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:
Jul. 22, 2003
Filed:
Sep. 27, 2001
Kazuo Shimizu, Saitama, JP;
Nippon Piston Ring Co., Ltd., , JP;
Abstract
The present invention provides a chrome-plated sliding member free from periodical decreases in wear resistance or seizure resistance without the necessity to intentionally bend a multi-layer hard chrome plating film. This is a sliding member having a multi-layer hard chrome plating film on the sliding surface of the substrate . Microcracks opening to the outer surface side of the individual hard chrome plating layers are distributed in hard chrome plating layers and . The microcracks of the individual hard chrome plating layers comprise relatively shallow portions where bottoms stop within a single layer, and relatively deep portions and where cracks run through two or more layers. The quantities of the microcracks expressed by the area ratios of microcracks on a cross-section of the hard chrome plating film include a quantity of the portions where cracks stop within a single layer within a range of from 1.5 to 35.0%, a quantity of the portions where cracks run through two or more layers within a range of from 0.5 to 25.0%, and a total quantity of microcracks within a range of from 2.0 to 40.0%.