| 摘要 |
<p>A kelly for the realization of bored piles, constituted by a battery of rods (7, 19) displaceably inserted the one into the other and wherein the most inner one (9) supports an excavation tool (5); a rotary table (1), vertically sliding along the drilling mast (2) of the operating machine (3) which bears the kelly, is provided with means (8a) adapted for putting into rotation the battery of rods (7, 19) around its longitudinal axis; means (10) adapted for displacing and recompacting the rods of the battery and motorized means (6) adapted for exerting a traction and a thrust on the rods during the excavation are also provided; the kelly being characterized in that at least part of the rods (19) of the battery is entirely positioned under the rotary table (1) by which it is put in rotation.Figure 1</p> |
