| 摘要 |
<p>The stroke limiting unit is esp. for the hydraulic cylinders of a jib crane. A pump feeds a slide control valve, which operates the adjusting unit. A limiting valve is in switch connection with the control valve. A by-pass from the main feed pipe to the return pipe contains a reversing valve, pressure charged by a maintained pressure pipe toward its blocking position and against pressure from the by-pass pipe. The maintained pressure pipe may be connected to the return pipe, via a passage in the slide control valve, and the limiting valve. This valve is formed by an overload valve, charged with signal pressure from the auxiliary feed pipe and/or a mechanically actuated end switch valve.</p> |
