A fluid actuator arrangement comprises a piston rod member, at least two cylinders each said cylinder having a piston body, and a clamping mechanism associated to each cylinder. Each clamping mechanism is arranged to engage and disengage the piston body of the cylinder to the piston rod member. The fluid actuator arrangement comprises further a control element arranged to control a back and forward movement of the respective piston body so that forward movement is slower than the backward movement and to control the movement of the respective piston bodies in relation to each other such that at least one piston body is always moving forward and such that an overlap exists wherein at least two of the piston bodies are moving forward simultaneously during a cycle.

A fluid actuator arrangement comprises a piston rod member, at least two cylinders each said cylinder having a piston body, and a clamping mechanism associated to each cylinder. Each clamping mechanism is arranged to engage and disengage the piston body of the cylinder to the piston rod member. The fluid actuator arrangement comprises further a control element arranged to control a back and forward movement of the respective piston body so that forward movement is slower than the backward movement and to control the movement of the respective piston bodies in relation to each other such that at least one piston body is always moving forward and such that an overlap exists wherein at least two of the piston bodies are moving forward simultaneously during a cycle.

The subject matter of this specification can be embodied in, among other things, an assembly that includes a piston having a piston inner surface defining a cylindrical cavity and includes a first axial portion, a piston face at a first end of the first axial portion, a second axial portion at a second end of the first axial portion, and a helical piston thread defined upon the piston inner surface, a bushing configured to contact the piston inner surface, and a lock nut configured to engage the piston and the bushing.

A hydraulic control circuit operable to selectively hydraulically link first and second hydraulic actuators and to bypass that hydraulic link.

A tracked vehicle, controller for the tracked vehicle, and a method performed thereon are provided that enable the pilot to steer the tracked vehicle using an existing joystick of the tracked vehicle.

A tracked vehicle, controller for the tracked vehicle, and a method performed thereon are provided that enable the pilot to steer the tracked vehicle using an existing joystick of the tracked vehicle.

An actuator system for controlling a control surface of an aircraft, which includes a control structure which defines the control surface and the control structure has an axis of rotation about which the control structure can rotate relative to the aircraft. A first actuator assembly has a first actuator arm and a second actuator assembly has a second actuator arm. The first actuator assembly and the second actuator assembly are spaced apart from one another along the axis of rotation. The first actuator arm is connected to a first band member and the first band member is connected to the control structure on a first side of the axis of rotation and the second actuator arm is connected to a second band member and the second band member is connected to the control structure on a second opposing side of the axis of rotation.

An actuator system for controlling a control surface of an aircraft, which includes a control structure which defines the control surface and the control structure has an axis of rotation about which the control structure can rotate relative to the aircraft. A first actuator assembly has a first actuator arm and a second actuator assembly has a second actuator arm. The first actuator assembly and the second actuator assembly are spaced apart from one another along the axis of rotation. The first actuator arm is connected to a first band member and the first band member is connected to the control structure on a first side of the axis of rotation and the second actuator arm is connected to a second band member and the second band member is connected to the control structure on a second opposing side of the axis of rotation.

A thrust reverser actuation system for a jet propulsion engine for a vehicle, the thrust reverser actuation system comprising: a plurality of hydraulically-driven thrust reverser actuators for actuating one or more thrust reverser components of the jet propulsion engine, each actuator comprising: a hydraulic circuit; and a bi-directional electrically-driven pump configured to pump hydraulic fluid through the hydraulic circuit, wherein the hydraulic circuit and the pump are configured such that the direction of the pump dictates the direction of the actuation of the actuator.

A thrust reverser actuation system for a jet propulsion engine for a vehicle, the thrust reverser actuation system comprising: a plurality of hydraulically-driven thrust reverser actuators for actuating one or more thrust reverser components of the jet propulsion engine, each actuator comprising: a hydraulic circuit; and a bi-directional electrically-driven pump configured to pump hydraulic fluid through the hydraulic circuit, wherein the hydraulic circuit and the pump are configured such that the direction of the pump dictates the direction of the actuation of the actuator.