US1354785A - Die-cushion - Google Patents

Description

D. STRAND.

A mE cusmon.

APPLICATION FILED MAY l, I9L8..

1,354,785. Patented on. 5,1920. l SHEET l.

6 SHERTS- m Il D. STRAND.

DIE cusHloN.

APPLICATION FILED MAY 7, 191.8- A 1,354,785. Patented Oct. 5,1920..

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n, SIRAND. DIE CUSHION.

APPLICATION FILED MAY 7, 1916.

Patenwd Oct. 5, 1920.

QW. www@ Q/ M M m Patented Oct. 5, 1920.

6 SHEETS-SHEET 4.

Inde/tor D. STRAND.

DIE CUSHION.

APPLICATION FILED MAY Z, I9I.8. 1,354,785.

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DIECUSHION.

APPLICATION FILED MAY7, 1918. l

Patented Oct. 5, 1920.

6 SHEETS-SHEET 5.

D. STRAND.

DIE CUSHION.

^ APPLICATIQN man MH, 1918.

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DAVID STRAND, or CHICAGO, ILLINOIS, AssICNo'R, BY MESNE ASSIGNMENTS, To

' RUDOLPH W. CLASNER, or CHICAGO, ILLINOIS.,

DIE-CUSHION.

in die cushions of the fluid pressure type adapted to be secured to ,a die press, wherebytlie same may be readlly attached to or detached from the machine as a Single 1 1n1t, and one ofthe objects of the invent1on 1s to provide an improved self-contained unitary device of this character embodying means constituting` a self-pumping mechanism fo supplying uid to the cushion.`

A further object is to provide an improved device of this character which will be simple, durable, and compact .1n constructionand eective andefiicient 1n operation.

To the accomplishment of these ends, and the equipment of other new and useful obiects 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 1n the accompanying drawings, in which:-

Figure 1' is a vertical sectional view of a portion of a die press having a cushion attached thereto constructed in accordance with the principles of this invention.

Fig. 2 vis a viewA similar to' Fig. 10fanother form.

Fig. 3 is a similar view of another-form of the invention.

Fig. 4 is a similar view o f yanother form of the invention.

Fig. 5 is a similar viewv of another form of the invention. v, l,

Fig. 6 is a similar view of still another form of the invention.

Referring more particularly `to the drawings, the numeral l10 designates generally a bolster plate of a die press having mounted thereon a dieL holding plate 11, in which is arranged a cutting vdie 12'which encompasses a forming block 13.' A pressure ring 14 is preferably disposed between the vforming block and the cutting die 12, which cooperates lwith a cutting `die 15, the latter being mounted upon a reciprocating mem- Specication of Letters Patent. v

Application led May 7, 1918. 'Serial N0. 233,084.

- Patented Oct. 5, 1920.

ber or structure 16, as heretofore known in machines 'of this character. Y

Connected with the machine in a manner to coperate with the pressure ring 14 is a uidpressure cushion` which preferably comprises two cylinder members 16, 17 having their respective outer ends 18, 19 closed with the adjacentends open and telesco'ping with each other, so as to form a chamber or. recep`tacle within the cushion and vin which chamber of the receptacle a lubricant 20 is adapted-to be held. The'element 17 of .the cushion preferably serves in the capacity of a lpiston elementgfnd may be constructed 1n any desirable or suitable manner, but preferably comprises a section 2l which telescopes with the'elements 17 and the two are held; together in any desired Aor suitable manner, such as by means of fastening devices 23 in the form vof screws which/pass loosely through the closed end 19 of the element 17, and then have engagement with the element 21 so Ithat the parts maybe relatively adjusted. The open'end of the element 21 is preferably shaped to form a seat 23 which extends circumferentially ofthe element 21; and the free end 24 of the element 17 terminates short of the seat 23 so as to form a space for packing material 25 arrangedk therein, and which packing material is adapted to contact with the vinner face of the wall of the element 16.

It will be manifest that with this construction, and when the lubricant '20 isheld within the cushion, and when a reciprocating or relative movement is imparted to the] members ofthe cushion, the packing will be moved into' and out of the lubricant 20, and when-it is desired, thel elements 17 21 may be adjusted relatively to each other so as to force thepacking against the wall of the element 16. K

. The cushion thus formed lis adapted` to be secured t'ojthe machine in lany desired or suitable manner,- preferably by means of tie rods26 whichv have engagement at one end with the closed end 18 of the element 16 and are'connected by their other ends with an annular member 27' preferably ,provided with a shoulder 28 adapted to engage and rest upon the upper edge of the element 16.

The ring or element 27 is connected with a stationary portion of the machine, by means is depressed, the element 17 of the cushion will also'be depressed to cause a compression within the cylinder, and this is accom- -plishedthrough the medium of the pins 31 and plate disposed between the pressure rin 14 and the end of the element 17.

ir is supplied to the cushion in any desired or suitable manner, preferably by means of a pumping apparatus which, in the form'of the invention shown in Figs. l and 2, comprise a stationary piston element 32 which is secured to any fixed portion of the cushion, preferably the end 18 of the element 16 by means of suitable fastening devices 33, and a cylinder element 34, pref; erably arranged within the cushion, is connected with the movable element 17 in any suitable manner such as by means of the fastening screws 22, so that when the ele# ments 17, 16 are moved relatively with relation toy each other, the cylinder element 34 will pass over the piston element 32 and any air which has been drawn into the cylinder 34 will be forced therefrom through the valved controlled outlet 35 into the cushion. The supply of air for the pump mechanism is drawn from the atmosphere through a suitable inlet opening 36 controlled by a valve 37 and a packing box 38 is provided between the cylinder 34 and piston element 32, as will be understood.

The pressure within the cylinder is maintained substantiallyl constant and this is accomplished by means of a suitable outlet 39 which extends preferably through the closed end 18 of the element 16 and terminates at a'point above the level of the lubricant 20 therein. Connected with this outlet 39 is a valve 40 adapted to be actuated under an abnormal pressure, and which valve may be of any desirable or suitable construction adapted tobe set so as to maintain a predetermined pressure, but when the pressure is excessive, the valve will yield and the air or fluid will pass therefrom into the atmosphere. A pressure gage 41 may be provided, which is connected with the valve 40, and by means of which pressure gage the predetermined pressure may be determmed.

In the form of the invention shown in Fig. 1, a plurality of pump devices are shown as being arranged Within the cushion, but in the'form of the invention shown in Fig. 2, a single pump apparatus is disclosed,

and in this form of the invetion the pressure within the cushion is maintained substantially constant by means of a suitable compressed air tank 42 which lhas communication with the interior of the cushion by means of a, pipe 43, so that as the cushion is operated and as the pressure iscreated, the

Huid will flow freely into and out of the' cushion and out of and" into the tank 42.

In the vform of the invention' shown in Fig. 3, the pump devices are disposed exterior of the cushion and have connection with the cushion through the medium of suitably connecting pipes 44, and which connections are controlled by a -valve 45, the free end 46 of the connecting pipes 44 extend into the cushion and terminate ata point above the level of the lubricant 20 therein.

In the form of the invention shown in Fig. 4, the pumping apparatus consists essentially of a cylinder element 47, which is preferably arranged interior of the cushion and has an opening 48 through the closed end` 18 of the element 16. The closed end 49 of the cylinder 47 is provided with an opening 50 controlled by a valve 51 and a piston 52 having a valve opening 53, which is arranged to reciprocate within the cylinder 47. This piston 52 is provided witha piston rod 54 surrounding which isv an adjustable collar collar 55 is threaded and the bar ormember 59 is itself supported, preferably by means of a suitable number of bars 60 which have an adjustable connection withthe bar 59, preferably by passing loosely therethrough and which are held in position by means of suitable fastening devices 61, such as screws or the like. The other ends of the bars 60 are preferably detachably connected with the pin plate 30.

With this improved construction it will be manifest that when the pressure ring 14 is operated toI depress the pin plate 30, the latterwill, through the medium of the bars 60 and 59 move the piston 52 in the cylinder 46 and this will cause air to pass through the valved opening 53 into thespace between 'the end 49 of theF cylinder 47 and the piston 52, to be dischaiged therefrom through the opening 50 into the cushion to be compressed therein. The pressure maybe maintained substantially constant in the cushion, in this form of the device, in any suitable manner,

it will be manifest that by adjusting the. same with respect to the bar 59, the relative movement of 'the piston 52 with respect to the cylinder 47 may be 'varied while the stroke orrelative movement-of the cushion elements will re ain constant and by this means, it will b lmanifest that the pressure may be varied. x

It is thought that the operation of this improved apparatus will be clearly understood from the above description, but briefly stated it is as follows:

. Assuming that a metal sheet has been placed on the part 12, the memberr16 and.

its associated 'elements descend, the coperating cutting dies 15 and 12 acting to cut out a blank of the proper size and shape,

the die 15 entering the die 12, as will be. readily understood. As it does s0, the mar- 5 ginal portion lof the blank will be gripped or clamped between the pressure ring 14 and the lower face of the punch or die 15. During the continued descent of the part 16, thev pressure ring 14, which is. forced downwardly by it, is pressed upwardly, securely clamping the sheet metal blank by reason of the action of the compressed air in-the cushion acting 'against the moving member 17 of the cushion, it being understood that the pressure, of course, is to be regulated either by the valve 40 when used or the compressed air tank 42 when that form is used.

The downward, movement of the pressure ring 14, of course, causes a relative movement of the cushion elements, one with relation to the other, and a portion of the air within the cushion,` will be forced out of the outlet 39, when the pressure exceeds the predetermined pressure to which the valve 40 is set; and this, it will be manifest, will maintain the pressure substantially constant within the cushion.

The pressure around the ring, that is, around the forming block 13, is also sub.- stantially uniform. In thus pressing the sheet downwardly it is formed or drawn into shape around the fixed forming block 13, the co-acting descending part 15 and 14 during this operation, clamping the edge of the blank sufficiently to prevent its wrinkling or folding, but not sufficient, however, to 'cause the article being formed to tear or become severed. It will also be obvious that, during the relative movement of the elements 16, 17 of the cushion, air will be pumped into the cushion by means of the pumping apparatus. It is sometimes desirable, to slightly release the gripping movement of the pressure advance of the forming operation, so as to permit the blank to slip slightly. This may be accomplished in any desirable or suitablemanner, but preferably by means of arms or bars 63 which latter are preferably concommences to enter thekdie 12, and when thev element 16 'engages the ends of these elements 63, theelement 17 of the cushion will be slightly depressed, allowing the pressure rin llease the blank.v An adjusting device 65 'may be connected with the'ends of the bars or members 63 for regulating the time at which this releasing movement will take place. These adjusting devices 65 may be in the form of nuts 0r collars screwed upon the threaded extremity 66 of the bars 63 and held in their adjusted positions by means of nuts or collars 67. l

If desired, a portion of the air within the cleaning or blowing off articles from the pressure ring 14 or the ie 12, and to that end there may be provided a nozzle 68, with which is connected a tube or pipe 69, the free end of which extendsinto the cushion and terminates as at 70 at a point above the level of'the lubricant therein, so that when the element 17 is forced into the element 16 of the cushion, a portion of the air will be forced throughthe pipe 69 to be discharged through the nozzle 68 against the work, and which nozzle may be supported by a suitable bracket 71 supported to a fixed portion of the machine. A

While the preferred forms of the invention have been herein shown and described, it is obvious-that various changes may be made in the details of construction and in the combination and arrangement of the several parts, within the sco o ,f the claims Vwithout departing from the spiri+ of this ing on said blank, gripping means during such relative movement of vsaid gripping means and block, said' cushion embodying relatively movable opposed coperating cylindrical elements, each element having an open and a closed end, the open ends of the elements telescoping, one-of said lele- 14 to recede slightly and thereby recushion may be employed as a means for" ments being fixed and the other of said elements being operatively related to the said gripping means, said cushion also embodying means whereby the relative movement of the. cushion elements will supply fluid between the said elements.

2. The combination of a forming block, means adapted to grip a sheet metal blank, means to move said gripping means and block relatively one with relation to the other to cause the shaping of the blank over the block, and a fluid pressure cushion acting on said blank-gripping means during such relative movement of said gripping means and block, said cushion embodying relatively movable opposed cooperating cylindrical elements, each element having an open and a closed end, the open ends of the elements telescoping, one of said elements being fixed, the other of the said elements "being responsive in its operation to the operation of the said gripping means, and provisions whereby fluid will be supplied to the cushion by the relative movement of the said elements.

3. The combination of a forming block, means adapted to nfrip a sheet metal blank, means to move said gripping means and -block relatively one with relation to the other to causethe shaping of the blank over the block, and a fluid pressure cushion acting on'said blank gripping means during such relative movement of said gripping means and block, said cushion being freely detachable and self-contained and embodying relatively movable opposed coperating cylindrical elements having open telescoping ends, one of said elements being fixed, the other of said elements being responsive in its operation tothe operation of said gripping means, and provisions whereby Huid will be supplied between the elements by the relative movement of the said elements. l

4. The combination of a forming block,

means adapted to grip a sheet metal blank,

means to move said gripping means and block. relatively one with relation to the other to cause the shaping of the blank over the block, and a fluid pressure cushion acting on said blank gripping means and block, said cushion being freely detachable and self-contained and embodying relatively movable opposed coperating cylindrical elements having open telescoping ends, one of said elements being fixed, the other of said elements being responsive in its operation to the operation of the said gripping means, provisions whereby fluid will be supplied between the .elements by the relative movement4 of the said elements, and

means whereby the pressure within the cushz ion will be automatically controlled.

5; The combination of a forming block, means adapted to grip a sheet metal blank,

means to move said gripping means and block relatively, one with relation to the other to cause the shaping of the blank over the block, and a self-contained and freely detachable fluid pressure cushion acting on said blank gripping means during such relative movement of' said gripping means and block, said cushion embodying opposed cylindrical elements having open telescoping ends, one of said elements being fixed, the other element being operatively related to the said gripping means, one of said elements forming an oil chamber into which the other element telescopes, means whereby the relative movement of the'cushion elements will supply fluid between the cushion elements, there being an outlet for the fluid leading from between the elements, and means for controlling said outlet.

6. The combination of a forming block, means adapted to grip a sheet` metal blank, means to move said gripping means and block relatively one with relation to the other to cause the shaping of the blank over the block, and a fluid pressure cushion acting on said blank gripping means during such relative movement of said gripping means and block, said cushion embodying relatively movable opposed coperating cylindrical elements, each element having an open and a closed end, the open ends of the elements telescoping, one of said elements being fixed and the other of said elements being operatively related to the said gripping means, said cushion 'also embodying means whereby the relative movement of the cushion elementsy will supply fluid between the said elementsthe last recited means embodying a pump structure carried with the said cushion.

7. A self-contained freely vattachable and detachable fluid pressure cushion for sheet metal die machines, said cushion embodying opposed relatively movable cylindrical elements having their outer en ds closed and their inner ends open and telescoping, means for anchoring one of the said elements, one of the elements constituting an oil chamber into and out of which oil the other elements move, meanswhereby the relative movement of the said elements will supply fiuid to be compressed between the said elements, there being an outlet for the fluid leading from between the elements above the level of the oil in the cushion.

8. A self-contained freely attachable and detachable fluid pressure cushion for sheet metal die machines, said cushion embodying opposed relatively movable cylinder elements havingl their outer ends closed'an'd theirinner ends open and telescoping, means for anchoring one of the said elements, one of the elements constituting an oil chamber into and out of which oil the other element moves, means whereby the relative moveto be compressed between the saidv elements,

and means for maintaining a substantially unvarying pressure in the cushionpfbetween said elements. l

9. A self-contained freely attachable and detachable-fluid pressure cushion for sheet metal die machines, said Cushion embodying opposed relatively movable cylinder elements having closed outer ends and open telescoping inner ends, means for anchoring one of the said elements, a pump structure carried with' the cushion and adapted to supply fluid' to the cushion by the relative movement of the' said elements, and means for maintaining a predetermined pressure in the cushion.

10. A self-contained freely attachable and detachable fluid pressure cushion for sheet metal die machines, said cushion embodying opposed relatively movable cylinder elements, having closed outer and' open telescoping inner ends, means for anchoring one of the said elements, means whereby 4the relative movement of said elements will supply fluid to the cushion to be compressedA therein, means for maintaining a predetermined pressure in the cushion, one of said elements Iembodying telescoping sections, one of the sections having a packing seat, packing between the saidsections and engaging said seat, and means adjustably securing the said sections together for holding and compressing said packing, said packing forming a fluid tightl joint between the cushion elements.

11. A self-contained freely attachable and detachable fluid pressure cushion for sheet metal die machines, said cushion embodying opposed relatively movable telescoping cylinder elements having closed outer ends, means 'for anchoring one` of the elements, said means embodying a tubular element secured to the end of one of the cushion elements and passing through the other cushion element and upon which the latter slides,-

a fastening device passing through the tubular element, one end of the fastening device Vextendingbeyond one end of the tubular element, said fastening device having a shoulden engaging the other end of the tubular element, and means whereby the relative movement of the cushion elements will supply fluid to the cushion to'be compressed detachable fluid pressure cushion for sheet metal die machines, said cushion embodying opposed relatively movable telescoping cylinder elements having closed outer ends, means for anchoring one of the elements,

said means embodying mechanism secured to one of the cushion-elements and anchored to afiXed part of the machine, means whereby the relative movement of the cushion elements will supply fluid to the cushion to beV compressed between the cushion elements, one of the cushionv elements forming a lubricant receiver, there being an outlet leading from the cushion from above the lubricant, and means for controlling said outlet.

13. A self-contained freely attachable and detachable fluid pressure cushion forsheet metal die machines, said cushion embodying opposed relatively movable cylinder elements having closed outer ends and open telescoping inner ends, means for anchoring one, of the said elements, a pump structure carried with the cushion and adapted to supply fluid to the cushion by the relative movement of the said elements, and means for maintaining a predetermined pressure in the cushion, said pump structure being located within the cushion and being disposed between the said cushion elements.

14. A self-contained freely attachable and detachable fluid pressure cushion for sheet metal die machines, said cushion embodying opposed relatively movable cylinder elements having closed outer ends and open telescoping inner ends, means for anchoring one of the said elements, a pump structure carried with the cushion and adapted to supply fluid to the cushion by the relative movement of the saidy elements, means for maintaining a predetermined pressurein the cushion, said pump structure embodying a cylinder and piston, said pump cylinder being connected with one of the cushion elements and said piston being connected with the other cylinder element whereby the relative movement of the cylinder elements will actu'ate the pump.

15. A sheet metal press embodying a forming block, means adapted to grip a sheet metal blank, means to move said gripping means and bloc'k relatively to one another to cause the shaping of the blank over the block, inl combination with a freely attachable and detachable fluid pressure cushion acting on said blank gripping means with substantially unvarying pressure during such relative movement of said gripping means and block, and means operating automatically to slightly relieve the pressure of ^the said gripping means upon the blank at a predetermined point in the shaping of the blank.

16.' A sheet metal press embodying a forming block, means adapted to grip a sheet metal blank, means to move said gripping means and block relatively to one anotherto cause the shaping of the blank over the block, in combination with a freely attachable and detachable fluid pressure cushion acting on said blank gripping means with substantially unvarying pressure during such relative movement of said gripping -means and block, and means operating automatically to slightly relieve the pressure of the said gripping means upon the blank at a predetermined point in the shaping of the blank, the said pressure relieving means being operatively related to the said cushion.

17. A sheet metal. press embodying. a forming block, means adapted to grip a sheet metal blank, means to movel said gripping means and block relatively to one another t'o cause the shaping of the blank over the block, in combination with a freely attachable and detachable fluid pressure cushion acting on said blank gripping means with substantially unvarying pressure during such relativevmovement of said gripping means and block, means operating automatically to slightly relieve the pressure of the said gripping means upon the blank at a predetermined point in the shaping of the blank, and means whereby the time of operation of the said pressure relieving means may be varied at will.

18. A sheet metal press embodying a forming block, means adapted to grip a sheet metal blank, means to move said gripping means and block relatively to4 one another to cause the shapingof the blank over the block, in combination with a freely attachable and detachable fluid. pressure cushion acting on said blank gripping means with substantially unvarying pressure, during such relative movement of said gripping means and block, means whereby a portion of the fluid will be discharged from the cushion during such relative movement, and means for discharging a blast of fluid from the cushion adjacent the forming block.

19. A self-contained freely attachable and detachable fluid pressure cushion for sheet metal die machines, said cushion embodying opposed relatively movable cylinder elements having closed outer ends and open telescoping inner ends, means for anchoring one of the said elements, a pump structure carried with the cushion and adapted to supply fluid to the cushion by the relative movement of said elements, and a compressed fluid tank having communication with the cylinder, whereby the pressure in the cushion land tank is always maintained substantially the same. y

420. A self-contained freely attachable and detachable fluid pressure cushion forsheet metal die machines, said cushion embodying opposed relatively movable cylinder elements having closed outer ends and opentelescoping inner ends, means for anchoring one of said elements, and a pump structure adapted to supply fluid to the cushion, said pump being operableby the relative moveinents having closed outer ends and open telescoping inner ends, means for anchoring one of said elements, a pump mechanism responsive in its operation to the relative movement of the cushion elements, said pump mechanism operating to supply iiuid to the cushion, and means operating automatically to maintain a substantially unvaryi'lg pressure in the cushion.

22. self-contained freely attachable and detachable fluid pressure cushion for sheet metal die machines, said cushion embodying opposed relatively movable 4cylinder elements having closed outer and open telescoping inner ends, means for anchoring one of said elements, and pump mechanism responsive in its operation to the relative movement of the cushion elements, and adapted to supply fluid to the cushion. betweenA the elements thereof, said pump mechanism receiving its vsupply of fluid from the atmosphere.

23. A self-contained freely attachable and detachable fluid pressure cushion for sheet metal die machines, said cushion embodying opposed relatively movable cylinder elements having closed outer and open telescoping innerl ends, means for anchoring one of said elements, and pump mechanism responsive in its operation to the relative movement of the cushion elements, adapted to supply Huid to the4 cushion between the elements thereof, said pump mechanism receiving its supply of fluidfrom the atmosphere, and means operating to automatically maintain a substantially unvarying pressure in the cushion.

24. The combination of 'a sheet metal shaping member, means coperating with said member for shaping thematerial and embodying gripping means for the material, a freely-detachable and self-contained fluid pressure means for maintaining a substantiallyunyarying pressure on the gripping means during the operation of shaping the material, said iiuid pressure means embodying a piston and a .cylinder element, means whereby the gripping means will be responsive in its operation'to the operation of one of the parts of the cushion, and means embodying pump mechanism responsive in its4 115 operation to the relative movement of the cushion elements forl supplying fluid between the cushion elements.

25. The combination of a sheet metal shaping member, means coperating with said member for shaping the material and embodying gripping means for the material,

a freely detachable and self-contained fluid pressure means for maintaining a substantially unvarying pressure on the gripping means during the operation of 'shaping the material, said fluid pressure means embodying a piston and a cylinder element, means whereby the gripping means will be responsive in its operation to the operation of one 1 30 of the parts of the cushion, means embodying pump mechanism responsive in its operation to the relative movement of the cushion elements for supplying fluid between the cushion elements, and means operating to maintain aI substantially unvarying pressure in the said cushion.

26. The combination of a sheet metal shaping member, means coperating with said member for shaping the material and embodying gripping means for the material, a freely detachable and self-contained fluid pressure means for maintaining a substantially lunvaryi'ng pressure on the gripping means during the operation of shaping the material, said fluid pressure means em"- bodying a piston and a cylinder element, means whereby the gripping means will be responsive in its operation to the operation of one of the parts of the cushion, means embodying mechanismresponsive in its operation to the relative movement of the cushion elements for supplying fluid between the cushion elements, and means operating to maintain a substantially unvarying pressure in the said cushion, the said fluid supplying mechanism receiving its supply from the atmosphere.

27. The combination of a sheet metal shaping member, means coperating with said member for shaping the material and embodying gripping means for the material,

a freely detachable and self-contained fluid pressure means for maintaining a substantially unvarying pressure on the gripping means during the operation of shaping the material, said fluid pressure means embodying a piston and a cylinder element, means whereby the gripping means will be responsive in its operation to the operation of one of the parts of the cushion, and means embodying pump mechanism responsive in its operation to the relative movement of the cushion elements for supplying fluid between the cushion elements, the last recited means embodying mechanism whereby the operative stroke of the pump mechanism may be varied with relation to the said relative movement of the cushion elements.

28. A self-contained freely attachable and detachable fluid pressure cushion for sheet metal die machines, said cushion embodying opposed relatively movable cushion elements, means for anchoring one of the cushion elements, mechanism to the operation of which the other cushion element is responsive to cause a relative movement of the cushion elements, pump mechanism for supplying fluid between the cushion elements, said pump mechanism embodying a cylinder and piston, the said cylinder and piston being one connected. -with the anchored cushion element, and the other having an operative connection withthe first recited mechanism.

2 9. A self-contained freely attachable and termined pressure in the cushion.

detachable fluid pressure cushion for sheet metal die machines, said cushion embodying opposed relatively movable cushion elements,

.means for anchoring one of the cushion elements, mechanism to the operation of which the lother cushion element is responsive to cause a relative movement of the cushion elements, pump mechanism for supplying fluid between the cushion elements, saidl pump mechanism embodying a cylinder and piston, the said cylinder and piston being one connected with the anchored cushion element, and the other having an adjustable .operative connection with the first recited mechanism whereby the operative movement of the pump mechanism with respect to the relative movement of the cushion elements may be varied.

30. A self-contained freely attachable and detachable fluid pressure cushion for sheet metal die machines, said cushion embodying opposed relatively movable cushion elements, means for anchoring one of the cushion elements, mechanism `to the operation of whichA 3l. A self-contained freely attachable and detachable fluid pressure cushion for sheet metal die machines, said cushion embodying opposed relatively movable cushion elements,

Ameans for anchoring one of the cushion elements, mechanism to the operation of which the other cushion-element is responsive to cause a relative movement of the cushion elements, pump mechanism for supplying Huid between the cushion elements, said pump mechanism embodying a cylinder and piston, the said cylinderv and piston being one connected with the anchored cushion element, and the other having an operative con' nection with the first recited mechanism, the said pump mechanism receiving its supply from the atmosphere.

32. A self contained freely attachable andY detachable fluid pressure lcushion for sheet metal die machines, said cushion embodying a cylinder and piston movable relatively one A with relation to the other, means for anchor- 4ing one of the parts of the cushion, a pump structure carried with the cushion and adapted to supply fluid to the cushion, by the relative; movement of the cushion elements, and means for maintaining a prede- 33. A self-contained freely attachableand detachable fluid pressure cushion for sheet metal die machines, said cushion embodying detachable fluid pressure cushion for sheet a cylinder and piston elements relatively metal die machines, said cushion embodying movable, means for anchoring one of the eleacylinder and piston, means for anchoring ments, a pump mechanism responsive in its one of the parts of the cushion, and apump l5 5 operation .to the relative movement of the structure adapted to supply fluid to the cushcushion elements, said pump mechanism opion, said pump being operable by the relative erating to supply Huid tothe cushion, and movement of the cushion elements. i means operating. automatically to maintain a In testimony whereof I have signed my substantially unvarying pressure in the name to this specication on this 2nd day of 2o 10 cushion.V May, A. D. 1918.

34. A self contained freely attachable and DAVID STRAND.

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