| 摘要 |
An access door is constituted by an outer framework adapted to be fitted in a rough opening formed in a building ceiling, wall, or the like, an inner framework set in an opening in the outer framework, a cover plate secured to the inner framework so as to close an opening in the inner framework, a pair of bearings and axis for pivotally connecting the inner framework to the outer framework, and a locking means for locking the inner framework to the outer framework when the inner framework closes the opening in the outer framework. The bearings are projected on one framework of the opposite inner surfaces of the outer framework and the opposite outer surfaces of the inner framework, and have U-shaped bearing surfaces. The axis are projected on another framework of the opposite inner surfaces of the outer surfaces of the inner framework, and pivotally supported to the bearings, respectively.
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