US1076667A - Shears. - Google Patents

Description

(I. PARRINGTON.

SHEARS.

APPLIOATION FILED MAR.20,1913.

1,076,667.. Patented 00a. 28, 1913.

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TTED STATES PATENT OFFICE.

JOEL FARRINGTON, 0F SPRING-B030, PENNSYLVANIA, ASSIGNOE TO MINNIE E. SHELDON, OF SPRINGBORO, PENNEIYLVANIA.

SHEARS.

Specification of Letters Patent.

Patented Oct. 28, 1913.

Application filed March 20, 1913. Serial No. 755,618.

To all whom it may concern:

Be it known that I, JOEL FARRINGTON, a citizen of the United States, residing at Springboro, in the county of Crawford and State of Pennsylvania, have invented new and useful Improvements in Shears, of which the following is a specification.

This invention relates to shears and consists in certain improvements in the construction thereof as will be hereinafter fully described and pointed out in the claims.

More particularly the invention relates to that type of shears wherein great pressures are required on the shearing blades as for instance in the clipping of bolts and like material.

The invention is illustrated in the accompanying drawings as follows Figure 1 is a side elevation of the shears. Fig. 2 is a plan view partly in section. Fig. 3 is a section taken along the longitudinal axis of the device and on the line 3-3 in Fig. 2.

11 marks the shearing blades, and 2-2 the bolts on which the shearing blades are pivoted. The bolts extend through the links 33 and thus form a pivotal mounting for the blades. One of the blades 1 is provided with a projection 1 which extends into the detent 5 in the opposite blade. This holds the blades in. proper relation or against end movement of one relatively to the other. The blades are provided with the shanks 6-4-3. Operating levers 9 9 are pivoted at their outer ends to the rear ends of the shanks by means of the bolts 88. Operating handles extend from the levers 99. The levers 9--9 are connected through the end 10 of a link 11. Bolts 12-12 extend through the levers S 9 and the end 10. It will be readily seen that as the levers 9-9 are swung into and out of alinement the shanks 66 are swung apart and the blades 1-l together and as the arms 9 approach alinement the leverage increases. The ends 1313 of the shanks are rounded with the pivotal axis as a center and the levers 9 have the shoulders 1 1 which operate against the surfaces 13 thus taking the pressure off the bolts 8. The ends of the arms at 15-15 are also rounded with the pivotal axis at the center of the bolt as a een-. ter so that as these levers are swung they roll on the surface 15, thus relieving the bolts 12-12 from strain. The links 1616 of a toggle lever are connected with the shanks by the bolts 1717. The endsof the links 1616 are connected by a bolt 18, this bolt extending through the links 11. It will be readily observed that as the levers 9 are swung to throw open the shanks 6, the link 11 is forced forward, thus forcing the links 16-16 toward alinement so that there is an outward pressure by reason of the links 1616 as well as by reason of the levers 9 9. The links 16-16 are so proportioned with relation to the throw of the lovers 9-4) that they exert pressure on the shanks 6 as well as the levers 99 as the levers are swung. Thus, there is a distribution of pressure on the shanks and a greater pressure delivered to the blades 1-1.

I prefer to provide one of the links 16 with a curved surface 19 which operates on a curved surface 20, said surfaces forming arcs with the axis of the bolt 18 as a center. In this way the bolt 18 is relieved of some of its wear. A stop 21 is preferably provided to limit the inward movement of the operating handles. It may be made adjustable if desired so as to compensate for the wear on the blades and where this is the case the levers 1616 are not initially brought to complete alinement but approximately permitting of further movement to take up the wear on the blades 1-1 by the adjustment of the stop.

While I have shown the invention as involving the blades 1-1 extending in alinement with the shanks, it will be understood that the cutting edge may be parallel to the axis of the bolts 2 or otherwise arranged as desired.

It will be noted that the link 11 with its end 10 operating on the pivots formed by the bolts 12 is maintained in alinement with the central line of the shears by the connection of the front end of the link 11 with the bolt 18. The effect of this to compel a uniform movement of the two blades and of the handles 7. This function of the link 11 I consider an important one in my invention.

While I have described the cutting blades as shear blades I wish to be understood as including any type of blade alfecting a cutting action, and while I have shown the device with a cutting edge lengthwise of the shear I do not wish to be limited by such a direction of the cutting edge.

What I claim as new is 1. In a pair of shears, the combination of blades; a pivotal mounting for the blades; shanks extending from said blades; levers having their outer ends pivoted to the rear ends of said shanks; operating handles extending from the levers; a connection be tween the inner ends of said levers; a toggle lever between said shanks; and a connection between said first mentioned levers and said toggle lever.

2. In a pair of shears, the combination of blades; a pivotal mounting for said blades; shanks extending from said blades; levers having their outer ends pivoted to the rear end of said shanks; opera-ting handles extending from said levers; a connection between the inner ends of said levers; a toggle lever between said shanks; and a link connection between said first mentioned levers and said toggle lever the links of said toggle lever being formed of curved surfaces to sustain the thrust.

3. In a pair of shears the combination of blades; a pivotal mounting for the blades; shanks extending from said blades; levers having their outer ends pivoted on said shanks; operating handles extending from said levers; a connection between the inner ends of said levers, the levers being separately pivoted to said connection and having curved surfaces engaging as the levers are swung to sustain the thrust; a toggle lever between said shanks; and a connection between said first mentioned levers and said toggle lever.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

JOEL FARRINGTON,

itnesses:

B. M. HARTMAN, MINNIE E. MILLER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of latents, Washington, D. G.

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