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

FIELD: hole drilling in mining industry with bottom-hole blown with compressed air or air-water mixture. SUBSTANCE: roller-cutting drilling bit has check valve built in shank cavity and includes cylindrical body connected with central blowing nozzle of drilling bit so that inlet holes of cylindrical body are located above shank end face; flow distributor with a number of inlet windows corresponding to that of body windows in working position of drilling bit due to presence of lock of flow distributor from angular displacement relative to body and limiting of axial motion; cover closing flow distributor and spring. Flow distributor is made in the form of stage cylinder whose small stage embraces the body, and spring is fitted on body with spring one end resting on washer located in point of body connection to blowing nozzle, and spring other end rests on end face of flow distributor whose extreme position is limited by locknut connected with body free end. Flow distributor lock is made in the form of guide pins. EFFECT: simplified design and higher operating reliability of roller-cutter drilling bit. 1 dwg