gas recirculation ratio) for the time being by an influence of a timewise change or the like, the worsening of exhaust gas is caused for that period. Furthermore, when this device is in abnormal state, due to a deterioration of parts in the EGR control device, the abnormality of the device is difficult to be detected since the EGR flow quantity can not be detected directly.
On the other hand, in the above-mentioned conventional failure diagnose device of the EGR control device, although the clogging of the EGR valve can be detected to some degree, a failure diagnosis in case that the EGR flow quantity is increased due to a deterioration of BPT or the like, can not be performed accurately.
SUMMARY OF THE INVENTION
It is an object of the present invention to solve the above problems.
According to an aspect of the present invention, there is provided an exhaust gas recirculation control device adapted to control a recirculation of a part of exhaust gas of an internal combustion engine back to the internal combustion engine which comprises a recirculation pipe for recirculating the exhaust gas of the internal combustion engine back to an intake air pipe; a recirculation valve for controlling a flow quantity of the exhaust gas flowing in the recirculation pipe; a recirculation valve passage area controlling means for controlling a passage area of the recirculation valve; a running condition detecting means for detecting a running condition of the internal combustion engine; a pressure difference detecting means for detecting a pressure difference between pressures at two arbitrary points in the recirculation pipe from an exit of the recirculation valve to the intake air pipe or a pressure difference between pressures at two arbitrary points in the recirculation pipe from an inlet of the recirculation valve to an exhaust pipe; a first exhaust gas recirculation ratio calculating means for calculating a first exhaust gas recirculation ratio from the pressure difference and a detected value of the running condition detecting means; and a second exhaust gas recirculation ratio calculating means for calculating a second exhaust gas recirculation ratio corresponding with the detected value of the running condition detecting means; wherein a feed back control is performed in which the passage area of the recirculation valve is increased or decreased so that a difference between the first exhaust gas recirculation ratio and the second exhaust gas recirculation ratio is nullified.
According to another aspect of the present invention, there is provided the exhaust gas recirculation control device of the first invention, wherein the pressure difference is a difference between pressure values of the intake air pipe and at the exit of the recirculation valve.
According to another aspect of the present invention, there is provided the exhaust gas recirculation control device of the first invention, further comprising a memory means for memorizing the difference between the first and the second exhaust gas recirculation ratios, or a value corresponding with the difference.
According to another aspect of the present invention, there is provided the exhaust gas recirculation control device of the first invention, further comprising a failure diagnosis means for diagnosing a failure of the exhaust gas recirculation control device by detecting a disagreement between the first and the second exhaust gas recirculation ratios.
According to another aspect of the present invention, there is provided a failure diagnosis device of an exhaust gas recirculation device adapted to control a recirculation of a part of exhaust gas of an internal combustion engine back to the internal combustion engine which comprises a recirculation pipe for recirculating the exhaust gas of the internal combustion engine back to an intake air pipe; a recirculation valve for controlling a flow quantity of the exhaust gas flowing in the recirculation pipe; a recirculation valve passage area controlling means for controlling a passage area of the recirculation valve; a running condition detecting means for detecting a running condition of the internal combustion engine; a pressure detecting means for detecting a pressure at an exit of the recirculation valve; a pressure difference detecting and correcting means for detecting a pressure difference between an intake air pipe pressure detected by the running condition detecting means and the pressure at the exit of the recirculation valve, and correcting the pressure difference based on the intake air pipe pressure; a determining means for determining whether a corrected value of the pressure difference is in a predetermined range; and an alarming means for alarming when the determining means determines that the corrected value of the pressure difference is out of the predetermined range.
In the preceding invention, it is possible to correct the pressure difference, by a value of a function of a measured value of an intake air quantity for the internal combustion engine or a revolution number of the internal combustion engine, and a throttle opening degree.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing an embodiment of an exhaust gas recirculation control device according to the present invention;
FIG. 2 is a block diagram of an electronic control unit which controls the device;
FIGS. 3 and 4 are explanatory diagrams describing characteristics of the device;
FIGS. 5 and 6 are flow charts describing the operation of the device;
FIGS. 7 and 8 are graphs showing the characteristic of the device;
FIG. 9 is an explanatory diagram describing a control duty of the device;
FIGS. 10 and 11 are flow charts describing an operation of a second embodiment of the device;
FIGS. 12 through 14 are flow charts describing an operation of a third embodiment of the device;
FIG. 15 is a block diagram showing an embodiment of a failure diagnose device of an exhaust gas recirculation control device according to the present invention;
FIG. 16 is a block diagram of an electronic control unit which performs a control of the failure diagnose device;
FIG. 17 is an explanatory diagram describing a relationship between pressures of a recirculation valve and an intake air pipe in the exhaust gas recirculation control device;
FIG. 18 is a graph showing a relationship between a pressure difference between pressures at an intake air pipe and an exit of the recirculation valve and EGR ratio in the exhaust gas recirculation control device; and
FIG. 19 is a flow chart describing an operation of the failure diagnosis device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Next, explanation will be given to an exhaust gas recirculation control device of the present invention referring the drawings.
FIG. 1 is a block diagram showing an embodiment of the exhaust gas recirculation control device according to the present invention. In FIG. 1, a reference numeral designates an engine, 3, an intake air pipe, 4, an intake manifold, 5, an injector, 6, a pressure sensor, 7, a throttle valve, 8, a throttle opening degree sensor, 11, a recirculation valve, 12, a passage area control actuator (hereinafter, EGR solenoid), 13, an ignition coil, 14, an igniter, 15, an exhaust pipe, 17, a water temperature sensor, 18, a pressure difference sensor, 20, a battery, 21, an ignition key switch, 22, an electronic control unit, and 23, an alarming lamp.
In FIG. 1, the pressure sensor 6 is a semiconductor type pressure sensor which detects an intake air pressure for measuring a quantity of air sucked to the engine 1 from the intake air pipe 3 through the intake manifold 4. The injector 5 is located at the upstream side of the throttle valve 7, and performs fuel injection. The throttle opening sensor 8 is attached to the throttle valve 7 for detecting an opening degree of the throttle valve. The water temperature sensor 17 is a thermister type sensor which detects a cooling water temperature of the engine 1. The ignition coil 13 performs ignition by a signal from the igniter 14, and sends the generated ignition signal to the electronic control unit 22.
The recirculation valve 11 is a vacuum servo type valve which is located in an exhaust gas recirculation passage which connects the intake air pipe 3 with the exhaust pipe 15. The EGR solenoid 12 is connected to between a diaphragm chamber of the recirculation valve 11 and the intake air pipe 3, and controls a negative pressure of gas to the diaphragm chamber of the recirculation valve 11 by a signal from the electronic control unit 22. The passage area of the recirculation valve 11 becomes variable by the negative pressure of the diagram chamber. A bypass of the recirculation passage of the exhaust gas is provided between the intake air pipe 3 and a place adjacents to an exit of the recirculation valve 11. The pressure difference sensor 18 is provided in the bypass, which detects the pressure difference between the pressure values of the intake air pipe and a place at adjacent to the exit of the recirculation valve 11, that is, a pressure difference between two points.
Next, the electronic control unit 22 receives the respective signals of the pressure sensor 6, the throttle opening degree sensor 8, the ignition coil 13, and the water temperature sensor 17, and controls the passage area of the EGR recirculation valve 11. Accordingly, the electronic control unit 22 obtains a control quantity of the EGR solenoid 12 for controlling the EGR quantity, and controls to drive EGR solenoid 12. FIG. 2 is a detailed block diagram of the electronic control unit 22. In FIG. 2, a reference numeral 100 designates a microcomputer, which is composed of the CPU 200 which calculates a control quantity of the EGR solenoid 12 or the like following predetermined programs, the free running counter 201 for measuring a rotation period of the engine 1, the timer 202 which measures by clock a duty ratio of the drive signal applied to the EGR solenoid, the A/D converter 203 which converts an analogue input signal to a digital signal, the RAM 205 utilized as a work memory, the ROM 206 which memorizes programs, the output port 207 for outputting the drive signal, and the common bus 208 or the like. A numeral 101 designates a first input interface circuit which shapes a primary side ignition signal of the ignition coil 13, and outputs it to the microcomputer 100 as an interruption signal. When the interruption signal is generated, the CPU 200 reads the value of the counter 201, calculates the period of the engine revolution number from difference between the current read value and the preceding read value, which is memorized by the RAM 205. A numeral 102 designates a second input interface circuit, which receives respective signals of the pressure sensor 6, the throttle opening degree sensor 8, the water temperature sensor 17 and the pressure difference sensor 18 or the like, and outputs them to the A/D converter 203. A numeral 104 designates an output interface circuit, which amplifies the drive output of the output port 207, and outputs it to the EGR solenoid 12.
FIG. 3 is an explanatory diagram showing a relationship between a pressure difference between two points which is outputted from a pressure of the intake air pipe 3, and the pressure difference sensor 18. According to the explanatory diagram, the more the EGR flow quantity, the larger the output value of the pressure difference between two points, that is, the output value of the pressure difference sensor 18.
FIG. 4 is an explanatory diagram showing a relationship between the output of the pressure difference sensor 18 and the EGR ratio in different running conditions, that is, in different load states of the internal combustion engine. According to the explanatory diagram, the pressure difference between two points of the pressure difference sensor 18 and the EGR ratio becomes different between case A and case B of the load state of the internal combustion engine. In this invention, calculation of the actual EGR ratio is performed considering the load state of the internal combustion engine. As a result, a pertinent EGR flow quantity is controlled which corresponds with a running condition of the engine.
In the followings, explanation will be given to the operation of the CPU 200 of the exhaust gas recirculation control device of the present invention, referring flow charts of FIGS. 5 and 6.
FIG. 5 shows the processing of the main routine. In step 300, the operation performs other control processings. When the other control processing is finished, in step 301, the operation performs the EGR control processing which carries out the recirculation control of the exhaust gas, and the operation returns to step 300 again.
Next, explanation will be given to the EGR control processing referring to FIG. 6.
In step 350, the operation detects the engine revolution number, Ne. In step 351, the operation detects the intake air pipe pressure Pb. In step 352, the operation determines the EGR operational range. In step 353, the operation determines whether the engine is in the EGR operation range. When the engine is out of the EGR operational range, in step 354, the operation calculates the target EGR ratio T EGR (second exhaust gas recirculation ratio) from the engine revolution number Ne and the intake air pipe pressure value Pb, and in step 355, the operation calculates the basic EGR control quantity K BASE corresponding with the target EGR ratio T EGR .
Furthermore, in step 356, the operation detects the pressure difference P1 between pressures of the intake air pipe 3 and the recirculation valve 11 from a signal of the pressure difference sensor 18. Since the relationship between the pressure difference P1 and the actual EGR ratio P EGR , as shown in FIG. 4, differs depending on the running condition of the internal combustion engine, in step 357, the operation corrects the pressure difference P1 based on the load state of the internal combustion engine and calculates the actual EGR ratio P EGR (first exhaust gas recirculation ratio). That is to say, the operation detects the pressure value pb of the intake air pipe 3, and based on the detected value, calculates the actual EGR ratio P EGR by correcting the pressure difference P1. In step 358, the operation calculates the control gain ΔK EGR by a value which is obtained by subtracting the actual EGR ratio P EGR from the actual EGR ratio T EGR based on the graph shown in FIG. 7.
FIG. 7 is a graph showing a characteristic of the control gain ΔK EGR . The value which is obtained by subtracting the actual EGR ratio P EGR from the target EGR ratio T EGR is denoted in the abscissa, and the value of the control gain ΔK EGR which corresponds with the subtracted value is denoted in the ordinate, respectively.
In step 359, the operation calculates T EGR control correction value K EGR by adding the control gain ΔK EGR to the control correction value K EGR before calculation. In step 360, the operation calculates the EGR control value K by adding the basic control quantity K BASE to the EGR control correction value K EGR which is obtained in step 359. In step 361, the operation calculates the control duty D EGR from the obtained EGR control value K, based on the graph of FIG. 8 showing the relationship between the EGR control value K and control duty D. In step 362, the operation drives the EGR solenoid 12 based on the control duty D EGR . By such control, the difference between the target EGR ratio T EGR and the actual EGR ratio P EGR is nullified, and the target EGR ratio T EGR and the actual EGR ratio P EGR agree. FIG. 9 is an explanatory diagram showing the definition of the control duty D. Assuming the ON time as T ON , and a single period as T, the control duty D is shown by the following equation. ##EQU1##
Furthermore, when the engine is for instance in an idling state, and not in the EGR operational range, the operation determines as N in step 353, and the operation sets the EGR control quantity K as 0 in step 363, as no EGR flow quantity. In step 361, the operation calculates the control duty D EGR from the EGR control quantity the value of which is 0. In step 362, the operation drives the EGR solenoid 12 by the control duty T EGR .
Next, FIGS. 10 and 11 are flow charts showing a second embodiment of the EGR control device according to the present invention. First of all, explanation will be given to the flow chart in FIG. 10.
In step 400, the operation determines whether power is ON, for the first time after the provision of the battery 20. The operation determines by detecting that the output voltage of the second power circuit 106 connected to the battery 20, becomes a high voltage value from a low voltage value. When the operation determines as Y, in step 401, the operation sets the EGR control correction value K EGR as 0. After that, the operation successively performs the other control processing (step 402) and the EGR control processing (step 403). Furthermore, in step 400, when the operation determines the determination whether the power is on for the first time after the provision of the battery 20, as N, that is, when the battery 20 is already provided, and the ignition key switch 21 is ON, the operation does not set the EGR control correction value K EGR as 0, but the operation uses the EGR control correction value K EGR which is memorized in the RAM 205 beforehand, which is utilized in the processing of steps 402 and 403.
Next, explanation will be given to the flow chart of FIG. 11.
The processings in step 450 through 459 of this flow chart, are the same with those in steps 350 through 359 of the flow chart of FIG. 6. Therefore, the detailed explanation will be omitted. In steps 450 through 459, the operation calculates the EGR control correction value K EGR in the operation range of the EGR. In step 460, the operation memorizes the calculated EGR control correction value K EGR . In step 461, the operation calculates the EGR control value K by adding the basic control quantity K BASE to the EGR control correction value K EGR which is obtained in step 459. In step 462, the operation calculates the control duty T EGR from the obtained EGR control value K. In step 463, the operation drives the EGR solenoid 12 based on the control duty T EGR .
As stated above, the EGR control correction value K EGR is memorized when it is calculated. When the power is ON in this device, in case that it is not the first power ON after the provision of the battery 20, the operation uses the memorized EGR control correction value K EGR as a correction value thereof before calculation. Therefore, the EGR control just after the ignition key switch 21 is ON, is accurately performed.
Furthermore, FIGS. 12 through 14 are flow charts showing an operation of a third embodiment of the EGR control device for the present invention. First of all, explanation will be given to the flow chart of FIG. 12.
In steps 500 and 501, similar to steps 300 and 301 of the flow chart of FIG. 5, the operation performs successively the other control processing and the EGR control processing. After the EGR control processing is performed in step 501, the operation performs the failure determination processing in step 502, and returns to step 500.
Next, explanation will be given to the details of the failure determination processing of the device according to the flow chart of FIG. 13.
In step 550, the operation performs the determination whether the EGR control correction value K EGR is smaller than the predetermined value E which is below a standard value as a result of, for instance, an exhaust gas test. When the EGR control correction value K EGR is larger than the predetermined value E, in step 551, the operation performs determination whether the EGR control correction value K EGR is larger than the predetermined value F which is above a standard value as a result of, for instance, an exhaust gas test. When the EGR control correction value K EGR is smaller than the predetermined value F, in step 552, the operation determines the EGR control device as normal, and set a flag of normality, and turns off the alarming lamp 23, in step 553. Furthermore, when the EGR control correction value K EGR is smaller than the predetermined value E, and the operation determines as Y in step 550, or when the EGR control correction value K EGR is larger than the predetermined value F, and the operation determines as Y in step 551, the operation determines the EGR control device as abnormal in step 554, and sets a flag of abnormality, and turns on the alarming lamp 23, in step 555. Therefore, in this invention, this EGR control device is determined as in failure, by detecting the disagreement between the target EGR ratio T EGR on the actual EGR ratio T EGR .
Next, explanation will be given to another embodiment of the determination of failure of the EGR control device based on the flow chart of FIG. 14.
In step 600, the operation determines the absolute value of a value which is obtained by subtracting the actual EGR ratio T EGR from the target EGR ratio T EGR , as G. In step 601, the operation performs the determination whether the absolute value G is larger than the predetermined value H the value which is a permissible standard as a result of, for instance, an exhaust gas test. When this absolute value H is smaller than the predetermined value H, in step 602, the operation determines the EGR control device as normal, and sets a flag of normality, and turn off the alarming lamp 23, in step 603. When the absolute value E is larger than the predetermined value H, and the operation determines as Y in step 601, the operation determines the EGR control device as abnormal in step 604, and sets a flag of abnormality, and turns on the alarming lamp 23, in step 605.
Furthermore, in this embodiment, the operation compares the absolute value G which shows the difference between the target EGR ratio T EGR and the actual EGR ratio P EGR , and the predetermined value H, and as the result, determines the failure of the device at once. However, the operation may determine the failure of the device by recognizing that the relationship between the absolute value G and the predetermined value H continues for a certain time by introducing the clock means of the timer 202. The operation may count the number of abnormality in, for instance, the failure determination in steps 550 and 551 in FIG. 13 using the counter 201. The operation determines the failure, when the number of abnormality continuously amounts to a predetermined value.
Furthermore, in this embodiment, the operation determines the pressure difference between the pressures of the intake air pipe 3 and the recirculation valve 11 by providing the pressure difference sensor 18, as the pressure difference between two points. However, this pressure difference may be the difference between the absolute value of the pressure which is detected at adjacent to the exit of the recirculation valve 11, and the pressure value of the intake air pipe 3.
As apparent from the above explanation, the exhaust gas recirculation control device of this invention performs the control of increasing or decreasing of the passage area of the recirculation valve, so that the first exhaust gas recirculation ratio and the second exhaust gas recirculation ratio agree. Therefore, an accurate exhaust gas recirculation control can be performed which corresponds with the various running conditions. Furthermore, the difference between the first exhaust gas recirculation ratio and second exhaust gas recirculation ratio, or a value which corresponds with the difference, is memorized. Therefore, the exhaust gas recirculation control can be performed swiftly and accurately when the ignition switch is ON. Furthermore, since the failure is determined by detecting the disagreement between the first exhaust gas recirculation ratio and the second exhaust gas recirculation ratio, the failure of the device is directly and accurately detected.
Next, a failure diagnosis device of an exhaust gas recirculation control device of the present invention, will be explained referring the drawings.
FIG. 15 is a block diagram showing an embodiment of the failure diagnosis device of the exhaust gas recirculation control device according to the present invention. In FIG. 15, a reference numeral 1 designates an engine, 3, an intake air pipe, 4, an intake manifold, 5, an injector, 6, a pressure sensor which detects a pressure of the intake air pipe 3, 7, a throttle valve, 8, a throttle opening degree sensor, 11, a recirculation valve, 112, a pressure sensor provided at adjacent to an exit of the recirculation valve 11, 13, an ignition coil, 14, an igniter, 15, an exhaust pipe, 20, a battery, 21, an ignition key switch, 22, an electronic control unit, 23, an alarming lamp, and 25, a BPT valve.
In FIG. 15, the pressure sensor 6 is a semiconductor type pressure sensor which detects an intake air pressure for measuring a quantity of air which is sucked to the engine 1 from the intake air pipe 3 through the intake manifold 4. The injector 5 is located at the upstream of the throttle valve 7, and performs fuel injection. The throttle opening degree sensor 8 for detecting the opening degree of the throttle valve, is attached to the throttle valve 7. The ignition coil 13 performs the ignition by a signal from the igniter 14, and sends the generated ignition signal to the electronic control unit 22.
The recirculation valve 11 is a vacuum servo type valve which is located at the exhaust gas recirculation passage which connects the intake air pipe 3 with the exhaust pipe 15. The pressure sensor 112 is located at adjacent to the exit of the recirculation valve 11, detects a pressure of the exhaust gas recirculated from the recirculation valve 11, and sends the detected signal to the electronic control unit 22. The electronic control units 22 receives the respective signals of the pressure sensor 6, the throttle opening degree sensor 8 and the ignition coil 13, and controls the passage area of the EGR recirculation valve 11. The electronic control unit 22 receives the respective signals, obtains a control quantity of an EGR solenoid, not shown, for controlling the EGR flow quantity.
FIG. 16 is a detailed block diagram of the electronic control unit 22. In FIG. 16, a numeral 100 designates a microcomputer, which is composed of the CPU 200 which calculates the control quantity of the EGR solenoid or the like according to the predetermined programs, the free running counter 201 for measuring a rotation period of the engine 1, the timer 202 which measures by clock a duty ratio of a drive signal which is applied to the EGR solenoid, the A/D converter 203 which converts an analogue signal to a digital signal, the RAM 205 which is utilized as a work memory, the ROM 206 in which programs are memorized, the output port 207 for outputting the drive signal and the common path 208 or the like. A numeral 101 designates the first input interface circuit which shapes a primary side ignition signal of the ignition coil 13 and outputs it to the microcomputer 100, as an interruption signal. When this interruption signal is generated, the CPU 200 is a value of the counter 201, and calculates a period of an engine revolution number from the difference between the currently read value and the preceding read value, which is memorized in the RAM 205. A numeral 102 designates a second input interface circuit, which receives the respective signals of the pressure sensors 6 and 112 and the throttle opening degree sensor 8, and outputs them to the A/D converter 203. A numeral 104 designates an output interface circuit, which amplifies the drive output from the output port 207, and outputs it to an EGR solenoid, not shown, so that the alarming lamp 23 is turned on when the EGR control device is in failure.
Next, FIG. 17 is an explanatory diagram showing a relationship between a pressure value at adjacent to an exit of the recirculation valve 11, detected by the pressure sensor 112, and a pressure value of the intake air pipe 3 which is detected by the pressure sensor 6. Generally speaking, as shown in FIG. 3, the larger the EGR quantity, the larger the pressure difference between the pressure value of the intake air pipe 3 and the pressure value at adjacent to the exit of the recirculation valve 11.
FIG. 18 is a graph showing a relationship between the EGR ratio, and the pressure difference between the pressure value of the intake air pipe 3 and the pressure value at adjacent to the exit of the recirculation valve 11. Case A and case B in the diagram show load states of the internal combustion engine. When the EGR ratio is in the predetermined range of 5 to 15%, and when the engine is in the load state B, the difference portion (P2-P1) of the pressure difference corresponding with the range of the EGR ratio of 15% and 5%, is large compared with the difference portion (P2'-P1') of the pressure difference when the load state of the engine is A. Therefore, it is shown that the relationship between the EGR ratio and the pressure difference between the pressure value at the intake air pipe 3 and the pressure value at adjacent to the exit of the recirculation valve 11, differs depending on the load state of the internal combustion engine. In this invention, the pressure difference between the pressure value of the intake air pipe 3 and the pressure value at adjacent to the exit of the recirculation valve 11, is detected, and the detected value is corrected corresponding with the load state, and the device is determined as in failure when the corrected value is determined to be out of the predetermined range.
In the followings, explanation will be given to a detailed operation of the failure diagnosis device based on the flow chart of FIG. 19.
First of all, the operation performs the determination whether the engine is in the EGR applied range, in step 300. When there is the EGR flow quantity, and determination is Y, in step 301, the operation measures the pressure P out of the EGR valve, that is, at adjacent to the exit of the recirculation valve 11, through the pressure sensor 62. In step 302, the operation measures the pressure Pb of the intake air pipe 3 through the pressure sensor 6. In step 303, the operation calculates the pressure difference (P out -Pb) between the pressure value at adjacent to the exit of the recirculation valve 11 and the pressure value of the intake air pipe 3.
When the pressure difference (P out -Pb) is calculated, the load state of the engine is determined from the detected pressure value Pb of the intake air pipe 3, to make correction on the calculated pressure difference (P out -Pb) corresponding with the load state of the internal combustion engine. In step 304, the operation corrects the pressure difference (P out -Pb) corresponding with the pressure value Pb of the intake air pipe 3.
In step 305, the operation determines whether corrected pressure difference, that is, the pressure difference correction value is in a predetermined range. When the pressure difference correction value is in the predetermined range, in step 306, the operation determines the EGR control device as normal, and sets a flag of normality, and turns off the alarming lamp 23, in step 311. Furthermore, when the pressure difference correction value is out of the predetermined range, and the operation determines as N in step 305, the operation determines the EGR control device as abnormal in step 308, and sets a flag of abnormality, and turns on the alarming lamp 23 in step 309.
Furthermore, in this embodiment, the operation determines the running condition of the internal combustion engine, that is, the load state of the internal combustion engine from the pressure value Pb of the intake air pipe 3 which is already detected, and corrects the pressure difference (P out -Pb) between the pressure value at adjacent to the exit of the recirculation valve 11 and the pressure value of the intake air pipe 3 based on this load state. However, the correction may be performed based on a function value which shows a relationship between the engine revolution number and the throttle opening degree, or a measured value intake air quantity.
As apparent in the above explanation, in the first invention of the failure diagnosis device of the exhaust gas recirculation control device according to the present invention, the difference pressure between the intake air pipe pressure which is detected by the running condition detecting means, and the pressure at the exit of the recirculation valve which is detected by the pressure detecting means, is calculated, and the difference is corrected based on the intake air pipe pressure, and the alarming is outputted when the correction value is out of the predetermined range. Furthermore, in the second invention, the difference pressure is corrected based on the measured value of the intake air quantity to the internal combustion engine, or the function value of the engine revolution number and the throttle opening degree. Therefore, the invention has an effect in which a failure state of the device by the increase of the EGR flow quantity due to the deterioration of BPT in the exhaust gas recirculation control device, and by the decrease of the EGR flow quantity due to the clogging of the valve, can precisely be diagnosed corresponding with the load state of the internal combustion engine.
|
An exhaust gas recirculation control device adapted to control a recirculation of part of exhaust gas of an internal combustion engine back to the engine which comprises a recirculation pipe for recirculating the exhaust gas of the internal combustion engine back to an intake air pipe; a recirculation valve for controlling a flow quantity of the exhaust gas flowing in the recirculation pipe; a recirculation valve passage area controlling means for controlling a passage area of the recirculation valve; a running condition detecting means for detecting a running condition of the internal combustion engine; a pressure difference detecting means for detecting a pressure difference between pressures at two arbitrary points in the recirculation pipe from an exit of the recirculation valve to the intake air pipe or a pressure difference between pressures at two arbitrary points in the recirculation pipe from an inlet of the recirculation valve to an exhaust pipe; a first exhaust gas recirculation ratio calculating means for calculating a first exhaust gas recirculation ratio from the pressure difference and a detected value of the running condition detecting means; and a second exhaust gas recirculation ratio calculating means for calculating a second exhaust gas recirculation ratio corresponding with the detected value of the running condition detecting means; wherein a feed back control is performed in which the passage area of the recirculation valve is increased or decreased so that a difference between the first exhaust gas recirculation ratio and a second exhaust gas recirculation ratio is nullified.
| 5
|
This is a division of application Ser. No. 410,412, filed Aug. 23, 1982 and now U.S. Pat. No. 4,524,486.
FIELD OF THE INVENTION
This invention relates to spring frames and, more particularly, to improved pin and hinge components thereof typically utilized in the manufacture of key cases, handbags, brief cases, eyeglass cases and the like.
BACKGROUND OF THE INVENTION
Clothing and accessory fashion brought about rapid changes in the direction of reduced use of heavy components and ornaments on items such as handbags, pocketbooks, attache cases, tobacco pouches, coin purses and similar soft cloth and leather products. In order to still effectively tightly close these new items without the use of an unsightly large clasp or zipper the so-called spring frame is ordinarily used. It consists generally of four components namely two mating spring steel hinge frames and two hinge pins. These parts are finally assembled at the time of completion of the article. For instance, each frame must be slipped into its individual pocket at each side of the intended handbag opening. Thereafter the hinge pin is inserted at each hinge. U.S. Pat. No. 2,903,033 discloses typical closure devices such as the frame, hinge and pin.
Conventional means for accomplishing this final assembly can take several forms. For instance, FIG. 1 illustrates an often used means consisting of a guide pin 10 and a rivet 12. The guide pin has a lower extended aligning tapered section 13, a cylindrical upper region 14, a platform 15 and a centering pin 16. The diameter and length of the centering pin are such that it snuggly occupies the provided recess of rivet 12 shown in cross section 17. The rivet is inserted onto the guide pin 19 and both are worked down into the hinge. The tapered section 13 aides in aligning the three hinge curls. The diameter of the guide pin at region 14 and rivet shank are the same. This allows for a smooth transition of the developing inherent tension as the wider upper diameter of the guide pin advances through the hinge from the guide pin onto the rivet. The height of the rivet is such that as the bottom of the rivet emerges from the hinge the guide pin no longer is tensionably held in communication with the rivet and by gravity drops off. Subsequently the reusable guide pin must be retrieved from the assembled product. The assembly is not considered complete because the rivet pin, under the tension and rotational movement of the working hinge about the inserted rivet could be caused to ride up out of the hinge and become dislodged. To avoid this problem, in an additional step, the rivet recess 17 is flared out by the action of an aligned anvil tip and hammer. Its radial dimension is thereby increased beyond that of the internal diameter of the spring hinge. This awkward flaring process, now inside the crowded end of the assembled piece, can result in the rivet flare interfering with full rotational movement about the rivet. Furthermore, if an error was made in the assembly it becomes difficult to remove the flared rivet.
Another method of final frame assembly calls for the use of a blunt nosed pin. The nose radius is typically that of the cylindrical upper portion of the hinge pin. Since there is no tapered aligning section in this pin the tension of the hinge is generally overcome by applying jaw pressure via a foot press to the hinge components. This squeezes them together, aligns the openings of the three curls and permits reduced effort in driving the leading hemisphere blunt nosed pin "home". Unfortunately under the action of the jaws used to align the hinge curl holes, problems can develop. Initially, the proper location for the jaws to be positioned is difficult to establish since the hinge is not generally visible this time being covered with nontransparent material, such as cloth, plastic or leather. Also an oversqueeze of the hinge develops a set in the tang spring thereby reducing its effective force. Once this type hinge pin has been inserted it usually is secured in place by a second procedure wherein the assembled piece must be first opened and then a cap nut is forced over the blunt nose. The cap nut can be held in place by a score line provided around the lower end of the hinge pin. If a strap, handle, etc. is to be used to carry the final item it is imperative that the pin be securely locked in place.
If only two of the three hinge curls are "caught" by the inserted pin it could go undetected as visually the misaligned bottom curl is hidden deeper within the recess of the assembled item. Obviously the hinge under that circumstance would be inoperable and/or damaged. Since the curls of conventional spring hinges are essentially cylindrical the opportunity exists for the aforementioned misalignment to occur.
Accordingly, it is therefore an object of the present invention to provide an improved method and apparatus for assembly of spring hinges and frames which will serve to avoid restricted rotational movement.
A further object of the invention is to allow for a single step assembly of spring hinges; eliminating the prior multi-step process.
An additional important object of the invention is to provide for a new unique hinge pin which is both self-aligning and self-locking, that becomes a part of the final assembly and does not require the use of any additional fastener or process.
Yet another object of the instant invention is to provide for audio confirmation that the new pin has been properly assembled in all the intended curl elements of the spring hinge.
Another object of the invention is to enable final assembly of the end product from the outside only thereby not necessitating entry into the completed item.
It is still a further object of the invention to provide for a spring hinge pin that is secure and self-locking yet can be disassembled easily and in a totally nondestructive manner.
Another object of the invention is to provide a spring hinge and pin which allows for a flush finish in the assembled parts.
SUMMARY OF THE INVENTION
Briefly the instant invention eliminates the drawbacks of the conventional spring hinge pin construction and assembly discussed above by providing for a unique pin having three essential features. These are identified as a lower conical section, a reduced stepped midsection and a stopping element.
The conical section initially allows for alignment of the upper and middle curls of the hinge. By leverage action from the top of the pin, and with assistance as required by moderate squeezing pressure at the hinge to reduce the tension being developed, the stepped pin midsection enters the upper hinge curl. As additional manual pressure is applied at the top of the pin the step is both felt and heard to skip from the edge of the lower curl onto the off-set middle curl. In a preferred embodiment of the pin design the stepped mid-section would also likewise skip from the bottom of the middle inner curl onto the upper region of the second curl, thereby affording an additional measure of security against the pin escaping movement. Further passage of the pin through the hinge curls is afforded by a stopping element which typically would be an ornamental sphere, flat plate, ring for the subsequent attachment of a handle or the like. The only requirement that the stopping element have is that its maximum cross-sectional dimension be greater than that of the stepped midsection of the pin. The design of the step platform can be an abrupt 90°, or less or more depending upon the desired locking intensity for that pin.
In a further embodiment of the present invention, the spring hinge pin has a conical stopping element which is received by an upper hinge curl which is also conical. The terminal alignment of the pin is thereby improved and allows for the top of the pin to finish flush with the plane of the upper curl.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects and advantages of the present invention can be more fully appreciated by reference to the following detailed description and drawings, wherein:
FIG. 1 is an illustration of a separated typical flattop rivet and guide pin of prior art, with a rivet broken away.
FIG. 2 is a portion of a perspective view of an opened hinge utilizing a pin constructed in accordance with the present invention; partially broken away at the region of the juncture of the single curl and lower double curl.
FIG. 3 is a front view of the hinge pin of the present invention with a sphere as its stopping element.
FIG. 4 is a front view of the hinge pin with an upper conical stopping element to be employed in conjunction with the double curl hinge of FIG. 5.
FIG. 5 is a perspective view of a portion of a double curl hinge as made to receive the pin of FIG. 4.
FIG. 6 is a front view of a hinge pin made in accordance with the principles of the present invention and having a ring as its stopping element.
FIG. 7 is a perspective view showing a typical final assembly of a complete closed spring hinge using two pins of FIG. 3.
FIG. 8 is a front view of a recessing hinge pin of the invention utilizing a cylindrically headed pin.
FIG. 9 is a partial sectional view of the hinge, pin and tang of FIG. 2 illustrating in further detail the stepped pin midsection as well as the double and single curls positioned thereon.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, FIG. 2 best illustrates the working components of the fully assembled hinge. It can be seen that the double curl hinge element generally shown as 30 is here illustrated fastened to its spring steel extension 31 by two rivets 32. Between the upper curl 34 and lower curl 35 is the hinge tang 36. The single curl hinge element, generally show as 38 likewise is fastened to its spring steel extension 39 by rivets 32. The curl 33 itself can be seen to have cam 40 protruding outwardly therefrom. The flat top ring hinge pin 41 is of the same design as the pin of FIG. 3 except for the different stopping element atop the pin.
The hinges 30 and 38 are typically made of high carbon steel, heat treated and tempered. Since they will generally be visible they are electroplated to offer an attractive finish. After the two hinge elements are inserted into their respective receiving pockets at the mouth of the intended article the hinges are brought close together and approximately parallel to one another. FIG. 7 shows this uncovered arrangement but already pinned. In this assembly position the tang 36 rests in the area 42 which does not have the cam elevation as found at 40. The cam therefore does not substantially interfere with the alignment of the holes formed by curls 34, 33, and 35. Nevertheless the holes typically only overlap and intersect partially because of a slight inward offset at the tang. After the hinges are brought together the lower tapered end 43 of pin 41 is inserted into the upper curl 34. Continued pressure is applied and the tip enters the single curl 33. As pin 41 advances it exerts pressure against the interior wall of curl 33 which in turn deflects the tang 36 bringing the curls further into alignment. The tip 43 is made to continue until the entire self-aligning zone 44 of the pin has passed into the curls. At this position the tang 36 is tensioned against area 42 making the single curl hinge element 38 offset 45 from the double curl element 30. There is typically a desired amount of "play" in a hinge of this type. As the pin is still further advanced into the hinge the step of the pin 46 passes from the lower edge of upper curl 34 onto the upper edge of single curl 33. The instant that this occurs a clicking sound is heard and the pin is felt, if manually inserted, to absorb the tang's energy in the transition onto the stepped midsection of the pin 48. The pin is already actually locked in place, even though only being partially inserted. The step 46 finds itself located partly under the arc of curl 34, generally diametrically across from the point on curl 33 where tang 36 rides. The amplitude of the acoustical confirmation that the pin has ridden off curl 34 onto curl 33 is primarily a function of the tang tension, the clearance within curls 34 and 33, the width of the step 46 as well as the shape of the step. These latter two design variables will be discussed at greater length later in this description. The tang tension causing the offset 45 of the curls 34 and 33 causes upper curl 34 to relax slightly once the step 46 has cleared it. Curl 34 now rests on the stepped midsection of the pin 48. Any attempt to remove the pin is found to meet with considerable resistance because step 46 is intersecting a portion of the lower rim of curl 34 and is tensionably being positioned there. Continued advancement of pin 41 into the hing similarly meets with a second audio signal at the transition of step 46 from the lower edge of curl 33 onto curl 35. The step 46 now finds itself partly under the arc of curl 33, at the area of tang 36°-180° opposed to where the locking region was identified earlier. Curl 35 now exerts a leverage type force on the pin at the upper region of self-aligning zone 44 keeping it offset as at 45.
The stepped midsection 48 of pin 41 has a height measured from the underside of head 49 to step 46 being slightly greater than the height from the top of curl 34 to the bottom of curl 33. This relationship assures that both locking positions would be utilized. The pin 41, as another embodiment of the invention, could have had the stepped midsection 48 height shorter. For instance, it need be, at the least, only taller than the maximum height of upper curl 34. In this variation the pin would have had but one opportunity to be locked in place. Conversely, the stepped midsection 48 could have been taller, having a height greater than the maximum distance between curls 34 and 35. The step 46 of pin 41 would then terminally rest under the lower edge of curl 35 affording the hinge a total of three locks. The corresponding degree of security therefore can be selected from options depending upon the need. The assembly of the spring hinge frame would be as mentioned appearing in FIG. 7. As the center of the spring steel is pulled apart the tang 36 which has been resting against area 42 when in the closed position now begins to ride onto cam 40. Once the resistance is overcome and upon being opened to an approximate angle of 90° the tang rests on the level portion of 33 with a portion of the tang also resting on the side of cam 40. This position keeps the finished article in an unattended open position. To close the article the steel frame is again grasped in the center and as the hinges freely rotate about the pin the tang rides over the cam and securely brings the two parts together once again. The force associated with which these two operations are accomplished is regulated by those skilled in the art by varying the tang set, cam height and location, pin clearance, spring steel design, etc.
Referring to FIG. 9, which is a sectional view taken through the pinned hinge of FIG. 2, the final transverse relationships of the curls and pin can be appreciated. The tension created by double curl tang 36 contacting and acting against single curl 33 causes it to be lockingly held in place over step 46. A clearance between the stepped midsection 48 and curl 33 is neccessarily developed diametrically across from the tang. Likewise double curl elements 34 and 35 are tensionally held respectively against the midsection 48 and upper region of the self-aligning zone 44.
In the embodiment shown in FIG. 3 the self-aligning, self-locking pin 41 of FIG. 2 has been modified to have a sphere 50 as its stopping element instead of the flat top ring design. The pin of FIG. 3 additionally consists of the stepped midsection 51 whose diameter 52 is less than that at 53, the pin region juxtapositioned to the stepped midsection. The pin of FIG. 3 is also shown with provision for a region 55 having a cylindrical shape with diameter 53. Longitudinally beyond region 55 is included frustoconical portion 56 which tapers from a maximum diameter adjacent region 55 to a minimum diameter at the rounded free end 57 of the pin. The length of this tapered section 56 can be greater than the height of the curls, which in FIG. 2 would be the outside distance between curls 34 and 35. Likewise its shortest length need be no more than the length of the lower curl 35. The angle that the taper makes with the vertical 54 can vary from very small, about 5°, up to an effective angle of 90°. This angle governs the length of the self-aligning region of the pin. Thus, small angles result in a longer tapered pin which is easier to insert while larger angles result in a shorter tapered pin requiring correspondingly more care in the external application of force necessary to properly align the hinge curls beforehand. Even if the bottom of the pin were perfectly flat, the stepped midsection 51 would still provide a unique positive locking arrangement for the pin.
The pivot pin as described in FIG. 3, as well as other embodiments mentioned herein, can be made of any suitable rigid material, such as aluminum, plastic, steel, alloys and the like. Further, the pin elements can also be separately machined and then secured together before or during the finished article final assembly. For instance, the sphere 50 could be welded onto the stepped midsection 51 if they had been individually made. The pin could be die cast from a zinc aluminum alloy and be electroplated thereafter in order to attain an attractive luster. If made from plastic, the injection molding technique could be used with or without plating thereafter.
The diameter of sphere 50, in order to remain visible, would have a maximum diameter greater than the internal clearance of the spring hinge curl. The stepped midsection 51 diameter 52 is typically reduced from that found at diameter 53 so strength is retained in the pin and excessive play is not developed between the curls and midsection 51. An excessively reduced diameter 52, unless compensated for elsewhere, could adversely affect the workings of the spring tang and cam. The length of the stepped midsection 51 can be varied greatly, as explained in detail above, depending upon the degree of security necessary at the hinge. For example, a light weight coin purse may use a shorter stepped midsection, while a heavy handbag with a strap attached may require a stepped midsection the full length of the entire hinge in order to securely support the anticipated weight.
The cylindrical region of the pin 55 is regarded as optional to the basic elements of the invention. Its purpose is to center the pin at the lowest hinge curl, increase the bearing surface on which the curl rides and serve as the outermost surface defining the raised step 59. The pin can be constructed with the tapering frustoconical portion directly adjacent step 59. Although illustrated as having two 90° angles at the step 59, embodiments of the invention could have greater or lesser angles with their corresponding attendant change in locking power. For instance, if step 59 is inclined with its surface adjacent midsection 51 to be closer the free end 57 a recessed rim is formed next to the lowermost end of midsection 51. Conversely if step 59 surface is inclined toward stopping element end 50 a gradual step from midsection 51 onto cylindrical section 55 would result. The latter design would have less, while the former more, locking potential than that achievable with the pin of FIG. 3.
The pin of FIG. 6 is similar to that in FIG. 2 and 3 except that the stopping element is a ring 60. Also the step 61 is not perpendicular to midsection 63 but forms an acute angle therewith as described above. A portion of the lowermost arc of the ring 60 will rest within curl 34. The orientation of the ring 60 with respect to the final article opening could be controlled by notching the curl 34 or the straight band forming it. Another technique for orientation of a hole or ring that is used in the art calls for the attachment of a feature to the head of the pin which resembles an inverted "L". The long arm of the "L" is attached to the pin via the short arm of the "L". The long arm then rests within the article and is kept orientated when the two spring frames are closed.
The diameter of the stepped midsection and the conical shape of the self-aligning portion of the pin have been described with a certain amount of particularity. However, it should be understood that any cross sectional shape can be utilized without departing from the concept of the present invention. For example a square, rectangular, oval, triangular or regular polygon can be substituted for that illustrated. A fluted surface, likewise, would provide means for achieving the same functional desired result.
FIG. 8 illustrates a modification of the pin of FIG. 3 wherein the stopping element has been reduced in size to where it actually becomes completely recessed within the topmost curl of the assembled hinge. The head 98 would have a diameter 97 less than the internal clearance of the curl. Stepped midsection 99 would correspond to a length at least greater than the height of the single curl. Region 100, also having diameter 97, would be where the lower curl of the double curl hinge would come to rest. The tapered section 101 and free end 102 aid in insertion of the pin as earlier discussed.
Turning now to further embodiments of the present invention, attention is directed to FIGS. 4 and 5. In FIG. 5 is shown a modified double curl spring hinge component. In like fashion to that described for FIG. 2, the hinge 65 has been fastened to its partially shown flexible spring steel member 66 by rivets 67. The upper coil 68 can be seen to be conically shaped unlike the cylindrical shape curl 34 generally used. Closer examination of curl 68 reveals that its frustoconical upper internal diameter 69 is larger than the lower internal diameter 70. The slight aformentioned set 71 in tang 72 provides the spring action when hinge 65 cooperates with a single curl hinge component such as seen at 38 in FIG. 2. The second curl 73 is of conventional design. Curl 68 has a height 74. In order to create curl 68 it would be desirable to remove a small quantity of excess material from the lower leading edge of the band intended to ultimately become curl 68. The reason being the small circumference 70 requires less material than necessary to create the larger diameter 69 and, in fact, if not removed could interfere with proper alignment with the single curl component of the hinge as well as curl 73.
The pivot pin of FIG. 4 is designed to be used in conjunction with hinge component 65 when a flush finish is desired at the hinge. It has a frustoconical stopping element 80 with a free end diameter 81 and a truncated diameter 82. The stepped midsection 83, step 84, cylindrical portion 85, conical section 86 and tip 87 complete the pin. For use along with the hinge component of FIG. 5, the pin outside diameter 88 must be less than the lower diameter 70 of curl 65. This will allow the entire self-aligning portion of the pin to travel thru curl 68. The height of the stopping element 80 is the same as the curl height 74. Upper pin diameter 81 is slightly less than curl diameter 69 and lower pin diameter 82 is similarly less than the curl diameter 70 providing for a more centered pin that is flush across the upper curl opening.
FIG. 7 depicts the final typical assembled hinge utilizing the sphere topped pin of FIG. 3. The double curl components 90 and single curl components 91 are connected via rivets 93 and the spring steel bands 94. It is to be realized that the assembly of FIG. 7 would ordinarily be covered with material at the opening of the article in question but is exposed herein to fully explain the invention features. In order to disassemble this hinge, as might become necessary if an error were made in the final article construction or a repair were required, a simple procedure is followed. A slight squeezing pressure is applied to the sides of hinge components 90 and 91 while simultaneously providing an upward pressure to pin tip 95. The pin is surprisingly found to be removable relatively easily, generally without the use of any tools. Furthermore, the pin as well as the hinge components have not been destroyed as is the case with prior art disassembly of fastened hinges.
While the invention has been described with a certain degree of particularity, it will be understood that the description was by way of example only, that the principles of the present invention would be adaptable for spring steel hinges of any size or shape, and that numerous variations and modifications, as may become apparent to those skilled in the art, can be made without departing from the scope of the invention as hereinafter claimed.
|
A method and apparatus are disclosed for assembling spring frame hinges that utilize a pin having a tapered self-aligning section, a stepped midsection and a raised diameter stopping element. By harvesting the offsetting tension created by the hinge tang and curls the pin is easily inserted, lockingly held securely in place without the use of any additional fastening technique and yet can be non-destructively disassembled with little difficulty. In preferred embodiments of the invention audio confirmation that the pin has been properly inserted is achieved and a locking flush pin is disclosed.
| 4
|
BACKGROUND OF THE INVENTION
This invention pertains to a diving meter. More particularly, it pertains to a diving depth gauge or meter of the type which provides digital information to a viewer. The digital information can be obtained as to respective pressures of the tank pressure, as well as the surrounding ambient pressure. This can be obtained by means of analog to digital conversion from an analog reading of a pressure source. This is known in the art with regard to providing for a reading of ambient pressure in a depth situation as well as pressure of breathing gas within a diver's tank.
THE PRIOR ART
The known prior art pertaining to depth gauges or meters resides within various digital depth gauges or meters that have been used and are on the market. Such digital depth gauges or meters incorporate various means of reading the respective pressures of the breathing gas in a tank as well as ambient pressure. Such meters function to calculate in some cases the dive time remaining based upon breathing gas in the high pressure tank as well as appropriate times at certain depths or how long one should remain at such depths.
The simpler digital pressure gauges or meters merely provide tank pressure and ambient pressure which is analogized to depth in the readout. They also in some cases provide the time of the dive, as well as the times at certain depths including the time at the bottom of the dive.
When such gauges or meters are utilized, it is common to read them by picking them from a storage pocket. In some cases they merely dangle or hang from the end of a line connected to a source of high pressure gas which is connected to the gas pressure within the tank.
When handling such digital depth gauges or meters they have been relatively difficult to manipulate and turn toward one's view. This is particularly true in the restrictive aspects of diving due to the fact that diving takes place within a particularly cumbersome environment due to the equipment as well as the surroundings. Thus, it has been found that an improvement in reading digital depth gauges or meters would be a substantial improvement as to convenience and safety for a diver.
This invention is directed toward providing easily read information on a depth gauge or meter by an angular configuration which creates information on a readout that can be easily manipulated and handled by a diver. This will be borne out and seen in the respective portions of this application which follow.
SUMMARY OF THE INVENTION
In summation, this invention comprises a digital depth gauge or meter having information on a readout which can be viewed by a diver at an easily readable and accessable position.
More particularly, it encompasses a digital depth gauge or meter having a face plate. The face plate incorporates information thereon such as tank pressure, maximum depth, bottom time, dive time remaining, and other information. This is presented based upon an output by electronic means.
The information is presented on a screen to a user, which is encapsulated within a boot or cover for the electronics as well as the screen.
A portion of the boot or cover is angled at its neck within the range of 10° to 80° from the axis of the line of direction of the information that is to be read on the gauge or meter. This angled configuration is in the form of an angular encapsulation or neck for providing a handle to a user. This handle for the user is such wherein the user can manipulate and hold the pressure gauge to view the material presented thereon in an easy and facile manner.
The angular configuration is such wherein it is enhanced by having ribs to provide a gripping surface for a user.
The entire configuration enhances the overall ability to use and read information on a digital depth gauge or meter by a diver. It should be viewed as a different configuration and a substantial improvement over the prior art of digital depth gauges and meters as to configuration and presentation of information.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more clearly understood by reference to the description below taken in conjunction with the accompanying drawings wherein:
FIG. 1 shows a perspective view of the frontal portion of the depth gauge or meter wherein the information is presented;
FIG. 2 shows a plan view looking downwardly on the view shown in FIG. 1;
FIG. 3 shows the back of the depth gauge or meter which is hidden from view in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Looking more particularly at FIG. 1, it can be seen wherein a digital depth gauge or meter 10 is shown. The term digital depth gauge, meter, gauge, digital meter and diving instrument shall be used interchangeably herein as referring to an instrument for providing a diver with information. The gauge 10 has a face plate 12. The face plate 12 has a readout such as that which can be provided by liquid crystal displays, light emitting diodes, or any other type of display in order to provide for various readouts, based upon the underlying electronic instrumentation.
As can be seen, the plate 12 incorporates thereunder an alpha numeric readout as to the dive time remaining, the time on the bottom or bottom time, with a maximum depth, the then existing depth, the tank pressure, as well as analog displays thereof and other diving information.
The foregoing alpha numeric information is provided by means of pressure transducers. The pressure transducers are such wherein they pick up the pressure against a particular surface and provide an electronic analog readout. This electronic analog readout is converted to digital information through a well known and well practiced analog to digital conversion. This analog to digital conversion can be provided to a chip to make calculations or provide other related functions and outputs. Such calculations and outputs enhance the overall function of the chip so as to create a total output and readout for a diver as to information required.
The underlying electronic instrumentation usually includes a power source such as a battery and appropriate power supply in order to have the proper voltage for the electronics of the instrument. The proper voltage for the electronics of the instrument as well as the respectively required power can be provided by a rechargeable battery and a power supply which are well known in the art.
The entire instrumentation can be encapsulated so that it is subjected to an analog input from the ambient pressure, as well as an analog input from a tank having breathing gas as pressurized therein.
Looking more specifically at the plate 12 overlying the information, it can be seen wherein a bezzle or frame 14 is shown in which the plate is mounted. The plate can be a glass or plastic plate depending upon the specific impact requirements.
The frame is formed within a boot, cover, case or shroud 16. The boot 16 is such wherein it is formed of an elastomeric, plastic, or other conformation to receive the instrumentation. The boot 16, cover, case or surrounding encapsulation means is provided with ribs 18 on the back surface. The ribs 18 continue toward a neck 20 or angular extension of the boot 16. The neck 20 or angular extension continues as a ribbed configuration 22 at the neck.
Extending from the neck 22 is a tubular member 24. The tubular member receives the pressure from the breathing gas tank through its open center conduit 26. This pressure through opening 26 can be in the form of actual pressure seen in the tank. In other cases it can be an electrical output from the high pressure gas of the breathing gas tank. In the alternative, the pressure can be seen directly through the opening 26 of the tube as it is presented to a transducer within the boot 16 in adjacent relationship or within the electronic instrumentation. Whatever way it is provided it should be understood that pressure should be seen either through a direct pressure port through the opening 26 to a transducer within the boot, or an electrical output from the area near the breathing gas tank which is then transmitted through the opening 26 to the instrumentation of the pressure gauge.
Other sources of information can be provided through the opening 26 from the area near the breathing gas tank including regulator operation, information pertaining to the ambient conditions, or anything that could be read and provided on the face plate 12 of the gauge or meter 10. Suffice it to say, information received at the face of the plate 12 is important in allowing the entire function of the diver's information requirements to be viewed thereon.
The ribs shown as ribs 18 and detailed as lands 30 and grooves 32 on the neck 22 as well as lands 34 and grooves 36 allow for a gripping of one's hand around the angled or neck portion 20. This gripping creates an ease in handling of the entire depth gauge or meter in a facile manner.
Of significant importance is the presentation of the information to a diver. As can be seen, an axis 38 is shown through the midline area of the plate 12. This axis of information is generally within the same line of information detailed across the face of the plate 12. In other words, when reading the information on the plate 12, the reading from left to right or as viewed is generally within the general axis of one'view, namely axis or line 38. This axis of the plate 12 or line of information displayed on the gauge 10, is shown extending in the direction of the left hand side of the gauge as viewed in FIG. 2. The axis 38 is also shown having a normal or 90° line 40 extending therefrom. This normal or 90° line 40 extending from the axis 38 defines the relationship between the information on the plate 12 and the axis with respect to a 90° line from the axis of the information when reading the information.
The neck 20 including its extension 22 as shown has been extended at an angle of 60° from the axis 38. This angle can be seen as axis line 44 extending through the neck 20. This axial line 44 is at an angle of 60° thereby providing an included angle of 60° and a supplementary angle of 30° between line 44 and normal line 40.
Two additional lines are shown wherein one line 48 is shown 10° from the axis 38 and another line 50 is shown 10° from the vertical or normal line 40. Thus, an entire sweep of 70° is shown between the two respective lines 48 and 50. This defines the useful angles between the respective axies of the neck 20 and the extension 22 with the line of information or axis 38.
In particular, the neck 20 or angular extension can be seen as neck 20a extending from the boot 16 and neck 20b. These have been shown in dotted configuration in order to show the angle thereof away from the axis 38. These orientations of the neck, namely 20a and 20b, are not believed to be optimum. It is believed that the angular range of 40° to 70° from the axial or general information line 38 is deemed to be such wherein the view of the information is optimized.
The foregoing angular configurations and the ranges can vary depending upon a user. Certain users have differently configured hands, and grips. The angles that they customarily use insofar as handling material that is to be read and viewed, cause the ranges to vary within the foregoing ranges and still provide a degree of utilization of information in an optimum manner. However, it is believed that the ranges closest to 60° as shown in the 60° angular line between axes 38 and 44 are such wherein they substantially enhance the overall function of the gauge or meter 10.
The foregoing configuration can be presented in any angular configuration to enhance the user's ability to grip the neck 20 and enable the gauge to function in a responsive and readable manner. The ranges as set forth should be considered to be descriptive and any angular configuration up to the normal can be used with regard to axis 40 and line 38. However, as previously stated the preferred angle has been found to be within the foregoing ranges as set forth and particularly with regard to the range of 40° to 70° in the included angle between the axis of the neck 44 and the axis of the gauge 38. Thus, the following claims should be read broadly in light of the prior art with respect to this gauge and those of the prior art.
|
The disclosure in the specification sets forth a digital diving meter providing information on an axis to be readily observed in reading the information along the axial line of the display. The display is incorporated within the diving meter movement having a cover thereover. The cover comprises a cover for the digital dive meter having a handle extending therefrom at an axis form the axial line of display for ease of holding and reading the information.
| 6
|
FIELD OF THE INVENTION
The present invention relates generally to automobile wheels, and more particularly to injection molded plastic composite automobile wheels.
BACKGROUND
The automotive industry has increasingly been motivated to provide automobiles with decreased mass. A general trend toward more fuel efficient vehicles has influenced automobile manufacturers to develop more economical, light weight vehicle components. In order to produce vehicles which are lighter and less expensive there has been a strong movement in the automotive industry to develop vehicle body components which have been molded from plastic.
The present invention recognizes that the cost of an automobile can be reduced by minimizing the weight of its wheels. The cost of a lightweight automobile is relatively low because, among other things, a lightweight automobile can be propelled by a relatively small fuel-efficient power plant. Additionally, certain lightweight materials happen to be inexpensive, and easy to manufacture.
Furthermore, the present invention recognizes that still further weight and cost savings would accrue from using plastic composite as the material for the wheels. More particularly, the reduced weight of plastic wheels may make it possible to incorporate a comparatively simplified, cost effective, lighter weight suspension system because of the less unsprung wheel mass.
Although plastic compostite wheels represent substantial benefits, they also present a common drawback of having decreased structural strength. More specifically the compression strength generally is reduced from conventional steel or alloy wheel rims. In order to overcome this problem, it is necessary to provide a reinforced plastic wheel capable of increased structural strength.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a two piece structural fiber reinforced composite wheel.
It is yet another object of the present invention to provide a lightweight automobile wheel that has radial spoke sections that have substantially box shaped cross sections.
A further object of the present invention is to provide a lightweight automobile wheel that meets wheel durability and serviceability requirements under heavy structural loading.
Still another object of the present invention is to provide a lightweight automobile wheel which is simple in structure, inexpensive to manufacture and refined in appearance.
These and other objects of the present invention are obtained by providing a lightweight automobile wheel which includes an outboard unitary composite wheel rim which defines an inboard oriented engagement surface. Additionally, the wheel includes an inboard unitary composite wheel rim that defines an outboard oriented engagement surface which is formed for mating with the inboard oriented engagement surface.
In the preferred embodiment, a plurality of fasteners are engaged with the rims within the spoke sections for holding the rims together. The rims are also held together by an adhesive. The inboard composite wheel rim and the outboard composite wheel rim engage such that the adhesive provides an air tight seal between the two rims making it suitable to accept a tire. The spoke sections join at a central disc-shaped portion having apertures suitably incorporated to engage a wheel hub member. Reinforcing wall portions are incorporated in the spoke sections for structural support.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood however that the detailed description and specific examples, while indicating preferred embodiments of the invention, are intended for purposes of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
FIG. 1 is a perspective view of the outboard surface of the outboard unitary composite wheel rim constructed in accordance with the teachings of the preferred embodiment of the present invention.
FIG. 2 is a perspective view of the inboard surface of the outboard unitary composite wheel rim constructed in accordance with the teachings of the preferred embodiment of the present invention.
FIG. 3 is a perspective view of the outboard surface of the inboard unitary composite wheel rim constructed in accordance with the teachings of the preferred embodiment of the present invention.
FIG. 4 is a perspective view of the inboard surface of the inboard unitary composite wheel rim constructed in accordance with the teachings of the preferred embodiment of the present invention.
FIG. 5 is a perspective view of the inboard and outboard rim sections aligned prior to engagement.
FIG. 6 is a perspective view of the inboard and outboard rims operatively engaged.
FIG. 7 is a perspective view of a spoke section with a cutaway of the outboard unitary composite wheel rim for purposes of illustrating the interior spoke fastening members.
FIG. 8 is a cross sectional view of a spoke section taken along line 8 — 8 of FIG. 7 to illustrate a fastener interface in a spoke section.
FIG. 9 is a cross sectional view of a lug nut area taken along line 9 — 9 of FIG. 6 shown to illustrate wheel stud, rim, lugnut interface.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention provides a two piece composite wheel. With reference to the drawings, the two piece composite wheel constructed in accordance to the teachings of the present invention is illustrated and identified with reference numeral 10 . More specifically, the two piece composite wheel 10 includes an outboard composite rim 20 and an inboard composite rim 50 , as shown in FIG. 5 . The outboard composite rim 20 and inboard composite rim 50 are both molded of fiber reinforced plastic. One process for creating the fiber reinforced plastic includes injection molding or compression molding around a structural fiber material residing in the mold. The structural fiber material is preformed to encourage repeatable results and may include carbon, fiberglass, KEVLAR, nylon, mesh polymer or the like. The structural fiber material can also comprise a screen-like, woven material or a loose fiber configuration.
Referring now to FIGS. 1 and 2, a perspective view of the outboard face 25 of the outboard composite rim 20 is shown. The outboard composite rim 20 includes a plurality of radial outer spoke sections 27 . The outer spoke sections 27 connect to an outer hub portion 28 in the center of the outboard composite rim 20 . An indented reinforcement section 31 is integrated in the outer portion of the outer spoke sections 27 for structural enhancement. The inboard side of outer spoke sections 27 include outer wall extensions 29 located on each side of the outer spoke sections 27 , best shown in FIG. 2 . The outer hub portion 28 includes an aperture 33 defining the centerpoint of the outboard composite rim 20 . The outer hub portion 28 also includes a plurality of inset portions 32 with disk shaped end portions 34 defining an aperture 35 to receive a wheel stud (not shown). The disk shaped end portions 34 act as the mating surface for lug nuts (not shown). The outer spoke sections 27 extend radially outwardly from the outer hub portion 28 to circumferential wall portion 44 . Intermediate to the outer spoke sections 27 , flange sections 37 protrude inboard from the circumferential wall portion 44 .
FIG. 2 shows the inboard face 40 of the outboard composite rim 20 . The flange sections 37 include a plurality of support fins 42 offsetting the flange sections 37 at an inward angle of the circumferential wall portion 44 . The outer spoke sections 27 include inner wall sections 46 lying substantially perpendicular to the inboard face 40 of the outboard composite rim 20 . The inner surface of the outer spoke sections 27 include boss sections 39 adapted to receive fasteners 70 as shown and described herein with reference to FIG. 8 . The boss sections 39 are connected by inner wall sections 46 providing structural support. Ridge portions 48 extend between the outer wall extensions 29 of the outer spoke sections 27 .
FIG. 3 shows the outboard face 55 of the inboard composite rim 50 . The inboard composite rim 50 includes a plurality of radial inner spoke sections 57 . The inner spoke sections 57 are radially connected to an inner hub portion 58 in the center of the inboard composite rim 50 by an inwardly ramped section 59 . The inner hub portion 58 includes a plurality of outset portions 90 with disk shaped end portions 92 defining an aperture 94 to receive a wheel stud (not shown). The inner hub portion 58 includes an aperture 53 defining the centerpoint of the inboard composite rim 50 .
The inner spoke sections 57 are outwardly offset by wall extension portions 60 connecting the inner spoke sections 57 to a radial step portion 61 of the circumferential wall portion 62 . The wall extension portions 60 of the inner spoke sections 57 include a ramped step portion 65 . The face 67 of the ramped step portion 65 seats to the inboard face 40 of the circumferential wall portion 44 of the outboard composite rim 20 when the inboard composite rim 50 is mated with the outboard composite rim 20 .
The inner spoke sections 57 of the inboard composite rim 50 further include wall sections 72 that seat between the outer wall extensions 29 of the outer spoke sections 27 of the outboard composite rim 20 when the inboard composite rim 50 is mated with the outboard composite rim 20 . The inner spoke sections 57 further include reception portions 74 which receive the boss sections 39 of the outboard composite rim 20 and together accept a fastener 70 as shown in FIG. 8 for securing the outboard composite rim 20 to the inboard composite rim 50 . A wall portion 75 extends from the inboardmost reception portion 74 between the wall sections 72 . An outer flange 81 projects outward from the outer portion of the inner spoke sections 57 . Tab supports 82 extend in an outward direction from the wall extension portions 60 .
The mating surface is defined by and an adhesive is applied to the outside of wall sections 72 , up and around the wall portion 75 and around the inwardly ramped section 59 . The adhesive is further applied to the tab supports 82 , the reception portions 74 and the face 67 of the ramped step portion 65 . Bead extrusions 73 line the mating surface of the outboard face 55 of the inboard composite rim 50 to ensure the adhesive will not overflow as the inboard composite rim 50 and outboard composite rim 20 are mated. It is apparent however, that the bead extrusions 73 may be located along the mating surface of the inboard face 40 of the outboard composite rim 20 .
When the outboard composite rim 20 mates with the inboard composite rim 50 , the face 67 of the ramped step portion 65 of the inboard composite rim 50 mates to the outside of the flange sections 37 of the outboard composite rim 20 . Similarly, the tab supports 82 of the inboard composite rim 50 mate with the inner wall sections 46 of the outboard composite rim 20 . The wall sections 72 , outer flange portions 81 , wall portion 75 and reception portions 74 of the inboard composite rim 50 mate with the outer wall extensions 29 , ridge portions 48 , the inboard face 40 and the boss sections 39 of the outboard composite rim 20 respectively. Accordingly, the inner hub portion 58 of the inboard composite rim 50 mates with the outer hub portion 28 of the outboard composite rim 20 . An air tight fit results around the respective mating portions.
FIG. 4 shows the inboard face 77 of the inboard composite rim 50 . The inner spoke sections 57 of the inboard composite rim 50 include a plurality of inset portions 78 with disk shaped end portions 79 defining an aperture 80 to receive a fastener 70 as shown in FIG. 8 .
FIG. 5 illustrates the alignment of the inboard composite rim 50 and the outboard composite rim 20 prior to engagement. The spoke sections from the respective rims create box sections when joined. Specifically, the outer wall extensions 29 from the outboard composite rim 20 serve as the first parallel walls that lie substantially perpendicular to inner spoke sections 57 of the inboard composite rim 50 and outer spoke sections 27 of the outboard composite rim 20 which serve as the other parallel walls. FIG. 6 illustrates the inboard composite rim 50 engaged to the outboard composite rim 20 . The inner spoke sections 57 of the inboard composite rim 50 align with the outer spoke sections 27 of the outboard composite rim 20 and the outer wall extensions 29 of the outboard composite rim 20 to form substantially box shaped spoke sections.
FIG. 7 and 8 show the interface between inner spoke sections 57 of the inboard composite rim 50 and outer spoke sections 27 of the outboard composite rim 20 . The boss sections 39 of the outer spoke sections 27 of the outboard composite rim 20 are received into the reception portions 74 of the inner spoke sections 57 of the inboard composite rim 50 .
FIG. 9 shows a lug nut 85 engaged with a wheel stud 89 extending through an aperture 69 of the inboard composite rim 50 and an aperture 35 of the outboard composite rim 20 which connects the wheel 10 to a vehicle (not shown).
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
|
A two piece fiber reinforced composite wheel includes a molded inner rim portion defining an outboard engagement surface and a molded outer rim portion defining an inboard engagement surface. The inner and outer rim portions are conformed so as to interlock together and are adhesively bonded. The inner and outer rim portions engage forming a plurality of spoke sections having substantially box shaped cross sections. The spoke sections are further connected with fasteners.
| 1
|
FIELD OF THE INVENTION
[0001] The present invention relates to patient beds, particularly to adjustable patient beds for healthcare facilities, such as hospitals and long-term care facilities. In particular, the present invention relates to an emergency system for such beds.
BACKGROUND OF THE INVENTION
[0002] Patient beds in healthcare facilities are designed so that various parts of the bed can adopt a number of positions to provide for greater patient comfort and/or to facilitate the tasks of an attendant, for example a nurse. For example, beds may be raised or lowered to different heights. Patient support platforms may be tilted to achieve the Trendelenburg and reverse Trendelenburg positions. Patient support platforms may comprise back rests and/or knee rests that can be raised or lowered to support a patient's back and knees in a variety of positions.
[0003] Adjusting the position of the bed or parts of the bed may be accomplished by a variety of means, for example, by mechanical, hydraulic and electrical means and combinations thereof. Purely mechanical means, including linkages, gears, cranks, etc., have traditionally been used but generally require manual power for their operation. Consequently, physical limitations of the bed's operator represent significant limitations to the design of beds where position changes are accomplished solely by mechanical means. The additional use of hydraulics permits bed design where the physical limitations of the operator are less of a factor. However, the use of electrical components, for example motors, switches, electronic controllers, etc., in combination with mechanical and/or hydraulic components has greatly simplified the design and use of patient beds throughout the healthcare industry. Beds designed with electrical components permit extensive operation of the bed with minimal operator effort.
[0004] Electrically operated patient beds are generally equipped with a plurality of switches to control the various adjustments that can be made to the bed. Switches are often localized on a single control panel for easy access by an operator. Where access to the switches by the patient is undesirable, the control panel may be located in an area of the bed that is normally inaccessible to the patient in the bed, for example, on the outside face of the foot board.
[0005] Despite the flexibility offered by the use of electrical components, there remains limitations, often driven by regulatory considerations, to the use of electrical components in patient beds. Thus, in a number of instances, mechanical means are still used for some operations of the bed. This is particularly evident in the design of emergency systems for patient beds.
[0006] Design of medical electrical equipment is regulated by International Standards. In particular, two standards applicable to electrically operated patient beds are:
UL 2601-1, the Underwriters Laboratories Inc. Standard for Safety, Medical Electrical Equipment, Part 1: General Requirements for Safety (1997); and, IEC 601-2-38 International Standard, Medical Electrical Equipment—Part 2: Particular requirements for the safety of electrically operated hospital beds (1996).
[0009] According to Section 22.4 of UL 2601-1,
“Movements of EQUIPMENT or EQUIPMENT parts which may cause physical injury to the PATIENT shall be possible only by the continuous activation of the control by the OPERATOR of these EQUIPMENT parts.”
[0011] According to Section 22.4.101 of IEC 601-2-38,
“Electrically powered functional movements of the BED shall be possible only by means of MOMENTARY CONTACT SWITCHES.”
[0013] Momentary Contact Switch is defined in Section 2.1.106 of IEC 601-2-38:
“Control device which initiates and maintains operation of operating elements only as long as the control (actuator) is actuated. The manual control (actuator) returns automatically to the stop position when released. MOMENTARY CONTACT SWITCHES are also known as “hold-to-run control devices”.”
[0015] In an emergency situation, for instance when a patient has a heart attack or goes into shock, an attendant must quickly perform emergency procedures on the patient, for example CPR (cardiopulmonary resuscitation). However, a patient in a patient bed, may be in any number of positions at the onset of the emergency. For instance, the back and knee rests may be raised so that the patient is in a sitting position, for example, to watch television, to eat, etc. In such an instance, it is necessary for the back and knee rests to be lowered quickly to a flat position so that emergency procedures may be administered more effectively. It is desirable, therefore, that the bed have a system by which the back and knee rests may be lowered quickly to the flat position, while at the same time permitting the attendant to begin administering emergency procedures.
[0016] However, in light of the above-noted standards, all electrical control of moving parts on an electrically operated patient bed has heretofore been by way of momentary contact switches. Since momentary contact switches turn off the functioning of a moving part when the switch is released, electrical activation of an emergency system on a patient bed has been heretofore considered impossible within the context of the above-noted standards. Instead, emergency systems on patient beds have been designed to activate manually, even on beds otherwise electrically operated, in order to remain within the above-noted standards.
[0017] Therefore, there is a need in the art for an electrically activated emergency system on a patient bed, which meets the regulatory requirements of the standards governing electrically operated patient beds.
SUMMARY OF THE INVENTION
[0018] According to an aspect of the present invention, there is provided an emergency system for a patient bed comprising: an electrically powered linear actuator operable to drive a back rest of the patient bed from a lowered back rest position to a raised back rest position, and operable to permit the back rest to lower from the raised back rest position to the lowered back rest position without being driven by the linear actuator; and, an independent electrical activation means for activating the linear actuator to permit the back rest to lower from the raised back rest position to the lowered back rest position without being driven by the linear actuator, the electrical activation means not requiring continued operator attendance for continued lowering of the back rest.
[0019] According to another aspect of the present invention, there is provided a patient bed comprising a patient support platform having a back rest portion; an electrically powered linear actuator operable to drive the back rest from a lowered back rest position to a raised back rest position, characterized in that the linear actuator is operable to permit the back rest to lower from the raised back rest position to the lowered back rest position without being driven by the linear actuator; and, the bed further comprises an emergency back rest lowering system comprising an independent electrical activation means for activating the linear actuator to permit the back rest to lower from the raised back rest position to the lowered back rest position without being driven by the linear actuator, the electrical activation means not requiring continued operator attendance for continued lowering of the back rest.
[0020] The patient support platform generally comprises a hard support surface and may also comprise a mattress, sheets, blankets or other bedding to provide greater comfort to the patient. A patient support platform useful in the present invention has a back rest portion. The back rest may be raised from a lowered position to a raised position so that a patient is able to sit up in the bed, for example, to watch television, to eat, etc. Conversely, the back rest may be lowered from the raised position to the lowered position. For administering emergency procedures, for example CPR, the lowered position is preferably a flat position in respect of the patient support platform. The raised position may be any position between the lowered position and a maximum raised position. It is clear to one skilled in the art that the back rest may also be raised and lowered between positions intermediate between the lowered position and the maximum raised position.
[0021] The patient support platform may also have a knee rest portion and/or other portions that may be adjustable to provide different options for patient positioning on the patient support platform. Raising and lowering the knee rest and/or other portions of the support platform is similar to that described for the back rest.
[0022] The patient support platform is generally supported on the ground or floor by a support means. There are numerous suitable ways in the art for supporting a patient support platform on the ground or floor. For example, U.S. patent Publication 2003/0172459 published Sep. 18, 2003, the disclosure of which is herein incorporated by reference, describes a suitable leg arrangement for supporting a patient support platform.
[0023] In electrically operated patient beds, various parts of the bed may be adjusted to achieve various positions. Positional adjustment may be accomplished by a variety of means known in the art. Electrically powered linear actuators are particularly preferred in patient beds of the present invention. Linear actuators may adjust the height of the bed, for example as disclosed in U.S. patent Publication 2003/0172459. Linear actuators may also be used to adjust the position of the back rest, knee rest and other portions of the patient support platform. A single linear actuator may be used to adjust a number of features, however, it is preferred to use a linear actuator for each feature to be adjusted. Thus, the back rest and knee rest are each preferably adjusted by its own linear actuator.
[0024] A linear actuator useful in the present invention is operable to drive the back rest from a lowered back rest position to a raised back rest position, and operable to permit the back rest to lower from the raised back rest position to the lowered back rest position without being driven by the linear actuator. Thus, the linear actuator drives the back rest when it is being raised but does not actually drive the back rest when it is being lowered. The back rest lowers only under an applied external force, such as gravity, the weight of the patient, etc. As a consequence, lowering of the back rest is not an electrically powered functional movement of the bed that may cause injury, and is therefore not subject to the standards described above. This aspect of the linear actuator surprisingly may be utilized in an electrically activated emergency system that meets the standards described above. A particularly preferred electrically powered linear actuator is a Linak™-LA31 having a spline feature.
[0025] Control of electrically powered linear actuators is accomplished by electrical activation means. The term “electrical activation means” in this context encompasses any component that may be used in a control circuit that functions using electricity, for example, switches, timers, microprocessors, voltage regulators, logic gates, and any other electrical or electronic components. Such components may be embodied in software of a controller. Electrical power to operate all electrical functions of the bed may be supplied by the main power of a building and/or by an internal power supply (e.g. a battery).
[0026] While the emergency system of the present invention and other control systems of the bed may share various common elements, activation of the emergency system is independent of activation of the other control systems. Other control systems include the systems that control the raising and lowering of the back rest and knee rest under normal conditions. Thus, the electrical activation means for the emergency system may comprise its own switch, whereby triggering the switch activates the linear actuator to permit the back rest to lower from the raised back rest position to the lowered back rest position. Preferably, a single, dedicated user operated switch activates all elements of the emergency system. For example, triggering one switch may cause both the back rest and a knee rest to lower. The switch may be any suitable type, for example, push button switches, leaf switches, etc. The switch may be located anywhere on or off the bed. For example, the switch may be conveniently located on a control panel or a control pendant containing other control switches for the bed. The switch may be hard wired in the emergency system's control circuit or signals from the switch may be sent to the control circuit wirelessly.
[0027] It is an important aspect of the emergency system of the present invention that the electrical activation means does not require continued operator attendance for continued functioning. As stated above, the standard for electrically powered beds requires that electrically powered functional movements of the bed be possible only by means of momentary contact switches that stop the movement when the switch is released. Therefore, it is surprising to one skilled in the art that an electrically activated emergency system, such as the emergency system provided by the present invention, can work without momentary contact switches that stop the linear actuators when the switch is released.
[0028] Preferably, the electrical activation means comprises a timer for continuing to provide a signal so that the linear actuator is powered for at least a maximum time required for the back rest to achieve the lowered back rest position. The timer frees an operator to immediately begin administering emergency procedures to the patient (e.g. CPR) rather than attending to the activation means until the back rest reaches the lowered back rest position. The maximum length of time depends on the type of bed and the type of linear actuator. For example, for a bed of the type described in U.S. patent Publication 2003/0172459 and a Linak™-LA31 having a spline feature, the maximum time required to lower the back rest to the lowered back rest position is about 8 seconds. In this case, the timer should be set for at least 8 seconds, and may be set for longer. A setting of from about 8-20 seconds is preferred, particularly about 15 seconds.
[0029] Limit switches may also be used to cut power to electrically activated components of the emergency system and/or other electrically operated parts of the bed. In such instances, movement of a moving part beyond a pre-selected point would trip a limit switch to cut electrical power to the moving part. Limit switches are generally used as an added safety measure, to reduce power consumption, etc.
[0030] Further features of the invention will be described or will become apparent in the course of the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] In order that the invention may be more clearly understood, embodiments thereof will now be described in detail by way of example, with reference to the accompanying drawings, in which:
[0032] FIG. 1 is an electrical schematic of an emergency system of the present invention;
[0033] FIG. 2 is a schematic drawing of a linear actuator useful in an emergency system of the present invention;
[0034] FIG. 3 is a schematic drawing of a disengaging spline of the linear actuator of FIG. 2 ;
[0035] FIG. 4 a is a perspective view of an electrically operated patient bed comprising the emergency system of FIG. 1 ;
[0036] FIG. 4 b is a schematic perspective view of the patient support platform of the bed depicted in FIG. 4 a;
[0037] FIG. 4 c is a schematic side view of a support platform of the bed depicted in FIG. 4 a in which back and knee rests are in a raised position; and,
[0038] FIG. 4 d is a perspective view of the bed depicted in FIG. 4 a in which back and knee rests are in a raised position.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0039] Referring to FIG. 1 , an electrical schematic of an emergency system of the present invention is depicted. A single push-button emergency switch 127 is located on a control panel 126 on a foot board of an electrically operated patient bed. Associated with the control panel 126 is a control panel microcontroller 161 , which together form a foot board staff control unit 160 . Other control buttons (not shown) are also on the control panel 126 and are associated with the control panel microcontroller 161 . The control panel microcontroller 161 comprises, among other elements (not shown), a button decoder 162 , a timer 163 and a first UART serial port 164 . In an emergency situation, an attendant pushes the emergency switch 127 thereby sending a signal to the button decoder 162 which is programmed to distinguish between the buttons on the control panel. Having determined that the emergency switch 127 was pushed, the button decoder 162 sends a signal to the timer 163 which is programmed to continue sending the signal for 15 seconds. The signal goes from the timer 163 to the first UART serial port 164 and is carried by a wire 165 to an actuator control box 170 located elsewhere on the bed.
[0040] The actuator control box 170 comprises, among other elements (not shown), a second UART serial port 171 in an actuator microcontroller 172 , and two sets of NPN transistors 173 , 174 , relays 175 , 176 and field effect transistors (FET) 177 , 178 . The signal carried by the wire 165 enters the actuator microcontroller 172 at the second UART serial port 171 . The actuator microcontroller 172 recognizes the signal as one intended to operate a first linear actuator 140 and a second linear actuator 150 . The first linear actuator 140 operates a back rest of the bed and the second linear actuator 150 operates a knee rest of the bed. From the actuator microcontroller 172 , the signal is sent to the NPN transistors 173 , 174 , which power the coils 180 , 181 of the relays 175 , 176 . Powering the coils 181 , 182 activates armatures which pull down on contacts 183 , 184 thereby permitting 24 V DC power to flow to the linear actuators 140 , 150 . The field effect transistors 177 , 178 momentarily keep the circuit open when the contacts 183 , 184 close in order to prevent arcing in the contacts. Power to the linear actuators 140 , 150 drives motors in the linear actuators which permits lowering of the back and knee rests as described below. Fifteen seconds after the emergency switch 127 is pushed, the timer 163 terminates the signal. The linear actuators 140 , 150 may switch off before the timer 163 terminates the signal since the linear actuators may reach the fully retracted position before the 15-second time period elapses. The 15-second time period is programmed into the timer 163 to allow ample time for the linear actuators to reach the fully retracted position.
[0041] Referring to FIG. 2 , a linear actuator having a disengaging spline is depicted. A DC motor 50 drives a worm gear 51 which in turn drives a bevel gear 52 . The bevel gear 52 is connected to a flexible clutch 53 which is connected to a ball bearing spindle mount 54 . The spindle mount is connected to a lead screw 55 . Rotation of the bevel gear 52 causes rotation of the lead screw 55 . The lead screw 55 is disengageably connected to a hollow steel piston rod 57 by a disengaging spline (not shown). Part of the lead screw, the disengaging spline and part of the piston rod are housed in an outer tube 58 . End stroke limit switches 59 are mounted near one end of the outer tube 58 . A casing 70 houses most of the elements of the linear actuator. The piston rod 57 comprises an eye 71 at one end for connection to bed elements which raise and lower the back or knee rest.
[0042] Referring to FIG. 3 , a schematic drawing of the disengaging spline of the linear actuator of FIG. 1 is shown in context with the lead screw 55 , piston rod 57 and outer tube 58 . The disengaging spline comprises a female part 61 connected to the piston rod 57 , and a male part 62 on a lead screw nut 63 threaded on to the lead screw 55 . The lead screw nut 63 comprises an O-ring 64 for sealing against the inside of the outer tube 58 . For clarity, FIG. 3 depicts the male part 62 and the female part 61 of the disengaging spline in a disengaged position.
[0043] Referring to FIGS. 2 and 3 , when the lead screw 55 is driven in a forward (extending) direction (to the left in FIGS. 2 and 3 ), and the male part 62 of the disengaging spline on the lead screw nut 63 is seated in the female part 61 of the disengaging spline, the lead screw nut 63 cannot rotate. Instead, the lead screw 55 rotates in a threaded portion inside the lead screw nut 63 driving the lead screw nut forward thereby driving the piston rod 57 forward. Since the piston rod is connected to bed elements which raise the back or knee rest, the back or knee rest is thereby raised. When the lead screw 55 is driven in a reverse (retracting) direction (to the right in FIGS. 2 and 3 ), the lead screw nut 63 threads in the retracting direction along the lead screw 55 and the male part 62 of the disengaging spline disengages from the female part 61 . Therefore, the piston rod 57 is not driven in the retracting direction and the piston rod 57 only moves in the retracting direction by virtue of applied forces (e.g. the weight of the patient, weight of the back or knee rest, etc.). Movement of the piston rod 57 by such applied forces keeps the female part 61 of the disengaging spline seated in the male part 62 . Use of the disengaging spline means that the piston rod is not attached to the lead screw nut and that the piston rod is free to move independently of the lead screw nut. Therefore, during lowering of the back or knee rest, an applied force on the back or knee rest in the opposite direction, such as when the back or knee rest meets an obstacle, will cause the male part 62 to disengage from the female part 61 . The male part continues along with the lead screw nut 63 while the female part stays with the piston rod 57 which cannot move due to the opposite applied force. In fact, it is possible to physically lift the back or knee rest to a raised position even while the linear actuator is causing the lead screw nut 63 to travel in the reverse (retracting) direction.
[0044] At the end of the forward and reverse strokes of the linear actuator, the outer tube 58 is urged forward and backward respectively thereby triggering limit switches 59 which cut power to the motor 50 to automatically stop the linear actuator at the end of each stroke.
[0045] Referring to FIGS. 4 a , 4 b , 4 c and 4 d , an electrically operated patient bed comprising the emergency system of the present invention is shown in which a patient support platform 100 (shown in broken line in FIG. 4 a ), having a back rest portion 105 and a knee rest portion 110 , shown in their lowered (flat) positions in FIGS. 4 a and 4 b , rests on a bed frame 115 . A head board 120 and a foot board 125 are located at the ends of the patient support platform. All switches for electrical activation of bed features are located on a single control panel 126 located on the outside of the foot board 125 . The control panel 126 has a single push-button emergency switch 127 dedicated to activating the emergency system.
[0046] Pivotally attached to the frame 115 are legs 130 having foot/caster arrangements 131 , which support the bed on the floor or ground. Electrically powered linear actuators 135 activated from the control panel 126 operate to raise and lower the bed.
[0047] Referring specifically to FIG. 4 b , the back rest portion 105 is hingedly attached to the support platform 100 along axis A-A. Along axes A-B and B-B, the back rest is not attached to the support platform so that the back rest can be raised to a raised back rest position by pivoting on the axis A-A. The knee rest portion 110 is hingedly attached to the support platform 100 along axis C-C. The knee rest is divided into two sections defined by rectangles C-C-D-D and D-D-E-E respectively. Axis D-D is also hinged to permit the two sections of the knee rest to pivot in respect of each other. Along axes C-E and E-E, the knee rest is not attached to the support platform so that the knee rest can be raised to a raised knee rest position by pivoting on the axes C-C and D-D. The raised back rest and knee rest positions are illustrated in FIGS. 4 c and 4 d.
[0048] Under normal conditions, raising and lowering of the back rest 105 is accomplished by a first linear actuator 140 activated by momentary contact switches on the control panel 126 . The first linear actuator 140 is linked to a transverse back rest pivot element 141 rotationally mounted on the frame 115 . Back rest support arms 142 are each fixed at one end to the back rest pivot element 141 . Proximal another end of each of the back rest support arms 142 are back rest support wheels 143 rotationally attached to the support arms 142 . The back rest 105 rests on the support wheels 143 without being fixedly attached to the back rest support arms 142 . When the first linear actuator 140 is activated to raise the back rest 105 by pressing one of the momentary contact switches, the linear actuator rotationally drives the back rest pivot element 141 which causes the back rest support arms 142 to raise which in turn causes the back rest 105 to raise while riding on the back rest support wheels 143 . Lowering the back rest 105 requires pressing a separate momentary contact switch which drives the first linear actuator 140 in the reverse direction which permits the back rest to lower. Under normal conditions, raising and lowering the back rest requires continued pressing of the appropriate momentary contact switch by the operator.
[0049] Under normal conditions, raising and lowering of the knee rest 110 is accomplished by a second linear actuator 150 activated by momentary contact switches on the control panel 126 . The second linear actuator 150 is linked to a transverse knee rest pivot element 151 rotationally mounted on the frame 115 . Knee rest support arms 152 are each fixed at one end to the knee rest pivot element 151 . Proximal another end of each of the knee rest support arms 152 are knee rest support wheels 153 rotationally attached to the support arms 152 . The section of the knee rest 110 described by rectangle C-C-D-D rests on the support wheels 153 without the knee rest 110 being fixedly attached to the knee rest support arms 152 . When the second linear actuator 150 is activated to raise the knee rest 110 , the linear actuator rotationally drives the knee rest pivot element 151 which causes the knee rest support arms 152 to raise which in turn causes the C-C-D-D section of the knee rest 110 to raise while riding on the knee rest support wheels 153 . The D-D-E-E section of the knee rest 110 pivots down along the axis D-D so that the knee rest assumes an inverted V-configuration in the raised position, as illustrated in FIGS. 4 c and 4 d . Lowering the knee rest 110 requires pressing a separate momentary contact switch, which drives the second linear actuator 150 in the reverse direction which permits the knee rest to lower. Under normal conditions, raising and lowering the knee rest requires continued pressing of the appropriate momentary contact switch by the operator.
[0050] In an emergency situation, with the back rest 105 and the knee rest 110 in the raised position, as depicted in FIGS. 4 c and 4 d , an operator may press the emergency switch 127 , which is electrically connected to both the first linear actuator 140 and the second linear actuator 150 in a manner as described above with reference to FIG. 1 . Thus, pressing the emergency switch 127 causes the linear actuators 140 , 150 to operate in the reverse direction and after the operator releases the emergency switch 127 , power continues to flow to both of the linear actuators. However, since the linear actuators 140 , 150 are equipped with disengaging splines as described above with reference to FIGS. 2 and 3 , the back and knee rests lower to the flat position under the weight of a patient in the bed, rather than being driven by their respective linear actuators. When the linear actuators reach their fully retracted positions, the switch off. The 15-second time period programmed into the timer is enough time for the back and knee rests to achieve their respective flat positions. During lowering of the back and knee rests the operator is free to begin performing emergency procedures such as CPR. Since the linear actuators 140 , 150 do not actually drive the back and knee rests, body parts of the operator and/or patient will not be badly hurt if they get caught under the back and/or knee rest.
[0051] Other advantages which are inherent to the structure are obvious to one skilled in the art. The embodiments are described herein illustratively and are not meant to limit the scope of the invention as claimed. Variations of the foregoing embodiments will be evident to a person of ordinary skill and are intended by the inventor to be encompassed by the following claims.
|
An electrically activated emergency system for a patient bed comprises: an electrically powered linear actuator for driving a back rest of the patient bed from a lowered back rest position to a raised back rest position and operable to permit the back rest to lower from the raised back rest position to the lowered back rest position without being driven by the linear actuator; and, an independent emergency back rest lowering feature comprising an electrical activation means for activating the linear actuator to permit the back rest to lower from the raised back rest position to the lowered back rest position without being driven by the linear actuator, the electrical activation means not requiring continued operator attendance for continued lowering of the back rest. The present invention permits an attendant, for example a nurse, to press a single button to bring the back rest to a lowered back rest position without having to keep the button pressed so that the attendant is free to immediately begin administering emergency procedures while the back rest is lowering.
| 8
|
FIELD OF THE INVENTION
This invention relates to a system for the enhanced reduction of nitrogen by a photoelectrolytic process.
BACKGROUND OF THE INVENTION
Nitrogen fixation can be achieved either biologically or through a nonbiological process. Industrial nitrogen fixation currently involves the catalytic combination of molecular nitrogen and molecular hydrogen into ammmonia at high pressure (˜350 atm) and high temperature (˜500° C.) via the well-known Haber process. Ammonia is then used directly as a fertilizer, or it is converted to other useful reduced or oxidized nitrogen compounds.
Biological nitrogen fixation occurs by the action of certain very limited classes of bacteria; these bacteria are sometimes associated with the root systems of certain plants such as soybean, alfalfa, clover, tropical herbs, and aquatic ferns.
E. E. Van Tamelen and co-workers have reported (Journal of the American Chemical Society, Vol. 90, page 4492 (1968) and Vol. 91, page 5194 (1969)) the electrolytic reduction of N 2 to NH 3 using a non-aqueous electrolyte of glyme (1,2-dimethyoxyethane), aluminum chloride, and titanium tetraisopropoxide. An external voltage of 90 volts was applied across two platinum electrodes while N 2 was bubbled through the electrolyte. Upon hydrolysis of the electrolyte, ammonia was recovered in a 10% yield based on the total titanium originally present.
A report on a process for photoelectrolytic molecular nitrogen fixation employing TiO 2 powder is found in Chemical and Engineering News, Oct. 3, 1977, page 19.
G. N. Schrauzer et al. in Journal of the American Chemical Society, Vol. 99, page 7189 (1977) disclose photolysis of water and photoreduction of nitrogen on titanium dioxide powder.
In U.S. Pat. No. 4,011,149 the photoelectrolytic dissociation of water into hydrogen and oxygen is disclosed. This process, called photoelectrolysis, involves the conversion of optical energy into chemical energy through an endoergic chemical reaction using photoactive semiconductor electrodes.
Steven N. Frank and Allen J. Bard in Journal of the American Chemical Society Vol. 99, page 4667 (1977) broadly suggest that photoassisted reductions at p-type materials can be carried out to produce new materials with light, rather than electrical or chemical energy, supplying the driving force for the reaction.
In accordance with private information received in a letter dated May 19, 1978 from M. Halmann, Associate Professor, The Weizmann Institute of Science, Rehovot, Israel, the writer of the letter has been working on an unspecified novel application of p-type semiconductor electrodes for photoassisted reduction reactions in the field of organic chemistry.
A photoelectrolytical process is characterized by the conversion of optical energy into chemical energy. A photocatalytic process is characterized by the conversion of optical energy into the activation energy required to drive the chemical reaction.
The prior art processes for nitrogen fixation under mild, ambient conditions are relatively inefficient. Furthermore, the prior art electrolysis processes require either an external voltage source or a strong reducing agent, such as sodium or potassium metal, which is expended during the process.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a new and simple process for the fixation of nitrogen under mild conditions.
It is another object of the present invention to provide an efficient process for nitrogen fixation.
It is a further object of the invention to provide a system for nitrogen fixation which does not require an external voltage source, but which uses sunlight to provide the activation energy for the nitrogen fixation reaction.
It is another object of the invention to provide a system for photocatalytic reduction of nitrogen which uses solar energy as the source of the activation energy required by the reduction reaction.
It is another object of the present invention to provide an electrolytic cell adapted to general photoreduction of nitrogen molecules.
The present invention provides a process for the reduction of nitrogen molecules bound to complexes and capable of being reduced. Electrons are being provided by a p-type semiconductor cathode having a band gap between about 0.8 and 3 eV in contact with an electrolyte solution containing nitrogen molecules bound to complexes and capable of being reduced. The cathode is irradiated with light having photons of an energy of between about 0.8 and 3 eV. The electrons generated by the incident light on the cathode surface are injected into the electrolyte solution in contact with the cathode surface for reducing the nitrogen molecules bound to the complexes and capable of being reduced.
Protons are provided to the reduced nitrogen complexes and electrical holes traveling to the anode are eliminated by electrons provided by an oxidation reaction.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows a schematic diagram of the energy levels involved in the photoenhanced reduction process;
FIG. 2 shows a schematic diagram of an apparatus for photoelectric fixation of nitrogen; and
FIG. 3 shows a schematic diagram of an assembly of a photoelectrode for photoelectric fixation of nitrogen.
DETAILED DESCRIPTION OF THE INVENTION
The apparatus used to carry out the invention consists essentially of a photoelectrochemical cell which comprises p-type semiconductor cathodes which are in short circuit electrical contact with an anode. The cathode and anode regions may comprise a single entity or particle, such as a photochemical diode described in commonly assigned patent application Ser. No. 728,474 filed Sept. 30, 1976; alternatively, the cathode and anode may be separate elements connected by a conducting wire or substrate. The two electrodes are immersed in an electrolyte which contains the chemical species to be reduced in the vicinity of the cathode. The reducing agent comprises either the anode itself or a chemical species provided in the vicinity of the anode.
For the case of nitrogen reduction or fixation, nitrogen gas is bubbled through the electrolyte in the vicinity of the p-type semiconductor cathode.
Reduction is achieved by illumination of the p-type semiconductor cathode with light having photon energies greater than the band gap of the semiconductor. This produces electron-hole pairs in the semiconductor which separate in the space charge layer present in the semiconductor near the semiconductor-electrolyte junction. The photo-generated electrons are injected, due to the potentials at the interface, into the electrolyte with a reduction potential which is greatly enhanced. Electrons are withdrawn through the external circuit from the anode, whereby holes are effectively injected into the electrolyte at the normal oxidation potential of the reducing agent being oxidized at the anode. The external circuit between cathode and anode can contain a voltage source.
Sources for nitrogen molecules suitable in the present invention for nitrogen fixation include nitrogen gas, vapors from liquid nitrogen, air, nitrogen mixed with noble gases, and residual burner gases. The nitrogen containing gas can be introduced at the bottom of the solution near the cathode.
The pressure of the nitrogen gas can be between about 0.1 atm and 100 atm and preferably between about 1/2 atm and 2 atm.
The photons suitable in the present invention have an energy between about 0.5 eV and about 4 eV and preferably between about 1 eV and 3 eV.
Optical sources providing such energy distributions include any radiation source such as direct light from the sun, light from incandescent lamps, light from arc lamps, light from gas discharges, light from diodes, light from lasers, light from vapors, light from hot bodies, and light from hot liquids.
The light can be guided from its source to the semiconductor surface by means of optical elements such as mirrors, lenses, gratings, optical fibers and light guides.
p-Type semiconductors useful in the present invention are found in the following classes of semiconductors: Group IV, Group II-VI, Group III-V, Group IV-VI and Group III-VI layered compounds, transition metal oxides, Group I-III-VI 2 and II-IV-V 2 ternary compounds, and ternary oxides, where "group" refers to a group or groups of the Periodic Table of the Elements, as designated by the numbers shown.
Preferred p-type semiconductors have band gaps ranging from about 1 eV to 3 eV and include Si, Ge, SiC, Cu 2 O, NiO, Cu 2 S, CdTe, ZnTe, GaP, GaAs, InP, InAs, AlAs, AlSb, GaSb, InP, CuInS 2 , CuGaS 2 , CuAlS 2 , CuAlSe 2 , ZnSiAs 2 , ZnGeP 2 , ZnSnAs 2 , ZnSnP 2 , CdSnP 2 , CdSnAs 2 , GaSe, GaS, GeS, GeSe, GeTe, SnS, SnTe, SnSe, MoS 2 , and WS 2 . Preferred semiconductors have electrical conductivities ranging from 10 -3 to 1 ohm -1 cm -1 .
Solvents to be useful in forming electrolyte solutions for purposes of this invention should be non-corrosive to semiconductor surfaces and should show good transparency to visible light. Such solvents include water and solvents such as alcohols, tetrahydrofuran, 1,2-dimethoxyethane, and bis(2methoxyethyl)ether. Sufficient conductivity of the solution may be provided by dissolving in the solvent a conductivity supporting electrolyte such as tetrabutylammonium chloride, bromide, perchlorate, fluoroborate, potassium chloride, potassium bromide, aluminum chloride and the like.
In the case of N 2 fixation, it is necessary to first bind molecular nitrogen molecules into a molecular complex in the electrolyte solution so that the nitrogen can be subsequently reduced. This is achieved by including in the electrolyte solution certain transition metal complexes, such as complexing species which are known to bind molecular nitrogen and which include ions of titanium, chromium, vanadium, molybdenum, cobalt, tungsten, nickel, and iron, and metalloorganic complexes of these metal ions.
Preferred complexing species for nitrogen include
(a) titanium isoalkoxides with each alkoxide radical comprising up to eight carbon atoms,
(b) 1,2 dithiolene complexes including compounds of the formula ##STR1## wherein R=H, alkyl with up to eight carbon atoms, C 6 H 5 , CF 3 , CN; and wherein M is Mo, W, Cr, or V; and wherein if n=2: x=0, -1, -2; if n=3: x=0, -1, -2, -3;
(c) complexes of the formula ##STR2## where R=H, or alkyl group with up to 8 carbon atoms; n=2; x=0, -1, -2; and M is Mo, W, Cr or V;
(d) a complex of the formula ##STR3##
(e) a complex of the formula ##STR4##
(f) complexes of the formula
MCl.sub.4 (P(CH.sub.3)C.sub.6 H.sub.5).sub.2 wherein M=Mo, W;
(g) a complex of the formula
[(C.sub.5 (CH.sub.3).sub.5 ].sub.2 ZrCl.sub.2
More preferred is titanium tetraisopropoxide [Ti(O-i-C 3 H 7 )] 4 as a complex for photoenhanced reduction of nitrogen.
The concentrations of the solution are in the range of about 10 -3 to 10 molar.
The anode, at which the oxidation reaction occurs and where the reducing agent in the system is oxidized, can consist of metals such as platinum, stainless steel, transition metals, and aluminum. The reducing agent which is oxidized at the anode can be introduced into the electrolyte at an inert electrode, such as, for example, hydrogen gas over a platinum electrode; or the anode itself can be a reducing agent and become oxidized, such as is the case for example, with aluminum electrodes. In the latter case, the aluminum anode is consumed during the photoreduction process.
In the case of nitrogen reduction with formation of protonated nitrogen derivatives, such as ammonia or hydrazine or nitrogen hydrogen acid (hydrozoic acid), it is necessary to provide a proton source in the electrolyte to ultimately combine with the reduced nitrogen. This proton source may be H 2 gas which is introduced into the cell and oxidized to H + at an inert anode such as platiinum. Alternatively, the proton source may be the solvent itself or a solute species dissolved in the electrolyte solution. These proton sources include alcohols, ethers, esters, and other organic compounds containing detachable H atoms, such as methylalcohol, ethylalcohol, ethylacetate and ethylether. A particularly attractive and inexpensive proton source is water; however, water can only be used if the electrolyte and semiconductor electrode are stable in the presence of water.
In the absence of a proton source during reduction, the reduced nitrogen is converted to hydrazine and/or ammonia by the addition of a proton source, such as acid, base, or alcohol, to the system after the photon-enhanced reduction step is completed.
The temperature of the solution is not critical. A preferred solution temperature is between about 5° C. and 95° C., with a more preferred range being between about 20° C. and 60° C.
The externally applied potential between anode and cathode should be between about 0 V and about 10 V, with preferably no external voltage applied. To provide a calibration of the photoenhanced potential obtained in accordance with this invention, several redox reactions can be used which involve a color change when one species is reduced. Transition metal complexes are suitable for such indication such as those useful in forming reducible complexes with nitrogen. Titanium isopropoxide nitrogen complexes exhibit such color changes.
The energetics of this process is shown schematically in FIG. 1. A p-type semiconductor cathode 1 with band gap E g is connected through an ohmic contact 2 to a metal anode 3. Light 4 with energy, h ν (h is Planck's constant and ν is the frequency of the light), greater than E g is absorbed in the space charge region 5 to produce electrons 6 and holes 7. A reducing agent is introduced into the electrolyte near the anode such that the reducing agent 8 is oxidized at its normal reduction potential (R/R + ). The Fermi level 9a in the semiconductor coincides with the R/R + reduction potential. The photogenerated electron is available as a reducing agent at a reduction potential which is much greater than the reduction potential of the reducing agent introduced into the electrolyte. The minimum enhanced reduction potential, E, in volts is equal to:
E=E.sub.g -V.sub.B -ΔE.sub.F (1)
where E g is the semicondutor band gap in eV, V B is the band bending 9 at the semiconductor-electrolyte interface in eV, and ΔE F is the energy difference between the Fermi level and the valence band edge in eV. For any given reducing agent introduced into the electrolyte, the reduction potential of this reducing agent can be enhanced by at least an amount given by Equation (1). Even greater reduction potentials can be obtained if the electrons are injected into the electrolyte before they undergo full intraband relaxation in the semiconductor depletion layer. Thus, reduction reactions which are difficult to perform or which have high activation energies can be driven with light via the photoenhanced reduction process.
Referring now to FIG. 2 there is shown an apparatus for photoelectric fixation of nitrogen.
A container 10 is filled with electrolyte 12. The container 10 is provided with a window 14 for transmitting photons 16 into the container and onto an electrode 18. Electrode 18 is connected with a conductive wire 20 to a load 22 and the other side of the load is connected with a conductive wire 24 to an anode 26. An inlet tube 28 is provided for bringing nitrogen molecules into the electrolyte 12. An outlet tube 30 is provided for removing excess nitrogen. The container 10 is otherwise closed at its top with a cover 31. Tube 30 can run into a trap 32 for providing a buffer towards the ambient air. Trap 32 can be filled with a liquid 34 such as diluted sulfuric acid through which excess nitrogen 36 is bubbled. Above the level of the liquid 34 an exit 38 is provided for releasing the excess nitrogen into the ambient air; the trap 32 is closed off against the ambient by a sealing stopper 40. Optionally a magnetic stirrer 42 can be provided to agitate the electrolyte for better dispersion of the N 2 gas into the electrolyte.
Referring now to FIG. 3 there is shown an assembly of a photoelectrode 18 used for the reduction of nitrogen.
A photoactive p-type semiconducting element 50 is in contact with an ohmic contact 52. The semiconducting element 50 can be p-type gallium phosphide having a bandgap of about 2.3 eV. The ohmic contact 52 should be made from a material which prevents the development of a Schottky barrier, such as a 1% Zn in Au alloy for p-type gallium phosphide. The ohmic contact may be between about 0.1 and 2 microns thick. The ohmic contact 52 is contacted with a conducting material 54, such as a conducting silver epoxy. The conducting epoxy material 54 then bonds a conducting wire 58 to the electrode, and the wire 58 is protected against the electrolyte by an insulating sleeve 60. The wire 58 can be a copper wire and the sleeve can be a polyethylene insulation. Insulation 62 covers ohmic contact 52 and conductive epoxy 54.
For purposes of this invention, a p-type gallium phosphide crystal wafer can be provided with a photoactive surface by first polishing with 5 micron alumina, etching in aqua regia for about fifteen minutes, followed by etching in 1:1:3 H 2 O/H 2 O 2 /H 2 SO 4 solution. The ohmic contact can be produced by evaporating a 1% Zn/Au alloy onto the back surface of the gallium phosphide. Thicknesses as small as 0.1-0.2 microns provide ohmic contacts. The resistance of such evaporated contacts as measured for a 1 mm separation of two such electrodes on the gallium phosphide surface can be about 20 ohm before heat treatment. After heat treatment of the evaporated contact in a hydrogen atmosphere at a temperature of between about 200° C. and 600° C. the resistance of the evaporated contact to the gallium phosphide is reduced to less than about 3 ohm.
EXAMPLE 1
A photoelectrochemical process was observed when hydrogen gas was bubbled over a platinum anode that was short circuited to a p-GaAs or p-GaP cathode. Upon illumination, hydrogen bubbles appeared on the cathode with little or no applied bias. The process involves the oxidation of hydrogen gas to hydrogen ions at the platinum anode and the reduction of hydrogen ions back to hydrogen gas at the illuminated cathode. However, the reduction potential produced at the illuminated semiconductor is enhanced over the standard hydrogen reduction potential by an amount approximately equal to the difference between the conduction band edge and the hydrogen-hydrogen ion redox couple (Equation (1)). Because the reduction potential is photo-enhanced at the semiconductor electrode, difficult chemical reduction reactions, requiring large activation energies are possible with this process.
EXAMPLE 2
Nitrogen gas was continuously purged through a flow cell like that shown in FIG. 2.
The cell contained an electrolyte consisting of a mixture of Ti(OC 3 H 7 ) 4 and AlCl 3 in a 1:1.5 molar ratio dissolved in 1,2-dimethoxyethane. Specifically, the electrolyte composition was:
titanium isopropoxide: 11.4 g (40 millimoles)
aluminum chloride: 8.4 g (60 millimoles)
1,2-dimethoxyethane: 80 ml
The trap contained 0.2 NH 2 SO 4 .
The dimethoxyethane was doubly distilled over sodium metal. The double distillation removed any ammonia initially present in the 1,2-dimethoxyethane. None of the starting materials showed a positive reaction to Nessler's reagent (potassium mercury iodide), indicating that the amount of ammonium ion present was less than about 0.2 parts per million.
To obtain a clear electrolyte solution, the aluminum chloride was first added to the 1,2-dimethoxy ethane; then the titanium isopropoxide was added which caused complete dissolution of the aluminum chloride.
The cell electrodes were a p-GaP cathode and an aluminum anode. The ohmic contact to the p-gallium phosphide was an evaporated Au-1% Zn alloy, and the carrier concentration of p-gallium phosphide was about 1.4·10 17 cm -3 . The purging nitrogen gas flowed at a rate of 0.03 cubic feet/hour. The light intensity was 100 mw/cm 2 of white light produced by a xenon lamp, and the samples were exposed for a 24 hour period. The weight loss of the aluminum anode, the total charge, and the amount of ammonium ion produced were monitored during the run. Typical photocurrents produced were between about 0.2 and 1 ma/cm 2 .
As the reaction proceeds, the solution turns from clear amber to green to blue to black. This is caused by reduction of the Ti 4+ complex in the electrolyte to a Ti 2+ complex through a series of steps: ##STR5##
Reduced titanium complexes bind molecular nitrogen, and the bound nitrogen is then reduced in solution and "fixed". Ammonia or hydrogen is formed when the reduced nitrogen is protonated. The electrolyte and the acid trap are analyzed for NH 4 + ions to determine the extent of N 2 reduction.
The amount of NH 4 + ion formed in this system was found to be between 1 and 10 atomic percent of the total titanium present in the system. This degree of N 2 reduction was achieved with no external bias applied to the cell. The amount of NH 4 + found in the electrolyte and trap varied widely among the experiments, but the total NH 4 + produced was always much greater for the illuminated cell compared to control experiments in the dark. This variation is most likely due to changes in the flow rate of the nitrogen gas caused by a restriction of the entrance port by dried electrolyte.
A control experiment was conducted where the flowing nitrogen was replaced by argon. All other conditions remained identical. As expected, no significant yield of reduced nitrogen was found.
The reducing agent in this example is the aluminum anode. During the run, aluminum metal is oxidized to aluminum ion, and a loss of weight of the aluminum anode is observed.
EXAMPLE 3
The conditions were the same as in Example 2, however the aluminum anode was replaced by platinum over which hydrogen was bubbled. The p-GaP/Pt system produced photocurrents comparable to the p-GaP/Al system, but the degree of nitrogen fixation was lower by a factor of about ten.
EXAMPLE 4
The electrolyte of Example 2 was exposed to light with no electrodes present. The solution darkened indicating the presence of reduced titanium. However, no NH 4 + production was observed without the presence of electrodes.
EXAMPLES 5-9
A closed cell was constructed for simultaneous observation of several variables. The entire system was evacuated and back filled with nitrogen gas to slightly less than atmospheric pressure. The cell was then filled with several ml of electrolyte and illuminated. The total gas pressure, total charge, weight loss of aluminum electrode, and ammonia production were all measured.
Several experiments were completed in the closed cell. Examples 5 and 6 were identical and used an electrolyte of Example 2 composed of the 1:1.5 molar ratio of Ti(OC 3 H 7 ) 4 and AlCl 3 in 1,2-dimethoxyethane and p-GaP and Al electrodes. Example 7 used an external voltage source connected to platinum and aluminum electrodes to reduce the nitrogen electrolytically without light. Finally, Examples 8 and 9, one where the nitrogen was replaced by argon and one where the titanium was omitted, were performed.
In Examples 5 and 6 the yields of NH 4 + produced relative to the total titanium present, based on NH 4 + analyses using Nessler's reagent, were several percent. This is similar to the results obtained with the p-GaP/Al electrodes in the flow cell of Example 2. The results of Example 7 were comparable to Examples 5 and 6, indicating that the external voltage source could be replaced by light.
Essentially no yield of ammonia (1/2%) was found when argon replaced the nitrogen in Examples 8 and 9. Finally, when the titanium ester was omitted, the AlCl 3 did not dissolve in the glyme. The solution did not conduct, and no significant ammonia yield was found.
EXAMPLE 10
Calibration of Photo-enhanced Reduction Potential
A visual demonstration of photo-enhanced reduction was obtained using n-heptyl viologen bromide, which turns purple on reduction. Upon illumination of a p-GaP/Pt photochemical diode immersed in a 0.1 M KBr electrolyte containing 0.01 M concentration of the viologen compound, a bright purple coloration appeared on the GaP portion of the diode. The reaction is ##STR6## where R is the n-heptyl group. The air sensitive free radical is the purple film which appears on the GaP electrode.
The viologen compound was also used to measure the reduction potential for various electrode systems and gas purges, by observing the point at which color appears as a bias voltage is applied. For example, a -1.2 V bias applied between two Pt electrodes was required to reduce the viologen compound in the dark. When p-GaP/Al and p-GaP/Pt electrodes were used in the presence of light, the reduction occurred with no applied bias. In fact, an anodic bias of +0.8 V and +0.3 V was required to prevent the reduction when p-GaP/Al and p-GaP/Pt electrodes were used respectively. Thus, nearly a 2.0 V and a 1.5 V "enhancement" occurred for the p-GaP/Al and p-GaP/Pt system, respectively.
EXAMPLE 11
Observation of the process of photo-enhanced reduction was visually made with vanadium ions in aqueous solution. The reduction of V +3 to V +2 involves a color change from light blue to violet and the reaction is above the H 2 /H + redox level; hence H 2 would not normally reduce V +3 to V +2 . The reduction occurs on illuminated p-GaP because of the photo-enhanced reduction effect. The color change was observed when Sn and W were used as anodes (anodic oxidation potentials of Sn and W are also below the V 3+ /V 3+ redox level). No bias was required to observe the color change but a large bias of 1.8 V was required to permit this observation in a few minutes.
EXAMPLE 12
Nitrogen-15 experiments were performed to show conclusively that nitrogen was fixed by photo-enhanced reduction. The same experiments as those described by Examples 6 and 7 were performed except that nitrogen-15 was used instead of natural occurring nitrogen. Analysis of the electrolyte by Fourier Transform infrared spectroscopy revealed the presence of 15 NH 3 . This means that nitrogen gas is indeed reduced to ammonia, and that the ammonia did result from reduction of some more easily reducible nitrogen compound present as an impurity.
|
A system for the photoenhanced reduction of nitrogen. A p-type semiconductor cathode with a band gap between about 0.8 and 3.0 eV is irradiated with light falling within such energy range. The cathode is in contact with an electrolyte and capable of injecting photogenerated electrons into the electrolyte. An anode provides for removal of the resulting holes from the cathode. Cathode and anode are short circuited. For nitrogen molecule reduction, the electrolyte solution contains a chemical species capable in reduced form of chemically binding molecular nitrogen and of facilitating a series of reduction steps on the nitrogen. Specifically, such a chemical species is titanium isopropoxide.
| 2
|
This is a continuation of application Ser. No. 765,463 filed Feb. 4, 1977 now abandoned.
BACKGROUND OF THE INVENTION
A wide variety of mechanisms have been designed and developed for translating motion from one element to another. The present mechanism relates to a structure for actuating a bail between first and second positions usually along a portion of an arc which may comprise some fifty or sixty degrees of arc to eighty or one hundred degrees. Such mechanisms may appear in varied devices, such as camera shutters, typewriter mechanisms, display devices, factory machines, and extension levers for actuating recessed light switches or circuit breakers.
The invention is specifically directed to the reciprocal actuation of a bail in response to the actuation of a lever. In some types of linkages, the bail may have to be driven from a first position to a second position. In other types of systems, the bail may be acted upon by auxiliary forces, so that once the bail is urged from an initial position to a critical position, the auxiliary forces urge the bail towards its destination independent of the force of the actuating linkage. In such systems, it is sometimes desirable to allow at least some free travel of the bail once it has reached the critical point. In some structures, it is desirable to have the actuating cam in intimate contact with the bail when the bail is at either at rest position so that tactile feedback can be provided to indicate the bail position. Phrased differently, it is sometimes desirable to have no "lost motion" of the actuating lever when the bail is in an at rest position. However, as mentioned above, there are mechanisms wherein it is desirable to allow the bail to have at least some free motion independent of the actuating cam during at least part of the time that the bail is intermediate of its at rest positions.
The structure disclosed herein is directed to mechanisms of the class which require no lost motion of the actuating lever when the bail is at its at rest positions and which requires at least some free motion of the bail when it is intermediate of its at rest positions. However, the invention could readily be adapted to an inverse application wherein at least some lost motion of the actuating lever is required when the bail is at its at rest positions and which requires reduced free motion of the bail when it is intermediate of its at rest positions.
An example of a practical structure having the first requirements is that of a circuit breaker within an enclosure and actuated by an auxiliary lever extending through a wall of the enclosure. When the circuit breaker is at either at rest position, the auxiliary lever should have minimum free motion so that, by tactile feedback, one manipulating the auxiliary lever could sense the position of the circuit breaker. When the circuit breaker is being moved from its closed circuit to its open circuit position, it is desirable for the circuit breaker arm to be allowed at least some free motion during the time the contacts are actually being opened.
A variety of linkages have been developed for providing features similar to those described. Such prior art linkages have frequently employed a plurality of parts including some or all of the following: auxiliary springs, auxiliary lost motion structures, knuckles, separate on and off levers, and a variety of other structures.
SUMMARY OF THE INVENTION
The present invention provides a simple member having first and second cam surfaces, one of which initiates bail actuation in one direction and the other of which initiates bail actuation in the other direction. The geometry of the actuating lever, the bail, and the cam surfaces are arranged and constructed to provide a structure wherein there is minimum clearance between the bail and the first and second cam surfaces when the bail is in either at rest position. At least part of the effective portion of both cam surfaces diverge from each other. As the bail and the actuating lever pivot about their respective centers, the bail slides, or rolls, on the active cam surface. Thus the cam moves to a point wherein the bail is in contact with only one cam surface and at least some free motion of the bail is possible before contacting the other cam surface if the actuating lever is held stationary and the bail moved by auxiliary forces.
In one embodiment, the first and second cam surfaces are symmetrical about a center line of the cam member. The angle of the cam surface with the center line of the cam member, while not critical, must be within certain limits. For the structure illustrated in FIGS. 1 through 4, the bail is located between the pivot point of the bail and the pivot point of the cam member. With this structure, a relatively large angle between the cam surface and the center line of the cam member will provide a high initial force to initiate bail actuation. However, a small angle is required to provide a high effective force to urge the bail to an at rest position. Accordingly, the angle of the cam surface with respect to the center line of the cam member must be a compromise angle which provides adequate effective forces and which permits sufficient free motion of the bail. For other relationships of pivot points and members, the cam angle may vary.
It is an object of this invention to provide a new and improved structure for actuating a bail between first and second at rest positions.
It is another object of this invention to provide a bail actuating mechanism wherein there is minimum lost motion of the actuating mechanism when the bail is in either at rest position.
It is another object of this invention to provide a bail actuating mechanism which provides for at least some free motion of the bail when it is intermediate of its at rest positions.
It is another object of the invention to provide a pivoted bail actuating mechanism having two cam surfaces, both of which are in contact, or nearly so, with the bail when the bail is in either at rest position.
It is a further object of the invention to provide a pivoted double cam actuating mechanism for actuating a pivoted bail which provides for at least some free motion of the bail when it is intermediate of its at rest positions and which permits minimum free motion of the bail when it is at either at rest position.
It is another object of the invention to provide cam surfaces for actuating a pivoted bail as afore described and which provides adequate effective force for initiating bail motion and for completing bail motion.
BRIEF DESCRIPTION OF THE DRAWING
A preferred embodiment of the invention will be described, together with the drawing figures, in which like elements are given like numbers except that in FIG. 6, which illustrates an alternate structure, the elements are numbered so that the last two digits correspond with the last two digits of the elements of the other figures which most nearly correspond, and in which:
FIG. 1 constitutes a front view of a structure which embodies the invention, partly in cross section and partly cut away;
FIG. 2 is a side view of the same structure with parts in cross section and part cut away;
FIG. 3 comprises an enlarged view illustrating the vector forces available for the initial movement and the final return of the bail member;
FIG. 4 is an enlarged view showing the relationship between the bail member and the cam member with the bail member in a variety of positions;
FIG. 5 is a view of the cam member; and
FIG. 6 illustrates an alternate structure with the pivot points of the bail and the cam member on the same side as the cam.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Considering now more specifically FIGS. 1 and 2, taken together, there will be seen therein a structure in which the invention may be incorporated. More specifically, the invention comprises a linkage for actuating a bail in a setting wherein the bail constitutes the actuating arm of a circuit breaker enclosed within an explosion proof container and having a linkage for actuating the circuit breaker by manipulating an external lever. Such a structure finds particular utility where it is necessary to provide a circuit breaker in an atmosphere which might include explosive gases. In such situations, the circuit breaker is enclosed in an explosion proof box so that an explosion cannot be initiated from a spark created when the circuit breaker opens. In order to permit one to feel the external lever and determine the position of the circuit breaker arm, it is desirable to have minimum lost motion of the linkage connecting the external lever and the circuit breaker arm. That is, if the circuit breaker is in either its open or closed position, there should be minimum possible motion of the external lever without providing a feeling that it is contacting the circuit breaker arm and moving it. However, when one is using the external lever to open the circuit breaker, it is desirable to allow free motion of the circuit breaker arm during at least the time that the contacts are being opened so that the contacts may separate quickly and quench any spark. Accordingly, the linkage connecting the external lever and the circuit breaker arm is designed to provide minimum lost motion of the external lever when the circuit breaker is at either at rest position, but to allow at least some free motion of the circuit breaker arm after the external lever and associated linkage has moved the circuit breaker arm from its at rest position.
The explosion proof box containing the circuit breaker is indicated generally as 101. The box 101 includes a cover 102 and the container section 103. Contained within the box 101 is the circuit breaker 104. Wiring may be brought into and/or out of the box 101 through openings 105 in which a fitting (not shown) may be placed to seal the wiring in the opening 105 and prevent an exchange of atmosphere between the interior and exterior of the box 101. Another opening 107 is provided through which a mechanism couples to the linkage which actuates the circuit breaker 104 and about which more will be said below. Threaded into the opening 107 is a plug 108 having a flange 109 with a circular groove 110 accommodating an 0-ring 111 which contacts a portion of the container 103 to provide a seal. The plug 108 includes a hole 112 in which a shaft 113 is journalled. Another groove 114 and 0-ring 115 seal the shaft 113 to prevent an exchange of atmosphere between the interior and exterior of the box 101. Secured to the shaft 113 is an operating arm 116 which may be secured to the shaft 113 by any convenient means, such as a key or set screw 117. To prevent end play of the shaft 113, locking collars 118 are secured to the shaft 113 by set screws 119.
The shaft 113 includes an upturned end 120 having a flattened surface 121 and two tapped holes 122. Secured to the flat surface 121, by means of screws 123 into the tapped holes 122, is a cam member 124, shown in more detail in FIG. 5.
As may be seen in FIG. 5, the cam 124 includes a slot 125 through which the screws 123 pass to secure the cam 124 to the upturned end 120 of the shaft 113. The slot 125 allows some vertical adjustment of the cam 124 with respect to the upturned end 120 and/or the circuit breaker 104. As may be readily envisioned, the pivoting of arm 116 will rotate shaft 113 and cause the upturned end 120 and the attached cam 124 to pivot between two limits about the center line 126 of the shaft 113. The cam member 124 includes two cam surfaces 127 and 128.
By way of review of salient features, the cam member 124 pivots about pivot point 126 in response to actuation of the arm 116, and the slot 125 provides for adjustment of the cam member to modify slightly the location of the cam member 124 relative to the center of rotation 126.
Considering now more specifically FIG. 1, there will be seen a view of the cam member 124 and the circuit breaker 104, including the circuit breaker actuating arm 129 which pivots about a center 130 from an on position, as indicated by the arm 129, to an intermediate position, as indicated by 129' , and an off position, as indicated by 129". A plane indicating the limit of the downward motion of the circuit breaker arm 129 is indicated at 131. A greatly enlarged view of a portion of the cam member 124 and the circuit breaker arm 129 is illustrated in FIG. 3, and FIG. 5 is a view of the cam member 124 as used in the structure of FIGS. 1 and 2.
The circuit breaker arm or bail 129 is illustrated as having a circular cross section, and in many conventional and commercial circuit breakers such is the case. In fact, it is not unusual for a circuit breaker arm to include a rotating member on the arm. However, the present application is not limited to circuit breakers having this configuration and many other configurations could be accommodated with the same cam or perhaps a slightly modified cam. For the present discussion, it will be assumed that the circuit breaker 104 is in the on position when the arm 129 is to the right. That is, when the arm 129 is at the right, the contacts in the circuit breaker 104 are closed and current may pass through the wires connected to the circuit breaker 104. When the arm 129 is moved to the left, the circuit breaker contacts are open and no current may pass through the wires connected to the circuit breaker 104. Those familiar with circuit breaker actuation will recall that when the arm is moved from the on to the off position, a relatively high initial actuating force is required, but that after the arm is moved to a critical point, usually less than half the total travel, the arm snaps to the left under control of internal forces. The electrical contacts are opened during the initial part of the free motion of the circuit breaker arm and it is highly desirable to allow such free motion to allow the contacts to open rapidly and quench any sparks therebetween. It will be seen that the structure disclosed provides for this free flight of the actuating arm 129 when it is intermediate of its two at rest positions. However, in order to get good tactile feedback and permit an operator to determine the position of the circuit breaker by feeling the resistance to motion of the external arm 116, it is necessary to have the cam member 124 in contact with the arm 129 when it is at either of its at rest positions. Returning now more specifically to FIG. 3, there will be seen an enlarged view of the cam surfaces 127 and 128 of the cam member 124 and the arm 129. The arm 129 is illustrated at the right with the circuit breaker in the on position. The line 131 represents the plane that limits the downward motion of the arm 129 and determines the left and right at rest positions of the arm 129. Point 132 represents the center of the arm 129, and 130 is the center of rotation of the arm 129 and, therefore, the arc 133 represents the locus of the point 132 as the arm 129 is moved from one position to another. If the shaft 113 is rotated by actuation of the arm 116, the cam member 124 will be pivoted clockwise about center line 126 of the shaft 113. This will cause cam surface 128 to bear against the arm 129 and apply a force against the arm 129. The cam surface 128 is, or course, tangent to the arm 129 and the force acts at the point of tangency and passes through the center 132. The applicable force is illustrated by vector F1. Since the arm 129 can only move along the arc 133, that portion of the force F1, which is effective to move the arm 129 along the arc 133, is the vector component which passes through point 132 and is tangent to the arc 133. This vector force is illustrated as vector F2. Vector F3 is the vector component which combines with F2 to provide the resultant vector F1. If line 134 represents the center line of the cam member 124, it will be evident that if the angle between cam face 128 and center line 134 were increased, the vector component F2 would become larger; and with a sufficiently large angle, vector F2 would approach F1 in value and F3 would diminish to zero. The reason for not increasing the angle between cam face 128 and the center line 134 to provide a maximum initial effective vector force will become more apparent as the description proceeds.
Consider now the forces applied to the arm 129 at the final instant that the arm 129 is restored from the open position to the closed position. Under these conditions, the cam surface 127 will be acting on the arm 129 to restore it to its right hand at rest position. The cam surface 127 is, of course, tangent to the arm 129 and the force applied is at right angles to the cam face 127 at the point of tangency and acts towards the point 132. This vector is illustrated as force F4. The portion of the vector F4 which is effective to urge the arm 129 towards its right hand position is the vector component which is tangent to the locus 133 at the point 132. This vector component is illustrated as F5. The remaining vector component is illustrated as F6. It will be evident that if the angle between the cam surface 127 and the center line 134 was reduced or even made such that the intersection of the line 127 representing the cam surface and the center line 134 would intersect at a point above 132, the vector force F5 would be increased.
If the arm 129 is now envisioned as at the left in its off position, it will be seen that the cam surfce 127 must provide the force for initiating the movement of the arm 129 from the left to the right, and that the available force will correspond to the vectors F1, F2 and F3. Thus it may be seen that the cam surfaces 127 and 128 are each required to provide both an initial and final force to move the arm 129, and that the cam face orientation which provides a maximum initiating force would not provide a suitable final force, and that a cam orientation which would provide a maximum final force would not provide a satisfactory initial force. Accordingly, a compromise cam face orientation must be employed. Although the described application for operating a circuit breaker does not require a symmetrical cam, it is considered desirable to provide a symmetrical cam in order to eliminate the possibility of improper assembly. The illustrated application does not require a symmetrical cam because the cam surface 128 is not required to provide any substantial force to move the arm 129 to its final left hand at rest position. That is, as previously mentioned, internal forces within the circuit breaker 104 urge the arm 129 towards its left hand position, once the arm 129 has advanced to a certain critical point along the locus 133.
Another factor which may effect cam angle design is the strength of the cam member. If the angle is too large, the structure may be weakened, or the cam member may be required to have greater overall dimensions.
It will be observed that with the arm 129 in its at rest position, as illustrated in FIG. 3, that cam surfaces 127 and 128 are both in contact with the arm 129. Accordingly, any attempt to wiggle the arm 116 will immediately provide a tactile feedback as one or the other of the cam surfaces 127 or 128 will contact the arm 129 and motion will be resisted. That is, the arm 116 has no lost motion. The same relationship exists when the arm 129 is as its left hand position. If the cam member 124 is moved slightly by taking advantage of the adjustment provided by slot 125 and screws 123, the magnitude of the free motion of the arm 129 may be adjusted at the at rest positions and the intermediate positions.
Attention should now be directed more specifically to FIG. 4 which constitutes an enlarged view of a portion of the cam member 124 (but not enlarged as much as shown in FIG. 3) and with the cam member 124 illustrated in three positions; a first position in solid lines; and a second and third positions in different styles of dashed lines. The arm 129 is illustrated in its left and right at rest positions and two intermediate positions. The center of the arm 129, when it is in its right hand at rest position, is illustrated by point 132. When the cam member 124 has been pivoted clockwise about the center of rotation 126 to the position shown by solid lines in FIG. 4, the arm 129 will have its center 132 moved along the locus 133 to point 135 by the forces applied by cam surface 128. It will be observed that when the arm 129 has its center point 135, no portion of the arm 129 is in contact with cam surface 127. Accordingly, if position 135 represents the tripping position of the circuit breaker 104, the arm 129 may move, by forces applied internally of the circuit breaker 104, and the center 135 will jump to position 136. That is, without any further movement of the cam member 124, the arm 129 may move its center from position 135 to 136 or, phrased differently, while the arm 129 is at a point intermediate of its two at rest positions, there is room for free travel of the arm 129. For the remainder of the travel of the arm 129, from point 136 to its left hand at rest position point 137, the cam face 127 will actually be restraining the motion of the arm 129. However, as illustrated by the dashed outline of the cam faces 127 and 128, both such faces are in contact with the arm 129 while it is at its left hand at rest position.
There has been shown a linkage for actuating a bail, such as a circuit breaker arm, wherein there is negligible lost motion of the linkage when the bail is in its at rest position and which provides for a least some free travel of the bail while it is at an intermediate position. In the examples illustrated thus far, the bail is intermediate of the pivot point of the cam member and the bail. This particular relationship may not always be available and it may be necessary to provide a similar structure wherein the pivot points of the cam member and the bail are both on the same side of the bail. Such a situation is illustrated in FIG. 6. Most of the elements of FIG. 6 correspond very closely with elements in the other figures and, therefore, the elements of FIG. 6 have been given identifying numbers wherein the last two digits correspond to the last two digits of the most closely related elements in the other figures. In FIG. 6, the cam member 224 is pivoted about point 226 and the cam faces 227 and 228 act on the bail 229. As may be seen, the locus of the center of the bail 229, as it moves from one rest position to the other, is along arc 233 which has its center at 230. It will be seen that the bail cannot move from either at rest position because of the constraining influence of the cam faces 227 and 228. However, when the bail 229 is at an intermediate position, for example, as shown with its center at point 236, there is room for free motion of the bail 229 between the cam faces 227 and 228.
In some structures it may be desirable to move a bail along a straight line instead of an arc. This may be pictured as a structure similar to that shown in FIG. 4 wherein the radius of the locus of the center of the bail 129 is of infinite radius. In such case, the cam member would be similar to that shown in FIG. 4.
A relationship may also exist wherein the bail is pivoted, but the cam member has a straight line motion which may be envisioned as pivoting from a center of infinite radius. In such case, cam members similar to those shown may be used.
Situations may also arise wherein it is desired to permit free travel of the bail while in its at rest position, but to have more restricted free motion of the bail while it is at an intermediate position. These objectives may be met by using the cam member 224 of FIG. 6 with the structure of FIG. 1, or the cam member 124 of FIG. 5 with the structure of FIG. 6.
In summary, there has been shown a linkage for actuating a bail which allows no free motion of the bail when it is in its at rest position, but which allows some free motion of the bail when it is in an intermediate position. The bail may move on either a straight line or arc course and the cam member may move on either a straight line or arc course as long as at least one or the other is moving along an arc.
While there has been shown and described what is considered at the present to be a preferred embodiment of the invention, modifications thereto will readily occur to those skilled in the related arts. It is believed that no further analysis or description is required and that the foregoing so fully reveals the gist of the present invention that those skilled in the applicable arts can adapt it to meet the exigencies of their specific requirements. It is not desired, therefore, that the invention be limited to the embodiments shown and described, and it is intended to cover in the appended claims all such modifications as fall within the true spirit and scope of the invention
|
A simplified linkage and cam member having first and second cam surfaces for interacting with a bail to drive said bail between first and second limits is provided. The cam surfaces restrict the movement of the bail when the bail is at either limit. However, when the bail is intermediate of the limits, the relationship of the effective portions of the cam surfaces allow increased bail movement for a given position of the cam member and associated cam surfaces. The structure is particularly well adapted for actuating a bail from a first to a second position wherein forces other than those applied by the cam also act on the bail; and at a critical bail position, the other forces take control and urge continued motion of the bail independent of the cam member. In such structure, the bail is first urged to move by the first cam surface, and at a critical point in its movement, it jumps from the first cam surface to the second cam surface and, for at least part of the remaining motion of the bail, the second cam surface serves to restrain the bail motion. The cam surfaces may be symmetrical in design and provide effective forces on the bail at both the start and end of the motion. The bail may, for example, constitute the actuating arm of a circuit breaker which is within an enclosure and actuated by an external arm coupled by the linkage and cam member.
| 8
|
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No. 2010-091900 filed in Japan on Apr. 13, 2010, the entire contents of which are hereby incorporated by reference.
TECHNICAL FIELD
[0002] This invention relates to a heat-conductive silicone grease composition which is readily dispensable due to a low initial viscosity and increases its viscosity with moisture at room temperature to become a silicone grease having heat-dissipating and anti-sagging properties.
BACKGROUND ART
[0003] To take an approach to the low-carbon society, an increasing need for careful management of energy exists in the electric/electronic, transportation and other fields. This requires more precise control of a system which is, in turn, equipped with more than ever electronic components. In fact, the automotive field, for example, has the trend that the proportion of hybrid vehicles, plug-in hybrid vehicles, and electric vehicles replacing gasoline vehicles is increasing in the market. These hybrid and electric vehicles must be loaded with motors, inverters, batteries, and other electronic components which are unnecessary for gasoline vehicles. Since these electronic components generate heat during operation, efficient heat dissipation is essential to insure normal operation of the components. Accordingly, the heat-dissipating materials become of greater importance.
[0004] More than ever electronic components must be mounted within a limited space, indicating that electronic Components are kept under widely varying conditions including temperature, mount angle, etc. Under the circumstances, heat-generating electronic components and heatsinks are not always held horizontal and accordingly, a heat-conductive material connecting them is often mounted at a certain angle. In such a service environment, a heat-conductive silicone adhesive material, heat-conductive potting material, or RTV heat-conductive silicone rubber composition is used in order to prevent the heat-conductive material from sagging and falling out of the space between the heat-generating component and the heatsink, as disclosed in JP-A H08-208993, JP-A S61-157569, and JP-A 2004-352947. However, all these heat-conductive materials form a complete bond to members and undesirably lack re-workability. Since the heat-conductive material becomes very hard after bonding, it cannot withstand repeated stresses induced by thermal strain and separates apart from the heat-generating component to allow for the entry of air, leading to a ramp of thermal resistance.
[0005] The above problem can be solved by a one package addition cure heat-conductive silicone composition as disclosed in JP-A 2002-327116. This composition remains re-workable and anti-sagging even after heat curing, and the cured composition is soft enough to play the role of a stress relief agent. Nevertheless, this heat-conductive material suffers from several problems. For example, it must be stored in a refrigerator or freezer and thawed prior to use. In applying the heat-conductive material, it must be heated and cooled. Then the manufacturing system must be equipped with a heating/cooling oven. The heating and cooling steps take a long time, leading to a reduction of manufacturing efficiency. From the standpoint of energy efficiency, these steps are inefficient because not only the heat-conductive material, but also an overall component must be heated. Additionally, there is a potential risk that if any cure inhibitor is present on the coating surface, the heat-conductive material remains under-cured even when heated.
[0006] To obviate the cumbersome handling of heat-conductive material including refrigeration/thaw management for storage and heating/cooling steps for application, JP-A 2003-301189 proposes a one package addition cure heat-conductive silicone composition which has been heat crosslinked during preparation. This heat-conductive material has overcome the above-discussed problems, but the tradeoff is that it has too high a viscosity to coat. There are problems that heavy loading of filler is difficult due to the high viscosity of the base polymer and the manufacture process involving crosslinking reaction takes a long time.
[0007] It would be of significance to have a heat-conductive silicone grease composition which is amenable to coat at the initial, thereafter increases its viscosity at room temperature rather than curing at room temperature so that it remains flexible, easy to re-work and anti-sagging, does not need refrigeration or freezing for storage, does not need heating upon application, avoids any undesired viscosity buildup, is easy to manufacture, allows for heavy loading of filler, and offers high heat transfer.
[0008] CITATION LIST
[0009] Patent Document 1: JP-A H08-208993
[0010] Patent Document 2: JP-A S61-157569
[0011] Patent Document 3: JP-A 2004-352947 (US 2004242762, DE 102004025867, CN 100374490)
[0012] Patent Document 4: JP-A 2002-327116 (EP 1254924 B1, U.S. Pat. No. 6,649,258)
[0013] Patent Document 5: JP-A 2003-301189 (EP 1352947 A1, U.S. Pat. No. 6,818,600)
SUMMARY OF INVENTION
[0014] An object of the invention is to provide a heat-conductive silicone grease composition which is amenable to coat at the initial, thereafter increases its viscosity with moisture at room temperature rather than curing at room temperature so that it remains flexible, anti-sagging, and easy to re-work, eliminates a need for refrigeration or freezing during storage and for heating upon application, avoids any undesired viscosity buildup, is easy to manufacture, and allows for heavy loading of filler.
[0015] The inventors have found that a heat-conductive silicone grease composition comprising (A) a trialkoxysilyl-endcapped organopolysiloxane having a viscosity of 0.1 to 1,000 Pa·s at 25° C., (B) an organopolysiloxane having the general formula (1) shown below, (C) a heat-conductive filler having a heat conductivity of at least 10 W/m° C., and (D) a condensation catalyst as essential components is amenable to coat at the initial, thereafter increases its viscosity with moisture at room temperature rather than curing at room temperature so that it remains flexible, easy to re-work, and anti-sagging, eliminates a need for refrigeration or freezing during storage and for heating upon application, avoids any undesired viscosity buildup, is easy to manufacture, allows for heavy loading, and has good heat transfer.
[0016] The invention provides a heat-conductive silicone grease composition that will increase its viscosity with moisture at room temperature, comprising
[0017] (A) 1 to 40 parts by weight of an organopolysiloxane capped with trialkoxysilyl at both ends and having a viscosity of 0.1 to 1,000 Pa·s at 25° C.,
[0018] (B) 60 to 99 parts by weight of having the general formula (1):
[0000]
[0000] wherein R 1 is each independently a substituted or unsubstituted monovalent hydrocarbon radical, R 2 is each independently an alkyl, alkoxyalkyl, alkenyl or acyl radical, n is an integer of 5 to 100, and a is an integer of 1 to 3, the sum of components (A) and (B) being 100 parts by weight,
[0019] (C) 100 to 2,000 parts by weight of a heat-conductive filler having a heat conductivity of at least 10 W/m° C., and
[0020] (D) 0.1 to 20 parts by weight of a condensation catalyst.
[0021] In a preferred embodiment, the composition may further comprising, relative to 100 parts by weight of components (A) and (B) combined,
[0022] (E) 0.1 to 20 parts by weight of an organosilane having the general formula (2):
[0000] R 3 b R 4 c Si(OR 5 ) 4-a-b (2)
[0000] wherein R 3 is each independently an unsubstituted C 6 -C 20 alkyl radical, R 4 is each independently a substituted or unsubstituted, C 1 -C 20 monovalent hydrocarbon radical, R 5 is each independently a C 1 -C 6 alkyl radical, b is an integer of 1 to 3, c is an integer of 0 to 2, and b+c is 1 to 3, or a partial hydrolytic condensate thereof, and/or
[0023] (F) 0.1 to 900 parts by weight of an organopolysiloxane of the average compositional formula (3):
[0000] R 6 d SiO (4-d)/2 (3)
[0000] wherein R 6 is each independently a substituted or unsubstituted, C 1 -C 18 monovalent hydrocarbon radical, and d is a positive number of 1.8 to 2.2, and having a viscosity of 0.05 to 1,000 Pa·s at 25° C.
ADVANTAGEOUS EFFECTS OF INVENTION
[0024] The heat-conductive silicone grease composition is amenable to coat at the initial, thereafter increases its viscosity with moisture at room temperature rather than curing at room temperature so that it remains flexible, anti-sagging, and easy to re-work. Also the composition eliminates a need for refrigeration or freezing during storage and for heating upon application, avoids any undesired viscosity buildup, is easy to manufacture, and allows for heavy loading.
DESCRIPTION OF EMBODIMENTS
[0025] As used herein, the notation (Cn-Cm) means a radical containing from n to m carbon atoms per radical.
[0026] Briefly stated, the heat-conductive silicone grease composition that will increase its viscosity with moisture at room temperature comprises (A) a trialkoxysilyl-endcapped organopolysiloxane having a viscosity of 0.1 to 1,000 Pa·s at 25° C., (B) an organopolysiloxane having the general formula (1), (C) a heat-conductive filler having a heat conductivity of at least 10 W/m° C., and (D) a condensation catalyst as essential components. These components are described in detail.
[0027] Component (A) which is a base polymer of the composition is an organopolysiloxane capped with trialkoxysilyl at both ends. The trialkoxysilyl radicals at both ends of the molecular chain include those wherein each alkoxy moiety is of 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms, such as trimethoxysilyl and triethoxysilyl.
[0028] The structure of the organopolysiloxane other than the terminal structure is not particularly limited. It may be any conventional linear organopolysiloxane which cures into an elastomer. Substituent radicals bonded to silicon atoms other than the terminal silicon include C 1 -C 8 monovalent hydrocarbon radicals, for example, alkyl radicals such as methyl, ethyl, propyl, butyl, pentyl and hexyl, cycloalkyl radicals such as cyclohexyl, alkenyl radicals such as vinyl and allyl, and aryl radicals such as phenyl and tolyl, and halogenated forms of the foregoing monovalent hydrocarbon radicals in which some or all hydrogen atoms are substituted by halogen atoms (e.g., chloro, fluoro or bromo), such as chloromethyl and trifluoromethyl.
[0029] The organopolysiloxane as component (A) should have a viscosity at 25° C. of 0.1 to 1,000 Pa·s, preferably 0.2 to 500 Pa·s, and more preferably 0.3 to 100 Pa·s. An organopolysiloxane with a viscosity of less than 0.1 Pa·s cures rather than increasing its viscosity. An organopolysiloxane having a viscosity in excess of 1,000 Pa·s provides the silicone grease composition with too high a viscosity to coat. It is noted that throughout the disclosure the viscosity is measured by a rotational viscometer.
[0030] Preferably component (A) is an organopolysiloxane having the following formula (4).
[0000]
[0000] Herein R 7 is each independently a C 1 -C 4 alkyl radical, such as methyl, ethyl, propyl or butyl, with methyl and ethyl being preferred. R 8 is each independently a substituted or unsubstituted, C 1 -C 8 monovalent hydrocarbon radical, examples of which include alkyl radicals such as methyl, ethyl, propyl, butyl, pentyl, hexyl, and heptyl, aryl radicals such as phenyl and tolyl, and halogenated forms of the foregoing monovalent hydrocarbon radicals in which some or all hydrogen atoms are substituted by halogen atoms (e.g., chloro, fluoro or bromo), such as chloromethyl, 3-chloropropyl, and trifluoromethyl. Inter alia, methyl and ethyl are preferred. The subscript m is such a number that the organopolysiloxane of formula (4) may have a viscosity of 0.1 to 1,000 Pa·s at 25° C.
[0031] Component (A) is used in an amount of 1 to 40 parts by weight, preferably 5 to 30 parts by weight, provided that components (A) and (B) total to 100 parts by weight. A composition containing less than 1 part by weight of component (A) does not increase its viscosity whereas a composition containing more than 40 parts by weight of component (A) cures rather than viscosity buildup.
[0032] Component (B) is an organopolysiloxane having the general formula (1):
[0000]
[0000] wherein R 1 is each independently a substituted or unsubstituted monovalent hydrocarbon radical, R 2 is each independently an alkyl, alkoxyalkyl, alkenyl or acyl radical, n is an integer of 5 to 100, and a is an integer of 1 to 3. This organopolysiloxane should preferably have a viscosity of 0.005 to 100 Pa·s at 25° C.
[0033] Component (B) serves as a crosslinker. It also plays the role of rendering the silicone grease composition flowable and easy to handle even when the composition is so heavily loaded with the heat-conductive filler (C) that the composition may become highly heat conductive.
[0034] In formula (1), R 1 is each independently a substituted or unsubstituted monovalent hydrocarbon radical, preferably of 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and even more preferably 1 to 3 carbon atoms. Examples include straight, branched and cyclic alkyl, alkenyl, aryl, aralkyl and halogenated alkyl radicals. Suitable straight alkyl radicals include methyl, ethyl, propyl, hexyl and octyl. Suitable branched alkyl radicals include isopropyl, isobutyl, tert-butyl and 2-ethylhexyl. Suitable cyclic alkyl radicals include cyclopentyl and cyclohexyl. Suitable alkenyl radicals include vinyl and allyl. Suitable aryl radicals include phenyl and tolyl. Suitable aralkyl radicals include 2-phenylethyl and 2-methyl-2-phenylethyl. Suitable haloalkyl radicals include 3,3,3-trifluoropropyl, 2-(nonafluorobutyl)ethyl, and 2-(heptadecafluorooctyl)ethyl. Preferably R 1 is methyl, phenyl or vinyl.
[0035] R 2 is each independently an alkyl, alkoxyalkyl, alkenyl or acyl radical. Suitable alkyl radicals include straight, branched and cyclic alkyl radicals as exemplified above for R 1 . Suitable alkoxyalkyl radicals include methoxyethyl and methoxypropyl. Suitable alkenyl radicals include vinyl and allyl. Suitable acyl radicals include acetyl and octanoyl. Preferably R 2 is alkyl, and more preferably methyl or ethyl.
[0036] The subscript n is an integer of 5 to 100, preferably 10 to 50, and a is an integer of 1 to 3, preferably equal to 3.
[0037] The organopolysiloxane as component (B) should preferably have a viscosity at 25° C. of 0.005 to 100 Pa·s, more preferably 0.005 to 50 Pa·s. If the organopolysiloxane has a viscosity of less than 0.005 Pa·s, the resulting silicone grease composition is susceptible to oil bleeding and sagging. If this viscosity is in excess of 100 Pa·s, the resulting silicone grease composition becomes less flowable and ineffective in coating operation.
[0038] Illustrative non-limiting examples of the organopolysiloxane as component (B) are given below where Me stands for methyl.
[0000]
[0039] Component (B) is used in an amount of 60 to 99 parts by weight, preferably 70 to 99 parts by weight, provided that the sum of components (A) and (B) is 100 parts by weight. A composition containing less than 60 parts by weight of component (B) becomes hard rather than flexible after viscosity buildup whereas a composition containing more than 99 part by weight of component (B) does not increase its viscosity.
[0040] Component (C) is a heat conductive filler having a thermal conductivity of at least 10 W/m° C. If a filler with a thermal conductivity of less than 10 W/m° C. is used, the silicone grease composition also has a lower than desired thermal conductivity. Examples of the heat conductive filler include aluminum, copper, silver, nickel, gold, alumina, zinc oxide, magnesium oxide, aluminum nitride, boron nitride, silicon nitride, diamond, and carbon, all in powder form. Any desired filler can be used as long as it has a thermal conductivity of at least 10 W/m° C. A powder of one type or a mixture of two or more types may be used.
[0041] The heat conductive filler is typically particulate and may be of any desired shape including irregular and spherical shapes. Preferably the heat conductive filler has an average particle size in the range of 0.1 to 200 μm, more preferably 0.1 to 100 μm. With an average particle size of less than 0.1 μm, the composition may lose grease nature and become less spreadable. If the average particle size is more than 200 μm, the grease composition may lose uniformity. As used herein, the “average particle size” is a weight average value or median diameter on particle size measurement by the laser light diffraction method or the like.
[0042] Component (C) is loaded in an amount of 100 to 2,000 parts by weight, preferably 500 to 1,500 parts by weight, relative to 100 parts by weight of components (A) and (B) combined. Less than 100 parts by weight of component (C) fails to provide the desired heat conductivity whereas composition with more than 2,000 parts by weight of component (C) loses grease nature and becomes less spreadable.
[0043] Since the heat-conductive silicone grease composition increases its viscosity through condensation, a catalyst is used therein as component (D). Suitable catalysts include alkyltin esters such as dibutyltin diacetate, dibutyltin dilaurate and dibutyltin dioctoate; titanic acid esters such as tetraisopropoxytitanium, tetra-n-butoxytitanium, tetrakis(2-ethylhexoxy)titanium, dipropoxybis(acetylacetonato)titanium, and titanium isopropoxyoctylene glycol; titanium chelates such as diisopropoxybis(ethyl acetoacetate)titanium, diisopropoxybis(methyl acetoacetate) titanium, diisopropoxybis(acetylacetonate)titanium, dibutoxybis(ethyl acetoacetonate)titanium, and dimethoxybis(ethyl acetoacetonate)titanium; organometallic compounds such as zinc naphthenate, zinc stearate, zinc 2-ethyloctoate, iron 2-ethylhexoate, cobalt 2-ethylhexoate, manganese 2-ethylhexoate, cobalt naphthenate, and alkoxyaluminum compounds; aminoalkyl-substituted alkoxysilanes such as 3-aminopropyltriethoxysilane and N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane; amine compounds and salts thereof such as hexylamine and dodecylamine phosphate; quaternary ammonium salts such as benzyltriethylammonium acetate; alkali metal salts of lower fatty acids such as potassium acetate, sodium acetate and lithium oxalate; dialkylhydroxylamines such as dimethylhydroxylamine and diethylhydroxylamine; and guanidyl-containing silanes or siloxanes such as tetramethylguanidyl propyltrimethoxysilane, tetramethylguanidyl propylmethyldimethoxysilane, and tetramethylguanidyl propyltris(trimethylsiloxy)silane. These catalysts may be used alone or in admixture of two or more. Of these, the titanium chelates are preferred.
[0044] Component (D) is used in an amount of 0.1 to 20 parts by weight, preferably 5 to 15 parts by weight, relative to 100 parts by weight of components (A) and (B) combined. Outside the range, less amounts of component (D) lead to a loss of storage stability and a short shelf life whereas an excess of component (D) is uneconomical.
[0045] To the silicone grease composition, (E) an organosilane having the general formula (2):
[0000] R 3 b R 4 c Si(OR 5 ) 4-b-c (2)
[0000] wherein R 3 is each independently an unsubstituted C 6 -C 20 alkyl radical, R 4 is each independently a substituted or unsubstituted, C 1 -C 20 monovalent hydrocarbon radical, R 5 is each independently a C 1 -C 6 alkyl radical, b is an integer of 1 to 3, c is an integer of 0 to 2, and b+c is 1 to 3 or a partial hydrolytic condensate thereof may be compounded, if desired, for further reducing the viscosity of the composition.
[0046] In formula (2), R 3 is an unsubstituted C 6 -C 20 alkyl radical, for example, hexyl, octyl, decyl, dodecyl, tetradecyl, hexadecyl, and octadecyl. Of these, C 6 -C 14 alkyl radicals are preferred.
[0047] R 4 is a substituted or unsubstituted, C 1 -C 20 monovalent hydrocarbon radical, examples of which include alkyl radicals such as methyl, ethyl and propyl, cycloalkyl radicals such as cyclopentyl and cyclohexyl, alkenyl radicals such as vinyl and allyl, aryl radicals such as phenyl and tolyl, aralkyl radicals such as 2-phenylethyl and 2-methyl-2-phenylethyl, and halogenated forms of the foregoing monovalent hydrocarbon radicals in which some or all hydrogen atoms are substituted by halogen atoms (e.g., chloro, fluoro or bromo), such as 3,3,3-trifluoropropyl, 2-(perfluorobutyl)ethyl, 2-(perfluorooctyl)ethyl and p-chlorophenyl. Inter alia, methyl is preferred.
[0048] R 5 is a C 1 -C 6 alkyl radical, such as methyl, ethyl, propyl, butyl, pentyl or hexyl. Inter alia, methyl and ethyl are preferred. The subscript b is an integer of 1 to 3, c is an integer of 0 to 2, and b+c is 1, 2 or 3, preferably equal to 1.
[0049] The organosilane or partial hydrolytic condensate thereof as component (E) is used in an amount of 0.1 to 20 parts by weight, preferably 1 to 10 parts by weight, relative to 100 parts by weight of components (A) and (B) combined. With less than 0.1 part by weight of component (E), the water resistance of the heat-conductive filler or the viscosity reducing effect may be poor. More than 20 parts by weight of component (E) may achieve no further effect and be uneconomical.
[0050] To the silicone grease composition, (F) an organopolysiloxane of the average compositional formula (3):
[0000] R 6 d SiO (4-d)/2 (3)
[0000] wherein R 6 is each independently a substituted or unsubstituted, C 1 -C 18 monovalent hydrocarbon radical, and d is a positive number of 1.8 to 2.2, and having a viscosity of 0.05 to 1,000 Pa·s at 25° C. may be compounded, if desired, for adjusting the initial viscosity of the composition.
[0051] In formula (3), R 6 is a substituted or unsubstituted, C 1 -C 18 monovalent hydrocarbon radical, examples of which include alkyl radicals such as methyl, ethyl, propyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl and octadecyl, cycloalkyl radicals such as cyclopentyl and cyclohexyl, alkenyl radicals such as vinyl and allyl, aryl radicals such as phenyl and tolyl, aralkyl radicals such as 2-phenylethyl and 2-methyl-2-phenylethyl, and halogenated forms of the foregoing monovalent hydrocarbon radicals in which some or all hydrogen atoms are substituted by halogen atoms (e.g., chloro, fluoro or bromo), such as 3,3,3-trifluoropropyl, 2-(perfluorobutyl)ethyl, 2-(perfluorooctyl)ethyl and p-chlorophenyl. Inter alia, methyl, phenyl and C 6 -C 14 alkyl radicals are preferred.
[0052] The subscript d is a positive number of 1.8 to 2.2, preferably 1.9 to 2.2, when considered from the standpoint of the desired viscosity of the silicone grease composition.
[0053] The organopolysiloxane as component (F) should preferably have a viscosity at 25° C. of 0.05 to 1,000 Pa·s, more preferably 0.5 to 100 Pa·s. If the organopolysiloxane has a viscosity of less than 0.05 Pa·s, the resulting silicone grease composition may be susceptible to oil bleeding. If this viscosity is in excess of 1,000 Pa·s, the resulting silicone grease composition may become ineffective in coating operation.
[0054] Illustrative non-limiting examples of the organopolysiloxane as component (F) are given below wherein Me stands for methyl.
[0000]
[0055] The organopolysilane as component (F) is used in an amount of 0.1 to 900 parts by weight, preferably 1 to 300 parts by weight, relative to 100 parts by weight of components (A) and (B) combined. If the amount of component (F) is more than 900 parts by weight, the resulting silicone grease composition may not readily increase its viscosity with moisture at room temperature.
[0056] The silicone grease composition of the invention is prepared by mixing the essential and optional components on any well-known means until uniform. The composition thus obtained should preferably have a viscosity at 25° C. of 5 to 350 Pa·s, more preferably 10 to 300 Pa·s, and even more preferably 50 to 250 Pa·s.
[0057] Also preferably the silicone grease composition has a heat conductivity of at least 0.5 W/m° C. as measured by the hot disk method using a thermal conductivity analyzer TPA-501 (Kyoto Electronics Mfg. Co., Ltd.).
[0058] The heat-conductive silicone grease composition is distinguished from ordinary silicone rubber compositions in that it increases its viscosity without curing. As long as moisture is available, the composition increases its viscosity even at room temperature, eliminating a step of heating. The composition may be stored without a need for refrigeration or freezing.
[0059] The heat-conductive silicone grease composition increases its viscosity under ambient conditions, for example, at a temperature of 23±2° C. and a relative humidity (RH) of 50±5% for 7 days.
[0060] When the heat-conductive silicone grease composition increases its viscosity, the ultimate viscosity preferably corresponds to a hardness of 1 to 100 units, more preferably 10 to 80 units, and even more preferably 15 to 60 units, as measured by an Asker hardness tester for ultra-soft material CS-R2 (Kobunshi Keiki Co., Ltd.).
[0061] The heat-conductive silicone grease composition has many advantages since it merely increases its viscosity without curing as mentioned above. On use as heat-dissipating grease, it is readily dispensable due to a low initial viscosity. Since the composition increases its viscosity with moisture at room temperature, it is unlikely to sag and remains re-workable. Therefore, the composition is useful in a wide variety of heat-dissipating applications such as electric/electronic and transportation fields where it is desired to minimize the installation investment and manufacture expense.
EXAMPLE
[0062] Examples of the invention are given below by way of illustration and not by way of limitation. In Examples, Me stands for methyl.
[0063] The following components were prepared.
Component A
[0000]
A-1: dimethylpolysiloxane capped with trimethoxysilyl at both ends and having a viscosity of 1 Pa·s at 25° C.
A-2: dimethylpolysiloxane capped with trimethoxysilyl at both ends and having a viscosity of 20 Pa·s at 25° C.
A-3 (comparison): dimethylpolysiloxane capped with trimethoxysilyl at both ends and having a viscosity of 0.08 Pa·s at 25° C.
A-4 (comparison): dimethylpolysiloxane capped with trimethoxysilyl at both ends and having a viscosity of 1,100 Pa·s at 25° C.
Component B
[0000]
B-1: organopolysiloxane of the following formula.
[0000]
B-2: organopolysiloxane of the following formula.
[0000]
Component C
[0070] Powders C-1 to C-3 were prepared by milling the following powders (1), (2) and (3) in a mixing ratio shown in Table 1 for 15 minutes on a 5-L gate mixer (5-L Planetary Mixer by Inoue Mfg. Co., Ltd.).
[0071] (1) aluminum powder with average particle size 4.9 μm (236 W/m° C.)
[0072] (2) aluminum powder with average particle size 15.0 (236 W/m° C.)
[0073] (3) zinc oxide powder with average particle size 1.0 μm (54 W/m° C.)
[0000]
TABLE 1
4.9 μm
Component
aluminum
15.0 μm
1.0 μm
C
powder, g
aluminum powder, g
zinc oxide powder, g
C-1
2,000
0
500
C-2
0
2,000
500
C-3
0
0
500
Component D
[0000]
D-1: diisopropoxybis(ethyl acetoacetate) titanium
Component E
[0000]
E-1: organosilane of C 10 H 21 Si(OCH 3 ) 3
Component F
[0000]
F-1: organopolysiloxane of the following formula having a viscosity of 5 Pa·s at 25° C.
[0000]
Examples 1 to 6 and Comparative Examples 1 to 6
[0077] Compositions of Examples and Comparative Examples were prepared by mixing components (A) to (F) in the amounts shown in Tables 2 and 3. Specifically, a 5-L gate mixer (5-L Planetary Mixer by Inoue Mfg. Co., Ltd.) was charged with the predetermined amounts of components (A), (B) and (C), and optionally component (F), followed by agitation at 150° C. for 3 hours while deaerating. The mixture was then cooled to room temperature, to which component (D) and optionally component (E) were added. The mixture was agitated at room temperature until uniform while deaerating. The resulting grease composition was measured for viscosity, heat conductivity, and hardness by the test methods shown below. The results are also shown in Tables 2 and 3.
Viscosity
[0078] The initial viscosity of a grease composition was measured at 25° C. by a spiral viscometer PC-1T (Malcom Co., Ltd.).
Heat Conductivity
[0079] A grease composition was sandwiched between a pair of aluminum disks having a diameter of 2.5 mm and a thickness of 1.0 mm to form a test piece. The thickness of the test piece was measured by a micrometer (Mitsutoyo Co., Ltd.). The thickness of the grease composition was computed by subtracting the thickness of two aluminum plates from the overall thickness. In this way, several test pieces having grease layers with different thickness were prepared. The thermal resistance (mm 2 -K/W) of the grease composition was measured at 25° C. using the test piece and a thermal resistance analyzer based on the laser flash method (xenon flash lamp analyzer LFA447 NanoFlash® by Netzsch GmbH). For each grease composition, the thermal resistance values of grease are plotted as a function of thickness to draw a straight line, and a heat conductivity was computed from the reciprocal of a gradient of that line.
Hardness
[0080] A grease composition of 3 mm thick was held at 23±2° C. and RH 50±5% for 7 days, after which it was measured for hardness by an Asker hardness tester for ultra-soft material CS-R2 (Kobunshi Keiki Co., Ltd.). Notably the cured compositions of Comparative Examples were measured for hardness by a Durometer Type A hardness tester for hard material.
[0000]
TABLE 2
Formulation
Example
(pbw)
1
2
3
4
5
6
Component A
A-1
10
10
0
10
30
30
A-2
0
0
10
0
0
0
A-3
0
0
0
0
0
0
A-4
0
0
0
0
0
0
Component B
B-1
90
0
90
90
70
70
B-2
0
90
0
0
0
0
Component C
C-1
0
0
0
1,000
0
0
C-2
1,100
1,100
1,100
0
0
0
C-3
0
0
0
0
400
450
Component D
D-1
8
8
8
8
7
7
Component E
E-1
2
2
2
2
0
3
Component F
F-1
0
0
0
0
0
100
Test results
Initial viscosity
65
70
150
100
60
250
(Pa-s)
Heat conductivity
4.7
4.6
4.7
3.5
1.1
1.2
(W/m ° C.)
Hardness after
20
22
30
18
45
50
viscosity buildup
(Asker CS-R2)
[0000]
TABLE 3
Formulation
Comparative Example
(pbw)
1
2
3
4
5
6
Component A
A-1
90
0
0
10
10
0.1
A-2
0
0
0
0
0
0
A-3
0
10
0
0
0
0
A-4
0
0
10
0
0
0
Component B
B-1
10
90
90
90
90
99.9
B-2
0
0
0
0
0
0
Component C
C-1
0
0
0
2,200
90
0
C-2
1,100
1,100
1,100
0
0
1,100
C-3
0
0
0
0
0
0
Component D
D-1
1
8
8
8
8
8
Component E
E-1
0
2
2
2
0
2
Component F
F-1
0
0
0
0
0
1,000
Test results
Initial viscosity
350
40
not
not
10
100
(Pa-s)
greasy
greasy
Heat conductivity
4.9
4.7
unmeasurable
unmeasurable
0.4
1.3
(W/m ° C.)
Hardness after curing
90
100
unmeasurable
unmeasurable
unmeasurable
no viscosity
(Durometer Type A )
buildup
[0081] Japanese Patent Application No. 2010-091900 is incorporated herein by reference.
[0082] Although some preferred embodiments have been described, many modifications and variations may be made thereto in light of the above teachings. It is therefore to be understood that the invention may be practiced otherwise than as specifically described without departing from the scope of the appended claims.
|
A heat-conductive silicone grease composition is provided comprising (A) a trialkoxysilyl-endcapped organopolysiloxane having a viscosity of 0.1-1,000 Pa·s at 25° C., (B) a specific organopolysiloxane, (C) a heat-conductive filler, and (D) a condensation catalyst. The composition is amenable to coat at the initial, thereafter increases its viscosity with moisture at room temperature rather than curing so that it remains flexible, easy to re-work, and anti-sagging, eliminates a need for cold storage and for hot application, avoids any undesired viscosity buildup, is easy to manufacture, and has good heat transfer.
| 2
|
BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to methods of, and apparatus for, growing crystalline material; and more particularly, to a method affording real-time analysis and control of melt-chemistry in crystal growing operations.
It is conventional to grow a single-crystalline ingot from a polycrystalline material by preparing a melt of such material and contacting the surface of the melt with a previously prepared seed crystal of the same material but with the desired crystalline lattice orientation. In growing the single crystalline ingot, the seed crystal is withdrawn from the melt at a rate of the order of a few inches per hour while the seed crystal (and hence the ingot), is counter-rotated with respect to the melt. With this technique, single crystalline ingots several feed in length and several inches in diameter are routinely grown, particularly in the silicon semiconductor industry.
In this industry, it is conventional to dope the melt with either an N-type dopant impurity, such as phosphorus, antimony, or arsenic, and/or a P-type dopant impurity, such as boron, aluminum and gallium.
A serious problem facing this industry is the difficulty of controlling the dopant concentration of the melt and the ultimately grown single crystalline ingot, and hence the resistivity of such ingot. There are many reasons why it is desirable to control the resistivity of the grown crystalline ingot. For example, control of resistivity is required for the preparation of electrically isolated portions of wafers which have been cut from the ingot in the manufacture of integrated circuits. Also, since resistivity has a bearing on the depth to which dopant impurities may be diffused and a bearing on the concentration gradient of diffused dopant impurities, it is necessary to control resistivity. Often the manufacture of certain semiconductor devices requires the control of resistivity of wafers used in making the devices to within narrow, and difficult to achieve, ranges.
One reason for the difficulty of controlling resistivity is that while growing a crystalline ingot from a melt, the chemistry of the melt (i.e., the concentration of dopant impurity with respect to the basic material, for example silicon) does not remain constant as the growing operation, which may require many hours, proceeds. Rather, the dopant impurity tends to evaporate from the melt at a rate depending in complex ways upon temperature, temperature gradients, geometry, concentration, and vapor pressure in the crystal growing apparatus.
Another reason for the difficulty of controlling the resistivity is segregation effects, whereby the concentration of the dopant impurity which becomes a part of the grown crystalline ingot is not the same as the concentration of the dopant impurity in the melt itself. More specifically, the concentration of the dopant impurity is usually less in the grown crystalline ingot than in the melt. As a result, the dopant concentration within the ingot itself increases with longitudinal position in a complex way which is not readily predictable precisely from prior empirical results.
The evaporation and segregation effects previously mentioned are particularly troublesome for melts which have been recharged several times. This recharging involves growing a single crystalline ingot of less than full length and width from a polycrystalline melt, adding new polycrystalline material to the melt, melting such material, and continuing to grow the single crystalline ingot.
Moreover, it is advantageous to reconstitute a melt after a crystalline ingot has been grown by adding more polycrystalline material. Thus, avoidable is the costly and time-consuming process of cooling the remaining melt and completely restarting the system with a new charge of polycrystalline material and dopant impurity, and achievable is uniformity of resistivity among the successively grown ingots. From this aspect, it is desirable in general to analyze a melt from which a crystalline ingot has been grown, or while a crystalline ingot is being grown, and to recharge that melt with a proper amount of polycrystalline material and/or dopant impurity so that second and successive crystalline ingots can be grown without cooling down the system with a consequent substantial saving in electrical energy, polycrystalline material and crucibles for the melt.
It is highly advantageous for ecological and economic reasons to recycle various portions of grown crystalline ingots which are not suitable for other uses for whatever reasons. Such portions may include the ends of grown crystalline ingots, as well as junk which may be broken or otherwise deleteriously affected in subsequent processing. Because such material, which may be referred to as primary material, has various concentrations of dopant impurities, it is difficult to control the resistivity of the grown crystalline ingot. Using real-time analysis and control of melt-chemistry in a crystal growing operation, a quantity of material of undetermined chemistry can be melted, analyzed, and, by adding amounts of primary material and/or dopant impurity, the melt-chemistry can be adjusted to a desired composition known to be suitable for growing a crystalline ingot of a predetermined desired resistivity.
Still another reason for the difficulty of controlling the resistivity of the grown crystalline ingot are the random sources of dopant and other impurities that increase the impurities beyond the desired amount. Such impurities are phosphorus and/or boron which are often contained in the primary material or the crucible for holding the melt.
SUMMARY OF THE INVENTION
In view of the aforementioned and other problems inherent in conventional methods and apparatus for growing crystalline material, it is an object of this invention to provide new and improved methods and apparatus to enable real-time analysis and control of melt-chemistry in crystal growing processes.
The aforementioned and other objects are achieved in accordance with this invention by withdrawing a sample from the melt, cooling and analyzing the sample. Based on the analysis, controlled additional amounts of primary material and/or dopant impurity are added directly to the melt to establish a known desired chemical composition avoiding the need for cooling of the old melt and restarting the system with a completely new charge of primary material and dopant impurity.
In accordance with one presently preferred embodiment of the invention, a melt is sampled by inserting a small diameter tube into the system through a port, and withdrawing a sample of the melt into the tube. The sample is rapidly cooled and solidified (or frozen) thus producing a polycrystalline sample, which is then inserted into a waveguide. a microwave absorption measurement in the waveguide provides a number which is readily converted into resistivity of the sample and then into doping level of the melt.
Once the doping level of the melt is known, the amount of primary material and/or dopant material needed to establish the melt at a desired quantity and doping level can be readily determined and added to the system.
Advantageously, the sample tube is of quartz material such that the polycrystalline sample therein can be inserted into the waveguide while still encased in the quartz. The quartz sampler preferably is of a particular configuration, so that the polycrystalline material drawn thereinto is of a known configuration and volume, thus facilitating repeatable microwave measurements without recalibration. The quartz is also advantageous in that it reduces the amount of reflection of the microwave power from the sample, in accordance with principles used in optics to produce anti-reflection coatings by building up layers of varying indices of refraction.
BRIEF DESCRIPTION OF THE DRAWING
The aforementioned and other features, characteristics and advantages and the invention in general will be better understood from the following more detailed description taken in conjunction with the accompanying drawing in which:
FIG. 1 is a partially broken-away, cross-sectional view of a crystal grower, illustrating a technique for withdrawing a sample from a melt;
FIG. 2 is a pictorial view of a sampler suitable for use in accordance with one embodiment of this invention;
FIG. 3 is a pictorial view of another sampler suitable for use in accordance with one embodiment of this invention;
FIG. 4 illustrates a waveguide and suitable associated electronic apparatus, partially in schematic, for performing microwave absorption measurements in accordance with one embodiment of this invention;
FIG. 5 is a cross-sectional view showing a sample in a waveguide; and
FIG. 6 illustrates a calibration diagram for relating microwave attenuation with concentration of dopant impurity in a melt.
Throughout the figures, reference numerals are repeated to indicate corresponding features where appropriate; and it will be appreciated that the figures are not necessarily drawn to scale.
DETAILED DESCRIPTION
For simplicity and clarity of explanation, the invention will be described hereinafter principally in connection with a Czochralski-type crystal grower adapted for producing a single crystalline silicon ingot from a polycrystalline silicon melt which may, but need not be, doped with an impurity for determining the conductivity type and resistivity of the grown crystalline ingot. However, it is to be understood that the described real-time sampling analysis and control techniques in accordance with this invention may well be used with other apparatus for producing other solid crystalline material and the control of other impurities.
With reference now to FIG. 1, there is illustrated in a frontal, cross-sectional, partially broken-away view a Czochralski-type crystal grower, designated generally by the numeral 11. As in typical Czochralski-type crystal growers, material 12 from which a crystalline ingot is to be grown is held in a molten state within a heated crucible 13. A seed crystal 14 is held in the end of a seed shaft 15. The free end of the seed crystal 14 is touched to the surface of the molten material 12, while the crucible 13 and the seed shaft 15 are counter-rotated, i.e., in opposite directions.
After the seed crystal 14 is touched to the surface of the molten material 12 under temperature and other conditions known to those skilled in the art, the molten material solidifies on the seed crystal with the same lattice orientation as the seed crystal. By slowly withdrawing the seed crystal, typically at the rate of the order of a few inches an hour, and rotating the seed shaft 15, a single crystalline ingot 16 is grown from the molten material 12.
Operation of at least one type of Czochralski crystal grower is described in U.S. Pat. No. 3,679,370 issued July 25, 1972, to J. J. Czeck et al., and further details of operation may be found in U.S. Pat. No. 3,698,872 issued Oct. 17, 1972, to R. E. Reusser, both patents being assigned to the assignee hereof.
In FIG. 1 the crucible 13, which is typically formed of quartz where the molten material 12 is of silicon, is surrounded and supported by a black body housing 17. The housing 17 typically is formed of graphite and in the art is typically referred to as a "susceptor" for historical reasons. In early crystal growers, heating was provided primarily by radio frequency heating, and the housing 17 operated as a susceptor to convert the radio frequency energy into thermal energy. However, with the use of larger masses of molten material, radio frequency heating was supplanted with thermal resistance, radiative-type heating.
Such thermal resistance heating is contemplated for the crystal grower 11 of FIG. 1 and is illustrated generally as element 18, which is a resistance-type heater connected to a source of electrical power (not shown) through water-cooled electrodes 19. The crucible 13, the susceptor 17 and the heating element 18 are all contained within an insulated chamber designated generally by the numeral 20. The chamber 20 is provided with fluid-cooled metallic sidewalls 21 and a fluid-cooled metallic bottom plate 22. An insulating member, designated generally by the numeral 31, is located within the chamber 20. The member includes a metllic support element 32 and an insulating element 33, advantageously of graphite felt. The bottom plate 22 is covered by a cup-shaped member 41 of solid graphite. Overlying the member 41 is a layer 42 of graphite felt for providing protection against breakout of the molten material 12 in the event that the crucible 13 should rupture, all of which is described in greater detail in the above-referenced R. E. Reusser U.S. Pat. No. 3,698,872.
A shaft 52 is coupled through seals 53 to provide a means for rotating and vertically moving the crucible 13 and the susceptor 17 theresurrounding. It should also be noted that chamber 20 is provided with a large vacuum port 55 through which roughing vacuum can be provided to the chamber 20 prior to introduction of a positive pressure atmosphere of an inert gas, such as argon, in which the crystalline ingot 16 typically is grown in accordance with the Czochralski technique.
With reference now to the upper portion of FIG. 1, there is shown a viewing port, designated generally 61, coupled by a passageway 62 into the top of the crystal grower 11. Port 61 typically includes a transparent plate at the opening thereof, through which the crystal growing operation can be viewed while in process. The port 61 is typically 3 to 5 inches in diameter and provides one convenient means by which a sampler, designated generally 71, can be inserted into the crystal grower 11. It is recognized that alternate access port designs may be advantageously employed to minimize the disturbance to a growing crystal during real-time sampling. Such insertion without introducing undue contaminants is facilitated by the above-mentioned fact that during the crystal growing operation, the internal portion of the crystal grower 11 is under a positive pressure of an inert gas such as argon.
The structure of sampler 71 can be seen in more detail in FIG. 2, which is a pictorial view. As seen, sampler 71 includes a hollow, tubular portion 72 communicating with a hollow, rectangular portion 73. A flexible hollow ball portion 75 is attached to one end of tubular portion 72. Portions 72 and 73 advantageously are formed from a solid refractory material capable of withstanding the high temperatures, in the order of about 1400° C to about 1500° C, that occur in the crystal grower 11 without contaminating the grower or its materials. Quartz is a particularly advantageous material for use because it is relatively inert and lossless at microwave frequencies; however, this material must be quickly inserted and withdrawn from the melt to minimize shape distortion. Because of this lossless property of the sampler at microwave frequencies, a sample withdrawn and cooled in sampler 71 can be inserted directly into a waveguide for microwave absorption measurements without removal from the sampler, a distinct advantage which will be discussed in detail hereinbelow.
To withdraw a sample from crystal grower 11, sampler 71 is inserted through port 61, as shown in FIG. 1, sufficiently to immerse the rectangular portion 73 thereof into the molten material 12. By squeezing the flexible ball portion 75 before the sampler is immersed into the material, a partial vacuum is created in the sampler 71, and this enables some of the molten material 12 to be withdrawn into the sampler by releasing the pressure from the ball portion 75.
Once some of the molten material 12 has been withdrawn from the crystal grower, the sampler 71 is removed from the port 61 and a cover is replaced over the port 61 to avoid entrance of undesired contaminates thereinto. The molten material in the removed sampler 71 is rapidly cooled, for example, within a few seconds, in air or by other suitable cooling means or media to solidify the material in the sampler 71.
Relatively rapid solidification is desirable to prevent the dopant impurities in the polycrystalline sample from migrating to grain boundaries during the cooling process. If such migration to grain boundaries were allowed, subsequent microwave analysis would detect only those impurities which has not migrated to grain boundaries and would thus provide less accurate results.
Also, if the sample is withdrawn too slowly, segregation effects may result and the concentration in the sample would not represent that of the melt.
In FIG. 3, there is shown an alternate form of a sampler suitable for use in accordance with this invention. As seen in FIG. 4, the sampler 76 includes a hollow, tubular portion 77, again advantageously of quartz, and a section of flexible tubing 78 slipped relatively tightly around one end of tubular portion 78. A plug 79 is inserted in the end of flexible tubing 78 to create an air-tight seal, so that by squeezing portion 78, air may be expelled from quartz tubular portion 77 to enable drawing a sample thereinto by a partial vacuum.
With reference to FIG. 4, there is shown partially schematically and in block diagram form a waveguide system including suitable associated electronic apparatus for performing microwave absorption measurements in accordance with one embodiment of this invention. As seen, a waveguide 81 of the system is of generally rectangular configuration, with the size of the rectangle being larger than the rectangular portion 73 (FIG. 2) of the sample 71. That rectangular portion 73 of sampler 71 is inserted into a slot 82 in waveguide 81 for performing the microwave absorption measurement. For that measurement, microwave power of a predetermined magnitude and frequency is provided by a source 83 through a coaxial coupling 84 to one end of the waveguide 81. A network analyzer 85 and a power meter 86 are coupled coaxially to the other end of waveguide 81. Either or both the analyzer and meter may be used to determine the amount of microwave power transmitted from the source 83 and through a sample which may be in the slot 82.
In operation, with a sample of polycrystalline material encased in the portion 73 of the sampler 71 located in the slot 82, power is supplied from the source 83, transmitted through the waveguide 81, and through the sample to the network analyzer 85 and the power meter 86. A reading is taken from either the network analyzer 85 or the power meter 86 to determine the magnitude of the transmitted power. Thereafter, the sample is withdrawn from the slot 82 and the same magnitude of power is transmitted from the source 83 into the waveguide 81 and is acted upon by a calibrated variable attenuator 87, which is adjusted while observing the power meter 86 to produce the same attenuation, and thus to enable transmitting of the same magnitude of power to the meter 86 as was transmitted by the sample previously. In this manner, with the calibrated attenuator, one can readily determine the amount of attenuation which was previously produced by the sample.
In FIG. 5 there is illustrated in side view a sample 88 encased in the quartz rectangular portion 73 in the slot 82 in the waveguide 81. As seen the slot 82 is adapted in size to be just sufficient to receive the portion 73 without an undue degree of looseness of fit.
As will be appreciated, the amount of attenuation caused by sample 88 will depend upon its geometry, thickness, volume, and other physical parameters. As such, for repeatable measurements without recalibration, a sample of known and repeatable geometry must be obtained for measurement. It is for this reason that the rectangular sample is taken in the sampler 71 shown in FIG. 2 so that the sample is always of the same geometry. A sample of the type obtainable in the sampler 71 in FIG. 2 is preferred because it can be inserted as shown in FIG. 5 into the rectangular waveguide 81 so as to cover the entire transmitting section, i.e., interior, cross-sectional area of the waveguide 81, and thus cause a greater degree of attenuation than would a test sample of the type obtainable in a sampler such as shown in FIG. 3. This of course is because attenuation is on a per unit volume basis and a greater degree of volume is exposed to the transmitting microwave with the sample 88.
With reference now to FIG. 6, there is shown a calibration diagram in which attenuation caused by the sample is shown on the vertical axis and the corresponding concentration of dopant impurities in a melt is shown on the horizontal axis.
Data for such a diagram can be obtained by sampling melts of known chemistry and them performing microwave absorption (attenuation) analysis measurements on these samples. Alternatively, of course, such data can be theoretically calculated and/or empirically derived by other means which will be apparent to those in the art.
More specifically and by way of an example, a melt of polycrystalline silicon was doped to a boron concentration of 65 parts per billion, ppb. Then a sample was withdrawn in the sampler 76 of FIG. 3, which has an inside diameter of to 0.188 inch. Then, undoped polycrystalline silicon was added to the melt reducing the concentration to 45 ppb and again a sample was withdrawn. The dilution process was continued until a melt concentration of 10 ppb was obtained. The calculated melt concentration based on dilution assumes no evaporation of boron from the melt or residual boron in the undoped polycrystalline silicon.
As seen from FIG. 6, the microwave absorption of the polycrystalline silicon sample withdrawn from the melt at each dilution does vary as a function of melt concentration. This means the microwave absorption of such a sample can be used to control and/or determine melt chemistry.
Similar curves are obtainable for arsenic doped melts and different sample geometries. The flattening out of the curve above 40 ppb is due to the "skin effect" of the microwave measurements and for most applications the sampler 71 of FIG. 2 eliminates this effect.
With reference now to the microwave absorption measurements, it is known that the amount of reflection a traveling microwave experiences encountering a medium of different indices of refraction is an easily calculated quantity. For example, at a wave length of 2.5 microns relative to air, 30% of an incident electromagnetic wave will be reflected from a silicon surface where the silicon has an index of refraction equal to 3.42. As is also well known, it is possible to reduce the amount of reflection by coating the surface with a material having an intermediate index of refraction. Silicon dioxide or quartz having an index of refraction of 1.42 is a nearly ideal intermediate layer. For this reason, the measurement of the polycrystalline silicon samples drawn from the melt while still encased in the quartz samplers is an advantageous aspect of this one embodiment of the present invention. This of course is due to the fact that more of the energy is transmitted through the sample rather than being reflected therefrom, resulting in a higher measured attenuation due to sample absorption compared to the sample's reflection. For this reason, a better and a more accurate measurement can be obtained.
At this point, it is believed that principles of this invention have been described in sufficient detail to enable one skilled in the art to practice the invention. Although the invention has been described in part by making detailed reference to a specific embodiment, such detail is intended to be and is understood to be instructive rather than restrictive. It will be appreciated by those skilled in the art that many variations may be made in the structure and in the modes of operation without departing from the spirit and scope of the invention as disclosed in the foregoing teachings.
For example, the invention need not be limited to dopant impurities. In the growing of single crystal silicon, oxygen and carbon impurities are also of interest. Excessive amounts of carbon may result in the grown crystalline ingot losing its dislocation-free state and going to a polycrystalline state. Moreover, oxygen can affect the grown ingot as it is processed into semiconductor devices and thereby reduce control of the involved processes and the ultimately produced devices.
More specifically, using the sampler 71, a sample of the polycrystalline silicon melt was taken from the crucible 13. The sample was then removed from the sampler 71 and using a conventional infrared spectrophotometer and previously published calibration curves for carbon content of single crystal silicon, a melt concentration of 17.8 ppm was measured. Adjusting the melt concentration of carbon by its well known segregation coefficient (k equals 0.07) a value of 1.3 ppm of carbon was obtained. Thus, by measuring the melt concentration for carbon, it can be determined a priori when the melt concentration is such that the level would exceed approximately 10 ppm, which is the level where single crystal perfection can be lost.
Moreover, it is apparent that the sampler 71 need not be made of quartz but may be of any suitable refractory material capable of withstanding the temperatures involved, provided, of course, that such material does not provide deleteriously contaminating impurities into the sample being withdrawn or into the melt being sampled.
Further, as allued to above, the microwave absorption measurement need not be made with the material encased in the sampler 71. Rather, the sample may be removed from the material by breaking or by other means prior to the measurement.
|
To improve the control over resistivity of grown single crystalline ingots, to reduce the turn-around time between growth of successive ingots in a particular crystal grower and to enable recycling of otherwise junk material, a sample of a molten material (the "melt") from which the ingot is to be grown is withdrawn from the crystal grower, cooled, and analyzed. Based on the analysis, controlled additional amounts of the material and/or a dopant impurity are added directly to the melt to restore it to a desired chemical composition. Thus, avoidable is costly and time-consuming cooling of the melt and restarting the system with a completely new charge of material and impurity, and achievable is uniformity of resistivity among the successively grown ingots. Preferably the sample is withdrawn from the melt into a quartz tube which is inserted into the system through a port. The sample is rapidly cooled and solidified and inserted into a waveguide system where a microwave absorption measurement provides a number which is readily converted into resistivity of the sample, and then, into doping level of the melt.
| 2
|
FIELD OF THE INVENTION
[0001] The subject invention is a process to make yarns that when incorporated into textiles and tufted fabrics create excellent substrates for printing.
BACKGROUND OF THE INVENTION
[0002] It has long been an object of the textile industry to create fabrics having intricate patterns of distinct colors. In recent years improved printers and inks have markedly increased the potential for design variety in many fabric substrates. Textiles of polyamide fibers, including tufted goods, are challenging substrates for printing. While a wide variety of dyes can be applied to polyamides, sharp print definition is more difficult. Dye formulations that work well for dyeing fabrics in bulk tend to smear together on untreated nylon fabrics, especially at the elevated temperatures needed to fix such dyes. Irregularities of surface coatings on the fabric also result in non-uniform dye uptake. The non-uniform surface structure of polyamides can also make it difficult to obtain uniformly complete dye absorption with the limited amount of dye that can be applied in a print spray.
[0003] In the past, nylon fabrics (e.g., carpets) have required special treatment with various surface-active agents such as fluorinated organic polymers prior to printing in order to achieve acceptable print quality. U.S. Pat. No. 4,231,744 (Russell et al.) and U.S. Pat. No. 4,256,459 (Moot) are representative of such technology. Such fluoropolymer materials are known to have low surface energy and it might be inferred that their mechanism of action in fabric dyeing is to reduce the contact angle between the dye drops and the fabric, and so prevent the dye from running before it can be absorbed by the fabric. As a result the dye pattern spreads less on the fabric surface.
[0004] In addition to fluorinated organic chemicals, other chemicals such as silicones having similar surface-active properties have also been found to improve print definition when applied to other substrates, such as paper.
[0005] Low surface energy chemicals for such fabric treatments are generally not very water-soluble, and do not necessarily coat the exposed fabrics uniformly, so they are normally formulated as dispersions and emulsions. Methods such as “padding” may be used to apply surface modification agents, but such low cost methods are incapable of coating the fabric with sufficient uniformity, so print quality is limited. Surface modification chemicals may also be applied via treatment baths, but this tends to raise processing cost. The high cost of fluorinated chemicals, the need for additional processing equipment and the requirement to maintain consistency with the rest of the dyeing and finishing process are all disadvantages of treatment bath addition. A further disadvantage of treatment bath application is the issue of additional waste disposal volume.
[0006] While it would seem to be desirable to provide a yarn with low surface energy for printing, this has proven to be difficult to accomplish. The fluorinated polymeric materials that have been used thus far to improve fabric printing are generally incompatible with spinning and yarn processing. One reason for this is the high yarn-metal friction occurs with fluorinated polymers, and if applied in spinning, water insoluble fluoropolymeric species tend to accumulate on the exposed surfaces of spinning and processing equipment leading to yarn breakage and staining, frequent shutdowns for cleanup, and substantially reduced process yield.
[0007] In addition to the above process problems, the addition of polymeric chemicals to spin finishes also causes reduced coating uniformity and thus reduces printing uniformity. Where the coating is too thick, dye may be poorly absorbed, while incomplete coatings cause poor print definition and clarity. Uniform finish application in spinning is naturally impossible if the finish emulsion accumulates on the yarn contact surfaces, breaks down into its individual components, or is incompatible with the properties of other finishes that are required to operate the spinning process. All of these problems occur with suspensions and emulsions of insoluble fluorochemicals, which is why they have generally not been successfully applied in spinning.
[0008] As described above, a secondary problem with polyamide print quality relates to depth and rate of dye absorption. The more completely the fabric takes up the dye, the deeper the color. The faster it reacts, the better the final print image sharpness. These properties are not perfectly compatible, as deeper dyeing polymers may take longer to achieve dye exhaustion. So far, polyamide fibers used in printing have been a compromise of properties in terms of dye depth and dye rate, and they have required pretreatment of the fabric before printing.
[0009] In view of the foregoing it is believed to be desirable to provide a printing yarn having properties such that, after conversion to fabric, it could, without a chemical coating pretreatment, accept very small drops of ink or dye and absorb them quickly, deeply and uniformly, so that the fabric would become permanently dyed in the pattern that the dye drops were applied with the least possible running and smearing of the drops. It would be especially desirable that the yarn accepts dye in sufficient quantity to provide deep, rich colors.
SUMMARY OF THE INVENTION
[0010] The present invention is directed to a method of manufacture of a rapid dyeing, deep dyeing, open structure polyamide yarn and to the yarn and to a fabric produced from the yarn. The polyamide yarn produced by the method can be printed directly as yarn, or after being made into a fabric, without the requirement for additional pretreatment coating chemicals to achieve acceptable print image definition. The yarn of the subject invention is formed from a polyamide polymer having amine ends sufficient to accept deep acid dye colors and having polymer modifiers such that the yarn maintains a relatively open surface structure through the process of spinning, air quenching, drawing and bulk texturing such that the subject yarn reacts quickly with dye. The present invention further involves the process of treating the subject yarn filaments prior to winding with an aqueous fluorinated surfactant solution in a separate finish application step. The aqueous finish applied in accordance with the present invention consists essentially of a fluorosurfactant at an effective concentration level of at least 150 parts per million by weight of flourine on yarn, and preferably 150 to 1000 parts per million by weight of flourine on yarn, and more preferably 150 to 600 parts per million by weight of flourine on yarn. The aqueous fluorosurfactant finish is applied in an enclosed chamber at a point in the yarn production process after texturizing and before windup.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The invention will be more fully understood from the following detailed description taken in connection with the accompanying drawings, which form a part of this application and in which:
[0012] FIG. 1 is a schematic illustration of a spinning and drawing process for forming a multi-filament bulked continuous filament yarn in accordance with the present invention;
[0013] FIG. 2 is an enlarged view of the finish applicator used in the process illustrated in FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
[0014] Throughout the following detailed description similar reference numerals refer to similar elements in all figures of the drawings.
[0015] With reference to FIG. 1 shown is a schematic illustration of a spinning and drawing process for forming a multi-filament effectively printable bulked continuous filament polyamide yarn in accordance with the present invention.
[0016] A polyamide flake rich in amine ends and modified as needed to assure other desired properties is melted and extruded through a spinneret 10 to form filaments F. In the case of making a printable BCF yarn for use in flooring or furnishings the preferred polymer, from the standpoint of durability, resilience, stain resistance and resistance to attack from UV and ozone exposure, is Nylon 66, a polymer of adipic acid and hexamethylenediamine. Such Nylon 66 homopolymer, however, does not dye deeply enough, rapidly enough, to be used effectively in the present invention. Instead, a polymer of adipic acid and hexamethylenediamine, modified with 1-methyl-pentamethylenediamine and terephthalic and/or isophthalic acid, herein afterwards described as a “terpolymer” of Nylon 66, has the most advantageous combination of rapid and deep dyeing characteristics, while still maintaining the essential advantages of Nylon 66. The preferred polymer is a Nylon 66 terpolymer containing about 42.9% hexamethylenediamine, 47.0% adipic acid, 2.7% terephthalic acid and 7.4% methylpentamethylenediamine. The preparation of such a Nylon 66 terpolymer is disclosed U.S. Pat. No. 5,378,800 (Mok et al.), assigned to the assignee of the present invention.
[0017] The reason for the advantageous properties of the above polymer composition with respect to printing is believed to be the compatible but irregular monomer structures included in the described terpolymer which may serve to provide an “open structure” on the fiber surface, suitable for rapid and deep dyeing. Somewhat less advantageous properties may be generally be found in applying the present invention to yarns spun from other amine-end rich polyamides, including Nylon 6 (poly-iminocarbonylpentamethylene) that has been chemically modified to increase the availability of free amine ends, either by end capping of acid ends or by the addition of dyeable amine ends, or both, by such means as are known to one skilled in the art, and Nylon 66 polymers modified with caprolactam and/or other compatible but “irregular” monomers which are known in the art.
[0018] The openings in the spinneret 10 can take any convenient or desired shape, thereby to impart any predetermined cross section configuration to the filaments F. The filaments F are air-quenched in a chimney 14 wherein cooling air at a predetermined temperature is blown at a predetermined flow rate past the filaments F. The filaments F forming a yarn bundle are pulled from the spinneret and through the quench zone by one (or more) feed roll(s) 16 rotating at a predetermined rotational speed.
[0019] At the bottom of the chimney the filaments pass through a finish position 18 where the filaments F are coated with a primary finish to facilitate drawing and texturing. The finish may be applied using any of the devices commonly known in the art as finish applicators, such as finish rolls or finish applicator tips.
[0020] The filaments F next pass around the feed roll 16 and are drawn over a pair of heated draw pins 20 by a pair of heated draw rolls 22 . An insulated enclosure 22 E reduces the loss of heat energy from the draw rolls 22 . As is known in the art additional draw rolls may be provided if a multi-step draw is desired.
[0021] After draw the filaments F are textured and form a coherent, rapid dyeing, open structure bulked continuous filament (BCF) polyamide yarn. Texturing may be accomplished by passing the filaments through the combination of a bulking jet 26 and rotating perforated drum 28 with mist quench. Alternatively, the filaments may be textured using stuffer jets (not shown), as is widely practiced in the art. In the subject process the texturizing elements are housed within a heat retaining enclosure 30 . After texturizing the filaments of the resulting yarn are advanced by take up roll 36 and then pass to a winder 36 that forms the yarn into packages 40 , 40 a.
[0022] In accordance with the present invention immediately after texturizing the combined filaments of the yarn undergo a change in direction around members 32 A, 32 B and then pass through a finish applicator 34 also disposed within the heat retaining enclosure 30 . The yarn direction again is changed by the finish applicator and directed toward the take-up 36 .
[0023] The applicator 34 , seen in more detail in FIG. 2 , has a groove 34 G formed therein. As the yarn wraps along the base of the groove 34 G an aqueous fluorosurfactant finish is applied. The wrap angle of the filaments of the yarn around the applicator 34 must be sufficient to maintain the yarn in operative finish-receiving contact with the applicator. In the design shown the applicator should be positioned such that the wrap angle should be at least two hundred degrees and, preferably, about two hundred seventy degrees, to be effective in applying finish to the filaments of the yarn.
[0024] As seen from FIG. 1 the applicator 34 is disposed within the heat retaining enclosure 30 . Because the temperature at this region of application is about eighty to one hundred degrees Centigrade, it would not be usual to apply a spin finish at this location, as spin finishes are usually temperature sensitive emulsions. Surprisingly, the disclosed location has been found to be especially well suited to the application of the dilute fluorosurfactant solution in accordance with the present invention. The location of the applicator 34 (i.e., within the enclosure 30 at a change in direction point) is believed especially advantageous location to apply the secondary finish of the present invention. This location immediately after bulking is conducive to thorough and highly uniform application of the finish to each of the individual yarn filaments, while excess moisture is naturally removed and any aerosolized fluorosurfactant from the yarn is easily contained. By applying the fluorosurfactant to the filaments within the enclosure 30 any finish material that evolves into mist or becomes. airborne is confined within the enclosure and its release to the operating environment can be prevented. Because the fluorosurfactant finish of the present invention is a solution of two components, fluorosurfactant and water, and not an emulsion, it is inherently heat stable. As may be fully understood by one skilled in the art, the aqueous fluorosurfactant secondary finish of the present invention may also be applied at alternative enclosed and vented locations anywhere after the heated drawing rolls, preferably after the bulk texturing step, of the yarn spinning process.
[0025] As described above, the secondary finish of the subject invention is a dilute aqueous dispersion of a fluorosurfactant. Preferably the dispersion, containing about 0.1 to 10%, and more preferably, 1 to 3% fluorosurfactant in water, is used at the appropriate application rate to provide an effective concentration level of at least 150 parts per million by weight of flourine on yarn, and preferably 150 to 1000 parts per million by weight of flourine on yarn, and more preferably 150 to 600 parts per million by weight of flourine on yarn.
[0026] The fluorosurfactant used in the present invention is a polar chemical having both substantial perfluourinated organic functionality and any of cationic, anionic or amphoteric functionality, and having a water solubility greater than about ten percent (10%) and preferably greater than about twenty-five percent (25%) by weight. The fluorosurfactant having anionic functionality sold by E. I. Du Pont de Nemours and Company as Zonyl® FSP is preferred.
[0027] The yarn of the subject invention is found to be an effectively printable yarn that accepts very small drops of ink or dye and absorbs them quickly, deeply and uniformly. Fabrics constructed of such yarn has been shown to maintain these advantageous properties. These properties are achieved for both the yarn and the fabric without the requirement of treatment with a fluoropolymer species, and so avoid the attendant disadvantages as described above.
|
A method of manufacture of a rapid dyeing, deep dyeing, open structure polyamide yarn and to the yarn and to a fabric produced from the yarn includes the step of applying an aqueous finish to substantially all of the rapid dyeing, deep dyeing, open structure polyamide filaments. The aqueous finish consists essentially of a fluorosurfactant dissolved in water that is applied to bulked continuous filament yarn at an effective concentration level of preferably 150 to 600 parts per million by weight of flourine on yarn. The aqueous fluorosurfactant finish is applied at a point after texturizing and before windup.
| 3
|
BACKGROUND OF THE INVENTION
This invention relates to a simple, inexpensive controlled fast-rate battery charger. More particularly, it relates to a charging apparatus having the capability of initiating and controlling fast charging of a sealed secondary cell in response to the temperature of the cell being charged.
An increasing number of consumer products are operated by one or more rechargeable sealed cells, such as nickel-cadmium cells. These cells are available in many different physical sizes with various electrical charging characteristics. Typical nickel-cadmium cells are capable of being charged at a very fast rate.
If the cell characteristics are known, and the state of charge of the cell is known, a timed charge of extremely fast rate can be safely put into the cell without risk of permanent cell damage. Even if the state of charge is not known, it is still possible to safely and reliably inject a significant amount of charge (less than in the known discharged state) at a fast rate.
The timed fast-rate charge can be applied as an exclusive charge method or can be followed with a slow-rate charge. In the timed approach, a constant-current charging source of appropriate output is connected to the cell through a timed switch. Conventional chargers utilize mechanical, thermal, electrical, or even chemical timing methods to control the duration of the fast-rate charging current. Once the timer is actuated, the fast-rate charging current is fed to the cell for a predetermined time, and then interrupted. For example, a completely discharged 1.0 ampere-hour cell in a given application may be fast-charged safely at its 5C rate, 5.0 amperes, for up to 10 minutes before the timer cuts off its fast charge. The timed-only charge system works best when, in normal use, the device presents an essentially discharged cell to the charger. Under such conditions, the time and rate can be selected to provide a charge which will utilize a significantly high percentage of the cell capacity.
Where the charger application presents a high probability that partially-charged or even fully-charged, cells will be connected to the charger, then the fast-rate charge input (product of current and time) must be reduced to a value which the cell can safely withstand.
An optimal charging apparatus for providing a controlled fast-rate charging current should have several basic capabilities. First, the apparatus should be versatile and reliable. It should be able to initiate controlled fast charging of a sealed rechargeable battery independently of the initial temperature of the battery. Second, the apparatus should be immune to electrical noise. And finally, the device should be simple and cost effective. The chargers heretofore used fail in meeting one or more of these objectives.
One method for controlling fast charging of sealed rechargeable cells, is to terminate the fast-rate charging current when the battery temperature as a result of overcharging at the fast rate, rises by some predetermined increment above room (ambient) temperature. Thereupon, the fast charge rate is shifted and latched to a slow charge rate tolerable for continuous overcharge. Latching to the slow charge rate condition precludes reinitiation of the fast-rate when the battery temperature falls back toward the ambient temperature. This approach has been generally referred to as ΔTCO designating incremental temperature cutoff, and is predicated on the property of sealed cells generating heat in overcharge, resulting in a rise in temperature of the battery.
The ΔTCO latching system has been found to have several limitations and drawbacks. In particular, when a battery having a temperature greater than the ambient by more than the cutoff increment is connected to the charger, the charger will immediately latch into the slow charge rate state. This means that the user must wait until the battery temperature has dropped below the cutoff increment in order to initiate fast charging. It also may require a series of attempts because the user has no way of knowing the battery temperature in relation to the ambient temperature. This limitation may be ameliorated by adding logic circuitry which remembers that the battery has not seen fast-rate charge current when the battery temperature drops below the cutoff increment and initiates fast-rate charging at that time. However, the additional circuitry required to implement this approach tends to result in greater circuit complexity, decreased reliability and increased cost. Also, because this type of system latches into the slow charge rate state, it is susceptible to having an electrical noise spike prematurely shift its operation to the slow charge rate. Therefore, noise filtering circuits are required to achieve high reliability, and these, too, add to the complexity and cost.
In one type of conventional latching system a temperature-sensing thermistor in the battery package develops a voltage that is applied to a current control circuit. At a predetermined battery temperature, the current control circuit acts to open a series-connected switch and latch the charger to a slow charge rate. Notwithstanding the advantages of this approach, it has a tendency to be latched into the slow charge rate state when the battery is connected. To avoid this drawback a reset capability, such as a push button switch, is required to enable the battery to initially receive fast charging current and thereafter proceed through the fast to slow-rate charging sequence.
It is a general object of the present invention to provide a controlled fast charger which is not accompanied by the limitations and drawbacks associated with conventional timed fast chargers, and which has attributes more nearly approaching those of the optimal charger.
It is a particular object of the invention to provide a controlled fast charger of automatically initiating fast charging independent of the initial temperature of the battery.
It is a further object of the invention to provide a simple, low-cost charger for providing a controlled fast-rate charging mode.
Other objects will be apparent in the following detailed description and the practice of the invention.
SUMMARY OF THE INVENTION
The foregoing and other objects and advantages are achieved by the present invention, which supplies a controlled charging current to a sealed rechargeable cell and comprises: means connectable to an external electrical source for providing charging current; controllable switching means connected in series between said charging current means and said rechargeable cell and being operable between a conducting state, wherein said charging current is supplied to said cell, and a non-conducting state wherein said charging current is interrupted; thermal sensing means including first means in thermal proximity to said rechargeable cell for sensing the temperature of said rechargeable cell, and second means for sensing the ambient temperature; and switching control means responsive to said thermal sensing means for maintaining said switching means in the conducting state, and thereby providing a path for the delivery of said charging current to said rechargeable cell, until the cell temperature exceeds the ambient temperature by a predetermined amount and thereafter maintaining that temperature difference.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of the preferred embodiment of a controlled fast charger, incorporating the present invention; and
FIGS. 2(a), (b) illustrates the ΔT non-latching control approach implemented in the controlled fast charger.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIG. 1, the controlled fast charger comprises the elements designated by the letter C and is operative to supply a controlled charging current to a rechargeable battery B connected between positive battery terminal O 1 and negative battery terminal O 2 . As indicated, the battery B may be comprised of one or more series-connected rechargeable cells.
The charger C is connectable to an external source of AC power V. Primary input terminals P 1 and P 2 of voltage transformer T connect to the power source V. The transformer secondary center tap output terminal S 3 is connected to the negative battery terminal O 2 via fast charge current limiting resistor R 7 . The transformer secondary output terminals S 1 ,S 2 are each connected to the anode of a respective rectifier diode D 1 ,D 2 of a full-wave rectifier circuit to provide pulsed unidirectional rectified charging current. An electronic switch consisting of a silicon controlled rectifier (SCR) is connected in series between the common cathodes of rectifier diodes D 1 and D 2 and positive battery terminal O 1 . When the SCR is conducting, it establishes a low impedance, fast-rate charging current path between the rectifier diodes D 1 ,D 2 of the transformer charging circuit and the rechargeable battery B.
The conduction of the SCR is controlled by a non-latching switching control circuit comprising a bridge network N, an operational amplifier A and a switching transistor Q. As illustrated in FIG. 1, the bridge network N consists of resistors R 5 ,R 6 and thermistors T 1 ,T 2 configured to provide two parallel legs connected across the DC battery potential, each leg comprising a resistor connected in series with a thermistor. Thermistors T 1 ,T 2 have negative temperature coefficients; i.e., as temperature increases, their resistance decreases. Thermistor T 2 senses and develops a voltage corresponding to the battery temperature and thermistor T 1 senses and develops a voltage corresponding to the ambient temperature. The electrical/thermal characteristics of T 1 and T 2 would ideally be identical. Resistance R 5 is higher in value than resistance R 6 . Accordingly, when the battery and ambient temperature are equal, the inverting input of operational amplifier A is higher in potential than the noninverting input, causing the output of the operational amplifier A to be low. The low output condition biases transistor Q in a non-conducting state. With transistor Q non-conducting, the control electrode of the SCR receives gate current via resistor R 2 causing the SCR to turn on with each positive half-wave pulse and conduct the charging current pulses from the full-wave rectifier circuit to the rechargeable battery.
As already mentioned, when the SCR is conductive, there is a low impedance path from the rectifier to the battery. Thus, the SCR conducts fast-rate current pulses. The delivery of fast-rate charging current continues until the battery temperature exceeds the ambient temperature by a predetermined increment, as in FIGS. 2(a), (b) established by the relative values of resistors R 5 ,R 6 and the thermistor characteristics. At that point, the potential at the inverting input to the operational amplifier A goes low relative to the noninverting input, driving the output of operational amplifier A high. The high output condition biases transistor Q in a conducting state. When transistor Q is conducting, the control electrode of the SCR is at a much lower potential than the cathode. No gate current flows, and the SCR turns off to at least momentarily terminate the fast-rate charging current.
The SCR will turn on when the battery temperature has fallen very slightly below the threshold value for the temperature differential, and will turn off again when the temperature rises above this threshold value. In an ambient of constant temperature, the SCR will conduct periodically delivering an average current just sufficient to maintain the predetermined battery/ambient differential.
Characteristic on-off cycling of room heating and cooling systems in a habitation result in slight variations in the room ambient temperature about some mean value. The thermal time constant of batteries is typically much greater than that of the ambient temperature sensing thermistor. The result of a cycling ambient temperature is to cause the duration of the on and off times of the fast charge current to be longer. The extended periods of fast-rate overcharge current can be harmful to the battery. One solution is to provide a slow-rate charge path by means of optional resistor R 1 in shunt with the SCR. The slow-rate current can be made of such value that it alone will maintain the battery in overcharge at a temperature above ambient which is slightly greater than the control circuit attempts to maintain. An alternative solution to this problem is to add thermal mass to the ambient sensing thermistor to give it the same thermal time constant as the battery described in a copending patent application entitled, "Indicator of Full Charge for Secondary Cell or Battery Thereof" of Ferdinand H. Mullersman and Charles R. Blake, filed on Sept. 22, 1980, bearing Ser. No. 189,337 and assigned to the assignee of the present invention.
Selection of the components for a controlled fast charger incorporating the present invention will be appreciated from the following exemplary embodiment which supplies a controlled fast-rate charging current of 2 amperes to four series-connected nickel-cadmium AA cells having a nominal open circuit voltage of 1.25 volts each.
The following components were utilized to implement the circuit illustrated in FIG. 1 and achieve a ΔT of 10° C. Transformer T-- Stancor P--8662 24 VCT/2A; rectifier diodes D 1 ,D 2 -- General Electric type A14; resistor R 2 -- 5.6K ohms; resistor R 3 -- 1.8K ohms; resistor R 4 -- 22K ohms; resistor R 5 -- 3.9K ohms; resistor R 6 -- 3.0K ohms; resistor R 7 -- 2.5 ohms; thermistor T 1 -- 1D201 (NTC 3K ohms); thermistor T 2 -- 1D201 (NTC 3K ohms); SCR-- General Electric type C104; A-- CA3130; and Q-- 2N5172. A resistor of value 29 ohms at R 1 was found to be capable of eliminating fast charge current pulses in overcharge in an air conditioned ambient with temperature varying cyclically as is normal for air conditioners. Biasing resistors R 2 , R 3 and R 4 were selected in accordance with standard design techniques.
The ΔT control approach described above overcomes the indicated shortcomings of the conventional ΔTCO latching control approach. In particular, if a discharged battery having a temperature greater than the charger ambient by an amount exceeding the ΔT control level is connected to the charger, the charger will not deliver fast-rate charging current initially. However, when the battery temperature drops below the ΔT control level, the SCR will turn on and fast-rate charging current will be delivered until the battery temperature again exceeds the ambient temperature by the ΔT control differential. Because the fast-rate charging current is continuously responsive to the temperature differential ΔT, there is no latching of the fast-rate charging current to an off condition. Thus, the ΔT control method is immune to electrical noise and requires no special operation such as pushing a reset button to initiate fast-rate charging operation.
Although the embodiment described above utilizes one technique for implementing the controlled fast-rate charger, certain modifications and variations thereof are possible. Thus, the above description of the preferred embodiment is exemplary and should not be considered as limiting the scope of the present invention.
|
A charger supplies a battery of sealed electrochemical cells with fast rate charging current in a controlled manner. A controllable circuit element is connected between the charge current source and the battery. This element is caused to modulate the charge current in a manner so as to initially fast charge the sealed battery, but to limit its subsequent rise in temperature above the ambient to a predetermined small differential and to maintain that differential. This temperature rise limit brings about a reduction of charge rate as the battery approaches the full charged condition resulting in an acceptable current level for long term overcharge operation.
| 7
|
BACKGROUND OF THE INVENTION
1. FIELD OF THE INVENTION
The present invention relates to a hydraulic control system for controlling a flow control valve to drive a hydraulic actuator in response to operation of a manual control device (such as a control lever or control pedal).
2. DESCRIPTION OF THE RELATED ART
The hydraulic control system noted above includes a position sensor for detecting shift positions of the manual control device. The flow control valve is operable to a position corresponding to a shift position of the manual control device detected by the sensor.
According to this control system, when the manual control device lies in a neutral stop position, the control valve is also placed in a neutral position to maintain the hydraulic actuator in a standstill state. As the manual control device is shifted from the neutral stop position to an operative position, the control valve is opened by an amount corresponding to the position of the control device, such that pressure oil is delivered at the higher flow rate from the control valve, the greater the amount of operation of the control device.
Thus, the hydraulic actuator is operable at the higher rate, the greater amount the control lever is operated from the neutral stop position. By selecting a shift position of the manual control device, the hydraulic actuator may be driven at a desired speed. That is, the shift position of the manual control device and the opening amount of the control valve are in a one-to-one relationship.
Thus, when it is desired to slightly move a working implement standing still, the manual control device must be shifted from the neutral stop position slightly to an operative position. This opens the control valve slightly, which in turn operates the hydraulic actuator slightly.
In practice, however, it is difficult for the operator to shift the manual control device from the neutral stop position to an operative position by a precise, slight amount. The manual control device is, more often than not, shifted from the neutral stop position to excess. Thus, slightly moving the working implement standing still requires a difficult operation.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a hydraulic control system which enables a smooth control for slightly operating a hydraulic actuator standing still.
The above object is fulfilled, according to the present invention, by a hydraulic control system comprising:
position detecting means for detecting a shift position of the control device;
speed detecting means for detecting a shifting speed of the control device;
control signal generating means for generating a control signal to control the flow control valve based on the shift position and the shifting speed of the control device; and
control signal output means for outputting the control signal to the flow control valve.
This hydraulic system uses a difference between a slow operation and a fast operation of the control device, i.e. a shifting speed of the control device, as a parameter for controlling the flow control valve. Thus, the shifting speed of the control device is joined with movement of the flow control valve, hence movement of the hydraulic actuator. For example, the lower the shifting speed of the control device is, the smaller amount the flow control valve is opened. This is convenient when the hydraulic actuator is slightly operated for slightly moving a working implement standing still. When, for example, the control device is slowly shifted right or left from a neutral stop position, the flow control valve receives a control signal that opens the control valve by a smaller amount than when the control device is shifted fast. As a result, the hydraulic actuator tends to move slowly. This facilitates movement of the hydraulic actuator to a desired position.
Conversely, when it is desired to move the hydraulic actuator standing still to a different position quickly, the control device is shifted rapidly from the neutral stop position to a position corresponding to the different position. Since, in this case, the hydraulic actuator is operable following the shift of the control device, a quick control is realized though stopping precision may be somewhat low.
Thus, with the hydraulic control system according to the present invention, the hydraulic actuator may be started to operate slowly, with a limited opening amount of the control valve, by slowly shifting the manual control device from the neutral stop position to a certain high speed position without taking special care. This control system dispenses with the need for the operator to shift the control device slightly from the neutral stop position, with great care, as in the prior art, in order to start the hydraulic actuator slowly.
The operation is now carded out with increased facility to slightly move a working implement standing still. The hydraulic actuator is given improved operability.
Other features and advantages of the present invention will be apparent from the following description of a preferred embodiment of the invention taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation of a tractor with a dozer implement and a backhoe implement attached thereto, and having a hydraulic control system according to the present invention.
FIG. 2 is a diagram of hydraulic circuitry for controlling the backhoe implement.
FIG. 3 is a block diagram of a control unit.
FIGS. 4A, 4B and 4C are schematic views showing different positions of a swing bracket and hydraulic cylinders of the backhoe implement.
FIG. 5A is a view showing a relationship between control currents applied to an electromagnetic proportional control valve and shift positions of a left control lever after the left control lever begins to shift from a neutral stop position.
FIG. 5B is a view showing a relationship among control currents applied to the electromagnetic proportional control valve, shift positions of the left control lever and lapse of time after the left control lever begins to shift from the neutral stop position.
FIG. 6 is a view showing a relationship between positions of the swing bracket and flow rates of pressure oil to the hydraulic cylinders.
FIG. 7 is a view showing a control current occurring when the swing bracket reaches a left or right limit of a swinging range.
FIG. 8 is a flowchart showing a first half of a control sequence for automatically stopping the swing bracket at a target position stored in memory.
FIG. 9 is a flowchart showing a second half of the control sequence for automatically stopping the swing bracket at the target position stored in memory.
FIG. 10 is a view showing control currents applied to the electromagnetic proportional control valve for automatically stopping the swing bracket at the target position stored in memory.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIG. 1, a tractor, which is one example of working vehicles, includes a pair of front wheels 1 and a pair of rear wheels 2 supporting a tractor body. The tractor body includes an engine 3 disposed in a front position, a driver's section 4 disposed in a middle position, and a transmission case 5 disposed in a rear position thereof. A dozer implement 6 is attached to the front of the tractor, and a backhoe implement 7 attached to the rear of the tractor.
The backhoe implement 7 will be described next.
As shown in FIG. 1, the backhoe implement 7 includes a support 8 connected rearwardly of the transmission case 8. The support 8 supports a swing bracket 11 swingable left and right about a vertical axis P1 by a pair of left and right hydraulic cylinder 9 and 10 (corresponding to hydraulic actuators). The swing bracket 11 supports a boom 12 pivotable about a horizontal axis P2 by a hydraulic cylinder 15. The boom 12 supports an ann 13 pivotable about a horizontal axis P3 at an extreme end of the boom 12 by a hydraulic cylinder 16. The ann 13 supports a bucket 14 pivotable about a horizontal axis P4 at an extreme end of the arm 13 by a hydraulic cylinder 17. The backhoe implement 7 further includes a pair of left and right outriggers 33 vertically movable by hydraulic cylinders 34, and a control section 18 fixed to the support 8.
A hydraulic control system for controlling the backhoe implement 7 will be described next.
As shown in FIG. 2, this control system includes an electromagnetic proportional control valve 19 for controlling flow rates of pressure oil to the pair of hydraulic cylinder 9 and 10 to control the swing bracket 11, a control valve 20 connected to the hydraulic cylinder 15 to control the boom 12, a pair of control valves 35 connected to the hydraulic cylinders 34 to control the outriggers 33, a control valve 21 connected to the hydraulic cylinder 16 to control the arm 13, and a control valve 22 connected to the hydraulic cylinder 17 to control the bucket 14. The electromagnetic proportional control valve 19 is a center bypass, neutral restoring type valve. Further, the electromagnetic proportional control valve 19 has an opening amount adjustable by a pulse signal acting as a control signal having varied duty ratios. The control valves 20, 21, 22 and 35 are center bypass type, mechanically operated valves. The electromagnetic proportional control valve 19 and control valves 20, 21, 22 and 35 are connected in parallel to one another to a pump 25.
As shown in FIGS. 1 and 2, the control section 18 of the backhoe implement 7 includes a right control lever 23 and a left control lever 24 (corresponding to the control device) operable fore and aft and left and right. The right control lever 23 is mechanically interlocked to the control valve 20 for controlling the boom 12, and to the control valve 20 for controlling the bucket 14. When the right control lever 23 is operated fore and aft, the control valve 20 is switched to swing the boom 12. When the right control lever 23 is operated left and right, the control valve 22 is switched to swing the bucket 14. The left control lever 24 is mechanically interlocked to the control valve 21 for controlling the arm 13. When the left control lever 24 is operated fore and aft, the control valve 21 is switched to swing the arm 13. A position sensor 26 is provided to detect left and right control positions of the left control lever 24. The position sensor 26 outputs detection values to be inputted to a control unit 27.
As shown in FIG. 3, the control unit 27 includes a speed detector 27A, an operating signal generator 27B, an operating signal output 27C and a corrector 27D. The speed detector 27A computes a shifting speed of the control lever 24 based on a detection value provided by the position sensor 25. The operating signal generator 27B generates an operating signal or control current for controlling the electromagnetic proportional control valve 19. The operating signal output 27C transmits the control current to the electromagnetic proportional control valve 19. The corrector 27D corrects the control current as necessary.
When the left control lever 24 is operated left or right, the control unit 27 outputs to the electromagnetic proportional control valve 19 a control current acting as a pulse signal having a duty ratio corresponding to a value computed in the control unit 27. The electromagnetic proportional control valve 19 is thereby operated to swing the swing bracket 11 left or right. For expediency of description, this pulse signal acting as the operating signal is regarded as the control current hereinafter.
Operation of the swing bracket 11 of the backhoe implement 7 will be described next.
As shown in FIGS. 4A and 1, the swing bracket 11 is supported to be swingable left and right about the vertical axis P1 of the support 8 of the backhoe implement 7. The pair of left and right hydraulic cylinders 9 and 10 of the double acting type are opposed to each other across the vertical axis P1 and connected to the swing bracket 11.
As shown in FIGS. 4A and 2, a pair of oil lines 28 and 29 extend from the electromagnetic proportional control valve 19. One of the oil lines 28 is connected in parallel to an oil chamber 9a for extending one of the hydraulic cylinders 9 and to an oil chamber 10b for contracting the other hydraulic cylinder 10. The other oil line 29 is connected in parallel to an oil chamber 9b for contracting one of the hydraulic cylinders 9 and to an oil chamber 10a for extending the other hydraulic cylinder 10.
FIG. 4A shows the swing bracket 11 lying in a transversely middle position. When, in this position, pressure oil is supplied from the electromagnetic proportional control valve 19 to the oil line 28, for example, one of the hydraulic cylinders 9 begins to extend, and the other hydraulic cylinder 10 begins to contract, whereby the swing bracket 11 begins to swing leftward.
When one of the hydraulic cylinders 9 reaches the vertical axis P1 as shown in FIG. 4B, the hydraulic cylinder 9 is extended near a stroke end. Then, the pressure oil drained from the extension-side oil chamber 10a of the other hydraulic cylinder 10 as a result of contraction thereof is supplied to the contraction-side oil chamber 9b of the hydraulic cylinder 9. Consequently, the hydraulic cylinder 9 is also contracted, whereby the swing bracket 11 reaches a leftward limit of its swinging range as shown in FIG. 4C.
A similar situation occurs when swinging the swing bracket 11 rightward.
Operation of the left control lever 24 to control the hydraulic cylinders 9 and 10 of the swing bracket 11 will be described next.
Based on left and right shift positions of the left control lever 24 (detection values of the position sensor 26), the control unit 27 supplies control currents to the electromagnetic proportional control valve 19 so that moving speeds of the swing bracket 11 correspond to the shift positions of the left control lever 24. Thus, opening amounts of the electromagnetic proportional control valve 19 correspond to the shift positions of the left control lever 24.
With this setting, when the left control lever 24 is operated to a neutral stop position N, the control current for the electromagnetic proportional control valve 19 becomes zero. Then, the proportional control valve 19 moves to a neutral position by its own neutral restoring function. The hydraulic cylinders 9 and 10 stop as a result.
Next, as the left control lever 24 is operated from the neutral stop position N toward a right shift position R or a left shift position L, the control unit 27 outputs a progressively increasing control current to the electromagnetic proportional control valve 19 to open the control valve 19 to a greater degree. Thus, the greater the amount of operation of the left control lever 24, the higher is the flow rate of pressure oil from the electromagnetic proportional control valve 19. At this time, a shifting velocity of the control lever 24 is also used as a control parameter.
FIG. 5A shows a relationship: Ia=f between amount of operation: δ of the left control lever 24 and control current: Ia applied to the electromagnetic proportional control valve 19. Control current: Ia is expressed as the linear function of δ, and its linear equation has different gradients for three regions of amount of operation: δ. The relationship of control current: Ia to the amount of operation: δ may of course be a square or other function.
FIG. 5B shows a relationship between lapse of time t after shifting the left control lever 24 from the neutral stop position N and control current: Ib applied to the electromagnetic proportional control valve 19. This relationship also includes shifting velocity: v of the left control lever 24 as a parameter, and its function is expressed as Ib=φ(t, v). The shifting velocity: v is divided into three stages, i.e. high speed, intermediate speed and low speed. The three functions, Ib=φ(t, high speed), Ib=φ (t, intermediate speed) and Ib=φ (t, low speed), are shown as linear functions, but may be other functions. These functions are stored in the form of a table in the control unit 27. The speed detector 27A in the control unit 27 computes the shifting velocity of the left control lever 24 from the detection value provided by the position sensor 26.
When the left control lever 24 is operated from the neutral stop position N toward the right shift position R or left shift position L, the operating signal generator 27B determines a corresponding Ia from the relationship: f(δ) between amount of operation: δ of the left control lever 24 and control current: Ia to be applied to the electromagnetic proportional control valve 19 as shown in FIG. 5A, and a corresponding Ib (=φ(t, v)) from the relationship between lapse of time t after shifting the left control lever 24 from the neutral stop position N and control current: Ib to be applied to the electromagnetic proportional control valve 19. The smaller of the two values Ia and Ib is selected as the control current by a comparing unit 40 and applied to the electromagnetic proportional control valve 19 through the operating signal output 27C.
Consequently, control current: Ib based on the relationship shown in FIG. 5B is employed for a time the left control lever 24 is operated from the neutral stop position N toward the right shift position R or left shift position L. Thus, the electromagnetic proportional control valve 19 receives a control current corresponding to a shifting velocity of the control lever 24. After lapse of that time, the value of lb increases, and control current Ia shown in FIG. 5A is employed.
For slightly moving the swing bracket 11, for example, the left control lever 24 is operated slowly from the neutral stop position N. As a result, the corresponding cylinder 9 or 10 receives a small quantity of oil for the amount of operation of the control lever 24. This enables the swing bracket 11 to be set to a selected position accurately. That is, when the left control lever 24 is operated slowly, it takes a little while before the control current outputted from the control unit 27 reaches a value corresponding to an amount of operation of the control lever 24.
Reverting to FIG. 2, the electromagnetic proportional control valve 19 has an exhaust oil line 38 connected through oil lines 37 having check valves 36 to the oil lines 28 and 29 extending to the hydraulic cylinders 9 and 10, respectively. With this construction, pressure oil is supplemented from the exhaust oil line 38 through the oil lines 37 to the oil lines 28 and 29, as necessary, to avoid cavitation.
The swing bracket 11 is swung by the two hydraulic cylinders 9 and 10. When the swing bracket 11 lies between the positions shown in FIGS. 4B and 4C, the two hydraulic cylinders 9 and 10 are extended or contracted in the same direction to swing the swing bracket 11. When the swing bracket 11 lies between the positions shown in FIGS. 4A and 4B, the two hydraulic cylinders 9 and 10 are extended or contracted in opposite directions to swing the swing bracket 11.
When starting to swing the swing bracket 11 standing still between the positions shown in FIGS. 4B and 4C, one of the hydraulic cylinders 9 and 10 has a higher pressure than the other. Once the swing bracket 11 is in swinging motion, a desired speed is achieved with a relatively low flow rate of pressure oil.
When one of the hydraulic cylinders 9 and 10 lies on the vertical axis P1 as shown in FIG. 4B, this hydraulic cylinder does not take part in the operation to swing the swing bracket 11. At this time, only the other hydraulic cylinder 9 or 10 swings the swing bracket 11. As a result, the swinging speed of the swing bracket 11 could become slightly lower than the swinging speed corresponding to the shift position of the left control lever 24.
As a countermeasure to this inconvenience, the control unit 27 in this embodiment includes the corrector 27D for correcting the control current determined by the operating signal generator 27B.
As shown in FIGS. 4A and 2, a potentiometer 30 is disposed on the vertical axis P1 of the swing bracket 11 for detecting positions of the swing bracket 11. The corrector 27D is operable to establish the relationships shown in FIG. 5 for the flow rates through the oil lines 28 and 29 in response to positions of the swing bracket 11 swingable through a 0 to 180 degree range. In this case, the flow rate through the oil line 28 or 29 reaches a maximum value when the swing bracket 11 is in the position shown in FIG. 4B or in a position symmetrical thereto.
Thus, when the left control lever 24 is operated the same amount from the neutral stop position N, the swing bracket 11 is swung at a constant speed from whichever position in the 0 to 180 degree range.
When varying the speed of the swing bracket 11 based on a left or right shift position of the left control lever 24 as described hereinbefore, solid lines in Fig. 6 are shifted in a flow rate increasing or decreasing direction while maintaining the relationship shown in the solid lines. Consequently, the swing bracket 11 is swung from whichever position in the 0 to 180 degree range, at a speed corresponding to a shift position of the left control lever 24.
In swinging the swing bracket 11 by operating the left control lever 24, the electromagnetic proportional control valve 19 may be controlled with a characteristic as shown in FIG. 7, to stop the swing bracket 11 at a left or right limit (a 0 or 180 degree position).
Assume that, as shown in FIG. 7, the swing bracket 11 approaches the left or right limit, with the electromagnetic proportional control valve 19 supplied with control current I1 corresponding to a shift position of the left control lever 24. When the swing bracket 11 reaches a predetermined distance to the left or right limit, control current I1 is decreased linearly regardless of the operation of the left control lever 24. When a change has been made from control current I1 to control current I2, the latter is maintained. When the swing bracket 11 reaches the limit, control current I2 falls to zero.
In the characteristic shown in FIG. 7, if an initial shift position (corresponding to control current I1) of the left control lever 24 is a high speed position (close to the right or left position R or L), the solid line and maintained control current I2 in FIG. 7 are as a whole shifted in a low current direction. If the initial shift position (corresponding to control current I1) of the left control lever 24 is a low speed position (close to the neutral stop position N), the solid line and maintained control current I2 in FIG. 7 are as a whole shifted in a high current direction.
As shown in FIG. 2, a sensor 32 is provided for detecting a rotating rate of the engine 3. When the engine 3 rotates at a high rate, the maintained control current I2 in FIG. 7 is shifted in the low current direction. When the engine 3 rotates at a low rate, the maintained control current I2 in FIG. 7 is shifted in the high current direction.
When the swing bracket 11 is stopped at a position between the right and left limits by rapidly returning the left control lever 24 to the neutral stop position N, the electromagnetic proportional control valve 19 is operated back in an opening direction for an instant as the swing bracket 11 stops. This is effective to avoid a pressure lock in the hydraulic cylinders 9 and 10 and lighten a shock occurring with stoppage of the swing bracket 11.
When the electromagnetic proportional control valve 19 is rapidly returned to the neutral position, pressure oil is supplemented from the exhaust oil line 38 through the oil line 37 to the oil line 28 or 29 to prevent a negative pressure from being generated in the pushing hydraulic cylinder 9 or 10 (the right hydraulic cylinder 9 when the swing bracket 11 is swung left). This avoids instability of the swing bracket 11 after stoppage.
In swinging the swing bracket 11, the control unit 27 may store a stopping position as a target position of the swing bracket 11, and automatically stop the swing bracket 11 at the target position. A sequence of this automatic stopping control will be described next.
Referring to FIGS. 8 and 9, the left control lever 24 is operated to swing the swing bracket 11 to a desired position and then the left control lever 24 is returned to the neutral stop position N (step S1). In this state, a storage switch 31 as shown in FIG. 2 is pressed (step S2). Based on a detection value provided by the potentiometer 30, this position of the swing bracket 11 is stored as a target position (step S3).
Next, the left control lever 24 is shifted to a position corresponding to control current 13, as shown in a solid line in FIG. 10, which is higher than a predetermined control current 14 to be supplied to the electromagnetic proportional control valve 19 (step S4). If the swing bracket 11 is swung toward the target position stored (step S5), a position from which the swing bracket 11 is swung is checked against a set position having a predetermined distance to the target position (step S6). If the swing starting position is outside the set position, the control current I3 is lowered linearly or smoothly to the predetermined control current I4 (step S7).
Conversely, if the swing starting position is inside the set position, the control current 13 is lowered sharply to the predetermined control current I4 (step S8).
Thus, the control current supplied to the electromagnetic proportional control valve 19 is lowered to control current I4, thereby to decelerate movement of the swing bracket 11. This control current I4 is maintained (step S9). When the swing bracket 11 reaches the target position stored (step S10), the control current for the electromagnetic proportional control valve 19 is lowered to zero, whereby the swing bracket 11 automatically stops at the target position (step S11).
If the left control lever 24 is returned to the neutral stop position N after the swing bracket 11 has stopped at the target position (step S12), the swing bracket 11 is reinstated in the original state swingable by operation of the left control lever 24 (step S13).
If the left control lever 24 is returned to the neutral stop position N before the swing bracket 11 reaches the target position, the swing bracket 11 stops short of the target position. Then, the swing bracket 11 may be swung away from the target position by shifting the left control lever 24 in the opposite direction.
Assume that, at step S4, the left control lever 24 is shifted to a position corresponding to control current 15, as shown in the dot-and-dash line in FIG. 10, which is lower than the predetermined control current 14. Even if the swing bracket 11 is swung toward the target position stored in this state, the above deceleration does not take place (step S14). The swing bracket 11 continues to swing with the low control current I5. When the swing bracket 11 reaches the target position (step S10), the swing bracket 11 automatically stops at the target position (step S11).
If the left control lever 24 is returned to the neutral stop position N while the swing bracket 11 is swinging with the low control current I5, the swing bracket 11 stops short of the target position. Then, the swing bracket 11 may be swung away from the target position by shifting the left control lever 24 in the opposite direction.
When automatically stopping the swing bracket 11 at the target position with the characteristics shown in the solid lines in FIG. 10, the hydraulic cylinders 9 and 10 are in varied states in each position in the 0 to 180 degree swinging range of the swing bracket 11 as described hereinbefore.
Thus, the 0 to 180 degree swinging range of the swing bracket 11 is divided into a plurality of regions, and the region including the target position stored is determined. If the target position lies in the region adjacent the 90 degree position, the predetermined control current I4 shown in the solid line in FIG. 10 is slightly raised. Conversely, if the target position lies in the region adjacent one of the limits of the swinging range (0 or 180 degree position), the predetermined control current I4 is slightly lowered.
The foregoing embodiment uses the electromagnetic proportional control valve 19 for controlling the hydraulic cylinders 9 and 10. Alternatively, a pilot-operated flow control valve may be used.
The hydraulic control system described in the above embodiment is applicable not only to the swing bracket 11 of the backhoe implement 7, but to the boom 12, arm 13 or other component of the backhoe implement 7. Further, this control system is not limited in application to the backhoe implement 7, but may be applied to the dozer implement 6 or other working implement also.
|
A control system for controlling a flow control valve to drive a hydraulic actuator in response to operation of a control device. This system includes a position detecting sensor for detecting a shift position of the control device, a speed detecting unit for detecting a shifting speed of the control device, and a controller for generating a control signal to control the flow control valve based on the shift position and shifting speed of the control device, and outputting this control signal to the flow control valve. The controller includes a first signal computing unit for determining a first control signal value based on a shift of the control device, a second control signal computing unit for determining a second control signal value based on lapse of time from start of the shift of the control device and the shifting speed of the control device, and a comparing unit for comparing the first control signal value and the second control signal value and selecting the value providing the smaller opening amount of the flow control valve to act as the control signal. The control signal generated is such that the lower the shifting speed is, the smaller amount the flow control valve is opened, whereby the slower the control device is shifted, the slower the hydraulic actuator is operated.
| 5
|
This application is a continuation in part of U.S. patent application Ser. No. 09/037,289 entitled “Reduced voltage input/reduced voltage output ti-state buffers and methods therefor,” filed Mar. 9, 1998 U.S. Pat. No. 6,181,165, which is incorporated herein by reference.
RELATED APPLICATIONS
This application is related to the following applications, which are filed on the same date herewith and incorporated herein by reference:
Application entitled “MIXED SWING VOLTAGE REPEATERS FOR HIGH RESISTANCE OR HIGH CAPACITANCE SIGNAL LINES AND METHODS THEREFOR” filed by inventors Gerhard Mueller and David R. Hanson on the same date.
Application entitled “FULL SWING VOLTAGE INPUT/FULL SWING VOLTAGE OUTPUT BI-DIRECTIONAL REPEATERS FOR HIGH RESISTANCE OR HIGH CAPACITANCE B-DIRECTIONAL SIGNAL LINES AND METHODS THEREFOR” filed by inventors Gerhard Mueller and David R. Hanson on the same date.
BACKGROUND OF THE INVENTION
The present invention relates to repeater circuits for high resistance and/or high capacitance signal lines on an integrated circuit. More particularly, the present invention relates to reduced voltage input/reduced voltage output repeaters which, when employed on a high resistance and/or high capacitance signal line, reduces the signal propagation delay, power dissipation, chip area, electrical noise, and/or electromigration.
In some integrated circuits, there exist signal lines which span long distances and/or coupled to many circuits. In modern dynamic random access memory circuits, for examples, certain unidirectional signal lines such as address lines may be coupled to many circuits and may therefore have a high capacitive load and/or resistance associated therewith. Likewise, certain bi-directional lines such as read write data (RWD) lines may also be coupled to many circuits and may therefore also have a high capacitive load and/or resistance associated therewith. The same issue also applies for many signal lines in modern microprocessors, digital signal processors, or the like. By way of example, the same issue may be seen with loaded read data lines and write data lines of memory circuits, clock lines of an integrated circuit, command lines, and/or any loaded signal carrying conductor of an integrated circuit. The propagation delay times for these signal lines, if left unremedied, may be unduly high for optimal circuit performance.
To facilitate discussion, FIG. 1 illustrates an exemplary signal line 100 , representing a signal conductor that may be found in a typical integrated circuit. Signal line 100 includes resistors 102 and 104 , representing the distributed resistance associated with signal line 100 . Resistors 102 and 104 have values which vary with, among others, the length of signal line 100 . There are also shown capacitors 106 and 108 , representing the distributed capacitance loads associated with the wire or signal bus and the circuits coupled to signal line 100 .
The resistance and capacitance associated with signal line 100 contribute significantly to a signal propagation delay between an input 110 and an output 112 . As discussed in a reference entitled “Principles of CMOS VLSI design: A Systems Perspective” by Neil Weste and Kamran Eshraghian, 2nd ed. (1992), the propagation delay of a typical signal line may be approximately represented by the equation
t delay =0.7( RC )( n )( n+ 1)/2 Eq. 1
wherein n equals the number of section, R equals the resistance value, C equals the capacitance value. For the signal line of FIG. 1, the propagation delay is therefore approximately 2.1 RC (for n=2).
If the resistance value (R) and/or the capacitance value (C) is high, the propagation delay with signal line 100 may be significantly large and may unduly affect the performance of the integrated circuit on which signal line 100 is implemented. For this reason, repeaters are often employed in such signal lines to reduce the propagation delay.
FIG. 2 depicts a signal line 200 , representing a signal line having thereon a repeater to reduce its propagation delay. Signal line 200 is essentially signal line 100 of FIG. 1 with the addition of a repeater 202 disposed between an input 210 and an output 212 . In the example of FIG. 2, repeater 202 is implemented by a pair of cascaded CMOS inverter gates 204 and 206 as shown. For ease of discussion, repeater 202 is disposed such that it essentially halves the distributed resistance and capacitance of signal line 200 .
In this case, the application of Eq. 1 yields a propagation delay of 0.7 (RC)+t DPS +t DPS +0.7 (RC) or 1.4 (RC)+2t DPS , wherein t DPS represents the time delay per inverter stage. Since t DPS may be made very small (e.g., typically 250 ps or less in most cases), the use of repeater 202 substantially reduces the propagation delay of the signal line, particularly when the delay associated with the value of R and/or C is relatively large compared to the value of t DPS.
Although the use of CMOS repeater 202 proves to be useful in reducing the propagation delay for some signal lines, such an CMOS inverter-based repeater approach fails to provide adequate performance in reduced voltage input/reduced voltage output applications. Reduced voltage input refers to input voltages that are lower than the full V int or V DD , the internal voltage at which the chip operates. By way of example, if V int is equal to 2 V, reduced voltage signal may swing from 0-1 V or −0.5 V to 0.5 V. In some cases, the reduced voltage may be low enough (e.g., 1 V) that it approaches the threshold voltage of the transistors (typically at 0.7 V or so). Likewise, reduced voltage output refers to output voltages that are lower than the full V int , the internal voltage at which the chip operates.
To appreciate the problems encountered when reduced voltage signals are employed in the inverter-based repeater, which is operated at V int or V DD , consider the situation wherein the input of the inverter is logically high but is represented by a reduced voltage signal (e.g., around 1 V). In this case, not only does the n-FET of the CMOS inverter stage conduct as expected but the p-FET, which is in series thereto, may also be softly on, causing leakage current to traverse the p-FET. The presence of the leakage current significantly degrades the signal on the output of the repeater circuit (and/or greatly increasing power consumption).
Despite the fact that CMOS inverter-based repeaters do not provide a satisfactory solution in reduced voltage applications, chip designers continue to search for ways to implement repeaters in the reduced voltage integrated circuits. Reduced voltage signals are attractive to designers since reduced voltage signals tend to dramatically reduce the power consumption of the integrated circuit. Further, the use of reduced voltage signals leads to decreased electromigration in the conductors (e.g., aluminum conductors) of the integrated circuit. With reduced electromigration, the chance of developing voids or shorts in the conductors is concomitantly reduced. Further, the reduction in the power consumption also leads to decreased electrical noise since less charge is dumped on the ground and power buses of the integrated circuit at any given time.
As can be appreciated from the foregoing, there is a desire for improved techniques for implementing reduced voltage input/reduced voltage output repeaters on the high resistance and/or high capacitance signal lines of an integrated circuit.
SUMMARY OF THE INVENTION
The invention relates, in one embodiment, to a method in an integrated circuit for implementing a reduced voltage repeater circuit on a signal line having thereon reduced voltage signals. The reduced voltage signals has a voltage level that is below V DD . The reduced voltage repeater circuit is configured to be coupled to the signal line and having an input node coupled to a first portion of the signal line for receiving a first reduced voltage signal and an output node coupled to a second portion of the signal line for outputting a second reduced voltage signal. The method includes coupling the input node to the first portion of the signal line. The input node is coupled to an input stage of the reduced voltage repeater circuit. The input stage is configured to receive the first reduced voltage signal on the signal line. The input stage is also coupled to a level shifter stage that is arranged to output a set of level shifter stage control signals responsive to the first reduced voltage signal. A voltage range of the set of level shifter stage control signals is higher than a voltage range associated with the first reduced voltage signal.
There is further included coupling the output node to the second portion of the signal line. The output node also is coupled to an output stage of the reduced voltage repeater circuit. The output stage is configured to output the second reduced voltage signal on the output node responsive to the set of level shifter stage control signals. A voltage range of the second reduced voltage signal is lower than the voltage range of the set of level shifter stage control signals.
In another embodiment, the invention relates to a method, in an integrated circuit, for implementing a reduced voltage repeater circuit on a signal line having thereon reduced voltage signals. The reduced voltage signals has a voltage level that is below V DD . The reduced voltage repeater circuit is configured to be coupled to the signal line and has an input node coupled to a first portion of the signal line for receiving a first reduced voltage signal and an output node coupled to a second portion of the signal line for outputting a second reduced voltage signal. The method includes receiving the first reduced voltage signal using an input stage of a reduced voltage repeater circuit, the input stage being coupled to the input node. Additionally, there is included forming, using a level shifter stage of the reduced voltage repeater circuit, a set of control signals responsive to the first reduced voltage signal, a voltage range of the set of control signals being higher than a voltage range associated with the first reduced voltage signal. Furthermore, there is included outputting, using an output stage of the reduced voltage repeater circuit, a second reduced voltage signal responsive to the set of control signals, a voltage range associated with the second reduced voltage signal being lower than the voltage range of the control signals.
In another embodiment, the invention relates to a reduced voltage bi-directional repeater circuit configured to be coupled to a reduced voltage bi-directional repeater circuit on a signal line having thereon reduced voltage signals. The reduced voltage signals has a voltage level that is below V DD . The reduced voltage bi-directional repeater circuit is configured to be coupled to the signal line and has a first data port configured to be coupled to a first portion of the signal line and a second data port configured to be coupled to a second portion of the signal line. The repeater circuit includes a first enable node configured to receive a first repeater enable signal at the reduced voltage bi-directional repeater circuit. The first repeater enable signal indicates a direction of signal transmission from the first data port to the second data port. The repeater circuit further includes a second enable node configured to receive a second repeater enable signal at the reduced voltage bi-directional repeater circuit. The second repeater enable signal indicates a direction of signal transmission from the second data port to the first data port, wherein the first data port is coupled to both an input stage of a first reduced voltage repeater circuit and an output stage of a second reduced voltage repeater circuit.
These and other features of the present invention will be described in more detail below in the detailed description of the invention and in conjunction with the following figures.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be readily understood by the followingdetailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which:
FIG. 1 illustrates an exemplary signal line, representing a signal conductor that may be found in a typical integrated circuit.
FIG. 2 depicts the signal line of FIG. 1 having thereon a repeater to reduce its propagation delay FIG. 3A illustrates, in accordance with one embodiment of the present invention, a simplified reduced voltage signal tri-state buffer circuit, representing a circuit that may be employed as a reduced voltage signal unidirectional repeater.
FIG. 3B illustrates, in accordance with one embodiment of the present invention, a simplified reduced voltage bi-directional repeater.
FIG. 4A illustrates, in greater detail and in accordance with one embodiment of the present invention, a tri-state buffer circuit that is capable of passing reduced voltage signals.
FIG. 4B illustrates, in greater detail and in accordance with one embodiment of the present invention, a reduced voltage bi-directional repeater.
FIGS. 5-12 illustrate, in accordance with various embodiments of the present invention, various alternative configurations of the reduced voltage input/reduced voltage output tri-state buffer circuit that may be employed for a unidirectional repeater or a bi-directional repeater application.
FIG. 13 illustrates, to facilitate discussion, a diagrammatic representation of an exemplary DRAM architecture, including a RWD line.
FIGS. 14 a , 14 b and 14 c illustrate a representation of the DRAM architecture of FIGS. 13 a , 13 b and 13 c , including a bi-directional repeater implemented on the RWD line in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will now be described in detail with reference to a few preferred embodiments thereof as illustrated in the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without some or all of these specific details. In other instances, well known structures and/or process steps have not been described in detail in order to not unnecessarily obscure the present invention.
The invention relates, in one embodiment, to a technique for improving performance in reduced voltage integrated circuits. In accordance with one aspect of the present invention, various reduced voltage tri-state buffer configurations are disclosed as being suitable candidates for unidirectional or bi-directional repeater applications. In accordance with one aspect of the present invention, reduced voltage unidirectional repeaters are employed on high resistance and/or high capacitance unidirectional line(s) of an integrated circuit to reduce the signal propagation delay, power dissipation, chip area, electrical noise, and/or electromigration. In accordance with another aspect of the present invention, reduced voltage bi-directional repeaters are employed on high resistance and/or high capacitance bi-directional line(s) of an integrated circuit to reduce the signal propagation delay, power dissipation, chip area, electrical noise, and/or electromigration of the integrated circuit.
The features and advantages of the present invention may be better understood with reference to the figures that follow. FIG. 3A illustrates, in accordance with one embodiment of the present invention, a simplified tri-state buffer circuit 200 , including input stage 202 , level shifting stage 204 , and output stage 206 . Tri-state buffer circuit 200 represents a repeater circuit suitable for use in a unidirectional low voltage input/low voltage output application. As shown, the buffer enable signal is optionally coupled to input stage 202 to control transistors therein, which pass the reduced voltage input signal on terminal 208 to level shifting stage 204 . As will be shown later herein, the buffer enable signal is also employed in some embodiments to control the passage of signals within level shifter stage 204 and/or the output stage 206 .
Within level shifting stage 204 , transistors therein shift the received input signal to a higher voltage range to control gates of transistors within output stage 206 . The higher voltage control signals permit transistors within output stage 206 to be controlled with a higher overdrive voltage, thereby permitting transistors within output stage 206 to source/sink a greater amount of current, thus more rapidly drive the load coupled to the buffer output to the desired reduced voltage level.
FIG. 3B illustrates, in accordance with one embodiment of the present invention, a simplified bi-directional repeater circuit 250 , including two tri-state buffers 252 and 254 . Each of tri-state buffers 252 and 254 may be implemented by, for example, the tri-state buffer circuit discussed in connection with FIG. 3 A and offers the advantages thereof.
As seen in FIG. 3B, the output of tri-state buffer 252 is coupled to the input of tri-state buffer 254 , forming PORT A. Likewise, the output of tri-state buffer 254 is coupled to the input of tri-state buffer 252 , forming PORT B. Both tri-state buffers 252 and 254 are controlled by control signals ENABLER and ENABLE-W, which are either complementary signals or both equal to a logic level ‘0’ (ground). Depending on the states of the control signals, PORT A may function as either an input port or an output port for reduced voltage signals (with PORT B functioning as the respective output port or input port). These control signals, which are coupled to the stages of the two tri-state buffers in accordance with techniques of the present invention, allow bi-directional repeater circuit to be implemented in reduced voltage applications such as in RWD signal lines of DRAM ICs.
FIG. 4A illustrates, in greater detail and in accordance with one embodiment of the present invention, a tri-state buffer circuit 300 , representing a non-inverting tri-state buffer capable of accepting a reduced voltage input and driving a load with its reduced voltage output to function as a unidirectional repeater or a building block of a bi-directional repeater. Buffer circuit 300 includes an input stage 302 , a level shifter stage 304 , and an output stage 306 . Input shifter stage 302 includes two field effect transistors (FETs) 308 and 310 , whose gates are controlled by buffer enable signal ENp on conductor 312 . Note that buffer enable signal ENp and its complement ENc are optional and may be tied high and low respectively without impacting the ability of the circuit of FIG. 4A to function as a basic reduced voltage input/reduced voltage output unidirectional buffer/repeater. The reduced voltage input signal is received at buffer input node 314 and passed by FETs 308 and 310 to nodes 316 and 318 when the buffer enable signal is enabled (i.e., when signal ENp is high).
It should be noted that although FETs 308 and 310 are represented in the drawing as low-threshold n-FETs (the low threshold characteristic is represented by the circle surrounding the transistor symbol), such is not a requirement as long as the threshold voltage of these input transistors is lower than the input voltage range. Low threshold transistors are, however, preferred (but not required) for these transistors. In general, low threshold FETs may have a lower threshold voltage (e.g., about 0.4 V to about 0.5 V) than typical FETs (which may be around 0.6 V-0.7 V).
Level shifter stage 304 receives the signals from input stage 302 and shifts the received signals to a higher voltage range to control gates of FETs 320 and 322 in output stage 306 . Depending on the value of the reduced voltage input signal on input node 314 , output stage 306 outputs either a logical low (V SS ) or a logical high (the high value of the reduced voltage range, or V REDUCED herein). Accordingly, a reduced voltage input/reduced voltage output buffer circuit is formed.
Like transistors 310 and 308 , output transistors 320 and 322 are represented in the drawing as low-threshold n-FETs (the low threshold characteristic is represented by the circle surrounding the transistor symbol). Although low threshold transistors are preferred for these output transistors for optimum performance, transistors which may have a more typical threshold voltage range may also be employed.
To facilitate further understanding, the operation of tri-state buffer 300 will now be explained in detail. Consider the situation wherein the buffer enable signal is disabled to permit tri-state buffer to enter the tri-state mode. In the circuit of FIG. 4A, the tri-state mode is entered when signal ENp on conductor 312 is low. With low signal ENp, n-type FETs 308 and 310 are off, thereby preventing the signal at input node 314 from being passed to level shifter stage 304 . Note that inverters 324 and 328 are operated with an upper power level equal to V DD . As the term is employed herein, V DD represents the voltage level at which the integrated circuit operates, which is higher than the reduced voltage level V REDUCED but may be equal to or lower than the voltage level supplied to the integrated circuit from externally.
Inverter 324 causes signal ENc (which is the inverse of signal ENp) to go high on conductor 326 , thereby putting tri-state inverter 328 in a high impedance state and decoupling the tri-state inverter output from its input. A high signal ENc also turns on n-FET 330 to pull node 332 low, thereby turning off n-type FET 320 . Thus, buffer output 334 is decoupled from voltage source V REDUCED 336 .
The low signal ENp on conductor 312 turns on p-type FET 338 , thereby pulling node 318 high to turn on n-FET 340 . When FET 340 conducts, node 342 is pulled to V SS , thereby turning on p-FET 344 of level shifter stage 304 . When FET 344 conducts, node 316 is pulled towards V DD (by V DD voltage source 346 ) to turn off p-FET 348 , thereby decoupling node 342 from V DD voltage source 350 and keeping node 342 at the V SS level (dueto the fact that FET 340 conducts).
Since node 342 is low, FET 322 is also off, thereby decoupling buffer output 334 from V SS . With FETs 320 and 322 off, buffer output 334 is decoupled from the remainder of the buffer circuit, V REDUCED , and V SS . In other words, buffer circuit 300 is tri-stated and decoupled from the load.
When the buffer enable signal is enabled (i.e., when signal ENp of FIG. 4A is high), buffer circuit 300 is taken out of the tri-state mode. Accordingly, the voltage value on buffer output 334 will vary within the range 0-V REDUCED responsive to the voltage value on input node 314 .
Consider the situation when signal ENp is high and a V SS voltage level appears on input node 314 . The high signal ENp causes FETs 308 and 310 to turn on, passing the V SS voltage level to nodes 318 and 316 respectively. Since FET 310 conducts, node 316 goes low to turn on FET 348 , thereby pulling node 342 to V DD (by V DD voltage source 350 ). Since ENp is high and its inverted ENc signal is low, tri-state inverter 328 passes the value on node 342 to node 332 , causing node 332 to go low (since tri-state inverter 328 inverts its output relative to its input). The low signal ENc turns off FET 330 , thereby decoupling node 332 from V SS . Since node 332 is at V SS , FET 320 is turned off to decouple buffer output 334 from V REDUCED voltage source 336 .
The low node 318 (p-FET 338 is turned off by the high ENp signal to ensure that node 318 stays low) turns off FET 340 to decouple node 342 from V SS and ensuring that node 342 stays at the V DD level (due to the fact that FET 348 conducts). With node 342 at the high V DD level, this full V DD voltage is applied to the gate of output FET 322 , allowing FET 320 to sink current from the load via buffer output 334 and to quickly pull buffer output 334 to the V SS voltage level. Thus, the presence of level shifter stage 304 allows gates of transistors 320 and 322 to be controlled by control signals having the full voltage range from V SS -V DD . As can be appreciated from the foregoing, a V SS input signal on input node 314 causes a V SS output signal to appear on output node 334 when buffer circuit 300 is not tri-stated.
Consider the situation when signal ENp is high (i.e., buffer circuit 300 is not tri-stated) and a V REDUCED voltage level appears on input node 314 . The high signal ENp causes FETs 308 and 310 to turn on, passing the V REDUCED voltage level to nodes 318 and 316 respectively. Since FET 308 conducts, the V REDUCED voltage level is passed to node 318 , thereby turning on FET 340 to pull node 342 to V SS When node 342 is pulled to V SS , p-FET 344 is fully on to pull node 316 to about V DD (by V DD voltage source 346 ). Thus node 316 is at about V DD although the conduction of FET 310 causes V REDUCED to be passed to node 316 from input node 314 .
Since node 316 is at about V DD , this full V DD voltage is applied to the gate of p-FET 348 to turn FET 348 off, thereby decoupling node 342 from V DD voltage source 350 and ensuring that node 342 stays at the V SS level. It should be appreciated that level shifter stage 304 also functions to stabilize the voltage at node 342 at the V SS value to ensure that FET 322 stays fully off to decouple buffer output 334 from V SS . Otherwise, FET 348 may be softly on when V REDUCED is passed to node 316 by FET 310 , pulling the voltage at node 342 above the desired V SS value and degrading performance and/or causing the buffer circuit to malfunction and/or consuming an undue amount of power.
With signal ENp high and its inverted signal ENc low, the V SS value on node 342 causes node 332 to go to V DD (since tri-state inverter 328 outputs the inverted value of its input). The low signal ENc also turns off FET 330 to decouple node 332 from V SS . With node 332 at the high V DD level, this full V DD voltage is applied to the gate of output FET 320 , allowing FET 320 to source current to the load via buffer output 334 and to quickly pull buffer output 334 to the V REDUCED voltage level (by V REDUCED voltage source 336 ). Thus, the presence of level shifter stage 304 allows gates of transistors 320 and 322 to be controlled by control signals having the full voltage range from V SS -V DD . As can be appreciated from the foregoing, a V REDUCED input signal on input node 314 causes a V REDUCED output signal to appear on output node 334 when buffer circuit 300 is not tri-stated.
Note that although buffer circuit 300 is configured as a tri-state buffer circuit that is noninverting, such is not a requirement. Accordingly, the inventions herein are not necessarily limited to the inverting (or noninverting) feature of the reduced input voltage/reduced output voltage tri-state buffer circuit.
By using control signals having the full voltage swing (V SS -V DD ) to control gates of output FETs 320 and 322 , a higher overdrive voltage is obtained to turn on and off these FETs. If the reduced voltage V REDUCED had been employed to control gates of these output FETs, the FETs would need to be larger to source/sink the same amount of current in the same amount of time. Because the invention employs control signals having the full voltage swing (V SS -V DD ) to control gates of output FETs 320 and 322 , these FETs may be made smaller, which reduces space usage on chip.
Reducing the size of the output FETs also reduces the capacitive load to which the buffer circuit is coupled. This is advantageous in applications wherein multiple buffer circuits are employed to assert signals on a common bus conductor and multiple buffer circuit output stages may be coupled to that same common bus. By reducing the size and capacitance associated with the output FETs of the output stage in each buffer circuit, less load capacitance is presented to the buffer circuit that actually drives the bus conductor. With reduced load capacitance, latency and power consumption is advantageously reduced.
FIG. 4B illustrates, in accordance with one aspect of the present invention, a bi-directional repeater which employs two tri-state buffer circuits 300 a and 300 b coupled in opposite directions. In one preferred embodiment, each of tri-state buffers 300 a and 300 b is implemented by the tri-state buffer circuit discussed in connection with FIG. 4 A. For ease of illustration and comprehension, the various components of these tri-state buffers are numbered using the same reference numbering system employed in FIG. 4 A.To distinguish the components belonging to the upper tri-state buffer 300 a from the components belonging to the lower tri-state buffer 300 b , however, these reference numbers are appended with the letter “a” or “b”.
Control signal ENRp is coupled to the input stage of tri-state buffer 300 a and more specifically to nFETs 310 a and 308 a . Control signal ENRP is also coupled to inverter 324 a of the level shifting stage of tri-state buffer 300 a . Control signal ENWp, which is the complementary signal of control signal ENRp is coupled to the input stage of tri-state buffer 300 b and more specifically to nFETs 310 b and 308 b . Control signal ENWp is also coupled to inverter 324 b of the level shifting stage of tri-state buffer 300 b . Note that ENRp and ENWp can also both be equal to a logic level ‘0’ (ground).
In operation, when control signal ENRp is high, tri-state buffer 300 a functions as a unidirectional repeater that passes a reduced voltage signal at port RWD 1 to RWD 0 . Reference may be made back to FIG. 4A for specific details pertaining to the operation of tri-state buffer 300 a when control signal ENRp is high. At the same time, control signal ENWp goes low, essentially turning off nFETs 308 b and 310 b of tri-state buffer circuit 300 b . Thus, tri-state buffer circuit 300 b is essentially tri-stated and decoupled from port RWD 0 and port RWD 1 . In this case, the entire bi-directional repeater circuit of FIG. 4B functions as a unidirectional repeater which passes a reduced voltage input signal at port RWD 1 to port RWD 0 (i.e., left to right of FIG. 4 B).
In the reverse direction, when control signal ENWp is high, tri-state buffer 300 b functions as a unidirectional repeater which passes a reduced voltage signal at port RWD 0 to RWD 1 . Again, reference may be made back to FIG. 4A for specific details pertaining to the operation of tri-state buffer 300 b when control signal ENWp is high. At the same time, control signal ENRP goes low, essentially turning off nFETs 308 a and 310 a of tri-state buffer circuit 300 a . Thus, tri-state buffer circuit 300 a is essentially tri-stated and decoupled from port RWD 1 and port RWD 0 . In this case, the entire bi-directional repeater circuit of FIG. 4B functions as a unidirectional repeater which passes a reduced voltage input signal at port RWD 0 to port RWD 1 (i.e., right to left of FIG. 4 B). In general, the enable signal is preferably valid before the data arrives at the repeater to prevent signal transmission delay.
FIGS. 5-12 depict various alternative embodiments, showing the various exemplary manners in which input stage, the level shifter stage, and/or output stage may be configured. One of ordinary skills in the art will readily appreciate that any of the exemplary embodiments discussed in these figures may be employed as a unidirectional repeater (e.g., for address lines in DRAMs and/or other loaded unidirectional signal carrying conductors in integrated circuits) or as a bi-directional repeater stage (e.g., for RWD lines in DRAMs and/or other loaded bi-directional signal carrying conductors in integrated circuits). In the case of a bi-directional repeater, any of the tri-state buffers shown in FIGS. 4 A and 5 - 12 may be substituted for either of tri-state buffers 252 and 254 of FIG. 3 B.
In each of these FIGS. 5-12, the level shifter stage is employed to boost the reduced voltage input signal into control signals having a greater voltage range to control the output transistors in the output stage. The output transistors are connected in series between V REDUCED and V SS to output signals in this reduced voltage range. With the output transistors turned on and off by the higher voltage control signals from the level shifter stage, these transistors can advantageously source or sink a greater amount of current to drive the load with reduced latency.
In FIG. 5, the level shifter stage is implemented by a NOR gate 392 instead of a tri-state inverter as in the case of FIG. 4 A. In FIG. 6, a transmission gate 402 is employed instead in the level shifter stage. Transmission gate 402 functions to pass the voltage between its two nodes, i.e., between nodes 404 and node 406 , responsive to control signals 408 and 410 . Again, the level shifter stage comprising transmission gate 402 , transistors 412 , 414 , and 416 ensures that node 404 stays low when a logical high signal having a reduced voltage (e.g., 1 V) appears at the buffer input. The remainder of the buffer of FIG. 6 functions roughly in an analogous manner to the buffer of FIG. 4A, and the operation of the buffer of FIG. 6 is readily understandable to one skilled in the art in view of this disclosure.
In FIG. 7, an inverter 502 is employed in the level shifter stage to furnish control signals having the voltage range between V SS and V DD to the output transistor 502 . Two inverters are shown coupled to the gate of transistor 504 to source sufficient current for properly controlling transistor 504 . However, they may be omitted if the buffer enable signal can sufficiently control transistor 504 . There are three output transistors in the output stage, of which transistor 504 acts to quickly decouple the V REDUCED voltage source from the output when signal ENp is low. As a tradeoff, however, each of output transistors 504 and 506 may be required to be larger to reduce the resistance in series between the V REDUCED voltage source and the output. The larger transistor 506 may contribute to a higher capacitive load, especially when multiple tri-state buffers are coupled to the same output. In FIG. 8, output transistor 602 is added to ensure that V SS is also quickly decoupled from the output when the ENp signal is low. Again, the tradeoff results in larger transistors 602 and 604 to overcome the series resistance. The remainder of the buffers of FIGS. 7 and 8 function roughly in an analogous manner to the buffer of FIG. 4A, and the operation of these buffers is readily understandable to one skilled in the art in view of this disclosure.
In FIG. 9, a tri-state inverter 702 is employed in the level shifter stage. Tri-state inverter 702 operates in an analogous manner to tri-state inverter 328 of FIG. 4 A. In FIG. 10, transistors 802 and 804 in the output stage are coupled to signal ENpx (generated by inverters 806 and 808 of the level shifter stage) to facilitate fast decoupling of the output from both V SS and V REDUCED . However, the presence of four transistors in series in the output stage may require larger devices to be employed to overcome the series resistance. In FIG. 11, decoupling of the output from V SS is performed in the same manner as was done in the buffer of FIG. 4 A. Decoupling of the output from V REDUCED is accomplished by transistor 902 , albeit at the potential cost of requiring larger devices to be employed for transistors 902 and 904 . In FIG. 12, decoupling of the output from V REDUCED is performed in the same manner as was done in the buffer of FIG. 4 A. Decoupling of the output from V SS is accomplished by transistor 1002 , albeit at the potential cost of requiring larger devices to be employed for transistors 1002 and 1004 . The remainder of the buffers of FIGS. 9-12 function in a roughly analogous manner to the buffer of FIG. 4A, and the operation of these buffers are readily understandable to one skilled in the art in view of the remainder of this disclosure.
As mentioned earlier, any of the buffers disclosed herein may be employed as a reduced voltage input/reduced voltage output repeater for a unidirectional signal line (such as an address line in a DRAM, a microprocessor, a DSP, or the like). Likewise, any of the buffers disclosed herein may be employed as either the upper half or the lower half of a bi-directional repeater to reduce, among others, the propagation delay associated with high capacitance and/or high resistance bi-directional signal lines.
To facilitate discussion of the application of the bi-directional repeater of the present invention in a modern high density integrated circuit, FIGS. 13 a , 13 b and 13 c (referred to collectively herein as FIG. 13) illustrates, a diagrammatic representation of an exemplary DRAM architecture, which shows a RWD line 1302 coupled to a driver/receiver pair 1304 and to each of the sixteen abstract driver/receiver pairs 1306 ( a )-( p ). In FIG. 13, the tri-state buffers within outline 1340 represent the generalized driver/receiver circuit. In this example, each of driver/receiver pairs 1306 ( a )-( p ) represents the driver/receiver pair associated with a second sense amplifier, i.e., the sense amplifier that is employed to further amplify the signal from a cell after that signal has been amplified once by a first sense amplifier.
Data lines D 0 -D 15 from each of the cells represents the data to be read from or written to the cells, or more specifically to the first sense amplifier associated with the cell depending on the state of the signals that control drivers 1308 and 1310 associated with each of these driver/receiver pairs 1306 . If data is to be written to the cell that is coupled to data line D 12 , for example, the bit of data may be received by driver/receiver pair 1304 and driven onto RWD line 1302 . Driver 1304 (or more specifically driver 1312 therein) is turned on to pass the data to 1308 which then drives the data onto data line D 12 to be written to the cell. If data is to be read from the cell that is coupled to data line D 12 , for example, the bit of data may be received by driver/receiver pair 1306 ( a ) and driven onto RWD line 1302 . Driver/receiver pair 1304 (or more specifically driver 1313 therein) is turned on to pass the data from data line D 12 to a FIFO or off-chip driver circuit.
As can be seen, RWD line 1302 is a bi-directional line that is employed to pass data from off chip to one of the cells or from one of the cells to a FIFO or off-chip driver circuit and ultimately off chip. Note that for simplicity the FIFO and/or off-chip driver circuits have been omitted. With reference to FIG. 13, each driver/receiver pair 1306 has associated with it a capacitor 1320 , representing the capacitive load of that driver/receiver pair 1306 as seen from RWD line 1302 and includes the input capacitance of driver 1308 as well as the output capacitance of driver 1310 . RWD line 1302 then has a capacitive load distributed along its length that includes the capacitance associated with each of the driver/receiver pair 1306 as well as the capacitance of the RWD line itself. Furthermore, RWD line 1302 is a long signal line and tends to have a significant resistance along its length, particularly between driver/receiver pair 1306 (such as driver/receiver pair 1306 ( p )) and driver/receiver pair 1304 . The large resistance and capacitance associated with RWD line 1302 degrades performance both when writing to a cell and when reading therefrom.
FIGS. 14 a , 14 b and 14 c (referred to collectively as FIG. 14) shows, in accordance with one embodiment of the present invention, the DRAM circuit portion of FIG. 13, including a bi-directional repeater 1402 disposed in between driver/receiver pair 1304 and the driver/receiver pairs of the cell array.
Bi-directional repeater 1402 is preferably disposed such that it is positioned on RWD line 1302 between driver/receiver pair 1304 and all reduced voltage driver/receiver pairs 1306 . That is, it is preferable that any data written to or read from a driver/receiver pair 1306 via the RWD line traverses the bi-directional repeater. When so disposed, bi-directional repeater 1402 serves to decouple a portion of the capacitance associated with RWD line 1302 to improve performance during reading and writing. Note that FIG. 14 is not drawn to scale, e.g., in DRAMS the resistance Rx representing the resistance of a spine RWD can be substantial, i.e., R 1 +R 2 +R 3 . Further, the presence of bi-directional repeater 1402 reduces the amount of resistance seen by driver 1310 of driver/receiver pair 1306 when reading data and reduces the amount of resistance seen by driver 1312 of driver/receiver pair 1304 when writing data to the cell.
As can be seen from the foregoing, the use of the repeater of the present invention advantageously reduces the propagation delay associated with high capacitance, high resistance load lines. Furthermore, the use of the repeater of the present invention at strategic locations on the high capacitive load, high resistance lines advantageously improves signaling, i.e., improving the rise and fall edges to counteract the attenuation effects and/or propagation delay of the signal line. The improvement of the rise and fall times is essential to realize high bandwidth data transfer. Without this improvement, the timing window for which the transmitted data is valid is reduced and consequently the frequency at which the bus can be run is limited. If a reduced voltage unidirectional or bi-directional repeater is implemented on an integrated circuit (such as a DRAM, a microprocessor, a DSP chip, or the like) that also employs reduced voltage signals, further advantages in terms of power dissipation, electrical noise, electromigration, and chip area usage is also realized.
While this invention has been described in terms of several preferred embodiments, there are alterations, permutations, and equivalents which fall within the scope of this invention. It should also be noted that there are many alternative ways of implementing the methods and apparatuses of the present invention. It is therefore intended that the following appended claims be interpreted as including all such alterations, permutations, and equivalents as fall within the true spirit and scope of the present invention.
|
A method in an integrated circuit for implementing a reduced voltage repeater circuit on a signal line having thereon reduced voltage signals. The reduced voltage signals has a voltage level that is below V DD . The reduced voltage repeater circuit is configured to be coupled to the signal line and having an input node coupled to a first portion of the signal line for receiving a first reduced voltage signal and an output node coupled to a second portion of the signal line for outputting a second reduced voltage signal. The method includes coupling the input node to the first portion of the signal line. The input node is coupled to an input stage of the reduced voltage repeater circuit. The input stage is configured to receive the first reduced voltage signal on the signal line. The input stage is also coupled to a level shifter stage that is arranged to output a set of level shifter stage control signals responsive to the first reduced voltage signal. A voltage range of the set of level shifter stage control signals is higher than a voltage range associated with the first reduced voltage signal. There is further included coupling the output node to the second portion of the signal line. The output node also is coupled to an output stage of the reduced voltage repeater circuit. The output stage is configured to output the second reduced voltage signal on the output node responsive to the set of level shifter stage control signals. A voltage range of the second reduced voltage signal is lower than the voltage range of the set of level shifter stage control signals.
| 1
|
This application is a division of U.S. Non-Provisional patent application Ser. No. 11/430,178, filed May 9, 2006 in the U.S. Patent and Trademark Office, and issued on Feb. 15, 2011 as U.S. Pat. No. 7,887,757, the disclosure of which is incorporated herein by reference in its entirety
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to diagnostic test strips for testing biological fluids. More specifically, the present invention relates to an apparatus and method for storing and dispensing diagnostic test strips.
2. Background of the Invention
Diagnostic test strips are used to measure analyte concentrations in biological fluids. For example, diagnostic test strips are often used by diabetic patients to monitor blood glucose levels.
To preserve their integrity, diagnostic test strips must be maintained in appropriate environmental conditions. That is, the test strips should be maintained at appropriate humidity levels, and should remain free of foreign substances. Furthermore, to avoid contamination by oils or foreign substances, test strips should not be handled prior to use.
Thus, to preserve test strips, they are typically maintained in a storage vial or the like. In order to use the test strip, a user must reach into the vial, and retrieve a single test strip. However, many users, such as diabetic patients, have impaired vision or physical dexterity. Such users may find it difficult to retrieve a single test strip from a storage vial. Further, users may accidentally touch multiple test strips while reaching into the storage vial to withdraw a test strip, and potentially contaminate the unused test strips.
Accordingly, there is a need for an apparatus for storing diagnostic test strips in appropriate environmental conditions, and for conveniently dispensing the test strips one at a time.
SUMMARY OF THE INVENTION
An object of the present invention is to address at least the above problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an object of the present invention is to provide an apparatus for storing a plurality of test strips and for dispensing the test strips one at a time.
According to one embodiment of the present invention, the above and other objects are achieved by an apparatus for storing and dispensing a test strip which comprises a container configured to store a stack of test strips, a roller disposed in the container, the roller adapted to contact one test strip of the stack of test strips, and an actuator for actuating the roller to dispense the one test strip from the container.
According to another embodiment of the present invention, an apparatus for storing and dispensing a test strip comprises a container configured to store a stack of test strips, a lid connected to the container by a living hinge, and a linkage assembly operatively connected to the lid. The linkage assembly is adapted to contact one test strip of the stack of test strips so that when the lid is opened, a test strip is dispensed.
According to yet another embodiment of the present invention, an apparatus for storing and dispensing test strips comprises a container configured to store a stack of test strips, a spring disposed in the container, the spring adapted to contact one test strip of the stack of test strips, and an actuator for actuating the spring to dispense the one test strip from the container.
According to still another embodiment of the present invention, an apparatus for storing and dispensing test strips comprises means for storing a stack of test strips, means for contacting one test strip of the stack of test strips, and means for actuating the contacting means to dispense the contacted test strip.
According to a still further embodiment of present invention, a method of storing and dispensing test strips comprises the steps of arranging a plurality of test strips to form a stack of test strips, storing the plurality of test strips in a storage container, urging the stack of test strips toward a dispensing position, engaging the stack of test strips with an engaging member, actuating the engaging member to dispense the contacted test strip, and urging the remaining test strips toward the dispensing position so that another test strip is placed into a dispensing position.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features, and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a perspective view of a storage vial for storing and dispensing test strips, according to a first exemplary embodiment of the present invention;
FIG. 2 is a front view of the storage vial shown in FIG. 1 ;
FIG. 3 is a top view of the storage vial shown in FIG. 1 ;
FIG. 4 is a sectional view taken along the line 4 - 4 in FIG. 3 ;
FIG. 5 is a sectional view taken along the line 5 - 5 in FIG. 3 ;
FIG. 6 is a partially cut-away perspective view of the storage vial shown in FIG. 1 , with a test strip partially dispensed;
FIG. 7 is a perspective view of the storage vial shown in FIG. 1 , with a motor for operating the dispenser;
FIG. 8 is a perspective view of a storage vial for storing and dispensing test strips according to a second exemplary embodiment of the present invention;
FIG. 9 is a top view of the storage vial shown in FIG. 8 ;
FIG. 10 is a sectional view taken along the line 10 - 10 in FIG. 9 ;
FIG. 11 is a sectional view taken along the line 11 - 11 in FIG. 9 ;
FIG. 12 is an enlarged sectional view of certain elements of the storage vial shown in FIG. 8 ;
FIG. 13 is a sectional view of a storage vial for storing and dispensing test strips according to a third exemplary embodiment of the present invention;
FIG. 14 is another sectional view of the storage vial shown in FIG. 13 ;
FIG. 15 is a cut-away perspective view of a storage vial for storing and dispensing test strips according to a fourth exemplary embodiment of the present invention;
FIG. 16 is an enlarged view of certain elements of the storage vial shown in FIG. 15 ;
FIG. 17 is a sectional view of the storage vial shown in FIG. 15 , with a partially dispensed test strip;
FIG. 18 is a cut-away perspective view of a storage vial for storing and dispensing test strips according to a fifth exemplary embodiment of the present invention;
FIG. 19 is a cut-away perspective view of the storage vial shown in FIG. 18 , with a partially dispensed test strip;
FIG. 20 is a perspective view of a linkage member of the storage vial shown in FIG. 18 ;
FIG. 21 is a sectional view of a storage vial for storing and dispensing test strips according to a sixth exemplary embodiment of the present invention;
FIG. 22 is a sectional view of a storage vial for storing and dispensing test strips according to a seventh exemplary embodiment of the present invention;
FIG. 23 is a perspective view of a storage vial for storing and dispensing test strips according to a eighth exemplary embodiment of the present invention; and
FIG. 24 is perspective view of a cartridge of the storage vial shown in FIG. 23 .
Throughout the drawings, the same reference numerals will be understood to refer to the same elements, features and structures.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
The matters defined in the description such as detailed construction and elements are provided to assist in a comprehensive understanding of the embodiments of the invention. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. Also, descriptions of well-known functions and constructions are omitted for clarity and conciseness.
First Exemplary Embodiment
Referring to FIGS. 1-7 , a storage vial 100 for storing and dispensing test strips according to a first exemplary embodiment of the present invention includes a storage container 102 configured to store a stack of test strips 104 , a strip roller 106 rotatably disposed in the container, and a thumbwheel 108 rotatably disposed in the container. The strip roller 106 contacts one test strip 142 of the stack of test strips 104 . The thumbwheel 108 operates the strip roller 106 so that when the thumbwheel 108 is rotated, the strip roller 106 rotates to dispense the test strip 142 in contact with the strip roller 106 .
The storage container 102 includes a lower body portion 110 and a top wall 112 mounted in the lower body portion 110 . The lower body portion 110 of the storage container 102 is generally rectangular and forms a cavity 123 which is configured to store a stack of test strips 104 . A test strip supporting wall 116 extends upwardly from the bottom wall 118 of the container. The test strip supporting wall 116 is tall enough to provide support for the stack of test strips 104 loaded in the storage container 102 . The test strip supporting wall 116 may end short of the strip roller 106 so that it does not interfere with the strip roller 106 . Alternatively, the test strip supporting wall may extend to the bottom surface of the top wall 112 of the storage container 102 , and have an elongated slot to provide clearance for installation and operation of the strip roller 106 (refer to element 331 in FIG. 14 ).
The storage container 102 may be formed of a desiccant entrained polymer to regulate the specific relative humidity inside the container. U.S. Pat. No. 5,911,937, which is hereby incorporated by reference in its entirety, discloses one suitable desiccant entrained polymer. Alternatively, the storage container 102 may be formed of a polymer with an insert-molded desiccant, or a desiccant may be placed in the cavity 123 .
The top wall 112 of the storage container 102 is preferably formed separately from the remainder of the storage container 102 for easier manufacturing and assembly. After the test strips 104 are loaded into the storage container 102 , the top wall 112 may be fixed to the storage container 102 by ultrasonic welding, by an adhesive, by mechanical engagement (such as a snap-fit), or by any other suitable method known to those skilled in the art. The top wall 112 of the storage container 102 forms a dispensing slot 120 through which test strips are dispensed. The top surface 122 of the top wall 112 may bear indicia 136 (such as an arrow) for indicating the direction to rotate the thumbwheel 108 to dispense a test strip. A first supporting member 124 extends from the bottom surface 126 of the top wall 112 to rotatably support the strip roller 106 , as will be discussed in detail below. A second supporting member 128 also extends from the bottom surface of the top wall 112 . The thumbwheel 108 is rotatably supported by the second supporting member 128 , and the thumbwheel 108 extends through a second slot through the top wall 112 of the storage container 102 . A downwardly extending test strip supporting wall may be located adjacent to the test strip dispensing slot 120 to support and guide test strips into the dispensing slot 120 while they are being dispensed (refer to element 831 in FIG. 14 ).
The storage container 102 may be provided with a lid 138 to prevent humidity and other environmental contaminants from entering the storage container 102 . The lid 138 may be a separate component, but preferably the lid 138 is connected to the storage container 102 by a hinge 140 . In the illustrated embodiment, the lid 138 is formed integrally with the lower body portion 110 of the storage container 102 so that it is connected to the storage container 121 by a living hinge 140 . The lid 138 preferably forms a substantially hermetic seal with the lower body portion 110 of the storage container 102 . Such seals are known to those skilled in the art, and therefore, a detailed description of the seal will be omitted for conciseness. Also, for convenience of explanation, the lid is only shown in some of the drawings.
A biasing element 132 , such as a compression spring or a leaf spring, urges the stack of test strips 104 stored in the storage container 102 into contact with the strip roller 106 . A platform 134 may be disposed between the biasing element 132 and the stack of test strips 104 to uniformly distribute the force generated by the biasing element 132 along the length of the stack of test strips 104 . If the test strips are sufficiently rigid, however, the biasing element 132 may directly contact the test strips.
The strip roller 106 is rotatably supported by the first supporting member 124 , which extends downwardly from the top wall 112 of the storage container 102 . The strip roller 106 contacts one of the test strips 142 in the stack of test strips 104 . In the illustrated embodiment, ( FIG. 4 ), the strip roller 106 engages the right-most test strip 142 . Preferably, the strip roller 106 engages the test strip in the upper portion of the test strip. The outer circumferential surface 144 of the strip roller 106 should have a sufficient coefficient of friction to frictionally engage and dispense a test strip. For example, the strip roller 106 may be formed of rubber bonded to a metal or molded plastic roller insert. A strip roller gear 146 is located on one side of the strip roller 106 .
A thumbwheel 108 is rotatably supported by the second supporting member 128 . A plurality of gear teeth 148 are located around the outer circumference of the thumbwheel 108 , and the gear teeth 148 on the thumbwheel 108 engage the strip roller gear 146 . The gear teeth 148 also provide friction to allow a user to more conveniently operate the thumbwheel 108 with a thumb, a finger, or the like.
Alternatively, as illustrated in FIG. 7 , the storage container 102 may be used in a fully automated test strip dispenser. In this case, the automated test strip dispenser is provided with a motor 150 with a pinion gear 152 , and the storage container 102 is disposed in the automated test strip dispenser so that the pinion gear 152 engages the thumbwheel 108 . The automated test strip dispenser can, if desired, be combined with a blood glucose meter that reads the test strips 104 .
Furthermore, a locking member 154 , such as a ratchet or pawl, may be disposed on the storage container 102 to engage the thumbwheel 108 . The locking member 154 allows the thumbwheel 108 to rotate in one direction (that is, a dispensing direction), but prevents the thumbwheel 108 from rotating in the opposite direction.
The method of using the storage vial for storing and dispensing test strips according to the first exemplary embodiment of the invention will now be described. Initially, the strip roller 106 and the thumbwheel 108 are assembled to the first and second supporting members 124 , 128 , respectively, on the top wall 112 of the storage container 102 . A stack of test strips 104 is loaded into the lower body portion 110 of the storage container 102 so that the stack of test strips 104 is disposed between the platform 132 and the test strip supporting wall 130 . The biasing element 132 is installed in the cavity 123 between the platform 132 and the opposite wall of the storage container. The top wall 112 , with the strip roller 106 and the thumbwheel 108 installed, is then assembled to the lower body of the storage container 102 . The lid 138 is placed on the storage container 102 to form a substantially hermetic seal. The storage vial 100 may now be stored, and the stack of test strips 104 will be protected from environmental hazards, such as moisture. Typically, these steps will be performed by a manufacturer, rather than an end user of the storage vial.
To dispense a test strip, a user opens the lid 138 to expose the thumbwheel 108 and the strip dispensing slot 120 . The user then rotates the thumbwheel 108 in the dispensing direction by manipulating the thumbwheel 108 , with the user's fingers or the like. Upon rotation of the thumbwheel 108 , the thumbwheel 108 transmits the rotational force to the strip roller 106 through the gear teeth 148 on the thumbwheel 108 and the strip roller gear 146 . Therefore, the strip roller 106 rotates. The strip roller 106 contacts one test strip 142 of the stack of test strips 104 , and through frictional force generated between the strip roller 106 and the contacted test strip 142 , dispenses the contacted test strip 142 through the test strip dispensing slot 120 . The thumbwheel 108 may be rotated so that the test strip 142 is completely dispensed out of the storage container 102 , or the test strip 142 may be partially dispensed from the storage container 102 to expose the test strip so that a user may grasp the exposed test strip 142 to completely withdraw the test strip and use the test strip.
Once the test strip is completely dispensed from the storage container 102 , the biasing element 132 urges the remaining test strips in the stack of test strips 104 toward the strip roller 106 so that a new test strip is placed into contact with the strip roller 106 . Thus, to dispense another test strip, the user rotates the thumbwheel 108 again. After dispensing the desired number of test strips, the user may then replace the lid on the storage container 102 to store the remaining test strips for future use.
After all of the stored test strips stored in the storage container 102 have been dispensed, the storage vial 100 may be discarded, or may be returned to the manufacturer for recycling. Alternatively, the storage container 102 may be adapted to be reusable (e.g., by making the top wall 112 removable from the lower body portion 110 ).
Second Exemplary Embodiment
Referring to FIGS. 8-12 , a storage vial 200 for storing and dispensing test strips according to a second exemplary embodiment of the present invention includes a storage container 202 configured to store a stack of test strips 204 , a strip roller 206 rotatably disposed in the storage container 202 , and a pushbutton 208 disposed in the container. The strip roller 206 contacts one test strip 226 of the stack of test strips 204 . The pushbutton 208 is connected with the strip roller 206 by a gear train 230 so that when the pushbutton 208 is pushed, the strip roller 206 rotates to dispense the test strip 226 in contact with the strip roller.
The storage container 202 includes a lower body portion 210 and a top wall 212 mounted in the lower body portion 210 . The lower body portion 210 of the storage container 202 is configured substantially the same as the lower body portion 110 of the storage container 100 of the first exemplary embodiment of the invention. Accordingly, a detailed description of the lower body portion 210 will not be repeated.
The top wall 212 of the storage container 202 has a test strip dispensing slot 216 through which test strips are dispensed. A first supporting member 218 extends from the bottom surface 220 of the top wall 212 to rotatably support the strip roller 206 , as will be discussed in detail below. A second supporting member 222 extends from the bottom surface 220 of the top wall 212 to rotatably support an intermediate gear 232 .
The pushbutton 208 has a first end 234 and a second end 236 . The first end 234 of the pushbutton 208 extends through a slot located in the top wall 212 of the storage container 202 so that it may be manipulated by a user. The second end 236 of the pushbutton 208 is disposed inside the cavity 214 of the storage container 202 . A rack gear 238 is formed along the length of the pushbutton 208 near the second end 236 of the pushbutton 208 .
The pushbutton is movable between a resting position (illustrated in FIG. 10 , for example) and a dispensing position. A biasing element 240 , such as an extension spring, is disposed between the top wall 212 and the pushbutton 208 . The biasing element 240 urges the pushbutton 208 toward the resting position.
The pushbutton 208 has at least one track 242 located on one side of the pushbutton, and may have tracks located on both sides of the pushbutton 208 . The tracks 242 are configured to guide the movement of the pushbutton 208 so that when the pushbutton 208 is pressed to dispense a test strip, the rack gear 238 on the pushbutton 208 engages the intermediate gear 232 . When the pushbutton 208 is released, the tracks 242 are configured to cause the rack gear 238 to disengage from the intermediate gear 232 . Therefore, the pushbutton 208 may be restored from the dispensing position to the resting position without rotating the intermediate gear 238 .
The intermediate gear 232 is rotatably disposed on the second supporting member 222 which extends downwardly from the bottom surface 220 of the top wall 212 of the storage container 202 . The intermediate gear 232 is disposed between the rack gear 238 on the pushbutton 208 and the strip roller gear 228 on the strip roller 206 to operatively connect the gears and form a gear train 230 .
The strip roller 206 is rotatably supported by the first supporting member 218 , which extends downwardly from bottom surface 220 of the top wall 212 of the storage container 202 . The strip roller 206 is generally configured the same as the strip roller 106 of the first exemplary embodiment of the present invention. Accordingly, a detailed description of the strip roller 206 will not be repeated.
The method of using the storage vial 200 for storing and dispensing test strips according to the second exemplary embodiment of the invention will now be described. Initially, the strip roller 206 , the pushbutton 208 , the biasing element 240 , and the intermediate gear 232 are assembled to the top wall 212 of the storage container 202 . A stack of test strips 204 is loaded into the lower body portion 210 of the storage container 202 so that the stack of test strips 204 is disposed between the platform 246 (and the biasing element 232 ) and the test strip supporting wall 224 . The top wall 212 , with the installed components, is then assembled to the lower body portion 210 of the storage container 202 so that the strip roller 206 engages one test strip 226 of the stack of test strips 226 . The lid 224 may then be closed, and the stack of test strips may be stored as long as desired.
To dispense a test strip, a user opens the lid 224 , and pushes the pushbutton 208 to move the pushbutton 208 from a resting position to a dispensing position. Initially, the tracks 242 on the pushbutton 208 cause the rack gear 238 to engage the intermediate gear 232 . Consequently, movement of the pushbutton 208 causes the rack gear 238 to rotate the intermediate gear 232 . The rotation of the intermediate gear 232 rotates the strip roller gear 228 and causes the strip roller 206 to dispense the test strip 226 which the strip roller 206 contacts. The pushbutton 208 may be configured to completely dispense the test strip 226 out of the storage container 202 , or the test strip 226 may be partially dispensed from the storage container 202 to expose the test strip so that a user may grasp the exposed test strip 226 to completely withdraw the test strip from the storage container 202 .
After the test strip 226 has been dispensed, the biasing element 244 urges the platform 246 and the stack of test strips 204 against the test strip supporting wall 248 so that a new test strip may be dispensed.
When a user releases the pushbutton 108 , the configuration of the tracks 242 on the pushbutton cause the pushbutton 208 , along with the rack gear 238 , to move away from and disengage the intermediate gear 232 . Therefore, the pushbutton 208 may be returned to the resting position without rotating the intermediate and strip roller gears 232 , 228 in a reverse direction.
Third Exemplary Embodiment
Referring to FIGS. 13-14 , a storage vial 300 for storing and dispensing test strips according to a third exemplary embodiment of the present invention includes a storage container 302 configured to store a stack of test strips, a strip roller 306 rotatably disposed in the storage container 302 , and a pushbutton 308 disposed in the storage container 302 . The strip roller 306 contacts one test strip of the stack of test strips. The pushbutton 308 is connected with the strip roller 306 by a gear train so that when the pushbutton 308 is pushed, the strip roller 306 rotates to dispense the test strip in contact with the strip roller 306 .
The storage container 302 of the third exemplary embodiment of the present invention is generally the same as the storage container 202 of the second exemplary embodiment of the present invention, except for the configuration of the intermediate gear 316 of the gear train and the pushbutton 308 .
In this embodiment of the invention, the pushbutton 308 does not have tracks for engaging and disengaging the rack gear from the intermediate gear 316 . Instead, the pushbutton 308 has extended guide pins (not shown) which are disposed in and guided by pushbutton guide tracks 310 disposed on the inner surface of the outer wall of the lower body portion 304 of the storage container 302 . The guide tracks 310 are generally parallel to the edge of the lower body portion so that the pushbutton member moves substantially straight into and out of the storage container 302 .
The intermediate gear 316 of this embodiment of the invention is not supported by a supporting member which extends from the top wall of the storage container. Instead, the intermediate gear 316 has extended shaft portions (not shown) which are disposed in and guided by a pair of intermediate gear guide tracks 312 formed on the inner surface of the outer wall of the lower body portion 304 of the storage container 302 . Accordingly, the intermediate gear 316 is free to move linearly along the length of the intermediate gear guide tracks 312 .
The method of using the storage vial 300 for storing and dispensing test strips according to the third exemplary embodiment of the invention will now be described. Initially, the storage vial 300 is loaded with a stack of test strips and assembled in substantially the same manner described above.
To dispense a test strip, a user pushes the pushbutton 308 to move the pushbutton 308 from a resting position to a dispensing position. Initially, a rack gear on the pushbutton 308 engages the intermediate gear 316 , and the intermediate gear 316 moves linearly toward the lower end 314 of the intermediate gear guide tracks 312 . Upon reaching the lower end 314 of the intermediate gear guide tracks 312 , the guide tracks 312 prevent the intermediate gear 316 from any further linear movement. Accordingly, further movement of the pushbutton 308 causes the rack gear on the pushbutton 308 to rotate the intermediate gear 316 . The rotation of the intermediate gear 316 rotates a strip roller gear and causes the strip roller 306 to dispense a test strip. The pushbutton 308 may be configured to completely dispense a test strip, or a test strip may be partially dispensed from the storage container 302 to expose the test strip so that a user may grasp the exposed test strip to completely withdraw the test strip from the storage container 302 .
When a user releases the pushbutton 308 , a biasing element urges the pushbutton 308 from the dispensing position back to the resting position. During the initial movement of the pushbutton 308 toward the resting position, the intermediate gear 316 translates along the intermediate gear guide tracks 312 to move toward the upper end of the guide tracks. When the intermediate gear 316 moves far enough, it disengages the strip roller gear. Therefore, the pushbutton 308 may be returned to the resting position without rotating the strip roller gear in a reverse direction.
Fourth Exemplary Embodiment
Referring to FIGS. 15-17 , a storage vial 400 for storing and dispensing test strips according to a fourth exemplary embodiment of the present invention includes a storage container 402 configured to store a stack of test strips 404 , a lid 406 connected to the storage container by a hinge 408 , and a linkage assembly 410 operatively connected to the lid 406 . When the lid 406 is opened, the linkage assembly 410 engages one test strip 412 of the stack of test strips 404 and dispenses the test strip 412 .
The storage container 402 has a generally rectangular lower body portion 414 and forms a cavity 416 which is configured to store a stack of test strips 404 . The storage container 402 is formed of any suitable material, as previously discussed.
The storage vial 400 is provided with a lid 406 to prevent humidity and other environmental contaminants from entering the storage container. The lid 406 is connected to the storage vial by a hinge 408 . In the illustrated embodiment, the lid 406 is formed integrally with the lower body portion of the storage container so that it is connected by a living hinge 408 . Any type of hinge arrangement may be used, however. The lid 406 preferably forms a hermetic seal with the lower body portion 414 of the storage container 402 .
The linkage assembly 410 includes a first arm member 418 connected to the lid 406 , a second arm member 420 connected to the first arm member 418 by a living hinge 428 , and a third arm member 422 connected to the second arm member 420 by a living hinge 428 . The first arm member 418 is a generally V-shaped member. The two legs of the V-shaped member form, in the illustrated embodiment, an obtuse angle with respect to one another. The first arm member 418 is attached to the lid 406 by heat staking, by ultrasonic welding, by mechanical attachment, or by any other suitable method known to those skilled in the art.
The second arm member 420 joins the first and third arm members 418 , 422 by living hinges 428 at both ends of the second arm. The use of living hinges provide certain benefits, such as lower manufacturing costs, but it should be understood that the arms also may be joined by other types of hinges.
The third arm member 422 has guide members 430 , such as guide pins, which are disposed in and configured to travel in rails located in the side wall of the lower body portion 414 of the storage container 402 . The third arm member 422 has a lower contacting member 426 which is configured to contact the lower edge of one test strip 412 of the stack of test strips 404 . In particular, in the illustrated embodiment, the third arm member 422 contacts the lower edge of the right-most test strip 412 .
As illustrated, one set of first, second, and third arm members is provided at the front side of the storage container 402 . For stability, a second set of first, second, and third arm members, which is substantially identical to the first set of first, second, and third arm members, may be located at the back side of the storage container 402 .
The method of using the storage vial 400 for storing and dispensing test strips according to the fourth exemplary embodiment of the invention will now be described. Initially, the lid 406 is opened, a stack of test strips 404 is loaded into the container between a platform 432 and the outer wall 434 of the storage container 402 , and the lid 406 is closed. With the lid 406 closed, the linkage assembly 410 is placed into a resting position. In the resting position, the third arm member 422 is located at the bottom of the storage container, and the lower contacting member 426 is located underneath the bottom edge of the right-most test strip 412 .
To dispense a test strip, a user opens the lid 406 of the storage container 402 . The opening of the lid 406 causes the first arm member 418 to rotate up and out of the storage container. The second and third arm members 420 , 422 , which are connected to the first arm member 418 , are also raised. The third arm member 422 travels substantially vertically up due to the cooperation of the guide member 430 and the guide rails and is raised up to a dispensing position. Since the lower contacting member 426 of the third arm member 422 is located under a test strip 412 , it raises and dispenses the test strip 412 . Once the third arm member 422 reaches the dispensing position, a user may grasp the test strip and remove the dispensed test strip 412 . The first, second, and third arm members 418 , 420 , and 422 may be configured to completely dispense the test strip 412 out of the storage container 402 , or the test strip 412 may be partially dispensed from the storage container 402 to expose the test strip so that a user may grasp the exposed test strip 412 to completely withdraw the test strip from the storage container 402 and use the test strip.
After the test strip 412 has been dispensed, a user may then close the lid 406 . Closing the lid 406 causes the linkage assembly 410 to return to its resting position. When the linkage assembly 410 , and the third arm member 422 in particular, reaches the resting position, the biasing element 436 urges the stack of test strips 404 toward the outer wall 434 so that a new test strip is placed over the lower contacting member 426 of the new test strip. Consequently, the storage vial 400 is ready to dispense another test strip.
Fifth Exemplary Embodiment
Referring to FIGS. 18-20 , a storage vial 500 for storing and dispensing test strips according to a fifth exemplary embodiment of the present invention includes a storage container 502 configured to store a stack of test strips, a lid 504 connected to the storage container 502 by a hinge 506 , and a linkage assembly 508 operatively connected to the lid 504 . When the lid 504 is opened, the linkage assembly 508 engages one test strip 510 of the stack of test strips and dispenses the test strip.
The storage container 502 and lid 504 of this embodiment is generally configured the same as the storage container 402 and lid 404 of the fourth exemplary embodiment.
The linkage assembly 508 includes at least one slider arm 512 , at least one first linkage member 514 , and at least one second linkage member 516 . In the illustrated embodiment, a pair of slider arms 512 , a pair of first linkage members 514 , and a pair of second linkage members 516 are provided to increase the stability and reliability of the linkage assembly.
First ends 518 of the slider arms 512 are pivotably connected to the lid 504 . Second ends 520 of the slider arms 512 are pivotably connected to the first linkage members 514 . Each of the slider arms 512 has a slot 522 that engages a guide boss 536 disposed on the storage container 502 .
First ends 524 of the first linkage members 514 are pivotably connected to the second ends 520 of the slider arms 512 , and second ends 526 of the first linkage members 514 are pivotably connected to the second linkage members 516 .
The second linkage members 516 have guide members 528 , such as guide pins, which are disposed in and configured to travel in guide rails located in the side walls of the storage container 502 . The first ends 530 of the second linkage members 516 are connected to the second ends 526 of the first linkage members 514 . A lower contacting member 534 is disposed between the second ends 532 of the second linkage members 516 . The lower contacting member contacts one test strip 510 so that the test strip 510 is dispensed when the lid 504 is opened.
The method of using the storage vial 500 for storing and dispensing test strips according to the fifth exemplary embodiment of the invention will now be described. Initially, the lid 504 is opened, a stack of test strips is loaded into the storage container 502 , and the lid 504 is closed. With the lid 504 closed, the linkage assembly 508 is placed into a resting position. In the resting position, the second linkage members 516 are located at the bottom of the storage container 502 , and the lower contacting member 534 is located underneath the lower edge of the bottom edge of the right-most test strip 510 .
To dispense a test strip, a user opens the lid 504 of the storage container 502 . The opening of the lid 504 causes the slider arms 512 to rotate up and out of the storage container 502 . The slider arms 512 are guided by cooperation of the guide bosses 536 and the slots in the slider arms 512 along a predetermined path. The second ends 520 of the slider arms 512 pull the first linkage members 514 , which, in turn, pull the second linkage members 516 . The second linkage members 516 travel substantially vertically up insider the storage container 502 due to the cooperation of the guide members 528 and guide rails and is raised up to a dispensing position. Since the lower contacting member 534 is located under a test strip, it raises and dispenses the test strip. Once the second linkage members 516 reach the dispensing position, a user may grasp the test strip and remove the dispensed test strip. The slider arms 512 and the first and second linkage members 514 , 516 may be configured to completely dispense a test strip out of the storage container 502 , or the test strip may be partially dispensed from the storage container 502 to expose the test strip so that a user may grasp the exposed test strip to completely withdraw the test strip from the storage container and use the test strip.
After the test strip has been dispensed, a user may then close the lid 504 . Closing the lid 504 causes the linkage assembly 508 to return to its resting position. When the linkage assembly 508 , and the second linkage members 516 in particular, reach the resting position, a biasing element urges the stack of test strips towards the side wall of the storage container 502 so that a new test strip is placed over the lower contacting member. Consequently, the storage container 502 is ready to dispense another test strip.
Sixth Exemplary Embodiment
Referring to FIG. 21 , a storage vial 600 for storing and dispensing test strips according to a sixth exemplary embodiment of the present invention includes a storage container 602 configured to store a stack of test strips, a spiral pusher spring 604 , and a thumbwheel 606 connected to the spiral pusher spring 604 by a gear train 628 so that rotation of the thumbwheel 606 causes the spring to dispense one test strip of the stack of test strips.
The storage container 602 is generally rectangular and forms a cavity 612 which is configured to receive a cartridge 610 for storing a stack of test strips. The storage container 602 may be formed of any suitable material, as previously discussed.
The storage vial 600 is provided with a lid 608 to prevent humidity and other environmental contaminants from entering the storage container 602 . The lid 608 may be connected to the storage vial by any suitable type of hinge, such as a living hinge.
A cartridge 610 is inserted into the cavity in the storage container 602 . The spiral pusher spring 604 and the associated gear train 628 are disposed in the cartridge 610 . The cavity 612 in the cartridge 610 is configured to hold a stack of test strips, and a platform, as well as a biasing element, are located in the cavity to urge the stack of elements toward one wall of the cartridge 610 . The cartridge 610 may be removable from the storage container 602 or permanently affixed thereto.
The spiral pusher spring 604 is wound around a cylindrical spring drum 614 . A first end 616 of the spiral pusher spring 604 is disposed in a guide track 618 formed in the cartridge 610 . A second end 620 of the spiral pusher spring 604 is fixed to the cylindrical spring drum 614 . The first end 616 of the spiral pusher spring 604 is configured to contact the edge of a test strip. Accordingly, when the spring drum 614 is rotated, the first end 616 of the spiral pusher spring 604 is extended and moves along the guide track 618 to dispense a test strip.
In the illustrated embodiment, the gear train 628 comprises a thumbwheel driving gear 606 , a first idler gear 622 , a second idler gear 624 , and a spring drum driving gear 626 . The thumbwheel driving gear 606 is partially exposed to the outside of the storage container 602 so that a user may manipulate the thumbwheel 606 . The first and second idler gears 622 , 624 engage the thumbwheel 606 , and transmit a rotational force generated by the thumbwheel 606 to the spring drum driving gear 626 . The gear train 628 may be configured with any desired gear ratios.
The method of using the storage vial 600 for storing and dispensing test strips according to the sixth exemplary embodiment of the invention will now be described. Initially, a stack of test strips is loaded into the cartridge 610 , the spiral pusher spring 604 is retracted into an initial resting position, and the cartridge is inserted into the storage container 602 . In the resting position, the spiral pusher spring 604 is retracted so that the end of the spring is located at the bottom of the storage container 602 and is underneath the lower edge of one edge of a test strip.
To dispense a test strip, a user rotates the exposed thumbwheel 606 in a dispensing direction. The rotational force of the thumbwheel 606 is transmitted to the spiral pusher spring 604 through the gear train 628 . The spiral pusher spring 604 is extended and dispenses the test strip. The thumbwheel 606 may be rotated so that the test strip is completely dispensed out of the storage container 602 , or the test strip may be partially dispensed from the storage container 602 to expose the test strip so that a user may grasp the exposed test strip to completely withdraw the test strip and use the test strip.
After the test strip has been dispensed, a user may then rotate the thumbwheel 606 in an opposite direction to the dispensing direction to return the spiral pusher spring 604 to its resting position. Alternatively, the inherent spring force of the spiral pusher spring 604 may cause it to return to its resting position automatically. When the spiral pusher spring 604 reaches the resting position, the biasing element urges the stack of test strips towards the spiral spring so that a new test strip is placed over the end of the pusher spring. Consequently, the storage container 602 is ready to dispense another test strip.
Seventh Exemplary Embodiment
Referring to FIG. 22 , a storage vial 700 for storing and dispensing test strips according to a seventh exemplary embodiment of the present invention includes a storage container 702 configured to store a stack of test strips, a spring 704 configured to contact one test strip of the stack of test strips, a rack 706 connected to the spring 704 , a pinion 708 engaging the rack 706 , and a thumbwheel 710 engaging the pinion 708 so that rotation of the thumbwheel 710 displaces the rack 706 and causes the spring 704 to dispense the contacted test strip.
The storage container 702 and lid of this embodiment is generally configured the same as the storage container 702 and lid of the sixth exemplary embodiment.
A cartridge 712 is inserted into a cavity 714 in the storage container 702 502 . The cartridge 712 has a cavity which is configured to hold a stack of test strips, and a platform, as well as a biasing element, are located in the cartridge 712 to urge the stack of test strips toward one wall of the cartridge 712 . The cartridge 712 may be removable from the storage container 602 or permanently affixed thereto.
The spring 704 is disposed in a guide track 722 formed in the cartridge 712 . A first end 716 of the spring 704 is guided by the guide track 722 and is configured to contact the edge of a test strip. A second end 718 of the spring 704 is fixed to the rack 706 .
The rack 706 is linearly movable within the storage container 702 . The rack 706 has a rack gear 720 located on one side of the rack.
A pinion gear 708 is rotatably disposed on the cartridge 712 , and engages the rack gear 720 .
The thumbwheel 710 is also rotatable disposed on the cartridge 712 , and engages the pinion gear 708 . Accordingly, when the thumbwheel 710 is rotated, the pinion gear 708 rotates, and the rack 706 translates linearly. Thus, the first end of the attached spring 704 is moved along the guide track 722 .
The method of using the storage vial for storing and dispensing test strips according to the seventh exemplary embodiment of the invention will now be described. Initially, a stack of test strips is loaded into the cartridge 712 , the pusher spring 704 and rack 706 are placed into an initial resting position, and the cartridge is inserted into the storage container 702 . In the resting position, the rack 706 and pusher spring 704 are retracted so that the end of the spring 704 is located at the bottom of the storage container 702 and is underneath the lower edge of one edge of a test strip.
To dispense a test strip, a user rotates the exposed thumbwheel 710 in a dispensing direction. The rotational force of the thumbwheel 710 is transmitted to the pinion 708 gear, and the pinion gear 708 engages the rack 706 gear to translate the rotational force of the pinion gear 708 into linear movement of the rack 706 . The linear movement of the rack 706 extends the pusher spring 704 , and dispenses the test strip. The thumbwheel 710 may be rotated so that the test strip is completely dispensed out of the storage container 702 , or the test strip may be partially dispensed from the storage container 702 to expose the test strip so that a user may grasp the exposed test strip to completely withdraw the test strip and use the test strip.
After the test strip has been dispensed, a user may then rotate the thumbwheel 710 in an opposite direction to the dispensing direction to return the pusher spring 704 to its resting position. Alternatively, the pusher spring can return to its resting position automatically. When the pusher spring 704 reaches the resting position, the biasing element urges the stack of test strips towards the pusher spring 704 so that a new test strip is placed over the end of the pusher spring 704 . Consequently, the storage container 702 is ready to dispense another test strip.
Eighth Exemplary Embodiment
Referring to FIGS. 23-24 , a storage vial 800 for storing and dispensing test strips according to an eighth exemplary embodiment of the present invention includes a storage container 802 configured to store a stack of test strips rack, a spring 804 configured to contact one test strip of the stack of test strips, and a lever arm 806 that pivots about a pivot point 808 . A first end 810 of the lever arm 806 is connected to the spring 804 to drive the spring 804 so that pivoting of the lever causes the spring 804 to dispense the contacted test strip.
The storage container 802 and lid (not shown) of this embodiment is generally configured the same as the storage container 602 and lid 608 of the sixth exemplary embodiment.
A cartridge 814 is inserted into a cavity in the storage container 802 . A cavity in the cartridge 814 is configured to hold a stack of test strips, and a platform, as well as a biasing element, are located in the cavity to urge the stack of test strips toward one wall of the cartridge. The cartridge 814 may be removable from the storage container 802 or permanently affixed thereto.
The spring 804 is disposed in a guide track 818 formed by the cartridge and 814 . The first end 820 of the spring 804 is guided by the guide track 818 and is configured to contact the edge of a test strip 816 . A second end 822 of the spring 804 is fixed to a first end 810 of the lever arm 806 .
The lever arm 806 is pivotably disposed about a pivot point 808 on the cartridge. The second end 824 of the lever arm 806 extends above the top end of the cartridge so that a user may manipulate the lever arm 806 .
The method of using the storage vial 800 for storing and dispensing test strips according to the eighth exemplary embodiment of the invention will now be described. Initially, a stack of test strips is loaded into the cartridge 814 , the lever arm 806 and the pusher spring 804 are placed into an initial resting position, and the cartridge is inserted into the storage container 802 . In the resting position, the lever arm 806 is pivoted to one side of the storage container 802 , and the pusher spring 804 is retracted so that the end of the spring 804 is located at the bottom of the storage container 802 and is underneath the lower edge of one edge of a test strip.
To dispense a test strip, a user presses the lever arm 806 to pivot the lever arm 806 . The pivoting of the lever arm 806 causes the pusher spring 804 to extend along the guide track, and dispenses the test strip. The lever arm 806 is pivoted far enough for a user to grasp the test strip and remove the dispensed test strip.
After removing the test strip, a user may then pivot the lever arm 806 back to its initial resting position. Alternatively, the lever arm may return to its resting position automatically. When the lever arm 806 reaches the resting position, the biasing element urges the stack of test strips towards the pusher spring 804 so that a new test strip is placed over the end of the pusher spring 804 . Consequently, the storage container 802 is ready to dispense another test strip.
While various embodiments have been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims.
|
An apparatus for storing and dispensing a test strip includes a container configured to store a stack of test strips. The container maintains appropriate environmental conditions, such as humidity, for storing the test strips. An engaging member is disposed in the container and is adapted to contact one test strip of the stack of test strips. An actuator actuates the engaging member to dispense the one test strip from the container. Since one test strip is dispensed at a time, the remaining test strips are not handled by the user. Accordingly, the unused test strips remain free of contaminants such as naturally occurring oils on the user's hand.
| 6
|
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to German Patent Application No. 202014001511.2 filed on Feb. 20, 2014, the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The invention relates to an apparatus for inserting a solid manure storage into a soil layer. This type of apparatus is used in agricultural production to spread solid manure on an area for crop plant cultivation. It is generally known to spray said solid manure by means of a distributor apparatus above the soil surface thus covering the cultivation area with solid manure. This solid manure then partly seeps into the ground, i.e. its liquid content, and remains partly as top layer on the ground. Said method and apparatus for implementing said method make it possible to spread solid manure on the crop plant cultivation area in an economically feasible manner, in particular because the solid manure is dispensed from a tank through a relatively large opening and then spread by means of a centrifugal disc, centrifugal distributor or the like with a low risk of blockage, and the superficial spreading and subsequent percolation allow for a relatively favorable arrangement of the solid manure near the surface. However, said type of spreading has the disadvantage of significant odor and ammonia emissions. This type of odor emission is regulated differently according to national or supranational regulations and requirements. These regulations range from requirements regarding emission limits to requirements that only allow this type of manure spreading in connection with subsequent soil preparation for inserting the manure layer into the soil by subsequently turning the soil within a predetermined maximum period of time after spreading the manure.
[0003] Generally, spreading the manure by distributing it above the cultivation surface and subsequent insertion helps to achieve low-odor and low-ammonia insertion of solid manure into the soil. However, this procedure has the disadvantage that it is necessary to work the soil twice and to travel over the soil twice accordingly, which requires additional working time as well as additional fuel and material. In addition, it has proved a disadvantage that inserting the manure in a second step causes significant corrosion of the soil cultivation equipment due to high chemical aggressiveness.
[0004] Besides said established spreading procedures for solid manure it is meanwhile also known to insert solid manure into a soil cultivation area not by spraying it above the surface but is directly inserted into the soil to a predetermined depth. With this procedure, the outlet opening is arranged at a lower end of a soil prong which is inserted into the soil to a predetermined depth. Typically, with this procedure, the manure is spread via several such openings on accordingly several tines, which are arranged adjacently to each other with regard to a driving direction and are dragged through the soil in driving direction during soil preparation. This creates several parallel and laterally spaced manure storages in the form of several strands of solid manure which are located at a specific depth of the soil.
[0005] The advantage of this type of manure insertion is that it is almost free of emissions and thus the solid must not be worked subsequently for emission protection reasons. The disadvantage of this type of insertion is, however, the locally very limited arrangement of solid manure which, with regard to the fertilizing effect of the manure, causes a disadvantageous distribution on the soil surface and thus does not ideally support the growth of the crop plants. In particular, this type of insertion leaves a large part of the soil layer low in nutrients, while a locally very limited part of the soil is left with a too high concentration of nutrients. This is desired in some, but not in all cases. For this reason, in part for the purpose of a more favorable distribution of nutrients from the solid manure, the soil is nevertheless worked subsequently, which, however, has the above mentioned disadvantages.
[0006] Another problem of the direct insertion of the manure through several discharge openings that are inserted into the soil is the specific composition of the solid manure. While it is comparatively easy to feed such solid manure from a tank through a large discharge opening and to spray it by means of a centrifugal disk or a centrifugal distributor above the surface, spreading through several small openings is problematic, since these openings can become blocked. Since it is not possible to intensively process and homogenize the solid manure for economic reasons, it has to be dealt with the fact that during spreading, the solid manure may contain solid parts of different sizes and composition, ranging from fine fiber components to large fiber lumps, branches or pieces of branches or mineral solids of different sizes. The spreading of such solid manure from a tank is a regular problem if during the spreading, the solid manure is to be distributed from a large passage cross section to several small passage cross sections. Scientific information indicates that a finer distribution of the solid manure in the form of individual strands that are laterally spaced from each other, makes the insertion into and distribution of nutrients over the cultivation area economically advantageous. From a practical point of view, such insertion of solid manure is, however, often not reliable, since the inadequate distribution regularly leads to blockages which in turn lead to an unreasonable maintenance effort and in addition—since such local blockages cannot be identified during the spreading procedure—to an unreliable spreading.
BRIEF SUMMARY OF THE INVENTION
[0007] The invention is based on the task of providing an apparatus and a method for spreading solid manure which ensures a low-emission insertion of solid manure with a more favorable distribution of nutrients than previously known spreading procedures, without thereby impairing the efficiency of the discharge procedure.
[0008] This task is solved by an apparatus of the type described above comprising the following construction elements: an insertion apparatus with a set of first discharge openings and a set of second discharge openings which are spaced vertically from the first discharge openings in the operating position of the insertion apparatus, a distributor comprising a distributor interior, an intake opening that opens into the distributor interior for feeding solid manure, a first set of several first exit openings for diverting the solid manure from the distributor space, and a second set of several second exit openings for diverting the solid manure from the distributor space, a first set of several first connecting lines, whereby each first connecting line extends from a beginning of the line to an end of the line, is connected at its beginning to a first exit opening and at its end to a first discharge opening from the set of first discharge openings, a second set of several second connecting lines, whereby each second connecting line extends from a beginning of the line to an end of the line, is connected at its beginning to a second exit opening and at its end to a second discharge opening.
[0009] The insertion apparatus according to the invention makes it possible to insert solid manure into a cultivation area at least two vertically spaced heights in an economical and reliable manner. This is achieved by distributing the solid manure in a distributor across a first set of respectively several exit openings from the distributor interior, and by connecting each of these exit openings to a respective connecting line for conveying the solid manure. The first set of exit openings is accordingly in fluid contact with several first connecting lines with a plurality of first discharge openings. Said first set of discharge openings places the solid manure directly from the distributor interior at a first, predetermined depth of the soil without another branching or cross-section constriction being required, and can be applied as a plurality of parallel strands at this depth. A second set of exit openings, connecting lines and second discharge openings then insert the solid manure into the soil to a second predetermined depth which is vertically spaced to the first depth. Here also, the solid manure is inserted into the soil as a plurality of parallel, laterally spaced strands and can, for example, be inserted at a second depth, which is above the first depth.
[0010] The invention thus achieves placement of a plurality of respectively two vertically spaced strands of solid manure and prevents the unfavorable, high local concentration that is associated with the previously known type of solid manure spreading and the requirement to work the area subsequently for a second time to achieve a favorable and low-emission distribution over the soil surface. Said favorable distribution is achieved without branches or cross-section reductions being required during the transit of the solid manure from the distributor to the discharge openings, and is therefore low-maintenance and resistant to blockages.
[0011] According to a first preferred embodiment, it is provided that the first exit openings have a larger cross section than the second exit openings. This embodiment provides for a difference in cross section size between the first and the second exit openings of the distributor. The cross section size is the size of the cross section through which the solid manure flows when it passes through the exit opening. Due to the higher or lower throttling effect, which depends on the cross section size, the cross section size of the exit opening thus determines the size of the volume flow through the exit opening. In general, it is to be understood that, on the basis of the exit opening, also the cross section size of all fluid carrying components below, such as the connecting piece for the connecting line, the connecting line and the discharge opening should match the cross section size of the exit opening. In principle, larger cross section sizes in one or several of these components can be provided behind the exit opening. Preferably however, the cross section size of the following components is not smaller than the cross section size of the exit opening.
[0012] By providing different cross section sizes of the first exit opening compared to the second exit opening it is possible to spread a different amount of solid manure through the first discharge opening than through the second discharge opening. This is in particular preferable in order to, for example, insert a thicker strand of solid manure through the first exit openings up to a lower soil level and a smaller strand of solid manure up to a soil layer that is close to the surface. This distribution causes a quick provision of nutrients for the planted seedling or plant seeds and a provision of a larger amount of nutrients after a period of time in which the seedling's roots have already grown in the depth where they reach the nutrient depot at the lower level.
[0013] The apparatus according to the invention can also be designed by a third set of several third exit openings for discharging the solid manure from the distributor space and a third set of several third connecting lines, whereby each third connecting line extends from one beginning of the line to an end of the line, is connected at its beginning to a third exit opening and at the end to a first discharge opening from a set of the first discharge openings. This embodiment provides a total of three sets of exit openings from the distributor interior. The exit openings of the second set with accordingly second connecting lines are connected to the set of second exit openings in a 1:1 assignment so that each outlet opening is connected directly to respectively one discharge opening via a connecting line. The exit openings of the first and third set are also connected to a connecting line of a first and third set so that there is a 1:1 assignment of each exit opening to a connecting line. The end of the line of both the first connecting line which extends from a first exit opening as well as the third connecting line extending from a third exit opening is connected to a single first discharge opening so that here a single first discharge opening is supplied with solid manure from respectively a first and a third exit opening. This ensures that each first discharge opening is supplied with a larger volume flow of solid manure than the second discharge openings.
[0014] It is furthermore particularly preferred that the first, second and, if applicable, third exit openings have the same cross section size. With this embodiment, all exit openings of the distributor have the same cross section size. This type of construction enables an advantageous production since the dimensions of these exit openings are identical in design. In addition, the distributor can be used universally, since manure storages can be positioned at different depths out of the exit openings in the manner according to the invention, but the distributor can also be used to lay rows of three or more vertically arranged manure storages or a large amount of horizontally spaced manure storages by connecting the connections to the exit openings by means of respective connecting lines to respectively several discharge openings. This modified manner of use ensures that each exit opening is supplied with the same volume flow. In the same manner it is possible for the distributor to spread the manure storages at a single level, which in turn provides for an increased working width due to the then larger amount of discharge openings at the single level or a shorter distance between the spread strands with an equal working width.
[0015] According to another preferred embodiment it is provided that the first and second exit openings have an equal cross section size and the first and third exit openings have different cross section sizes. With this embodiment, an additional volume flow to the first discharge openings is provided through the third exit openings, which does not represent a mere doubling of the volume flow compared to the one through the second discharge openings. Instead, the volume flow can be chosen to be more than twice as large by making the third exit openings larger than the first and second exit openings or less than twice as large by making the third exit openings smaller than the first and second exit openings.
[0016] Alternatively, it can be provided that the first and second exit openings have an equal cross section size and the first and third exit openings have different cross section sizes. This embodiment makes it possible that the first discharge openings are supplied with solid manure through two first and third exit openings of matching size and the second discharge opening is supplied through a second exit opening, the size of which is different from the cross section size of this first and third exit opening, i.e. larger or smaller.
[0017] Preferably, each exit opening is fluidly connected to respectively a connecting piece so as to attach the respective connecting line hereto and feed the solid manure from the exit opening via the connecting piece to the connecting line. The connecting pieces can preferably have a passage cross section which has the same size as the passage cross section area of the respective exit opening. Preferably it can also be provided that the connecting pieces of all exit openings have matching connection dimensions for the connecting lines, i.e. according to the embodiment, for example the same outer diameter to ensure the use of matching connecting lines for all two or three sets of connecting lines. This can be designed in a way that the connecting pieces have matching inner diameters and thus inner passage cross section areas, whereby these are preferably larger than or equal to the largest passage cross section of the first, second and third exit openings.
[0018] Furthermore it is preferably provided that a cutting apparatus is positioned in the distributor interior which is movable relative to the first and second exit openings. By providing said cutting apparatus in the distributor interior the solids in the manure can be cut so as to reduce the risk of or prevent blockage of the openings or lines in flow direction behind the distributor. In addition, said cutting apparatus can cause a circulation or mixing in the distributor interior by designing the cutting apparatus as cutting/mixing apparatus. Said circulation or mixing in the distributor interior can help to dissolve blockages that are forming and thus maintain the passage through all openings and lines.
[0019] The cutting apparatus can further be designed to cover a part of the exit openings and separate it from the supply of solid manure and connect another part of the exit openings to the supply of solid manure from the distributor interior and move it in such a way that all exit openings are intermittently covered and released by the movement or at least a part of the exit openings is intermittently covered and released and another part is permanently released. The cutting apparatus intermittently covers and releases the exit openings, which achieves a pressure pulse supply of the exit openings and all following fluid carrying components with solid manure which favorably prevents blockages. Also, the supply pressure from the distributor interior is favorably released only for a reduced number of exit openings thus further reducing the risk of blockage.
[0020] Here, it is particularly preferred if the cutting apparatus strokes across the edge of at least some, preferably all first, second and/or third exit openings. With this embodiment, the cutting apparatus and the exit openings or a part of the exit openings of the first, second and/or third set together have a shearing cutting effect. For this, the exit openings can be completely or partly arranged on a cutting plate, which can, for example, be an even or bent cutting plate. The edges of the exit openings on this plate thereby form a cutting edge and the cutting apparatus with its cutting edge moves relatively to the cutting edge at the exit opening. This causes a shearing effect with respect to the solids that enter into the exit opening and achieves an efficient cutting of the solids as they enter the exit openings. Here it is particularly preferred if the cutting edge strokes across all first, second and, if applicable, third exit openings so that this shearing effect and cutting of the solids occurs at all exit openings thus preventing blockage of all lines and discharge openings.
[0021] Further, it is preferred that the cutting apparatus has several cutting edges out of which respectively each strokes across at least a number of first, second and/or, if applicable, third openings. Said embodiment of a cutting apparatus with several cutting edges can stroke across all first, second and, if applicable, third openings or a number thereof with its cutting edges with a higher frequency so as to achieve a higher cutting performance. At the same time, the wear of the cutting edges is reduced by distributing the cutting effect across several cutting edges. The cutting edges can be straight or curved. The cutting apparatus can further comprise a pre-tension apparatus which presses the cutting edges with an elastic pre-tension force against the cutting plate which has the first, second, and, if applicable third exit openings, and the cutting edges must be readjusted if they are worn.
[0022] Further, it is preferably provided that the cutting apparatus can pivot around a rotation axis and is set into rotary or swinging motion by means of a drive mechanism. Said embodiment of the cutting apparatus as rotating cutting knife with one or several cutting edges that are moved relative to the exit openings on an even or curved plate, for example the inner wall of a plate designed as a tube, allows for a robust drive design and at the same time a simple maintenance of the cutting apparatus. The driving mechanism can for example be an electric or hydraulic engine. Similarly, the cutting apparatus as driving mechanism can have a coupling shaft which can be coupled to a respective connecting apparatus with an external actuator, for example the power take-off shaft of a hauler.
[0023] In particular, it is further preferred that the first, second and, if applicable, third openings are arranged in an even cutting plate. The embodiment of the distributor apparatus with an even cutting plate which has the first, second and, if applicable, third openings makes it possible to provide a cutting apparatus whose cutting edge or cutting edges can be moved on this even cutting plate in a rotating motion. Here, the exit openings can be connected to a respectively axially extending connecting piece, which, for example, extends axially and radially outwards so as to allow for an easy connection of the connecting lines. Said design of the distributor apparatus makes it possible to insert the injection openings on one side axially into the distributor interior and to drive a cutting knife rotor and provide on the opposite side the connections for the connecting lines from the first, second and, if applicable, third outlet openings.
[0024] According to another preferred embodiment, it is provided that the passage cross section of a fluid carrying path extending from one or each exit opening to a discharge opening does not decrease. This design reliably prevents blocking due to solids that remain when the solid manure passes through from the exit opening of the first, second and/or third set to the discharge opening. In particular, preferably the cross section of the fluid line extending from the exit opening to the discharge opening can be kept constant or can expand section by section or as a whole.
[0025] Finally, it is provided according to another preferred embodiment that the first and second discharge openings are arranged on a hollow cultivator tine, which has a hollow space in the inside which joins the first and, if applicable, third connecting line and is in fluid contact with the second discharge opening. With this embodiment, the first and second discharge opening can be arranged at a specifically defined height by inserting the cultivator tine into the soil layer. The second output opening is then supplied with solid manure via a flow path leading through the cultivator tine. The cultivator tine can, for example, be a cylindrical pipe, a pipe with an elliptical cross-section or the like. The first discharge opening can also be arranged integrally in the cultivator tine and be supplied with solid manure via a respective flow path, which is preferably separated from the flow path to the second discharge opening. In this case, two connections are provided on the cultivator tine and, if applicable, three connections for the respective connecting lines to the first and second discharge opening. Similarly, the first discharge opening can be merely directly or indirectly connected to the cultivator tine, for example by means of a respective connecting piece that is attached to the cultivator tine and which itself is in fluid contact with the connecting line.
[0026] Another aspect of the invention is a distributor apparatus for distributing solid manure over a plurality of discharge openings comprising an distributor interior, an intake opening leading into the distributor interior for the supply of solid manure, a first set of several first exit openings for diverting the solid manure from the distributor interior, and a second set of several second exit openings for diverting the solid manure from the distributor interior, a first set of several first connecting pieces, whereby each first connecting piece is in fluid communication with one of the first exit openings and is designed for a connection to a first connecting line, a second set of several second connecting pieces, whereby each second connecting piece is in fluid communication with one of the second exit openings and is designed for a connection to a second connecting line. This distributor apparatus corresponds to the distributor apparatus described above in connection with the apparatus according to the invention for inserting a solid manure storage, and is suitable to distribute solid manure of this kind over several lines so that they can be inserted by a respective insertion apparatus at two vertically spaced levels into a soil layer.
[0027] Here, it is to be understood that the distributor apparatus can be designed according to the above further embodiments for the distributor apparatus of the insertion apparatus according to the invention; in particular the first and second exit openings can be designed according to the preferred embodiments described above; a set of third exit openings can be provided with respectively third connecting pieces, and a cutting apparatus with the above described design can be provided.
[0028] Finally, another aspect of the invention is a method for inserting solid manure into a soil layer comprising the following steps: inserting a plurality of first manure storages from a respective plurality of first discharge openings into a first layer that is away from the surface, inserting a plurality of second manure storages from a respective plurality of second discharge openings into a second layer that is close to the surface, feeding the solid manure to the first discharge openings via a plurality of first connecting lines, whereby the beginning of each first connecting line is in connection with respectively a first outlet opening of a respective plurality of first outlet openings and the end of each first connecting line is in connection with respectively one of the first outlet openings, feeding the solid manure to the second discharge openings via a plurality of second connecting lines, whereby the beginning of each second connecting line is in connection with respectively a second outlet opening of a respective plurality of second outlet openings and the end of each second connecting line is in connection with respectively one of the second outlet openings, introducing the solid manure into the distributor interior and distributing the solid manure from the distributor interior over the first and second outlet openings.
[0029] The method can be designed in a way that the solid manure is led from the intake opening via a distributor apparatus and connecting lines connected to this distributor apparatus and an insertion apparatus of the design explained above to the first and second discharge openings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Preferred embodiments of the invention are explained through the attached figures. The following is shown in:
[0031] FIG. 1 is a schematic side view of an apparatus according to the invention for inserting a manure storage into a soil layer in an application on a cultivator coupled to a tanker,
[0032] FIG. 2 a is a schematic, perspective view diagonally from above of a distributor apparatus according to the invention without inserted cutting rotor in a first embodiment,
[0033] FIG. 2 b is the view according to FIG. 2 a with an inserted cutting rotor,
[0034] FIG. 2 c is a top view of the embodiment according to FIGS. 2 a and b without inserted cutting rotor,
[0035] FIG. 2 d : is a top view according to FIG. 2 c with inserted cutting rotor,
[0036] FIG. 3 a - d: views according to FIGS. 2 a - d of a second embodiment of a distributor according to the invention,
[0037] FIG. 4 a - d: views according to FIGS. 2 a - d of a third embodiment of a distributor according to the invention,
[0038] FIG. 5 a - d: views according to FIGS. 2 a - d of a fourth embodiment of a distributor according to the invention,
DETAILED DESCRIPTION
[0039] Initially with regard to FIG. 1 , tanker 10 is shown which, for example, can be towed by a tractor across a cultivation area in parallel lanes. Tanker 10 comprises tank 10 a, which takes a supply of solid manure. The solid manure is led via a tank outlet 11 to a pump apparatus, such as a rotary piston pump 12 and led via said pump apparatus through supply tube 13 to a distributor apparatus 20 according to the invention. Supply tube 13 is connected to intake opening 21 of distributor apparatus 20 and leads the solid manure in distributor interior 22 . Intake opening 21 leads on one side in axial direction to distributor interior 22 .
[0040] On the opposite side, a plurality of outlet openings 23 a, b, c, 24 a, b, c are arranged. These outlet openings are arranged in alignment with connecting pieces 43 a, b, c, 44 a, b, c.
[0041] The outlet openings 23 a, b, c, 24 a, b, c are arranged in a cutting plate 27 , which is arranged in the distributor interior on the axial front side that is opposite intake opening 21 and is fixed mounted.
[0042] Cutting knifes 31 , 32 are attached to a knife carrier that is arranged in distributor interior 22 (not shown in FIG. 1 ) and are set into rotation by driving engine 40 . Cutting knifes 31 , 32 lie on the side facing to the interior of cutting plate 27 and thus stroke across outlet openings 23 a, b, c, 24 a, b, c . This leads to a shearing effect between cutting knifes 31 , 32 and the edges of outlet openings 23 a, b, c, 24 a, b, c that are facing to the distributor interior.
[0043] A plurality of hose lines 53 a, b, c, 54 a, b, c are connected to connecting pieces 43 a, b, c, 44 a, b, c . These hose lines connect the distributor apparatus to a plurality of first discharge openings and a plurality of second discharge openings.
[0044] The side view according to FIG. 1 merely shows a first discharge opening 63 a and a second discharge opening 64 a. The other discharge openings are in row transversely to the driving direction of tanker 10 behind this first and second discharge opening 63 a, 64 a.
[0045] Connecting piece 23 a is part of the first set of connecting pieces and discharge openings and is connected to the internal cavity of cultivator tine 61 a by means of hose line 53 a of the first set of hose lines. The solid manure flows from the first discharge opening 23 a through connecting hose 53 a to cultivator tine 61 a and within the cultivator tine to discharge opening 63 a which is arranged at the lower end of the cultivator tine.
[0046] Outlet opening 24 a is connected to connecting hose 54 a by means of connecting piece 44 a. Connecting hose 54 a is connected to insertion connecting piece 62 a, which is aligned in driving direction behind cultivator tine 61 a. Insertion connecting piece 62 a extends to an upper soil layer and has a second discharge opening 64 at its lower end. This second discharge opening 64 a is positioned at a higher level than the first discharge opening 63 a.
[0047] As can be further seen, the second outlet opening 24 a, the second outlet connection piece 44 a, the second connecting hose 54 a and the second discharge opening 64 a have a smaller diameter than respectively the first outlet opening 23 a, the first connecting piece 43 a, the first connecting hose 53 a and the second discharge opening 63 a.
[0048] The cross section size of the second outlet opening and the fluid carrying elements to the second discharge opening is therefore smaller than the cross section size of the first outlet opening.
[0049] FIG. 2 shows a first embodiment of a distributor apparatus according to the invention in a perspective view diagonally from above in a) and b) and a top view in c) and d). In all illustrations, the top housing cover is not shown for a better understanding of the functioning. In addition, in Figures a and c, no knife rotor is inserted into the distributor interior.
[0050] The distributor apparatus according to FIG. 2 has a distributor interior 122 which is limited laterally by pipe wall section 125 . The distributor interior is limited upwards by a housing cover (not shown), which has an intake opening for the supply of the distributor interior with solid manure.
[0051] The distributor interior is limited downwards by cutting plate 120 . The cutting plate has a large central opening 126 which has a knife flange 133 protruding through it. Knife flange 133 is coupled to drive engine 140 which is below cutting plate 120 and is set into rotation by this driving engine, which is shown as electronic motor as an exemplary embodiment. Driving engine 140 is outside the distributor interior.
[0052] The annular cutting plate 120 has a first set of a total of eight outlet openings 123 a,b,c, which have a first diameter. These outlet openings 123 a,b,c thus provide a first outlet cross section through which the solid manure passes from the distributor interior.
[0053] Furthermore, the cutting plate has a second set of a total of eight second outlet openings 124 a,b,c, which have a second diameter. This second diameter is smaller than the first diameter, which means that the second outlet openings have a smaller outlet cross section than the first outlet openings.
[0054] The first and second outlet openings are evenly distributed over a circular path, which is concentrically positioned to the rotary axis of cutting knife flange 133 and respectively alternately arranged in such a way that a second outlet opening is respectively positioned between two first outlet openings and vice versa.
[0055] Each first outlet opening is in fluid contact with a first connecting piece 143 a,b,c. The first connecting pieces extend from the underside of the distributor with a primarily axial alignment and incline slightly radially outward. The first mounting flanges 143 a,b,c are designed as circular tube sections and have an inner diameter that corresponds to the diameter of the first outlet openings.
[0056] In the same way, the second outlet openings 124 a,b,c are in fluid contact with the second connecting pieces 144 a,b,c, which in turn extend axially-diagonally radially outward. The second connecting pieces 144 a,b,c are also designed as circular tube sections and have an inner diameter that corresponds to the diameter of the second outlet openings.
[0057] The first and second connecting pieces 143 a,b,c; 144 a,b,c are attached to a lower housing plate 127 . Cutting plate 120 rests on housing plate 127 and is non-rotatably mounted to it.
[0058] As can be seen in FIGS. 2 b ) and 2 d ), a cutting knife carrier 134 , which is more or less rectangular, is non-rotatably mounted to rotating knife flange 133 . The cutting knife carrier covers about ten of the total of 16 exit openings thus, in the position shown, preventing passage through the outlet openings, which are not shown in FIG. 2 . This ensures that respectively only a third of the number of exit openings is supplied with solid manure.
[0059] The cutting knife carrier is set into rotation by driving engine 140 so that constantly other exit openings are released and supplied with solid manure. The driving engine can be a hydraulic engine. Similarly, a driving engine can be connected by means of a power take-off. Similarly, the driving engine could be an electric engine. By way of the interaction of the cutting knife carrier with the exit openings and its rotation over the exit openings, the exit openings are supplied by way of pulsation with solid manure. Here, the solid manure can be fed into an interior of the rotating knife carrier and fed from this interior to the outlet openings. In this case, the distributor interior outside the cutting knife carrier is not supplied with solid manure. This part of the distributor interior can be ventilated so that air can be fed to the outlet openings which leads to blocks of manure and air intermittently flowing through the hose lines, and thus to an increased accuracy of distribution and flow uniformity. According to the invention, the solid manure can also be fed to the part of the distributor interior that is outside the knife carrier. In this case, the solid manure flows from the part of the distributor interior that is outside the knife rotor to the outlet openings. The interior of the knife carrier can also be ventilated to allow for incoming air, uniform distribution and continuous flow. For high application rates, the number of outlet openings that are covered by the interior of the knife carrier can be selected to be high, like in the first case, or to be low according to the second alternative. In an alternative embodiment, the part of the distributor interior that is both inside as well as outside of the knife carrier interior can be supplied with solid manure.
[0060] Cutting knife 135 is mounted to cutting knife carrier 134 on the side facing to cutting plate 120 . The cutting knifes have cutting edges 135 a,b that face to cutting plate 120 and rest on it. The rotation of the cutting knife carrier moves these cutting edges relative to the exit openings and have a shearing effect on the solids of the manure at the edges of the outlet openings. The constant rotation of the cutting knife edges in the distributor interior causes cutting of the solid parts of the manure in the area of the exit openings thus preventing blocking of the exit opening. The cutting of the solids further results in a good flowability of the solid manure through the connecting piece and the connected fluid carrying components thus effectively preventing blocking of the down-stream components.
[0061] The first embodiment shown serves to connect a first set of connecting lines to the first connecting piece thus inserting a deep manure storage into the soil layer. A second set of connecting lines is to be connected to the second connecting piece and inserts a high manure storage above into the soil layer. This high manure storage has a smaller volume than the deep manure storage.
[0062] FIGS. 3 a - d show a second embodiment of a distributor according to the invention. The distributor is identical in design to the distributor according to the first embodiment according to FIGS. 2 a - d and merely differs from the first embodiment in the design of the outlet openings and connecting pieces.
[0063] Contrary to the first embodiment, a first set of outlet openings 223 a,b,c, a second set outlet openings 224 a,b,c and a third set of outlet openings 225 a,b,c in a cutting plate 220 are provided in the second embodiment. The first outlet openings have a first diameter and thus a first passage cross section size and are in fluid contact with a first set of connecting pieces 243 a,b,c. The first connecting pieces have the same inner diameter as the first outlet openings and extend in the same manner as the connecting pieces of the first embodiment.
[0064] The second outlet openings 224 a,b,c have a smaller diameter and thus a smaller passage cross section size as the first outlet openings. They are in fluid contact with a set of second connecting pieces 244 a,b,c, which have the same inner diameter as the second outlet openings.
[0065] The third outlet openings 225 a,b,c have the same diameter as the first exit openings 223 a,b,c and have thus the same passage cross section size. The third outlet openings are in fluid contact with the third connecting pieces 245 a,b,c which have the same inner diameter as the third outlet openings.
[0066] Respectively a first and a third exit opening are arranged adjacent to each other, in circumferential direction followed by a second exit opening so that a sequence of a first, second and third exit opening results respectively alternately on a circular path of cutting plate 220 . The distance between the centers of the exit openings is the same so that the exit openings are distributed evenly across the circular path.
[0067] The second embodiment serves to establish a connection between the first and third connection lines and the first and third exit openings and connecting pieces so as to supply a low-lying discharge opening with solid manure in order to insert a larger and deep manure storage into the soil layer than with the first embodiment. The second exit openings are in turn connected to the second connecting lines via the second connecting pieces so as to supply a second discharge opening with solid manure to insert a smaller, high manure storage into the soil layer. The second embodiment can alternatively also be connected to the discharge openings in a way that the first and second exit openings are connected with a first, low-lying discharge opening and the third exit openings with a second discharge opening for spreading a high manure storage. In this case, the difference in volume between the low manure storage and the high manure storage is lower and equals merely the amount of manure that is additionally fed through the small second exit openings.
[0068] FIG. 4 (positions 343 a,b,c are not included in the text) shows a third embodiment of a distributor apparatus according to the invention which, in regard to the embodiment of the distributor interior and the cutting plate as well as the exit openings arranged therein, corresponds to the first embodiment according to FIG. 2 . The third embodiment, however, differs from the first embodiment in that connecting pieces 344 a,b,c have a larger inner diameter than the second exit openings 324 a,b,c and in particular an inner diameter that equals the inner diameter of the first connecting piece. By this, with this distributor apparatus, the first and second connecting lines can be inserted with a matching connecting diameter which simplifies assembly and possible alternative retrofit measures, since uniform tube dimensions can be used and the tubes can be exchanged in regard to their connecting point.
[0069] FIG. 5 shows a fourth embodiment of the distributor apparatus according to the invention which is designed in analogy to the second embodiment as the third to the first embodiment. In turn, the first, second and third outlet openings match the first, second and third outlet openings of the second embodiment, however differ from said second embodiment in their connection to connecting pieces 443 a,b,c, 444 a,b,c, 445 a,b,c which have the same inner diameter, which matches the diameter of the first and third outlet opening. The advantages of the fourth embodiment are in particular that the connecting lines between the first, second and third connecting piece can be easily replaced, so that the volume supplied to the discharge openings through the respective variable connection of the connecting lines to the distributor apparatus can vary without the need to use new components.
|
The invention relates to an apparatus for inserting a solid manure storage into a soil layer, comprising an insertion apparatus with a set of first and second discharge openings which are spaced vertically from each other in the operating position of the insertion apparatus, a distributor comprising a distributor interior, an intake opening that opens into the distributor interior for feeding solid manure, a first and a second set of several first or second exit openings for diverting the solid manure from the distributor space, a first and a second set of several first or second connecting lines, whereby each first and each second connecting line extends from a beginning of the line to an end of the line, is connected at its beginning to a first or second exit opening and at its end to a first or second discharge opening from the set of first or second discharge openings.
| 0
|
CROSS REFERENCE TO RELATED APPLICATION
Applicants claim priority under 35 USC 119 for application P 29 42 279.5, filed Oct. 19, 1979 in the Patent Office of the Federal Republic of Germany.
BACKGROUND OF THE INVENTION
The field of the invention is ozonolysis and the present invention is particularly concerned with the reaction of olefins with ozone in a carboxylic acid medium.
The state of the art of ozonolysis may be ascertained by reference to the Kirk-Othmer, Encyclopedia of Chemical Technology, 2nd Edition, Vol. 8 (1966) pp. 821-822 and Vol. 14 (1967) under the section OZONE, pp. 410-432, particularly pp. 418-420 where ozonides and ozonide reactions are disclosed, p. 430 where the ozonolysis of oleic acid is disclosed, pp. 421-427 where ozone generation is disclosed, and U.S. Pat. Nos. 2,813,113 and 2,804,473, the disclosures of which are incorporated herein.
The reaction of olefins with ozone (ozonolysis) is known as disclosed in Kirk-Othmer, Vol. 14, pp. 418-419, ibid. In addition to its significance regarding manufacture and analysis, ozonolysis is becoming increasingly important in the chemical industry as a synthetic process. Both linear hydrocarbons and cyclic hydrocarbons with one or more double bonds are suitable as input olefins. For economic reasons, the use of relatively expensive ozone especially for the higher olefins is of interest only for a relatively low specific consumption of ozone per unit mass of the olefin and for a high degree of added value of the end product(s).
Depending on the process, ozonolysis results in peroxidic, aldehydic and/or carboxylic-acidic sequential products or their derivatives (P. S. BAILEY, Chem. Rev. 58, 925, 1958).
As a rule the industrial process does not stop at the stage of the peroxidic ozonolysis products, rather these intermediate products are subjected to a post-treatment in order to obtain stable reaction products. Since the ozonides and di- or oligomeric peroxides most often cannot be converted simply, and then only with a moderate yield into stable end products, the ozonolysis reaction is carried out in so-called participating solvents such as alcohols and carboxylic acids when further reaction of the ozonolysis products is intended. Carboxylic acids are the especially preferred solvents and contrary to the alcohols, they are not attacked by ozone in an oxidizing manner. By further suitably processing by thermolysis, reduction or oxidizing thermolysis the reaction products contained in such solvents, aldehydes, aldehyde/carboxylic-acid mixtures of carboxylic acids are obtained. When cyclic olefins are used, dialdehydes, aldehyde carboxylic acids or dicarboxylic acids are obtained.
Besides air, pure oxygen and mixtures or gases containing oxygen are applicable as the input gas for ozone production. However, even when pure oxygen is used which offers economic advantages over air and mixtures of gases containing oxygen, as much as and more than 90% by volume of the gas used for ozone production remains unutilized. Accordingly, where relatively costly input gases are involved, such as oxygen, oxygen-rich gas mixtures and oxygen-enriched air, there is a problem of economically making use of the practically ozone-free residual gas after the ozonolysis reaction. It is the exception that the residual gas from the ozonolysis is used without further purification for another production run. Even when this is the case, all the shortcomings of two mutually coupled processes arise. Therefore, the preferable approach for utilizing the residual gas is to feed it back, following a pertinent purification, into the ozone production.
Gas purification using electrostatic separation as known from the process of U.S. Pat. No. 2,813,113 is not a generally satisfactory solution. The voltages at which such an apparatus is operated may result in arc formation on account of electric breakdown and hence the oxygenated gas laden with organic substances may ignite. Furthermore, the moisture from humidity introduced with the gas into purification apparatus additionally affects the operational reliability of the electrostatic separators.
SUMMARY OF THE INVENTION
Having in mind the limitations of the prior art, it is an object of the present invention to improve upon the process of reacting olefins with ozone in a carboxylic acid medium by purifying the flow of gas leaving the ozonolysis stage so that it can be fed back to the ozone generator.
This object is accomplished according to the present invention wherein olefins are reacted with ozone in a carboxylic acid medium using oxygen or an oxygenated gas mixture for the ozone production and the oxygen containing gas leaving the ozonizing stage is processed by:
(a) washing the oxygen containing gas with the carboxylic acid input of the ozonizing stage;
(b) treating the carboxylic acid washed oxygen containing gas with an alkalinically reacting substance; and
(c) drying the treated gas and feeding the dry oxygen containing gas back to the ozonizer.
BRIEF DESCRIPTION OF THE DRAWING
The FIGURE of the drawing is a flow sheet showing the apparatus and process stages of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The olefins used in the process of the present invention can be both linear and cyclic and can be simple or polyunsaturated hydrocarbons. For reasons of safety, olefins having less than 5 C atoms are not to be used. As a rule olefins having 6 to 30, preferably 8 to 24 C atoms are used. Typical of the series of linear and cyclic olefins are for instance alpha-olefins having C numbers from 12 to 18, such as oleic acid, elaidic acid, erucic acid, cyclooctene, cyclododecene, cyclooctadiene and cyclododecatriene.
Suitable carboxylic acids useful in the present invention have up to 12 C atoms. However, those monocarboxylic acids are preferred which have 1 to 4 C atoms, for instance, formic acid, acetic acid and propionic acid. Acetic acid and propionic acid are preferred because they have less corrosiveness than that of formic acid, because of their cheap availability and their advantageous dissolving power and boiling points. When appropriate for carrying out the process of the present invention, carboxylic acid anhydrides may also be used in addition to the carboxylic acids.
As a rule, the carboxylic acid(s) is (are) used in at least equimolar amounts with respect to the olefin. The use of olefinic raw materials which bear one or more carboxyl groups makes possible the use of less than molar amounts of carboxylic acids (down to as little as approximately 0.5 moles of carboxylic acid per mole of olefin). It is suitable, however, to use from 2 to 20 units by weight of carboxylic acid per unit weight of olefin.
Applicable raw material gases for the production of ozone are air, oxygenated gas mixtures, for instance, mixtures with nitrogen, argon and carbon dioxide containing at least 20% by volume of oxygen. The ozone concentration used is about 0.01 to 10% by volume.
The following table gives examples of the overall combination of olefin starting material, carboxylic acid medium, ozone concentration and end product as processed according to the present invention.
______________________________________ Ozone Concen- tration % byOlefin RCOOH volume End Product______________________________________cyclododecene propionic acid 2.41 dodecanedioic acidcyclododecene acetic acid 2,00 dodecanedioic acidcyclododecene acetic acid 1,00 dodecanedioic acidcyclododecene acetic acid 0,50 dodecanedioic acidcyclooctene propionic acid 2,50 octanedioic acidcyclooctene acetic acid 1,00 octanedioic acidoleic acid acetic acid 1,00 pelargonic acid + nonanedioic acidoleic acid propionic acid 1,00 pelargonic acid + nonanedioic acidoleic acid pelargonic 1,00 pelargonic acid + acid nonanedioic aciddodecene-1 propionic acid 1,00 undecanoic acid______________________________________
The process of the present invention is explained in further detail below with reference to the FIGURE of the drawing.
A mixture of olefin from line 2 and carboxylic acid from line 4 is exposed to the ozone-containing gas flow from line 6 in a first reaction stage R 1 . The reactor R 1 is for instance an agitated vessel having a gas intake conduit dipping into the liquid. Apparatus permitting complete conversion both of the olefin and the ozone is for instance a bubble column or a trickling tower reactor in which a gas (from line 6 below) or a liquid (from lines 2 and 4 above) respectively are passed in counterflow and such apparatus is especially advantageous.
In a first purification or wash stage W 1 , the ozone-free or at least largely ozone-free exhaust gases rising through line 4 are washed with the carboxylic acid entering from line 8 used as the solvent for the olefin, with a carboxylic acid anhydride or with a mixture of carboxylic acid and carboxylic acid anhydride.
The discharge from the first washing stage W 1 then is fed through line 4 to the ozonolysis reactor R 1 . A suitable purification stage W 1 , for instance, is a trickling tower and the gas to be purified is fed in counterflow through line 4 from below to the washing liquid from line 8. When the input of carboxylic acid used as solvent for the ozonolysis suffices to ensure effective gas purification for a simple passage through the washing column W 1 , there is no need for operating the washing liquid from line 8 in the closed circuit 10 shown in dotted lines and pump 11. When circulation, however, is required to increase the liquid flow rate in the first purification stage W 1 , then the input into the washing circuit is controlled so that the withdrawal of solvent for the ozonolysis reaction R 1 through line 12 and the losses due to entraining in the gas flow are compensated.
The exhaust gas leaving the first purification stage W 1 through line 14 appropriately is partly freed by condensation prior to another wash, in order to minimize the loss of wash with high vapor pressures, from its organic components. This is implemented for instance, in that the gas is cooled to a temperature above the solidification point of the wash used in stage W 1 , whereby the organic components are partly recovered as a liquid condensate.
The gas, pretreated or not, then arrives at the second purification stage W 2 from line 14 where it is freed from the solvent or solvent residues from the first stage W 1 . The second washing liquid introduced from line 18 is at least 0.1% by weight of aqueous solutions of alkalinically reacting substances such as hydroxides, carbonates and bicarbonates of alkali or earth-alkali metals. Typical substances are NaOH, KOH, Na 2 CO 3 and NaHCO 3 . When gas mixtures containing carbon dioxide are used for the production of ozone, solutions of bicarbonates are appropriately employed as a washing medium.
The washing procedure in the second purification stage W 2 is carried out, for instance, so that the gas is fed through line 14 from below into a trickling tower, bubble column or a bubble tray column in counterflow to the circulating washing liquid pumped through line 18 by pump 19.
The exhaust gas leaving the second purification stage W 2 , through line 20 appropriately is freed as much as possible from any entrained water vapor in order to minimize the load on the subsequent drying procedure. Here as for the first purification stage W 1 , the procedure is the same as for the cooling system behind the stage.
In the third purification stage T the exhaust gas lastly is rid of moisture by suitable drying procedures down to a dew point less than or equal to -20° C., preferably, however, less than or equal to -50° C. The dessicant can be arranged in towers where the gas flows through it. Suitable dessicants are, for instance CaCl 2 , NaSO 4 , P 2 O 5 and silica gel. When proceeding commercially, preferably a molecular sieve of suitable pore size is used, as thereby simple regeneration is possible. To ensure continuous operation of the ozone generator, two drying units connected in parallel are appropriately operated in alternation.
The gas separated from organic substances and humidity now can be introduced through line 22 into the ozone generator of a conventional design as disclosed in Kirk-Othmer, ibid., Vol. 14, pp. 421-427 for the purpose of renewed ozone production. To maintain circulation of the gas and overcome the counterpressure building up in the apparatus, the gas is compressed by a suitable compressor or blower 24. In order to minimize the presence of inorganic components (for instance N 2 , Ar, CO 2 , etc.), these components are tapped out of the gas circulation line 20 (gas tap G). To replace these gas losses and also to make up for the oxygen used for ozone production, fresh gas is steadily supplied through line 26.
The liquid reaction mixture leaving the ozonolysis stage R 1 through line 12 as a rule is converted in a post-treatment stage R 2 , either by reduction, thermolytically or by combined oxidation and thermolysis into stable end products. When the post-treatment is completed, the reaction mixture is passed through line 28, reprocessed in stage A and the solvent so recovered is fed back through line 30 as a washing medium into the first purification stage W 1 .
The following variations in procedure are possible embodiments of the post-treatment R 2 by oxidation/thermolysis:
(1) The ozonolysis mixture from line 12 is oxidized in R 2 at a high temperature up to 150° C. depending on the treatment with an oxygenated gas mixture of a different composition than the input gas used for ozone production or the exhaust gas from the ozonolysis stage by way of dotted line 32. In this case, the post-treatment stage may be provided with its own gas circuit and possibly with suitable purification stages. When the gas used for the post-oxidation is air, gas-feedback by way of dotted line 34 can be eliminated.
(2) The ozonolysis mixture from line 12 is post-treated in R 2 in oxidizing manner again at high temperature with part of the exhaust gas from the ozonolysis stage admitted through line 32. The exhaust gas leaving the post-treatment stage following condensation of the organic components is fed back by line 34 to the gas circuit of the ozonolysis of the first purification stage W 1 .
To replace the oxygen used up in the post-treatment, an increased amount of fresh gas is fed to the ozonolysis gas circuit through line 6. When the oxygen of the gas used for post-treatment is extensively or entirely converted, then the exhaust gas from the post-treatment stage passing through dotted line 34 is eliminated from being fed into the ozonolysis gas circuit. In such a case, tapping a side flow from the ozonolysis gas circuit to remove inorganic components (N 2 , Ar, CO 2 , etc.) at G is superfluous.
The process of the present invention is commercially applicable to all ozonolysis procedures which are carried out in a carboxylic acid medium.
Unless otherwise indicated, all percentages below are by weight.
The example below serves to further explain the process of the present invention.
EXAMPLE
166 Parts by weight of cyclododecene an hour are loaded through line 2 into the ozonolysis reactor R 1 . Furthermore, 830 parts by weight of propionic acid an hour are fed through line 8, the first purification stage W 1 and line 4 into the ozonolysis reactor R 1 . A flow of oxygen containing 2.41% by volume of ozone with 48 parts of ozone per hour is passed through line 6 from below through the trickle-tower-ozonolysis-reactor R 1 , water-cooled to a temperature of 20° C. in counterflow to the liquid components of the reaction mixture entering through lines 2 and 4. The reaction is noticeable in the reactor bed of R 1 by a temperature rise of about 20° C. and is controlled so that the reaction zone is always about at the center of the ozonolysis reactor. Complete conversion of olefin and ozone is ensured in this manner. The liquid reaction mixture drains continuously through line 12 and is fed to an oxidizing-thermolytic post-treatment reactor R 2 .
The presently ozone-free oxygen leaving the ozonolysis reactor through line 4 then is washed in a trickling tower W 1 with 830 parts by weight of propionic acid an hour entering line 8. The dwell time of the propionic acid in the trickling tower W 1 is 2.5 hours for a cross-sectional load of 66.4 g/cm 2 ·h of propionic acid. The content is C 12 compounds and shorter chain decomposition products in the exhaust gas through line 14 of the purification stage all together is less than 1 ppm.
After the first purification stage, the gas flow is freed, by condensation at a cooling temperature of -18° C., to such an extent from propionic acid that only about 3 parts by weight/hr of propionic acid are discharged through line 14, which then are removed by counterflow washing with 10% soda liquor in W 2 . By pumping a circulatory flow of soda liquor of 60,000 parts by weight an hour in W 2 and by observing a dwell time of 15 minutes and a cross-sectional load of 1,200 g/cm 2 ·hr of soda liquor, it is possible to wash the propionic acid out of the exhaust gas to values less than 0.5 ppm leaving line 20.
The gas so purified is predried by sol cooling (+5° C.) and then is rid of moisture in a drying column T filled with a commercial molecular sieve down to a dew point <-50° C. The loading of the drying column through line 20 is 62 liters of gas per liter of dessicant an hour.
By feeding fresh gas through line 26 with an O 2 content greater than 99.5% by volume to replenish that used up in the reaction or lost through the tap G, the gas is reintroduced into the ozone generator through line 22 operating on the Siemens ozonizer tube principle. After leaving the ozonizer, the ozone-containing oxygen is compressed by compressor 24 to overcome the counterpressure present in the apparatus.
The ozonlysis mixture leaving R 1 through line 12, after addition of 200 parts water, is post-treated in oxidizing-thermolytic manner in reactor R 2 designed as a bubble column. The dwell time of the input mixture into R 2 is 10 hours for a cross-sectional load of 24 g/cm 2 ·hr of liquid. Three different temperature levels are set by three separate heating or cooling zones in the bubble reactor R 2 : the upper third is at 70° C., the center third is at 90° C., and the lower third is at 100° C. 5% of the exhaust gas from the ozonolysis stage are fed through line 32 as oxidizing means in counterflow to the input mixture fed through line 12 in at the top. The exhaust gas leaving the bubble column through line 34 after extensive condensation of the organic components is fed back into the ozonolysis circuit before the first purification stage W 1 .
The reaction mixture leaving the post-treatment reactor through line 28 is cooled. The raw product so obtained is filtered. The residue obtained after concentrating the filtrate in A is combined with the raw product and recrystallized in propionic acid. The dodecanoic acid is obtained in a yield of 83% and a purity of 99% as end product.
|
The process for reacting olefins with ozone in a carboxylic acid medium using pure oxygen or an oxygenated gas mixture for the ozone production, is improved by recycling the oxygen or the oxygenated gas mixture leaving the ozonizing stage.
The oxygen containing gas leaving the ozonizing stage is:
(a) washed with the carboxylic acid input of the ozonizing stage,
(b) treated with an aqueous solution of an alkalinically reacting substance, and lastly,
(c) dried and fed back to the ozonizer.
| 2
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to hose fitting assemblies; and, more particularly, to detachable reusable fitting assemblies for fluid connection to a reinforced hose.
2. Description of the Prior Art
In my U.S. Pat. No. 3,752,506, I disclose a fitting assembly for reinforced hose. This assembly provides a fluid tight seal with reinforced hose having an inner fluid sealing tube and an outer tubular reinforcement. The fitting assembly disclosed in my patent is of the lip-seal detachable and reusable type and includes a nipple having a received in the fluid sealing tube. The nipple also has an integral enlarged diameter portion, and a shoulder portion joining the cylindrical portions, the enlarged portion outer surface having an annular O-ring recess therein axially adjacent the shoulder. An annular connector wire recess is provided on the surface thereof and spaced axially away from the shoulder. A swivel adapter having external threads, is provided, the adapter including a nut portion with an inner diameter of the sleeve portion so as to define an internal annular shoulder. The inner diameter of the nut portion is only slightly larger than the external diameter of the enlarged portion of the nipple for receiving the enlarged portion in snug relation, the inner surface of the nut portion having an annular connector wire recess therein. A wire connector is disposed in the annular wire recesses when in registry to prevent relative axial movement between the adapter and nipple but permitting relative rotation therebetween. An O-ring is disposed in the O-ring recess, and a socket receives therein the adapter sleeve portion and the nipple elongated cylindrical portion. The socket has an internally threaded section adjacent one end for threaded engagement with the adapter and an intermediate section with a diameter greater than the external diameter of the adapter sleeve portion so as to define a second annular space receiving the hose outer tubular reinforcement and a portion of the hose inner tubing. A remaining section of the adapter has an axially rearwardly decreasing diameter and means for gripping the reinforcement when the socket is axially advanced by threaded engagement with the sleeve thereby forcing a portion of the hose inner tube into the first annular space between the sleeve and nipple and forcing a portion of the hose inner tube and the reinforcement into the second annular space between the sleeve and the socket.
Although a certain amount of misalignment can be compensated for in the fitting assembly disclosed in my patent due to the rotation or swiveling of parts, there is no linear adjustment. Thus, there is a need for allowing the nipple of my patented swivel assembly to move in and out in the direction of its longitudinal axis thus allowing like linear adjustment of the final hose assembly. Such feature would make the fitting assembly of my patent quite versatile since the combination of the swivel and limited linear adjustment would compensate for many misalignment problems.
SUMMARY OF THE INVENTION
It is an object of this invention to provide an improved fitting assembly for reinforced hose.
It is a further object of this invention to provide a fitting assembly having limited longitudinal adjustment along with rotational relationship of the parts to compensate for misalignment of the hose assembly.
These and other objects are preferably accomplished by providing an adjustable and detachable fitting assembly for reinforced hose having an inner fluid sealing tube and an outer reinforcement. The assembly has a nipple insertible into the tube and a sleeve surrounding the nipple but spaced therefrom so that a cutting edge in the sleeve separates the tube structure allowing one separated portion of the tube to fill the space between the sleeve and nipple with the other separated portion of the tube and the reinforcement filling a space between the outer surface of the sleeve and a socket threaded thereto. The sleeve rotates about the nipple and is longitudinally adjustable with respect thereto while maintaining connection of the sleeve to the nipple. This allows for compensation for misalignment.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is an exemplary embodiment in cross-section of a fitting assembly having a nipple attached to a forged elbow connection in accordance with the invention;
FIG. 2 is a vertical view, partly in section, of the fitting assembly of FIG. 1;
FIG. 3 is a partial sectional view showing the start of engagement of the reinforced hose with the fitting shown in FIGS. 1 and 2;
FIG. 4 is a partial sectional view as in FIG. 3 showing the fitting completely assembled;
FIG. 5 is a vertical view, partly in section, of a second exemplary embodiment of a fitting with the nipple integral with a bent tube elbow connection;
FIG. 6 is a vertical view, partly in section, of a portion of a third exemplary embodiment of a straight sealed fitting for reinforced hose with a female end fitting in accordance with the invention; and
FIG. 7 is a partial view of the embodiment of FIG. 6 showing a male end fitting integral with the nipple thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1 of the drawing, a sealed fitting assembly 10 for reinforced hose is disclosed. Assembly 10 includes a nipple 11, a swivel adapter 12, and a socket 13. Nipple 11 is part of an elbow body 14 and a throughbore 15 extends through nipple 11 and body 14. The elbow body 14 terminates in an outwardly flared opening at end 16 (FIG. 2). A coupling member 17 is rotatably connected to end 16. This is accomplished by providing an annular groove 18 on the outer surface of elbow body 14 adjacent end 16 and a like mating annular groove 19 on the inner wall of coupling member 17. The end 16 of elbow body 14 may be of an outer diameter less than the outer diameter of the remainder of elbow body 14 forming a reduced area 20 in which groove 18 is provided. Thus, a shoulder 21 is formed and coupling member 17 can abut thereagainst. The interior of coupling member 17 is threaded at threaded section 22 and a wire member 23 is disposed in mating grooves 18, 19. As is well known in the art, this wire member 23 extends through a hole in coupling member 17 which hole opens at the exterior of member 17 (as at opening 24--FIG. 2), the end of wire member 23 terminating thereat. The exterior of coupling member 17 is a nut as seen at flats 25 in FIG. 2. Thus, coupling member 17 is permanently and axially connected to elbow body 14 yet rotates or swivels with respect thereto.
Nipple 11 includes an elongated generally cylindrical portion 26 having a smooth forward edge 27. The nipple 11 further includes an integral enlarged cylindrical portion 28 having an outer diameter greater than the outer diameter of portion 26 but with the same inner diameter. A shoulder 29 is formed at the intersection of portions 26 and 28. The exterior surface of portion 28 is provided with an annular O-ring recess 30.
The swivel adapter 12 includes a cylindrical sleeve portion 31 having a sharp forward edge 32. Sleeve portion 31 has an internal diameter greater than the external diameter of the elongated cylindrical portion 26 of nipple 11. External threads 33 are provided on the exterior surface of sleeve portion 31.
Swivel adapter 12 also includes an integral nut portion 34 (see also FIG. 2) of hexagonal configuration. The internal diameter of nut portion 34 is greater than the internal diameter of sleeve portion 31 and a shoulder 35 is provided at the junction thereof. An annular space 36 is formed between the inner surface of the sleeve portion 31 of swivel adapter 12 and the exterior surface of the cylindrical portion 26 of nipple 11 as seen in FIG. 1. An O-ring 37' is positioned in the annular recess 30 of nipple 11 when the parts are assembled and the swivel adapter 12 is positioned as shown in FIG. 1.
Assembly 10 further includes socket 13 having a forward internally threaded section 37 including threads 38 for mating engagement with the external threads 33 of swivel adapter 12. The exterior of the threaded section 37 forms a conventional hexagonal nut surface 39 (see also FIG. 2) so that socket 13 may be tightened relative to swivel adapter 12. Socket 13 further includes an intermediate section 40 which, when socket 13 is threaded onto swivel adapter 12 as seen in FIG. 1, defines an annular space 41 between the exterior surface of the sleeve portion 31 of adapter 12 and the internal surface of socket portion intermediate section 40. Socket 13 also includes an axially rearwardly decreasing outer diameter section 42 which includes gripping means 43 for gripping the outer tubular reinforcement of a hose 44 as seen in FIG. 3 and as will be discussed further hereinbelow. Further, rearwardly of gripping means 43, the internal diameter of socket 13 is again increased to a diameter which will accommodate the hose with which the fitting assembly is to be used.
As particularly contemplated in the present invention, limited longitudinal adjustment movement and axial rotation means 45 are provided for both allowing limited longitudinal adjustment of assembly 10 and rotational or swivel coupling means of the swivel adapter 12 to the nipple 11. Such means 45 includes an annular groove or recess 46 on the inner surface 47 of nut portion 34 receiving therein a connector wire member 48 which is inserted through a suitable opening in the nut portion 34 of swivel adapter 12 as is well known in the art, having the end 49 thereof (FIG. 2) terminating at opening 50 on the exterior outer surface of nut portion 34.
Means 45 further includes an elongated annular groove 51 formed in the outer surface of enlarged portion 28. Abutment shoulders 52, 53 define the axial limits of groove 51 and act as a stop for wire member 48. That is, the elbow body 14 and coupling member 17 are longitudinally axially adjustable with respect to swivel adapter 12 and the parts coupled thereto. This provides limited axial adjustment of the parts between shoulders 52, 53. At the same time, the swivel adapter 12 is axially secured to nipple 11 while allowing adapter 12 to be rotated relative to nipple 11. Thus, the improved fitting assembly 10 disclosed herein is quite versatile allowing both swiveling of the parts and limited axial adjustment to compensate for misalignment.
Referring now to FIGS. 3 and 4, it can be seen that the fitting assembly 10 is assembled by first placing socket 13 over the end of hose 44 (having an inner rubber or elastomeric tube 54 and an outer tubular reinforcement 55 of conventional wire braid) so that the forward edge of the hose 44 extends into the space 41 of of socket 13 at which time the socket 13 and hose 44 are in position to be mated with the nipple 11 and swivel adapter 12.
As seen best in FIG. 3, during assembly, the smaller diameter elongated cylindrical portion 26 of the nipple 11 is inserted into the hose inner tube 54 and the external diameter of the nipple portion 26 is only slighter larger than the internal diameter of the inner tube 54 so that the nipple 11 may be freely but snugly forced into the hose 44. As the threads of the socket 38 begin to engage the external threads 33 of the swivel adapter 12, the sharpened forward edge 32 of the swivel adapter 12 engages the forward face of the inner tube 54 of the hose 44 as seen in FIG. 3. When the swivel adapter 12 is rotated relative to the socket 13 during threading engagement, the rotational motion of the forward edge 32 of the swivel adapter 12 will cut into the forward face of the hose lip so as to form an inner and outer flap as seen best in FIG. 4. The inner flap completely fills the annular space 41 and the outer flap, together with the outer tubular reinforcement 55, is forced radially outwardly into the intermediate portion 40 of the socket 13 as well as into the grooves 56 which constitute the means for gripping the hose. It will now be apparent that a lip seal is formed along the engaging faces of the outer surface of the nipple portion 26 and the inner face of the inner tube 54 which forms the primary seal. Any fluid which may pass such seal is retained by the fitting assembly 10 by virtue of the O-ring 37' which provides a second or supplementary seal at one end of the fitting assembly 10 and of course both the inner and outer surfaces of the sleeve portion of the swivel adapter 12 which are in engagement with the inner and outer flaps cut into the lip of the hose 44 to provide a second seal at the opposite end of the fitting.
The means 45 allows limited longitudinal adjustment of the parts so that a fluid-tight connection is presented yet the distance between the elbow body 14 and the socket 13 can be longitudinally adjusted yet the swivel adapter 12 and socket 13 threaded thereto can still swivel or rotate. Thus, slight misalignments and/or hose distances can be quickly and easily accommodated.
The foregoing embodiment in FIGS. 1 to 4 illustrate a nipple having a forged elbow connection. As seen in FIG. 5, wherein like numerals refer to like parts of the embodiment of FIGS. 1 to 4, a fitting assembly 57 is shown having a nipple 58 which is integrally formed with an elbow connection 59. The elbow connection 59 and nipple 58 comprises a conventional piece of metal tubing which is bent at a right angle, one end of which forms the nipple 58 while the other end is rotatably connected to a female coupling member 60.
While the swivel adapter 12 and socket 13 are identical to those shown in the two previous exemplary embodiments, the nipple 58, due to the method of construction, differs. More specifically, prior to bending the tubing which forms the elbow connection and the nipple, the elongated substantially cylindrical portion 26 is formed by turning down the wall of the tubing to a lesser diameter so as to form a slightly enlarged portion 61. To form the complete enlarged portion 62, it is necessary to increase the diameter of the portion 61 by positioning an annular band 63 over the nipple portion of the tubing so that one edge of the band is axially aligned with the shoulder formed where the enlarged portion 61 of the tubing joins the elongated portion 26. The annular band 63 is then brazed or otherwise permanently secured, as at 64, to the portion 61 of the tubing so as to form the complete enlarged portion 62. Of course, the annular band 63 is provided on its exterior surface with the annular recesses 30 and groove 51 for receiving the O-ring 37 and wire connector 48. It will therefore be apparent that a fitting assembly may be constructed by using a forged elbow connection as in FIGS. 1-4 with subsequent machining or an ordinary conventional piece of tubing may be used suitably machined and brazed so as to have an annular band which forms the enlarged portion 62 as shown in FIG. 5.
The assembly and operation of the fitting assembly 57 of the embodiment of FIG. 5 is identical to the embodiment shown in FIGS. 1 to 4 and further discussion thereof is deemed unnecessary.
Still another embodiment of the invention is shown in FIG. 6. In this embodiment, where again like numerals refer to like parts of the embodiment of FIGS. 1 to 4, a portion of a straight fitting assembly 65 is shown also having a nipple 66, a swivel adapter 12, a socket (not shown), and a coupling member 67. Nipple 11 in this embodiment does not have an elbow body but is coupled directly to coupling member 67. This is accomplished by providing an enlarged integral portion 68 at the rearward end of nipple 66 having an internal diameter equal to the internal diameter of the remainder of the nipple and having an outwardly flared opening at its rearward end. The further enlarged diameter portion 68 joins the enlarged diameter portion 28 so as to form an external shoulder 69. Female coupling member 67 completes the fitting assembly and, in the exemplary embodiment shown in FIG. 6, comprises a member having a conventional hexagonal outer surface with internal threads 70 adapted to be matingly engaged to a male threaded connection. Internally, at the forward end of the member 67, the internal diameter is slightly larger than the external diameter of the further enlarged portion 68 of nipple 60 and at its forwardmost end the member has an opening 71 with a diameter slightly larger than the enlarged portion 28 of nipple 11 so that an internal shoulder is formed which will matingly engage with the external shoulder 69 of the nipple 66. Such construction is entirely conventional and well known in the art.
Similar limited adjustment means 45 is provided on nipple 66 and the assembly and operation thereof is identical to the assembly and operation of the embodiment illustrated in FIGS. 1 to 4.
As seen in FIG. 7, the straight fitting there shown is identical in all respects to the fitting shown in FIG. 6 except for the non-hose-connecting portion. Instead of the female coupling member 67, which is rotatable relative to the nipple 66, the male end 72 is integral with the nipple 66 and thus rotates therewith.
In all embodiments, the groove or recess 51 receiving pin or wire member 48 therein allows the nipple to move in and out in an axial direction which in turn allows linear adjustment of the final hose assembly. The assemblies discussed hereinabove can be used on any suitable hose construction, such as Teflon hose.
The advantage of the construction of the present invention is particularly apparent from the elbow connections shown in FIGS. 1-4 and the nonrotating end portion fitting shown in FIG. 7. With conventional constructions, if an elbow connection is secured at each end of a hose and one end is secured, the free elbow end may not be properly aligned as required to be secured. The latter elbow connection must be rotated, therefore, but such rotation will break the seal between the nipple and the inner tube of the hose. On the other hand, with the present invention, one elbow connection when rotated relative to the other will break only the seal between the outer surface of the nipple portion and the hose but not between the inner surface of the sleeve portion of the swivel adapter which also seals against the exterior surface of the inner flap of the hose as previously explained.
The male end fitting of FIG. 7 also permits rotation of the connecting portion of the fitting while only breaking one seal. Thus, the present invention when used with rotatable connection portions integral with the nipple is superior to presently available connections as commonly used on neoprene hose.
Of course, other modifications and variations of the present invention are possible as will be apparent to those having skill in the art without departing from the scope of the invention.
|
An adjustable and detachable fitting assembly for reinforced hose having an inner fluid sealing tube and an outer reinforcement. The assembly has a nipple insertible into the tube and a sleeve surrounding the nipple but spaced therefrom so that a cutting edge on the sleeve separates the tube structure allowing one separated portion of the tube to fill the space between the sleeve and nipple with the outer separated portion of the tube and the reinforcement filling a space between the outer surface of the sleeve and a socket threaded thereto. The sleeve rotates about the nipple and is longitudinally adjustable with respect thereto while maintaining connection of the sleeve to the nipple. This allows for compensation for misalignment.
| 5
|
RELATED APPLICATIONS
This application relates to copending application Ser. No. 07/590,611 filed by inventors Corey A. Billington and Margaret L. Brandeau, entitled "System and Method for Optimum Operation Assignments in Printed Circuit Board Manufacturing", which is owned by the assignee of the present application and is incorporated herein by reference.
BACKGROUND OF THE INVENTION
This invention relates generally to work allocation in an assembly line, and more specifically to operation assignment problems in a printed circuit (PC) board assembly process.
The problem faced by engineers designing a new surface mount technology (SMT) production line fairly represents the difficulty encountered by other manufacturers of low-volume, high technology printed circuit assemblies (PCAs). The assemblies have relatively low component part commonality. Demand for the products varies greatly. And the plant must provide support-life boards for discontinued products as well as prototype boards for a multitude of new products.
The "greedy board" approach proved especially useful for the problem at hand because it weighs volume against part commonality when assigning boards to cells. Other group technology technique typically ignore the impact of volume. The algorithm requires a list of boards, board volumes, and a bill of materials for each board.
OBJECTS AND SUMMARY OF THE INVENTION
The new SMT line, once implemented, needed to meet a number of stringent criteria in order to be considered successful. First and foremost, it had to deliver high-quality, low-cost products. It also had to operate consistent with just-in-time philosophy, which meant little work-in-progress inventory (WIP) and short cycle times. Underlying these constraints was the expectation of rapid growth of SMT volumes and types of products, so the new line'design also had to support a sound growth strategy with little change in layout or operating policy.
This chronicles the successful application of the "greedy board" heuristic to the problem of assigning individual printed circuit board assemblies to product cells in a high-mix, capacity-constrained production environment. The specific case presented concerns the design of a high-speed surface mount line, but the approach can be readily generalized to other electronics manufacturing problems.
In this case, temporal cells were designed to run at different times on the same set of equipment (two series Fuji CP-IIIs). The components in the first cell, comprising the highest volume boards, were fixed on the entire first machine and half of the second. The remaining bank of the second machine was used to set up additional cells to run all remaining boards. Thus, high-volume boards could run at any time, while operators set up cells for low-volume work during high-volume board production. This approach improves machine utilization, accommodates changing mix, and permits simple operational alternatives.
As an additional feature, color coding is used to identify all component parts included in a cell, and number identifications are used to facilitate proper sequential placement of the component parts in the feeder slots of the machines.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1a and 1b shows two typical surface mount technology (SMT) lines using pick-and-place machines in series or parallel configurations;
FIG. 2 shows a presently preferred embodiment of the invention incorporated in the series configuration of FIG. 1 wherein the work flow on an assembly line is shifted between different individual product families (cells), allowing the steps for cell 2 or cell 3 to be accomplished off-line while the products of cell 1 are being built on-line;
FIG. 3 shows a preferred method of labeling part feeders for easy accurate setup of parts used in building all of the boards included in one product family or cell;
FIG. 4 and FIGS. 5A and 5B schematically show an exemplary overlap of parts occurring between products making up different product families or cells;
FIG. 6 schematically shows the off-line storage of parts for cells not currently set up on the assembly line;
FIG. 7 schematically shows how parts can be duplicated in the feeders of sequential machines in order to flexibly achieve balance between such sequential machines;
FIGS. 8A, 8B and 8C shows in tabular form how cells are formed by selecting a board based on a preference of high volume boards needing the fewest additional parts not already included in the cell, in accordance with the so-called "greedy board" heuristic;
FIG. 9 illustrates how certain feeder slots can be left vacant in order to allow future boards with additional parts to be added to an existing cell; and
FIG. 10 graphically shows the assembly board volume and the assembly board uniqueness for exemplary cells 1-5 formed in accordance with the teachings of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The equipment set for the line included one Fuji GSP-II stencil machine, two Fuji CP-III high-speed pick-and-place machines (to be arranged either in series with the other machines or in parallel), a Fuji IP-II general-purpose pick-and-place machine, and a Vitronics infrared solder reflow oven. A preliminary analysis of demand on each of these machines and their respective capacities revealed that the bottleneck process would be the two CP-IIIs, regardless of the arrangement of the two machines, and subsequent efforts focused on developing a plan for the use of those machines. FIG. 1 shows the two material flows considered.
One aspect of the CP-IIIs that makes them the bottleneck is that it takes a long time to set up new parts on the machine when changing from batch to batch. Each machine holds about 100 parts (part capacity is a function of individual part sizes, which are variable). Yet the site supports hundreds of parts more than the capacity of the machines, making it impossible to put all parts on line, even with the machines in series. Between any two batches, there would be dozens of CP-III parts to set up.
In the absence of a clever setup reduction scheme, the expected average parts setup time from one run to the next would be about 60 minutes. By comparison, actual run times for average boards at the site are about four minutes. Thus, for a typical run of ten boards, the run would consist of 60% setup and 40% running time on a CP-III. With equipment costs as high as they are, this sort of machine utilization was unacceptable.
Cells in PCA
For this SMT line design, the definition of a cell is simply a group of products that can be built with a single part setup on the CP-IIIs. With SMT boards it is important not to have solder-stenciled boards sitting for longer than about thirty minutes before reflow, so ti is essential that boards to completed with only one pass through the machines, an additional constraint faced in this situation. All CP-III parts must be set up for all boards in the cell.
Another consideration complicating the development of a group technology solution was the flow through the two CP-IIIs. With the two machines in series, more parts could be dedicated, allowing more boards in each cell. With the CP-IIIs in parallel, on the other hand, two cells could be set up at a time. Parallel machines were tempting, for it is easier to balance work on them. With series machines, more blocking or starving would be expected, a curse for a bottleneck process.
The parallel arrangement was ultimately rejected for several reasons. First, the stencil printer and the IP-II have significant setup times of their own, and they could not process boards for the two CP-IIIs simultaneously. This would lead to large buffers before and after the CP-III area, violating the goals of low WIP and cycle times. Also, duplicate setups on two machines (or two setups with high part overlap) would require an undesirable, increased part feeder and inventory cost. Finally, the parallel arrangement would result in a more complicated material flow, presenting more opportunities for errors and confusion.
With only one line with machines in series, the decision to use a group technology approach implied that temporal cells would be defined, rather than physically separate manufacturing cells. That is, a particular production cell would be set up by placing the appropriate parts on the machines, then all of the boards using that setup would be built before time would ge taken to set up the next family of boards. No significant setup to the machine would be required between runs of any two boards in the same cell.
With multiple cells running on the same line (albeit at different times), the issue of setups between cells remains important. As setups between individual boards in a single cell are nil, it is therefore desirable to have as great a volume of boards as possible in a given cell. This transcends the notion that the greatest number of separate board numbers is key. The proper way to view the problem, from a qualitative point of view, is to reduce as much as possible the expectation that the next board built is in another cell (with another setup). This requires weighting by volume; the greater the demand for a particular board, the more likely it is to appear in the production schedule, especially when multiple, small batches run daily.
Group Technology
Reducing or eliminating lot-to-lot setups quickly became the key objective of the design process. Since it would be impossible to put all of the parts on line, a process-based solution became imperative. Operating policies based on a group technology approach were the answer.
Group technology traditionally refers to the manufacture of parts or products groups together into "families," or "cells," on the basis of similarities between key attributes. The similarities might be a function of the design, the necessary manufacturing processes, or both. The grouping of similar products permits the same tools and fixtures to be used, vastly reducing the time spent setting up each batch. Products that have distinctly different characteristics run in another cell on a different machine, or at a different time on the same machines, following a single major setup.
New products resembling existing products can be introduced with little trouble or expense, but completely new designs that do not fit in an established group might cost more due to increased setups. Thus, the use of clever grouping in manufacturing can reduce costs. Designers can consider the cost of deviating from current designs as they create new products.
The PCA situation, featuring assembly rather than fabrication, suggests a slightly different approach to the grouping process than the one typically encountered. Most significantly, no complicated, new coding system is required to classify products for sorting into groups as is often used for grouping fabricated parts. 2 Instead, products can be grouped on the basis of common part numbers. At the most rudimentary level, only a list of each board's constituent components is required to divide PCAs into production cells.
Techniques abound for actually dividing a list of products into production cells. Given a production schedule and a set of physical constraints (like the number of parts that can fit on a machine), it is possible to cast the problem of minimizing setups as a simple mixed-integer linear program. Such a formulation to define a single production cell would take this form:
minimize setup time
subject to:
all components set up for board
demand met for all boards
machine part capacity not exceeded
However, for situations such as this, where there are dozens of products to consider, each drawing from a pool of several hundred possible component parts, the actual solution time for the problem is prohibitively large. Also, the optimal result produced is only valid for the explicit conditions in the model--and conditions change frequently on the production floor. Heuristic assignment techniques, while suboptimal, provide a quick, flexible, and effective alternative.
The Greedy Board Heuristic
The details of the greedy board heuristic are straightforward. Again, the only data required is the list of part numbers on each board and the expected demand for each board. Specifically, cells are added one at a time by selecting the remaining unassigned boards with the lower ratio of new parts added to the cell to board volume.
For this example consider the following boards with the stated average monthly volumes and constituent components:
______________________________________appaloosa 1400 E, H, N, Pbobcat 132 C, Njaguar 2668 B, D, F, H, Nmorgan 1100 F, J, M, Nocelot 668 G, H, Q, Lpuma 1332 B, D, H, Ntarzan 900 A, J, K, N______________________________________
Boards are added to the cell by checking the ratio of parts that must be added to the cell to include the board to the volume of the board. To find the first board, pick the lowest ratio:
______________________________________current parts in Cell 1: noneBoard New Parts Volume Ratio______________________________________appaloosa 4 1400 0.0029bobcat 2 132 0.0152jaguar 5 2668 0.0019*morgan 4 1100 0.0036ocelot 4 668 0.0060puma 4 1332 0.0030tarzan 4 900 0.0044______________________________________
Jaguar is lowest, so it is the first board added to the cell. It has the highest product volume added per part slot consumed. Jaguar adds five components (B, D, F, H, and N); assume that there is a limit of eight parts in the cell for this example.
For the next board, the ratios change as follows, since B, D, F, H, and N are now already in the cell:
______________________________________current parts in Cell 1: B, D, F, H, NBoard New Parts Volume Ratio______________________________________appaloosa 2 1400 0.0014bobcat 1 132 0.0076morgan 2 1100 0.0018ocelot 3 668 0.0045puma 0 1332 0.0000*tarzan 3 900 0.0033______________________________________
Now puma has a lowest ratio, since its part set is a complete subset of the parts already in the cell. Since adding puma to the cell does not require the addition of any parts, the parts-to-volume ratios above still apply. The next lowest is appaloosa, which adds two new parts to the cell (E and P). That brings the total number of parts in the cell to seven, still within the physical constraint.
After adding appaloosa, the part-to-volume ratio for the remaining, unassigned boards become:
______________________________________current parts in Cell 1: B, D, E, F, H, N, PBoard New Parts Volume Ratio______________________________________bobcat 1 132 0.0076morgan 2 1100 0.0018ocelot 3 668 0.0045tarzan 3 900 0.0033______________________________________
Now morgan has the lowest ratio. However, to add the morgan board requires two new parts in the cell which will not fit. Bobcat is the only board left that will fit, so it is added, even though it has the lowest theoretical contribution. It is only due to the physical constraint on the size of the cell that makes bobcat attractive. Adding bobcat fills Cell 1, which is made up of parts B, C, D, E, F, H, N, and P.
The second cell is defined by following the same procedure for the remaining boards:
______________________________________current parts in Cell 2: noneBoard New Parts Volume Ratio______________________________________morgan 4 1100 0.0036*ocelot 4 668 0.0060tarzan 4 900 0.0044______________________________________
Morgan is added first. After adding parts F, J, M, and N, the following part-to-volume ratios result:
______________________________________current parts in Cell 2: F, J, M, NBoard New Parts Volume Ratio______________________________________ocelot 4 668 0.0060tarzan 2 900 0.0022*______________________________________
Tarzan is added, bringing the total part count to six in the cell (A, F, J, K, M, N). Ocelot still has four parts not in the cell, so it will not fit in Cell 2 without violating the total part ceiling. It must go in Cell 3. Note that Cell 2 is left with two unused part slots, and Cell 3 has four unused slots that can be used to accommodate new boards.
The final cell definitions are:
______________________________________Cell Board Volume Parts______________________________________1 5532 B, C, D, E, F, H, N, P2 2000 A, F, J, K, M, N3 668 G, H, Q, L______________________________________
Cell 1 contains 67% of the total board volume; the volume falls off precipitously with the succeeding cells. Some parts appear in more than one cell.
Assigning Boards to Cell
The greedy board heuristic performs well when high setup costs dominate placement costs. The goal is a list of component part numbers to dedicate on the machines. A cell is defined by adding boards one at a time until the physical machine constraint is reached. Thus, the heuristic greedily adds boards to the cell until no more fit. Component part volume is of no consequence. Rather, the volume of boards produced by the cell drives the solution.
The SMT PCA situation called for the use of the greedy board heuristic because of the time required for setups on the CP-IIIs. The heuristic was used to define one cell at a time, ultimately producing a complete list of cells to run at different times on the same machines. The first pass of the heuristic defined the first cell, filled primarily with the highest volume boards (and other boards with high part overlap). The second and subsequent passes were made after removing the first cell's boards, essentially starting fresh each time but pulling from an increasingly smaller set of boards.
Many approaches were proposed in the course of applying the greedy board heuristic to the SMT line. The simplest application called for single cells, holding about 200 different parts each, which could be set up as needed. This would result in the largest possible cells, thus reducing the total number of cells required to include all of the shop's boards. However, there would be a major setup every time a switch was made from one cell to the next.
A feature of the Fuji CP-IIIs is that each machine is actually split into two banks, each holding 50 parts. It is possible with this split-bank feature to run the machine with only one of the banks on line; the other bank can be off line. This permits an operator to work on setting up half the machine while the other bank is busy placing parts on boards. The feature allowed a more refined solution to the problem. The first cell, Cell 1, was defined so that it would use three of the four available part banks, and it would hold about 150 different parts. Since the first cell defined using the greedy board heuristic contains the highest volume boards, it would be used frequently int he course of a normal production day. To make quick response to demand for one of the high volume boards possible, this cell was kept on line at all times. That is, the parts in Cell 1 were dedicated.
Subsequent cells, holding the lower volume boards and/or boards with relatively little part overlap, have additional parts set up on the remaining bank. The 150 parts dedicated to the three CP-III part banks of Cell 1 would also be available for the boards in the other cells when the fourth bank was put in place, so Cells 2 to n could utilize parts from the Cell 1 setup plus additional parts from the flexible fourth bank. In practice, the heuristic was used to define Cells 2 to N by first stripping from the material list the parts dedicated in Cell 1, since those parts were already guaranteed to be on line.
FIG. 2 shows how a day's work might flow through the line. Cell 1 boards will be built while Cell 2 is being set up. Then, once the setup for Cell 2 is complete, current demand for boards in that cell will be produced. Once that demand is satisfied, more Cell 1 boards will run and the next cell will be set up, as demand warrants. Each day a schedule is released of boards necessary to replenish the demand-pull queues. The operator responsible for initiating flow through the line releases boards in groups so that they run together when their respective cells are set up.
Should a situation arise where a significant change to the daily schedule must be accommodated, a board in any cell can be started through the line with a maximum delay of only about an hour. That is the time required to completely tear down one setup on the fourth bank and install another. Cell 1 boards could be built during the setup time, too. If the change requires building a board in Cell 1, which would be the most likely event, then the board could be run immediately, since that cell is always set up.
This approach eliminates the problem of machine idle time during cell setup. Because Cell 1 has such a large expected volume, boards from that cell can be run through the line while the fourth bank is changed over from one of the smaller cells to the next. There will almost always be sufficient demand for Cell 1 boards to fill the time required to execute the setup for the next cell; most of the time, the setup will be completed before the Cell 1 boards are completed. This arrangement results in essentially zero expected idle time due to setup for the machine--a far cry from the base case of 60% setup idle time.
Using this approach resulted in the definition of five separate cells for the new line. Results shown in Table 1 reveal that Cell 1, the cell with the 150 dedicated parts, accounts for the vast majority of the expected work. Roughly speaking, Cell 1 should be running about three quarters of the time, even though it accounts for only about a third of the factory's unique assemblies.
TABLE 1______________________________________Division of Work Between Cells unique assemblyCell # assemblies volume placements______________________________________1 35% 75% 75%2 35 15 153 15 6 74 10 4 35 5 <1 <1______________________________________
Implementation
The key to success of the group technology approach hinges on the actual implementation on the shop floor. The analysis described so far, while based on realistic data, ignores some practical issues that must be addressed in order to generate a truly workable solution.
Foremost among the problems encountered in taking the group technology cells from the drawing board to the shop floor was the challenge of balancing work between the two series CP-IIIs. In practice there will almost always be an imbalance that results in starving the downstream machine of work (when the upstream machine takes longer to process the board) or blocking the upstream machine (when the downstream machine takes longer). Problems with blocking and starving can be mitigated by the use of buffers of work in progress, but the objective was to reduce WIP as much as possible.
Two further enhancements allowed for better work balance between the CP-IIIs in series. First, work was balanced between the CP-IIIs using another heuristic approach. This heuristic balanced work board by board considering the quantity required of each part number, the time for the machine to place that part type, and specific machine constraints (for example, "tall" parts must be placed on a board last and therefore must always be set up on the second CP-III). The balance was further improved by making a few of the most common parts available on both machines. These components, mostly common resistors and capacitors, occurred in high volume on many boards. In sacrificing a few part slots and putting just a few parts (roughly a half dozen) on each machine, the expected work balance was greatly improved.
Second, because the general purpose pick-and-place machine (the IP-II) has unused capacity, parts unique to a single board were moved to the IP-II. Those parts would have a limited contribution to any production cell, since they would only be used for one board. Parts originally classified as CP-III parts were reassigned to the IP-II on a board-to-board basis, and the material list used to define the CP-III cells was modified accordingly. Calculations showed that the additional time required to set up the IP-II would not jeopardize the flow; the CP-IIIs would still be the bottleneck and the IP-II would still have some idle time.
One of the many concerns that was raised about the implementation of the group technology solution addressed the ability of the operators to accurately set up the cells each time. In fact, the likelihood of inaccurate setups should be greatly reduced because there are fewer unique setups. With no cells, each assembly has its own setup. The operator is required to carefully sequence part feeders by matching a nondescriptive, multicharacter part number. The difficulty of ensuring the proper order, in fact, accounts for much of the time required for a normal setup operation.
With the introduction of cell-based production, the setup process was greatly simplified. First of all, with cells there are only a few different setups to manage, and the largest, Cell 1, is fixed in place. Cells 2-5 are defined for the operator using a simple scheme using colored tape and numbers. The part feeders for each cell set up off line are marked with a different color. Then, the feeders are numbered in the order of their appearance on the CP-III feeder bank. Thus, when Cell 3 is set up, all of the feeders with blue labels should be lined up in numerical order; no other feeders should have blue labels. With this practice in place, the difficult setup requiring matching of the part codes is eliminated. Simple visual cues indicate quickly that the machine is ready to run. The simplicity of this approach leads to higher quality products, as there are fewer defects attributable to setup errors.
FIG. 3 shows how the different component parts constituting each cell are coded for easy identification by the operators. FIGS. 4-5 show now multiple parts can be included in more than one cell, and FIG. 6 shows the off-line part storage for parts of cells which are not currently in production.
As new boards are added and old boards drop off in volume, the performance of the system degrades. The load balancing between the two machines deteriorates. Also, some of the ostensibly low-volume cells (Cells 2-5) might be run more and more often as demand increases for boards in those cells. Redefining the cells is thus a natural part of running the SMT line. Each redefinition requires the generation of new pattern files, and the labels on the part feeders have to be redone. With an automated system, cells are examined and rebalanced every few weeks. This keeps changes to a minimum, favoring frequent, minor changes over infrequent but substantial changes. Newly introduced products are also handled in this way, and the changes keep cell alignment and part balance close to optimal. Feeder relabelling to redefine cells is timed to coincide with preventive maintenance of the machines.
Qualitative Advantages
The principal advantage of the group technology approach with the use of the Fuji split bank feature is bringing batch setup times close to zero. Along with this obvious, quantifiable improvement in operating efficiency (machines running close to 100% of the time), there are many qualitative advantages to the solution.
First, with no machine setup required between board types within a cell, batch size is not an issue. Low-volume boards can run in very small batches, as small as the other process steps can accommodate. This allows a demand-pull strategy and avoids building to stock. The line can build in any quantities needed.
The group technology solution also has a positive effect on quality. Since the parts for 75% of the board volume (Cell 1) are dedicated to machine slots, those boards do not suffer defects due to errors in part set up. For the remaining 25% of the board volume falling into other cells, the part set up is so simplified due to colored tape labelling that set up errors are virtually eliminated. Since many small SMT parts are unmarked by the vendor, defects due to part set up errors cannot be detected visually and are not found until the test step at the end of the process. By the time an error is discovered, a number of boards may have been produced, generating a great deal of repair work. Thus, eliminating or reducing set up errors has a significant impact on both quality and the anticipated cost of repair.
Another advantage of this approach is a reduction in the number of production personnel required to run the line. Since part setups occur on only one CP-III, a single operator can run both CP-III's.
Finally, this solution allows for growth as volumes and number of board types increase. As the capacity of the first line is reached, a second line with the same configuration will be installed. This second line will be given a different set of cells, with many boards fitting cells on both lines to allow for load balancing.
Conclusion
The group technology approach incorporating the use of the split bank feature to take cell set up off-line met all of the goals for a process design. The goal of flexibility to build any board in any quantity as requested by the demand-pull system was met by the virtual elimination of batch setup time. Overall system cost was reduced by increasing line efficiency (run time approaching 100%). Savings are also attributed to reduce finished goods inventories, reduced defects, and reduced production personnel. Finally, the series configuration provides a smooth, linear flow, minimizing queuing on the line. This flow keeps levels of WIP and cycle time as low as possible.
While the examples cited here demonstrate the success of group technology at SMT line design, the ideas can be easily applied to other printed circuit assembly production areas. Similar advantages can be expected in through-hole assembly shops and shops with mixed technologies.
While preferred exemplary embodiments of the invention have bee described, it is to be understood that various changes and modifications can be made without departing from the spirit and scope of the invention as defined by the following claims.
|
A technique for efficient use of component placement apparatus used for assembling many different printed circuit boards, wherein all of the printed circuit boards are collectively comprised of more parts than can be handled by a single setup. A portion of the apparatus is dedicated to producing a first family of boards whose identity is determined by their high volume as well as by their parts overlap, while another portion is periodically changed in order to optionally produce different families of boards characterized by their lower volume and lower parts overlap. The changed setups required for the different families of boards are accomplished off-line while the first family of boards is in on-line production.
| 8
|
RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 60/487,343, filed Jul. 15, 2003, the entire contents of which are herein incorporated by reference.
TECHNICAL FIELD
[0002] The present invention generally relates to building materials and more particularly relates to window sill flashing for a window frame to prevent the ingress of water.
BACKGROUND OF THE INVENTION
[0003] Typical wall construction techniques include forming a rough opening from framing members such that a window opening is formed. The bottom portion of the window opening (called the sill) is susceptible to rotting if water is not prevented from penetrating from around the window perimeter. Additionally, adjacent ceilings, plastered walls, and the like are susceptible to damage if rain-water infiltrates under the window sill.
[0004] Many systems are used to solve the problem of water intrusion. One method includes providing a means to collect and control the water that does infiltrate the window perimeter. Alternatively, surface sealing agents, such as caulk, expanding foam, and the like are used as filling agents to fill openings between the periphery of the window and the adjacent, wall surfaces. However, over time, the filling agents have a tendency to dry, crack and shrink, thereby exposing gaps which provide a passageway for water to infiltrate the window perimeter.
SUMMARY OF THE INVENTION
[0005] The present invention is directed towards a window sill flashing comprising a base having a substantially rectangular shape. A front flange projects perpendicularly downward from a front edge of the base and at least one side flange extends vertically from a side edge of the base. The side flange includes a front surface. The window sill flashing is made from a vacuum formed, rigid homopolymer vinyl film.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is an isometric view of a wall having a window opening and a flashing according to an embodiment of the present invention.
[0007] FIG. 2 is an isometric view of a flashing and window assembly according to an embodiment of the present invention.
[0008] FIG. 3 is a cross-sectional view taken along line 3 - 3 of FIG. 2 .
[0009] FIG. 4 is an isometric view of the flashing and window assembly according to an alternate embodiment of the present invention.
[0010] FIG. 5 is a cross-sectional view taken along line 5 - 5 of FIG. 4 .
[0011] FIG. 6 is a isometric view of the flashing according to yet another alternate embodiment of the present invention.
[0012] FIG. 7 is a cross-sectional view taken along line 7 - 7 of FIG. 6 .
[0013] FIG. 8 is an isometric view of the flashing according to still yet another alternate embodiment of the present invention.
[0014] FIG. 9 is a cross-sectional view taken along line 9 - 9 of FIG. 8 .
[0015] FIG. 10 is a perspective view of a wall having a window opening covered with housewrap.
[0016] FIG. 11 is a perspective view of a wall having a window opening with the housewrap folded to the proper positions for window installation.
[0017] FIG. 12 is a perspective view of a wall having a window opening with a first portion of the flashing of the present invention installed.
[0018] FIG. 13 is a perspective view of a wall having a window opening with a second portion of the flashing installed.
[0019] FIG. 14 is a perspective view of a wall having a window opening with two flashing portions taped according to an embodiment of the present invention.
DETAILED DESCRIPTION
[0020] Referring to FIG. 1 , a window sill flashing (hereinafter referred to as “flashing”) 10 is generally shown according to an embodiment of the present invention. The flashing 10 is formed to fit within and snugly conform to a bottom portion 12 of a window opening 14 of a wall 15 . Window opening 14 has a width W and is adapted to accept a window assembly 13 . As illustrated, the face portion (or flange) 22 of flashing 10 is generally U-shaped and constructed as one piece. The flashing 10 comprises a base 16 , a first side flange 18 integrally formed with base 16 at one end, a second side flange 20 integrally formed with base 16 at an opposite end, and a front flange 22 integrally formed with base 16 . Preferably base 16 , side flanges 18 , 20 and front flange 22 are all vacuum formed from a common sheet. Front (U-shaped) flange 22 extends perpendicularly downward from an edge of base 16 . First side flange 18 includes a front surface 18 a and second side flange 20 includes a front surface 20 a. The flashing 10 is glued, calked, taped, or otherwise permanently secured within window opening 14 . It is contemplated that flashing 10 of FIG. 1 is formed in various standard size lengths and widths to accommodate various standard window openings 14 and wall thicknesses.
[0021] FIGS. 2 and 3 illustrate a first alternative embodiment of the flashing of FIG. 1 , wherein like features are indicated by the same reference number. Flashing 10 a is fabricated as two separate portions 10 a ′ and 10 a ″. Portions 10 a ′ and 10 a ″ form the left and right side of flashing 10 . Alternatively, flashing 10 a is fabricated as a one piece member with a length (prior to cutting) that spans beyond the width W of window opening 14 . Prior to installation of flashing 10 a into window opening 14 , flashing 10 a is cut, resulting in portions of flashings 10 a ′ and 10 a ″. It can be appreciated that flashing 10 a may be cut at any point along its length, so long as flashings 10 a ′ and 10 a ″ fit within window opening 14 . Thereafter, portions 10 a ′ and 10 a ″ are placed so that they partially overlap one another in a region 24 producing flashing 10 a having length L that is generally equal to the width W of window opening 14 . FIG. 3 is a cross-sectional view of the overlap region 24 of portions 10 a ′ and 10 a ″. One advantage of flashing 10 a is that flashing 10 a may be cut to size in the field to accommodate any width W of window opening 14 .
[0022] FIGS. 4 and 5 illustrate a further alternate embodiment of the flashing of the present invention. Flashing 10 b is similar to flashing 10 and flashing 10 a, except portions of flashing 10 b ′ and 10 b ″ do not overlap at region 24 . Instead, portions 10 b ′ and 10 b ″ are separated by a gap 26 . As illustrated, gap 26 is narrow relative to the width W of window opening 14 . However, it can be appreciated that gap 26 may be any desired length. For instance, gap 26 may expose a substantial portion of width W of window opening 14 . Further, gap 26 may be optionally covered with a sill flashing cap 28 .
[0023] FIGS. 6 and 7 illustrate a further embodiment of the flashing of the present invention. Flashing 10 c is substantially similar to flashing 10 a ; however, flashing 10 c includes a rear, vertical rising wall 30 to further impede the ingress of water. Rear, vertical rising wall 30 is located along an edge of base 16 , opposite of front flange 22 and extends perpendicularly upward from base 16 .
[0024] FIGS. 8 and 9 illustrate yet another embodiment of the flashing of the present invention. Flashing 10 d is substantially similar to flashing 10 b ; however, flashing 10 b includes rear, vertical rising wall 30 .
[0025] FIGS. 10-14 illustrate the steps for installing flashing 10 within window opening 14 . Initially, the window opening 14 is covered with housewrap 32 . Housewrap 32 is then cut along perforated lines 34 . Perforated lines 34 divide housewrap 32 into upper section 32 a, lower section 32 b, left side 32 c and right side 32 d. The lower section 32 b and left and right sides 32 c, 32 d of housewrap 32 are folded inwardly, towards the interior surface of wall 15 . Upper section 32 a is rolled up towards the exterior of wall 15 , in the direction of arrows A (see FIG. 11 ). Thereafter, flashing 10 or portions of flashing 10 a″ , 10 b ″, 10 c ″ or 10 d ″ are placed on top of bottom portion 12 of window opening 14 (see FIG. 12 ). FIG. 13 illustrate flashing portions 10 a ′, 10 b ′, 10 c ′, or 10 d ′ being placed along bottom portion 12 . Finally, flashing 10 is secured to bottom portion 12 . FIG. 14 illustrates flashing 10 being secured to bottom portion 12 with adhesive tape 36 . Adhesive tape 36 is also used to seal the seam created by the overlap 24 between right and left portions of the flashing 10 . Where there is no overlap 24 , adhesive tape 36 may be used to cover the bottom portion 12 of window opening 14 . Thereafter, a window 13 is installed within window opening 14 .
[0026] The flashing 10 of the present invention is preferably manufactured from sheets of thermoforming film, such as a rigid homopolymer vinyl film, or polyvinyl chloride (PVC), or the like. The preferable material properties for flashing 10 are listed in the table below:
Property Units Value Gauge Range Mils 7.5-35 Gauge Tolerance % ±5 Specific Gravity — 1.33 Material Yield (Nominal) in. 2 /lb. 2770 (7.5 mil) 2080 (10.0 mil) 1390 (15.0 mil) 1040 (20.0 mil) Tensile Strength (Yield) lb./in. 2 6600 Elongation (Break) % 180 Tensile Impact Strength ft-lb./in. 2 275 Cold Break Temperature ° C. −30 Heat Deflection Temperature at 264 psi ° F. 162 Gloss % 115
It can be appreciated that the flashing 10 may be covered with a silicone coating for ease of manufacturing and separation of the flashing 10 and for ease in installation of window assembly 13 .
[0028] Flashing 10 is preferably fabricated using vacuum forming techniques. Vacuum forming flashing 10 from thin gage material allows the first and second side flanges 18 , 20 to be substantially perpendicular to base 16 . The material properties, including the material thickness, provides flexibility to flashing 10 , thus allowing the vacuum forming dies to separate from the flashing 10 once the vacuum forming process is completed. Additionally, vacuum forming flashing 10 allows the material to have a minimum thickness (as thin as 7.5 mm). Therefore, when portions of flashing 10 overlap, the resultant gap under the flashing 10 is minimal and does not allow water intrusions.
[0029] Due to the geometry and thinness of flashing 10 , flashing 10 cannot be manufactured using an injection molding process. If flashing 10 were to be manufactured by injection molding, the minimum thickness feasible for flashing 10 is 40 mm, significantly higher than the practical thickness of flashing 10 formed by the vacuum forming process. Moreover, to maintain the perpendicularity of surfaces 16 , 18 , 20 and 22 over the depth of base 16 , flashing 10 would require ribs, or support struts, to be molded into base 16 . These ribs would detract from the functionality of flashing 10 . Furthermore, it would be necessary to include ports along base 16 to ensure that sufficient material flows across and covers the entire base 16 . These ports would give rise to dimples, or other imperfections in the surface of base 16 . The imperfections could create gaps or openings along the window sill, thereby comprising the water impermeability of flashing 10 . Even with the use of ports along base 16 , obtaining complete flow coverage of injected material is problematic because the preferred depth of base 16 is in the range of 1 inches to 3¼ inches.
[0030] The embodiments disclosed herein have been discussed for the purpose of familiarizing the reader with novel aspects of the invention. Although preferred embodiments of the invention have been shown and described, many changes, modifications and substitutions may be made by one having ordinary skill in the art without necessarily departing from the spirit and scope of the invention as described in the following claims.
|
The present invention is directed towards a window sill flashing comprising a base having a substantially rectangular shape. A front flange projects perpendicularly downward from a front edge of the base and at least one side flange extends vertically from a side edge of the base. The side flange includes a front surface. The window sill flashing is made from a rigid homopolymer vinyl film.
| 4
|
FIELD OF THE INVENTION
The present invention pertains to the category of medical biodegradable materials, more particularly it relates to a polycondensation method for high biosafety of polylactic acid (PLA) using biomaterial (nontoxic organic material produced in human metabolism) creatinine catalyst.
BACKGROUND OF THE INVENTION
In recent years, along with the rapid development of pharmacological and biomedical science, medical biodegradable materials having excellent biocompatibility and biosafety are increasingly demanded internationally and domestically. The biodegradable PLA has been significantly applied in pharmacological and biomedical science, for example, it is used as the carrier for targeting drugs and controlled release drugs, hard tissue repair material and supporting material for biologically active species in biomedical engineering. By using PLA as the drug carrier, the medical effect can be largely improved, and the dosage and drug's side effects can be reduced. When PLA is used as the drug carrier, the polymer with the weight average molecular weight (Mw) 1.5×10 4 ˜3.0×10 4 is generally used (Zhao, Y.; Wang, Z.; Yang, F. J. Appl. Polym. Sci., 2005, 97, 195-200). However, such polymer should not contain any toxic metal and other toxic components. Currently, commercial PLA is produced mainly by the following two methods: 1. It is synthesized by using stannous octoate to catalyze lactide by ring-opening polymerization; and 2. It is synthesized by using stannous chloride to catalyze lactic acid by direct polycondensation. Although these two methods can be used to synthesize the required polymer, the catalyst tin salt cannot be completely removed from the polymer after polymerization reaction. Many researches have been conducted by foreign and Chinese scholars to prove that stannous octoate and stannous chloride have cytotoxicity. Consequently, scientists around the world start to question the safety of PLA that is synthesized by using stannous octoate and stannous chloride as the catalyst and which is used as the pharmaceutical carrier. The most important problem raised by worldwide biomedical material scientists to be solved is to use the high-effective and nontoxic catalyst to synthesize the medical PLA. At present, there are two methods using non-metal catalysts to synthesize the biodegradable PLA in terms of ring-opening polymerization: 1. Two-component catalysis. This method is developed by American scholar J. L. Hedrick et al. The principle is that a strong phosphine-amine nucleophilic reagent (e.g. triphenylphosphine, 4-dimethylaminopyridine, etc.) is used as the catalyst and alcohol (e.g. pyrenyl butanol, methanol, benzyl alcohol, etc.) as the initiator to prepare the PLA biodegradable polymer in terms of the ring-opening polymerization; and 2. Nontoxic and non-metal organic guanidine is used to synthesize the PLA. This method is firstly developed by Chinese scholar Li Hong (Distinguished Professor of School of the Environment, Nanjing University). The non-toxic and biomimetic organic guanidine (creatinine, creatine, glycocyamine, six alkyl acid guanidine, etc.) without metal and biomaterial is used as the mono-component catalyst to trigger the lactide activity to synthesize the PLA in terms of the controlled ring-opening polymerization. The direct polycondensation method used to synthesize the PLA is the one developed by Japanese scholar Y. Kimura by using stannous chloride to catalyze lactic acid. The advantage of such method is that lactic acid is directly used as the monomer (the ring-opening polymerization needs high purity of lactide made by lactic acid cyclic dimer as the monomer) and high-purity of monomer is not required, therefore, PLA production costs are largely reduced and it is possible for industrialization.
SUMMARY OF THE INVENTION
In view of the above-described problems, it is one objective of the invention to overcome the potential safety problem of PLA as pharmaceutical carrier synthesized in terms of polycondensation by the catalyst stannous chloride that cannot be completely removed from the polymer by providing a direct polycondensation method for medical biodegradable polylactic acid with high biosafety using nontoxic organic guanidine compounds without metal biomaterials as the catalyst.
In the present invention, a new polycondensation method for the high biosafety of PLA using the nontoxic organic guanidine compounds (the arginine metabolite creatinine in human body) without metal biomaterials as the catalyst and the lactic acid (85-90% aqueous solution) as the monomer is firstly developed.
The preferred IUPAC name for the nontoxic organic guanidine compounds without metal biomaterials—creatinine used in the invention is 2-amino-1-methyl-2-imidazolin-4-one, English name creatinine (CR) and the molecular structure is:
The direct polycondensation method for medical biodegradable polylactic acid using creatinine catalyzed lactic acid provided by the invention uses the biomaterial organic guanidine compounds (the arginine metabolite creatinine in human body) as the catalyst and the lactic acid (85-90% aqueous solution) as the monomer to synthesize the high biosafety of PLA in terms of the polycondensation method, specifically, it includes:
Synthetic Route:
Synthetic Steps:
Step 1: Synthesis of Oligomers of Lactic Acid (OLA)
Use industrial lactic acid (LA, mass content 85-90%, aqueous solution) as the monomer to firstly synthesize the OLA with number average molecular weight (Mn) of 400-600. Synthesis conditions: add lactic acid in a reaction vessel and repeatedly vacuumize the vessel and fill in the argon gas for three times. Heat under argon atmosphere and normal pressure until the temperature reaches 130-150° C. and dehydrate for 1-6 hrs. Reduce the pressure of the reaction vessel to 100 Torr and further dehydrate for 1-6 hrs under the temperature of 130-150° C. Afterwards, reduce the pressure of the reaction vessel to 30 Torr and further dehydrate for 1-6 hrs under the temperature of 130-150° C.
Step 2: Synthesis of PLA
Use the OLA obtained from step 1 as the raw material and commercialized creatinine as the catalyst to synthesize the high biosafety of medical PLA under reduced pressure and certain temperature in terms of melt polycondensation. Synthesis conditions: add the catalyst creatinine to the reaction vessel, control the mol ratio of the creatinine to the lactic acid within 1:100-1:1000, reduce the pressure of the reaction vessel to 10 Torr and raise the temperature to 150-190° C. to dehydrate for 48-96 hrs.
The molecular weight of the PLA synthesized by the method provided herein is 1.5˜3.0×10 4 and the polydispersity index (PDI) is 1.70-1.90.
The PLA synthesized by the method provided herein does not contain any metal and other toxic components; therefore, it can be used as the carrier for targeting drugs and controlled release drugs.
Advantages and beneficial effects of the invention are summarized below:
1. The catalyst used in the invention has high biocompatibility and biosafety;
2. The PLA synthesized in the invention does not contain any metal and other toxic components, therefore, it can be used as the carrier for targeting drugs and controlled release drugs;
3. The green catalyst and green processing method (no solvent applied and no toxic products produced) are used in the invention to synthesize green biodegradable PLA with high biosafety;
4. The polymerization reaction is simple and the raw materials required are low in costs, thus it is easy for industrialization.
5. The molecular weight distribution for all synthesized products is narrow and the molecular weight is controllable within 1.5-3.0×10 4 .
DETAILED DESCRIPTION OF THE EMBODIMENTS
Example 1
Add 100 g of L-lactic acid (mass content 85-90%) to a reaction vessel and repeatedly vacuumize the vessel and fill in the argon gas for three times. Heat under the argon atmosphere and normal pressure until the temperature reaches 130° C. and dehydrate for 6 hrs. Afterwards, reduce the pressure of the reaction vessel to 100 Torr and further dehydrate for 6 hrs under the temperature of 130° C. After that, reduce the pressure of the reaction vessel to 30 Torr and further dehydrate for 6 hrs under the temperature of 130° C. to obtain the OLA.
Add 204 mg of catalyst creatinine to the reaction vessel, reduce the pressure of the reaction vessel to 10 Torr, and raise the temperature to 165° C. to dehydrate for 48 hrs. After the dehydration stops, cool the reaction vessel to room temperature, use acetone to dissolve the obtained polymer, fill the solution into 0° C. of ethanol, vacuum filtration of the solution, and dry the obtained solid under the temperature of 50° C. and vacuum condition for 36 hrs to obtain the white solid, i.e. high biosafety of medical PLA with yield at 85.0% and polymer's molecular weight at 2.0×10 4 , PDI 1.70.
Example 2
Add 100 g of D, L-lactic acid (mass content 85-90%) to a reaction vessel and repeatedly vacuumize the vessel and fill in the argon gas for three times. Heat under the argon atmosphere and normal pressure until the temperature reaches 130° C. and dehydrate for 6 hrs. Afterwards, reduce the pressure of the reaction vessel to 100 Torr and further dehydrate for 6 hrs under the temperature of 130° C. After that, reduce the pressure of the reaction vessel to 30 Torr and further dehydrate for 6 hrs under the temperature of 130° C. to obtain the OLA.
Add 204 mg of catalyst creatinine to the reaction vessel, reduce the pressure of the reaction vessel to 10 Torr, and raise the temperature to 150° C. to dehydrate for 96 hrs. After the dehydration stops, cool the reaction vessel to room temperature, use acetone to dissolve the obtained polymer, fill the solution into 0° C. of ethanol, vacuum filtration of the solution, and dry the obtained solid under the temperature of 50° C. and vacuum condition for 36 hrs to obtain the white solid, i.e. high biosafety of medical PLA with yield at 85.9% and polymer's molecular weight at 1.9×10 4 , PDI 1.72.
Example 3
Add 100 g of L-lactic acid (mass content 85-90%) to a reaction vessel and repeatedly vacuumize the vessel and fill in the argon gas for three times. Heat under the argon atmosphere and normal pressure until the temperature reaches 150° C. and dehydrate for 1 h. Afterwards, reduce the pressure of the reaction vessel to 100 Torr and further dehydrate for 1 h under the temperature of 150° C. After that, reduce the pressure of the reaction vessel to 30 Torr and further dehydrate for 1 h under the temperature of 150° C. to obtain the OLA.
Add 204 mg of catalyst creatinine to the reaction vessel, reduce the pressure of the reaction vessel to 10 Torr, and raise the temperature to 150° C. to dehydrate for 96 hrs. After the dehydration stops, cool the reaction vessel to room temperature, use acetone to dissolve the obtained polymer, fill the solution into 0° C. of ethanol, vacuum filtration of the solution, and dry the obtained solid under the temperature of 50° C. and vacuum condition for 36 hrs to obtain the white solid, i.e. high biosafety of medical PLA with yield at 87.2% and polymer's molecular weight at 3.0×10 4 , PDI 1.90.
Example 4
Add 100 g of D, L-lactic acid (mass content 85-90%) to a reaction vessel and repeatedly vacuumize the vessel and fill in the argon gas for three times. Heat under the argon atmosphere and normal pressure until the temperature reaches 150° C. and dehydrate for 1 h. Afterwards, reduce the pressure of the reaction vessel to 100 Torr and further dehydrate for 1 h under the temperature of 150° C. After that, reduce the pressure of the reaction vessel to 30 Torr and further dehydrate for 1 h under the temperature of 150° C. to obtain the OLA.
Add 204 mg of catalyst creatinine to the reaction vessel, reduce the pressure of the reaction vessel to 10 Torr, and raise the temperature to 150° C. to dehydrate for 96 hrs. After the dehydration stops, cool the reaction vessel to room temperature, use acetone to dissolve the obtained polymer, fill the solution into 0° C. of ethanol, vacuum filtration of the solution, and dry the obtained solid under the temperature of 50° C. and vacuum condition for 36 hrs to obtain the white solid, i.e. high biosafety of medical PLA with yield at 87.2% and polymer's molecular weight at 2.9×10 4 , PDI 1.88.
Example 5
Add 100 g of L-lactic acid (mass content 85-90%) to a reaction vessel and repeatedly vacuumize the vessel and fill in the argon gas for three times. Heat under the argon atmosphere and normal pressure until the temperature reaches 150° C. and dehydrate for 1 h. Afterwards, reduce the pressure of the reaction vessel to 100 Torr and further dehydrate for 1 h under the temperature of 150° C. After that, reduce the pressure of the reaction vessel to 30 Torr and further dehydrate for 1 h under the temperature of 150° C. to obtain the OLA.
Add 204 mg of catalyst creatinine to the reaction vessel, reduce the pressure of the reaction vessel to 10 Torr, and raise the temperature to 180° C. to dehydrate for 48 hrs. After the dehydration stops, cool the reaction vessel to room temperature, use acetone to dissolve the obtained polymer, fill the solution into 0° C. of ethanol, vacuum filtration of the solution, and dry the obtained solid under the temperature of 50° C. and vacuum condition for 36 hrs to obtain the white solid, i.e. high biosafety of medical PLA with yield at 88.3% and polymer's molecular weight at 2.7×10 4 , PDI 1.90.
Example 6
Add 100 g of D, L-lactic acid (mass content 85-90%) to a reaction vessel and repeatedly vacuumize the vessel and fill in the argon gas for three times. Heat under the argon atmosphere and normal pressure until the temperature reaches 150° C. and dehydrate for 1 h. Afterwards, reduce the pressure of the reaction vessel to 100 Torr and further dehydrate for 1 h under the temperature of 150° C. After that, reduce the pressure of the reaction vessel to 30 Torr and further dehydrate for 1 h under the temperature of 150° C. to obtain the OLA.
Add 204 mg of catalyst creatinine to the reaction vessel, reduce the pressure of the reaction vessel to 10 Torr, and raise the temperature to 180° C. to dehydrate for 48 hrs. After the dehydration stops, cool the reaction vessel to room temperature, use acetone to dissolve the obtained polymer, fill the solution into 0° C. of ethanol, vacuum filtration of the solution, and dry the obtained solid under the temperature of 50° C. and vacuum condition for 36 hrs to obtain the white solid, i.e. high biosafety of medical PLA with yield at 87.8% and polymer's molecular weight at 2.9×10 4 , PDI 1.89.
Example 7
Add 100 g of L-lactic acid (mass content 85-90%) to a reaction vessel and repeatedly vacuumize the vessel and fill in the argon gas for three times. Heat under the argon atmosphere and normal pressure until the temperature reaches 140° C. and dehydrate for 3 hrs. Afterwards, reduce the pressure of the reaction vessel to 100 Torr and further dehydrate for 3 hrs under the temperature of 140° C. After that, reduce the pressure of the reaction vessel to 30 Torr and further dehydrate for 3 hrs under the temperature of 140° C. to obtain the OLA.
Add 204 mg of catalyst creatinine to the reaction vessel, reduce the pressure of the reaction vessel to 10 Torr, and raise the temperature to 190° C. to dehydrate for 60 hrs. After the dehydration stops, cool the reaction vessel to room temperature, use acetone to dissolve the obtained polymer, fill the solution into 0° C. of ethanol, vacuum filtration of the solution, and dry the obtained solid under the temperature of 50° C. and vacuum condition for 36 hrs to obtain the white solid, i.e. high biosafety of medical PLA with yield at 83.2% and polymer's molecular weight at 2.4×10 4 , PDI 1.81.
Example 8
Add 100 g of L-lactic acid (mass content 85-90%) to a reaction vessel and repeatedly vacuumize the vessel and fill in the argon gas for three times. Heat under the argon atmosphere and normal pressure until the temperature reaches 150° C. and dehydrate for 3 hrs. Afterwards, reduce the pressure of the reaction vessel to 100 Torr and further dehydrate for 3 hrs under the temperature of 150° C. After that, reduce the pressure of the reaction vessel to 30 Torr and further dehydrate for 3 hrs under the temperature of 150° C. to obtain the OLA.
Add 107 mg of catalyst creatinine to the reaction vessel, reduce the pressure of the reaction vessel to 10 Torr, and raise the temperature to 180° C. to dehydrate for 72 hrs. After the dehydration stops, cool the reaction vessel to room temperature, use acetone to dissolve the obtained polymer, fill the solution into 0° C. of ethanol, vacuum filtration of the solution, and dry the obtained solid under the temperature of 50° C. and vacuum condition for 36 hrs to obtain the white solid, i.e. high biosafety of medical PLA with yield at 88.1% and polymer's molecular weight at 2.6×10 4 , PDI 1.79.
Example 9
Add 100 g of L-lactic acid (mass content 85-90%) to a reaction vessel and repeatedly vacuumize the vessel and fill in the argon gas for three times. Heat under the argon atmosphere and normal pressure until the temperature reaches 150° C. and dehydrate for 1 h. Afterwards, reduce the pressure of the reaction vessel to 100 Torr and further dehydrate for 1 h under the temperature of 150° C. After that, reduce the pressure of the reaction vessel to 30 Torr and further dehydrate for 1 h under the temperature of 150° C. to obtain the OLA.
Add 534 mg of catalyst creatinine to the reaction vessel, reduce the pressure of the reaction vessel to 10 Torr, and raise the temperature to 150° C. to dehydrate for 72 hrs. After the dehydration stops, cool the reaction vessel to room temperature, use acetone to dissolve the obtained polymer, fill the solution into 0° C. of ethanol, vacuum filtration of the solution, and dry the obtained solid under the temperature of 50° C. and vacuum condition for 36 hrs to obtain the white solid, i.c. high biosafety of medical PLA with yield at 83.2% and polymer's molecular weight at 2.2×10 4 , PDI 1.87.
Example 10
Add 100 g of D, L-lactic acid (mass content 85-90%) to a reaction vessel and repeatedly vacuumize the vessel and fill in the argon gas for three times. Heat under the argon atmosphere and normal pressure until the temperature reaches 130° C. and dehydrate for 3 hrs. Afterwards, reduce the pressure of the reaction vessel to 100 Torr and further dehydrate for 3 hrs under the temperature of 130° C. After that, reduce the pressure of the reaction vessel to 30 Torr and further dehydrate for 3 hrs under the temperature of 130° C. to obtain the OLA.
Add 1068 mg of catalyst creatinine to the reaction vessel, reduce the pressure of the reaction vessel to 10 Torr, and raise the temperature to 160° C. to dehydrate for 72 hrs. After the dehydration stops, cool the reaction vessel to room temperature, use acetone to dissolve the obtained polymer, fill the solution into 0° C. of ethanol, vacuum filtration of the solution, and dry the obtained solid under the temperature of 50° C. and vacuum condition for 36 hrs to obtain the white solid, i.e. high biosafety of medical PLA with yield at 84.8% and polymer's molecular weight at 1.8×10 4 , PDI 1.82.
|
A direct polycondensation method for medical biodegradable polylactic acid (PLA). The invention uses commercialized creatinine (a type of biomaterial organic guanidine compounds—the arginine metabolite creatinine in human body) as the catalyst and industrial lactic acid (mass content 85-90%, aqueous solution) as the monomer to synthesize the PLA in terms of second polycondensation without solvent. Instead of tin catalysts having cytotoxicity, the catalyst used in the invention has high biocompatibility and biosafety. The synthesized PLA does not contain any metal and other toxic components; therefore, it can be used as the carrier for targeting drugs and controlled release drugs. The green catalyst and green processing method (no solvent applied and no toxic products produced) are used to synthesize the green biodegradable PLA with high biosafety. The molecular weight distribution for all synthesized products is narrow and the molecular weight is controllable within 1.5-3.0×10 4 .
| 2
|
TECHNICAL FIELD
This invention relates to passive Q-switching of a laser system. In particular the invention relates to a passive Q-switch that may be used in a laser system to produce laser pulses having variable output characteristics. The Q-switch may include a semiconductor wafer. The output characteristics of the laser pulses may be tuned by changing the transmittance of the wafer. The output characteristics may include pulse duration and pulse repetition rate of the Q-switched laser beam. The same semiconductor wafer may be simultaneously used as the output coupler of the cavity of the laser to render the laser system more compact.
BACKGROUND OF THE INVENTION AND PRIOR ART
Q-switching is a common and effective technique to achieve optical pulses with short duration, high repetition rate and high peak power. These characteristics are required for laser ranging, nonlinear studies, medicine, laser micro-machining, and other important applications. Q-switching can be effected using an active device which is controlled or driven by an external signal. Q-switching can also be performed using a passive structure that has no external control, but instead operates periodically as a result of its own properties. The present invention relates to a laser system using such a passive Q-switching method.
Passive Q-switching employing a saturable absorber as a Q-switch element is economical, simple and practical. There are many different materials and configurations for passive Q-switching.
U.S. Pat. No. 3,997,854 entitled “Passive Q-Switch Cell”, issued to Buchman et al, discloses a passive Q-switch cell of a liquid saturable solution of dye used on the laser wavelength of 1.06 μm. U.S. Pat. No. 4,637,030 entitled “Switching Laser”, issued to Midavaine et al, discloses a passive Q-switching method with absorption gas used on the laser wavelength of 10.6 μm. U.S. Pat. No. 5,414,724 entitled “Monolithic Self Q-Switched Laser”, issued to Zhou et al, discloses a monolithic self-Q-switched laser with a single Cr:Nd:YAG crystal to generate laser pulses at the wavelength of 1.06 μm. U.S. Pat. No. 5,832,008 entitled “Eyesafe Laser System Using Transition Metal-Doped Group II-VI Semiconductor as a Passive Saturable Absorber Q-Switch”, issued to Bimbaum et al, discloses a passive Q-switch element of Co:ZnSe for laser system at the wavelength of 1.54 μm and 1.6 μm. U.S. Pat. No. 5,724,372 entitled “Diode-Pumped Laser System Using Uranium-Doped Q-Switch”, issued to Stultz et al, discloses a diode-pumped Er:Yb:Glass laser with an output from about 1.5 μm to 1.6 μm and Q-switched with U:CaF 2 . U.S. Pat. No. 5,802,083 entitled “Saturable Absorber Q-Switches for 2-μm Laser”, issued to Bimbaum et al, discloses a passively Q-switched laser with an output from about 1.6 μm to 2.3 μm using Ho:YLF or Ho:YVO 4 as Q-switch material. U.S. Pat. No. 5,237,577 entitled “Monolithically Integrated Fabry-Perot Saturable Absorber”, issued to Keller et al, discloses a Fabry-Perot saturable absorber with a construction of multiple quantum well of AlAs/GaAs, which can be used as a saturable absorber in passive Q-switching and passive modelocking. It was also used as the end mirror of a diode-end-pumped Nd:YLF laser.
Active Q-switching allows a user to vary the output characteristics of a laser beam. A major disadvantage of passive Q-switching, as compared to active Q-switching, is non-adjustability of the parameters of the Q-switched pulses. There is no effective way to control or adjust the parameters of passive Q-switching. It would be useful to devise a technique that is capable of adjusting the parameters of passively Q-switched pulses using a single saturable absorber in the laser cavity.
Saturable absorbers are known to be key elements for passive Q-switching. Materials such as solids, liquids and gases have been used as saturable absorbers based upon the chosen wavelength of laser operation. Generally, the theoretically shortest pulse duration achievable from a Q-switched laser system is limited by the round-trip time of the laser cavity. The shorter the laser cavity, the shorter the Q-switched pulse duration. Therefore shortening the laser cavity is an effective way to get shorter pulses.
Existing Q-switches are mainly made of active devices that make use of acousto-optic or electro-optic effects. These Q-switches require drivers to operate. It would be desirable to provide a tunable passive Q-switch that is a simple device requiring no external drivers and hence may offer reduced operating costs and can render a laser resonator very compact.
Kajava et al [Optics Letters, 21(6), 1996] use a piece of GaAs wafer inside the cavity of an end-pumped Nd:YAG laser to achieve passive Q-switching. The GaAs wafer has a fixed transmittance value. By changing the pump power, the output characteristics of the laser, such as the pulse repetition rate and pulse duration, will vary. However, there are disadvantages in using pump power as the control variable as the emission wavelength of the diode laser may drift away from its optimum value, the temperature of the diode laser may take a long time to stabilise, and the beam quality of the Nd:YAG laser output may change substantially.
Through experimental and theoretical studies [J. H. Gu, et al, SPIE Vol. 3398, pp.170-177, November 1999], it is found that the GaAs wafers used for passive Q-switching may exhibit Fabry-Perot (F-P) effect. Furthermore, effective transmittance of a GaAs wafer, which is generated by this F-P effect, could create a large impact on the output characteristics of the passively Q-switched laser. Based on this prior art, further improvements were made and the following details the improvements.
SUMMARY OF THE INVENTION
The current invention is conceptualized based on this new development. By applying gradient coating on a single piece of GaAs wafer, the effective transmittance of the GaAs wafer can be varied. Therefore, using a single piece of gradient coated GaAs wafer, the laser output characteristics of the GaAs Q-switch, operating at a fixed pump power, can be varied. This improvement avoids the many disadvantages of using pump power as the variable parameter in changing the laser output characteristics.
According to the present invention there is provided a semiconductor passive Q-switch providing variable output suitable for use in a laser system to produce laser pulses having defined output characteristics including a lasing wavelength, said Q-switch including variable transmittance means at the lasing wavelength for adjusting said output characteristics of said laser pulses.
Typically, the laser system may employ a Nd:YVO 4 crystal lasing at the wavelength of 1.06 μm with a diode laser used as the pumping source at the wavelength of 808 nm. A piece of undoped semiconductor wafer may serve as a Q-switch. This wafer may also serve as the output coupler of the laser cavity. One advantage of employing such a construction is that there is no need to insert extra elements into the laser cavity as a Q-switch element or as an output coupler, so that the length of the laser cavity can be shortened, and consequently shorter-duration Q-switched pulses can be obtained.
The Q-switch may include a wafer of GaAs. The surface of the GaAs wafer may be coated so that the transmittance varies for different parts of the wafer. Variations can be effected in a stepwise manner, such that different patches of the wafer may give different transmissions. The variation can also be effected in a gradual manner along a linear length of the wafer, or along a curvilinear path on the wafer. The parameters of the Q-switched laser pulses may be adjusted by moving the wafer with respect to the axis of the laser cavity.
Typically, the Q-switch utilizes a piece of undoped GaAs wafer, which has the characteristics of saturable absorption, in the spectrum of the IR range. Other doped and undoped semiconductors with the property of saturable absorption, such as AlGaAs, InP, InGas, etc., can be used as the Q-switch element in this technique. Multiple-quantum-well semiconductor structures are also suitable candidates.
The device can be applied to Q-switched solid-state lasers for scientific and technological applications such as micro-machining (e.g. sensors and actuators, laser cleaning of hard discs, etc.), micro-fabrication (microlithography, laser assisted thin film deposition, etc.), biomedical studies (tattoo removal, dental treatment, etc.), etc.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the present invention will now be described with reference to the accompanying drawings wherein:
FIG. 1 is a schematic drawing of a laser system that utilizes the present invention;
FIG. 2 a shows a typical measured transmission distribution curve of the passive Q-switch shown in FIG. 1 , using a piece of graded GaAs wafer as the tunable element at the wavelength of 1.06 μm;
FIGS. 2 b (i) to 2 b (iv) show typical patterns and structure for the passive Q-switch;
FIG. 3 shows typical measured results of variations of pulse duration and pulse repetition rate of the Q-switched pulses when the wafer is adjusted along its length direction, while keeping all other operating conditions of the laser system unchanged;
FIG. 4 shows typical measured results of variations of averaged power and peak power of the Q-switched output pulses when moving the wafer along its length direction, while keeping all other operating conditions of the laser system unchanged; and
FIG. 5 shows a typical oscilloscope trace of a laser pulse as a function of time for the laser system of FIG. 1 , using a GaAs wafer as a Q-switch as well as an output coupler of FIG. 2 a.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates schematically the use of a semiconductor wafer in a laser system including a pumping source 10 , a beam shaping system 20 , a laser gain material 30 , and a passive Q-switch 40 , which also serves as the output coupler for the laser system. In an alternative embodiment, the tunable passive Q-switch may not operate simultaneously as the output coupler of the laser system. In such a case, in line with common practice in the trade, a partially transmitting mirror at the laser wavelength may be used as the output coupler.
The pumping source 10 consists of a diode laser 11 and delivery optical fiber 12 , providing a pumping laser beam 13 , which has a center wavelength matching the absorption peak of the laser crystal 32 . The laser beam 13 is collimated by a first lens 21 and then focused by a second lens 22 to a laser crystal 32 . The laser crystal 32 is 1% (by atomic weight) doped Nd:YVO 4 , with one facet 31 anti-reflection (AR) coated at the wavelength of 808 nm and high-reflection (HR) coated at the wavelength of 1.06 μm and serving as a total reflection mirror of the laser cavity, and another facet 33 AR coated at the wavelength of 1.06 μm. Element 40 includes a piece of semiconductor wafer 41 , which is coated gradually on its surface 42 and/or surface 43 , and a miniature translation stage 44 , on which element 41 is mounted. Element 40 serves as a passive Q-switch as well as the output coupler of the laser cavity.
In other embodiments, the end-pumping geometry may be altered or simplified. In yet other embodiments, the laser medium 30 may be pumped by the diode laser 10 from the side, or may be pumped simultaneously from the end and by the side.
FIG. 2 a shows details of an example of the Q-switch element 40 . The element 40 is a piece of undoped GaAs wafer with a dimension of 20 mm in length, 10 mm in width and 625 μm in thickness. Its two faces are optically polished, and both of its two surfaces are gradually coated with AR coating. The curve in FIG. 2 a indicates the measured distribution of transmission at the wavelength of 1.06 μm in the direction along the length of the wafer. It has a homogenous transmission distribution in the direction along the width of the wafer.
In other embodiments, one side of the wafer may be coated to provide variable transmission, and the other side of the wafer may be uncoated. In yet other embodiments, discrete patches giving different transmittance values may be used instead of a graded structure, or variation of transmittance may be effected by rotation instead of linear translation. Variable transmittance may also be effected by using a semiconductor with variable thickness, e.g., a wedge. Typical patterns and structures for element 41 are shown in FIGS. 2 b (i) to 2 b (iv).
In FIG. 2 b (i), element 411 represents a rectangular structure of element 41 with a gradient distribution of transmittance and in FIG. 2 ( b )(ii) element 412 represents a rectangular structure of element 41 but with a discrete distribution of transmittance. In FIG. 2 b (iii) element 413 represents a circular structure of element 41 with a gradient or discrete azimuthal distribution of transmittance and in FIG. 2 b (iv) element 414 represents a wedged structure of element 41 , having a different transmittance at each different thickness.
One theory of using a semiconductor material for passive Q-switching is presented herein. More detailed descriptions can be found in J. H. Gu et al ( Optical Engineering, 38 (11), pp. 1785-1788 (1999). The bandgap of GaAs is 1.42 eV and the photon energy of the laser radiation at the wavelength of 1.06 μm is 1.17 eV. Therefore, there is no band-to-band absorption occurring at this wavelength. However, because the EL2 defect energy level is 0.82 eV below the conduction band, GaAs exhibits saturable absorption characteristics at the wavelength of around 1.0 μm, mainly contributed by processes of two-photon-absorption and free-carrier-absorption. The property of saturable absorption makes GaAs a good candidate to be used as a saturable absorber in a laser cavity to perform passive Q-switching.
Q-switching is accomplished by making the cavity loss an explicit function of photon density, as in the case of the passive Q-switching by saturable absorption of GaAs. In the present invention, element 40 provides both saturable loss as a saturable absorber and coupling loss as an output coupler of the laser cavity. The parameters of passively Q-switched laser pulses, such as pulse duration, pulse repetition rate, peak power, and averaged output power, are determined by the loss property of the laser cavity.
According to conventional rate equations which can be used to describe the output characteristics of Q-switched operation, it is well known that under a certain pumping condition, the loss of the laser cavity will be a unique parameter determining photon density inside the laser cavity and population inversion density within the laser gain material. Therefore, the parameters of the Q-switched laser pulses can be adjusted by changing the loss property of the laser cavity: This makes it possible to improve a major disadvantage of passive Q-switching, namely its general inability to provide adjustability to its output characteristics.
In the present invention, adjusting translation stage 44 to move element 40 with properties as indicated in FIG. 2 a along its length, will change the transmission of the output coupler as well as the loss properties of the laser cavity. Therefore, the parameters of the passively Q-switched laser pulses can be adjusted continuously or discretely.
FIG. 3 shows a typical result of variations of measured pulse duration and pulse repetition rate from the laser system shown in FIG. 1 at different locations when the element 40 is moved from one end to the other. Pulse duration increases from 5.7 ns to 14.5 ns and the corresponding pulse repetition rate increases from 250 kHz to 1.0 MHz when the distance to the edge with low transmission is increased from 4 mm to 16 mm, while keeping all other parameters of the laser operation unchanged: the beam power of the pumping diode laser is 3.9 W at the wavelength of 808 nm; the laser crystal 32 has a dimension of 3 mm×3 mm×5 mm; the gap between the GaAs wafer 41 and the laser crystal 32 is 1 mm; and the physical length of the laser cavity is 6 mm. During adjustment, the transmittance of element 40 increases from 4.8% to 45.6% as shown in FIG. 2 a.
FIG. 4 shows the variation of measured averaged output power and peak power from the passively Q-switched laser system of FIG. 1 operating with the same settings described above. The average output power increases from 0.17 W to 0.4 W when the transmittance increases from 4.8% to 45.6%.
In another embodiment, the shortest pulse duration obtained from the passively Q-switched laser system is 1.6 ns. This is evident from the oscilloscope trace of the temporal development of a laser pulse shown in FIG. 5 . The results are obtained with element 40 being a piece of GaAs wafer with a thickness of 625 μm and with one side uncoated and the other side coated to form a gradient transmission profile. The measured output characteristics of the passively Q-switched pulses have similar tuning capabilities as described above by adjusting the position of element 40 in FIG. 1 .
The present invention may thus provide a means of passively Q-switching a laser system with a variable transmittance semiconductor wafer as a Q-switch element. The wafer can double-up as an output coupler. Using this device, the operating characteristics of the passively Q-switched laser pulses can be adjusted by changing the location of the wafer while keeping the laser operating parameters unchanged. Such characteristics include the pulse duration, pulse repetition rate, and output power of the laser beam.
Although the present invention has been described with reference to a particular embodiment, viz. a diode-pumped solid-state laser, it will be apparent to persons skilled in the art that the present invention may be applied to other kinds of solid-state lasers, such as lamp-pumped solid-state lasers, and suitable lasers in general. Furthermore, the present invention can also be used for other IR wavelengths because certain types of semiconductor materials and bandgap-engineered materials have the properties of both saturable absorption, which is required as a passive Q-switch, and partial transmission in the IR spectrum which is required as an intracavity element or as an output coupler.
Finally, it is to be understood that various alterations, modifications and/or additions may be introduced into the constructions and arrangements of parts previously described without departing from the spirit or ambit of the invention.
|
A semiconductor wafer with variable transmittance, serves as a saturable absorber for performing passive Q-switching in a laser system to produce laser pulses having defined output characteristics. By translating or rotating the semiconductor saturable absorber, loss properties of a laser cavity may be altered. In this manner, the output characteristics of the laser pulses can be varied without changing other parameters of laser operation. The output characteristics may include pulse duration, pulse repetition rate, peak power and average output power of the laser pulses. The semiconductor wafer can be made of doped or undoped GaAs, AlGaAs, InP, etc. Furthermore, the tunable Q-switch may simultaneously serve as an output coupler for the laser cavity.
| 7
|
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to PCT Application No. PCT/CN2006/001125, filed May 29, 2006 and entitled “COMPOSITIONS FOR TREATING AND PREVENTING HYPERLIPIDEMIA”.
FIELD OF THE INVENTION
[0002] The present invention relates to prevention and treatment of hyperlipidemia, and particularly relates to treatment and prevention of hyperlipidemia using a composition of phytosterols, flavones derived from bamboo leaf, procyanidins and β-glucan.
BACKGROUND OF THE INVENTION
[0003] Blood lipids mainly refer to cholesterol and triglyceride in serum. The increases of cholesterol level, triglyceride level or both are all called hyperlipidemia. Hyperlipidemia and hypercholesteremia play a major role in development of atherosclerosis, which are the main causes of blood vessel and heart diseases. The research on medicaments for lowering levels of cholesterol and low density lipoprotein has long been the main focus on R & D work of lipid-lowering drugs.
[0004] Phytosterols are one category of sterols, which have a basic core structure of a heterocyclic compound (non aromatic substance) formed by three C6 rings (different from benzene ring) and one C5 ring, are constituents of various tissues and cells, and bond with proteins to form lipoprotein and constitute various membranes of cells, such as cellular membrane, nuclear membrane, mitochondrial membrane, and endoplasmic reticulum membrane etc. From aspect of structure, phytosterols have very similar structure with that of cholesterol, and the difference is only in structure of branch thereof. Phytosterols are mainly β-sitosterol, stigmasterol, and campesterol, etc. (see formula I). As phytosterols have similar structure with that of cholesterol, phytosterols, phytostanols, and their esters can compete with cholesterol in vivo for inhibiting its absorption in small intestine, reduce plasma cholesterol level, and have the function of lowering levels of total cholesterol and low density lipoprotein (LDL) by added into special food useful as functional food.
[0000]
[0005] Bamboo leaf has long been used as medicine and food in China, which is a well known drug for clearing away heat and toxins in traditional Chinese medicine. Recent study shows that bamboo leaf contains large amounts of flavones, phenolic acids, anthraquinones compounds, and bioactive polysaccharides, etc. Flavone glycosides are main functional factors of bamboo leaf, which mainly comprise C-glycosides; the four main C-glycosylflavones (flavones derived from bamboo leaf) of bamboo leaf are respectively orientin, homoorientin, vitexin, and isoviextin. Studies have proved that flavones derived from bamboo leaf can significantly reduce the levels of triglyceride, total cholesterol, and low density lipoprotein (LDL) in human body, and increase the level of high density lipoprotein (HDL), have functions of inhibiting lipid peroxidation, dilating coronary vessels, and inhibiting myocardial infarction, etc.
[0006] Procyanidins (PC) are general name of a major category of polyphenol compounds, widely existing in plants, which are polymers formed by different amounts of catechin, epicatechin, or gallic acid linked together. Study shows that procyanidins are good oxygen free radical scavenger and lipid peroxidation inhibitor, have functions of protecting blood vessels, inhibiting atherosclerosis, platelet agglomeration, and myocardial ischemia, hypertension and regulating lipid, and receive more and more attention in fields of nutrition and health care.
[0007] Glucan is a category of polysaccharides with glucose as basic constituent unit, and is divided into two types, α-glucan and β-glucan. The natural glucan usually exists in form of β-glucan. β-glucan is a mixed linked glucan, whose molecular structure contains three glucoside bonds, β-1,3, β-1, 4, and β-1,6, in which β-glucan of barley is β-1,3/1,4-glucan, can prevent and treat cardiovascular and cerebrovascular diseases caused by hyperlipidemia, and has functions of significantly reducing levels of lipid and serum cholesterol.
[0008] The aforementioned four kinds of substances respectively have certain effects on preventing and treating hyperlipidemia, cardiovascular diseases, coronary heart disease, atherosclerosis, and the like. Research on whether more effective treatment and prevention of hyperlipidemia can be achieved by using their combination has been done. From available literatures, most literatures disclose compositions consisting of only two kinds of the aforementioned substances, for example patents US2003068357, WO03105600, WO2005072761, and WO0130359 have disclosed extract or composition containing phytosterols and β-glucan which can influence cholesterol level, and patent US2005227930 has disclosed a composition at least containing flavones derived from citrus, phytosterols or phytostanols which can lower cholesterol level. But until now, there is no report related to the composition of the present invention, and more effective products capable of achieving better synergistic effects need to be developed. After repeated research work and verification, the inventor of the present invention has finally found the composition on capable of more effectively treating and preventing hyperlipidemia in order to complete the present invention.
SUMMARY OF THE INVENTION
[0009] The object of the present invention is to provide a composition capable of more effectively treating and preventing hyperlipidemia.
[0010] The composition of the present invention selects phytosterols, flavones derived from bamboo leaf, procyanidins and β-glucan for combination to achieve synergistic effects among the components, so as to more effectively treat and prevent hyperlipidemia. Phytosterols only have inhibition effects on absorption of cholesterol acquired from food, and have no effects on cholesterol produced by liver which is the main cause of high cholesterol. While flavones derived from bamboo leaf, procyanidins and β-glucan are mainly capable of reducing cholesterol produced by liver, the combination of the four kinds of compounds can achieve synergistic effect, and lower levels of cholesterol and triglycerides derived from food and produced by liver in human body, so as to reduce lipid level.
[0011] The amounts of composition in the present invention are obtained through large amounts of experiment by the inventor, and desirable treatment effect can be achieved by amounts of each components within following mass percentage range:
[0000] phytosterols or phytostanols 30-50%, flavones derived from 20-40% bamboo leaf, 10-25% procyanidins, and 5-20% β-glucan.
[0012] The preferred composition of the component is: 30% phytosterols or phytostanols, 40% flavones derived from bamboo leaf, 20% procyanidins, and 10% β-glucan.
[0013] Another preferred composition is: 50% phytosterols or phytostanols, 20% flavones derived from bamboo leaf, 25% procyanidins, and 5% β-glucan.
[0014] The most preferred scheme of the present invention is: the composition consists of 40% phytosterols or phytostanols, 30% flavones derived from bamboo leaf, 10% procyanidins, and 20% β-glucan. The treatment effect achieved by the scheme is more remarkable, and will be explained in details as below.
[0015] Each component of the composition according to present invention can be obtained and prepared by the method and step well known in the field.
[0016] Preferably, the said phytosterols are obtained from deodorized soybean oil through extraction and separation. The said phytosterols are selected from at least one of β-sitosterol, stigmasterol, and campesterol. The said phytostanols are obtained from phytosterols through hydrogenation.
[0017] The said flavones derived from bamboo leaf are C-glycosylflavones extracted from bamboo leaf.
[0018] The said procyanidins can be extracted from plants like grape seed or guava.
[0019] The said β-glucan is β-1,3/1,4-glucan, which can be extracted from plants like barley, oat, or rye.
[0020] The composition according to present invention is prepared by fully mixing the components according to the aforementioned mass percentage.
[0021] Compositions according to present invention are prepared by mixing phytosterols or phytostanols, and one or two of the other three components at various ratios are subjected to clinical trial to compare their treatment effects of hyperlipidemia with those of the proceeding and phytosterols. The results show that the composition of the present invention has the best treatment effect for hyperlipidemia. By applying the composition of the present invention to nutrient supplement and medicament, synergistic effect can be achieved to prevent and treat hyperlipidemia, cardiovascular diseases, coronary heart disease, atherosclerosis, and the like.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is T-test analytical chart, in which 0 is the data before administration, 1.7, 2.7, and 3.7 are the datas for the composition of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0023] The terms adopted in the present invention usually have general meaning which is well known for those skill person in this area unless otherwise stated
[0024] The term “phytosterols” used in the present invention includes at least one of β-sitosterol, stigmasterol, and campesterol. The term “phytostanols” refers to saturated or hydrogenated phytosterols. It should be understood that the term “phytosterols” includes phytosterols and phytostanols in the case of uncertainty in the descriptions, i.e. the two terms are mutually replaceable, unless specified otherwise.
[0025] Phytosterols, flavones derived from bamboo leaf, procyanidins and β-glucan in the following embodiments are prepared through known methods in the present invention, for example the preparation method of phytosterols refers to “Purification and recovery processes of phytosterols from deodorizer distillates” (Xu Wenlin, Wang Yaqiong, Lu Ping, The Chinese Journal of Process Engineering, Vol. 2, No. 2, April 2002); the preparation method of flavones derived from bamboo leaf refers to “Studies on the productive technology of flavonoids extract from the leaves of Phyllostachys pubescens” (Li Hongyu, Sun Jingyun, Dai Shiwen, The Chinese Journal of Modern Applied Pharmacy, Vol. 21, No. 5, October 2004); the preparation method of procyanidins refers to “Research on extract technology of grape seed polyphenol extract” (Li Hua, Wang Weixin, Yuan Chunlong, Food Research and development, Vol. 26, No. 6, 2005); the preparation method of β-glucan refers to “Studies on ‘Water Method’ Isolation and Characterization of Tibetan Hulless Barley B2-glucan” (Zeng Yu, Zhang Beichuan, Yan Fang, Tang Lin, Chen Fang, Journal of Sichuan University (Natural Science Edition), Vol. 40, No. 2, April 2003).
Embodiment 1
Clinical Observation of Treatment and Prevention of Hyperlipidemia Using the Composition of the Present Invention
[0026] Phytosterols, flavones derived from bamboo leaf, procyanidins and β-glucan are prepared according to routine methods, and the various components are then fully mixed according to components and mass ratios in Table 1 into eight compositions of A1-A8:
[0000]
TABLE 1
flavones
derived from
Phytosterols
bamboo leaf
procyanidins
β-glucan
Composition
(%)
(%)
(%)
(%)
A1
30
70
0
0
A2
30
0
70
0
A3
30
0
0
70
A4
30
35
35
0
A5
30
35
0
35
A6
30
0
35
35
A7 (Composition
of the present
30
40
20
10
invention)
A8
100
0
0
0
[0027] 80 Trial subjects are selected and divided into 8 groups, each of which consisted of 10 trial subjects. The total cholesterol level of each trail subject is above 210 mg/dL, low density lipoprotein (LDL) is above 140 mg/dL, and triglyceride is less than 300 mg/dL. All the trial subjects have similar other health conditions, stop administration of any lipid-lowering drugs and nutrient supplement before one month for the trial, and have identical dietary during the trial period. The trial subjects of the eight groups are respectively administered with the aforementioned eight compositions at 200 mg per day. After the compositions are administered for six weeks, the trial subjects are tested for total cholesterol (TC), low density lipoprotein (LDL), high density lipoprotein (HDL), triglycerides (TG), and systolic blood pressure (SBP) and diastolic blood pressure (DBP), and the datas are shown in Table 2.
[0000]
TABLE 2
Treatment effect indicator improvement after six weeks of treatment using the A1-A8 compositions
(TC)
(LDL)
(HDL)
(TG)
(SBP)
(DBP)
Indicator
(mg/dL)
(mg/dL)
(mg/dL)
(mg/dL)
(mmHg)
(mmHg)
Before
230.12 ± 20.26
162.50 ± 25.65
45.26 ± 12.51
66.23 ± 36.50
111.2 ± 20.32
78.50 ± 12.63
administration
After
A1
217.77 ± 23.56
159.15 ± 22.10
45.59 ± 11.52
63.02 ± 29.99
108.66 ± 20.33
78.00 ± 12.79
adminis-
A2
218.25 ± 25.22
160.01 ± 22.19
45.47 ± 12.50
64.98 ± 31.25
109.1 ± 20.00
78.27 ± 12.01
tration
A3
221.9 ± 25.78
160.99 ± 23.22
45.36 ± 12.24
65.37 ± 30.17
111.02 ± 19.21
78.38 ± 12.50
A4
194.98 ± 21.15
145.00 ± 20.15
46.68 ± 10.56
51.18 ± 30.57
106.90 ± 19.54
77.39 ± 11.43
A5
195.85 ± 20.09
145.44 ± 19.89
46.52 ± 11.22
52.19 ± 30.23
107.00 ± 19.47
77.46 ± 11.57
A6
198.02 ± 20.11
148.21 ± 19.81
46.22 ± 10.85
55.46 ± 29.96
107.37 ± 20.79
77.61 ± 11.00
A7
183.19 ± 20.15
123.35 ± 22.56
50.55 ± 11.52
36.58 ± 20.57
96.1 ± 18.22
70.01 ± 10.12
A8
200.12 ± 19.80
153.01 ± 21.07
46.09 ± 10.87
57.53 ± 30.44
107.51 ± 19.15
77.68 ± 10.64
[0028] The above trial results show that there are different treatment effects among different compositions, phytosterols play a major role in reducing cholesterol level, and flavones derived from bamboo leaf are the second to them. When phytosterols are compounded with the other components, their function has changes to various extents. The synergistic effect is not desirable when phytosterols are mixed only with one of the other components (A1, A2, and A3); but when phytosterols are mixed with two or three of the other components (A4-A7), the synergistic effects are significantly better than that of single phytosterols, especially the treatment effect of combination of four of the components is the best, which can lower total cholesterol level by 28%, and lower low density lipoprotein level by 24%.
Embodiment 2
Clinical Observation of Treatment and Prevention of Hyperlipidemia Using the Compositions of the Present Invention
[0029] Phytosterols derived from soybean, flavones derived from bamboo leaf, procyanidins and β-glucan (β-1,3/1,4-glucan) are prepared according to routine methods, and which are then prepared into eight compositions B1-B8 according to components and mass percentages in Table 3, wherein the B7 is the composition of the present invention.
[0000]
TABLE 3
flavones
derived from
Phytosterols
bamboo leaf
procyanidins
β-glucan
Composition
(%)
(%)
(%)
(%)
B1
40
60
0
0
B2
40
0
60
0
B3
40
0
0
60
B4
40
30
30
0
B5
40
30
0
30
B6
40
0
30
30
B7 (Composition
of the present
40
30
10
20
inventionn)
B8
100
0
0
0
[0030] 80 Trial subjects are selected and divided into 8 groups, each of which consists of 10 trial subjects. The total cholesterol level of each trail subject is above 210 mg/dL, low density lipoprotein (LDL) is above 140 mg/dL, and triglyceride is less than 300 mg/dL. All the trial subjects have similar other health conditions, stop administration of any lipid-lowering drugs and nutrient supplement before one month for the trial, and have identical dietary during the trial period. The trial subjects of the eight groups are respectively administered with the aforementioned eight compositions at 200 mg per day. After the compositions are administered for six weeks, the trial subjects are tested for total cholesterol (TC), low density lipoprotein (LDL), high density lipoprotein (HDL), triglycerides (TG), and systolic blood pressure (SBP) and diastolic blood pressure (DBP), and the datas are shown in Table 4.
[0000]
TABLE 4
Treatment effect indicator improvement after six weeks of treatment using the B1-B8 compositions
(TC)
(LDL)
(HDL)
(TG)
(SBP)
(DBP)
Indicator
(mg/dL)
(mg/dL)
(mg/dL)
(mg/dL)
(mmHg)
(mmHg)
Before
230.12 ± 20.26
162.50 ± 25.65
45.26 ± 12.51
66.23 ± 36.50
111.2 ± 20.32
78.50 ± 12.63
administration
After
B1
207.01 ± 20.13
154.90 ± 22.93
45.80 ± 10.22
60.03 ± 29.79
108.02 ± 19.36
77.86 ± 10.97
adminis-
B2
208.55 ± 22.12
156.79 ± 24.25
45.74 ± 10.56
61.68 ± 30.02
108.10 ± 20.10
77.90 ± 11.23
tration
B3
209.12 ± 20.19
157.21 ± 23.01
45.62 ± 10.73
62.13 ± 29.21
108.23 ± 19.98
77.95 ± 11.78
B4
189.19 ± 20.78
139.91 ± 20.35
47.19 ± 11.25
47.78 ± 30.56
105.97 ± 19.38
76.89 ± 11.21
B5
190.22 ± 21.56
141.17 ± 20.03
47.07 ± 11.01
48.20 ± 30.47
106.15 ± 20.47
77.02 ± 10.56
B6
197.90 ± 21.03
147.55 ± 20.01
46.36 ± 11.57
51.01 ± 30.12
107.15 ± 20.38
77.55 ± 12.34
B7
181.32 ± 21.20
110.74 ± 20.11
51.30 ± 12.89
34.43 ± 16.11
95.89 ± 18.37
68.52 ± 10.34
B8
200.02 ± 19.99
151.90 ± 20.15
46.04 ± 10.78
57.04 ± 31.24
107.55 ± 19.78
77.70 ± 10.56
[0031] The above trial results show that there are different treatment effects among different compositions. When phytosterols are compounded with the other components, their function has changes to various extents. The synergistic effect is not desirable when phytosterols are mixed only with one of the other components (B1-B3); but when phytosterols are mixed with two or three of the other components (B4-B7), the synergistic effects are significantly better than that of single phytosterols, especially the treatment effect of combination (the inventive composition B7) of four of the components is the best, which can lower total cholesterol level by about 39%, and lower low density lipoprotein level by about 32%.
Embodiment 3
Clinical Observation of Treatment and Prevention of Hyperlipidemia Using the Composition of the Present Invention
[0032] Phytosterols, flavones derived from bamboo leaf, procyanidins and β-glucan are prepared according to routine methods, and which are then prepared into eight compositions C1-C8 according to components and mass ratios in Table 5.
[0000]
TABLE 5
flavones
derived from
Phytosterols
bamboo leaf
procyanidins
β-glucan
Compositions
(%)
(%)
(%)
(%)
C1
50
50
0
0
C2
50
0
50
0
C3
50
0
0
50
C4
50
40
10
0
C5
50
40
0
10
C6
50
0
40
10
C7 (Composition
of the present
50
20
25
5
invention)
C8
100
0
0
0
[0033] 80 Trial subjects are selected and divided into 8 groups, each of which consists of 10 trial subjects. The total cholesterol level of each trial subject is above 210 mg/dL, low density lipoprotein (LDL) is above 140 mg/dL, and triglycerides is less than 300 mg/dL. All the trial subjects have similar other health conditions, stop administration of any lipid-lowering drugs and nutrient supplement before one month for the trial, and have identical dietary during the trial period. The trial subjects of the eight groups are respectively administered with the aforementioned eight compositions at 200 mg per day. After the compositions are administered for six weeks, the trial subjects are tested for total cholesterol (TC), low density lipoprotein (LDL), high density lipoprotein (HDL), triglycerides (TG), and systolic blood pressure (SBP) and diastolic blood pressure (DBP), and the datas are shown in Table 6.
[0000]
TABLE 6
Treatment effect indicator improvement after six weeks of treatment using the C1-C8 compositions
(TC)
(LDL)
(HDL)
(TG)
(SBP)
(DBP)
Indicator
(mg/dL)
(mg/dL)
(mg/dL)
(mg/dL)
(mmHg)
(mmHg)
Before
230.12 ± 20.26
162.50 ± 25.65
45.26 ± 12.51
66.23 ± 36.50
111.2 ± 20.32
78.50 ± 12.63
administration
After
C1
198.79 ± 20.38
151.04 ± 20.78
46.16 ± 10.15
56.85 ± 30.00
107.50 ± 20.36
77.65 ± 11.02
adminis-
C2
201.87 ± 19.98
153.55 ± 21.14
45.97 ± 10.33
57.97 ± 30.13
107.64 ± 19.97
77.73 ± 11.13
tration
C3
206.71 ± 20.00
154.00 ± 20.76
45.89 ± 11.25
58.86 ± 30.14
107.93 ± 20.04
77.80 ± 11.01
C4
193.51 ± 20.07
143.53 ± 21.11
46.98 ± 10.57
49.34 ± 28.98
106.23 ± 20.37
77.11 ± 10.37
C5
194.10 ± 20.90
144.04 ± 20.04
46.80 ± 10.15
50.25 ± 29.56
106.55 ± 18.99
77.29 ± 10.79
C6
196.86 ± 20.15
146.54 ± 20.21
46.43 ± 10.79
53.77 ± 30.56
107.04 ± 20.56
77.50 ± 12.11
C7
187.22 ± 20.77
130.12 ± 21.21
47.89 ± 11.10
38.19 ± 21.34
97.32 ± 17.97
71.45 ± 10.21
C8
200.34 ± 20.01
152.57 ± 19.64
46.09 ± 10.44
57.58 ± 30.35
107.60 ± 19.12
77.67 ± 9.99
[0034] The above trial results show that there are different treatment effects among different compositions. When phytosterols are compounded with the other components, their function has changes to various extents. The synergistic effect is not desirable when phytosterols are mixed only with one of the other components (C1-C3); but when phytosterols are mixed with flavones derived from bamboo leaf at the same ratio (C3), the treatment effect is better than that of single phytosterols but still lower than those of the compositions C4-C7, especially the treatment effect of the composition C7 of the present invention is the best, which can lower total cholesterol level by about 26%, and lower low density lipoprotein level by about 20%.
Embodiment 4
[0035] The aforementioned trial results are consolidated and analyzed by Statistic software, and the analytical datas are shown in Table 7, wherein 0.8 is 100% phytosterols, 1.x, 2.x, and 3.x are respectively seven compositions in the embodiment 1, 2, and 3. The Table 7 shows that the compositions A4, A5, and A7 in the embodiment 1, the compositions B4, B5, and B7 in the embodiment 2, and the composition C7 in the embodiment 3 show significant influence on treatment effect indicator levels of hyperlipidemia after administration, especially the inventive compositions A7, B7, and C7 of the present invention (see FIG. 1 ).
[0000]
TABLE 7
T-test
Variable
Standard variable
P value
1.3
74.22891
0.298002
1.2
73.06035
0.204435
1.1
72.95518
0.136117
2.3
70.08382
0.178566
2.2
69.90697
0.169478
2.1
69.35320
0.143056
3.3
68.96152
0.146322
3.2
67.66104
0.151825
0.8
67.51731
0.118817
3.1
66.55177
0.140900
1.6
66.37436
0.111398
2.6
66.41657
0.102667
3.6
65.49546
0.118845
1.5
65.66848
0.097738
1.4
65.47012
0.095718
3.5
64.69565
0.106062
3.4
64.54825
0.101863
2.5
63.64977
0.095492
2.4
63.22516
0.093809
3.7
61.84116
0.048376
1.7
60.22315
0.047923
2.7
59.41613
0.049862
Embodiment 5
[0036] Phytosterols are hydrogenated into phytostanols, then the phytostanols are mixed with flavones derived from bamboo leaf, procyanidins and β-glucan respectively according to formulation schemes in the embodiments 1-3 to prepare into corresponding compositions. Clinical observation is carried out according to the method in the embodiments 1-3 to obtain similar results. Compared with other compositions, the composition of the present invention shows better treatment effect.
|
A composition for treatment and prevention of hyperlipidemia consists of phytosterols and phytostanols 30-50%, flavones derived from bamboo leaf 20-40%, procyanidins 10-25% and β-glucan of 5-20% by weight. Said composition demonstrates markedly therapeutic effects on preventing and treating hyperlipidemia, compared with the combinations of two or three components selected from phytosterols or phytostanols, flavones derived from bamboo leaf, procyanidins and β-glucan. When applied in supplementary nutrient foods or medicaments, the present composition can effectively lower the levels of cholesterol and triglyceride in blood, therefore can be useful for treating and preventing hyperlipidemia, cardiovascular diseases, coronary heart disease, atherosclerosis, heart disease and the like.
| 0
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.