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:
Jan. 31, 2012
Filed:
Sep. 29, 2009
Naoya Hirase, Osaka, JP;
Tomio Yamakawa, Osaka, JP;
Kazuhiro Shimoda, Osaka, JP;
Sumitomo Metal Industries, Ltd., Osaka, JP;
Abstract
A piercing mill includes a plurality of inclined rolls, a plug, a pusher, and an undriven guide roll. The pusher pushes a round billet from the rear end at least until the round billet advances for a prescribed distance after contacting the inclined rolls. The guide roll is between the inclined rolls and the pusher and includes a roll shaft and a roll surface, with the roll shaft arranged obliquely with respect to a pass line PL. The sectional shape of the roll surface is a concave arch shape. The round billet is rotated by the guide roll and the friction force generated when the round billet contacts the inclined rolls is reduced. Consequently, the wear of the inclined rolls can be restrained if the round billet is pierced and rolled while it is pushed in between the inclined rolls using the pusher.