| 摘要 |
<p>The mechanism has a tubular casing (2) and a tubular electrical motor (3) that is equipped with a rotary driving shaft (4). A current generator (5) is utilized for providing electrical supply to the tubular electrical motor. An electronic unit (6) is provided for the tubular electrical motor. One of a set of rings (12, 14) is arranged interdependent of the shaft. The ring is freely rotated with respect to the casing. The rings have dimensions adapted to have external peripheral surfaces defining circumferential support zones overhanging with respect to circumference of the casing.</p> |
