| 摘要 |
<p>An interlocking isolation valve assembly is described. The valve assembly is adapted to be connected to a hydraulic circuit, and it includes: a first isolation valve and a second isolation valve and an interlock means wherein the second valve is inhibited from moving to a return position if the first valve is at least partially in an open position, and the first valve is inhibited from moving to the open position if the second valve is in the return position. There is also described a method for venting a high pressure hydraulic machine such as for example a longwall roof support, in which the high pressure circuit is vented to the return circuit. Another aspect of the invention is a high pressure hydraulic machine which in one form is a longwall roof support, which is removed from a closed loop circuit by venting a high pressure circuit to a return circuit.</p> |
