| 摘要 |
<p>A lowering and retrieving system that may be used when core drilling, either up or down, including drilling at any inclination. A flexible seal element is mounted around the periphery of a lowering and retrieving device and looped over a pin on a movable actuator element. The flexible seal element forms a fluid seal with a hollow drill string allowing the lowering and retrieving device to be pumped through the drill string. An elongated spear head on a retractable core barrel contacts and moves the movable actuator element thereby changing the position of the flexible seal element and a fluid channel around the lowering and retrieving device is opened.</p> |
