GB192510A - Improvements in automatic train control apparatus - Google Patents

Abstract

192,510. Beaumont, J., and Regan, J. B. Nov. 9, 1921. Track apparatus for stopping trains and actuating signals on trains-A train control system includes a track ramp which may be de-energized, or energized positively or negatively, a polarized relay on the train for controlling the brake valve, two audible indicators actuated according to the condition of the ramp, and two manually controlled switches, one to be operated after a caution indication has been given and both to be operated simultaneously to restore the vehicle apparatus after a stop indication. The ramp A is connected with the signal system or with the track circuits to repeat the indications. The apparatus shown in the Figure above the ramp is on the vehicle, the unlimited speed circuit being shown in full lines. A plunger P is held in its low position by springs or brake pipe pressure and carries contact segments which normally bridge contact brushes 4, 5 and 8, 9. The battery B supplies current through the relay contact 2, contact brushes 4, 5, relay winding R, brushes 8, 9, and relay contact 11 to hold the relay contacts in the position shown, in which contact 19 completes the circuit to the brake coil E so that the brakes are held off. As the plunger rides up the ramp the contacts 14, 15 are made and then the contacts 4, 9 are broken. If the line is clear the ramp is energized frcm the positive side of the signal circuit and the relay is maintained in its normal position. The circuit of the bell 42 is completed through relay contact 40 and earth and gives the audible indication for clear. As the plunger leaves the ramp the normal condition is restored. Where a caution indication is given the ramp is energized negatively so that the current through the coil R is in the opposite direction to that in the last case. The relay contacts then occupy the right hand positions shown in dotted lines. The brakes are applied by the valve ceil E being deenergized by the opening of the contacts 25 and the switch SW, and the whistle W' is sounded. After the plunger leaves the ramp the contacts 25 close, the switch SW is operated by the driver, and the relay is held in its operated position by reason of its own maintaining circuit. The brakes are then taken off while the whistle W' continues to sound. When a stop signal is to be repeated the ramp is not energized at all, This causes the relay to move to its central position. The coils E, E<1> are de-energized, the brakes are applied and both whistles W, W<1> are sounded. The relay can then only be replaced bv simultaneous operation of the switches SW, SW<1> and these mav be so situated that two men are required to perform the operation. The lamps G, Y, R<1> are connected in circuit to give visible indications for clear, caution, and stop respectively. Specification 158,966 is referred to.