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. 01, 2013
Filed:
Aug. 18, 2011
Yasuto Higashida, Osaka, JP;
Yasuyoshi Hidaka, Osaka, JP;
Kazuhiro Shimoda, Osaka, JP;
Tomio Yamakawa, Osaka, JP;
Yasuto Higashida, Osaka, JP;
Yasuyoshi Hidaka, Osaka, JP;
Kazuhiro Shimoda, Osaka, JP;
Tomio Yamakawa, Osaka, JP;
Nippon Steel & Sumitomo Metal Corporation, Tokyo, JP;
Abstract
A plug includes a front edge portion having a convex curvature; a cylindrical portion having a truly or nearly cylindrical shape; a trunk portion having an outer diameter gradually increasing toward a rear edge thereof; a mandrel joint provided in a rear edge portion of the plug; a lubricant ejection hole running through the trunk portion from the mandrel joint that opens on the surface of the cylindrical portion; and a coating comprising oxides and Fe that is formed on the base metal surface of each of the front edge portion as well as the trunk portion by arc spraying using an iron wire. In this way, the plug can prevent inner surface flaws from occurring in a hollow blank that is deformed by piercing-rolling, and can extend its life without requiring a long time for making it.