US2642138A - Hydraulically actuated press - Google Patents

Description

June 16, 1953 J. MACEWKA 2,642,138

I HYDRAULICALLY ACTUATED PRESS Filed March 7, 1951 2 Sheets-Sheet l "a 7 iv N INVENTOR.

Joy/v M405 w/m June 16, 1953 J. MACEWKA 2,642,138

HYDRAULICALLY ACTUATED PRESS Filed March 7, 1951 i2 Sheets-Sheet 2 INVENTOR. ./0/-//v MACZ'WAA BYW ATTOPNEV Patented June 16, 1953 UNITED STATES; PATENTQFFICE 2,642,138 HYDRAULICALLY ACTUATED PRESS John Maccwka, Royal Oak, Mich. 7 Application March. 7, 1951, Serial No. 214,398

, 1 The present invention relates to'an hydraulically actuated press and more particularly to such a press including an assembly of hydraulic pistons adapted to actuate a press tool and the accompanying stripper plate in proper sequence. This application is related. to my copending application, Serial No. 114,022, filed September 3, 1949, entitled Hydraulic Cylinder. It'is well known that press constructions embody a pressure plate or other means forholding 'a workpiece in position for the press operation, and also a. stripper plate which will separate the finished workpiece from the press tool after the pressoperation is completed. The stripper plate andpressure plate are often combined into one. elementknown asthe stripper clamp. The stripper clamp is placed upon the workpiece under pressure to holdthe workpiece in position, the press operation is performed, and the stripper clamp is maintained on the workpiece to hold it in position While the press tool'is removed from the workpiece. Conventional press constructions using this stripper clamp have generally utilized a coma plicated system of hydraulic circuits to effect the necessary'operations, such systems embracing an excessively large space. Factory space is extremely valuable and plant layout engineers are ever attempting to utilize every bit of area to its best advantage. Thus, an eflicient hydraulic press construction has been soughtwhich is simple,

easy tomaintain. andco'mpact.

" Another disadvantage of conventional construe jtions has been the necessity of providing a large number of heavy, closely machined ways or guides on the'strip'per clamps so that such guides will accurately seat the stripper clamps, and withstand the pressures to which they are subject. Therefore, stripper clamp constructions which are efficient, and whichhave an accurate, simple, and

sturdy-"guiding means have long been desired.

It is, -accordingly, a primary object of the present invention to provide a simple and et- 'ficient hydraulic press construction embodying a stripper clamp and a press mechanism cooperating therewith, which are actuated in proper sequence by a simple and compact hydraulic unit.

It is a further object of the present invention to provide a press construction embodying a stripper, clamp which has simple and efficient supporting and guiding means. i I V It is a further object of the present inventionito provide an hydraulic press employing a plurality er hydraulic cylinders so disposed and arranged with; respect'to the press tool and stripper clamp J 7 Claims. (Cl. ice-95),

that the stripper clamp and press tool'will move relative to each other to provide the necessary holding, working, and stripping operations.

It is another object of the present invention to provide an hydraulic press including a main piston rigidly and transversely connected with a ondarypiston in limited sliding engagement therewith, said secondary pistons being rigidly affixed'to a stripper clamp to effect relative movement between the press tool and the stripper clamp.

Other objects of this invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views. Y

In the drawings:

Fig. 1 is a midsection of an hydraulic press embodying one modification of the present invention, with portions of the pistons and stripper clamp being broken away for clarity.

Fig. 2 is a sectional view taken along the line 2-4 in the direction of the arrows Fig. 1.

Fig; 3 is a side view of an hydraulic press embodying another modification of the present invention, with portions broken away to disclose the internal construction.

Fig. 4 is an end view of the embodiment shown in Fi 3. I

Before explaining the present invention in detail, it is to be understood that the invention is notlirnited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawingssince the inventionis capable of other embodiments and of being practiced or carried-out in various ways. Also, itjis to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

Referring to the modification of th present invention shown in Figs. 1 and 2 of the drawings, an hydraulic press is shown comprising the housing Ill havin the cylinders I2, It, and I6 formed therein. 'The main piston 20, and the supplemental pistons I8 and ii are disposed in the cylinders 'lz, I4, and I B respectively. An elongated!" slot 23 is formed in the housing IE3 and connects seals 25 are-provided oneach of the pistons I8,

3 28, and 22 to prevent the hydraulic fluid from leaking around the piston walls.

The ends of the housing I8 are closed by the end plates 26 and 28. The slot 23, which extends through the outer side walls of the housing I8, is closed by the side plates 34 and 36 respectively.

The main piston 28 has the press tool 38, in

this instance a pun-ch, afiixed to its free end. The tops of the supplemental pistons I8 and 22 are provided with the hollow interiors 48 and 42. The interiors of these two piston constructions are identical and the remarks in connection with the supplemental piston I8 will also apply to the supplemental piston 22. The foot of the supplemental piston I8 is provided with the secondary cylinder portion 44 having disposed therein a secondary piston 46. A suitable piston ring or seal is indicated at 41. The secondary piston 48 is provided along its side with the elongated slot 48. Disposed within this slot 48 is the pin 58 which is rigidly affixed to the supplemental piston I8. The free end of the secondary piston 46 comprises the guide rod 52. The corresponding parts in the supplemental piston 22 are the secondary piston 53, the slot 54, the pin 56, and the guide rod 58. The guide rods 52 and 58 are connected by any suitable means such as the bolt 68 to the stripper clamp 62. The stripper clamp 62 in this instance is provided with the holes 64 and 66 to accommodate the punches 68 and I8 on the press tool 38. Conduits I2 and I4 are provided in the body of the supplemental piston I8 and connect the chamber 48 with the cylinder 44. Similar conduits I6 and (8 are provided in the body of the supplemental piston 22.

Ports 88, 82, and 84 are provided in the housing I8 to adapt the housing I8 for connection with an hydraulic circuit. These ports are screw-threaded to facilitate connection with the screw-threaded connecting caps which are provided on hydraulic hoses. Mounting holes 86, 88, 88 and 82 are provided in the housing I8 to adapt the housing for mounting on a press frame. Passages 84 and 96 are provided at the left end of the housing I8 (Fig. 1) to connect the cylinders I2, I4, and I6. Suitable bearings 88 and I88 are disposed at one end of the housing I8 adjacent the end plate 28. These bearings guide and support the rods 52 and 58. Seals I82 and I84 are provided in the bearings 98 and I88 to prevent leakage of hydraulic fluid through the end plate 28.

Operation The operation of the modification shown in Figs. 1 and 2 of the drawings is as follows:

Hydraulic fluid is introduced through the port 84 against the top of the piston 28 and passes through passages 84 and 96 into the cylinders Hand I6. The hydraulic fluid passes into the chamber 48 in the supplemental piston I8 through the conduits I2 and I4, into the secondary cylinder chamber 44 and against the top of the secondary piston 46. The same action takes place in connection with the supplemental piston 22. The secondary pistons 46 and 53 are forced to the right relative to the pins 58 and 56 and thus, the stripper clamp 62 precedes the press tool 38 in operative travel. The workpiece is first engaged by the stripper clamp 62 and then the press tool 38 follows through to perform the punching operation, the pins 58 and 56 moving within the slots 48 and 54, respectively. When the operation is completed, the hydraulic fluid is introduced through the ports 88 and 82 into the bottom of the cylinders I8 and 22. At this point, the pins 58 and 56 are near the right end of the slots 48 and 54. As fluid is introduced through the ports 88 and 82 the pressure within the bottom of supplemental cylinders I4 and I6 is increased to a, point where it is greater than the pressure being exerted within the chambers 48 and 42 in the heads of the supplemental pistons I8 and 22. Thusythe supplemental pistons I8 and 22 are moved leftward against the fluid pressure in the top of the supplemental cylinders I4 and I6 and in the chambers 48 and 42. As the supplemental pistons I8 and 22 move leftward, fluid from the chambers 48 and 42 moves through the conduits I2 and I4 and maintains the pressure on the heads of the secondary pistons 52 and 58, thereby holding the stripper clamp 62 in position on the workpiece. The supplemental pistons I8 and 22 thus move leftward until the pins 58 and 56 contact the left walls of the slots 48 and 54, thus moving the press tool 38 away from the workpiece while the stripper clamp 62 is held thereon, and pulling the punches 68 and I8 through the openings 64 and 66 in the stripper clamp 62. Thus, the supplemental pistons I8 and 22 and the press tool 38 are moved leftward a distance approximately the length of one of the slots 48 or 54 before the said supplemental pistons start to effect the leftward movement of the rods 52 and 58 and the stripper clamp 62 connected thereto. When the punches 68 and I8 have cleared the workpiece, the pins 58 and 58 have reached their leftward limit of travel in the slots 48 and 54, respectively, and the guide rods 52 and 58 with the stripper plate 62 affixed thereto are carried leftward. Thus, the cycle is completed with a simple hydraulic unit and with a simple and compact mechanism.

A modification of the device shown in Figs. 1 and 2 is demonstrated in Figs. 3 and 4 of the drawings. The important difference in this construction is the provision of the separate hydraulic feed line 288. This line is connected with the passage 282 in the lower piston 284 which communicates with the cylinder chamber 286 and in which chamber the secondary piston 288 is disposed. Thus, it will be seen that the passage 282 in this modification is substituted for, and performs the same function as, the passages I2, I4, I6 and I8, shown in Fig. 2 of the drawings. The operation of this modification is similar to that shown in Figs. 1 and 2 of the drawings. The pistons 284 and 2I8 are of identical construction and the supplemental piston 2I8 utilizes the hydraulic feed line 2 I2.

Suitable seals, such as the neoprene T seals 2I4 are provided on the various pistons to prevent leakage of the hydraulic fluid; In addition, a bearing 2I6 is provided at one end of the housing 2I8 adjacent the end plate 228 in each of the cylinders 222 and 224 to guide and support the rods 226 and 228. A retaining ring .238 is disposed around the rod 228 and contains suitable sealing means suchas the neoprene U seal 232. A similar construction is positioned around the rod 226. i

Operation In discussing the operation of the modification shown in Figs. 3 and 4 of the drawings, the operation of only one of the supplemental pistons, the supplemental piston 284, will be described. However, it is to; be understood that the supplementalzpiston 210 and ts accompanying con- 'struction operate in an identical manner.

1 In operation, hydraulic fluid isintroduced through the feed line 200 which moves. the secondary piston 208 to therightrelative to .the

supplemental piston 204. In the meantime, hy- I draulic fluid is introduced through the inlet port 231 which fluid has started the rightward travel of the connected pistons 204, 2H] and 238. 'The stripper clamp 24% reachesthe workpiece first the top thereof. This fluid pressure causes the supplemental. piston to' move leftward :against the fluid.pressure;-.exerted upon the top of the piston, ,Since thereis no'component of the fluid pressure acting to the left. on the secondary pis, ton, the secondary piston will remain in position under pressu'reuntil the pin 234, which is aflixed to thesupplemental piston 204, contacts the left wall of the slot 236. The pressitool 242 is moved leftward while the stripper clamp 24!] remains in position. The stripper clamp, thus, holds the workpiece inplace so that the press tool 242 may be'removed without displacing and distorting the workpiece; As the pin 234 hits the left wallof thev slot.236, the press tool 242 has been removedfrom contact with the work piece and thesecondary piston 2.138 is then carried leftward by the pin 234 which .is rigidly affixed to the supplemental piston 294.- Thus, the stripper. clamp 240 is moved away from the workpiece. and .the workpiece may be removed. The returnline for the supplemental piston 2) is designated at 2 26. v

It will be understood, :of course, that upon the return stroke, thehydraulic" fluid'in the cylinder 224 and the secondaryicylinder 206 is dispelled through: the lines1231 and 200, respectivelyyso that these lines, which were originally feed lines, now become drain lines. I J

EaCh 0f"thB modifications illustrated herein embodythe novel features of the present inventionto providea simple and'eflicient press construction utilizing "a combination stripper and pressure platein the form of a stripper clamp,

a simple and compact hydraulic circuit, sturdy guide and support means for the stripper clamp,

and a secondary pistonassembly whiohefiects relative movement between the press tool an the stripper clamp.

Having thus described my invention, I claim: 1. An hydraulically actuated press comprising a housing having a plurality of parallel cylinder bores therein and also having anelongated 'slot therein" extending in the direction of the"ax'es 'of'said bores, said slot' interconnecting said bores,

a main piston disposed in one of said bores and adapted for connection with a press tool, a supplemental piston disposed in another of said bores and adapted for connection to a stripper clamp, a dowel member extending through said slot in said housing and rigidly connecting said main piston and said supplemental piston, a secondary piston disposed within the foot of said supplemental piston in limited sliding engagement therewith so that said secondary piston may movea limited distance relative to said supplemental piston, means for hydraulically actuating said secondary piston, means for thereafter hydraulically actuating said main andsupplemental pistons; and return means for returning first said secondary piston and then said main piston and supplemental pistons to their initial positions.

. 2. An hydraulically actuatedpress adapted to hold a workpiece in position, perform awork operation thereon with a press tool, and strip said workpiece from said press tool, including a housingwith amain cylinder and supplemental cylinders parallel to said main cylinder formed therein, a main piston disposed in said main cylinder, a press tool connected to the free end of said main piston, a plurality of supplemental pistons'disposed one in each of said supplemental cylinders and rigidly connected to said main pistonso that main piston and supplemental pistons will move together, each of said supplemental pistons having a secondary cylinder formed therein, a plurality of secondary pistons disposed one in limited sliding engagement with each of said supplemental pistons in the supplemental cylinder formed therein, a stripper clamp attached to, the free ends of said secondary pistons, andan hydraulic system including means to feed said main, supplemental, and secondary cylinders so that said secondary pistons will move relative to said supplemental pistons to eifect the necessary holding and stripping operations.

3.. An hydraulically actuated press comprising a housing having a plurality of parallel cylinder bores therein and also having an elongated slot therein extending in the direction of the axes of said bores, said slot interconnecting said bores, a main piston disposed in one of said cylinder bores and adapted for connection with apress tool, a plurality of supplemental pistons disposed one in each of the other of said bores, each of said supplementalpistons having anopen chamber formed in the head thereof and a secondary open cylinder formed at the foot thereof which are connected by a passage, a dowel member extending through said housing slot and rigidly connecting said main and supplemental pistons together, a plurality of secondary pistons disposed one in each of the secondary cylinders in said supplemental pistons and having an elongated slot therethrough extending in the direction of its axis, a pin rigidly affixed to said supplemental piston and extending through said slot, 2,- connecting rod extending from the free end of said secondary piston and adapted for connection to a stripper clamp, inlet means com,- municating with the head of said main and supplemental cylinders and adapted to first actuate said secondary pistons through the passages in said supplemental pistons until the side .wall of the slot insaid secondary piston contacts the pin and moves the supplemental piston, and then moves said main and supplemental pistons, return means communicating with the other end of each of said supplemental cylinders and adapted to move said supplemental pistons in the return stroke until the pins afiixed thereto contact the side walls of the slots in said secondary pistons atwhich time the secondary pistons also move, and a source of hydraulic fluid connected with said inlet and return means.

4. An hydraulically actuated press comprising a housing having a plurality of parallel cylinder bores therein and also having an elongated slot therein extending in the direction of the axes of said bores, said slot interconnecting said bores and extending through at least one external side wall of said housing, a main piston disposed in one of said cylinder bores and adapted for connection to a press tool, a plurality of supplemental pistons disposed one in each of the other of said bores, a dowel member extending through said housing slot and rigidly connecting said main piston and said supplemental pistons together, a secondary open cylinder formed at the foot of each of said supplemental pistons, a secondary piston disposed in each of the secondary cylinders in said supplemental pistons and having an elongated slot therethrough extending in the direction of its axis, a pin rigidly aflixed to said supplemental piston and extending through said slot, a connecting rod extending from the free end of said secondary piston and adapted for connection to a stripper clamp, a passage extending from the side of at least one of said supplemental pistons and communicating with the secondary cylinder formed therein, inlet means connected to the opening of the passage in the side of said supplemental piston and extending through the slot in the external side wall of said housing, inlet means communicating with the head of the main and supplemental cylinders, and return means communicating with the foot of at least one of said supplemental cylinders, all of said inlet means and return means being adapted for connection to a source of hydraulic fluid under pressure.

5. An hydraulically actuated press adapted to hold a workpiece, perform a work operation thereon with a press tool, and strip said workpiece from said press tool comprising a housing having a plurality of cylinder bores therein a main piston disposed in one of said cylinder bores, a press tool aifixed to the free end of said main piston, a supplemental piston disposed in another of said cylinder bores and having a secondary cylinder formed therein, said main piston and supplemental piston being directly connected to move together, a secondary piston disposed in limited sliding engagement with said supplemental piston in the secondary cylinder formed therein, a stripper clamp affixed to the free end of said secondary piston, and hydraulic means for feeding saidmain, supplemental and secondary cylinders so that said secondary pistons will move relative to said supplemental pistons to effect the necessary holding and stripping operations.

6. An hydraulically actuated press comprising a housing having a plurality of cylinder bores therein, a main piston disposed in one of said cylinder bores and adapted for connection with a press tool, a supplemental piston disposed in another of said bores and rigidly affixed to said main piston for movement therewith, said supplemental piston having an open chamber formed in the head thereof and a secondary cylinder formed at the foot thereof which are connected by a passage, a. secondary piston disposed in said secondary cylinder and having an elongated slot therethrough extending in the direction of its axis, a pin rigidly affixed to said supplemental piston and extending through said slot, a connecting rod extending from the free end ofsaid secondary piston and adapted for connection to a stripper clamp, inlet means communicating with the head of said main and supplemental cylinders and adapted to first actuate said secondary piston through the passage in said Isupplemental piston until the side wall of the slot in said secondary piston contacts the pin and moves the supplemental piston, and then moves said main and supplemental pistons, return means communicating with the other end of each of said supplemental cylinders and adapted to move said supplemental pistons in the return stroke until the pins affixed thereto contact the side walls of the slots in said secondary piston at which time the secondary piston also moves, and a source of hydraulic fluid connected with said inlet and return means.

'7. An hydraulically actuatedpress comprising a housing having a plurality of parallel cylinder bores therein and also having an elongated slot extending through an external sidewall thereof in the direction of the axes of said bores, a main piston disposed in one of said cylinder bores and adapted for connection to a press tool, a supplemental piston disposed in another of said bores and rigidly aflixed to said main piston for movement, therewith, said supplemental piston having a secondary cylinder formed at the foot thereof, a secondary piston disposed in said secondary cylinder and having an elongated slot therethrough extending in the direction of its axis, a pin rigidly afiixed to said supplemental piston and extending through said slot, a connecting rod extending from the free end of said secondary piston and adapted for connection to a stripper clamp, apassage extending from the side of said supplemental piston and communicating with the secondary cylinder formed therein, inlet means connected to the opening of the passage in the side of said supplemental piston andsextending through the slot in the external side wall of said housing, inlet means communicating with the head of the main and supplemental cylinders, and return means communicating with the foot, of said supplemental cylinder, all of said inlet means and return means being adapted for connection to a source of thydraulic fluid under pressure.

JOHN MACEWKA.

References Cited in the file of this patent UNITED STATES PATENTS Number

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