Reinforcement ring and seat for butterfly valve

Abstract

An annular, rigid reinforcement ring embedded in a body of molded elastomeric material forms a valve seat for a butterfly valve. The seat has a pair of diametrically aligned shaft openings for the valve disc supporting and actuating shaft. These holes extend through the elastomeric material and the reinforcement ring and, during molding of the elastomeric material, are occupied by removable cores which center the reinforcement ring about the cores between the end faces of the mold and position it concentrically between the inner and outer circumferential walls of the mold cavity. To prevent the reinforcement ring from rotating about the cores and to center it positively between the end faces of the mold, a pair of support extensions are provided aligned axially of the ring. One support extension protrudes from each edge or end face of the reinforcement ring. The pair of support extensions maintains proper alignment of the reinforcement ring with the end faces of the mold. These support extensions are located circumferentially along the reinforcement ring approximately halfway between the cores. A second pair of support extensions may be used, positioned from the first pair approximately diametrically on the reinforcement ring.

Dependencies are inferred from the claim text.