| 摘要 |
PROBLEM TO BE SOLVED: To reduce the rotation resistance of a handle, to easily hold a valve rod in a valve-opened state, and to improve operability.SOLUTION: A bush 10 is fixed into valve rod support hardware 6 in an upper part of a valve box 3, and in the bush, a plurality of pockets for rollingly holding balls 9 are formed at equal intervals in circumferential directions. A valve rod 5 which vertically moves in the bush, and is held to pull-up hardware 7 having a locking groove 7b at its entire circumference by screw-joining is energized downwardly. A sleeve 11 which vertically moves at an external periphery of the bush, and has a groove 22 at its entire circumference is energized upwardly, and an operation shaft 13 is rotatably held to the valve rod support hardware. The pull-up hardware vertically moves, a locking groove opposes the pockets of the bush, the balls are fit into the locking groove, and the pull-up hardware is locked to the balls. The sleeve moves downwardly by being pressed to a protrusion 13a by the rotation of the operation shaft, the groove of the sleeve opposes the pockets of the bush, the balls move to the groove and are removed from the locking groove of the pull-up hardware, the valve rod 5 moves downwardly, and a valve body 4 is seated on a valve seat 2 and brought into a valve-closed state. |
