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. 11, 1997
Filed:
Dec. 20, 1995
Applicant:
Inventors:
Assignee:
Teikoku Piston Ring Co., Ltd., Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
F16J / ;
U.S. Cl.
CPC ...
2772 / ;
Abstract
A hard film is formed on the outer circumferential surface of a piston ring by means of a physical vapor deposition process. The hard film is a ternary film comprising molybdenum, chromium, and 4 to 22 percent nitrogen by weight, and includes at least molybdenum nitride and chromium nitride. The film has a Vickers hardness of 1400 to 2600, and the crystal grain size of the film is less than 1 .mu.m.