Induction motor control with plural wound rotors which are axially relatively movable for torque control

Claim 1

IN AN A.C. MOTOR THE COMBINATION COMPRISING A SOURCE OF A.C. CURRENT, A FRAME, FIRST AND SECOND STATORS ARRANGED SIDE BY SIDE IN SAID FRAME AND HAVING SUBSTANTIALLY IDENTICAL WINDINGS THEREON FOR SETTING UP SEPARATE ROTATING FIELDS, A ROTOR ROTATABLY MOUNTING IN SAID FRAME FOR COOPERATION WITH THE STATORS AND HAVING A SINGLE SET OF WINDINGS THEREON WITH VOLTAGES BEING INDUCED IN SEPARATE PORTIONS THEREOF BY THE STATOR FIELDS, SAID STATORS BOTH BEING RELATIVELY MOVABLE IN SAID FRAME BETWEEN A NULL PHASE RELATION IN WHICH THE INDUCED VOLTAGES CANCEL FOR PRODUCTION OF SUBSTANTIALLY ZERO TORQUE AND OFFSET POSITIONS ON EACH SIDE OF THE NULL PHASE RELATION FOR PRODUCTION OF PROGRESSIVELY INCREASED TORQUE, A DIFFERENTIAL LINKAGE FOR INTERCONNECTING THE STATORS AND THE FRAME SO THAT THE STATORS ARE CONSTRAINED TO MOVE EQUALLY IN OPPOSITE DIRECTIONS FROM THE NULL PHASE RELATION, A CONTROL MEMBER COUPLED TO SAID LINKAGE SO THAT THE OUTPUT