Patent GB-550584-A (GB)
Title: Improvements in typewriting machines
IPC: B41J17/00
Filed: 1942-01-06
Abstract: 550,584. Typewriters. UNDERWOOD ELLIOTT FISHER CO. Jan. 6, 1942, No. 205. Convention date, Dec. 27, 1940. [Class 100 (iv)] Carbon-sheet arrangements.- In web-manifolding arrangements comprising a carbon-sheet trolley movable towards and retractable from the platen of a typewriter, retraction is performed by poweroperated means. In the construction shown in Fig. 1, the carbon-sheet trolly 71 runs on a platform 45 which runs on a rail 54 and is yieldably coupled to a rod 48 on the platen-carriage 10 by means of springs. The platen 21 is mounted in a sub-frame 18 which is trunnioned in the shaftframe 17 and can be swung forwards by means of a bar 101 to permit of straightening the webs preparatory to retraction of the carbon sheets. The trolly 71 is connected to a belt 116 which winds on and off spring drums 121, 118 on the platform 45. The spring drum 121 serves to counterbalance the trailing part of the webs. The spring drum 118 is mounted on a pivoted arm 127 and is provided with a ring-gear 123 for co-operation with a pinion 142 which is mounted on a bracket 164, Fig. 17, on the platform and is connected by a flexible shaft 145 and worm-gearing to a shaft which is mounted on the typewriter framework 13 and is driven continuously by the usual carriage-returning motor 95. The arm 127 is urged towards the pinion 142 by a spring 173, but is normally restrained by a device comprising a bell-crank 171 which is pivoted at 174 to a bracket 157 on the platform and carries a forked link 172 which engages a pin 177 on the arm. The spring 173 and a spring 197 connected to the bell-crank cause a lug 175 thereon to abut on the bracket 157. When the sub-frame 18 is swung forwards, a tripdog 178 thereon rocks an arm 183, linkage 184 .. 188 rocks the bell-crank 171, and the arm 127 is released. Thereupon, the arm is swung by the spring 127, the gear 123 engages the pinion 142, and the trolly 71 is retracted. When the dog 178 is tripped from the arm 183, the bell-crank 171 is retained by co-operation of the lug 175 with a latch 211. The arm is retained by co-operation of a lug 203 thereon with a lug 202 on a latch 201. A spring-urged bar 194, having slight longitudinal freedom on the platform, is provided with a hook 204 for holding the latch in engagement with the lug. At the end of the retraction movement, the trolly engages an adjustable stop 88 on the bar 194, and during slight longitudinal movement thereof, lugs 207, 213 release the latches 201, 211, the arm 127 is returned by the belt 116, and the gear 123 is separated from the pinion 142. In a modification, the motor is normally stopped, and the arm 127 is arranged to close and open the motor-circuit. Paper-carriages.-The pivoted sub-frame 18, Figs. 1 and 4, carrying the platen 21 is normally locked to the shift-frame 17 by means of latches 31 mounted on a shaft 32 on the shift-frame. The bar 101, on which is mounted the web-gauge 102, is secured to a shaft 103 mounted in the sub-frame and provided with an arm 104 carrying a dog 11 which abuts on a pin 110 on one of the latches. When the bar 101 is swung forwards, the dog releases the latches, and the bar then abuts on a cross-bar 25 of the subframe and swings forwards the latter.