FACILITY TO EXPAND BORE HOLE Russian patent published in 2003 - IPC

FIELD: mining industry, expansion of drilled bore holes. SUBSTANCE: facility comprises body with central axial and radial conduits. Longitudinal grooves in which blades are suspended with use of turning joints are uniformly arranged on outside of body. These longitudinal grooves can be made in outer surface of body in several levels by height. Jet nozzles are placed in radial conduits, they can be positioned opposite to lower parts of blades. The latter can come in the form of bars of round or other section or in the form of pins carrying rotating cutters. Outer surface of blades is reinforced with wear-resistant material. EFFECT: enhanced reliability and efficiency of operation of facility in process of expansion of drilled bore hole. 4 cl, 4 dwg