DRILL Russian patent published in 2008 - IPC B23B51/02 

FIELD: technological processes.

SUBSTANCE: drill consists of casing, in the seat of which there is axisymmetric cutting plate with two main cutting edges and transverse edge between them that has two frontal surfaces and two support surfaces that are opposite to them. In order to increase capacity by means of increase in casing seat support walls contact rigidity, it is equipped with two bushings made of highly consistent material that are rigidly connected to the casings and on the external surfaces of which the casing seat support walls are installed, and central openings are intended for supply of lubricant cooling liquid. Central part of cutting plate, which is adjacent to transverse cutting edge, is made in the form of truncated wedge, which is located symmetrically in relation to plate symmetry axis, imaginary top of wedge is located from the side transverse to cutting edge, and for interaction with above mentioned wedge there are elastic clamping bulges with surfaces installed in the casing. There might be longitudinal grooves on seat support walls, and the grooves are connected with radial openings with their central openings.

EFFECT: increase of contact rigidity of casing seat support walls.

2 cl, 7 dwg