Composite pipe having an integral bell end

Claim 1

A discrete length of composite reinforced pipe comprising a generally cylindrical tubular portion defining a spigot end and an opposite integral annular bell end adapted to receive the spigot end of a similarly configured pipe therein, said cylindrical tubular portion including an inner liner defined by a resin impregnated surfacing veil extending the full length of said cylindrical tubular portion, an annular butting area formed circumferentially of said inner liner adjacent said bell end so as to define an annular surface for abuttment with the spigot end of a mating pipe inserted into said bell end, an inner layer of resin reinforced continuous fiberglass roving formed coaxially on the outer surface of said inner liner and butting area and extending axially forwardly of said butting area to define said bell end of the pipe, said inner layer comprising a plurality of concentric layers of continuous fiberglass roving and defining an annular seal receiving groove internally of said bell end, a sand-resin core layer of substantially uniform radial thickness disposed circumferentially about said inner layer along only said cylindrical tubular portion of said pipe so as to terminate generally at said bell end and not form a part thereof, said sand-resin core having a sand to resin weight ratio in the range of approximately 80:20 to 70:30, and an outer layer comprising a plurality of concentric layers of resin inpregnated continuous fiberglass roving disposed circumferentially about said core layer and the exposed surface of said inner layer defining said bell end so as to cooperate with said inner layer in defining said bell end.