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:
Feb. 17, 1998
Filed:
Dec. 18, 1995
Christian Peclat, Neuchatel, CH;
Kaspar Trumpy, Soleure, CH;
Eta Fabriques d'Ebauches, Grenchen, CH;
Abstract
Along the inner lying rotor trailing surface (21) of an annular rotor (20) are successively provided regions (26a-c) of small wall thicknesses (29) and regions (25a-c) of larger wall thicknesses, which differ with respect to the acoustic impedance spectrum. During the state of operation, i.e. when the rotor (20) turns, the mentioned regions (24a-c; 25a-c) are excited alternately by the piezoelectric excitor (15) of the stator (13). The acoustic impedance spectrum which changes periodically, influences the electrical impedance spectrum of the motor (10) in an analog manner. These changes are measured via the voltage supply connections of the motor (10) and are interpreted as relative positional changes between the stator (13) and the rotor (20).