Valve packing ring

Claim 1

A PACKING RING FOR USE IN A BALL VALVE INCLUDING A BODY, SAID BODY HAVING SPACED OPPOSED ANNULAR RECESSES FOR RECEIVING PACKING RINGS AND A BALL VALVE MEMBER ROTATABLY DISPOSED WITHIN SAID BODY BETWEEN SAID RECESSES, SAID PACKING RING BEING OF THREE PLY CONSTRUCTION AND COMPRISING A FIRST RING OF RELATIVELY HARD PLASTIC MATERIAL, A SECOND RING OF RELATIVELY SOFT PLASTIC MATERIAL, AND A THIRD RING OF RELATIVELY HARD PLASTIC MATERIAL, SAID RINGS BEING BONDED TOGETHER TO PROVIDE A UNITARY STRUCTURE, SAID FIRST AND THIRD RINGS HAVING A CYLINDRICAL OUTER PERIPHERAL SURFACE AND A SPHERICAL INNER PERIPHERAL SURFACE, SAID SECOND RING PROJECTING OUTWARDLY OF SAID OUTER PERIPHERAL SURFACE AND INWARDLY OF SAID SPHERICAL SURFACE AT SUBSTANTIALLY RIGHT ANGLES TO A TANGENT TO SAID SPHERICAL SURFACE, WHEREBY WITH SAID PACKING RINGS DISPOSED IN THE ANNULAR RECESSES OF THE VALVE BODY, SAID SPHERICAL SURFACES WILL ENGAGE THE BALL VALVE MEMBER TO PROVIDE BEARING SURFACES, THE PROJECTING PORTIONS OF SAID SECOND RING ENGAGING THE SURFACE OF THE BALL VALVE MEMBER AND A WALL OF THE RECESSES AND BE COMPRESSED TO PROVIDE A SEAL.