| 摘要 |
An adjustable manhole cover frame assembly suitable for mounting on a manhole basin upper section has an outer ring, capable of resting on the top surface of the upper section, and an inner ring engaging the outer ring by screw threads and having support for a manhole cover. The lower surface of the frame assembly has a part spherically curved surface resting on a similarly curved surface of the manhole basin upper section and which allows the orientation of the frame assembly to be adjusted. Also, the frame assembly itself may have parts with part spherical mating surfaces allowing an upper part to be adjusted for slope when the remainder of the frame assembly has been fixed.
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