Patent GB-361840-A (GB)
Title: Improvements in or relating to electric cable telegraph systems
IPC: H04L5/18
Filed: 1930-08-15
Abstract: 361,840. Telegraphy. ELECTRICAL RESEARCH PRODUCTS, Inc., 195, Broadway, New York, U.S.A.-(Assignees of Dowd, A. D. ; 1201, Washington Street, Hoboken, New Jersey, Kerr, M. B. ; Durkee Manor, Rosebank, Staten Island, and Locke, G. A.; 9, Maple Avenue, Glen Cove, both in New York, all in U.S.A.) Aug. 15, 1930, No. 24488. Convention date, Aug. 19, 1929. Addition to 346,434. [Class 40 (iii).] A telegraphic system with automatically reversing simplex traffic comprises an 8-channel cable with a mid-cable repeating station, together with two 4-channel continuation lines at each end, the system being symmetrical. Five storing relays are provided at each of the repeating stations and are so arranged that they serve the eight channels for both directions of traffic. Means are provided for monitoring both incoming and outgoing signals on siphon recorders, one or more channels being however monitored on a printer. System of lines and stations. At the west terminal WT, Fig. 1, multiplex transmitters A .. D feed into the line 311 through distributer 500, and transmitters E .. H feed into the line 312, through distributer 501, so that the phase of E .. H is half a segment behind that of A .. D. At the west repeater station WR the signals pass through distributers 800, 801, to five storing relays 802, which interleave the impulses of message A with those of message E, message B with message F, and so on, and pass them on through distributer 900 and shaping network 1000 to cable 1013. At the mid-cable retransmitting station 1R, Fig. 2, the signals pass through a shaping network and an amplifier 1400 (described in Specification 258,614, [Class 40 (iii), Telegraphs, Electric], storing relays 1801, distributer 1501, and sending network 1900 to cable 1913. At east repeating station ER the signals pass through amplifier 1002<1> and storing relays 802<1> to 4-channel distributers 11001, 1101<1>, which divide them between sending-on relays 1111<1>, 1112<1>. These feed the printers J<1>.. Q<1> through lines 311<1>, 312<1> and receiving distributers 300<1>, 301<1>. Speed is controlled by a tuning-fork at each station, and synchronism is effected by mechanical correctors 600, 600<1>, controlled by signals in pilot lines 1113, 1113<1> at the terminal stations; and under control of the cable signals, through differential transformers 1300, 1800, 13001 as described in Specification 348,595, at the repeating stations. The direction of working is reversed by cam switches at each station, those at the terminal stations being controlled over the pilot lines 1113, 1113<1> from the nearest repeater stations. Multiplex telegraphy. Marking signals are + for channels A, B, E, F, and - for channels C, D, G, H, and the order of transmission in the cable is (AE), (BF), (CG), (DH), the impulses of the bracketed pairs being interleaved by the storing relays (see below). At each terminal station there are two quad distributer faces, each serving one of the 4-channel duplex lines and comprising the transmitter rings and receiver rings for that line. The receiving rings are orientable, while all the brushes are on the same shaft. At each of the cable-end repeater stations, one distributer face comprises four concentric receiver and transmitter rings for the two four-channel lines, and these operate through storing relays into a second distributer face driven by the same motor and comprising 8-channel receiving and transmitting rings. At the mid-cable station two 8-channel distributer faces are employed. The auxiliary distributer rings for phasing, synchronizing, and monitoring by oscillographs are mounted on the above main distributers, but the apparatus for timing, reversing, and monitoring by printers at each repeater station is driven by a separate motor controlled by the same tuning-fork as the main motor. The solid rings are divided into quadrants, each quadrant serving one channel in the 4-channel distributers and two channels in the 8-channel distributers. Storing relays. Each repeater-station has a set of five storing relays such as 802, Fig. 8, which serves in turn for all channels and both directions of working, the left-hand windings being used for one direction of transmission while the right-hand windings are disconnected, and vice versa. At the west cable-end station WR, during west-east transmission, the armatures of line relays 811 (channels A .. D) and 812 (channels E .. H) feed the solid rings of the receiving distributers 800, 801, respectively via leads 831 and shunted siphon-recorders (monitors) 817, 821 and so control the left-hand windings of storing relays 802, relay 812 being operated by incoming impulses which lag somewhat behind those that operate relay 811. The live segments of segmented ring 814 operate alternately with those of ring 816, and the connections with distributers 900, 901, Fig. 9, are such that the first of the storing relays 802 serves alternately the first impulses in the A .. D channels and the third impulses in the E .. H channels; the remaining relays 802 being connected in such a way that they similarly serve the channels alternately for the remaining impulses. The armatures of the storing relays 802 pass on current from the batteries 836 (which are earthed via 1014e) through the leads 833 to the solid ring 915 and via lead 917 and reversing-switch 1011, Fig. 10, to the eastward cable 1013. During east-west transmission, on the other hand, the received signals, after passing through an amplifier 1002 and vibrator relays 1015, 1016, are applied via lead 1022, Fig. 8, to the right-hand windings of the storing relays 802, which are earthed via lead 825 and reversing cam 721, Fig. 7. The lead 917 being earthed for east-west transmission, the armatures of relays 802 feed the A .. D distributer 1100 and E .. H distributer 1101, the connections being again such that the impulses of the two groups of channels are interleaved. These distributers feed the westward lines 311, 312 through sending-on relays 1111, 1112. A similar arrangement, mutatis mutandis, is provided at the mid-cable repeaterstation. Montoring. At the terminal stations, two sets of monitoring oscillographs record incoming and outgoing signals respectively, these instruments being connected in shunt to the main signal circuits via a segmented ring which is added to each of the distributers, for this purpose. At the cable-end repeating station WR incoming signals during west-east transmission pass through the groups 817, 821, Fig. 8, of monitoring oscillographs, which are in series between the armatures of line relays 811, 812, and the distributers which feed the storing relays 802. The west-east B .. H signals are again monitored on the outgoing side, in shunt with the cable, by oscillographs 918 which are connected to the lower segments of distributer 900, whereof the upper segments are fed by storing relays 802, the solid ring 915 being connected to the cable. During east-west transmission incoming signals of channels B<1> .. H<1> at the same station are monitored by oscillographs 1213, Fig. 12 (not shown), which are fed by the vibrator relays 1015, 1016, Fig. 10, via leads 1023, 1231, distributer 1200, and earthed lead 1222, Fig. 12. These eastwest signals are again monitored on the outgoing side by groups 1117, 1121 of oscillographs, which are fed by the storing relays 802 in series with sending rings 1100, 1101 and sending-on relays 1111, 1112. In addition to the oscillograph records, printer records are taken on channels A and A<1> (i.e. in both directions) on the incoming and also on the outgoing sides. The monitoring relay 929 is associated with the lines 311, 312, leading to the terminal station WT, and is controlled during west-east traffic by its left-hand winding, which is fed by the line receiving relays 811, 812 in series with the receiving rings 800, 801. This relay 929 feeds the monitoring printer 913, which monitors the incoming west-east signals in channel A, in conjunction with distributer 901 whose solid ring is connected to negative of battery 943 via cam switch 719. During east-west traffic, on the other hand, the same relay 929 is controlled through its right-hand winding by the armatures of storing relays 802 in series with the windings of sending-on relays 1111, 1112, so that it registers outgoing eastwest signals on channel A<1>. Cam 719 having connected negative of battery 943 to the solid ring of distributer 1201, Fig. 12, instead of 901, these signals are recorded by printer 1226. Monitor relay 930, on the other hand, is associated with the cable and is, during west-east traffic, controlled through its left-hand winding by the armatures of storing relays 802 through distributer 900 similarly to the oscillographs 918 of the B .. H channels, and feeds printer 926 which is connected to battery 939 through distributer 902 and cam switch 720, so as to record outgoing west-east signals. For east-west traffic the cable-side relay 930 is controlled through its right-hand winding by the vibrator relays via distributer 1200, co-ordinately with the oscillographs 1213 of the B<1> .. H<1> channels ; and it now feeds the east-west receiving monitor printer 1223, which has been connected in place of printer 926 by cam switch 719. If the monitoring printers 913, 1226, are to be connected to one of the channels E .. H, El .. H<1> instead of to one of the channels A .. D, A<1> .. D<1>, switches 826, 1132 are reversed so as to transfer the connections from relays 811, 1111, to relays 812, 1112. The monitoring arrangements at the mid-cable station IR are on each side similar to those on the cable side of the cable-end station WR; these arrangements are duplicated so that the circuit diagram for IR is symmetrical. Restoring imperfect signals. Sending networks 1000 and receiving amplifiers 1002, as described in Specification 258,614, [Class 40 (iii), Telegraphs, Electric], are provided at the repeating stations. Lost impulses ar