| 摘要 |
PURPOSE:To obtain a small-type printer consuming less electric power, capable of secure operation and suitable for high-speed printing, by engaging two worm members selectively rotated and stopped through a controlling means with a gear rotated as one body with a type wheel. CONSTITUTION:First and second worms 30, 40 constituted of double-start threads are engaged with a type wheel gear 12 on a carriage 10 to effect rotation of a type wheel 13 for selecting a type, spacing of the carriage 10 and returning of the carriage 10 toward a home position, and are engaged with a paper-feeding gear 80 to effect paper feeding. Partial gears 32, 42 provided at end parts of the worms 30, 40 are constructed as one-way clutches, and since two types corresponds to one rotation of the worm, it is necessary to select every other type. An odd number of types are provided on the type wheel 13, the type wheel gear 12 is provided with an odd number of teeth synchronously with the odd number of types, and all the types can be selected through two rotations of the type wheel 13. |
