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:
Sep. 21, 1976
Filed:
May. 08, 1975
Gerald Dean Barth, Elgin, IL (US);
David Prugh Wagner, Geneva, IL (US);
Illinois Tool Works Inc., Chicago, IL (US);
Abstract
A method and apparatus for assembling a screw and an axially compressible washer and rolling threads on the screw blank in a single operation that results in a shank configuration immediately beneath the head of the screw that allows complete compression of the washer. The method involves assembling a washer on the blank and retaining it thereon while the washer and screw assembly are subjected to swaging forces from opposing reciprocating thread rolling dies. The washer is retained on the blank in such a manner as to allow the thread rolling dies to swage an upper section of the blank and thereafter move the washer upwardly directly adjacent the head in a single thread rolling pass.