Patent ID: 8696269
Filing Date: 2014-04-15
Classification: B23B,Y10T

Abstract:
1. A drill body for the machining of holes in workpieces of metal, comprising: front and rear ends between which an axis extends through, said drill body rotatable about said axis and with which a rotationally symmetrical envelope surface is concentric; a peripheral cutting insert arranged in the front end; and a support pad projecting radially beyond the envelope surface and comprises a cross-sectionally convexly arched outer surface having a rotationally symmetrical shape, an inner surface, front and rear end surfaces, as well as a pair of spaced-apart side surfaces, between the outer surface and at least the front end surface a convexly arched entering surface being formed that has a rotationally symmetrical shape and extends between a pair of tangentially spaced-apart front and rear borderlines, the entering surface being orientated in such a way that imaginary generatrices, which run forward from the rear borderline along the entering surface, point inward toward the rotation axis so as to facilitate the penetration of the support pad into a hole, the rear borderline separating the outer surface from the entering surface and having a shape of a convex arc line as viewed in planar view toward the outer surface.