GB1373350A - Clearing solid material from elongate tubes and passages - Google Patents

Abstract

1373350 Drilling machine details HUNTING OILFIELD SERVICES Ltd 26 Jan 1972 [12 March 1971] 6715/71 Heading B3C [Also in Division F2] Solid material 12 in a pipe 10 is broken up by a rotary cutter 44<SP>1</SP>, mounted on the end of a rotatably-driven hollow stem 46, 40, and the broken-up particles of material are withdrawn from the pipe 10 through the interior of the stem, which is connected at 52 to a suction device (not shown). The cutter may comprise (as shown), a blade 44<SP>1</SP> combined with an eccentric material-crushing cam 58 and centring flanges 60 or (Fig. 1, not shown), a bit with a conical cutting surface. Broken-up particles enter the stem through apertures 48<SP>1</SP>. The cutter may be secured directly to the lower end of a Kelly 40. Alternatively one or more drill string sections 46 may be interposed between the Kelly and the cutter. Connections between adjacent drill string parts are by way of frustoconical screw threads. The Kelly is rotatably driven by a pneumatic or electric motor (Fig. 1, not shown), through chain or belt 24, wheel 22, rotatable bushing 20 and Kelly bushing 38. Co-operating slots and projections 34, 36 permit lifting of bushing 38 from bushing 20 when the drill string is raised to alter the number of sections 46. A generally U-shaped frame (Figs. 4-6, not shown), is engageable with the top of drive unit casing 16 and a flange 46b on a particular section 46 to lock the string angularly relative to the casing 16 and to prevent the string from falling back into pipe 10. The screw-threaded connection between the particular section 46 and the section immediately above same may then be undone to add or remove sections 46. Instead of gravity, a hydraulic or pneumatic ram (not shown), may provide the axial thrust at the cutter.