Abstract: The multiple channel duct assembly for cables includes a plurality of plastic inner ducts (10) contiguous, co-directionally extending, substantially parallel, and in abutting contact with each other. Each of the inner ducts (10) has a cross sectional area sufficient to contain at least one cable. A plastic outer duct (20) encircles the inner ducts over their entire length to retain them in their contiguous relationship. The outer duct (20) has a corrugated tubular section including a plurality of contiguous ridges (21) and troughs (22) extending over their entire length. The assembly is sufficiently flexible that it can be coiled around transportable reels as well as sufficiently strong that it can withstand dirt in a trench.

Abstract: The present invention resides in that a plurality of pre-molded inner ducts are fed to a cross-head die, and a melted outer duct is extruded around the inner ducts from the cross-head die, and then the pre-molded inner ducts and a melted outer duct are supplied into the corrugated tunnel of a molding die in which a melted outer duct is molded to have corrugations, thus producing a multiple channel duct assembly which includes a plurality of elongated inner ducts and a corrugated outer duct which encircles the inner ducts over their entire length to retain them. This method of continuously manufacturing a multiple channel duct assembly by using an extrusion molding machine with a cross-head die and a molding means has not been known heretofore.