Tool holder

Claim 1

In combination, a tool holder and a cutting tool insert of equilateral triangular shape having a cutting edge at each of the three corners thereof which extends transversely between the two opposite side faces of the cutter, said holder comprising a shank having a generally vertically extending recess at the forward end thereof, said recess being defined by two perpendicularly related walls, said forward end of the shank having a generally flat upper face portion, both of said walls extending to and intersecting said upper face portion, said one wall being disposed in a plane perpendicular to the plane of the upper face portion and said other wall being disposed in a plane inclined at an angle of 60* to the plane of said upper face portion, said insert being disposed in said recess with one of said opposite side faces in coplanar engagement with said one wall and one of said end faces in coplanar engagement with said other wall, said insert having a circular opening therethrough at the center thereof, a pin mounted in said holder and projecting outwardly from said one wall with its axis perpendicular to the plane of said one wall, said pin extending through the central opening in said insert and having a smaller diameter than that of the opening, clamp means mounted on said top face portion for urging said insert downwardly along said other wall, said pin being sufficiently smaller in diameter than said opening so that the contact area between the pin and the opening is located circumferentially of the pin between a line extending from the center of the pin perpendicular to said other wall and a second line extending from the center of the pin to the upper rear corner of the insert, whereby said clamp means applies a downward force on the insert to lock the insert in said recess by means of a wedging action between said pin and said other wall.