摘要 |
<p>Rock drilling equipment and drill string components (2;18) for top hammer drilling and down-the-hole drilling for positioning between a drill rig and a drill bit include a pipe-shaped element (3;19), which is arranged for transferring only rotational movements from the drill rig to the drill hit. A vibration-damping structure (12) is arranged adjoining to at least a part of an inside (11) of the pipe-shaped element in a space (41) formed inwardly of the inside (11).</p> |