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. 29, 1989
Filed:
Jun. 13, 1988
Applicant:
Inventors:
Yutaka Kato, Sakai, JP;
Eizo Isoyama, Sakai, JP;
Assignee:
Showa Aluminum Corporation, Osaka, JP;
Primary Examiner:
Int. Cl.
CPC ...
B21C / ;
U.S. Cl.
CPC ...
72 38 ; 722531 ; 72269 ;
Abstract
A process for preparing a hollow aluminum extrudate for use in a vacuum characterized in that dry air or pure oxygen is supplied to the hollow portion of the shaped material being extruded. During the extrusion, the inner surface of the extrudate defining the hollow portion is held out of contact with the atmospheric air containing water to form a compact oxide coating on the inner surface without permitting formation of any hydrated oxide coating.