GB183969A - Improvements in means for stopping trains independently of drivers - Google Patents

Abstract

183,969. Shepherd, B. May 27, 1921. Electrical systems, automatic; track apparatus for stopping trains.-In a system for stopping trains automatically, at least, one track rail has insulated sections; the circuits of train stop coils or signal coils are controlled by the presence of trains on sections ahead or behind the coils to prevent trains from meeting or overtaking others. As shown in Fig. 1, both track rails are in sections, the sections of rail A being connected to one side of the electric supply, the other side of the supply being connected to treadle contacts. The treadle b is connected to train stop coils and thence to a distant section of the rail A<1>. When a train enters the first section, the treadle is depressed but the coil circuits are not complete unless a train is on the distant section. The coils T then raise stops to actuate valves on the engine to apply brakes. In a modification, the coils T operate signals, or each circuit may include one train stop coil and one signal coil. The treadle may be discarded and two coils used on each piece of apparatus so arranged that both must be de-energized to allow the apparatus to operate. In the arrangement shown in Fig. 4, only one rail is in sections and a battery is connected to each section. The signal coils S and train stop coils T are normally energized, but when a train enters a section the coils, two sections ahead and two sections behind, are de-energized, thus preventing another train from meeting or overtaking it. Solenoids may be used to cause lamps to show red or green lights. In another modification, relays are connected across the track rails and connect a high voltage to the train stop coils.