ROLLING DRILLING BIT Russian patent published in 2010 - IPC E21B10/12 

FIELD: mining.

SUBSTANCE: rolling drilling bit includes legs with trunnions on which by means of a locking device on sliding bearing there installed are rolling cutters with rock cutting elements. Bit is equipped with an additional rolling cutter installed on locking device made in the form of an axis, the end sections of which are fixed in grooves made on opposite edges of trunnions of legs; at that, between edges of the additional rolling cutter and edges of trunnions there arranged are springs, and additional rolling cutter is installed with possibility of being moved along the axis. At that, rock cutting elements of the additional rolling cutter are made from material with larger hardness in comparison to rock cutting elements of the main rolling cutters.

EFFECT: increasing the drilled distance and mechanical drilling speed owing to decrease of power consumption required for breaking the central part of mine face.

2 cl, 1 dwg