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:
Feb. 04, 1997
Filed:
Aug. 09, 1994
Applicant:
Inventors:
Assignee:
Horikiri Spring Manufacturing Co., Ltd., Yachiyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B21D / ;
U.S. Cl.
CPC ...
72369 ; 72217 ; 72307 ; 72388 ;
Abstract
A method of manufacture of a hollow stabilizer for automobiles which uses a heat-finished seamless steel pipe 20 as a material, comprising an inner surface and/or an outer surface of a part corresponding to a bending R portion A-B of the steel pipe 20 is polished to remove defects of the surface of the steel pipe, and after the above surface roughness is made less than Rmax 50 .mu.m, the part corresponding to the above bending R portion is previously formed an ellipse in section, and then the section after bending process accesses to a true circle to alleviate stress concentration of the bending part.