GB158147A - Improvements in paper carriage feed mechanism for typewriters - Google Patents

Abstract

158,147. Fairweather, W. C., (Underwood Typewriter Co.). Dec. 31, 1919. Letter-spacing mechanism; back-spacing mechanism.-Carriage-feed mechanism, comprising a spring drum, escapement mechanism, and a backspacing pawl co-operating with the escapementwheel, is mounted as a detachable unit on a sheetmetal plate 67, Fig. 8, attachable to the rear plate 18 of the carriage-shift frame by set-screws 74, Fig. 2. The plate 67 is formed with an end bracket 68 for supporting the spring drum 21, intermediate ears 90 carrying the dog-rocker 24 on vertical pivots 53, a bracket 69 for supporting the back-spacing pawl 61, and a bent-over end for supporting the arbor 28 of the escapement-wheel 27. The plate 18 is formed with an opening 92 for access to the unit, and when the parts are assembled, as shown in Fig. 2, a ratchet-wheel 70 on the hub of the spring drum projects through the opening into engagement with a pawl 72 pivoted behind an ear 91 on the plate 18. The bent-over portion 76 of the plate 67 provides a flexible bracket for taking up lost motion in ball bearings 75, Fig 4, in races formed by the ends of the hub 77 of the escapement wheel and members 79, 80 mounted in the parts 67, 76. The arbor is in the form of a threaded bolt and nut for effecting the adjustment, and has a slotted head 82 accessible through an opening 81 in the plate 18. The dog-rocker 24 carries fast and loose dogs 22, 23, the latter pivoted and controlled by a single spring 31. Detachable engagement of the dog-rocker with the universal-bar connections is provided by a forked end 52, allowing also for the carriage-shift movements. The forked end 52 is engaged by a headed screw 50, Fig. 2, on an arm 49 of a rock-shaft 46 carrying a universal bail 39 formed of sheet metal with an integral bar 36 underlying the key-levers. The escapement pinion 29 and the hub of the escapement wheel are formed with corresponding flat surfaces 50 placed in relation to the teeth as to ensure correct cooperative position of the teeth when the parts are assembled with the flat surfaces in contact. The back-spacing pawl 61, Figs. 2 and 8, is pivoted at 62 to a spring-retracted link 59 connectible with a bell-crank 58 actuated by the back-spacing keylever 57. Space-key actions.-The space-key 44, Fig. 2, is mounted on a rock-shaft 43 provided with an arm 42 connected by an adjustable link 41 to an arm 40 on the universal bail 39.