| 摘要 |
<p>The tool comprises a long, cylindrical tool rod (11) with a drill part (11a) on the tip and a fitting part (11c) to prevent its rotation, formed near the end opposite to the tip. A holder (12) has an engaging part (12a) which allows either end of the tool rod to be inserted detachably into it and engages with the fitting part to prevent the rotation of the tool rod and further prevents the insertion of the rod in excess of a specified let length. A sleeve part (13) is fitted loosely to the periphery of the tool rod, mounted to the holder to allow the tool rod to be secured to the holder. The inside diameter of the sleeve part is approximately equal to the diameter of a filling plug.</p> |
