ROTARY DRILLING BIT Russian patent published in 2008 - IPC E21B10/08 

FIELD: building.

SUBSTANCE: invention refers to rock-breaking tool, namely to rotary drilling bits. The rotary drilling bit contains a pin with a cutter established on the pin by means of the frictionless bearings, one of which being roller-type. The cutter is fixed from axial movement by ring segments established on a roller bearing and rigidly mounted on to the cutter. Distinguishing feature of the offered bearer is that the ring segments are executed from an outer end with longitudinal ledges and recesses, while the inside face of the cutter with return recesses and ledges, and an inside face of ring segments is executed with the longitudinal ledges placed between rollers and forming a separator for them. The cutter and ring segments are connected on a press fit and form a locking unit for fixing the cutter from axial movement.

EFFECT: increased working resource of a bearer and a drilling bit.

2 cl, 2 dwg