Patent GB-118303-A (GB)
Title: Improvements in Typewriters and analogous Devices adapted to be Operated by a Perforated Tape or the like.
IPC: B41J5/38
Filed: 1917-07-21
Abstract: 118,303. Fraser, A., and Eastern Telegraph Co. July 21, 1917. Addition to 1822/12. Strip-controlled driving-mechanism; type-wheel actions; platen-impression arrangements; web feeding and guiding arrangements; letter-spacing mechanism.-The machine described in the parent Specification is improved or modified in the following respects. (i) The co-operating projections 4, 5, Fig. 5, on the rocking bars a, d that are connected to the peckers and the type-selecting slides 9 respectively, are supplemented by special projections 5<x>, Fig. 10, for preventing any letter from being printed by an erroneously punched signal that could release more than one of the slides 9. An example of such a signal. which would release both the a ' and the 't ' slides 9, is provided by a dash punched in line with the dot of the a signal. The special projections 5<x> are normally cut of the path of the projections 4, but are obstructed when the erroneous signal is presented; thus in the case of the above-mentioned signal, one of more of the projections 4 associated with the 'a ' signal would obstruct projections 5<x> on the ' t ' slide, and vice versa. To indicate the omission of a letter from the message tape due to the presentation of an erroneous signal, devices may be provided for ringing an alarm and for marking the message tape. The peckers are released and returned by a longitudinally movable comb, which engages the upper edges of the rocking bars a and is operated by a cam k, Fig. 5, on a driving-shaft, which is arranged at the rear of the machine. The slides 9 are released and returned by a rocking plate 12 which engages recesses 13. The plate is secured to a shaft 14 provided with an arm 16 which is rocked by a cam on the driving-shaft. The slides 9 operate individual slides 11, arranged opposite pegs 69 on a barrel 68 which is secured to the shaft of the type-wheel v, Fig. 2. The barrel is geared by pinions r, s, Fig. 5, to a shaft o which is geared by bevel-wheels to the driving- shaft. The slides 11 are mounted at the rear in a comb 10, and, at the front, are suspended from springs 22 and guided by a comb 20. The slides 11 are released and returned by a rocking plate 17, connected by a link 154 to an arm 153 on a rockshaft 149 which is connected to an arm 146 on a rock shaft 143 operated by a cam on the shaft o. (2) The differential feed of the perforated strip is determined by a rocking plate 24, which is arrested by arms 23 of graded heights formed on the slides 11. The plate is secured to a rock shaft 65, Fig. 5, provided with an arm 138, Fig. 2, connected by a link to a lever operated by a cam on the shaft o. At each cycle of operations, the cam lifts the plate and a spring then depresses the plate until it is arrested bv one of the arms 23. The shaft 65 is also provided with an arm 64, Fig. 2, co-operating with a stop-lever 60 which is connected by a link 62 to ratchet-mechanism for driving the strip-feeding wheel 27. The ratchet-mechanism comprises a pawl 35 mounted on a loose sleeve 40 gearing with a sector 42 which is connected to the link 62. A link 56, Fig. 8, has a slot connexion with a lever 49, secured to a shaft 47 and provided with a yielding rod 50 for driving an arm 46 which is loose on the shaft and is coupled to an arm 44 on the sector 42. The lever 49 is urged by a spring and the link 56 is operated by a cam j, Fig. 5, on the driving-shaft. In operation, the movement of the plate 24 determines the setting of the lever 60 and consequently the arc of retraction of the pawl 35, which is then moved forward by the link 56 to cause the strip to be fed. To prevent the strip from being given a maximum feed when, owing to an erroneous signal being presented, a slide is not operated, the plate 24 is provided with an arm 66 adapted to engage the end 67 of the lever 60 and thereby reduce the feed to a single unit, or, if desired, to suppress the feed. The plate 24 may be arranged to operate the alarm and the marking-device mentioned above. (3). To prevent an erroneous letter from being printed owing to the unit feed determined by the lever 60 causing a part of the signal corresponding to a letter to be presented to the peckers, an additional pair of peckers is arranged in advance of the usual peckers. The peckers are normally held back by the spaces on the strip, but when a part of a signal is presented, these peckers advance and cause the slides 9 to be locked by the engagement of projections 4 associated with these peckers with projections 5<x>. (4). The platen-roller 120, Fig. 2, is moved into contact with the type-wheel v by means of devices operated by the slides 11. The platen-roller is mounted on an arm 119 on a shaft 116, Fig. 9, which is connected by a slotted arm 103 to a lever 87 carrying a pawl 84 adapted to engage a ratchet-wheel 86 on the shaft of the typewheel. The slides 11, on being engaged by the pegs 69, depress a plate 70 carried bv a rock-shaft 73. An arm 76 on the rock-shaft engages a link 78 coupled to a catch-lever 79, which normally engages the tail 83 of the pawl 84 and holds the pawl out of engagement. The parts are arranged so that when any peg 69 engages its slide 11, the associated type on the type-wheel v is at the printing point and the platen-roller is moved for impcession. The depression of the plate 70 by the selected slide effects the coupling of the pawl 84 to the ratchet-wheel, and the lever 87 is then rocked until the pawl is released by the tail 83 engaging a stop 89, the lever being held in the displaced position by a roller 93, which passes over a hump on a spring 95. The lever 87 rocks the platen-roller arm 119 and causes the platen-roller to press the message tape against the selected type. The lever 87 and the arm 119 are returned by a pin 141 which engages a lever 105 connected to the lever 87. The pin is carried by an arm which is operated by the shaft 143. The return movements of the lever 87 and the arm 119 are effected when blank parts of the ratchet-wheel and the type-wheel are presented to the pawl and the platen-roller respectively. (5). The message tape passes round the platen-roller 120, Fig. 2, and round guides 123, 124 arranged near the shaft. 116. The tape passes from the guide 123 over a roller 125 and thence between a feed-roller 115 and a roller 126 carried by a lever 127 which is pressed by a spring 130. The shaft 113 of the feed-roller is provided with a ratchet-wheel 108, Fig. 9, engaged by a feed-pawl 107 which is carried by an arm 106 of the lever 105. The ratchet-wheel 108 also engages a detent 110.