Sewer cleaning shoe with dam and jet nozzles

A sewer cleaning shoe comprising:

• a sled-like partly-cylindrical framework including skids for location in the invert of a sewer;
• transverse barrier means connected to said framework, said transverse barrier means being arranged to substantially fill the lower part of said sewer to form a dam extending across said sewer, said transverse barrier means having a top edge arranged below the top of said sewer, said transverse barrier means including a portion inclined to the vertical, whereby said top edge of said transverse barrier means is forward of its base;
• three elongate nozzles extending through said transverse barrier means adjacent its base, a centrally located and lowermost nozzle arranged to provide a jet of effluent extending in a direction parallel to an axis of said framework of said shoe and the two outermost nozzles arranged to provide jets of effluent which are angled downwards and slightly towards one another whereby all three jets of effluent converge towards said invert of said sewer;
• at least one projection attached to said framework and extending forwards in front of said nozzles with said projection arranged adjacent said invert of said sewer whereby said projection engages any accumulations of detritus or sedimentary matter in said invert of said sewer, a part of the flow of effluent carried by said sewer being jetted through said nozzles to scour detritus and sedimentary matter from said invert of said sewer and a part of said flow of effluent flow over said top edge of said transverse barrier means to entrain and carry away said scoured detritus and sedimentary matter, said location of said top edge of said transverse barrier means and that of said nozzles being arranged whereby said cascade of effluent overflowing over said top edge of said transverse barrier means falls in front of said jets of effluent produced by said nozzles.