Floor selector for an elevator control system

Claim 1

IN A FLOOR SELECTOR FOR CONTROLLING OPERATION OF AN ELEVATOR CAR SERVING A PLURALITY OF FLOORS OF A BUILDING STRUCTURE, A CARRIAGE, A SUPPORTING STRUCTURE HAVING ONLY A SINGLE GUIDE RAIL FOR GUIDING SAID CARRIAGE ALONG A PREDETERMINED PATH, A PLURALITY OF FLOOR UNITS SPACED IN THE DIRECTION OF SAID PATH AND SECURED TO SAID RAIL, ROLLER MEANS MOUNTING SAID CARRIAGE ON SAID RAIL FOR MOVEMENT RELATIVE TO SAID SUPPORTING STRUCTURE ALONG SAID PATH, SAID ROLLER MEANS COMPRISING A FIRST AND A SECOND ROLLER SPACED IN THE DIRECTION OF SAID PATH AND ENGAGING A FIRST SIDE OF SAID RAIL, SAID ROLLER MEANS ALSO INCLUDING A THIRD ROLLER ENGAGING A SECOND SIDE OF SAID RAIL OPPOSITE SAID FIRST SIDE, MEANS MOUNTING SAID FIRST, SECOND AND THIRD ROLLERS ON SAID CARRIAGE FOR ROTATION RELATIVE TO SAID CARRIAGE AND TO SAID RAIL ABOUT SPACED PARALLEL RESPECTIVE FIRST, SECOND AND THIRD AXES, SAID THIRD AXIS BEING DISPOSED ON A FIRST LINE DRAWN FROM SAID THIRD AXIS TO A SECOND LINE TRANSVERSE TO SAID FIRST LINE AND EXTENDING BETWEEN AND TRANSVERSE TO SAID FIRST AND SECOND AXES, MEANS BIASING SAID THIRD ROLLER TOWARD SAID FIRST AND SECOND ROLLERS, AND TRANSLATING MEANS HAVING A FIRST COMPONENT ON EACH OF SAID FLOOR UNITS AND A SECOND COMPONENT ON SAID CARRIAGE, SAID TRANSLATING MEANS BEING RESPONSIVE UNDER PREDETERMINED CONDITIONS TO A PREDETERMINED POSITION OF SAID CARRIAGE RELATIVE TO EACH OF SAID FLOOR UNITS.