Patent GB-220923-A (GB)
Title: Improvements in or relating to telephone systems
IPC: H04Q3/00
Filed: 1924-03-12
Abstract: 220,923. Automatic Telephone Manufacturing Co., Ltd., (Assignees of Bellamy, J. I., and Gardner, J. E.). Aug. 25, 1923, [Convention date]. Automatic exchange systems.-A register-controller which begins to retransmit a number before the calling party has finished dialling, is provided with means whereby if the impulse sending mechanism of the registercontroller catches up the registering mechanism, the calling line is switched through and the remaining switches are operated directly by the dialling impulses. The invention is described as applied to a register-controller of the type which translates the first portion of the designation of a wanted subscriber into a routing-number which may comprise a variable number of digits. A calling line A, Fig. 1, is extended by a line switch C to a repeater R, with which is associated an idle first selector, and a non-numerical switch SS which takes into use an idle registercontroller, Figs. 2 to 5. A sequence switch S, Fig. 2, directs the dialled impulses to the stepping magnets of the registers OR, Fig. 4, DR1 - - DR4, Fig. 5, and advances a step after each digit has been recorded, whilst a sequence switch S<1>, Fig. 2, associates the impulse sending mechanism SEN, Fig. 3, with the register wipers in succession, and advances a step after the retransmission of each digit. Each numerical digit register DR1 - - DR4, Fig. 5, is provided with a normal contact which is connected over a lead 227 to a conductor 75. Fig. 1, so that if the switch S<1>, Fig. 2, grounds a stop conductor 151 - - 154 extending to a register DR1 - - DR4 in its normal position, (which means that the sending mechanism has caught up with the registering mechanism), the conductor 75 is earthed and a switching relay 43 is energized. The relay 43 causes the register-controller to be disconnected and transfers the control of the repeating relay 44 to the line relay 41. Means are provided for preventing any impulses from being mutilated or lost in case a digit is dialled about the time that this switch-over is taking place. By operating a key K, Fig. 3, circuit changes may be effected wherebv the register-controller does not switch-over when .the sending apparatus catches up. An arrangement is also described whereby after the register-controller has been disconnected, busy potential is maintained on its test wire until its component switches have restored to normal. Normal operation of register-controller. The non-numerical switches C, SS. Fig. 1, operate in the usual way. The repeater line relay 41 energizes relay 42, which earths the holding wire 29. The switching relay 61 grounds the wire 74 to energize relay 203, Fig. 3. and at armature 64 completes a bridge across the trunk 56, 58. The wanted number is now dialled, the impulses being repeated by relay 41 over circuit 75, 102, 107 to the vertical and rotary magnets 307, 306, Fig. 4, of the exchange register OR, and to the magnets 401, 402, &c. of the numerical registers DR1 - - DR4, Fig. 5, these magnets being brought into circuit in turn by the switch S, Fig. 2, which is advanced a step at the termination of each digit by its magnet 103, which receives an impulse from the series relay 102. At the termination of the second digit, the wiper 106 grounds a starting wire 114, and since the first two contacts of the terminal set selected by the exchange register OR are jumpered over the frame IDF to the skip conductor 305 (assuming only two exchange routing-digits are required), a circuit 111, 141, 311, 321, 305 is completed for the magnet 108 of the switch S', Fig. 2, which is driven to its second position, where another circuit is completed over the conductors 142, 305 to drive it into its third position. On the grounding of the starting wire 114, an interrupter 226, Fig. 3, intermittently energizes an impulse-sending relay 204, which completes at armature 214 an intermittent circuit for the magnet 223 of the sending switch SEN. When the wiper 224 engages its first contact, a circuit is closed for a pick-up relay 205, which at armature 215 energizes the magnet 108 of the switch S', Fig. 2, and at armature 216 prepares the impulse sending circuit, so that at each subsequent response of the relay 204, a circuit is closed over conductor 73 for the repeating relay 44, Fig. 1, which at armature 55 opens the bridge across the trunk 56, 58. The switch SEN continues to advance until the wiper 225 engages the stop conductor at this time grounded over the wiper 111 of the switch S<1> in its third position, conductor 143, wiper 313 of the register OR, and a jumper of the frame IDF. The stop relay 206 energizes in this circuit, locks up, disconnects the impulse relay 204, de-energizes the magnet 108 of the switch S', which advances to its fourth position, and closes a restoring circuit for the switch SEN. The relays 205, 206 relapse after an interval sufficient to permit a hunting operation to take place at the first selector, and the relay 204 then again starts to vibrate. The impulse-sending operations are now repeated and the second routing-digit is sent out, the circuit for the stop relav 204 extending this time over the fourth wiper 314 of the switch OR and the wiper 111 of the switch S' in its fourth position. The thousands, hundreds, tens, and units digits are transmitted in like manner in the fifth, sixth, seventh, and eight positions of the switch S'. .Release of register-controller. When the units digit has been transmitted, the switch S' is driven to its ninth position, in which ground over the conductor 75 energizes the switching relay 43, Fig. 1, which locks to the holding wire 29, transfers the control of the repeating relay 44 to the line relay 41, and de-energizes relay 61. Relay 61 removes ground from the test wire 74, but the register-controller is still marked busy by ground supplied over a circuit 310, 112, 202. On the relapse of relay 61, a short-circuit is removed from the upper winding of relay 202, which energizes in series with the release relay 203, and locks up over its sensitively-adjusted armature 208 in series with the release magnets of the switches S, DR1 - - DR4. The armature 207 is pulled up just after the armature 208, and de-energizes relay 203, which closes restoring circuits for the switches S<1>, SEN in series with the lower wind. ing of relay 202. The relay 202 thereby maintains the test conductor 74 grounded at armature 207 until all the switches in the register-controller are restored. Release of connection. When the calling party hangs up, line relay 41 closes a circuit for the repeating relay 44, which opens the bridge across the trunk 56, 58, thereby de-energizing a release relay at the connector and causing ground to be removed from the release wire 57. Ground also having been removed from the release wire 29 by the relapse of relay 42, all the switches release in known manner. If the conductor 57 is not extended beyond the repeater R, the connection is released immediately ground is removed from the conductor 57 by the relay 42. Operation if transmitting mechanism catches up the registering mechanism. Assuming that for some reason the calling party stops dialling after dialling the exchange digits, when the exchange routing-number has been transmitted and the switch S<1>, Fig. 2. moves to its fifth position, it finds the register DR1, Fig. 5, in its normal position, and ground from the wire 114 is extended to the wire 75 over a circuit 111, 151, 405, 227, 229. The switching relay 43, Fig. 1, is energized, and locks up over its lightly-adjusted armature 51 before the magnet 401, which is also energized over the wire 75, steps on the register DR1 and opens the original circuit of the relay 43. The registercontroller is released as previously described, and the relay 43 transfers the control of the repeating relay 44 to the line relay 41, so that subsequent dialling impulses are repeated directly to the relay 44, which opens the bridge across the trunk 56, 58. If the calling party re-commences to dial just before or about the time that the above-described switch-over is commenced (i.e. before the relay 43 has locked over armature 51), the first relapse of the line relay armature 46 opens the circuit of the relay 43 and closes a circuit over conductor 75 to step the register DR1 to its first position. When the register DR1 leaves its normal position, the switch-over circuit of the relay 43 is broken and cannot be re-made until the switch S<1> is stepped on. The next digit is therefore recorded on the register DR1 and re-transmitted in normal manner. The switch-over circuit for relay 43 is taken over an armature 229 of the slow-release stop relay 206, Fig. 3, in order to allow sufficient time for a hunting operation to take place before the switch-over is effected and it is made possible for the next impulse series to be repeated directly ahead. If the sending apparatus has caught up and the calling party re-commences to dial before the stop relay 204 has relapsed. the register DR1 is set. To prevent the sending switch SEN from overtaking the register in these circumstances, a sluggish relay 231, which is energized over conductor 227, opens the circuit of the sending relay 204' for an interval long enough to give the register a sufficient start. Circuit changes effected by key K, Fig. 3. If the register-controllers are used for a mixed service system, as described for example in Specification 200,484, where part of the offices are manual and part automatic, and in the case of manual calls an extra digit is dialled to cause the call indicators to display the numbers, the switch-over when the sending apparatus catches up is undesirable, and this operation is nullified by operating the key K. The conductor 227 is thereby disconnected from the switching relay 43 and connected to the stop relay 206, so that if the sending apparatus catches up, the switch-ov