| 摘要 |
PURPOSE:To promote the improvement of work efficiency, by placing a tool, mounted to an insertion shaft, to be surely positioned in the outer or the inner of the peripheral surface of a rotary shaft by its direction of rotation so that a position of the tool is set in accordance with a machining content. CONSTITUTION:When a rotary shaft 2 rotates in an arrow head direction C, an adaptation surface 8a of a power transmitting concave 8 is adapted to an adaptation surface 13a of a power transmitting protrusion 13, and a tool 12 is positioned in the outer of the peripheral surface of the rotary shaft 2. Next, when the rotary shaft 2 rotates in an arrow head direction D, the tool 12 is positioned in the inner from the peripheral surface of the rotary shaft 2. And the rotary shaft 2, externally fitting an inertia member 4, enhances the action of inertia force for an insertion shaft 3 enabling the tool 12 to be surely positioned even if the rotary shaft 2 generates a low rotary speed. Accordingly, the improvement of work efficiency can be promoted by permitting a workpiece to perform its boring work with no necessity for moving the workpiece to, for instance, a milling machine. |
