Patent ID: 8978692
Filing Date: 2015-03-17
Classification: G05D,Y10T

Abstract:
1. A fluid supply system comprising (i) a fluid-actuated pressure reducing valve and (ii) a pilot valve connected to the fluid-actuated pressure reducing valve for controlling an output pressure of the fluid-actuated pressure reducing valve, the pilot valve including: a housing, a first valve member and a second valve member whose relative positions control flow through the pilot valve; the first valve member being provided on a movable spring-engaging member which engages a spring and which is mounted in the housing for movement relative to the housing in a longitudinal direction in response to the outlet pressure of the pressure reducing valve, movement of the spring-engaging member changing the relative positions of the first and second valve members; an adjuster for varying the relative rotational positions of the first and second valve members about the longitudinal direction for a given position of the spring-engaging member, so as to cause the output pressure of the pressure reducing valve to alter; and a motor connected to the adjuster for rotating the adjuster; wherein one of the first and second valve members includes an aperture directed laterally of the longitudinal direction; the other of the first and second valve members includes a portion defining an edge which is positively-inclined relative to the longitudinal direction, and which extends completely across the aperture, and which is arranged for relative sliding movement across the aperture to vary the flow cross section through the aperture and thus the flow through the pilot valve; and the adjuster is arranged to adjust the relative rotational positions of the edge-defining portion and the aperture by sliding movement so as to adjust the flow cross section through the aperture for a given position of the spring-engaging member.