| 摘要 |
PROBLEM TO BE SOLVED: To prevent malfunctions by external noise by providing a mechanical reverse rotation prevention device between an electric motor rotary shaft and a feed screw. SOLUTION: A small gear 7 is fixed to the rotary shaft of an electric motor 6 and is engaged with a large gear 8 mounted to the feed screw 5 through a unidirectional clutch 9. A parallelly movably provided slider 3 engaged with the feed screw 5 is engaged with the end part of a sucker 2. By the constitution, when the electric motor 6 is driven in a prescribed direction, the unidirectional clutch 9 is operated in a transmission direction, the feed screw 5 is rotated and the slider 3 is operated so as to make the sucker 2 push transfusion in a discharging direction. However, when the driving electric motor 6 is reversely rotated by the cause of some external noise, the unidirectional clutch 9 is slid and rotation is not transmitted to the feed screw 5. Thus, the reverse movement of the sucker 2 by the slider 3 is not present. In such a manner, the malfunction by the external noise is prevented. |
