Patent GB-391315-A (GB)
Title: Improvements in or relating to ribbon feed means for copywriters for attachment to typewriters and like machines
IPC: B41J35/22
Filed: 1932-05-03
Abstract: 391,315. Typewriters &c. THORNBLADE, C. H., 669, Dexter Horton Building, Seattle, Washington, U.S.A. May 3, 1932, No. 12754. [Class 100 (iv).] Ink-ribbon mechanism.-A typewriter is provided with one or more ink ribbons in addition to the usual ribbon to enable inkduplicates to be obtained, each ribbon being carried by a pair of reels mounted one at each end of the machine and provided with mechanism to take up any slack in the ribbon, together with a device for guiding and positioning each ribbon between the reels in printing position. The device is mounted in a carriage 2 pivoted on a base 20 secured to the paper carriage 90 of the typewriter so that the device can be swung out of the way when desired. Each reel comprises a cupped disc 31, Figs. 6 and 8, rotatably held in position on a spindle 30 by a screwed collar 33 and normally held against rotation by a spring washer 32. The recessed part of the disc 31 is covered by a flange 34 secured by means of a struck-out portion 34 to rotate with a drum 3 on which the ribbon is wound. The outer flange 38 of the reel is rotatable with the drum and is held in place by a nut 39 screwing on to the spindle 30 and formed with a long sleeve 391 forming the journal of the drum. The space between-the disc 31 and flange 34 contains a coiled spring 35 one end of which is bent round a struck-up part of the flange. The other end of the spring is formed with a knob 351 which normally contacts with a shoulder on a short spring 37 housed in the space between the disc and flange. As the drum and flange 34 normally rotate relatively to the disc 31, any tension in the ribbon will tension the spring 35 which will tend to keep the ribbon taut when the tension therein is relaxed. If the tension becomes too great, the knob 35<1> will slip past the shoulder on the spring 37 and be arrested by the other shoulder, thus permitting the tension to be slightly relaxed ; also, the disc 31 may slip past the washer 32. When feeding the ribbon out, it is necessary to relieve the tension by rotating the disc 31, and any undesired slackness can be taken in by rotating the disc in the opposite direction. In normal use, one reel is wound up and allowance is made automatically in the other reel for the tension produced. The reels are mounted in pairs at opposite ends of the carriage 2, and the ribbon on the rear pair is led by means of guide rods underneath the forward ribbon. The ribbons are passed through slots in guides 4 so as to pass along the whole length of the platen roller 9. The guides 4 are carried by blocks 40, slidable on vertical guide rods 41 mounted in the frame, under the influence of arms 42, 43 provided with finger buttons 42<1>, 43<1> movable in slots in the wall of the carriage 2, so as to enable any ribbon to be moved into or out of operative position. The corresponding arms 42, 43 on opposite sides of the carriage 2 are connected together by means of a rod 46 and a concentric sleeve 45. The guides 4 are connected to the blocks 40 by screw-and-slot connections to enable the ribbons to be adjusted to the correct height, and collars are secured to the rods 41 to limit the downward movement of the blocks 40. In order to prevent a reversed impression from appearing on the back of any sheet, a shield ribbon may be provided overlying any of the ink ribbons. The shield ribbon may be semipermanently attached in position since it does not require inking, and, in the case of the lower ribbons, may be attached to the lower end of the guides 4 which are formed with teeth for this purpose ; in the case of the upper ribbon the shield may be formed with bent-over ends to clip on to the ends of arms pivoted to the guides 4 on blocks 40. In a modification, the carriage is pivoted on a rod behind the platen so that it can be swung completely away from the platen. Paper-guiding arrangements.-A paper finger 95 is pivotally supported on a hollow spacer 49 surrounding the sleeve 45 instead of in front of the platen in order to avoid interference with the ribbons.