US2191709A - Die - Google Patents

Description

Feb. 27, 1940. F. J. DEDRICK DIE Filed April 22, 1939 F. J. DEDRICK Gttorneg UNITED STATES I Patented Feb.27, 1940 PATENT OFFICE DIE Francis J. Dedrick, Red Lion, Pa. Application April 22, 1939, SerialNo. 269,366 Claims. (o1. 164- 29) This invention relates to cutting dies for use in a clicking press for dieing out blanks from sheet material such as upper leather for boots and shoes. e

5 An object of the present invention is to -provide an improved die in the nature of a closed frame formed from a strip of steel bent into curves and angles of the desired contour, an

edge of the frame being beveled on both sides 7 to form a cutitng edge, and in which a'single 'Another object of the invention is to provide astock for use in making clicker dies and com-' prising a cold drawn steel strip possessing the necessary'qualities and characteristics and es 25 sentially preshaped with three angularly disposed flat sections which are at the inside of the die when the die is formed and having three arcuate sections on the outside wall, the intermediate arcuate section being convex and the other two 0: arcuate sections being concave with respect to the body of the die, so asto provide, with the an gularly disposed inner wall sections, beveled sur- .faces along the top and bottom of the'die.

With the foregoing and otherobjects and adg vantages in view, the invention consists in the preferred construction and arrangement of the several parts which will-be hereinafter fully describedand claimed.

; In the accompanying drawing:

4 *Figure 1 is a perspective view of one type of doubled edged clicker die constructed according to the present invention;

Fig. 2 is a vertical transverse section taken onthe'line 2'2 of Fig. 1; and

Fig. 3 is a View similar to Fig. 2 of a single edged clicker die.

Y The clicker dies heretofore constructed have had their cutting edges extending from a relativefrom the heavy body to the cutting edge in such a manner that there isno surface by which the dies'can be firmly gripped-and held by an op- ,erator. Also these dies frequently crack in the ly, heavy body portion. By such construction the I dies are very dimcult to handle, as they taper oif region of the heavy body portion, due to the development of fatigue cracks.

In order to overcome the above defects, considerable experimental work has been done on improving the construction of clickerdies. Since 5' these dies are a relatively cheap article of commerce and are used in large quantities, they require-attributes to assure satisfactory work and an economical life.

Furthermore clicker dies have a recognized 10.

field for cutting out materials to a definite pattern. Therefore, the dies must be constructed of suitable material having characteristics by which the dies can be properly shaped. The ma terial used in constructing clicker dies should be of small size and yet its outline must be of such accuracy that the handling must not deform the cutting edges or the pattern outline.

In order toproduce clicker'dies according to the present invention, it was first necessary to produce. suitable material from which the dies couldbe formed. Preferably the material used in constructing the clicker dies of the present invention is cold drawn steel which is rolled in strips so as to provide a die stock having definite characteristics, as will be hereinafter more fully described.

Referring. to the drawing, the. clicker die H comprises a closed frame which, as is well known,

may. be of varying outline in accordance with 0 the particular shoe pattern to be cut. Such dies are commonly made of a single piece of die stock, out to the proper length, bent into curves and angles of the desired contour, such as shown,

in Fig. l, and having its ends connected by 35.

welding.

A die, in accordance with the present invention, may be either single or double edged.

In order to construct the clicker dies so that such dies will have certain characteristics by which the defects of the earlier types of clicker dies are overcome, it has been necessary to produce the dies from stock designed with a definite form. 1

Thus, in the case of a double edged die, the

stock preferably has the cross section shown in Fig. 2, while in the case of a' single edge die] the stock preferably has the cross section shown in Fig. 3.

Referring to Fig.2, the side of the stock used in forming the die II, on the side constituting the inside. of the frame,-is formed with three angularly disposed fiat sections, the intermediate section [2 being substantially vertically disposed and the other twosections l3, [4, being disposed at an angle to said vertical section I2 and being inclined outwardly towards the outer side wall of the frame.

The angle at which the inclined surfaces I 3, I4 are disposed with respect to the vertical section I2, is approximately 10, as indicated in Fig. 2.

On the other hand, the side of the stock constituting the outer side of the frame of the die I I is formed with three arcuate sections, the intermediate arcuate section I5 being curved in wardly toward the inside wall of the frame, and the other two outside arcuate sections I6, I! being curved reversely with respect to said intermediate arcuate section I5. The arcuate sections IS, I! extend in opposite directions from the ends of the intermediate arcuate section I5 towards the angularly disposed inner wall sections l3, I 4, respectively. The construction is such that the intermediate arcuate section I5 constitutes a channel which is co-extensive with the frame of the die II, and has a height equal approximately to one-third of the height of the die.

The pairs of angularly disposed or tapered walls formed by the surfaces I3, I6 and I4, ll, respectively, provide edges along the top and bottom of the frame of the die II, which edges are adapted to be ground in well known manner to provide sharp cutting edges, as indicated at l 8, Fig. 1.

In Figs. 2 and 3, the cutting edges are not shown ground, since these views represent enlarged cross sections of the die stock. However,

the cutting edges are indicated by broken lines.

As shown in Fig. 2, in order that the die M will have great stability while in use, the die stock is so formed as to provide a thickened structure at the portions of the. die requiring reinforcement. However, in order to reduce the weight of the material as much as possible and at the same time provide a structure which arcuate sections it, It and I I, should be such.

that the three arcuate sections constituting the outside peripheral wall of the die, are approximately of equal heights.

These arcuate sections can be so constructed that the radius of curvature of the arcuate sections I6 and H are approximately six times the length of the radius of curvature of the intermediate arcuate section I5. In this way a cutting edge will be provided by which the material will be cut cleanly and the die can be easily removed from the severed material at the completion of the cutting action.

It will be noted that the contour of the die stock in cross section thus provides material from which the cutting edges I8 can be readily formed by grinding both the outside and inside peripheral surfaces of the frame. Also the body of metal on opposite sides of the channel I5 is considerably heavier than at the central body portion and this assures adequate strength for the cutting edges. The straightening of the die is more readily accomplished with this rela-y' tively thinner central body as compared to the former constructions of dies.

The reduced section or channel I5 is not only I highly advantageous in making straightening easier, but in use, it permits the operator to grasp the die in order to transfer the same from one material to another material.

The body portion constructed in the above manner becomes a definite limit to any ten-.

dency of fatigue cracks tospread. It also facili-i 1 tates accurate joining of the edges of the die' during the. welding step.

A modified form of clicking die 2I of the single edge type is shown in Fig. 3, and this has the same vertical plane peripheral surface 22 v on the inside and an inclined plane peripheral surface 23 which extends downwardly from the lower portion of the verticalsurface 22 towards the cutting edge 24. I g I The outside of the die ZI has an intermediate channel formed by the arcuate. peripheral groove Extending from the lower edge of the channel 25 is a concaved surface 21 which is so disposed as to intersect the bottom of'the inner inclined-v plane peripheral surface 23. so as to form the lower cutting edge 24, which edge is adapted to be ground in well known manner to provide a sharp cutting edge, as indicated by the brokenlines in Fig. 3.

In the single edge form of die, shown in Fig.3,

- the radius of curvature of the arcuate surface 25 is the same as the length of the radius of the arcuate surface I5. On the other hand, theradius of curvature of the surface 21 is approxi mately ten and one-half times the radius of. curvature of the channel 25. This provides a gradually tapered body for the die leading from the thickest part of the die towards the cutting. edge Opposite to the cutting edge portion of the d-ie" there is a blunt edge 28.

However, the die has the same advantages, of the double. edged die shown in Figs. 1 and 2', and can be used in the same clicking presses. I I I While there is shown herein preferred forms of embodiment of the present invention, it is .to be understood that other modifications may be made thereto and I, therefore, desire abroad interpretation of my, invention within the scope and spirit of the disclosure herein and ofv the claims appended hereinafter.

Having thus described my invention, whatI.

claim is:

1. A clicker die of theclass described comprising a continuous stripof steel bent into curves and angles of the desired contour and having its;

ends connected to form a closed frame, an edge of said strip being beveled .on both sides to form and angles of the desired contour and having its ends. connected toform a closed frame, an edge described comprisof said strip being beveled on both sides to form a cutting edge, a single channel formed longitudinally in the exterior side of the frame, said channel being disposed equidistant with respect to the opposite longitudinal edges of the frame and having a height equal approximately to one-third of the height of the die. I

3. A clicker die of the class described compristhe beveled portion on the outer wall of the frame being arcuate inform, the curvature of said arcuate portion being substantially greater than the height of the frame.

4. A clicker die of the class described comprising a continuous strip of steel bent into curves and angles of the desired contour and having its ends connected to form a closedframe, the strip of steel comprising said die in cross. section having three angularly disposed fiat peripheral sections on the wall constituting the inside of said frame, the intermediate section of said three sections being substantially vertically disposed and the other two sections being disposed at an an-.

gle to said vertical section and being inclined outwardly towards the outer side wall of said frame, the outer side wall of the frame compris ing three arcuate peripheral sections, the intermediate arcuate section being curved inwardly towards the inside wall of the frame, and the other two outside arcuate sections being curved reversely with respect to said intermediate arcuatesection and extending in opposite directions from the ends of the intermediate section towards said angularly disposed inner wall sections, whereby to provide cutting edges respectively along the top and bottom of said frame.

5. A clicker die comprising a continuous integral wall, thinner in its middle and'presenting inwardly an intermediate"substantially vertically disposed peripheral plane surface and upper and lower peripheral plane surfaces angularly disposed with respect to said intermediate surface and inclined outwardly therefrom, and presenting outwardly an intermediate convexed unbroken peripheral surface and upper and lower concaved peripheral surfaces extending from said convexed surface and joined at their upper and lower edges by the edges of said'inner inclined plane surfaces, respectively.

FRANCISJ. DEDRICK.

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