Patent ID: 8840347

Claim:
Drilling tool for chip removing machining, comprising: a basic body having front and rear ends, and an envelope surface that includes two countersunk chip flutes and is concentric with a first center axis around which the basic body is rotatable in a given direction of rotation; and a loose top that includes front and rear ends, the rear end serving as an axial contact surface, and an envelope surface that is concentric with a second center axis and includes two countersunk chip flutes between which two bars projecting radially from a central core are delimited, wherein each bar includes a cutting edge in the front and a number of clearance surfaces positioned rotationally behind the cutting edge, wherein a front end of the basic body comprises a jaw that is delimited by a bottom forming an axial support surface and two peripherally situated branches that protrude axially from the axial support surface, are elastically bendable, and clamp the loose top in the jaw, wherein a pair of inner support surfaces of the branches are resiliently pressed against a pair of external side contact surfaces of the loose top during operation, wherein the loose top is turnable into and out of engagement with the jaw of the basic body, wherein the two side contact surfaces of the loose top extend rearward from at least one clearance surface included in the front end, and a greatest diametrical dimension between the side contact surfaces in a first reference plane, which is perpendicular to the second center axis and situated nearer the front end than the rear end, is greater than an analogous diametrical dimension between the inner support surfaces of the branches when the branches are unloaded, and wherein each of the two peripherally situated branches include an inner support surface, a tangential support surface and a front end surface and, when the branches are unloaded, a first diametrical dimension between the inner support surfaces is equally great in an arbitrary reference plane, which is perpendicular to the first center axis, along a major portion of an axial distance from a first end of the inner support surface that is proximate the axial support surface to a second end of the inner support surface that is proximate the front end surface, and wherein the branches are deflectable, radially outward relative to the first center axis, from an unloaded position when a portion of the side contact surfaces of the loose top corresponding to the greatest diametrical dimension are turned to contact a portion of the inner support surfaces of the branches corresponding to the first diametrical dimension.