LEVER ACTUATOR COMPRISING A LONGITUDINAL-EFFECT ELECTROEXPANSIVE TRANSDUCER AND DESIGNED TO PREVENT ACTUATION FROM DEGRADING THE ACTUATOR

摘要

A lever actuator which may be used in an impact printer is described. As in conventional actuators of this type an elongated electroexpansive transducer block made of a piezoelectric or electrostrictive material is connected between a base portion and a lever portion of a frame. A power source is connected to the block to produce a reversible strain in the block thereby tending to displace the two end surfaces of the block relative to each other. In the conventional arrangement the block bends which degrades the block. In the invention, the block is connected to the lever portion through a bendable plate and to the base portion through another bendable plate. Bending takes place in these plates rather than the block when the block is energized thus avoiding the degradation problem.