Patent GB-533070-A (GB)
Title: Improvements in or relating to justifying mechanism for typewriting machines
IPC: B41J19/64
Filed: 1939-10-05
Abstract: 533,070. Typewriters. INTERNATIONAL BUSINESS MACHINES CORPORATION. Oct. 5, 1939, No. 27272. Convention date, Oct. 12; 1938. [Class 100 (iv)] Letter-spacing mechanism. - In machines having variable-spacing mechanism comprising escapement-mechanisms selectively operable in combination, justification is effected by increasing the word-spaces on operation of the space-bar, the increase being determined by a device which is set manually in accordance with the number of word-spaces and line-deficit in a trial line. The mechanism shown in Figs. 4 and 8 includes, as described in Specification 504,774, poweroperated escapement-devices comprising escapement-wheels 48, 49, 50 co-operating with dogrockers 106 having operating-arms 147, 148, 149 which are selectively depressed, under control of the keys, into position for co-operating with studs 15b on a slide 152 operated by the universal bail or the space-bar. The escapement-wheels when released singly or in combination, permit the paper-carriage to move through two, three ... seven spacing units, the unit being 0.022 inches. The escapement-mechanism is now associated with a control-means which is mounted in a bracket 220 on the side of the typewriter and comprises dials 221, 222 for adjusting a series of cams 243 ... 250 which, as described below, set the arms 147, 148, 149. The dial 222 is secured to a hub 228 on a sleeve 227 which is mounted in the bracket 220 by means of the hub 228 and another hub 232. The dial 221 is secured to a hub 225 which is splined to a shaft 226 by means of a pin 231 and is provided with a projection 225a which can be engaged with any one of sixteen radial grooves 228a in the hub 228 by manipulating a knob 229. The dial 222 has letter-space unit graduations and is set with reference to a fixed pointer 224, whilst the dial 221 has a zero graduation; and graduations A, B ...representing the number of word-spaces in a line, and is set with reference to a mark 223 on the dial 222. The hub 232 is connected to a coiled spring 239 and is provided with staggered escapementwheels 234 co-operating with spring-urged pawls 235 operated by a lever 238. A lever 291, abutting on the lever 238, is connected by a link 293 to an arm on shaft 172 which is rocked on operation of the space-bar. The pawls 235 cooperate alternately with the wheels 234 to permit the sleeve 227, shaft 226, dials 221, 222 and knob 229 to rotate through one graduation of the dial 222 on each operation of the space-bar. Each of the cams 243 .. 250 has a quadrantal high part, and the high parts of each pair 243, 244 ... 249, 250 are arranged in tandem. The cams 243, 244 are secured to a hub 233 on the shaft 226, the cams 249, 250 are secured to the hub 232, and the cams 245, 246 and 247, 248 are secured to loose hubs 251 and 252 on the sleeve 227. A bail 253 secured to the cams 249, 250 engages arms 254, 255 loosely mounted on the hubs 233, 251. A pinion 259 on the arm 254 engages pinions 257, 258 on the hubs 233, 251. A pinion 246 on the arm 255 engages pinions 261, 263 on the hubs 251, 252. The gearing is so arranged that when the knob 229 is turned to adjust the dial 221, the cams 243 .. 248 are displaced relatively to the cams 249, 250, the displacement of the pair 243, 244 being equal to that of the knob, whilst the displacement of the pair 245, 246 is less than that of the pair 243, 244 but greater than that of the pair 247, 248. The cams 243, 250 co-operate with rocking arms 268, 272 and the pairs 244 and 245, 246 and 247, 248 and 249 of cams cooperate with feelers 273 pivoted on rocking arms 269, 270, 271. The rocking arms are formed with lugs 272a for selectively obstructing bails 265, 266, 267 abutting on bell-cranks 275, 276, 277 carrying pivoted arms 278, 279, 280 which engage the escapement-operating arms 147, 148, 149. The arms 278, 279, 280 are connected by links 281 to an arm 282 which is depressed each time the space-bar is operated. For this purpose, an arm 283 on the shaft 172 is connected to a link 284 which engages a roller 285 on the arm 282, and is' formed at the rear with an incline co-operating with a roller 286 on the framework. When the space-bar is operated, the arm 282 depresses the links 281 and the arms 278, 279, 280 are raised or depressed according as to whether the bell-cranks 275, 276, 277 are free to swing, or are obstructed by the bails 265, 266, 267. When the dials 221, 222 are in zero position, the cams 243 .. 250 are in the positions shown in Fig. 8, the arm 272, bail 266, and bell-crank 276 are obstructed, the other arms, bails, and bellcranks being free, and on operation of the spacebar, the arm 279 depresses the arm 148 and the carriage receives a three-unit spacing movement. To type a justified line, a trial line is typed to determine the number of word-spaces and the line-deficit, and the dials 221, 222 are set to the corresponding graduations. On each depression of the space-bar the cams 243 .. 250 control selective operation of the arms 147, 148, 149 to increase the normal three-units wordspace, and the cam-assembly is stepped backwards to change the relationship of the cams to the arms 268 .. 272. If the line-deficit, for instance 20 units, is not exactly divisible by the number, for instance 7, of word-spaces, all the word-spaces are increased by two units, and the first few word-spaces are further increased to take up the balance of six units. In typing a line containing blanks, or a large number of word-spaces, justification can be started at an intermediate point in the line. When the justified line has been typed, the cams 243 .. 250 and dials 221, 222 are, on return of the paper-carriage, automatically returned to the zero position by means of the spring 239. For this purpose, the pawls 235 are released by means of a rocking arm in connection with another arm which is rocked into the path of the left-hand margin stop when the carriage-returning key is operated. A space - key for operating the spacing- mechanism independently of the justifying- mechanism is connected to a rocking arm 300, Fig. 4, having a lug 300a co-operating with the operating-arms 147 of dog-rocker associated with the escapement-wheel 50. For indicating, during typing of a trial line, the line-deficit or excess, a dial 191, Fig. 10, on the front plate of the machine is read by a pointer 196a on an arm 196 secured to a pivot 195 which is provided with a pinion 197 engaging a sector 203. A link 214 connects the sector to a rock-shaft having a crank-pin abutting on a slide provided with a projection which is engaged by the margin stop when the paper-carriage is thirty-five units short of the margin position. The dial is graduated to show line-deficit or excess in units, the pointer being opposite the central zerograduation when the paper-carriage is in the zero position. If line-excess is indicated, a shorter trial-line is re-typed.