DRILLING MACHINE Russian patent published in 1997 - IPC

FIELD: drilling equipment. SUBSTANCE: drilling machine can be used for directed drilling of blast-holes, degassing and prospecting bore-holes or other spaciously oriented technological bore-holes in mining industry. In drilling machine, return line of drill string driving hydraulic motor accommodates two-position double-line hydraulic control valve actuated from special-shape cam and with spring-biased return, and delivery pressure line accommodates two-position three-line hydraulic control valve with its one outlet being connected to pneumo-hydraulic accumulator, and second outlet being connected to rod spaces of drill string feed hydraulic cylinders. Installed in return line of additional hydraulic pump are safety valve and three-position four-line hydraulic control valve with adjustable throttle valve mounted in its return line. EFFECT: high efficiency. 1 dwg