Safety screw
OwnerAlexander Cernyinventor
Life of this patent
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Abstract
A screw having a threaded shaft, a head on the shaft and means to permit rotation of the screw. There is a longitudinal slot extending along at least a portion of the threaded shaft to receive a locking member. The invention has a particular application in a wood screw and the locking member is, preferably, a flat body having a sharpen tip. Using the invention a wood screw may be secured against vandalism.
Claims5
In a screw having a threaded shaft, a head on the shaft, said head including means to permit rotation of the screw and said threaded shaft narrowing with distance from said head, the improvement comprising a longitudinal slot extending along at least a portion of the threaded shaft to receive a locking member, said slot being unobstructed at its end remote from the head, to permit the path followed by the locking member to be a straight line.
In combination, a screw having a threaded shaft, a head on the shaft, said head including means to permit rotation of the screw, and said shaft narrowing with distance from the head, a longitudinal slot extending from the head along the threaded shaft to receive a locking member, said slot being unobstructed at its end remote from the head to avoid distortion of the locking member;
- and
- a locking member able to locate in the slot to prevent the screw from rotating, said slot having a depth less than the width of the locking member whereby the locking member, in the locking position, protrudes radially from the slot.
Dependencies are inferred from the claim text.