Ground drill for underwater boring - has hollow main drill shaft with rotor alongside also reamers hinged to tool for swivelling out as piston ascends in cylinder on shaft

摘要

Ground drill for use under water comprises sludge pump and bit drive in a common drill collar. A main drilling shaft (4) carrying the main tools (2) and a pair of reamers (3) is hollow and has an entry (1) forward and is powered by a rotor drive (12) arranged alongside the shaft. The shaft is rotatably coupled to the sludge pump entry (18) so that the pump lines up with the shaft as assembled. Pref. the shaft passes through a hydraulic cylinder (5) the base of the collar (3), and runs through the piston rod (6). Each reamer should be pinned to the piston and additionally hinged to the main tool (2) so that the rod ascends, the hydraulic pressure swivels the reamers outward round the hinge pin.