| 摘要 |
PROBLEM TO BE SOLVED: To provide an actuator of an emergency cut-off valve which can simply and surely perform the fixed holding of the valve in an intermediate opening state for a long time. SOLUTION: When hydraulic pressure is applied, a ram 3 moves in the axial direction, and an output shaft 1 connected to a valve stem is turned. A brake body 10 having a tapered surface is fitted on the outer surface of the ram 3. A push spring 15 acts on the rear surface of the brake body 10, and the tapered surface is tightly engaged with the tapered portion 14 of a casing, and a brake is operated. A pressure chamber 17 is provided on the front surface of the brake body 10, and the brake is released by applying the hydraulic pressure. The brake shoe 12 of the brake body 10 has a plurality of slits 13, and can be easily deformed so as to reduce its diameter. COPYRIGHT: (C)2008,JPO&INPIT
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