摘要 |
This supporting arm has two arm parallelograms which are connected to one another in an articulated fashion, are mutually balanced and each consist of at least two hollow rods (2, 3; 5, 6) which are connected pivotably at their ends to an articulated part (1, 4; 4, 7). One rod (3, 5) each of each arm parallelogram contains a spring element (13) whose one end is supported in the interior of said rod. The other end of each of the spring elements acts on a sliding member (15) which is displaceably arranged in the rod, which are connected via movable connecting means (14) to the respectively adjacent articulated part (7) or to the closest end of the neighbouring rod. This balancing permits satisfactory operation within a substantially larger range. <IMAGE> |