GB530080A - Improvements in signalling devices for use on railroads - Google Patents

Abstract

530,080. Signalling on trains. GREEN, H., and FROST, J. F. June 16, 1939. No. 17574. [Class 105] A signal showing whether a track section is clear or occupied is given in the cab by means of a wiper 31 on the train co-operating with track switch devices 1, 2 at the entrance and exit ends of the section respectively. Both devices are spring supported and are depressed by the wiper. The wiper is rotatably mounted so that it may be set for the engine working backward or forward, and carries insulated contacts 15, 16, 17. When the train enter an unoccupied section a contact bar 3 of device 1 bridges contacts 15, 16 to close the circuit of an electromagnet 19, the pivoted armature 20 being thereby attracted to close contacts 21 in the circuit of a green signal lamp 23. The contacts 21 remain closed after magnet 19 is de-energized until arm 20 is operated. Bar 3 is connected to the core 5 of a solenoid and is depressed by the wiper to close contacts 7, 8 in the solenoid circuit whereby the bar is further depressed and held out of the path of the wiper on a following train. When the train leaves the section a contact bar 11 of device 2 is depressed and opens contacts 13, 14 in the solenoid circuit to restore device 1 to normal position. At the same time bar 11 bridges contacts 16, 17 to close the circuit of an electromagnet 25 whereby armature 20 is attracted to break contacts 21 and close contacts 26 in the circuit of a red lamp 27. A train normally enters a section with red lamp 27 lit, and if the entered section is occupied device 1 has been made inoperative by the preceding train so that the red indication is not changed. To warn the driver that a track device is about to be passed a train contact moves over a series of fixed track contacts 28 to close intermittently the circuit of a warning lamp 30.