Patent GB-754403-A (GB)
Abstract: 754,403. Typewriters. NATIONAL CASH REGISTER CO. Aug. 25,1954 [Feb. 24, 1954], No. 24720/54. Class 100 (4). [Also in Group XIX] A calculating machine (see Group XIX) has a travelling paper carriage having a rockable platen frame manually depressible against the action of springs from an open front-feed position to a closed printing position in which it is latched. The latch may be disabled by a handlever or undercarriage control. Paper feeding arrangements.-The platen shaft 419, Fig. 5, is journalled in a pair of plates 392, 520, Fig. 14, pinned to a shaft 521 journalled in end plates 283, 282 of the carriage. The platen frame is urged by springs 524 to an upper front-feed position from which it may be manually rocked to a printing position in which it is held by latches 533, fast with a bail 530. The platen frame may be released for upward movement by rocking a hand-lever 46, which rocks the bail 530. As the platen moves upwardly a front paper table in the form of a transparent plate in a frame 542 is rocked by a coupling with the platen frame to enable record material to be fed from the front and under the platen on to a rear paper table. A further table 40 for rear-fed material is pivoted on a shaft 523 in the plates 392, 520, and is urged by spring fingers to maintain pressure rollers carried on its lower edge in contact with the platen. A hand-lever, Fig. 1 (not shown), may be rocked to render the spring fingers ineffective and so release the pressure rollers. This hand-lever also releases a paper bail which engages the top of the platen. The rear paper table carries on fingers at its front end a pressure plate which drops away from the platen when the latter is moved upwardly. Front pressure rollers are arranged between the fingers and may be released by a further hand-lever. Paper guides are carried by the front table and the rear-feeding table 40. Column stops are adjustably carried by a bar 288 removably mounted on the carriage. The platen frame may be released for movement to the frontfeed position by a carriage control member 574 having an adjustable projection 578. In the effective position shown, the projection acts on a by-pass pawl 571 during carriage return and cams upwardly a yoke 563 carrying the pawl to rock the carriage-opening bail 530. A control member having a forward projection 578 co-operates with a second pawl 568 to open the carriage during tabulation. As the carriage opens, the platen is line-spaced as described below and the bail 530 actuates a plunger to open a switch in the motor circuit. Tabulating.-The carriage is urged to the left by a cord secured to a spring reel 295, Fig. 5, but is held in a columnar position by the engagement of the upper surface of a column stop with an arm 297, Fig. 11. At the end of a machine operation, a cam 312 acts through a by-pass arm 313 to move a slide 316 bearing a stud 319. This stud engages the end 311 of a lever 310 in turn engaging a lug 306 of a bracket 300 secured to the arm 297 which is thus raised to release the carriage for tabulation to the next stop. The arm 297 may also be raised by a bail 307 carried by the carriage and rocked by a handlever 50, Fig. 5. An enlarged terminal stop is provided. On depression of a " vertical " bar 27, Fig. 10, a lever 321 is rocked as described below, and a stud 322 therein rocks the slide 316 through a link 324 out of the path of its operating arm 313, to prevent tabulation. Line-spacing.-A ratchet-wheel 418, Fig. 5, normally clutched to the platen is engaged for line-spacing by a pawl 415 carried by an arm fast with a bail 402 pivoted in the carriage frame. A yoke 408 embraces the bail and an arm 411 thereof is engaged by a cam to rock the bail. The pawl 415 co-operates with a blocking surface 421 of a hand lever 54 which can be set to cause single or double line-spacing or to prevent line-spacing. Line-spacing is, however, normally prevented by an arm 431, Fig. 10, of the lever 321 which blocks movement of the arm 411, but is permitted prior to a carriage return movement when the hand-lever 34, Fig. 17, is moved from a forward to a central position, and in all operations when the lever 34 is in a rear position. When in its central position, the hand-lever 34 so positions a cam plate 433 (see also Fig. 13), which controls an arm 446 pivoted on the carriage return yoke 337, that when the latter is rocked, the arm 446 strikes the stud 322 in the lever 321 and so rocks the blocking arm 431 of the latter to ineffective position. When the lever 34 is in its rear position, a lever 448 is rocked and engages the stud 322 to rock the blocking arm 431. A block 452 on the lever 448 in these circumstances co-operates with a stud 450 in the yoke 337 to prevent its rocking to initiate a carriage return. Line-spacing also occurs in all operations initiated by the " vertical " bar 27, Fig. 10. Depression of this bar rocks coupled levers 478, 479 and the latter is latched by an arm 477 until the end of the operation. The lever 478 is also connected to a link 320 which rocks the blocking arm 431 to ineffective position. As the platen moves to its front-feed position, the ratchet-wheel 418, Fig. 5, engages a pawl 590 which is ineffective or advances the platen by one or two lines according to the setting of a cam 61.