Patent ID: 7665936
Filing Date: 2010-02-23
Classification: B27G,Y10T

Abstract:
1. A wood drill bit with a cylindrical drilling head and a connecting portion adjoining the head in opposite relationship to the drilling direction for connection to a drive means, wherein the drilling head has at its end a centering tip which is disposed on the longitudinal axis of the drill bit and which projects in the drilling direction for centering the wood bit, at least two main cutters which are arranged diametrically and radially or substantially radially and have main cutting edges, and a part-cylindrical guide bell, and adjoining each main cutter is a chip ejection space which is partially open towards the connecting portion, wherein at least one of said at least two main cutters extends with a radially inwardly disposed portion into the centering tip and the chip ejection space is enlarged into the centering tip by means of a pre-chip ejection groove, characterized in that at least one of said at least two main cutters forms in said radially inwardly disposed portion a side face in said centering tip which faces radially outwardly and axially in opposite relationship to the drilling direction.