| 摘要 |
Apparatus for driving casing, piles, or conductor pipe into the ground comprises in combination; an external reciprocal impact driving means supported atop the conductor pipe, internal rotatable drilling means supported within the conductor pipe, and means associated therewith for introducing air and water under pressure for creating a pressure differential to evacuate the drilling debris and cuttings to the surface. The drilling means is supported within said conductor pipe at the bottom portion thereof near the point of least energy absorption and rebound. The driving and drilling operations may be performed simultaneously or sequentially. |
