| 摘要 |
Access equipment comprising an articulated boom arrangement (1, 3) for supporting a cage (11), in which a lower boom (1) and an upper boom (3) are pivotally connected (at 9) and the lower boom is pivoted (at 7) to a turntable platform (5) rotatable (about axis 53) with respect to a towable trolley portion (43, 41, 61), has a first ram (25) for moving the upper boom (3) relatively to the lower boom (1) and a second ram (29) for moving the lower boom relatively to the platform (5). With a view to avoiding the need to provide complex control gear, movement of the lower boom (1) under the control of its ram (29) is limited (conveniently by the stroke of the ram) so that, in its rest position, the lower boom (1) is arranged to extend upwardly with respect to the platform (5) at an angle theta such that, in operation, the booms (1, 3) are not movable into positions in which the equipment becomes unstable. |
