Patent GB-265806-A (GB)
Title: Improvements in multi-channel telegraphy
IPC: H04L5/22
Filed: 1925-08-15
Abstract: 265,806. Pernot, F. E. Aug. 15, 1925. Diplex and multiplex telegraphs; automatic telegraphs; restoring or modifying imperfect signals; repeating systems using contact making relays.-A different speed of signalling is employed in each channel of a synchronous diplex or multiplex system, each speed being preferably a simple multiple of a given speed. Aggregating the signals for transmission. Signals produced by apparatus A and X, Fig. 2, driven through gearing from a shaft 4 at a speed ratio of 3 to 2, are delivered over leads 5 and 6 to electromagnetic devices 8 and 7 respectively. The shaft 4 makes a half revolution per signal from apparatus X. The apparatus A may be such as described in Specification 213,302 for regenerating signals received over a cable C and for maintaining the shaft 4 in synchronism with these signals, and the apparatus X may be an automatic transmitter. The device 7 comprises a magnet 7<1>. Fig. 3, receiving dot currents over leads 6<1>, and a magnet 7<11> receiving dash currents over leads 6<11>, these magnets being carried by a frame 15 adjustable about the axis of the shaft 4 and being arranged at opposite sides of a disc R<1> fixed to the shaft. The device 8 is similarly constructed and similarly arranged in relation to a disc R<11> fixed to the shaft. The disc R' carries a pair of pivoted armatures b<1>, b<11>, and diametrically opposite these a second pair d', d<11>, and as the disc rotates the armatures b<1>, d<1> pass in front of the magnet 7<1> and the annatures b<11>, d<11> pass in front of the magnet 7<11> and are actuated or not according to whether the corresponding magnet is or is not energized. Each armature is held in either of its positions by a jockey roller, and, if actuated, is returned to unactuated position by a member 14<1> or 14<11> carried by 'the frame 15 during the subsequent rotation of the disc. The disc R<11> similarly carries three pairs of armatures equally spaced around it. A frame 27 fixed to the shaft 4 carries, equally spaced around it, five pairs of magnets such as 22<1>, 22<11>, Fig. 3, each provided with a spring - controlled armature 23<1> or 23<11>. Each armature, such as b<1> actuated by the dot magnet 7<1> or 8<1> closes a circuit from a battery 16 through slip rings 17 to energize a corresponding one of the magnets 22<1>, and each armature such as b" actuated by the dash magnet 7" or 8<11> closes similarly a circuit to energize a corresponding one of the magnets 22". Each of the armatures 23<1>, 23<11> in moving to its actuated position places a pin 24' or 24" in position to act on a corresponding spring-controlled lever 25<1> or 25" as the shaft 4 rotates, thus rocking this lever on its pivot 34, Fig. 5, to move a corresponding contact arm 29 for sending a dot or dash to line, the duration or degree of curbing of the signal being determined by the angle O through which the shaft rotates while the pin is acting on the lever. Figs. 7 and 8 show a modification in which the selection and operation of the pins for actuating the transmitting levers 73, 73<1> corresponding to the levers 25<1>, 25<11>, Fig. 3, are effected mechanically. The shaft 51, magnets 56, 56<1>, discs 52, 53, and frame 54 correspond to the parts 4, 7<1>, 7<11>, R<1>, R<11>, and 27 respectively of Fig. 3. Spring- controlled pivoted armatures 57, 57<1> of the magnets 56, 56<1> move between stops 58, 59 and 58<1>, 591 and carry bell-crank arms 60, 60<1> respectively, each forked to engage the grooved hub of a corresponding rotatable wheel 62, 62<1> slidable on a rod 63 adjacent to the periphery of the disc 52. A pin 72 slidable in the frame 54 to cooperate with one or other of the levers 73, 73<1> is operated by a lever 70 connected by a rod 69 to the arm 67 of a T-shaped member pivoted at 68 within the disc 52. The ends 66, 66<1> of the head of the T are arranged to co-operate with transmitting and receiving mechanisms may be driving members 65, 65<1> pivoted on a shaft 64 carried bv the disc. When one of the magnets 56 or 56<1> is energized the corresponding wheel 62 or 62<1> is moved against the corresponding member 65 or 65<1> which, due to the rotation of the disc, moves inwardly to operate the T- member in one direction or the other. Fixed wheels 77, Fig. 8., act on the members 65, 65<1> slightly in advance of the wheels 62, 62<1> to restore them to neutral position. A link 61 connecting the arms 60, 60<1> prevents positioning of the wheels 62, 62<1> for acting on the T-member simultaneously. Alternatively the circuit of each of the magnets 56, 56<1> may, for this purpose, be completed through the back stop contact 58 or 58<1> closed by the armature of the other magnet. Fig. 9 shows a mechanical equivalent of the above devices in which the mounting of moving mechanisms on the main shaft is avoided. Signal-producing apparatus 79 and 80, supplied from a common battery 89, are geared together for a speed ratio of 2 to 1 and are geared to a shaft 88 making one revolution per signal element from apparatus 80 and carry cams 104, 96, 130, 147, and 113. Dot and dash signals from apparatus 79 energize windings 106' and 106<11> of magnets P' and P" respectively upon closure of a contact 108 by the cam 104 and energize magnets 100<1> and 100" respectively upon closure of a diametrically-opposed contact 102 by the cam, such closures being arranged to occur at about the middle of each signal interval. Dot and dash signals from apparatus 80 similarly energize magnets 92<1> and 92<11> respectively upon closureof a contact 94 by the cam 96. Bell-crank arms 111<1>, 111<11> of the spring-controlled pivoted armatures 110<1>, 110" of magnets P<1>, P<11> carry members 116<1>, 116<11> respectively, each of which, when the corresponding magnet is energized, is interposed between a follower 114 of the cam 113 and a projection 117<1>, 117<11> on a corresponding bell-crank 119<1>, 119<11> arranged to operate the dot and dash transmission keys 139<1> 139<11> respectively. The magnets P<1>, P" are provided with a hold-on circuit adapted to be. operated by the cam 130. The magnets 100<1>, 100<11> control bellcranks 145', 145<11> and the magnets 92<1>, 92" control bell-cranks 146<1>, 146<11> which, similarly to the bell cranks 119<1>, 119" operate the keys- 139', 139", and similar hold-on circuits are provided for these magnets. Fig. 10 shows a further modification employing slip ring segmental contacts instead of cam-operated contacts. Signal-producing apparatus 148, 149 supplied from a common battery 155 are geared together for a speed ratio of 2 to 1 and are geared to a shaft 61 making one revolution per signal element from apparatus 149 and carrying sliprings 159, 160, 191, and 176. Dot and dash signals from apparatus 148 energize magnets L, L<11> respectively through brush 163 and conducting segment 158 of slip ring 160, and similarly energize magnets M<1>, M<11> respectively throughbrush 164 disposed diametrically opposite to the brush 163. Dot and dash signals from apparatus- 149 similarly energize magnets N<1>, N<11> respectively through brush 162 of slip ring 159. Each of the magnets L<1> L<11>, M<1>, M<11>, N', N<11> is provided with two independent windings, and when, for example, a dash current from apparatus 148 is delivered 'through brush 164 to magnet M<11>, one winding 165 is first energized and armatures 167 and 169 are attracted. Armature 167 closes at 168 a circuit for a dash current from battery 180<11 >through leads 179" and 175 to conducting segment M<0> of slip ring 176, and thence to brush 177 to line 178, 182. Battery 180<1> is similarly associated with magnet M<1> and segment M<0> for sending to line a dot current from apparatus 148, and conducting segments L<0>, N<0> of ring 176 are similarly associated with magnets L<1>, L<11> and N<1>, N<11> respectively. Armature 169 closes at 170 a circuit from battery 183 through leads 184, 185, winding 186 of magnet M", lead 187, armature 172 of magnet M<1>, leads 173, 188, brush 189 of slip ring 191, and lead 193. Magnet M<11> is thus maintained energized until insulating segment 192 is engaged by brush 189, and this is adjusted to occur shortly before the succeeding engagement of brush 164 with segment 158 of the ring 160. Segregating the signals for reception. This is effected by synchronized apparatus similar but operating reversely to that used for aggregating the signals. Thus, the segregating devices at the receiving station, Fig. 2, are carried by a shaft 43 running synchronously with the shaft 4, and comprise a disc 46 similar to the discs R' and R", and two frames 47<1>, 47" similar to the. frame 27. The disc 46 carries five pairs of magnet armatures a<2> - - e<2>, similar to the pairs of armatures such as b<1>, b<11>, Fig. 3, and each pair is acted on in turn by a pair of dot and dash receiving magnets indicated at 45 and corresponding to the pair 7<1>, 7<11> or 8<1>, 8<11>, Fig. 3. The frames 47<1>, 47<11> carry respectively two and three pairs of magnets corresponding to the pair 22<1>, 22<11>, Fig. 3, energized from the corresponding armatures on the disc 46, and pairs of contact arms at 48<1> and 48<11> similar to the arms 29, Fig. 5, deliver the segregated signals to their appropriate channels. Segregating devices similar to the aggregating devices, Fig. 7, may be used comprising a shaft carryin one disc similar to the discs 52, 53 and two frames similar to the frame 54 and associated mechanism similar to that shown in Fig. 7. Segregating devices similar to the aggregating devices of Figs. 9 and 10 are obtained by similar modifications of the arrangements shown in 'these figures. Synchronism of obtained as described in Specifications 213,302 or transmitting and receiving mechanisms may be 196,971. According to the Provisional Specification the system may be used in association with a synchronous transmitter such as that described in Specification 234,894.