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.

Date of Patent:
Nov. 06, 1990

Filed:

Oct. 17, 1989
Applicant:
Inventors:

Toshio Watanabe, Tochigi, JP;

Atsumi Takasugi, Tochigi, JP;

Kazumi Kato, Tochigi, JP;

Hirokazu Yamaguchi, Tochigi, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B21C / ; B21C / ;
U.S. Cl.
CPC ...
72264 ;
Abstract

A method of manufacturing extruded seamless hollow materials characterized in that, prior to extruding a hollow billet from container liner through extrusion dies, a process wherein a centering jig for holding the tip portion of mandrel at the center of extrusion is provided on the extruding side or in the extrusion dies on the extruding side of the container liner, a process wherein the tip portion of mandrel is inserted into the centering jig to be held and a process wherein the hollow billet is pressurized to fill up said billet in the container liner are included.


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