US1706073A - Hydraulic cushion for metal presses - Google Patents

Description

March 19,' 1929., F. J. RODE HYDRAULIC CUSHION FOR METAL PRESSES Filed April 18. 1927 Patented Mar. 19,.: 1.929. UNITED STATES PATENT OFFICE.

FREDRICH J'. RODE, OF CHICAGO, ILLINOIS, QOMPANY, AOlla" CHICAGO, ILLINOIS,

ASSIGNOB. T MARQUETTE TOOL MFG. A CORPORATION OF ILLINOIS.

HYDRAULIC CUSHION 'FOR METAL' PRESSES.

Application filed April 18, 1927. Serial No.. 184,603.

This invention relates to improvements in` 10 die member,

hydraulic cushions particularly adapted v though not necessarily limited in its use in sheet metal presses in which. the metal is shaped by means of coopera-ting 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 work holding element that co-operates with a reciprocable the blank or Work holding element being resisted in its movement iny one direction by the said cushion, and one of the objects of the invention is-to provide an improved hydraulic cushion of this character in l5 which a predetermined quantity of liquid is used inthe cushion, the cushion embodying cylinder and piston members, the liquid being circulated from one side to the other of the piston for establishing the resistance pressure and to the other side of the piston to permit the pressure to be relieved.

A further object is to provide improved means for restoring the blank or work holder to its normal position.

To the attainment of these ends and the acoomplishmentof 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 hereinafterinore fully described and claimed and shown in the accompanying drawing illustrating this invent-ion, andin which'- A Y Figure 1 isa view in side elevation, partly broken away, partly in section and with parts omitted of a sheet metal press having an hydraulic cushion constructed in accordance with vthe principles of thisinvention applied thereto.

Figure 2 i's an enlarged detail sectional view of the pressure controlling valve.

Figure 3 is a detail sectional View taken on line 3 3, Figure 2. l l

Referring more particularly to the drawing the numeral designates generally the frame of a.. sheet metaly press having a reciprocable ram 11 to which a die 12 is connected. rEhe ram is reciprocable by means of a link 13 connected with a crank shaft 14, the latter being driven in any suitable manner (not shown) Mounted upon the bed plate 15 of the ma chine is a die 16 with which a work or blank holding member 17 co-operates. The blank or work holding member 17 is supported byA means of pins 18, which in turn pass loosely through the bed plate l5 and are supported by means of a pressure pad oryplate 19.

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

Supported beneath the lbed of the machine, preferably in a pit 20, is a supporting member 2l held in position by means of suitable hangers 22 which are secured to a suitable fixed part of the machine.

3 Mounted upon the supporting member 2() is a cylinder 23 of any desired size and diameter and reciprocable in the cylinder is a piston 24, having a piston rod 25 which passes through a suitable packing 26 in the end of the cylinderand is secured in any suitable manner such as by means of fastening devices 27 to the bottom of the pin plate or pad 19.

rThe pad or plate 19 is supported by means of bars or rods 28 constituting hangers. These bars 28 are secured to the bed plate 15 in'any suitable manner, preferably by threading the ends of the rods thereinto. rllhe rods depend from the plate and are provided with adjustable nuts or collars 29 on the free end thereof.

Resiliently yielding members, such as coil springs 30 encompass the rods 28 with one end engaging the lower face of the pin plate or pad 19, and the other ends of the respective springs engage washers 31 which encompass the rods 28 and Vrest against the nuts 29.

rlhe cylinder is provided with a fill opening 32 above the piston 24, and liquid is supplied thereinto from a suitable source through a pipe 33 in which a controlling valve 34 may be arranged. A check valve 35 is also arranged in the pipe to prevent liquid from suitable guide 40. One end of a coil spring- 41 rests against a collar 42 secured to the valve stem 39. The other end of the spring engages a collar or abutment 43 carried by a stem 44 which has threaded engagement with an vabutment 45 Iand the stem 44'is provided with. an operating handle 46. By rotating the handle 46 the tension of the spring 41 may be varied and therebythe pressure which 11o openings 47 which form communication between the valve casing and the passage 36. A valve 48, preferably in the form of an annular member, is provided to close the be closed by the ton upon the liquid beneath the piston.

`the pin plate or pad 19 or pressure plate 19.

openings 47. This is accomplished by means y of rods 49 which are connected with the valve 48 and pass loosely through the adjacent wall of the valve casing 37. Springs 50 encompassA the rods 49 and tend normally to move the valve 48'in a direction to close the passages47. The valve casing 37 also has an openin 51 to which is'connected a pipe 52 that alsoxas communication with an opening 53 preferably adjacent the top of the cylinder, and on the' other side of the piston 24, so that the liquid may circulate from beneath the piston 24, through the pipe'52 to the top side of the piston through the opening 53.

The valves 47 and' 48 are disposed between the` opening 51 in the casing 37 and the opening 36, the valve 48 being unse'ated by the pressure of the liquid iiowing from the top of the piston so that the liquid will enter the bottom of the cylinder while the valve 48 will pressure created by the pis- The valve 38 is set for a predetermined pressure. and will be `unseated by pressure created upon the liquid under the piston 24 by the action of the piston upon they liquid and when such pressure eXcee s the pressure to which the valve 38 is set.

- The operation of the machine is as follows. In Figure 1 of the drawing the parts are shown in their normal or initial position, that is with the blank or work holding element 17 in position to co-operate with the die 16 to support the work 54, and the lpiston 24 will be at'thel limit of its upwardl stroke'in the cylinder 23. I

The valve,38 is first set to the pressure which it is desired to establish and the pressure pad or pin plate 19 will be supported by Y means. of the resiliently yielding elements 30.

When the ram 11 descends and the die 12 contacts with the work 54,. a further lower'- ing movement of the ram will cause the work to -be shaped over the dies.. `At the same time will be depressed by means of the pins 18 against the liquid in the cylinder' beneath thepiston 24. The

lowering movement of the pad 19 will also cause the reslliently yielding elements 30 tos be compressed so that energy will be stored therein. l

The springs 30 however serve only the purpose of returning or restoring the pad or pressure plate 19 and the energy stored -inthe springs will-be negligible with respect to any resistance pressure created thereby against' the lowering movement of the pad As the piston 24 descends the lowering movement of the pin plate or pad 19 will be yieldingly resisted by the hydraulic pressure created upon the liquid beneath the piston, )which pressure will continue until the pressure exceeds which holds the valve 38 upon its seat. When the pressure of the valve 38 is exceeded the valve be unseated by the liquid and the liquidwill iow into the valve casing 37, thence out of the opening pipe 52, intothe opening 53 to the top side of the piston 24.

When the ram 11 starts to ascend the pin plate or pad' 19 will be raised by the energy stored in the resiliently yielding element 30 and this will raise the piston 24 in the cylinder 221- The liquid on the top side'of the piston will be discharged through the'opening 53, through the pipe 52 chamber 37 and from the valve chamber 37 into the openings 49 against the valve 48 to lunseat the latter, which will permit the liquid to be vdischarged through the opening 36 back into the cylinder beneath the 'piston 24.

The valve 35 will be closed by pressure so as to prevent the liquid from being delivered into the pipe 33 on the upstrokeof the piston 24.

lVith this improved construction it will be manifest that the hydraulic pressure may be controlled at any time during the -cycle of operation of the press by adjustment of the tension of the resiliently yielding element 41by adjusting the handle 46.

Furthermore by adjusting the tension of the resiliently yielding element 41 the degree of pressure necessary to unseat the valve v38 may be controlled at will.

It will alsobe manifest that with this improved construction zi? predetermined quanti- 51, through the into the valve ty of liquid-may be employed and will be- I 'circulated from one'side to the other side of the piston durino the operation of the press.

While the prei? rred form of the invention has been herein shown and described, itis to be understood that various changes maybe made in thev details of construction and in the combination and arrangement of the sevleral parts, within the scope of the claims, 'without departing from the spirit of this invention.

What is claimed as new is 1. A pressure cushion for sheet metal presses embodying cylinder and piston members, hydraulic means for resisting the relative movement of said members in one direction, a single conduit for leading the liquid back and forth fromone'lside to the other side of the piston, a conduit for movement of the liquid 1n one direction therethrough, variably yielding means for holding said valve closed, and an additional valve for closing the @metten p resisting the relative movement of said memoperating K site directions,

1,706,073 s Q f duit `or movement of .the liquid in the lastv -said direction therethrough and operating to permit the liquid to.A flow through said pas- Sage in the opposite direction.

2. A pressure 'cushion for sheet metal presses embodying cylinder and piston members, hydraulic means forresisting' the relative movement of said members in one directionj, a single conduit for leading. the liquid back and forth from one side to'the other side of the piston, oppositely opening valves for controlling the iiovv of liquid through said single conduit,and means for establishing a 'predetermined pressure upon one of said valves and against which pressure the valve is adapted to be unseated by`the pressure-of the liquid thereupon.

3. A' pressure cushion for Sheet metal presses embodying cylinder and piston members, hydraulic means for resisting the rela. tive movement of said members in one direction, a single conduit for leading the liquid back and k'forth from one side to the other side of the piston, oppositely opening valves i for controlling the How of liquid through said single conduit, means'for establishinga predetermined pressure upon one of said valves and against which pressure the valve is adapted to be unseated by the pressure of' the liquid thereupon, and means for varying` at will the said the said valve. F v

LCA self-contained pressure cushion for sheet metal presses embodying cylinder and piston members,.said cylinder containing'a predetermined supply of liquid, said liquid predetermined pressure upon bers in one direction, a single'conduit for leading the liquid back and forth from one side to the other side of the piston, opposit'ely g valves for controllindthe flow' of liquid through said-single conduit in .oppoand means` for establishing 5 and maintaining a predetermined resistance pressure upon one of. said valves and against which pressure the valve'is adapted to be unseated by theoperation of the liquid there-l 'against.

5. A self-contained' pressure cushionfor sheet metal presses embodying cylinder and piston members, said cylinder containingja predetermined supply of liquid, said liquid A, resisting the relative movement of said mem- 'bers in one direction,

leading the liquid back and f orthfrom one side to the other sidelof the piston, oppositely operating valves for controlling the'iow of liquid through said single conduit in opposite directions, means for establishing and maintaining a predetermined resistance pressure upon one of said valves ,and agalnst which pressure the valve is adapted to .be unf seated bythe operation of the liquid thereagainst, and means for varying at will the Ysaid predetermined resistance pressure.

lbodying cylinder and piston members,

a single conduit for' 6. A pressure cushion for sheet metal presses embodying a pressure pad, a cushion for resisting the movement of the pad in one direction, said cushion embodying cylinder and piston members one of which is operatively connected with the said pad, a liquid in the cylinder, a conduit for leading the liquid from one side to the other side of the piston, means for controlling the conduit and operable under a predetermined pressure created upon the liquid by the movement of Vsaid pad, and means separate from the cushioning means for supporting the pad, the last said means operating to restore the pad.

7 A pressure cushion for sheet metal presses embodying a pressure pad, an hydraulic cushion for resisting the movement of the pad in one direction, saiducushion einbodying cylinder and piston members, a by` pass for transferring the liquid in the cylin-y der from one side to\the other side of the piston, a valve for controlling the by pass, means creating a predetermined pressure upon said valve and against Which pressure the valve is adapted to be opened by the pressure created Ayielding means being rendered active to'restqre the pad by the movement -of the pad in one direction. I v 8. A pressure cushion for sheet metal presses embodyingV a pressure pad, an hydraulic cushion for resisting the movement of the pad in one direction, vsaid cushion rellippass' for transferring the liquid in the cylin der from one side to the other side of the piston, a valve -for controlling the by pass, means creating a predetermined pressure upon said valve and against which pressure the valve is adapted to be opened by the pressurecreated upon the liquid under the movement of the pressure pad in one direction, means for varying at will the pressure of the last said means upon the valve, and resiliently yielding means separate from the cushioning means for supporting the said pad and serving to restore the pad, the said resiliently yielding means being rendered active to restore the pad by the movement of the pad in one direction. 9. A vpressure cushion v for sheet metal presses embodying a pressure pad, resiliently supporting the Said means from a stationary part of the press, the first said means operating to restore the pad, an hydraulic cushion for-resistingthe movement of the pad in one rylelding means separate from the cushioning `means for: supporting said pad, means for controlled valve for controlling the said conduit and for causing a predetermined pressure to be exertedupon the liquid before the conduit Will be opened, the said pad being restored entirely by the energy created in -said resiliently yieldingmeans When the pad is moved'against the said predetermined pressure in the cushion; Y

10. A pressure cushion for Dsheet metal presses embodying a pressure pad, hanger members connected With a fixed part of the press, resiliently yielding members separate from the cushioning means and supported by the hanger members and operating upon the pad to support and to restore the same, an hydraulic cushion for resisting the movement of the pad in onedirection, said cushion embodying cylinder and piston members relatively movable and one of which last said members is connected with the pad, a conduit for transferring the liquid in the cylinder from one side to the other side of the piston, a valve for co trolling" said conduit and adapted to be opened by the flow ofliquid in one direction through the conduit, and means 4 for creating a predetermined resistance pressure upon the valve against the actionof the 'A vliquid.

11. A pressure cushion for sheet 'metal presses embodying a pressure pad, hanger members connected with a fixed part of the press, resiliently yielding members separate from the cushioning means and supported by the hanger members and operating upon the pad to support and to restore the same,.an

hydraulic cushion for resisting the movement of the pad in one direction, said cushion embodying cylinder and piston members relatively movable and one of which last said members is connected with the pad, a conduit for transferring the liquid in the cylinder .from one side to the other side of the iston,

a valve for controlling said'conduit and 'from the cushioning means and supported by the hanger members and operating upon the pad to support and to restore the same, an hy:

draulic cushion for resisting the movement of the pad in one direction, said cushion embodying cylinder and piston members relatively movable and one of which last. said members 'dis connected with the pad, said cylinder holding and maintaining a predetermined supply of liquid therein, a conduit for transferring the. liquid in the cylinder from one side to the other side of the piston, a valve for controlling said conduit and adapted to be opened by the flow of liquid in one direction through the conduit, and means for creating a predetermined 'resistance pressure -upon the valve against the action of the liquid. l

13. The combination with a movable support for a blank .or Work holder, resiliently yielding means separate from the cushioning means for supporting and restoring said support, an hydraulic cushion for resisting the movement of said support and draw ring in one direction, said cushion embodying cylinder and piston members relatively movable and one of which is connected with said support, variable resistance means for controlling the resistance exerted by the cushion element upon the liquid, and means whereby the liquid may be conveyed from the 'pressure side of the piston to the other side thereof,`the resistance of the said resiliently yielding means to the movement of the work holder port, variable resistance means for control-Y ling the resistance exerted by the cushion element uppn the liquid, and means whereby the liquid may be conveyed from the pressure side of the piston to the other side thereof, Athe resistance of the. said resiliently yielding means to the movement of the work holder and support in a direction to create a resistance pressure upon the liquid being negligible, the said resiliently yielding means constituting the sole means for restoring the draw ring and support therefor.

15. A pressure cushion for sheet metal resses embodying cylinder and piston mem- .ers, hydraulic means for resisting the .relaf tive movement of said members in one direcyembodying a lmember having an opening therethrough, a valve to close said opening from one side ofthe member, 'there being additional openings through said member, a

valve for closing said additional ,openings from the opposite (side o'said member, said valves Workin in oppositionto each other and variable elding means for holding one of the said va ves closed.

16. A pressure .cushion for sheet -meta presses embodying cylinder and piston members, hydraulic means for resistingthe relative movement of saidmembers in one direction, a conduit for leading the liquid back and forth from one side to the other side of the piston, a valve for controlling the movement of the liquid through the conduit, said valve embodying a member having an opening therethrough, a valve to close said opening from one side of the member, there being additional openings through said member, a

10 valve for closing said additional openings from the opposite vside of said member,v said valves Working in opposition to each other, springs individual to the valves for respectively seating them, and means for varying at Will the stress of one of the springs upon its respective valve.

In testimony whereof I have signed my' FREDRICH J. RODE.

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