The invention to which this application relates is pipe coupling apparatus of a type which is provided to allow two ends of pipeline to be connected together and held in an engaged position. In particular, the apparatus is provided to allow a pipeline to be formed of a plastics material to be retained in position.

When forming any type of pipeline, it is commonly the case that the pipeline will be formed of a series of sections and with the adjacent abutting or overlapping ends of the sections retained together so as to form a continuous pipeline from the series of pipeline sections.

In general, and in particular with a pipeline formed of plastics material, there is a tendency for the sections of pipeline to move relative to each other and in particular, movement along the respective longitudinal axis of the pipeline sections, can lead to leakage between a gap formed between the adjacent pipeline section ends which, at best, can cause time and effort to be required to be spent on the leakage and possibly also incur loss of the materials which carried along the pipeline which can cause economical loss and environmental impact. More specifically when the pipe sections are formed of certain materials, such as MOPVC (Molecular Orientated PVC) which is a form of PVC that does not crack or suffer damage by propagation where a small hole, tear or piece of damage turns into a big one, there can be problems in that as MOPVC is light and smooth this causes problems when a pipe has a thrust issue (usually at a corner or stop end) which in turn tries to separate the joints between the pipe sections.

The aim of the present invention is therefore to provide a pipeline coupling apparatus for adjacent sections of pipeline which allows the abutting, overlapping or otherwise adjoining ends of the said sections to be fitted in an adjacent and sealed position and to be retained in the same. In a first aspect of the present invention, there is provided a pipeline coupling apparatus to couple first and second ends of adjacent pipeline sections, in use, said coupling including: a first part and at least a second part; engagement means provided to join said first and second parts together to form the coupling, the interface between the first and second pipeline sections, in use, being retained by the formed coupling; each of said first and second parts including a first end portion for engagement with a first pipeline section, adjacent the end of the same, in use; and each of said first and second parts including a second end portion for location with the second pipeline adjacent the end of the same, in use, and characterized in that at least one of said first or second end portions includes retention means formed so as to protrude into and/ or exert a pressure force on, the external surface of the respective first and/or second pipeline sections, in use.

In one embodiment, said first and second end portions extend around the respective pipeline sections with which the same are engaged, in use, so as to exert a retention force around the external surface of the pipeline, in use.

In one embodiment, said engagement means are provided in the form of one or more bolt members, provided to attach the first and second parts together at an interface between the same. Typically, the engagement between the first and second parts is provided along a longitudinal axis of the coupling apparatus. Further typically, said engagement interface and thus the longitudinal axis of the coupling apparatus is provided to be parallel with a longitudinal axis of the pipeline sections, in use. In some embodiments, said first and second parts may be joined via engagement means in the form of a hinged arrangement, wherein on a first side of the coupling apparatus, along a longitudinal axis thereof, there is provided one or more hinge members, and on an opposing second side of the coupling apparatus along the longitudinal apparatus there is provided one or more attachment members to secure the first part to the second part, around the pipeline sections, in use.

Typically, said first and second end portions are joined via an intermediate portion.

In one embodiment, said intermediate portion is provided as a series of rods and/or elongate bolt members. Typically, said rods and/or bolt members permit adjustment of the distance between said first and second end portions.

In one embodiment, said intermediate portion is provided as a series of cross-linking members. Typically, said cross-linking members are formed integrally with said first and second end portions.

In a preferred embodiment, said intermediate portion is provided as a single, bridging section, such that each of said first and second parts forms a single, unitary body and when engaged to form said coupling apparatus, the coupling apparatus forms a substantially tubular member. Typically, said coupling apparatus is formed to enclose the interface between the first and second pipeline sections, in use.

Typically, said end portions are provided to have a substantially semicircular cross-sectional profile, when viewed down a longitudinal axis of the coupling apparatus. In one embodiment, at least said end portions are formed to match the profile of the pipeline sections, in use. Typically, said retention means are formed on an inner surface of at least one of said end portions. In one embodiment, said retention means are formed on the inner surface of least one of the first end portions on the first or second part, and at least one of the second end portions on the first or second part. Preferably, said retention means are formed on the inner surface of each of said end portions.

Typically, said retention means are formed on an inner surface of each of the first and second end portions of the first and second parts.

In one embodiment, said retention means are formed as one or more annular teeth members, located on an inner surface of one or more of the end portions. Typically, said retention means are formed as one or more annular teeth members located on an inner surface of each of the first and second end portions of the first and second parts.

Preferably, a plurality of annular teeth members is provided on each of the end portions.

In one embodiment, said annular teeth members are provided to be angled in a central direction along the longitudinal axis of the coupling apparatus. Typically, said annular teeth members are angled towards the interface of the pipeline sections, in use.

Typically, said retention means are formed as a series of teeth and said teeth are angled with respect to the external surface of the pipeline, in use, so as to exert a greater retention force in one direction of possible movement of the pipeline than in the opposing direction of possible movement.

Typically, the said direction of possible movement on which the greater retention force is applied is the direction of the respective pipeline away from the adjacent/ connecting pipeline so that, in combination, the retention force is applied by the two sets of retention means on the first and second end portions of the coupling, act to encourage the ends of the respective pipelines to be moved towards each other or at least prevent movement away from each other, in use.

In one embodiment, the first and second parts of the pipeline coupling are provided with engagement means which allow the engagement of the first and second parts along an interface which is substantially parallel with the longitudinal axis of the pipeline sections when the same are retained in position by the coupling.

In one embodiment, the axis along which the retention means are formed, is perpendicular to the axis of the interface of the coupling parts.

In one embodiment, the engagement means for the said coupling parts, are a series of bolts provided to pass through apertures in the respective parts adjacent to the interface of the parts and, the act of moving the engagement bolts into an engaging position, acts to press the retention means onto and potentially into the external surface of the pipeline sections, in use.

In one embodiment, said retention means are provided on the first and second parts as part of a band, such then when the first and second parts are brought together, a band is formed around the external surface of each of the first and second pipeline sections.

In one embodiment, a first band which is formed for the first pipeline section and a second band which is formed for the second pipeline section, are spaced apart and the respective ends of the first and second pipeline sections are located intermediate the said first and second bands.

Typically, the first and second bands therefore determine the location of the retention means on the respective pipeline sections and preferably, determine the position so that the retention means are located at the optimum position so as to optimise the retention force supplied to the said pipeline sections.

In one embodiment, the spacing between the said first and second bands, is set by longitudinal members which extend between the same and which are integrally formed with the said bands and typically each of the first and second parts are formed as unitary parts.

Alternatively, the spacing between the said first and second bands, is determined by a series of elongate members which are selectively located with the said first and second bands. In one embodiment, the length of the said members between the said bands, can be selected by the user and/ or can be adjusted by the user at the time of installation to suit the particular installation requirement.

In another aspect of the present invention, there is provided a pipeline coupling apparatus to couple first and second ends of adjacent pipeline sections, in use, said coupling including: a first part and at least a second part; each of said first and second parts having first and second end portions; the respective first and second end portions of the first and second parts arranged to engage and join to form the coupling apparatus; wherein the first end portions of the coupling apparatus form a first band engaging the first pipeline section, in use, and the second end portions of the coupling apparatus form a second band engaging the second pipeline section, in use; characterized in that retention means are formed on an interior surface of the first and second bands so as to protrude into and/or exert a pressure force on, the said external surface of the respective first and/or second pipeline sections, in use. In another aspect of the present invention, there is provided a pipeline coupling apparatus for first and second pipeline sections, said coupling apparatus including: a first part and at least a second part joined together to enclose and retain an interface between ends of said first and second pipeline sections; said coupling including a first engaging portion to engage the first pipeline section, and a second engaging portion to engage the second pipeline section; and characterized in that said first and second engaging portions each include retention means to protrude into and/or exert a pressure force on the external surface of the respective first and second pipeline sections.

In a further aspect of the invention, there is provided a method of retaining abutting, overlapping or otherwise adjoining ends of first and second pipeline sections in an adjacent and sealed position, said method comprising the steps of: locating first and second pipeline sections with adjacent ends in an abutting, overlapping or otherwise adjoining relationship; placing a first part of a coupling apparatus to a first side of the pipeline sections; placing at least a second part of a coupling apparatus to a, second, opposing side of the pipeline sections; locating said first and second parts such that the interface between the first and second pipeline sections lie intermediate first and second end portions formed on the first and second parts; applying engagement means so as to engage the said first and second parts of the coupling apparatus along an interface between the same to form the coupling; and the act of engagement of the coupling apparatus serves to move retention means formed on the end portions of the coupling apparatus onto an external surface of the pipeline sections and/or into the external surface of the pipeline sections so as to exert a retaining force on the respective pipeline sections to retain the same in an abutting, overlapping or otherwise adjoining relationship.

In one embodiment, the method includes a step of adjusting the spacing between the first and second end portions on which the retaining portions are formed.

In one embodiment, the pipe sections are formed as socket spigot pipes and the ends of which are joined and retained together by the apparatus to provide ‘end restraint’, or ‘end loading’, and thereby resist the possibility of the same being hydraulically forced apart and/or linearly separated.

Typically, the apparatus is fitted over socket spigot joints in areas where thrust is an issue, and an end restraint is needed.

Typically, the number of retention means provided on the apparatus may be varied with respect to the size of the apparatus and pipe sections with which the same is to be used. For example, apparatus for use with 160mm diameter pipe may be provided to have 5 sets of retention means, or rows of annular teeth members whilst apparatus for use with larger pipeline sections may have more.

Typically, the profile and shape of the retaining means teeth remains constant although variations in depth of the retaining means may be utilised for different sizes.

Specific embodiments of the invention are now described with reference to the accompanying drawings, wherein:

Figures la-e illustrate various views of a coupling apparatus in engagement with adjacent pipeline sections, in accordance with an embodiment of the present invention; Figures 2a-i illustrate various views and detail of a first part of a coupling apparatus, in accordance with an embodiment of the present invention;

Figure 3 illustrates another example of a coupling apparatus in engagement with adjacent pipeline sections, in accordance with an embodiment of the present invention; and

Figure 4 illustrates another example of a coupling apparatus in engagement with adjacent pipeline sections, in accordance with an embodiment of the present invention.

Referring now to the figures and firstly to Figures la-e, there is shown a pipeline coupling apparatus 1 in accordance with embodiments of the present invention and in engagement with two pipeline end sections 3, 5. The end sections can engage with one another in an abutting, overlapping or otherwise adjoining relationship and it can be seen in the cut-away image of Figure le that in the present example, pipeline sections 3, 5 are provided to overlap one another, with the end of first pipeline section 3 locating within the end of second pipeline section 5 to form the pipeline. The coupling apparatus is provided to engage with the interface of the two pipeline sections and retain the same in place, preventing any separation of the two sections 3, 5. Figure la shows a side view of the arrangement while Figure lb illustrate a fronton view looking down the pipeline from one of the ends, and Figure 1 c illustrates a perspective view of the arrangement.

The coupling apparatus 1 is formed from at least two parts: a lower first part 7 and an upper second part 9. The first part 7 locates around a first, lower side of the pipeline sections 3, 5 while the second part 9 locates around the upper side of the pipeline sections 3, 5. The two parts 7, 9 engage with one another along an interface 11 which runs parallel with the longitudinal axis of the pipeline. Typically, the two parts 7, 9 are fixed together via a series of bolts 13 provided to join them at their interface 11. In some other embodiments, the parts 7, 9 may be provided in a hinged relationship, wherein on one side of their interface 11 there are provided a number of hinges (not shown) and on the other side bolts or other fixing means may be provided to join the two parts 7, 9 together around the pipeline sections 3, 5.

Figure I d illustrates a perspective view of a first, lower part 7 of the coupling apparatus 1. The part 7 includes a first end portion 15 and a second end portion 17. Similar first and second end portions 15, 17 are provided with the second part 9. As can be seen, the end portions 15, 17 are provided to have a generally semi-circular profile, in particular to match that of the pipeline sections 3, 5 with which they attach and so when the parts are brought together bands are formed at each end. On the inner surface 19 of the end portions 15, 17 there is provided retention means for the coupling apparatus in the form of a series of annular teeth formations 21. As the parts 7, 9 are brought together and attaching to the pipeline sections 3, 5, the teeth 21 are provided to engage with the exterior surface of the pipeline sections 3, 5 and exerts a pressure force on the same to retain them in place. The teeth may also be formed to as to protrude into the exterior surface of the pipeline sections 3, 5 thereby increasing their grip and consequently retention force on the pipeline sections 3, 5.

Further detail of the make-up of the parts 7, 9 and teeth formations 21 can be seen in Figures 2a-i. Figure 2a illustrates a side view of one of the parts 7, 9; Figure 2b illustrates an overhead view of the interior side of the parts 7, 9 where in particular it can be seen that the teeth formations extend the width of the part across the each of the end portions 15, 17. Figures 2c-d illustrate views from the respective end portions 15, 17, and Figure 2e illustrates a cross-sectional view of the part 7 along line E. In Figure 2e the sections of the teeth formations 21 on the interior surface 19 can be seen, which is shown in more detail in zoomed in Figure 2g and again in Figure 2h. The teeth formations are provided to be angled towards a central portion of the part 7 on which they are located, which serves to increase the retention force and further prevent separation of the pipeline sections 3, 5 when the coupling apparatus 1 is attached thereto. Figure 2h illustrates on embodiment in which such an effect may be achieved. The crosssection of the tooth 21 shows a first side 23 of the tooth 21, located nearer a central portion of part 7 on which it is located, which is substantially at a right-angle with respect to the interior surface 19 on which it is located. A second side 25 of the tooth 21, nearer an end of the part 7, is provided to be inclined from the interior surface 19, rising to meet the top of the first side 23 at an apex 27. The apex 27 creates a point at which the tooth 21 may bite, protrude into or otherwise grip the exterior surface of the pipeline section 3, 5 with which it attaches, in use, creating the retention force. As mentioned above, the teeth 21 extend across the width of the end portions 15, 17. At their ends 29, the teeth 21 are formed to be chamfered to provide a smooth transition from the apex 27 of the tooth 21 to the surface 19.

Thus, as the first and second parts 7, 9 of the coupling 1 are brought together around the interface of the pipeline sections 3, 5 and fixed together along their own interface via the bolts 13, the first and second end portions 15, 17 of each part 7, 9 essentially form first and second bands 31, 33 which wrap around and grip the respective pipeline sections 3, 5, holding the same together. The inner surface 19 of each of the bands 31, 33 include a series of annular teeth 21 which bite, protrude into or otherwise grip the exterior surface of the pipeline sections 3, 5 and which serve to exert a retention force on the pipeline sections 3, 5, retaining the same together at their interface. The annular teeth formations 21 formed on the inner surfaces 19 of the end portions 15, 17 may be varied in number depending on the size of the apparatus 1 and pipe sections 3, 5 with which the apparatus 1 is to be used. For example, a coupling apparatus 1 for use with 160mm diameter pipe may be provided to have, for example, five sets, or rows of annular teeth 21 at each end portion 15, 17 whilst coupling apparatus 1 for use with larger pipeline sections may have more. The profile and shape of the teeth 21 remains constant although variations in their depth / height may be utilised for different sizes.

Figure 2i illustrates the part 9 in a perspective view (wherein it can be placed atop the part 7 shown in Figure I d to form the coupling 1) . The coupling apparatus 1 shown in Figures la-2i illustrates a first embodiment, wherein the first and second respective end portions 15, 17 are joined by an intermediate, bridging portion 35. In this embodiment, the intermediate portion 31 is provided as a single bridging section 35, such that each of the parts 7, 9 form single unitary bodies joining their respective end portions 15, 17, and when the parts 7, 9 are engaged to form the coupling apparatus 1, the coupling 1 forms a substantially tubular member, which encloses the interface between the first 3 and second 5 pipeline sections, in use. The bridging section 35 is raised slightly with respect to its adjacent end portions 15, 17 such that it does not directly contact the exterior surface of the pipeline sections 3, 5, shown most clearly in Figure le. In other embodiments of the present invention, the intermediate portion may be provided as a series of cross-linking members 37, formed integrally with the end portions 15, 17, and shown in Figure 3. In other embodiments, the bridging portion may be provided as a series of rod and/ or bolts 39, shown in Figure 4. In such embodiments, the distance between the first and second end portions 15, 17 of each part 7, 9 may be adjusted as is required by a user for the appropriate pipeline section interface.

The coupling apparatus 1 of the present invention forms what is known in the art as a “gripping fitting”, and is provided to be used with a number differing types of adjoining pipeline sections. Figure le illustrates an example where the pipeline sections 3, 5 are formed as socket spigot pipes and the ends of which are joined and retained together by the apparatus 1 , whose end portions 15, 17 grip and retain respective ends of the pipeline sections 3, 5 to provide an “end restraint”, or “end loading”, thereby enabling the pipeline to resist the possibility of the same being hydraulically forced apart and/or linearly separated. In particular, the coupling 1 can be fitted over socket spigot joints in areas where thrust is an issue, and an end restraint is needed.

The present invention therefore provides and improved coupling apparatus 1 which serves to hold two pipeline sections 3, 5 together at their interface in an abutting, overlapping or otherwise adjoining relationship. The provision of annular teeth 21 which can bite or protrude into the exterior surface of the pipeline sections greatly improves the grip the coupling apparatus 1 can exert on the pipeline sections 3, 5, preventing any slippage. Further, by providing the teeth 21 to be angled centrally and towards the interface of the pipeline sections 3, 5, this further helps to prevent linear separation of those sections, maintaining the pipeline intact and preventing any leaking of material therefrom.