| 摘要 |
A molded plastic extension member for use in increasing the height of manholes, or catch basins when surfacing or resurfacing a roadway. The extension member may be formed having a sloping upper planar support surface to thereby adjust the angle of the catch basin support frame or the manhole cover support frame. An outer surface of the extension member includes indicia that allows the user to align the slope of the upper planar support surface parallel with the roadway surface. When several sloped extension members are stacked, the indicia may be used to create a complex angle of slope relative to the underlying base members vertical axis. The extension member includes a pocket adaptable for receiving and retaining mortar between two stacked extensions. Planar surfaces may extend from both the upper and lower edge of the extension member, thereby providing support and added stacking surface for the stacked extension members. The extension member also includes a tapered shoulder that interlocks with either the manhole cone, the catch basin cone, or with other stackable angled plastic members. |
