GB2469858A

GB2469858A - Pipe coupling

Info

Publication number: GB2469858A
Application number: GB0907485A
Authority: GB
Inventors: Raymond Ernest Smith
Original assignee: VIP POLYMERS Ltd
Current assignee: VIP POLYMERS Ltd
Priority date: 2009-04-30
Filing date: 2009-04-30
Publication date: 2010-11-03
Anticipated expiration: 2029-04-30
Also published as: GB2469858B; GB0907485D0

Abstract

An annular pipe coupling 1 comprising an inner cylindrical pipe-receiving surface 3a wherein the pipe-receiving surface comprises at least one sealing band 5 having multifaceted protrusions 9 and 13. A first set of protrusions may run parallel to the length of the coupling and may be intersected by a second series of parallel protrusions running annularly around the inner surface of the coupling. The layer of protrusions could be s-shaped or x-shaped and there may be two or more layers of protrusions. The protrusions are preferably deformable and a second layer of protrusions may be more deformable than the first. The invention sets out to provide an improved coupling with less leakage.

Description

Pipe Coupling The present invention relates to a coupling for pipes, and more specifically to a band seal for joining co-axial pipes.

Annular "band" seals or couplings are used to seal two pipes together. The pipes may be made of plastics, clay, concrete, steel, or iron and often the two pipes to be coupled together are of different diameters.

The inner surface of the annular seal is often "stepped" to allow for the difference in the diameter of the two pipes which it seals together. The inner surface of the coupling may be smooth or have ribs or ridges running along the seal in a direction parallel to the length of the pipes which it receives. However, such seals are prone to leaks. Longitudinal ribs concentrate the clamping pressure of the seal to make it more likely that the seal will deform to compensate for any pipe irregularities.

However, it has been found that, in practice, a number of band seals are required to increase the chance of sealing pipes with multiple irregularities. If any leakage escapes from a rib it is possible for the liquid to then travel around the pipe between two parallel ribs and escape from the seal. Any leakage increases the waste of the fluid, such as drinking water, that is being transported through the pipes. Leaks also increase the time and cost of maintaining a pipe network. The most common cause of such leaks is irregularities in the pipe surfaces, which leads to a poor fit with the annular coupling. Is.. * S*

* The present invention sets out to provide an improved pipe * coupling, which alleviates the problems described above by providing a band seal which offers a more secure seal to the pipes which it receives. *..

Accordingly, the present invention provides an annular pipe * coupling comprising an inner cylindrical pipe-receiving surface comprising *..SsS * at least one sealing band having multifaceted protrusions.

Within the context of this specification the word

"comprises" is taken to mean "includes, among other things". It is not intended to be construed as "consists of only".

The term "multifaceted" is taken to mean that the protrusions extend in more than one direction with respect to the length of the pipe/s to be received within the coupling.

A sealing band with protrusions extending in more than one direction, in use, improves the seal between the coupling and the pipe/s which it receives such that the likelihood of leaks is significantly reduced. It has been found that even if fluid leaks from one rib, the leak will be stopped by an adjacent rib extending in a different direction.

Preferably, the or each sealing band comprises at least one layer of "waffle" protrusions.

Waffle protrusions are understood to comprise a first series of parallel protrusions or ribs running parallel to the length of the coupling intersected by a second series of parallel protrusions or ribs running annularly around the inner surface of the coupling.

Waffle protrusions have been found to offer improved sealing by compensating, in use, for any irregularities in the surface of the *..S . : pipe/s which are received by the coupling. A "waffle seal" compensates for any surface irregularities running substantially parallel to the length of the : pipe and/or any irregularities running circumferentially around the pipe's outer surface. S..

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Optionally, the or each sealing band comprises at least one layer of S-shaped or X-shaped protrusions.

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Preferably, the or each sealing band comprises two or more layers of multifaceted protrusions.

Preferably the or each protrusion extends between about 0.6 and 5mm perpendicularly from the inner pipe-receiving surface of the coupling.

Preferably, the coupling has a thickness of between 7mm and 15mm.

Preferably, for a coupling of 140mm diameter the or each protrusion extends between 0.6mm and 1.0mm from the inner pipe-receiving surface of the coupling.

Within this specification, the term "about" is interpreted to mean optionally �20%, preferably optionally �10%, more preferably optionally � 5%.

Preferably, the protrusions are deformable.

Deformable protrusions improved the sealing between the coupling and the pipes which is receives.

Preferably, the sealing band comprises a first layer of multi-faceted protrusions and a second layer of multi-faceted protrusions wherein the second layer is more deformable than the first layer. * S., * *5

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**. . . ****. For the purposes of clarity and a concise description, features are * described herein as part of the same or separate embodiments; however :.: it will be appreciated that the scope of the invention may include embodiments having combinations of all or some of the features described.

The invention will now be described by way of example with reference to the accompanying diagrammatic drawings, in which:-Figure 1 is a perspective view of a pipe coupling constructed in accordance with the present invention; Figure 2 is an enlarged perspective view of the area marked A in Figure 1, showing the configuration of the sealing band of the present invention; Figure 3 is a side view of the pipe coupling of Figure 1; Figure 4 is a longitudinal sectional view through the sealing band of the pipe coupling along line A-A of Figure 3; and Figure 5 is a transverse sectional view through the sealing band on the pipe coupling along line B-B of Figure 3.

As can be seen from Figures 1 and 3, the pipe coupling 1 of the present invention is substantially cylindrical. However, the diameter at the first end of the coupling is greater than the diameter at the second end of the coupling. Both the inner cylindrical surface 3a and the outer cylindrical surface 3b are "stepped" to account for this difference in diameter.

However, it is envisaged that the coupling 1 may be of uniform diameter along its length. As shown in Figure 1, an annular sealing band 5 extends around both the first and second ends of the coupling 1. For a coupling 1 of length 100mm each sealing band 5 has a width of 12mm. In the S...

: example shown, the sealing bands 5 are only at the ends of the coupling 1. In alternative embodiments a single sealing band 5 extends along the full length of the coupling 1 or further sealing bands 5 extend at further positions inwards of the openings of the coupling 1.

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Referring to Figure 2, the sealing band 5 comprises a multi-faceted waffle formation. A first series of equidistant parallel protrusions or ribs 7 *..S..

* parallel to the length of the coupling 1 are intersected by a second series of equidistant parallel protrusions or ribs 9 running annularly around the inner surface of the coupling 1. The ribs 7, 9 are of thickness 2mm and extend a distance in the region of 0.6mm perpendicular to the pipe-receiving surface of the coupling 1.

In a preferred embodiment, illustrated by Figures 4 and 5, the waffle formation comprises two further series of ribs 11, 13. These further ribs 11, 13 are finer and more flexible than the first and second series of ribs 7, 9. In use, these further ribs 11, 13 deform in response to any small irregularities in the pipe/s outer surface. A third series of equidistant parallel ribs 11 parallel to the length of the coupling 1 sits on the second series of annular ribs 9. A fourth series 13 of equidistant parallel ribs also sit on the second series of annular ribs 9 and run annularly around the inner surface of the coupling 3a. The third and fourth series of ribs 11, 13 are of thickness 0.2mm and extend a distance in the region of 0.2mm perpendicular to the pipe-receiving surface of the coupling 1.

Although the multi-faceted protrusions described in the above embodiment comprise a waffle formation, it is envisaged that the protrusions may be in the form of a series of interlinking X-shaped protrusions. The X-shaped protrusions are in the form of equidistant, parallel ribs running diagonally to the length of the pipe/s which are received by the coupling 1. Alternatively the multi-faceted protrusions are in the form or a series of curved S-shaped protrusions, which again are equidistant and parallel to each other. * * S ** S

* The coupling 1 is moulded from a natural or synthetic elastomer, such as ethylene propylene diene monomer rubber (EPDM) or nitrile ** butadiene rubber (NBR). The waffle depth is in the region of 0.6mm for a 100mm diameter pipe to 5mm for a 1000mm diameter pipe. * S. * . S

In use, a first pipe is inserted into a first end of the coupling 1 and * ..SSS * a second pipe is inserted into the opposing second end of the coupling 1.

Each pipe is inserted an equal distance into the coupling 1 and is gripped by a respective sealing band 5. The innermost, finer ribs 11, 13 contact the pipe/s and are flexible to deform according to any irregularities in the pipe/s outer surface. The outermost ribs 7, 9 are also flexible, but to a lesser extent that ribs 7, 9, and also allow the sealing band to deform according to any irregularities in the pipe/s outer surface.

The above described embodiment has been given by way of example only, and the skilled reader will naturally appreciate that many variations could be made thereto without departing from the scope of the claims. * *** * S S *S S S... * S S.'. * S. * . S S.. S

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S * .. * . S 5S *

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*SSSS. S *

Claims

Claims 1. An annular pipe coupling comprising an inner cylindrical pipe-receiving surface wherein the pipe-receiving surface comprises at least one sealing band having multifaceted protrusions.
2. An annular pipe coupling according to claim 1 wherein the or each sealing band comprises a first series of parallel protrusions running parallel to the length of the coupling intersected by a second series of parallel protrusions running annularly around the inner surface of the coupling.
3. An annular pipe coupling according to claim 1 wherein the or each sealing band comprises at least one layer of S-shaped or X-shaped protrusions.
4. An annular pipe coupling according to any preceding claim wherein the or each sealing band comprises two or more layers of multifaceted protrusions.
5. An annular pipe coupling according to any preceding claim wherein the or each protrusion extends between about 0.6 and 5.0mm perpendicularly from the inner pipe-receiving surface of the coupling. * * * * S
6. An annular pipe coupling according to any preceding claim wherein the **** coupling has a thickness of between 7mm and 15mm.
7. An annular pipe coupling according to any preceding claim wherein the * ** coupling has a diameter of 140mm and the or each protrusion extends :.: between 0.6mm and 1.0mm from the inner pipe-receiving surface of the *5*5.* * coupling.
8. An annular pipe coupling according to any preceding claim wherein the protrusions are deformable.
9. An annular pipe coupling according to any preceding claim wherein the sealing band comprises a first layer of multi-faceted protrusions and a second layer of multi-faceted protrusions wherein the second layer is more deformable than the first layer.
10. An annular pipe coupling substantially as hereinbefore described or referred to in Figures 1 to 5. * * * ** * * * **-.. * ** * * . S.. *S * * S. * a * 5*0 SS*..S.*S