The invention relates to boltless pipe connectors suitable for attachment on or adjacent the end of a plain end pipe to enable coupling of said pipe to a further pipe, pump, valve, end cap or the like. These connectors are universal, that is they have a wide tolerance within a certain size range: pipes of a given nominal diameter do not all have the same outside diameter.
EP 727026 uses grease under pressure to grip and seal pipes as they are joined. This technology has been limited to small tolerances, typically 4 or 5 mm, in pipe diameter. The maximum movement of the grippers is approximately half thickness of the grippers or they would slip out of the container groove in the housing.
In the connector described and shown in the present application, a seal located in an annular recess in an inner surface of the connector has segmental grippers of L-shaped cross-section comprising a leg between the seal and a wall of the recess, and a foot having a serrated inner surface for engagement with the pipe. This allows for a tolerance exceeding 10 or 15 mm thereby allowing the pipe connection to be used with all pipes of a given nominal diameter.
A metal shim may be provided between the legs of the adjacent grippers. Grippers may be provided between one or each side of the seal and an adjacent wall of the recess. The housing is provided with an inlet for a sealing fluid which may be a nipple for the supply of grease or oil under pressure or components for the formation of an epoxy resin to make the seal permanent. The housing is generally provided with an air bleed offset from the sealing fluid inlet for use during assembly when the recess is filled with grease or oil as sealing fluid.