Patent GB-189267-A (GB)
Title: Improvements in apparatus for transmitting electric signals
IPC: H03M5/00
Filed: 1921-09-07
Abstract: 189,267. Miniotti, G. Sept. 7, 1921. Automatic transmitters; type-printing telegraphs.-In transmitting-apparatus of the kind having a signal storing device allowing the operator to work at variable speeds, signals are set up by arranging balls in seatings according to a code along a series of lines of any kind, these balls operating a transmitter arranged to pass over them. The invention is described as applied to the Baudot system. Setting up and storing signals. The apparatus for setting-up signals comprises a series of key levers 7 with notches at their ends 9, Fig. 3, corresponding to the signal peculiar to the key. and a disc 20, Fig. 1, formed with teeth 22 in its rim and five concentric rings of holes in its surface and having fixed thereto a notched escapement ring 24. A reservoir of balls 34 is arranged over the disc, and five distributing conduits 35 leading therefrom supply balls to the series of five holes under them at any moment. On depressing one of the keys 8 certain of five combination frames 12, Figs. 2, 3, and 4, are raised certain of five rocking levers 29, Fig. 8, so as to open corresponding shutters 28 and allow certain balls to be pushed by the spring pressed shoes 31 into the chamber 30. At the same time the frame 13, Figs 2, 3, and 4, is lifted and through the lever 14 moves the rod 15, Fig. 7, to the left against the spring 39. The slide 17 on the rod 15 moves the pawl 18<1> into the position shown in Fig. 12, and through levers 37, 38 raises the movable bottom 36 of the reservoir 34, Fig. 8, On release of the key 8, the spring 39 restores the rod 15 to its. normal position. Levers 14, 29 are so made that the displacement of the rod 15 is greater than that of the shutters 28 so that there is some delay before the part 40 on the rod 15 closes the shutters 28. The latter on their return force the balls which have fallen, past the " valve " 33, Fig. 8, towards the conduit 30. At the same time the pawl 18<1> is moved up to the stop 26, Fig. 12, so that the disc 20 is stepped round one tooth in the direction of the arrow a, Fig. 1, and the movable bottom 36, Fig. 8, is returned to the position shown. Transmitting signals. The transmitter 41 is carried on an arm 42 rotated intermittently by the spring 43, Fig. 5, under control of a magnetically operated escapement worked from the Baudot apparatus, in the direction of the arrow b, Fig. 1. The frame 41 carries positive and negative bars 49, 50 with contact screws 51, Fig. 19, and five levers 52 carrying contact springs 53 which touch positive or negative contacts according as the shoe of their lever is on a ball or not. The shoes are so dimensioned that contact is maintained the whole time they are passing over a succession of balls. The transmitter 41 and electromagnet 45 are connected with terminals on board 60, Fig. 1, which are themselves connected to the Baudot apparatus, by a flexible cable 59, Figs. 22 and 30, containing nine conductors, five for the contact springs, two for the positive and negative bars 49, 50 and two for the magnet 45. The cable is wound in one or two turns round the axle 21 and the turns enclosed in casings 58, 58<1>, Fig. 22, loosely mounted on a sleeve 62 so as to rotate independently of each other. The cable is led through a hole in the top casing to the terminal board 60 and through a hole in the lower casing to the transmitter &c. Escapement mechanism. When magnet 45 is de-energized, armature 72, Fig. 13, is pressed by spring 73 against arm 65, pawl 46 engages a notch in toothed rim 24 and pawl 47 is in an inclined position, Fig. 16, under influence of spring 74 under the adjacent notch in direction b. When the magnet is energized, the pawl 47 enters its notch and is pulled into the vertical position against spring 74 by the rotation of the arm 42, and the pawl 46 is disengaged and above the notch in which the pawl 47 is engaged. When the magnet 45 is again de-energized the parts are returned to the position shown in Fig. 16 and the pawl 46 engages the notch previously occupied by the pawl 47 while the pawl 47 is brought under the adjacent notch in direction " b." The arm 42 is disengaged from the rim 24 by depressing the lever 61, Fig. 5, which depresses the sleeve 62 against the spring 76, Fig. 13, and causes the inclined surface 63 to move the rod 64 against the spring 77 so as to free both pawls 46, 47 from the rim 24. At the same time a projection 78, Figs. 16, 28 comes against the inclined surface 48<1> to free the pawl 48. The lever 61 indicates at any instant the position of the transmitter 41 and may be used to set it in any desired position. Operation of the transmitter in its extreme positions. If the transmitter moves more slowly than the disc 20 it will gradually reach position m, Fig. 1, when the maximum number of signals is stored, but if more quickly it will ultimately arrive in position r. In this position, after the last stored signal has been sent the arm 42 advances a little until the commutator arm 56, Figs. 1 and 30, comes against the screw 57. This causes the arm 56 to leave the contact 79 and come against the contact 80 so that five negative impulses are sent to line whatever combination may be under the transmitter shoes. In the circuit of the magnet 45 is a push button switch 67, Fig. 3, which on the depression of the key 66 opens the circuit and on a subsequent depression closes it again. Key 66 has no notches in its end 9 and so operates all the shutters 28. If it is operated when the transmitter is in the position r the latter thus stops over a section with no balls in it, and sends five negative impulses .to line continuously. Signals may now be stored until the transmitter reaches position m when the key 66 is again depressed and the transmitter advances step by step sending the stored signals. This arrangement is useful for inexperienced operators who work very slowly.