| 摘要 |
PURPOSE:To decide the outer-diameter of a tool held in a drill chuck by producing a signal proportional to the outer-diameter of the tool held in a drill chuck while providing means for holding sail value. CONSTITUTION:The flexible gear 5 of a motor machine tool is geared with the casing gear section formed at the tool body side of a casing 4 coupled at the outside of the body 3, and each tooth is determined such that when the diameter of the drill 1 has varied to the maximum diameter the relative rotary displacement between the casing 4 and the gear 5 will be within 360 deg.. The casing matching mark 8 and the gear matching mark 9 are marked on the casing 4 and the gear 5 in order to decide the optically or magnetically detectable relative rotary displacement. Consequently the diameter of the drill 1 held in the drill chuck 1 can be decided from the shift between both marks 8, 9. |
