US2429450A

US2429450A - Torque measuring screw driver

Info

Publication number: US2429450A
Application number: US559765A
Authority: US
Inventors: Hugh W Bunting
Original assignee: Individual
Current assignee: Individual
Priority date: 1944-10-21
Filing date: 1944-10-21
Publication date: 1947-10-21
Anticipated expiration: 1964-10-21

Description

Patented Oct. 21, 1947 UNITED STATES PTENT OFFICE TORQUE MEASURING SCREW DRIVER Hugh W. Bunting, Liberal, Kans.

Application October 21, 1944, Serial No. 559,765

1 Claim. 1

This invention relates to a tension screwdriver and it is primarily an object of the invention to provide a tool of this kind whereby it is possible to tighten screws all at the same tension with the advantage of eliminating liability of springing and warping of the material with which the screws are employed.

A more specific object of the invention is to provide a tool of this kind including a shank and an operating handle therefor and wherein said handle and shank are connected in a manner to allow relative turning movement of the handle member and shank, whereby the twist of the shank will determine the tension applied by the tool to the screw.

The invention consists in the details of construction and in the combination and arrangement of the several parts of my improved screwdriver whereby certain important advantages are attained, as will be hereinafter more fully set forth.

In order that my invention may be the better understood, I wil] now proceed to describe the same with reference to the accompanying drawings, wherein:

Figure 1 is a view partly in elevation and partly in section illustrating a tension screwdriver constructed in accordance with an embodiment of the invention;

Figure 2 is a sectional view taken substantially on the line 22 of Figure 1; and

Figure 3 is a sectional view taken substantially on the line 33 of Figure 1.

In the embodiment of the invention as illustrated in the accompanying drawings, l denotes an elongated shank of spring steel having its outer extremity formed to provide a conventional blade 2 for usual engagement with the head of a screw. The opposite end portion of the shank l is continued by an elongated flat bar 3 integral with the shank I and disposed substantially diametrically thereacross.

The handle member 4 for the tool is tubular and has one end portion of its bore 5 reduced, as at 6, to provide a cylindrical opening I through which the inner portion of the shank l freely passes and which shank is cylindrical in form. The bar 3 is entirely housed within the handle member 4 and extends alon the major portion of said handle member with the outer end of the bar 3 rigidly connected by welding or otherwise as may be desired to the rear or back head 8 of the handle member.

The opening I hereinbefore referred to is continued through a front head 9 for the handle member and which head is welded to or otherwise made rigid with the handle and is circular in form with its outer face flat. In close contact with the outer flat face of the front head 9 is the rear flat face of a cylindrical head I0 keyed, as at II, or otherwise fixedly secured to the rear portion of the shank l.

The heads 9 and I0 are of the same radii so that the peripheral faces thereof are flush. These peripheral faces of the heads 9 and i0 carry the suitably spaced graduations [2 to provide ready reading to determine the tension of the blade 2 upon a screw during a working operation. These graduations 12 are adapted to be read in connection with a proper chart which is to be furnished with the tool.

It is believed to be readily apparent that during a working operation, there will be a tendency of the handle member 4 in its turning operation to twist the bar 3 and it is the extent of this twisting action which determines the tension applied by the tool to the screw. The extent of this tension can be readily determined by the workman through the medium of the graduations 12 hereinbefore referred to.

It is believed to be readily apparent that by the use of a tension screwdriver constructed in accordance with an embodiment of the present invention, it is possible to tighten a number of screws with the same tension so that liability of springing and warping the work is eliminated, together with the further liability of the screws breaking off.

From the foregoing description it is thought to be obvious that a tension screwdriver constructed in accordance With my invention is particularly well adapted for use by reason of the convenience and facility with which it may be assembled and operated.

What is claimed is:

A screwdriver of the character stated comprising a relatively long hollow handle closed at one end having a reduced axial opening through the other end, a screwdriver unit having a relatively long round shank formed at one end to provide 3 4 a blade, the other end of the shank extending through and turning freely in the said opening in REFERENCES CITED said handle, aflat torsion bar forming an integral The following references are of record in the continuation of the said other end of the shank, file of this patent! said bar passing thru the hollow handle and 5 being secured to the said closed end of the handle, UNITED STATES PATENTS and a head mounted upon and secured to said Number Name Date shank adjacent to the end of the handle through 1,686,714 Smith Oct. 9, 1928 which the shank passes, and co-acting indicia 1,773,483 Guze Aug. 19, 1930 upon the surface of the head and the surface 10 2,205,510 Wolfram June 25, 1940 of the adjacent end of the handle. 2,394,022 Storrie Feb. 5, 1946 HUGH W. BUNTING.