| 摘要 |
The tools for boring into the ground (39) are mounted asymmetrically and interchangeably on the side of the tube (2). The main boring tool consist of cutting blades (9) mounted on a single support bar (8) extending horizontally from the lower end of the tube, above the drilling trepan (4). Application to the boring of any ground, and particularly in zones which are difficult to access. <IMAGE>
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