Patent GB-190900784-A (GB)
Title: An Improvement in Signalling and Interlocking for Railways and Tramways.
IPC: B61L23/12
Filed: 1909-01-12
Granted: 1910-01-12
Abstract: 784. Dutton, C., and McKenzie & Holland. Jan. 12. Signalling - instruments, interlocking.-In order to permit a track to be used at different times as an "up" or "down" line, a duplicate set of instruments and semaphores with necessary levers is provided for each direction, and by means of a commutator switch and a master lever which are locked by the same keys, for example, by an Annett's lock, the instruments and apparatus are changed over for up or down traffic, and are arranged so that the apparatus is only free to permit traffic in one direction at a time. Fig. 1. shows the apparatus at an end station A of the universal line, and Fig. 2 an intermediate station B equipped with an initiating switch 30, i.e., a switch by which the change of direction of traffic is initiated. Each intermediate station has an "up" instrnment 1 and a "down" instrument 2, of which only one is in use at a time ; the end station A has one instrument with a plunger only, and one with a receiver only. The instruments are interlocked with the signal levers by rods 4, 4<a>, 4<b>, 4<c>, and these rods are also interlocked with the commutator switches 6, 7 by the rods 16, 17, which lock the rods 4 &c. by means of projections 18. The commutator switches are locked in one position by the armatures of the magnets 8, 9, and when unlocked may be turned by a key, which is also used for unlocking the master lever which locks either the "up" signal levers or the "down" signal levers and has two locks 28, 29, operated by different keys for locking it in its end positions. In the drawings the heavy lines represent the instrument line-wires. The apparatus is set for "up" traffic working from B to A. To change over, the signalman at B ascertains that the line is clear and then closes the switch 30, which is held closed by a tooth on the member 37. A current passes from battery 42, contacts 44 of switch 7, switch 30, and line 46 to the station at the down end of the line, through contacts 26, to the magnet 8 controlling the switch 6. The drum of this switch is unlocked by the armature and a disk 10 is shown. The s'gnalnian at that station then turns the drum 6 and so breaks the circuit to the magnet 8. After turning the switch, the key is free and is used to unlock the master lever lock 28. This lever is moved and locked by the lock 29 in the position for "down" working, and the key of the lock 29 is thereby released and may be used to turn the switch 7, so as to close a circuit from the lead 46 through the switch 7 to the magnet of switch 6 at the next station towards A. A similar sequence of operations is gone through at each station until the station on the down side of B is reached ; the switch 7 at that station energizes the magnet 8 at the station A and finally the operator at station B is enabled to change over his apparatus. The movement of the switch 7 at B releases the switch 30 by means of the rods 17 and the extension 39 thereof. A double diagram of the roads is used, one road only being visible at a time ; or an arrow may be used to give the direction of traffic according to the position of the master lever. The contacts 26 are opened by the removal of the dropping-rod 25 when the pluuger 3 is pressed, thereby removing the lower end of the rod 25 from its support on the extension of the rod 4<a>, 4<c>. These contacts 26 prevent reversal of working traffic if the block instruments and levers are not in normal position. The plunger 3 is locked against operation by the piece 22, which is pushed by the plunger against the rod 21 unless that rod is in such a position that the piece 22 is opposite a notch in the rod 21, which is actuated by a pin in a cam-slot 24 on the rod 16.