US2322547A

US2322547A - Punch and die mechanism

Info

Publication number: US2322547A
Application number: US409365A
Authority: US
Inventors: Edmund F Shalla
Original assignee: Western Electric Co Inc
Current assignee: AT&T Corp
Priority date: 1941-09-03
Filing date: 1941-09-03
Publication date: 1943-06-22
Anticipated expiration: 1960-06-22

Description

Muua u 2,322,547 A, i i,

FIP79Q4 June 22, 1943. E. F. sHALLA PUNCH AND DIE MECHANISMS Filed Sept 5, 1941 2 Sheets-s L "WM/T0,? 5 ALLA er W Search Rooffi June 22, 1943. sH 2,322,547

I PUNCH AND DIE MECHANISMS Filed Sept. 3, 1941 2 Sheets-Sheet 2 28 nvvzwroe E. E SHAL LA ATTOR/Vf) UNITED Search Room STATES PATENT OFFICE r, 2,322,547 PUNCH AND om MECHANISM Edmund F. Shalla, Baltimore, Md., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application September 3, 1941, Serial No. 409,365

4 Claims.

This invention relates to punch and die mechanisms and particularly to a shedder for compound type punch and die mechanisms.

In a compound type punch and die mechanism, the article is usually formed complete in one step and after being blanked from the material and/or perforated is reinserted in the opening in the material and remains therein during the advance of the material and until removed by suitable means. To return the blanked article to the material there is provided in one type of compound punch and die mechanism an elastically mounted shedder reciprocable in the die aperture. During the blanking operation the shedder yields as the blank moves into the die aperture and during the return movement of the blanking punch the shedder follows and presses the blanked article into the Opening in the material from which it was punched. In the punching of articles such as washers or nuts from some materials, for instance, brass, fine brass dust slivers or particles are produced which have a tendency to work their way between the sliding or bearing surfaces of the shedder and cause it to bind or deleteriously score the same. This results in increased maintenance on the mechanism and frequent delays in production.

An object of the present invention is to overcome the above objectionable features by providing a simple and practical shedder so constructed that scoring of its bearing surfaces or binding thereon is substantially eliminated.

In attaining this object, in one embodiment of the invention as applied to a compound punch and die mechanism for blanking washers there is provided a tubular shedder having formed in its outer and inner peripheral surfaces continuous helical grooves. The grooves are semi-circular in cross-section and the inner grooves are spaced substantially closer together than the outer grooves and each groove is open at its upper end to receive fine dust sliver particles produced in the blanking operation. In practice any particles tending to get between the inner and outer peripheral surfaces of the shedder and their bearing surfaces on the perforator and the blanking die aperture, respectively, are lodged in the grooves, thus eliminating deleterious scoring of,

Fig. 2 is a plan view thereof with the punch removed;

Fig. 3 is a fragmentary view similar to Fig. 1 showing the punch and shedder after a blanking operation and before returning to their normal postions;

Fig, 4 is an enlarged detail vertical sectional View, partly in elevation, of the improved shedder, and

Fig. 5 is a plan view of the shedder.

In the drawings, this invention is illustrated as used in connection with a simple form of compound type punch and die mechanism, shown fragmentarily, and indicated in general at IU. By way of illustration, the mechanism 10 is effective to blank washers ll, one at a time, from brass strip material l2. The mechanism Ill comprises abolster plate 13 which is fixedly supported upon a punch press frame I4 and a reciprocatory ram (not shown) of the press carries a hollow punch l5, shown fragmentarily.

Fixed to the upper surface of the bolster plate I3 is a die plate holder l6 carrying a die plate l8 having a die aperture l9 which in cooperation with the reciprocatory punch I5 blanks the washers H from the strip l2. The strip l2 rests upon the upper surface of the die plate l8 and is intermittently advanced after each punching operation by suitable mechanism in a manner well known in the art to present a new surface to the punch l5. Arranged above and with a suitable clearance from the strip I2 is an apertured stripper plate 20 supported upon the dial plate l8 by a plurality of clamping dogs 2|, the strip in its advance being guided by the dogs and the stripper plate.

Secured to the die plate holder it within a recess in its bottom surface is a plate 24 to which is fixed a perforating punch 25 which extends upwardly from the plate into an aperture 26 in the die plate holder. The perforating punch 25 is axially aligned with the die aperture I9 and the blanking punch l5 and a reduced upper end of the punch terminates in the plane of the upper surface of the die plate 18.

A tubular shedder embodying the features of this invention is indicated at 21 and surrounds the perforating punch 25, and its upper end surface normally lies in the plane of the upper surface of the die plate l8. The shedder 2'! in the operation of the punch and die mechanism I0 slides on the perforating punch 25 and the peripheral wall of the die aperture l9 and is closely fitted thereto. At its lower end the shedder 21 is formed with a supporting flange 28 which rests upon a yieldable plate 31 which is fitted closely to the peripheral wall of the die plate-holder aperture 26. The plate 3| through which extends the upper reduced end of the perforating punch 25 rests upon a plurality of plunger rods 32 arranged to slide in apertures formed in the plate 24, the bolster plate l3 and an attached block 34. At their lower ends the plunger rods 32 engage the upper surface of a plate 35 which is spaced from a similar plate 36 by a block of rubber 31. The

plates

35 and 36 and the block of rubber 31 are attached as a unit to the block 34 by a screw 38 which extends therethrough and is threaded in the block 34, the lower end of the screw having threaded thereon a pair of nuts 39. By adjusting the nuts 39 on the screw 38 the yieldability of the rubber block 31. may be varied.

Referring particularly to Figs. 4 and 5, the improved shedder 21 has formed in its outer and inner peripheral surfaces helical grooves 4| and 42, respectively. The grooves 4| and 42 in the present embodiment are semi-circular in crosssection and each is a continuous groove extending from the upper end of the shedder to the upper surface of the flange 28. As shown, the upper ends of the grooves 4| and 42 are open at the upper end surface of the shedder as indicated at 43 and 44, respectively, for a purpose to be presently described. In order not to deleteriously Weaken the wall of the shedder 21 by the forming therein of the grooves 4| and 42 the helices of the outer grove 4| are spaced further apart than the helices of the inner groove 42. In the present. embodiment the spacing is such that the outer helices are aligned with each alternate helix of the inner groove, thus providing a stronger wall to the shedder 21.

It will be apparent that in the operation of the mechanism It] in blanking and perforating washers H from the brass strip material 12 that fine dust sliver particles are produced during such operation and tend to get between the inner and outer peripheral surfaces of the shedder 21 and their bearing surfaces on the perforating punch 25 and the peripheral surface of the blanking die aperture l9 and will readily find lodgement in the grooves 4i and 42, first at their open

upper ends

43 and 44, respectively, and secondly therebelow along successive helices of the grooves. Thus the dust particles or slivers are received in the grooves 4| and 42 and stored therein for subsequent removal and consequently deleterious scoring of the bearing surfaces of the shedder or the binding thereof is eliminated.

In Fig. 1 the blanking punch I and the shedo'er 21 are in their upper positions and the punch is about to start a washer blanking operation. During a continuous downward movement of the hollow punch l5 it enters the apertured stripper plate 2a, engages the strip l2 and blanks the washer l therefrom and in cooperation with the die aperture l9 and the stationary punch 25 simultaneously perforates it, the washer I| being carried below the strip l2 to the position shown in Fig. 3, which illustrates the mechanism at the end of the blanking and perforating stroke. The shedder 21 yields during the blanking operation and through its connection, previously described, with the rubber block 31, the block is compressed. In the retraction of the punch I5 the rubber block 31 expands and moves the shedder 21 upwardly to its normal position (Fig. 1) during which movement the washer H is returned to the opening in the strip l2 from which it was punched. Each successive punching produced by the hollow blanking punch I5 and perforating punch 25 rises into the punch I5 and is removed at its upper end by a blast of air directed by suitable means (not shown).

It is obvious that the grooves 4| and 42 formed in the shedder 2! do not necessarily have to be semi-circular in cross section, but may be V- shaped, square or of any other suitable contour. Also, a series of circular grooves may be substituted for each of the helical grooves 4| and 42, if desired.

It will be understood that the embodiment herein described is merely illustrative of the invention and one application thereof, the invention being limited only by the scope of the appended claims.

What is claimed is:

1. In a punch and die mechanism, a die having an aperture, a punch in said aperture, and a tubular shedder operable in said aperture, surrounding said punch and having an external and internal bearing on the peripheral surfaces of said die aperture and said punch, said shedder having external and internal grooves to prevent scoring of its bearing surfaces, the helices of the external groove being differently spaced between helices than the helices of the internal groove.

2. In a punch and die mechanism, a die having an aperture, a punch in said aperture, and a tubular shedder operable in said aperture, surrounding said punch and having an external and internal bearing on the peripheral surfaces of said die aperture and said punch, said shedder having external and internal continuous helical grooves open at their upper ends in the plane of the upper end surface of the shedder for receiving dust and sliver particles to prevent scoring of its earing surfaces, the external groove having a greater spacing between helices than the helices of the internal groove.

3. A compound punch and die mechanism for punching articles from material comprising a cooperating reciprocable punch and a stationary die having an aperture for punching an article from said material during a downward movement of said punch, and means arranged below the material for returning the punched article into the material comprising an elastically mounted shedder member movable in said die aperture during the punching operation, said shedder member having an external groove effective for receiving dust and sliver particles to prevent scoring the wall of said die aperture.

4. A compound punch and die mechanism for punching articles from material comprising an upper cooperating reciprocable punch and a stationary die having an aperture for punching an article from said material during a downward movement of said punch, a perforating punch below the material, and means arranged below and abutting the material for returning the punched article into the material comprising a tubular elastically mounted shedder member movable in said die aperture during the punching operation and surrounding said perforating punch, said shedder member having external and internal helical grooves open at their upper ends in the plane of the upper end surface of the shedder member for receiving dust and sliver particles to prevent scoring the wall of said die aperture.

EDMUND F. SHALLA.