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:
Mar. 09, 1982
Filed:
Dec. 19, 1979
Applicant:
Inventors:
Seishiro Yoshiwara, Kitakyushu, JP;
Hirokichi Higashiyama, Kitakyushu, JP;
Assignee:
Nippon Steel Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B21B / ;
U.S. Cl.
CPC ...
72370 ; 72 97 ; 72209 ;
Abstract
A solid square cross-section bloom or billet is pierced to form a hollow cylindrical piece with a closed end, using a combination of a mandrel carrying a plug or piercing point at its leading end and a set of rolls. The closed-end cylindrical workpiece and the piercing mandrel together, at the completion of piercing, are fed into a rotary elongating mill, with the closed end of the workpiece foremost. Rotary elongation is performed on the workpiece while pushing the mandrel until the plug has at least passed the point at which the closed end of the workpiece clears the delivery end of the elongation rolls.