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:
Dec. 31, 1991
Filed:
Jun. 14, 1991
Applicant:
Inventor:
Munekatsu Furugen, Amagasaki, JP;
Assignee:
Sumitomo Metal Industries, Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B21B / ; B21C / ;
U.S. Cl.
CPC ...
72 41 ; 72283 ;
Abstract
A method of manufacturing a long tube having a small diameter, such as a tube for use in a heat exchanger, by cold working. A plug drawing using a pressurized lubricating oil of 500 kgf/cm.sup.2 or more accompanied by the reduction in wall-thickness is adopted as at least the final cold work. In the case where a tube having desired dimensions is not obtained by this plug drawing, subsequent free-loaded drawing can be conducted.