Machine for making bored piles

A machine for making bored piles, the machine comprising:

• vertical guide means;
• a rotary drive head that is movable relative to said vertical guide means;
• an auger having a hollow core and at least one helical blade, said core having open top and bottom ends;
• an extender tube whose bottom end is secured to the top end of the core of the auger, said rotary drive head co-operating with said extender tube to rotate the assembly constituted by the auger and the extender tube;
• a dip tube slidably mounted in the hollow core of the auger and in the extender tube, the dip tube having a top end connected to a concrete feed pipe and a bottom end provided with at least one outlet;
• actuator means having a first end constrained in translation relative to the top end of said extender tube and a second end constrained in translation relative to the top end of said dip tube;
• and
• means for controlling said actuator means to modify the position of the bottom end of said dip tube relative to the position of the bottom end of the core of said auger, between a first position wherein the bottom end of the dip tube is within said core auger and a second position wherein said at least one outlet of said dip tube are out of said core auger.