Pipe gasket

A pipe gasket adapted for use in forming a pipe joint having a central longitudinal axis, the pipe joint being made up of an outer pipe having an annular groove adjacent a mouth opening thereof for receiving the gasket and an inner pipe inserted within the outer pipe, the gasket comprising:

• a unitary body having a first portion formed of relatively low durometer rubber to provide sealing against the outer pipe groove and having a second portion of a harder, less resilient plastic material, the second portion having a tapered entry surface on an interior surface thereof which joins an integrally formed band region, wherein the band region circumscribes the central longitudinal axis of the pipe and has a constant internal diameter with respect to the central longitudinal axis, the first portion of said unitary body also having an inwardly extending projection which extends directly from the constant internal diameter of said band region to define an annular conical sealing surface for said unitary body, said annular conical sealing surface providing an elongated deformation length which serves as a sealing area with respect to the inner pipe when the inner and outer pipes are assembled;
• wherein the less resilient, second portion of the unitary body has an exterior defined by a straight portion, when viewed in section, which is inclined in relation to the longitudinal axis of the pipe and which is adapted to directly contact the annular pipe groove adjacent the mouth opening thereof, the remainder of the exterior of the unitary body being comprised of said low durometer first portion which occupies the remainder of the annular pipe groove;
• and
• the harder, less resilient entry surface and band region being resistant to deformation so that the unitary body is securely maintained in the groove of the outer pipe during installation of the inner pipe.