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:
Nov. 21, 1989
Filed:
Mar. 25, 1988
Toichi Hirata, Ushiku, JP;
Masakazu Haga, Chiyoda, JP;
Ichiro Hirami, Chiyoda, JP;
Kuniaki Yoshida, Tsuchiura, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
A drive control system, which is suitable for use in a hydraulic machine, is equipped with an electric lever device having a manipulation lever and a potentiometer for generating an electrical manipulation signal corresponding to the degree of each manipulation of the lever, a control valve connected to a hydraulic circuit adapted to actuate a hydraulic actuator, and a controller unit equipped with a main controller for receiving the manipulation signal and computing a control signal for the control valve on the basis of the manipulation signal and an output device for generating an electrical actuation signal corresponding to the control signal. The system also includes a neutral position sensing means provided with the electric lever device and adapted to sense a neutral position of the manipulation lever and an inhibition device which receives an output signal from the neutral position sensing means and when the manipulation lever is at the neutral position, inhibits the transmission of a signal between the main controller of the control means and the control valve.