| 摘要 |
<p>An upper end (10) for the inner tube of a core drill has a marking device comprising a pendulum (350) or hard ball (30) which runs in a circumferential track (24). The marking device adapted to be carried within a tubular upper end casing (12) which surrounds a spindle (11) which supports the inner tube of the drill. An indent washer (25) is positionable below the marking device and is oriented relative to the casing. When the upper end (10) is lifted, the marking device is driven into contact with the washer (25) and makes an impression. The orientation of the impression reveals the orientation of the drill. The impressioned washer (25) can be used to assist in noting or marking the core orientation after the drill is removed from the earth.</p> |
