US 3470725 A
Description (OCR text may contain errors)
Oct. 7, 1969 C. J. BROWN ET AL HYDRAULIC SPINDLE PRESS FOR DRAWING METAL Filed July 18, 1966 If I I V 1 il 26 10 Sheets-Sheet l ENTOR ATTORNEYS l0 Sheets-Sheet ATTORNEY5 Oct. 7, 1969 c. .1. BROWN ET AL HYDRAULIC SPINDLE PRESS FOR DRAWING METAL Filed July 18, 1966 Get. 7, 1969 J, BROWN ETAL 3,470,725 HYDRAULIC SPINDLE PRESS FOR DRAWING METAL Filed July 18, 1966 10 Sheets-Shea t 3 INVENTOR ATTORNEYS Oct. 7,1969 c. J. BROWN ET A HYDRAULIC SPINDLE PRESS FOR DRAWING METAL 1O Sheets-Sheet 4 Filed July 18, 1966 FIGS ATTORNEY5 10 Sheets-Sheet 5 lflii? ATTORNEYS C. J. BROWN ET AL HYDRAULIC SPINDLE PRESS FOR DRAWING METAL Filed July 18, 1966 Oct. 7, 1969 2 4 4 Z 27 02 m c a M av Ki 2 r Oct. 7, 1969 c. J. BROWN ET AL 3,470,725
HYDRAULIC SPINDLE PRESS FOR DRAWING METAL Filed July 18, 1966 10 Sheets-Sheet e TIG. 9
6M4 MW .6 W QZMWWJ ATTORNFY5 Oct. 7, 1969 c. J. BROWN ET AL 3,470,725
HYDRAULIC SPINDLE PRESS FOR DRAWING METAL Filed July 18, 1966 10 Sheets-Sheet 7 ATTORNEYS Oct. 7, 1969 c. J. BROWN ETAL HYDRAULIC SPINDLE PRESS FOR DRAWING METAL Filed July 18, 1966 10 Sheets-Sheet 8 M Z M TIGJZA E I 5; INVENTOR ATTORNEYS Oct. 7, 1969 c. J. BROWN ETAL HYDRAULIC SPINDLE PRESS FOR DRAWING METAL l0 SheetsSheet 3 Filed July 18, 1966 Oct. 7, 1969 c. J. BRQWN ET L HYDRAULIC SPINDLE PRESS FOR DRAWING METAL Filed July 18, 1966 .0 Sheets-Sheet 10 R E O P QR w m 9% WQM (J W United States Patent ()fifice 3,470,725 Patented Oct. 7, 1969 HYDRAULIC SPINDLE PRESS FOR DRAWING METAL Charles J. Brown, Greenwich, and Morton Z. Baumgarten, South Nor-walk, Conn., assiguors, by mesne assignments, to Metal Flo Corporation of Ohio, a
corporation of Ohio Filed July 18, 1966, Ser. No. 569,788 Int. Cl. B2111 22/20, 51/26, 28/00 US. Cl. 72-336 22 Claims ABSTRACT OF THE DISCLOSURE Cans for use in the fields above indicated are so shaped that they cannot be nested following fabrication. As a result, they are bulky and expensive to ship and handle prior to being filled and closed. For this reason, it is advantageous to be able to fabricate the cans from coiled sheet metal stock in the plant of the processor. To that end the present invention is well adapted as (l) the improved apparatus may be readily fabricated in any reasonable multiple of spindles to provide the desired hourly production of cans, (2) the apparatus requires a minimum amount of floor space, (3) it permits the use of thin gauge material without sacrificing strength, and (4) it provides over eighty percent utilization of the sheet material in the fabrication of the cans.
Broadly stated, in structural detail the invention, in its preferred form, contemplates a vertical hydraulic press comprising a plurality of tool sets so arranged that a sheet metal strip passed between the upper and lower sections of the press is fabricated with a maximum utilization of the strip material. The tool sets are preferably in the form of axially aligned with a plurality of axially aligned and spaced dies whereby the sheet material is capable of being deep drawn during a single continuous stroke of the press.
More specifically, the nested punches are disposed for relative movement in fluid structure defining the upper section of the press while the axially aligned and spaced dies are mounted in fixed structure defining the lower section of the press. Each tool set is independently mounted in the upper and lower sections of the press with the number of tool sets determined by the number of cans desired each stroke of the press.
The nested or telescoping punches of each tool set are an intimate part of the hydraulic spindle assembly and preferably constitute extensions of piston-ram eletrnents which are supported for relative axial movement in a fixed housing in the upper section of the press and which, under the actuation of fluid pressure, provide the nested punches with sequential movement relative to each other and to the dies in the lower section. The piston-ram elements, on which the nested punches are carried, telescope with one another an dare preferably disposed with in a fixed housing located in the upper section, the housing functioning as a cylinder for the outermost pistonram element with each of such elements, in turn, having the dual function of acting first as a piston and then as a cylinder wall, as the sequential movement of the elements takes place, to impart a corresponding sequential movement to the nested punches carried thereby.
Associated with certain of the piston-ram elements of the individual hydraulic spindles of each tool set are one or more stops, preferably adjustable, which enable the punches carried upon each of such elements to perform the dal function of drawing the metal, as well as acting as a hold-down for the following forming operation. In the illustrated embodiment of the invention, These stops radially project through clearance slots in the telescoping piston-run elements to engage each other as well as to engage, directly or indirectly, with fixed structure in the upper section of the press. A fixed piston guide or core, located within the telescoping assembly of the pistonram elements of each hydraulic spindle, is of step down construction and functions as fluid pressure conduit means as well as means enabling retraction of the elements and their associated punches at the completion of the down stroke of the press.
While it is considered that the present invention embodies many of the basic concepts of copending application Ser. No. 362,004, filed Apr. 23, 1964, it is deemed to provide many advancements thereover through simplification of the hydraulic actuating and control system of said copending application with accompanying compactness of structure, one of the principal improvements being deemed to reside in the use of a slightly deformable resilient pad for supporting the drawing dies where telescoping punches engage rigid stops when functioning as hold-downs.
Thus, an object of the invention is to provide a highproduction apparatus for the deep drawing of seamless cans and similar products in which a plurality of tool sets are independently supported and actuated in fixed punch and die section to simultaneously blank and form a plurality of cans from strip material passed between the sections.
Another object of the invention is to provide a compact, hydraulically actuated high-production apparatus for the deep drawing of seamless cans, or the like, in which nested punches are axially aligned with a plurality of axially aligned and spaced dies to effect the blanking and forming of the can in a single continuous stroke of the apparatus in a novel manner.
Another object is to provide a high-production, deep drawing apparatus comprising a cluster of independently supported and actuated hydraulic spindles each having telescoping piston-ram elements carrying nested punches which are axially aligned and sequentially actuated relative to axially aligned and spaced dies.
A further object is to provide an improved fluid spindle for the sequential operation of a plurality of telescoping punches in a metal forming apparatus in which each punch is attached to a piston-ram element, each telescoping element having a radially extending surface against which fluid pressure is exerted to effect relative axial movement of the elements as well as having an axially extending surface to define in part a fluid pressure chamber in which a radially extending surface of an adjacent element is disposed.
A still further object of the invention is to provide a fluid spindle for the sequential operation of a plurality of telescoping metal-forming elements, each element having a radially extending surface of different area subjected to fluid-actuating pressure.
A still further object is to provide a fluid spindle for the sequential axial operation of a plurality of telescoping metal-forming elements, there being radially extending stop means on the elements to control their axial movement.
Another object of the invention is to provide a fluid spindle of a metal-forming machine tool having a fixed outer housing and a stepped fixed core, there being a plurality of telescoping tool-carrying elements disposed within the housing and embracing the core.
Another object is to provide an improved fluid press for the drawing of cylindrical containers and the like from strip metal, the press having a fluid spindle section and a die section, each spindle of the spindle section having telescoping punches for blanking and drawing a container, and "each spindle comprising a cylindrical fixed housing approximating, in its major diameter, the diameter of the blank to be sheared from the strip metal and being arranged in a cluster with the longitudinal axis of each spindle in parallel arrangement.
A still further object is to provide, in combination with a pair of telescoping punches for drawing metal having rigid stops for controlling the position of one of the punches relative to a draw die to enable the punch to act as a hold-down, of a. draw die supported on a rigid base and having a slightly deformable, resilient pad disposed between the base and the die.
A still further object is to provide an improved hydraulic spindle having a plurality of fluid pressure actuated, concentrically disposed piston-ram elements carrying telescoping punches for drawing metal, at least one of the elements being subjected to continuously acting fluid pressure for returning to and retaining all of said elements in retracted position and all of said elements being sequentially operated by fluid pressure from their retracted position.
These and other objects and advantages of the present invention will become apparent from the following description and the appended claims.
Referring to the drawings,
FIG. 1 is an elevational view of a fluid press embodying the present invention, taken from one side.
FIG. 2 is a fragmented elevational view of the press of FIG. 1 taken from another side,
FIG. 3 is a plan view taken on line III-III of FIG. 1,
FIG. 4 is a vertical section taken on line IV-IV of FIG. 3,
FIG. 5 is a plan view of the spindle section taken on line V-V of FIG. 1,
FIG. 6 is a fragmentary vertical section of the can-handling chutes,
FIG. 7 is a fragmentary vertical section of a set of tools located in the lower portion of the upper spindle section and in the lower die section,
FIG. 8 is a view of one of the stripper machanisms taken on line VIIIVIII of FIG. 7,
FIG. 9 is a horizontal section taken on line IX--IX of FIG. 1 showing the underside of the plate supporting the blanking die assembly of each spindle,
FIG. 10 is a horizontal section taken on line XX of FIG. 1 showing the perforation of metal strip and the location of the spindles of the spindle section.
FIGS. 11A and 11B constitute a two-part fragmentary vertical section of a spindle shown in its up position,
FIGS. 12A, 12B and 12C constitute a three-part fragmentary vertical section of the spindle of FIGS. 11A and 11B shown in its fully extended or down position,
FIG. 13 is a broken, side-elevational view, partly shown in cross-section, of the piston guide or core,
FIG. 14 is a cross-sectional view of a spindle taken on line XIV-XIV of FIG. 1,
FIG. 15 is an enlarged fragmentary view showing a punch functioning as a hold-down for the can being drawn, and
FIG. 16 is a diagrammatical layout of a simplified control circuitry for a single spindle press embodying the present invention.
In the illustrated embodiment of the invention, FIG. 1 shows a press 10 having a base 12. supported on a suitable foundation 14. A plurality of fluid spindles 16 constitute the spindle section 17 of the press 10, being supported at their lower ends in headplate 18 of the die section 20. Ten spindles 16, in the illustrated form, are shown so clustered in the plate 18 that the strip of material 22 being indexed through the press 10 by suitable strip-feeding mechanism will be economically blanked as shown in FIG. 10, the fully perforated portion of the strip being indicated at 22'.
SPINDLES The spindles 16 are preferably identical and interchangeable in construction when it is desired to produce ten identical cans 23 each stroke of the press 10. Only one spindle 16 will be hereinafter described, it being understood that a single spindle may constitute the entire press without departing from the invention. As each spindle 16 is independently mounted and independently actuated from a suitable source of fluid pressure, the fluid pressure actuating system for operating all the spindles 16 in unison may take many forms and constitutes no part of the present invention.
Each spindle 16 comprises a fixed housing 24, preferably of stepped cylindrical form having an upper tubular part 24' and a lower tubular part 24. Secured to the top of the part 24 is a flange 26 of a piston guide or fixed core 28 (shown removed from the parts 24 and 24" in FIG. 13). At its lower end a fluid sealing plug 30 is threadedly attached at 32. Core 28 is shown with five axially extending passages for conducting actuating fluid to and from the spindle 16. Passage 34 extends from the upper end of the core 28 to a cross port 36 located between the stepped sealing ring portions 38 and 40. Passage 42, likewise, extends from the upper end and terminates at the cross port 44 between the stepped sealing ring portions 40 and 46. Passage 48 extends from the upper end of the core 28 to the cross port 50. Passage 52, in a similar manner, extends to the port 54, While the central passage 56 extends the full length of the core 28, being sealed off at the lower end by the sealing plug 30. Cross ports 58 open into the passage 56. Sealing ring assemblies 60 formed of static O-section sealing rings and double delta Teflon dynamic sealings rings, disposed in suitable grooves, are indicated in the portions 38, 40 and 46 and plug 30.
CYLINDER PISTON-RAM ELEMENTS Fixed portions 24' and 24 of each spindle 16 are preferably welded to each other at the location of the ring 24". Within the fixed housing, thus defined, are telescoping tubular elements 62, 64, 66 and 68, the upper portions 62, 64, 66 and 68 Of which function as cylinder walls as well as pistons while the lower portions 62", 64", 66" and 68" are of increased diameter and act as rams, the upper and lower portions of the elements 62, 64 and 66 being preferably welded together by rings 70 corresponding in purpose to the ring 24'. Sealing rings 72 are indicated as disposed between element 62 and the interior wall of part 24', between element 64 and the interior wall of element 62, and between element 66 and the interior wall of element 64 and core 28. At their lower ends the portions 62", 64 66 and 68 carry bearing and tool portions as hereinafter described.
FLUID PISTONS Cross port 36 of the core 28 opens into an annular chamber 74 (see FIG. 11B) defined in part by a radial surface constituting one end of the tubular element 62 which functions as a piston in the annular chamber 74 defined by the interior wall of the part 24 and the interior surface of the core 28. The cross port 44 of the core 28 opens into an annular chamber 76 defined in part by a radial surface constituting one end of the tubular element 64 which, like the element 62, functions as a piston in the annular chamber 76 defined by the interior wall of the element 62 and the exterior surface of the core 28.
In a similar manner, the cross ports 50 and 54 of the core 28 open into the annular chambers 78 and 80 in which the elements 66 and 68 function as pistons, respectively.
Fluid pressure in each of the annular chambers 74, 76, 78 and 80 act to displace the elements 62, 64, 66 and 68, in their function as pistons, downwardly from the position shown in FIGS. 11A and 11B, which is the up or retracted position, into the down or projected position shown in FIGS. 12A, 12B and 12C.
STOP MECHANISM In order to control the extended or down position of each of the telescoping elements 62, 64 and 66, adjustable stops 82, 84 and 86 are attached to the lower portions 62", 64" and 66", respectively. As shown, each element 64 and 66 has three stops spaced at 120 about its circumference and, in the case of the stops 84 and 86, radially projecting through axially extending clearance slots 88, 90 and 92 in the embracing structure. Element 62 has four stops spaced at 90 about its circumference. Each stop has an adjustable abutment 94 in the form of a screw.
As more clearly shown in FIG. 11A, the elements 62, 64, 66 and 68 are moved into and retained in the up or retracted position by fluid pressure from the passage 56 being directed through the cross ports 58 into the annular chamber 96 where it reacts against the radial surface 98 of the element 68. With the element 68 fully extended in the down position of FIG. 12A, the fluid pressure in the chamber 96 will cause the element 68 to move vertically bringing the shoulder 100, cushioned by the washer 102, into engagement with the radial surface 104 of the element 66. The elements 66 and 68 then move upwardly in unison to bring the shoulder 106, cushioned by the washer 108, into engagement with the radial surface 110 of the element 64. As the element 64 rises in unison with elements 66 and 68, the shoulder 112, cushioned by the washer 114 engages the surface 116 of the element 62 to lift the elements 62, 64, 66 and 68 in unison until all vertical movement is arrested by the shoulder 118 abutting the stack of cushioning washers 120, the top washer 120 of the stack seating against the radial surface 122 of the fixed housing of the spindle 24.
SPINDLE SECTION TOOLING In the illustrated form of the invention, the metal-forming tools carried by each spindle 16 are either attached to or an integral part of the ram portions 62", 64", 66" and 68".
Portion 62" has the blanking assembly 124 threadedly attached at 126. Portion 64" has the draw punch 128 threadedly attached at 130. The first redraw punch 132 is preferably silver-soldered to the portion 66". Second redraw and ironing punch 134 is threadedly attached to the ram portion 68" at 136. Bearing portions carried by the portions 62", 64" and 66 are indicated at 138.
DIE SECTION TOOLING The top or headplate 18 of the die section of the machine has counterbores 140 in which the lower ends of each spindle 16 is received and supported in axial alignment with the drawing and ironing dies of the plates 142, 144 and 146. In the illustrated embodiment, the base plate 148 carries the dimpling dies 150 supported upon a perforated shuttle member 152 which is actuated in a plane normal to the longitudinal axis of the spindles 24 to shift dies 150 from axial alignment with the spindles 16 into an offset position to axially align the spindles 16 with the openings 154 in the member 152 in time to permit the cans 23, being stripped from the punches 134 of the innermost elements 68", to fall by gravity through the openings 154 into the tubes 156 and then upon the moving conveyor 158.
As shown in FIGS. 7 and 11A, the pressure pad and blanking die assembly 124 is threadedly attached at 126 to the portion 62", the pilot portion 160 being closely fitted to the cylindrical portion 162 of the ram portion 62". Assembly 124 comprises a shear punch having parts 164 and 166 piloted for slight relative axial movement on the bushing 168. Between spaced radial shoulders 170 and 172 on the parts 164 and 166, respectively, is an annular pad 174 of suitable shock-absorbing material capable of retaining its resiliency under high-compression forces in the order of 1500 pounds per square inch, with set and creep in the order of 2% of the original thickness. Pads of rubber-impregnated, closely woven, light weight cotton duck having a Shore durometer hardness in the order of 90, such as sold under the trademark Fabreeka, have proven satisfactory for the purpose hereinafter described. Cap screws 176 hold the parts 164 and 166 assembled and act to preload the pad 174. An adjustment shim 178 is shown between the pad 174 and the shoulder 172. A suitable hold-down pad for the strip material 22 from which the workpieces are blanked is shown at 182 piloted on the punch portion 116. Springs 184, nested in opposed pockets 186 and 188, and bolts 190 hold the pad 182 in operative relation, in a well-known manner.
The shear die 192 is piloted on the draw die ring 194 which, in turn, has a slightly undersized pilot portion 196 located in the counterbore 198 of the bore 200 in the plate 142. This enables the shear die 192 to adjust itself to the shear punch part 166. Cap screws 202 function to hold the die 192 in its adjusted position. A draw die 194 is removably supported by the die 192 on the plate 142. Adjustment shims are shown at 204 and 206. Located within the counterbore 198 is the first redraw die 208 supported on a pad 210, preferably of material similar to the pad 174. A spacer 212 is disposed between the die ring 194 and the die 208.
Axially aligned with the first redraw die 208 is the second redraw die 214 disposed in the counterbore 216 of the bore 218 of plate 144. A pad 220, similar to the pad 210, supports the die 214. A ring 222 and cap screws 224 retain the die 214 in the counterbore 216. Adjustment shims are shown at 226 and 228. An ironing die 230 is shown supported on plate 146 within the counterbore 232 of the bore 234. On the under side of the plate 146, suitable stripper mechanism 236 is provided to strip the can from the inntermost punch 134 of the spindle 24. As shown in FIG. 8, the stripper mechanism comprises a pair of hinged members 238 which yield to the can on the punch during the down stroke of the press. After the can on the punch has cleaned the members 238 on the down stroke, they spring back into engagement with the punch above the can. Thereafter, on the up stroke of the press, the arcuate edges 2400f the members 238 engage the top edge of the can to strip the can from the punch 134.
With shuttle plate 152 in the position shown in FIG. 7, each can bottom-detailing die 150 will be axially aligned with the punch 134. As the end of the down stroke of the punch 134 is approached, the bottom of the cam engages the die 150 to move the same against the tension of the spring 242. When the shock pad 244 arrests further movement of the die 150, the concave end of the punch 134 will detail the can bottom as the down stroke of the press is completed.
SHUTTLE MEMBER The shuttle member 152, shown in FIGS. 3 and 4, is in the form of a plate held to the surface of the plate 148 by ways 246. A cylinder 248, attached to the plate 148, has a piston rod 250 connected to a flange 252 attached to the member 152 for shifting the member 152 back and forth to alternately align the die 150 and holes 154 with the longitudinal axes of the spindle 16. When the punches of spindle 16 are being retracted to strip the cans 23 from the punches 134, the cylinder 248 is energized to shift the member 152 to the right, as viewed in FIGS. 3 and 4. This will dipose the holes 154 directly below the punches 134 and directly above the top openings 254 of the chutes 156 whereby the cans 23 being stripped from the punches 134 will fall by gravity into the chutes 156 and directly on the channels 256 of the flexible conveyor belt 153 (see FIG. 6). Suitable bumpers 257 on plate 148 engage abutments 257' on the member 152 to define the limit of movement of the member 152 by the cylinder 248.
The plates 18, 142, 144 and 146 of the die section 20 are all supported from the base plate 148 on channelshaped spacers 258 of selected length to provide the desired distance between the plates. The spacers 258 embrace the posts 260 upon which the plates are aligned. Bolts 262 retain the spacers in place against removal by lateral movement. With this arrangement, the length of the spacers 258 may be changed and the spacing of the plates 142, 144 and 146 varied without removing the same from the posts 260.
SPINDLE MOUNTING To mount a spindle 16 of the spindle section 17 in a counterbore 140 of a bore 141 of the plate 18, the blanking assembly 124 is removed from the threaded attachment at 126 and the lower portion 24" of the spindle 16 is lowered into the counterbore 140 and secured in position by cap screws 266. The assembly 124 is then threadedly attached at 126 from the underside of the plate 18. Stop plates 268 are located 120 apart in the counterbore 140 and received in the slots 88 of the portion 24" of the housing 24. Cap screws 270 hold the plate 268 in position. In FIG. 12A the stop 86 on the ram portion 66" is shown abutting the stop 84 on the ram portion 64" with the stop 84, in turn, abutting the stop plate 268.
PUNCH HOLD-DOWN To enable the punch portions 128, 132 and 166 to function as hold-downs relative to the draw dies 208, 214 and 194, respectively, rigid abutment structure, in the form of the stops 82, 84 and 86 and stop plates 268, is provided to arrest the movement of the portions 62", 64 and 66 to squeeze the deformable pads 174, 210 and 220 a predetermined amount to grip the can 23 between the punch portion 166 and the die 194 and the punch portion 128 and the die 208 and the punch portion 132 and the die 214. This arrangement will be best seen in FIG. wherein the punch portion 128 is shown deflecting the die 208 squeezing the pad 220 and the punch portion 132 is shown drawing the can 23 over the die 208. With the punch portion 128, as shown in FIG. 15, the adjustment screw 94 of the stop 84 will be engaging the stop plate 268, as shown in FIG. 12A.
The use of deformable pads, such as the pad 220 in FIG. 15, relieves the heretofore requirement of critical adjustment of a predetermined space between punch 128 and its die 208. For example, if the adjustment screw 94 of the stop 84 is set to produce too great a gripping force on the can 23 between the punch 128 and the die 208, the descending punch 132, pulling on the can 23, deflects the deformable pad 220 still further, thus relieving the too great a gripping force. Therefore, it can be understood that the selection of the material of the pad 220 is important in determining the drawing characteristics of the can 23. Also, variations in can material thickness become less significant because the pads provide automatic compensation. Still another advantage provided by the pads is that they dampen the shock of the punch impacting against the die.
The use of pads 174, 210 and 220 in combination with the adjustable stops 82, 84 and 86, has been found particularly advantageous with thin gauge sheet metal. With .010 sheet steel, deflection of the pads in the order of .040" with the Shore durometer indicated above has been found necessary to prevent wrinkling during the drawing operation. Thus, the adjustment screws 94 on the stops 82, 84 and 86 would not engage their rigid abutment until deflection of the drawing dies and pads exceeds that required to prevent wrinkling. Should the press be cycled without a workblank in the dies, the punches would,
nevertherless, contact and deflect the dies along with the pads before the screws 94 would engage their rigid abutments. Also, the pads absorb the impact of the punches on the dies with or without a workpiece in the press. At the same time the screws 94 protect the pads and workblank from the full effect of the available fluid pressure action of the piston-ram" elements. In practice, it has been found that when there is sufficient deflection of the dies and pad to draw without wrinkling, commercial variation in thickness of the sheet stock will automatically be compensated for without any difficulty. Should the material of the pads take a slight set during a long production run, the screws 94 need only be slightly adjusted to compensate for this condition. As will be obvious, by changing the Shore durometer of the material from which the pads are fabricated, the amount of deflection of the drawing dies and pads to effect wrinkle-free drawing of the can 23 may be varied.
SEQUENTIAL OPERATIONS Communicating with the passages 34, 42, 52 and 56 of the core 28 of FIG. 13 are hydraulic lines 34', 42', 52' and 56, respectively, extending to suitable sources of fluid pressure. For example, the lines 34', 42', 48, 52 and 56' may be connected to a relatively high-pressure fluid source to effect the blanking, drawing, ironing and retracting operations by the piston-ram elements 62, 64, 66 and 68.
Preferably, the sequential introduction of high-pressure fluid into the chambers 74, 76, 78 and 80 will be under control of suitable sequence valve structures which are triggered by the pressure build up which resutls when movement of the piston-ram elements are arrested by the stop mechanism 82, 84 and 86.
It will be noted that the area of the piston-ram element exposed to the fluid pressure in chambers 74, 76, 78 and 80 is greatest in the chamber 74 and decreases progressively as the diameter of the core 28 is decreased, with the smallest area being exposed in the chamber 80. This decrease in area is directly related to the power requirement for the series of operations being performed during the single continuous stroke of the press. The piston-ram element 62, which performs the blanking operation, requires the greatest amount of power and it has the largest exposed area in chamber 74. The ironing operation is carried out by element 68 and requires the least amount of power and it has the smallest exposed areas in chamber 80.
In practice, when fabricating the beverage cans 23 from .010 sheet steel, it has been found satisfactory to employ a source of fluid pressure of 3500# psi. to perform the blanking, drawing and ironing operations with a back pressure of 500# p.s.i. being continuously present in the chamber 96 and acting on the radial surface 98 of the element 68 to hold the punches 128, 132 and 134 in the retracted nested arrangement shown in FIG. 11A during the sequential projection of the elements 62, 64, 66 and 68 and the structure associated therewith. For example, the admission of fluid at 3500# p.s.i. into the chamber 74, through the line 34 and passage 34 to effect downward displacement of the element 62 and blanking of the strip 22, is carried out against the fluid at 500# p.s.i. continuously present in the chamber 96.
It will be understood that the chambers 74, 76 78 and 80 must be filled with fluid at all times. Thus, when the operating pressure for eflecting the blanking operation is admitted to the chamber 74, movement of the element 62 as a piston by the operating pressure directed against the end of the element 62 will enlarge the chambers 76, 78 and 80 and the fluid to fill the same i drawn from a suitable pressurized reservoir.
When the movement of the element 62 by the 3500# p.s.i. operating pressure has effected the blanking of the strip 22 by the die 166, and the stop screw 94 of the stop mechanism 82 has engaged the hold-down ring 182, the pressure buildup which takes place in the fluid pressure system communicating with the line 34' will rise until the pressure setting of the first draw sequence valve is reached to open the valve and direct the operating fluid into the chamber 76 to effect relative movement between the elements 62 and 64 to project the element 64 and its punch portion 128 to draw the blank in the draw die 194. At the same time the operating pressure in the chamber 74 is acting upon the shear die 166 to maintain the adjustment screws 94 of the stop 82 against the ring 182 so that the pad 174 may provide the predetermined hold-down force to prevent the blank from wrinkling while it is being drawn by the punch portion 128. Movement of the element 64 and punch portion 128 continues until the adjustment abutment screw 94 of the stop 86 engages the stop plate 268 and arrests further downward movement to locate the punch portion 128 a predetermined distance from the first redraw die 208 whereby the portion 128 is in position to act as a holddown.
When the plate 268 is engaged by the screw 94 of the stop 86, the pressure in the fluid system communicating with the line 42 and passage 42 will rise until the pressure setting of the first redraw sequence valve is reached to open the valve and direct the operating fluid into the chamber 78. This causes the element 66, carrying the punch portion 132, to move downwardly relative to the element 64 to draw the can 23 upon the first redraw die 208, as shown in FIG. 15. Continued downward movement of the portion 132 takes place to complete the first redraw until the adjustable abutment screw 94 of the stop 86 engages the stop 84 to effect predetermined clearance between the punch portion 132 and the second redraw die 214 for the same reasons given above in regard to the punch portion 128. (See FIG. 12A.) The rise in fluid pressure thereafter, in the fluid system communicating with the line 48 and passage 48, will cause the second draw sequence valve (for the same reasons stated above) to direct operating fluid pressure into the chamber 80 against the end of the element 68 to cause the same to move downwardly relative to the element 66 to draw the can 23 in the second redraw die 214. After the can 23 leaves the die 214 on the punch 134 it is carried on through the ironing die 230 and the bottom of the can 23 is detailed by the termination die 150, as shown in FIG. 12A.
The pressure rise in the chamber 80, which results from the die 150 engaging the shock pads 244, may be employed to reduce the operating pressure on the elements 62, 64, 66 and 68 so the introduction of high-pressure fluid into chamber 98 Will be able to effect the up stroke of the press to strip the can 23 from the punch 134 and to return each of the elements 62, 64, 66 and 68 to their fully nested position shown in FIG. 11A.
The pressure rise in chamber 80, which occurs at the end of the down stroke of the press, may also be employed to energize the piston 248 to shift the plate 152 and die 150 to expose the chutes 156 to the cans 23 being stripped from the punch 134. With the spindle 16 in the position of FIG. 11A, the strip 22 is advanced slightly more than twice the diameter of the blank and the cylinder 248 is energized in the opposite direction to return the plate 152 and die 150 to the position of FIG. 4. A new cycle of operation of the press may now be initiated.
In FIG. 16 is shown a simplified diagrammatic layout of the control circuitry suitable for the sequential operation of any one of the spindles 16 carried out in timed relation to the handling of the completed can 23 and the feeding of the strip stock 22.
To adapt the ten-spindle press to the control mechanism of FIG. 16 it is only necessary to provide manifold structure for extending the fluid pressure to all ten spindles of the press, as will be readily understood.
Referring to FIG. 16, the fluid reservoir 270 is connected to the inlet of the centrifugal pump 272 which,
in turn, discharges through the filter 274 into the fixed displacement pump 276 connected to the high-pressure supply line 278. A relief valve 280 connects the line 278 with the return line 282 for conducting the fluid to the reservoir 270. Located in the line 278 is a check valve 284, an accumulator 286 and a suitable throttle valve 288.
A two-position, double solenoid, pilot-operated, directional valve 290 is located in the line 278. In one position of the valve 290, fluid pressure flows in the line 278 to the needle valve 292 and, thence, to the passage 34 of the spindle 16 to provide high-pressure fluid in the chamber 74 to actuate the piston-ram element 62 carrying the shear punch parts 164 and 166.
A sequence valve 294 is located in the line 296 extending between the line 278 and the line: 298. When the down stroke of the element 62 is arrested by the stop 82, the fluid pressure in the line 278 will build up to exceed the setting of the sequence valve 294 whereupon the pressure of the line 278 is directed by the valve 294 into the line 298, past the needle valve 300 and into the passage 42 of the spindle 16 to provide high-pressure fluid in the chamber 76 to actuate the piston-ram element 64 carrying the draw punch 128.
In the line 302, extending between the lines 298 and 304, is a sequence valve 306 similar to the valve 294 and performing a similar function. When the stop 84 on the element 64 arrests the down stroke of the element 64, the pressure buildup in the line: 298 will exceed the setting of the valve 306 and high-pressure fluid will be directed into the line 304, past the needle valve 308 and into the passage 48 and chamber 78 to actuate the pistonram element 66 carrying the first redraw punch 132.
A sequential movement of the element 68, carrying the second redraw and ironing punch 134, takes place in the same manner as described with reference to the punch 32. In the line 310, connecting the lines 304 and 312, is a sequential valve 314. When the down stroke of the element 66 is arrested by the stop 86, the pressure setting of the valve 314 is exceeded and high-pressure is directed into the line 312, past the needle valve 316, into the passage 52 of the spindle 16 and, thus, to the chamber 80 to actuate the element 68.
To supply the chambers in which the elements 62, 64, 66 and 68 operate with fluid and to provide a back-pressure which will hold the punches in their nested position, a low-pressure accumulator 318 is provided, along with a back-pressure relief valve 320, both located in the line 322 connected with the return line 282. Pilot-operated check valves 324, 326 and 328 will permit the fluid pressure in the accumulator 318 to supply the chambers in the spindle 16, during the down stroke of the press through the lines 298, 304 and 312. When its sequence valve 294 opens to direct high-pressure fluid into the line 298, the valve 324 will act to check the high-pressure fluid from entering the line 322 and flowing past the valve 320 to the return line 282.
With the valve 290 in the position just described, the line 330, extending to the passage 56, exhausts fluid from the retraction chamber 96, during the down stroke, past the needle valve 332, through the pilot-operated check valve 334 and relief valve 320 to the return line 282. Pilot lines 336 subject the pilots 338 to fluid pressure of the line 330, it being understood that the springs 340 resist actuation of the pilots 338 by the back pressure of the accumulator 318.
To start the up stroke of the press, the valve 290 is shifted into its other position which directs high-pressure fluid from the line 278 into the line 330 to overcome the springs 340 to exhaust fluid from the passages 42, 48 and 52 to the return line 282 as well as to direct high-pressure fluid into the retraction chamber 96 to raise the element 68 to strip the can 23 from the punch 134. As the element 68 is raised, the surface 102 will engage the surface 104 to cause the element 66 to move up in unison with the element 68. When the surface 108 engages the surface 110 of the element 64, the element 64 will then move up in unison with elements 66 and 68. When surface 114 engages the surface 116, the element 62 will move in unison with elements 64, 66 and 68 until the upward movement of all the elements is arrested when the surface 118 engages the surface 120 at the top of the upward stroke of the press.
Throughout the down stroke of the press, the fluid in the chamber 96 must be discharged through port 58 and passage 56 to the lines 330, 322 and 282 to the reservoir 270. This is accomplished by the high-pressure fluid in the line 342 connecting with the line 278 overcoming the spring 340 of the pilot-operated check valve.
Any suitable mechanism may be employed to properly time the movement of the strip stock 22 and the shifting of the plate 152 by the cylinder 248 during the cycle of operation of the press. In FIG. 16, one arrangement for timing the actuation of the strip stock feed and the plate 152 is diagrammatically shown and described as follows:
When the die 150 is depressed by the punch 134, it will actuate the limit switch 346 to energize the solenoid 348 to shift the valve 290 to direct high-pressure fluid into the retraction chamber 96, as well as to energize the timedelay relay 350. This causes the piston-ram element 68 to come to a stop and begin its return stroke. Further, it opens lines 278, 298 and 304 to the reservoir 270 to enable the Denison sequence valves 294, 306 and 314 to reset themselves for the next cycle of operation.
After sufficient time has elapsed to permit return of the die 150 to its starting position, the time-delay relay 350 times out energizing the solenoid 352 of the double solenoid, two-position, directional valve 354, shifting the valve 354 to direct high-pressure fluid from the line 278 through the lines 356 and 358 to the piston side of the cylinder 248 to shift the plate 152 to align the chute 156 with the center line of the spindle to enable the cam 23, being stripped from the punch 134, to drop by gravity into the chute 156.
During the retraction or up stroke of the press, the stop 86 on the element 66 engages the limit switch 360 which, in turn, energizes the feed for the strip stock 22, as well as the time-delay relay 362. After a sufficient time to permit stock indexing, the time-delay relay 362 times out energizing the solenoids 364 and 366 to direct high pressure fluid from the line 278 through the lines 356 and 368 to the piston rod side of the cylinder 248 to shift the plate 152 in the opposite direction to return the die 150 to the center line of the spindle 16, as well as to initiate the downstroke of the press by directing highpressure fluid into the passage 34 and the chamber 74 of the element 62 carrying the blank assembly 124.
1. A set of tools for the deep drawing of tubular metallic parts and workpieces comprising axially aligned telescoping inner and outer punches and axially aligned inner and outer dies, said punches being tubular and axially slidable relative to each other, a fixed core disposed within said punches, said inner punch having a first radial portion defining a first annular piston embracing said core and having fluid sealing sliding relation with one portion of said core, said outer punch extending axially beyond said inner punch and having a second radial portion defining a second annular piston embracing said core and having fluid sealing sliding relation with another portion of said core axially spaced from said one portion, a first annular fluid pressure piston chamber defined by said core and said outer punch in which said first annular piston is disposed, first means defining with said another portion of said core a second annular fluid pressure piston chamber in which said second annular piston is disposed, and second means for directing fluid pressure into said piston chambers to move said punches relative to said core and to said die in one axial direction.
2. A set of tools as defined in claim 1 wherein at least one of said punches carries stop means for restricting its movement relative to one of said dies.
3. A set of tools as defined in claim 1 wherein said stop means is located on the outer punch of said telescoping punches.
4. A set of tools as defined in claim 1 wherein said stop means are located upon both punches.
5. A set of tools as defined in claim 4 wherein one of said stop means engages the other upon sequential actuation of said punches relative to said dies.
6. A set of tools as defined in claim 4 wherein the stop means on the inner punch radially projects into the path of movement of the outer punch, there being clearancedefining means in the outer punch for said stop means of said inner punch.
7. A set of tools as defined in claim 1 wherein said inner punch has a second radial portion and said core has a conduit portion for directing fluid pressure against said second radial portion of said inner punch to move said inner punch in the opposite axial direction.
8. A set of tools as defined in claim 1, wherein said first means takes the form of a fixed housing for said punches, said housing confiningfluid pressure directed against the outer of said punches, and sealing means between said housing and said outer punch.
9. A set of tools as defined in claim 7 wherein said punches have associated means for retraction of all the punches upon movement of said inner punch in said opposite direction.
10. A high-production, hydraulic press for multiple, simultaneous manufacture of similar deep drawn cans from a sheet metal strip comprising a hydraulic punch section and a die section, means for feeding a metal strip between said sections each stroke of the press in an amount slightly in excess of twice the width of each blank to be sheared from said strip, said punch section comprising at least a pair of hydraulic spindles, fixed means in said punch section for supporting said spindles with their longitudinal axes normal to the path of movement of said strip between said sections and spacing said longitudinal axes approximately twice the width of said blanks, said spindles each comprising a fixed outer housing, a plurality of telescoping, relatively movable tubular piston-ram tool-carrying members within said housing, the outermost of said members having at one end means for shearing blanks from said strip, a second of said members directly adjacent said outermost of said members having a combination draw punch and hold-down at one end thereof adjacent said shearing means with said members in their retracted position, a third of said members located within said second of said members having at one end a punch for redrawing the blank drawn with said draw punch acting as a hold-down, all of said members having at their opposite ends radially extending surfaces against which fluid pressure acts, means for isolating each said opposite end within a separate fluid pressure chamber, axially aligned and spaced blank and draw dies in said die section with which said members coact to shear and draw blanks from said strip, a source of fluid pressure, and means for sequentially directing fluid pressure within said pressure chambers against said radially extending surfaces to shear and draw blanks from said strip in said die section during a single continuous stroke of the press.
11. A hydraulic spindle for a metal-drawing press comprising a pair of concentric telescoping piston elements, means for applying a lesser fluid pressure against one of said elements to hold the same in a retracted position within the other of said elements, means for applying a greater fluid pressure against said other element to move 1 the same in the opposite direction while retaining said element in said retracted position within said other element by said lesser fluid pressure, whereby said elements move in unison in said opposite direction, stop means for arresting the movement of said other element in said opposite direction, and additional means for applying said greater fluid pressure against said one element to move the same in said opposite direction against said lesser pres sure after movement of said other element is arrested, telescoping draw punches carried by said piston elements and adapted to have sequential engagement with the part to be drawn upon movement thereof in said opposite direction, means for reducing said greater pressure and increasing said lesser pressure to move said one element in said one direction into said retracted position and said elements in unison, and means to arrest said unison movement in said one direction.
12. In a set of tools for a sheet metal drawing press, a hydraulic spindle comprising a fixed vertical housing, a pair of concentric telescoping inside and outside piston elements located in said housing for vertical movement, means for applying fluid pressure against said inside element to move the same up into a retracted position within said outside element, engaging means on said elements for moving said elements in unison upon continued up movement of said inside element, means for applying fluid pressure against said outside element to move the same down in unison with said inside element against a fluid back-pressure on said inside element, stop means for arresting the down movement of said outside element, means for applying a fluid pressure against said inside element greater than said back-pressure to move the same down relative to said outside element following its arrestment by said stop means to continue the down stroke of the press, telescoping draw punches carried by said elements and adapted to have sequential engagement with the part to be drawn upon the downward movement of said elements, and means for changing the pressure differential acting upon said inside element to retract said inside element into said outside element and restore said elements to the up position of the press.
13. In a set of tools, a hydraulic spindle as defined in claim 12, wherein said stop means for said outside piston element includes a radial projection, and clearance means defined in said housing in which said projection has axial movement.
14. In a set of tools, a hydraulic spindle as defined in claim 12, wherein said inside element has stop means projecting radially therefrom, and clearance means defined in said outside element in which said radially projecting stop means has axial movement.
15. In a set of tools, a hydraulic spindle as defined in claim 12, wherein said stop means for said outside piston element includes a radial projection, clearance means defined in said housing in which said projection has axial movement, stop means on said inside element projecting radially therefrom, and clearance means defined in said outside element in which the stop means on said inside element has axial movement.
16. In a set of tools, a hydraulic spindle as defined in claim 12, wherein said stop means is constituted by rigid abutment structure, draw dies axially aligned with said elements, and a punch on said outside element having its down movement therewith arrested by said stop means in predetermined spaced relation to one of said draw dies.
17. In a set of tools, a hydraulic spindle as defined in claim 16, wherein a slightly deformable resilient support is provided for said one draw die to provide deflection thereof by said punch prior to said stop means being effective.
18. In a set of tools for a sheet metal drawing press, a hydraulic spindle comprising inside and outside concentric telescoping piston elements, means supporting said elements for relative axial movement, telescoping punches carried by said elements, a pair of dies axially aligned with said piston elements, and rigid stop means on said outside element for arresting the movement of the punch carried thereby in predetermined relation to one of said dies, and a slightly deformable resilient support is provided for said one die to provide deflection of the one die by the punch on said outside element acting as a holddown.
19. A tool set for drawing sheet metal comprising holddown means, a punch and a die all axially aligned, stop mechanism associated with said hold-down means, and a slightly deformable resilient pad against which said hold-down means reacts prior to said stop mechanism becoming effective whereby said hold-down acts upon the metal being drawn in said die by said punch to prevent wrinkling against the reaction of said pad and said stop means controls the position of said hold-down means and the amount of deformation of said pad.
20. A tool set as defined in claim 19 wherein said holddown means takes the form of a punch in which said first punch telescopes.
21. A tool set as defined in claim 19 wherein said pad supports said die.
22. A tool set as defined in claim 19 wherein said die is axially and radially floated upon said pad.
References Cited UNITED STATES PATENTS 1,462,094 7/1923 Walsh 72329 1,548,457 8/1925 Greayer 72-349 1,720,375 7/1929 Parker 72-349 1,967,245 7/ 1934 Hothersall 72-351 2,547,331 4/1951 Lent 72-35O 2,843,070 7/1958 Berkley et a1. 72334 FOREIGN PATENTS 223,430 10/ 1924 Great Britain.
RICHARD J. HERBST, Primary Examiner US. Cl. X.R. 72349