Lifting device for use at a manual work station

A lifting device (1) for use at a manual work station, the lifting device (1) comprising:

• a framework (2);
• an elongate manipulator arm (8) pivotally connected to the framework (2) by a first joint (9), which elongate manipulator arm (8) comprises a first end portion (19) and a second end portion (13) located on opposite sides of the first joint (9) as seen in the longitudinal direction of the manipulator arm (8), wherein the second end portion (13) is adapted to carry at least one tool (20);
• a balancing arrangement (7;
• 30, 39) comprising a first part (7a;
• 30a;
• 39a) connected to the framework (2), so that said framework (2) connects the first part (7a;
• 30;
• 39a) of the balancing arrangement (7;
• 30, 39) and the first joint (9), and a second part (7b;
• 30b;
• 39b) connected to the first end portion (19) of the manipulator arm (8),
• wherein the balancing arrangement (7;
• 30;
• 39) comprises a first balancing device (11;
• 31;
• 34), which first balancing device (11;
• 31;
• 34) is extendable to ensure that the interaction between the second part (7b;
• 30b;
• 39b) of the balancing arrangement (7;
• 30;
• 39) and the first end portion (19) of the manipulator arm (8) is maintained when the manipulator arm (8) is rotated about the first joint (9), and which first balancing device (11;
• 31;
• 34) is adapted to generate a first balancing force which, through the interaction between the first end portion (19) of the manipulator arm (8) and the second part (7b;
• 30b;
• 39b) of the balancing arrangement (7;
• 30;
• 39), maintains a moment balance about the first joint (9) with respect to the gravitational force acting on the manipulator arm (8) so that the gravitational force is counteracted by the balancing arrangement that acts to rotate the manipulator arm about the first joint in the opposite direction, and
• wherein the first joint (9) provides the manipulator arm (8) with at least two rotational degrees of freedom relative to the framework (2) at the first joint (9) in a first spherical coordinate system (17) which has a center point that coincides with the rotational center of the first joint (9).