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:
Jan. 30, 2018
Filed:
Mar. 18, 2015
Hitachi Construction Machinery Co., Ltd., Bunkyo-ku, Tokyo, JP;
Teppei Saitoh, Tokyo, JP;
Juri Shimizu, Tokyo, JP;
Mariko Mizuochi, Tokyo, JP;
Kenji Hiraku, Tsuchiura, JP;
Akinori Ishii, Tsuchiura, JP;
Hiromasa Takahashi, Tsuchiura, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
To provide a hydraulic driving device configured to smoothly extend a hydraulic cylinder. The present invention includes the open circuit E, the closed circuit A, a control device, and a control lever. The open circuit E is provided with a flow passagefor connecting an outlet port of the open circuit pumpand a head chamberof the boom cylinder, a selector valveprovided in the flow passage, a discharge flow passagefor connecting a hydraulic fluid tankand a flow passage, and a bleed-off valveprovided in the discharge flow passage. The control deviceis configured in such a manner that when a manipulate signal for extending the boom cylinderis input from the control lever, the bleed-off valveis closed, the selector valveis subsequently opened, and the open circuit pumpis controlled.