Transformer control switch

Claim 1

IN A TAP SELECTOR SWITCH FOR CONTROLLING THE OUTPUT VOLTAGE OF A THREE-PHASE TRANSFORMER INCLUDING THREE PHASE SWITCHES EACH COMPRISING A SERIES OF FIXED TAP CONTACTS, A COMMON CONTACT, AND MEANS FOR PROGRESSIVELY CONNECTING THE COMMON CONTACT WITH ONE OF SAID FIXED TAP CONTACTS OF SAID SERIES OF FIXED TAP CONTACTS, THE IMPROVEMENT COMPRISING A Y AND DELTA SWITCHING MECHANISM MECHANICALLY CONNECTED TO THE PHASE SWITCHES AND OPERABLE WHEN ALL OF OF THE COMMON CONTACTS HAVE SUCCESSIVELY ADVANCED THROUGH ALL OF THE RESPECTIVE FIXED TAP CONTACTS OF EACH OF THE SERIES OF FIXED TAP CONTACTS, SAID SWITCHING MECHANISM COMPRISING THREE PAIRS OF FISED CONTACTS EACH PAIR COMPRISING A Y CONTACT AND A DELTA CONTACT, THREE MOVABLE CONTACTS EACH DISPOSED ADJACNET TO ONE OF SAID PAIRS OF FIXED CONTACTS, AND ALTERNATELY CONNECTABLE WITH SAID Y CONTACT AND SAID DELTA CONTACT OF SAID ADJACENT PAIR OF FIXED CONTACTS, AND MEANS FOR SIMULTANEOUSLY MOVING SAID MOVABLE CONTACTS FROM CONNECTION WITH SAID RESPECTIVE Y CONTACTS TO CONNECTION WITH SAID RESPECTIVE DELTA CONTACTS VICE VERSA.