Abstract: In order to ensure that a manhole/inspection cover or grating is firmly seated in a road or other surface within which it is installed and is substantially non-rocking, it is supported on opposite sides by two frame members each of which comprises two seating blocks joined together by an elongate bar. The seating blocks have angled seating faces which are inclined downwardly towards each other and which are engaged by correspondingly inclined angled faces on the cover or grating. Furthermore the bar is provided with an additional angled seating face which is inclined in a direction transverse to the longitudinal axis of the bar and is engaged by one or more correspondingly inclined angled faces on the cover or grating. Optionally the or each frame member is double-sided, that is it incorporates a respective additional angled seating face on each side of the bar, so as to support two covers or gratings in side-by side relationship.

Abstract: A frame, for a manhole/access cover and frame assembly, has outer peripheral portions which are generally of inverted U-shape in cross-section, and the outer surfaces of the peripheral portions, forming the outer limb of the inverted U, are formed with a plurality of apertures or cut-outs to facilitate the flow of concrete into the space within the peripheral portions to bed the frame securely into the concrete.

Abstract: In a manhole/access cover and frame assembly the cover is supported on the frame by pairs of downwardly facing, oppositely inclined support surfaces on the cover which are engageable respectively with corresponding upwardly facing, oppositely inclined support faces on the frame, and the cover has a substantially continuous downwardly facing ridged peripheral sealing surface which, when the cover is supported on the frame, overlies a substantially continuous upwardly facing ridged peripheral sealing surface on the frame. The engagement between the aforesaid support surfaces so locates the cover with respect to the frame that ridges on the sealing surfaces are interleaved but are held out of supporting contact with one another along substantially the whole of their length, so that the tortuous path between the ridges may be packed with grease to provide a gas and water tight seal.

Abstract: In order to span an access pit or manhole having a clear opening of relatively large area, one or more I-section steel beams are laid across the opening so as to divide the area to be covered into a number of smaller areas. One or more frame members, each of which is shaped so as to support parts of two covers or gratings which are adjacent and on opposite sides of the associated beam, are then positioned directly above the center line of the or each beam and bolted to the beam. Finally the areas between the or each beam and the sides of the pit or manhole, and between the beams themselves, are covered by covers or gratings supported by the frame members. Such an arrangement ensures that eccentric loading of the beams does not occur under heavy loading conditions.