US627647A - Mortising-chisel. - Google Patents

Description

Patented June 27, I899.

M. LAMONT.

MORTISING CHISEL.

(Application filed Oct. 14, 1898.;

Model.)

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UNITED STATES PATENT OFFICE.

MARTHA LAMONT, OFNEWV YORK, N. Y.

MORTlSING-CHISEL.

SPECIFICATION forming part of Letters Patent No. 627,647, dated J 'une 27, 1899. Application filed October 14,1898. Serial No. 693,565. (ModeL) To all whom it may concern:

Be it known that I, MARTHA LAMONT, a citizen of the United States,residing in New York city, borough of Brooklyn, county of Kings, and State of New York,have invented certain new and useful Improvements in Mortising- Chisels, of whichthe following is a specification, reference being had to the accompanying drawings.

This invention relates to chisels, especially such as are intended to be used in mortisingmachines, though the chisel may also be used by hand.

The object of my invention is to produce a mortising-chisel which shall be self-clear- I ing and which shall cut easily with a minimum amount of strain upon the chisel and the wood.

Figure l is a perspective view of the chisel. Fig. 2 is a longitudinal verticalsection through the chisel. Fig. 3 is aplan view of the chisel. Fig. 4 is a transverse section taken on the line 44 of Fig. 3. Fig. 5 is an end elevation of the chisel. Fig. 6 is a transverse section taken on the line 6 6 of Fig. 3.

The body A of the chisel is provided with a longitudinally plane floorl, which constitutes the bottom of the chip-receiving channel B. The floor 1 is of equal width through its entire length, and its forward end is inclined or beveled, terminating at the plane of the under face of the chisel in a sharp edge 2. The rear end wall 3 of the channel B is upwardly curved. The interior sidewalls of the chisel are at right angles with the floor 1.

From a predetermined point rearwardly the side walls of the chisel are curved over the floor 1, forming thereby flanges 4:. These flanges may meet each other over the floor of the chisel, or they may be made with a slight space separating each other, and which latter I consider the preferable way. These flanges4at theirlower ends are given a downward slope, following the direction of the for ward end of the floor of the chisel, as indicated by 5, and terminate at an acute angle with the outer walls of'the chisel at the sharp edge 6 of said wall, which extends beyond the main cutting edge 2 and at right angles to its plane. The lower part of the flange 5 is beveled or undercut, forming a knife-edge, as at 7. The projecting edges of the chisel at 6 prevent the wood from splitting in making a thin mortise, and the knife-edges 7 reduce the strain of the cutting upon both the chisel and the wood. a

Having thus described my invention, what Iclaim as new, and desire to secure by Letters Patent, is'

1. A mortising-chisel having side walls and the upper portions thereof bent over and horizontal to form flanges, the lower portions of said flanges beingundercut or beveled to a cutting edge, said cutting edges meeting the outer walls of the chisel at an acute angle, substantially as described.

2. A mortising-chisel having side walls and the upper portions thereof bent over and horizontal to form flanges, the lower portion of said flanges being undercut or beveled to cutting edges which meet the outer walls of the chisel at an acute angle, said outer walls extending beyond and being at rightangles to the plane of the main cutting edge, substantially as described.

MARTHA LAMONT.

Witnesses:

H. N. ROBINSON,

WILLIAM C. RELYEA.

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