Pipe coupling

In a pipe coupling of the type comprising an elastomer sealing sleeve which is approximately C-shaped in cross-section and defines sealing lips which extend toward each other and are each supported on a sleeve web, and annular beads interposed between said lips and said web;

• a housing which surrounds the sleeve and which defines radial end walls and an axially extending longitudinal gap;
• a closure comprising tensioning bolts operative to constrict the housing;
• and an insert sheet which is inserted between the sleeve and the housing and bridges the longitudinal gap;
• wherein the sealing lips of the sleeve define first, larger dimensions before the housing is constricted and wherein it is possible for said sealing lips to be compressed in the circumferential direction and to be pressed snugly onto a pipe wall due to compression of the annular beads as the housing is constricted;
• the improvement comprising:
• an annular insert which is elastically flexible and constrictable in a circumferential direction but substantially rigid in the axial direction and which is supported with a base part against the sleeve web essentially over the full surface of the sleeve web;
• wherein the insert is constructed as a snap ring.

In a pipe coupling of the type comprising an elastomer sealing sleeve which is approximately C-shaped in cross-section and defines sealing lips which extend toward each other and are each supported on a sleeve web, and annular beads interposed between said lips and said web;

• a housing which surrounds the sleeve and which defines radial end walls and an axially extending longitudinal gap;
• a closure comprising tensioning bolts operative to constrict the housing;
• and an insert sheet which is inserted between the sleeve and the housing and bridges the longitudinal gap;
• wherein the sealing tips of the sleeve define first, larger dimensions before the housing is constricted and wherein it is possible for said sealing lips to be compressed in the circumferential direction and to be pressed snugly onto a pipe wall due to compression of the annular beads as the housing is constricted;
• the improvement comprising:
• an annular insert which is elastically flexible and constrictable in a circumferential direction but substantially rigid in the axial direction and which is supported with a base part against the sleeve web essentially over the full surface of the sleeve web;
• wherein the insert comprises a radially inwardly directed annular rib having an inside diameter which, in a unconstricted state of the coupling, is larger than a nominal diameter of a pipe to be coupled and, in a constricted state, is smaller than said nominal diameter;
• wherein the insert defines at least one circumferential section having an enlarged radius of curvature of the annular rib such that an inside diameter of the annular rib is correspondingly reduced.