Cutting tool assembly and cutting insert therefor

A cutting insert having a regular octagonal shape, the cutting insert having a top surface, a bottom surface and a side surface therebetween, the cutting insert being indexable about an axis of indexing symmetry (B) and reflection symmetric about a median plane (M), parallel to the top and bottom surfaces, wherein:

• each of the top and bottom surfaces meet with the side surface at eight cutting edges, adjacent cutting edges meet at a cutting corner, a land merges with the cutting edges and the cutting corners in each of the top and bottom surfaces, the land merges with a rake surface having edge portions adjacent cutting edges and corner portions adjacent cutting corners,
• a continuously extending tangential abutment surface merges with the rake surface in an inward direction of the cutting insert, said tangential abutment surface is further distanced from the median plane (M) than the cutting edges, flat, perpendicular to the axis (B) and ground, the tangential abutment surface has radially extending protrusions merging with each corner portion,
• clamping surfaces extend from the tangential abutment surface in an inward direction towards the axis (B) and towards the median plane (M) and are directed at an angle (β)with respect to the median plane (M),
• negative relief flanks which are ground merge with the cutting edges and the cutting corners in the side surface, and
• axial abutment surfaces which are ground and directed at an acute angle (γ) with respect to the median plane (M) extend inwardly from the relief flanks towards the axis (B) and merge at the median plane (M).

A cutting tool assembly having an axis of rotation (A) and comprising:

• a tool having a plurality of peripherally distributed insert receiving pockets, the tool comprising:
• a tool body having a front face divided into a peripheral portion having a periphery, and an inner portion, the peripheral portion having equally peripherally distributed substantially radially directed recesses;
• and
• a crown having a front face, a rear face, a peripheral side face between the front and rear faces, and a plurality of peripherally distributed generally radially directed insert receiving slots opening into the front, rear and peripheral side faces, the crown being distinct from the tool body and the tool being adjustable between a disassembled position in which the crown and tool body are separated from each other and an assembled position in which the crown is affixed to the tool body with the insert receiving slots of the crown merging with the recesses of the tool body;
• wherein:
• the insert receiving pockets comprise the insert receiving slots bound axially by the peripheral portion of the tool body front face, when the tool is in the assembled position;
• each insert receiving pocket has tangential, radial and axial abutment surfaces, being generally tangentially, radially and axially directed, respectively, the axial abutment surfaces being a portion of the peripheral portion of the front face of the tool body;
• and
• each insert receiving pocket is open in a radial direction so that at least a portion of the insert clamped therein extends radially beyond the tool.

A cutting tool assembly having a forward end, a rear end, and an axis of rotation A passing through the forward and rear ends, and comprising a tool having a plurality of insert pockets with an indexable cutting insert retained in each insert pocket;

• the tool comprising a disc-shaped crown secured to a tool body;
• the crown having a front face, a rear face having a rear abutment surface, an outwardly facing peripheral side face extending therebetween, and a plurality of identical receiving slots equally spaced about the axis A;
• each receiving slot is inwardly recessed from the peripheral side face and extends between the front and rear faces, and has an outwardly facing radial abutment surface and a tangentially facing tangential abutment surface extending from the radial abutment surface to the peripheral surface;
• the tool body having a generally forwardly facing front face having a front abutment surface and a peripheral portion having a periphery, the peripheral portion being inclined with respect to the axis A at an angle a rearwardly directed from the periphery;
• the peripheral portion having a plurality of recesses equally spaced about the axis A, each recess being a recessed portion of the peripheral portion and extending radially inward from the periphery;
• the crown is affixed to the tool body with its rear abutment surface bearing against the front abutment surface of the tool body and each insert receiving slot forms, together with a portion of the peripheral portion in the vicinity thereof, an insert receiving pocket, the portion of the peripheral portion including at least a portion of a given recess;
• each cutting insert having a top surface, an identical opposing bottom surface generally parallel to the top surface, a side surface extending between the top and bottom surfaces, an axis of symmetry B passing through the top and bottom surfaces, a median plane M generally parallel to the top and bottom surfaces about which the cutting insert has reflection symmetry, and a planar tangential abutment surface that is parallel to the median plane M on the top and bottom surfaces;
• each of the top and bottom surfaces meet with the side surface at edges, at least a portion of the edges forming a cutting edge;
• adjacent each cutting edge on the side surface is a relief flank and adjacent each relief flank is an axial abutment surface;
• each axial abutment surface extends inwardly from an associated relief flank towards the axis B at an acute angle γ with respect to the median plane M, each axial abutment surface has an associated reflection symmetric axial abutment surface;
• wherein for each cutting insert retained in each insert pocket, the tangential abutment surface of the cutting insert abuts the tangential abutment surface of the slot, a first section of the side surface of the cutting insert abuts a corresponding radial abutment surface, and a given axial abutment surface, of a second section of the side surface, abuts the peripheral portion adjacent the recess with the associated reflection symmetric axial abutment surface of the given axial abutment surface freely located in the recess.

A tool for milling having a forward end, a rear end, and an axis of rotation A passing through the forward and rear ends, and a plurality of insert pockets;

• the tool comprising a disc-shaped crown secured to a tool body;
• the crown having a front face, a rear face having a rear abutment surface, an outwardly facing peripheral side face extending therebetween, and a plurality of identical receiving slots equally spaced about the axis A;
• each receiving slot is inwardly recessed from the peripheral side face and extends between the front and rear faces, and has an outwardly facing radial abutment surface and a tangentially facing tangential abutment surface extending from the radial abutment surface to the peripheral surface;
• the tool body having a generally forwardly facing front face having a front abutment surface and a peripheral portion having a periphery, the peripheral portion being inclined with respect to the axis A at an angle c~ rearwardly directed from the periphery;
• the peripheral portion having a plurality of recesses equally spaced about the axis A, each recess being a recessed portion of the peripheral portion and extending radially inward from the periphery;
• the crown is affixed to the tool body with its rear abutment surface bearing against the front abutment surface of the tool body and each insert receiving slot forms, together with a portion of the peripheral portion in the vicinity thereof, an insert receiving pocket, the portion of the peripheral portion including at least a portion of a given recess.

A cutting tool assembly having an axis of rotation (A) and comprising:

• a tool comprising a tool body and a separate crown, the tool being adjustable between a disassembled position in which the crown and tool body are separated from each other and an assembled position in which the crown is affixed to the tool body;
• the tool body having a front face divided into a peripheral portion having a periphery, and an inner portion, the peripheral portion having equally peripherally distributed substantially radially directed recesses;
• and
• the crown having a front face, a rear face, a peripheral side face between the front and rear faces, and a plurality of peripherally distributed generally radially directed insert receiving slots opening into the front, rear and peripheral side faces, wherein:
• the insert receiving slots of the crown merge with the recesses of the tool body to thereby form insert receiving pockets, when the tool is in the assembled position,
• each insert receiving pocket having tangential, radial and axial abutment surfaces with the axial abutment surfaces being a portion of the peripheral portion of the front face of the tool body, and
• each insert receiving pocket is open in a radial direction so that at least a portion of the insert clamped therein extends radially beyond the tool.

A double-sided cutting insert having a regular polygonal shape, the cutting insert having a top surface, a bottom surface and a side surface therebetween, the cutting insert being indexable about an axis of indexing symmetry (B) and reflection symmetric about a median plane (M), parallel to the top and bottom surfaces, wherein:

• each of the top and bottom surfaces meet with the side surface at cutting edges, adjacent cutting edges meet at a cutting corner, a rake surface has edge portions adjacent cutting edges and corner portions adjacent cutting corners,
• a continuously extending tangential abutment surface merges with the rake surface in an inward direction of the cutting insert, said tangential abutment surface is further distanced from the median plane (M) than the cutting edges, flat, perpendicular to the axis (B) and ground, the tangential abutment surface has radially extending protrusions merging with each corner portion,
• relief flanks which merge with the cutting edges and the cutting corners in the side surface, and
• axial abutment surfaces which are ground and directed at an acute angle (γ) with respect to the median plane (M) extend inwardly from the relief flanks towards the axis (B) and merge at the median plane (M).