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:
Dec. 31, 2013
Filed:
May. 19, 2011
Keita Naito, Ishikawa, JP;
Shunji Oka, Ishikawa, JP;
Osamu Takatori, Ishikawa, JP;
Komatsu Ltd., Minato-ku, Tokyo, JP;
Abstract
A construction machine includes a negative parking brake whose braking state is released by a supply of hydraulic fluid. It also includes a parking brake hydraulic circuit that is branched from a hydraulic fluid supplying circuit, which supplies the hydraulic fluid to a transmission of the construction machine, and supplies the hydraulic fluid to the parking brake. The parking brake hydraulic circuit includes a check valve that prevents backflow of the hydraulic fluid of the parking brake to the hydraulic fluid supplying circuit, and it includes an operation switching valve, which is provided closer to the parking brake than the check valve, for switching between an activation and a release of the parking brake. The parking brake hydraulic circuit also includes a relief valve, which is interposed between the check valve and the operation switching valve and which discharges the hydraulic fluid of the parking brake when the relief valve is opened.