Title:
HYDRAULIC CONTROL VALVE SYSTEM WITH PRESSURE COMPENSATED FLOW CONTROL
Document Type and Number:
WIPO Patent Application WO2002012732
Kind Code:
A3
Abstract:
An assembly of valves (12) controls hydraulic fluid flowing to several hydraulic actuators (20,21,22) from a variable displacement pump (18) that produces an output pressure equal to a control input pressure plus a predefined margin pressure. The control input pressure is a function of the greatest load pressure at the hydraulic actuators. Each valve (18,14,15) has an associated pressure compensating valve (48) which regulates the pressure differential across a metering orifice of each valve to a predefined level, usually the pump's margin pressure. A flow regulator (70) is associated with at least one of the valves (15) and reduces the output pressure from the pump to produce a reduced pressure that controls the associated pressure compensating valve. Operation of the flow regulator causes the pressure differential across a metering orifice of the associated valve to be less than the pump's margin pressure thus allowing adjustment of the fluid flow.
Inventors:
BARBER DENNIS R
Application Number:
PCT/US2001/023382
Publication Date:
August 07, 2003
Filing Date:
July 25, 2001
Export Citation:
Assignee:
HUSCO INT INC (US)
International Classes:
F15B11/05; F15B11/00; F15B11/16; F16D31/02; (IPC1-7): F15B11/16
Domestic Patent References:
| WO1996037708A1 | 1996-11-28 |
Foreign References:
| EP0926349A2 | 1999-06-30 | |||
| US5077972A | 1992-01-07 | |||
| US5138837A | 1992-08-18 | |||
| EP0411151A1 | 1991-02-06 | |||
| US4739617A | 1988-04-26 | |||
| US5791142A | 1998-08-11 | |||
| DE4235709A1 | 1994-04-28 | |||
| EP0801231A1 | 1997-10-15 | |||
| EP0877169A2 | 1998-11-11 |
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