Self restraining gasket and pipe joint

A pipe joint, comprising:

• a female iron pipe having a bell end opening with a circumferential recess for receiving a sealing gasket, the bell end opening being sized to receive the spigot end of a mating male plastic pipe having an interior surface and an exterior surface, the female iron pipe also having an external flange formed thereon;
• a self-restrained pressure gasket located within the circumferential recess provided in the bell end opening of the female iron pipe capable of both sealing the female iron pipe to the male plastic pipe and restraining the pipes in position, the gasket comprising:
• an annular gasket body made of a resilient elastomeric material, the annular gasket body having an inner circumferential region and an outer circumferential region, the inner circumferential region having a circumferential recess located therein;
• a relatively rigid ring located on the inner circumferential region of the gasket body within the circumferential recess of the gasket body, the ring having an inner circumferential surface, an outer circumferential surface and one opening at one circumferential location which creates one overall gap between opposing faces of the ring of a predetermined distance between the opposing faces when the gasket is in a relaxed state, the inner circumferential surface of the ring being at least partly exposed from the material of the gasket body;
• at least one row of gripping teeth located on the inner circumferential surface of the ring for engaging selected points on the exterior surface of the mating male plastic pipe;
• wherein the overall gap between the opposing faces of the relatively rigid ring is at least partly filled with a mass of rubber having opposite end regions which form a rubber partition between the opposing faces of the ring and wherein the opposing faces of the relatively rigid ring are spaced apart from at least one of the rubber end regions by a secondary gap in a relaxed state prior to assembly of the pipe joint;
• wherein the overall gap in the ring closes by a predetermined amount as the pipe joint is assembled, the distance between the opposing faces of the ring being selected to prevent the gripping teeth from engaging the exterior surface of the male plastic pipe prematurely before the gasket has been compressed enough to create a seal;
• and
• a circumferential gland fitting sized to be received about the exterior surface of the mating male plastic pipe for engaging the flange formed on the female iron pipe, the gland fitting having a forward lip region which contacts and compresses the gasket body as the joint is assembled.