Patent GB-311188-A (GB)
Title: Improvements in or relating to electric controlling and signalling systems
IPC: B61L7/08
Filed: 1929-05-06
Abstract: 311,188. Associated Telephone & Telegraph Co., (Assignees of Hershey, H. E.). May 5, 1928, [Convention date]. Selective distant control systems; tell-tale apparatus.-In an arrangement for operating or supervising remote apparatus at a plurality of stations by means of stepping switches, the switch at each station controls the switch at the next station while the switch at the last station controls the switch at the central station. The application to a train dispatching system is shown, Fig. 1 being the control station and Fig. 2 showing two remote stations provided with stepping switches S1 S2. Operation of stepping switches. The operation of key K interrupts the circuit of the normally energized relay 7 which causes relays 8, 10 to operate of which the former re-energizes relay 7 while the latter locks itself, operates an alarm relay 11, and at contact 49 applies potential to the line wire 71 to operate relay 115 which energizes stepping magnet 113. At contact 150 relay 114 is energized to energize a relay 119 at the next station which energizes the stepping magnet 117 and relay 118. At the last station the relay 118 closes line wire 72 to energize relay 13 thus energizing stepping magnet 15 which by energizing relay 14 breaks the line wire circuit 71 thus deenergizing relays 115, 114 and the stepping magnet 113 to operate switch S1 one step. Similarly switch S2 is stepped and relays 119, 118 and stepping magnet 117 de-energized which deenergizes relay 13 and by the release of the stepping magnet 13 switch S is operated and relay 14 de-energized. The wipers 37, 131, 133 in this position energize pole-changing relays 12, 116, 120 and release relay 9 which de-energizes relays 8, 10 and thus relay 11 to stop the alarm. Contact 47 effects the re-energization of relay 115 and stepping magnet 113 with current of reverse polarity and the stepping cycle is repeated through all stations with alternating polarity until on the return to normal relay 9 is re-energized. Operation of apparatus. The key K marks a contact of the selector 36 with positive, negative or alternating current and operates over line wire 70 a three position polarized relay P. An alternating current signal energizes relay 104 which opens the polarizing winding 103 which restores the relay P to the mid-position. Relay P controls a relay 101 which is preferably an existing threeposition relay in a train dispatching system. Tell-tale apparatus. A track relay 111 of a known track circuit type indicates at the control station the movement of a train. As shown with relay 106 de-energized positive potential is applied to the line 70 and operates relays 6 energizing lamp 18 each time a stepping operation is effected. The release of relay 111 momentarily breaks the circuit of relay 107 which de-energizes and when the switches return to normal initiates a further stepping cycle when the operation of relay 106 will cause the changed condition to be indicated. If the switches are off normal when relay 106 energizes the signal is stored and on the return to normal a stepping cycle is initiated and relay 105 is energized so that relay 107 is re-energized and locks itself. A recorder may be associated with relay 6. At the control station additional keys K2, K3 may be provided to lock in all super. visory signals and to sound the alarm continuously respectively. A train dispatching keyboard TD and selectors TD1, TD2 of known type may also be operated over line wire 72.