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. 20, 2010
Filed:
Aug. 13, 2007
Hideki Haramoto, Tsuchiura, JP;
Hidetoshi Satake, Ichioka, JP;
Yukihiro Tatsuno, Tsukuba, JP;
Kazuhiro Ichimura, Niihari, JP;
Hideki Haramoto, Tsuchiura, JP;
Hidetoshi Satake, Ichioka, JP;
Yukihiro Tatsuno, Tsukuba, JP;
Kazuhiro Ichimura, Niihari, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
The present invention includes: a hydraulic pumpthat is driven by a driving motor; a travel motion motorthat is driven with pressure oil supplied from the hydraulic pump; a travel motion control valvethat controls a flow rate of the pressure oil supplied from the hydraulic pumpto the travel motion motor; a means for operationwith which the travel motion control valveis operated; a means for rotation rate detectionthat detects a rotation rate N of the travel motion motor; and a means for motor over rotation preventionthat reduces the rotation rate of the travel motion motorif the means for rotation rate detectiondetects a rotation rate equal to or higher than a predetermined rotation rate upper limit Nmax.