Ribbed tubular structure and method of making same

Abstract From the Canadian patent

A pipe mate of fiberglass or the like includes a helical reinforcing member bonded to its outer surface substantially over its length with adjacent convolutions spaced with respect to each other. The reinforcing member or rib includes a filament-wound composite of a series of continuous resin impregnated glass filaments arranged in a bundle and surrounded by a helical fiber having spaced adjacent convolutions. An alternative construction further includes a core of paper or plastic or metal within the bundle to increase the rib height. An auxiliary bundle forming apparatus is employed with a filament winding machine so that the same winding machine and additional lengths of continuous glass …