Patent GB-181454-A (GB)
Abstract: 181,454. Western Electric Co., Ltd., (Western Electric Co., Inc.). March 9, 1921. Automatic and semi-automatic exchange systems.-The keys depressed bv an operator jointly control the setting of what is termed a translator switch, and the position taken up by the translator switch determines the setting of the registers of the sending equipment. In full automatic systems the translator switch is positioned by the registers responsive to the subscriber's impulses. The employment of the translator switch enables the routing of calls to be altered without altering the wiring of each individual sender, this being effected merely by changes in the wiring between the terminal banks of the translator switches and a common auxiliary switch through which the registers are controlled. The invention is illustrated in connection with a semi-automatic system of the kind described in Specification 130,329. An incoming call from an A-operator, arriving on the line 101, 102, Fig. 1, is dealt with by a socalled cordless operator, who depresses keys H, V, Fig. 6, representing the exchange to which the wanted subscriber belongs. She also depresses keys representing the number of the wanted subscriber, but these keys are not shown, only that part of the system being described which relates to the selection of the wanted exchange. There are ten keys H and twenty keys V, and one key of each set is depressed to represent one out of 200 exchanges to which connection may be made. The translator switch, shown at the left of Fig. 6, sets itself under control of the depressed keys to one of 200 positions, connecting its brushes 670 - - 673 to terminals which are wired, in a different combination for each position, to the brushes 626 - - 636 of a common transfer switch 625. This switch is constantly rotating, and in the course of one rotation controls, over its outgoing brushes 637 - - 640, the relay registers shown in Fig. 7, to record the wanted exchange on them, and the translator switch is then restored to normal. At the same time that she depressed the keys H, V the operator also depressed the key 112, Fig. 1, which started the operation of a link circuit, Fig. 2, comprising a cord-finder and sender selector, to connect an idle sending-equipment, Figs. 3, 4, and 5, to the connecting circuit shown in Fig. 1. The records on the registers shown in Fig. 7 are now transferred to the regis. ters, Fig. 5, of the sending-equipment, the transfer taking place by means of weak or strong currents in the circuits 239, 252, 249, 245, Figs. 7 and 2, and the registers, Fig. 7, together with the keyboard are released for other service. Finally the sending-equipment controls the setting up of the wanted connection, in a manner generally similar to that described in Specification 130,329, and is released. The sending registers, Fig. 5, include a class register switch 534, for determining the different treatment of different classes of call. In general a call is extended through a district selector, Fig. 1, and an office selector to the wanted exchange, where it is completed by other selectors. For the purpose of describing the present invention, however, it is assumed that the call arriving on the line 101, 102 is to be extended by the district selector to a B-operator at the same exchange. In this case the class register 534 is set to such a position that the operation of the district selector is immediately followed by the release of the sending-equipment and the movement of the switch 100 to talking position. Operation of the cord-finder and sender selector, Fig. 2. When an A-operator seizes the line 101, 102, relays 104, 106 are energized to light a lamp 108 in front of the cordless operator, who converses with the A-operator over an order-wire and presses the key 112 to move the switch 100 to its 2nd position, de-energizing relay 106 and energizing relay 201, which energizes relay 204 to move the switch 200 to its 2nd position, energizing the up-drive magnets 207, 220. When the test brush 210 reaches the terminal 211, which is grounded over the circuit 213, 115, 111, the relay 208 is energized and open-circuits relay 201 to stop the cord-finder, and when the test brush 217 reaches the ungrounded terminal of an idle sending-equipment the relay 204, which had locked itself in the circuit 216, 217, relapses and stops the sender selector. Circuits are then closed for moving the switch 100 to its 5th position. 200 to its 6th position, and 300 to its 6th position. Operation of the translator switch, Fig. 6. This switch has five sets of brushes each serving 40 sets of terminals. The cordless operator depresses a key in each of the rows H, V. Under control of the depressed kev H a set of brushes is selected and is either moved twenty steps or not; the brushes are then moved a.number of steps corresponding to the depressed key V. The depression of a key H energizes a relay 701, Fig. 7, which moves the switch 700 to its 2nd position, energizing the up-drive magnet 601 and relay 603. When the brush 605 reaches a terminal corresponding to the depressed key H it energizes a relay 708, which de-energizes relay 701, which stops the translator and moves the switch 700 to its 3rd position, in which the trip magnet 614 is energized. If the depressed key H is one of the series 1 - - 5, the switch 700 is driven at once to its 4th position over the wire 720 and to its 5th position over a back contact of the relay 701, but if the depressed key is one of the series 6 - - 10 the relay 701 is energized over the wire 704 and drives the switch 700 to its 4th position, and the up-drive magnet 601 is again energized. In this case after 20 steps the brush 605 engages the terminal 618 and energizes the relay 708, which de-energizes the relay 701 so as to stop the translator and to move the switch 700 to its 5th position. The relay 701 is now energized again over the wire 718 and the depressed key V, driving the switch 700 to its 6th position and again energizing the up-drive magnet 601. When the brush 605 reaches the termninal 620 corresponding to the depressed key V, the relay 708 is energized and de-energizes the relay 701 to stop the translator and to move the switch 700 to its 7th position, energizing the relay 721. The translator switch is now in a position corresponding to the combined signification of the depressed keys Hand V. Operation of the registers. Fig. 7, in accordance with the position to which the translator switch has been set. There are six registers each consisting of a horizontal row of four relays. Inspection will show that each of the four outgoing brushes 637 - - 640 of the common transfer switch 625, which are connected to battery in turn by the contacts 676 - - 668, can energize one relay in each register, but whether a relay is energized or not depends on whether at the same moment a relay individual to that register in the series 753 - - 75& is energized, and this in turn depends on whether the corresponding brush 670 - - 673 of the translator switch is at that moment connected to battery through the transfer switch, which depends on the manner in which the terminals 669 - - 672 are wired to the brushes 626 - - 636 of the transfer switch. Thus in one revolution of the switch 625, starting from whatever position it is in at the moment when the relay 721 becomes energized, a particular combination of the register relays become energized and locked up, the combination depending on the position to which the translator switch was set. Metering the numbers of calls of different classes dealt with. The register consisting of the four relays 764 - - 757 'designates the class of call recorded and selects one of a number of circuits, such as 802, connected to counting devices for recording the numbers of calls of different classes dealt with. Restoration of the translator switch. Each time the brush 629 makes contact with a segment 657, 678 it energizes a relay 771 which repeats an impulse to a chain of counting relays 768 - - 770. After three impulses, that is to say after the transfer switch 625 has performed rather more than a complete revolution, the relay 770 becomes energized and drives the switch 700 to its 8th position, de-energizing relay 721 which completes a circuit for the down-drive magnet 679 of the translator switch. Transfer of the record from the registers shown in Fig. 7 to the registers shown in Fig. 5. Five registers are shown in Fig. 5, a class register consisting of the four relays 502 - - 500, which serve for setting the class register switch 534. and four registers each consisting of three relays such as 509, 510, 515, each of which serves for picking out one of five circuits, indicated by the numerals 0 - - 4 in circles. In addition there are two translating or add-five relays 524, 532. The arrangement of the registers and translating relays is generally similar to that described in Specification 130,329, and the means by which they are controlled from the registers shown in Fig. 7 is closely similar to the means by which they are controlled from the operator's keyboard in the above-mentioned Specification, and will not therefore be described in detail. The operation proceeds in stages, the switches 700, 300 being at first in their 8th and 6th positions and proceeding step-by-step to their 11th and 9th positions. At each stage circuits are closed over the four wires 239, 252, 249, 245, Fig. 7, which extend through the link circuit, Fig. 2, to the sending equipment, high or low resistances being included in these circuits according to the record impressed on the registers of Fig. 7, so that relays belonging to the registers of Fig. 5 and connected in the other ends of these circuits are energized in the one case only if they are sensitive, and in the other case whether they are sensitive or marginal. When the transfer is completed the switches 700, 300 move to their 12th an