Thermally actuated devices

摘要

A thermally actuated device comprising a shape memory alloy which has an improved temperature response. The shape memory alloy is combined with a bias load to provide a two-way action and the temperature-deflection relationship at an operating temperature range is such that the shear strain of the shape memory alloy corresponding to the point of transit from a first shape recovery process to a second shape recovery process resulting from the heating is smaller than that corresponding to the point of termination of a first strain induced process by the counteracting bias load resulting from the cooling. The difference between said two sheer strains is restricted to the range of operating strain of the shape memory alloy.