US472591A

US472591A - Screw-driver

Info

Publication number: US472591A
Authority: US
Publication date: 1892-04-12
Anticipated expiration: 1909-04-12

Description

I (No Model.)

J. P. S'I'BWARD.

' SGRBW DRIVER.v

'No'. 472,591. Pate'nted Apr. 12, 1892.

UNITED STATES PATENT OFFICE.

JOHN F. STEWARD, OF CHICAGO, ILLINOIS.

SCREW-DRIVER.

SI 'ECIFICATION forming' part of Letters Patent No. 472,591, dated April 12, 1892.

Application filed August 19, 1891. Serial No. 403.139. (No model.)

T all whom it ntay con/087%:

Be it known that I, JOHN F. STEWARD, of Chicago, in the county of Cook and State of Illinois, have invented an Improved Screw- Driver, of which the followingisafull description, reference being had to the accompanying drawings.

Figure 1 shows the tool in its simplest and cheapest form, and Fig. 2 represents a modified form.

The tool here shown is designed so as to render it more convenient to the hand operating it than that forming the subject-matter of my Letters Patent of the United States,

dated September 29, 1891, No. 460,256; and the nature of the inventiou consists in providing a thu mb and finger pad to enable the operator to apply a great amount of Stress tov the tool When starting a screw, when running t out, or in driving it fully home.

A is the shank of the screW-driver having a crank With a diagonal wrist at one end provided with a handle a', preferably loose on the wrist, and a tool formed at the other end. The in'vention is applicable to any tool that requires rotation.l w

a is a pad, so located that the thumb or forefinger of the hand holding the tool may reach it and the handle of the tool, as a whole, be held and turned With a positive force. 'The pad a must of course be located so as to be in convenient reach and may be formed as a special part, as shown in Fig. 2, or formed by recurving the shank, as shown in Fig. l, or by other means. The pad is preferably roughened. If the handle be grasped with one hand, the pad a will always be in such a position that it may be pressed upon by the forefinger or the thumb of thehand that holds it. The handle proper, being loose, cannot serve as an ordinary screw-driver handle, nor by gripping it tightly can the screw be turned if the resistance be great; but if the pad be used the tool may be rotated with a positive force, and by using the thu mb and the fingeralternately during each half-revolution a screw may be given several turns more than if the swinging action of the handle alone be depended upon. The tool being made as shown in my patent above referred to, the hand that holds it cannot prevent the blade from swinging, and the otherwise free hand must be used to guide the point into the screW-head. The part a of the present improvement is brought so far up that the thumb or finger may so control that the tool may be guided by the hand that holds.

What I claim is- In a sorew-d riveror other tool that is adapted to do its work by rotation, the combination of the blade A, the crank having the diagonal wrist a', and the pad a, the latter so near to said crank that the finger and thumb of the hand holding the tool may reach and press upon the same, substantially as described.

' JOHN F. STEWARD.

Witnesses:

IDA E. I-IILLs, S. L. STEWARD.