Patent GB-386337-A (GB)
Title: Improvements in or relating to electric remote control systems
IPC: B61L7/08
Filed: 1931-07-10
Abstract: 386,337. Electric signalling and remote-control systems. S T A N D A R D TELEPHONES & CABLES, Ltd., FLINT, J. G., BATES, E. F., and GRIFFITHS, J. B., Connaught House, Aldwych, London. July 10, 1931, No. 19917. [Class 40 (i).] In an electric signalling and remote control system in which signals and controls are transmitted between a control station and a number of sub-stations connected along a line, if the line becomes disconnected apparatus at the control station automatically earths the battery and, when a sub-station is about to transmit signals, apparatus at the sub-station tests the line to determine the position of the disconnection and patches the line to earth on the disconnected side. Working from shorted stations is also described. Signals and controls are transmitted by codes comprising a fixed number of impulses divided into three groups, the codes being cut on cams which are clutched to driving mechanisms when required. The invention is described as applied to a system in which railway signals and points are controlled from a central station, the positions of the remote apparatus being signalled back to set a mimic diagram. Interlocking of the apparatus prevents inconsistent setting of points and signals. In the event of battery failure all signals change over to " danger " whilst points remain locked in their last settings. Signals are returned to indicate battery failure or the failure of individual lamps. Confirmatory signals of the position of all apparatus can be obtained. Final indicator. Fig. 6 shows the section of the final indicator corresponding to a single. sub-station. The down and up main and branch lines are indicated at DM, UM, DB and UB respectively, and are connected by points P1, P2 represented by mimic point contacts. The actual points are controlled by buttons PM, PB whilst the diagram points are set by supervisory trains from the sub-station. Mimic signal lamps Sl .. S4 are set by supervisory trains from the sub-point when the down main, down branch, up main and up branch signals change their positions and control buttons such as DPB, CPB mounted on the mimic signal panels control the remote signals. The interlocking prevents inconsistent setting such that for example P1 can only be moved to the branch position if S1 and S3 are at danger and only when P1 is set can S2 be moved to proceed. The points cannot be reset unless S2 has again been set at danger. Normal operation of control station apparatus. Fig. 4 shows a section of the control station apparatus, all signals being set at danger and the points normal. It is assumed that P1 is to be moved to the branch position and then S2 set at proceed. The key PB, Fig. 6, associated with P1 is depressed and springs O in P1C, Fig. 4, close, completing a circuit over contacts of S1, S3, S5 for P10. P10 looks to cam RC, clutch magnet C operates and cam P10C is driven round to send its code to the line via relay 1R. The,substation apparatus is set in the manner described hereafter and when the points have operated, a code is returned to the control station to step the selectors 1S1 .. 1S7 so that 1S6 makes its contact 9 and coil 0 of relay S5 is energized and as the relay is polarized, the contacts remain in their operated condition. Relay P101 of P1C is energized and moves the mimic diagram point PI into its reversed position. The circuit of S20 is prepared by the energization of S5 so that the depression of key 0 of S2C is now effective to operate S20 and cam S20C transmits its code to set the down branch signal to proceed. When the signal has operated, a code is received at the control station to set 1S3 to position 3 and coil 0 of S2 is energized to light the green lamp in S2C. The diagram now indicates a clear ,route from A to E, Fig. 6. The inter-wiring of the relays in Fig. 4 is such that the signals S1 and S3 cannot now be operated but the points P2 and signal S4 can be controlled to allow a train on the up branch line to proceed. Normal operation of substation apparatus, Fig. 5. The impulse codes are received by relay L which repeats them to selectors SMS, SS1 .. SS4, SP1, SP2. If, for example, SS1 is set to contact 2, a circuit is completed, with the apparatus in the position indicated, for relay S1 to operate. Relay S1 locks up and can be reset only by the setting of SS1 to contact 1, which shorts S1 down. SC1 pulls up, changing the signal over from red to green and energizing 1R1. Relay LO1 pulls up and code cam 2 is connected to terminal W and its code is transmitted to the control station in the manner described hereafter. When the code has been successfully transmitted earth is connected to terminal T and CC1 pulls up. LO1 releases to stop the transmission. IR1 and CC1 remain energized until SC1 is released, when a further code is transmitted by cam 1, to reset the mimic diagram indication and, when earth is again connected to T, CC1 restores to normal. The relays LO1..LO7 are wired so that, should circuits for other relays be completed whilst one is energized, transmission of the later codes are held up and are then transmitted in turn. Substation apparatus fault arrangements. The relays SC1 .. SC4 are arranged to release, on battery failure, to set all signals at danger, but the relays PC1A, PC1B, PC2A, PC2B, which control the points, remain locked in their last operated position. An ammeter movement Q is provided in the lamp supply circuit which detects alteration in the current flow to the lamps, the number of lamps burning being constant, and controls the transmission of a signal back to the control station if the current flow varies, due, for example, to a lamp burning out. The transmission is effected by IR7 and CC7. Disconnection of lamp' current supply. In systems shutting down at night the lamp current supply-is controlled by selector SMS and relay MSS. Checking indications. All indications may be checked by setting the substation selectors to energize CH. The connections to relays IR1 .. IR6 are thereby reversed and impulse trains are transmitted to the control station to reverse the condition of all apparatus on the mimic diagram. The checking selector is then set to its second position, CH releases and the IR relays return to their original positions, a further series of impulse trains being transmitted to reset the mimic diagram. During checking the actual apparatus connections are unaltered. Normal transmission arrangements from substation. The substation transmission equipment is indicated in Fig. 1. When a signal train is to be transmitted, earth is placed on lead S, as described above, and C operates. The short circuit across the substation is removed and, if no other station is sending, S1 operates in the line circuit. The code cam transmits its code over W, and CS repeats the signal train to the main station. Shortly before the end of the train C1 closes temporarily and earths T, C is released as described above, but the sequence switch completes a full revolution under control of off-normal contacts. Succession working. Should another station be sending when C operates, Sl pulses in synchronism with the code transmitted. The cam contacts OF are made at the commencement of the movement of the sequence switch and S2 pulls up, when S1 releases, and locks. The local code cam continues to rotate and transmits its code to W, but S3 responds, instead of CS, and locks to C2. The circuit from C1 to T is consequently broken so that the substation apparatus is not operated and C is not released when C1 closes but S2 is shorted down. At the termination of the first revolution of the switch, C2 opens, S3 releases and the switch commences a second revolution, the cycle being repeated until S1 remains up for the period of closure of OF, when the code is transmitted to the main station as described above. Disconnected line working. Should the line be disconnected, S1 will not operate when C pulls up and S2 energizes as described above. S2 completes a circuit for clutch magnet MC and if S1 is not pulsing in synchronism with another station, the circuit of MC is maintained to allow contacts MC1 to make. E1 operates and earths the left-hand side of Sl. As described hereafter, when the loop becomes disconnected the control station apparatus connects the lines together and to one pole of the battery and earths the other pole, so that if the disconnection is to the left of S1, S1 now operates, releasing MC, holding El and allowing the code to be transmitted on the second revolution of the switch as described above. If, however, the disconnection is to the right of S1, the relay does not pull up when E1 energizes and shortly afterwards first MC2 closes to energize E2, shorting S1, and then MC1 opens to release E1. S1 now operates, MC releases and E2 locks up. The code is transmitted during the second revolution of the sequence switch over the left-hand half of the loop. The energized relay E1 or E2 is held during the transmission over contacts of C. Short circuit working. Should the lines become connected so that the substation is shorted, signals can still be sent to the main station following the earthing of the line by E1, the battery connections at the main station being suitably altered under these circumstances as described hereafter. Operation of main station receiving equipment, Fig. 2. The lines L1, L2 are normally connected through relays T1 and T2 to relay R and the battery, the relay R repeating the impulse trains to suitable selectors not shown. Should a disconnection occur in the loop relay R will release and remain de-energized for a sufficient length of time to allow clutch magnet MC to operate and PC to be energized. In addition T1 and T2 fall away and circuits are completed for A and C which relays lock to contacts of T1 and T2 respectively in circuits independent of PC. Relay P pulls up over contacts of A, locks to the cancel key CK, connects L1 and L2 together and t