| 摘要 |
<p>The telescopic ram comprises a cylindrical housing closed at one end by a cover, and accommodating a first piston having a concentric tube protruding from the ther end. A second piston with a concentric tube works in the first one and a medium under pressure is delivered to one or more pistons via the end cover. The first annular chamber (26) between the husing and the first tube is connected via a port (27) in the first tube close to where the latter is secured to the first piston to a second closed chamber (28) between the two pistons and the first tube, both chambers being filled with fluid. When the medium under pressure is delivered to the first piston the volume of the first chamber is educed and that of the second one increased, thus forcing the second piston and tube (19) outwards.</p> |
