Patent ID: 6397875
Filing Date: 2002-06-04
Classification: G05D,Y10T

Abstract:
A method of controlling the pressure of a hydraulic fluid in a pilot conduit which receives fluid at an at least substantially constant pressure from a constant-pressure conduit by way of a flow restrictor and a pilot valve which is adjustable to permit outflow of fluid from the pilot conduit through a branch conduit at a variable rate and to thus lower the static pressure of fluid in the pilot conduit in response to increasing rate of fluid outflow from the pilot conduit, comprising the steps of:establishing for the flow of fluid from the pilot conduit by way of the constant-pressure conduit to the pilot valve an evacuating path extending from the pilot conduit, first through the flow restrictor and thereupon through the branch conduit into and through the pilot valve; and varying the speed of fluid flowing through the flow restrictor to thus influence the static pressure of fluid in the pilot conduit such that the static pressure of the fluid in the pilot conduit decreases in response to increasing rate of fluid outflow from the pilot conduit.