Patent ID: 6357335
Filing Date: 2002-03-19
Classification: B60T,G05D,Y10T

Abstract:
In a system for controlling the position of a pneumatically-operated valve, the improvement comprising:an actuator provided with an internal operating chamber adapted to receive operating gas under pressure, said actuator including a movable part within said operating chamber movable in response to an increase in volume of pressurized gas within the chamber, said movable part being adapted to be operably coupled with the valve for shifting the valve in response to movement of said part; a source gas at an operating pressure; an operating circuit between the gas source and the actuator for communicating the gas source with the operating chamber of the actuator, said operating circuit including volume booster mechanism for controlling whether the gas source is in or out of communication with the operating chamber of the actuator; a pilot circuit between the gas source and the volume booster mechanism, said pilot circuit including pilot valve mechanism responsive to a control signal to produce a pilot gas output at said operating pressure, said volume booster mechanism being operable to produce a flow of operating gas at a higher volumetric rate than said pilot gas output; and a controller connected with said pilot valve mechanism and operable to send a control signal to said pilot valve mechanism, said volume booster mechanism being responsive to pilot gas output at said operating pressure from said pilot valve mechanism to selectively communicate the actuator with the gas source or atmosphere, said pilot valve mechanism including piezo devices.