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:
Aug. 25, 1992
Filed:
Jan. 04, 1991
Minobu Sukimoto, Tochigi, JP;
Hitoshi Akiyoshi, Tochigi, JP;
Seijiro Taguchi, Ibaraki, JP;
Kazuo Sugiyama, Ibaraki, JP;
Isao Watanabe, Tochigi, JP;
Showa Aluminum Corporation, Osaka, JP;
Abstract
An aluminum pipe according to the present invention is used in forming a plurality of bulged portions on the peripheral wall thereof. At the same time by bulging has been so refined as to exhibit an elongation of at least 40% and a recrystallization texture of up to 60 .mu.m in grain size during bulging. The aluminum pipe to be bulged is produced by a process characterized by drawing an extruded aluminum pipe at a cold working ratio of at least 40%, and thereafter annealing the drawn pipe at a temperature of 350.degree. to 420.degree. C., whereby the pipe is refined to exhibit the specified elongation and recrystallization texture.