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:
Jul. 06, 1999

Filed:

Apr. 22, 1998
Applicant:
Inventors:

Masayasu Kojima, Takarazuka, JP;

Saburo Inoue, Tama, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B21D / ;
U.S. Cl.
CPC ...
72 58 ; 72 62 ;
Abstract

A method and apparatus for hydroforming a metallic tube including the steps of: preliminarily expanding the metallic tube over an axial section longer than the length of the expanded portion of a final product as measured in the axial direction of the metallic tube; and compressing the preliminarily expanded portion in the axial direction of the metallic tube so as to form the shape of the expanded portion of the final product. According to the method and apparatus of the invention, frictional resistance between the metallic tube and processing tools can be reduced, and moreover, the internal pressure within the metallic tube can be reduced during expansion processing. Furthermore, the cost for the manufacture of metallic die is reduced, and in addition, yield is improved


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