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:
Sep. 21, 2010
Filed:
Aug. 22, 2006
Tomohiko Yasuda, Tsuchiura, JP;
Takashi Yagyu, Tsuchiura, JP;
Yasuo Tanaka, Tsuchiura, JP;
Michio Fushiki, Tsuchiura, JP;
Satoru Kaneko, Tsuchiura, JP;
Tomohiko Yasuda, Tsuchiura, JP;
Takashi Yagyu, Tsuchiura, JP;
Yasuo Tanaka, Tsuchiura, JP;
Michio Fushiki, Tsuchiura, JP;
Satoru Kaneko, Tsuchiura, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
A hydraulic drive system is provided with a generatorfor outputting electricity corresponding to a rotation speed of an engine, an electric motordrivable responsive to the electricity from the generator, hydraulic pumpsdrivable by the electric motor, truck-body elevating cylindersfor pivoting a truck bodyin an up-and-down direction, and a stroke detectorfor detecting a stroke of the control apparatus of the truck-body elevating cylinders, and is also provided with a controllerfor performing control of engine rotation speed. The controllerincludes a motor electric-power computing meansfor determining electric power for the electric motor, which corresponds to the stroke detected by the stroke detector, and a discrimination meansfor discriminating whether or not the electricity from the generatorhas become greater than the thus-determined electric power for the electric motor