ROLLER-CUTTER DRILLING BIT Russian patent published in 2002 - IPC

FIELD: roller-cutter drilling bits for drilling of holes with a hole blowing with air or air-water mixture. SUBSTANCE: roller-cutter drilling hit has a shank with air sources for blowing of bearings, blowing nozzle secured in central hole of drilling bit, check valve including flow distributor installed for axial motion on body made in the form of two-stage cylinder in which stage of body small diameter is connected with blowing nozzle and has side windows, and stage of large diameter is closed by dead cover and made with holes at its base. Flow distributor is made in the form of two-stage cylinder. Stages of large and small diameters embrace body corresponding stages. Located in circular chamber between walls of bit body and flow distributor is spring resting with its one end onto internal step of stages of flow distributor, and with its other end resting on external step of bit body stages. Side windows are so located that in nonworking position of valve, one part of then, through half of its height, is closed by small diameter stage of flow distributor resting on limiting ring, while the other, comes to circular chamber between bit body and flow distributor. EFFECT: simplified design and higher operating reliability. 1 dwg