| 摘要 |
PURPOSE:To prevent a ribbon take-up shaft from being reversely rotated and prevent the generation of noise at the time of taking up a ribbon, by dividing the ribbon take-up shaft into two parts aligned in the axial direction so that when a cassette knob is reversely rotated, the two parts are spaced apart from each other in the axial direction to result in a locked condition. CONSTITUTION:A ribbon take-up shaft 27 is divided into two parts aligned in the axial direction, namely, an upper shaft part 31 and a lower shaft part 32, which are engaged with each other through ratchet tooth profiles 33, 34 provided at end faces thereof. The upper shaft part 31 is provided with a cas sette knob 29 as a knob part for manual rotation, whereas the lower shaft part 32 is provided with ribbon-feeding teeth 28. When the knob 29 is reversely rotated by an erroneous operation or the like, the upper and lower shaft parts 31, 32 of the take-up shaft 27 are spaced from each other, and the upper end lower end faces 38, 39 of the shaft 27 are pressed against the inner surfaces of a cassette casing 11, 12, resulting in a locked state. |
