Actuator control valve arrangement

An actuator control arrangement comprising:

• a hydraulic actuator having a housing and a piston rod axially moveable within the housing between a neutral position, a retracted position and an extended position with respect to the housing in response to application of pressure to the piston rod;
• a solenoid valve arranged between a pressure source and the actuator, the solenoid valve switchable between a first mode and a second mode in response to an electric control signal, wherein, in the first mode, the solenoid valve creates a fluid flow path from the pressure source to the actuator and in the second mode, the solenoid valve creates a fluid flow path to release pressure from the actuator;
• an anti-extension valve provided between the pressure source and the actuator, configured to move between a first position in which a fluid path is created between the pressure source and the actuator and a second, anti-extension position to prevent extension of the piston rod with respect to the housing in the event of pressure loss, wherein the anti-extension valve has a first pressure input arranged to receive pressure from the pressure source and a second pressure input arranged to receive pressure from the actuator, the sum of the pressure at the first input and at the second input acting against a spring biasing the anti-extension valve into the second position;
• and
• an outlet port in the actuator housing arranged to be closed when the solenoid valve is in the first position and open when the solenoid valve is in the second position and, when open, to convey pressure from the actuator to a third input of the anti-extension valve to add to the pressure acting against the spring.