US624875A - Chusetts - Google Patents

Description

No. 624,875. Patented m 9, I899. B. E. SAWYER & w, n. ARNOTT.

SCREW DRIVER. (Application filed Sept. 13, 1898.)

(No Model.)

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PAT NT 7 OFFICE.

BURNSIDE E. SAWYER AND WILLIAM'D. ARNOTT, OF ATHOL, MASSA- OHUSETTS.

SCREW-DRIVER.

SPECIFICATION forming part of Letters Patent No. 624,875, dated May 9, 1899. Application filed September 13,1898. Serial No. 690,842. (No model.)

To all whom it may concern:

Be it known that we, BURNSIDE E. SAWYER and WILLIAM D. ARNOTT, of Athol, in the county of Worcester and State of Massachusetts, have invented a new and Improved Screw-Driver,of which the following is a speci fication. 1

As is well known, the sides of the blade or point of the ordinary screw-driver are beveled, and hence the same is liable to slip out of the nick of a screw or to upset the edges of the nick, and thus deface and injure the screw-head.

We have devised an improvement by which a series of insertible and removable parallelsided or flat blades made of high-grade or tool steel are provided for one common holder or stock, whereby the following advantages are attained:

First. The insertible flat blades are of uni; form thickness and inserted in a holder not necessarily made of tool or high-grade steel. The sides of the blade being parallel and made to fit slots of standard screws it will not slip out when great strain is put upon it, as in the case of screw-drivers having the ordi-. nary wedge-shaped point.

Second. In case a blade is broken (which is a very common occurence) a new one can be inserted at a trifling cost, thus putting the tool in its original condition with but little delay.

Third. A very important point is, as the blade does not project beyond the face of the stock enough to bottom in the slot in the head of the screw, the face of the head of the screw rests upon the end of the stock, thereby steadying the tool and enabling it to drive home the screw straight without danger of its wabbling about or flying off and injuring any work upon which it is used. Another strong point is that the support of the stock is brought down so far on the blade as to'enable a greater strain to be applied without danger of twist- 5 ing or breaking the blade.

In the accompanying drawings, Figure 1 includes a side view of our improved screwdriver and a central longitudinal section of the lower end of thestock. Fig. 2 is a section showing the blade inserted in the stock. Fig. 3 is a perspective view showing a modification. Fig. 4 includes a side view and section of another modification.

The shank or stock A is provided at its end with a central lengthwise bore a, a transverse hole a at the upper end of said bore, and a transverse slot 0. at the lower end of the same, the said slot being arranged at right angles to the transverse bore. A blade B, having a fiat tapered shank, Fig. 2, is adapted to fit in said bore or. and slot ct -that is to say, the

' blade is-essentially T-shaped,the blade proper,

b, fitting the slot a and the shank b fitting the bore a tightly when the device is forced up into place, as shown in Fig. 2. proper, 1), projects from the stock A suificiently to adapt it to enter a nick in the head of a screw, but it is not intended it shall reach quite to the bottom of the nick, and hence it cannot jam therein.

upper end of the bore a that a. suitable tool may be inserted therein forthe purpose of forcing out the blade B when required.

In Fig. 4 the stock A is provided with a .vertical slot a in place of the transverse hole before described. The said slot 0. is cut in the side of the stock lengthwise and extends inward, so as to communicate with the bore, as shown. The said slot permits the insertion of a tool for ejecting the blade.

In Fig. 3 we show a modification in which the slot A is constructed, as in Figs. 1, 3,and 4, save that the longitudinal bore is enlarged to adapt it to receive a cylindrical pin biwhich is split or slotted longitudinally more than half its length.

The bladeB may be T-shaped,-as before stated, or it may be constructed without a shank, as shown at B In either case the blade is inserted and held in the slot of the pin b, as shown, and said pin being forced The blade The transverse hole a is so'located. at the I up into the bore in the stock A its spring-jaws cient to expose the end of it, so that it may be IO are caused to clamp the blade firmly, so that loosened or ejected from said bore, all pracit is held with due security. tically as shown and described.

What We clan 1S BURNSIDE E. SAWYER.

A screw-driver comprisinga stock, the end T r of Which is slotted, a central bore in said end WILLIAM OT afiording an annular bearing, a T-shaped Witnesses: blade which fits tightly into said bore and T DENNIS COLLINS, slot, an orifice at the end of such blade suffi- ANDREW J. HAMILTON;

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