US254733A - Mortising-chisel - Google Patents

Description

(No Model.)`

Gr. R. VALENTINE.

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NiTnD STATES PATENT ertoe.

'GEORGE R. VALENTINE, OF NEW BEDFORD, MASSACHUSETTS.

MORTISING-CHISEL.

SPECIFICATION forming part of Letters Patent No. 254,733, dated March '7, 1882-I Application liled December 10, 1880. (No modell) To all whom it may concern:

Be it known that I, GEORGE R. VALENTINE, of New Bedford, in the county of Bristol, State of Massachusetts, have invented certain new and useful Improvements in Mortisi ng-Chisels 5 and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, making a part of this specification, in Which- Figure l is a perspective view of my chisel from the front. Fig. 2 is a like view of the same from the rear. y Fig. 3 is a central longitudinal section; and Figs. 4 and 5 are cross-sections upon lines .fr and z z, respectively, of Fig. 3.

Letters of like name and kind refer to like parts in each of the figures. v

The design of my invention is to cause the removal of chips from a mortise during the operation of cutting the same; and to this end it consists in a mortising-chisel provided withinits back with alongitudinal groove which has its sides or flanks serrated to form horizontal cut-ters or teeth, substantially as and for the purpose hereinafter specified.

In the annexed drawings, A represents a mortising-chisel intended for use in cutting a right-angled mortise, the front side of said chisel being straight and plainT its lower end having the usual cutting-point, c, and its upper end being provided with a shank, c.

Within the back of the chisel is formed a longitudinal groove, a2, which has preferably a V-shape in horizontal section, and terminates at or near the point a. The sides of said groove a2 are provided at" regular intervals with serrations or teeth c3,which extend horizontally across the same and rake upward, so

that when said chisel is moved in such direc-V tion they will engage with and carry upward 4o the chips which have been formed by the down ward movement of said chisel.

The edges a4 of the chisel A, formed by the intersection of its grooved back, are preferably made to operate as cutting-edges, being sharp horizontally, and divided vertically into a number of saw-shaped teeth by the ends of the serrations a3.

As thus constructed the chisel is used in the ordinary manner, its point c and cutting- 5o edges t4 operating to form the end and sides of the mortise downward stroke, while upon the upward stroke the teeth or serrations a3 engage with and carry in the same direction the chips formed by said chisel. y

In consequence of the form of the groove a2 the chips formed by the downward movement of the chisel A are forced from each side of the mortise inward and rearward, and relieve said chisel from the pressure which usually causes chisels to become wedged when iirstcansed to operate within a mortise.

Having thus fully7 set forth the nature and merits ot' my invention, what I claim as new 1s- A mortising-chisel provided within its back with alongitudinal groove, which has its sides or Hanks serrated to form horizontal cutters or teeth, substantially as and for the purpose specied.

In testimony whereofI hereunto set my hand this 2d day of December, 1880.

. GEO. R. VALENTINE.

Witnesses-z R. H. EDDY, E. B. PRATT.

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