US 4,932,210 A · Shape memory metal precision actuator

Abstract

A shape memory metal actuator for accurately pointing or aligning a moveable piece of equipment or other object. The memory metal components (12, 14, 16, 18) are stretched along their axes and arranged in a push-pull configuration so that one element (14) in the activated state moves the object while another element (18) on the opposite side of the object is strained while it is in the soft state to act as a dynamic damper to prevent overtravel of the object. The wires can be heated with external heaters or by electrical current passed directly therethrough. Two separate actuator assemblies using orthogonal pairs of shaped memory metal wires (42, 44, 46, 48 and 52, 54, 56, 58) are used to enable pivotal movement about a floating pivot point 41, while a cantilevered arrangement of Nitinol bars (88, 90, 92 and 94) are used to enable pivotal movement about a fixed flexure point F.

Claims24

Dependent claims

An actuator comprising:

a pair of wires made of shape memory metal, each of said wires being stretched along its longitudinal axis from a memory length to an intermediate length, each of said wires recovering to said memory length when heated to a predetermined activation temperature, one end of each wire being fixed to a support structure, the other end of each wire being attached to an object to be moved, said wires supporting the object from said support structure, said wires being attached at different points on said object to develop opposing forces on the object when either one of the wires is heated to said activation temperature;
and
means for heating one of said wires to said activation temperature.

Dependencies are inferred from the claim text.

Shape memory metal precision actuator

Life of this patent

Shape memory metal precision actuator

Life of this patent

Abstract

Claims24