Tool holder with nubs for clamping a cutting insert with notches

A cutting insert for a tool holder comprising a first side, a second side, a third parallel to the first side and a fourth side parallel to the second side, a first corner at an intersection between the first and second sides, a second corner opposite the first corner at intersection between the third and four sides, a third corner at an intersection between the first and fourth corner opposite the third corner at an intersection between the second and third sides, a top surface, a bottom surface, and a first notch formed in the first corner and a second notch formed in the second corner, the first notch including a first forward surface, a first rearward surface and a first root between the first forward surface and the first rearward surface, the second notch including a second forward surface, a second rearward surface and a second root between the second forward surface and the second rearward surface, the first and second roots being intersected by a plane that is perpendicular to a longitudinal axis of the cutting insert that intersects the third and fourth corners, a the first and second roots having a minimum radius,

• wherein the rearward surface of each notch engage a rearward surface of a respective nub on a curved nose portion of a clamp of the tool holder in such a way that only a forward lower face of the nose portion engages the top surface of the insert to exert a downward and rearward force on the insert when the clamp is brought into pressing engagement with the insert.

A method of clamping a cutting insert to a tool holder, the insert comprising a first side, a second side, a third side parallel to the first side and a first side parallel to the second side, a first corner at an intersection between the first and second sides, a second corner opposite the first corner at an intersection between the third and four sides, a third corner at an intersection between the first and fourth sides, a fourth corner opposite the third corner at an intersection between the second and third sides, a top surface, a bottom surface, a first notch formed in the first corner and a second notch formed in the second corner, the first notch including a first forward surface, a first rearward surface and a first root between the first forward surface and the first rearwards surface, the second notch including a second forward surface, a second rearward surface and a second root between the second forward surface and the second rearward surface, the first and second roots being intersected by a plane that is perpendicular to a longitudinal axis of the cutting insert, which intersects the third and fourth corners, the tool holder including a clamp including a curved nose portion with a forward lower face, the curved nose portion having a pair of nubs extending downward from the curved nose portion, the method comprising the steps of:

• placing the cutting insert within an insert-receiving pocket of the tool holder;
• aligning an aperture of the clamp with a clamp-securing bore of the tool holder;
• and
• inserting a clamp screw into the aperture of the clamp such that the clamp screw is at least partially received in the clamp-securing bore of the tool holder to bring the clamp into pressing engagement with the insert,
• wherein the pair of nubs of the clamp engage the pair of notches in the cutting insert to exert a downward and rearward force on the insert when the clamp is brought into pressing engagement with the insert, thereby securely clamping the cutting insert in the insert-receiving pocket of the tool holder.