Patent GB-355337-A (GB)
Title: Improvements in or relating to train control systems
IPC: B61L3/12
Filed: 1930-05-22
Abstract: 355,337. Train control and cab signalling systems. ASSOCIATED TELEPHONE & TELEGRAPH CO., 1033, West Van Buren Street, Chicago, U.S.A. May 22, 1930, No. 15805. Convention date, July 11, 1929. [Class 105.] Relates to train control and cab signalling apparatus of the intermittent magnetic induction type. The locomotive apparatus shown comprises end and intermediate collecting plates symmetrically arranged across the mid line of the locomotive and armatures which are selectively operated, the arrangement being such that one field of whatever polarity will effect a brake application and cab signal although different armatures are operated depending on the polarity of the field. The invention is described in its application to a wholly automatic system with wayside light signals, the track arrangements being shown in Figs. 10 and 10a., the latter of which should be placed to the right of Fig. 10, and the locomotive arrangements being shown in Fig. 4. The track magnets for acting on the train apparatus comprise permanent magnets A<1> .., electromagnets B<1> .. with like outer poles and a middle intermediate pole, and devices C<1> .. comprising permanent magnets which are rendered ineffective by associated electromagnets. The electromagnets B<1> .. are normally or reversely energized and the devices C<1>.. made effective or ineffective in dependence on the occupation of sections ahead by means of track relays T<1> ... The track magnets have angle-iron polepieces from which the permanent magnets are slightly spaced, the latter being carried in notched wooden supports. The locomotive receiver R, Fig. 4, comprises collector plates 102<1> .. 102<6> with polepieces between which are situated four polarized armatures 1251 .. 125<4>. The armatures 125<3>, 125<4> control the cab light signals G, Y, R and the armatures 125<1>, 125<2> when moved from the position shown deenergize an electropneumatic relay EPV which initiates a braking action and causes a whistle W to sound ; the braking can be cancelled by pressing an acknowledging button AB to energize magnets 88, 88<1> which restore the armatures 1251, 1252 to the position shown but the button AB must be returned immediately as on depression it opens at contact 74 a second point in the circuit to the electropneumatic valve EPV. The armatures 125<3>, 125<4> if both are in the inner position shown light a green lamp G ; if both are in the outer position they light a yellow lamp Y ; and if one is in the inner and one in the outer position a red lamp R is lit over back contacts of an armature of a lightcontrol relay LCR, coils 52, 52<1> of which are energized in parallel with lamp G and lamp Y respectively. The power is supplied by a generator GEN on the engine while the receiver R is mounted on the tender with the various wires connected to terminals in a junction box JB. The positive lead 72 of the generator GEN goes to the acknowledging button AB and then by lead 61 to the junction box, then through a loop 200 and back to a terminal of the junction box whence it branches into leads 54, 55, 57 to the receiver armatures. The loop 200 is sheared by the scissors action of one of the receiver supporting rods 157 and its attachment bracket 155, Fig. 8, in the event of the receiver meeting any obstruction on the track. The lamp G is connected by wires 77, 63 to the receiver lead 56 and the lamp Y by wires 76, 64 to receiver lead 53. The receiver lead 60 is connected by wires 66, 67, 68 to the electro-pneumatic valve EPV. The common return wire 78 of the lamps G, Y, R is connected by wires 87, 85 to the negative lead 71 of the generator. The receiver armatures 1251 .. 1254 are so polarized by magnets 84<1> .. 84 that if the outer collector plates receive magnetic flux from a North pole on the track the armatures move to the inner positions. Referring now to Figs. 10 and 10a, the effect of the presence of a vehicle V2 in section G of the track on the track signals S<1>, S<2>, S<3> and on the train control and cab signals of an overtaking train V<1> will be described. The track signals S<1>, S<2>, S<3> each comprise red, yellow, and green lamps R, Y, G, and energized in parallel with the lamps Y and G are relays such as Y<3>, G<3> which control the energization of the track magnets B<3>, C<3>. The dropping of the armatures of the track relay T<3> of the occupied section G opens the circuit of a line relay L1<3> which circuit extends to a line relay L2<2> of the previous section F ; the dropped armature of relay L2<2> prepares a circuit for the yellow caution lamp Y of signal S<2> which is however open at the contact of line relay L1<2> until the train V<1> enters the section E and causes the dropping of track relay T<1> which causes the de-energization of line relay L1<2>. The train V<1> in section D has de-energized line relay L1<1> so that the green clear lamp G of signal S<1> is lit from battery EB since the armatures of track relay T<1> and line relay L2<1> are in their upper position; the relay G<1> is also energized so that its armatures cause the energization of the electromagnets of track device C<1> which is therefore made ineffective and the energization of the track electromagnets B<1> with the outer poles of North polarity. When the train passes over the permanent magnets A<1> the South poles thereof move the receiver armatures 125<4>, 125<2> to the outer position but as almost immediately the train passes over the electromagnets B<1> the outside poles of which are of North polarity the armatures 125<4>,125<2> are restored to the inner position. The effect is a momentary extinction of the green cab lamp G and the sounding of the whistle E. When the train enters into section E the track relay T<1> drops its armatures and the red lamp R of the signal S<1> is lit since the armature of relay L1<1> is still dropped owing to the track relay T<1> opening its top armature. Before entering section F the yellow lamp Y of signal S<2> is lit over the dropped armature of line relay L1<2>; energization of the corresponding relay Y<2> also takes place so that the device C<2> is rendered ineffective as in the case of device C<1> but the track electromagnet B<2> is reversely energized so that the outer poles are of South polarity and the armatures 1251 .. 125<4> all move to the outer position. The result is that the brake and whistle actions are initiated as before, but can be cancelled by the acknowledging button AB and that a caution lamp Y in the cab is maintained lit as the armatures 125<3>, 125<4> remain at the outer position. When the train V<1> reaches the device C<3>, which is in its effective condition since neither of relays Y<3> or G<3> are energized, the brake and whistle actions are initiated and must be cancelled by the button AB ; the armatures 125<3>, 125<4> are out of phase so that both cab lamps Y and G and their associated coils 52 and 52<1> are dead and accordingly the red cab lamp R is lit over the dropped armature of the light-control relay LCR. At the track permanent magnet A<3> a second brake initiation takes place and a second acknowledgment must be made by depressing the button AB. An arrangement is also described, Figs. 11 and 11a (not shown), using track relays having polarized armatures to avoid the use of the line relays L and applied to the protection of crossing lines by the signal for one line on being put to " clear " causing the track relay of the other line to drop. Two devices C are provided at the crossing so that at danger conditions three acknowledgments are necessary. At a siding a thermorelay is provided giving a delay action to prevent reversal of the points during the approach of a train. Specification 315,716, [Class 105, Railway signals &c.], is referred to.