Patent ID: 7766302

Claim:
A fluid actuator, comprising a housing having first and second fluid ports; an actuation cylinder in the housing defining a longitudinal axis and having first and second ends in first and second directions; an actuation piston in the cylinder with first and second surfaces moveable along the longitudinal axis; a spring subsystem biasing the actuation piston to a neutral position; a second piston rod operably connected with the actuation piston and the spring subsystem; a first fluid space defined by the first end of the actuation cylinder and the first surface of the actuation piston; a second fluid space defined by the second end of the actuation cylinder and the second surface of the actuation piston, and separated, within the actuation cylinder, from the first fluid space by the actuation piston in the entire travel range of the actuation piston; a first flow mechanism controlling fluid communication between the first fluid space and the first port; and a second flow mechanism controlling fluid communication between the second fluid space and the second port.