| 摘要 |
A flat and centrally apertured wafer-like insert of cutting material provides a plurality of angularly spaced available cutting tips and is located edgewise against angularly related abutments upstanding from the inner edge of a supporting surface or platform against which the insert is clamped in the final seating in a conical end of the insert aperture of the mating conical head of a screw extending through the insert aperture and threading into a hole in the platform. The insert aperture is larger than the screw shank, and the outer end of the screw hole axis is inclined relative to the axis of the insert cone at a small angle and toward the abutment corner. As a result and in the final tightening of the screw after edgewise camming of the insert against said abutments, the screw shank bends laterally to allow seating of the coned screw head in the insert recess around substantially the full peripheries of the mating cones. |
