Patent GB-166351-A (GB)
Abstract: 166,351. Automatic Telephone Manufacturing Co., Ltd., and Mercer, R., (Automatic-Electric Co.). April 14, 1920. Exchange systems.-Relates to means for automatically dealing with calls in the order in which they arrive, or approximately in that order, especially in systems in which the wanted number is set up on an operator's indicator by impulses from the calling substation, as when calls arrive at manuel exchanges from automatic exchanges. Each operator may have a single indicator and an ordered series of register-sets, and a register-set on which a wanted number has been recorded transfers its record to the indicator when the calls stored in preceding register-sets have been dealt with. The indicator may consist of rows (one for each digit) of transparent figures (0 to 9) which can be illuminated by lamps, and at the same time that the appropriate lamps are energized to denote a wanted number, a lamp is lit individual to the calling junction that requires that number. Or the indicator may be of a mechanical nature, in which case a lamp at the indicator is lit simultaneously with the calling-lamp. In one of the arrangements described, Fig. 2, the calls are stored in successive register-sets in the order of their arrival. In another arrangement, Fig. 6, the calls are stored in no particular order, but the stored records are transferred to the indicator in the order in which they are completed. The method of connecting a calling-junction line to a register-set is shown in Fig. 1, and alternative methods of controlling the successive connection of the register-sets to the indicator are shown in Figs. 3, 4 and 5. Connection of calling-line to register-set R, Fig. 1; general operation of register-set. A relay 14, energized over the grounded wire 11 of a calling line, closes a circuit through the stepping-magnet 19 and relay 13 and connects an intermediate point of this circuit to the test wiper 17, so that the switch C advances in known manner until a register-set is reached of which the terminal 37 is ungrounded. The relay 13, which is then energized, locks itself up, grounds the wiper 17, and energizes a relay 21. The impulses for the first digit are transmitted over the lead 23 and operate the stepping-magnet 28 of the first register of the set. At the first impulse a relay 31 is energized by an off-normal contact 29 and opens the original impulse circuit, but the succeeding impulses reach the magnet 28 over the front contact of a series relay 27, of the slow-release type, which remains energized until the impulses cease. The relay 27 then relapses, so that the next set of impulses goes to the next register of the set, and so on. When the last digit has been recorded, a wire 34 is grounded to energize a relay 35, and as soon as the operator has dealt with preceding calls a relay 36 is energized, as described in a later paragraph, and energizes relays 48 (one for each register of the set) which energize the appropriate indicator lamps through contacts in the registers. The relay 48 of the register in which the final digit is stored grounds a wire 49 to light a lamp in the circuit 51 individual to the calling line. As soon as the operator has dealt with the call, ground is taken off the wire 11, de-energizing relav 13, so that the register-set R is released. The switch C, however, is of the no-normal type and remains in the position to which it was set. Distributing calls to successive register-sets in the order of their arrival. This is effected by arranging the relay 21 of the different register-sets to control the potential on the test terminals 37 of the switches C, Fig. 1, in the manner shown in Fig. 2. When the first register-set is seized and its relay 21 energized, ground is connected to the test terminals 37 of all the register-sets except the second, so that if a second call arrives before the first is dealt with by the operator it is connected to the second register-set, and in the same way if a third call arrives before the second is dealt with (even if the first call has now been dealt with) it is connected to the third register-set, and so on. Connection of successive register-sets to indicator; first arrangement, Fig. 3. The relays 36 of the different register-sets, which must be energized to complete the connections to the indicator, are interconnected as shown. When a call has been recorded on the first register-set, the relays 35, 36 of this set are energized. The relay 35 disconnects battery from the energizing circuit of the next relay 36 and the relay 36 disconnects ground from the lower ends of the relays 36 of all succeeding register-sets and connects ground to their upper ends. If now, before the first call has been dealt with by the operator, a second call has been completely stored in the second register-set, the second relay 35 is energized, but the second relay 36 is not energized until the relays 35, 36 of the first register-set are de-energized. If the second and third relays 35 had both been energized while the first call was being dealt with, the second relay 36 would alone become energized upon the relapse of the first pair of relays 35, 36, the third relay 36 becoming energized in turn upon the relapse of the second pair of relays. If the third relay 35 had become energized before the second relay 35, owing to the third calling subscriber completing his dialling operations more quickly than the second, and if the first pair of relays 35, 36 became de-energized in the interval between the energization of the third and second relays 35, the third relay 36 would become energized and transfer the third call to the indicator, but on the deenergizatior of the third relay 36, when this call had been dealt with by the operator, the second relay 36 (assuming the second relay 35 to be now energized) would be energized in preference to that of any later register-set. That is to say the actual order of indication of the calls is the order in which the calling subscribers complete their dialling operations. Second arrangement, Fig. 4. In this modification, the different register-sets may be seized and operated in my order. For example, suppose that the third relay 35 is first energized, and that the first and seventh relays 35 are then energized while the first call is being dealt with; in this case the third, seventh and first relays 36 will be energized in the order named, to transfer the indications of the corresponding register-sets to the indicator in that order. All the relays 36 have energizing circuits through the back contact of a slow-release relay 51, so that if, to begin with, all the relays are de-energized, the energization of any relay 35 energizes the associated relay 36. The relay 36 energizes an associated slow-release relay 50, which energizes relay 51 and locks up the relay 36 by a circuit through the back contacts of all the other relays 36. As long as relays 35, 36 remain energized, all the other relays 36 are shortcircuited. On the de-energization of relays 35, 36 relays 50, 51 remain momentarily energized, so that if several relays 35 have meanwhile become energized, a circuit is closed over a front contact of the still-energized relay 50 to energize the relay 36 associated with the next energized relay 35. Third arrangement, Fig. 5. In this modification, which performs the same functions as the arrangement described in the previous paragraph, a switch S of the no-normal type is associated with the pairs of relays 35, 36. A common relay 61, energized in parallel with any of the relays 35, causes the switch S to step round until it finds the terminal from which ground has been removed by the relay @5. The relays 65, 66 then momentarily connect ground to the wiper 72 to energize the corresponding relay 36, which locks itself and holds the switch by grounding the terminal on which the wiper rests. When the relay 36 is deenergized the switch S is released, and if one or more relays 35 are energized the switch steps forward again until it finds the terminal corresponding to the next energized relay. Operation of the alternative system shown in Fig. 6. When a call. has been stored in a registerset, a switch P individual to the register-set is started by relays 35, 75 and advances until the test wiper 82 finds a terminal which has not been grounded by a relay 88 or 86. It will be assumed that none of the relays 88, 86 are energized, so that the switch P takes only a single step. A relay 79 is then energized and grounds the wipers 82, 85, energizing a relay 86 in series with relay 88, which locks itself up, and relay 87 starts a switch Q, individual to the indicator, which is assumed to be disengaged. The switch Q advances until the test wiper 94 finds the terminal from which ground has been removed by the relay 86, and the slow-release series relay 95, which is energized as long as the switch is in motion, then relapses and closes a circuit through the wipers 93, 100 to effect the transference of the register record to the indicator. When the call has been dealt with the switch P is released and the relay 86 relapses and grounds the terminal on which the wiper 94 is resting. If the switch P of a second register-set has in the meantime set itself to the second position (second relay 86) the relay 87 will remain energized and the switch Q will take a step forward and will transfer the record of the second register-set to the indicator. The relays 88, once they have been energized, remain locked as long as the relay 87 is energized, so that if the switch P of a third register-set is started while the second call is being dealt with it will set itself to the third position (third relay 86) in spite of the fact that the first relay 86 has been released. But when a switch P sets itself to the last position, the last relay 86 opens the locking circuit of the relays 88, so that the next switch P can set itself to the first position. Relays 88 ar