Patent ID: 6179518
Filing Date: 2001-01-30
Classification: E02D

Abstract:
An adjustable manhole cover frame suitable for mounting on an annular top surface of a manhole basin, comprising:an outer ring having a base capable of resting on said top surface and having internal screw threads;an inner ring having external screw threads engaging said internal screw threads, and having support means for a manhole cover;said inner ring carrying screw jacks having lower ends suitable for contacting said top surface and capable of being rotated to lift the inner ring;whereby the inner ring may be rotated within the outer ring to adjust the height of the manhole cover support means, and whereby both screw jacks may be used both to stabilize the inner ring while the outer ring base remains close to, or in contact with, said top surface, and may also be used to lift both rings out of contact with said top surface when additional raising of the inner ring is required.