Automatic electric train control system and apparatus

Claim 1

AN AUTOMATIC ELECTRIC TRAIN OPERATION SYSTEM WHEREIN COMMAND CURRENT SIGNALS ARE PROVIDED FOR THE CONTROL OF THE RUNNING AND BREAKING OF TRAINS, THE SIGNALS EACH HAVING A FREQUENCY DETERMINED BY A CONTROL FUNCTION TO BE PERFORMED THEREBY AND BEING SELECTIVELY APPLIED TO LENGTHS OF RAIL AT PREDETERMINED POINTS ALONG THE TRACK, COIL MEANS CARRIED BY THE TRAIN AND RESPONSIVE TO SIGNALS APPLIED TO THE TRACK, A MULTI-STAGE TRACK SIGNAL COUNTER ARRANGED TO COUNT A PREDETERMINED NUMBER OF THE SIGNALS PICKED UP BY SAID COIL MEANS, A MULTI-STAGE TRAIN SPEED COUNTER ARRANGED TO BE SUPPLIED WITH AND TO COUNT SIGNALS HAVING A FREQUENCY PROPORTIONAL TO THE SPEED OF THE TRAIN, THE COUNTS IN THE TRACK SIGNAL COUNTER AND THE TRAIN SPEED COUNTER BEING INITIATED IN RESPONSE TO THE RECEIPT OF A COMMAND SIGNAL FROM THE TRACK, AND TERMINATED WHEN THE TRACK SIGNAL COUNTER RECEIVES SAID PREDETERMINED NUMBER OF SIGNALS FROM THE TRACK, AND MEANS FOR PRODUCING A SIGNAL INDICATIVE OF THE CONTENT OF THE TRAIN SPEED COUNTER AND THUS OF THE SPEED OF THE TRAIN SUCH THAT A BRAKE APPLICATION OR RELEASE MAY BE MADE ACCORDING TO WHETHER THE SPEED OF THE TRAIN IS IN EXCESS OF OR BELOW A PREDETERMINED ALLOWABLE VALUE.