AU4356399A

AU4356399A - Locked socket joint

Info

Publication number: AU4356399A
Application number: AU43563/99A
Authority: AU
Inventors: Pierre Holzherr; Christian Schmassmann
Original assignee: Von Roll Infratec AG
Current assignee: Von Roll Infratec AG
Priority date: 1998-07-09
Filing date: 1999-06-29
Publication date: 2000-02-01
Anticipated expiration: 2019-06-29
Also published as: DE59901515D1; AU745072B2; ATE217949T1; ES2177281T3; WO2000003171A1; EP1095225B1; EP1095225A1

Abstract

The invention relates to a socket joint for two pipe elements (1, 2) one of which has a spigot end (21) and the other an end with a sleeve (11), whereby the spigot end (21) of the one pipe element (2) is inserted into the sleeve (11) of the other pipe element (1). A sealing ring (3) and a retaining ring (4) embodied separately from the sealing ring are arranged in the sleeve (11). The retaining ring (4) has a plurality of retaining elements (42) which are positioned in the direction of circumference at a distance from each other and are arranged such that they are able to rotate in the sleeve (11). The retaining ring (4) further has a substantially compressed elastic ring (41) which exerts a torque force onto the retaining elements (42) which force permanently presses the side of the retaining elements (42) facing the spigot end (21) against said spigot end (21). Because the retaining elements (42) are rotationally arranged and are permanently pressed against the spigot end (21), said spigot end (21) is prevented at all times from carrying out a reverse movement.

Description

Axially secured plug-in spigot and socket joint The present invention relates to a plug-in spigot and socket joint having two pipeline elements as 5 is defined in the preamble of independent Patent Claim 1. The plug-in spigot and socket joint, in which the spigot of one pipeline element is plugged into the socket of the other pipeline element, is a known and 10 commonly used type of joint for pipeline elements, the joint being used, in particular, for cast pressure pipes, mouldings and fittings and having also proven successful for difficult operating conditions. Sealing between the socket and spigot normally takes place by 15 means of a sealing ring arranged therebetween. In order for it to be possible to absorb axially acting forces between the socket and spigot, additional locking means have to be provided. It is known, for example, from EP-B-0 526 373 20 to provide, within the basically elastic sealing ring of the plug-in spigot and socket joint, a multiplicity of rigid retaining elements which are spaced apart from one ~another in the circumferential direction, have inwardly directed teeth and, when the spigot is plugged 25 into the socket, are rotated outwards by the outer surface of the spigot, the elastic sealing-ring body being compressed in the process. The compressed elastic sealing-ring body ensures that the teeth butt constantly against the outer surface of the spigot. 30 Once the spigot has been introduced to the full extent into the socket and the pipeline elements have been subjected to pressure, axial forces which tend to move -2 the spigot out of the socket may occur. This movement is prevented by the rigid retaining elements, which butt against the socket, on the one hand, and the spigot, on the other hand. 5 Such plug-in spigot and socket joints having a sealing ring with integrated retaining elements have the disadvantage that the locking means and the sealing means cannot be installed and replaced separately. Moreover, the elastic sealing-ring body, which forces 10 the retaining elements against the spigot, is in constant contact with the spigot, which renders even slight deflections of the spigot in relation to the socket problematic since the friction is at a relatively high level and the elastic material is 15 simultaneously expanded in part and compressed in part, during the deflection, and there is a risk of the teeth of the retaining elements adversely affecting or destroying the elastic sealing-ring body. This results, inter alia, in the pipeline elements being harder to 20 install. A further disadvantage is that, when the spigot is plugged into the socket, the teeth of the retaining elements carve slits into the spigot, and it is possible for water to pass out through said slits during a slight rearward displacement of the spigot, 25 e.g. as a result of dilatation. Full sealing is thus no longer ensured. An example of a plug-in spigot and socket joint having a retaining ring which is formed separately from the sealing ring and has a multiplicity of rigid 30 retaining elements which are spaced apart from one another in the circumferential direction and have inwardly directed teeth is described in EP-B-0 235 818.

-3 The retaining elements have a convex outer lateral surf ace which, when axial forces occur, interact with an inner surface of the socket, said inner surface tapering conically to the end, and force the teeth 5 against the spigot. An elastomeric retaining part which is integrally formed on the retaining ring and can be secured at the end of the socket is intended to prevent the situation where the retaining ring, when the spigot is plugged into the socket, is drawn along therewith 10 and, when axial forces occur, together with the spigot, must first of all be moved back again to the conical inner surface before the latter forces the teeth of the retaining elements into the spigot and locks said spigot. Since, however, a certain axial displacement of 15 the retaining elements in the socket is necessary in order for it to be possible for the spigot to be plugged in, and the teeth are only forced into the spigot once axial forces have occurred, the locking action is delayed here as well. 20 Another example of a separate retaining ring is the axial-securing ring TKF-Z from Thyssen Guss AG, Gelsenkirchen/DE, of which the retaining elements, on the one hand, butt against the conical inner surface of the socket and, on the other hand, are kept in the 25 desired position between the socket and spigot by a thin lip ring. It is also the case with a plug-in spigot and socket joint with such a retaining ring that the teeth are only forced into the spigot once axial forces have occurred, as a result of which the locking 30 action is delayed. A similar plug-in spigot and socket joint having a separate retaining ring is disclosed in -4 DE-U-296 22 772. The retaining elements of said retaining ring have a retaining surface which is provided with teeth, is directed towards the spigot and is aligned parallel to the spigot both before and after 5 the spigot has been plugged into the socket. When the spigot is plugged into the socket, the retaining elements are displaced, on the one hand, axially and, on the other hand, perpendicularly to the axis, without being rotated. Once again, the teeth are only forced 10 into the spigot once axial forces have occurred, in the opposite direction. In view of the disadvantages of the previously known plug-in spigot and socket joints described above, the object of the invention is to provide a plug-in 15 spigot and socket joint of the type mentioned in the introduction which allows straightforward installation of the pipeline elements and in the case of which the locking of the spigot in the socket takes place as far as possible directly, without there being any risk of 20 the seal being destroyed or of the sealing being impaired. This object is achieved by the plug-in spigot and socket joint according to the invention as is defined in independent Patent Claim 1. Patent Claim 13 25 relates to a retaining ring for such a plug-in spigot and socket joint. Preferred variants can be gathered from the dependent patent claims. The essence of the invention is that, in the case of a plug-in spigot and socket joint having two 30 pipeline elements, of which one has a spigot and the other has an end with a socket and the spigot of one pipeline element is plugged into the socket of the other pipeline element, there being arranged in the socket a sealing ring and a retaining ring, which is formed separately from said sealing ring and has a multiplicity of retaining elements which are spaced 5 apart from one another in the circumferential direction, the retaining elements are arranged rotatably in the socket, and the retaining ring also has an essentially compressed elastic ring which subjects the retaining elements to a rotational force 10 which forces permanently against the spigot that side of the retaining elements which is directed towards the spigot. By virtue of the rotatable arrangement of the retaining elements and of the latter being forced 15 permanently against the spigot by means of the compressed elastic ring, the spigot is prevented from moving rearwards at any point in time. Moreover, the same retaining ring can be used for spigots of different diameters. Since the retaining ring is formed 20 separately from the sealing ring, the two can be installed or replaced separately. Furthermore, there is no risk of the sealing ring being adversely affected or destroyed by the retaining elements, and deflection of the spigot in the socket is more easily possible since 25 there is no need for any elastic parts with double function. In the case of a slight rearward displacement of the spigot, slits carved into the spigot by any tooth of the retaining elements do not result in water passing out since the sealing ring is arranged in the 30 socket in a spatially displaced manner. A further advantage of the plug-in spigot and socket joint according to the invention is that the socket need not -6 be provided with an inner surface which tapers conically to the end. This allows the plug-in spigot and socket joint to be kept short. In an advantageous variant of the plug-in 5 spigot and socket joint according to the invention, the retaining ring, rather than being a continuous ring, is interrupted at one location, it being possible for the elastic ring to be formed from a longitudinal profile. Such an open retaining ring can be placed more easily 10 in the socket. The plug-in spigot and socket joint according to the invention is described in more detail hereinbelow by way of twq exemplary embodiments and with reference to the attached drawings, in which: 15 Figure 1 shows a longitudinal section through a first exemplary embodiment of a plug-in spigot and socket joint according to the invention, which has retaining elements with teeth; Figure 2 shows a front view of the retaining ring of 20 the plug-in spigot and socket joint from Figure 1; Figure 3 shows a section through the retaining ring from Figure 2 along line A-A; Figure 4 shows the plug-in spigot and socket joint 25 from Figure 1 as the spigot is plugged into the socket; Figure 5 shows a longitudinal section through a second exemplary embodiment of a plug-in spigot and socket joint according to the invention, 30 which has a spigot with a weld bead; -7 Figure 6 shows a front view of the retaining ring of the plug-in spigot and socket joint from Figure 5; and Figure 7 shows a section through the retaining. ring 5 from Figure 6. First exemplary embodiment - Figures 1 to 4 In the plug-in spigot and socket joint illustrated, a pipeline element 1 has a socket 11 and a 10 pipeline element 2 has a spigot 21. The spigot 21 is plugged into the socket 11, a sealing ring 3 and a retaining ring 4 being arranged therebetween in inner grooves of the socket 11. For reliable mounting of the sealing ring 3, which seals the gap between the spigot 15 21 and socket 11, the inside of the socket 11 is provided with a profile. The retaining ring 4 comprises an elastic ring 41, twelve rigid retaining elements 42, which are distributed over the circumference of the elastic ring 41 and each have two teeth 421, and a 20 sealing-lip ring 43. The elastic ring 41, the sealing lip ring 43 and the sealing ring 3 are made, for example, of rubber, while the retaining elements 42 are made, for example, of metal, in particular stainless steel. 25 For the purpose of mounting the retaining ring 4, the socket 11 is provided with a retaining-ring inner groove 111, which is subdivided by an annular bead 112. The annular bead 112 and the end wall 113 of the socket bound an annular groove which is of 30 approximately semicircular cross section and in which the retaining elements 42 are mounted rotatably, that side of said retaining elements which is directed -8 towards the socket 11 being of approximately semi cylindrical design. The retaining elements 42 are guided in this way during the rotation. The retaining ring 4 is designed and mounted such that the elastic 5 ring 41 does not come into contact with the spigot 21. This means that the spigot 21 can easily be rotated through 40 or more in the socket 11, which facilitates the installation of the pipeline elements 1, 2. The sealing-lip ring 43 is formed integrally 10 with the elastic ring 41 and prevents dirt from passing into the gap between the spigot 21 and socket 11. At the same time, it also shows that the plug-in spigot and socket joint is provided with a retaining ring 4. It can be seen from Figure 4 that, when the 15 spigot 21 is introduced into the socket 11, the outer surface of the spigot 21 forces the teeth 421 of the retaining elements 42 outwards and thus rotates the retaining elements 42. The elastic ring 41 is thus compressed and consequently subjects the retaining 20 elements 42 to a rotational force which forces the teeth 421 of the retaining elements 42 permanently against the spigot 21. The rotational force to which each retaining element 42 is subjected is preferably more than 400 N, said force obviously depending, inter 25 alia, on the material of the elastic ring 41 and the geometrical conditions. ' The rotatable arrangement of the retaining elements 42 makes it possible to use the same retaining ring 4 for spigots 21 of different diameters. 30 -9 Second exemplary embodiment - Figures 5 to 7 This plug-in spigot and socket joint differs from the first exemplary embodiment essentially in that a weld bead 5 is provided over the entire circumference 5 of the spigot 21 of the pipeline element 2. This makes it possible to dispense with teeth for the retaining elements 42' of the retaining ring 4'. The elastic ring 41' corresponds, in principle, to the elastic ring 41 of the first exemplary embodiment, but 24, rather than 10 12, retaining elements 42' are arranged in it. A sealing-lip ring has been dispensed with here. The rest of the plug-in spigot and socket joint is analogous to the first exemplary embodiment. It is possible to realize further design 15 variations for the abovedescribed plug-in spigot and socket joint according to the invention and the following should be expressly mentioned here: - The retaining ring 4 according to the invention may also be easily combined with sealing rings of 20 other types not illustrated here. - The retaining ring, rather than necessarily being a continuous ring, may also be interrupted at one location. This makes it easier for the ring to be inserted into the socket. 25

Claims

1. Plug-in spigot and socket joint having two pipeline elements (1, 2), of which one has a spigot 5 (21) and the other has an end with a socket (11) and the spigot (21) of one pipeline element (2) is plugged into the socket (11) of the other pipeline element (1), there being arranged in the socket (11) a sealing ring (3) and a retaining ring (4; 4'), which is formed 10 separately from said sealing ring and has a multiplicity of retaining elements (42; 42') which are spaced apart from one another in the circumferential direction, characterized in that the retaining elements (42; 42') are arranged rotatably in the socket (11), 15 and the retaining ring (4; 4') also has an essentially compressed elastic ring (41; 41') which subjects the retaining elements (42; 4k') to a rotational force which forces permanently against the spigot (21) that side of the retaining elements (42; 42') which is 20 directed towards the spigot (21).

2. Plug-in spigot and socket joint according to Claim 1, characterized in that the elastic ring (41; 41') and the retaining elements (42; 42') are designed 25 and arranged such that the elastic ring (41; 41') subjects the retaining elements (42; 42') to a rotational force of in each case at least 250 N, in particular more than 400 N. 30

3. Plug-in spigot and socket joint according to Claim 1 or 2, characterized in that that side of the retaining elements (42) which is directed towards the - 11 spigot (21) has in each case a means which allows a firm grip on the outer circumference of the spigot (21), in particular teeth (421), protrusions, spikes or roughened areas. 5

4. Plug-in spigot and socket joint according to one of Claims 1 to 3, characterized in that a weld bead (5) is provided on the spigot (21), and this allows the force fit between the spigot (21) and the retaining 10 ring (4').

5. Plug-in spigot and socket joint according to one of Claims 1 to 4, characterized in that arranged on the retaining ring (4) is a sealing-lip ring (43) which 15 closes the gap between the spigot (21) and the socket (11).

6. Plug-in spigot and socket joint according to Claim 5, characterized in that the sealing-lip ring 20 (43) extends beyond the end wall (113) of the socket from the retaining elements (42).

7. Plug-in spigot and socket joint according to one of Claims 1 to 6, characterized in that the elastic 25 ring (41; 41') and the retaining elements (42; 42') of the retaining ring (4; 4') are arranged in a retaining ring inner groove (111) in the socket (11), it being possible for the retaining-ring inner groove (111) to be subdivided by an annular bead (112) between the 30 elastic ring (41; 41') and the retaining elements (42; 42'). - 12

8. Plug-in spigot and socket joint according to one of Claims 1 to 7, characterized in that that side of the retaining elements (42; 42') which is directed towards the socket (11) is of approximately semi 5 cylindrical design and is preferably mounted in a complementary part of the socket (11).

9. Plug-in spigot and socket joint according to one of Claims 1 to 8, characterized in that the elastic 10 ring (41; 41') and/or the sealing-lip ring (43) are/is made of rubber and/or the retaining elements (42; 42') are made of metal, in particular stainless steel.

10. Plug-in spigot and socket joint according to 15 one of Claims 1 to 8, characterized in that the retaining elements (42; 42') are made of a non conductive material, in particular dimensionally stable plastic or ceramic material. 20

11. Plug-in spigot and socket joint according to one of Claims 1 to 10, characterized in that the retaining ring, rather than being a continuous ring, is interrupted at one location. 25

12. Plug-in spigot and socket joint according to Claim 11, characterized in that the elastic ring is formed from a longitudinal profile.

13. Retaining ring (4; 4') for a plug-in spigot and 30 socket joint according to one of Claims 1 to 12, having a multiplicity of retaining elements (42; 42') which are spaced apart from one another in the - 13 circumferential direction, and having an elastic ring (41; 41') for subjecting the retaining elements (42; 42') to a rotational force.