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:
Mar. 22, 1994
Filed:
Mar. 22, 1993
Akira Harayama, Okaya, JP;
Kazuyoshi Aruga, Okaya, JP;
Teikoku Piston Ring Co., Ltd., Tokyo, JP;
Abstract
A combined oil ring is comprised of a steel oil ring having a generally I-shaped section consisting of upper and lower rails and a web connecting the both rails and a coil expander for forcing the oil ring outwardly. Each of the outer circumferential sliding surfaces of the circumferential outer projecting portions in the upper and lower rails forms a nitrided surface with a hardness of Hv 900 or more, at least one of the upper and lower surfaces in the circumferential outer projecting portion forms a surface with a hardness of lower than Hv 700, and a width of the outer circumferential sliding surface is smaller than 0.25 mm. The other surface of the upper and lower surfaces forms a nitrided surface with a hardness of Hv 900 or more or a surface with a hardness of lower than Hv 700.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile