| 摘要 |
<p>The mechanism opens and shuts a flexible screen in a greenhouse etc., the guard being wound on and off a shaft to which one of its ends is fixed. It has haulage components (M,2,4, 12) attached to the other end (6a) of the screen (6), so as to move it in opposite directions (t,s) for opening and shutting. A drive mechanism (7,13-15) incorporates one or more springs (15) exerting a constant return force, turning the shaft (5) so as to roll up the screen. The haulage mechanism can incorporate a long drive shaft and a reversible motor, ropes being attached to the shaft and reeved round pulleys to the screen end.</p> |
