GB213055A - Improvements relating to train control and fog signalling apparatus - Google Patents

Abstract

213,055. Kerr, A. Jan. 31, 1923. Track apparatus actuating signals on trains and for stopping trains.-The brakes and whistles operated by air entering or leaving the brake system are controlled by a venting valve which is opened by the simultaneous opening of a valve tripped by engagement of a traincontact with a fixed track ramp and an electromagnetically controlled valve, the electromagnet of which is energized by current from the same ramp, to hold the valve closed when a clear signal is to be given. The track ramps are set to move the train carried contacts 7, 8 to right or left according to direction of travel, the displacements being greater at home signals than at distant signals. Two contacts are fitted to provide for the locomotive running tender first. At a distant signal the arm 12 is deflected only sufficiently for a cam on the spindle 13 to open the valve 20, the valve 24 being unaffected. Air then passes through the pipe 20<c> to the cylinder 21 and the piston 21a lifts the valve 21b to admit air from the line clear whistle and port 21<c> to the brakepipe connection 5<d>. If the signal is clear, the magnet 6 is energized by current collected by the brush 10 and the contacts 7, 8 from the track ramp and the valve 5 is kept closed. If the signal is at danger, the air from cylinder 21 raises the valves 5, 5<b> and a danger whistle is sounded and the brakes are partially applied. At a stop signal, the valve 24 is also opened by the cam on the spindle 13 and air enters conduit 24<b> by way of the port 20<k>, and, if the signal is at danger, passes through an annular channel 5f to the cylinder 23, the piston of which operates a full bore vent valve 23<b>, which is kept open by a spring detent 23<c> until reset by hand. The magnet 6 may be in the circuit from the brush 10 and contacts 7, 8, or, in order to permit the use of very short ramps, a self-holding relay 32 may be provided. The coil 32 is in series with the brush 10 and the energization of the relay establishes a holding circuit which includes the core 32a and the armature 35 and a contact 45 which is opened on restoration of the piston 21 to normal. The rate of movement of the piston is predetermined by the size of the ports 21<g> in the piston. The trip-operated valves are reset by a spring 20<f>, the operation being retarded by the escape of air, which entered through a non-return valve 20<g>, through a small perforation in a flexible diaphragm 20<d>. When a train runs in reverse direction along the track over a ramp which is intended to apply only to normal running, the arm 12 is moved so that the cam on spindle 13 operates another valve 80 which may be utilized to give a special signal. According to the Provisional Specification the valves used may be similar to the valves described in Specification 121,327.