Patent GB-310575-A (GB)
Title: Improvements in or relating to telephone systems
IPC: H04M3/22
Filed: 1928-02-02
Abstract: 310,575. Automatic Telephone Manufacturing Co., Ltd., and Pearce, O. A. Feb. 2,1928. Automatic exchange systems and apparatus.- An automatic routiner tests the operation of a relay group supplying battery feed to the calling party, by establishing a connection therefrom over final selector to a test line connected to the routiner. The invention is described in connection with a junction relay group associated with a B-operators' position, and in a complete test the connection is set up twice for checking its operation under idle and busy conditions of the test line. The B-position is of the type described in Specification 229,765. The routiner comprises two primary position distributors PPD1, PPD2, Fig. 11, over which access is obtained in turn to the operators' positions, and two secondary distributors SPD1. SPD2, Fig. 7, which follow the movements of the primary distributors and serve chiefly to connect a sending switch SS, Fig. 1, to the registers at the positions. The tests are controlled by a test switch TC, Fig. 2, a fault being indicated by lamps 1-16 and an audible alarm. After testing, a position is marked, and the distributors perform continuous cycles until, during a cycle, they fail to pick up an idle or untested position, a signal being then given and the test stopped. If a position is taken into use during a test, the particular junction under test is marked busy to prevent its assignment and the test switch is returned to normal. If the operator withdraws, the test is re-commenced, if not, the distributor passes to the next position. 'The routiner has access to 50 junctions over distributors JD1, JD2, Fig. 12. Distributor JD1 has direct access to junctions 1 to 24 and JD2 to junctions 25 to 46, the other four junctions being connected to the initial sets of terminals of JD1 over switching relays EJE, JE operated by a key. Keys are, provided to enable any particular position or junction to be selected for testing, and a rapid test may be made by confining the test to the first four junctions at each position. A junction may be tested with the assistance of a B-operator, who, in this case, sets up the connection. - Fault imitation keys enable the routiner to be tested. Specification 283,643 also is referred to. Operation of position distributors. Relay S, Fig. 6, operated by the starting-key 10 completes a circuit over 12 for ST, Fig. 10, which at 33 completes a circuit for the relay GX, Fig. 9, controlling the circuits of the wipers of the first primary position-distributor PPD1 and connecting relay AX, Fig. 5, over 41 to wiper 42 of the first secondary distributor SPD1. Relay S also closes, over 45, a circuit for GD in series with springs 49 and magnet DM1 of the test switch TC, Fig. 2. the magnet remaining inoperative. Relay PS, Fig. 5, and magnet DM2 of PPD1 now operate in series over 16, 18, 19, 20, 21, 22, 15, Fig. 6, 24, conductor 28, 29, 31. Relay PS operates P, H which energizes slow-to-pull-up relay PP to open the circuit of DM2 and PS so that PPD1 steps on to first contacts and relays PS, PH, PP restore. The contacts of wipers 55, 56 of distributors PPD1, PPD2 are grounded over contacts of battery feed relays at non-staffed B-operators' positions. Distributor PPD1 is therefore stepped on until the first grounded contact is reached when this ground is extended over 55, 40, key 68, 71, 72, 74, Fig. 6, 75, 76, 78. relays PT and YR (upper), Fig. 9. Relay YR remains inoperative but PT, at 21, transfers the circuit of PS from magnet DM2 to the magnet DM3 of the first secondary distributor SPD1, the circuit being traced as above but from 21 over 79. 80, 82. The banks of wipers 84 (PPD1) and 42 (SPD1) are connected in multiple so that ground from 85, Fig. 10, is extended over 86, wiper 84 and its selected contact, to the corresponding contact of wiper 42. Distributor SPD1 is therefore stepped on to this contact and ground is extended over wiper 42 to energize relay AX which breaks the circuit of DM3 at 82 and also connects up the wipers of SPD1 in readiness for testing. A branch of the above-traced circuit of PT extends over 62, Fig. 10, 39 and wiper 59 (PPD1), position-indicating lamp and switch 87 to ground. A circuit is also closed over contact 90 of PT for relav APT which at 95 connects intermittent ground from 94 to relay LF, Fig. 9, and at 62 changes the lamp circuit so as to include contacts of relay LF. The lamp flashes until the position is completely routined when, as will be described later, intermittent battery over wiper 59 is replaced by ground to mark the position tested. The test attendaht may ground the lamp circuits by jacks such as 503 so as to prevent any particular position from being tested. By reversing the switch 87, the attendant may light the lamps to ascertain which positions have been tested. The purpose of relay YR is to prevent abnormal current in its circuit, due to direct ground over wiper 59, by cutting in its second winding. Relay PT relapses when the position has been routined and completes the driving circuit, for PPD1 which moves on to the next unstaffed position and is followed by SPD1 as before. When all the positions available from PPD1 have been tested, PPD1 moves to position 21 in which ground from 85, Fig. 10, over 86, 36 is extended over wiper 84 to relay PG. Fig. 9. Relay GY pulls up and GX releases so that. the various testing- and stepping conductors are transferred from PPD1 to PPD2 which is stepped on to the first. unstaffed position and is followed by SPD2. Relay AY operates in place of AX to connect the wipers of SPD2 to the sending switch. The unstaffed positions accessible over P1D2 are then tested and when PPD2 reaches position 23, relay PGL. Fig. 9, operates over wiper 324, short-circuits a winding to make it slow to release, operates relay K over 327, and at 328 operates GX which releases GY. Relay K, at 330, completes a circuit for DM8 of PPD2, but release of GY is followed by release of PGL and K in turn so that this circuit is broken and PPD2 moves to position 24. The release of GY completes an alternative circuit for GX and the circuits are now re-transferred to PPD1 to pick up any position which escaped the first test cycle. When the distributors make a complete cycle without encountering an untested or unstaffed position, relay PT has not operated and consequently RR is not energized so that PPD2 on passing position 21 connects ground from 85 over wiper 324 to two-step relay RF which first shortcircuits its upper winding and then pulls up fully when PPD2 moves off position 21, its circuit including start key 10 and restart key 98 (unoperated). Ground from contact 338 of RF is connected over 341 and wiper 342 to magnet DM2 to home PPD1 and when this switch reaches its last contact, the homing circuit is extended over 344 to magnet DM8 of PPD2. Operation of junction distributors JD1, JD2. Relay APT energized as described in the preceding paragraph completes a circuit (14, Fig. 10. 89, key 98, 101 - - 105, key 107) for relay RS which at 504 closes an alternative circuit for itself independent of 104, operates relay TARL Fig. 3, at 161, and at 109 operates relay RR, Fig. 10, which locks up over 111. Relay RS also connects ground over 156 and wiper 159 of test switch TO, Fig. 2, to light lamp 1, and at 116 connects ground from 115 to relay M, Fig. 5, which at 120 operates EJ. Relay EJ transfers the operating circuit of M to RC. At the instant when contacts 121, 122 are both operated, ground is extended over 123, 125 and 126, Fig. 10, 128, Fig. 6, 130, Fig. 10, 131, 38, wiper 133 of PPD1 to back-stroke magnet DM4 of JD1 which moves on to contacts of the first junction. At the same time lamp 135 Fig. 4, is lit over 137. If the first junction is busy, ground on the corresponding lamp at the B-operator's position is connected up over wiper 138 of JDI to the lower winding of LP, Fig. 4. which at 144 holds EJ and at 145 completes a circuit for PS, Fig. 5, and DM4 in series. The magnet operates and PS energizes PH and PP to open the circuit. The distributor is thus stepped until an idle junction is found and when the test on this junction has been completed, JD1 is moved on to the next idle junction. When all the junctions available over JD1 have been tested (JD1 in position 24), ground over wiper 290 operates CO, Fig. 10. Relay ACO now pulls up so that the next pulse over 121, 122, Fig. 5, operates the magnets of both JD1 and t D2, magnet DM4 being energized in the previously traced circuit with contact 294 substituted for 130, while from 130 the circuit passes over 295, 296, 37 wiper 298 of PPD1 to magnet DM7. JD1 is stepped on to its last contacts and, as the wipers of the two distributors are connected in multiple, the test proceeds on junctions availabla over JD2. Relay CO releases but ACO maintains the stepping circuit of JD2. When the last junction available over JD2 has been tested (JD2 in position 23), ground over wiper 300 operates PCO which, at 89, releases ACO and APT but, as ACO is slow to release, momentary ground over 312 is connected over 295, 296 and the previosly traced circuit to DM7 which moves JD2 to position 24. Ground over wiper 300 is now connected over wiper 59 of PPD1 to short circuit relay FT and mark the position tested. Testing junction lamp and conductors. When JD1 moves on to the first idle junction, LP, Fig. 4. does not operate and EJ releases followed by RC. but momentary ground is connected over 120, 147, 148, and wiper 150 of test switch TC to relay TS which at, 46, releases GD and closes a circuit for magnet DM1 of TC which moves to position 2. At the end of a test, DM1 is stepped on under the control of TS but if a fault is found, TS remains unoperated and time alarm relay TAR, Fig. 3. operates over its lower winding to ground at 161 and brings in an alarm as will be described later in connection with the routine completed signal. In position 2, relay TL operates and