Patent GB-676779-A (GB)
Title: Printing telegraph apparatus
IPC: H04L13/04
Filed: 1949-04-19
Abstract: 676,779. Type-printing telegraphy. TELETYPE CORPORATION. April 19, 1949 [April 22, 1948], No. 10342/49. Class 100 (iv). [Also in Groups XXIV and XL (b)] Printing-telegraph apparatus in which character-spacing movement is imparted to a typecarriage by means of a character-spacing mechanism comprises character-selecting means operating independently of the character spacing mechanism for displacing the type carriage in either of two directions to select a character to be printed and the character-selecting movement of the carriage in either direction is decelerated by a knee-action toggle lever cushioning mechanism prior to the arrestment of the carriage by an adjustable stop arrangement which serves to limit its displacement. The character is selected by movement in one of two directions parallel to the character spacing movement and a further movement, in a perpendicular direction, which is also decelerated by a knee-action toggle lever mechanism. Control of selector mechanism. The received signals are applied to a magnet 13 having an armature 17 biased to the spacing position by a spring 18 and co-operating with a number of sequentially controlled levers 23. In response to a marking element a lever 23 is permitted to rotate clockwise out to fall behind the end of a slidable interponent 31 so that the anticlockwise movement of the lever 23 by its cam moves the member 31 to the left and rocks an associated three-armed lever 34 which is articulated to a bell-crank 36 linked with an associated code bar 62, 63.... The downwardly extending arms of the levers 34 are formed with shoulders 41, 42, which are associated with stepped portions 45, 46 of members 43, 44 which are reciprocated in opposite directions by a member 53 carried on a shaft 54 rocked in opposite directions by an eccentric on a shaft 27 released by the start impulse of the signal combination, the armature in its released position allowing a lever 71, Fig. 9, to move to the right and rock a connected bell-crank lever 75 so that an arm 78 is removed from engagement with a clutch control lever 74. Character selection. The typemembers 155 are mounted in a type-box 99 mounted on a carriage attached to a frame 332 connected by arms 329, 331 to two pairs of toggle levers 321, 325 and 322, 326 respectively connected at 318, 319 to a movable member 264 which is arrested by the ends 259, 261 of abutment members 254, 255, 256 positioned by the two final elements of the code signal. A direction code bar, positioned by the third impulse of the code combination, rocks a lever 316 which actuates a member 271 carrying projections 313, 314 coacting with cam surfaces 280, 290 of knee-action toggle levers 274-282, 275-287, so that one of these is partially collapsed. The operation of levers 283, 288 by the shaft controlling the position of the type carrier causes the straightened toggle link to move the member 264 until a buffer member 263 meets the operative abutment. The toggle bends and decelerates the movement of the member 264 which is positively arrested by the engagement of the surface 357 with the projected abutment. In the alternative position of the direction bar the toggle pair 274-282 is partially collapsed, and the pair 275-287 being straightened, the movement of the levers 283, 288 moves the member 264 to the right until it is arrested by the appropriate projection 261 of the members 254, 255, 256. The vertical movement of the type-carrier 99 is effected by the selective setting of the code-bars 63, 65, 67 in accordance with the first two impulses of the signal code combination the arrangement being that if the first or second code impulse is a mark, the bar 63 or 65 is moved to the right and the bar 67 is moved to the right, Fig. 20, or left, Fig. 13, only when the first two impulses are marks. In the case of two spacing elements the upward movement of the type carrier is determined by a fixed bar 70. The type-carrier 99 which has upper and lower rollers 161, 162 running on a channel member 163, is secured to a frame member having an arm 165 with a projection 221 and a toggle lever 195, 197 having a projection 199 which engages the appropriate bar 63, 65, 67, 70 and cushions the impact of the projection 221 with the said bar. A locking bar 232 having a cam surface 234 engaging a fixed member 235 operates a holding lever 231 having a tooth 237 to maintain the type-carrier in the elevated position. Case-shift operation. The characters on the carrier 99, Fig. 6, are arranged so that the lower case is constituted by four vertical rows of type members on each side of the line 361, the upper case being represented by four rows on each side of the line 363. To print from the upper case group, the member supporting the type carriage is moved so that the normal position of the printing hammer is opposite the line 363, the toggle pair 321, 325 being straightened and the pair 322, 326 collapsed. The operation of the function bar 389, Fig. 12, corresponding to case shift, rocks a member 392, 393 so that a bar 400 is moved laterally. A lever 408 connected to the bar 400 is also moved laterally so that a further bar 413 is moved to the right soon after it has been raised by the links 415, 416. The toe portion 433 of the lever 413 engages a projection 423 on an arm 422 so that the toggle pair 322, 326 is collapsed, the opposite pair 321, 325 being simultaneously straightened so that the line 363 is opposite the printing hammer. Printing action. The type members 155, Fig. 22, are mounted in the carrier 99 by individual compression springs 156 and the type hammer 362 has its outer portion rockable about the rim of the inner portion, Fig. 23, the two portions being held together by a spring 503. The printing operation is controlled by cams 473 moving an arm 467 linked to levers 464 engaging apertures in a bar 458 extending across the platen member 499. An actuating plate 455 has lugs 456, 457 engaging the upper and lower surfaces of the bar 458. A conditioning lever 453 and an operating lever 454 are pivoted at 452 and a spring 476 is attached to the conditioning lever 453, the latter being connected by a spring 482 to the lever 454. On upward movement of the plate 455 the conditioning lever 453 is rocked, tensioning the spring 476 and a shoulder on the member 453 is latched by an extension 491 of the latching lever 487. On the downward movement of the plate 455 an arm 494 carrying a screw 495 depresses the latch 487 so that the printing lever 454 engaged by a flange 481 on the conditioning lever 453 moves forward and projects the hammer 362 against the selected type member 155. Line-feed. The platen carries a gear wheel 575, Fig. 34, engaged alternately by toothed members 576, 577 actuated by separate eccentrics on the shaft released by the line-feed function bar. The members are arranged to have a variable fulcrum by the provision of slots 583, 584 engaging a friction roller 582 carried on a bell crank 585 pivoted at 586 and biased by a spring 587 against a stop 588. Character-spacing, carriage return and backspacing. An eccentric on the main operating shaft rocks a U-shaped member carrying pivoted driving pawls 517, 518 held against the teeth 519 of a drum 362 by springs 521, 522. In one direction of rocking the pawl drives the drum and the pawl 517 is moved idly over one tooth so that when the member 515 is rocked in the opposite direction, the pawl 517 moves the drum 362 through one step thus providing two steps for each spacing operation. For carriage return a function lever operates a lever 536 actuating a lever 535 carrying a stud 544 disengaging the pawls 517, 518 from the teeth of the drum which rotates under spring action. The lever 536 is latched by a detent 562 which is released by an arm 561 when the carriage returns to its normal position. An arm 524 engages the plunger 526 of a dash-pot 527 and the drum is returned to its normal starting position by a spring-actuated arm 533. For the back spacing operation a function bar is operated rocking a lever which operates the stud 544 to disengage the driving pawls 517, 518 and at the same time rocks two levers 556 and 564 in opposite directions to allow the drum to step back one tooth. Ribbon-feed. The inking ribbon is carried on spools 593, 594 having spindles 599 connected to toothed cup members 603, 612 engaged by pairs of pawls 613, 614 and 644, 691. Platforms 192, 219 are rocked during the character spacing movement of the mechanism and the operative pair of pawls, e.g. 613, 614, effects stepping of the spools during the upward and downward movement of the associated platform. When the ribbon on a reel is almost exhausted a rivet in the ribbon engages an arm of a pivoted lever 625 or 633 to operate an arm 626 or 632 on the next upward movement of the platform 192 or 219. If, for example, the spool 593 is being driven by pawls 613, 614 and the ribbon on the spool 594 is nearly exhausted, the ribbon reversing lever 633 engages a shoulder on lever 632 during the upward movement of the platform 219. Upward movement of the lever 632 allows the pawls 643, 691 to become operative on the teeth of member 603 to drive the spool 594. A lever 627 is also rocked and lowers lever 626 associated with the spool 593 so that the pawls 614 and 613 are disengaged from the teeth of the member 612. A modified construction of spacing device, Figs. 47-50 (not shown), comprises a gear train driven by a grab clutch from the spacing shaft and rotating the drum controlling character spacing. A function lever operated by the carriage return signal disengages the clutch and a latch member holds the clutch in its inoperative position until the normal position of the carriage is attained. Specifications 274,448, [Class 40 (iii)], 433,503, 556,700, 626,999, [Group XL (b)], 666,687, [Group XXIV], and U.S.A. Specification 1,595,472 are referred to.