| 摘要 |
<p>An electrically operated roller door driving mechanism for operating a roller door curtain 20 comprising a reversible electrical motor (23) (not shown) fixedly mounted to one of the roller door curtain supporting drum wheels 18 and housed within the core of the roller door curtain, the motor and drum wheel being arranged to rotate simultaneously, and a ring gear (35) (Fig. 2, not shown) operatively associated with said motor via a reduction gear mechanism, the ring gear being capable of being held stationary with respect to the rotating drum wheel 18 but also being capable of rotating in unison with the drum wheel to thereby enable the roller door curtain 20 to be manually opened and closed by operation of a manually-releasable pin 45 in the event of a motor malfunction or power failure. <IMAGE></p> |
