Patent GB-190915862-A (GB)
Title: Improvements in Electrical Block Signalling Systems.
IPC: B61L23/16
Filed: 1909-07-07
Abstract: 15,862. Richardson, E. A., and Compagnie de Signaux Electriques pour Chemins de Fer. July 11, 1908, [Convention date]. Void. [Published under Section 91 of the Act.] Electrical systems, automatic. -In systems using insulated sectional rails and track relays for controlling the signals, all the circuits are normally open and the relays de-energized. An approaching train energizes the relays of sections in advance and leaves the circuits de-energized behind it, and, if the main line is left clear by the train entering a siding, the whole of the apparatus is re-set to normal. In Fig. 2 the section f1, g1 is a terminus section, and a train standing thereon closes the circuit from the battery h, to the relay c1, through the rails and train-axles. The relay c1 being excited, its armatures close the circuits from the battery h1<1> to the relay s1, the rail g1<1>, contact 10, the relay d1 and the rail f1<1>. The contact 18 of relay s, closes the circuit from the battery v1 to the relay e1. Contact 66 of relay e1 closes the circuit from the battery y1 to the contact 66 of relay e1, contact 20 of the relay s1, rail f1<11>, wire 74, contact 36 of relay d1<1> (closed if the relay is unexcited), wire 75, relay c1<1>, rail g1<11>, and coil t1<b> of relay t1. The coil t1<a> of the relay t1 is also energized but in opposition to the coil t1<b>, so the relay t1 does not draw its armatures. The relay c1<1> establishes a circuit from the battery h1<111>, relay s1<1>, rail g1<111>, relay d1<1>, contact 30, and rail f1<111>. A circuit is thus made by the relays s1, d1<1>, from the battery u<1>, relay c1<1>, rail g1<11>, wire 76, relay t1 (both coils in series), contact 20 of relay s1, rail f1<11>, wire 74, contact 36, (closed if relay d1<1> is excited), and battery u1. One of the contacts of relay t1 shortcircuits the coil of relay e1, which breaks the circuit of battery y1 so that relay t1 is only excited by the battery u1. The signals a1, b1 are driven to clear, if the track is clear, by the current from battery w1, through contact 26 of relay t1, contact 22 of relay s1, contact 68 of relay e1, signals a1, b1, contact 14 of relay d1, contact 12 of relay c1, and return line wire. The circuits for corresponding signals and relays in other sections are similar to those above described. When the train passes the signal b1, the relay d1 is shunted and opens the circuit of that signal, but that of signal a is kept closed by contact 16 of relay d1 when unexcited. The signal a1 is put to danger as the train passes by the shunting of relay t1. When the train passes the signal b1<1>, the relay d1<1> is neutralized, and this also breaks the circuit of relay c1<1>. If the train enters a siding at any point of the track, all relays are de-energized. If no sidings occur on the track, a modification may be made by which one wire less is used between each home signal and the distant signal in advance. In this modified form of the system, the relay corresponding to c1<1> is connected across the track rails as is also the relay corresponding to relay d1<1>, which is further made self-holding after energization.