| 摘要 |
<p>A hydraulically controllable, leakproof holding valve is disclosed, and which is adapted to be attached in the lifting hydraulic line leading to a working cylinder or the like. The holding valve includes a slidably mounted control piston, which functions as a controlled non-return valve during periods when the working cylinder is stationary or being lifted, and the piston also functions as a throttling valve during periods when the working cylinder is being lowered.</p> |
