| 摘要 |
A tamperproof lock with shock absorber for a fire hydrant. A spring is mounted at one end on the fire hydrant housing. Power transmitting means are mounted on a threaded operating rod extending within the housing chamber. Hydraulic means operatively associated with the power transmitting means prevents sudden closing of the hydrant valve. The power transmitting means transmit power to the threaded rod against the spring and the hydraulic means. A swivel plate is freely mounted on the power transmitting means for rotational movement thereon. The swivel plate has a contoured hub portion adapted to fit within an aperture within the fire hydrant bonnet. The hub portion is exposed to the exterior of the bonnet. Power means for applying power substantially along the axis of the threaded rod to move the rod against the spring and the hydraulic means are removably mounted on the bonnet. Means for preventing axial and rotational movement of the power means is pivotably connected thereto by means of a double pivot joint.
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