| 摘要 |
The invention relates to a device 1 for making concrete piles in the ground, intended to be fixed on the base 2 of a boring element 4 with a tubular core 3. It comprises a body 7 of revolution about the axis of the core, hollowed from end to end by a cylindrical bore 8 and constituted by a narrow upper portion 9 capable of being fixed rigidly on the base 2 of the boring element, a lower portion 12 of maximum external diameter D greater than the maximum external diameter d of the upper portion 9 and an intermediate connecting portion 13 with radial openings 14. A free piston 15 provided with a boring tool 23, is housed in a joined manner in the cylindrical bore 8 of the body 1 in such a way that it slides axially in the latter between a position in which the openings 14 are covered and a position in which these openings 14 are cleared. <IMAGE>
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