Busy track safety system - has frequency-sensitive decoders with outputs fed to AND=gates to ensure spacing of vehicles within limits

摘要

The system is required for short distance traffic services where vehicles can travel between two destinations, but overtaking is impossible without causing complete breakdown. A number of control signals are gathered together along the track from the signal conductor, which can be a slotted guide working in conjunction with antennae on the vehicles. These signals are led to a central system which contains a receiver and decoding devices which are frequency sensitive. The outputs from the decoders are fed to and gates and thence to a transmitter which provides all vehicles with a coded permission-to-travel signal, thence to a receiver which lifts the brake of the relevant vehicle.