Patent GB-191404819-A (GB)
Title: Improvements in or relating to Selectors, especially suitable for use with Automatic or Semi-automatic Telephone Systems.
Inventor: BETULANDER GOTTHILF ANSGARIUS
Filed: 1914-02-24
Granted: 1914-10-29
Abstract: 4819. Betulander, G. A. March 1, 1913, [Convention date]. Automatic and semi-automatic exchange systems.-In a relay selector, the impulses for the two or more digits representing a wanted line are received by two or more chains of selecting- relays, and after all the impulses have been received the effects of the different digits are combined by means of ' combining-relays.' The invention is illustrated in its application to a selector of the type which is used temporarily to ' mark ' the line of a wanted subscriber, the connexion with the wanted line being then effected by separate connecting-relays while the selector is released. In the arrangement for 100 lines shown in Fig. 2, the selecting-relays comprise sets of tens relays 27 and units relays 28. The tens relays serve to select one of the combining-relays 4, 5, and the units relays select one of a group of circuits to which the selected combining-relay gives access. The impulse system consists in earthing one of the incoming wires 36 while impulses are sent over the other wire 35, the wire 36 being then momentarily disconnected before the next set of impulses is sent over the wire 35. The preliminary earthing of the wire 36 energizes the relays 30, 32. The first impulse in the wire 35 energizes the first relay of an auxiliary chain 29, which energizes the first tens and units relays 27, 28, which lock themselves up. The relay 29 remains energized over contacts 46, 45 until the impulse ceases. The second impulse energizes, over contacts 45, 47, the second relay 29, which energizes the second tens and units relays, and so on. At the termination of the tens series of impulses the circuit 36 is momentarily opened, de-energizing the relay 30 but not the relay 32, which is of slow-release type. The deenergization of the relay 30 unlocks the units relays 28, the energization of which at this stage has been merely incidental and of no effect, but the tens relays 27 remain locked over a contact of the relay 32. The de-energization of the relay 30 also energizes a relay 33, which locks itself up and prepares the circuit of a relay 31, which is energized when the wire 36 is earthed again. The units series of impulses now energizes the relays 29 and the units relays 28, but does not affect the tens relays 27, the building-up circuit of these relays being now open at the contact 40 of the relay 33. At the termination of the units series of impulses, the relay 30 is de-energized as before, but the units relays are not now unlocked because their circuit is maintained through the contacts 51, 39. Ground is now connected through contacts 53, 52, front contacts 54 of the energized tens relays, and back contact 34 of the first unenergized tens relay, to a combining-relay 4 or 5, which completes a circuit from ground, through contacts 53, 52, front contacts 55 of the energized units relays, back contact 56 of the first unenergized units relay, and through one of its own contacts 16, to the connecting - relay of the wanted line. A moment later the circuits of the relay selector are unlocked by the de-energization of the slowrelease relays 31, 32. The three-digit selector for 1,000 lines represented skeletonically in Fig. 1 comprise three sets of combining-relays 1, 2, 3; 4, 5, 6; and 7. 8, 9. By energizing one relay in eacli of these three sets, the circuits of any one of the 1,000 connecting-relays 10 can be selected.