Patent GB-190505662-A (GB)
Title: Improvements in and relating to Electric Signalling for Railways, and Controlling Equipment and Track Construction therefor.
Inventor: THOMPSON GUION
Filed: 1905-03-17
Granted: 1906-03-15
Abstract: 5662. Thompson, G., and Merchant, H. W. March 17. Electric railways and tramways.-In an automatic electric-r a i l w a y signalling - system using insulated track sections, track contacts, and track relays, the signals are given on the locomotive by a locomotive circuit lighting a lamp or actuating another signal, and controlling the steam valve and air brakes or the controller switch on an electric locomotive. The arrangement of the track insulated sections is modified when either rail is used as a power current conductor in electric railways. The main block sections A, A', A', Fig. 1, are separated by track-rail insulation pieces 1<b>, 2<b> and 1<g>, 2<g>, and further pieces 1<c>, 2<c> and 1<f>, 2<f> define short sections C, C<1>, upon entering which the engine may receive signals that the main-track relay F has failed to give a necessary danger signal Other mutually staggered insulation pieces 1<a>, 2a, 1<d>, 2<d>, 1<e>, 2<e>, 1<h>, 2<h> are only introduced when a rail is used to convey power current in an electric railway, the staggering positions ensuring that the successive sections shall be successively raised to the potential of the power sections A, A', A<2> by the passage of the trolly wheels of the locomotive. This result is obtained in the case of the sections C, C' by either slightly staggering the insulation pieces 1<a>, 2<a>, 1<b>, 2<b> and 1<f>, 2<f>, 1<g>, 2<g>, or by making the forward locomotive track of sufficient length momentarily to connect the section C with its adjacent section B or D, and the section C' with its adjacent section B' or D<1>. The power current will not, therefore, interfere with the signalling-circuit on the engine. This engine circuit extends from the front and back trollies 16, which are separated by insulations 17, a battery G, lamp signal 20, and solenoid 21 being included in the circuit. The armature 22 of this solenoid 21 controls the steam-regulator valve, or the electric controller on an electric locomotive, and may also control an air - brake valve. The engine circuit is normally completed through one or other of the track rails, or when the trollies span insulators 1<b>, 2<b>, 1<c>, 2<c>, 1<f>, 2<f>, 1<g>, 2<g>, through track wires and contacts, and a danger signal is given, and the train is stopped when this circuit is broken. A track trolly E and a solenoid F with armature contacts 8, 9, 4<a>, 5<a>, 15<b> are provided together with pairs of track contacts 6, 6<a>, 6<c>, 6<d>, which are engaged by an insulated contact-piece 24 on the engine. Other track contacts 6<f>, 6<g>, 6<h>, 6<l> are provided when the track is a single track. The engine circuit is closed through one or other track rail until the trollies span the insulations 1<b>, 2<b>, when, if no other train is in the section A<1> ahead, the engine circuit is completed from section B through the wire 5, closed contacts 4<a>, 5<a>, wire 4 to section C. The shoe 24 then closes the contacts 6, 6<a>, energizing the coil F, the circuit being : contact 6, wires 7, 11, battery E, coil F, wire 12, contact 6<a>. The armature of the coil F is attracted and closes a holding-circuit from the battery E through the coil F and the contacts 8, 9. Also the contacts 4<a>, 15<b> are closed, and the train circuit is still thereby closed when the trolly 16 spans the insulations 1<c>, 2<c>, the circuit being from section C through wire 4, contacts 4<a>, 15b, wires 15<a>, 15 to section D, and the train circuit is still closed through the wires of this circuit on spanning the insulations 1<f>, 2<f>. The shoe 24 then bridges the contacts 6<c>, 6<d> in leaving the section A<1>, thus shortcircuiting the battery E through the wires 11, 7, contact to wire 13, contacts 6<a>, 6<c>, and wire 14. The magnet F is thus again de-energized, and the train, in proceeding, spans the insulations 1<g>, 2<g>, when the engine circuit is completed from section C<1> through wire 4, contacts 4<a>, 5<a>, and wire 5 to section B. If a train occupies the section A<1>, the engine circuit of a following train will be broken when the trolly spans either the insulations 1<b>, 2<b> or 1<g>, 2<g>, because the magnet F will be energized and the contacts 4<a>, 5<a> thereby separated. If, however, in this case the magnet F or battery E failed, the danger signal would be given when the train crossed the insulations 1<c>, 2<c> in one direction or 1<f>, 2<f> in the opposite direction. A clear signal here could only be given by the energized magnet F closing the contacts 4<a>, 15<b> ; hence the failure would be signalled at the ends of the comparatively short sections 0 or C<1>. The shoe 24 may be moved from side to side to engage the proper track contacts when running tender foremost ; or separate shoes at each side may be employed, and raised out of action if necessary. The insulations 1<a>, 2<a>, 1<d>, 2<d>, 1<e>, 2<e>, 1<f>, 2<h> are dispensed with where a rail is not required for power current in an electric railway. In a modified form, the track contacts 6, 6<d>, 6<f>, 6<h> are obtained by using the rail sections C, C<1> as these contacts, so that some portions of the track wires serve two purposes. In a further modification, the ordinary track rails are not divided, a third trolly rail being provided and divided as described, while a special trolly connecting to the engine circuit runs upon this third rail. In this form the undivided track rails may form power conductors in electric railways. Fig. 4 shows an alternative method of breaking the circuit of the magnet F when a train leaves a section. The usual holding-circuit of the magnet F and battery E includes a contact k normally closed by the fallen armature 16 of an auxiliary magnet G in circuit with a battery H and the track contacts 6<c>, 6<d> or 6<i>, 6<h>. The contact shoe bridging either pair of these contacts energizes the magnet G, which attracts its armature 16 to break the circuit of the magnet F.