초록 ▼

The system controls the position of a pneumatically operated valve using an electrical control signal from a controller. A pilot circuit of the system has multiple piezo valves that are subject to electrical signals from the controller to provide pneumatic output signals to a volume booster circuit

The system controls the position of a pneumatically operated valve using an electrical control signal from a controller. A pilot circuit of the system has multiple piezo valves that are subject to electrical signals from the controller to provide pneumatic output signals to a volume booster circuit of the system. Relatively small volume pneumatic pilot signals from the piezo valves are used to determine the opened or closed state of higher volume valve assemblies of the booster circuit which connect or disconnect the actuator of the valve to be operated with a source of pressurized gas. Both the piezo valves and the booster valve assemblies are subjected to gas at the same operating pressure, but the surface area of pistons in the booster valve assemblies exposed to the piezo valves is substantially larger than the surface area of the pistons exposed to operating pressure such that the pneumatic signals shift the pistons even when pressure is the same on both sides thereof. Both single-acting and double-acting embodiments are disclosed, as well as alternative versions of booster valve assemblies.

대표청구항 ▼

1. 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

1. 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.