Importance

Loading Importance Indicators...

Abstract

A force transmitting fluid actuator for use with a control device wherein an actuator member, movable within an actuator housing, actuates the control device due to the urging force of a plurality of pistons which can be selectively pressurized in unitary increments. The plurality of pistons are disposed within pressure chambers formed in the actuator housing in a symmetrical ring-shaped arrangement concentric to a single pressure chamber disposed on the vertical axis of the housing. A number of passageways interconnect the plurality of pressure chambers to form groupings of pressure chambers which act simultaneously in response to operation of a solenoid valve associated with each passageway. In addition to the symmetrical arrangement of the pressure chambers, the valve and passageway arrangement provide for a symmetric pressurization of the pressure chambers thereby resulting in a balanced force being exerted on the actuator. The amount of force each piston can exert on the actuator is limited by a piston stop designed to contact a portion of the housing while the actual piston force is transmitted by a spring disposed between each piston and the actuator. In this manner, fluctuations in the pressurizing force are not transmitted from the piston to the actuator.

Loading the Abstract Image...

First Claim