Patent ID: 6851648

Claim:
Ball screw actuator for aircraft control surfaces, comprising: a lead screw having a thread; motor means to set the screw in rotation about its own longitudinal axis; a primary body connected to a control surface and engaged on the lead screw by means of a plurality of balls movable on the thread of said screw; a secondary body connected to the primary body and having an auxiliary portion provided with an engagement surface facing the thread of the control screw at a predetermined distance; the engagement surface being shaped to engage the thread of said lead screw; wherein it further comprises means for de-coupling the secondary body from the auxiliary portion in the rotation motion about the longitudinal axis radially interposed between said secondary body and said auxiliary portion; with the secondary body de-coupled from the auxiliary portion, said auxiliary portion being free to rotate together with the screw with respect to the secondary body upon any rotation of the screw.