| 摘要 |
<p>The drainage pipe laying machine has a rotatable superstructure mounted on a tracked chassis. A pivoted arm mounts a channel forming and pipe laying tool, a double acting hydraulic cylinder adjusting the position of the arm. A fluid distributor is connected to the feed pipes of the two cylinder chambers a valve selectively isolating or communicating the chambers. A reversible fluid motor controls the position of the superstructure, a valve being connected to the motor feed and return lines to isolate or communicate them. Both valve are pref. connected to a single control.</p> |
