James Paul Nicholas

US Patent:

52213790, Jun 22, 1993

Filed:

Jan 18, 1991

Appl. No.:

7/642912

Inventors:

James G. Nicholas - San Jose CA

International Classification:

B60C 1116
A43C 1514

US Classification:

152212

Abstract:

A stud for a tire to improve traction on a roadway which includes a hardened pin mounted in a steel jacket and extending therefrom to engage the roadway, wherein the stud is sized for insertion into openings in the tire tread. The pin is retractable into the jacket thereby removing the pin from contact with the road surface and providing non-studded as well as studded service from the same tire. A spring in the stud jacket is used to propel the pin out of the jacket into the extended position when the pin is released from the securing mechanism. The securing mechanism consists of a series of projections on the pin in interaction with a series of grooves in the interior of the stud jacket. The pin is released from the retracted position by manually pressing the pin further into the jacket until the securing mechanism releases it. The spring also acts to ensure that the pin protrudes the proper distance, when in contact with the roadway, from the surface of the tire by providing less force than necessary to keep the pin extended when the pin is extended more than the proper distance and more force than necessary when the pin is extended less than the proper distance.