| 摘要 |
PURPOSE: An extension type waterproof iron cover is provided to periodically increase the height, instead of whole replacement, by replacing an extension ring. CONSTITUTION: An extension type waterproof iron cover(100) comprises a ring-shaped base seat frame(10), a ring-shaped upper seat frame(20), and an extension ring(30). The ring-shaped base seat frame is installed on an anchor bolt(3) in an opening(2) of a concrete manhole(1) of an underground structure or laminated on an existing cover plate seat frame(4) installed in the opening of the concrete manhole or an edge part(5) defining the opening. The ring-shaped upper seat frame is installed on the base seat frame by a coupling unit and has a ring-shaped seat part(21) in which a cover plate(90) can be placed. The extension ring comprises a plurality of upper brackets(33) in an upper edge part(31) and a plurality of lower bracket(34) in a lower edge part(32). |
