| 摘要 |
A spring device comprises at least one elastic band which, in released or wound-up position, is rolled against the inside of an outer path and, in wound-up or released position, respectively, is rolled on the outside of a drum which is positioned within the outer path and is rotatable relative thereto. The band is adapted, as it is unrolled from the drum or vice versa, by the action of two or more members which are spaced at least substantially evenly along the periphery of the drum, to maintain its rolled-up position on respectively the outside of the drum and the inside of the outer path to a point from which it directly passes to, and is rolled up on respectively the inside of the outer path and the outside of the drum. |
