US4704A - Improvement in wood-screws - Google Patents

Description

,UNITED STATES PATENT OFFICE.

THOMAS J. SLOAN, OF NEW YORK, N. Y.

IMPROVEMENT IN WOOD-SCREWS.

Speciiication forming part of Letters Patent N o. 4,704, dated August 20, 1846.

To aZZ whom it may concern,.-

Be it known that I, THOMAS J. SLOAN, of the city, county, and State of New York, have invented an Improved Wood-Screw, which I denominate the threaded conical-point Woodscrew; and I do hereby declare that the following is a full, clear, and exact description of the principle or character which distinguishes it from all other things before known, and of the manner of making, constructing, and

using the same, reference being had to the.

accompanying drawings, making part of this specification, in whichm Figure l is the perfect screw. Fig. 2 is the core of the screw with the thread removed to show its form.

Screws have heretofore been formed gradually tapering at the core from Where the thread starts to the end by dressing the thread at each turn, and tapering screws have also been formed; but they have been found not to hold as well as those of common construction by reason of the taper of the main part of the core; but the nature of my improved screw consists in forming on a screw of the ordinary shape a conical point and extending the thread of the screw with the saine pitch, but gradually diminishing in width to the end of said point, by which means the screw can be entered into the Wood Without boring, unless the wood is very hard, in which case it -follows better, works straight, and holds more firmly than any other heretofore made. The screw is formed by any machinery that will make a perfect thread, which is cut into the blank of ordinary make, and when it reaches the full depth it runs down to near the point, shaping the core cylindrical, as shown in Fig. 2 at a. The cutters then form the point of the core conical, as shown at b, Fig. 2, and at the same time cut a thread on it of the same pitch as .that on the body of the screw, and gradually diminishing it in depth to the extreme point, Where it terminatesas represented at Fig. l.

What I claim as my invention, and desire to secure by Letters Patent, is-v Forming on a Wood-screw of ordinary shape a conical threaded. point, substantially as herein described, the thread on said point being gradually diminished to the end, as

aboveset forth.

THOS. J. SLOAN. Witnesses:

A. P. BROWNE, WM. H. BrsHoP.

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