Split tank closure and diaphragm assembly

Claim 1

A hydropneumatic filament wound pressure vessel having a split tank closure and diaphragm assembly comprising first and second cup shaped plastic tank liners, said liners having oblate ellipsoidal end portions and cylindrical sidewall portions terminating in circular open mouth portions, said sidewall portions having recessed end portions, ring means for joining and sealing the open mouth portions together to form a sealed container, said ring means being defined by a cylindrical outer surface having an outside diameter corresponding to the outside diameter of the cylindrical sidewall portions of the liners, being defined by a pair of spaced intermediate cylindrical surfaces having end portions and an outside diameter corresponding to an inside diameter of the recessed end portions of the cylindrical sidewall portions of the liners, being defined by circumferential recesses at the end portions of the intermediate circumferential surfaces, and being defined by a pair of conical surfaces joining the cylindrical outer surface and the spaced intermediate surfaces and tapering radially inwardly toward each other from the outer surface to the intermediate surfaces, the open mouth portions being telescopically received on the intermediate circumferential surfaces and having end edges tapered to conform to said conical surfaces, an interface between the inner surface of a liner and one of said intermediate surfaces and an interface between the inner surface of a liner and the other one of said intermediate surfaces, the inner surfaces of said recessed end portions of said liners and said circumferential recesses forming a pair of circumferential grooves, an O-ring seal in one of said grooves sealing the interface between the inner surface of a liner and one of said intermediate surfaces, a flexible diaphragm separating the interior of said liners into discrete variable volume pressure chambers, the periphery of said diaphragm having a bulbous portion and being received in the other of said grooves sealing the interface between the inner surface of a liner and the other one of said intermediate surfaces, and a resin impregnated filament winding covering the liners and the outer cylindrical surface of said ring means in a predetermined winding pattern.