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:
Oct. 04, 1977
Filed:
Feb. 18, 1976
William Eugene Clark, Chelsea, MI (US);
Federal-Mogul Corporation, Southfield, MI (US);
Abstract
A method for manufacturing bidirectional hydrodynamic polytetrafluoroethylene shaft seals. A flat annular wafer of polytetrafluoroethylene of constant thickness is coined at an annular inner portion adjacent the inner periphery to provide first and second circular ribs and a series of straight segmental ribs, each of which extends tangential to the inner side of the inner rib, thereby intersecting the inner rib, the crest of the straight ribs projecting out further than the crest of the inner rib. Then the annular inner portion is formed into a generally frustoconical shape, whereby the straight ribs appear as curved ribs. The frustoconical portion is flexed on installation on a shaft to be generally cylindrical from at least the outer rib to the inner periphery.