Abstract: A secondary flight control system comprising: a first flight control surface system; a second flight control surface system; and a power distribution unit operably connected to the first flight control surface system and the second flight control surface system, wherein the power distribution unit is configured to generate torque to actuate the first flight control surface system and the second flight control surface system.

Abstract: A method of prognostic health monitoring is provided for use with an aircraft. The method includes performing real-time monitoring of torque generated for controlling positions of controllable surfaces at right- and left-hand-sides (RHS and LHS) of the aircraft, generating RHS and LHS torque information from results of the monitoring and comparing the RHS and LHS torque information at least with each other or with corresponding historic torque information.

Abstract: A kinematic system is provided that includes an outer cylinder, a mid-cylinder and an inner cylinder. The mid-cylinder is within the outer cylinder, and mated with the outer cylinder at a mid-outer threaded interface configured to transform axial translation of the outer cylinder into rotational motion of the mid cylinder along an axis. The inner cylinder is within the mid-cylinder, and mated with the mid-cylinder at a mid-inner threaded interface configured to transform the rotational movement of the mid-cylinder into axial translation of the inner cylinder along the axis. A first one of the mid-outer threaded interface and the mid-inner threaded interface includes a thread configured with a first thread portion and a second thread portion. The first thread portion is disposed at a first angle relative to the axis. The second thread portion is disposed at a second angle relative to the axis that is different from the first angle.

Abstract: A control system may be used to control actuators that actuate movement of flight control surfaces of an aircraft. Each actuator is couplable to a flight control surface and includes a motion control assembly having a hydraulic motor and a drive path from the hydraulic motor to the flight control surface. Each hydraulic motor includes an extend port and a retract port. The system includes a hydraulic control module fluidly connected to the extend port and the retract port of each hydraulic motor and a controller operable to output hydraulic power from the hydraulic control module to the motion control assembly to actuate movement of the flight control surfaces. The controller is configured to identify an actuator that positionally leads the other actuators and reduce hydraulic power to the motion control assembly assigned to such actuator.

Abstract: An actuator hardover monitor for a control surface includes an actuator sensor for detecting an actuator position, a command model of an expected position of the actuator based on an input command, and a monitor to determine whether a difference between the actuator position and the expected position exceeds a threshold for a predetermined duration. A method of preventing a hardover event for a control surface includes commanding an actuator valve to a commanded position, determining continuously when the commanded position, or an actuator valve position, or a control-surface position, or a modeled actuator valve position exceeds a predetermined limit to provide an exceedance. The method may further include filtering a signal of the exceedance based on a time constant to provide a filtered exceedance, and switching to a backup control-surface actuator when the filtered exceedance exceeds the predetermined limit for a predetermined duration.

Abstract: A coupling comprising a driven part and a driving part that is connected by a safety pin so as to drive the driven part together with the driving part in a travel direction, one of the parts having a male portion engaged in a female portion of the other part, the male and female portions respectively having a first guide surface and a second guide surface facing each other in such a manner that, in the event of the pin breaking, the driving part is capable of moving relative to the driven part in the travel direction, the pin extending perpendicularly to said direction through corresponding holes made in the male and female portions, the coupling being characterized in that the hole made in the male portion opens out in the bottom of a setback in the second guide surface.

Abstract: A method for determining the position of a component in a high lift system of an aircraft, the high lift system comprising a central power control unit for providing rotational power by means of a transmission shaft; and actuator drive stations coupled with the power control unit and movable high lift surfaces. The method comprises the steps of acquiring a first rotational position of a first position pick-off unit mechanically coupled with the power control unit by means of a first gear having a first gear ratio, acquiring at least one second rotational position of at least one second position pick-off unit mechanically coupled with a driven element in at least one drive station, and determining the number of full rotations the first position pick-off unit has already accomplished between a neutral position and an intended maximum number of rotations.

Abstract: A method for generating hydraulic power in an aircraft, the aircraft having a drive system comprising at least one transmission shaft connected to a power control unit, the power control unit having an electric motor and a hydraulic displacement machine connected to a differential gear unit for driving a common output shaft. The method includes switching the hydraulic displacement machine into a pump mode, arresting the output shaft, rotating the electric motor such that the hydraulic displacement machine is driven due to the arrested output shaft and supplying the fluid flow into a hydraulic system. A drive system of an aircraft may thereby be used for either moving control surfaces or for generating hydraulic power in an aircraft. This hydraulic power may be used to cover hydraulic load peaks during aircraft operation or to power hydraulic devices without the need of additional hydraulic power generation components.

Abstract: A hydraulic drive for an aircraft includes: a gear, a first hydraulic pump and a second hydraulic pump, wherein the gear is installed in a gear housing and wherein the first hydraulic pump and the second hydraulic pump in each case are installed in a pump housing that is affixed to the gear housing, or the two together are installed in a pump housing that is affixed to the gear housing; a hydraulic supply device including a first and a second hydraulic system for operating actuators of the aircraft; and a monitoring and drive device, with the hydraulic supply device including a first hydraulic drive for coupling the latter to a first engine, and a second hydraulic drive for coupling the latter to a second engine, wherein each hydraulic drive includes: a gear drive shaft for coupling the respective hydraulic drive to an engine output shaft of the respective associated engine; two hydraulic pumps that are coupled to a gear output shaft, in each case with a connection device for connecting the hydraulic pump to

Abstract: A flaperon mechanism that provides jam protection while preventing the component departing from the airplane or causing unacceptable collateral damage. The jam protection feature comprises a controlled failure (fused) mechanism that is associated with the flaperon and flaperon hinge panel and maintains functional movement of the devices. Additional features can be added to the mechanism to block, shield, allow runout and shed other obstruction avenues.

Abstract: A method for regulating an actuator for a control surface is provided, which actuator has an angular position controlled by an autopilot on an aircraft with mechanical flight control. When the value of the torque exerted by the actuator is less than a threshold torque value, the actuator is regulated in terms of position and the maximum speed of movement of the control surface is limited to a value that is dependent on the torque value. When the value of the torque exerted by the actuator is greater than the threshold torque value, the actuator is regulated in terms of torque.

Abstract: A stabilizer actuator has a first end for connecting to an aircraft support structure and a second end for connecting to a stabilizer. The actuator includes a primary load path for transmittal of loads acting on the stabilizer to the aircraft support structure, and a secondary load path for transmittal of loads acting on the stabilizer to the aircraft support structure upon failure of the primary load path. The secondary load path includes a tie rod extending along a longitudinal axis, a load path locking mechanism coupled to the tie rod, a lock housing having a central bore for receiving the locking mechanism, and at least one radially movable segment that, upon failure of the primary load path, moves radially to lock the tie rod to the lock housing against axial and/or radial movement.

Abstract: A device (13) for detecting the breakage of a primary path in a flight control actuator, said actuator having a primary path (1) comprising a rotary hollow screw (2), a secondary path (10) comprising a safety rod (3) that reacts the load passing through the screw (2), said device (13) being characterized in that it comprises a position sensor (15), connected to the screw (2), to measure information representative of the angular position thereof, and a disconnection system (17) able to disconnect the screw (2) position sensor (15) in the event of relative movement of the rod (3) with respect to the screw (2) if there is a break in the primary path (1).

Abstract: The present disclosure provides an actuation system for a flight control surface of an aircraft, having: a support frame for supporting a flight control surface, the support frame being configured to be mounted to an airframe structure of the aircraft for movement between a first position and a second position to operate and move the control surface; an actuation mechanism configured to effect movement of the support frame between the second position and the first position; and a detection device for detecting a fault in the actuation mechanism, the detection device comprising a deflector configured to deflect or skew the support frame away from or out of the first position in the event of a fault in the actuation mechanism.

Abstract: An actuator is arranged to move an aircraft component such as a landing gear leg, flap or aileron between a first position and a second position, net load from external forces acting on the aircraft component tending to drive it towards the first position. The actuator comprises a threaded screw and a threaded nut. A main prime mover is configured to apply torque to the screw or nut acting in opposition to the net load under normal operating conditions. An emergency prime mover is configured to apply torque to the screw or nut acting in the same sense as the net load under emergency operating conditions in which the interface between the nut and the screw has become partially jammed to the extent that the component cannot be moved from the second position to the first position by operation of the net load alone.

Abstract: The invention relates to a device for selectively transmitting force, the device comprising a first element and a second element that is movably mounted on the first element, a friction member being arranged between the first element and the second element to exert a friction force between them, which force presents a maximum value that depends on prestress imparted by a presser member. The device includes control means for varying the prestress imparted by the presser member to the friction member and arranged, where appropriate, to substantially release the prestress imparted by the presser member so that the prestress becomes substantially zero.

Abstract: A fault-tolerant actuating system with at least one flap, adjustable on a respective wing of an aircraft, and with a control and monitoring device, includes: drive devices that are functionally connected to the control and monitoring device, with one of these drive devices in each case being associated with a flap, where each flap in each case is associated with a drive device, in each case including: two drive motors, two brake mechanisms, where each drive motor is associated with a brake mechanism for stopping rotation of the output of the respective drive motor, a differential that couples the outputs of the aforesaid to the aforesaid in a summing manner, an output shaft for coupling the output of the differential to drive connections, and a differential lock that is functionally connected to the control and monitoring device, which differential lock is coupled to the control and monitoring device in this manner, where each of the brake mechanisms as well as the differential lock can be operated by way of

Abstract: A hydraulic system for aircraft wherein at least one circuit includes two hydraulic pumps, at least one of which is driven by an engine that may suffer uncontained failure that can damage hydraulic lines close to the pump, is equipped with pressure sensors for the hydraulic fluid in the lines close to the pump and a sensor for the hydraulic fluid level in a hydraulic tank of the circuit supplied by the pump. A control system for a cut-out valve installed on a suction line wherein the fluid arrives at the pump includes logic that determines the occurrence of an uncontained engine failure requiring the isolation of the pumps from line elements that may have been damaged from measurements of the fluid pressures in the lines, from measurement of the level of fluid in the tank and from information supplied late by a uncontained engine failure detection system to command the closure of the cut-out valve.

Abstract: Vehicles commonly include control-surfaces and other components that are selectively moved during operation among a plurality of positions. Movement of aircraft control-surface components is crucial in flight, and an actuating assembly must consistently and dependably perform during normal operation and be prepared to survive situations outside normal operation and/or to compensate for circumstances causing loss of actuator control. Jam tolerant electromechanically operated actuation systems, of both the rotary and linear types, together with their methods of operation are described herein. Specifically, electrical jam-detection and control systems and associated locking and damping devices can be electrically and mechanically engaged and disengaged, are automatically reversible, and are testable.

Abstract: The detection device includes, but is not limited to a device that is configured to determine a control error corresponding to the difference between a first control instruction and a control surface position, a second device that is configured to calculate the difference between this control error and a second control instruction in such a way as to form a comparison signal, and a third device that is configured to detect a jamming of the control surface if this comparison signal is greater than a threshold value.

Abstract: Embodiments pertain to a flap adjusting system including a regulating flap mounted on an airfoil using at least two bearing devices and movable relative to the airfoil, and an adjusting device. The adjusting device includes an actuator and adjusting kinematics with a drive rod that couples the actuator to the regulating flap using a first and a second joint, as well as a load sensor. The adjusting kinematics are configured such that, at a maximum adjustment travel of the regulating flap, the second joint between the drive rod and the regulating flap is adjusted by an angle less than 50% of the angle by which the first joint is adjusted. The load sensor is arranged in at least one adjusting device and in the second joint, which couples the drive rod to the regulating flap. The load sensor is configured to measure the forces in this load path.

Abstract: An electric fail-safe is operable to move a first ramp between distinct positions. The first ramp is associated with the second ramp. There are balls intermediate the first and second ramps. When the electric fail-safe brake is in an actuated condition, the second ramp forces stationary brake disks to engage rotating brake disks which rotate with a shaft to cause braking of the shaft. There is a keeper associated with the second ramp which abuts a stop surface to limit the amount of torque applied to the rotary and stationary disks after a predetermined amount of braking force has occurred. A brake with a test switch is also disclosed.

Abstract: An actuator is arranged to move an aircraft component such as a landing gear leg, flap or aileron between a first position and a second position, net load from external forces acting on the aircraft component tending to drive it towards the first position. The actuator comprises a threaded screw and a threaded nut. A main prime mover is configured to apply torque to the screw or nut acting in opposition to the net load under normal operating conditions. An emergency prime mover is configured to apply torque to the screw or nut acting in the same sense as the net load under emergency operating conditions in which the interface between the nut and the screw has become partially jammed to the extent that the component cannot be moved from the second position to the first position by operation of the net load alone.

Abstract: The invention relates to a method and a device for controlling the power supply of at least one aircraft maintenance actuator (7) from an electrical power supply network (10) of the aircraft comprising means (14) for controlling the electrical power supply of at least one maintenance actuator, and means (15) for establishing communication between the control means and at least one control unit (16) allowing a user to control the operation of at least one actuator. The control means are designed to compare the state of at least one control unit with at least one reference state (SBR) and/or an abnormal state (SBE1, SBE2, SBE3) for switching-on purposes, and to prohibit the activation of the actuator if the state of the control unit is different from a reference state (SBR) or corresponds.

Abstract: Provided is an actuator characterized by the use of a shuttle that shifts in response to an overload. The shuttle is movable axially relative to a rotary input member by continued rotation of the rotary input member so that a stop on the shuttle moves from an ambush position allowing free rotation of the rotary input member to a blocking position preventing further rotation of the rotary input member. In this way, the shuttle prevents rotation of a rotary input member during an overload of a control surface.

Abstract: The invention concerns a device for a adjustable flap adjustably mounted on a main wing surface of an aeroplane wing, in particular, a landing flap, with at least one adjustment unit for purposes of adjustment of the adjustable flap, which has an actuator arranged, or that can be arranged, on the main wing surface, and has a kinematic adjustment mechanism running between the actuator and the adjustable flap, wherein the adjustable flap is mechanically coupled with the actuator via the kinematic adjustment mechanism. At least one damping unit for purposes of damping a dynamic loading effected by the adjustable flap on the adjustment unit, which can occur as a result of a critical malfunction event occurring in the region of the adjustable flap, is arranged, or can be arranged, between the main wing surface and the adjustable flap.

Abstract: The invention relates to a flight control system for an aircraft comprising control surfaces and actuators associated with the control surfaces to control flight functions, including roll, yaw, pitching, and aerodynamic braking of the aircraft. The actuators associated with the control surfaces that control at least one of the flight control functions are electromechanical actuators. A part of the control surfaces associated with the electromechanical actuators is divided, where each of the divided control surfaces is comprised of at least two independent surfaces.

Abstract: An electromechanical actuator incorporates a drive housing connected to a motor for rotational motion. A screw is employed with an actuating nut having protruding engagement bosses and a drive coupling is concentrically received within the drive housing having segments equal to the number of engagement bosses. Each segment has a cavity to receive a respective one of the engagement bosses and the segments are cooperatively positionable from an active position radially compressed to engage the bosses within the cavities to a released position radially expanded to disengage the bosses from the cavities.

Abstract: The actuator locking mechanism is a bi-directional secondary load path lock that operates under both compression and tension loads via a radial locking wedge and axial slide lock system. This locking mechanism is designed to effectively protect against structural disconnect after a primary load path failure occurs and to minimize the axial play in the engaged secondary load path. To avoid the dormancy of such a failure, the activated mechanism jams/stalls the actuator drive thereby alerting the aircrew and the maintenance crew of the fault condition and allowing safe continued flight and landing. This locking mechanism is impervious to relative deflection between the primary and secondary load path such that under a non-failed condition, the mechanism will not jam. A jam only occurs when axial displacement (tension or compression direction) is greater than a predetermined relative deflection. This axial displacement is eliminated by the slide locking system minimizing the axial play.

Abstract: A flaperon mechanism that provides jam protection while preventing the component departing from the airplane or causing unacceptable collateral damage. The jam protection feature comprises a controlled failure (fused) mechanism that is associated with the flaperon and flaperon hinge panel and maintains functional movement of the devices. Additional features can be added to the mechanism to block, shield, allow runout and shed other obstruction avenues.

Abstract: Methods and apparatus are provided for controlling an unmanned air vehicle (UAV) that includes a plurality of independently controllable control vanes. Control vane position commands are supplied that will move each of the control vanes to a position that will cause the UAV to implement a commanded maneuver. Inoperability of one of the control vanes is sensed, and the position of the inoperable control vane is determined New control vane position commands are determined, based on the determined position of the inoperable control vane, which will also cause the UAV to implement the commanded maneuver.

Abstract: Method and device for detecting an uncontrolled movement of an aircraft control surface. The detection device (1) comprises means (29) for calculating the difference between a theoretical command and an actual command in order to form a residual value, and means (40) for detecting an uncontrolled movement of the control surface, if a comparison value depending on this residual value is greater than a threshold value (?).

Abstract: In a vehicle, having a fixed supporting structure and a load movable relative thereto, a jam tolerant actuating system, a method for controlling this system including: Locating a physical coupling/decoupling mechanism between the load and an actuator assembly as close a practicable to the load; constructing the coupling/uncoupling mechanism to be reversible, and hence testable; and controlling the connection/disconnection via decision making electronics which will detect any system failure by monitoring, at a minimum: actuator main motor load and speed, and actuator output load. Also set forth are specific embodiments of pivotable rotary geared actuators as well as linear ball screw type actuators embodying the coupling/uncoupling mechanisms of this invention.

Abstract: In a vehicle, having a fixed supporting structure and a load movable relative thereto, a jam tolerant actuating system, a method for controlling this system including: Locating a physical coupling/decoupling mechanism between the load and an actuator assembly as close a practicable to the load; constructing the coupling/uncoupling mechanism to be reversible, and hence testable; and controlling the connection/disconnection via decision making electronics which will detect any system failure by monitoring, at a minimum: actuator main motor load and speed, and actuator output load. Also set forth are specific embodiments of pivotable rotary geared actuators as well as linear ball screw type actuators embodying the coupling/uncoupling mechanisms of this invention.

Abstract: This disclosure relates to a landing gear system that includes a landing gear strut rotatable between stowed and deployed positions. A lock-stay is connected to the landing gear strut and is movable between locked and unlocked conditions. An unlock actuator is connected to the lock-stay and includes first and second members movable relative to one another. The first member is movable between first and second positions that correspond to the locked and unlocked conditions. A controller is in communication with the unlock actuator and is configured to command the unlock actuator between the first and second positions in response to an input. The second member is permitted to free-drive relative to the first member between the stowed and deployed positions with the lock-stay in the unlocked condition.

Abstract: A method for modeling error-driven adaptive control of an aircraft. Normal aircraft plant dynamics is modeled, using an original plant description in which a controller responds to a tracking error e(k) to drive the component to a normal reference value according to an asymptote curve. Where the system senses that (1) at least one aircraft plant component is experiencing an excursion and (2) the return of this component value toward its reference value is not proceeding according to the expected controller characteristics, neural network (NN) modeling of aircraft plant operation may be changed. However, if (1) is satisfied but the error component is returning toward its reference value according to expected controller characteristics, the NN will continue to model operation of the aircraft plant according to an original description.

Abstract: An actuator, comprises a housing, a first prime mover for producing rotary motion, a first gearbox arranged to convert in use the rotary motion from the first prime mover into rotary motion having higher torque and lower speed. The first gearbox comprises a casing mounted for rotation relative to the housing of the actuator and a second gearbox arranged to convert rotary motion of the casing of the first gearbox into rotary motion having lower torque and higher speed. A brake is arranged to act on the rotary motion having lower torque and higher speed from the second gearbox. In use when the first gearbox is not jammed, the brake may be applied to resist relative rotation between the casing of the first gearbox and the housing of the actuator. When the first gearbox is jammed, the brake may be released thereby allowing the casing of the first gearbox to rotate relative to the housing of the actuator. The actuator may thereby be jam-tolerant. A second motor may also be provided.

Abstract: A method and a device for providing automatic load alleviation to a high lift surface system, in particular to a landing flap system, of an aircraft when a blockage occurs, wherein in response to a control signal emitted by a control device at least one high lift surface, which is actuated by means of a local mechanical final control element, is brought to a predetermined position by a central drive unit that is connected by way of a rotary shaft arrangement to the local final control element by generating a torque transmitted by the central drive unit to the rotary shaft arrangement. If a signal is registered that indicates that there is a blockage within the high lift surface system, the torque transmitted by the central drive unit to the rotary shaft arrangement is automatically reduced to a predetermined low torque value, and the position of the high lift surface system is fixed.

Abstract: A landing flap drive system, in one example, includes a first drive motor for operating a landing flap. In this arrangement, the landing flap drive system is integrated in a track of the landing flap such that final assembly and integration of the system are facilitated to a significant extent.

Abstract: The invention relates to a no-back device for a mobile element actuating device including a screw shaft having first and second braking means each comprising a ratchet wheel. These ratchet wheels are mounted opposite one another so that the first braking means are adapted to resist an unwanted movement of the screw shaft in a first direction, and the second braking means are adapted to resist an unwanted movement of the screw shaft in an opposite direction. The no-back device also includes means for detecting the state of the rotation of the ratchet wheels and indicating means for furnishing, according to the state of the rotation of the wheels, an indication concerning the operating state of the no-back device.

Abstract: This disclosure relates to a landing gear system that includes a landing gear strut rotatable between stowed and deployed positions. A lock-stay is connected to the landing gear strut and is movable between locked and unlocked conditions. An unlock actuator is connected to the lock-stay and includes first and second members movable relative to one another. The first member is movable between first and second positions that correspond to the locked and unlocked conditions. A controller is in communication with the unlock actuator and is configured to command the unlock actuator between the first and second positions in response to an input. The second member is permitted to free-drive relative to the first member between the stowed and deployed positions with the lock-stay in the unlocked condition.

Abstract: Electromechanical actuation systems and methods are provided. The electromechanical actuation system includes first, second, and third linear actuators having respective first, second, and third ranges of motion and an output member coupled to the first, second, and third linear actuators such that a position of a selected portion of the output member is based on actuation of the first, second, and third linear actuators.

Abstract: The present invention relates to a method and a system for monitoring of an actuator equipped with a no-back device or no-back brake and in particular an adjustable horizontal trim actuator provided in aircraft. The method comprises the steps consisting in: determining a value representative of the mechanical work produced by the said actuator; comparing the said determined value with ranges of values so as to detect a dysfunctioning of the said no-back device. In the case of an actuator of screw/nut type and a hydraulic motor, the said value representative of the mechanical work is determined from an algebraic velocity of the motor and an algebraic differential of hydraulic pressure at the terminals of the said motor. A negative value corresponding to negative mechanical work then identifies a failure of the no-back device.

Abstract: An actuator includes first and second linear motion devices, each able to extend the actuator and arranged such that jamming of one of the first and second linear motion devices does not preclude operation of the other. The first linear motion device includes a first linear screw, a first nut, and a first prime mover arranged to impart relative linear motion between the screw and nut. Similarly, the second linear motion device includes a second linear screw, a second nut, and a second prime mover arranged to impart relative linear motion between the second screw and nut.

Abstract: Actuator systems and associated methods are disclosed herein. One aspect of the disclosure is directed toward an actuator system that includes a first structure and a second structure movable relative to the first structure. The system further includes an actuator apparatus and an actuator device coupled in series between the first structure and the second structure. The system can still further include a controller operably coupled to the actuator apparatus and the actuator device. The controller can be programmed with instructions to automatically actuate the actuator apparatus and the actuator device so that a position of the first structure relative to the second structure after the actuator apparatus and the actuator device have been actuated is at least approximately the same as a position of the first structure relative to the second structure before the actuator apparatus and the actuator device have been actuated.

Abstract: The control system (1) comprises at least one control panel (P1, Pn) comprising a plurality of operable control means (2) for controllable pieces of equipment (EC1, ECk) of the aircraft, each of which is controlled by first and second computers (3A1, 3Ak, 3B1, 3Bk), and a communication system (4) comprising a first and a second communication channel (5, 6) which are separate from each other and follow different paths (C1, C2), the first communication channel (5) connecting the control means (2) to the first computers (3A1, 3Ak) and the second communication channel (6) connecting the control means (2) to the second computers (3B1, 3Bk), each of said communication channels (5, 6) comprising two different digital communication buses (8, 9; 10, 11).

Abstract: An electromechanical actuating assembly (100) can have a redundant design with a first electric motor (300A) providing actuator-moving power via a first drive train (400A) and a second electric motor (300B) providing actuator-moving power via a second drive train (400B). A first decoupling train (600A) can transmit decoupling power to decouple the first drive train (400A) from the actuator (200) and a second decoupling train (600B) for transmit decoupling power to decouple the second drive train (400B) from the actuator (200). The assembly (100) is operable in a fault-tolerant mode wherein actuator-moving power is transferred only through one drive train (400A/400B) and the other drive train (400B/400A) is decoupled from the actuator (200).

Abstract: An actuator, comprises a housing, a first prime mover for producing rotary motion, a first gearbox arranged to convert in use the rotary motion from the first prime mover into rotary motion having higher torque and lower speed. The first gearbox comprises a casing mounted for rotation relative to the housing of the actuator and a second gearbox arranged to convert rotary motion of the casing of the first gearbox into rotary motion having lower torque and higher speed. A brake is arranged to act on the rotary motion having lower torque and higher speed from the second gearbox. In use when the first gearbox is not jammed, the brake may be applied to resist relative rotation between the casing of the first gearbox and the housing of the actuator. When the first gearbox is jammed, the brake may be released thereby allowing the casing of the first gearbox to rotate relative to the housing of the actuator. The actuator may thereby be jam-tolerant. A second motor may also be provided.

Abstract: In a vehicle, having a fixed supporting structure and a load movable relative thereto, a jam tolerant actuating system, a method for controlling this system including: Locating a physical coupling/decoupling mechanism between the load and an actuator assembly as close a practicable to the load; constructing the coupling/uncoupling mechanism to be reversible, and hence testable; and controlling the connection/disconnection via decision making electronics which will detect any system failure by monitoring, at a minimum: actuator main motor load and speed, and actuator output load. Also set forth are specific embodiments of pivotable rotary geared actuators as well as linear ball screw type actuators embodying the coupling/uncoupling mechanisms of this invention.

Abstract: In a vehicle, having a fixed supporting structure and a load movable relative thereto, a jam tolerant actuating system, a method for controlling this system including: Locating a physical coupling/decoupling mechanism between the load and an actuator assembly as close a practicable to the load; constructing the coupling/uncoupling mechanism to be reversible, and hence testable; and controlling the connection/disconnection via decision making electronics which will detect any system failure by monitoring, at a minimum: actuator main motor load and speed, and actuator output load. Also set forth are specific embodiments of pivotable rotary geared actuators as well as linear ball screw type actuators embodying the coupling/uncoupling mechanisms of this invention.