Patent GB-473614-A (GB)
Title: Printing telegraph receiver
IPC: H04L17/26
Filed: 1936-04-16
Abstract: 473,614. Type - printing telegraphy. KLEINSCHMIDT, E. E. April 16, 1936, No. 10951. Convention date, April 29, 1935. [Class 40 (iii)] [Also in Group XVI] The type-wheelshaftis stopped after ¢, “, #, <1>/16, or <1>/32 of a revolution, or after combinations of these fractions, by stops which are selected by received signal impulses. The positioning of the type wheel takes place during receipt of the impulses, and storage of signals is not required. The receiver may be of the start-stop or of the continuously running type. Start - stop mechanism. Release of the magnet 20, Figs. 1 and 3, permits the stop 117, Fig. 3, to release the stop arm 118 which turns about its pivot 119 so that the hook 129, which is integral with it, releases the selector shaft and permits the five selection transfer devices 141, which are carried by a spider on the shaft, to rotate. At the end of the rotation a cam 134 acts on a second hook 128 to restore the stop arm 118 and stop the rotation. The phase of the rotation can be adjusted by rotating the orientation plate 121 which carries the stop-arm pivot 119. Selective positioning of the type wheel. The type wheel 38, having two rows of type and 32 positions, is geared up from the shaft 56, Fig. 1, so as to perform a full revolution for each half-revolution of the shaft. The frictionally-driven shaft 56 is positioned by the engagement of six sets of fingers 86, 81 ... 85, arranged in six different planes, with corresponding stop levers comprising a zero stop lever 96 and five selective stop levers 95 .. 91, of which 96 is shown in Fig. 3 and corresponds to the zero position of the type wheel. There are two evenly spaced stop fingers 85, four such fingers 84, eight fingers 83, sixteen 82 and thirty-two 81, while an additional pair of zero-position fingers 86 is arranged in quadrature with the pair 85. Each set of fingers bisects the angles determined by the preceding sets, so that sixty-four positions in all are determined. The stop levers 91 .. 95 are selectively actuated one at a time in the clockwise direction into the engaging position, and as each lever is actuated it releases the previously engaged lever from the latch 106, pivoted at 107, so that the shaft 56 is released and rotates until the newly actuated stop finger is engaged, the rotations becoming progressively smaller as selection proceeds. In this way, by the summation of the rotations determined by the selected stop levers 91 .. 95, the shaft 56 is finally arrested in one of 64 possible positions. The type wheel is geared up so as to rotate through an angular displacement twice as great as that of the shaft 56. The stop levers 91 .. 95 are selectively actuated, or not, in accordance with successive impulses of the received signal, and when actuated they move clockwise into position for stopping the shaft 56. To this end every current impulse, as opposed to a no-current impulse, keeps the roller 116, Figs. 1 and 3, in the path of a lug 147 on a corresponding transfer element 141. Five such transfer elements are arranged on a spider that revolves with the start-stop shaft 68, which is coaxial with, and in Fig. 3 hidden behind, the stud 117. The lug 147, being lifted by the roller 116, causes the finger 148 to lift the arm 102 and release the corresponding stop lever 91 .. 95. A no-current impulse permits the roller 116 to move out of the path of the lugs 148 and so fails to release the corresponding stop lever. Towards the end of the rotation of shaft 68 all the stop levers 91 . . 95 are released by a cam 154 acting on the latch 106, but immediately thereafter the zero stop lever 96 is re-engaged with the latch by the action of a cam 158 on the shaft. Thus the type-wheel shaft returns to a zero position determined by the parts 96, 86. The behaviour of the mechanism under continuous-working as distinct from start-stop conditions is explained in the Specification. Printing action. A frictionally, driven function shaft 160, Fig. 1, is released for one third of a revolution by trip mechanism, Fig. 11 (not shown), actuated by a cam on the start-stop shaft 68. The function shaft 160 carries a printing-cam 179, Fig. 4, which permits a printing-arm 181, at the appropriate moments, to turn the square shaft 48 anticlockwise and so turn the type-wheel carriage, which slides on the shaft, causing the type wheel 38 to strike the platen 53. At the same time a centring finger 188, Fig. 3, moves into engagement with a notched disc 187 so as to position the wheel accurately. The gears driving the type wheel 51, 52, Fig. 5 (not shown) are meanwhile unmeshed to permit of accurate centring. Letter spacing. The type-wheel carriage moves on a square shaft 48, Fig. 1, and after the printing of each letter is pushed one step to the right by a pawl 199, mounted upon it, whenever the cam 178 is turned through one third of a revolution with the function shaft 160. To this end a wheel 217, carried by a spacing ratchet bar 205 which co-operates with the pawl 199, drops into a depression in the cam 178 so that the ratchet bar makes a movement to the right and returns, the carriage being retained by a holding-pawl and fixed rack 200, 206, Figs. 5 and 7 (not shown). When a function signal is such as to require that letter spacing shall not occur, a cam on the pull-bar appropriate to the function in question causes the latch 329, Figs. 1 and 4, to engage a notch 333, Fig. 1, in the ratchet bar 205. Inking. The type wheel is in contact with an inking roller 220, Fig. 1, and as a result of each carriage-return operation the roller makes contact with the wick of an ink reservoir 223. Function-selecting mechanism. The shaft 56 which drives the type-wheel shaft carries fingers 291 ... 294 in duplicate, Figs. 1 and 4, which move in different planes, for selecting the case-shift and other function mechanisms. When the shaft 56 stops with a finger such as 293 in the downward position, a pull-bar such as 250 is depressed so that it can be engaged by a bail 161 carried by the function shaft 160. When the function shaft performs one third of a revolution, as described above under " Printing action," the bail draws the selected pull-bar forward, Figs. 2, 6 (not shown). When a function signal is received the finger 188, Fig. 4, is set opposite to a shallow notch in the disc 187 and thus prevents the type wheel 38 from striking the platen 53. In a modification, Fig. 17 (not shown), the arrangement is such that the fingers 291 ... 294 do not strike upon the pull-bars in rotating. Bell signal. When a combination for giving a bell signal, comprising a figures signal followed by a special signal, is received, it sets the shaft 56 so that the finger 294, Fig. 4, depresses a pull-bar 338, bringing its projection 339 into engagement with the bail 161 so that the pull-bar is drawn to the right, drawing with it the lever 346 which, on release, causes the hammer 347 to strike the bell 348. Line feed and carriage return. In letter spacing the type-wheel carriage is moved to the right, Fig. 1, against the action of a pair of pivoted arms 312, 315, Fig. 1 and Fig. 9 (not shown), which are drawn together by a spring 309. The line-feed-and-carriage-return signal selects a pull-bar 260, which is drawn to the right in Fig. 4 by the bail 161 and retained, until released by the return of the carriage, by mechanism illustrated in Fig. 7 (not shown). The line-feed pawl lever 243 is operated by the pull-bar 250 through link-work 247, 246. The pullbar also acts, Fig. 6 (not shown), to lift the driving and retaining pawls of the letter-shift mechanism so that the carriage is free to be returned to the left, Fig. 1, by the spring 309. Case-shift. When an upper-case shift signal is received, the function-selecting mechanism causes a pull-bar 264, Fig. 15, to be drawn to the right by the bail 161, whereby through levers 257 (pivoted at 251) and 254 (rigid with frame 227 and pivoted at 228) the platen 53 is lowered, the platen frame being positioned by jockey rollers 282. For shifting back to lower case, another pull-bar 270, Fig. 14 (not shown) is selected and acts through a lever 268 (not shown) on a stud 261 to turn the platen frame counterclockwise.