| 摘要 |
<p>A roller door including an elongate, flexible closure member (12), a hollow roller (13) to which one end of said closure member is secured, and means for rotating said roller whereby said closure can be wound onto said roller to open said door and unwound from said roller to close said door, said roller in use being positioned adjacent to the upper edge of the doorway, a spindle (16) extending in said roller (13), torsion springs (21) coupling the roller and the spindle for rotation together while affording limited relative rotation of the spindle and roller accompanied by corresponding stressing of the torsion spring (21), drive chains (34) extending parallel to the direction of movement of the closure member and being in driving engagement with said spindle and idler wheels (35) positioned in use adjacent the lower edge of the doorway and the free end of the closure member being secured to said drive chains (34) at points along the length of the drive chains (34) such that said torsion springs (21) are stressed in a direction to rotate said roller (13) relative to said spindle (16) to wind said closure member (12) into said roller and thus apply tension to the closure member between the roller and its point of anchorage on the drive chains (34), and a motor arrangement (27,28) for rotating the roller and thereby the spindle to wind or to unwind the closure member.</p> |
