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:
Apr. 19, 1977
Filed:
Apr. 30, 1976
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., , JA;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B21C / ;
U.S. Cl.
CPC ...
72467 ;
Abstract
When cylindrical parts are produced by extrusion from a metallic material having high mechanical strength, the dies tend to be easily broken and worn, and it is difficult to secure accuracy of finishing of the product. According to the present invention, with regard to the form of a die, the ironing portion is reduced in contact area thereof, is formed into such a configuration that the contact area thereof does not increase even if the dies are worn to some extent, and a die angle and configurations of an ironing portion and a relief portion are selected properly, thus preventing the dies from being easily broken or worn.