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:
Aug. 25, 1987
Filed:
May. 15, 1986
Robert L La Barge, Ben Avon Borough, PA (US);
Ronald J Ewing, Allegheny Township, Armstrong County, PA (US);
Aluminum Company of America, Pittsburgh, PA (US);
Abstract
A method of joining together two or more pieces of malleable material. The method includes the steps of placing thoroughly cleaned surfaces of the pieces in intimate contact with each other and forming a flanged hole through all of them at the same time. This is accomplished by producing a starting hole and then directing a draw punch against the pieces and directing the same into the opening of a die while the material is compressively stressed to a value substantially equal to the yield strength of the material. The punch provides the completed flanges with an hourglass shape, such shape locking the inner and outer flanges together against axial displacement.