| 摘要 |
<p>The drill head (1) is of a cylindrical shape and has a cylindrical extension (15) of a smaller diameter for being joined to the shaft. It is provided with a specifically shaped lateral area for joining a cutting unit (7). An elliptical projection (3) is positioned on top of a circular contact surface, matching the shape of a recess in the element (7) holding the cutting blade. The element (7) is secured with a threaded bolt (12) guided through a bore in the center.</p> |
