| 摘要 |
<p>A tandem windbar system for a flexible curtain rollup door (10) includes a first windbar (42) adapted to be guided in opposed guide channels (28, 30) of a door assembly and supported by flexible strap members (46a, 46b) which are secured at one end to a rotatable drum (12) for rolling a flexible curtain closure member (18) onto and off of the drum to open and close the door. Opposite ends of the strap members are secured to stationary structures, such as the upper ends of opposed guide channels for the door curtain and the first windbar. A second windbar (54) is supported below the first windbar by opposed flexible straps (58, 60) which are operably connected at one end to the first windbar by a bearing tube member (62) which may rotate relative to and is supported on the first windbar. The straps of the second set are trained around and support the second windbar and are connected at their opposite ends to the curtain drum for rolling onto and off of the drum. The second windbar ascends and descends at 1.50 times the speed of the first windbar during opening and closing movements of the door curtain to position the second windbar midway between the first windbar and the lower edge of the door curtain in the closed position. The second windbar is also positioned directly adjacent the first windbar is also positioned directly adjacent the first windbar in an open position of the door and directly below the curtain support drum.</p> |
