Locking device for preventing a rotation and/or an axial movement of a pin, including shape memory releasing means

A locking device for preventing the rotation and/or the axial movement of a pin, including at least a coil spring wound around a portion of said pin and having one end rigidly connected to a support structure, said spring having, in its undeformed condition, an internal diameter smaller than the diameter of said pin, whereby in a resting condition the spring is tightened around said pin to prevent a rotation thereof at least in one direction and/or an axial movement in any direction, wherein means are provided for causing an unwinding of the turns of the spring for enabling a rotation and/or an axial movement of the pin;

• wherein said means for causing the unwinding of the turns of the spring are shape memory actuating means:
• and
• wherein said shape memory means comprises a shape memory wire arranged through an axial cavity of the pin and having one end connected to the pin and the opposite end connected to a slidable actuating element for causing a loosening of the turns of said coil spring as a result of a reduction in length of said shape memory wire caused by the overcoming of the transition temperature of the shape memory material forming the wire.