| 摘要 |
An extractor for an increment borer, which consists of a tubular body having internally a cylindric portion, which at its forward end 3 transforms to a conic portion 6, and which borer on its outer surface is provided with bore threads. The extractor 2 comprises a cylindric tube, the outer diameter of which corresponds to the inner diameter of the increment borer 1, and the inner diameter of which corresponds to the smallest diameter of the increment borer 1 at the forward end 3 thereof. An indent 11, preferably a V-shaped indent, or a slit is located in the wall of the forward end 9 of the extractor 2, so that said forward end 9 is deformed plastically when this end is pressed against the said conic portion 6 of the increment borer 1. |
