The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 30, 1993
Filed:
Jun. 29, 1992
James R Kennedy, Huntington, NY (US);
David J Larson, Jr, Huntington Station, NY (US);
Grumman Aerospace Corporation, Bethpage, NY (US);
Abstract
Fatigue lifetime enhancement of the holes formed in structural members occurs by introducing a cold working tool or interference fit fasteners fabricated from shape memory alloy materials. The tool may be employed to expand the wall of a hole while the tool material is raised above the critical transitional temperature. Then, upon lowering the tool material below the critical transitional material, it contracts permitting it to be withdrawn. Bushings and interference fit fasteners may be installed in holes formed in structural members when a shape alloy material bushing or fastener is heated above the critical transitional temperature so that an interference fit results and the hole is cold worked. If the alloy material is not cooled below the critical transitional temperature, the interference fit may be permanently maintained, thereby further enhancing the fatigue life of the members.