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:
Mar. 10, 2009
Filed:
Mar. 29, 2005
Mamoru Zennyoji, Tochigi-ken, JP;
Mamoru Zennyoji, Tochigi-ken, JP;
Mitsuba Corporation, Gunma, JP;
Abstract
A plurality of axial grooves are formed on the outer circumferential surface of a shaft member by applying an arcuate edge defined between an end surface and outer circumferential surface of a rotatable cylindrical forming tool having a generally smooth surface. Typically, the rotational center of the forming tool is tilted backward as it is moved along the length of the shaft member. Owing to the plastic flow of the material of the shaft member, a pair of ridges are formed on either side of the groove. The end surface of the forming tool causes a more pronounced plastic flow than the outer circumferential surface of the forming tool so that one of the ridges is greater in height and higher in hardness than the other. This provides various benefits when this shaft member is press fitted into a bore of an armature core or the like.