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:
Nov. 22, 1983
Filed:
Jul. 09, 1981
Applicant:
Inventor:
Chihiro Hayashi, Amagasaki, JP;
Assignee:
Sumitomo Kinzoku Kogyo Kabushiki Kaisha, Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B21B / ;
U.S. Cl.
CPC ...
72 68 ; 72100 ; 72368 ;
Abstract
The present invention relates to the manufacture of seamless metal tubes by a cross-roll helical rolling process such as Mannesmann mandrel mill process or by a press piercing process such as Ugine Sejournet process. Shells being worked are subjected to outside-diameter reduction by means of a rotary mill having 3 or 4 rolls, without using internal tools such as plug and mandrel bar, so that wall eccentricity is significantly improved, which fact assured higher quality of finished product.