| 摘要 |
This invention relates to a device for driving a flexible protection element rolled up on a winding shaft, the free end of the element being connected through one or a plurality of flexible bonds to a winding drum. The winding drums and the winding shaft are coupled through reversible reduction gears to corresponding electric motors and to a pair of electromagnetic brakes of the type operating by current deficiency. The first motor is adapted to rotate in a first direction for rolling up the flexible bonds. The second motor is adapted to rotate in a direction opposite to that of the first motor for rolling up the flexible protection element. Electrical or electronic means are provided for actuating anyone of the two motors and simultaneously energizing the two brakes. This invention is applicable notably for driving protection tents, canvasses and the like in glasshouses, greenhouses and the like. |
