| 摘要 |
A hydraulic drill boom arrangement for drifting and tunnelling comprises a boom proper (10) that is universally pivotably carried by a support plate (13) and carries a feed beam (40) for a rock drill (41) at its outer end. Two hydraulic cylinders (16, 17) are coupled between the support plate and the boom and located on each side of the boom so that both cylinders are loaded by the weight of the boom, which makes the boom very stable in all positions. |
