Cutting head for mounting on a tool holder in a self-clamping manner

A tool shank for co-axial coupling with a replaceable cutting head in a self-clamping fashion along a coupling axis to form a cutting tool assembly for rotary cutting operations, the cutting head having at least one cutting edge, the tool shank having a mounting portion mating with the mounting portion of the cutting head formed adjacent a trailing end thereof, the coupling axis forming an axis of rotation of the cutting head and of the tool shank about which each rotate in a given direction of rotation during a cutting operation, said mounting portion of the tool shank comprising:

• a positioning section, disposed at front face of the tool shank, said front face being oriented substantially perpendicularly to the axis of rotation and formed with wedge-like protrusions which are disposed peripherally and which extend and are spaced apart in a substantially circumferential direction, each wedge-like protrusion having a positioning surface, inclined with respect to the coupling axis, for the provision of axial support of the cutting head on the tool shank;
• a centering section in the form of an open-ended cavity extending rearwardly from the front face of the tool shank to a rear end of the tool shank along the axis of rotation, the centering section being substantially elongated in the axial direction and being formed with circumferentially spaced apart fixation wings separated by recessed portions, the fixation wings being axially spaced from the wedge-like protrusions, each fixation wing being formed with a peripheral centering surface, the peripheral centering surfaces being part of a common imaginary conical surface generally defining a peripheral centering surface of the centering section, the imaginary conical surface diverging rearwardly towards the rear end of the centering section.

A replaceable cutting head for co-axial coupling thereof, along a coupling axis, with a tool shank in a self-clamping fashion, the cutting head having a cutting portion with at least one cutting edge formed adjacent a leading end thereof and a mounting portion extending between said cutting portion and a trailing end of the cutting head and mating with a mounting portion of the tool shank;

• said mounting portion of the cutting head comprising:
• a centering section having a peripherally centering surface which extends circumferentially with respect to said coupling axis and has a substantially conical shape on at least two portions thereof, which portions diverge along said axis towards a broad end of the peripheral centering surface;
• a positioning section having at least two peripherally disposed and circumferentially extending and spaced apart positioning surfaces adapted for the provision of an axial support of the cutting head on the tool shank, each positioning surface being inclined with respect to said coupling axis so that an axial distance therefrom to said broad end of the peripheral centering surface increases in a direction generally corresponding to a direction of cutting forces acting on said at least one cutting edge during a cutting operation;
• one of the positioning and centering sections being formed with at least two circumferentially spaced apart fixation wings with, respectively, either said positioning surfaces and/or said portions of the centering surface belonging thereto, wherein
• said mounting portion of the cutting head is an integral part of a central body portion of the cutting head with the fixation wings being disposed adjacent the trailing end of the cutting head, and
• said positioning surfaces belong to wedge-shaped protrusions formed on a base surface, each positioning surface continuously merging with the base surface at a circumferentially leading end of one of said wedge-shaped protrusions and forming a step relative to the base surface at a circumferentially trailing end of said one of said wedge-shaped protrusions.