| 摘要 |
Access equipment of the kind comprising an articulated boom structure which consists of a first boom pivotally and preferably rotatably mounted on a vehicle or like supporting structure, and at least one further boom pivotally connected to the free end of the first boom, hydraulic actuating cylinders being provided for effecting relative pivotal movement of the booms one to the other, and both to the supporting structure, means being associated with each boom and movable therewith for transmitting movements of the booms individually and collectively to a plurality of stops which are thus movable to actuate control valves for the hydraulic actuating cylinders, the stops being arranged in response to movements of the booms and in accordance with permitted degrees of pivotal movement thereof to arrest operation of the actuating cylinders as appropriate to prevent the boom structure assuming a potentially unstable configuration. |
