US344160A - Screw-driver - Google Patents

Description

(No Model.)

H. S. BROWNSON.

SCREW DRIVE-R.

Patented June 22, 1886.

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HERBERT S. BROIVNSON, OF PORTLAND, MAINE.

SCREW-DRIVER.

SPECIFICATION forming part of Letters Patent No. 344,160, dated June 22, 1886.

Serial No. 174932. (No model.)

To all whom it may concern:

Be it known that I, HERBERT S. BROWN- soN, residing at Portland, in the county of Cumberland and State of Maine, have invented certain new and useful Improvements in Screw- Drivers; and I do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to a new and useful improvement in that class of wood-working tools commonly known as screw-drivers, and whereby the general usefulness of the same is greatly increased by means of a reversible ratchet movement contained within the handle.

The invention consists in the use of a facegear, a pawl, and a pawtoperating spring, so constructed, combined, and arranged that an operative rotary motion back and forth in opposite directions can be readily imparted to the screw-driver by rotating the handle in a forward direction.

In the accompanying` drawings, Figure l is a front view or elevation. Fig. 2 represents a longitudinal section showing the parts in position for forcing a screw forward. Fig. 3 shows same view with parts reversed for eX- tracting a screw. Fig. 4 is an enlarged detail of the pawl.

Similar letters of reference indicate corresponding parts.

A is a screw-driver, made of a length of round steel, and shaped at its extreme endf to engage with the slot of a screw-head.

C shows a handle, preferably of wood, pro vided with a bore, d, to receive the shank of the driver A. To the end ofthe handle I attach, by means of pins or screws c 0, a castmetal cap or head, F, which has a recess or chamber, G, for holding the mechanical parts composing my newly organized reversible ratchet movement. At the bottom of the chamber G is a socket, 71, which all'ords a con venient bearing-point for the shank end ofthe driver A to rotate upon.

I is a face-gear made fast to the shank d by means of a pin, i, passing through a collar, k, on the back ofthe gear.

L is a pawl swinging upon a pivot-pin, m, at its lower end. The free or top end of the pawl is provided with a projecting spur, n,

having ashoulder or recess, o, ou each side, to engage with the teeth on the gear I.

l is a spiral spring which encircles 4the screw-driver shank. One end of the spring rests upon the face or rim of the socket h. The other end is carried away from the shank and connected to the spur end of the pawl L.

In putting the parts together the shank d is passed through the bore of the handle C. The mee-gear I is then slipped over the shank, and at the proper point is made secure by means of the pin The pawl L is put in its place in the chamber, and then rendered secure by the pivot-pin 7.1. The spiral spring I? is set upright over the socket h, throwing the pawl L into a vertical position. The end of the shank d is thrust through the center of the coil Pand ttedinto the bearing-socket 71. The rim of the chambered cap F is presented to the end of the hollow handle and secured thereto by the pins e e.

In reversing the operations of the device it is necessary that the driver-shank d should be capable of a limited longitudinal movement through thehandle. To permit said movement, care should be exercised in assembling the parts to leave a space between the face-gear I and the end of thehandle O. Further, a countersink, S, is made in the end of the handleto receive the collar K.

That the uses of the device may be fully understood, I will describe the several operations necessary for driving and extracting a woodscrew. Assuming the pawl L to be in direct engagement with the gear I, as shown in Fig. 2, the operator grasps the handle G, inserts the point Z) in the screw-slot, and then rotates the device in a forward direction so far as his wrist can turn conveniently. This operation drives the screw to a. greater or less degree. The direction of movement of the handle is then reversed, and as this disengages the pawl from the gear the driver A becomes inoperative. Immediately upon turning the handle forward the pawl engages with the face-gear and forces the screw further forward. Thus by alternately twisting his wrist from side to side backward and forward the operator drives the screw till it is firmly embedded in its place. \Vithout disengaging the point b from the screw-slot, the driver can be rendered operative for extracting the same screw. Upon IOO relaxing the pressure necessary to keep the point b in iirm union with the slot of the screw the spring I?, which has been compressed between the face-gear L and socket h, elongates of driving; but the reversal of the pawl causes c the driver vto be operative for the purpose of reversing the operation first described.

What I claim as my invention, and desire to y secure by Letters Patent, is

l. In a reversible screw-driver, the driver A, having the facegears I attached to its shank, combined with thc pawl L, pivoted to the bit-shank and swinging on the pivot-pin m, and adapted to engage with the gear I, and the spring I), connected tothe spur end of said pawl, all substantially as and for the purposes described.

2. The handle C and the hollow head or cap F, secured thereto, having at its bottom the socket h, combined with theshank ofthe driver, (the end of which tits into said socket,) and having the facegear thereon, and the spring-pawl pivoted to the bit-shank and over said gear, and adapted to engage therewith, substantially as described.

In testimony that I claim the foregoing as 35 my own I have affixed my signature in the presence of two witnesses.

HERBERT S. BROWNSON.

Witnesses: Y

WM. H. MorLnr, H. G. BRIGGs.

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