| 摘要 |
PURPOSE:To facilitate the positioning of cutting tips, lessen the ununiformity among positioning pieces and make the suppression of run-out possible by a method wherein a rotary board is produced by laminating unit sheets so as to form a recess, which is peripherally on the same line with the outer peripheral end, by axially expanding their outer peripheral ends and, in addition, a positioning piece, which is to be inserted in the recess, is formed on the fixing surface of each cutting tip. CONSTITUTION:A rotary board 2 is produced by laminating formed sheets 10 and 12 as unit sheet to each other so as to be pasted together. The outer peripheral edges 32 and 34 of the respective formed sheets 10 and 12 are bent outwards nearly symmetrically so as to be expanded. Thus, a nearly V-shaped recess 38 having the radial depth of t1 is produced at the outer peripheral surface 36 of the rotary board 2. A positioning piece 40, which has a nearly triangular cross section and is to be inserted in the recess 36, is produced over the whole longitudinal direction on the fixing surface 8a of each cutting tip 8. Under the condition that cementing material 42 such as silver solder or the like is interposed between the outer peripheral surface of the rotary board and the fixing surface of the cutting tip, the positioning piece 40 is inserted in the recess 38 so as to easily position and fix the cutting tips 8 to the outer peripheral surface 36. |
