SUB-DUCT FOR CABLES

摘要

A collapsible sub-duct (101) for holding a cable (2) within a main duct (4), comprises an elongate tubular member having an outer wall (112) and within the outer wall an interior volume (108) extending along the length of the tubular member for holding the cable. The wall is formed from a polymeric material and has a plurality of longitudinally extending lines of flexibility (110, 110'), these lines defining a plurality of panels (114, 114') in the material. The lines of flexibility allow each of the panels to be folded and unfolded with respect to each other along the lines of flexibility. In use, the panels can first be folded to reduce the interior volume and thereby aid insertion of the sub -duct into the main duct and then unfolded to expand the interior volume to aid insertion of a cable down the length of the interior volume, and then folded again to reduce the interior volume and thereby reduce the volume occupied by the sub -duct in the main duct.