US 1951652 A
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Description (OCR text may contain errors)
March 20,1934. N, v, @OT FF 1,951,652
SCREW DRIVER Filed June 1933 INVENTOR Patented Mar. 20, 1934 UNITED STATES- PATENT OFFICE scnnw nnrvnn Nicholas V. Fedotofl, Lynbrook, N. Y. Application June 15, 1933, Serial No. 676,034
6 Claims. (01. 145-5 This invention relates to screwdrivers and has for its object facilitating the application of a screwdriver to a screw head.
In accordance with this invention resilient means is associated with the driving blade of a screwdriver which maintains a relatively tight engagement of the blade with the slot of ascrew. By virtue of this resiliently tight engagement with the screw head, it is possible to use the screwdriver in many relatively inaccessible positions where it would otherwise create considerable difllculty.
The invention is carried out by bifurcating the driving end of the screwdriver blade, and fastening within the space between the two bifurcated portions a resilient spring-like member which is almost, but not quite, co-planar with the blade portions. When inserting the screwdriver within the slot in a screw head, the resilient member is strained so that continual pressure is exerted by the screwdriver blade against the walls of the slot; thus serving to prevent any inadvertent disengagement from the screw head. The fact that the driving blade is. bifurcated does not reduce the strength-and rigidity of the blade below that required for ordinary operation, for no metal is removed from the edges, which are the realdriving-portions.
Although the provision of a screw driver havao ing means for effecting tight engagement with a screw head is, broadly, not novel, the particular arrangement of this invention is believed to be novel, wherein the engaging means is resilient, and the driving portions of the blade are not substantially weakened by the resilient grippin'g means.
Another feature which may or may not be incorporated, as desired, is the burring oi the engaging member of thescrewdriver; this feature 40 serving to further prevent unintentional removal of the screwdriver from the screw slot.
For a better understanding of the invention attention is directed to the following detailed description and the accompanying drawing, of
which Fig. 1 shows a screwdriver having a blade embodying the invention; and
Fig. 2 is a side view of the screwdriver showing the blade partially in section.
Referring to this drawing, the screwdriver comprises a body portion 1. having mounted on the upper end thereof a handle 2. The lower end of the body is formed into the screwdriver blade at 3 in the usual manner.
In accordance with this invention there is prodesirable to burr the outer lower edge of the vided at the central portion of the driving blade a slot 4 which may be formed by removing a narrow strip of metal along the longitudinal axis of an ordinary screwdriver blade, thus bifurcating the driving blade. The length of this slot may conveniently be about one-half inch, more or less, depending upon the size of the screwdriver. There is drilled a hole, or channel, 5 of small diameter along the longitudinal axis of the screwdriver, beginning at the end of the slot 4 and extending upward toward the body. It is advisable, although not absolutely essential, to drill a hole 6 transversely through the blade at the upper extremity of the longitudinal hole 5.
A resilient wire spring 7, of the proper length to extend from the hole 6 to the driving end of the blade, is forced through the longitudinal hole 5, as shown. It may be desirable, particularly if the wire spring does not'flt tightly in hole 5, to fill the transverse hole 6 with solder to secure the upper end of the wire spring, this being one of the functions of the hole 6. If desired, instead of applying solder, the upper end of the wire spring may be bent or flattened in hole 6.
The wire spring '7 does not lie flush in the slot between the two portions of the bifurcated blade, but instead, is slanted or curved so that the lower end thereof protrudes beyond one of the flat faces of the blade, as shown in Fig. 2.
In operation, the screwdriver blade is inserted into the slot in the head of a screw 8 by straining the wire spring '7 toward the face 01' the blade. when in the screw slot, then, the spring action will cause a continual pressure to be exerted by the driving blade and the spring against the sides of the screw head slot; thus tending to hold the screwdriver in position.
To increase the gripping action between the screwdriver blade and the screw slot, it may be sideration is to maintain the strength and rigidity of the outer portions of the blade; and no material is removed from the outer blade portions by the arrangement of this invention.
,The addition of the spring member 7 into the slot ofthe screwdriver does not substantially increase the outside dimensions of the screwdriver, 110
obscure visibility or otherwise hinder the application of the screwdriver.
1. A screwdriver comprising a rigid driving blade provided with a longitudinal slot at the driving end thereof, and a resilient member of less thickness and much less rigidity than said blade, fastened within said slot and normally protruding beyond the flat surface of the blade at said driving end, whereby said blade and resilient member cooperate to firmly engage the slot of a screw head. a
2. Ascrewdriver comprising a rigid bifurcated driving blade and a resilient wire of much less rigidity than said blade, situated nearly longitudinally within the slot between the bifurcated v portions of said blade, said wire being fastened at its uppermost end and protruding at its lower end beyond the fiat face of said blad I 3. A screwdriver according to claim 2 in which a burr is formed on the edges of the bifurcated portions of the blade at the side opposite that from which said resilient wire protrudes.
4. A screwdriver according to claim 2 in which burrs are formed on the protruding edge of said wire and on the edges of the bifurcated blade portions at the side opposite that from which said 7 driving end by a longitudinal slot extending substantially along the longitudinal axis for some distance, a hole formed longitudinally in said blade beginning at the upper extremity of 'said slot and extending toward said body portion, and a resilient wire having one end inserted through said hole, the other end of said wire extending toward the driving edge and protruding beyond the flat driving surface of the blade.
6. A screwdriver according to claim 5 in which a transversehole is formed through said blade at the upper end of said longitudinal hole, the upper end of said resilient wire extending into said transverse hole, said wire being secured at said transverse hole.
NICHOLAS V. FEDOTOFF.