An electronically actuated switching valve for controlling the flow of gas streams in a pneumatic system. The preferred embodiment of the invention comprises a double piloted three-way spool valve which moves within a valve housing having a plurality of ports which cooperate with the spool valve to direct gas streams in a predtermined manner. The position of the valve spool within the housing is controlled by pressure pilots on either side of the valve spool. Electronically actuated solenoid exhaust valves are operable to cause pressure drops in the pressure pilots to cause the valve spool to change position. Once the valve spool has changed position, it is maintained in that position without the need for a continuous supply of electric current to the electronic actuators.
William D. Perry; Donald H. Heihn