Joints for pipes in a socket

Claim 1

In a join for a pipe in a socket wherein at least one sealing ring is detachably disposed near the socket entrance in an inner annular readiness space, the inside diameter of said sealing ring being smaller than the outside diameter of the pipe, a socket wall constriction is disposed adjacent to and inwardly of said inner annular readiness space, a second inner annular space is disposed inwardly of the wall constriction, as sealing ring space, and the spigot end of a pipe is inserted into the socket such that the sealing ring snaps and partially expands, said sealing ring being rolled out of the first inner annular space by frictional entrainment and being compressed by the socket wall constriction, the improvement wherein the inside diameter (D4) of said sealing ring space is approximately the same as the inside diameter (D5) of said readiness space, directly behind and closely adjacent to the sealing ring space (13, 14, 13'', 13'''', 130, 130'') an abutment (15, 15'', 15a, 15b) with an elastic sealing surface for the spigot end of the pipe is provided, and the socket wall constriction comprises a compression collar (11, 12, 11'', 11'''', 110, 110'') for the sealing ring (17, 17c) whose axial cross-sectional width is smaller than the cross-sectional diameter of the sealing ring, the spigot end of the pipe being inserted in the socket into engagement with said elastic abutment surface, whereby the sealing ring rolls over the compression collar suddenly with creation of an axial shock component and, after its partial expansion into the second sealing ring space, is pressed against a peripheral region of the compression collar away from the abutment by the counter-pressure produced by the elastic abutment surface on the spigot end.