Improvements in Automatic Block Signals for Railways for Absolute or Permissive Working.

摘要

11,801. Salmon, W. W., and Dodgson, F. L. May 13. Electrical systems, automatic.-Signals indicating ' danger,' ' caution,' and ' clear ' are set differently for a second train according to the direction in which a first train enters the section. Two two-position signals or one threeposition signal may be used; or, if it is desired to indicate more particularly the position in the section of the first train, a two-position and a three-position signal may be used in combination. Fig. 1 shows the first-mentioned arrangement. The system is a normal danger one; signal 6, at clear, indicates that the sections 2, 3 are clear; signal 5, if put to clear by a train entering at the end a, indicates that a train is on sections 2, 3 moving from a to b. Both signals at danger, when a train on section 1 approaches them, indicate that a train is moving from b to a on the section. If the sections are all clear, a train entering section 1, de-energizes the relay 12, and its armature closes the circuit operating the signal 6 from battery 10, over armature 81, contact 64 on the signal, to motor 6', which moves the signal to clear, in which position it is held by the locking-device controlled by the magnet 62 until the relay 12 is again energized as the section 1 is cleared. The train when on sections 2, 3 de-energizes the relays 22, 32 controlling the relay 8, which drops its armature, and signal 6 returns to danger. As the train passes from section 1 to section 2, the relay armature 25 and the switch arm 65 on the signal 6 complete the circuit from battery 10 through the relay 7, and the armature of relay 8 closes a holding-circuit therefor through the resistance 9, which keeps the relay 7 energized until the relay 8 is again energized, when both sections 2, 3 are clear of traffic. If, now, a second train enters the section 1, the relay 12 closes the circuit from battery 10, through armature 71, switch arm 54, to motor 51, which sets the signal 5 to clear, where it is held by the locking-device controlled by the magnet 52, until the train clears section 1. If it is desired to indicate in which section 2, 3 the first train is, the signal 5 is a three-position signal and is controlled bv the arrangement shown in Fig. 1 with the addition of another circuit controlled by the armature 24. If the first train enters section 3 from the end b, the relay 32 is deenergized, and this de-energizes relay 8 but does not energize the relay 7, so that the second train, when on section 1, does not operate either signal 5 or 6 to clear. For a normal clear system, the relay 12 is not used, the wire 77 being inserted to complete the signal circuits.