| 摘要 |
A shock absorbing device is shown having a cartridge attached to a valve, and an actuator. The valve houses a stem which is activated by the actuator to move between an open and a closed position. The actuator includes a cam having a cam surface and a roller which rides along at least a portion of the cam surface. A yoke, which is moved by the roller, is interconnected to a plunger which is attached to the stem. The cartridge includes an upper piston, a lower piston, and a plug having a channel therethrough, positioned between the pistons, the upper piston being spring biased towards the plug. The pistons are positioned in relation to the plug and cartridge housing so as to form an upper and lower reservoir, which are substantially filled with fluid, preferably ethylene glycol. The lower piston is capable of being in contact with the actuator yoke. The plug channel is sufficiently small to avoid flow of the fluid during an impact of a predetermined force and large enough to permit flow of the fluid during manual operation of the valve; the channel is preferably about one sixty-fourth of an inch in diameter. In operation, for example, moving the stem from the closed to the open position causes the lower piston to force fluid from the lower reservoir, through the channel and into the upper reservoir. When the stem is returned to the closed position, the spring biased upper piston forces fluid into the lower reservoir.
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