Patent GB-334584-A (GB)
Title: Improvements in or relating to telephone systems
IPC: H04Q1/20
Filed: 1929-06-06
Abstract: 334,584. Automatic Telephone Manufacturing Co., Ltd., Pearce, O. A., and Simpson, L. M. June 6, 1929. Automatic exchange systems.-A routiner has access to a group selector over the incoming wires, and has also connections to the test wiper, whereby the selector can be made to drive to 11th terminals independently of the condition of the trunks encountered, and to post springs whereby the selector signal that it has reached the correct level in accordance with impulses sent in by the routiner (position 14 of the i sequence switch TSW). Means are provided also for testing the incoming speech wires for faults (position 3), the sensitiveness of the line relay (5 - - 8 and 18), the return of dialling tone (9), the release time of the release relay (11), the hunting time and return of busy tone (15), seizure of a selector and operation of switching relay (19 to 22), the speech wires incoming to the seized selector (23). Distributing arrangements; normal operation. 0n the operation of the start key SK, ST, STA, BST, Fig. 11, pull up and PSR, Fig. 3, interacts with PDM to move PD one step. AST pulls up, locks and energizes SR, Fig. 8, in series with SRR (which does not operate). SR now interacts with APDM to drive the auxiliary primary distributor APD to the position in which PD is standing, whereupon SR is short-circuited and SRR energizes RSR, Fig. 11. SH pulls up in series with a shelf-indicating lamp and a relay such as U and operates ONS, Fig. 8, which releases STA. SDM and SH then interact, until the secondary distributor SD reaches home, whereupon ONS falls, STA re-operates, STR pulls up, and a new circuit, is made for SDM and broken shortly afterwards by SSR, Fig. 8, to move SD off-normal. SHR, Fig. 11, now pulls up and locks itself, and is followed by SHX, RAR, and SH, U are operated again. AH, Fig. 8, pulls up in series with the selector-indicating lamp and energizes ONA which releases BST. AH then interacts with ACM until the distributor ACS reaches home, whereupon AH remains back, ONA falls and BST pulls up again, followed shortly afterwards by AAR to step ACS off normal. RS then pulls up to initiate the test on the selector now engaged. At the end of each test cycle, TC, Fig. 2, releases PA, Fig. 8, giving an impulse to ACM. When ACS reaches its 22nd terminals, SS pulls up in series with AH which interacts with ACM until ACS reaches home. SS is followed by AP, RAP, Fig. 11. When ACS is home, these relays fall in succession and impulses are thus sent to SDM, which drives SD one step, and RSR which locks itself and energizes SSR which unlocks RSR. SHR, SHX, RAR, ATR, AAR then co-operate as described above to drive the new distributor ACS one step off normal. When SD reaches its last terminals, APS pulls up in series with SH, which interacts with SDM to send SD home, and energizes BPS, Fig. 3. When SD gets home, APS, BPS fall in succession and an impulse is sent to PS, Fig. 3, which unlocks AST and repeats the impulse to PDM. SRR falls and also STR, SHR, SHX, RS, RRS, ATR and SR interacts with APDM to cause APD to follow up PD. The new distributor SD is driven one step from normal as already described and a new test cycle begins. SD is stepped - through positions corresponding to unequipped shelves by the operation of NPR, Fig. 8, over resistance 17, Fig. 9. SHR is prevented from operating and NER, Fig. 10, SHX, AP, NE pull up. NE in due course cuts off NER. AP and a momentary circuit is thus made for SDM. NER releases NE and then pulls up again and the cycle is repeated until NPR is no longer energized and NER is thus prevented from operating. In a similar manner if ACS reaches an unequipped posifion, NPR is operated over 22 and prevents the operation of RS, and NER, NE, PA interact to drive on ACS until a live position is reached and NPR falls back. Distributing arrangements-operation for continuous routine tests of particular switch, shelf, bay or group of 4 bays. If SCRK is thrown, CR pulls up and the distributors PD, SD, ACS can be set by hand by the keys PDSK, SDSK, ACSSK. The start key is then operated and the particular selector is tested indefinitely since the automatic stepping circuits of the distributors are open. For continuous routining of a particular shelf, SHCR is thrown, CR operates as before, but the circuits are now such that PD, SD may be set by hand and ACS steps automatically as in a normal routine test. For routining a particular bay, BCRK is pressed to energize CR to enable PD to be controlled manually, and then one of the bay selecting keys BSK1 - - BSK4. On the operation of the start key, U is operated as described above, and if any of the keys but BSK1 is operated, a circuit is made for NPR which causes the automatic advance of ACS over unwanted bays as if the positions were unequipped. When the wanted key is reached, SHR pulls up and the test cycle begins. When all the switches have been tested, SHR falls and ACS runs round again to the marked bay. If all the bay selecting keys are pressed, NPR has no circuit and all the selectors on ACS are tested in turn. Distributing arrangements-re-set and step-on keys. After the fault on a selector has been cleared, it may be tested again by throwing RK to release SR and operate RER. K falls to prevent TC from operating and so causing ACS to be stepped on. The switch TS goes home, KD pulls up and RER falls allowing K to re-operate and start a new test cycle. If. on the other hand, the fault cannot at once be cleared, SOK, Fig. 6, is operated to energize, SO. RER pulls up and homes TS, and TC gives an impulse to drive ACS on. KD releases RER, SO when TS reaches home The tests. (1) KD and K, Fig. 3, are energized when ST operates and when RS pulls up to initiate the cycle of tests, it is followed by RRS, HR, Fig. 10, PG, PGR, Fig. 3, AR, Fig. 2, RG. Fig. 3, HSC, Fig. 7, TDM then operates and opens its own circuit advancing test sequence switch TSW to its 2nd terminals releasing HSG (2) If the group selector engaged by ACS is busy. AR is held over 29 and the test wire, and if this condition persists, ALM pulls up in two steps and connects the pulse wire 31 to AM which gives an alarm. When the selector is released, AR falls and connects RG to the test wire over which it holds in series with the switching relay until the selector reaches normal and then falls marking the selector busy and re-operating HSC which drives TSW one step and falls back. (3) TT, Fig. 7, PT, Fig. 3, AR, Fig. 2, RG pull up in succession, and differential relays TN, TX, Fig. 2, are connected to the - and + wires respectively which also are bridged by a battery fed choke RD. If there is a battery or earth fault, or a. reversal of polarity, TN and/or TX pulls up, operating one of three lamps in series with DA, Fig. 7, which prevents the advance of TD. Failing operation of DA, two-step relay TS which was connected by TT over a contact of the constantly impulsing relay DR extends the impulse circuit to TDM to drive TSW. (4) TT, TS fall and PG, PGR being already up, TSW goes straight through. (5) and (6). The selector is succes. sively seized and released, PG, PGR controlling the stepping of TSW. (7) The + and - wires are bridged by resistances Y9, Y5, Y4 which should not operate the distant line relay and DR, TS co-operate as described above to drive the switch TS on after a short interval. (8) OT pulls up and locks itself unlocking TS. TS, however, operates again in two steps as described above. Y9, Y5 alone are connected across the + and - wires to seize the selector and PG and PGR fall so that the impulse following the operation of TS drives on TSW. (9) DTR bridges the + and - wires and connects them to the amplifier shown in'Fig. 1. Dial tone operates TR. IPG, Fig. 1, pulls up on the 1st relapse of DR following operation of DTR and extends impulses to TGR which pulls up in two steps to step on the switch TSW. TSW is made to skip this test when all the 1st groups selectors have been tested by a relay DTC, Fig. 5, operated by the primary distributor. (10) The selector is released and PG, PGR drive TSW on. (11) DTR falls. The + and - wires are bridged via last terminals of the timing switch RTS and PG, PGR fall back. RGT, Fig. 2, pulls up and arranges for GIP to pull up when next the 20-persecond spring MPS break and connect them to RDM which drives the timing switch RTS. As soon as the latter moves off normal, the selector is releasd and after an interval allows PG, PGR to pull up again, stopping RTS. If the time taken for the selector release relay to fall back is too long or too short, a signal circuit is made over 37 or 38, Fig. 6. If the release relay sticks, RTS is stopped on its last terminals and impulses are delivered by DR to LF which flashes the too long " signal. If the release time is correct, ground on 39 steps on TSW. (12) The + and - wires are bridged via Y9, Y6 and PG, PGR fall back. SEP, Fig. 2, pulls up and puts ground via 40 on the test wiper of the selector. RGT falls and RTS goes home and then sends TSW on. (13) STS, Fig. 2, locks SEP and operates PTR, Fig. 5, when next the 10-per-second springs SPS open. PTR connects the springs to sending switch magnet SSDM. 9 impulses are then sent over the + and - wires by LPS. Pick up, and stop relays SA, SZ, Fig. 5, operate as in a register controller, and then drive TSW on. (14) The group selector on level 9 by means of post springs puts earth on 44 to operate NPR to drive on TSW. The lower winding of CCL which was operated by SZ and locked up is disconnected to make it drop its armature ccl2 over which an alarm is given if the selector does not give this signal. (15) BTR, Fig. 2, pulls up. Ground being permanently connected to the test wiper by SEP, the selector goes to its 11th terminal and sends back busy tone to operate, TR. PTS. the magnet of which is connected by SZ, GIP to the 20-per-second springs MPS, starts to move at the same time as the selector. If the latter is