Patent ID: 6462463
Filing Date: 2002-10-08
Classification: F16D,H02N

Abstract:
An actuator comprising a guide jacket and a piston suitable for moving axially in said jacket, said piston comprising a plurality of successive segments of multilayer piezoelectric material, said-actuator including control means suitable for applying control voltages to said segments to cause the segments to expand in such a manner that they become blocked relative to the guide jacket and to lengthen other segments inside said jacket, these expansions and lengthenings being controlled by said control means in sequences that displace the piston in said jacket, the actuator being characterized in that the control means are suitable for applying a voltage to each of the segments to shorten said segment and block it in the guide jacket and an opposite voltage which releases said segment relative to said jacket and lengthens it therein, these two voltages being applied in succession to said segment during a piston-displacement sequence, each segment thus being used for blocking purposes and for lengthening purposes during such a sequence.