Patent ID: 7709995

Claim:
A linear motion actuator comprising: a housing having a cavity; a actuator shaft has a first end that is received in an opening formed in the housing, the actuator shaft may be in a ready position in which the actuator shaft is partially retracted within the housing and the actuator shaft may be placed in an actuated position in which the actuator shaft is extended from the housing to a greater extent than when the actuator shaft is in the ready position; a spring attached to the actuator shaft that exerts a biasing force on the actuator shaft to bias the actuator shaft toward the actuated position; a latching ring is disposed within the housing and receives the first end of the actuator shaft in an opening formed in the latching ring, the latching ring having a locking element that holds the actuator shaft within the latching ring when in the ready position, the locking element being selectively released by rotating the latching ring; a shape memory alloy link anchored to the housing and extending a first length partially around the latching ring and being secured to the latching ring, the link being shortened to a second length that is shorter than the first length when a current is applied to the link, wherein the link rotates the latching ring when shortened and causes the locking element to be released.