Patent ID: 6651686
Filing Date: 2003-11-25
Classification: G05D,Y10T

Abstract:
An actuator system for a system valve exposable to a source of system pressure comprising:a sensing assembly, comprising: a sensing vessel having a tubular internal cavity; a piston assembly comprising: a piston positioned within the internal cavity, the piston having at least a first position and a second position, longitudinally offset from the first position in a second direction; a piston control system adapted to move the piston from its first position to its second position in response to a designated system pressure, comprising: a sensing fluid path interconnecting the source of system pressure with the internal cavity of the sensing vessel; a biasing element, coupled to the piston and disposed to oppose longitudinal movement of the piston in the second direction, the biasing element adapted to undergo a designated deformation once such designated system pressure is established within the internal cavity; and a latch system having a unreleased state, in which the latch system prevents movement of the piston to its second position, and a released state, in which the latch system permits such movement, wherein the latch system is adapted to shift from its unreleased state to its released state in response to the designated deformation of the biasing element; an actuator, adapted for engagement with the system valve, the actuator adapted to shift from an unactuated state to an actuated state in response to a predetermined change in pressure at the actuator; an actuator pressure source interconnectable with the actuator by an actuator fluid path; and an actuator control valve interposed in the actuator fluid path, the actuator control valve coupled to the piston and producing the predetermined change in pressure at the actuator in response to movement of the piston from its first to its second position.