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:
Jan. 24, 1978
Filed:
May. 26, 1976
Richard P Nelson, Bellbrook, OH (US);
William H Roth, Miamisburg, OH (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A wheel cylinder piston is made of sintered powdered metal having a boss provided with a flare on the bossed end surface to assist in holding the wheel cylinder boot in place on the piston. The piston is of the type that directly engages an abutment on a brake shoe instead of utilizing a pin to transmit force between the piston and the brake shoe. The flare is formed by striking a peripherally extending surface section of the boss end with an annular mandrel, the striking action axially compressing a cylindrical portion of the boss and creating an annular shear fracture extending substantially parallel to the center line of the boss. The compressed section extends to a depth controlled by the striking force and stroke and characteristics of the powdered metal material. The sheared cylindrical portion flares outwardly to form a flared end on the boss.