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

FIELD: process engineering.

SUBSTANCE: invention relates to machine building and may be used for boring by composite drill bits with mechanical bracing of cutting plates. Proposed drill bit comprises body consisting of working part and shank. Two identical cutting plates with orifices fastened by screws with heads fitted in said orifices are arranged on working part end face, on thrust sections between chip flutes. Every said cutting plate is confined by front and rear surfaces with major cutting edge located at their intersection and by thrust surface located opposite said rear surface to interact with thrust section. Drill bit is furnished with nuts fitted in threaded holes made in drill body. Two crosswise through threaded holes are made in every nut for alternating interaction with fastener screw, orifice axes being located at 90° to each other. Thrust surfaces are provided with flutes to interact with grooves made on cutting plate thrust surfaces, said flutes being arranged parallel with said threaded orifices for nuts. Every thrust section of the body has through oval hole to receive fastener screw arranged between thrust section and said threaded orifice for nut. Larger axis of said oval hole is parallel with flutes.

EFFECT: adjustment of cutting plate radial position, expanded performances.

5 dwg