Patent GB-419399-A (GB)
Title: Improvements in systems for the communication of control or signal influences, more particularly for centralised traffic controlling installations for railways
IPC: B61L7/08
Filed: 1933-09-08
Abstract: 419,399. Electric selective signalling and remote-oontrol systems. GENERAL RAILWAY SIGNAL CO., Rochester, New York, U.S.A.-(Assignees of Judge, T. J. ; 172, Warwick Avenue, and Bushnell, C. S. ; 53, Hancock Street, both in Rochester, New York, U.S.A.) Sept. 8, 1933, No. 24955. Convention date, Oct. 28, 1932. [Class 40 (i).] In a signalling and control system in which signals and control impulses are transmitted by codes sent simultaneously over separate indication and control leads, the impulse spacing is controlled at the control station, control codes being sent during the make periods of the impulses whilst indication codes are sent during both make and break periods. Relay-chains distribute the codes, which are of the positive-negative type, the same relaychains distributing incoming and outgoing impulses, and the impulses are spaced by a group of interacting relays, one of which is slow-to-release. The codes over the control lines are received by three-position biassed-toneutral polarized relays, whilst those on the indication circuit are passed to relays in front and back loop circuits, the circuits being connected up in turn and in synchronism at both main and sub-stations. The invention is described as applied to a railway signalling system in which points are set from a remote controlling-station and indications of track occupation and signal positions are transmitted from the field positions to the controlling-station. General operation (Figs. 1 and 2). When a control is to be transmitted to a remote point a train of positive and negative impulses is transmitted over the control lines 10, 12, the polarity of the individual impulses being determined by relays NC and PC and the timing of the impulses being controlled by relay EP. The three-position biassed-to-neutral polarized relays F<1> F<2> &c. at the field-stations respond and build up relay chains, the chain being completed only at that station at which the apparatus required is situated, and the unit being operated by the final pulse in the signal train. Should a field station initiate the transmission of an indication train, an impulse train is again sent over the control lines, the code used in such instances being a code reserved for indication purposes. As relay EP pulses, relays DV, FP and 2FP at the main station and relay FP<1> at the sub-station connect the front and back loops shewn into the indication line 14, 16 so that relays MB and MF at the main station repeat the condition of PB<1> and PF<1> (or PB<2> and PF<2> &c.) to a relay chain which selects relays appropriate to the station signalling and controlled by the final pulses received to control units on a mimic diagram. Instead of the transmission over the control line of the particular indication code when an indication transmission is initiated, a control code can be sent, the two codes being sent simultaneously over the control and indication circuits. Transmission of control code (Figs. 4 and 5). It is assumed that the motor SM (Fig. 3) is to be controlled to move the points TS. Lever SML (Fig. 5) is moved into the dotted position and button 1SB is depressed. Relay 1CH operates followed in turn by relays CHP, C, 1CD and CDS and one of the relays NC or PC pulls up depending on the position of the first code jumper 40. In the position indicated PC is energized over 46 .. 41 and a positive impulse is applied to the control line. Relay F at the control station, as well as the relays F', F<2> &c. at the field-stations, responds to this impulse and relay FP is energized followed by relays 2FP, SA and 2SA. Relay VP energizes and E pulls up followed by EP. Relay EP opens the line circuit to terminate the impulse so that F, FP and 2FP fall away. Relay SA is slow enough to hold up during the train. When 2FP falls away, relay IV pulls up and locks and opens the circuit of relay E so that EP falls away to reclose the line circuit and also, at 44, transfers the operating circuits of relays NC and PC to the second wiper 55. With the wiper in the position shown, PC is again energized and the second pulse is of positive polarity. Relays F, FP and 2FP again respond and 2FP opens the holding circuit of VP which falls away. The circuit of E is thus recompleted and EP is energized to terminate the pulse. When 2FP falls away, relay 2V energizes and locks, opening the circuit of E and completing the circuit of either relay NC or PC over wiper 58. In the position shown NC is energized so that the third pulse is of negative polarity. When relay FP pulls up on the third pulse, relay VP re-energizes and E operates to allow EP to pull up and terminate the third pulse. Relay 3V energizes when 2FP falls away connecting lever SML into the circuit of NC or PC and releasing E and EP to close the line for the fourth pulse. The polarity of this pulse is determined by the position of lever SML, the pulse being negative with the lever in the position shown, and is used to control the apparatus selected by the preceding code train. When 2FP pulls up on the fourth pulse, VP de-energizes and completes the circuit of slow-acting relay LV. When LV has operated E pulls up and EP energizes to open the line circuit. Relay LV also opens the circuit of relay CHP so that this relay falls away followed by relays ICD and ICH. As no further pulses are to be transmitted the line circuit is opened for a sufficient time to allow relays SA and 2SA to fall away whereupon all energized relays are released. Receipt of control code (Fig. 3). The control code is repeated by the relays such as F1 at all field-stations. On the receipt of the first pulse relays FP<1>, SA<1> and SB<1> are energized and if the pulse is of the correct polarity for the particular station, relays SO' and SOS<1> are energized over wiper 111. Relay SO<1> remains up, if energized, during the break portion of the impulse train and, if the second impulse is also of correct polarity, remains held during this impulse over wiper 112. If the second impulse is not of correct polarity, SO' falls away and cannot be re-operated during the impulse train. The process of elimination continues until only the required station has its relay SO<1> operated. In the example described seven stations are contemplated so that the station is selected by the third pulse and as the code transmitted was +, +, -, the station shown in Fig. 3 is picked up. The relays VP<1>, IV<1>, 2V<1> and 3V<1> operate in synchronism with relays VP, IV, 2V, 3V at the control station and connect the impulse receiving contact 114 in turn to wipers 111, 112 and 113. On the termination of the third impulse the contact 114 is connected to relay SMR, the circuit being completed over either contact 115 or 119, depending on whether the fourth pulse is of positive or negative polarity, so that contact 150 is moved to control motor SM to move the points TS. When the pulse terminates, relay LV<1> at the selected substation energizes to release relay SO' and at all stations relays FP<1>, SA<1> and SB<1> fall away to release all energized relays. Supervisory signalling. Should either the track relay T or the signal relay M at the substation fall away, the circuit of normally energized relay CH<1> is broken and relay LO' is energized and locks, completing the indicating circuit at contact 156 to energize relay MB at the control station. Relay FC (Fig. 5) pulls up and locks, energizing relay NC to connect a negative pulse to the control lines. Relays F, FP, 2FP, SA and 2SA pull up and an impulse cycle is transmitted over the control lines, the cycle comprising all negative pulses. This code is reserved for this feature and is not assigned to a field station. At the initiating field station relay LO1 is locked up and as its contacts are in parallel with those of SO<1>, the relays IV<1>, 2V<1>, 3V<1> are energized in sequence. As the relays SO' at all stations are released at some stage during the transmission, the sequence relays IV<1>, 2V<1>, 3V<1> are not all energized at any other station. During the energized periods of FP<1>, relay PB<1> is connected in turn by relays IV<1>, 2V<1> and 3V<1> to wipers 180, 181 and contact 192 of T and this relay is positioned according to the polarity on these units. The relay, when energized, locks up during the de-energized periods of FP<1> and during these periods its contact 191 is in an effective part of the indication line. Similarly relay PF<1> is connected in turn to and positioned by wipers 182, 183 and contact 201 of relay M during the de-energized periods of FP<1> and maintains its position during the following energized period of FP<1>, its contact 199 then controlling the indicating circuit. At the control station relays MB and MF are connected to the indication loop during the de-energized and energized periods of FP respectively so that these relays follow the movements of PB<1> and PF<1> respectively and, by means of the relay chain 1V, 2V, 3V, pass on the signal received to energize the required combination of relays 1PF, 2PF, 1PB, 2PB (Fig. 6). The first four pulses received, determined by the connections of wipers 180, 182, 181, 183 respectively determine the sending unit and select a relay such as 1ST, 2ST at the control station which relay operates and connects relays such as 1RF, 1RB to front contacts of relay 3V. The impulses received during the fourth impulse period, the polarity of which are determined by relays T and M at the field station, position relays 1RF and 1RB to control the mimic diagram. Relay CH<1> is reset during the second impulse period and when the cycle ends SA<1> releases and allows LO<1> to fall away. All other relays are released in a manner similar to that described above in connection with the transmission of a control. Duplex working. A control and an indication code may be transmitted simultaneously, the only difference from the conditions described above being in that the code transmitted over the control line