Patent GB-511890-A (GB)
Title: Improvements in route control systems for railways
IPC: B61L19/06
Filed: 1938-06-08
Abstract: 511,890. Route setting apparatus for railways. GENERAL RAILWAY SIGNAL CO. June 8, 1938, No. 17059. Convention date, June 12, 1937. [Class 105] A route relay is energized by the momentary operation of entrance and exit buttons corresponding to the ends of a route whereby the various points are set to the required position and the signal cleared. Thus all the buttons may be of the self-restoring type. The entrance and exit buttons may be located on a miniature diagram which is arranged to illuminate the proposed route in one colour as soon as the buttons are operated while when the route has actually been set up the diagram illuminates the route in a different colour. The route control of the points and signals and the return indicator may be effected by code transmission initiated by a starting button, a code system such as that described in Specification 419,399, [Group XXXVIII], being employed. Figs. 1A, 1B show in skeleton form the apparatus at a central office and Figs. 2A, 2B, 2C, 2D the associated apparatus at a field station whereby a control code effects the operation of the points and signals. Fig. 4 shows the arrangements for giving the display indications at the office as transmitted from the field station by the apparatus shown in Fig. 3B and received at the office by the apparatus shown in Fig. 3A. To set up a route from signal 3 to signal 6 on the track layout of Fig. 2D the operator actuates the entrance and exit buttons 3NB, 6XB, Fig. 1A, which are of the rotary and press type and automatically restore when released. No transmission is effected until the operator depresses a start button ST. The entrance button 3NB picks up a stick relay 3NR by a circuit from +ve, button contact 73, winding of the relay 3NR, wire 61, back contact 62 of a relay RS, back contact 63 of a relay SA, wire 82, contact 83 of a cancel button CA in unoperated position to -ve. With the relay 3NR thus closing its front contact 77 and with the exit button 6XB depressed a route relay 3-6 is energized by a circuit from +ve, back contact 65 of a relay 2NR, front contact 77 of the relay 3NR, upper winding of the route relay 3-6, back contact 78 of a relay 6NR, contact 79 of operated exit button 6XB, to -ve. The route relay 3-6 is maintained energized by a stick circuit from B+, right-hand and front contacts 80, 81 of the route relay 3-6, its lower winding, wire 70, winding of a relay RS, back contact 71 of a relay E, wire 72, contact 74 of unoperated cancel button CA, to CN. The operator starts the code transmission by depressing the start button ST which closes a circuit from -ve, contact 251 of operated button ST, wire 75, upper winding of a change-storing relay CHP, back contact 26 of a field-starting relay FC, back contact 25 of a relay SA, to +ve. The relay CHP is held up by a stick circuit through its lower winding until the code cycle at its termination opens a back contact 30 of the last stepping relay LV. A front contact 29 of the relay CHP picks up a relay C which starts the transmission of a control code by closing its front contact 41 whereby +ve is applied over back contacts 130-136 of stepping relays 7V-1V, wire 121, front contact 111 of the route relay 3-6, jumper 101, bus wire 48, to negative-impulse relay NC which by its front contacts 50, 54 puts a negative impulse on the control-code line wires 10, 12. This gives the first energized period of the code which continues until relays SA, 2SA and a half-step relay VP have lifted and closed a circuit to the relay E by an arrangement described with reference to Fig. 5 (not shown). The first pulse is terminated on the opening of a contact 52 of a relay EP which is a repeater of the relay E. This first 'step initiates the code cycle and succeeding steps are positive or negative according as the jumper connections 102, 103, the position of polar contact 104 of the route relay 3-6, and the jumper connections 105, 106, 107 connect the wires 122 ... 127 to the bus wires 47 or 48 leading respectively to the +ve and -ve relays PC, NC. The final pulse is +ve or -ve according as the wire 128 (which is connected to the same wire by all the route relays) is connected to the bus wire 47 or 48 by the back or front contact 108 of a stop relay SR. This stop relay SR is picked up if the operator, after having set up a route wishes to return the signal to danger, first actuates the stop button STP and then again actuates the entrance and exit and start buttons. At the end of a code cycle the route relay together with the relay RS and the stop relay SR if picked up all drop. At the field stations the control code selects one station on its earlier steps by such station having a relay SO' maintained energized in the manner described in Specification 419,399, [Group XXXVIII]. Subsequent steps, such as the fourth, energize relays such as 4PS or 4NS according as the fourth impulse is +ve or -ve, Fig. 2A, and at the end of the cycle a front contact 270 of the final stepping relay LV<1> completes an executing circuit to pick up a route relay at the station. In the case of the office route relay 3-6 being energized the code on the fourth to the eighth steps is -, +, -, -, +, so that the field relays 4NS, 5PS, 6NS, 7NS, 8PS are energized and the executing circuit extends from +ve over front contact 270 of the relay LV<1>, back contact 271 or relay 4PS, front contact 272 of relay 4NS, back contact 273 of relay 5NS, front contact 274 of relay 5PS; back contact 275 of relay 6PS, front contact 276 of relay 6NS, back contact 277 of relay 7PS, front contact 278 of relay 7NS, back contact 279 of relay 8NS, front contact 280 of relay 8PS, wire 281 (Figs. 2B, 2C), through the lower winding of field route relay 3-6R, back contact 282 of 'field route relay 6-3R and back contacts 283 ... 286 of field route relays 3-4R, 4-3R, 3-5R, 5-3R, to -ve. The field route relay 3-6R, is then held by a stick circuit extending from +ve over a front contact 287 of track repeater relay ITP (Fig. 2D), wire 288, wire 289 (Fig. 2C) and stick contact 290, the remainder of the circuit being as before. The entry of a train drops the track relay IT to close a back contact 301 (maintaining the application of potential) before the tracks repeater relay ITP opens the front contact 287 and therefore the field route relay is not dropped until the route has been entered and vacated. Thus a field route relay for a conflicting route cannot be picked up while the train is passing through. In the event that the operator transmits the stop code for the route the final step of the code is negative whereby the relay 8NS is energized instead of 8PS and the former executing circuit from front contact 270 or relay LV<1> now proceeds over back contact 280 of relay 8PS, front contact 279 of relay 8NS, wire 303 (Figs. 2B, 2C), front contact 304 of the picked up and stuck field route relay 3-6R, upper winding of the relay 3-6R to -ve. The two windings of the relay are differential and therefore the relay now drops. In its energized state the field route relay 3-6R closed its contact 291 to set the points for the route and at its front contact 297 closed a circuit to the signal clearing relay 3G, this circuit being from +ve, over front and normal contacts 294, 295 of points repeater relay 7WP (Fig. 2B) in correct position, wire 296, front contact 297 of the field route relay 3-6R, wire 298, to the relay 3G. It will be seen that the opening of contact 297 when the stop code is sent will return the signal 3 to danger. Return indications are sent from the field stations to the office when any change occurs. Referring to Fig. 3B it will be seen that on any signal relay 2G,3G ... points repeater relay 7WP .. or track relay 1T ... 8T, dropping or lifting, a stick relay CH' is dropped whereby a lockout relay LO<1> is picked up. The lifting of contact 156 of the relay LO' cuts off the more distant stations from the indication-code line wires 14, 16 and connects these line wires 14, 16 through its lower winding whereby current flows from an office battery 1B, Fig. 3A, through a message relay MB and the line wire circuit. A front contact 162 of the relay MB thereupon energizes a field-starting relay FC, Fig. 1B, whereby a circuit is completed from +ve, over back contact 41 of the controlstarting relay C, front contact 166 of the relay FC, to the -ve-impulse relay NC which then energizes the control line-wires 10, 12 to initiate a cycle of the stepping relays. The station apparatus Fig. 3B so conditions the indication line wires 14, 16 as to transmit an indication during both the on and the off periods in the cycle of the stepping relays. For instance, with the points repeater relay 7WP at normal a circuit is closed from +ve, over front and normal contacts 330, 331, wire 404, front contact 332 of stepping relay IV<1>, back contacts 333,334, 335 of stepping relays 3V<1>, 5V<1>, 7V<1>, back contact 329 of half-step relay VP', back contact 197 of a relay FP' (repeating the relay F<1> in the control line-wires 10, 12), to a relay PF'. This occurs at the second "off " period. At the third "on" period this relay PF<1> and the relay FP<1> by reason of their respective contacts 199, 173 being closed connect the indication line-wires 14, 16 it being noted that contacts 172 of relay SB<1> and 156 of relay LO' are closed throughout the cycle as described in the above-mentioned Specification 419,399. Thus at the office on the third "on" period the message relay MF is energized and on the third "off" period a front contact 217 of this relay MF applies potential from B+ve, over front contact 218 of relay SA, back contact 209 of relay FP, front contact 219 of half-step relay VP, back contact 336 of relay 6V, back contact 337 of relay 4V, front contact 338 of relay 2V, wire 504, front contact 340 of station-registering relay 1ST (energized by the earlier part of the indication code) to the indication relay 7NK. If the points repeater relay 7W