US1706074A - Cushion for sheet-metal presses - Google Patents

Description

March 19, 1929. RODE 1,706,074

CUSHION FOR SHEET METAL PRESSES Filed May 5, 1927 2 Sheets-Shee 1 March 19, 1929. J RODE 1,706,074

CUSHION FOR SHEET METAL PRESSES Filed May 5, 1927 2 Sheets-Sheet 2 Patented Mari 19, 1929.

. 'UNlTED STATES PATENT OFFICE.

rnnnmona. RODE, or CHICAGO, ILLINOIS, ASSIGNOR 'ro MAYYRQUETTE TOOL a me. comrnnv, or Caressa-rumors, A coaroaarron or rumors.

, CUSHION ron SHEET-METAL PRESSES.

Applicationfiled m 5, 1927. Serial no. 188,969.

This invention relates to improvements in cushions partic'ularly adapted, though not necessarily limited in its use for sheet metal presses in which the metal is shaped \by 6 means of co-operating dies, one of which dies is reciprocable toward and' away from the other, the work being clamped or held by means of a blank or workholding element that co-operates with a reciprocable die mem- 10 her, the blank or work holding member be- .ing resisted in its movement in one direction by the said cushion. and one of the objects of the invention is to provide an improved combined hydraulic and pneumatic cushion of this character whereby 'a doublewdrawing operation upon the material may be produced in what is commonly known as a' single acting' press, that is in a press in which the double drawing operation is performed upon a single stroke of the ram of the press and at 7 different points in the cycle ofmovemen-t of i the ram in one direction. 7 i

A further object is to provide an improved cushion of this character embodying hydraulic and pneumatic cushion elements, one of which is rendered inactive while the other is active, and improved'means whereby the stress exerted against the work thecushion v elements may be transferred from one of said cushion elements to the other, automatically and at a'predetermined time in the cycle of operation of the press. 3 n

' A further object is to provide improved *means whereby theresistance pressure of thesaid cushion may be varied at will.

To the attainment of these ends and the accomplishment of other new and useful objects as will appear, the invention consists in the features of novelty in substantially the,

construction, combination and arrangement of the several parts, hereinafter more fully described and claimed and shown inthe accompanying drawings illustrating this invention, and in whichmetal press having a cushion embodying the principles of this invention attached thereto, parts being shown in section, :parts broken away, and partsomitted. f

Figure 2 is an enlarged detail sectional view of a portion of the cushion and the cooperating dies,with the parts in one position orin the position they will assume at the completion of the first step in the drawing operation. r

' 26 is a piston rod 27 which :suitable stufiing box 28 in the end of the Figure 1 is a view-in elevation of a sheet 5 at the limit of its upward movement.-

Figure 3 is a view similar to Figure 2, showing the parts in the position they will assume at the end of the second'step in the operation or upon the completion of the draw.

Referring more particularly to the drawings the numeral 10 designates generally a sheet metal press having a bed or bolster plate 111, uprights 12, a reciprocating ram 13, a crank shaft 14, and a link 15 connecting 06 the ram with the crank shaft and which crank shaft is driven in any suitable manner and from any suitable sburce of power, not shown, preferably by means of a gear wheel 16 meshing with an internal gear wheel 17.

All of the above referred to parts are of the ordinary and well known construction.

Mounted upon the bed plate 11 in any suitable manner is a die 18. having-a co-operating die member 19 and supportedby the bed plate 11 is another die'20, having a movable die 3 member 21.

Beneath the bed of the press and preferably arranged within a pit 22 is a support 23 held in position in any suitable manner from a fixed art of themachine, preferably by means of hanger rods 24. supportedby the member 23 is a cylinder 25 of any desired size and diameter, in which cylinder a piston 26 is reciprocable. Connected with the piston passes through a cylinder." The piston rod 27 is connected with a pressure or pin plate 29 preferably by 9 means of a suitable fastening device 30, and s resting upon the pad or plate 29 or ins31, any number of which may be provi ed and these pins support the movable member 19 which co-operates with the die 18, the pins '31 passing loosely through-the bed plate 11 and are of a lengthto normally hold the top of the-member 19 substantially flush with the top of the die 18 when the pad or plate 29 is i They end 32 of the cylinder 25 is shaped to form a piston, preferably of a cup shaped configuration and telescoping over the is- I ten 32 is a cylinder 33, the bottom of whic is open. The cylinder and piston 32 are held against displacement with respect to each other in anv suitable manner such as by means of a. fastening ring 34: secured to the cylinder 33, which engages under a circumferential flange 35on-the piston 32. Z

Thepiston rod 27 passes loosely through the end of the cylinder 33 and a stufiing box or packing 36 may beprovided'to form a fluid tight joint.

Supported by the cylinder 33 are pins 37, any number of which may be provided and these pins pass loosely through the bed or bolster plate 11 and are of a length to support the movable members 21 of the die 20.

A fluid, such as air, is supplied to the cylinder 33 under any desired predetermined pressure and from any suitable source, preferably from a tank or container 38, through the medium of a pipe 39 which preferably passes through the piston 32.

Within the cylinder 25 is a'liquid 40 which may be initially supplied thereto from any suitable source preferably through a pipe 41, having a check valve 42 therein.

A predetermined quantity of liquid is supplied to the cylinder. 25 and is adapted to be forced from beneath the piston 26 to the upper side thereof, when the piston 26 is lowered, through a pipe or conduit 43 which has communicationwith the cylinder adjacent the bottomthereof through an opening 44 and also with the top of the cylinder above the piston through an opening 45.

. A valve 46 is provided for controlling the opening 44. A spring 47 controls the valve 46 and. an operating handle 48 serves the means whereby the stress of the spring 4 may be varied at will.

In operation the valve 46 is seated with a predetermined pressure of the spring 47 and against which pressure it is necessary to unseat the valve 46 by the pressure upon the liquid 40 exerted by the piston 26 as the latter descends. By the adjustment of the spring '47 a variable and predetermined resistance pressure may be imparted to the valve 46.

When the valve 46 is unseated the liquid will flow through the conduit 43 to the top side of the piston.

When the piston 26 rises the liquid on the top of the pistonwill be discharged through an opening 49 from the cylinder into a conduit 50 and back into the cylinder through an opening 51 on the other side'of the piston.

A check valve 52 is provided in .the conduit 50 to prevent the liquid from being forced through the conduit 50 when the piston 26 descends. The valve 52 will, however, open under the pressure of the liquid when the piston 26 rises.

It' will therefore be manifest'that by adjusting the spring 47 any predetermined resistance pressure of the liquid 40 may be exerted upon the movable member .19 which co-operates with the surface 53 of the die 54 that is connected with the rant 13.

Withinthe conduit 43 a valve designated generally by the reference numeral 551s provided. This valve may be ofany ordinary and well known construction adapted when in one position, to open. the conduit to the passage of liquid and when in another position to-close the conduit against the passage of liquid.

' This valve 55 is controlled in its operation from any movable part of the cushion or press' In the present form of the invention,

however, it is controlled by the movement of the cylinder 33 and is operated first to open and then close the same at predetermined times in the cycle of operation or movement of the cylinder 33. Such operation is accomplished preferably by means of a link 56 which is connected at one end with an arm 57 connected with the valve. The link 56 passes through a guide 58 on the cylinder 33 and adjustable collars or nuts 59-60 are provided on the link and so positioned that at a predetermined time in the cycle of lowering movement of the cylinder 33 the guide 58 will engage the nut or collar 59 to lower the link and rock the arm 57 to open the valve 55. When the cylinder 33 rises the guide 58 will at apredetermined point during its rising movement engage the nut or collar 60 to again close the valve 55.

This valve 55 andthe operation thereof is necessary so as to prevent the lowering of the piston 26 during the first. step in the draw ing operation as it is necessary to maintain the piston and the pin plate or pad 29 against 7 a lowering movementwhile the work 61 is being formed over the die 18 and the co-operating member 19, as shown in Figure 2 of the drawings.

After the'completion of this first step in the forming operation the guide 58 on the cylinder 33 will engage the nut or collar 59 on the link 56 to open the valve 55. A further lowering movement of the ram 13 and die 54 from the] position shown in Figure 2, will then depress the piston 26. When a pressure is created by the lowering of the piston 26 upon the liquid 40 sufiicient to unseat the valve 46 against the stress of the spring 47, the liquid will flow through the conduit 43 to permit the piston .26 and member 19, which co-operates with the die 18, to be. lowered to the position shown in the in Figure 3, whereby the second stepl t ework pressure'of the ram and work upon the cylinder 33 is relieved the fluid (such as air) will the piston 26 will be drawn upwardly inthe cylinder 25.

e As the die member 19 rises it will act as a til the completion of the first step in'the drawdifferent from the said pneumatic cushion I the movement of the other pad ing operation. At this time the resistance pressure will then be shifted automatically by means of the control valve 55 from the,

pneumatic to the hydraulic cushioning elements. i

As the cylinder 33 is lowered the fluid will be forced from the cylinder out of the pipe 39 back into .the tank or receiver 38.

An automatic regulator or pressure control valve 62, of the ordinary and well known type may be provided in the fluid pressure supply line. I

While the preferred form of the invention has been herein shown and described, it is to be understood that various changes may be.

made in the details of construction and in-the combination and arrangement of the several parts, within the scope of the claims, without departing from the spirit of this invention. -What is claimed as new is: I

1, In a sheet metal press aplurality of pressure pads, a pneumatic pressure cushion element for resisting the movement of one of said pads in one direction, a cushion element having a resistance creating liquid therein for resisting intone diretcion, and means for shifting the active resistance pressure from one of said cushion elements to the other at a predetermined point in the cycle of operation of the press.

2. In a sheet metal press a plurality of pressure pads, a pneumatic pressure cushion element for resisting the movement of one of said pads in one direction, a cushion element having a resistance creating liquid therein different from the said pneumatic cushion for resisting the movement of the other pad in one direction, means for maintaining one of said cushion elements inactive during one portion of operation of the press and while the other cushion element is active, and means for rendering the inactive cushion element active. i

3. In a sheet metal press, a ram, ity of pressure pads, a fluid pressure cushion element for resisting the movement of one of said pads in one direction, an hydraulic cushion element for resisting the movement,

of the other pad in one direction, means for varying at will the resistance pressure of the maintain its a plural.

hydraulic cushion element, means for maintaming the hydraulic cushion element 111- active under the stress of the ram, whereby the said fluid pressure cushion will be active in advance of the hydraulic cushion element, and means for rendering the last recited means inactive at a predetermined time in the cycle of operation of the press to render the hydraulic cushion element active.

4. In a sheet metal press, a ram, aplurality of pressure pads, a pneumatic pressure cushion element for resisting the movement of one of said pads in one direction, a cushion active under thestress of the ram, the last I recited means being responsive in its operation to a movable part of the press for rendering the hydraulic cushion element active.

5. In a sheetmetal press, a ram, a plurality of pressure pads, a fluid pressure cushion element for resisting the movement of one of said pads in one direction, an hydraulic cushion element for. resisting the movement of the other pad in one direction, means for varying at will the resistance pressure of the hydraulic cushion element, means for maintaining the hydraulic cushion element inactive under the stress of the ram, and means responsive in its operation to the actuation of the fluid pressure cushion for actuating the last recited means to render the hydraulic cushion active.

6. In a sheet metal press, a ram, a plurality of .pressure pads, a pneumatic pressure cushion for resisting the movement of one of the pads in one direction, a cushion having a resistance creating fluid therein different from the said. pneumatic cushion for resisting the movement of the other pad in one direction, one of said cushions being inactive tov respective pressure pad against movement under the stress of the ram of the press while the other pad is movable under the stress of the ram and against the stress of its respective cushion, and means automaticallyrendering the said inactive cushion active at a predetermined time in the cycle of operation of the press whereby the active stress of the ram upon the work will be transferred from the first to the second recited the said pneumatic cushion for resisting the movement of the other pad in one direction, one of said cushions being mactive to maintain its respective pressure pad against movement under the stress ofithe ram of the press while the other pad is movable under the stress of the ram and against the stress of its respective cushion, means automatically ren-- 8. Ina sheet metal press, a ram, a plurality e of pressure pads, a pneumatic pressure cushion for resisting the movement of one of the pads in one direction, a cushion having a resistance creati w fluid'therein difierent from the said pneumatic cushion for resisting the movement of. the other pad in one direction,

the last said cushion being inactive to maintain its respective co-operating pad against movement-under the stress of the ram of the said, first said pressure cushion to transfer press while the other pad is movable underthe stress ofthe, ram and against thelstress of its respective cushion, and means jresponsive to the actuation ofa movable part of the theworking stress of theramfrorn the first said to the second said cushion. v

9. In a sheet metal press, a ram, .a plurality of pressure pads, a fluid pressure cushion for resisting the movement of one of the pads in one direction, an hydraulic cushion for resisting the movement of the other pad in one. 7 direction, said hydraulic cushion being inac-' :tive to maintain its respective co-operating pad against movement under the stressof the ram of the press while the other pad is movable under the stress of the ram andiagainst the stress of its respective cushion, means re-' sponsive to the actuation of'a movableparti i of the said fluid pressure cushion to transfer the working stress 'of the ram from the fluid to the hydraulic cushion, and means for'varying at willthe resistance; pressure of the hydraulic cushion. I

s 10. A cushioning device for sheet metal presses, said cushion embodying a cylinder and piston members, a liquid in said cylinder for creating a resistance pressure against the relative movement of the piston and cylinder, one end of said cylinder constituting a piston, a second cylinder in which the last said piston operates, means for supplying to the second recited cylinder a fluid diflerent from the said liquid for resisting the relative movement of the last said cylinder andits piston, pressure pads individual to and operating against the stress of the respective cushions, a ram, and means for lockingthe hydraulic cushion: against operation, the last said means being automatically rendered inactive at a predetermined point in the cycle of operation of the press to transfer the operative action otthe-ram from one to the other of the cushlOIlS. 11. A cushioning 'd'evice .for sheet metal presses, said cushion embodying a cylinder and piston members, a liquid in said cylinder for creating a resistance pressure against the relative movement of the piston and cylinder, one end of said cylinder constituting a piston, a second cylinder in'which the last said piston operates, means for supplying to the second recited cylinder a fluid different from the said liquid for resisting the relative inovement' of the last said cylinder and its piston, pressure pads individual to and operating against the stress of the respective cushions,

means for lacking the hydraulic cushion against operation, and means responsive in its operation to the operation of one of said pads for controlling the said locking means;

In testimony whereof I have signed my of April-,A. D. 1927 L name to this specification, on this 26th day 35

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