Abstract: An actuation system comprises a plurality of actuators, a common power drive unit for driving the actuators and a transmission line transmitting drive from the common drive unit to the plurality of actuators. A clutch is arranged in the transmission line between the power drive unit and the plurality of actuators for selectively disconnecting the power drive unit from the plurality of actuators. At least one sensor is provided for sensing an abnormal load condition in the actuation system. The at least one sensor is operatively coupled to a clutch control which is configured such that when the at least one sensor senses an abnormal load condition, the clutch control is operative to disengage the clutch so as to disconnect the power drive unit from the plurality of actuators. A brake is operative to brake the actuators upon disengagement of the clutch.

Abstract: A control system comprises a TRAS actuator 14, a VAFN actuator 40, and a control arrangement 52 operable to control the operation of the TRAS actuator 14 and the VAFN actuator 40, wherein at least one control circuit 54 of the control arrangement 52 is a common control circuit, common to the operation of both the TRAS actuator 14 and the VAFN actuator 40.

Abstract: A control system comprises a TRAS actuator 14, a VAFN actuator 40, and a control arrangement 52 operable to control the operation of the TRAS actuator 14 and the VAFN actuator 40, wherein at least one control circuit 54 of the control arrangement 52 is a common control circuit, common to the operation of both the TRAS actuator 14 and the VAFN actuator 40.

Abstract: A geared rotary actuator comprising first and second reduction gear trains, an earth for fixing the actuator in use, and an output member moveable relative to said earth for connection to a component to be moved by the actuator, said first and second reduction gear trains each including a respective rotary input member and a respective output, said first and second gear train input members being arranged in use to be driven by respective sources of rotary movement and said gear trains having fixed, equal, step-down gear ratios between their input and output, and, the actuator further including output summing means interconnecting said outputs of said first and second gear reduction trains with said output member of the actuator whereby movement of said output member relative to said earth in response to rotation of said gear train input members is the sum of the movements of said gear train outputs.

Abstract: A thrust reverser assembly comprising at least one thrust reverser element which, during normal use in association with a jet engine, is movable between a stowed position and a deployed position and is so arranged as to experience an assisting load during movement of the element from the stowed position towards the deployed position, a source of hydraulic fluid under pressure, and, a double-acting hydraulic piston and cylinder device for moving said element between said stowed and deployed positions, said hydraulic piston and cylinder device having a first port through which hydraulic fluid under pressure from said source is admitted to one side of said device, said one side of the device being a high pressure side during operation of the device in a thrust reverser element deploy mode, to displace said element from its stowed position, a second port through which hydraulic fluid is displaced from a low pressure side of the device during operation in said deploy mode, a return line through which hydraulic flu

Abstract: A geared rotary actuator comprising first and second reduction gear trains, an earth for fixing the actuator in use, and an output member moveable relative to said earth for connection to a component to be moved by the actuator, said first and second reduction gear trains each including a respective rotary input member and a respective output, said first and second gear train input members being arranged in use to be driven by respective sources of rotary movement and said gear trains having fixed, equal, step-down gear ratios between their input and output, and, the actuator farther including output summing means interconnecting said outputs of said first and second gear reduction trains with said output member of the actuator whereby movement of said output member relative to said earth in response to rotation of said gear train input members is the sum of the movements of said gear train outputs.

Abstract: A skew detection system for use in sensing the occurrence of a skew condition in a system having a plurality of control surfaces located adjacent one another and which, in use, are driven to move simultaneously and at the same speed as one another, the skew detection system comprising a detector arrangement extending over and movable with the surfaces, between a first location on one of the surfaces and a second location on another of the surfaces, at least part of the detector arrangement being arranged to move in the event that one or more of the surfaces becomes skewed, and a sensor arranged to permit a change in the position of the said part of the detector arrangement to be detected. In one embodiment, a skew condition can be sensed using two sensors.

Abstract: An actuator system comprising a rotary actuator having an input member, a first output and a second output, the first and second outputs being arranged to move at substantially the same regular speed upon rotation of the input member, a drive shaft coupled to the input, and first and second output shafts coupled, respectively, to the first and second outputs. The invention also relates to a rotary actuator for use in the actuator system.

Abstract: A brake assembly of the constant friction type has a rotary transmission shaft fitted with a constant friction brake device including a first set of friction plates carried on the shaft and a second set of friction plates interleaved with the friction plate and mounted on a friction element support. The friction brake device acts on the shaft to apply a braking torque thereto in at least one direction of rotary movement. The friction element support is rotatable relative to the shaft and to a housing of the assembly. A detent mechanism acts between the housing and the friction element support so as to retain the support against rotation below a predetermined braking torque. A signalling means such as a proximity sensor is arranged to be operated when the friction element support moves relative to the housing.

Abstract: A hydraulic motor arrangement including a hydraulic motor having an inlet port arranged to receive a driving fluid, and an outlet port whereby fluid can exhaust from the motor, the arrangement incorporating a by-pass line interconnecting the inlet and the outlet ports, a non-return valve being located within the by-pass line and being arranged to permit fluid flow from the outlet port to the inlet port but to substantially prevent fluid flow in the reverse direction.