ROLLER-CUTTER DRILLING BIT Russian patent published in 2003 - IPC

FIELD: mining industry, applicable in hole drilling with bottomhole flushing with air or air-water mixture. SUBSTANCE: drilling bit has check valve built in shank cavity and including hollow body in form of stepped cylinder with intake windows located in zone of steps conjugation; hollow piston with spacer tube secured in its end so that its one end enters piston cavity and the other end enters cavity of adapter connecting body small step with flushing nozzle; spring located in piston cavity and body top cover. Cover center has hole in which pusher with longitudinal slot hole in which pusher with longitudinal slot is installed for axial motion so that with closed valve, gap is formed between pusher are selected so that in piston upper position, longitudinal slot protrudes from cover and its lower part remains open to valve cavity. EFFECT: higher efficiency of bottomhole flushing. 1 dwg