US2390371A - Punching machine - Google Patents

Description

J. 'l".V IVY PUNGHING MACHINE Dec; 4, 1945;

Filed March 13, 1945 2 sheets-shea 1 INVENTOR. JfJs/E 77 /VY BY A ml irme/vnf Patented Dec. 4, 1945 l, UNITED STATES PATENT OFFICE p j 2,390,371

PUNCHINGMACHINE Jessie T. Ivy, Seattle, Wash. Application March 13, 1945, Serial No. 582,516 v (ci. 164-119) 9 Claims.

This invention relates to improvements in punching tools and machines, and has reference more particularly lto hand portable 'punching machines but is not necessarily `coniined thereto; the present machine being adapted primarily for thepunching of small holes in sheet metal and being especially useful in the airplane manufacturing and like industries for the punching of holes for rivets, bolts, etc., in the sheet metal members used in the making of the wings, fuselage and other parts of the airplane.

It isthe principal object of this invention to provide a hand portable machine of the above stated kind, including a die and reciprocating punch for forming the holes, and having a plate clamp and stripper member and novel means for effecting and for coordinating Vthe .functional movements of the stripper and punch so that, after the tool has `been applied, the stripper will be moved to engage the piece to be punched as a clamp prior to and during the action ofthe punch thereon, and the punch, after punching its hole, will be withdrawn from the piece prior to the release of the stripper therefrom, and ii` allythe stripper` will be lifted into the clear for the release of the punched pieceand to permit the Withdrawal of the tool, or its application at another place on the plate.

`It is also an object of this invention to elect the functional Amovement; of the punch and stripper member throughthe mediacy of a novel arrangement of links and levers in a toggle clamp assemblyof parts, driven by a crankshaft `for a most effective application of power, particularly inthe driving of the punch through a piece of sheet metal.

Still another object of the invention is to provide a .machine usi-ng the crankshaft `as the me` dium through which the punch and stripperare actuated and which `shaft may -be rotated in eitherdirection to `:accomplish the same coorcli nation lof movements of the `punch and stripper.

Sti-1l Ifurther objects of the invention are "to bc found in th'e Ydetails of construction :and in the combination of partsgfand in their mode vof operation as will herein-after be fully described.

."In'l'accomplishing :the above stated .and other ob'jects of the invention, I have provided the improved details of construction, the Ipreferred forms of which are illustrated 'in the accompanying drawingswherein- Fig. 1 is a front 'edge view `of the `present ma#` chine.

` Fig. l2 is a side view of the same; parts of vthe better illustration and understanding.

Fig. 3 is a cross section taken on line 3-3 in Fig. 2, showing the crankshaft and its connection with the toggle linkage which actuates the punch and stripper. f

Fig. 4 is a cross section on line 4-4 in Fig. 2.

Figs. 5, 6 and '7 respectively are views with` some parts in cross section, showing the connection of the toggle linkage with the crankshaft, and illustrating the action of the linkage for ei"- fecting the coordinated movements of the punch and stripper.

Fig. 8 is a sectional detail showingthe guiding and mounting bearings orblocks `for the punch and stripper.

Referring more in detail to the drawings- In its present preferred form ofconstruction, the tool, or machine, comprises a substantial metal frame or housing in which the movable parts, including punch stripper, crankshaft and linkage, are contained. The frame comprises what may be termed its handle, or holding porframe portion being broken away for purpose ci tion l; the die mounting bracket 2 that extends from the lower end of the handle at a right angle thereto, and the housing 3 that extends from the upper end portion of the handle .and is spaced somewhat above the bracket, leaving a clearance space 4 between them, as noted ,in Fig. 2. Mounted in the outer end portion of the bracket 2 is a die 5, here shown to bewof tubular form, vertically disposed and removably seated in a pocket 6 in the bracket 2. The bracketis formed With an opening 1 coinciding with the passage through thedie for the discharge of punched out pieces.

The housing 3, as shown best in Fig. 3, com-` prises spaced opposite side walls 8 and 8 between which a crankshaft 9 extends. The throw of the crankshaft is contained within the housing and the opposite end' portions of the shaft are revolubly contained in bearings Iii in th-e side walls. At one end, the crankshaft is equipped with Aa driving worm gear Il with which a driven worm I2 is in operative mesh, as shown in Fig. 1.

It will be understood by reference to Fig. 2 that the worm I2 is mounted on a driving shaft i3, which shaft is revoluble in bearings M M in a gear` case |5. The case is adjustably applied to the` sidewall of housing 3 to overlie :the gear .Il and the peripheral wall of the case is notched, as at I5, to receive similarly shaped projections on the housing Wall, thus to keep the case from rotating. The case is held in place by the head I1' of a bolt I1 that extends through a hole I8 in the case and is threaded into the crankshaft. A friction washer I9 is located between the case and bolt head, as noted in Fig. 3.

It is a feature of the invention that, by loosening the bolt, the case may be rotatably adjusted to place the drive shaft in the most advantageous position. 'I'he outer end of the drive shaft I3 equipped with means at its end to receive any desirable form of exble shaft driving connection, or it may have the chuck of an electric drill or similar machine applied thereto as the power medium.

The throw of the crank shaft mounts a pit:

man, or link 2| which, in Fig. 2, is shovvnto'exn tend in a horizontal direction and at,Y its `outer end to be pivotally mounted on the central portion of a transverse pivot boltior pin v22.2v Mounted on the pin, closely adjacent the opposite sides of the pitman, are the lower ends of a `pair of upwardly extended links.2323 which, at.- their upper ends, are pivotally connected by a. pivot bolt 26 with a lug or web 28 in the upper outer end portion of the housing3. Y

Extending downwardly'from the housing 3, directly above the die mounting. portion of the bracket 2, is a tubular guide member 30, which at its lower end, terminates at an interval above the die 5. Fixed within the lower .end of the tubular guide portion 30 is a bearing sleeve or bushing` 35, and reciprocally slidable through this sleeve, is lthe clamp and strippertube 36 which, at its upper end, is adjustably threaded into a guide and bearing :block 38. The block 38 is reciprocallycontained in that portion of the tubular guide member 30 thatis immediately above `the sleeve 35. The sleeve is. removable from the guide member, butis held against accidental displacement in use by Vaset screw y39.1 threaded into the member 30 and seated against the sleeve, as noted in Fig. 2. j l

. The stripper member 36 `threads at itsupper end into the blockV 38 and is `held againstun;

threading by. a set screw 4i) that threads through the block as shown in Fig. Ll.4 The'screw passes through a vertical slot 4 I inthe guideway b3l) and does not interfere with the reciprocal action of the Da1`t38. n

Reciprocally `contained coaxially within `the stripper tube is a punch 42. This punch comprises a straight shaft that extends at its upper end beyond the stripper tube and through a bearing block 44 in which it is xed byV nuts 45 and 45' threaded thereonto and tightened against upper and lower sides of the block. The block 44 is reciprocally contained in theupperpend portion of the tubular guideway 38. A pair of levers 48 and 48' have upper `ends pivotally connected with the outer ends of the pivot pin22, and intermediate their ends, are pivotally mount'- e`d on transversely alined pivot studs 4.9-49 that extend from the opposite sides of the block 44 and through vertical slots Soin the side walls of the guidew'ay. j

The lower' end' portions of the levers`48-g-48 are somewhat flared and are formed with `horizontally directed" cam slots 52 which contain therein studs 53 which extend from the opposite sides of the block-38 and through vertical slots 54 in the guideway. l

The connection of the pitman 2I with the links 23-23 and leversr 43.-.48f is such that withV a 180 Vturn ofthe crank shaft, the, iinks and levers are movedfrom ,the positionfof verticalI alinement in which theyaremshown `in Figs.

and 7, to the angular position or relationship shown in Fig. 5. This action of the toggle linkage causes the guide blocks 38 and 44 both to be lifted; the block 44 being moved upwardly in the guideway by reason of the toggle action of the Y connected links and the other by reason of the toggle action as modied by that movement that is caused by reason of the design of cam slots 52 in which studs 53 are contained.

`In order that the movements of the stripper and punch be coordinated for the purposes prefully extended Vwhen. the .crankshaft is inqthe l position shown in Fig. Y5,.,and .will-.be fullpretracted when theshaft hasturned .throughy an arc of 180 from the position of Fig. 5.

Whenv the parts are. in the position. seen .in Fig. 7, the punch and vstripper are Vthenretracted to such a position that their lower ends` are flush with the at lower surface ofthe guide .bearing 38 and sleeve 35. The tool may then bean.- plied to Ythemetal sheet.

end` of the. die 5 ina hole .of tl'letemplate. As-

,suming that the tool has been'applied as in Fig.,

'7 and thatthe crank shaft,starting Vfrom. theV position shown in Fi'g. '7, has rotated through the angleindicatedby arrow a inFig. 6, thepunch and stripper will have been simultaneously .ex tended and brought `into contact rwiththe iglat'e.;4 the Q stripper then engaging ,the plate ,with a 40 clamping effect that holds it rmly against the die .forvthe subsequent hole forming action ofthe punch- Y Y Y Y ...It Will here rbe uexplained' that prior,tood p;

ing operation.. the extent towhioh the, .Strnper will be extended for this clamping .eiTeLct should be accurately determined. This is donebx place ing on the die a pieceof. metalofthe same thick, ness of that to be punched.` Then therankshaft is rotatedv Ato bring `the .linkage toth,e 'position shown in Fig. 6, and thestripper 36 is then untlvreaded from the block 38 toladjust its end surface, iirmly against the plate. 2Then set -screw 40 is tightened to hold this adjustment. AI n this;

position `ofrthetoggle linkage, the studs `53, on,

mock 3s, are 'located ,in the oom` nots 5,2 at, thopositions where downward travel of v,the block,

by reason of themovement ofthe toggle linkage and cam action ceases. The design of both cam4 slots is'alike. Each is of'angular formation and is directed transverselyacross the base end portion of its lever v48 or 48 and each comprisesan end portion 52a at oneV side of a medial location that is arcuately curved about a center that is coincident vwith the axial center'ofV the pivot749 and it vcomprises 'an' opposite end portion 521).,that

38y either through the straightening.out-ofthe links or through the cam action, but ,the block will be held stationary.

Assuming that theparts have `been actu When. the` templates` used, the punch isapplied by.locating lthe upper nieguen positions o'f Eig. L7, :and have rea'ched the "position of 26 `at'vvhich the lower end 'of the stripper member '36 fis clamped tightly against 4the plate p, farther feXtendin'g-o'f the itogglel-ink- -age =to jthe position of Fig. 5,` 'causes the punch lthat isaiiixedto block 544, Ato be projected through the plate p to form the hole therein. While at thes'ame time, thefstripper 36 is 'retained 'clamped against the plate.

After the Vhole has been punched, the continued rotation of the crank shaft from position in Fig. 5, retracts the toggle, and this moves block 44 upwardly, to withdraw the punch clear of the plate; then, as the punch leaves the plate, the stripper and punch move upwardly together, and nally are restored to the starting position which corresponds to the position of parts in Fig. 7.

In the operation of the device, the punch pressure is effected directly by the toggle linkage acting against the block 44 while the action of the stripper is through the toggle linkage as modified by the cam slot and stud connection between the levers 48 and the block 38.

If it is desired to set the machine for work on plate of a different thickness, proper adjust.. ment must be made in the setting of the stripper and in some cases, readjustment of the punch is required. Adjustment of the punch is effected Aby making adjustment of the holding nuts 45-45' which are applied thereon and which engage the upper and lower faces of the block 44.

It is also anticipated that punches of different diameters might be interchangeably used and this would require the removal of a stripper and punch from position and replacing with parts of the desired size.

Devices of this character are especially useful where a hand portable tool is required. The tool may be conveniently held by grasping the handle `portion I and any suitable form of driving device may be applied to the worm shaft I3. It is anticipated that the usual form of electric drill miglft be used as the power medium merely by applying the chuck of the drill to the end of the shaft I3.

Tools of this character may be made of various materials, of various sizes, and it is possible that modifications in structure might be made without departing from the spirit of the invention.

Having thus described my invention, what I claim as new therein and desire to secure by Letters Patent is:

1. A punch of tle character described comprising a frame including a punch die, a punch and a stripper reciprocally movable on the frame toward and from the die, a rotatably driven shaft, and a toggle linkage c-onnected with the frame and with the punch and with the stripper, Y

and means connecting the toggle linkage with the rotatably driven shaft to effect an advancing and a withdrawal movement of the punch, and a synchronized reciprocal action of the stripper to move it into contact with the piece to be punched and to maintain it there during the advancing and withdrawal travel of the punch, and then to retract the stripper.

2.V A punch as recited in claim 1 wherein the frame portion includes a guide bearing, the stripper is reciprocally movable in the guide bearing and is of tubular form and the punch is reciprocally mounted in the tubular stripper.

3. A punch of the character described comprising a frame including a punch die and a guide Jbearing alined therewith, a stripper sleeve reciprocally :contained lin the .stripper sleeve lto c'o 'actwith the die 'for punching a piece placed lbetween them, a rotatably driven crank shaft, a tcggle linkage :pivotally :connected at one end 'to the frame and fha-ving connection with the punch land stripper, and `operable by rotation of Lthe .crank shaft to :eiect lan 'advancing and withdrawal 4movement of 'the punch and a synchrovnized faction lof the stripper to 4cause it to be moved into clamping contact `with the punched piece durin-g the advancing and withdrawal of the punch and then to be retracted to release the piece.

4. A punch as recited in claim 3 wherein the toggle linkage comprises a pair of pivotally joined links, one being connected at its outer end to the frame and the other link being pivotally connected with the punch and having a pin and cam slot connection with the stripper, and the intermediate joint of the linkage being connected with the crank shaft whereby, in its rotation, it effects the reciprocal action of punch and stripper. t

5. A punch as recited in claim 3 wherein the toggle linkage comprises a pair of pivotally joined links; one being connected at its outer end to the frame and the other link being pivotally connected with the punch and having a pin and cam slot connection with the stripper, and the intermediate joint of the linkage being connected with the crank shaft whereby, in its rotation, it eiects the reciprocal action of the punch and stripper; the pin and cam slot connection providing the synchronized actions of the punch and stripper. l

6. A portable punch of the character described comprising a frame including a punch die for support of a piece to be punched, and -a guide bearing. alined with the die, a tubular stripper sleeve mounted on the bearing for endwise movement from and toward the die, a punch reciprocally mounted in the stripper sleeve, a pair of pivotally joined links forming a toggle; the link at one end thereof being pivotally fixed. to the frame, and the link at the other end thereof having pivotal connection with the punch for effecting its reciprocal action and an operative connection with the stripper sleeve, a crank shaft mounted on the frame, a connection 'between the crank shaftV and toggle for actuating it to cause reciprocal actions of the punch and stripper; said stripper having a stud xed thereto and the second mentioned link of the toggle having a cam slot containing the stud therein, and so shaped as to effect an endwise movement of the stripper into holding contact with a work piece during the extension and retraction of the punch, and then to retract it from the held piece.

7. A punch as recited in claim 6 wherein the inner end of the stripper sleeve and the inner end of the punch are mounted on bearing blocks reciprocally contained in the guide bearing, and the second mentioned link of the toggle has a xed pivotal connection with the bearing block of the punch and wherein the stud which operates in the cam slot is mounted on the bearing block of the stripper sleeve.

8. A portable punch of the character described comprising a frame including a support for a work piece to be punched, and a guide bearing alined therewith, a tubular stripper sleeve mounted reciprocally in the bearing, a punch reciprocally mounted in the sleeve, guide blocks fixed to the inner ends of the punch and sleeve,

,studs extended from the opposite sides thereof,

two-pairs of toggle links, with upper ends pivotally ixed in the frame and lower links pivotally mounted on the studs of the punchvguide block, and a crank shaft having a rod connection with the toggles whereby with each rotation of the shaft, the toggles Will be moved from a retracted position to an extended position and then back to avv retracted position to effect the actuation of the punch through a Work piece and its retraction therefrom; said lower links of the tcggles l0 respective guide'blocks.

having cam slots thereincontainin'g'ithe -studs ofthe stripper sleeve guide-block and-said slots being'so shaped 4as to cause lthefsleeve'toY-be .actuated into holding contact With the piece during the extension and retraction of vthe'punch therefrom and then 'to loeV moved to retracted position.

9. A punch as in claim 8 wherein the punch and the sleeve are adjustable endwise in their JEssIE T.

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