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. 07, 1992
Filed:
Jul. 03, 1990
Donald L Bianchetta, Coal City, IL (US);
Gene R St Germain, Plainfield, IL (US);
Caterpillar Inc., Peoria, IL (US);
Abstract
Load sensing hydraulic systems are useful for distributing fluid from a variable displacement pump to the individual work circuits in accordance with the demand of each work circuit. Preventing load pressure from being drained from the motors of the work circuits during some operating functions heretofore required the use of a pair of pressure compensating valves and a pair of shuttle valves at each of the directional control valves. The subject load pressure duplicating circuit includes a single load pressure duplicating valve having an end subjected to the load pressure in a signal network and reduces pump pressure entering the valve to a pressure level at the output thereof equal to the load pressure. This duplicated pressure is then utilized as the control fluid for the pressure compensating valves and a displacement controller of the pump. The system is greatly simplified by the use of only a single duplicating valve for a hydraulic system having a plurality of work circuits.