| 摘要 |
A bi-fold door is equipped with door lifting devices operated with an electr ic motor drive to selectively open and close the door. The door lifting devices have winches operable to wind and unwind elongated webs connected at one end to rotatable members of the winches and anchored at the opposite end to the door. Anchors mounted on the door have adjustable sleeves operable to adjust the working lengths of the webs.< /SDOAB> |
