The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 08, 2002
Filed:
Jan. 18, 2002
Jean-Thierry Audren, Saint-Rémy-lès-Chevreuse, FR;
Sagem S.A., Paris, FR;
Abstract
The invention concerns an actuator comprising a sliding sleeve ( ) and a piston ( ) axially mobile in said sleeve, said piston comprising a plurality of piezoelectric sections made of multilayer material, control means for applying on said sections control voltages for expanding said sections so that they are locked relative to the sliding sleeve and extend other sections inside said sleeve, said expansions and extensions being controlled by said control means according to the sequences moving the piston in said sleeve. The invention is characterised in that the control means are capable of applying to each of the sections a voltage which shortens said section and locks it in the sliding sleeve and an inverse voltage which releases said section relative to said sleeve and extends it therein, one and the other of said voltages being applied successively to said section during a sequence displacing the piston, each section being thus used both for locking and extending during such a sequence.