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:
Jan. 25, 2000
Filed:
Mar. 12, 1998
Applicant:
Inventors:
Assignees:
Chuo Hatsujo Kabshiki Kaisha, Nagoya, JP;
Honda Giken Kogyo Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B21F / ; C21D / ;
U.S. Cl.
CPC ...
428544 ; 148208 ; 148212 ; 148215 ; 148230 ; 148233 ; 148580 ; 148599 ; 148660 ; 148901 ; 148908 ; 267166 ; 428592 ; 428906 ;
Abstract
A coil spring made of an oil-tempered steel wire with internal hardness of more than Hv 550 in cross-section, the surface hardness of the oil-tempered steel wire being determined in an extent between Hv 420 in a minimum value and hardness defined by subtraction of Hv 50 from the internal hardness in a maximum value.