Patent GB-283643-A (GB)
Title: Improvements in telephone systems
IPC: H04M3/22
Filed: 1926-10-14
Abstract: 283,643. Automatic Telephone Manufacturing Co., Ltd., Simpson, L. M., and Ray, A. J. Oct. 14, 1926. Automatic exchange systems and apparatus.- In a routine testing system idle pieces of a large group of similar pieces of apparatus are taken into use by a hunting switch and tested in turn, tested pieces being marked to prevent them being connected with again during further rotation of the hunting switch. If the hunting switch makes a complete revolution without finding an idle piece of apparatus it is stopped and a signal given. Should a piece be seized for use while under test, the test is suspended for an interval, and if the piece of apparatus is freed within this interval the test is resumed, but if the time interval is exceeded, the next idle piece is connected with and the partly tested piece is fully dealt with when it becomes free. The hunting apparatus may be stepped under the control of the testing attendant in order that a particular piece of apparatus may be connected with and tested. In such case the piece may be in use at the time and certain tests may be carried out in conjunction with the user. An indication of the piece of apparatus under test is given to the attendant and he may also at any time ascertain which pieces have been tested. The testing operation includes the setting up of a test connection back to the testing equipment. Means are associated with the testing equipment wherebv irregular conditions which may occur are simulated in order to test the testing equipment itself. The invention is described as applied to the routine testing of sixty key-sending operators' positions of the kind described in Specification 229,765, each position having fifty incoming junctions and means for associating four impulse senders with the position at a time. Two junction distributors JD1, JD2, Fig. 4, having access to fifty junctions are allotted in the routine equipment to each position. A primary position distributor PD connects up in turn three secondary position distributors SD1 - - SD3 each of which has access to twenty positions. As it is impossible to provide the secondary position distributors with sufficient wipers for all the required functions, each one has associated with it an auxiliary switch such as ASD1. The tests are carried out in the various positions of a test switch TS, Fig. 3. Operation of distributing apparatus. The operation of the start key SK, Fig. 1, energizes relays 115 and 119. Relay 119 opens the homing circuit of the primary position distributor PD, Fig. 4, opens an alarm circuit over lead 57, and closes a series circuit for relay 127 over wiper 506 of the switch TS. Relay 12<7> energizes the driving magnet 610, Fig. 4, of the secondary position distributor SD1 in series with relay 264, Fig. 2, and battery feed relay 233, Fig 1. Pulsing relays 264, 266, Fig. 2, then operate to send impulses to the magnet 610 which steps the switch SD1 until its wiper 611 engages a contact earthed over armature 534, Fig. 3, of a relay 533 at an operator s position de-energized when the operator leaves this position. Relay 131 then pulls up, energizes relays 109, 152, and transfers the pulsing circuit to the driving magnet 647 of the auxiliary secondary distributor ASD1, Fig. 4. which rotates until it reaches a position corresponding to that of its associated switch SD1, when relay 185 pulls up, opens the driving circuit, and energizes relay 180 which earths wiper 501, Fig. 3, and lights lamp 542 to indicate that a free position has been found, and energizes relay 229 which locks up. Relay 330, Fig. 2, is connected to an interrupter 485 and energizes the magnet 507 of the switch TS which advances to its third position due to interaction between relay 330 and magnet 507, and sends an impulse over wiper 613 of the switch SD1, Fig. 4, to the magnet 631 of the first junction distributor JD1 allotted to the selected position. If a call is still in progress over the first junction, earth on the wiper 625 energizes relay 376, Fig. 2, which energizes relay 334, a pulsing circuit being thereby completed for advancing the switch JD1 to an idle junction, whereupon relay 376 falls away, opens the stepping circuit, and closes a stepping circuit for the test switch TS which goes through the routine testing cycle described later. When the switch TS has made a complete revolution and again reaches its third position, the junction distributor SD1 will be advanced similarly to select the next idle junction. All the idle junctions connected to the switch JD1 are in this manner tested in turn. When the 24th junction is engaged, relay 172, Fig. 1, is energized over wiper 629 and completes a circuit for relay 175 which prepares the driving circuit of the magnet 638, Fig. 4, so that the next impulse advances the switch JD1 to its 25th or normal position, and also the second associated junction distributor JD2 to its first junction. Relay 172 now relapses and all further impulses only step the switch JD2 which connects up for test all the idle junctions in its bank. When the switch JD2 reaches its 23rd position, relay 166, Fig. 1, is energized over wiper 636 and de-energizes relays 109, 152, 175, 180 after which the switch JD2 moves to its 24th position, in which relav 131 is short-circuited and connects the pulsing circuit to the secondary position distributor SD1, which hunts for the next idle position, the junctions of which are tested in like manner. When all the idle positions accessible from the switch SD1 have been tested, a relay 297, Fig. 2, is energized in position 21 and closes a circuit for the magnet 607, Fig. 4, of the primary position distributor PD. This circuit is opened when the switch SD1 moves to its 22nd position, the switch PD being thereby advanced to connect up the next secondary position distributor SD2. All the positions accessible from this switch having been routined the distributor PD connects up the third secondary switch SD3, the positions accessible from which are then continued. On the switch SD3 reaching its 21st position, if a position has been routined during the preceding operations, relay 2'29, Fig. 1, will be locked up and the switch advances to its 23rd position, in which relay 292, Fig. 2, unlocks relay 229 and closes a circuit for stepping on the primary distributor PD to connect up the first secondary distributor SD1 again. Another routining cycle is now commenced during which the secondary switches SD1 - - SD3 pass over positions routined during the first cycle since their associated junction switches JD2 are in their 24th positions and short-circuit the test relay 131 over their wipers 636. If all the secondary distributors pass over their banks without finding one position in a condition to be tested, relays 131, 180, 229 will not be energized and in position 21 of the switch SD3, relay 285, Fig. 2, is energized, completes a circuit for a routine finished lamp 284 and a relay 314, opens the pulsing circuit for the secondary distributors and closes homing circuits for these switches. The apparatus may be left to await the freeing of other positions and it can be re-started by operating the key RS, Fig. 1, which unlocks relay 285 and permits the routining to continue. When it is desired to stop routining, the start key SK is restored, thereby de-energizing relays 115, 119 and causing homing circuits to be closed for the primary and secondary position distributors PD. SD1 - - SD3 and for all the junction distributors JD1, JD2 &c. If relay 285 is operated it is unlocked by operating the re-start key RS, but it can be made dependent on relay 115. Testing lamp lead and trunk conductors. In position 4 of the test switch TS, relay 336, Fig. 2, energizes over wiper 503, connects relay 376 to the lamp lead over wiper 625 of the junction distributor JD1 which has seized a trunk for test, connects the two windings of relay 385 in series opposition to the negative side of the trunk over wiper 627, and connects relay 389 to the positive side of the trunk over wiper 628. If the lamp lead is open or either of the trunk conductors is faulty, relay 376 will not pull up or relay 385 or 389 will respond and one or more of the fault lamps 538 - - 540, Fig. 3, will light over the earthed wiper 501. If no fault exists, relay 330 is energized and advances the test switch TS to position 5. Testing assignment. In position 5 relay 341 is energized over wipers 503, earths the negative junction over relay 385 and wiper 627, and connects battery to the position junction over relay 389 and wiper 628: this is equivalent to the " A " operator taking the junction before assignment. If the junction line relay duly energizes, the flicker pulses over the lamp lead and wiper 625 are transmitted to relay 376 which drives the test switch to position 8 : in positions 5 to 7 the indicating lamp 543 is lighted over pipe 501. From position 8 the switch is advanced by interrupted earth 485 to position 10, in position 9 the assignment lead being earthed over wipers 626, 503. In positions 8 to 11 the lamp 544 is lighted. When the junction has been assigned and the sender finder and junction finder complete their operation, two flash impulses over the lamp lead energize relay 376 which advances the switch TS to position 12 in which indicator lamp 545 is lighted and relay 344 is energized to connect wipers 525 - - 528 of the number set-up switch NS, Fig. 3, to wipers 641 - - 644 of the auxiliary secondarv distributor ASD1, Fig. 4. Setting up the test number. Relay 344 also closes a circuit for relay 264 in series with magnet 531 and relays 264, 266, 268 interact to step round the switch NS, the contacts in the four upper banks of which are suitably jumpered to earth to effect the setting up of the test number which will route the test call back to the routiner. In position 16 of the switch NS, the test switch TS is driven to position 13 in which