Patent ID: 8443600

Claim:
An actuator employing elements made of a shape memory alloy comprising: a first element made of a shape memory alloy capable of modifying its shape upon heating, having a stationary first end and a second end linked to a controlled mechanical part; heating means for heating said first element made of a shape memory alloy; bias means for allowing return of said first element to its original shape during cooling, the bias means having a first end connected to the second end of said first element and a second end connected to an inner restraint of the actuator; and moving means capable of moving said inner restraint of the actuator to increase a load applied onto said bias means when external temperature exceeds a value M 1 of complete transformation into a martensitic phase of said first element made of shape memory alloy, wherein said moving means capable of moving said inner restraint of the actuator is such to autonomously react to an increase of the external temperature.