| 摘要 |
PURPOSE:To ensure that the angle of winding of an ink ribbon on a wind slack- preventive spring can be maintained at a constantly fixed value, by providing a roller at an intermediate position between a pay-out spool and the wind slack- preventive spring for exerting a tension on the ribbon. CONSTITUTION:A pay-out spool 1, on which an ink ribbon 2 is wound and to which a central bent part of a substantially V-shaped wind slack-preventive spring 3 is attached, is fitted on a pay-out spool support shaft 5a projected from a casing 5. The ink ribbon 2 is taken up on a take-up spool similarly provided in the casing 5. A roller 6 is fitted over a roller support shaft 5b projected from a bottom surface of the casing 5, the ribbon 2 is brought into contact with an outer peripheral surface of the roller 6, and is sequentially supplied to an ink ribbon winding part 3a bent rectangularly, of the spring 3 for exerting a tension on the ribbon 2. With this construction, the positional relationship between the roller 6 and the ribbon winding part 3a of the spring 3 is substantially unchanged, so that the angle A of winding of the ribbon 2 on the ribbon winding part 3a can be maintained to be constant irrespective of the roll diameter of the ribbon 2, from beginning to end of winding. |
