| 摘要 |
PURPOSE:To keep each portion such as a driving portion and so on from unnecessary load produced by balancing means by fixing a chain or wire through a balancing spring to a supporting point for hanging up a cantilever. CONSTITUTION:When with a chain 9 extended, an adjust nut 8 is adjusted, so that balancing force is worked upon the other end 1a of a cantilever 1 by a plate spring 7, the spring force for pushing down the other end 1a of the cantilever 1 with the plate spring 7 works equally to the weight of the general balance weight W3. As both ends of the chain 9 are fixed to the same rigid body integral with the cantilever 1 to be endless, when the cantilever 1 and a supporting point P are raised, the position of the plate spring 7 is also raised by the same distance. Therefore, there is no fluctuations in load of the chain 9, and the spring force of the plate spring 7 is not changed, so that the spring force W3 for balancing always works. Thus, a problem such as an increase in load of a driving motor or a hanging chain can be avoided, and the mechanism can be disposed above the second floor to reduce the installation space for the balancing means. |
