DRILLING BIT FOR TREATMENT OF STONE OR SIMILAR MATERIALS Russian patent published in 2010 - IPC B23B51/00 B28D1/14 

FIELD: mechanics.

SUBSTANCE: drilling bit includes the cutting plate having the shape of roof in side view and containing one cutting edge including the front cutting surface and rear free surface on each side of its "roof". At that, transverse edge is formed with mutually adjacent free surfaces in the area of the roof crown. Each free surface is concave in sub-zone near transverse edge so that radial external ends of transverse edge are projected in axial direction near end surface of the plate relative to intermediate centre of transverse edge (10).

EFFECT: increasing the supply during the drilling process, each cutting edge includes at least one cavity and diverts from roof-type shape; at that, two segments of each cutting edge, which are adjacent to the cavity, are made parallel in axial direction and offset relative to each other; at that, in addition, cutting edges divert from roof-type shape.

16 cl, 5 dwg