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:
Oct. 07, 2008
Filed:
Dec. 29, 2005
Dal Sik Jang, Seoul, KR;
Ki Nam Jung, Chungchoongnam-do, KR;
Dal Sik Jang, Seoul, KR;
Ki Nam Jung, Chungchoongnam-do, KR;
Doosan Infracore Co., ltd., Ichon, KR;
Abstract
A fluid pump control system for excavators enables fluid pumps to produce hydraulic flows of a quantity great enough to actuate hydraulic actuators for smooth composite operations. The system includes variable displacement fluid pumps, fluid quantity control mechanisms for controlling the discharge quantity of the respective fluid pumps, fluid quantity control signal lines respectively connected to the fluid quantity control mechanisms, signal pressure control lines for bringing the fluid quantity control signal lines into connection with a fluid tank to drop the fluid quantity control signal pressures within the fluid quantity control signal lines, and a plurality of cutoff valves attached to the signal pressure control lines in tandem and shiftable in concert with the shifting movement of spools of a control valve for increasing the fluid quantity control signal pressures within the signal pressure control lines in proportion to the shifting amounts of the cutoff valves.