Patent GB-190312769-A (GB)
Title: Improvements in Safety Appliances for Railways.
Inventor: BERGMANN CHARLES
Filed: 1903-06-06
Granted: 1903-07-16
Abstract: 12,769. Bergmann, C. June 6. Stopping engines and trains; signalling between trains; indicating condition of bridges and permanent way lamp sagnals.-The air brakes of railway trains are applied automatically in the event of danger, either on account of another train being too near in front or on account of a disturbance of the safe condition of the permanent way. Signals on the engine are operated automatically at the same time. The apparatus is adapted to work in connection with electric circuits on the rails, as usually employed in the automatic block system of railways, and will work whether the system adopted for wiring the rails be the open-circuit or the closed-circuit system or both. Fig. 4 shows a section of the principal parts of the apparatus on the engine for applying the brakes and operating the signal. With the opencircuit of wiring, when an engine attempts to enter a block or section from the other end of which a preceding train is just de. parting, a current from the line battery passes through an electromagnet 34. The armature 43, being attracted, moves a plunger valve 45, which will then admit air from the main reservoir of the brake system through a lateral port in the casing 32 into an axial passage 46 in the valve. From this passage, a part of the air passes into a cylinder 25 and operates a piston 26, which opens a valve to apply the brakes ; another part passes upwards to a cylinder 56 and moves a piston, which raises a signal. The signal preferably consists of two coloured lenses fitted in a frame and adapted to be moved in front of a lamp at night. The brakeapplying piston 26 moves a plunger valve 15, so that a groove 20 in it opens a communication between the atmosphere, through the exhaust port 22, and the engineer's valve, through the pipe 9. The train-pipe air thus escapes, and the brakes are applied. At the same time, the plunger valve 15 closes communication between the engineer's valve and the main reservoir, which is connected with the pipe 10. The engineer, therefore, cannot release the brakes. The train-pipe air, in escaping, sounds a whistle 22<a> or other alarm. Before the brakes can be released, the engineer must break the electric circuit through the magnet by means of a switch ; all the parts of the apparatus will then be returned to their original positions by springs. The air in the cylinder 25, in escaping to the atmosphere through a port 48, sounds whistle 52. Where the closed-circuit system of wiring the rails is adopted, a current from the line battery passes normally through the frame of the engine and through a second electromagnet 76, Fig. 6, on the engine. The armature 79, thus attracted, holds the contacts 87, 88 away from the contact points 89, 89<a> and against stops 90, 90<a>. If there is a disturbance on the permanent way, such as a broken bridge or open points, which would cause an interruption of the circuit, the magnet 76 ceases to attract its armature, which is then moved by springs so as to bring the contacts 87, 88 up to the contact points 89, 89<a> ; a current from a battery on the engine will then pass through the magnet 34, Fig. 4, and operate the apparatus as described above. To allow of the release of the brakes in this case, the engineer is provided with a speciallyconstructed switch.