GB972580A - A typewriting machine with two ribbon guides - Google Patents

Abstract

972,580. Ink-ribbon mechanisms. OLYMPIA WERKE A.G. June 7, 1961 [June 18, 1960], No. 20538/61. Heading B6F. A typewriter (manual or electric) has selectively operable guides 1, 3 respectively for the normal two-colour ribbon 2 and a once-through carbon paper ribbon 4, the latter being fed, only when being used, by a friction drive acting on the ribbon itself. Each time a typing action occurs a rod 25 is pulled forwards to swing a bell-crank 24 anticlockwise about shaft 23 against spring 27 and this depresses a pull lever 29 the upper end of which is pivoted in a slot of shift guide 28b formed integrally with lifting lever 28 for ribbon guide 1. Thus guide 28b and lever 28 are swung anticlockwise about their pivot to raise guide 1 at each typing action. Depending on whether lever 29 acts on the near end of the slot, further along the slot, or in the first enlargement of the slot the ribbon will be raised to type blue, raised more to type red, or not raised for stencilling. The slot has a further enlargement 28c and when lever 29 acts in this, lever 28 is not moved but a dog 29a on lever 29 engages a bent end 30a of lever 30 to raise guide 3 for the carbon paper ribbon. The position of lever 29 in the slot is set by rotating a cam 19 which, through push rod 20, rotates shaft 23 and lever arm 23a which swings lever 29 by connecting rod 23b. Ribbon feed.-Carbon paper ribbon 4 is fed from a braked supply spool 5 through guides 3 and 7 to waste spool 6 by intermittently-driven friction rolls 8, 9 driven through shaft 12 by a pawl and ratchet 11, 10 operated at each typing action by oscillating lever 17 carrying the pawl. When the normal ribbon is being used, push rod 20 is retracted and tensions a spring 20d between the pawl and an extension of rod 20 so that the pawl is out of engagement with the ratchet. When the carbon paper ribbon is in use, rod 20 is pushed back and the spring is relaxed to allow engagement of the pawl with its ratchet and, hence feed of the carbon-paper ribbon. Waste spool 6 is driven through a resilient slipping pulley 14 by the ratchet mechanism, the drive ratio being such that the feed is satisfactory whatever the effective diameter of the waste spool.