Spiral drive system for threaded fasteners
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.
Claims30
A threaded fastener having a longitudinal axis and a driver-engageable recess at an end of the fastener, the recess comprising:
- a central portion;
- a plurality of wings radiating outwardly from the central portion, the wings each being defined by a pair of side walls;
- at least one of the side walls being configured to define a segment of a spiral that has an initial point spaced from the longitudinal axis of the fastener 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 threaded fastener having a longitudinal axis and a driver-engageable recess at an end of the fastener, the recess comprising:
- an installation drive wall and a removal drive wall;
- at least one of the drive walls being configured to define a segment of a spiral that has an initial point spaced from the longitudinal axis of the fastener 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 threaded fastener having a longitudinal axis and a head comprising:
- an external surface extending about at least part of the periphery of the head, the external surface including at least one side wall configured to define a segment of a spiral that has an initial point spaced from the longitudinal axis of the fastener 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 threaded fastener having a longitudinal axis and a head comprising:
- the head being formed to include driver engageable surfaces disposed about the longitudinal axis, at least one of the surfaces being configured to define a segment of a spiral that has an initial point spaced from the longitudinal axis of the fastener 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.
Dependencies are inferred from the claim text.