Screw driver

Nov. 6, 1934.

H. S. FORSBERG

SCREW DRIVER

1,979,460

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Patented Nov. 6, 1934

1,979,460

UNITED STATES PATENT OFFICE

1,979,460 SCREW DRIVER Harold S. Forsberg, Stratford, Conn. Application January 29, 1932, Serial No. 589,606 5 Claims. (Cl. 145—61)

This invention relates to new and useful improvements in screw drivers.

An object of the invention is to provide a screw driver including a novel handle construction 6 whereby a better grip may be obtained, and whereby the possibility of the hand of the operator slipping over the handle and into engagement with electrical wires or moving parts of machinery or the like is eliminated.

Another object is to provide a: screw driver including a handle so constructed as to prevent rolling of the screw driver when placed on a flat supporting surface.

Additional objects and advantages will become 15 apparent from a consideration of the following detailed description taken in connection with the ; accompanying drawing wherein a satisfactory embodiment of the invention is shown. However, it is to be understood that this description and 20 accompanying drawing are for the purpose of disclosing one embodiment of the invention and that the invention is not limited to the details disclosed but includes all such variations and. modifications as fall within the spirit of the in25 vention and the scope of the appended claims to which claims reference should be had for a definition of the invention.

In the drawing:

Fig. 1 is a side elevational view showing a screw 30 driver in accordance with the invention, the instrument being shown in use;

Fig. 2 is a view taken at right angles to Fig. 1 and on an enlarged scale;

: Fig. 3 is a view of a portion of the blade of

Fig. 2, the view being taken at right, angles to Fig. 2;

Mg. 4 is a transverse sectional view on the line 4—4 of Fig. 2;

Fig. 5 is a transverse sectional view on the line 40 5—5 of Fig. 2; and

Fig. 6 is a transverse sectional view on the line 6—6 of Mg. 2.

Referring in detail to the drawing, the improved handle is generally indicated at 10 and 45 the blade is generally indicated by the reference character 11. Blade 11 includes a bit portion 12 and a shank 13 and intermediate its ends a portion of the shank is flatted on opposite sides as at. 14 whereby the shank may be gripped with 50 a wrench or other tool for turning. The shank may be provided with the flat surfaces 14 in any 'convenient or desired manner, as by swaging.

The improved handle 10 is molded of a suitable insulating material and is preferably molded 55 directly onto the blade 11 although if desired the handle may be molded with an opening and the blade later attached. Although, the handle is molded preferably of an imitation hard rubber composition it will be understood that it may be made of any moldable insulating material, as 60 bakelite or other phenolic condensation product. Also, the material used may contain a pigment to give any desired color or the handles may be painted or the like.

Hi idle 10 is molded with a smooth outer or 65 palm engaging portion 15 and. is provided along a substantial portion or the major portion of its length with grooves or flutes 16 and the ridges or portions 17 between such grooves or flutes are preferably knurled or roughened in the molding 70 operation whereby a better grip mey be obtained on the handle. It will be noted that since the handle is molded the grooves 16 are formed in the handle without any additional cost of manufacture and that the portions 17 between said 75 grooves are formed with the knurled or roughened surfaces during the molding operation and without additional expense.

Intermediate its ends but toward its forward portion the handle is shaped to provide a reduced 80 neck portion, or a portion of less diameter, 18. For a portion of its length rearwardly from this neck 18 the handle inclines as at 19 and it should be noted that the grooves or flutes are extended through this inclined portion and are of gradually 85 decreasing width as they approach the neck or the end of the inclined portion.

Forwardly of the neck 18 the handle-is enlarged or flared as at 20 to provide a guard. As here disclosed this guard portion 20 is provided with 90 six relatively long flat surfaces 21 (see Mg. 5) and the adjacent ends of these surfaces are connected by relatively short also preferably fiat portions 22. When the screw driver is in use, as, for example, in the driving of a screw 23 as 95 suggested in Fig. 1, the thumb 24 and the index finger 25 of a hand indicated at 26 are shown as engaging or pressing forwardly against the guard 20.

Since this guard represents a relatively abrupt 100 increase in the diameter of the handle following the neck portion 18 it will be appreciated that the guard will prevent the hand from slipping forwardly over the blade 11 and possibly into engagement with charged wires or moving parts 105 of a machine or the like. Further, it will be readily apparent that the knurled or roughened surfaces 17 will, to some extent, prevent the hand slipping on the handle and it will, also be appreciated that since the handle is molded of an j χθ

1,97© insulating material with an end portion of the blade completely embedded in the handle the danger of shocks in the use of the device is eliminated.

A further feature of the present handle is the flat surfaces 21 before referred to. The guard 20 is of an appreciable diameter, and is, in fact, of a slightly greater diameter than the knurled portion of the handle and the flat surfaces of the 10 guard portion will therefore prevent rolling of the screw driver when the latter is placed on a flat surface. In this connection it will be seen that the portion of the handle to be gripped is generally circular in cross section and does not 15 therefore present any sharp corners to prevent the handle being tightly gripped.

While the guard portion 20 of the handle is here disclosed as substantially in the form of a hexagon it will be undei’stood that the guard may 20 be formed with a greater or lesser number of flat surfaces as required or as may be more pleasing to individual tastes.