Code rate

Claim 1

A SYSTEM FOR CONTROLLING VEHICLE TRAFFIC IN ONE DIRECTION ALONG A STRETCH OF RAILWAY TRACK DIVIDED BY INSULATED RAIL JOINTS INTO SUCCESSIVE TRACK SECTIONS, EACH SECTION HAVING A LENGTH AT LEAST AS GREAT AS THE BRAKING DISTANCE REQUIRED TO STOP A VEHICLE TRAVELLING AT A PREDETERMINED MAXIMUM SPEED COMPRISING, (A) MEANS FOR ENERGIZING THE TRACK RAILS INCLUDING A PLURALITY OF DISTINCTIVE HIGH FREQUENCY TRANSMITTERS CONNECTED TO THE TRACK RAILS OF EACH SECTION AT SUBSTANTIALLY EVENLY SPACED INTERVALS RESPECTIVELY, (B) SAID ENERGIZING MEANS BEING NORMALLY EFFECTIVE TO ENERGIZE THE TRACK RAILS BY THE TRANSMITTERS FOR THE ASSOCIATED TRACK SECTIONS ONLY, (C) MEANS RESPONSIVE TO THE PRESENCE OF A FIRST VEHICLE IN ONE OF THE TRACK SECTIONS FOR BY-PASSING THE INSULATED JOINTS SEPARATING THE NEXT TRACK SECTION IN THE REAR TO PERMIT THE ENERGIZATION OF THE TRACK RAILS IN SAID SECTION IN THE REAR BY FREQUENCIES TRANSMITTED THROUGH THE TRACK RAILS OF SAID ONE TRACK SECTION, AND (D) RECEIVING MEANS ON THE LEADING END OF EACH VEHICLE EFFECTIVE TO PICKUP EACH OF THE DIFFERENT FREQUENCY SIGNALS BEING APPLIED TO THE TRACK RAILS AHEAD OF THE VEHICLE, WHEREBY A FOLLOWING OR SECOND VEHICLE OPERATING IN SAID NEXT TRACK SECTION IN THE REAR OF SAID FIRST VEHICLE RECEIVES A PLURALITY OF DIFFERENT FREQUENCY SIGNALS, THE NUMBER OF WHICH IS INDICATIVE OF THE SPACE BETWEEN THE LEADING END OF THE FOLLOWING VEHICLE AND THE TRAILING END OF THE FIRST VEHICLE.