Patent GB-191391-A (GB)
Title: Improvements in telephone systems
IPC: H04Q3/42
Filed: 1923-01-05
Abstract: 191,391. Western Electric Co., Ltd., (Assignees of Matthies, W. H.). Jan. 5, 1922, [Convention date]. Automatic and semi-automatic exchange systems.-In systems using registers to control the setting of rumerical selectors, certain of the registers are individual to and permanently associated with a selector trunk while others are temporarily associated with the trunk in the usual way. This arrangement avoids the possible loss of impulses due to delay in connecting up an idle register set when a manual exchange operator plugs into a trunk to an automatic exchange, or when a call is extended from an exchange having selectors directly controlled by the selecting impulses to an exchange having selectors controlled by registers. In the system described, a calling line is connected by automatic switches 2, 4, Fig. 1, to a trunk 8, 9 having a selector of the panel type, this trunk having individual thereto a thousands register A, Fig. 2, and a sender selector SS, Fig. 2, which connects up an idle set of registers B, C, D, E, Fig. 3. The registers A, C, D, E are step-by-step switches, which are set by the successive digit impulses, but the thousands register B consists of four relays 24, 25, 35, 41 to which the setting of the register A is transferred. The registers are wired to effect the necessary translation. Setting of individual register A, Fig. 2, and selection of dle register set, Fig. 3. When the trunk 8, 9 is taken ipto use, the relays 5, Fig. 2, 10, 17, 18, energize in succession, relay 17 energizing the stepping magnet 14 of the sender selector SS. When the wiper 19 reaches an idle register set, the locking-circuit of relay 17 is opened, relay 20 energizes, and relay 18 earths the wiper 19 energizing relay 21, Fig. 3. The first set of impulses is repeated by relay 5 through relay 12 to the stepping magnet 13 of the register A, and at the end of the impulses relay 12 removes a short-circuit around relay 11 which extends the impulse circuit over the armatures of relays 5, 10, 11, 20 and wiper 46 to the register set. Transfer of setting of register A to relay register B, and setting of registers C, D. E. The lefthand winding of the relays 24, 25, 35, 41 are connected over sequence switch contacts 26, 37, 42, and wipers 28, 39, 44 of switch SS to the wipers 24, 36, 45, respectively of register A, the contacts engaged by these wipers being connected directly, or through high or low-resistances 31, 32, to battery by relay 11. One or more of the register relays are thus energized according to the. setting of the register A, and the energized relays lock up over their right windings. The hundreds impulses are repeated by relay 5 over wiper 46 and series relay 48 to the stepping magnet 16 of register C. At the end of the impulses, relay 48 removes a short circuit from relay 49 which extends the impulse circuit to the stepping magnet 53 of register D which is set by the tens impulses. When these cease, the series relay 48 removes a short circuit around relay 54 which extends the impulse circuit to the magnet 58 of the units register E. Control of selector, Fig. 1. When the calling subscriber transmits the hundreds digit, series relay 48, F:g. 3, causes relay 60 to move the sender sequence switch 61 into position 2, in which relay 70, Fig. 2, is energized to restore register A. Relay 70 also energizes a relay 40, which completes the fundamental circuit extending from the right-hand winding of relay 64 over circuit 65, 66, 67, 68, 69, 39, 38, to the stepping- relay 75, Fig. 3, and thence over circuit 42, 43, 44, 76, 77, 78 to ground. Relay 64 moves the selector sequence switch 79 into position 2 in which the up-drive magnet 83 is energized, and a locking circuit for relay 64 closed over its righthand winding, springs 81, 66, 67 &c. as before. When the brush 85 engages commutator 86, the stepping relay 75, Fig. 3, is intermittently shortcircuited, these impulses being repeated by relay 75 in position 2 of switch 61 over spring 73, armature of relay 75, springs 90, 82, and contacts of the register relays 24, 35, 25 to the selected relay of the relay chain R, the leads 0, 1 - - 9 of which are connected to the correspond leads indicated by the circled numerals of all the registers B, C, D. E. When the chain has run down in the usual way, relay 0<1> opens the fundamental circuit and moves switch 61 into position 3, unlocking the relays. Relay 64 disconnects the updrive magnet 83 and moves switch 79 into position 3. When the transmission of the hundreds digit is completed, relay 48 again energizes relay 60 to move switch 61 into position 4, in which the fundamental circuit is closed, relay 64, Fig. 1, moving switch 79 into position 4 in which the up-drive magnet is again energized. As the brushes move up, the selected set is tripped by magnet 92 and group selection is effected under control of brush 93 which intermittently engages commutator 94, thereby short-circuiting relay 75, Fig. 3, which repeats these impulses over spring 73, armature of relay 75, contacts 90, 82, wiper 91 of register C, and one armature of relay 41 to one of the chain relays, determined by the thousands and hundreds digits of the wanted line. When the chain has run down, the fundamental circuit is again opened, relay 0<1> moving switch 61 into position 6 and relay 64 moving switch 79 into position 6 in which an idle trunk in the wanted group is selected under control of relay 64, which locks up over the test lead of busy trunks. When an idle trunk is found, relay 64 de-energizes, moves switch 79 into position 8, and then energizes and locks up over the lead 102 of the selected trunk. Control of final selector, Fig. 4. The fundamental circuit is now closed from contact 105, Fig. 4, right-hand winding of relay 106, springs 107, 108, lead 109 and through the register set to ground. Relay 106 energizes relay 113, which locks over the test lead and moves switch 116 to position 2 in which the fast up-drive magnet 120 is energized. Brush 122 moving over commutator 123 short-circuits the stepping-relay 75, which repeats these impulses, in position 6 of switch 61, over springs 73, 90, 118, and wiper 119 of register C to the chain relay determined by the hundreds digit. When the chain has run down, the fundamental circuit is opened, switch 61 moving into position 7 to await completion of the tens registration, and switch 116, Fig. 4, into position 3. When the tens digit has been registered, relay 48 causes relay 60 to move switch 61 into position 8, the fundamental circuit being re-established to control tens selection. Relay 106 moves switch 116 into position 4, in which the fast updrive magnet is again energized. As the brushes move upwards, the selected set is tripped by magnet 129, and the brush 127 engaging commutator 128 short-circuits the stepping-relay 75, which repeats the impulses over springs 73, 90, 118 and wiper 126 of the register D to the chain relay determined by the tens digit. When the chain relay 0<1> opens the fundamental circuit, relav 106 moves switch 116 into position 5 and switch 61 moves to position 9 to await units registration. When this is effected, relay 48 causes relay 60 to move switch 61 into position 10, reestablishing the fundamental circuit. Relay 106 moves switch 116 into position 6 and closes the circuit of the slow up-drive magnet 135. As brush 122 engages commutator 136, the stepping-magnet 75 is intermittently short-circuited and repeats the impulses over springs 73, 90, 118 and wiper 134 of register E to the chain relays. When the fundamental circuit is opened by relay 0<1>, switch 61 moves into position 14, and switch 116 moves out of position 6. Disconnection and restoration of register sets. When switch 116 leaves position 8, its spring 104 opens the circuit of relay 64, Fig. 1, which moves switch 79 into position 9, in which relay 64 is again energized over the register set and moves switch 79 into position 11, wherein relay 7 energizes to connect the calling line to the repeater 152 and to open the circuit of the impulse relay 5, Fig. 2. Relays 10, 18, 20, 70, 40 de-energize in succession, and the units register E is restored. The registers C, D were restored as soon as the tens selection was completed. Busy test, signal, and release. Relay 106 is de-energized as soon as switch 116 leaves position 8 provided the wanted line is free, and the switch moves into position 14. If the wanted line is busy, the test relay 140 is energized in position 8 over springs 139, 141, armature of relay 106, spring 112 and test brush 144, and main tains the circuit of relay 106 so that switch 116 comes to rest in position 13, in which the downdrive magnet 145 restores the selector. In position 17, a busy signal BZ is connected over springs 150, 105, 112, armature of relay 106 (which is intermittently energized by interrupter 148), spring 143, trunk 102 to the repeater 152, Fig. 1, and thence to the calling line. Party-line ringing current. When the calling line is connected through to the repeater 152, relay 160 energized over the calling loop, locks up relay 7, and energizes relay 64 which locks up under control of the ringing-cut-off relay 164. For party line working, the polarity of the ringing current is selected in known manner by commutator segments 158, 159, and in position 13 of the switch 79, ringing current passes from the generator 165 through relay 164, spring 166, 100, and trunk 102 to earth at the called station. When the subscriber replies, relay 164 unlocks relay 64 to disconnect ringing current and move switch 79 into talking position 14. The supervisory relay 151 energizes over the called line and causes relay 161 to reverse the current over the calling line. Release. When the calling subscriber hangs up, relay 160 opens the circuit of relay 64 which moves switch 79 into position 18 in which the down-drive magnet 167 is energized. The ope