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. 07, 1998
Filed:
May. 22, 1997
Applicant:
Inventors:
Yuji Yoshitomi, Ibaraki-ken, JP;
Shinji Tanaka, Ushiku, JP;
Shota Iwakura, Ibaraki-ken, JP;
Takeshi Araya, Hitachi, JP;
Takamitsu Nakazaki, Takahagi, JP;
Norio Yokoba, Hitachi, JP;
Toshimi Sato, Hitachi, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
B21D / ;
U.S. Cl.
CPC ...
72 57 ; 72 58 ; 294211 ;
Abstract
A method of forming a non-circular pipe having a different sectional shape in the longitudinal direction thereof by bending a raw pipe while applying pressure to the inside of the raw pipe, wherein the circumference of a section of the raw pipe is substantially equalized to the circumference of a section, corresponding to the section of the raw pipe, of the non-circular pipe after formed.