US145724A - Improvement in saw-sets - Google Patents

Description

n. r. 600K.

Saw-Sets.

No. 145,724. Patented Dec.23,1s?3.

UNITED STATES PATENT OFFICE.

ROSWELL F. COOK, OF WEST POTSDAM, NEW YORK.

IMPROVEMENT IN SAW-SETS.

Specification formingpart of Letters Patent No.145,724, dated December 23,1873; application tiled October 9, 1873.

A represents the frame or holder, whichv may be attached to the bench, or may be so constructed as to be held in the hand. In the rea-r lower portion of the holder is a recess, b, in the lower side of which is a series of notches, c. In the rear upper portion of the holder lugs Z are formed, and between these lugs the hammer E'and lever G are pivoted. In the heel of the hammer is a notch, j', which enga-ges with one end of the spring H, the

* other end of which engages with one of the series of notches cin the recess b. The spring H consists ot' a iiat strip of metal, bent midway of its length, so as to form a resemblance to the letter V with its point rounded, and having its ends bent outward for engagement with the notches.

It will be seen that when the spring is thus attached to the parts, as the hammer rises the rear or central bent portion of the spring rises toward the hammer; and, as the hammer falls the spring falls in an opposite direction, thus oscillating in an are of a circle, of which the lower end of the sprin g' forms the center.

By moving the lower end of the spring farther into the recess, the force of the hammer is increased, and by moving it farther out the force is diminished, as the distance traveled and the consequent power exerted by the spring depends upon the position of its lower end, which forms fthe center of oscillation. Thus the force of the blow of the hamsprin g is readily removed and replaced, springs of different degrees of tension may be used when desired, and a new spring may be inserted in place of a broken one without the use of tools, and without loss of time.

The lever G has its fulcrum on the same pivot with the hammer, and engages with the hammer at a point between the fulcrum and the long arm by means of a pin or stud, 7c, working between two shoulders or projections, l l, on the upper portion of the heel of the hammer.

By this arrangement the manipulation of the lever is facilitated, as the lever is in nearly an upright position, and consequently vmore out of the way ofthe hammer than when in a nearly horizontal position, the parts are more easily inserted in place, and more power is aequired than if the point of engagement were beyond or below the fulcrum. By the oscillation of the spring on the lower end as a center, the upper end, or the end which operates the hammer, travels a distance three times as great, and thus acquires more power than a spring which has one end iixed; and, by having the spring so arranged as to rise toward the hammer as the hammer rises, it forms a bearing for the heel of the hammer and holds it in a raised position. When the lever is moved back it raises the hammer until it passes the dead point, when the hammer springs farther back, so that its heel comes in contact with the flat portion of the spring, an d is held in a raised position. A slight forward movement of the lever starts the hammer downward again until it passes the deadpoint, when the spring completes the downstroke with a sudden blow.

I claim as new and desire to secure by Let` ters Patent- The combination, substantially as described, in a saw-set, of a notched frame and lever with a hammer having' an oscillating spring for operatin g the same.

Images