摘要 |
A speed controlling hydraulic dampener comprises a tubular housing defining a closed cylindrical chamber for containing a hydraulic fluid. The chamber containing two separate pistons and piston rods that extend through sealed openings in the ends of the housing. The second piston is spring-biased. First and second orifices are provided in the wall of the housing which are connected by a tubular passageway. A special seal arrangement cooperates with the first piston rod and with the wall of the housing defining the cylindrical chamber. This seal includes a third orifice extending longitudinally therethrough and cooperating with this orifice is a flow-controlling needle valve that can be used to adjust the rate of flow of hydraulic fluid from a first portion of the chamber through the first orifice, the tubular passageway and the second orifice to a zone between the first and second pistons.
|