Nondestructive system for adjusting manhole and catch-basin elevations

An assembly for adjusting the elevation of a catch-basin structure for incorporation into a road construction, the assembly comprising:

• a generally rectangular base rim comprising a generally rectangular outer wall and a support shoulder on an inside of the outer wall spaced from a top edge of the outer wall and extending laterally inward from the outer wall;
• a generally rectangular adapter configured to fit with the base rim and to receive and support a cover at an elevation above the top edge of the outer wall of the base rim, the adapter comprising a lower member positionable within the outer wall of the base rim and on the support shoulder, and an upper member extending laterally outward from the lower member and over the top edge of the outer wall of the base rim and extending upwardly above the top edge of the outer wall of the base rim to form an upward extension of the outer wall of the base rim, at least one adapter protrusion which connects the upper and lower members, and the cover having at least one indentation dimensioned to fit with the adapter protrusion.

An assembly for adjusting the elevation of a catch basin structure having a base rim surrounded by pavement, the base rim comprising a generally rectangular outer wall and a support shoulder extending inwardly from the outer wall and spaced from a top edge of the outer wall, the assembly comprising a generally rectangular catch basin cover, an adapter formed in a single piece to support the catch basin cover thereon, the adapter having upper and lower members, the lower member being receivable within the outer wall of the base rim to be supported by the support shoulder, the upper member extending laterally outward from the lower member, and extending upwardly relative to the top edge of the outer wall to form an upward extension of the outer wall, interconnections between the lower and upper members of the adapter, the catch basin cover having indentations which fit around the interconnections between the lower and upper members of the adapter, whereby the elevation of the catch basin structure may be increased by installation of the adapter between the base rim and the catch basin cover.

An adjustable catch basin assembly comprising:

• a base rim having a generally rectangular outer wall and a support shoulder which extends inwardly from the outer wall and spaced from a top edge of the outer wall, the support shoulder having at least one raised step;
• a cover dimensioned to fit within the base rim and contact the support shoulder, the cover having at least one indentation which fits with the at least one raised step of the support shoulder, and
• an adapter having upper and lower members, and at least one structural connection between the upper and lower members, the lower member being receivable within the outer wall for contact with the support shoulder of the outer wall, the upper member located laterally outward from the lower member for contact with the top edge of the outer wall, the indentation in the cover fitting with the at least one structural connection between the upper and lower members.

A height-adjustable manhole assembly, comprising:

• a generally circular base rim surrounded by pavement, the base rim comprising a generally circular outer wall and an annular support shoulder on an inside of the outer wall and extending toward a center of the base rim, the support shoulder having at least one raised step;
• and a cover having at least one indentation which fits with the raised step in the support shoulder of the base rim, and
• a generally circular adapter which fits with the base rim and supports the cover, the adapter comprising a lower member positionable within the outer wall of the base rim and supported by the support shoulder, and an upper member extending laterally outward from the lower member and extending upwardly from the top edge of the outer wall to form an upward extension of the outer wall, wherein the lower member includes at least one structural connection which extends upwardly to connect the upper and lower members, the at least one indentation in the cover fitting with the at least one structural connection of the adapter.