Deformable sealing ring

Claim 1

A sealing ring for interposition between pipe sections with complementally formed portions comprising an annular body permanently deformed under pressure of said pipe sections, said body before deformation by said pipe sections having inner and outer surfaces and terminal surfaces at its ends, said terminal surfaces meeting the inner and outer surfaces at end edges, said body being of uniform thickness throughout its length, each of said inner and outer surfaces being continuously reversely curved from one end edge to another to form a convex surface and a concave surface joined at a point of inflection, the diameter of one end of said annular body being smaller than the diameter at the other end of said annular body, and the inner and outer surfaces being directed substantially parallel to the longitudinal axis of the annular body at each end edge, the average radius of curvature, in mm., Rm, of the inner and outer surfaces being expressed by the formula: Rm (b2 + c2 - 2bc cos theta /2(b cos theta - c))b being the half length in mm. of a line extending between the edge of the sealing ring furthest from the longitudinal axis of the annular body and the diagonally opposed edge nearest to the said axis, c being the half thickness in mm. of the seal and theta being the difference between 90* and the angle measured in degrees between said diagonal line and the said axis of the sealing ring.