Patent GB-392919-A (GB)
Title: Improvements in or relating to electrical signalling systems
IPC: H02J13/00
Filed: 1931-11-24
Abstract: 392,919. Electric signalling systems. AUTOMATIC ELECTRIC CO., Ltd., Strowger Works, Liverpool. Nov. 24, 1931, No. 32587. Convention date, Dec. 13, 1930. [Class 40 (i).] Indicating devices, such as devices on a mimic diagram indicator board, are selected over a train of automatic switches, one of which is a bi-directional selector connecting with two switches from each level and with a different wiper of the selected switch from each contact. A lamp indicator shows the position to which each switch is set before the next switch is operated. The last two switches in a train can be released and reset without affecting the first switch and the final switch can be stepped from contact to contact. To select a device, :such as that connected to contact 555707, the key 14 is operated and the first digit, 5, dialled. Relay 101 responds and the vertical magnet 110 steps wipers 129 .. 133 to the fifth level. Relay 102 holds up during the train and 103 operates. When the train ends, 102 releases and 104 operates in series with 103 and locks to 140. Relay 104 changes over to the rotary magnet 111, which, in response to the second impulse train, steps the wipers to their fifth rotary contact, relay 105 energizing when 102 pulls up and looking in series with 106 when 102 releases. Should the group selector, Fig. 3, be busy, relay 107 operates over 129 before 102 falls away, and locks to earth on the selected. contact, so that when 102 releases, the busy lamp B is lit. When the group selector becomes free 107 releases and 108 operates. If the selector tested was free 107 does not pull up and when 102 falls away, 108 operates. Relay 108 extends the dialling circuit over 130 to conductor 144, extends the operating circuit 142 over 131 to conductor 145 and connects earth to 132 and 133 to energise relays 201 .. 204 and to light the lamps 5 in the first two indicator sections, over ten conductor cables 148, 147, indicating that the first switch is standing on the-5th contact in the 5th level. The relays 201 .. 204 each have 10 armatures and extend the 10 conductor cables 209 .. 212 to cables 213 .. 216 connected with the selected group selector and the final selectors. The next digit, 5, is repeated by 101 to magnet 370, relay 353 operating in series with 370 to energize 354. Relay 352 is slow to operate and does not pull up during impulsing. When the train ceases 353 falls away and 355 pulls up in series with 354, changing over to the rotary magnet 371. The next impulse series moves the wipers 380 .. 383 into the seventh position on the fifth level, 357 operating when the train terminates to extend the impulsing conductor and to earth wiper 383 which controls, over cables 213, 214, the 3rd and 4th lamp indicators. The group selector connects with two final selectors, Fig. 4, from each level, the first five contacts connecting with the first of the two, whilst the control lead, which is extended over wiper 382, is connected with a different one of the wipers 411 .. 415, 466 .. 470 on each contact. As the fourth digit dialled was seven, wiper 467 is connected with conductor 145 over 382 ; had the digit been nine, connection would have been to wiper 469. The next impulse train is repeated by 101, over 381 and 388, to the vertical magnet 462, which steps wipers 466 .. 471 to their tenth level, relay 359 energizing when the train terminates to extend the impulse lead to wiper 380. At the same time the release of 353 connects earth to conductor 385 and over wiper 472 and cable 384 to operate 310. Relay 310 locks and energizes, over cable 215, the " O " lamp in the fifth indicator group. The final digit is repeated over 380 to rotary magnet 461 so that the wipers 466 .. 471 are rotated to their seventh contacts in the tenth level. Conductor 385 is again earthed and the seventh lamp in the sixth indicator group is energized over 471 and cable 216. The lamp indicator then shows the number, 555707, of the unit to which the switches are connected and this unit can be operated by key 15. If the operator now wishes to control another unit connected after 7 in the " O " level of 5557, he dials 1, 2 or 3 impulses which step the wipers 466.. 471 to terminal 555708, 555709 and 555700 respectively. When the switch is re-operated the lighted lamp in the sixth indicator group is extinguished and another lamp is lit to indicate the new position of the switch. The final two switches (Figs. 3 and 4) can be released by the operation of key 11 for a period long enough for slow operate relay 352 to pull up: Earth, is removed from 378 to release relays 364 .. 359 and relay 310, whilst the earth connected to 379 operates the release magnets 365 and 463 of the operated switches. When the key 11 is restored, relay 352 releases and the group selector can be reset to select another final switch. The whole switch train is released by the restoration of key 14 which removes earth from 140 to release 103.. 106 108 and 351, and energizes 109 to release the first selector. The release of 351 removes earth from 378 and connects earth to 379 to release the group and. final switches. Specification 371,844 is referred to.