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. 15, 2008
Filed:
Sep. 17, 2004
Yukihiro Tatsuno, Tsuchiura, JP;
Kazuhiro Ichimura, Tsuchiura, JP;
Yukihiro Tatsuno, Tsuchiura, JP;
Kazuhiro Ichimura, Tsuchiura, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
The present invention includes a hydraulic pumpdriven by a prime mover, a traveling motordriven with pressure oil delivered from the hydraulic pump, a control valvefor traveling that controls a flow rate of the pressure oil delivered from the hydraulic pumpto the traveling motor, a counterbalance valveswitched in response to a motor load pressure supplied via the control valve, that generates a braking pressure at a conduit LA or LB disposed on a return side of the traveling motoras the load pressure becomes lower, an overspeed detection meansfor detecting an overspeed state in the traveling motor, and a motor overspeed inhibiting meansfor inhibiting rotation of the traveling motorif the overspeed detection meansdetects an overspeed state in the traveling motoruntil a braking pressure is generated through a switchover at the counterbalance valveand the traveling motoris no longer in the overspeed state.