Patent GB-101411-A (GB)
Title: Means for Operating Apparatus at a Receiving Station from a Sending Station by means of Electric Pulsations.
Inventor: SAERNMARK AXEL UNO
IPC: H04L25/493
Filed: 1916-09-01
Abstract: 101,411. Sarnmark, A. U. Sept. 17, 1915, [Convention date]. Electric selectors.-Apparatus at a distant station is selectively operated by means of sequences of electric current impulses of different sign transmitted through one or more conductors with earth or wire return. The devices selected may be the lamps of a signalling system, the printing-magnets of a type-printer, or switches for igniting mines. As applied to signalling, a single conductor is used, and the impulses, set up by the continuous rotation of a contact device, comprise one negative impulse preceded by 0, 1, 2 &c. positive impulses according to the position of the switch operated at the sending-station; and the sequence of positive impulses selects and prepares the corresponding signal or lamp circuit at the receiving station, the circuit being closed by the final negative impulse. The selection at the receiving station is effected by a combination of polarized relays responding respectively to positive and negative impulses. When applied to printing telegraphy, a second conductor is employed along which one or more positive impulses only are sent. The positive and negative impulses conveyed along the first conductor act as before to connect, at the receiving station, one pole of a local battery to a selected column of printing- magnets, while the positive impulses along the second conductor connect the other pole of the battery to a selected row of magnets, the particular magnet situated at the intersection of the column and row being thus energised. Electric signalling systems. The rotary contact device at the sending station A is shown developed in Fig. 1 and comprises a continuous ring 4 connected on the left to a narrow strip 6, and on the right to a number of strips 7, 9, 11, 13 of decreasing length. A second continuous ring 5 is connected to a number of strips 8, 10, 12 of equal length. A series of stationary brushes 15 - - 21 are arranged in line across the rotary member, and a brush 14 is arranged to make contact with the strip 6 just before the latter reaches the brush 15. The brushes 16, 17 bear continuously on the rings 4, 5 and the brushes 18 - - 21 are connected respectively to contacts on the signalling-pushes II, III &c. The push I is arranged to bridge a pair of leads, and the pushes II, III &c. in addition to bridging the same pair of leads also couple the brush 18, 19 &c. to the wire 51. If the switch II is closed, the rotation of the contact device 3 makes a momentary circuit from the positive pole of the battery through the brushes 15, 16, relay 24, contacts 49, to the earthed centre of the battery. The armature 27 is attracted and closes a locking-device rendering the relay 24 independent of the rotary contact 3. As this rotates, the brush 18 engages the strip 7 and this makes a circuit from the positive pole of the battery 2 through armature 27, brush 16, contact strips 4, 7, push contact 50, wire 51, armature 25 to the line 1, which thus receives a single positive impulse. If the push connected to the brush 20 had been operated, the rotation of the contact maker 3 would have sent three positive impulses to line. The positive impulses are separated by weak negative impulses which are sent out as the brush 20 passes over the strips 8, 10, 12. These negative impulses serve to discharge the line, but do not operate the relays at the receiving-station. At the conclusion of the positive impulses, the contact strip 6 engages the brush 14 and makes a circuit from the positive pole of the battery, through armature 27, brushes 23, 22, push contacts 49, to the battery centre. The armature 26 of the relay 23 closes a locking- circuit for both relays, and the relay 22 moves the switch 25 into circuit with the negative side of the battery, which thus sends a negative current to the line 1. When the push II is released, the relays 22, 23, 24 are de-energized and the parts resume the position shown. At the receiving-station, B, the positive impulse passes through the armature 40, relay +30, which responds, and relay - 29, which does not respond, the sign indicating that the relay is so polarised as to respond only to impulses of that sign. The armature 38 thus closes a local battery eircuit through relay 34 and switch 44. The armature 42 is attracted and locks itself at the contact 52. At the conclusion of the positive impulse, the armature 38 returns and makes a circuit through a relay 32, which opens the switch 40. If a further positive impulse is received, it is passed on through the contact 54 to the next series of relays 31, 33, 35, and causes the armature 43 to be attracted. The positive impulses thus prepare the circuit of the selected lamp II<1>, III<1> &c., and the concluding negative impulse energizes the relay -29 and completes the lamp circuit at the switch 37. If no positive impulses have been received, i.e. if the push I has been operated, the single impulse completes the circuit of the lamp I<1>. At the conclusion of the negative impulse, a relay 36 in a circuit inductively related to the lamp circuits, is momentarily energised and opens a switch 44 to de-energize the relays. The relays -29, +30 may be arranged in parallel instead of in series. In another modification, the line circuit, instead of passing through the positive relays +30, +31, &c. passes through a single positive relay which closes a local circuit containing the relays +30, +31. The switch 63, Fig. 4, controlled by the single relay +62 may normally form a short circuit for the battery 64, the relav 62 when active, serving to open the short circuit. In a further modification, the line circuit 1 itself supplies current to the circuit G, H when the switch 63 is open. Type-printing telegraphy. The pushes Ia, IIa, Ilia, Fig. 6, act in the same manner as in Fig. 1; to send positive impulses to the line 101 followed by a negative impulse. The second row of pushes IVa, Va, VIa send the same series of impulses to the first line 101, and, in addition, each sends one positive impulse to the line 201, the additional contacts in these pushes being coupled on the one hand to the brush 118, and on the other hand to the wire 251 which communicates with the second line 201 through a switch 225. The third row of pushes VIIa, VIIIa, IXa send the same series of positive impulses followed by a negative impulse to the line 101, and each push also sends two positive impulses to the second line 201. At the receiving station, the positive impulses in the line 101 operate one or more of the switches 342, 313, as described with reference to Fig. 1, and thus connect the positive pole of the local battery 128 with one or other of the vertical leads 175, 176, 177. The positive impulses in the second line 201 similarly connect the negative pole of the battery with one or other of the horizontal leads 275, 276, 277. Thus the push VIIIa at the sending station A' is operated, one positive followed by one negative impulse is sent to the line 101 and the single positive impulse causes the vertical lead 176 to be selected at the receiving station B<1>. Also two positive impulses are sent on the line 201, causing the horizontal lead 277 to be selected. Finally the circuit of the printing-magnet VIIIa is closed when the final negative impulse operates the relay -129 and closes the switch 137. When the impulse ceases the switch 137 opens and the induced current in a relay 136 operates a re-setting switch 144.