Patent GB-190804277-A (GB)
Title: Improvements in Typewriting Machines.
Inventor: BROWN ALEXANDER TIMOTHY
Filed: 1908-02-25
Granted: 1908-12-31
Abstract: 4277. Brown, A. T. Feb. 25. Typewriters.-Relates more particularly to the ribbon mechanism and comprises means for driving and reversing the feed ot the ribbon, for varying the throw of the vibrator to bring different parts of the ribbon into use, and for throwing the vibrator out of action. The paper-carriage 10 is guided upon an inclined rail 7 by balls or rollers 8, and carries a feed-rack 12 which is engaged by two gear-wheels 13, 14 loosely mounted on a shaft 15. The carriage is drawn along by a spring attached at one end to the wheel 13 and at the other end to a part of the machine frame. The wheel 14 gears with a pinion 19 on a shaft 20, which is connected by skew-gearing with a shaft 25. A tooth 26 on the shaft 25 is engaged by dogs 27 on a lever 28 having at its upper end a curved universal bar 29, Fig. 15, which is struck by the free ends of the type-bars. The shaft 25 makes a complete rotation, and the carriage moves through one letter-space at each operation of the universal bar. The pinion 19 is so arranged as to rotate the shaft 20 in one direction only. The type-bars are in two sets 33, 34 mounted on segments 35, 36 respectively. The type-bars are connected by links to sub-levers 40 mounted in a segment 39 and connected by links 43 to levers 44, which are actuated by keys 46. The ribbon-spools 52, 53. Fig. 7, are mounted loosely on a shaft 54 which is driven in one direction through pawl-and-ratchet mechanism from the wheel 14. The adjacent faces of the spools are formed with ratchet-teeth which are engaged by a dog 71, Fig. 10, pivoted on and turning with the shaft 54. Toe dog is held in engagement with either spool by a spring, and is rocked into engagement with the other spool so as to reverse the feed of the ribbon by a pair of cams 89, 97, independently pivoted on a rod 86. To the cams are secured arms 87, 93 which 'are pressed by springs against the ribbon on the spools, so that, as each spool fills, one of the cams engages the dog 71 and reverses the feed of the ribbon. The feed mav be reversed by hand by means of a sleeve 81, Fig. 7, sliding on the shaft 54 and connected by a rod with the dog 71. A ribbon-vibrator 100, of the form shown in Fig. 15, is carried by an arm 101 on a shaft 102, which is connected by an arm 106 and link 107 to an arm 108, Fig. 1, on a shaft 109. An arm 130 on the shaft 109 is connected to a universal bar 121 which is rocked by projections 48 on the sub-levers 40. The universal bar is supported by arms 124 on a shaft 125, an arm 133 on which is connected by a link 132 to an arm 131 on the shaft 109. The vibrator is guided to move vertically by a bracket 116. A curved plate 118 placed over the bearings of the type-bars serves as a dustguard. The universal bar 121 is retracted by a spring 130<a> and is arrested by pads or cushions of felt &c. secured to the segment 39. The throw of the vibrator is varied by moving the lower end of the link 107 along the arm 108. The shaft 109 is formed with a recessed part 136, Fig. 6, so that the end of the link 107 may be moved into line with the axis of the shaft, in which case the vibrator is not actuated. The link 107 is connected by a link 144 to a lever 146, which can be rocked into either of two positions by means of keys 150, 153 to bring either of two fields of the ribbon into use. A movable stop 160 permits the lever 146 to be moved into a third position in which the vibrator is not actuated. In a modification, the recessed part 136 of the shaft 109 is so formed that the end of the link 107 cau move past the axis of the shaft 109. In this case, the ribbon stands normally only a short distance below the line of writing and, when not required, is slightly depressed at each actuation of a key. The carriagedriving, escapement, and ribbon-spool mechanisms are mounted in a frame comprisiug a bracket 30 and two plates 16, 17 detachably secured to the top plate 5 of the machine.