Improvements in writing telegraphs and like systems
Реферат: 266,707. Tuscher, J. E. Feb. 23, 1926, [Convention date]. Writing telegraphs. -Relates to writing telegraphs of the kind in which the movement of a stylus at the transmitter varies a resistance a, Fig. 1, and so governs the current in a coil f, which, influenced by a constant magnetic field and a control-spring, controls the movement of a stylus at the receiver. According to the present invention the resistance a varies with displacement of the cursor c in proportion to the ordinates of a hyperbola, in order that the line current may be proportional to that displacement. The receiver stylus is lifted out of action simultaneously with the transmitter stylus under the control of alternating current. Transmitter. In the transmitter, Fig. 7, the writing is traced by a stylus 1 mounted at the apex of a pantograph which comprises links 3, 3<1> pivoted to arms 4, 4<1>, which rotate upon shafts 5, 5<1>, carrying cursors 8, 8<1>. The cursors serve to tap off varying amounts of resistance from the hyperbolically wound rheostats 7, 7<1>, which are capable of angular adjustment about the shafts 5, 5<1>, and are in series respectively with the adjustable resistances 12, 12<1>, and with the line terminals 13, 13<1> and common return 10. The magnitudes of the resistances are such that the currents in the lines are proportional to the displacement of the cursors. When the stylus 1 and arms 3, 3<1> are raised, an alternating current circuit is closed through the terminals 14, 13<1> by a switch which comprises a frame 18 pivoted at 19. The frame is lifted' by a spring when the arms 3, 3<1> are raised, and thereby brings the spring 16 upwards into contact with a terminal 15. In a modification in which A.C. replaces the D.C. current, the resistances 7, 7<1> are wound so that their intercepts are inversely proportional to the squares of the displacements of the cursors. Receiver. The receiver may comprise a pantograph 53, 53, 54, 54, Fig. 10, carrying a stylus 29 for marking a travelling paper band. Each pivoted arm 54 is controlled by a spring 5, is counterweighted at 28, and is integral with a coil f located in a magnetic field, the coil taking up a position corresponding to the strength of the current received from the lines through the terminals 33, 33<1> and common return terminal 37, regulating resistances 34, 34 being also provided. When the stylus at the transmitting station is lifted, alternating current is superimposed on the direct current supplied to the terminals 33, 37 and the R.M.S. current through the coil 38 then becomes strong enough to pull down the armature 41, raising the frame 43 which is pivoted at 40 and lifting the arms 53. In modifications (a) various types of winding may be substituted for the coils f, or the magnetic rield may be provided by a solenoid; (b) the arms 54, 54 may be pivoted on a common axis, and (c) a relay arrangement may be adopted, each arm 54 controlling a hyperbolically, wound rheostat in the circuit of a further receiving apparatus similar to that described above.
Improvements in or relating to detectors for smoke and like particles
Номер патента: GB1129402A. Автор: William Harvey. Владелец: Walter Kidde Ltd. Дата публикации: 1968-10-02.