US Patent 10190608 Actuator

An actuator comprising: an inner cylinder received in an outer cylinder and a piston received in the inner cylinder that extends from the inner cylinder and the outer cylinder, the piston being slideable relative to the inner cylinder and the outer cylinder in response to the application of fluid pressure to cause the piston to extend further from the inner cylinder and the outer cylinder; and an auxiliary drive mechanism operable to cause the inner cylinder to extend from the outer cylinder, wherein the piston moves together with the inner cylinder relative to the outer cylinder.