| 摘要 |
<p>PURPOSE: To easily ensure change in a mounting position and angle according to wear of an edge by enabling protrusion and rotation of an adjustable blade around a pivot from a conical back surface opposite to a cutting plane of a circular base. CONSTITUTION: An adjustable blade 40 around a pivot 42 is protruded from a conical back surface opposite to a cutting plane of a circular base 1 so as to be rotatable together with the base 1. At this time, according to wear of an edge, the blade 40 is rotated around the pivot 42, whereby the mounting position and angle to the base 1 can be changed easily. Otherwise, the blade 40 is formed as a disc 2 with a circular edge and attached adjustably to a notch or recess 10 in the conically tapered circumferential edge of the base.</p> |
