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:
Apr. 05, 2016
Filed:
Apr. 21, 2014
Kabushiki Kaisha Riken, Tokyo, JP;
Akira Kunimoto, Kumagaya, JP;
KABUSHIKI KAISHA RIKEN, Tokyo, JP;
Abstract
A combined oil control ring comprising a pair of circular side rails each having a gap, and a spacer expander longitudinally sandwiched by the side rails, which has seating tabs for pushing inner surfaces of the side rails on the inner side, a side rail-pushing surface of each seating tab being provided with one or more grooves extending substantially longitudinally; each of the side rail-pushing surfaces including the grooves being provided with a nitride layer, and the depth d (μm) of the grooves, the surface hardness h (micro-Vickers hardness HV0.1) of the nitride layer, and the thickness t (μm) of the nitride layer having micro-Vickers hardness HV0.1 of 700 or more meeting the relation of the0.05≦1000×/()≦0.45  (1).