Patent GB-190222551-A (GB)
Title: Improved Electrical Signalling System for Railways
Inventor: MILLS CHARLES WILLARD
Filed: 1902-10-16
Granted: 1903-07-30
Abstract: 22,551. Mills, C. W., and Piddington, W. W. Oct. 16. Signalling and communicating between trains; signals on engines and trains; lamp signals; ; indicators and repeaters, point or switch; indicating condition of bridges; contacts, electric.-Relates to an electric signalling-system for steam or electric railways, the rails of which may be employed to form part of the controlling- circuits. The rails 1, 2, Fig. 1, are arranged in insulated sections, and a duplex conductor 3 divided into corresponding sections is mounted parallel with the rails. The conductor 3 consists of two strips 4, 5, Figs. 1 and 3, secured to and preferably countersunk in an insulating wooden body, the strips being engaged by the insulated contact - discs 13, which are mounted on a spindle 10 in hangers 12 depending from the engine or car. At alternate breaks in the rail sections, the rails 1, 2 are connected by wires 15, 16 to the strips 4, 5 respectively. At the intervening breaks, the parts 1, 3 and 2, 5 are crossconnected, as shown in Fig. 1, by wires 17, 18, 19, 20. The discs 13 on the engine or car are separately connected through the arms 35, 36 of the switch 32 to signals 29, 28, which are preferably lamps, coloured green and red respectively. The lead 25, which connects the lamps to the battery 22, includes a relay magnet 24, adapted to complete a local circuit 53 through an audible alarm, such as a bell 50. The battery 22 is preferably a secondary battery, and is connected by the lead 40 and the vehicle wheels to the rails 1, 2. When two vehicles or trains 7, 8, travelling in opposite directions, approach each other, as indicated in Fig. 1, a circuit is completed through the red lamps 28 on both engines &c. If the trains are travelling in the same direction, and the second approaches too near the first, the red lamp of the second train and the green lamp of the first train are illuminated, the connections between the strips 4, 5 and the discs 13 of the first train being in this case reversed. When the lamp-signalling circuit is completed, the relays 24 close the circuits of the bells 50 to give an audible warning to the drivers. At switches, the ordinary rail is connected through by a wire 21, and a wire 47 connected to the strip 4 is provided with a contact 48, adapted to be engaged by the switch tongue 46 when the latter is open, so that, if a train approaches an open switch from either side, the circuit of its red lamp will be completed at the contact 48. At drawbridges &c., a similar short-circuiting connection is effected by means of the contact shown in Figs. 4 and 5. The lever 70 connected to the rail 1 has a knife-edge contact 69, which is normally held out of engagement with the contacts 72 on the yoke-pieces 63 connected to the strip 4, by the projection 67 on the bridge slide &c. engaging the bevelled head 66 of the lever. When the slide is opened, the lever 70 is released, and is raised by the spring 68 to make the contact. A telephone is provided on each engine &c., for communication between drivers, the switches 32 being thrown over to cut out the signals and connect up the telephones.