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US 4,151,621 AGranted
Tools for punching fastener heads
AssigneePhillips Screw Company
InventorFrederick A. Simmons
Life of this patent
Estimating the term…
Abstract
A punch for forming a screw head is provided with grooves which will form projections on selected of the driver-engageable surfaces of the head. The projections are arranged to interlock with surfaces and edges of the driver to reduce the tendency for the driver to slip out of the recess during driving and also to provide a temporary stick-fit between the driver and the recess.
Claims10
An impact tool for forming driver-engageable surfaces at an end of a rotatable fastener comprising:
- a body portion having an axis and having an end region lying along said axis, the end region having primary surfaces which define a primary geometrical shape substantially corresponding to that of the primary driver-engageable surfaces to be formed;
- and
- means forming at least one elongate groove of relatively small cross-sectional dimensions in at least one of said primary surfaces of said end region, said groove extending generally longitudinally of said axis, whereby when the end region of said tool is impacted into the material of the rotatable fastener, the primary surfaces of the end region will form said geometrically shaped primary driver-engageable surfaces and said elongate groove will form a projection of relatively small cross-sectional dimension extending from said at least one primary driver-engageable surface.
An impact tool for forming driver-engageable surfaces at the end of a rotatable fastener comprising:
- a body portion having an axis and having a nib extending from an end of the body portion, the nib lying along said axis;
- said nib including a central core and a plurality of blades radiating generally outwardly from said core, each of said blades having opposite sidewalls and an end wall;
- means forming at least one elongate groove along one of said sidewalls of at least one of said blades, said groove extending from the juncture of said end wall and one of said sidewalls and along one of said sidewalls.
Dependencies are inferred from the claim text.