Patent ID: 7119478

Claim:
A step-motion actuator comprising: a plurality of teeth; a movable drive pawl positioned so as to engage one or more of the teeth in a forward direction; a piezoelectric element adapted to convert electrical energy into kinetic energy in the form of movement of the drive pawl, causing the drive pawl to drive against the one or more teeth to accomplish a step-motion in the forward direction; a compression frame secured about the piezoelectric element and adapted to pre-compress the piezoelectric element so as to reduce tensile loads thereon; and a mass secured to an arm, wherein the mass is spring-biased toward the compression frame and the piezoelectric element such that the piezoelectric element converts electrical energy into kinetic energy in the form of movement of the mass and the arm, wherein the drive pawl is coupled with the arm such that movement of the mass and the arm causes movement of the drive pawl.