Electromagnetic indicator device having magnetic rotor positioned by peripheral electromagnets

Claim 1

IN AN ELECTROMAGNETIC INDICATOR DEVICE FOR DISPLAYING A PLURALITY OF DISCRETE INDICIA IN RESPONSE TO ELECTRICAL ENERGIZATION, SAID INDICATOR DEVICE BEING OF A TYPE INCLUDING A PERMANENT MAGNET ROTOR SUPPORTED FOR DEFLECTION ABOUT AN AXIS OF ROTATION THEREOF TO A PLURALITY OF DISCRETE ANGULARLY SPACED POSITIONS, AT LEAST ONE MAIN ELECTROMAGNETIC COIL, AND THE MAIN COIL BEING MOUNTED AT ONE SIDE OF SAID AXIS OF ROTATION WITH AN AXIS OF THE COIL EXTENDING RADIALLY IN A DIRECTION SUBSTANTIALLY PERPENDICULAR TO THE AXIS OF ROTATION OF SAID ROTOR, THE IMPROVEMENT COMPRISING A MAGNETIC SHUNTING MEMBER MOUNTED ON SAID PERMANENT MAGNET ROTOR AND HAVING AN AXIS EXTENDING IN AN ANGULAR RELATION TO A MAGNETIC AXIS OF SAID ROTOR OF LESS THAN NINETY DEGREES SO THAT UPON SELECTIVE ENERGIZATION OF SAID MAIN COIL WITH ELECTRICAL SIGNALS OF EITHER OF TWO OPPOSED POLARITIES ANGULAR MOVEMENT OF SAID PERMANENT MAGNET ROTOR ABOUT THE AXIS OF ROTATON THEREOF MAY BE EFFECTED FROM A FIRST POSITION TO A SECOND POSITION, SAID MAGNETIC SHUNTING MEMBER PROVIDING A PATH FOR MAGNETIC FLUX RESULTING FROM ENERGIZATION OF THE MAIN COIL, THEREBY PRODUCING A TURNING MOMENT SO AS TO PREVENT A CONDITION OF UNSTABLE EQUILIBRIUM IN SAID ROTOR WHEN IT IS DESIRED TO ANGULARLY