| 摘要 |
An overhead bi-fold door assembly comprises an upper door frame and a lower door frame foldable relative to one another about a horizontal axis so as to be operable between a closed position and an open position in which the bottom end of the lower door frame is raised upwardly towards the top end of the upper frame member in relation to the closed position. Hinges which pivotally support the door each include a pair of leaves joining respective sets of knuckles in which the leaves span plural structural members of the respective door frames to provide added structural support to the door frames. Bushings are supported in the knuckles to receive the respective horizontal hinge pins of the hinges therein.
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