Patent GB-165783-A (GB)
Title: Automatic telegraph systems
IPC: H04L7/00
Filed: 1921-06-08
Abstract: 165,783. Western Electric Co., Ltd., (Assignees of Bancroft, E. P., and Kerr, M. B.). July 1, 1920, [Convention date]. Type-printing telegraphs; distributor systems. -In a multiplex printing telegraph system the distributors are synchronized by sending a predetermined signal from a terminal station to a repeating station, and causing the latter to repeat back the said signal to the terminal station, thereby operating a mechanism for indicating the line lag, the sending apparatus at the terminal station being adjusted to compensate for the line lag indicated. At the repeating station, storing relays are employed to store signals received from one station and re-transmit them to others. One or more channels may be extended from the terminal stations to out-stations by means of startstop mechanism. Fig. 4 shows a system in which three terminal stations B, B<1>, B<11> are in communication with each other through a repeating station C. Some of the channels are shown extended by means of start-stop mechanism to out stations A, A', A<11>. Duplex working is used between all the stations. Assume that a message is to be transmitted over the system from outstation A to out-station A<1>, the start-stop distributor 120 at the terminal station, Fig. 9, is controlled from a local segment of the terminal multiplex receiving-distributor RD, Fig. 8. Each time the brush 66, Fig. 8, passes over the segment 65, a circuit is completed to cause the magnet 68, Fig. 9, to withdraw the pawl 76 from engagement with the brush arm 75 of the start-stop distributor, which thereupon makes one complete revolution. As soon as the brush 77 passes off the segment 78, the circuit from the battery 80 through the relay 81 is broken, and the armature 82 falls back and connects spacing current to the start-stop extension circuit, The relay 84 now opens the circuit through the release control relay 86, and the armature 87 connects battery 88 to the segment 89, energizing the release magnet 92 and the release control relay 93. The pawl 94 is thus withdrawn, starting the receiving distributor at the outstation. Relay 93 completes an energizing circuit for the release magnet 96, and a holding circuit for brush 97 of the out-station sending distributor is released. As soon as the brush 98 passes off the segment 99, the circuit through the relay 108 is broken, and its armature 109 connects spacing current to line causing the relay 83 to open-circuit release control relay 111, which connects battery 112 to the release magnet 116, thus starting the receiving distributor 110 at the terminal station. Signals set up on the transmitter T at the outstation, are thus received by the distributor 110, and cause the operation of appropriate storing relavs 70 - - 74. These cause the energization of certain segments of the multiplex sending distributor SD, Fig. 8, whereby impulses are sent to line and received through the line relay 11, Fig. 5, at the repeating station C. Relay 11 causes through the distributor segments the operation of storing relays. 19, 20 which through the contacts 155, 156 and 164, 165 energize the appropriate segments of the distributor SD associated with line LC. Impulses sent over line LC are received by the line relay 167, Fig. 8, at the terminal station B'. Operation of this relay causes the operation of the relays 170, 169, the latter through the brush 175 energizing appropriate segments of the distributor RD, and thus causing the operation of the storing relays 60 - - 64, Fig. 9. These complete holding circuits for themselves and put earth on some of the segments of the distributor 120 through pole-changing relay 81. On the release of the brush arm 75 signals will be sent out, and received by the printer R through the receiving distributor at the out-station A'. At a modified repeating station arrangements are made for some of the channels to terminate at the repeating station and others to be repeated through. In another repeating station shown in Fig. 7, a quadruple duplex circuit for line LA is forked at the repeating station into two double duplex circuits for lines LB, LC. In this arrangement, the sending segments of the double distributor D' are twice the length of those of the quadruple distributor D<11>. In this system the traffic channels of the quadruple circuit are so arranged that the first channel occupies the odd segments of the first ten segments, the second the even segments, and so on. Better results are obtained if the brushes of the double distributors are staggered with respect to each other; thus, when the quadruple receiving brush is on segment 35 the double sending brush for line LB should be on the latter part of segment 44, and the double sending brush for line LC on the latter part of segment 40 with a corresponding relation of the various receiving brushes. At each of the terminal stations, Morse keys 210 and sounders 211 are provided. Synchronizing. The synchronous motors at the terminal stations may be of any known type and are driven from a starting distributor or a driving fork 30, Fig. 8. The starting distributor comprises the rings 186, 187 connected up as shown. When the key 188 is moved to the right. current from battery 189 flows through one of the pairs of magnets 29, starting the motor and causing the brush 190 to move and thus energize the other pair. The motor is then run up to the desired speed which is indicated by the prolonged glowing or extinction of the lamp 191. The key 188 is now moved to the left and the motor placed under the control of the fork 30. The rate of vibration of the fork 30 may be varied by shortcircuiting the resistance 197. This may be done permanently by means of the key contact 198 or intermittingly through the correcting relay 201. Whenever the line relay 168 makes engagement with one of its contacts, the armature 171' is moved into engagement with one or other of its contacts. Current will thus flow through the relay winding 201 for a time depending on the position of the brush 205 and the interval between the making of a contact by relay armature 168 and the breaking of contact by relay armature 171'. For proper working of the system, the time lags in the lines from the repeater stations are compensated for at the sending distributors of the terminal stations. To effect this the phasing keys 21, 121, 221 are thrown at the repeating station. This causes a marking impulse to be sent from one of the distributor segments and spacing impulses from the other nineteen. The receiving brushes at the terminal are then adjusted until the correct character is recorded by the printer R or until a predetermined lamp, say 51, is illuminated if lamps are used as in Fig. 8. The phasing keys at the repeater arethen thrown to normal and those at the terminal 54 thrown so as to cause a single marking impulse to be sent from the terminal distributors in the same way as previously from the repeating- distributors. At the same time the repeater station's lag-finding keys 22 &c. are thrown so that signals are repeated back to the originating station. The sending brushes at the terminal arethen orientated until the same character as before falls on the same printer or the same lamp flashes. This adjustment compensates for twice the lag in the line, so the brushes have to be further adjusted to compensate only for half the lag indicated. Fig. 10 shows an arrangement for adjusting thebrushes. The brush arm 216 is driven by bevel gearing 220, 224. The bevel wheel 220 is carried by the member 225 which is normally stationarybut is movable by means of the handle 226 to advance or retard the brushes. Specifications. 3985/15, 162,616, and 162,621 are referred to.