Abstract: A connector for adjustably connecting an RVDT (rotary variable differential transformer) and a reductor shaft. The connector includes a body defining a bore configured to receive the reductor shaft. The bore has an inner wall and a threaded tightening member which is substantially parallel to a main axis (AA, BB) of the bore. A portion of the body is configured to deform upon tightening of the tightening member such that, when the reductor shaft is received by the bore, the reductor shaft is gripped by at least a portion of the inner wall.

Abstract: A screw actuator having a screw shaft and a nut arrangement is described herein, the nut arrangement comprising: a primary nut; a first secondary nut having a first thread; a second secondary nut having a second thread; and a first attachment means. The first nut, first secondary nut, and second secondary nut are connected to the first attachment means with a first, initial, axial spacing between the first and second secondary nuts. The first secondary nut is mounted to the first attachment means via bearings that allow the first secondary nut to rotate relative to the first attachment. The first secondary nut is connected to the second secondary nut via a screw thread connection having a pitch lower than a pitch of a screw thread of the screw actuator shaft.

Abstract: An attachment assembly for connecting an actuator to a frame, a method for manufacturing this attachment assembly and a method for reducing backlash in an attachment assembly. The attachment assembly comprises: an outer yoke having a first end and an opposite second end and defining an internal cavity at said second end. The outer yoke has an aperture provided at its second end connected to the cavity; and an inner yoke located within the cavity. A tie bar having a ball shaped end extends through said aperture such that the ball shaped end is positioned within the cavity and cannot pass through the aperture. A spring is provided at said first end of said outer yoke that is configured to bias the inner yoke in the direction of the aperture. The attachment also includes shearable means for holding the inner yoke.

Abstract: An attachment assembly for connecting an actuator to a frame, a method for manufacturing this attachment assembly and a method for reducing backlash in an attachment assembly. The attachment assembly comprises: an outer yoke having a first end and an opposite second end and defining an internal cavity at said second end. The outer yoke has an aperture provided at its second end connected to the cavity; and an inner yoke located within the cavity. A tie bar having a ball shaped end extends through said aperture such that the ball shaped end is positioned within the cavity and cannot pass through the aperture. A spring is provided at said first end of said outer yoke that is configured to bias the inner yoke in the direction of the aperture. The attachment also includes shearable means for holding the inner yoke.

Abstract: A screw actuator having a screw shaft and a nut arrangement is described herein, the nut arrangement comprising: a primary nut; a first secondary nut having a first thread; a second secondary nut having a second thread; and a first attachment means. The first nut, first secondary nut, and second secondary nut are connected to the first attachment means with a first, initial, axial spacing between the first and second secondary nuts. The first secondary nut is mounted to the first attachment means via bearings that allow the first secondary nut to rotate relative to the first attachment. The first secondary nut is connected to the second secondary nut via a screw thread connection having a pitch lower than a pitch of a screw thread of the screw actuator shaft.

Abstract: A lower attachment system for a trimmable horizontal stabiliser actuator comprising: a ballnut for being disposed on a screwshaft of the actuator and forming a part of a primary load path of the lower attachment system; a trunnion connected to the ballnut and forming a part of the primary load path of the lower attachment system; a failsafe plate disposed about the trunnion and forming a part of a secondary load path; a secondary connection connected to the failsafe plate and forming a part of the secondary load path; a sheet plate attached to a first mounting point on the secondary connection and a second mounting point on the ballnut; and an adjustment mechanism provided with the sheet plate for adjusting the size or position of the sheet plate to adapt it to fit a distance between the first and second mounting points.

Abstract: A test apparatus is provided for testing a sensorless check device of an actuator. The sensorless check device is arranged to be used by mechanically moving a check device pin from a resting position to an actuation position and then releasing the check device pin to allow it to return to a resting position urged by an elastic return mechanism. The test apparatus comprises: a piston for contact with an actuator surface associated with the check device pin; a piston spring for urging the piston toward the actuator surface, wherein the piston spring is softer than the elastic return mechanism of the check device; and an adjustment and testing mechanism.

Abstract: A connection for a lower attachment for a trimmable horizontal stabilizer actuator (THSA) for connecting the lower attachment to a flight control surface. The attachment includes: a surface bracket for coupling to the flight control surface, the surface bracket mounted about a gimbal of the lower attachment by a bushing disposed between the gimbal and the surface bracket; a failsafe plate fittingly engaged on a first end of the bushing; and a tightening ring mounted on a second end of the bushing opposite the first end and secured to the surface bracket by at least one contact screw, such that the contact screw is operable to urge the bushing against the failsafe plate.

Abstract: A test apparatus is provided for testing a sensorless check device of an actuator. The sensorless check device is arranged to be used by mechanically moving a check device pin from a resting position to an actuation position and then releasing the check device pin to allow it to return to a resting position urged by an elastic return mechanism. The test apparatus comprises: a piston for contact with an actuator surface associated with the check device pin; a piston spring for urging the piston toward the actuator surface, wherein the piston spring is softer than the elastic return mechanism of the check device; and an adjustment and testing mechanism.

Abstract: A lower attachment system for a trimmable horizontal stabiliser actuator comprising: a ballnut for being disposed on a screwshaft of the actuator and forming a part of a primary load path of the lower attachment system; a trunnion connected to the ballnut and forming a part of the primary load path of the lower attachment system; a failsafe plate disposed about the trunnion and forming a part of a secondary load path; a secondary connection connected to the failsafe plate and forming a part of the secondary load path; a sheet plate attached to a first mounting point on the secondary connection and a second mounting point on the ballnut; and an adjustment mechanism provided with the sheet plate for adjusting the size or position of the sheet plate to adapt it to fit a distance between the first and second mounting points.

Abstract: A connection for a lower attachment for a trimmable horizontal stabiliser actuator (THSA) for connecting the lower attachment to a flight control surface. The attachment includes: a surface bracket for coupling to the flight control surface, the surface bracket mounted about a gimbal of the lower attachment by a bushing disposed between the gimbal and the surface bracket; a failsafe plate fittingly engaged on a first end of the bushing; and a tightening ring mounted on a second end of the bushing opposite the first end and secured to the surface bracket by at least one contact screw, such that the contact screw is operable to urge the bushing against the failsafe plate.