US126443A - Improvement in pruning-shears - Google Patents

Description

UNITED STATES RANSOM BULLARD, OF LITCHFIELD, MICHIGAN.

IMPROVEMENTIN PRUNlNG-SHEARS.

Specification forming part of Letters Patent No. 126,443, dated May 7, 1872.

' To all lwhom 'it may concern:

y of a side view of my invention. Fig. 2 is a front view 0f the same. thereof.

This invention has relation to pruningshears; and its object is to provide a pair of shears whose blades will not cross and hack each other in the cutting, and whose levers shall be so connected that their operation will not be obstructed by the interposition of branches, foliage, or other obstructions of like nature.

In the accompanying drawing, the letter A represents a long wooden handle or lever, to one end of which is secured the shank a of one of the pruning-jaws B. Said shank is constructed with a slotted projection, b, part of which constitutes a shoulder, fitting into a recess in the handle, and designed to aid in holding said shank securely. C designates the other handle or lever, which is provided with a projection, b', which enters the cleft end of the projection b, and is pivoted thereto. To the opposite sides of the handle C, at its upper part, are secured the broad guiding-plates d, between which works the sliding shank of the knife D, slotted longitudinally, and workin g on a pin, d1, which passes through the slot d2. The upper part of the knife D is curved or hookshaped, the inner or cutting edge being convex. B represents the stationary jaw, secured, as above described, to the handle A. This jaw extends upward on each side of the knife D, in the form of two plates, between which said knife is pivoted. These plates extend upward and inward from the shank portion, forming a projecting part, E. From this part the blades of the jaw are curved outward, upward, and inward in semi- Fig. 3 is a rear view circular form, the cutting-edges being on the concave sides of said blades. The knife D is pivoted at about the center of the projecting portion E, and the arrangement is such that a part or continuation of the cutting edge shall at all times be within the cleft of the jaw B. The design of this construction is to prevent the blades from crossing in making the cut and hacking each other. Material aid in eifecting this object is derived from the broad shank of the knife D and the broad guiding plates d, between which it slides. Full allowance is made in the construction of the jaw B and its shank for the movement of the shank of the knife and the upper end of the lever C in opening the jaws to their full width. The end of the shank of the knife is arranged so that when the blades are open t0 their widest extent it will strike the inside of the opposite lever and st-op the movement.

It will be observed that the space z, bounded by the projections b b', and by the shanks of the jaws and the upper portion of the lever C, becomes enlarged when the jaws are brought together, so that there is no danger of obstruction in the cutting operation by the interposition of branches in this space.

The projecting stop F is placed some distance below the pivot-pieces b b sufficiently far down to be out of the way of branches in all ordinary operations. The stop is also of sufficient length to keep the levers well asunder, even when the jaws are closed. The projections b b', during the first part of the cut, are oblique to each other, butl come into line with each other at the end of the cut and during the greatest strain.

The cutting lever D is arranged in such a manner that its power shall rather be increased than diminished as the work of cutting through a branch progresses. lt will, as a lever, have more force in that portion of its cutting-edge nearest the fulcrum. The decrease of power which occurs as the action of the cutting-edge moves toward the point is compensated by a gradual lengthening of the power-arm of the cutting-lever, effected by means of the slot d2.

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

The combination of the curved concave jaw B, having bent shank a and double guidehereunto subscribed my name in the presence plates at and beyond the pivoted projection of two witnesses. E, with the convex-edged knife-lever D, slot- RANSOM BULLARD. ted at its lower end7 the guide-plates d, pin d', pivoted projections b b', handles A C, and Witnesses: projecting stop F, substantially as specied. M. G. WHITNEY,

In testimony that I claim the above I have ANSON BUCK.

Images