| 摘要 |
A shank 1 has, at the front end of its drive shaft 2, a drive collar 3 formed substantially integrally with the drive shaft 2. The drive collar 3 is formed, centrally of its front side, with a boss 4 projecting therefrom, and has a bolt receiving through-hole 7 bored therein at a position spaced apart from the boss 4 and in parallel relation to the axis of the shank 1. The base 16 of a hole saw body 15 has a center hole 18 bored in a center portion thereof for engagement with the boss 4, and also has at least one threaded hole 20 bored at a position spaced apart from the center hole 18. A bolt 6 for thread engagement with the threaded hole 20 of the base 16 of the hole saw body 15 is received in the bolt receiving through-hole 7 of the drive collar 3 in order to lock the hole saw body 15 to the drive collar 3 and to transmit drive torque to the hole saw body 15. |
