| 摘要 |
The invention relates to a simplified and reliably functioning drill tool for a sinker drill for drilling in loose earth, such as when reinforcing the foundations in connection with building. The drill tool according to the present invention is in two parts and consists of an upper cylindrical transition piece (1), its central axis coinciding with the rotary axis of the drill tool, and provided with an eccentric, cylindrical hole (4), and of a lower reamer piece (2) provided with an upwardly directed shaft (3) to fit into the hole. In operating position the shaft (3) is fully inserted into the hole (4) and the transition piece (1) and reamer piece (2) cooperate. In extraction position the shaft (3) is partially withdrawn from the hole (4) to permit the drill (1,2) to be drawn up through a casing-tube. |
