DRILLING BIT Russian patent published in 1994 - IPC

FIELD: rock-breaking tools. SUBSTANCE: hole 8 in elongated nozzle 4 is made eccentrically to nozzle axis 7. In operating bit the washing fluid brings about different elongations of the walls of nozzle 4. This deflects the lower end of the nozzle 4 from axis 7. Being acted upon by the reactive force of the jet flowing from the nozzle 4, the lower end of said nozzle is deflected in the opposite direction. Rotation of the bit also causes circular motions of the lower end so that it starts performing complicated motions resulting in efficient cleaning and cooling of rolling cutter and removal of sludge from the well bottom during bit lifting. EFFECT: higher efficiency of drilling bit achieved by longer life of nozzle, possibility of its vibratory motion when the bit is stationary, and simpler bit design. 2 dwg