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:
Feb. 07, 1984
Filed:
Apr. 15, 1981
Applicant:
Inventors:
Hiroya Murakami, Yokohama, JP;
Mitsuhiro Takasaki, Yokohama, JP;
Osamu Yamada, Yokohama, JP;
Atsuya Kamada, Kamakura, JP;
Katsuyoshi Hori, Kure, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B21D / ; B21D / ; B21C / ; B23P / ;
U.S. Cl.
CPC ...
72 17 ; 72136 ; 72142 ; 72205 ; 2915 / ;
Abstract
A method of and an apparatus for fabricating a spiral fin in which a strip of material is bent with rolling by a pair of rolls while being imparted with a tension to reduce the speed at which the strip is drawn between the pair of rolls to reduce a compressive force applied to a portion of the strip corresponding to an outer edge portion of the spiral fin, thereby improving the forming limit of the spiral fin.