Title:
SCREWDRIVER WITH TORQUE AMPLIFYING MEANS
United States Patent 3561510


Abstract:
A hand held screwdriver having a handle and an axially extending shank with screw engaging bit at its end and a drum head feature formed integrally upon the shank, as in a conventional ships capstan, having bar or lever accommodating sockets by which, when in use, increased torque or leverage is applied to the shank by an associated bar or lever means when setting or removing a wood screw that requires more force than can be exerted by the use of a present day screwdriver.



Inventors:
JOHNSON PETER F
Application Number:
04/766141
Publication Date:
02/09/1971
Filing Date:
10/09/1968
Assignee:
PETER F. JOHNSON
Primary Class:
Other Classes:
81/177.5, 81/439
International Classes:
B25G1/00; (IPC1-7): B25B15/02
Field of Search:
145/61--8,61,50 81
View Patent Images:
US Patent References:
2870809Tool handle1959-01-27Feldman et al.
2641291Ratchet clutch handle1953-06-09Yess



Foreign References:
GB154715A
FR748121A
Primary Examiner:
Condon, Theron E.
Assistant Examiner:
Parker Jr. V, Roscoe
Claims:
I claim

1. A hand tool for setting wood and machine screws having an elongated shank with a screw-engaging bit at one end and an axially extending handle at its other end, said shank having an enlarged capstan configuration formed integrally thereupon intermediate its bit and handle with a plurality of radially displaced and laterally extending bores through which a leverage-producing bar may be extended in different radially extending relationship with said screw-engaging bit, and a bar having an extending end projecting through one of the bores of said capstan by which increased torque may be imparted at different angles to said shank when applied to a screw.

2. The invention as set forth in claim 1, characterized by the fact that said capstan is in the form of a cube with transversally extending bores upon said shank at a point removed from said handle and adjacent the screw bit-engaging end thereof.

Description:
In the setting of the larger wood and machine screws there are often situations where the forces required to set a screw cannot be exerted through the wrist of a mechanic with a conventional handle and it is therefore a primary object of my invention to provide an improved form of screwdriver having a capstan configuration with which radially extending lever means may be used in a final screw-setting operation.

Other objects and advantages will be in part pointed out hereinafter and in part evident from the following description taken in connection with the accompanying drawing wherein there is shown by way of illustration and not of limitation preferred forms of the invention.

In the drawing wherein like numerals refer to like parts:

FIG. 1, is a side view of a conventional screwdriver with my invention applied thereto,

FIG. 2, is a modified form of the invention,

FIG. 3, is a fragmentary sectional view taken in a central and vertical plane as taken from FIG. 2, and

FIG. 4, is a sectional view taken along line 4-4 of FIG. 2 looking in direction of arrows.

For a more detailed description of the invention, reference is now made to FIG. 1 of the accompanying drawing wherein my tool is shown as having a shank 10 with a screw-engaging bit 11 at one end and a hand-accommodating handle 12 at its other end. Intermediate the ends of the shank 10 there is an enlarged integrally formed and cubicle capstan portion 13 with bores 14 extending therethrough and centrally of the shaft 10. The bores 10 of the cubicle portion 13 are of a size to accommodate a lever means or torque exerting bar 15 that will extend at different right angles to the axis of the shaft 10. In this showing the bar 15 has a handle 16 and at its extending end is formed with a screw-engaging bit 17 which may be employed to start a screw when its torque imparting portion is not required. While the capstan portion 13 of the shaft 10 is here shown as of cubicle configuration, it will be understood that this capstan portion may be in the form of a cylindrical drum head with bores or sockets 14 for the bar or lever 15.

In FIG. 2 there is shown a modification of the invention in which the cubical capstan portion 13 with its bar-accommodating bores 14 is located remote from the handle 12 and closely adjacent the screw bit-engaging end 11 of the shaft 10. In this instance, instead of a conventional handle 12, the shank 10 is shown as having an integrally drop forged portion 18 which will function as a handle for the tool.

FIG. 3 shows the bar or lever 15 as disposed at a right angle to the shank 10.

FIG. 4 shows the cross-sectional configuration of the handle portion 18 of the modified form as in FIG. 2.

While I have, for the sake of clearness and in order to disclose my invention so that the same can be readily understood, described and illustrated specific forms and arrangements, I desire to have it understood that all such changes as come within the scope of the appended claims are to be considered as part of this invention.