Safety process and apparatus for railway services

Claim 1

IN A SAFETY AUTOMATIC TRAIN CONTROL SYSTEM COMPRISING BOTH BEACONS AND FEEDER MEANS FOR TRANSMITTING INFORMATION FROM THE TRACK TO HE TRAIN IN THE FORM OF MODULATIONS IMPOSED UPON CARRIER FREQUENCIES, THE IMPROVEMENT WHICH COMPRISES MEANS FOR AUTOMATICALLY ADAPTING THE VEHICLE EQUIPMENT TO THE CORRECT RECEPTION OF SAID INFORMATION REGARDLESS OF WHETHER IT IS TRANSMITTED BY SAID FEEDER MEANS OR BY SUCCESSIVE BEACONS, SAID ADAPTING MEAN COMPRISING MEANS IN THE TRACK INSTALLATIONS FOR CAUSING AN ADDITIONAL MODULATION OF AT LEAST ONE OF SAID CARRIER FREQUENCIES, TWO BEACONS AT THE TRANSITION POINTS OF THE TRACK WHERE THE BEHICLE PASSES FROM A SECTION WITH INFORMATION BY FEEDER TO A SECTION WITH INFORMATION BY BEACONS, ONE OF SAID TWO BEACONS BEING LOCATED ON THE SIDE OF THE TRACK SECTION CORRESPONDING TO BEACON INFORMATION AND TRANSMITTING THE SAID AT LEAST ONE CARRIER FREQUENCY WITH SAID ADDITIONAL MODULATION, WHILE THE OTHER OF SAID TWO BEACONS IS LOCATED ON THE SIDE OF THE TRACK SECTION CORRESPONDING TO CONTINUOUS FEEDER INFORMATION AND TRANSMITS THE SAME CARRIER FREQUENCY WITHOUT SAID ADDITIONAL MODULATION, A RECEIVING AMPLIFIER ON THE VEHICLE FOR ONE CARRIER FREQUENCY, A FILTER CIRCUIT FOR PASSING SAID ADDITIONAL MODULATION THROUGH SAID AMPLIFIER, MEANS FOR STORING INFORMATION RECEIVED THROUGH SAID RECEIVING AMPLIFIER AND RELAY MEANS CONNECTED TO SAID FILTER-CIRCUIT AND FED BY THE CURRENT