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:
Jun. 11, 2013

Filed:

Feb. 14, 2006
Applicants:

Shoichi Abe, Maebashi, JP;

Yasushi Watanabe, Maebashi, JP;

Kazumi Shimoii, Maebashi, JP;

Atsushi Tomizawa, Osaka, JP;

Mitsutoshi Uchida, Osaka, JP;

Inventors:

Shoichi Abe, Maebashi, JP;

Yasushi Watanabe, Maebashi, JP;

Kazumi Shimoii, Maebashi, JP;

Atsushi Tomizawa, Osaka, JP;

Mitsutoshi Uchida, Osaka, JP;

Assignees:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B21D 26/00 (2006.01);
U.S. Cl.
CPC ...
Abstract

To form a through hole at one portion of a side wall, of an expanded portion made by plastically deforming one part of a metal tube radially outward, in a portion where the plate thickness gradually changes, a slide tool is withdrawn from inside a punch hole while applying hydraulic pressure to the inside of the side wall. At the instant of commencing withdrawal of the slide tool, the degree of progress in the shearing for the portions of the side wall matching with the two side edges of the punch hole is made different. Then, the timing for moving from shearing to rupture is made to coincide, so that of the side wall, the portions matching with the punch hole, are made reliably into a blank, and are extracted from the side wall.


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