| 摘要 |
PROBLEM TO BE SOLVED: To provide a plug device that shows an elevated yield, higher quality and a lower fraction defective. SOLUTION: A lever-type operation mechanism 20 includes a cam portion 25 for driving a stop valve 14. A lock mechanism 26 locks the stop valve 14 before the cam portion 25 shifted in a direction of opening the stop valve 14 is beyond its pressure dead point in the opening direction. In its opening, the stop valve 14 is loaded down by an operation lever 23 in the most effective manner as a function of the leverage.
|
