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. 21, 1980
Filed:
Jun. 16, 1978
Hiroshi Kazino, Komaki, JP;
Kabushiki Kaisha Aoyama Seisakusho, Nagoya, JP;
Abstract
An upset bolt provided with a pressure formed recess on the bolt head. The recess is formed by the combination of three separate surfaces, that is, concave, convex and flat standing surfaces which respectively form lower, middle and upper portions of the recess. By virture of provision of the concave and convex surfaces respectively in lower and middle portions of the recess, stress concentration occurs in the region along the concave and concave surfaces when the recess is pressure formed. Since the region of stress concentration is positioned away from the neck portion of the bolt body, the breaking strength is remarkably increased as compared with conventional upset bolt in which the stress concentration occurs in a region near the neck portion of the bolt body. Provision of the six flat standing surfaces along the periphery of the hexagonal bolt head makes it possible to sharply form the apexes of the bolt head without application of such an extremely great pressure force as to shorten the life of the dies used in deformation of the bolt head.