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:
Mar. 17, 2026
Filed:
Mar. 11, 2021
Hitachi Astemo, Ltd., Ibaraki, JP;
Yasuhisa Omata, Hitachinaka, JP;
Hideo Nagayama, Hitachinaka, JP;
Kosuke Tokunaga, Hitachinaka, JP;
Ryo Shinata, Hitachinaka, JP;
Reiji Nakagawa, Hitachinaka, JP;
Shoichiro Soeta, Hitachinaka, JP;
Hitachi Astemo, Ltd., Ibaraki, JP;
Abstract
This cylinder device of the present aspect includes: a cylinder having a bottomed tubular shape; a seal member provided at an opening of the cylinder; and a piston rod that is provided to protrude from the opening of the cylinder and slides with respect to the seal member. A sliding surface of the piston rod has a chrome-plated layer. In the sliding surface, as characteristic evaluation parameters of a plateau structure surface described in JIS B 0671-2 and ISO 13565-2, a reduced valley depth Rvk is 0.06 μm or more and less than a plating thickness, a reduced peak height Rpk is 0 μm or more and 0.04 μm or less, and a core roughness depth Rk is 0.08 μm or more and 0.16 μm or less.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile