| 摘要 |
The tool, comprising a rotating drilling cylinder 10, open on its lower face and closed on its upper face, a central axial rod 7 traversing the upper face 11 of the cylinder and provided at its lower free end with at least one drilling oring and/or centring accessory 8, 9, this rod rotating integrally with the cylinder by a conjugated profile connection and being capable of sliding axially with respect to the cylinder under the action of at least one jack 13, and a motor unit 3 for driving the cylinder and the axial rod in rotation, the casing of the said motor unit being fixed in rotation, is characterised in that the output shaft 5 of the motor unit, directed towards the cylinder 10, rigidly carries the upper end of the said central axial rod 7, and the sliding jack 13, having one of its ends 28, 31 integral with a fixed part 44, 2a of the tool and the other element axially integral with the cylinder 10 or with the rod 7 sliding with respect to the said fixed part of the tool, the cylinder being driven in rotation by the said central axial rod by the conjugated profile connection. <IMAGE>
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