초록 ▼

A liner for a manhole, inspection chamber or the like comprises one or more sections moulded from synthetic plastics material. The or each section comprises inner and outer skins (2,3) joined together by two series of webs (4,7) extending between and at right angles to the skins (2,3). The webs (4)

A liner for a manhole, inspection chamber or the like comprises one or more sections moulded from synthetic plastics material. The or each section comprises inner and outer skins (2,3) joined together by two series of webs (4,7) extending between and at right angles to the skins (2,3). The webs (4) are disposed at the upper edges (5,6,) of the section and the webs (7) extend between a position below those upper edges (5,6) and a position at its lower end. The upper edges (5,6) and lower periphery (9) of each section are formed so that superposed sections interlock. The arrangement provides an easily installable corrosion resistant load bearing yet light, rigid and deformation resisting structure.

대표청구항 ▼

[What is claimed is:] [1.]one or more sections molded from a synthetic plastics material, each section comprising inner and outer skins joined by a first series of webs and a second series of webs, each series of webs extending between the inner and outer skins so as to provide a substantially rigid

[What is claimed is:] [1.]one or more sections molded from a synthetic plastics material, each section comprising inner and outer skins joined by a first series of webs and a second series of webs, each series of webs extending between the inner and outer skins so as to provide a substantially rigid deformation resistant structure with first and second opposing ends formed to interlock with any adjacent section,wherein the first series of webs alternates with and is displaced from the second series of webs, one end of the webs of the first series disposed adjacent the first end of the section, and the webs of the second series extending between a position displaced from the first end of the section to the second end of the section.