Patent GB-190418540-A (GB)
Title: Improvements in or relating to Signalling Apparatus.
Inventor: BROWN HAROLD GILBERT
Filed: 1904-08-26
Granted: 1905-08-24
Abstract: 18,540. Brown, H. G., and Malan, E. de M. Aug. 26. Signalling-instruments; contacts, electric, mechanical, and pneumatic ; signalling to cabins and stations. -A number of definite signals may be transmitted to and received by a receiving-apparatus that records them and when desired repeats or annunciates them in the order of their transmission. The transmitter may be modified so as to be actuated by trains. Fig. 1 shows the whole of the apparatus, the receiver being shown both in end elevation and in section. The transmitter consists of an insulating-disc 1 provided with four concentric metal rings 2, 3, 4, 5 which are complete on the side on which the springs 6, 7, 8, 9 bear and are broken into sections on the side on which the springs 10,11,12, 13 bear. A fixed pointer 231 moves over a series of index numerals, and the disc is held in the desired position by the pawl 20. When the disc is set for the required signal, the switch 17 is closed and current is sent along any or all of the wires 39, 40, 41, 42 selected by the rings on the disc 1 to the magnets 33, 34, 35, 36 of the receiver. The receiver consists of a cylinder 23, carrying a number of sets of four spring plungers 28, which are operated by the armatures of the magnets 33 &c. and when pushed in are held by spring detents. The circuit between the transmitter and receiver includes the magnet 70, which at each signal attracts its armature 69 and so raises the weighted bar 61, with which are connected the pawls 60, 72, 76 ; the return of the bar 61 when the current ceases causes the pawl 60 to engage a pin 59 on the drum 23 and move it one space forward so as to bring a new set of plungers 28 over the magnets 33 &c. The pawl 52, which is mounted on the wheel 23 and engages the ratchet-wheel 48, drives this wheel forward with the drum 23. The wheel 48 carries one set of spring plungers 47 which may be depressed by plungers 28 that have been operated by the magnets 33 &c. These plungers 47 are connected through slip rings and brushes 96, 97, 98, 99, 100 to the magnets 103, 104, 105, 106, each of which operates a bar 115, 116, 117, 118 made up of metallic and insulating sections. These bars are connected by fixed bars 119, and in their various positions complete circuits from the battery 120 to the electromagnets 127 of the indicator. The bars 115 &c. also make or break contacts 122, thereby inserting a resistance 123 into the magnet circuit while the armatures are held. In order to read off any further signals received by the plungers 28, the plungers 47 are moved one step by completing the circuit from the battery 84 through slip rings 86, 87 to the magnet 55 mounted on the drum 23. The magnet operates the escapement 52, and the ratchet-wheel 48 is moved one tooth by a weight 80 that is hung on a cord round a pulley on the shaft. This weight is wound up by the movement of the drum 23. The relative movement of the wheel 48 and drum 23 causes fingers 83 on the wheel 48 to re-set the plungers 28. In the application of the invention to railways, the contacts are made by a switch as in Fig. 5, in which the bars carrying the brushes 131 are actuated by projections arranged on the engine. The switch may be replaced by treadles or other track contacts. The wires from the slip rings 96 &c. may pass to a second receiving-apparatus, if desired, instead of to an annunciator, thus repeating the signal. The Provisional Specification states that the treadles used for action by trains may operate the drum without the intervention of an electromagnet. Modifications may be made to adapt the invention for signalling by fluid pressure.