Patent GB-190915099-A (GB)
Title: Improvements in Automatic Block Systems for Railways.
Inventor: PRICE HAROLD WILBERFORCE
IPC: B61L3/22
Filed: 1909-06-28
Granted: 1910-01-20
Abstract: 15,099. Price, H. W. June 28. Electrical systems, automatic; single-track systems. -In an automatic electric system for single or double tracks using track-rails divided by insulating joints into block lengths and having short rail sections between the blocks, a circuit on the engine is broken as the collecting-wheels of a train pass out of a section on to the short rail if there is another train less than three block sections ahead ; the circuit on the engine is also broken if the insulation of a rail joint breaks down. The engine circuit controls the brakes. The drawings show five complete block sections Q, R, S, T, U, with the relay arrangements at the ends of such blocks A, B, C, D, E, F. The rails are divided into blocks by insulating pieces insulating short lengths 5, 6 in opposite rails from the longer lengths 7, 8, across which batteries 10 are connected to normally energize the track relays a. The long sections of rail 7 are connected by jumpers 9 so as to form a continuous return conductor for the batteries 32 supplying the line relays b, c, d ; the relays b, d control two armatures each, which are arranged so that one armature of each magnet bridges the insulating blocks at the section junctions and serves to maintain a continuous conductor at that point. The other armatures connect the line battery 30 to the relay d of the junction to the left, which is deenergized if both contacts 22, 26 are broken or if the contact 18 of the relay a is broken. A train on section Q short-circuits the relay a at B, thus opening contacts 14, 16, 18. Contact 14 breaks the circuit of the relay b at B through the armature 20 at B, lead 42, armature 16 of section to the left, and battery 32 at the junction to the left of A ; the contact 16 at B breaks the circuit from battery 32 at B to lead 41, relay c at C, and on by lead 42 to the relay b at D. The contact 18 at B breaks the circuit of relay d at A. Thus one contact 28 is broken at A and the contact 24 is broken at B, C, D. A train K in section T, that is less than three clear sections away from Q, will similarly open the contact 8 at D and contacts 22 at E, F, &c. Contacts 22, 28 being simultaneously open at D, a train passing that junction will be stopped by the opening of the circuit through the magnet 52. The other armature 22, 26 of the magnets b, d, at D being simultaneously open, the circuit from the battery 32 at D through the contact 18 of the relay a at D and the line wire 40 to the magnet d at C is broken, and that magnet drops its armatures; and the relay b at C being also de-energized by a train in section Q, the circuit to re'ay d at B is broken and that magnet is also de-energized. Thus either train in sections Q, T will be stopped as it passes the points B or D according to the direction of motion. If the insulation of the joints 1, 2 fails, the battery 32 is short-circuited through contacts 24, lead 30, and rail 5, and thence either by defective joint 1 to rail 7 or by defective joint 2 and jumper 9 to rail 7. If the joints 3, 4 fail, the voltage of the battery 32 is reduced to that of the track battery 10. The battery 32 has high resistance, or a resistance 31 may be used. In either case, the relays b, c, d will be de-energized and 'danger' indicated on the engine.