| 摘要 |
<p>The present invention relates to a threaded coupling between a female extension member (12) and a male extension member (32) in a drill string for percussive drilling. The female extension member (12) is provided with an internal thread (18) and the male extension member (32) is provided with an external thread (34). The internal and external threads respectively are designed for engagement with each other. The present invention relates to a coupling sleeve (32) that can be safely secured in one (12) of the extension drilling tubes/rods.</p> |
