Patent ID: 7108295

Claim:
A composite coupling for use in assembling a restrained joint between a plurality of pipes having pipe ends and external complementary restraining grooves axially spaced from the pipe ends, the composite coupling comprising: a cylindrical composite body, the cylindrical composite body defining an axis and having a first end, a second end, an exterior surface and an interior surface; a first retainer groove in the interior of the coupling, the first retainer groove being axially spaced from the first end; a first port, the first port communicating between the exterior surface and the first retainer groove; a second retainer groove in the interior of the coupling, the second retainer groove being axially spaced from the second end; a second port, the second port communicating between the exterior surface and the second retainer groove; and, wherein the cylindrical composite body comprises a plurality of concentrically arranged layers of wound filaments in a thermoset plastic matrix, each of the layers characterized by a winding angle opposing the winding angle of the adjoining layers and wherein the winding angle is front 40 degrees to 65 degrees and the opposing winding angle is from −40 degrees to −65 degrees.