EP0005084A1 - Apparatus for drawing and ironing containers - Google Patents
Apparatus for drawing and ironing containers Download PDFInfo
- Publication number
- EP0005084A1 EP0005084A1 EP19790300714 EP79300714A EP0005084A1 EP 0005084 A1 EP0005084 A1 EP 0005084A1 EP 19790300714 EP19790300714 EP 19790300714 EP 79300714 A EP79300714 A EP 79300714A EP 0005084 A1 EP0005084 A1 EP 0005084A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- support
- ring
- assembly
- path
- punch
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D45/00—Ejecting or stripping-off devices arranged in machines or tools dealt with in this subclass
- B21D45/06—Stripping-off devices
- B21D45/065—Stripping-off devices for deep-drawn cans, e.g. using stripping fingers
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D22/00—Shaping without cutting, by stamping, spinning, or deep-drawing
- B21D22/20—Deep-drawing
- B21D22/28—Deep-drawing of cylindrical articles using consecutive dies
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D22/00—Shaping without cutting, by stamping, spinning, or deep-drawing
- B21D22/20—Deep-drawing
- B21D22/28—Deep-drawing of cylindrical articles using consecutive dies
- B21D22/283—Deep-drawing of cylindrical articles using consecutive dies with ram and dies aligning means
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D22/00—Shaping without cutting, by stamping, spinning, or deep-drawing
- B21D22/20—Deep-drawing
- B21D22/28—Deep-drawing of cylindrical articles using consecutive dies
- B21D22/286—Deep-drawing of cylindrical articles using consecutive dies with lubricating or cooling means
Definitions
- the present invention relates generally to can making machines and more specifically to an improved floating arrangement for various components of a drawing and ironing machine.
- a punch normally cooperates with a plurality of ironing dies and the stroke of the punch is fairly long in order to produce conventional 12 and 16 ounce containers.
- the length of the stroke of the punch for the bodymaker or press has heretofore created substantial problems in producing a satisfactory container which has a uniform wall thickness in the sidewall thereof.
- One of the problems encountered has been in maintaining all of the elements in very accurate alignment with respect to each other in order to produce a finished container which has a uniform wall thickness around the entire perimeter thereof and also the entire length thereof.
- the particular arrangement for accomplishing the self-centering and floating feature in the assembly disclosed in the British patent consists of cooperating inclined surfaces between the ironing die and its support mechanism with a biasing mechanism which will automatically center the ironing dies with respect to a predetermined axis whenever external forces are removed.
- the biasing mechanism in this patent has been illustrated as either consisting of an elastomeric member or rubber ring which produces a centering action between an ironing die and a cooperating support.
- the centering means in the disclosed patent also shows the use of springs that cooperate with the ironing die and the support to center the ironing die with respect to a predetermined axis.
- such arrangement has not been too successful in accurately returning the ironing die to a centered position after being moved away from the centered position.
- cup holder sleeve in an accurate position with respect to the redraw ring just prior to the punch entering into the cup and forcing the cup through the redraw ring. It has been found that, under certain conditions, the cup holder sleeve is not accurately centered, while applying uniform hold-down pressure on the cup to hold the cup in a fixed position with respect to the redraw ring. This will produce an uneven redrawn cup which can produce a tear- off of the longer end either in the redraw state or in subsequent ironing stages.
- the wall thickness of selected portions of the cup may be reduced during the redraw process which results in ultimately having varying thicknesses in different portions of the sidewall of the finished container.
- the present invention is particularly adapted for a drawing and ironing machine that includes a frame which has a redraw assembly, at least one ironing assembly and a stripper assembly arranged in series, and each having an opening to define a path with a punch movable along the path through the openings.
- a cupholder sleeve assembly has an axial bore adapted to receive the punch and cooperates with the redraw die assembly to hold a cup while the cup is being forced through the redraw die assembly and through the respective ironing assemblies.
- a domer assembly is also located at the end of the path of the punch and reforms the end wall of the cup after it has passed through the respective assemblies and the stripper assembly engages the upper free edge of the partially finished container to strip the container from the punch as the punch is withdrawn through the respective assemblies.
- At least one of the redraw, ironing or stripper assemblies is designed to accommodate radial movement of the center of the opening through which the punch passes in order to accommodate any misalignment between the punch and the openings in the various assemblies.
- the domer assembly is likewise movable radially of the path for the punch to insure that the center of the domer is centered with respect to the axis of the punch.
- the primary aspect of the invention is the fact that the ironing dies are radially movable with respect to the path for the punch and are automatically returned to a centered position by circumferentially spaced centering spring means.
- the ironing dies are supported on an air float to reduce friction and lubricant is supplied to the opening in the die.
- a cup holder sleeve assembly is designed to be capable of allowing the cup holder sleeve to automatically be moved radially with respect to the axis of a drawing and ironing machine and also be capable of being tilted with respect to the axis to accommodate accurate positioning of the cup holder sleeve face with respect to the surface of the redraw ring and accurately position the cups with respect to a ring and apply uniform pressure to the cup.
- the cup holder sleeve assembly includes a support having an opening therein with a recess extending from the periphery of the opening and a cup holder sleeve and support element having portions received into the recess of the support.
- the support element and cup holder sleeve are normally maintained in a centered position with respect to the opening in the support by centering springs which accommodate radial movement of the support element and the cupper sleeve.
- the cup holder sleeve and support element have cooperating spherical surface segments that are normally maintained in engagement with each other through further hold-down springs which accommodate tilting of the axial bore in the sleeve with respect to the axis of the aperture in the support element.
- Lubricating means are provided for supplying lubricant between the cooperating spherical surface segments on the support element and the cup holder sleeve as well as the supporting surfaces between the support element and the support which accommodates radial movement of the support element and cup holder sleeve within the support.
- the redraw die assembly has a redraw die that is floatingly mounted with respect to the axis of the punch associated therewith so as to be movable in a radial plane with respect to the axis of the punch as well as the axis of the cup holder sleeve and the assembly is normally held in a centered position with respect to the path for the punch by biasing springs that cooperate with the periphery of the assembly.
- the assembly includes a support and a redraw ring carried by the support and also preferably includes an enlarged nesting ring which acts as a pilot for receiving and accurately positioning the cup with respect to the redraw ring.
- the redraw die assembly also incorporates lubricating means for supplying lubricant to the inner face between the redraw ring and the cup to reduce the frictional forces and produce a cup having a better finish.
- the lubricating means consists of an annular lubricating channel within the support surrounding the nesting ring with the channel being in communication with the opening in the ring through a plurality of circumferentially spaced flow paths which have their inner ends terminating non-radially with respect to the center of the opening in the ring. This arrangement creates a swirling or vortex flow for the lubricant fluid to the opening in the ring during the redraw operation and also cools the redraw ring during the remainder of the cycle.
- the redraw ring assembly also is supported on a fluid bearing within the frame for the assembly to reduce frictional forces and aid in accommodating radial movement of the assembly with respect to the path.
- the stripper assembly of the drawing and ironing assembly is also mounted for radial movement with respect to the path and is again centered with respect to the path by centering springs that cooperate with the periphery of the assembly and is supported on a fluid bearing.
- the domer assembly includes a support that has a recess with the base of the recess defining a support surface.
- a carrier element is located in the recess and has a cooperating surface which engages the bottom of the recess and both the carrier and the recess in the support are circular with the recess being enlarged so as to accommodate movement of the carrier element in all directions along a plane which extends perpendicular to the path of movement of the punch.
- the domer assembly also includes supply means for introducing a bearing fluid between the two surfaces with biasing means between the support and the carrier element which normally maintain the surfaces in a predetermined position with respect to each other and accommodate radial movement of the carrier element within the recess.
- the biasing means or springs are positioned such that the domer member or element supported on the carrier is always returned to the predetermined position whenever external forces are removed from the assembly.
- the support also includes prestressing means for prestressing the springs located between the support and the carrier element so that the carrier element is always returned to a predetermined position with respect to the path or axis of the punch regardless of variations in spring forces being applied by the respective springs.
- the prestressing means consists of a ring which surrounds a reduced portion of the carrier element and is spaced therefrom but is fixedly secured in a predetermined position with respect to an enlarged portion of the carrier element.
- the springs which are equally spaced circumferentially around the periphery of the reduced portion, are biased into engagement with the inner surface of the positioning ring and also engage a sidewall of a reduced portion of the recess.
- FIG. 1 of the drawings schematically illustrates selected portions of a bodymaker 10 used for converting a cup 12 into a finished container 14.
- Bodymaker 10 includes a cup holder sleeve 20 which has an axial bore 22 therein through which a punch 24 is adapted to be moved.
- Punch 24 is axially aligned with path P and is movable along a path P which has a plurality of die assemblies in a support 30.
- the first die assembly consists of a redraw ring assembly 26 and the other die assemblies are ironing ring assemblies 28.
- a cup 12 is generally aligned with redraw ring 26 through a cup locating mechanism (not shown) and cup holder sleeve 20 is then moved axially generally to the position illustrated in Fig. 1 to hold the cup 12 in a fixed position with respect to redraw ring 26...Punch 24 is then moved axially through bore 22 to force the cup initially through the redraw ring 26 wherein the cup diameter is decreased and the cup height is increased and subsequently through the ironing rings 28 which cooperate with the peripheral surface of punch 24 to reduce the sidewall thickness of cup 12.
- the lower end of the punch which is generally dome shape in cross section, cooperates with domer 34 to reform the bottom wall of the cup and produce a finished container.
- stripper assembly 32 engages the upper free edge of finished container 14 to strip the container from the punch.
- one of the problems encountered in producing satisfactory containers utilizing a process described above is to maintain accurate alignment of all of the various parts at all times. Any misalignment of any of the elements by even as little as one ten-thousandths of an inch will result in having a finished container which has a sidewall of uneven thickness.
- One of the most critical initial areas in the above described process is to make sure that the cup is accurately positioned with respect to the redraw ring and uniform hold-down pressure is applied to the cup before the drawing and ironing process is initiated.
- cup holder sleeve 20 is mounted for universal movement with respect to the path P to facilitate tilting and radial movement during a jam while still remaining aligned after a jam.
- cup holder sleeve 20 is supported in a cup holder sleeve support 40 which consists of first and second members 42 and 44 which have cooperating threads 46 to be assembled with respect to each other, for a purpose that will be described later.
- Support 40 has a substantial circular opening 48 therein which is aligned with the circular opening 50 that is defined in the redraw ring 26 and the centers of these openings are located along the path P of punch 24.
- Members 42 and 44 cooperate with each other to define a recess 52 extending from the periphery of opening 48 and recess 52 has a shoulder 54 which extends substantially radially from the axis of opening 48.
- a support element or cup holder sleeve support member 60 has a peripheral portion 62 which is received into recess 52 and also has a contiguous cooperating surface 64 which is in engagement with shoulder surface 54.
- Support element 60 also has a circular aperture 66, therein, which is generally of the same size as bore 22 in cup holder sleeve 20.
- cup holder support element 60 and cup holder sleeve 20 are normally centered with respect to opening 48 through centering means which will now be described.
- the centering means consists of four circumferentially spaced biasing means 70 that are equally spaced from each other around the perimeter of the substantially circular support 40.
- the respective biasing means 70 are spaced approximately 90 degrees from each other and produce equal forces around the perimeter of support element 60 to maintain the support element in a centered position with respect to the circular support 40 more particularly opening 48.
- the respective biasing means 70 are identical in construction and only one will be described in connection with Figs. 2 and 3.
- Each biasing means 70 consists of a spring 72 that has one end received into a cup 74 which has an annular shoulder 76 cooperating with an enlarged portion 78 of a radial opening in support 40.
- the opposite end of spring 70 engages the inner surface of a support ring 80 which forms part of support 40.
- the springs 72 are selected so as to produce an equal force and cup 74 is designed so that the inner surface thereof is in engagement with the periphery of support element 60 as illustrated in Figs. 2 and 3.
- the cups 74 are all accurately dimensioned so that when the shoulders 76 engage with support 40, the free ends of the cups are on a common circle which has a diameter that is equal to the peripheral diameter of the support element 60.
- the springs will accommodate radial movement to prevent permanent misalignment between opening 48 and redraw ring 26.
- the centering means or biasing spring 70 will, therefore, always accurately position support element 60 in a centered position with respect to opening 48 which is accurately centered with opening 50.
- the axis of bore 22 of cup holder sleeve 20 can also be tilted with respect to the path P if there is a misfed cup to apply a uniform hold-down pressure at all times.
- support element 60 has an arcuate or spherical surface segment 90 on the lower surface thereof surrounding aperture 66 and the concave surface segment 90 cooperates with a convex surface segment 92 defined on an enlarged portion 100 on the upper end of cupper sleeve 20.
- the cooperating surface segments 90 and 92 will accommodate movement of the lower free end of cup holder sleeve 20 to allow the cup holder sleeve to assume an angular position wherein the axis of bore 22 is axially aligned with the axis of punch 24.
- the centers of spherical surface segments 90 and 92 are located at a point 95 which is located on path P.
- Flat surfaces 54 and 64 and spherical surfaces 90 and 92 are normally held in engagement with each other through biasing means that cooperate with support 40 and cupper sleeve 20, as well as support element 60.
- enlarged portion 100 of cup holder sleeve 20 is received into recess 52 and spring biased tabs 102 are received in recesses 103 and cooperate with the lower surface of enlarged portion 100 for biasing the various surfaces into engagement with each other.
- each tab (there being four equally spaced around the perimeter of support 40) has a cup 104 secured thereto as by welding and a hold-down spring 106 is telescoped into the cup. Cup 104 is received in an opening 108 in member 42 and one end of the spring engages the surface on member 44 which forms part of support 40.
- each recess 103 in member 42 defines an accurate space between the tab and surface 54 and such spacing will be maintained even when the spring forces for the respective springs are different.
- each tab 102 is biased into the position illustrated in Fig. 3 wherein the axis of aperture 66 and the axis of bore 22 are aligned with the axes of openings 48 and 50.
- the tabs will allow a certain amount of tilting movement of the sleeve 20 with respect to support element 60.
- the various surfaces which are moved relative to each other are continuously lubricated through lubricating means which will now be described.
- the lubricating means is most clearly illustrated in Fig. 4 and consists of an opening 110 in member 42 which has a threaded exterior portion 111 to which a source of pressurized lubricant may be connected.
- the inner end of opening or bore 110 is in communication with a continuous circumferential recess 112 that is defined in shoulder surface 54 of member 42.
- the recess 112 extends around the entire perimeter of surface 54 and is also in communication with a second continuous recess 120 in surface 90 through one or more small openings 122.
- a continuous flow of fluid from a source (not shown) through opening 110 will provide a constant supply of lubricant between the relatively movable surfaces of the cup holder sleeve assembly.
- This arrangement substantially reduces the frictional forces that must be overcome when the various elements have to be moved with respect to each other.
- the continuous supply of lubricant to these relatively movable surfaces will also substantially reduce the wear of the overall assembly.
- redraw die assembly 26 is mounted on support 30 in a manner that allows radial movement of the assembly with respect to the normal path of movement P of punch 24 to allow the assembly to be moved to a centered position with respect to the axis A of punch 24, should the punch be offset from the path P.
- redraw die assembly 26 includes a support 230 which supports a redraw ring 232 that has a circular opening 234.
- Support 230 has a lower flat surface 236 which extends perpendicular to path P and is in extended engagement with a flat surface 238 that is defined in frame structure 225.
- the periphery of support 230 is preferably circular, and centering means 240 cooperate with the periphery of support 230 to normally maintain support 230 and ring 232 centered with respect to path P.
- the centering means 240 consists of an annular ring 242 which is held in a fixed position on frame 225 and has a plurality of circumferentially spaced spring assemblies 244 associated therewith.
- each spring assembly 244 includes a plunger 246 reciprocated in an opening 247 extending into the inner surface of ring 242.
- Plunger 246 has an enlarged flange 248 located in a cup 250 with a spring 252 also located in cup 250 which biases plunger 246 into engagement with the periphery of support 230.
- all plungers 246 are biased to a position illustrated in Fig. 5 wherein the flange 248 of each plunger 246 is in engagement with a surface of ring 242 around opening 247. This arrangement defines an extremely accurate centered position of the opening 234 with respect to path P.
- a fluid bearing is interposed between cooperating surfaces 236 and 238 to reduce the friction forces that must be overcome to allow radial movement of support 230 with respect to path P.
- support surface 236 has one or more annular recesses 260 defined therein and recesses 260 are in communication with a bore 262 which is defined in frame 225.
- a supply of pressurized fluid, such as air, is connected to the inlet end of bore 262 and is delivered to the respective annular recesses 260.
- the fluid will act as a bearing surface to tend to separate these surfaces when external forces are applied to the redraw die assembly which will assist in allowing the opening 234 to move to a predetermined centered position with respect to punch 24.
- the redraw die assembly also includes a centered mechanism for centering the cup 12 with respect to redraw ring 232 prior to having the punch enter the cup.
- This centering mechanism consists of a resting ring 266 that has ar. opening 268 which is larger than opening 234.
- Nesting ring 266 is held in a fixed position with respect to redraw ring 232 through a support ring 270 which is held in a fixed position with respect to support 230 by sc::ews 272 and thus forms a part of support 230.
- the diameter of opening 268 is substantially equal to the peripheral diameter of cup 12 as it is received by the redraw die assembly and is larger than the diameter of opening 234 so that a portion of the surface of ring 232 is exposed.
- the nesting ring 266 aids in centering the center of the cup with respect to the center of redraw ring 232 before punch 14 enters sleeve 20.
- This movement is in part assured by the fact that the lower peripheral end of cup 12 normally has a radiused portion 274 and the radiused portion will aid in guiding the periphery of cup 12 into opening 268 of centering ring 266.
- biasing means 240 will allow the entire redraw die assembly to move radially with respect to path P.
- the diameter of bore 22 in sleeve 20 is slightly larger than the diameter . of punch 14 so that redraw die assembly 26 and sleeve 20 with cup 12 clamped between them can move radially and the center of opening 234 will align with the axis of punch 14.
- nexting ring 266 also incorporates means for sup- -plying lubricant between the exposed surface of redraw ring 232, which initially supports the cup and the adjacent surface of cup 12.
- the lower surface of support ring 270 has an annular recess 280 defined therein and recess 280 is closed by a surface of support 230 to produce a channel.
- the channel is in communication with the periphery of support 230 through openings 282.
- a pressurized lubricant is supplied to openings 282 through an opening 284 in frame 225.
- Annular recess or channel 280 is in communication with opening 268 through a plurality of non-radial recesses 288 in one surface of nesting ring 266 and recesses 288 are circumferentially spaced around the perimeter of opening 268.
- the recesses are closed by adjacent surfaces of support 230 and redraw ring 232 to produce flow paths.
- all of the recesses or flow paths are generally linear and the axes of the flow paths are radially offset from the center of opening 268 in nesting ring 266. This arrangement insures that there is non-radial flow of the fluid from channel 280 through flow paths 288 into opening 268.
- the radiused peripheral lower edge 274 of cup 12 (Fig. 5 ) will cooperate with the upper exposed surface of redraw ring 232 and the annular inner surface of opening 268 to produce a small channel for lubricant flow around the perimeter of the cup to all areas of the exposed surface of redraw ring 232.
- the lubricant that is received into annular recess 280 flows through the respective recesses 288 into the channel created by the radius portion 274 and results in a circumferential flow of the lubricant within the channel during the redraw operation.
- the non-radial recesses or slots 288 distribute the lubricant, which also acts as a coolant, in a vortex pattern across the redraw die surface during the redraw operation. The lubricant also cleans and cools the redraw die surface after the cup has been redrawn.
- Each of the ironing assemblies 28 is generally identical in construction and again provides a floating arrangement for the ironing ring to accommodate radial movement of the ironing ring with respect to the path P and thereby insure more uniform wall thickness of the finished container.
- the details of one ironing assembly are illustrated in Fig. 5 and include an ironing die 300 that has a land 302 which cooperates with the peripheral surface of the punch 24 to reduce the sidewall thickness of a cup as it passes through the ironing die 300.
- Ironing die 300 is supported in a circular support 304 which has a recess 306 for receiving and supporting die 300.
- the ironing die assembly also has a locator die 310 supported on a circular plate 312 which acts as a guide for the cup as it leaves the ironing die 300.
- Support 302 and plate 312 have a peripheral band 314 engaging the peripheral surfaces thereof so that the ironing die and locator die 300 and 310 move as a unit when external forces are applied thereto.
- the lower surface 320 of support 312 is in sliding contact with a radial surface 322 defined on a support structure 324 for the ironing die.
- the upper surface 326 of upper ironing die support 302 is in sliding contact with a radial surface 328 that is also part of the support 324.
- the entire ironing die assembly 28 is again maintained in a predetermined position by a plurality of centering means 330 that are circumferentially spaced around the peripheral surface of ring or band 314 and are carried by support 324.
- Each centering means or spring assembly includes a cup 332 that has a base thereof in juxtaposed relation to the peripheral surface of band 314 and has a radially extending flange 334 at the opposite open end thereof.
- a spring 336 is telescoped into the cup and the outer end thereof engages a cover portion 338 that is removably secured to support 324 through suitable retaining means 340.
- spring assemblies 330 preferably there are four such spring assemblies 330 equally spaced at 90 degrees around the perimeter of band 314 and are dimensioned such that when flanges 334 engage adjacent shoulders defined on the support 324 the ironing land 304 is accurately centered with respect to the path of punch 24.
- the center of the opening defined by land 304 is slightly offset with respect to the axis of the punch 24, at least some, but not all, of the spring assemblies will be compressed and allow radial movement of the entire die assembly 28 to center the land opening with respect to the punch and insure a uniform wall thickness for the finished container.
- a fluid bearing is interposed between surfaces 320 and 322 and consists of annular recesses 346 that are in communication with an air supply through one or more openings 348.
- stripper assembly 32 is also designed to accommodate radial movement of the assembly with respect to path P during a drawing and ironing operation.
- the stripper assembly 32 is illustrated in greater detail in Fig. 6 and includes a stripper support element 410 that has an enlarged portion 412 received into a recess 414 defined in support 425.
- a plurality of pivoted jaws 416 are located around the perimeter of path P and the lower edges of jaws 416 cooperate to define an opening 418 through which the finished container and punch 24 pass during the last part of the stroke of a drawing and ironing process.
- the respective jaws or segments 416 are held in a predetermined position through a resilient support member 422 and support ring 423 as well as an elastomeric member 424 as illustrated in Fig. 6.
- the jaws are biased to a position wherein the opening 418 is slightly smaller than the peripheral diameter of the finished container which passes therethrough.
- the lower edges of pivoted jaws 416 are moved outwardly slightly to accommodate the movement of the container therethrough.
- the jaws will move inwardly into the path of return movement of the upper free end of the container.
- Stripper assembly 32 is again held in a centered position with respect to path P through biasing means 430 which can be identical to the biasing or centering means 240 described above.
- biasing means 430 will again accommodate radial movement of the entire stripper assembly with respect to path P to insure that there is no substantial interference between the container and the stripper jaws.
- support 410 and frame 425 have flat radially extending cooperating surfaces that accommodate such radial movement. This arrangement insures that all of the jaws are located in the same position with respect to the periphery of the punch. This insures that the jaws which engage the free edge will engage across the entire width of the edge for more reliable stripping and less damage to the free edge.
- the lower surface of enlarged portion 412 has a flat annular surface 432 which is supported on an annular flat surface 434 that is defined on frame structure 425.
- Frame structure 425 also has an upper annular surface 436 which cooperates with flat upper surface 438 of support member 410.
- one of the problems in producing satisfactory containers utilizing a process such as that described above is to maintain extremely accurate alignment between the axis of punch 14 and the center or axis of domer assembly 34. Any misalignment of these two elements with respect to each other by even a small increment will result in a defect in the end wall of the container which in turn will impair the strength of the container.
- the domer assembly 34 is constructed in such a fashion that the domer element which forms part of the assembly can - readily be moved in any direction radially of the axis or path P to move into a position in exact alignment with the center of punch 24 should the punch be offset from the path for any reason.
- domer assembly 34 (Fig. 8) consists of a support 530 which may be accurately positioned with respect to the remainder of the frame structure of the bodymaker 10 and is supported on a cushion such as air, for axial movement (not shown).
- Support 530 has a recess or opening 532 extending from the upper surface 534 and recess 532 has an enlarged portion 536 and a reduced portion 538 with a generally flat bottom wall or surface 540 defined in the reduced portion 538.
- the center of circular opening 532 is accurately positioned and centered with respect to path P.
- Domer assembly 34 also includes a support element or member 542 which has an enlarged portion 544 received into enlarged portion 536 of recess 532 and a reduced portion 546 with reduced portion 546 having a bottom surface 548 which is in extended engagement with bottom wall or surface 540 for recess 532.
- Recess 532 and carrier element 542 are both circular in cross section and carrier element 542 is smaller in dimension than the recess 532, as will be described later.
- domer assembly 34 consists of a domer element or tool 550 which is supported in an opening 552 in carrier element 542 and is secured thereto by a bolt 554.
- the threaded bolt or stud 554 extends through an opening 556 in carrier element 552 and is threaded into an opening in the domer element 550 so that the carrier element 542 and domer element 550 move as a unit in a radial direction with respect to path P.
- the domer assembly also includes biasing - means 560 between support 530 and carrier element 542.
- Biasing means 560 consists of four or more circumferentially equally spaced spring assemblies that each consist of a spring 562 having one end received into a cup 564 which is reciprocated in a bore 566 in carrier element 542 and the opposite end received into a reduced portion of bore 566. The inner end of each cup 564 is received into the enlarged portion of bore 566 and is biased into engagement with the sidewall of the reduced portion 538 of recess 532.
- the four or more spring assemblies will always maintain the domer assembly, particularly domer element 550, in a predetermined position with respect to the axis or path P.
- the various spring assemblies will allow carrier element 542 and domer element 550 to move radially with respect to the punch and to accurately align itself with the axis of the punch to produce a satisfactory finished container having a reformed end wall of any particular configuration.
- domer assembly 526 also includes prestressing means cooperating with the respective spring assemblies for insuring that the domer element 550 is always moved to a same exact centered position with respect to path P when the external forces are removed.
- a circular or annular ring 570 extends around and is spaced from the periphery of the reduced portion 546 of support carrier 542 and cooperates with the respective spring assemblies to maintain all of the springs in a certain prestressed condition at all times.
- Ring 570 is accurately positioned with respect to carrier element 542 by a cooperating offset portion 572 and a recess 574 respectively defined on the ring 570 and carrier element 542.
- Ring 570 is releasably secured to carrier element 542 through a plurality of threaded studs 576.
- each of the cups 564 can be positioned into openings 566 and ring 570 can then be telescoped to the position illustrated in Fig. 8 and secured to carrier element 542 through bolts or studs 572.
- the outer free edge of each of the cups which is generally spherically shaped, thus cooperates partially with the inner surface of ring 570 to maintain all of the springs in a prestressed condition, regardless of variations in spring force. If there is a need for the carrier element to move radially with respect to path P, only a certain number of spring assemblies, less than all, are further compressed, while the remainder of the spring assemblies remain in the same prestressed condition. Thus, when an external force is removed, after the carrier assembly has been moved off its normally centered position, there is no interference by certain springs preventing the carrier element 542 and domer 550 from moving to the predetermined centered position.
- domer assembly 526 also includes fluid means for supplying a bearing fluid between surfaces 540 and 548 of carrier element 542 and support 530.
- This fluid supply consists of a bore 580 extending through support 530 and in communication at its inner end with an annular recess or opening 582 that extends from surface 540.
- a pressurized fluid supply such as air, is attached to the outer end of bore 580 and supplies a constant flow of air to annular recess 582 which must then flow between bearing surfaces 540 and 548 which results in a fluid bearing between the surfaces.
- Such arrangement reduces the frictional forces encountered when carrier element 542 is attempted to be moved radially of path P.
- the carrier element 542 is releasably retained in recess 532 by a cap 590 secured to support 530 by screws 592.
- lubricating means could also be provided between surfaces 432, 434, 436, and 438 of stripper assembly 32, if desired.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Shaping Metal By Deep-Drawing, Or The Like (AREA)
Abstract
Description
- The present invention relates generally to can making machines and more specifically to an improved floating arrangement for various components of a drawing and ironing machine.
- In the formation of a "two-piece" container, it has been customary to utilize a plurality of die assemblies that cooperate with a punch for converting circular metal discs into finished containers which have a sidewall and an integral end wall. One of these processes consists of originally drawing a circular metal disc into a cup utilizing what is commonly referred to as a cupping machine. The cup is then transferred to a bodymaker wherein the cup is converted into the finished container. In one process, which is being used commercially, the preformed cup is first redrawn to a smaller diameter and larger height and then is substantially simultaneously converted to an ironed container wherein the sidewall thickness is reduced in one or more steps. One type of such commercial machine is produced by Ragsdale Bros., Inc. and is identified as a Model CR-24 canwall drawing and ironing press. Normally the material for such containers is either aluminum or tinplate.
- In such a process, a punch normally cooperates with a plurality of ironing dies and the stroke of the punch is fairly long in order to produce conventional 12 and 16 ounce containers. The length of the stroke of the punch for the bodymaker or press has heretofore created substantial problems in producing a satisfactory container which has a uniform wall thickness in the sidewall thereof. One of the problems encountered has been in maintaining all of the elements in very accurate alignment with respect to each other in order to produce a finished container which has a uniform wall thickness around the entire perimeter thereof and also the entire length thereof.
- In order to alleviate some of the problems in maintaining accurate alignment between the various dies and the punch, several proposals for producing floating ironing dies have been proposed. For example, British Patent No. 724,251 published February 16, 1955 discloses a method of supporting ironing dies that will accommodate movement of the dies with respect to the punch but will also provide a self-centering feature which theoretically will reposition the die to a predetermined position whenever all external forces have been removed.
- The particular arrangement for accomplishing the self-centering and floating feature in the assembly disclosed in the British patent consists of cooperating inclined surfaces between the ironing die and its support mechanism with a biasing mechanism which will automatically center the ironing dies with respect to a predetermined axis whenever external forces are removed. The biasing mechanism in this patent has been illustrated as either consisting of an elastomeric member or rubber ring which produces a centering action between an ironing die and a cooperating support. Alternatively, the centering means in the disclosed patent also shows the use of springs that cooperate with the ironing die and the support to center the ironing die with respect to a predetermined axis. However, such arrangement has not been too successful in accurately returning the ironing die to a centered position after being moved away from the centered position.
- One additional problem that has been encountered in the formation of two-piece drawn and ironed containers has been encountered when the cup is initially formed and then is redrawn just prior to the ironing of the sidewall. In a redraw operation just prior to the ironing of the sidewalls of the cups, it is customary to hold the cup through what may be termed a cup holder sleeve in an accurate position with respect to the redraw ring just prior to the punch entering into the cup and forcing the cup through the redraw ring. It has been found that, under certain conditions, the cup holder sleeve is not accurately centered, while applying uniform hold-down pressure on the cup to hold the cup in a fixed position with respect to the redraw ring. This will produce an uneven redrawn cup which can produce a tear- off of the longer end either in the redraw state or in subsequent ironing stages.
- It has also been found that when there is no accurate alignment between the punch and the redraw ring which reshapes the cup, the wall thickness of selected portions of the cup may be reduced during the redraw process which results in ultimately having varying thicknesses in different portions of the sidewall of the finished container.
- It has also been determined that if the cup holder sleeve face does not apply a uniform pressure to the cup it may wrinkle in selected areas during the redraw application.
- A further problem has also been encountered in insuring that the domer assembly and stripper assembly are accurately aligned with the punch as the end wall is reformed and the partially finished container is stripped from the punch.
- The present invention is particularly adapted for a drawing and ironing machine that includes a frame which has a redraw assembly, at least one ironing assembly and a stripper assembly arranged in series, and each having an opening to define a path with a punch movable along the path through the openings. A cupholder sleeve assembly has an axial bore adapted to receive the punch and cooperates with the redraw die assembly to hold a cup while the cup is being forced through the redraw die assembly and through the respective ironing assemblies. A domer assembly is also located at the end of the path of the punch and reforms the end wall of the cup after it has passed through the respective assemblies and the stripper assembly engages the upper free edge of the partially finished container to strip the container from the punch as the punch is withdrawn through the respective assemblies.
- According to the present invention, at least one of the redraw, ironing or stripper assemblies is designed to accommodate radial movement of the center of the opening through which the punch passes in order to accommodate any misalignment between the punch and the openings in the various assemblies. The domer assembly is likewise movable radially of the path for the punch to insure that the center of the domer is centered with respect to the axis of the punch.
- The primary aspect of the invention is the fact that the ironing dies are radially movable with respect to the path for the punch and are automatically returned to a centered position by circumferentially spaced centering spring means. The ironing dies are supported on an air float to reduce friction and lubricant is supplied to the opening in the die.
- According to one aspect of the present invention, a cup holder sleeve assembly is designed to be capable of allowing the cup holder sleeve to automatically be moved radially with respect to the axis of a drawing and ironing machine and also be capable of being tilted with respect to the axis to accommodate accurate positioning of the cup holder sleeve face with respect to the surface of the redraw ring and accurately position the cups with respect to a ring and apply uniform pressure to the cup.
- More specifically, the cup holder sleeve assembly includes a support having an opening therein with a recess extending from the periphery of the opening and a cup holder sleeve and support element having portions received into the recess of the support. The support element and cup holder sleeve are normally maintained in a centered position with respect to the opening in the support by centering springs which accommodate radial movement of the support element and the cupper sleeve. The cup holder sleeve and support element have cooperating spherical surface segments that are normally maintained in engagement with each other through further hold-down springs which accommodate tilting of the axial bore in the sleeve with respect to the axis of the aperture in the support element. Lubricating means are provided for supplying lubricant between the cooperating spherical surface segments on the support element and the cup holder sleeve as well as the supporting surfaces between the support element and the support which accommodates radial movement of the support element and cup holder sleeve within the support.
- According to a further aspect of the present invention, the redraw die assembly has a redraw die that is floatingly mounted with respect to the axis of the punch associated therewith so as to be movable in a radial plane with respect to the axis of the punch as well as the axis of the cup holder sleeve and the assembly is normally held in a centered position with respect to the path for the punch by biasing springs that cooperate with the periphery of the assembly. The assembly includes a support and a redraw ring carried by the support and also preferably includes an enlarged nesting ring which acts as a pilot for receiving and accurately positioning the cup with respect to the redraw ring.
- The redraw die assembly also incorporates lubricating means for supplying lubricant to the inner face between the redraw ring and the cup to reduce the frictional forces and produce a cup having a better finish. The lubricating means consists of an annular lubricating channel within the support surrounding the nesting ring with the channel being in communication with the opening in the ring through a plurality of circumferentially spaced flow paths which have their inner ends terminating non-radially with respect to the center of the opening in the ring. This arrangement creates a swirling or vortex flow for the lubricant fluid to the opening in the ring during the redraw operation and also cools the redraw ring during the remainder of the cycle.
- The redraw ring assembly also is supported on a fluid bearing within the frame for the assembly to reduce frictional forces and aid in accommodating radial movement of the assembly with respect to the path.
- According to a further aspect of the invention, the stripper assembly of the drawing and ironing assembly is also mounted for radial movement with respect to the path and is again centered with respect to the path by centering springs that cooperate with the periphery of the assembly and is supported on a fluid bearing.
- The domer assembly includes a support that has a recess with the base of the recess defining a support surface. A carrier element is located in the recess and has a cooperating surface which engages the bottom of the recess and both the carrier and the recess in the support are circular with the recess being enlarged so as to accommodate movement of the carrier element in all directions along a plane which extends perpendicular to the path of movement of the punch.
- The domer assembly also includes supply means for introducing a bearing fluid between the two surfaces with biasing means between the support and the carrier element which normally maintain the surfaces in a predetermined position with respect to each other and accommodate radial movement of the carrier element within the recess. The biasing means or springs are positioned such that the domer member or element supported on the carrier is always returned to the predetermined position whenever external forces are removed from the assembly.
- According to one aspect of the invention, the support also includes prestressing means for prestressing the springs located between the support and the carrier element so that the carrier element is always returned to a predetermined position with respect to the path or axis of the punch regardless of variations in spring forces being applied by the respective springs.
- The prestressing means consists of a ring which surrounds a reduced portion of the carrier element and is spaced therefrom but is fixedly secured in a predetermined position with respect to an enlarged portion of the carrier element. The springs, which are equally spaced circumferentially around the periphery of the reduced portion, are biased into engagement with the inner surface of the positioning ring and also engage a sidewall of a reduced portion of the recess.
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- Fig. 1 schematically illustrates a fragmentary sectional view of a drawing and ironing machine into which the present invention can be incorporated;
- Fig. 2 is an enlarged plan view of the cup holder sleeve support with portions thereof broken away for purpose of clarity;
- Fig. 3 is a fragmentary sectional view, as viewed along line 3-3 of Fig. 2;
- Fig. 4 is a fragmentary sectional view, as viewed along line 4-4 of Fig. 2;
- Fig. 5 is an enlarged fragmentary sectional view similar to Fig. 3 showing the details of the redraw and ironing die assemblies;
- Fig. 6 is an enlarged fragmentary sectional view similar to Fig. 3 showing the details of the stripper assembly;
- Fig. 7 is an enlarged fragmentary plan view, as viewed along line 7-7, showing part of the redraw assembly; and
- Fig. 8 is an enlarged fragmentary sectional view similar to Fig. 3 showing the details of the domer assembly.
- While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail preferred embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiments illustrated.
- Fig. 1 of the drawings schematically illustrates selected portions of a
bodymaker 10 used for converting acup 12 into a finishedcontainer 14. Bodymaker 10 includes acup holder sleeve 20 which has anaxial bore 22 therein through which apunch 24 is adapted to be moved.Punch 24 is axially aligned with path P and is movable along a path P which has a plurality of die assemblies in asupport 30. The first die assembly consists of a redrawring assembly 26 and the other die assemblies are ironingring assemblies 28. - Before the stroke of
punch 24 andcup holder sleeve 20 is initiated, acup 12 is generally aligned with redrawring 26 through a cup locating mechanism (not shown) andcup holder sleeve 20 is then moved axially generally to the position illustrated in Fig. 1 to hold thecup 12 in a fixed position with respect to redrawring 26...Punch 24 is then moved axially through bore 22 to force the cup initially through the redrawring 26 wherein the cup diameter is decreased and the cup height is increased and subsequently through the ironing rings 28 which cooperate with the peripheral surface ofpunch 24 to reduce the sidewall thickness ofcup 12. After the cup has been passed through the respective rings, the lower end of the punch, which is generally dome shape in cross section, cooperates with domer 34 to reform the bottom wall of the cup and produce a finished container. During the return stroke ofpunch 24,stripper assembly 32 engages the upper free edge offinished container 14 to strip the container from the punch. - As was indicated above, one of the problems encountered in producing satisfactory containers utilizing a process described above, is to maintain accurate alignment of all of the various parts at all times. Any misalignment of any of the elements by even as little as one ten-thousandths of an inch will result in having a finished container which has a sidewall of uneven thickness. One of the most critical initial areas in the above described process is to make sure that the cup is accurately positioned with respect to the redraw ring and uniform hold-down pressure is applied to the cup before the drawing and ironing process is initiated.
- For practical considerations, a clearance must be maintained between the periphery of
punch 24 and the inner surface ofcup holder sleeve 20. Therefore, the punch cannot be utilized for aligning the cup holder sleeve with respect to the axis of the punch which is presumed to be aligned with the center of the opening in redrawring 26. Therefore, in cases of jams, the large unsymmetrical forces that are developed in the system may force the cup holder sleeve out of alignment with the axis ofpunch 24 and redrawring 26. The result may be that the sleeve remains permanently misaligned after a jam and may become exaggerated during subsequent jams. - According to one aspect of the present invention,
cup holder sleeve 20 is mounted for universal movement with respect to the path P to facilitate tilting and radial movement during a jam while still remaining aligned after a jam. - As most clearly illustrated in Fig. 3,
cup holder sleeve 20 is supported in a cupholder sleeve support 40 which consists of first andsecond members threads 46 to be assembled with respect to each other, for a purpose that will be described later.Support 40 has a substantialcircular opening 48 therein which is aligned with thecircular opening 50 that is defined in the redrawring 26 and the centers of these openings are located along the path P ofpunch 24.Members shoulder 54 which extends substantially radially from the axis ofopening 48. A support element or cup holdersleeve support member 60 has aperipheral portion 62 which is received into recess 52 and also has a contiguous cooperatingsurface 64 which is in engagement withshoulder surface 54.Support element 60 also has acircular aperture 66, therein, which is generally of the same size asbore 22 incup holder sleeve 20. - According to one aspect of the invention, cup
holder support element 60 andcup holder sleeve 20 are normally centered with respect to opening 48 through centering means which will now be described. In the illustrated embodiment, the centering means consists of four circumferentially spaced biasing means 70 that are equally spaced from each other around the perimeter of the substantiallycircular support 40. The respective biasing means 70 are spaced approximately 90 degrees from each other and produce equal forces around the perimeter ofsupport element 60 to maintain the support element in a centered position with respect to thecircular support 40 more particularlyopening 48. The respective biasing means 70 are identical in construction and only one will be described in connection with Figs. 2 and 3. - Each biasing means 70 consists of a
spring 72 that has one end received into acup 74 which has anannular shoulder 76 cooperating with anenlarged portion 78 of a radial opening insupport 40. The opposite end ofspring 70 engages the inner surface of asupport ring 80 which forms part ofsupport 40. Thesprings 72 are selected so as to produce an equal force andcup 74 is designed so that the inner surface thereof is in engagement with the periphery ofsupport element 60 as illustrated in Figs. 2 and 3. - The
cups 74 are all accurately dimensioned so that when theshoulders 76 engage withsupport 40, the free ends of the cups are on a common circle which has a diameter that is equal to the peripheral diameter of thesupport element 60. However, if external forces are applied tocup holder sleeve 20 which may result from a misfed cup or a defective cup, the springs will accommodate radial movement to prevent permanent misalignment betweenopening 48 and redrawring 26. When the external forces are removed the springs which were compressed will return the sleeve to a centered position. The centering means or biasingspring 70 will, therefore, always accurately positionsupport element 60 in a centered position with respect to opening 48 which is accurately centered withopening 50. - According to a further aspect of the invention, the axis of
bore 22 ofcup holder sleeve 20 can also be tilted with respect to the path P if there is a misfed cup to apply a uniform hold-down pressure at all times. For this purpose,support element 60 has an arcuate orspherical surface segment 90 on the lower surface thereof surroundingaperture 66 and theconcave surface segment 90 cooperates with aconvex surface segment 92 defined on anenlarged portion 100 on the upper end ofcupper sleeve 20. The cooperatingsurface segments cup holder sleeve 20 to allow the cup holder sleeve to assume an angular position wherein the axis ofbore 22 is axially aligned with the axis ofpunch 24. The centers ofspherical surface segments point 95 which is located on path P. -
Flat surfaces spherical surfaces support 40 andcupper sleeve 20, as well assupport element 60. For this purpose,enlarged portion 100 ofcup holder sleeve 20 is received into recess 52 and springbiased tabs 102 are received inrecesses 103 and cooperate with the lower surface ofenlarged portion 100 for biasing the various surfaces into engagement with each other. More specifically, each tab (there being four equally spaced around the perimeter of support 40) has acup 104 secured thereto as by welding and a hold-downspring 106 is telescoped into the cup.Cup 104 is received in an opening 108 inmember 42 and one end of the spring engages the surface onmember 44 which forms part ofsupport 40. - The base of each
recess 103 inmember 42 defines an accurate space between the tab andsurface 54 and such spacing will be maintained even when the spring forces for the respective springs are different. - Thus, each
tab 102 is biased into the position illustrated in Fig. 3 wherein the axis ofaperture 66 and the axis ofbore 22 are aligned with the axes ofopenings cup holder sleeve 20 tilted with respect to the path P ofpunch 24, the tabs will allow a certain amount of tilting movement of thesleeve 20 with respect to supportelement 60. - According to a further aspect of the invention, the various surfaces which are moved relative to each other are continuously lubricated through lubricating means which will now be described. The lubricating means is most clearly illustrated in Fig. 4 and consists of an
opening 110 inmember 42 which has a threadedexterior portion 111 to which a source of pressurized lubricant may be connected. The inner end of opening or bore 110 is in communication with a continuouscircumferential recess 112 that is defined inshoulder surface 54 ofmember 42. Therecess 112 extends around the entire perimeter ofsurface 54 and is also in communication with a secondcontinuous recess 120 insurface 90 through one or moresmall openings 122. Therefore, a continuous flow of fluid from a source (not shown) throughopening 110 will provide a constant supply of lubricant between the relatively movable surfaces of the cup holder sleeve assembly. This arrangement substantially reduces the frictional forces that must be overcome when the various elements have to be moved with respect to each other. Of course, the continuous supply of lubricant to these relatively movable surfaces will also substantially reduce the wear of the overall assembly. - According to another aspect of the present invention, redraw
die assembly 26 is mounted onsupport 30 in a manner that allows radial movement of the assembly with respect to the normal path of movement P ofpunch 24 to allow the assembly to be moved to a centered position with respect to the axis A ofpunch 24, should the punch be offset from the path P. - As illustrated in Fig. 5, redraw
die assembly 26 includes asupport 230 which supports a redrawring 232 that has a circular opening 234.Support 230 has a lowerflat surface 236 which extends perpendicular to path P and is in extended engagement with aflat surface 238 that is defined inframe structure 225. The periphery ofsupport 230 is preferably circular, and centering means 240 cooperate with the periphery ofsupport 230 to normally maintainsupport 230 andring 232 centered with respect to path P. The centering means 240 consists of anannular ring 242 which is held in a fixed position onframe 225 and has a plurality of circumferentially spacedspring assemblies 244 associated therewith. Preferably, at least foursuch spring assemblies 244 are circumferentially equally spaced around the perimeter ofsupport 230 and eachspring assembly 244 includes a plunger 246 reciprocated in an opening 247 extending into the inner surface ofring 242. Plunger 246 has an enlarged flange 248 located in acup 250 with aspring 252 also located incup 250 which biases plunger 246 into engagement with the periphery ofsupport 230. Normally, all plungers 246 are biased to a position illustrated in Fig. 5 wherein the flange 248 of each plunger 246 is in engagement with a surface ofring 242 around opening 247. This arrangement defines an extremely accurate centered position of the opening 234 with respect to path P. However, should there be any misalignment between the axis of the punch and path P, one or more of thesprings 252 will be compressed andsupport 230 moves radially of path P to allow the axis of opening 234 to be aligned with the axis of the punch. During such radial movement, only a selected number, less than all, of thesprings 252 are compressed, while the remaining springs located on the side opposite the direction of movement ofsupport 230 will remain in their prestressed condition illustrated in Fig. 5. This arrangement insures that there is no resistance to having the die ring moved to a centered position with respect to path P after a cup has been forced through redrawring 232 bypunch 24. This arrangement also eliminates the possibility of having the redraw assembly off-center with respect to path P because of varying forces applied by the respective springs. - According to another aspect of the invention, a fluid bearing is interposed between cooperating
surfaces support 230 with respect to path P. For this purpose,support surface 236 has one or moreannular recesses 260 defined therein and recesses 260 are in communication with abore 262 which is defined inframe 225. A supply of pressurized fluid, such as air, is connected to the inlet end ofbore 262 and is delivered to the respectiveannular recesses 260. Since the only exit fromrecesses 260 is along thesurfaces - According to a further aspect of the invention, the redraw die assembly also includes a centered mechanism for centering the
cup 12 with respect to redrawring 232 prior to having the punch enter the cup. This centering mechanism consists of aresting ring 266 that has ar. opening 268 which is larger than opening 234.Nesting ring 266 is held in a fixed position with respect to redrawring 232 through asupport ring 270 which is held in a fixed position with respect to support 230 by sc::ews 272 and thus forms a part ofsupport 230. The diameter ofopening 268 is substantially equal to the peripheral diameter ofcup 12 as it is received by the redraw die assembly and is larger than the diameter of opening 234 so that a portion of the surface ofring 232 is exposed. - Thus, as the cup holder sleeve enters
cup 12 and moves towards redrawdie assembly 26, thenesting ring 266 aids in centering the center of the cup with respect to the center of redrawring 232 beforepunch 14 enterssleeve 20. This movement is in part assured by the fact that the lower peripheral end ofcup 12 normally has a radiusedportion 274 and the radiused portion will aid in guiding the periphery ofcup 12 intoopening 268 of centeringring 266. Of course, if there is axial misalignment between the center ofopenings 268 and 234 with respect to the center or axis ofcup 12, biasing means 240 will allow the entire redraw die assembly to move radially with respect to path P. The diameter ofbore 22 insleeve 20 is slightly larger than the diameter . ofpunch 14 so that redrawdie assembly 26 andsleeve 20 withcup 12 clamped between them can move radially and the center of opening 234 will align with the axis ofpunch 14. - According to a further aspect of the invention, the
nexting ring 266 also incorporates means for sup- -plying lubricant between the exposed surface of redrawring 232, which initially supports the cup and the adjacent surface ofcup 12. As most clearly illustrated in Fig. 7, the lower surface ofsupport ring 270 has anannular recess 280 defined therein andrecess 280 is closed by a surface ofsupport 230 to produce a channel. The channel is in communication with the periphery ofsupport 230 throughopenings 282. A pressurized lubricant is supplied toopenings 282 through an opening 284 inframe 225. Annular recess orchannel 280 is in communication withopening 268 through a plurality of non-radial recesses 288 in one surface ofnesting ring 266 and recesses 288 are circumferentially spaced around the perimeter ofopening 268. The recesses are closed by adjacent surfaces ofsupport 230 and redrawring 232 to produce flow paths. As illustrated in Fig. 7, all of the recesses or flow paths are generally linear and the axes of the flow paths are radially offset from the center of opening 268 innesting ring 266. This arrangement insures that there is non-radial flow of the fluid fromchannel 280 through flow paths 288 intoopening 268. Also, the radiused peripherallower edge 274 of cup 12 (Fig. 5) will cooperate with the upper exposed surface of redrawring 232 and the annular inner surface of opening 268 to produce a small channel for lubricant flow around the perimeter of the cup to all areas of the exposed surface of redrawring 232. - Thus, the lubricant that is received into
annular recess 280 flows through the respective recesses 288 into the channel created by theradius portion 274 and results in a circumferential flow of the lubricant within the channel during the redraw operation. Stated another way, the non-radial recesses or slots 288 distribute the lubricant, which also acts as a coolant, in a vortex pattern across the redraw die surface during the redraw operation. The lubricant also cleans and cools the redraw die surface after the cup has been redrawn. - Each of the
ironing assemblies 28 is generally identical in construction and again provides a floating arrangement for the ironing ring to accommodate radial movement of the ironing ring with respect to the path P and thereby insure more uniform wall thickness of the finished container. The details of one ironing assembly are illustrated in Fig. 5 and include an ironing die 300 that has aland 302 which cooperates with the peripheral surface of thepunch 24 to reduce the sidewall thickness of a cup as it passes through the ironing die 300. Ironing die 300 is supported in a circular support 304 which has arecess 306 for receiving and supportingdie 300. In the illustrated embodiment, the ironing die assembly also has a locator die 310 supported on acircular plate 312 which acts as a guide for the cup as it leaves the ironing die 300.Support 302 andplate 312 have aperipheral band 314 engaging the peripheral surfaces thereof so that the ironing die and locator die 300 and 310 move as a unit when external forces are applied thereto. - The
lower surface 320 ofsupport 312 is in sliding contact with aradial surface 322 defined on a support structure 324 for the ironing die. Likewise, theupper surface 326 of upper ironing diesupport 302 is in sliding contact with aradial surface 328 that is also part of the support 324. The entire ironing dieassembly 28 is again maintained in a predetermined position by a plurality of centering means 330 that are circumferentially spaced around the peripheral surface of ring orband 314 and are carried by support 324. Each centering means or spring assembly includes a cup 332 that has a base thereof in juxtaposed relation to the peripheral surface ofband 314 and has a radially extending flange 334 at the opposite open end thereof. Aspring 336 is telescoped into the cup and the outer end thereof engages acover portion 338 that is removably secured to support 324 through suitable retaining means 340. - Again, preferably there are four
such spring assemblies 330 equally spaced at 90 degrees around the perimeter ofband 314 and are dimensioned such that when flanges 334 engage adjacent shoulders defined on the support 324 the ironing land 304 is accurately centered with respect to the path ofpunch 24. However, if the center of the opening defined by land 304 is slightly offset with respect to the axis of thepunch 24, at least some, but not all, of the spring assemblies will be compressed and allow radial movement of theentire die assembly 28 to center the land opening with respect to the punch and insure a uniform wall thickness for the finished container. - Again, in order to reduce friction and accommodate this radial movement, a fluid bearing is interposed between
surfaces annular recesses 346 that are in communication with an air supply through one ormore openings 348. - While only one such die assembly has been disclosed, it will be appreciated that in most instances more than one ironing die assembly will be used so that a sidewall of a cup will be reduced in thickness in stages to increase the overall efficiency of the system.
- Accoring to a further aspect of the present invention,
stripper assembly 32 is also designed to accommodate radial movement of the assembly with respect to path P during a drawing and ironing operation. Thestripper assembly 32 is illustrated in greater detail in Fig. 6 and includes a stripper support element 410 that has anenlarged portion 412 received into arecess 414 defined insupport 425. A plurality of pivotedjaws 416 are located around the perimeter of path P and the lower edges ofjaws 416 cooperate to define anopening 418 through which the finished container and punch 24 pass during the last part of the stroke of a drawing and ironing process. The respective jaws orsegments 416 are held in a predetermined position through aresilient support member 422 andsupport ring 423 as well as an elastomeric member 424 as illustrated in Fig. 6. The jaws are biased to a position wherein theopening 418 is slightly smaller than the peripheral diameter of the finished container which passes therethrough. Thus, as the container and punch pass throughopening 418, the lower edges of pivotedjaws 416 are moved outwardly slightly to accommodate the movement of the container therethrough. However, after the upper free edge of the container moves beyond the lower edge of the pivotedjaws 416, the jaws will move inwardly into the path of return movement of the upper free end of the container. -
Stripper assembly 32 is again held in a centered position with respect to path P through biasing means 430 which can be identical to the biasing or centering means 240 described above. Thus, should for any reason, the axis ofpunch 24 with the finished container on it be offset somewhat from path P during the downward movement of the punch and container, the biasing means 430 will again accommodate radial movement of the entire stripper assembly with respect to path P to insure that there is no substantial interference between the container and the stripper jaws. Again, support 410 andframe 425 have flat radially extending cooperating surfaces that accommodate such radial movement. This arrangement insures that all of the jaws are located in the same position with respect to the periphery of the punch. This insures that the jaws which engage the free edge will engage across the entire width of the edge for more reliable stripping and less damage to the free edge. - As illustrated in Fig. 6, the lower surface of
enlarged portion 412 has a flatannular surface 432 which is supported on an annular flat surface 434 that is defined onframe structure 425.Frame structure 425 also has an upperannular surface 436 which cooperates with flat upper surface 438 of support member 410. - It has been found that the use of the floating redraw ring and stripper in combination with the plurality of floating ironing assemblies and the floating redraw assembly substantially increases the productivity of a bodymaker of this type and produces containers that have a better finished appearance and have a uniform wall thickness throughout the entire diameter of each container as well as throughout the length thereof.
- As was indicated above, one of the problems in producing satisfactory containers utilizing a process such as that described above, is to maintain extremely accurate alignment between the axis of
punch 14 and the center or axis of domer assembly 34. Any misalignment of these two elements with respect to each other by even a small increment will result in a defect in the end wall of the container which in turn will impair the strength of the container. - According to the present invention, the domer assembly 34 is constructed in such a fashion that the domer element which forms part of the assembly can - readily be moved in any direction radially of the axis or path P to move into a position in exact alignment with the center of
punch 24 should the punch be offset from the path for any reason. For this purpose, domer assembly 34 (Fig. 8) consists of asupport 530 which may be accurately positioned with respect to the remainder of the frame structure of thebodymaker 10 and is supported on a cushion such as air, for axial movement (not shown).Support 530 has a recess oropening 532 extending from theupper surface 534 andrecess 532 has anenlarged portion 536 and a reducedportion 538 with a generally flat bottom wall orsurface 540 defined in the reducedportion 538. The center ofcircular opening 532 is accurately positioned and centered with respect to path P. - Domer assembly 34 also includes a support element or
member 542 which has anenlarged portion 544 received intoenlarged portion 536 ofrecess 532 and a reduced portion 546 with reduced portion 546 having abottom surface 548 which is in extended engagement with bottom wall orsurface 540 forrecess 532.Recess 532 andcarrier element 542 are both circular in cross section andcarrier element 542 is smaller in dimension than therecess 532, as will be described later. - The remainder of domer assembly 34 consists of a domer element or tool 550 which is supported in an
opening 552 incarrier element 542 and is secured thereto by a bolt 554. The threaded bolt or stud 554 extends through an opening 556 incarrier element 552 and is threaded into an opening in the domer element 550 so that thecarrier element 542 and domer element 550 move as a unit in a radial direction with respect to path P. - The domer assembly also includes biasing -
means 560 betweensupport 530 andcarrier element 542. Biasing means 560 consists of four or more circumferentially equally spaced spring assemblies that each consist of a spring 562 having one end received into acup 564 which is reciprocated in abore 566 incarrier element 542 and the opposite end received into a reduced portion ofbore 566. The inner end of eachcup 564 is received into the enlarged portion ofbore 566 and is biased into engagement with the sidewall of the reducedportion 538 ofrecess 532. Thus, the four or more spring assemblies will always maintain the domer assembly, particularly domer element 550, in a predetermined position with respect to the axis or path P. However, should the axis ofpunch 24 be slightly offset from the path P, the various spring assemblies will allowcarrier element 542 and domer element 550 to move radially with respect to the punch and to accurately align itself with the axis of the punch to produce a satisfactory finished container having a reformed end wall of any particular configuration. - According to another aspect of the invention, domer assembly 526 also includes prestressing means cooperating with the respective spring assemblies for insuring that the domer element 550 is always moved to a same exact centered position with respect to path P when the external forces are removed. For this purpose, a circular or
annular ring 570 extends around and is spaced from the periphery of the reduced portion 546 ofsupport carrier 542 and cooperates with the respective spring assemblies to maintain all of the springs in a certain prestressed condition at all times.Ring 570 is accurately positioned with respect tocarrier element 542 by a cooperating offsetportion 572 and arecess 574 respectively defined on thering 570 andcarrier element 542.Ring 570 is releasably secured tocarrier element 542 through a plurality of threadedstuds 576. - With this arrangement, the various springs 562 and
cups 564 can be positioned intoopenings 566 andring 570 can then be telescoped to the position illustrated in Fig. 8 and secured tocarrier element 542 through bolts orstuds 572. The outer free edge of each of the cups, which is generally spherically shaped, thus cooperates partially with the inner surface ofring 570 to maintain all of the springs in a prestressed condition, regardless of variations in spring force. If there is a need for the carrier element to move radially with respect to path P, only a certain number of spring assemblies, less than all, are further compressed, while the remainder of the spring assemblies remain in the same prestressed condition. Thus, when an external force is removed, after the carrier assembly has been moved off its normally centered position, there is no interference by certain springs preventing thecarrier element 542 and domer 550 from moving to the predetermined centered position. - According to a further aspect of the invention, domer assembly 526 also includes fluid means for supplying a bearing fluid between
surfaces carrier element 542 andsupport 530. This fluid supply consists of abore 580 extending throughsupport 530 and in communication at its inner end with an annular recess or opening 582 that extends fromsurface 540. A pressurized fluid supply, such as air, is attached to the outer end ofbore 580 and supplies a constant flow of air to annular recess 582 which must then flow between bearingsurfaces carrier element 542 is attempted to be moved radially of path P. - The
carrier element 542 is releasably retained inrecess 532 by acap 590 secured to support 530 byscrews 592. - It should also be noted that while not specifically shown, lubricating means could also be provided between
surfaces stripper assembly 32, if desired. - In summary, having all the components, except the punch, that come into contact with the cup during the drawing and ironing process movable radially will result in a finished container having a more uniform wall thickness and will minimize tool damage in case of jams.
Claims (10)
Applications Claiming Priority (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US05/900,269 US4193279A (en) | 1978-04-26 | 1978-04-26 | Cup holder assembly |
US05/900,272 US4262512A (en) | 1978-04-26 | 1978-04-26 | Drawing and ironing assembly for bodymaker |
US05/900,270 US4179909A (en) | 1978-04-26 | 1978-04-26 | Domer assembly for ironing machine |
US900272 | 1978-04-26 | ||
US900269 | 1997-07-25 | ||
US900270 | 2004-07-28 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0005084A1 true EP0005084A1 (en) | 1979-10-31 |
EP0005084B1 EP0005084B1 (en) | 1985-07-31 |
Family
ID=27420581
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP19790300714 Expired EP0005084B1 (en) | 1978-04-26 | 1979-04-26 | Apparatus for drawing and ironing containers |
Country Status (2)
Country | Link |
---|---|
EP (1) | EP0005084B1 (en) |
DE (1) | DE2967489D1 (en) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2434666A1 (en) * | 1978-07-24 | 1980-03-28 | Reynolds Metals Co | ARRANGEMENT OF SMOOTHING DIES |
GB2181083A (en) * | 1985-10-04 | 1987-04-15 | Metal Box Plc | Deep drawing apparatus |
US4881394A (en) * | 1987-07-10 | 1989-11-21 | Hoogovens Groep B.V. | Method and apparatus for ironing the wall of a one-piece cylindrical body |
EP0572016A1 (en) * | 1992-05-29 | 1993-12-01 | Toyota Jidosha Kabushiki Kaisha | Process and apparatus for press-forming tubular container-like articles from strip, including forward and backward ironing steps |
GB2301055A (en) * | 1995-05-26 | 1996-11-27 | Metal Box Plc | Containers |
CN109986009A (en) * | 2018-11-30 | 2019-07-09 | 四川奥信紧固件制造有限公司 | A kind of automobile engine tappet body guarantee concentricity processing mold |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE108088C (en) * | ||||
US2528577A (en) * | 1949-05-05 | 1950-11-07 | Remington Arms Co Inc | Metal drawing stripper |
DE1652629A1 (en) * | 1968-02-13 | 1971-03-11 | Kaiser Aluminium Chem Corp | Device for the arrangement of deep-drawing dies |
DE2049686A1 (en) * | 1969-10-09 | 1971-04-15 | The Dunlop Co Ltd , London | Die tool |
DE2357802A1 (en) * | 1973-11-20 | 1975-05-22 | Donald Clifford Grigorenko | Deep drawing very long metal containers - by forming a cup and then reversing the direction of deep drawing |
DE2818379A1 (en) * | 1977-08-26 | 1979-03-01 | Carmet Co | TOOL HOLDER AND DEVICE AND METHOD FOR MANUFACTURING TIN CANS |
-
1979
- 1979-04-26 EP EP19790300714 patent/EP0005084B1/en not_active Expired
- 1979-04-26 DE DE7979300714T patent/DE2967489D1/en not_active Expired
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE108088C (en) * | ||||
US2528577A (en) * | 1949-05-05 | 1950-11-07 | Remington Arms Co Inc | Metal drawing stripper |
DE1652629A1 (en) * | 1968-02-13 | 1971-03-11 | Kaiser Aluminium Chem Corp | Device for the arrangement of deep-drawing dies |
DE2049686A1 (en) * | 1969-10-09 | 1971-04-15 | The Dunlop Co Ltd , London | Die tool |
DE2357802A1 (en) * | 1973-11-20 | 1975-05-22 | Donald Clifford Grigorenko | Deep drawing very long metal containers - by forming a cup and then reversing the direction of deep drawing |
DE2818379A1 (en) * | 1977-08-26 | 1979-03-01 | Carmet Co | TOOL HOLDER AND DEVICE AND METHOD FOR MANUFACTURING TIN CANS |
Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2434666A1 (en) * | 1978-07-24 | 1980-03-28 | Reynolds Metals Co | ARRANGEMENT OF SMOOTHING DIES |
GB2181083A (en) * | 1985-10-04 | 1987-04-15 | Metal Box Plc | Deep drawing apparatus |
GB2181083B (en) * | 1985-10-04 | 1989-11-01 | Metal Box Plc | Deep drawing apparatus |
US4881394A (en) * | 1987-07-10 | 1989-11-21 | Hoogovens Groep B.V. | Method and apparatus for ironing the wall of a one-piece cylindrical body |
EP0572016A1 (en) * | 1992-05-29 | 1993-12-01 | Toyota Jidosha Kabushiki Kaisha | Process and apparatus for press-forming tubular container-like articles from strip, including forward and backward ironing steps |
US5329799A (en) * | 1992-05-29 | 1994-07-19 | Toyota Jidosha Kabushiki Kaisha | Process and apparatus for press-forming tubular container-like article from strip, including forward and backward ironing steps |
GB2301055A (en) * | 1995-05-26 | 1996-11-27 | Metal Box Plc | Containers |
GB2301055B (en) * | 1995-05-26 | 1998-04-01 | Metal Box Plc | Containers |
US5740692A (en) * | 1995-05-26 | 1998-04-21 | Carnaudmetalbox (Holdings) Usa, Inc. | Containers |
CN109986009A (en) * | 2018-11-30 | 2019-07-09 | 四川奥信紧固件制造有限公司 | A kind of automobile engine tappet body guarantee concentricity processing mold |
Also Published As
Publication number | Publication date |
---|---|
EP0005084B1 (en) | 1985-07-31 |
DE2967489D1 (en) | 1985-09-05 |
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