US1619069A - Blank-holding means - Google Patents

Description

March 1 1927.

R. w. GLASNER ET AL BLANK HOLDING MEANS FiledAug. 6, 1924 2 Sheets-Sheet 1 March 1,1927. 1,619,069 R. w. GLASNER ET AL BLANK HOLDING MEANS Filed Aug. 6, 1924 2 Sheets-Sheet 2 -III 1 1&2

Patented Mar. 1, 1927. Y

UNITED ;STATES PAT ENT OFFICE.

RUDOLPH W. G'LASTNTER AND JOHN NELSON, OF CHICAGO, ILLINOIS, ASSIGNORS TO MARQUETTE TOOL & MANUFACTURING CO., OF CHICAGO, ILLINOIS, A CORPORA- TION OF ILLINOIS. i

BLANK-HOLDING MEANS.

Application filed August 6, 1924. Serial No. 730,352. 7

This invention relates to improvements in and with parts omitted and showing applied blank holding means and one of the objects thereto a plurality of cushioning means for 55 of the same is to provide power presses inthe blank holding means. tended for main connection with sheet metal Figure 3 is an enlarged detail sectional 5 drawing dies, with means to provide the View of the fluid pressure controlling valves. gripping means of these drawing 'dies with a Referring more particularly to the drawsubstantially unvarying pressure during the ings the numeral designates a portion of 60 stroke of the press, and further to eliminate a press having a ram 11 which is reciprocable in the press the objectionable back lash in the ordinary and well known manner.

10 caused by the release of this pressure at the Supported by the press is a bolster plate 12 bottom of the stroke of the press when the and mounted upon the bolster plate in any ram of the press is moving upward. This suitable manner is a center or punch block 65 back lash takes place at the time when the 18, with which a. female die member 14 cocrank of the press is passing over the center operates to shape the article, the die mem- 15 point at the bottom of its stroke or circular ber 14 being connected with the ram 11 for movement. movement therewith. Cooperating with the Another object of the invention is to procenter block or punch 13 is a draw ring 15 vide presses and dies of this character with which latter is supported by means of suiteven pressure blank gripping means, which able die pins 16 that pass loosely through the will be of a simple construction and of such bolster plate 12 and rest upon a suitable presdesign as will fit into the ordinary press and sure pad or member 17 below the bolster die such as are now being used, without neplate. Connected with the bolster plate 12 75 cessitating a specially designed press or speand depending therefrom is a stationary bar cially designed dies. or rod 18, one end of which is secured to the Another object of this invention is to probolster plate preferably. by bein screwed vide presses of larger dimensions with a dethereinto. This rod 18 passes loosely through vice of this character built as a unit but covthe pressure pad 17 and extends for any 'de- 3 ering a larger area of space through an open-- sired distance below the bolster plate 12.

/ ing in the bedof the press. The lower extremity of the rod 18 is thread- Another object of the invention is to proed as at 19 to receive a nut or collar 20 and vide means for metal drawing dies of the upon which nut or collar a spring supportcharacter described which will provide a ing plate 21 rests, and the rod 18 loosely constant pressure during the up and down passes through the plate 21. Encompassing movement. of the press and still permit a the rod 18 and resting upon the plate 21 by varying pressure at difierent points throughone end is a coil spring 22 upon the upper out the area of the blank gripping means. end of. which spring rests another spring To the attainment of these ends and the plate 23 that loosely surrounds the stationaccomplishment of other new anduseful ob-- ary rod 18. Loosely surrounding rod 18 jects as will appear, the invention consists in above the plate 23 and resting thereupon by the features of novelty in substantially the one end thereof, is a sleeye 24 which is proconstruction, combination and arrangement vided with external screw threads to receive of the several parts hereinafter more fully a nut or collar 25. Resting upon the nut or described and claimed and shown in the accollar 25 and loosely encompassing the rod coinpanying drawings illustrating this in- 18 and sleeve 24 is aspring supporting plate vention and in which, 26 which latter'is spaced for a considerable Figure 1 is a view partly in elevation distance below the pressurepa-d 17 A coil I partly in sectionof a draw press having a spring 27 loo ely ncom a th d 18,100

the plate 'blankholding means constructed in accordand one end of this spring engages ance with the principles of the invention ap- 26 While the other end of thespring engages plied thereto and with parts ofthe press the pressure pad 17.

- omitted. Pins or rods 28 engage the spring plate 23 Figure 2 is a view of a larger form of by one end and rest thereupon. The other press artly section ends of these pins or rods 28 have engagepartlyin elevation, p

I pressed.

. ment with the ram 11, so that when the ram 15 moved downwardly the rods 28, which pass loosely through the bolster plate andcauses the pins 28 to follow the ram.

" ring side of 7 Upon the downward movement of the ram 11 the draw ring 15 will be depressed by the female die member 14, and the draw will, through the medium of the pins 16, which latter pass loosely through the bolster plate 12 and engage the spring plate 17, depress the latter against the stress of the spring 27. I

The spring 27 operates to control the draw ring 15 and the tension of the spring 27 may be varied by adjusting the nut or collar-25 upon the sleeve 24. The action of the plus 28 upon the spring 22 through the med um of the plate 23 will compress the spring, while the action of the pins 16 upon the plate 17 will compress the spring 27. This combined action tends to impart a substantially unvarying pressure to the draw ring 15 and to relieve the ram of the press from considerable resistance of the draw ring.

Connected with the spring plate 23 for movement therewith is a cylinder 29 within 30 which is arranged a piston 30. The piston is preferably connected with the rod 18 so as to be maintained stationary while the cylinder 29 is reciprocable with respect to the piston. If ,desired the rod 18 may be of a sectional construction, the piston being connected with one section and the other section being secured to and depending from the 'cy spring 22. r V

The cylinder 29 is supplied on the lower from a suitable source of supply, such as a communication with the cylinder 29, through the medium of a'pipe 32, and the pipe may, if desired, pass loosely through an opening 33 in the member 21. Arranged in the connection 32 between the cylinder 29 and source of fluid supply,

connects with the pipe is controlled by a spring controlled valve 36 having means 37, for varying'the stress of the valve 36. .The valve 36 is so arranged that it will be unseated by the fluid flowing through the pipe 32 under pressure from the source of supply to the cylinder but when it is attempted to force the fluid back into the source of supply, the valve 36 will close the passage. A by-pass'38 is connected with the pipe 32 in advance-of the valve, 36'and is also connected with the valvecasing 34, behind the valve, a springcontrolled valve 39 being also provided in the casing to contr l the der to support the plate 21 and h the piston 30, with a suitable fluid b is a valve casing 34: which is provided with a passage 35 that 32, and this passageby-pass passage. An dj ti device 40 may be providedf or varying the How from the tank 31 into the cylinder 29- on the bottom side of the piston 30, the valve 36 will open to permit such passages of the fluid and the valve 39 will close. When, however, the piston 30a-nd cylinder 29 are relatively moved in the opposite direction the fluid will be forced from the cylinder 29 back into the tank. valve 36 will close and the to permit the fluid to flow through the passage 41' in the valve casing 34 back into the tank 31 throughthe pipe 32.

Obviously the elements 37 and 40 may be adjusted to vary the pressure necessary to unseat the respective valves 36, 39.

In operation and assuming the ram 11 to be elevated, the pressure pad 17 will rest against the bottom of the bolster plate 12 and the top of the draw ring 15 will be substantially flush with 13. The spring plate 23 will also be elevated to the limit of its upward movement and will be maintained in such elevated position through the stress of the spring 22; the sleeve 24 serving to prevent rising movement of the plate 23.

Withthe parts in this position the blank to be formed is laid on top of the draw ring 15 and across the center punch or die 13. As t e press ram 11 descends, carrying with it the-female die member this die 14 will engage the blank and hold it etween the die 14 and upper surface of the draw ring 15. The pins 16 engaging the pressure pad 17, will move the pad ainstthe pressure of the top spring and the stress of the spring. 27, will be exertedupon the blank to be drawn, thereby holding the blank at the correct tension to prevent wrinkling of the metal.

During the descending movement of the ram 11 the pins 28 are in contact with the press rain at the' same time that the die engages the blank. The ram then pushes against the lower spring 22 through the plate 23, and in this manner relieves the draw ring of the increasing pressure which would otherwise be caused through the compression of the top spring 27 and takes this increasing pressure off the blank to be drawn, at the initial pressure during the entire downward movement of the press. During this operation the fluid on the top side of the piston 30 will escapethrough the a further 14, the'lower face ofso that the blank is thereafter held At this time the valve 39 will open the center punch or die pass loosely throu h the plate 42 and have hanger rods 43 each one through the control valve 39 and this valve may be so set that it will retard the upward movement of the cylinder 29. The actlon of the fluid in this cylinder and through the medium of the various connections and parts will retard the upward movement of the pressure pad 17 which supports the die pins 16 and draw ring 15. A

This will eliminate the so called back lash of the press and will relieve the press clutch of great strain, and also prevent the so called repeats which are caused by the momentum of the ordinary cushioning device,.and also will eliminate accidents.

There is shown in Figure 2 of the drawing a press havin an extended or 'much greater capacity than the press shown in Figure 1, and has connected with a pluof the cushioning devices shown in rality Figure 1. In this form ofv the invention a supporting plate 42 is provided for supporting the cushioning devices and is suspended beneath the press in any desired or suitable manner, such as by means of of which passes through a suitable eye or projection 44, on the body of the press 45. .These rods 43 connected with their free extremity a nut or collar 46 which is threaded thereupon. A sleeve 47 encompasses the lower end of the bar or rod 18 and also loosely passes through the plate 42, so that the plate 21 of the respective cushioning: devices which is engaged by one end of the lower spring 22, may be readily adjusted with respect to the support 42, by adjusting the respective nut or collar 20.

With this form of the invention the pins 16 of the cushionin means pass loosely through the bolster p ate 12 and all engage a'common plate 48 against which the upper ends of the springs 27 of the cushioning means engage and which plate 48 serves the same function as the pressure pad 17. I

It will be manifest that with this form of the 'inventionthere will be a substantlally constant pressure upon the draw ring 15 by all of the cushioning devices during the operation of the press, but inasmuch as each of the cushioning devices is provided with an independent meansfOr varying at will the stress otthe springs of the respective cushioning devices, they may be independently adjusted with respect to each other as to produce or permitdifferent pressures of the draw ring at various points throughout the area of the draw ring.

At the same time the-piston and cylinder attachment provides a means by which'the' back lash will be prevented or overcome,

and which back lash in presses of this character occurs at the time when the press crank is passing the bottom of its stroke and just as the ram begins to recede and yielding it is to be understood that various changes may be madein 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. 1

What is claimed as new is p 1. A draw press including a forming die, a movable element co-operating with the die, a blank holding member, lresiliently yielding means for resisting the movement of the blank holding member, a second re siliently yielding means also operable to resist themovement of the blank holding mem-- ber, means responsive to the movement of the. said movable element and operating to relieve the pressure of the second recited yielding means upon the said blank holding member, and fluid pressure means operating to retard the return movement-of the said blank holdin means when the said movable member rece es. I

2. A draw press including a forming die, a movable element co-operatlng with the die, a blank holding member, resiliently yield: ing means for resisting the movement of the blank holding means, a second resiliently means also operable to resist the movement of the blank holding member, means responsive to the movement of the said movable element and operating to relieve the pressure of the second recited yielding means upon the said blank holding member, and fluid pressure means operating-to retard the return movement of the'said blank holding means when the saidinovable' member recedes, the said fluid pressure means embodying a relativelymovable cylinder and piston one operatively. connected with the blank holding member and the other anchored to 'a stationary. art'of the press and means for supplying uid to the cylinder. 3. A draw press including a forming die, a movable element co-operating with the die, a blank holding member, a plurality of separate and. resiliently yielding means operating upon the blank holding member, means whereby the said movable element will at a predetermined point in the cycle of operation of the press directly operate upon one of the said resiliently yielding means .to prevent an increasing pressure of the other of the resiliently yielding means upon the said blank holding member, whereby the work will be held by the blank holding member at a substantially unvarying pressure during the stroke of the press, and additional means for restraining the 'return movement of the blank holding means.

4. A draw press including a forming die, a -movable element co-operating with. the

die, a blank holding member, a plurality of separate and resiliently yielding means oper at-lng upon the blank holding member, means whereby the said movable element-will at a predetermined point in the' cycle of operat1on of the press directly operate upon one of the said resiliently yielding means to prevent an increasing pressure of the other of the resiliently yielding means upon the said blank holding member, whereby the work will be held by the blank holding member at a substantially unvarying pressure during the stroke of'the press,and fluid pressure means for restraining the return movement 'of the blank holding means, said fluid pressure means including a relatively movablecylinder and piston one'of which is operatlvely connected with the blank holding means and the other anchored to a stationary part of 'thepress and means for supplying fluid to the cylinder.

5. A. draw press including a forming die, a movable member co-operating with the die, a. blank holding member, superposed and separate resiliently yielding elements resisting the movement of the blank holding member, means whereby a movable part of the press will operate directly upon one of the said elements to relieve the pressure of the other of the resiliently yielding means upon the blank holding member, and fluid pressure means operating to retard the return movement-of the said blank holding means when the said movable member recedes. 1 p

' 6. A drawpress including a forming die, a movable member coo crating with the die, a blank holding mem er, superposed and separate resiliently yielding elements resist-r ing the movement of the blank holding memper, means whereby a movable part of the press will operate directly upon one of thesaid elements to relieve the pressure of the a other of the resiliently yielding means upon the blank holding member, fluid pressure means operating to retard-the return movement, of the said blank holding means when the said movable member recedes, and means individual to the said elements for varymg at will the stress of said elements.

7. 'A draw press including a forming die, a movable member co-operating with the die, a 'blank holding member, superposed and separate resiliently yielding elements'resisting the movement of the blank holding member, means whereby a movable part of the press will operate directly upon one. of the.

said elements to relieve the pressure of the other of the'resiliently yielding means upon the blank holding member, fluid pressure means operating to retard the return movement of the said blank holding means when Y the said movable member recedes, the said fluid pressure means embodging a cylinder and piston relatively mova 1e, one of the parts being connected with the blank'holdmg member and the other beinganchored to a stationary art of the press, and'means for supplying uid to the cylinder.

8. A draw press "including a forming die,

a movable member co-operating with the die,

a blank holding member, superposed and separate resiliently yielding elements resisting themovement of the blank holding member, means whereby a movable part of the press will operate directly upon one of the the said resiliently yielding means.

9. A draw press includin a forming die, a movable element co-operating with the die,

yielding blank holding means, and spring cushioning means providing the said blank holding means with a substantially unvarying pressure during the operative stroke of the said movable element, the last recited means including a plurality of resilient elements independent of each other and means individual to the said movable element and the said blank holding means for respectively controlling the operation of thesaid resilient elements, one of the said means which is individual to the movable element and the blank holding means operating at a predetermined time in the cycle of operation of the press to relieve the blank holding means of the stress of its respective resilient element.

10. A draw press including a forming d e, a movable element co-operating'with the d1e, yielding blank holding means, spring cushloning means providing the sald blank holding means with a substantially unvarymg pressure during the operative stroke of the said movable element, the last recited. means the said movable element, the last recited' means-including a plurality of resilient elements and 'means individual to the said movable element and the said blank holding means for respectively controlling the operationof one of the said resilient elements,

and means individual to the said resilient last recited elements one independently of elements for varying at will the stress of the the other.

12. A draw press including a forming die, a movable element co-operating with the die, yielding blank holding means, spring cushioning means providing the said blank holding means with a I substantially unvarying pressure during the operative stroke of the said movable element, the last recited means including a plurality of resilient element;-

and means individual to the said movable element and the said blank holding means for respectively controlling the operation of one of the-said resilient elements, and means for restraining back lash caused by the release of the pressure-upon ing means as the said movable element recedes.

13. A draw press including a forming die, a movable elementco-operating with the die, yielding blank holding means, spring cushioning means providing the said blank holding means with pressure during the operative stroke of the said movable element, the last recited means including a plurality of resilient elements and means individual to, the said movable element and the said blank holding means for respectively controlling the operation of the said resilient elements, and fluid pressure means for restraining back lash caused by the release of the pressure upon the blank holding means as the said movable element recedes.

14. A draw press including a forming die, a movable element co-operatingwith the die, yielding blank holding, means, spring cushioning means providing the said blank holding means with a substantially unvarying pressure during the operative stroke of the said movable element, the last recited means including a plurality of resilient elements and means individual to the said movable element and the said blank holding means for respectively controlling the operation of the said resilient elements, and fluid pressure means operating automatically to restrain. back lash caused by the release of the pressure upon the blank holding means as the said movable elements recedes.

15. A draw press including a forming die, a movable element co-operating with' the die, yielding blank holding means, spring cushioning means providing the said blank holding means with a substantially unvarying pressure during the operative stroke 0 the said movable element, the last recited means including a plurality of resilient elements and means individual to the said movable element and the said blank holding means for respectively controlling the operation of the said resilient elements, fluid p pressure means for restraining back lash caused by the release of the pressure upon the blank hold cushioning a substantial unvarying the blank holding means'as the said movable element recedes, and means for "varying at will the degree of thefiuid pressure.

16. A draw press including a forming die, a movable element co-operating with the die, yielding blank holding means, spring cushioning means providing the said blank holding means with a substantially unvarying pressure during the operative stroke of the said movable element, the last recited means including a plurality of resilient elements and means individual to the said movable element and the said blank holding means for respectively influencing the said'resilient elements, and means for varying at will the stress of the said resilient elements, one with relation to the other.

17. A draw press including a forming die, a movable element co-operating with the die, yielding blank holding means, spring means providing the said blank holding means with a substantially unvarying pressure during the operative stroke of the said movable element, the last recited means including a plurality of resilient elements and means individual to the said movable element and the said' blank holding means for respectively influencingthe said resilient elements, and means indiviual to the said resilient elements for independently varying the stress of ment and one with respect to the other.-

18. A draw press including a forming die, a movable element co-operating with the die, yielding blank holding means and. spring cushioning means providing the said blank holding means with a substantally unvarying pressure during the operative. stroke of the said movable element, the last recited means including a plurality of resilient elements and means individual to the said movable element and the said blank holding means for respectively controlling the opthe release of the pressure upon the blank the said resilient eleholding means as the said movable element recedes, the said restraining means including a relatively movable cylinder and piston one being anchored to a fixed part of the press and the other being operatively connected with a movable part of the press, and means for introducing a fluid into the cylinder.

19. A draw press including a forming die, a ram co-operating with the forming die, a

f blank holding member cooperating with the die a plurality of separate cushioning means co-operating with the said blank holding member for yieldingly restraining the member in its operation with respect to the said ram, the said cushioning means roviding the blank holding means with a substantially unvarying pressure during the active stroke of the said movable element,

1 blank holding mem and means individual to the means whereby the holding member for yieldingly restraining the member in its operation with respect to the said ram, the said cushioning means providing the blank holding means with a substantially 'unvarying pressure during the active stroke of the said movable element, means individual With said cushioning means whereby the pressure upon the said blank holdin, member may be varied at predetermine points throughout the area of the said blank holding member and means for restraining back lash caused by the release of the ressure of the said movable element upon the said blank holding member when the said movable element recedes.

21. A draw press including a forming die, a ram co-operating with the forming die, a blank holding member co-operating with the die, a plurality of separate cushioning means co-operating with the said blank holding member for yieldingly restraining the member in its operation withrespect to the said ram, the said'cushioning means providing the stantially tive stroke of the said -movab'le element, means individual to the said cushioning means whereby the pressure upon the said blank holdin member may be varied at predetermined of the said blank holding member, and fluid pressure means for restraining back lash"? caused by the release of pressure of the said movable element upon the said blank holding member when the said movable element recedes.

22. A draw press including a forming die,

blank holding means; with a subunvarying pressure during the ac points throughout the area a ram co-operating with the forming die, a blank holding member co-operating with the die, a plurality of separate cushioning means co-operating with the said blank holding member for yieldingly restraining the memoperation with respect to the said her in its ram the said Cushioning means providing the blank holding means with a substantially "unvarying pressure during the active stroke said fluid pressure means including a rela-' tively movable cylinder and piston one operatively connected with the blank holding member and the other anchored to a stationary part of the plying fluid to the cylinder.

23. A draw press including a forming die, a movable member co-operating with the die, a blank holding member, a plurality of separate resiliently yielding elements resisting the movement of the blank holding member, each ofthe elements embodying spaced plates and acoiled spring therebetween, pins engaging the blank holding member and one of the said plates of one of said elements, pins engaging and operating one of the plates of the other of said elements and a movable part ofthe press whereby the pressure of the last recited element upon the said blank holding member will be relieved,

and fluid pressure means for retarding the return movement of the'blank holdin means when the said movable member recedes.

In testimony whereof we have signed our names to this specification, on this 28th day of July, A. B41924,

' R VJ. GLASHER did "EN llELSQll.

press and means for sup-

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