Patent GB-486361-A (GB)
Title: Improvements in systems for the remote control of railway track switches and signals
IPC: B61L19/06
Filed: 1937-06-28
Abstract: 486,361. Route-setting apparatus for railways. GENERAL RAILWAY SIGNAL CO. June 28, 1937, No. 18011. Convention date, July 18, 1936. [Class 105] Route setting from a central office is effected by operating levers or buttons corresponding to the two ends of the route to transmit a code which selects means whereby the various points are set and the signal is cleared. The buttons are located on a diagram panel and additional levers are provided for emergency operation of the points without clearing a signal, for instance if the points are fouled. by snow, but these emergency levers are ineffective if the points have been set up in a route. The turning of an entrance button 1NB and brief depression of an exit button 2XB, Fig. 1, picks up a panel route relay 1-2. The opening of back contact 205 of the route relay 1-2 drops a starting relay 2SR so that a back contact 207 thereof applies potential over a lead 208 to a change relay 2CH, Fig. 2. Closure of contact 224 of the relay 2CH connects the negative pole to a lead 223 whereby a relay CHP, Fig. 3, is energized. Front contact 29 of the relay CHP picks up a code start relay C which closes its contact 35 whereby a circuit is completed from +ve, over a back contact 30 of the last relay LV of a series of stepping relays 1V, 2V ... , over the front contact 35, back contact 34 of a relay 2SA, back contact 36 of a relay CDS, back contact 37 of a relay 3CH, Fig. 2, front contact 38 of the relay 2CH to the winding of a code-determining relay 2CD. The code-determining relay 2CD has a stick lower winding which is now energized in series with the relay CDS from a front contact 63 of the relay CHP. The relays C and CHP remain up until the end of the code cycle. The first step of the cycle is given by the front contact 41 of the relay C applying potential over back contacts 238 ... 243 of the stepping relays 6V ... 1V to bus wire 244 and thence over front contact 245 of the code-determining relay 2CD, jumper 230, and wire 47 to the positive code-sending relay PC. As shown in Fig. 4 a positive impulse is placed on the line wires 12, 10 which extend to all the field stations. At the office this pulse energizes relays F, FP, 2FP, SA, 2SA in that order by the circuits shown. The closure of contact 71 of the relay SA picks up the half-step relay VP over the front contact 72 of the relay 2FP and back contact 73 of the stepping relay IV. The closure of front contact 92 of the half-step relay VP energizes over a back contact 93 of the stepping relay 1V a relay E which energizes a relay EP thereby opening the line circuit 12, 10 at contact 52 and so ending the first impulse of the code. The relays F, FP, 2FP therefore drop and the first stepping relay 1V is now picked up over front contact 75 of slow relay SA (which remains up throughout the code cycle), back contact 76 of the relay 2FP, front contact 77 of the half-step relay VP, and back contact 78 of the next stepping relay 2V. The opening of back contact 93 of the relay 1V de-energizes the relay E and thus the first off period in the line wires 12, 10 is terminated. Relay IV being energized its front contact 243, Fig. 3, applies potential to the next bus wire 246 and thence over front contact 247 of the code-determining relay 2CD and jumper 231 to the positive code-sending relay PC which causes the second pulse to be positive. Similar actions follow, the third pulse being negative by reason of the third jumper 232 being connected so as to energize the negative code-sending relay NC. The first three pulses select the field station and the succeeding pulses select the route relay at this field station, these latter pulses being of a polarity determined by the particular connections from the front and polar contacts 262 ... 266 of the panel route relay 1-2 to the wires 47, 48 which lead to the code-sending .relays PC, NC. A non-conflicting route such as that corresponding to the panel buttons 4NB, 6XB can be set up at the same time, the necessary code cycle being transmitted immediately after the first code cvcle. For instance the panel route relay 4-6 being energized causes a starting relay 1SR to drop whereby a back contact 216 of such relay 1SR applies potential to wire 217 to pick up a change relay 1CH. A front contact 39 of the relay 1CH picks up the code-determining relay 1CD as soon as a back contact 38 of the previously energized relay 2CH is closed; this occurs when the previous code cycle finishes. If the panel lever SML is operated to move the points but without clearing a signal a panel relay Z is energized and its front and polar contacts 279 .. 281, 289 cause appropriate polarity to be given to the code on the later steps. Such code must be initiated by a starting button SB which applies potential to the wire 220 to pick up the change relay 3CH. But if such emergency operation of the points is attempted while a route is already set up which includes such points then no change can be effected because one winding of the relay Z is already energized by a front contact of the route relay and the energization of the other winding causes the relay Z to drop as the windings are differential. With the relay Z dropped the front contacts 279'.. 281 thereof are open and so no operating code can be transmitted during the latter part of the cycle initiated by the emergency starting button SB. At the field stations the code operates a relay arrangement, Fig. 5, comprising relays such as F<1>, FP<1>, SA<1>, a half-step relay VP<1>, and stepping relays 1V<1>.. 6V<1>, LV<1>. The first part of the code selects the particular station by picking up and maintaining energized a relay SO<1> at that station which has its jumpers 111, 112, 113 arranged correspondingly to the particular code. The latter part of the cycle picks up on each step a positive or negative decoding relay 4PS or 4NS, 5PS or 5NS, ... , 7PS or 7NS and at the end of the cycle an executing circuit is completed to the particular field route relay. For example the field route relay 1-2R is picked up by a circuit over back contact 300, Fig. 6, of relay SA<1>, front contact 301 of slow relay LV<1>, back contact 302 of relay 4NS, back contact 303 of relay 5NS, back contact 304 of relay 6PS, back contact 305 of relay 7NS, front contact 306 of relay 4PS, front contact 307 of relay 5PS, front contact 308 of relay 6NS, front contact 309 of relay 7PS, wire 310, to, Fig. 7, back contact 311 of relay 2-1R and winding of the field route relay 1-2R. This field route relay at its front contact 314 energizes the points control relay WN ; when the points have responded so that a points repeater relay WP is energized in the normal sense the signal relay 1G is energized over front contact 324 of the route relay 1-2R. To return the field signal to danger the operator at the office restores the entrance turn button 1NB thereby dropping the panel route relay 1-2, so that the starting relay 2SR is again dropped to initiate a code cycle. The character of the latter part of the code is now determined by the back contacts 262 ..265 of the panel route relay 1-2. At the field station this particular code causes the relay 1-2S, Fig. 7, to be energized briefly and thereby open its back contact 312 in the stick circuit of the field route relay 1-2R. The signal relay 1G is thereupon de-energized by the opening of front contact 324 of the field route relay 1-2R. A cancelling button CNB, Fig. 2, allows the operator to cancel any stored up condition in the relays CH and CD which is awaiting transmission or being transmitted. Specifications 419,399, [Group XXXVIII], 440,765, and 477,671 are referred to.