Patent GB-266268-A (GB)
Title: Improvements in multi-channel telegraphy
IPC: H04L5/22
Filed: 1925-08-15
Abstract: 266,268. Pernot, F.E. Aug. 15, 1925.. Distributor systems; restoring or modifying imperfect signals; multi-station systems; synchronous movements and synchronism indicators. -Relates to multiplex telegraph systems of the rotary distributor type. According to the invention, which is particularly suitable for " recorder " or " cable " code, a control station maintains synchronism between outlying stations so that impulses entering a single channel from several branch channels can be aggregated for conjoint-transmission. Aggregating independent signals. The aggregating device is shown within the rectangle E, Fig. 1. Three transmitters 3, 3<1>, 3<11> are driven from a common shaft 4 together with a commutator 5 to successive 'segments of which the transmitters are connected. The output from the distributor is passed to the line 1 through a retransmitter 8 which is geared up to three times the speed of the distributor and is constructed as described in Specification 234,894 so as to shape the outgoing signals. Thus if the code signals emitted at 3, 3', 3" be represented by the curves T, T<1>, T", Fig. 2, the aggregated output to the line 1 will be as shown at S. The signals are retransmitted and reshaped by apparatus 3<111> constructed as described in Specifications 213,302 and 234,894.. Segregating means. The signals may be received, reshaped, and segregated by apparatus shown within the rectangle F, Fig. 1, and comprising a further regenerator or impulse-shaping device 9 geared to a distributor 11, synchronism being ensured by the signals themselves. The distributor segregates the signals and delivers them to three receivers 13, 13<1>, 13", the form of the received signals being shown at R, R', R", Fig. 2. System applicable to branched lines. The system shown in Fig. 3 employs distributors with two segments instead of the previously instanced three. A station A is to send and receive on two duplexed channels to stations C and D by way of a relay station B : Thus the output of transmitters Tc, Tn at station A is aggregated by apparatus 21 similar to that shown at E, Fig. 1, and is sent over the duplex line 26 and local conductors 28 to a segregating apparatus 29 similar to that shown at F, Fig. 1. The segregated signals are then sent via retransmitters 31, 31<1>, local conductors 33, 33<1>, and duplex lines 37, 37<1> to stations D and C respectively, where they are regenerated at 40, 40<1> and received at 41, 41<1>. Similarly, signals emanating from stations D, C at 42, 42<1> are respectively sent via the lines 37, 37<1>, local conductors 48, 48<1>, aggregating device 51, duplex line 26, and segregating device 62 to the appropriate receivers Rc, RD. In a modification the station D mav be local to the station B, in which case the parts 31, 36, 49, 37, 40, 42 are dispensed with, and in place of them a local receiver is connected to the conductors 30 and a transmitter to the conductors 50. Control of synchronism. Synchronism is effected by the signals themselves as described in the above-mentioned Specifications; or by superimposed alternating current as in Specification 196,971, and the transmitters may run at equal speeds or as described in Specification 265,806, at unequal speeds. The principles to be followed in the latter case are set forth in the Provisional Specification. To assist synchronization certain adjacent parts are mechanically geared together, as shown at 32, 43, and elsewhere. A differential gear 44 may be provided at station D for adjusting the phase of the local apparatus, and at the control station B the signals sent to A are duplicated in a local apparatus 62<1>, R'c, R<1>D corresponding to the receiving apparatus 62, Rc, RD of station A, so that by observing the duplicate signals the operator at B is enabled to adjust the phase of the apparatus 51 as required, by means of the manually operated differential gear 58.