Patent GB-191308249-A (GB)
Title: Improvements relating to Signalling Systems and the Control of Trains.
IPC: B61L3/10
Filed: 1913-04-08
Granted: 1914-04-08
Abstract: 8249. Marks, E. C. R., [Mascarenhas, E. G.]. April 8. Electrical systems, automatic ; track apparatus actuating signals on trains and for stopping trains.-In an ordinary track relay system, the track relay controls a circuit connecting two fixed track contacts, which operate engine contacts mechanically to control engine circuits for applying the brakes. Speed governor mechanism also controls the engine circuits according to the speed of the train. Pivoted engine contacts j, k, Figs. 3 and 3<a>, are operated by fixed track contacts c, d at signals to break the circuit m of a relay n at spring contacts q. The armature r then drops, and closes the circuit of a magnet p, which attracts its armature and allows a spring to actuate a valve n to apply the brakes. If, however, there is no train in the same block, the track relay f<1> is energized and closes the circuit of the ordinary semaphoreoperating means a to pull the semaphore to ' safety,' and also closes a circuit at contacts h, i between the track contacts c, d. The circuit of the relay n although broken at the contacts q is closed through the connected track contacts, and the brakes are not applied. When the engine contacts j, k are actuated, pin contacts v, w are made to close a circuit x, and operate a bell signal on the train and energize a relay y. If then the signal is at ' safety ' so that the relay n remains energized, and yet the train is travelling at too high a speed on passing over the track contacts, a speed governor device s driven from the wheels co-operates with the attracted armature 2 to close the circuit of the magnet p at the contacts z, and so apply the brakes. On the other hand, if the speed is sufficiently low on passing a ' danger ' signal, the speed governor device s is in such a position that it prevents the armature r from dropping and closing the circuit of the magnet p, so that the brakes are not applied. A switch 3 can he operated to cut the relay y out of action and another switch 4 may be operated to restore the magnet p and its valve u to normal position after application of the brakes. In a modified form, a sliding switch is operated by the speedgovernor device s, Fig. 6, and the brakes are applied by de-energizing the magnet p. In the low-speed position shown, the armature r is held up by the speed-governor device, and the circuit of the magnet p is closed. At high speed the sliding portion moves to the right, and the armature r drops, breaking the circuit of the magnet p at the armature r, and also at the point of contact of the sliding switch and the armature of the relay y. When the engine contacts j, k are clear of the contact rails c, d, the relay y is de-energized, and its armature closes the circuit of the magnet p, but if the speed is too high, the armature of the relay y engages an insulating piece 9 on the slide and so breaks the circuit of the magnet p, and applies the brakes. The magnet p may control the engine throttle valve or the motor circuit of an electrically-driven train. The Provisional Specification also states that rotary or commutator type make-and-break devices may be used instead of the contact levers upon the locomotive. Specifications 9418 / 05, 25,837 / 05, 28,435/07, 854/08, 4882/11, and 12,089/11 are referred to.