| 摘要 |
<p>Roll-up door comprising two door-leaves arranged to be wound onto and off a common roll-up roller. The door-leaves are kept spaced apart by a roller and a rigid profile member at the lower ends of the door leaves where the latter are interconnected. The rigid member is guided by carriages which are rotatably mounted at the member ends and travel in U-beams. Belts are secured to the carriages and are carried about a number of pulleys and are wound onto and off discs which are mounted on the same shaft as the roller onto which the door-leaves are wound on and off, whereby the door-leaves will be maintained tensioned and their weight balanced. Particularly in the case of wide and heavy doors a second tensioning device may be used to provide an additional balancing force. A weight acts on the roll-up roller in a direction counter to the direction of the action of the dead weight of the door-leaf on the same roller. The second tensioning device is applicable in both single and double door-leaf constructions.</p> |
