Driver for threaded fasteners with spiral drive
AssigneePhillips Screw Company
InventorW. Dodd Stacy
Life of this patent
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Abstract
A spiral drive system for threaded fasteners includes driver-engageable surfaces on the head end of the fastener in which at least some of the driver-engageable surfaces are defined by a spiral segment configured to maximize torque transmission while spreading the driving load over a broad driver-fastener interface to reduce the risk of development of high stress regions. Drivers and related tooling also are disclosed.
Claims17
A driver for driving a recess headed fastener, the device having a longitudinal axis, and comprising:
- a shank, a nib formed at the end of the shank, the nib having a central portion and a plurality of wings radiating outwardly from the central portion, each of the wings having an installation wall and a removal wall, the wings being configured so that at least one of the installation or removal walls defines a segment of a spiral that has an initial point spaced from the longitudinal axis by an initial radius and extends to an outer terminal point at a radius that is no more than about 3.5 times that of the initial radius.
A driver for a threaded fastener having a longitudinal axis and a head, the driver having a longitudinal axis comprising:
- a shank having a recess formed at its end, the recess having a central portion and a plurality of wings radiating outwardly from the central portion, each of the wings having an installation wall and a removal wall, the wings being configured so that at least one of the installation or removal walls defines a segment of a spiral that has an initial point spaced from the longitudinal axis of the driver by an initial radius and extends to an outer terminal point at a radius no more than about 3.5 times that of the initial radius.
Dependencies are inferred from the claim text.