Patent ID: 9657756
Date: 2017-05-23
CPC Classifications: F15B

Claim:
1. An actuator system comprising: a first electrohydraulic servo valve comprising a four-port valve comprising a first fluid supply port, a first fluid return port, a first extension port, and a first retraction port, wherein one of the first retraction port and the first extension port is connectable to the first fluid supply port in response to a first electrohydraulic servo valve control signal, and wherein another of the first retraction port and the first extension port is connectable to the first fluid return port in response to the first electrohydraulic servo valve control signal; a second electrohydraulic servo valve comprising a four-port valve comprising a second fluid supply port, a second fluid return port, a second extension port, and a second retraction port, wherein one of the second retraction port and the second extension port is connectable to the second fluid supply port in response to a second electrohydraulic servo valve control signal, and the other of the second retraction port and the second extension port is connectable to the second fluid return port in response to the second electrohydraulic servo valve control signal; wherein the first fluid supply port and the second fluid supply port are in fluid communication with a hydraulic supply; a switching solenoid valve comprising a return input, a fluid supply input, a selection control output, and a solenoid plunger, wherein the solenoid plunger connects one of the return input and the fluid supply input to the selection control output in response to a switching solenoid valve control signal; a control selector whereby one of the first electrical hydraulic servo valve and the second electrohydraulic servo valve is connected to a cylinder in response to the switching solenoid valve connecting one of the return input and the fluid supply input to the selection control output, wherein the control selector comprises: a cavity; and a piston disposed within the cavity and comprising: wherein the piston is movable within the cavity, whereby the first extension port and the second extension port are alternately connected to the extension selector, whereby the first retraction port and the second retraction port are alternately connected to the retraction selector, and whereby the first fluid return port and the second fluid return port are alternately connected to the isolation selector.