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Número de publicaciónUS20080053185 A1
Tipo de publicaciónSolicitud
Número de solicitudUS 11/468,666
Fecha de publicación6 Mar 2008
Fecha de presentación30 Ago 2006
Fecha de prioridad30 Ago 2006
Número de publicación11468666, 468666, US 2008/0053185 A1, US 2008/053185 A1, US 20080053185 A1, US 20080053185A1, US 2008053185 A1, US 2008053185A1, US-A1-20080053185, US-A1-2008053185, US2008/0053185A1, US2008/053185A1, US20080053185 A1, US20080053185A1, US2008053185 A1, US2008053185A1
InventoresAdam J. Morgan, James P. Rohl
Cesionario originalCardiac Pacemakers Inc.
Exportar citaBiBTeX, EndNote, RefMan
Enlaces externos: USPTO, Cesión de USPTO, Espacenet
System and method for die cutting manifold including a lubrication channel
US 20080053185 A1
Resumen
One embodiment of the present subject matter includes an assembly. The assembly includes a stripper plate having a stripper plate face and defining and elongate opening extending through the stripper plate face and into the stripper plate. A punch of the assembly is slidably disposed in the elongate opening, the punch having a punch profile shaped to conform to the elongate opening. The assembly includes a die in alignment with the stripper plate, the die having a die face opposed to the stripper plate face, the face defining a die opening which is substantially coextensive with the elongate opening of the stripper plate, the die defining a plurality of wetting lumens extending through the die, with each lumen terminating in the die face near the die opening, each of the lumens adapted to dispense a lubricant to the die face and along the die opening.
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Reclamaciones(31)
1. An assembly for punching a web, comprising:
a stripper plate having a stripper plate face defining an opening which extends into the stripper plate;
a punch slidably disposed in the opening, the punch having a punch profile shaped to conform to the opening;
a die in alignment with the stripper plate, the die having a die face opposed to the stripper plate face, the face defining a die opening which is substantially coextensive with the opening of the stripper plate, the die defining a plurality of wetting lumens extending through the die, with each lumen terminating in the die face near the die opening, each of the lumens adapted to dispense a lubricant to the die face and along the die opening.
2. The system of claim 1, further comprising a lubrication manifold sealed to the die with a seal, the lubrication manifold comprising a plurality of channels each having at least one respective inlet, the plurality of channels in fluid communication with the plurality of wetting lumens.
3. The system of claim 1, further comprising a plurality of gas lumens adapted to direct air toward the web to push the web away from the die.
4. The system of claim 1, wherein at least one of the plurality of wetting lumens includes a nozzle.
5. The system of claim 1, further comprising a punch block coupled to the punch and a punch holder coupled to the stripper plate, the punch block being slidably disposed in the punch holder.
6. The system of claim 5, wherein the punch holder includes carbide alloy.
7. The system of claim 1, wherein the punch is elongate, having a proximal portion and a distal portion, with the distal portion oriented toward the die, and further comprising a vacuum manifold coupled to the punch at the distal portion, the vacuum manifold including a plurality of manifold lumens which terminate at the distal portion of the punch.
8. The system of claim 7, wherein the punch includes a plurality of vacuum lumens.
9. The system of claim 8, wherein the manifold lumens are in fluid communication with a first vacuum coupling, and the vacuum lumens are in fluid communication with a second vacuum coupling.
10. The system of claim 1, wherein the die further defines an access opening connecting the die opening to a second die face.
11. The system of claim 10, wherein the second die face opposes the die face.
12. The system of claim 10, wherein the access opening is at least as big as the die opening.
13. The system of claim 12, wherein the access opening is larger than the die opening, and a step connects the die opening and the access opening.
14. A method for punching an electrode web with a punch assembly, the method comprising:
placing an electrode web between a punch and a die, the punch in alignment with the die to cut the web along an cutting opening to define an electrode with the cutting opening;
lubricating the die with a lubricant, the lubricant flowing from a plurality of lubricant lumens in the die, the lubricant lubricating the die by wetting the electrode web and the die along the cutting opening; and
punching the electrode from the electrode web by pressing the punch through the electrode web and into a die opening in the die.
15. The method of claim 14, further comprising applying a lubricative film on one side of the electrode.
16. The method of claim 14, further comprising picking the electrode off the punch through an access opening in the die.
17. The method of claim 16, further comprising registering a vacuum pick to the electrode web during punching.
18. The method of claim 17, further comprising positioning the electrode into a stack of electrodes in alignment.
19. The method of claim 14, further comprising holding the electrode web to the punch with a punch vacuum.
20. The method of claim 19, wherein the punch vacuum is a first punch vacuum, and further holding the electrode with a second punch vacuum which at a different pressure than the first punch vacuum.
21. The method of claim 14, further comprising blowing the electrode web away from the die with a gas.
22. The method of claim 21, further comprising directing the air toward the electrode web outside the cutting opening by positioning a plurality of gas lumens in the die outside a cutting opening defined by the die for cutting the electrode from the electrode web.
23. The method of claim 14, wherein the electrode web includes lithium.
24. The method of claim 23, wherein the electrode web includes nickel sandwiched between two layers of lithium.
25. The method of claim 14, further comprising lubricating the punch with lubrication as the punch slides in a stripper plate, the lubrication flowing through a lubrication channel in the stripper plate which surrounds a stripper opening through which the punch slides.
26. The method of claim 25, further comprising sliding a punch block through a punch holder which is connected to the stripper plate, the punch block sliding through the punch holder while the punch block is coupled to the punch.
27. The method of claim 25, further comprising cutting the die opening and the stripper opening into a monolithic block, and cutting the die and the stripper block from the monolithic block.
28. The method of claim 27, cutting the die opening and the stripper opening includes EDM cutting.
29. An apparatus, comprising:
die means for lubricating a die cutting edge by wetting; and
punch means for punching an electrode out of an electrode web by sliding through the electrode web and into the die means.
30. The apparatus of claim 29, further comprising a stripper plate having a stripper plate face and defining and elongate opening extending through the stripper plate face and into the stripper plate,
wherein the die means include a die in alignment with the stripper plate, the die having a die face opposed to the stripper plate face, the face defining a die opening which is substantially coextensive with the elongate opening of the stripper plate.
31. The apparatus of claim 30, wherein the die defines a plurality of wetting lumens extending through the die, with each lumen terminating in the die face near the die opening, each of the lumens adapted to dispense a lubricant to the die face and along the die opening.
Descripción
RELATED APPLICATION

The present subject matter is related to the commonly assigned U.S. patent application entitled, “Apparatus and Method for Cutting Electrode Foil Layers”, Ser. No. 10/731,882, filed Dec. 9, 2003, which is incorporated by reference herein in its entirety.

TECHNICAL FIELD

This disclosure relates generally to metal working, and more particularly to system and method for die cutting manifold including a lubrication channel.

BACKGROUND

When using a punch and die to excise a part, practitioners continually seek to increase cycle life of tooling, decrease defect rates, and improve through-put of parts. These ongoing needs apply to existing processes, as well as new processes.

New processes are needed for new technologies. For example, new technologies often include new parts which can be excised by a punch and a die. Using existing processes to make these parts can result in decreased cycle life due to erosion, galling, and other problems. These problems are often related to the new kinds of materials used to make the new parts. Existing processes often do not demonstrate sufficient through-put. Existing process also can cause increased defect rates. As such, new die and punch processes are needed to improve the manufacturing of new parts.

SUMMARY

The above-mentioned problems and others not expressly discussed herein are addressed by the present subject matter and will be understood by reading and studying this specification.

This Summary is an overview of some of the teachings of the present application and not intended to be an exclusive or exhaustive treatment of the present subject matter. Further details about the present subject matter are found in the detailed description and appended claims. Other aspects will be apparent to persons skilled in the art upon reading and understanding the following detailed description and viewing the drawings that form a part thereof, each of which are not to be taken in a limiting sense. The scope of the present invention is defined by the appended claims and their legal equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a partial cross section of a die, according to one embodiment of the present subject matter.

FIG. 2 shows a partial cross section of a punch, a stripper plate, and a die, according to one embodiment of the present subject matter.

FIG. 3A shows a partially transparent view of die holder, a die, and a lubrication manifold, according to one embodiment of the present subject matter.

FIG. 3B is close-up view of section 3B-3B from FIG. 3A.

FIG. 3C is a partial bottom view of the die of FIGS. 3A-3B.

FIG. 4A illustrates a punch assembly, according to various embodiments of the present subject matter.

FIG. 4B illustrates an exploded view of the punch assembly of FIG. 4A.

FIG. 5 is a perspective view of a lubrication manifold, according to one embodiment of the present subject matter.

FIG. 6 is a partial cross section of a punch assembly, according to various embodiments of the present subject matter.

DETAILED DESCRIPTION

The following detailed description of the present subject matter refers to subject matter in the accompanying drawings which show, by way of illustration, specific aspects and embodiments in which the present subject matter may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the present subject matter. References to “an”, “one”, or “various” embodiments in this disclosure are not necessarily to the same embodiment, and such references contemplate more than one embodiment. The following detailed description is demonstrative and not to be taken in a limiting sense. The scope of the present subject matter is defined by the appended claims, along with the full scope of legal equivalents to which such claims are entitled.

FIG. 1 shows a partial cross section of a die, according to one embodiment of the present subject matter. In various embodiments, the present subject matter includes a die 102 against which at least part of a workpiece 106 is pushed 114. As the workpiece is pushed 114 against the die 102, the workpiece is cut along axis 108. A cut along axis 108 may be linear, in various embodiments. Some embodiments include tearing. Additional changes performed to the workpiece 106 are additionally contemplated by the present subject matter. Various embodiments include a punch to push the workpiece against the die 102 for cutting. The die is constructed various materials in various embodiments. Materials suitable for a die include, but are not limited to, carbide, steel, tungsten, stainless steel, cobalt, and/or combinations thereof. Some embodiments use 10C carbide alloy. Additional materials use CPM 10V. Additional materials include, but are not limited to, A2, D2, 440C, and other suitable materials.

In various embodiments, materials for the die and/or punch are selected for their toughness. In some embodiments, materials for the die and/or punch are selected for their hardness. In various embodiments, such materials improve cycle life of the die and punch when used for cutting an electrode.

Some embodiments include a workpiece 106 which is a sheet. In various embodiments, the workpiece 106 is a web. In some embodiments, the workpiece 106 is a film. Some embodiments include a workpiece 106 which is a foil. In some of these embodiments, the workpiece is an electrode web. In some embodiments, capacitor electrodes are punched from an electrode web. In additional embodiments, battery electrodes are punched from an electrode web. The present subject matter includes lithium webs. The present subject matter additionally includes nickel webs. Some embodiments include a lithium web lined nickel foil. Polymer webs are contemplated. The present subject matter includes webs which include multiple layers. One embodiment includes a lithium web backed with a layer of polypropylene. These workpiece types are not exhaustive of exclusive of the present subject matter, and additional workpieces are contemplated.

In various embodiments, the workpiece 106 is pushed against the die while lubrication is present. Some embodiments include a workpiece pretreated with lubrication. For example, various embodiments provide a coating on a workpiece for lubrication. Some additional embodiments of the present subject matter lubricate during cutting by sandwiching a workpiece between two films. Some embodiments include a workpiece which has a film on one side. Various embodiments use one or more films which are polymeric, in various embodiments. The present subject matter includes polypropylene films. The present subject matter, in various embodiments, includes polyester films. The present material additionally includes, but is not limited it, polyethylene, polyester, biaxially-oriented polyethylene terephthalate, and other materials not listed expressly herein. Films disclosed herein provide lubrication in various embodiments. In additional embodiments, they serve additional purposes, including, but not limited to, preventing scratching, retaining the shape of another web, and other functions not expressly recited herein.

In various embodiments, films are selected due to their lubricious nature. Lubrication, in various embodiments, increases the cycle life of the die assembly by reducing tool wear. Lubrication additionally assists in separating a punched part from the punch assembly. In various embodiments, a film is used which presents a barrier which, throughout the punching process, reduces instances of the workpiece touching the die and/or the punch. In embodiments using materials in which the workpiece material is prone to stick to the die and/or punch material, such embodiments reduce such sticking. Some of these embodiments provide a film which reduces instances in which workpiece lithium sticks to a die material.

Workpiece materials sticking to a die is related to galling. In various embodiments, lubrication reduces galling. Galling can cause part profiles to migrate over time, which can impact downstream manufacturing processes. Other benefits not discussed herein expressly additionally are provided by the present subject matter.

Some embodiments dispense 118 a lubricant through a lumen 104. Various embodiments include a lumen 104 which terminates in die face 110. Additional embodiments include a lumen which terminates along axis 108. Embodiments contemplated by the present subject matter include hexane lubricants. Additional lubricants are also contemplated by the present subject matter, including, but not limited to, lubricants having non-polar hydrocarbons, single chain hydrocarbons, fluorinated organic compositions, FLUORINERT, and other compositions not expressly recited herein. FLUORINERT is a registered trademark of the 3M Corporation, which is incorporated in Delaware, and which has operations at 2501 Hudson Rd., Saint Paul, Minn. 55101.

An optional lumen 112 additionally introduces 116 fluid to the workpiece, in various embodiments. In some embodiments, lumen 112 is at a pressure which is different from atmosphere. As such, in various embodiments, lumen 112 introduces 116 gas onto the workpiece 106. Some of these embodiments are useful to push the workpiece away from the die 102. The lumen 112 can additionally be used to grasp the workpiece by applying a vacuum to the workpiece.

Lumen 112 is useful for cleansing the workpiece 106. Lumen 112, in various embodiments, is additionally useful to provide a lubricant out of phase with lumen 104. These benefits are not an exhaustive or exclusive list of the benefits provided by the present subject matter.

FIG. 2 shows a partial cross section of a punch, a stripper plate, and a die, according to one embodiment of the present subject matter. The embodiment includes a die 204 which is positioned for cutting a workpiece 202. In various embodiments, the workpiece 202 is sheared 222. Various embodiments shear 222 a workpiece 202 by sliding a punch 218 into a die opening 216 of a die 204.

Various embodiments align the punch 218 with the die 204. In some embodiments, the punch 218 is aligned with the die by aligning a stripper plate 214 with a die 204. Some embodiments of the present subject matter align the die 204 with the stripper plate 214 using dowels.

Various embodiments include a die surface 224. Some embodiments include a stripper plate surface 226. In various embodiments the die surface 224 is planar. In some embodiments, the stripper plate surface 226 is planar. In some embodiments, the die surface 224 is substantially parallel with the stripper plate surface 226. In some embodiments, the stripper plate surface 226 is opposed the die surface 224. A workpiece is disposed between the die surface 224 and the stripper plate surface 226, in various embodiments. In some embodiments, the workpiece is not bound between the die 204 and the stripper plate 214, and as such is freely positionable with respect to the die 204 and/or the stripper plate 214. In some of these embodiments, a gap exists between the die surface 224 and the stripper plate surface 226.

In various embodiments, the punch 218 has a profile shaped to conform to an opening 220 of the stripper plate 214. In some embodiments, the stripper plate opening 220 is in alignment with the die opening 216 of the die 204. Various embodiments include a die having a profile tolerance of approximately +/−0.000050 inches. Embodiments of the present subject matter are adapted to punch parts such that the parts have a tolerance of approximately +/−0.0001 inches. In various embodiments, the punch to die clearance is approximately 10% of the thickness of the workpiece being punched. In additional embodiments, the punch to die clearance is more or less. As such, in various embodiments, the punch to die clearance for a sheet having a thickness of approximately 0.001 inches is approximately 0.0001 inches. In various embodiments, material compresses during the punching process. As such, in some embodiments, the materials are thicker or thinner after processing than it was before processing. Such compressibility is taken into account in some embodiments. These tolerances apply to some of the embodiments of the present subject matter, but are not exhaustive or exclusive of the present subject matter, and other ranges additionally are contemplated.

Various embodiments include a lubrication lumen 208. In various embodiments, lubrication is forced into the workpiece along the perimeter of opening 216. In some of these embodiments, the lumen terminates in die surface 224. In various embodiments, the lubrication lumen 208 is located away from the die opening 216. In some of these embodiments, the lubrication travels to the die opening 216 by wetting. Various embodiments include a web having a surface energy which encourages wetting. Various embodiments additionally include a die surface 224 which encourages wetting. In some embodiments, it is the lubrication that is selected to provide a wetting mechanism. Lubrication materials having a wetting angle of approximately 18 degrees, when used with materials disclosed herein, are contemplated by the present subject matter. In some embodiments, the die surface 224 has a surface roughness of approximately 8 micro inches. These configurations are examples of configurations contemplated by the present subject matter, and are not exhaustive or exclusive of the embodiments of the present subject matter which provide lubrication through wetting.

Various embodiments include a lubrication channel 228. In various embodiments, the lubrication channel 228 extends through the stripper plate 214 and lubricates the punch 218 as it travels through the stripper plate 214. In various embodiments, the lubrication channel 228 is in fluid communication with a lumen 230. In various embodiments, the lumen 230 includes a fluid coupling. The lubrication channel 228 is pictured open to the workpiece 202. This embodiment is one of the embodiments contemplated by the present subject matter.

The present illustration shows as optional lubrication channel 234. In various embodiments, lubrication channel 234 is located in an opening 220. This lubrication channel 234 is not open to the stripper plate surface 226. In some of these embodiments, the lubrication channel 234 is connected to a lumen 232. In various embodiments, the lumen 232 includes a fluid coupling. Various embodiments are contemplated by the present subject matter including, but not limited to, embodiments which are open to the workpiece 202, and/or embodiments which are not open to the workpiece 202.

Various embodiments additionally include a gas lumen 206. In various embodiments, the gas lumen 206 introduces a gas into workpiece 202. In some of these embodiments, the lumens terminate in die surface 224. Various embodiments additionally force gas into the workpiece along the perimeter of opening 216.

The lumens discussed herein may be part of a plurality of lumens. For example, some embodiments include a plurality of lubrication lumens. Some embodiments include a plurality of gas lumens. These lumens include vacuum lumens. In various embodiments the lumens pass at least partially through a die. Additional embodiments can include other components through which the lumens pass. Various embodiments include interconnects and couplings to which the lumens connect. Some embodiments provide separate couplings, with a first coupling in fluid communication with a first lumen of a plurality of lumens, and with a second coupling in fluid communication with a second lumen of a plurality of lumens.

Various embodiments include lumens 212 in a punch 218. In various embodiments, a single lumen is provided. Some embodiments include a plurality of lumens 212. In some of these embodiments, the plurality of lumens 212 are in fluid communication with one another. Some embodiments partition the plurality of lumens, with at least a first lumen being in fluid communication with a first fluid coupling, and with at least a second lumen being in fluid communication with a second fluid coupling. Additional lumen partitions are used depending on the application. For example, a first group of lumens are in fluid communication with one another and a first fluid coupling, and a second group of lumens are in fluid communication with one another and with a second fluid coupling. The present subject matter is not restricted to these configurations, as these examples do not provide an exhaustive or exclusive list of the configurations contemplated by the present subject matter.

FIGS. 3A-3B show a transparent view of die holder, a die, and a lubrication manifold, according to one embodiment of the present subject matter. FIG. 3B is close-up view of section 3B-3B from FIG. 3A. Various embodiments include a die holder 302 which is connected to a die 318. In various embodiments, numerous fasteners 308A . . . 308N are used to hold the die 318 to the die holder 302. Some embodiments of the present subject matter sandwich a lubrication manifold 320 between a die holder 302 and a die 318. A first interface 322 exists between the die holder 302 and the lubrication manifold 320. In some embodiments, a seal extends along the first interface 322. A second interface 316 exists between the die 318 and the lubrication manifold 320. In some embodiments, a seal extends along the second interface 316.

Various seals are contemplated by the present subject matter. A seal can be two surfaces in contact, in various embodiments. In additional embodiments, a seal material is disposed along a seal interface. The present subject matter includes, but is not limited to, seals incorporating o-rings, epoxy, precision interface of ground parts, and other technologies not expressly recited herein.

Various embodiments of the die 318 include a step 310. In some embodiments, the step is for locating a vacuum pick assembly. For example, in some embodiments, a vacuum pick assembly is inserted through an opening in the die holder 302, through a lubrication manifold 320, and at least part of the way into a die 318, until the vacuum pick assembly hits the step 310. Embodiments which do not include a step are also contemplated by the present subject matter.

In various embodiments, the die manifold 320 includes a first lubrication channel 312. Additional embodiments include a second lubrication channel 314. In some embodiments, the die holder 302 includes a first die holder lubrication channel 304. In various embodiments, the first die holder lubrication channel 304 is in fluid communication with the first lubrication channel 312. In various embodiments, the interface includes a lubrication manifold inlet and a die holder outlet. In various embodiments, the lubrication manifold inlet is an opening which is substantially coextensive with the die holder outlet. In additional embodiments the die holder 302 includes a second die holder lubrication channel 306 which is in fluid communication with the second lubrication channel 314. Various embodiments provide a lubrication to the first and second lubrication channel, and then to lumens in the die 318 which are in fluid communication with the first and second lubrication channel. FIG. 3C is a partial bottom view of the die of FIGS. 3A-3B. The lumens 320 which extend through the die 318 are visible in this view. The lumens 320 terminate in a die surface at openings 324.

FIGS. 4A-B illustrates a punch assembly, according to various embodiments of the present subject matter. FIG. 4B illustrates an exploded view of the punch assembly of FIG. 4A. Punch assembly 400 includes a punch holder 438 and a stripper plate 442 coupled to the punch holder 438. Assembly 400 includes a die 446 coupled to a die holder 450. Members 438, 442, 446, and 450 are aligned to one another and held together by dowel 444, a second dowel, and fasteners 402, 454, 434, 404, 440. The numbers of dowels may vary, depending on which embodiment is contemplated. The number of fasteners may vary depending on which embodiment is contemplated. Punch assembly 400 also includes a punch base 424, a punch block 416, and a punch 436.

In some embodiments, forming a punch guide and punch assembly 400 including forming die 446 and stripper plate 442 from a single block of material. Die 446 and stripper plate 442 are formed by first forming openings 456, 458, and then separating the die 446 from the stripper plate 442, in various embodiments. In various embodiments, some material is removed from a face of one or both of the stripper plate 442 or the die 446, such that gap 464 is defined. The stripper plate 442 and the die section 446 are coupled together such that opening 456 of die 446 directly opposes opening portion 458 of stripper plate 442 across gap 464, in various embodiments.

In one embodiment, a wire cut electrical discharge machining process (wire EDM) is used to form an opening in a block of material. Wire EDM can achieve a tolerance of approximately +/−0.000050 inches. In some embodiments, wire EDM is used to cut an aperture in a block. In the embodiment, the block is separated at a cross section of the aperture into a first block portion having a first aperture, and a second block portion having a second aperture. This method allows for precise alignment of the first and second aperture. Some of these embodiments are used with a punch and demonstrate a punch to die clearance of approximately 0.00050 inches. Some embodiments of the present subject matter employing this method provide an improvement over methods which cut a first aperture into a first block independent of a second aperture which is cut in a second block.

In some embodiments, a workpiece punched by the present subject matter is a lithium web. In some embodiments, the lithium is backed by one or more lubricious films. Some embodiments punch a nickel web. In some embodiments, a nickel web is lined with one or more lubricious films. Some embodiments include a lithium web lined nickel foil. Some of these embodiments are backed by one or more lubricious films. These configurations are not exhaustive or exclusive of the present subject matter, as other configurations are contemplated.

The present system can provide a 1.25% to 10.0% clearance vs. thickness ratio. In various embodiments, the workpiece punched is 100 microns thick. In additional embodiments, the workpiece punched in 25.4 microns thick. Additional embodiments can have sheets having thicknesses ranging up to 600 micrometers. These thicknesses are not exhaustive or exclusive of the present subject matter and other thicknesses are contemplated by the present scope.

Punch block 416 can be constructed out of materials including, but not limited to, stainless steel. In various embodiments, a punch 436 is coupled to the punch block 416. Punch 436 includes an outer punch profile defining the shape of the final punched electrode. The punch profile, in various embodiments, can include different shapes depending on the shape of electrode desired. In this example, the perimeter of punch 436 defines what approximates an oval shaped electrode layer. Other shapes not expressly described herein also are possible within the present subject matter.

The punch 436 includes a punch surface 463 which faces a workpiece in use. The punch surface 463 includes a perimeter which defines the perimeter of a part punched from a workpiece, in various embodiments. In various embodiments, the punch surface 463 includes a substantially planar surface which has a shear angle relative to the die opening. Some embodiments include dual shear features. As such, in various embodiments, the punch 436 passes through die opening 456, the perimeter of punch surface 463 intersects with the plane of the die opening 456 gradually rather than all at once.

In some embodiments, punch surface 463 is shaped such that the perimeter of the punch surface includes at least a first and second large radii 466 and 470, with at least one small radii 468. In various embodiments, a shear angle of the punch surface 463 is oriented such that the highest point on punch surface 463 is located along the at least one larger radii 466 and the lowest point on the surface is located along the at least one small radii 468. Other punch surface configurations, including, but not limited to, double shear configurations, are additionally contemplated by the present subject matter.

In some embodiments, punching an electrode layer out of a sheet of material demonstrates increased stress points around the at least one small radii 468, while there is less stress around the first and second large radii 466, 470. In various embodiments, a shear angle allows the punch surface to first meet the material at a low-pressure point along the first large radius 466 and leave at a low-pressure point along the second large radius 470. Thus, when forming an electrode layer, one method of use includes placing a sheet between punch 436 and a die 446, the punch 436 having a punch surface 463 having a shear angle. The method includes striking the sheet with the punch such that the punch surface 463 enters and exits the sheet a reduced stress points at an interface between the sheet and the punch surface 463. This prevents or reduces cracking and chipping of the punched material, in some embodiments.

In additional embodiments, the shear angle can be oriented such that it does not enter or exit the material at a large radius of the punch surface. In various embodiments, the surface enters and exits the material at small radii. In some embodiments, this provides an increased stress. Embodiments including a shear angle along a die opening as well as a punch are additionally contemplated. Embodiments not having a shear angle are further contemplated by the present subject matter.

Punch holder 438 includes a guiding portion 472. Guiding portion 472 is dimensioned to guide punch block 416. In various embodiments, punch holder 438 provides a guiding lead-in, or pre-alignment, for punch 436. Guide portion 472 guides punch block 416 such that punch 436 is centered within stripper plate opening 458, in various embodiments.

In some embodiments, stripper plate opening 458 is wire cut to be 0.00005″ larger than the outer perimeter of punch 436. In various embodiments, as punch 436 is driven by punch block 416 towards stripper plate 442, guiding portion 472 of punch holder 438 guides punch block 416. Punch 436 enters punch stripper plate opening 458.

Die 446 includes die opening 456, in various embodiments. In some embodiments, die opening 456 is cut to be 0.00005″ larger than the outer perimeter of punch 436 and can be formed during the same cutting operation as stripper plate opening 458 of stripper plate 442. Opening 458 thus includes a surface which is 0.00005″ larger than the outer perimeter of punch 436, in various embodiments.

This distance can vary depending on the EDM equipment used. The distance is also dependent on the rate at which the EDM equipment cuts the material. Other variables related to EDM operations additionally impact distance. In some embodiments, clearance distance between the punch and the die is constant all the way around the perimeters of the two members. Thus, clearance between the punch perimeter and the die opening 456 is substantially constant around the entire perimeter of the punch surface. In one example, the clearance is substantially constant within a tolerance of +/−0.00050 inches. Providing a constant clearance helps reduce edge cracking and corner cracking of the brittle material being punched, in some embodiments.

Various embodiments include a lubrication manifold 406 coupled to die 446. In various embodiments, the lubrication manifold includes one or more inlets which are in sealed fluid communication with lubrication outlets of die holder 450. In various embodiments, die holder 450 includes fluid couplings 452 which are in fluid communication with the fluid outlets of the die holder 450. In various embodiments, the lubrication manifold 406 includes lubrication channels which extend through the lubrication manifold and are in fluid communication with the one or more inlets of the lubrication manifold. Various embodiments position the lubrication channels such that they are in sealed fluid communication with one or more lubrication lumens in die 442. In use, as a workpiece is cut between punch 436 and die 446, lubricant is directed to a surface of the die which surrounds die opening 456.

Die holder 450 is attached to die 446. In various embodiments, die holder opening 476 in die holder 450 is dimensioned to be at least as large as the cutting edge periphery of die opening 456. In one various embodiments, this allows a vacuum pick to enter die holder opening 476 to retrieve a cut part from the surface of punch 436. In one embodiment, a vacuums pick is actuated upwardly and the punched part is picked out of the die 446. A top surface of the punch extends through the die before the electrode layer is taken off of the punch, in various embodiments. In various embodiments, the opening through which a part is picked extends from a die face 478 to a second face 480. In various embodiments, the second die face 480 opposes the die face 478. In various embodiments, the second die face 480 is part of a die 446. Surface 462 provides one example of such a relationship. In additional embodiments, it is part of an assembly, and exists on a die holder 450. In various embodiments, the die face 480 is substantially parallel to the die face 478. Embodiments are contemplated in which the second die face 480 is not substantially parallel to die face 478.

In various embodiments, a step 482 connects a die opening 456 to an opening which is adapted for allowing a vacuum pick to remove a part. In various embodiments, the die 442 includes a die opening 456, which is used in creating a part, and a die access opening, which is larger than the die opening. In various embodiments, die opening 456 extends between the die access opening and the die opening 456. In various embodiments, the die access opening is substantially coextensive with a die holder opening 476. In additional embodiments, a die holder opening 476 is larger than a die access opening.

In various embodiments, the punch 436 is elongate, having a proximal portion 476 and a distal portion 474, with the distal portion 474 oriented toward the die. In various embodiments, the punch 436 includes a vacuum manifold 410 which is coupled to the punch at the distal portion 474. In various embodiments, the vacuum manifold 410 includes a plurality of manifold lumens which terminate at the distal portion of the punch. Various embodiments configure the plurality of lumens in the vacuum manifold 410 to exert a tailored level of suction force to a workpiece such as electrode 408. In various embodiments, at least some of the plurality of lumens of the vacuum manifold 410 and of the punch 436 are in are in fluid communication with a vacuum coupling 432. In some embodiments, a second vacuum coupling is in exclusive fluid communication with at least some of the plurality of lumens of the vacuum manifold 410 and of the punch 436.

A shim 412 is pictured which is disposed between punch 436 and punch block 416. In various embodiments, the shim is used to adjust the distance between a cutting surface of the punch and the stripper plate opening 458 when the punch is at rest and not actuated. Fasteners 414 are pictured which attached punch 436 to vacuum manifold 410, in various embodiments. A coupling 432 is shown which is adapted to connected a vacuum supply to one or more lumens in the punch 436 and/or the vacuum manifold 410, in various embodiments. Dowels 430 are shown which align punch block 416 to punch 436. Springs 418 return the punch to an open state, in various embodiments. Clamps 420, 428 are used to secure the assembly 400, and are attached to the punch guide 438 with fasteners 426, in various embodiments. Fastener 422 connects punch base 424, punch block 416, and punch 463, in various embodiments.

FIG. 5 is a perspective view of a lubrication manifold, according to one embodiment of the present subject matter. In various embodiments, the lubrication manifold 500 is disposed between a die holder and a die. In various embodiments, the lubrication manifold includes a first inlet 510, a second inlet 512, a third inlet 502, and a fourth inlet 504. Other numbers of inlets are possible without departing from the subject matter of the present application. In various embodiments, each inlet is in separate, exclusive fluid communication with an external fluid source. In additional embodiments, each inlet is not in exclusive fluid communication, and is connected to multiple fluid supply sources. Various embodiments include a first fluid channel 514 in fluid communication with the first inlet 510. Various embodiments include a second fluid channel 516 in fluid communication with second inlet 512. Various embodiments include a third fluid channel 508 in fluid communication with a third inlet 502. Various embodiments include a fourth fluid channel 506 in fluid communication with a fourth inlet 504. In various embodiments, a fluid channel is uniform in cross section. In additional embodiments, a fluid channel has a nonuniform cross section. Cross sections are selected based on an application, in various embodiments. Various embodiments of the present subject matter use computational fluid dynamics to predict pressure distributions associated with a fluid channel shape, and select a fluid channel shape based on that analysis. Some embodiments are selected to clean the workpiece with a blast of air. This list of applications is not exhaustive or exclusive of the present subject matter, and additional applications not recited herein expressly additionally fall within the present subject matter. In various embodiments, the fluid channels are positioned proximal to one or more lumens in a die, and fluids in the fluid channels are in fluid communication with one or more lumens in the die.

FIG. 6 is a partial cross section of a punch assembly, according to one embodiment of the present subject matter. Visible are a die 616 which is connected to a die holder 602. A lubrication manifold 618 is sandwiched between the die 616 and the die holder 602. A stripper plate 622 is visible, with a stripper plate insert 620 attached to the stripper plate. A punch 626 is shown disposed partially in the stripper plate 622. A punch block 636 is coupled to the punch 626. A punch holder 638 guides the punch block, and is coupled to the stripper plate 622. In various embodiments, the stripper plate insert is useful to keep lubricant away from a workpiece. This is useful in embodiments in which lubricant reacts with a workpiece in an undesired fashion.

The illustrated embodiment shows a number of pathways for fluids, which are present in various embodiments of the present subject matter. A first fluid channel 612 is shown, according to some embodiments of the present subject matter. Some embodiments additionally include a second fluid channel 614. In various embodiments, the first fluid channel 612 is connected to a portion 608 having a reduced cross section. In various embodiments, this portion 608 is in fluid communication with a lumen 610 extending through die 616. In various embodiments, the lumen 610 includes a nozzle. Various embodiments connect a fluid channel to multiple lumens. Various embodiments include additional channels, such as third channel 604 and fourth channel 606. In various embodiments, third channel 604 includes a lubricant which extends through a lumen in the die 616, and through a nozzle of the lumen, and onto a workpiece.

Various embodiments are configured such that fourth channel 606 includes a gas at a pressure differential from atmosphere. As such, fourth channel can include a positive pressure which blows gas against a workpiece, in various embodiments. Some of these embodiments communicate gas to a workpiece through lumen 646. Various embodiments include a fourth channel 606 which is at a negative pressure, drawing a vacuum and drawing a workpiece toward a lumen which extends through die 616 and is in fluid communication with fourth channel 606.

Embodiments are included in which at least one lumen 646 is pressurized to force a workpiece away from the die 616. In various embodiments, a plurality of lumens apply gas to a workpiece to force the workpiece away from the die 616. Various embodiments direct air toward the electrode web outside the cutting opening 644 by positioning the plurality of gas lumens, including lumen 646, in the die outside a cutting opening 644 defined by the die for cutting the electrode from the electrode web. In various embodiments, blowing the electrode web away from the die reduces defects and improves cycle time. An additional benefit overall is that maintenance frequency is reduced. In various embodiments, a seal is disposed between die 616 and lubrication manifold 618.

Various embodiments of the present subject matter include a punch 626 which includes lumen 628 which is adapted to carry fluid. In various embodiments, the lumen 628 subjects a workpiece to a pressure differential. As such, various embodiments subject a workpiece to a vacuum. Some embodiments push a workpiece away from punch 626. In various embodiments, lumen 628 is in fluid communication with a punch block plenum 634. Various embodiments include a vacuum manifold 630 which is coupled to the punch 626. In various embodiments, the vacuum manifold includes at least one lumen 640. In some embodiments, the vacuum manifold includes a plurality of lumens which are in fluid communication via a vacuum manifold plenum 642. In various embodiments, the vacuum manifold plenum 642 and the punch block plenum 634 are exclusive, and are connected to respective sources for pressure differential. As such, in one embodiment, the punch block plenum 634 is at a different pressure than the vacuum manifold plenum 642. These configurations are some of the configurations contemplated by the present subject matter. Embodiments which carry a fluid along a path defined by two mating parts are sealed, in various embodiments.

Various embodiments include a punch lubricating channel 624 which is open to the punch, and which is open to a workpiece. Various embodiments additionally include a punch lubricating channel 632 which is open to the punch and which is not open to the workpiece. Depending on which embodiments are studied, one or both of these lubrication channels may be used. Additional embodiments, including the one illustrated, include both. The embodiments depicted expressly herein are not representative of all of the possible embodiments contemplated by the present subject matter, as additional configurations are possible.

The present subject matter includes various processes for making an electrode. In various embodiments, an electrode web is punched with a punch assembly. Various embodiments include placing an electrode web between a punch 626 and a die 616, the punch in alignment with the die to cut the web along a cutting opening 644 to define an electrode having a perimeter which is shaped substantially similar to the shape of the cutting opening 644. The cutting openings shown herein are examples of the electrode shapes possible according to the present subject matter.

Various embodiments include lubricating the die 616 with a lubricant. In various embodiments, the lubricant flows from at least one lumen 610 to the cutting opening 644. In various embodiments, the mechanism for transport of the lubricant from the lumen 610 to the cutting opening 644 is wetting.

Various embodiments include punching the electrode from the electrode web by pressing the punch 626 through the electrode web and into a die opening 650 in the die 616. Various embodiments additionally include picking the electrode off the punch through an access opening 648 in the die assembly, which includes an access opening in the die. In various embodiments, a vacuum from a vacuum pick is applied to an electrode web prior to punching the web, such that the electrode punched from the electrode web is registered with respect to the vacuum pick. The orientation of the electrode with respect to the vacuum pick is stored, in various embodiments, in a computer. As such, in various embodiments, the vacuum pick can place the electrode into use in a registered fashion without performing additional registration operations. In various embodiments, such a process saves time as it eliminates an alignment step. In various embodiments, a vacuum pick positions an electrode into a stack without performing additional registration operations.

In various embodiments, the electrode layer is punched out of the electrode web without applying compression introduces to the electrode web before the punch contacts the electrode web. In some embodiments, a punch vacuum holds the electrode web in place prior to punching. Embodiments are included in which a first punch vacuum holds a first portion of an electrode web, and a second punch vacuum holds a second portion of an electrode web. In various embodiments, the first and second punch vacuums are at a different pressure. Embodiments are contemplated in which the first and second punch vacuums are at a substantially equal pressure.

One of ordinary skill in the art will understand that, the control systems shown and described herein can be implemented using software, hardware, and combinations of software and hardware. As such, the term “system” is intended to encompass software implementations, hardware implementations, and software and hardware implementations.

In various embodiments, the methods provided above are implemented as a computer data signal embodied in a carrier wave or propagated signal, that represents a sequence of instructions which, when executed by a processor, cause the processor to perform the respective method. In various embodiments, methods provided above are implemented as a set of instructions contained on a computer-accessible medium capable of directing a processor to perform the respective method. In various embodiments, the medium is a magnetic medium, an electronic medium, or an optical medium.

Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement which is calculated to achieve the same purpose may be substituted for the specific embodiment shown. This application is intended to cover adaptations or variations of the present subject matter. It is to be understood that the above description is intended to be illustrative, and not restrictive. Combinations of the above embodiments, and other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the present subject matter should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Citada por
Patente citante Fecha de presentación Fecha de publicación Solicitante Título
US80332029 Dic 200311 Oct 2011Cardiac Pacemakers, Inc.Apparatus and method for cutting electrode foil layers
Clasificaciones
Clasificación de EE.UU.72/405.16
Clasificación internacionalB21J11/00
Clasificación cooperativaB21D37/18, B21D28/14
Clasificación europeaB21D28/14, B21D37/18
Eventos legales
FechaCódigoEventoDescripción
7 Mar 2007ASAssignment
Owner name: CARDIAC PACEMAKERS, INC., MINNESOTA
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:MORGAN, ADAM J.;ROHL, JAMES P.;REEL/FRAME:018977/0588;SIGNING DATES FROM 20070208 TO 20070221