Patent GB-190416978-A (GB)
Title: Means for Receiving or Translating Electric Wireless or like Impulses.
Inventor: UNDERHILL CHARLES REGINALD
Filed: 1904-08-03
Granted: 1905-08-03
Abstract: 16,978. Underhill, C. R. Aug. 3. Telegraphs. - In a system of wireless telegraphy, the intermittent impulses forming the wireless signals are translated into continuous " dot " and " dash " signals which in turn actuate a typeprinting telegraph, of the same general nature as that described in Specification No. 16,871, A D. 1904. The printing - instrument is designed for the American Morse code in which "dashes" and " spaces" of more than the standard length are employed. Fig. 17 shows the system diagrammatically, the receiving-aÙrial 2 being connected by relay circuits with a de-coberer 18 and the relay magnet 19. In order to transform the intermittent impulses into continuous signals, the armature 21 is carried by a lever 22, frictionally mounted on a shaft 23 which is slowly rotated by worm gearing 24. The lever 22 also carries a spring 30, which contacts with 31 when the armature is attracted. When the magnet is de-energized, the lever 22 is slowly rotated, but, if the break in the circuit is only a short one, the spring 30 does not leave the contact 31. If, however, the break corresponds to a "space" in the Morse code, the lever 22 is rotated sufficiently to break the contact at 31. The relay magnet 34 thus receives signals of the ordinary Morse type. The mechanism for translating the Morse code signals into type-printed characters consists of two main parts-the analytic mechanism shown in Figs. 13 and 14 and the synthetic mechanism shown in Figs. 2 and 10, the electric connections being shown in Fig. 17. In the analytic mechanism, two selectors 53, 54, Figs. 13 and 14, are employed, one being operated when the circuit of the magnet 63 is closed and the other when it is open. The selectors 53, 54 slide upon bars 49, 50 and carry feedelements adapted to engage the screw-threads 42 on the rotating shaft 43. The bars 49, 50 are secured to rock-arms 70, 71 attached to the forked end of the lever 66, carrying the armature 64, and the arrangement is such that, when the armature is attracted, the feed-element on selector 53 engages the shaft 43, while, when the armature is not attracted, the feed-element on selector 54 engages the shaft 43. When the feed-elements engage the screw-threads 42, the selectors are moved along the bars 49, 50 to an extent depending on the length of the signal or space received, and the contactarms 57, 58 move over the contacts 86, 87, 88 and 89, 90, 91, Fig. 17, respectively. In Fig. 13, one such set of contacts is shown, the contacts being so arranged that, when a " dot" signal is received, the arm 57 does not reach the first contact 86 ; when an ordinary " dash " is received, the arm reaches the contact 86; with a " dash" for the letter L in the American Morse code, the contact 87 is reached, while, with a "dash" for the letter O, the contact 88 is reached. In the same way, the contact-arm 58 comes against the contacts 89, 90, 91 whep " spaces " of different lengths are received. The selectors 53, 54 are returned to their initial position by springs 81 as soon as their feedelements are brought away from the screw-threads by the movement of the armature 64. In the synthetic-mechanism the main shaft 92, Figs. 2 and 10, is driven from the motor 26, Fig. 17, by friction gearing 94, 100, 102 and carries a crownwheel 107 engaging with an arm 105, controlled by the magnet 106 in such a way that the shaft 92 is prevented from rotating except when the magnet 106 is energized, which occurs every time an impulse is received by the relay magnet 34. The shaft 92 also carries a sleeve 117 which is revoluble therewith and can be moved along the shaft a distance corresponding to the maximum number of impulses in a code character, viz., six. The sleeve 117 carries the main selector 118, Fig. 10, adapted to engage a number of pins 140, Fig. 17, projecting inwards from the drum 143. Each energization of the magnet 106 moves the sleeve and selector one step axially by means of a rack mechanism 119, thereby shifting the selector to successive positions corresponding to the successive periods of a code character. This movement occurs, however, when the magnet 106 becomes de-energized, that is, after the receipt of each "dot," or " dash." At the end of each character, the rack 119 is restored to its original position by the energizing of the restoring- magnet 133, Fig. 2. Two of the pins 140 in the drum 143 are movable, the first representing the shortest " dash " and being normally in position to arrest the selector 118. When this pin is withdrawn by the magnet 153, Figs. 10 and 17, the selector passes on to the second movable pin, corresponding to the " dash " of the letter L. When this pin 142, Fig. 10, is withdrawn by the magnet 154, the selector passes on to another fixed pin corresponding to the longest " dash " for the letter O. The pins 140 as a whole are divided into two main groups of six rows each, arranged in two overlapping sets of "dots" and "dashes" as described later in relation to Fig. 16. In order that the " dash " group may be brought into relation with the selector 118, the drum 143 may be shifted to the left in Fig. 2 by a shifting-lever 155 actuated by a magnet 162. In order to provide for the translation of code characters having extra spaces in them, the drum 143 may also be moved to the right by means of a magnet 164. The lever 155 is kept in its normal position by a spring 170 and two levers 172, 173, carrying contacts which engage with springs 268, 269, Fig. 17, when the lever 155 is attracted by either magnet. In the American Morse code, there are no characters in which a "dash" occurs after an extra space, and none in which an extra space occurs after a "dash." Means are therefore provided by which the "dash" magnet 162 cannot be operated after the "space" magnet 164 and vice versÔ. To this end, levers 182, 183, Fig. 17, actuated by the lever 155 break contacts 185, 186 and 187, 188, respectively, when the lever 155 is moved in one or the other direction. The type-wheel 203 and locking-wheel 204 are carried by the shaft 92, special arrangements of feed and inking mechanism being described. A form of zero stop is also described. The armature lever 196 of the printing-magnet 189 is adapted to control contacts 255, 256 as shown in Fig. 17. The method of arranging the pins 140 in the drum 143 differs greatly from that described in the beforementioned Specification. The letters are so arranged about the periphery of the type-wheel that each letter is chosen by simply moving the selector 118 to the next pin in the next column. Thus in Fig. 16, which represents the arrangement of the pins in the drum, :E is represented by a single dot and is controlled by a pin in column 1. The letter I is represented by two dots and the selector simply drops from the first pin in the first column to the first in the second. In the same way, the letters S, H, P, and the figure 6 are chosen by the selector moving successively to the next pin in the next column. If, however, a character to be selected contains an extra space, the drum 143 is shifted back one step, and the selector 118, instead of being stopped by the first pin in column 2, is stopped by the first pin in column 3, which is then in the position normally occupied by column 2. In this way, we get the numeral 0. The letters containing "dashes" may begin with either a "dot" or "dash." If they begin with a "dash," the selector turns at once to the 28th position when the drum is shifted ahead one step. If, however, they begin with a "dot," the pin representing the " dash " may occupy a position following such first " dot " or " dash " in the same column. Referring now to Fig. 17, each time the relay 34 receives a signal, the analytic magnet 63 and the synthetic magnet 106 are both energized, current flowing from ground through switches 274, 275, battery 273, switch 275, main return conductor 282, and thence through magnets 106, 63 in parallel to contacts 35 and ground. When a "dot" signal is received, the magnet 106 moves the selector 118 one step forwards. When a " dash " is received, the contact-arm 57 of the synthetic mechanism reaches the contact 86 and closes a circuit from ground through contacts 57, 86, wire 286, magnet 162, wire 284, contacts 265, 266 (closed by the energizing of the magnet 106), wire 283, and the conductor 282 to the battery 273 and ground. The actuation of the "dash" magnet 162 shifts the drum 143 to the left, and the selector moves round till it reaches the first "dash" pin (T). At the same time the lever 172 closes the contact 268 and maintains the circuit of the magnet 162. If the signal received is a "dash" longer than the ordinary one, the contact 57 comes up to contacts 87, 88 and closes a circuit from the conductor 282 through magnets 153, 154 to earth, thereby withdrawing one or both of the movable pins in the drum 143 and allowing the selector to rotate further till it comes to the L and O pins. When a "dash" signal is completed and the circuit broken at 35, the magnet 162 is de-energized and contacts 265, 266 broken, thus restoring the lever 155 to its normal position. If an extra space is received, the contact-arm 58 moves as far as the contacts 89 and completes a circuit from ground through contacts 58, 89, wire 297, magnet 164, and the wires 294, 281 to the battery and ground. The drum 143 is then shifted to the right, and the selector moves to the next pin in the next column but one. After all the signals of a code character have been received, the space following will be of such length that the contact-arm 58 will reach the contact 90 and complete a circuit through the wire 300, printing- magnet 189, wire 299, paper-shifting magnet 244, conductor 282, and the battery, thus printing the required letter. The breaking of the contact 255 opens the circuit of the spacing-magnet 164, while the closing of the contacts 256 completes a circuit through the wire 3