US1334102A - Double die for making l-punchings - Google Patents

Description

W. E. LAIRD.

DOUBLE DIE FOR MAKING L-PUNCHINGS. APPLICATION FILED DCT. 28. 1918.

UNITED sTATEs PATENT oEEioE.

WESLEY E. LAIRD, 0F PITTSFIELD, MASSACHUSETTS,`ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK. v

DOUBLE DIE FOR MAKING L-PUNCHINGS.

Specification of Letters Patent. Patented Mal'. 16, 1920.

Application led October 28, 1918. Serial No. 259,891.

To all whom it 4may concern.'

Be it known that I, WESLEY E. LAIRD, a citizen of the United States, residing at Pittsfield, in the county of Berkshire, State of Massachusetts, have invented certain new and useful Improvements in Double Dies for Making L-Punchings, of which the following is a 4spec-ication.

Hy invention relates to dies, and has for its object an arrangement of parts capable of producing an L-punching of a given size from a given piece of stock with the least possible waste of material.

More especially my invention relates to a die-having for its specific object the provision of an arrangement of parts for carrying into effect the method of producing L-shaped punchings, with the least possible waste of material disclosed in the application for Letters Patent, Serial No. 259,881, led by J. J. Frank, on October 26, 1918.

In the application above referred to it has been proposed to use a piece of metal stock of nearly twice the width normally required for making plain L-punchings, and as it passes through the machine, to punch two such Ls from the stock across the sheet having the squared ends of homologous legs of the Ls abutting where the shapes are not complementary, thereby avoiding the necessarily attendant waste in making Ls having the ends of its legs of desired shapes, along one entire edge of the stock.

In order to accomplish this saving without additional offsetting expenditures in the course of manufacture, it is not only desired that the two Ls, one from each side of the stock, should be made with only one handling of the material, and that the punch and die parts should be as simple and rugged as possible; it being especially desirable to avoid the use of a compound die by reason of its increased cost of manufacture and upkeep.

To this end the die of my invention is designed to have two separate L-shaped punches for shearing off the two L-shaped punchings independently, one punch being in advance of the other. This arrangement of punches and dies results in a shearing edge having a somewhat irregular contour but the resulting die has all the advantages of a simple die in the course of manufacture and upkeep.

For a more complete understanding of the nature and objects of my invention reference should be had to the following detailed description when taken in connection with the accompanying drawings in which Figure 1 shows a plan view of a coperating punch and die embodying my invention. is a sectional view of the die plate taken on line'2-2 in Fig. 1. `Fig. 3 is an explanatory diagram, and Fig. 4 is a fragmentary section taken on line 4-4 in Fig. 1.

Referring now to the drawing, 10 denotes a stationary member, or die plate, having therein two L-shaped cavities at A and B respectively, bounded by die steels or members 11, 12, 13, 14, etc., to 22, secured about those portions of the periphery of the two cavities, as shown in Fig. 2, which const-itutes the shearing edges, the other portions being bounded by metal guides, shown at 23, 24, and 25, having the upstanding ledges 23', 24 and 25 respectively, serving not only to prevent rapid wear of the metal in member 10 by the punches, but also as stops for the stock being fed.

The member 27 carries the L-shaped punches a and b (shown in section in Fig. 1) which coperate with the edges of the die steels 11, 12, 13, etc., to shear oil the punchings from the stock as it is advanced under the punches at each successive stroke of the ram. The member 27 is also provided with recesses, shown at r in'Fig. 4, for accommodating the ledges onguides 23, 24 and :25 on the down stroke.

The cavities A and B in the member 10 are preferably made slightly wider than the punches a and b so as to provide a slight clearance space between the punches and that portion of the walls of the cavities not bounded by die steels. The guiding ledges 23", 24 and 25', however, fit snugly against the punches a and b, and in order to prevent their displacement from this position, the under side of the base portion of each of these guides is provided with a depending lip 28, as shown in Fig. 4, arranged to extend slightly Vinto one of the cavities. This arrangement has the advantage that Fig. 2 A

the punchings shorn oft' by the dies may readily leave the punches, passing down through the cavities A and B by reason of the clearance space thus provided, but at the same time are prevented from springing of the strip 2.

back into the path of the punches, on account of any inherent resilience in the punchings, by means of the lips 28.

In addition to the cavities A and B, the member l0 is preferably provided with several minor cavities, such as shown at 30, 31, 32, etc., to 36, which servechiely as clearance spaces for securing the exact adjustment of the die steels which are held in place by means of suitable dowels or screws, such as shown at C. To insure that the stock being fed to the dies shall at all times be advanced under the dies in the right angular direction, I have provided the guide 37 having the laterally extending base iange 38 on which the edge of the stock which projects beyond member 10 is designed to slide. This guide is secured to the member 10 by any suitable means such as the boltsl shown at 39.

As before remarked, the punches and dies, in accordance with my invention, are arranged one in advance of the other; consequently I have shown the punch a as advanced beyond the punch so as to take an L-shaped punching out of what is here shown as the upper side of the stock, one stroke of the ram before the abutting L-shaped punching is taken out by the punch b. Obviously, however, the punch t need not be arranged to be only one stroke in advance of punch Z), but may be arranged any number of strokes in advance as conditions may indicate, which will be readily understood by reference to Fig. 3.

In Fig. 3, S denotes a piece of stock whose width is nearly twice that from which single Ls wouldy be normally struck. Suppose the upper edge of this piece of stock is traveling in the guide 37, then for the arrangement shown when the punch is up, the stock would be advanced until the straight edge of its end caught against the nose 40 of the die 17. The downward stroke oil the ram would cause punch a to take out the triangle 1 and punch b to take off the triangle 1. The stock S is then advanced upon the upstroke of the ram so that the V-shaped edge of the stock, formed by the removal of triangles 1 and 1, abuts against guides 23, 24 and 25. The downward movement of the ram now causes punch a to take out the fragmentary L `denoted 2, while punch b takes The third advance of the stock permits the third downward stroke of the punches t0 take out the imperfect Ls marked 3 and 3, respectively.

The sheared edge of the stock denoted by the lines 6,7, g, lz, and z' is now the standard contour which the stock will retain as it is y advanced under the punches to produce complete L-punchings, for on the fourth advance the punches will shear olf the complete Ls marked 4 and 4 respectively.

The subsequent advances of the stock re-' sult in the shearing 0H of Ls 5 and 5, then 6 and 6, etc. During the advance of the stock S the guides 23, 24 and 25, (particularly that at 21) will act to draw the stock laterally into coincidence with the contour of the cutting dies should there be any displacement of the stock in a sidewise direction, as occasionally occurs while punching due t0 the warping of stock from the strains occasioned by shearing.

From Fig. 3 it is clearly seen that the L whose homologous leg abuts the short leg of the L marked 4, is the L marked 3, which was taken out by the punch a one stroke before the punch b sheared off the L marked l. This advanced taking out of the L.

marked 3 by punch L forms the edges marked g, It and 71 so that it is unnecessary to provide the die member 17 with a cutting edge. In case the punch a is advanced more than one stroke ahead of punch Z9, the contour of the stock between lines f and IL would be a zig-zag line, following these portions marked c g and 7c. However, the edge of the die member 17, which coperates with punch b, is provided with a cutting edge to shear off any metal that might otherwise remain due to an irregularity in the feed of the stock and thereby produce an L having one leg too long.

-nose 40 is formed to cut out the; triangles marked t in Fig. 3, as the stock is advanced under punch a, and thus forming an L which would otherwise have a large interior llet.

The die member 16 gives the desired'interior contour to the L s stamped from the lower side of the stock so that it is necessary to provide the die member 23 to shear olf triangles u from the knee of the Ls abo-ut to be sheared off by punch b.

Having now described what is at present the best means known to me for carrying out an embodiment of my invention, I would have it understood that such means are merely illustrative and that I do not mean to be limited thereby to the exact details shown nor in the choice of recognized equivalents except as defined in my claims hereunto appended.

What I claim as new and desire to secure by Letters lPatent of the United States, is

1. The combination of two sets of relatively movable dies and punches, each set having cooperating uncomplementary L- shaped configurations of fixed dimensions, one set being located with respect to the other so as to take its punching out of the stock fed thereto simultaneously, a predetermined number of strokes in advance of said other set.

2. The combination of two sets of relatively movable dies and punches, each set having coperating uncomplementary L- shaped configurations of fixed dimensions, and a guide for the stock fed thereto, one of said sets being so located along the line of feed that it takes its punching out of the stock simultaneously a predetermined number of strokes in advance of the other set.

3. The combination' of two sets of relatively movable dies and punches, each set having cooperating uncomplementary L- shaped configurations of fixed dimensions, the sets being so arranged that homologous legs of the Ls extend in opposite directions, but displaced along the line of feed a distance equal to the advance for a punching.

l. The combination of two sets of relatively movable dies and punches each set having cooperating L-shaped configurations of fixed dimensions for taking uncomplementar f L-shaped punching out of a sheet of stock of substantially double width across the line of feed, the homologous legs of the Ls extending in opposite directions but displaced from each other along the line of feed a-distance equal to the advance for a punching.

5. tively movable dies and punches, each set having cooperating plain L-shaped configurations of the same fixed dimensions, and a guide for the stock fed thereto, the short legs of the Ls being arranged to extend toward each other and the long legs to extend away The combination of two sets of relafrom each other, the short leg of one set being displaced relatively to the other along the line of feed a distance equal to the advance for a punching.

6. The combination of two sets of relatively movable dies and punches, each set having cooperating plain L-shaped congurations of fixed dimensions, and stops for the stock being fed arranged adjacent to said dies so as to draw the shorn edge of the stock into coincidence with the contour 0f said dies, one of said sets being located a predetermined number of strokes in advance of the other set.

7. The combination of two sets of relatively movable dies and punches, each set having cooperating plain L-shaped configurations of fixed dimensions, a guide for the stock being fed, and stops for the stock arranged adJacent to said dies so as to draw the shorn edge of the stock into coincidence with the contour of said dies, one of said setsv being so located along the line of feed that it simultaneously takes its punchingout of the stock one stroke in advance of the other set. Y

8. The combination of two sets of relatively movable dies and punches, each set having cooperating L-shaped configurations of fixed dimensions, and stops for the stock being fed arranged adjacent to said dies each being provided with a depending lip extending slightly into the cavity bounded by said dies thereby providing a clearance space for the punchings in said cavity slightly below the shearing edges.

In witness whereof I) have hereunto set my hand this 24th day of October, 1918.

WESLEY E. LAIRD.

Images