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:
May. 31, 2022
Filed:
Nov. 28, 2018
Nippon Steel Corporation, Tokyo, JP;
NIPPON STEEL CORPORATION, Tokyo, JP;
Abstract
A mandrel bar of a piercing machine includes: a bar body; a coolant channel formed inside the bar body and through which a coolant flows; an inner surface cooling mechanism which is disposed in a cooling zone and is connected to the coolant channel and which, during piercing-rolling or during elongating rolling, ejects the coolant to outside of the bar body to cool an inner surface portion of a hollow shell inside the cooling zone; and an inner surface damming mechanism which is disposed adjacent to the cooling zone on a rearward side of the cooling zone and which, during piercing-rolling or during elongating rolling, suppresses the coolant that is ejected to outside of the bar body from contacting the inner surface portion of the hollow shell that is positioned rearward of the cooling zone.