| 摘要 |
PURPOSE:To decrease a slip between a friction wheel and a rotary head, shorten the accelerating and decelerating time, and lengthen the rotating time at the predetermined rotation by arranging fulcrums of levers on the rotating direction side of the rotary head and on the counter-rotating direction side respectively with respect to the friction wheel at one end. CONSTITUTION:The pressing force to a rotary head 7 of a friction wheel 19a fitted to a lever 16a, with its fulcrum 17a located at the rotating direction side of the rotary head 7, is applied strongly at deceleration, because the deceleration rotating direction of a drive gear 15 is the same as the direction in which one end side of the lever 16a is swayed and approaches the rotary head 7. The pressing force to the rotary head 7 of a friction wheel 19b fitted to a lever 16b, with its fulcrum 17b located at the counter-rotating direction side of the rotary head 7, is applied strongly at acceleration, because the acceleration rotating direction of the drive gear 15 is the same as the direction in which one end side of the lever 16b supporting a driven gear 18a engaged and driven by this drive gear 15 is swayed and approaches the rotary head 7. Accordingly, the quick acceleration end quick deceleration of the rotary head 7 is allowed by both friction wheels 19a, 19b.
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