A connector for sealing the end of a pipe and a sealing tube insert for such a connector

Abstract

Connector for sealing the end of a pipe P comprising a main body (10) with inwardly extending shoulder to provide an insert end stop (23), and an outer diameter O-ring seal (20) to seal with an outer diameter of a sealing tube insert (1). A gripper (13,14,15) to grip the pipe. The sealing tube insert (1) seals between the main body (10) and the pipe P and has a first end (5) to fit within the pipe and a larger second end (6) such that the distal end of the second end fits within the main body. An inner diameter O-ring seal (8) surrounds the first end to seal with the inner diameter of the pipe P. When the sealing tube insert (1) is fully inserted against the insert end stop (23), the outer diameter O- ring seal (20) seals against the outer diameter of the insert (1).

Description

[0001] A CONNECTOR FOR SEALING THE END OF A PIPE AND A SEALING TUBE INSERT FOR SUCH A CONNECTOR

[0002] The present invention relates to a connector for sealing the end of a pipe and a sealing tube insert for such a connector.

[0003] The connector and insert have been specifically designed to address a problem which arises in a multi-layer composite pipe. However, they can be used to seal the end of any type of pipe.

[0004] A multi-layer composite pipe suffers from a particular problem in that, if the end of the pipe is exposed to water, the layers of the composite pipe can delaminate which ultimately can lead to the pipe wall bursting.

[0005] In order to address this problem, a sealing tube insert is inserted into the end of the pipe. The insert has a narrower part with an inner diameter (ID) O-ring seal which is inserted into the pipe to seal on the inner diameter of the pipe, and a wider part provided with an outer diameter (OD) O-ring seal which seals against the inner wall of the main body of the connector. The connector may also have a second O-ring seal within the main body of the connector to seal against the pipe.

[0006] A difficulty arises in that, because of the way it is moulded, the inner wall of the main body of the connector may not always have a smooth surface. This is the wall engaged by the OD seal of the insert. As such this does not always form a reliable seal. A solution to this problem would be to create a main body with a smooth moulded inner wall surface.

[0007] However, this would require completely redesigning the mould tooling for the main body of the connector which is prohibitively expensive.

[0008] As a result of this, there is an unacceptably high risk that liquid will leak past the OD O-ring seal on the insert. This liquid will not leak from the connector if the second OD O-ring seal is present as this will contain it. However, as the second OD O-ring seal seals with the pipe, the end of the pipe is exposed to any liquid passing OD O-ring seal on the insert. As set out above, this can lead to delamination of the pipe and ultimately bursting of the pipe wall. According to a first aspect of the disclosure there is provided a connector for sealing the end of a pipe, the connector comprising, a main body having a throughway defining a central axis and receiving the pipe, in use, the main body having an inwardly extending shoulder to provide an insert end stop, and an outer diameter O-ring seal axially spaced from the insert end stop to seal, in use with an outer diameter of the insert; a gripper to grip the pipe and prevent its removal from the main body; and a sealing tube insert for sealing between the main body and the pipe, the sealing tube insert comprising: a tubular body having a first end with a first outer diameter to fit within the pipe and a second end which has a second outer diameter larger than the first diameter such that the proximal end of the second end can abut the end of the pipe and its distal end can fit within the main body and; an inner diameter O-ring seal surrounding the first end to seal with the inner diameter of the pipe; wherein the axial length of the second end is longer than the axial separation between the insert end stop and the outer diameter O-ring seal, such that when the sealing tube insert is fully inserted into the connector body against the insert end stop, the outer diameter O-ring seal seals against the outer diameter of the insert.

[0009] The approach that we have taken is to provide a redesigned insert with a relatively long second end which is long enough that it is able to extend to the OD O-ring seal that is provided within the connector. This is a counterintuitive step as it means that the end of the pipe is significantly displaced proximally as compared to known inserts which have a much shorter second end. This leaves a shorter length of pipe to be gripped by the gripper, which is generally considered undesirable. We have appreciated, however, that even implementing this longer second end, there is still sufficient room to allow the gripper to adequately grip the pipe.

[0010] As a result, the OD O-ring seal seals against the insert. The outer diameter of the insert can be easily manufactured with a smooth surface such that the seal can be reliably created. We have therefore made use of a seal which is already present within existing connectors which was previously redundant in preventing liquid from reaching the end of the pipe. We have therefore been able to make use of this seal in a manner which is effective in blocking any liquid flow to the end of the pipe. This is done in a manner which is compatible with existing connector bodies and therefore does not require a complex retool in order to produce a new connector body. Instead, it just requires moulding for a simple tubular component. The OD O-ring seal should be enough on its own to adequately seal between the insert and main body thereby protecting the end of the pipe from water damage. However, in order to provide some redundancy and depending on the desired performance rating of the connector / system, optionally the connector further comprises an auxiliary O-ring seal surrounding the outer diameter of the second end axially between the insert end stop and the outer diameter O-ring seal to seal with the inner diameter of the main body.

[0011] If the second end is too long, it may not be usable in an existing connector. This is because the gripper needs to grip the pipe reliably. As such the gripping point cannot be too close to the end of the pipe. If the second end is too long this moves the end of the pipe too far proximally and the connector body would have to be extended to accommodate the gripper. The need to do this can be avoided by carefully designing the geometry of the insert to ensure that there is an adequate length of the pipe to grip.

[0012] Optionally, a spacer washer is provided between the gripper and outer diameter O-ring seal to urge the outer diameter O-ring seal distally. This means that the outer diameter O-ring seal can be urged towards a distal location such that it can reliably seal on the insert thereby helping to avoid the need to extend the insert to allow for the outer diameter O-ring drifting proximally.

[0013] Another way to help deal with this issue is to effectively mount a collet in an inverted configuration. In this case the collet is mounted with a collet ring distally within the main body, collet legs extending proximally and having gripping teeth adjacent to the proximal end of the collet. This moves the gripping point on the pipe proximally, thereby allowing adequate grip on the pipe.

[0014] As compared with known inserts, the present insert has an unusually long second end. In this case, optionally, the axial length of the second end is between 0.5 and 1 .5 times its outer diameter.

[0015] This forms a second aspect of the disclosure, which provides a sealing tube insert for sealing between a connector body and a pipe, the insert comprising: a tubular body defining an axis and having a first end with a first outer diameter to fit within the pipe and a second end with a second outer diameter larger than the first diameter to fit within the connector body; an O-ring seal surrounding the first end to seal with the pipe; wherein the axial length of the second end is between 0.5 and 1 .5 times its outer diameter.

[0016] In this case, an auxiliary O-ring seal optionally surrounds the outer diameter of the second end.

[0017] Examples of a connector and sealing tube insert will now be described with reference to the accompanying drawings, in which:

[0018] Fig. 1 is a side view of a first insert;

[0019] Fig. 2 is a perspective view of the first insert and a pipe prior to the insertion of the insert; Fig. 3 is an axial cross-section of the first insert and pipe with the insert fully inserted into the pipe;

[0020] Fig. 4 is a partially disassembled side view of the connector incorporating the first insert; Fig. 5 is a view similar to Fig. 4 showing a later stage of assembly;

[0021] Fig. 6 is an axial cross-section through the fully assembled connector of Figs. 4 and 5;

[0022] Figs. 7 to 9 are views similar to Figs. 4 to 6 showing a second connector incorporating the first insert;

[0023] Fig. 10 is an axial cross-section similar to Fig. 3 showing a second insert;

[0024] Fig. 11 is a view similar to Fig. 6 showing the second insert; and

[0025] Fig. 12 is a view similar to Fig. 9 showing the second insert.

[0026] The specification references proximal and distal ends and directions. The proximal end is the open end of the connector, and the distal end is the end furthest from the open end. In the case of the double ended connector described, the distal end is effectively the centre of the connector. The proximal direction is the direction from the distal end towards the proximal end, i.e. out of the connector. The distal direction is the direction from the proximal end towards the distal end, i.e. into the connector.

[0027] The illustrated connectors are double ended straight connectors. Alternatively, the connector may be an elbow, tee, end stop or end, manifold with branches or any other suitable shape or fitting configuration. In other cases, the connector may be provided for one joint and a different type of coupling may be used for other joints. As a further alternative, the connector may be part of a larger component and provide a means to connect the larger component to a tube, such as a valve or other plumbing installation or apparatus.

[0028] A first example of a sealing tube insert is shown in Figs. 1 to 3. The sealing tube insert 1 has a tubular body defining an axial throughway 3 along a main axis 4. The tubular body has a first end 5 which has a smaller diameter than a second end 6. The first end has a groove 7 which receives an ID O-ring seal 8 which protrudes slightly beyond the outer diameter of the first end 5. When the first end 5 is inserted in a pipe P as shown in Fig. 3, the ID O-ring seal 8 seals with an inner diameter of the pipe P. The end of the pipe P abuts against an end stop in the form of a shoulder 9 at the transition between the first 5 and second 6 ends. The outer diameter of the second end 6 matches the outer diameter of the pipe P.

[0029] The pipe P is a multi-layer composite pipe having a plurality of layers L. However, the connector can be used with other pipes.

[0030] Figs. 4 to 6 illustrate how this insert is used with a first connector.

[0031] The connector comprises a main body 10 with connections at either end. As these have the same design, only one of these is described here.

[0032] A locking cap 11 is screwed on to the main body 10. The locking cap 11 is rotatable between a locked configuration shown the left-hand side of Figs. 4 and 5 and both sides of Fig. 6, and an unlocked configuration as shown on the right-hand side of Figs. 4 and 5. This is described in greater detail below.

[0033] A collet 12 protrudes from the proximal end of the locking cap 11 . This comprises a collet ring 13 from which a plurality of flexible collet legs 14 extend distally. At the distal end of the legs 14 are large collet heads 15 which are provided with teeth 16 to grip the pipe P. When the pipe P is pulled proximally, the collet heads 15 bear against a cap angle 17 on the locking cap 11 to grip the collet more tightly.

[0034] In the locked configuration, the collet 12 is incapable of axial movement. In the unlocked configuration, locking cap 11 is moved axially from the position shown in Fig. 6. In this position, it is possible for a user to push the collet ring 13 in the distal direction thereby holding the collet heads 15 away from the cap angle 17 to allow the release of the tube P.

[0035] This is a conventional operation of a quick release connector with a locking cap.

[0036] The present disclosure can also be applied to a connector without a locking cap.

[0037] The collet 12 can be replaced with a grab ring which are well know in the art.

[0038] In the body 10 is an OD O-ring seal 20. This sits on a shoulder 21 within the main body 10 and is urged into this position by washer 22 which abuts the collet heads 15 at its proximal end and the OD O-ring seal 20 at its distal end. This ensures that the OD O-ring 20 retains its axial position within the main body 10.

[0039] As shown in Figs. 4 to 6, the insert 1 is first inserted into the pipe P as depicted in Fig. 4, before the combined assembly is inserted into the connector as depicted in Fig. 5 to reach the position shown in Fig.6.

[0040] The second end 6 of the insert 1 lands on a shoulder 23 in the main body 10. Once in this position, the pipe P and insert 1 are fully inserted and the pipe is gripped by teeth 16. At this point, locking cap 11 can be rotated to the locked position, although it may be possible to insert the pipe P and insert 1 with the locking cap 11 already in the locked configuration.

[0041] As will be appreciated from Fig. 6, in the fully inserted configuration the length of the second end 6 is such that, with the distal end landed on the shoulder 23, the OD sealing ring 20 seals on the outer periphery of the second end. This is a circular face of a tubular component which can be moulded with a high degree of uniformity. As such, it provides a reliable sealing surface for the OD O-ring 20.

[0042] Any liquid in the pipe P which leaks into the gap between insert 1 and the main body 10 will therefore not pass the OD O-ring seal 20. As can be seen from Fig. 6, the OD O-ring seal 20 prevents liquid from reaching the pipe P. This prevents liquid from being able to delaminate the layers L of the pipe P. As a result of the extended second end 6, the distal end of the pipe P terminates at a location which is significantly closer to the proximal end of the connector than it would conventionally be. The geometry of the connector therefore requires careful design such that the teeth 16 of the collet 12 are able to reliably grip the pipe P at a safe distance from its distal end. The washer 22 helps in achieving this by ensuring that the OD O-ring seal 20 is reliably located at its distal location against the shoulder 21 . Although it is possible to omit the washer 22, it provides more margin for error in ensuring that the OD O-ring seal 20 seals against the second end 6, while the teeth 16 grip pipe P at a reliable location.

[0043] A second connector incorporating the first sealing tube insert 1 is shown in Figs. 7 to 9. In this, the pipe P, insert 1 , main body 10 and OD sealing ring 20 are all as previously described. However, this connector has a new collet 30 and locking cap 31 . The collet is described in greater detail in UK 2310856.6 which is incorporated herein by reference. Compared to the previous example, the collet 30 is in an inverted configuration with the collet ring 32 at the distal end, the collet legs 33 extending proximally, and the collet heads 35 at the proximal end of the collet. As a result of this, the cap angle 37 is repositioned at the proximal end of the locking cap 31 . As will be apparent from Figs. 7 to 9, the collet does not protrude from the locking cap 31 . An outwardly extending flange 38 limits the extent to which the collet 30 can move into the main body 10.

[0044] As previously, the OD O-ring seal 20 seals against the second end 6 of the insert 1 and the ID O-ring seal 8 seals against the pipe P. Because of the inverted nature of the collet, the position of the teeth 36 gripping the tube P is moved proximally with respect to the main body 10 in comparison with the first example (as is apparent from a comparison of Figs. 6 and 9). This provides greater leeway ensuring adequate sealing and gripping as described above.

[0045] Fig 10 describes a second insert 1A. Fig. 11 shows how this is incorporated into the first connector and Fig. 12 shows how this is incorporated into the second connector.

[0046] The only modification with the second example is the incorporation of an auxiliary O-ring seal 40 in an annular groove 41 at the distal end of the second end 6. As shown in Figs. 11 and 12, auxiliary seal 40 seals against the inner wall of the main body 10. As previously mentioned, this surface is not a consistently reliable surface on which to form a seal. However, it is likely that, in the vast majority of cases, the auxiliary O-ring seal 40 will provide a reliable outer diameter seal. In the event that it fails, the OD O-ring seal 20 will then provide the outer diameter seal. This arrangement therefore provides a degree of redundancy in the outer diameter seal.

Claims

CLAIMS:1 . A connector for sealing the end of a pipe, the connector comprising, a main body having a throughway defining a central axis and receiving the pipe, in use, the main body having an inwardly extending shoulder to provide an insert end stop, and an outer diameter O-ring seal axially spaced from the insert end stop to seal, in use with an outer diameter of the insert; a gripper to grip the pipe and prevent its removal from the main body; and a sealing tube insert for sealing between the main body and the pipe, the sealing tube insert comprising: a tubular body having a first end with a first outer diameter to fit within the pipe and a second end which has a second outer diameter larger than the first diameter such that the proximal end of the second end can abut the end of the pipe and its distal end can fit within the main body and; an inner diameter O-ring seal surrounding the first end to seal with the inner diameter of the pipe; wherein the axial length of the second end is longer than the axial separation between the insert end stop and the outer diameter O-ring seal, such that when the sealing tube insert is fully inserted into the connector body against the insert end stop, the outer diameter O-ring seal seals against the outer diameter of the insert.

2. A connector according to claim 1 , further comprising an auxiliary O-ring seal surrounding the outer diameter of the second end axially between the insert end stop and the outer diameter O-ring seal to seal with the inner diameter of the main body.

3. A connector according to claim 1 or claim 2, further comprising a spacer washer between the gripper and outer diameter O-ring seal to urge the outer diameter O-ring seal distally.

4. A connector according to any preceding claim, wherein the gripper is a collet mounted with a collet ring distally within the main body, collet legs extending proximally and having gripping teeth adjacent to the proximal end of the collet.

5. A connector according to any preceding claim, wherein the axial length of the second end is between 0.5 and 1 .5 times its outer diameter.

6. A sealing tube insert for sealing between a connector body and a pipe, the insert comprising: a tubular body defining an axis and having a first end with a first outer diameter to fit within the pipe and a second end with a second outer diameter larger than the first diameter to fit within the connector body; an O-ring seal surrounding the first end to seal with the pipe; wherein the axial length of the second end is between 0.5 and 1 .5 times its outer diameter.

7. A sealing tube insert according to claim 6, further comprising an auxiliary O-ring seal surrounding the outer diameter of the second end.

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