Patent GB-420820-A (GB)
Title: Improvements in and relating to telegraphic type printing and setting machines
IPC: H04L12/02
Filed: 1933-05-30
Abstract: 420,820. Type-printing telegraphy. FULD & CO. TELEPHON-UND TELEGRAPHENWERKE AKT.-GES., H., 136, Mainzerlandstrasse, Frankfort-on-Main, Germany. May 30, 1933, No. 16642. Convention date, May 30, 1932. [Class 40 (iii)] A printing telegraph instrument in which the type-selecting device is actuated by impulses produced by its own transmitter or by the transmitter of a distant station incorporates switch means which, on actuation, disconnect the line leading to a distant station and switch over the type-selecting device for internal use into a circuit associated solely with the machine. When the instrument at a station A is to be used solely as a typewriter the operator depresses a key SchT energizing the windings UIII and ZMII. Relay ZM comprising windings ZMI, ZMII on operation releases a latch member 41 actuating a contact assembly K having contacts 44 at which the driving motor M is connected to the mains N. The double contacts at the bottom of the group K are connected to battery, and winding I of the magnet ZM is short circuited. Relay U (comprising windings UI, UII, UIII), on operation closes at contact u2 a circuit through a holding winding UII and lights an indicator lamp SchL. At contact u1 a differential winding UI is connected across the line Lg which, at contacts u3, u4 is switched over to an artificial line KL. The home recording is effected through contacts SK and a receiving magnet EM, and the transmitting or receiving shaft closes contacts JKe or JKs respectively effecting the energization of the magnet ZM which prevents the motor M from being stopped. If an operator at station B desires to communicate with station A when the latter is engaged in type-writing he depresses his key FT energizing winding II of magnet ZM which sets his motor M into operation and lights his lamp FL over the bottom contacts of the group K. At the same time a circuit is completed through the winding I of relay U at the station A which opposes the current in winding II and releases. The release of contact u2 lights lamp FL, and advises the operator to prepare for communication from station B. At the same time the release of relay U connects the line Lg at contacts u3, u4, over to the transmitter SK and receiver EM. In normal operation when one station calls a distant station which is at rest, the depression of the key FT sets into operation the motor at the calling station, and at the distant station the winding I of the magnet ZM is energized, the motor started and the calling lamp FL subsequently lighted. The artificial lines KL are arranged so that the attracting force and the time constant of the magnets are the same for internal use with one voltage source connected as for external use when the operating voltages BSp derived from the mains are in series. The motors M may be driven from A.C. or D.C. mains, N. Fig. 4 shows a switching arrangement by which the motor M is disconnected from the mains when signalling has ceased for a predetermined time, say one minute, and is controlled by the magnet ZM and a slowly rotating shaft. When either of the windings of the magnet ZM is energized an arm 30 carried on the armature 28 rocks a pivoted member 33 so that a pivoted rod 42, 37 is unlatched and under the action of a spring 39 actuates the contact assembly K vertically to close contact 44 connecting the motor M to the mains N. The armature 28 also rocks a Z-shaped lever 22, 21, 18, 20 so that its arm 23 moves to the right a sleeve 3 connected to a fast running shaft 6 and carrying a cam 4. Simultaneously a projection 17 on the arm 21 is removed from a notch 16 in a drum 9 which is released for clockwise rotation under the action of a spring 13 until a projection 15 engages a fixed stop 14. The unnotched surface of the drum maintains the sleeve 3 in its right-hand position. The end 26 of the armature 28 engages a groove 25 on a sleeve 11 so that when the magnet ZM is energized the drum 9 is disconnected from the slowly rotating shaft 8 at the coupling 10. When the motor has been started, the sleeve 3 is held to the right so that the cam 4 is unable to coact with the projection 40 to depress the bar 42 to the position in which it is latched by the member 34 and opens the motor circuit. When signal transmission or reception has ceased for a predetermined interval, and, as a result, armature 28 has not been attracted, the drum 16 is rotated by the shaft 8 against the spring 13 until the projection 17 snaps into the notch 16. The cam 4 moves to the left and during the subsequent revolution of the shaft 6 the bar 42 is depressed and the opening of contact 44 stops the motor. During the intervals between signals, the drum 9 is rotated but is continually released to return under spring 13 by the operation of the magnet ZM, before it has completed half a revolution corresponding to the predetermined intervalsay one minute. For a rapid succession of signals the magnet ZM may remain energized so that the coupling 10 is not continually connected and disconnected. Specification 420,853 is referred to.