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:
Jan. 31, 1978
Filed:
May. 14, 1976
Claude Edmond Lombard, Boulogne-Billancourt, FR;
Jean-Marie Bouvet, Boulogne-Billancourt, FR;
Regie Nationale des Usines Renault, Boulogne-Billancourt, FR;
Abstract
Electromagnetic actuator, especially for actuating a hydraulic servo-control valve, which comprises a magnetic shell constituting a body of revolution and a concentric armature-forming permanent magnet, at least one annular field coil, the field coil and the armature being adapted to move axially in relation to each other. The movable member (field coil or armature) is caused to move by the resultant electromagnetic force resulting from the energization of the field coil to which a control direct current is applied and by the antagonistic force of a repulsion member incorporated in the magnetic shell. The field coil is longer than the armature so that the electromagnetic force is independent of the movement of the movable member and proportional to the control direct current. The movable member is caused to perform simultaneously a cyclic motion superposed to the axial movement in order to eliminate the friction hysteresis of the hydraulic valve.