EUROPEAN PATENT: An actuator device based on a shape memory alloy, and a wing flap assembly fitted with such an actuator device

The present invention refers to an actuator device and a wing-flap assembly. As it is known, the increase in lift required for the take-off and landing phases of an aircraft is mainly obtained through the deflection of a wing-flap around a hinging axis. Such a solution implies the presence of robust control lines and complex actuation devices which significantly contribute to the weight of the whole wing structure. From an aerodynamic point of view, the local modification of the curvature of the wing profile induced by a conventional flap is limited by the excursion range of the flap itself; for this reason only the profile curvatures compatible with the finite number of deflection angles of the mobile surface can be used in operating conditions. The purpose of the present invention is that of providing a wing-flap assembly which allows the weights as well as the operating and maintenance costs to be reduced with respect to conventional wing-flap technology, as well as allowing an optimization of the aerodynamic performances of the lift devices to be obtained. According to the invention the wing-flap is able to dynamically modify its own curvature (morphing flap) according to specific design requirements. The flap is controlled through one or more actuator devices based upon shape memory alloy, which enormously reduces the total weight of the group and makes the control system simpler to manufacture.