ROLLING CUTTER DRILL BIT WITH VALVE UNIT Russian patent published in 2006 - IPC E21B10/60 

FIELD: drilling equipment, possible use in drilling bits primarily during drilling of explosive wells with air blasting of bottomhole.

SUBSTANCE: drilling bit contains a suspended barrel with side windows rigidly held on a shelf of nipple wall, inside of which barrel valve washer and return spring are positioned, making it possible to maintain closed position of valve unit. Valve unit has elastic profiled collar acting as sealing element simultaneously for suspension barrel and valve washer when return spring is uncompressed. On the end facing the suspension barrel, elastic profiled collar has circular hollow, corresponding to shape of upper part of tail of suspension barrel, and with dimensions providing for tightness and pressurization of contact surfaces on internal and external sides of barrel.

EFFECT: increased penetration of drill bit, increased mechanical speed of drilling by means of providing for more efficient operation of valve unit.

2 cl, 1 dwg