| 主权项 |
1. A cutting tool comprising:
at least one indexable insert having a top chip breaking surface, a bottom mounting surface and a conical clearance surface extending between the top and bottom surfaces and intersecting the top surface to form therewith a cutting edge with a substantially circular extension, the insert comprising at least one flat lower portion disposed between the top and bottom surfaces such that a cross-section in a plane through the indexable insert parallel to the bottom mounting surface intersects both the flat lower portion and the conical clearance surface, the indexable insert having a center, a holder comprising at least one holder member having a bottom surface forming a seat for supporting the bottom surface of the insert and an upstanding wall forming part of a cone configured to form a lateral support for the insert, the holder member comprising at least one flat lower portion above the bottom surface such that bordering edges of the holder member when seen in the plane of the insert received in the holder member parallel to the bottom surface contain both the flat lower portion and the upstanding wall, and means for securing the insert to the holder, the upstanding holder wall and the insert clearance surface being designed so as to enable securing of the insert to the holder in a finite number of fixed relative positions,wherein in each relative position in the plane a first distance between the center and the lower portion of the insert is less than a second distance between the center and the lower portion of the holder member, which in turn is less than a third distance between the center and a curved portion of the upstanding wall laterally supporting the conical clearance surface. |
