Patent ID: 8721235

Claim:
A drilling tool with a basic body ( 32 ) having a central axis of rotation ( 24 ) and with a drill bit ( 34 ) connected releasably to the basic body ( 32 ), the drill bit ( 34 ) having a coupling part ( 96 ) which is couplable to an end-face coupling receptacle ( 94 ) of the basic body ( 32 ) and which has at least two convexly curved centering portions ( 40 ) which are arranged so as to be distributed over the circumference and which engage with an exact fit into concavely curved centering portions ( 42 ), complementary to said convexly curved centering portions, of the coupling receptacle ( 94 ), and the coupling part ( 96 ) having at least one complementary driver stop ( 46 ) meshing with a rotary driver ( 44 ) of the coupling receptacle ( 94 ), and the centering portions ( 40 , 42 ) of the coupling part ( 96 ) and/or of the coupling receptacle ( 94 ) having, up to the mutual abutment of the driver stop ( 46 ) and of the rotary driver ( 44 ), tension faces ( 48 , 50 ) running toward one another in the manner of a rotary wedge opposite to a predetermined working direction of rotation, characterized in that the tension faces ( 48 , 50 ) of the coupling part ( 96 ) form circle segments ( 40 ′, 40 ″) which lie diametrically opposite one another and are eccentric with respect to the axis of rotation ( 24 ) and with respect to one another, the concave centering portions ( 42 ) of the coupling receptacle ( 94 ) form in cross section part circles concentric with respect to the axis of rotation and having a predetermined radius (R 1 ), and the convex centering portions ( 40 ) of the coupling part ( 96 ) have a part-circular guide portion ( 40 ′) concentric with respect to the axis of rotation, with a radius (R 1 ) corresponding to the receptacle-side radius (R 1 ), and a part-circular tension portion ( 40 ″) tangentially adjoining said guide portion and eccentric with respect to the axis of rotation, with a radius (R 2 ′, R 2 ″) larger than the receptacle-side radius (R 1 ), the eccentric tension portions ( 40 ″) of the coupling part ( 96 ) and the part-circular centering portions ( 42 ) of the coupling receptacle ( 94 ) bearing non-positively one against the other in their tension position.