US172351A - Improvement in wood-screws - Google Patents

Description

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WOOD-SCREW.

Patented Ian. 18, 1876.

UNITED STATES PATENT QFFIGE.

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

IMPROVEMENT IN WOOD-SCREWS.

Specification forming part of Letters Patent No. 172,35l, dated January 18, 1876; application filed July 10, 1875.

To all whom it may concern Be it known that I, THOMAS J. SLoAN, of the city, county, and State of New York, have invented an Improvement in Wood-Screws, of which the following is a specification:

The object of this invention is to provide a wood-screw which may be driven either by a common square-ended screw-driver or by a driver constructed especially for it, the former permitting the use of the screw, under ordinary conditions, with as great efficiency as is possible with the common screw, and the latter enabling it to be driven under conditions in which the ordinary screw-driver would slip from the groove in the head of the screw, and, as frequently occurs, mar or fracture the head, injuring the symmetrical appearance of the head, and in many cases destroying the utility of the screw.

The invention consists in a screw constructed with a groove or nick having the usual depth at the center of the head and deepened outwardly, with sloping surfaces, to the sides of the head, whereby, as may be preferred, or as occasion may demand, a notched or specially-"constructed driver may be applied to the screw, to exert a great degree of force in driving the same without danger of slipping, or a common screw-driver employed to turn the screw in the ordinary manner.

Figure 1 is a partial longitudinal section of a wood-screw made according to my invention. Fig. 2 is a side view of the same. Fig. 3 is a partial section of a modification of the same. Fig. 4 is a top view of the same, and Fig. 5 is a side view of the driver more especially designed for use therewith.

The shank A and head B, except as hereinafter particularly specified, are of the usual form and structure, and therefore require no special description.

The nick or groove of the head of the screw is represented at a, but, instead of being flat or straightbottomed, as in the common woodscrew, or sloping laterally from a point fiush with the outer surface, as in screws hitherto proposed for use in connection with indented screw-drivers, the groove a in my aforesaid screw has at its center 0 the depth of the usual nick of the common screw, and, sloping laterally outward. and downward from this point to the sides of the head, (opening at or through the said sides,) as shown at f, is much deeper at its end portions than at its center. Such being the character of the groove, the notched driver shown in Fig. 5 may be inserted, and, holding not only at the center, but with a deeper and firmer hold at the ends of the groove than is possible with the straight-bottomed groove, enables a greater purchase to be had upon the screw than is possible with screws made with the straight bottomed grooves. Moreover, the groove in my aforesaid improved screw, having at its center a depth equal to that of the usual straight-bottomed groove, permits, in the absence of the indented driver, the insertion and use of the ordinary straight ended driver, with just-as much convenience and efficiency as is possible with the common wood-screw, and, furthermore, even with the ordinary driver aforesaid, my improved screw may be applied in use with greater efficiency and facility than the common screw, for the reason that the slopes f, in connection with the depth of the groove at the center 0 permits the driver to be held at a greater angle to the axis of the screw, without displacement from the groove, than would be possible with the common screw, or, for that matter, with lateral grooves or notches starting flush with the outer surface of the head, and designed for the reception of aforked or indented driver.

What I claim as my invention is- The wood-screw constructed with the groove a, having at its center 0 the depth of the nick of the common wood-screw, and deepened with sloping surfaces to and through the sides of the head, substantially as and for the purpose herein set forth.

THUS. J. SLOAN.

Attest WM. EDWARDS, ELBERT F. DEARBORN.

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