Abstract: A servo-control system for actuating an aircraft flight control member, the system including at least one hydraulic actuator together with actuation means for actuating said actuator, said hydraulic actuator being duplicated, said actuation means including first and second actuation assemblies each comprising two hydraulic circuits each controlled by a respective mechanically-controlled distributor valve, the two distributor valves of the same actuation assembly being actuated by common mechanical elements caused to move by motor means, the actuation means including control means controlling said motor means as a function of the position of the flight control member and of piloting orders received by the control means, detection means for detecting failures, and a selector valve which controls switching of the actuation assemblies between an active state and a reserve state.

Abstract: A suspension system for vehicles includes an arm that can oscillate relative to a support. The arm has an angular position of equilibrium relative to the support. Rotation of the arm is damped by a system comprising two complementary friction brake members, one fastened to the arm and the other to the support. The complementary brake members are pressed together to impede such rotation. The force with which the brake members are pressed together is conditioned according to the speed of rotation of the arm relative to the support. The damping curve may therefore be of any required shape, and in particular procure a constant damping force from a predetermined threshold of the speed of rotation of the arm relative to the support. This considerably simplifies dealing with heating problems arising from the damper action.

Abstract: A suspension unit for vehicles comprises a support fastened to a framework of the vehicle and a longitudinal arm, with a rolling member coupled to the arm, rotating relative to it about a transverse first axis. The arm is coupled to the support and rotates relative to it about a transverse second axis which is parallel to the first axis and offset relative to it in the longitudinal direction. Within the arm is a longitudinal cylinder within which slides a piston. A rod is coupled to the piston and to the support. The rod rotates relative to the support about a third axis parallel to the second axis and offset relative to it transversely. The rod rotates relative to the piston about a transverse fourth axis parallel to the third axis. It is pivoted to the piston by a mechanism comprising a slide member that slides longitudinally within the cylinder and is juxtaposed longitudinally to the piston on the same side as the rod. The rod is pivoted to the slide member for rotation about the fourth axis.