US496584A - Cutting-nippers - Google Patents

Description

(MOdel.)

S TAFT No. 496,584* GUTTING NIPPERS.

` Patented May 2 1893 Mmmmwwwwyxggggwww UNITED STATES PATENT OFFICE.

STEPHEN TAFT, OF MILLBURY, MASSACHUSETTS.

CUTTINGiNIPPERS.

SPECIFICATION forming part of Letters Patent No. 496,584, dated May 2, 1893.

Application filed May 7, 1888. Serial No. 273,148. (Model.)

To all whom it may concern:

Beit known that I, STEPHEN TAET, a citizen of the United States, residing at Millbury, in the county of Worcester and State ot' Massachusetts, have invented certain new and useful Improvements in Cutting-Nippers, of which the following is a specification, accompanied by drawings forming a part of the Specication and showing a pair of cuttingnippers embodying the essential features of my present invention, which relates to the form of the cutting-dies and to the method of attaching them to the jaws of the nippers; also, to certain other details of the construction of the cutting nippers, as hereinafter described, and pointed out in the subjoined claims.

Figure 1 ofthe accompanying drawings represents a perspective view of a pair of cutting nippers embodying my invention. Fig. 2 is a central longitudinal, sectional view on line X, X, Fig. 1, and Fig. 3 is an enlarged sectional view of the cutting dies and a portion of the jaws, on line Y, Y, Fig. 1.

Similar letters refer to similar parts in the several views.

A, A denote the jaws formed by the lateral extension of the levers A', A2. Each of the jaws A, A, is recessed by removing a rectangular corner from the outer side of the jaws, the recess being bounded by the side c, parallel with the line of strain upon the edges of the dies in the operation of cutting, and the side d at right angles thereto. The sides c extend behind the cutting dies and form a seat for them and the sides d act as shoulders to resist the direct thrust upon the edges of the dies.

Extending into the jaws A, A, at the intersection ot' the sides c and d are the mortises a, having their end walls concave as at f and the side walls slightly divergent from f, forming tapering mortises, one of said side walls, however being in the saine plane with the seat c.

The cutting dies B consist of blocks filling the rectangular recess in the jaws A, A, and having tongues b, which are slightly tapering in form and are provided with round or oonvex ends tting the concave ends fof the mortises ct. The dies B are held in place by the elastic, tapering pins e, e, which are driven through holes in the jaws A and tongues b, said holes being not coincident but so arranged that as the pins ai'e driven in the tongues b will be drawn into the mortises and the dies B are drawn firmly against the sides d; thereby producing a slight curvature of the pins e, c, which is illustrated in an exaggerated form in Fig. 3. The two sides of the cutting edge are the same in each die, except that the sides are reversed, and consist of the curved sides C and the straight side D, inclosing the acute angle between them which forms the cutting edge of the die; the curved side forming the outer side of one of the dies and the inner side of the opposite die, the cutting edges are sharp enough to part the metal to be cut and instead of approaching each other in the same plane as is usually the casein cutting nippers of the ordinary construction, they are placed in dierent planes as indicated by the parallel lines l, 1 and 2, 2, Fig. 3. When the cutting edges reach a common plane at right angles to the lines 1, 1; 2, 2, their motion is limited by an adjustable screw E held in one of the handles A' and coming incontact with the handle A2.

As I place the cutting edges of the dies in different planes I cause the metal to be cut to be pressed in opposite directions, that upon the outer side of the cutting edges b eing pressed in the direction of the arrow 3, Fig. 3, and that upon the inner side of the cutting edges being pressed in the direction of the arrow 4, and it will be observed that the curved side of the cutting edge is placed upon the side toward which the metal is pressed, and that the curved line at the angle forming the cutting edge is nearly or quite parallel with the lines 1, 1; 2, 2, thereby allowing the metal to be moved over the side of the die. action of the cutting edges is similar to those cutting nippers having a shear cut and the action of the cutting edges in my improved nippers may be said to .combine the action of both classes of cutting nippers, viz; those having a shear cut, so called, and those having a parting out, or in which the edges approach each other in the saine plane, and the cutting is accomplished by severing or parting the metal in a line at right angles to the line of This motion of the dies as they approach each other 1n the operation of cutting.

The levers A and A2 are pivoted at h and the plvotal pin is extended and enlarged forming the plate j with one edge resting against the shoulder la of one of the jaws. The inner end of the metal to be cut is pressed against the plate j as the jaws are brought together, the plate forming a fulcrum to hold the inner end of the metal while it is being cut by the cutting dies. The extension of the fulcrum p1n 1s not new as the same feature formed the subject of the Letters Patent No. 351,478, granted to me on the 26th day of October, 1886, but in my improved cutting nippers herein described the extension of the pivotal pin 1s enlarged so as to receive even the shortest end which may be cut off by the dies B, and th e pressure against the edge of the plate 1s recelved upon the shoulder 7c. The lever handles A', A2 I reduce in weight without materially decreasing their strength by making them hollow or U shaped by forming a groove H upon the inner sides of the handles, making two ribs m, m, upon the inner side of the handles. l

In order to afford a broad bearing for the dles B, the tongues b are reduced in thickness to lncrease the sides d, the tongues b, being required to simply hold the dies in place, allowlng the strain upon the edges of the cutting dies, which is exerted in a line parallel with the arrows 3, 4, Fig. 3, to be received upon the sides d, d. As the tongues b are only of sufcient thickness to serve to retain the dies in place, it becomes necessary to relleve them of any transverse strain produced by a strain upon the edges ofthe cutting dies 1n a direction at right angles to the arrows 3, 4, Fig. 3, which would cause a fracture of the tongues. This is accomplished by making the tongues slightly tapering and forming their ends round as at f, Figs. 2 and 3, and also by the yielding fastening eifected by the elastic pins e, e. Theoretically the dies B are firmly supported upon the sides c and d of the jaws and the tongues b are not moved in the operation of cutting, but in practice an unusual strain at right angles to the arrows 3, 4 will cause a transverse strain to be eX- erted upon the tongues b, which would produce a fracture of the tongues, were it not for the construction as shown by which the tongues are capable of not only a slight movement out of their mortises, but also ofaslight movement about their rounded ends f, which would not be possible if their ends were square and fitted mortises having plane end walls with angular corners. The form of the recess in which the dies are placed provide the sides c and d, the former at right angles to any lateral strain upon the cutting edges; and the latter at right angles to the strain tially as described.

in cutting, exerted parallel with the arrows 3, 4, Fig. 3.

I am aware that cutting nippers have been made having jaws provided with mortises to receive tongues or tenons upon the cutting dies, by which the dies were heldin place, such I do not herein claim, neither do I claim broadly the employment of elastic pins as such have been employed in other cases for analogous purposes, but

What I claim as my invention, and desire to secure by Letters Patent, is-

1. In a pair of pivoted cutting nippers, the combination of jaws moving in an arc of a circle and having rectangular recesses in their opposing corners bounded by the walls d, at right angles with the line of strain upon the cutting dies, and walls c, parallel with said line of strain, tapering mortises extending into said jaws from the inner corners of said recesses and parallel with said side c, cutting dies fitting said rectangular recesses and having tapering tenons entering said mortises and provided with cutting jaws placed in the central section of said dies and at one side of said tenons and elastic pins passing through said jaws and said tenons whereby said tenons are allowed to yield as the strain upon the cutting dies is changed from the Walls c, to the walls d, and vice versa, sub stantially as described. Y

2. In a pair of cutting nippers, having cutting dies which approach each other in an arc of a circle, the cutting dies B, B, each provided with cutting edges, the edge of one of said dies being included by a plane surface upon its inner side and by a concavev surface upon its outer side, and the other of said dies having a cutting edge included by a plane surface upon its outer side and aconcave surface upon itsinner side, substantially as described.

3. In a pair of cutting nippers, the combination with the jaws, having cutting edges which approach each other in an arc of a circle, one of said jaws being provided with a shoulder lo, of the plate j, formed by an extension of the pivotal pin of the nippers and resting against the shoulder 7c, substantially as described.

4. In a pair of cutting nippers the combination of jaws A, provided with tapering mortises a, cutting dies B, having tapering tenons b, beveled and concave surfaces C, and D, inclosing cutting edges, a shoulder k, formed on one of said jaws and a plate J, formed by the extension-of the pivotal pin and resting against lsaid shoulder, substan- STEPHEN TAFT. Witnesses:

RUFUs B. FowLER,

CHAs. A. WHITNEY.

IIO

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