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. 08, 1981
Filed:
Nov. 15, 1979
Benjamin I Bachrach, Dearborn, MI (US);
William J Fuhrman, Bloomfield Hills, MI (US);
Ford Motor Company, Dearborn, MI (US);
Abstract
A sleeve having a tapered outer surface is shrink or interference fitted over the outer surface of a die blank in which is formed a central bore, a larger diameter bore and a transition bore therebetween. The diametrical interference between the sleeve and the die blank is effective in producing an elastic deformation of the smaller diameter bore causing it to assume a conical shape. The die blank and sleeve are restrained within a casing and the inner surface of the die is formed by electrical discharge machining, electrical chemical machining or by other known methods. The die casing and sleeve are removed from the die, allowing the release of the stored strain energy of deformation which causes the smaller bore of the die to assume a conical shape tapering radially outwardly from its inner extremity. The sharp corner that results at the innermost end of the smaller bore is removed by lapping a straight-sided tool through the central opening of the die.