| 摘要 |
The manoeuvrable arm (4) at its outer end has a striker unit (5) with a support leg (6,8) for support against the ground (1), along which a machine-driven hammer (11) is movable arranged. The striker unit (5) is fixed to the arm (4) at its upper end, and is pivotable relatively to the arm (4) at least around a first articulated axis (16) in the arm longitudinal direction and around a second articulated axis (18), which crosses approximately at right-angles the first. - The striker unit (5) has its centre of gravity located so that with no other pivoting effect than that from gravitation it hangs vertically to the post longitudinal direction (2). The striker unit (5) is arranged rotatably (21) around its own longitudinal axis. |
