| 摘要 |
The herein disclosed system is composed of the circularly moving belt 1 encircling the pulley 6 by intervention of the elastic friction ring 5 and ending in a small-sized sheave 211 set at the tensioning member 21 fixed via spring 22 on the fixing member 20 screwed at a steady point. The spring 22 is in position to permanently stretch out the belt 1so that its adhesion via the friction ring 5 on the pulley 6 is conserved. At its entry point at the base 2, the front member 10 of the belt 1 passes through the blocking mechanism 203 allowing the unidirectional movement (downwards) of this member 10. Upon downward traction of the front member 10, the pulley 6 starts turning in conjunction with the belt 1 in order to wind up the rolling shutter3 around the shaft 7 while when the traction is stopped, the blocking mechanism 203 immobilizes the belt 1 and the pulley 6. Upon downward pressure the tension member 21, the spring 22 is compressed and the tension applied to the belt 1 is graduallyreduced along with the pressure force applied by the belt 1 to the friction ring 5. Thus, at a certain moment, the pulley 6 -under the weight of the rolling shutter 3 (deployment phase)-is commencing turning and the friction ring 5 is operating as afriction brake. Upon stopping of the pressure applied to the tension member 21, the adhesion between the friction ring 5 and the pulley 6 is reconstituted and the rolling shutter 3 stabilised at the position it is found. The same result is attained by upward traction exerted on the back member 11 of the belt 1. |
