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. 06, 2009
Filed:
Mar. 26, 2003
Sumie Suda, Kobe, JP;
Nobuhiko Ibaraki, Kobe, JP;
Nao Yoshihara, Kobe, JP;
Shigetsugu Yoshida, Kyoto, JP;
Koji Harada, Kyoto, JP;
Sumie Suda, Kobe, JP;
Nobuhiko Ibaraki, Kobe, JP;
Nao Yoshihara, Kobe, JP;
Shigetsugu Yoshida, Kyoto, JP;
Koji Harada, Kyoto, JP;
Kabushiki Kaisha Kobe Seiko Sho, Kobe-shi, JP;
Suncall Corporation, Kyoto-shi, JP;
Abstract
Disclosed is a hard-drawn spring which exhibits fatigue strength and sag resistance equal or superior to springs produced using an oil-tempered wire. The hard-drawn spring is produced using a steel wire containing 0.5 to 0.7 mass % of C, 1.0 to 1.95 mass % of Si, 0.5 to 1.5 mass % of Mn and 0.5 to 1.5 mass % of Cr, with the balance being Fe and inevitable impurities. In the steel wire, the number of carbides having circle-equivalent diameters of 0.1 μm or more is 5 particles/100 μmor less.