Patent GB-190909035-A (GB)
Title: Improvements in Electric Signalling Systems for Railways.
Inventor: HIGGINS WILLIAM JAMES
IPC: B61L3/12
Filed: 1909-04-16
Granted: 1910-03-10
Abstract: 9035. Higgins, W. J., and Sheridan, C. J. April 16. Electrical systems, automatic track apparatus actuating signals on trains; visual outdoor signals; lamp signals. -In track-relay systems having home and distant semaphore signals, means are provided for repeating the track signals on the engine cab by inductive interaction between apparatus on the train and on the track, whereby also steam may be cut off and the brakes applied. The track semaphores may have a waving motion imparted to them by electrically-operated means ; or intermittent signals may be given by utilizing the waving of the semaphores as a shutter before stationary lights. Two sets of transformer primaries are placed upon the track, the distant signal primaries 12 being on one side and the home signal primaries 22 on the other, two engine-carried secondaries being carried, one on either side, to co-operate therewith. The track rails 1 are divided into sections by insulation blocks 2, and each section has a battery 3 and a relay 4, 5, 6, 7, which relay is short-circuited by the presence of a train in its section, the relay 6 being shown thus sbort-circuited by a train at Z in section III. The back contacts 18 of these relays are connected to the line 20 supplying alternating current, so that when the relay 6 is short-circuited, current flows through the switch 8 through (1) wire 11 to the " distant " transformer primary 12, two sections in the rear, and through wire 14 to the operating- mechanism 15 of the corresponding distant signal 17, and the lamp 27 on the signal post, both returns being earthed (2) wire 21 to the " home " transformer primary 22 at the entrance to the section, and to the operating mechanism 23 of the home signal 24, together with the lamp 26. Instead of having earth return, metallic returns may be provided for all the circuits and transformers inserted between the line 20 and the switches 8, which are then inverted. The engine apparatus consists of two transformer secondaries 51, 77, Fig. 2, cooperating with the primaries 12, 22 respectively, the circuit of each secondary coil including two coils 34, 35 having cores 36 extending partly into them, the remainder of the coils being filled with plungers 37 pivoted to a lever 40 provided with a catch 41. This catch normally holds the end of a pivoted rod 42 provided with a weighted handle 45 and a spring 48, which tends to keep the lever in contact with the terminal 46 of a circuit wire 49, which is connected at its other end to the lever 42, and which circuit includes a battery, 50 and an electro-magnet 33. The armature 32 of this ekctro-magnet has a catch 31, which normally holds a shutter 30 in front of a signal lamp 28, 29, the left-hand lamp corresponding to the distant signal being coloured green, and the home signal lamp red. When a train passes over an energized " distant " primary 12, the coil 51 is energized and the lever 42 released to complete the circuit of the magnet 33, which lifts its armature and allows the shutter 30 to fall and expose the green lamp 28. The shutter is provided with a projection 52 which falls between two spring leaves 53 and closes the circuit 54 through a bell 55 and a battery 56, and also with a projection 57, which similarly closes the circuit 59 of a magnet 61, which lifts its armature 66 and releases the lever 64 from the catch 65, and allows the spring 67 to pull over that lever to close the steam-pipe valve 63, the lever 64 being held over until replaced by the driver by the ratchet-wheel 70 and pawl 69. Similarly, when the engine passes over an energized " home " primary 22, the coil 77 is energized, the red lamp 29 exposed, and the bell rung ; at the same time a lever 83 is released from the armature catch 82 and is drawn over by a spring 84 to open a valve 88 in the brake-pipe 89, the lever 83 being similarly hand-reset. To reset the apparatus, the levers 42 are lifted by the handles 45 and are held by catches 41, thus breaking the circuits of the magnets 33 and allowing the shutters 30 and the levers 64, 83 to be replaced. The apparatus on a signal post comprises an induction motor 23 for each semaphore 24, the semaphore being given an oscillatory up - and - down motion through spurwheels 90, 91 and the rod 92, the arm moving in front of the signal lamp, which is provided with a reflector and a coloured screen 94. A lamp may also be carried at the end of the arm itself, and an additional lamp 97 provided at the top of the post which is lighted when the signal is at "line clear" for which purpose it is placed in a circuit with the line 20, Fig. 1, and the front contact 9 of the switch 8, which is inverted for the purpose. The system may be adapted for warning trains approaching an open switch by placing coils on the track in advance of the switch and arranging that this circuit shall be closed when the switch is open. A crossing- track may also be wired to give signals to stop a train approaching a crossing over which another train is passing.