Elevator "wild car" system in which one car is always the wild car

Claim 1

AN ELEVATOR CONTROL SYSTEM FOR A GROUP OF ELEVATOR UNIT COMPRISING UP AND DOWN LANDING CALL MEANS AT EACH FLOOR COMMON TO ALL THE ELEVATORS IN THE GROUP, A MAIN CAR SELECTING MEANS OPERABLE WHEN ALL THE ELEVATOR UNITS ARE STANDING AT THE MAIN PARKING FLOOR TO SELECT ONE OF THE ELEVATOR UNITS AS A MAIN CAR TO RESPOND TO ANY LANDING CALL AND AFTER OPERATION TO REMAIN AT THE LAST FLOOR CALLED AND TO RESPOND TO ANY SUBSEQUENT LANDING CALL, AND LANDING CALL DIRECTION SELECTING MEANS OPERATIVELY INTERCOUPLED WITH SAID LANDING CALL MEANS AND SAID MAIN CAR SELECING MEANS AND OPERABLE IN CONJUNCTION WITH SAID MAIN CAR SELECTING MEANS IN A MANNER SUCH THAT ALL CARS OTHER THAN THE MAIN ONE ARE MADE NON-RESPONSIVE TO ANY LANDING CALL REQUESTING A SERVICE IN THE SAME DIRECTION AS THAT OF TRAVEL OF THE MAIN CAR IN OPERATION AND, MEANS FOR RENDERING ONE OF THE CARS OTHER THAN THE MAIN ONE RESPONSIVE IN CASE THE MAIN CAR REMAINS NOT RESPONSIVE TO THE LANDING CALL AFTER A PREDETERMINED TIME SETTING HAS EXPIRED, SAID LANDING CALL DIRECTION SELECTING MEANS FURTHER INCLUDING MEANS FOR RENDERING ONE OF THE CARS OTHER THAN THE MAIN ONE RESPONSIVE TO ANY LANDING CALL REQUESTING A SERVICE IN A DIRECTION OPPOSITE TO THAT OF TRAVEL OF THE MAIN CAR IN OPERATION, AND MEANS FOR STOPPING SAID MAIN CAR AT THE NEAREST LANDING UPON ANOTHER UNIT BEING PLACED IN OPERATION IN RESPONSE TO A LANDING CALL REQUESTING A SERVICE IN A DIRECTION OPPOSITE TO THAT OF TRAVEL OF THE MAIN CAR UNDER CIRCUMSTANCES WHERE THE MAIN CAR, CAR CALL MEANS HAVE NOT BEEN ACTUATED AND THE LANDING CALL IS ANSWERED BY ANOTHER UNIT.