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. 14, 1999
Filed:
Dec. 17, 1997
Eric P Hamkins, Waukesha, WI (US);
Husco International, Inc., Waukesha, WI (US);
Abstract
A hydraulic fluid is supplied from a tank to a plurality of actuators by a variable displacement pump which produces an output pressure that is a constant amount greater than a pressure at a control input. A mechanism senses the greatest pressure among the workports to provide a first load-dependent pressure and a second load-dependent pressure which is greater than the first load-dependent pressure when the pump operates a maximum flow capacity. Each valve section includes a pressure compensating valve which controls the fluid flow to the associated actuator in response to a pressure differential between the metering orifice and either the first or second load-dependent pressures. When the pump operates at maximum flow capacity, actuators connected to the valve sections in which the pressure compensating valve responds to the first load-dependent pressure receive the fluid flow on a priority basis as compared to the other valve sections. Thus the system operates the priority actuators as normally as possible during a maximum pump flow situation by reducing the fluid flow to non-priority actuators.