| 摘要 |
<p>A seismic tool assembly with a flange portion for effecting a drill hole and enlarging a lowermost end thereof whereby an anchor can be set more securely therein. A drill bit is inserted through an opening in a cap portion, which is mounted on a stabilizer mounted within at least a portion of the drill hole. The bit is then inserted through each of the cap portion and the stabilizer to attain a drilling position. The bit possesses extra cutting tips on an upper end thereof, with a view to widening the upper end of a drill hole so that a wider flange can be inserted therein. The bit also has an abutment member which permits limited tilting movement of the bit body during a drilling process to enlarge the lowermost end of the drill hole.</p> |
