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. 18, 2011
Filed:
Mar. 29, 2010
Kazuhiro Shimoda, Osaka, JP;
Tomio Yamakawa, Osaka, JP;
Koji Muramatsu, Osaka, JP;
Yuji Inoue, Osaka, JP;
Kazuhiro Shimoda, Osaka, JP;
Tomio Yamakawa, Osaka, JP;
Koji Muramatsu, Osaka, JP;
Yuji Inoue, Osaka, JP;
Sumitomo Metal Industries, Ltd., Osaka, JP;
Abstract
A holeis formed in the center of the rear end faceof a round billet. The holehas a predetermined depth from the rear end faceand a plurality of groovesare provided in the side surface thereof. Each grooveextends in the depth direction of the hole. Piercing and rolling of the round billethaving the holeis performed using a piercing mill having a plug. During piercing and rolling, the bottom surface of the holeis broken through by the plug and a protrusion which is to be the starting point of burrs is formed, and the protrusion is absorbed by the grooveas the plug advances. Consequently, formation of burrs at the rear end of a hollow shell after piercing-rolling thereof can be suppressed.