Slotted tubular drill for earth, etc.

摘要

It is known that, by mutual longitudinal displacements S (Fig. 2) of a longitudinally slit, thin-walled column (longitudinal slit 2) of round (Figs. 1 + 2) or polygonal cross-sections (Figs. 3 + 4 and 6), rotations of the column end cross-sections through the angle PHI relative to one another are obtained. According to the invention, this deformation - rotation and longitudinal movements - is utilised for the drilling of slots with drilling cores. In the process, the longitudinal displacements are carried out rhythmically at different frequencies and amplitudes so that percussion drilling also becomes possible. The drilling core can be clamped in place and withdrawn by increased longitudinal displacement S. By a diameter D/length ratio h1 of about 1, wobbling and thus reaming of the slotted drill can be achieved. A further advantage of the slotted drill consists in the fact that, even during withdrawal, the side which is then the front side performs the same movements as during the cutting and can thus ream again if the borehole could have closed up. One slotted tube can also be placed on the other (Fig. 5), while the drive (3 + 3a) always remains outside the borehole. This drill can also be used horizontally for drilling conduits, in which case the direction can be controlled by rotation. <IMAGE>