Abstract: A locking mechanism comprises an S-shaped locking member which comprises respective locking hooks arranged at the end of opposed arms of the locking member. A pivot is arranged between the arms of the locking member. The locking member rotates around the axis (A) of the pivot. The locking mechanism further comprises a coupling for coupling the locking member to an actuator for rotating the locking member around the pivot axis (A). The coupling comprises at least one coupling element, an actuator coupling for coupling the at least one coupling element to the actuator and first and second drive couplings for coupling the at least one coupling element independently to each arm of the locking member for transmitting rotational movement thereto, such that failure of one arm of the locking member will not cause loss of drive to the other arm of the locking member.

Abstract: A solenoid comprises first and second coils connected to an electrical power supply circuit. In a first mode of operation the power supply circuit is arranged to provide a current flowing in opposite directions through the respective first and second coils, e.g. to produce a self-heating effect. In a second mode of operation the power supply circuit is arranged to provide a current flowing in the same direction through the respective first and second coils, e.g. to generate a magnetic force. In some embodiments, the power supply circuit includes a bridge rectifier or full wave rectifier connected to a bi-directional current driver.

Abstract: A pressure relief valve assembly comprising a valve housing within which is provided a primary pressure relief valve having a valve ball and a valve spring, the valve spring biasing the valve ball in a first direction into a valve seat to prevent the passage of fluid from a fluid line through the valve, and wherein the spring force is selected such that a fluid force above a predetermined set point acting against the ball in a second direction opposite the first direction causes the ball to move out of the valve seat against the spring force to allow fluid to flow from the fluid line through the valve seat and through the valve, and wherein a secondary valve is positioned relative to the primary valve to retain fluid around the valve spring of the primary valve at a fluid force below the predetermined set point.

Abstract: A linear actuator includes: a screw shaft that has a screw thread and a longitudinal axis A and a nut movable along the screw shaft from a retracted position to an extended position. The actuator also includes a plurality of rollers movable with the nut, each of which includes a cylindrical surface configured to roll along one or more flanks of the screw thread, such that rotation of the screw shaft causes the rollers to roll along the flank(s) so that the nut translates in an axial direction along the screw shaft. The screw thread includes one or more detents (e.g., grooves) configured to lock the nut in one or more axial positions.

Abstract: A thrust reverser actuation system includes a first cowl actuation system for translating a first cowl of a thrust reverser and a second, separate cowl actuation system for translating a second cowl of the thrust reverser. The system also includes a device operatively connected between the first cowl actuation system and the second cowl actuation system, and configured to transmit drive from one of the first and second cowl actuation systems to the other of the first and second cowl actuation systems in the event of a failure of the other of the first and second cowl actuation systems.

Abstract: A gimbal assembly comprises a body, comprising at least one pivot boss projecting radially outwards along a first pivot axis (V) from an outer surface of the body; a gimbal, comprising an outer case surrounding the body and at least one hole projecting radially outwards along a second pivot axis (H) to receive a pivot pin to pivotally couple the gimbal to a fixed structure. The second pivot axis (H) is perpendicular to the first pivot axis (V) and the outer case is formed at least partially from carbon fibre-reinforced polymer matrix composite material. The outer case comprises at least one cavity on its inner surface in which the at least one pivot boss is located to pivotally couple the gimbal to the body.

Abstract: An anti-rotational locking apparatus for locking an elongate rotatable element in a particular rotational position with respect to a housing include: a sleeve having an internal profile for slidably receiving therethrough a rotatable elongate element having a portion with an external profile configured to positively engage with the internal profile of the sleeve; a housing; and a locking pin. The sleeve has a flange with a first opening therein and the housing has a second opening therein, the locking pin being insertable in the openings. The flange is arranged for slidable alignment with the second opening in the housing such that when the openings are aligned, the locking pin may be inserted in the openings to lock the flange to the housing and thereby prevent rotation of the flange and of an elongate element extending therethrough and engaged therewith with respect to the housing.

Abstract: A ballscrew assembly comprises a ballnut having a first helical groove and a ballscrew comprising a second helical groove opposed to the first helical groove so as to form a helical raceway. A plurality of balls is disposed in the helical raceway. A first seal is disposed at a first axial end of the ballnut to seal between the ballscrew and the ballnut. A second seal is provided for selectively sealing between the ballscrew and a second axial end of the ballnut, the second seal comprising a ballscrew seal mounted for axial movement with the ballscrew, and configured to make sealing engagement with the ballnut when the ballscrew is in a first axial position relative to the ballnut to form a chamber between the first and second seals, but not to make sealing engagement with the ballnut when the ballscrew assembly is in a second axial position relative thereto.

Abstract: An actuator system for controlling a movable surface has a main shaft connected between a power drive unit and the movable surface to transmit a command from the power drive unit to move the movable surface. If a failure in the main shaft is detected a failure control device connects a secondary shaft from the movable surface to the power drive unit e.g. by releasing a solenoid which releases gears so as to permit differential rotations between an outer ring and a sun gear of a planetary gear system, within prescribed limits. When these limits are exceeded, the solenoid brake is de-energised braking the planetary gear outer ring and tying the gears through an epicycle ratio corresponding to the ratio of gears connecting the main and secondary shafts. The gear system acts as a low mass asymmetry brake that allows post-failure operation of the surface control.

Abstract: A coupling e.g. for an actuator, includes a housing which is preferably in the form of a ring mounted around the end of an outer rod of the actuator and which can be mounted to a component e.g. a cowl being deployed. Within the housing of the coupling is provided an eccentric bearing mount and bearing arrangement mounted eccentrically to the housing so as to permit some eccentric movement.

Abstract: A monitoring system is disclosed for identifying an operating state of a motor, the system comprising: a speed sensor for determining a speed of a motor and providing a speed signal as a function of time in response thereto, and a processor configured to identify a symmetric and/or an asymmetric oscillation of the speed signal as a function of time.

Abstract: A ballscrew assembly comprises: a nut having a nut body with a radially inner surface and a helical groove formed on the radially inner surface; a screw shaft disposed within the nut, the screw shaft comprising a radially outer surface and a groove formed on the outer surface, the groove on the screw shaft cooperating with the groove on the nut to define a helical raceway for a plurality of balls; at least one lubricant reservoir formed in the nut body at or adjacent to an end of the helical raceway; and a lubricant passage extending through the nut body and fluidly coupled to the at least one lubricant reservoir; wherein the lubricant reservoir is fluidly linked to the helical groove of the nut via the lubricant passage.

Abstract: There is provided an electric motor comprising a rotor, a stator and a motor controller. The stator comprises a substantially cylindrical body, a plurality of teeth extending from the substantially cylindrical body in a radial direction, one or more first sets of electrical windings that are wound around said teeth and configured to drive the rotor, and one or more second sets of electrical windings electrically separate from the first set of electrical windings. The second set of electrical windings on the stator are electrically connected to the motor controller such that energy produced by the electric motor during a regenerative mode of operation in use is diverted to the second set of electrical windings on the stator for dissipating the energy produced in the regenerative mode.

Abstract: A hydraulic power drive unit (PDU) for a transmission system includes a hydraulic motor for converting hydraulic pressure into torque and rotation; a hydraulic brake system for applying a braking force to the hydraulic motor to prevent rotation of the hydraulic motor, wherein the hydraulic brake system is biased to apply the braking force to the hydraulic motor to prevent rotation of the hydraulic motor, and configured to remove the braking force in response to a supply of hydraulic fluid; and a hydraulic circuit for supplying a flow of hydraulic fluid to the hydraulic motor to pressurise and thereby operate the hydraulic motor and for supplying hydraulic fluid to the hydraulic brake system to pressurise the hydraulic brake system and thereby remove the braking force; wherein the hydraulic circuit comprises a brake supply line for supplying the hydraulic fluid to the hydraulic brake system.

Abstract: An epicyclic gear system having an epicyclic gear stage that includes a sun gear; a carrier, wherein the carrier comprises a plurality of planet gear axles; a plurality of planet gears, each planet gear being located on one of the planet gear axles; a ring gear. The stage also includes an output shaft, wherein the output shaft is connected to the carrier via a biasing mechanism positioned between the carrier and the output shaft, the biasing mechanism being configured to urge the carrier and the output shaft away from one another.

Abstract: A method of potting e.g. a stack of printed circuit boards, the method comprising applying a first potting material to selected regions of the circuit to be potted and then applying a second, different, potting material over the circuit to be potted.

Abstract: A torque limiting device comprises rotationally mounted input and output shafts, an intermediate drive element rotationally coupled to the input shaft and a plurality of jammer elements mounted between the intermediate drive element and the output shaft. A spring mechanism is connected between the input shaft and the intermediate drive element for aligning the intermediate drive element and the input shaft in a driving configuration in which rotation of the input shaft at a torque below a predetermined threshold is transmitted to the output shaft via the jammer element, but in which torque above the predetermined threshold moves the input shaft rotationally relative to the intermediate drive element against the force of the spring mechanism so as to disengage that jammer elements from driving engagement with the output shaft.

Abstract: An apparatus for a thrust reverser actuation system (“TRAS”), the apparatus comprising: an input shaft; a first component located concentrically around the input shaft; a second component located concentrically around the first component; a first balls crew mechanism between the input shaft and the first component, and configured such that rotational movement of the input shaft causes a translational movement of the first component via the first ballscrew mechanism; and a second ballscrew mechanism between the first component and the second component, and configured such that rotational movement of the first component causes a translational movement of the second component via the second ballscrew mechanism.

Abstract: A hydraulic thrust reverser system (TRAS) including a first return line having a first check valve therein, and a second return line having a second check valve therein, wherein the first return line and the second return line are in fluid communication with each other via a fluid restrictor located upstream of the first and second check valves, wherein the first return line extends from a piston system of the TRAS, the piston system being for moving at least one thrust reverser door, and wherein the second return line extends from a lock system of the TRAS, the lock system being for controlling locks to selectively prevent the movement of the at least one thrust reverser door.

Abstract: A thrust reverser is described that comprises a new type of locking means for locking an actuator in position so that maintenance can be performed on the machine. The locking means comprises a removable locking device for preventing movement of an actuator. The locking means may also function in one configuration as an end cap. An actuator is also described comprising a removable torque limiting device for limiting torque of the actuator.