| 摘要 |
PURPOSE:To provide the titled back-tensioning mechanism capable of imparting a fixed tension to a ribbon paid out from a holder, wherein a plurality of teeth are projected on the outer periphery of a rotatable ribbon holder, and a coil spring is elastically pressed against the outer periphery of the holder. CONSTITUTION:The ribbon holder 24 for fitting a printing ribbon and a correction ribbon in a printer is supported so that it can be rotated, and a plurality of teeth 28 are projected on the outer periphery of the holder 24. The shape of each of the teeth 28 is such that one side thereof with respect to the rotating direction of an arrow A of the holder 24 is a radial surface 29 directed to the center of the holder 24, and the back side thereof is a slant surface 30 the height of which is gradually reduced from the radial surface 29 in the rotating direction of an arrow B of the holder 24. The coil spring 26 is elastically pressed against the outer periphery of the holder 24 over a range of about 90 deg. in the condition of being stretched by pins 27. |
