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. 26, 2013
Filed:
Oct. 02, 2008
Mitsuru Urabe, Saitama, JP;
Hirokazu Murata, Saitama, JP;
Mitsuru Urabe, Saitama, JP;
Hirokazu Murata, Saitama, JP;
Nippon Piston Ring., Ltd., Saitama, JP;
Hino Jidosha Kabushikikaisha, Tokyo, JP;
Abstract
A cylinder realizing reduced reciprocation friction between a piston ring and a bore surface of the cylinder in a region where the piston ring slides. The cylinder in which a piston slides on a bore surface of the cylinder. A plurality of recesses is formed in a stroke center region in the bore surface of the cylinder. The stroke center region is a region between an under face position of a ring groove for a bottom piston ring at a top dead center of the piston and a top face position of a ring groove for a top piston ring at a bottom dead center of the piston. The total of areas of all of the recesses is in the range of 1% to 80% when an area of the stroke center region is 100%, and the recesses are not formed in a region other than the stroke center region of the bore surface of the cylinder.