| 摘要 |
A lifting device includes a framework (2) and a manipulator arm (8) pivotally connected to the framework. The manipulator arm includes a first end portion (19) and a second end portion (13) adapted to carry a tool (20). A balancing arrangement (7; 30, 39) includes a first part (7a; 30a; 39a) connected to the framework and a second part (7b; 30b; 39b) adapted to interact with the first end portion. At least one of the manipulator arm and the balancing arrangement includes a first balancing device (11; 31; 34), which is extendable to ensure that interaction between the second part and the first end portion is maintained. The first balancing device is adapted to generate a first balancing force which maintains a moment balance about the first joint. The manipulator arm has at least two rotational degrees of freedom in a first spherical coordinate system (17). |
