TODAY’S PATENT – VEHICLE ZERO SPEED DETECTION SYSTEM
This invention “Vehicle zero speed detection system” was invented by Richard S. Rhoton and assigned to Bombardier Transportation Holdings USA Inc, was granted patent on 15th May, 1976 by the USPTO bearing patent grant number US3958783A to the patentee. The current invention pertains to a signal transmitter that sends an oscillating signal to an antenna placed along a vehicle stopping area. To reverse the phase of the magnetic field generated at each transposition in response to the oscillatory signal, the antenna has incremental transpositions throughout its length.
The figure below shows a vehicle zero speed detection and door control system that does away with the requirement of tachometers for zero speed detection. The system only reacts to transmissions from the vehicle stopping area to confirm that the car is inside the zone and has attained the specified zero speed. A vehicle travel path contains a space for stopping vehicles, which could be a platform. When a magnetic field is produced in response to an oscillatory signal, a signal transmitting device like an oscillator feeds the oscillatory signal input to a device that shifts the magnetic field’s phase at predetermined or spaced intervals along the course taken by the vehicle.