| 摘要 |
<p>The stone boring tool has a cutting head (1) with a body part (4) having a conical cutting face (3) at the front, carrying cutting edges, where the body part is elliptical. The rear of the body (4) is stepped, and has a smaller diameter portion (2) which is welded into a blind hole in a circular section boring bar (5). The head is brazed into this hole. In an alternative design, the head carries the blind hole, and a spigot on the boring bar fits into the hole. The ratio between the smaller diameter and the larger diameter of the ellipse is between 1:1.1 and 1:1.7.</p> |
