ROLLING DRILLING BIT Russian patent published in 2013 - IPC E21B10/18 

FIELD: mining.

SUBSTANCE: rolling drilling bit includes legs with mounted on them cone rollers and blow-off valves, in which there are return valves that consist of protective casing and shut-off element spring-loaded in axial direction by compression spring. Protective casing of each return valve is made with stepped internal surface with formation of supporting step and shut-off element - with inclined channels for cleaning agent supply and annular collar at the top part, note that compression spring is mounted between supporting step of protective casing and annular collar of shut-off element. The bottom part of shut-off element can be made with open cavity connected to additional inclined channels, the output part of which is directed towards the well mouth.

EFFECT: increase of drilling bit efficiency, effective cleaning of bottom-hole from slug.

2 cl, 3 dwg