Method of making composite pipe having an integral bell end

A method of making a composite reinforced plastic pipe having a generally cylindrical tubular portion defining a spigot end and an opposite integral bell end adapted to receive the spigot end of a similarly configured pipe therein;

• said method comprising the steps of forming an annular inner liner or resin impregnated surfacing veil defining an axial passage having a first tubular portion of substantially uniform cylindrical cross section, forming an annular butting area circumferentially of said inner liner adjacent said bell end so as to define an annular surface for abutment with the spigot end of a mating pipe inserted into said bell end, forming an inner layer circumferentially of said inner liner by winding a resin impregnated continuous fiberglass roving helically on the outer surface of said inner liner and continuing said inner layer axially beyond one end of said inner liner and said butting area to form a second tubular portion defining said bell end, said inner layer defining an internal annular seal receiving groove in said bell end, forming a core layer of sand-resin composition circumferentially about and directly on the outer peripheral surface of said inner layer, said core layer being of substantially uniform cross section and formed along the length of said first tubular portion but terminating at said bell end so as not to form a part of said bell end, said sand-resin composition having a sand to resin weight ratio in the range of approximately 80:20 to 70:30, forming an outer layer of a plurality of lays of resin impregnated continuous fiberglass roving circumferentially about said core layer and the exposed surface of said inner layer so as to cooperate with said inner layer in defining said bell end, and curing the resulting composite pipe to effect bonding between the various layers.