US2798553A - Metal punching apparatus - Google Patents

Description

July 9, 1957 D. BERDAN 2,798,553

' METAL PUNCHING APPARATUS Filed Dec. 5, 1956 INVENTOR f DAVIDBEBDAN THEIR ATTORNEYS United States Patent METAL PUNCHIN G APPARATUS David Berdan, Freehold, N, J., assigner to Buck Engineering Company, Inc., Freehold, N. J., a corporation of New Jersey Application December 5, 1956, Serial No. 626,377 7 Claims. (Cl. 164-86) This invention` relates tometal working` apparatus4 and positioning fingers, pins and the like in order to assurev punching ofthe holes accurately therein. Such` locating apparatus 1s most useful for production on'a large scale,

but is' not very practical when only a few articles are to` be made,

for example, in prototype work or` template making.

Y rl"he present invention relates to a punching apparatus which may be' used with a standard punch pressto punch accurately located holes in sheet metal.

` More particularly,

press plunger and carries a slide adapted to receive a punch of a suitable type, size or shape. The` holder ist' provided with means whereby the punch mounted on the sl1de` can be projected from the punch holder` body so that a center-'point on the punch may be accurately alignedv with a' guide mark on the workpiece to assure the proper centering or location of the punch with respect to the workpiece; Movement of the punch into and out of engagement with the work for locating purposes can be accomplished byv means of a drive member which enables the punch to be raised and lowered relative to the punch holder body during the locating operation. Moreover, the apparatus includes means for automatically retracting the punch with the punch holder body after a punching operation has been accomplished so that the work piece is stripped automatically from the punch.`

The provision of means for accurately positioning the work with respect to the punch s'o that the hole formed therein by the punch is accurately located enables the punching operation tobe conducted quickly and-eiliciently and with as high a degree of accuracy as is possible with the guide and positioningmeans heretofore used in mass production operations. The new punch locating and actuating mechanism does away with the need for complicated and expensive fixtures and renders an ordinary punch pressi` entirely suitable lfor the production of high quality andaccurate sheet metal work.

For a better understanding of the present invention reference may be had to the accompanyingV drawings in which:

Figure 1 is' a front elevational and partially sectional view of a typicalform of apparatus embodying the present invention;

Figure 2 is a view in section taken on line 2--2' of FigureI 1;

Figure- 3 is an end elevational viewA of the apparatus; and

Figure' 4 isa cross-sectional view taken on4V line 444 ofFigure 2;

A` typical apparatus embodying the present inventionthe apparatus according to the present invention` mcludes a punch holder body to be mounted on a punch iatented July 9, 1957 is. illustrated inthe drawings. The apparatus P includes a punch holder body 10 whichmay be formed of suitably hardened steel or the like. As shown in Figures 1 to 3, the bodyy 10I is generally rectangular `in horizontal` and vertical cross-section having` an upper dat surface or end 11 to which isV secured a shank 12 to be received in the vertically reciprocating plunger of a punch press (not shown). The shank 12 may be secured to the upper end of the punchV holder body by means of an annular flange 13 on the shank andthe machine screws 14 which extend through the flange and are threaded into the upper end of the punch holder body.

A- cylindrical bore or hole 15 is formed in the body 10 substantially in axial alignment with the shank 12 to receive a cylindrical punch holding slide 16 for sliding movement therein. As shown in Figures 1 and 3, the bore 15 extends completely through the punch holder body 10 iromits top 11 to its bottom 17.

An axial` bore 18 is formed in the lower end of the punch slide 16 toreceive the shank 19 of a punch 20 of any desired conguration. A screw 211 inserted in a threadedradial hole 22 inthe punch slide 16 bears against an inclined surface 23 of a notch 24 in the shank 19 of the punch to` secure the punch to the punch holder and retain the upper surface of the punch in Contact with a collar. or flange 25 formed` on the lower end of the punch slide 16. As illustrated the punch 2l) has a cylindrical head provided with a male center point 26 for a purpose to be described herein.

As shown in Figures 2 and 3, the punch slide 16 is retained against a rotation during its sliding movement along the bore 15 by means of a screw 28 threaded into the front wall 29 of the punch body and engaging in a groove 30`which extends lengthwise ofl the punch slide 16.

It will be clear from the description of the apparatus thus' far that the punch slide 16 with the punch 2l) thereon is capable of' axial sliding movement in the bore 15. It is normally retained in a retracted position by means of a lock pin 31 which is slidably mounted in a bore 32 extending inwardly from one side of a larger bore 33 formed in one end 34 of the punch holder body 10.

A generally cylindrical pin holder 35 which carries the lock pin 31 eccentric to its axis is slidable in the bore 33. Thus the holder 35 and the pin 31 are capable of sliding movement to the right from the posit-ion shown in Figure 2. However, the pin 31 and holder 35 are normally biased toward the punch slide 16 by means of the coil spring 36 which bears against the right hand end ofthe' holder 35 and the left hand side oi a retaining disk 37 which is held in the outer end of the bore 33 by means of a snap ring 38 releasably engageable in a groove 39 around the inner circumference of the bore 33.

A bore40 in the punch holder is adapted to receive the end of the lock pin 31 as shown in Figure 2 to retain the punch slide 16 against axial movement relative to the punch holder body 1li. When the pin 31 is retracted, the punch slide 16 and the punch 20 thereon are released for movement relative to the body 1i).

Control of movement of the punch holder 16 is ob tained by means of a pinion 41 which is rotatably mounted on a shaft 42 extending lengthwise of a bore 43 which extends inwardly from the' side wall 44 of the punch holder body/.10. The pinion 41 is received in a smaller diameter portion 43a of ythe bore 43 and meshes with a rack. 45 formed ton a side of the punch slide 16.

A driver 46 including a knob 47 having a shank 48 thereon is provided for turning the pinion 41 and also for displacing the shaft 42 endwise. As shown in Figure 2', the shank 48of the driver has a non-circular enlargement or ilange 49 thereon which engages within a sleeve 50 and connects them for simultaneoussliding and rotation in the bore 43. A snap ring 51 retahs the sleeve 50=` and the driver 46 against detachment from the punch holder body l but permits the knob to be rotated and moved axially with the sleeve 50 to displace the shaft 42 endwise in a small bore 53 which connects the bore 43 with the bore 33. Endwise movement of the shaft 42 to the right displaces the lock pin holder 35 to release the punch slide 16. Upon release of the punch slide 16, it can drop inasmuch as the pinion 4l is rotatably mounted on the shaft 42 and thus is free to rotate. The pinion is maintained in mesh with the rack 45 by means of a sleeve 54 which is also rotatably mounted on the shaft 42 and is normally biased into 'engagement with the pinion 41 by means of a coil spring S5 mounted on the shaft 42 and interposed between the right-hand end of the enlargement 49 on the shaft 4S and the left hand end of the sleeve 54.

inasmuch as it is necessary to move `the punch holder up and down during the operation of the device, the sleeve 5l? is provided with internal splines or teeth 57 (Figs. 2 and 4) which are complemental to the teeth on the pinion 4l so that upon movement of the driver 46 to the right, the splines or teeth 57 on the sleeve 50 mesh with the teeth on the pinion 4l thereby connecting the knob 47 to the pinion 4l and enabling rotation of the latter by means of the knob to raise or lower the punch slide i6.

As shown in Figures lv and 3, the punch holder body also carries the usual stripping plate 60 which is mounted on the ends of the pins or bolts 6l, 62, which are vertically slidable in bores 63 and 64 extending between the top lll the bottom 17 of the punch holder body. The bores 63 and 64 are counterbored at their upper ends to receive the enlarged heads 65 and 66 on the pins or bolts 6?., 62 thereby to limit downward movement of the stripper plate.

Springs 67 and 68 are received in counterbores 69 and 7i) extending inwardly from the bottom i7 of the body 10 and have their lower ends engaging the upper surface of the stripper plate 6@ normally to bias it downwardly.

in use, the shank 12 of the punch holder body 10 is mounted in the vertically reciprocating plunger or slide of a punch press so that the entire punching apparatus is movable up and down thereby. A sheet metal object to be punched is center punched to indicate the center of a hole to be punched therein. The center punched object is then placed on the punch press table below the punch holder body lli. The knob 47 is then moved to the right to disengage the lock pin 3l from the punch holder 16 allowing the latter to move downwardly relative to the body l@ and the entire punch assembly is lowered to bring tie center point 26 into approximate alignment with the center punch mark. on the object. The knob 47 is then moved further to the right to engage the splined sleeve Sil with the pinion 4l so that the punch 20 and punch holder llo can be raised out of contact with the object. The object is then moved back and forth until the punch mark is directly below the center point 26 of the punch. The punch 2@ is then lowered by turning the knob 47 in the appropriate direction to engage the center point 2u with the mark thereby accurately aligning the punch 2li with the area to be punched. Actuation of the punch press then moves the entire punch holder body l() downwardly while the lowered punch 2) and punch slide i6 remain stationary until the upper surface of the flange 2,5 engages the bottom surface i7 of the punch holder body lil. Continued downward movement of the punch holder body causes the punch Ztl to punch a hole in the sheet metal object. At the time that the ange 25 engages the punch body lh, the lock pin 31 will be aligned with will enter the bore 4i) in the punch slide le to lock it to the punch body lh. Is/hen the punch press raises the punch holder body itl, the puncl slide i6 and the punch il@ move with the body while the stripper plate 69 presses against the punched sheet metal object to strip it from the punch 2li which is then ready for another punching operation.

It will be apparent that the above described apparatus enables ready centering of a punch with respect to an area of a sheet metal object in which a hole or holes are to be punched and it thereby does away with the need for other aligning, gauging, or positioning elements on the punch press.

it will be apparent the device is susceptible to considerable modification, such as for example, the provision of clearance surfaces '71 at the edges of the bore 4i) to prevent burrs being formed thereon. Also the mechanism for coupling the knob to the punch slide 16 and the lock pin may be modified.

Other similar changes which may occur to those skilled in the art are intended to be included within the scope of the invention. Y

I claim:

l. An apparatus for punching holes in metal comprising a body member attachable to a punch press for reciprocation thereby, a punch slide slidably mounted on said body for movement between a projected position and a retracted position, a locking pin slidably mounted in said body member adjacent to said slide, the latter having a hole therein to receive said pin and be retained thereby in retracted position, means in said body member normally urging said locking pin toward said punch slide, a manually-operated member mounted on said body member for moving said punch side relative to said body member, means interposed between the punch slide and the manually-operated member for connecting and disconnecting them in response to movement of said manually-operated member in opposite directions relative to said body member, and means responsive to movement of the manuallyoperated member in one direction to slide said locking pin out of the hole in said punch slide to release it for movement by said manually-operated member.

2. An apparatus for punching holes in metal and the like comprising a body member having means thereon for connecting it to a punch press for reciprocation thereby, a punch holding slide mounted on and slidable relative to said body member between projected and retracted positions in the direction of reciprocation thereof, a rotatable and axially movable driving member mounted on said body member, and engageable and disengageable driving connection between said driving member and said slide, said driving connection being engageable in response to axial movement of said driving member in one direction and disengageable by movement of the driving member in the opposite direction, said slide being slidable relative to said body member by rotation of said driving member when the driving connection is engaged, locking means for releasably retaining said slide in retracted position, and means responsive to axial movement of said driving member in said one direction for releasing said locking means to enable said slide to slide relative to said body member.

3. An apparatus for punching holes in metal and the like comprising a body member having means thereon for connecting it to a punch press for reciprocation thereby, a punch-holding slide mounted on and slidable relative to said body member between projected and retracted positions in the direction of reciprocation thereof, a rotatable and axially movable drivin-g member mounted on said body member, and engageable and disengageable driving connection between said driving member and said slide, said driving connection being engageable in response to axial movement of said driving member in one direction and disengageable by movement of the driving member in the opposite direction, said slide being slidable relative to said body member by rotation of said driving member when the driving connection is engaged, said slide having a hole therein, a locking member mounted in said body member for sliding movement into said hole to lock said slide in said retracted position, said locking member being retractable from said hole to release said slide and means responsive to axial movement of said driving member in said one direction for retracting said locking member.

4. An apparatus for punching holes in metal and the like comprising a body member having means thereon for connecting it to a punch press for reciprocation thereby, a punch-holding slide mounted on and slidable relative to said body member between projected and retracted positions in the direction of reciprocation thereof, a rotatable and axially movable driving member mounted on said body member, an engageable and disengageable driving connection between said driving member and said slide, said driving connection being engageable in response to axial movement of said driving member in one direction and disengageable by movement of the driving member in the opposite direction, said slide being slidable relative to said body member by rotation of said driving member when the driving connection is engaged, said slide having a hole therein, a locking member mounted in said body member for sliding movement into said hole to lock said slide in said retracted position, said locking member being retractable to form said hole to release said slide, means normally urging said locking member toward said slide, and means responsive to axial movement of said driving member in said one direction for retracting said locking member.

5. An apparatus for punching holes in metal and the like comprising a body member having means thereof for 'attaching it to a punch press for reciprocation thereby, a punch-holding slide slidable in Asaid body member `between retracted and projected positions in the direction of reciprocation of said lbody member, a driving member rotatably and axially movably mounted in said body member, a rack xed to said slide, a pinion engaging said rack, means responsive to axial movement of `said driving member in one direction for connecting said driving member to said pinion and to rotate the pinion and move the slide in response to rotation of said driving member, means biasing the driving member in the opposite direction to disconnect it from said pinion, a locking member slidable in said body member toward and away from said slide, said slide having a hole therein to receive lsaid locking member when the slide is in its retracted position,

6 and means for moving said locking member away from said slide in response to movement of said driving member in said one direction.

6. An apparatus for punching holes in metal and the like comprising a body member having means thereof for attaching it to a punch press for reciprocation thereby, a punch-ho1ding lslide slidable in said body member between retracted and projected positions in the direction of reciprocation of said body member, a driving member rotatably and axially movably mounted in said body member, a rack xed to said slide, a pinion engaging said rack, means responsive to axial movement of said driving mem-ber in yone direction for connecting said driving member `to said pinion and to rotate the pinion and move the slide in response to rotation of said driving member, means biasing the driving member in the opposite direc tion to disconnect it from said pinion, a locking member p slidable in said body member toward and away from said slide, said slide having a hole therein to receive said locl ing member when the slide is in its retracted position, means normally urging said locking member toward said slide, and means for moving said locking member away from said slide in response to movement of said driving member in said one direction.

7. The apparatus set forth in claim 6 in which the means for connecting the driving member to -said pinion comprises an internally-toothed sleeve fixed to said driving member in axial alignment with said pinion, and movable with said driving member into and out of telescopic meshed relation to said pinion.

References Cited in the file of this patent UNITED STATES PATENTS 840,859 Morse Ian. 8, 1907 1,124,893 Gustafson Jan. 12, 1913 1,468,271 Bechtel Sept. 18, 1923 1,856,175 Towle May 3, 1932 1,901,575 Altvater Mar. 14, 1933 2,108,619 Smith Feb. 15, 1938 2,197,349 Ruthven Apr. 16, 1940 2,703,143 Good et al. Mar. 1, 1955

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