Patent GB-386973-A (GB)
Title: Improvements in or relating to electrical signalling systems
IPC: B61L27/00
Filed: 1931-07-24
Abstract: 386,973. Electric signalling systems. AUTOMATIC ELECTRIC CO., Ltd. (formerly AUTOMATIC TELEPHONE MANUFACTURING CO., Ltd.), Strowger Works, Liverpool, OLIVER, E. C., 229, Sea Bank Road, Wallasey; Cheshire, and SIMPSON, L. M., The Bungalow, Laurel Bank, Stanks, near Leeds. July 24, 1931, No. 21212. [Class 40 (i).] In an electric signalling system more particularly for indicating at a cabin on a railway track, information regarding the passage of successive trains, the signals comprise one or more trains of impulses and the arrangement is such that after the transmission of an impulse in a train, a succeeding impulse cannot be transmitted until a checking signal is reverted from the receiving station. Figs. 1 to 11 show the transmitting apparatus, and Figs. 12 to 19 the equipment at the receiving station. Information regarding a train, viz. the number of a train passing to the receiving station, is transmitted as a three-train impulse code, the impulses being transmitted under the control of a stepping switch CNS adapted to be marked successively by groups of storage relays HP .. HU ; TP.. TU; UP.. UU which are set by the numeral keys 1 .. 10. Subsequently to the transmission of the number of the train, a further signal indicative of the destination as determined by keys 210 .. 290 and the associated storage relays WQ, WU, XP .. XU, is transmitted under the control of switch CNS. At the receiving station each train of incoming impulses operates a chain of counting relays, Fig. 15, 'which set the registers 2HP .. 2HU, 2TP .. 2TU, 2UP .. 2UU in turn to select the number and name display relays, Figs. 13, 18, and 19, and effect the operation of appropriate lamps in the indicator. Additional groups of storage relays similar to those shown in Figs. 13, 18, and 19 are provided to operate further lamp indicators in order that information relating to successive trains may be displayed simultaneously. Signals relating to a first train after being received in the storage groups, Figs. 13, 18, and 19, are transferred through the successive groups by the equipment shown in Fig. 14 and are displayed on the final lamp indicator. Subsequent signals relating to " second," " third," &c., trains are then displayed in successive indicators and further signals may be stored ready for display in the storage relays, Fig. 16. When the " first " train passes the receiving station, the indication is cancelled from the final indicator and the subsequently displayed and stored signals are transferred through the receiver so that the " second " train indication becomes the " first " train indication, and so on. This operation frees the initial storage equipment at the receiving station for further operation by the transmitter. Setting registers at the transmitter. The numerical designation of the train is transmitted as a three-digit code. Upon operation of the first numeral key in the group 1 .. 10, relay CK prepares the circuit of stepping magnet CNM and the associated storage relay in " hundreds " group HP .. HU is operated in series with relay P which operates PR to provide at contact pr1, Fig. 4, a locking circuit for the storage relays. The selected " hundreds " relay marks a contact in the bank 1a of switch CNS and lights the appropriate lamp in the " hundreds group, Fig. 8. Upon release of the numerical key, CK releases and switch CNS moves one step to operate relay HW over wiper 3a and thereby transfer the key leads to the " tens " storage relays TP ..TU. Operation of the " tens " digit key operates the appropriate relay in the associated storage group which marks the bank 1a of switch CNS and lights the corresponding lamp, Fig. 8. Release of the key connects the " unit " relays to the keys and the units digit is stored and displayed in a similar manner. Upon the 3rd step of the switch, relay UW closes a selfdrive circuit for the switch over wiper 4a and the switch steps automatically until the 7th position is reached. Upon operation of the " destination " key in one of the three groups a corresponding relay DA, DB or DC is operated to energize one or other or both of relays WQ, WU according to the group affected in order to effect a characteristic marking of the switch CNS over contacts wq, wu, Fig. 3. Operation of relay DA, DB, or DC moreover connects the keys to the storage relays XP .. XU, operation of which effects a marking of the switch in a manner characteristic of the depressed key. Operation of selected relays in the relay groups WQ, WU, XP.. XU .effect the selection of a particular circuit in the lower part of Fig. 8 to operate a " check " lamp opposite the destination label at the transmitter. The relays WQ, WU are operated in series with relay PW which operates SA over wiper 2a to prepare the " start " circuit. Depression of the " start " key operates relay ST which closes the circuit of line relay A over line wires a, b. Economy in the use of storage relays is effected by using the relays either independently or in combination with an additional relay, e.g. HU, which effects transfer from the first half of the marking conductors to the second half. Transmitting impulses to receiver ; checking transmission. Relay A operates in series with line-relay AS at the receiving station, Fig. 12. Relay A flickers a lamp during impulsing and operates SR which energizes the stepping magnet CNM. Receiver relay AS operates slow-release relays CB, which operates CH to prepare the counting chain, Fig. 15, and connect up the " hundreds " storage relays 2HP .. 2HU. Relay YH pulls up and operates 2XP which locks in series with PX, which however remains short-circuited. Relay 2XP operates Y which transfers the line wires a; b to line relay LS. Relays A, AS now release relay A, releasing SP which de-energizes the stepping magnet to operate the switch a further step. During the releasing period of SP, Z is operated and the line wires are transferred to line relay L at the transmitting station. Relays L, LS operate in series, relay LS releasing YH and permitting operation of PX which prepares the circuit of the next pair of counting relays QX, 2XQ and the circuit of the storage relay 2HP, Fig. 16. Line relay L restores Z which reconnects relay A to the live wires, and this action releases LS which allows Y to fall back and transfer the live wires again to relay AS. Relays A, AS are again operated and the cycle of reciprocal control is repeated to operate the next counting pair of relays 2XQ, QX and prepare the circuit of the next storage relay 2HQ. This action is continued until wiper 1a of switch CNS encounters the contact marked in accordance with the " hundreds " digit when relay SZ, Fig. 2, is operated. In these circumstances L is unable to restore Z since the latter relay is held over the contacts of SZ and relays L, LS are maintained in series for an extended period during which slow-release relay C at the receiving station falls back and operates over contacts C1 the appropriate relay in the " hundreds " storage group 2HP .. 2HU. The selected relay in this group prepares the circuit of a corresponding relay in group 5HP .. 5HU and is operated in series with HH which effects the transfer of the counting chain to the " tens " storage group 2TP .. 2TU by the action of relay CT. Relay CH is released to disconnect the " hundreds " group and release the counting chain. As both relays SZ, Z are operated a self-drive circuit is closed over wiper 2a and the switch steps until the wiper moves off the earthed multipled contacts. Thereafter stepping is dependent upon the marking of further contacts by relays MA; MB, MC; MD, CO. Self stepping therefore proceeds until the contact connected to ma5, Fig. 4, is reached. In this position relay MA, Fig. 2, is operated over wiper 1a to transfer the marking leads of the bank 1a to the marking contacts of the " tens " storage group and at contact ma2, Fig. 4, to remove earth from the associated contact in bank 2a in order to provide a stopping position for the switch after the transmission of the second train of impulses. Moreover contacts ma5 earth the engaged contact and stepping is resumed until the switch arrives in its 6th position. In this position SZ, Z are released and the switch is again stepped to transmit the second digit in a manner similar to that previously described. After transmission of the digit, MB is operated to prepare a new stopping position for the switch and effect marking of the bank 1a by the " units '' storage group. The " units " digit is then sent and relay MC operated to prepare for the similar transmission of the " destination " digits, transfer of the marking to the bank 1a being effected by the switching relays MC, MO. After the transmission of the final digit, a circuit is closed over wiper 1a and lead 17 for relays 1WQ, 1WU; 1XP.. 1XU; 1TP .. 1TU ; &c., in further storage groups selected in accordance with the operation of the groups WQ, WU ; XP .. XU; HP.. HU; &c. Depending upon the operation of, one relay in each group relay PL energizes to maintain the selected relays operated. The selected relays close circuits, Fig. 9, connected in parallel to those shown in Fig. 8 for the lamp) indicators and thus provide a check on the number and destination previously set up and effect the display of the " last train sent after signal transmission. Relay PL also operates relay CO which releases ST, PR the former opening the line circuit and the latter releasing the operated relays in groups WQ, WU ; XP .. XU ; &c. and also relay P, which closes a homing circuit for the switch CNS and allows CO to fall back. The transmitting apparatus is thus restored to normal. When a further description is set up operation of the first numerical key causes operation of CK which initiates stepping and also releases the storage relays associated' with the " last train sent " lamps. A " cancel " key is provided at the transmitter and is effective to release the storage