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:
May. 09, 2000
Filed:
Jun. 05, 1998
Teikoku Piston Ring Co., Ltd., Tokyo, JP;
Abstract
A hard film is covered on the outer circumferential surface of a piston ring by means of an arc ion plating. The hard film has a mixture of crystal structure of CrN and crystal structure of Mo.sub.2 N containing oxygen in a solid solution state, and comprises chromium at 40 to 78 percent by weight, molybdenum at 3 to 35 percent by weight, oxygen at 3 to 20 percent by weight and the remainder of nitrogen. The crystal particle size is less than 1 .mu.m. The Vickers hardness is within a range from 1600 to 2500. The film thickness is preferably 1 to 60 .mu.m. Carbon in a solid solution state at 0.5 to 8 percent by weight may be substituted for the oxygen. Alternatively, both oxygen and carbon may be contained in a solid solution state with oxygen at 3 to 20 percent by weight, carbon at 0.5 to 8 percent by weight with the total content of carbon and oxygen within 25 percent by weight.