Device for setting the rotor of a rotary switch

Claim 1

In a device for setting the rotor of a rotary switch into three possible positions, namely first and second end positions and a center position wherein: drive systems equipped with windings disposed at the stator are actuated to effect this setting, with each drive system being provided with two series-connected windings of which a first winding, if the respective drive system is actuated, rotates the rotor from a momentary one of said end positions into an auxiliary position associated with the center position; a magnetic detent moment curve is active in the auxiliary position and, after the respective drive system has been switched off, centers the rotor in the center position (Pos. 3); and, a respective second winding of each drive system, if the respective drive system is actuated, moves the rotor into the other end position; the improvement wherein: each drive system is actuatable by way of only one conductor pair; the auxiliary position lies closer to the first end position than to the center position; the detent moment curve is configured, by employing an additional permanent magnet on the stator side, so that, in this auxiliary position, after the respective drive system has been switched off, a moment driving in the direction of the center position rotates the rotor into the center position and said rotor is centered there; and each second winding is configured such that it becomes effective if the respective drive system is actuated again and rotates the rotor at least into the vicinity of its second end position.