| 摘要 |
A method and apparatus for maintaining a ring-like support in a predetermined location are disclosed herein. Both the method and apparatus are especially suitable for maintaining a ring-like luminaire support centered about a post as the luminaire support is moved up or down the latter. This is accomplished by providing a plurality of location maintaining arrangements which apply forces to the support for maintaining it in a centered position. These force imparting arrangements are interconnected to one another such that off-center movement of the luminaire support causes one or more of the arrangements to act in restoring the latter to its original position while, at this time, the remaining arrangements are automatically and temporarily removed so as not to interfere with the recentering function of the acting arrangements. |
