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:
Aug. 03, 2010
Filed:
May. 31, 2006
Noritoshi Takamura, Aikoh-gun, JP;
Satoru Tendo, Aikoh-gun, JP;
Noritoshi Takamura, Aikoh-gun, JP;
Satoru Tendo, Aikoh-gun, JP;
NHK Spring Co., Ltd., Yokohama-shi, JP;
Abstract
A coil spring reduces Hertzian stress on a first turn and bending stress on a coil end. A coil endis shifted in a diametral outer or inner direction of a coil spring relative to the first turn, to form a vertical gap between the coil endand the first turnin a free state without load on the coil spring. Due to the gap, the coil spring including the coil endand first turncan be entirely processed by shot peening as well as the remaining portion. The first turnreceives a combination of torsional stress and Hertzian stress (contact stress). Since the coil endthat receives high Hertzian stress is shifted in a diametral outer or inner direction of the coil spring relative to the first turn, a contact point on the first turnis shifted in the diametral outer or inner direction to reduce the torsional stress on the first turn. The shift and gap formed between the coil endand the first turnare effective to prevent excessive bending stress and breakage of the coil endwhen the coil endand first turnare repeatedly engaged and disengaged in the gap.