THE ASSEMBLED DRILL BIT Russian patent published in 2012 - IPC B23B51/00 

FIELD: materials processing.

SUBSTANCE: invention relates to the field of the material processing by means of cutting and can be applied to processing; the assembled drill bit comprises the housing its longitudinal axis coincides with the axis of the drill bit and at least two cutting plates located and fixed in the mortises of the housing; the central cutting plate is fixed in the housing to be intersected with the drill bit axis while the periphery plate is mounted in the housing to be interacted with the lateral surface of the drilled aperture; the central plate is made in the shape of polyhedron with the central aperture for the fixing screw and has two identical parallel surfaces in the shape of the polygon, the distance between them forms the thickness of this plate and the lateral surfaces located between the butting ends intersecting with them form the cutting edges; the lateral surface of the central cutting plate located at least between two angles of the butting ends is made in the shape of two surfaces tilted from away the butting ends towards the inside of the cutting plate; between the above surfaces there is a cross blade with the cross cutting edge overhanging the cutting edges made upon the intersection of the above lateral surfaces tilted to the inside with the butting ends of the central cutting plate; the cross cutting edge is located parallel to the butting ends of the central cutting plate, upon its installment to the housing mortise the axis of the drill bit goes through the middle part of the cross cutting plate, its length is bigger or equal to the thickness of the central cutting plate.

EFFECT: reduction of the axial thrust when drilling.

1 dwg, 7 dwg