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:
Nov. 03, 2015
Filed:
Jan. 30, 2015
Tpr Co., Ltd., Chiyoda-ku, Tokyo, JP;
Takatsugu Iwashita, Tokyo, JP;
Tomoyuki Sato, Tokyo, JP;
TPR Co., Ltd., , JP;
Abstract
A piston ring which is provided with a carbon-based coating which has a low friction property and wear resistance, that is, a piston ring which has a carbon-based coating formed over its sliding surface, in which piston ring, the coating is a multilayer coating comprised of two types of layers having different hardnesses laminated in at least two layers, a hardness difference between the two types of layers is 500 to 1700 HV, a high hardness layer has the same or greater thickness than a low hardness layer, and the coating as a whole has a thickness of 5.0 μm or more. The high hardness layer has a thickness of 5 to 90 nm. The surface on which the coating is formed has a base material roughness of 1.0 μmRz or less.