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:
Apr. 07, 2015
Filed:
Jul. 07, 2009
Kentaroh Norimatsu, Toyokawa, JP;
Takayuki Matsushita, Toyokawa, JP;
Hironori Yamamoto, Toyokawa, JP;
Kentaroh Norimatsu, Toyokawa, JP;
Takayuki Matsushita, Toyokawa, JP;
Hironori Yamamoto, Toyokawa, JP;
OSG Corporation, Toyokawa-shi, JP;
Abstract
A thread forming tap has a full thread portion and a leading portion contiguous with the full thread portion and reducing in diameter toward its tip. The full thread and leading portions are provided with external thread on which lobes and recesses are alternately formed. When δ represents an angle around a tool center line toward a thread forming side, the shape of the lobe varies along a quadratic curve relative to angle δ so that relief amount increases toward inflection point angle δ. However, in a rough plastic deformation section where angle δ is greater than inflection point angle θ and exceeds the working region, the shape varies along an Archimedean curve with clearance angle αso that the relief amount increases linearly relative to angle δ, and a margin section is substantially zero or within a range where angle δ is less than or equal to 1°.