| 摘要 |
<p>The boring tool is for making of recessed and conical bores. The tool has a copying mandrel, used pref. for boring of concrete, stone and for making boreholes in the ground. The boring tool has a shank with guides for accommodating cutters. These cutters slide, on making of the conical anchoring bores, over the copying tapered mandrel at the end of the boring arrangement. On sliding these cutters cut a conical bore of correct shape from the cylindrical bore. Instead of the tapered mandrel can be used also separate guiding segments. The protection tube of the boring tool has a spring for returning the spreading arm with cutters into its original position.</p> |
