Patent GB-190117271-A (GB)
Title: Improvements in Typewriting Machines.
Inventor: YETMAN CHARLES ELMER
Filed: 1901-08-28
Granted: 1901-10-26
Abstract: 17,271. Yetman, C. E. Aug. 28. Type-writers; copy-holders.- Relates to "front- " strike " type-bar machines. The keys e are arranged in four rows, and the key levers d are pivoted to a common fulcrum bar 10. The rear or vertical arms 11 of the key levers are not linked directly to the type-bars f, but are formed with notches in which engage pins 17 carried by supplementary levers h, of which some are pivoted to the bar 13 and others to the bar 14. The positions of the pins 17 are so calculated that a uniform stroke and "touch" is obtained at the keyboard. The bars 13, 14 are connected by pins adapted to slide vertically in the bar 10. A special lever is placed at the side of the keyboard, by depressing which the bars 13. 14 are raised and the pins 17 lifted from their seats in the upper ends of the arms 11, and at the same time the universal spacing-bar j is depressed. The keyboard is thus disconnected entirely from the other mechanism, and is rendered ineffective both as regards printing and carriage-feed. The side arms of the universal bar j are pivoted to the bar 10, and the bar j is formed with steps or notches, so that the shorter or longer key levers depress it equally. The aforesaid side arms are provided at the rear with upright arms connected by links to the carriage escapement mechanism. The space bar or key i carries the universal bar with it when it is depressed. Instead of notching the bar j, the key levers d may carry touch-plates 42, Fig. 13, adjustable by means of screws 43. The type-bars f are supported by hangers or brackets 20, Figs. 4 and 5, adjustably secured by bolts 21 tc the segmental support 19. The hanger is provided with fiat arms 22 riveted together by a pin 23. The pin 23 carries a screwed sleeve 26, on which are threaded the bearing-plates 25, which, together with the internally-grooved hub of the type-bar, enclose the antifriction balls 24. A space disc 27 separates the balls. Wear in the bearing is taken up by slightly turning one of the plates 25, and again heading down the rivet 23. The free ends of the type-bars rest on a pad 34 carried by a series of short sectional plates 35 provided with independant spring - controlled plungers 36. The carriage c is provided with grooved rails 47, which cooperate with fixed tracks 48 to retain the usual antifriction balls. The carriage is propelled by means of a strong helical tension spring, which pulls on a toothed sector k engaging with a pinion 57. (See plan view, Fig. 18.) The shaft 56 drives a short shaft 60 by means of bevel gearing, and on the shaft 60 are mounted fixed and loose gears 61, 62, both of which engage with the carriage-rack 63. A retracting-lever 55 enables the toothed sector to be turned by hand to bring back the carriage after a line is finished The loose gear 62, which is provided in order to prevent, backlash with the carriage rack, engages with a pinion 39 on a sleeve 66, which has a ratchet connection 28 with the shaft of the escapement-wheel m. By means of a finger-piece which projects from the left-hand side of the machine, the sleeve 83 can be shifted so as to release the sleeve 66 from all connection with the escapement-wheel shaft and completely free the carriage. The worm 135 gears with a wheel 136, Fig. 2, on the driving-shaft 134 of the inking- ribbon spools. The escapement dog l, Fig. 2, oscillates on its supporting-shaft under the control of the universal bar, with which it has a lostmotion connection. It is obliquely notched so as to form two teeth 67, 68, shown in horizontal section in Fig. 20. When a key is depressed, the dog 67 moves clear of the escapement tooth 69, and the wheel advances slightly so as to bring the tooth against the dog 68. On the return movement, the triangular escapement tooth slips through between the dogs 67, 68, and allows the carriage to advance. The platen g is mounted on a shaft 84 journalled in arms 86 pivoted to the carriage c. In order to shift the platen for change of case, it is rocked upwards on the arms 86 by means of levers actuated by the swinging plate 94 extending across the machine beneath the carriage. The plate 94 is rocked by the shift-key, and can also be rocked by means of a thumb-nut 100, Fig. 18, the shaft of which is provided with a spring-tensioned tumbler lock adapted to retain it in either of its two portions. Fig. 27 shows the platen, paperguides, and rolls, &c. in section. The rod 89 carries a paper-guide 107, the forward end of which is provided with a scale. Arms 108 pivoted to the rod 89 carry pressure-rolls 109, which project through openings in the plate 107, and are held against the platen by springs 110. The support or table 111 for the paper is secured to support 112 fitting in sockets in the rail 47 of the carriage. The table 111 is not therefore lifted by the shiftkey. The rod 88 carries pressure-rolls 113 and paper-guide fingers 117. Fig. 31 shows the ribbon guide employed in the machine. The ribbon passes from spools on the shaft 134, Fig. 2, over the guide-rolls n<1> and through the slots in the plate n, which stands vertically in front of the platen. The plate n is secured to vertical arms 124 guided at 125 and carried by a shaft 121. The shaft 121 is adapted to be moved outwards and upwards by arms 120 extending from a rockshaft 119, which is actuated by the universal bar. The ribbon guide is thus lifted and rocked towards the platen every time a key is depressed. A fixed shield covers the ribbon guide, and carries a printing-point indicator. Fig. 33 shows the shaft 134 and ribbon spools 129, 130 in plan. Extending from end to end of the shaft in a slot formed therein is a shifter-bar, provided with projecting portions 154 which co-operate with the spring- held rolls 155 to ensure its sudden and complete longitudinal shift. When shifted, the bar clutches one spool to the shaft 134 and releases the other. Automatic reversal of the ribbon is effected as follows:-Arms 152, 155 ride upon the ribbon on the spools, and are connected with detent pawls 150, 151. When a spool empties, one of the pawls falls into the path of a tooth on a sleeve 144 loosely mounted upon the shaft 134. The sleeve is detained for one quarter of a revolution, during which time an internal sinuous cam-groove in the sleeve actuates a stud on the shifter-bar and effects the longitudinal movement of the bar. A camplate fixed on the shaft then lifts the detent pawls, and the sleeve continues to rotate with the shaft until a spool is again empty. A copy-holder is secured to the machine frame above the keyboard and in front of the platen. It consists of an inclined frame provided a+ the lower end with an upturned lip to receive the lower edge of the paper &c., and having rearwardly-directed arms by which it is secured to the type-writer.