US1056448A - Cutting-die. - Google Patents

Description

- E. POGOCK.

CUTTING DIE.

APPLICATION FILED MAR. 29, 1910.

1,056,448, I Patented Mar. 18,1913.

mm sures PATENT onn on.

- EIBENEZER POCOCK, OF PARIS, ERANGE, ASSIGNOR T0 UNITED SHOE MACHINERY COM- PANY, OF PA'IERSON, NEW JERSEY, A CORPORATION OF NEW JERSEY.

CUTTING-DIE.

Specification of Letters Patent.

Application filed March 2e, 1910. Serial No. 552,254.

To all whom it may concern Be it known that I, EBENEZER Poooox, a subject of the King of England, residing. a Paris, France, have invented certain Improvements in Cutting-Dies, of which the.

following description, in connection with the accompanying drawings, is a-specification, like reference characters on the drawings indicating like parts in the several figures.

This invention relates to dies of the class used with clicking presses for cutting blanks from thin sheet material, and is particularly intended for use in dying out upper leather for boots and shoes.

. In order that a die may be used satisfactorily for dying out uppers, it must be so constructed as to maintain the predetermined contour of itscutting edge throughout its use so that all upper blanks cut by it shall be of the same size and shape.

Dies heretofore used for cutting uppers have been rigidly constructed from heavy and substantially inflexible stock. It has also been proposed to employ flexible stock for a cutting blade but-to support and con-.

for use in cutting upper leather may be formed of thin, fiexi le, ribbon steel and that such a die will maintain its contdur by virtue. of its elasticityor resiliency, so that, while it may be easily distorted, it will, when the distorting influence is removed, immediately return to its predetermined contour.

I have found that in making my novel die ll can use cold drawn or cold rolled untempered steel which is not in itself of a Very resilient nature and that when material of this kind is made into a die of closed contour, the resulting die exhibits marked re- Patented Mar. 18,1913.

siliency as a whole and will reassume its original outline with a surprising degree of accuracy after having been distorted.

The cost of manufacture of my novel die is very much less than that of dies heretofore used, chiefly because it can be made from thin steel, preferably untempered, which can be bent cold to the desired outline. Heretofore it has been-necessary to heat the die stock before bending it' and frequently in the case of sharp bends it has been necessary to heat the same portion of stock several times before the bend has been correctly made. The necessityfor so heating, and occasionally reheating, each por-' tion of the die stock which was to be bent,

and the necessity for further heating the die stock after the bends have been completed in order to remove the initial strain, or

bending strain, have by this invention been entirely obviated, together with numerous other operations heretofore necessary in the manufacture of dies. Thus the process of manufacture has been greatly simplified and the operation of conforming the cutting edge of my novel die to the desired contour may be performed easily and accurately and requires little skill.

A further important advantage of -my novel die is its extreme lightness. The die [shown and described weighs less than one third as much as a die -of the same size and contour heretofore in commercial use for cutting upper blanks. This greatly facilitates the handling of the die lightness y the workman and obviates any danger of I scratching or marring the u per leather as the die is moved about over it, and furthermorethe die-compares favorably in weight with the patterns heretofore used by hand ,cutters and may be handled as conveniently as such patterns, characteristics which make it much easier for the experienced hand outter to'change from. hand cutting to machine cutting.

Other advantages resulting from the use of dies ofmy invention in connection with a clicking press, such for example as, that disclosed in United States Letters Patent N 0. 921,503, granted Februar 16, 1909-may' be enumerated as follows; he improved dies require the application of comparatively little power to cause them to die out a blank cleanly andconsequently they are not driven deeply into the cutting block. The cutting block therefore suffers noticeably little wear. The dies of my invention moreover can be used with superior results upon a cuttin blockghaving an uneven surface.

This is important because ,in practice it is this invention as this die will merely bend found that cutting'blocks, even if frequently 1 planed, are more or less uneveni The planng not only takes time, but is expensive and the more frequently a block is laned the sooner it must be replaced. On t is account it often happens that cutting blocks are used with more or less uneven surfaces. A substantially rigid die will sink deeply into the upon the leather with its cutting edge uppermost. This occasionally happens under the present conditions and when a substantially rigid die is so misplaced the press arm is almost invariablybroken. Such a catastrophe is obviated by theuse of the die of and so permit the arm' of the ress to make its full stroke. It sometimes appens that the arm of the press is set too low with re s ect to the cuttin block or that it slips ownwardly upon t is post to which it is secured. When this occurs, while a substantially rigid die is in use, the eccentric which operates the press arm is likely to be broken and even if no actual break occurs the driving belt will be thrown'ofi' and the machine comes to a standstill with the knife so deeply embedded in the block that neither the arm nor the die can be moved without taking the machine apart, an operation which requires the better part of a day.

This exasper'ating occurrence is also obviated by the use of the die of the present invention for reasons above intimated. It has been found in practice that another advan-' tage incident to the flexibility of the improved die of this invention is that such a' die will receive a blow from the press arm u on one of its corners without detrimental e ect, whereas other dies, if mistreated in this manner, are invariably injured or rendered useless by breaking out at the corner.

Another advantage incident to the improved die is that it lends itself particularly well to certain shapes which it has been difiicult to produce'in the dies heretofore known. For

example, it is often desired to shape a die for cutting a Blucher vamp so as to cut out a portion of very small radius of curvature at either side of the tongue and the thickness of the die stock formerly used interferes with bringing the cutting edges of the die into conformity with such a curve. The thin die stock used in the construction of the flexible die of this invention, however, presents no such difliculty. Still another advantage incident to the im roved dies of this invention is apparentin t we cases where a cutter desires to measurea skin before cuttin by placing different dies upon it in or er to etermine how the skin can be cut to the best advantage. The improved dies can be placed so close together upon a skin that there is almost no waste between them and a very accurate determination f the best method of arranging the blanks is thus secured.

Other features and advantages of the invention will be set forth in the following description of a preferred embodiment thereof in connection with the drawing in which:

Figurel is a view in perspective of a die embodying my invention for cutting Blucher quarters; Fig. 2 is an enlarged sectional view on the line 22 of Fig.1.

The-die shown in the drawing comprises a continuous frame 20 of ribbon steel which conforms in contour with the outline desired in the blanks to be cut. The ends of the strip are shown as connected and maintained in alinement by amcchanical joint which,'in this case, comprises a short piece 24 of material similar to the die stock and tubular rivets 26 extending through the ends of. the strip 20 and the piece 24. It may, however, be preferred to weld together the ends of the strip in accordance with the' method described in Letters Patent No. 922,926 granted May 25, 1909, on an application of John M. Lynch. Neither method of connecting the ends of the'striprenders any port-ion of the die materially different in flexibility from the remainder, the closed frame offering to distorting pressure a resistance which is nearly uniformthroughout the circuit of the die. The upper edge of the die is adapted to receive the cutting pressure from the-arm of a clicking press and the-lower edge 22 is sharpened to form a cutting edge. Preferably the cutting edge is formed with a bevel on both sides of the die stock as the edge of a die sharpened in this way will cut through the material operated upon in a direction normal to the surface of the material without tendency to out under and bevel the edge of the blank as might be the case if the bevel of the cutting edge were formed entirely on the outside of aresilient die, particularly in using the dies on comparatively thick stock. Indentations from 0.05 to 0.12 of an inch in thickness,

having a proper proportion of carbon has been found to be suitable material from which to make dies of this character, it being preferable .to employ material which is capable of being bent cold to follow a comparatively sharp curve or angle. It is con-- templated that the thicker ribbon steel would only be used in constructing dies of the larger sizes. If steel as thick as 0.12 of an inch be used it is believed that it should contain only a low percentage of carbon in order that it may be bent at a sharp angle without breaking. It has been found that by selecting cold drawn or cold rolled steel having the proper proportion of carbon, the necessity for tempering or heat treating the die is avoided, a suflicient degree of hardness having been imparted to the steel by the dies or rolls during its manufacture. If desired, however, the cutting edge of the die may be tempered or case hardened after the die has been shaped and such treatment improves the wearing quality of the cutting edge, and also somewhat increases the characteristic resilierft properties of the die. While a die constructed of such material does not of course rigidly resist a distorting force and yields under such influence, l have found that the die is elastic and resilient and will immediately reassume its normal con our on the removal of such distorting force it is likely to be subjected to in the use for which it is intended, and that it is well adapted for use in dying out upper leather. The extent of I distortion occasioned in the use of dies of this type is, in the case of small or medium size dies, well within the elastic limit of the material and no permanent bending or distortion of the die results. However, it may be found desirable in the case of large size dies to limit the extent to which their longer portions may be deflected, and this result may be-ob tained, preferably, by means of one or more braces extending across the interior of the die. Such an arrangement would not be I outside the scope of this invention as the contour of the die as a whole would be preserved by means of its resiliency as above explained.

A die constructed in accordance with the present invention may be corrected in contour if it should become permanently distorted by accident or otherwise. Such operation may" be accomplished readily by hand or by the aid of simple bending tools, the contour of the cutting edge being compared with a pattern or templet ivi'ng the original outline of the die and t e die being bent again into conformity therewith. Another advantage incident to this die is that it may be reshaped within certain limits and thus adapted for dyingout blanks of different styles from those originally produced.

Having described my'invention, what I claim as new and desire to secure by Letters Patent of the United States is '1. A die for use with clicking presses or the like, comprising a closed, flexibly resilient frame normally conforming in contour with the outline desired in the blanks to be cut and having parallel pressure-receiving and cutting edges, said frame tending, by its structure and by the resiliency of its material, to maintain its normal contour and to reassume it on withdrawal of the distorting force.

2. A die for use with clicking presses or the like, comprising a continuous strip of flexible resilient steel, bent into curves and angles of the desired contour, and conformed by the rigid union of its ends into a closed frame, tending, by its structure and the resiliency of its material, to resist distortion and to return to contour on removal of the distorting force.

3. A die for use with clicking presses or the like, comprising a continuous strip of thin flexible ribbon steel permanently bent to the desired contour and having its ends connected and presenting a resilient closed frame capable of promptly returning to normal contour automatically after distorxtions incident to itsuse.

4. A die for use with clicking presses or the like, comprising a continuous strip of flexible ribbon steel normally conforming in contour with the outline desired in the blanks to be out, said die being resilient, yielding to a distorting force and reassuming its normal contour after being sprung out of form, one edge of said strip being beveled on both sides to form a cutting edge which will be forced through the material without being appreciably deflected from a normal path.

5. A die for use with clicking presses or.

the like, comprising a continuous unconstrained frame of thin flexible untempered ribbon steel, said frame normally conforming in contour with the outline desired in the blanks to be cut and being highly resilient, whereby it is enabled to resist distortion yieldingly and by reason of the flexible nature of its material is capable of being corrected readily in contour after being permanently distorted.

'6. Adie comprising a closed unconstrained name to this specification in the presence of frame having a pressure receiving edge and two subscribing witnesses. a cutting ed e and bein constructed 0 s r flexible I'ibbOI I steel of m edium resiliency EBENEAER POCOCK' 5 formed, by the rigid union 01": its ends, into Witnesses:

a closed frame of higher resiliency. JOHN BAKER,

In testimony whereof I have signed my DEAN B. MASON.

Images