Releasable plug-in socket pipe coupling

A plug-in socket coupling for pipes or pipe elements, comprising a socket member receiving at least one pipe end and which has in its interior, a radially inwardly directed projection, at least one circular groove for a packing, a passage opening, a chamber, a retaining element in said chamber fixing the pipe end which can be inserted up to the projection, wherein said retaining element comprises individual segmental portions, which largely embrace the pipe end and an elastic retaining ring in the chamber maintaining said segmental portions under pretension, each portion being tiltably supported with a top portion on the outer circumferential surface of the chamber and on the side facing the pipe end surface is provided with a base portion having at least a first cutting edge and wherein an axially movable release ring is arranged in operative connection to the retaining element and which is axially displaceable to pivot the tiltable portions into the release position.