Patent GB-386375-A (GB)
Title: Improvements in or relating to systems of electrical remote control and supervision
IPC: B61L7/08
Filed: 1931-10-09
Abstract: 386,375. Distant control systems. GENERAL ELECTRIC CO., Ltd., Magnet House, Kingsway, London, and COLLYER, J. E., of' General Electric Co., Stoke, Coventry. Oct. 9, 1931, No. 28084. [Class 40 (i).]. In a remote control and supervisory system, e.g. railway signalling and control systems or power station control systems, a number of outstations, each comprising a number of apparatus elements to be controlled or supervised, are connected in tandem to a control station, and outstation and apparatus selection are effected by transmitting a series of trains of impulses, station selection being effected by long (or short) trains in accordance with the position of such trains in the series while apparatus selection is effected by the short (or long) trains also in accordance with their position in the series. Indicating panels corresponding to the outstations and individual indicators thereon are similarly selected at the control station in response to supervisory impulse trains transmitted from the outstations. Arrangements are provided for preventing simultaneous transmission by the control station and outstations, and for checking the correct transmission and reception of the codes. General operation of system. The system described comprises arrangements for controlling and supervising the operation of points and signals and for supervising the condition of track relays on a railway. The control station, Figs. 1 to 4, comprises a panel, such as Fig. 1, for each outstation and comprising a sending group of two-position relays CPS-WSS controlled by keys RN, TG for changing the points and signals PT and 3 .. 6, Fig. 8, at an outstation, and a receiving group of supervisory relays of which CP-WS correspond to the sending relays, TA-TC supervise the condition of track relays TRA-TRC, Fig. 8, and MPC, LO supervise signals giving local or semi-automatic control (restoration of clear signal by passage of train). The common control apparatus comprises a relay group X-Z, Fig. 3, for producing impulses, a relay chain, Fig. 4, for counting both transmitted and received impulses, a sending control switch SCC, Fig. 2, a receiving control switch RC, Fig. 3, a counting switch GC used for checking purposes, receiving storage groups 3CA .. 3CG, 4CA .. 4CG for station panel selection and a group A .. H for apparatus indications which are transferred to the two-position receiving relays CP &c. on the panel selected. The outstation, Figs 5-8, comprises an impulsing group XX-ZX, Fig. 5, a relay counting chain, Fig. 7, a receiving control switch RU and storage group AX .. 3S for apparatus control, a receiving two-position relay group ON .. AW, a sending control switch CS and a two-position relay group CT . SP. The signals 3 .. 6 are controlled by relays LU, MU, LD, MD under the control of WMC .. ELC jointly controlled by EP, WD and point contacts PO1-PO3. The code comprises combinations of digits 1-4 of which 3, 4 effect outstation selection and 1, 2 control apparatus selection. Thus the codes 4, 2, 1, 3, 2 and 2, 3, 1, 2, 4 would select different outstations but the corresponding apparatus at each station. The circuits at each outstation are affected by the transmission but only the particular substations corresponding to the codes respond effectively. The two-position relays may be of the kind described in Specification 354,847, [Group XXXVII]. Transmission of code from control station, Figs. 1 to 4. It will be assumed that key RN 1, 2) is reversed to change the points PT, Fig. 8, and that a code 4, 2, 1, 1, 3, 1, 1 followed by a check digit 5 is required to effect this operation. Relay OCS is operated when any control key is positioned differently to a corresponding two-position relay CPS, ESS, WSS the position of which depends on the condition of the distant apparatus to be controlled. Start key SK operates SS which is followed by TP, Fig. 4, Z, Fig. 3, MS, MSA, Fig. 2, OC, Fig. 1. The operation of Z prepares a group of relays X-Z which operate and release in turn, impulses being repeated by X to relays AA, M, Fig. 4, which respectively send impulses over the line and to the counting relay chain, Fig. 4, which is operated in pairs (1A, 1B, &c.) for each make and break of M. AA pulls up to open the normally closed line circuit so that line relay J relapses to operate BC, ALS, BA, BB. Pendulum relay V is energized so that AJ pulls up and is maintained energized. for about 10 seconds by the vibrating armature of V when this relay is released by the relapse of ALS on operation of BB. TP and Z fall back and X pulls up to release AA and operate M, followed by CA which energizes CB, Fig. 3, and 4CP, Fig. 2, over wiper SCC2. Relay group X-Z sends impulses which are repeated to line and the counting chain until 4 impulses have been sent, whereupon Z is held (to stop impulsing) by 4B over SCC2 in series with ST which operates PCO, DEL and holds 4CP. At the end of the train CA, CB slowly relapse in turn, the counting chain restores, ST, 4CP fall back but COX pulls up to hold PCO. Relay DEL which prevents stepping of SCC at the end of the outstation digits also relapses. When CB has released, Z falls back and a second train of impulses (2) is sent out until Z is held by 2B in series with relay CPS and key RN1. When CA, CB relapse at the end of the train SCC takes a step together with a counting switch GC, Fig. 3. CPS releases but its armature remains in its set position. The next two trains comprise single impulses since Z is held by 1B over SCC3 (contacts 2 and 3) in series with relays ESS, WSS and keys TG1, TG2 respectively, SCC taking a step after each train. Relays WSS, ESS do not change position since the circuits pass over their lower windings. At the commencement of the next train (3 impulses) 3CP is operated over SCC2 (contact 4) by CA so that impulsing proceeds until 3B holds Z in series with ST which releases PCO and operates DEL to prevent SCC from stepping. When CA falls back ST relapses and STP pulls up to release 3CP. Two further trains of single impulses are sent out in similar manner, Z being held, to terminate the trains, over SCC3, leads NA, NB and keys SG, PC, switch SCC being stepped after each train so that it is now on contacts 6. DCH operates over SCC2, locks up, opens the counting chain circuit, and steps counting switch GC to contacts 3. The impulsing relays X-Z now send a train of 5 checking impulses to line during which time M steps GC instead of the counting chain, and on the 5th release of M, CC pulls up over GC2 (contact 7) if the trains have checked up properly, locks and breaks the circuit of M. When CA and CB have fallen back, X pulls up, releases AA to close the line and when BA ultimately releases the switches are homed and all sending apparatus is restored to normal. Code reception at outstation, Figs. 5-8. During the preliminary operation of AA at the control station, line relays LS at the outstations fall back. At the outstation shown, the relapse of LS operates BQ which is followed by BM, BN, and when AA falls back to close the loop, LS re-operates and S pulls up followed by CE, CY. Incoming impulses are repeated by LS and S to the counting chain IJ, 1R .. 4J, 4R which builds up in pairs, and at the end of the first digit (4), 4R operates 4S over wiper RU2 of the control switch. 4S looks up and CE, CY fall back in turn -to release the chain and step RU. On receipt of the next train (2 impulses) CE, CY re-energize, the counting chain builds up to 2R, and relay AX of the storage group operates over RU3 and locks up. RU takes another step at the end of the train, and as this digit is 2, counting switch CU also takes a step. The remaining code digits are received in similar manner, RU standing on contact 7 during reception of the last digit, so that BD pulls up over RU2 and locks dependent on BQ over a lead not shown. As the outstation shown corresponds to the code transmitted, 4S, 3S will have been operated to prepare the circuit of two-position relay CN selected by AX. At the end of the last code digit RU steps again and when both CE, CY have relapsed, CD pulls up, locks, and changes the impulse circuit from the counting chain to the counting switch CU which immediately steps to contact 3 and then, during reception of the check digit, to contact 7. Relay CZ thereupon pulls up over wipers CU2, RU2, locks, and completes the circuit for the control relay CN. The transmission has now been checked by (1) the operation of BD if the number of trains has not been too few, (2) the operation of CZ if the number of digits 2 is correct. If the number of trains had been excessive, one or more of them would have operated the counting switch. When the line circuit is finally completed, LS operates to release BQ which is followed by the release of S, BM, BN, CD and the storage group, Fig. 6. During the slow release of BN, the operation of GS, Fig. 5, is prevented to avoid backward signalling until the circuits at the control and outstation have completely restored. Relay CN operates GB over contacts 11 which are closed only when all the signals are normal as shown, and GB operates motor PS which moves the points and changes over contacts PO1-3 whereupon GS pulls up. Transmission of code from outstation to control station. This may be a supervisory signal in response to an operation such as described in the preceding paragraph or it may be originated directly by changes at the outstation, e.g. by train operation of a track relay TRB. Relay GS operates in response to any change at the outstation so that P, T, Fig. 7, pull up followed by AB, YX, VX, AM, R. Relay R opens the loop to the more distant outstations and prepares a local loop over impedance Q which matches the cut-off portion of the line. Line relay LS falls, BQ, BM, BN pull up and T falls back to release AB which restores the loop whereupon LS re-operates and energizes TS and TSA which prepares the circuits of counting switch CU and disables thos