Spigot-and-socket joint

1. A spigot-and-socket joint for connecting two pipes, pipe fittings or the like, having a longitudinal axis, comprising

a socket end which is assigned to one pipe and into which a spigot end of the other pipe, which has a support strip, can be inserted, the socket end having a radially inward-protruding edge with at least one ring segment-shaped recess, and

a locking device for locking the spigot end in the socket end, in that the support strip rests against the locking device and said locking device rests against the edge, the locking device comprising at least two ring segment-shaped locking elements,

wherein

at least four recesses are provided in the edge and are arranged with uniform spacing in the circumferential direction,

wherein the two locking elements each have two ring segment-shaped locking parts which are joined together via a respective web, the spacing between the two locking parts of each locking element corresponding to the spacing between two of the recesses, and further wherein the retaining element lies parallel to the web between the two locking parts and rests against the edge and thus prevents rotation of the locking element in the socket end.

2. The spigot-and-socket joint as claimed in claim 1 , wherein the web extends in the direction of the longitudinal axis and has at its end a lug which extends in the radial direction and lies parallel to the longitudinal axis, the lug being—when the locking parts are inserted—outside the socket end.

3. The spigot-and-socket joint as claimed in claim 1 , wherein the retaining element is made of a plastics material, preferably EPDM.

4. The spigot-and-socket joint as claimed in claim 1 , wherein the locking elements are made of metal, preferably a ductile cast iron, or a pressure-resistant plastics material.

5. The spigot-and-socket joint as claimed in claim 3 , wherein the retaining element conforms to the shape of the web and can be introduced into the recess beyond the lug.

6. The spigot-and-socket joint as claimed in claim 1 , wherein the socket end has on its inside a semicircular groove encircling in the circumferential direction and a circumferential surface which adjoins said groove and runs obliquely to the longitudinal axis, the groove and the circumferential surface being provided to receive a correspondingly embodied ring seal.

7. The spigot-and-socket joint as claimed in claim 6 , wherein the ring seal has a first longitudinal portion, which has an outwardly rounded (convex) surface, and has a second longitudinal portion which is embodied in a dovetailed manner, the first longitudinal portion serving as the retaining part and the second longitudinal portion as the sealing part.

8. The spigot-and-socket joint as claimed in claim 7 , wherein both the outwardly pointing and the inwardly pointing surface of the ring seal have—viewed in longitudinal section—a concave shape.

9. The spigot-and-socket joint as claimed in claim 6 , wherein the ring seal has a spring running in the circumferential direction in the region of the first longitudinal portion.

10. The spigot-and-socket joint as claimed in claim 9 , wherein the spring is vulcanized into the ring seal.

11. The spigot-and-socket joint as claimed in claim 1 , wherein the edge has a beveled inner ring surface, the angle between the ring surface and longitudinal axis of the socket end being approximately 30°.

12. A ring seal in combination with a spigot-and-socket joint for connecting two pipes, pipe fittings or the like, comprising a socket end which is assigned to one pipe and into which a spigot end of the other pipe, which has a support strip, can be inserted, the socket end having a radially inward-protruding edge with at least one ring segment-shaped recess, and a locking device for locking the spigot end in the socket end, in that the support strip rests against the locking device and said locking device rests against the edge, the locking device comprising at least two ring segment-shaped locking elements, wherein at least four recesses are provided in the edge and are arranged with uniform spacing in the circumferential direction, and the two locking elements each have two ring segment-shaped locking parts which are joined together via a respective web, the spacing between the two locking parts of each locking element corresponding to the spacing between two of the recesses,

wherein a longitudinal end of the ring seal is embodied in a dovetailed manner and the opposing other longitudinal end has an outwardly extending collar, and in that the outer and inner surfaces, which connect the two longitudinal ends, are—in longitudinal section—embodied in a concave manner,

wherein a retaining element is assigned to each locking element,

wherein the retaining element lies parallel to the web between the two locking parts and rests against the edge and thus prevents rotation of the locking element in the socket end.

13. The ring seal and joint combination as claimed in claim 12 , wherein a spring, which extends in the circumferential direction, is provided in the other longitudinal end.

14. The ring seal and joint combination as claimed in claim 13 , wherein the external end part of the dovetail is—in longitudinal section—configured in a flattened manner.

15. The ring seal and joint combination as claimed in claim 12 , wherein the external end part of the dovetail is—in longitudinal section—configured in a flattened manner.

16. A spigot-and-socket joint for connecting two pipes, pipe fittings or the like, having a longitudinal axis, comprising:

a socket end which is assigned to one pipe and into which a spigot end of the other pipe, which has a support strip, can be inserted, the socket end having a radially inward-protruding edge with at least one ring segment-shaped recess, and

a locking device for locking the spigot end in the socket end, in that the support strip rests against the locking device and said locking device rests against the edge, the locking device comprising at least two ring segment-shaped locking elements,

wherein at least four recesses are provided in the edge and are arranged with uniform spacing in the circumferential direction, and

wherein the two locking elements each have two ring segment-shaped locking parts which are joined together via a respective web, the spacing between the two locking parts of each locking element corresponding to the spacing between two of the recesses,

wherein the web extends in the direction of the longitudinal axis and has at its end a lug which extends in the radial direction and lies parallel to the longitudinal axis, the lug being, when the locking parts are inserted, outside the socket end; and further

wherein a retaining element is assigned to each locking element and the retaining element conforms to the shape of the web and can be introduced into the recess beyond the lug.