GB2578456A

GB2578456A - Rodding branch unit

Info

Publication number: GB2578456A
Application number: GB1817587.7A
Authority: GB
Inventors: Swinfield Murray; Hassall Matthew
Original assignee: Saint Gobain Construction Products UK Ltd
Current assignee: Saint Gobain Construction Products UK Ltd
Priority date: 2018-10-29
Filing date: 2018-10-29
Publication date: 2020-05-13
Also published as: GB201817587D0

Abstract

The branch unit (20, Figs 2a-2e) has an inlet pipe portion (22), and outlet pipe portion (26) arranged at an angle to the inlet, and a further pipe portion (28) providing access to the unit via an open end (30). The further pipe is provided with means for retaining an end cap (32). The retaining means may be retained by lugs 34 with bolts 36, the cap may threadingly engage the pipe, or there may be a push fit connection. In use the cap may be removed such that rodding equipment can be inserted to remove any blockages. The unit may include lugs 42a/b to facilitate attachment of the unit, by hanging or suspension, underneath a floor. The outlet pipe may be at a 45 degree angle to the inlet pipe. The outlet pipe and further pipe portion may be in line. The unit may also be used as a 2 to 1 junction to connect three pipes together, rather than for rodding access.

Description

Title: Rodding branch unit

Introduction

This invention relates to rodding access points, particularly but not exclusively for below slab or underfloor drainage systems. The invention is further particularly applicable within in-building installations, e.g. within a basement of a building.

Rodding access points allow drain systems to be inspected and cleaned. Pipe systems generally comprise lengths (usually straight) of pipe joined together by pipe joints at locations where there is a change of direction (e.g. a bend) in the pipe. Such pipe joints are usually small components/units (usually as short as possible) so that engineers can design bespoke pipe systems for each specific real-world situation.

Below slab or underfloor horizontal pipe systems, such as drainage systems are designed to carry rain water or foul drainage water. Such systems usually comprise a pipe extending from above ground level, through a floor slab, to an underground or underfloor level, such as a basement level. The pipe may then connect to an underfloor pipe system via a bend located at a high level, e.g. near a ceiling, of the basement. Rodding access is desirable at the first underfloor bend, as well as at further points in the system.

Statements of invention

Representative features are set out in the following statements, which stand alone or may be combined, in any combination, with one or more features disclosed in the text and/or drawings of the specification.

According to an aspect, the invention provides, a rodding branch unit arranged to join a first pipe and a second pipe and allow access to the junction, the unit comprising: an inlet pipe portion arranged to be attached to the first pipe; an outlet pipe portion arranged to be attached to the second pipe; and an access pipe portion arranged to provide access to the unit, the access pipe portion having an open end; wherein the unit further comprises end cap retaining means arranged to facilitate retaining an end cap on the open end.

Advantageously, no extra cast parts are required to provide access at the junction when using the inventive unit. Using current, known apparatus, assembly of multiple separate components is carried out on site. Using the inventive unit allows off-site production of a complex pipe section, and also ease of installation for an installer.

Current methods of production or assembly of pipe systems are done onsite to a variety of assemblies subject to the space and layout of each particular site.

This invention removes inefficiencies as it provides an offsite manufacturing solution.

The invention is particularly good for large installations/buildings, i.e. installations requiring multiple junctions. The time and resource saving is 30 magnified.

The inventive unit is particularly useful for solving a problem at the bend that comes vertically down, through a floor or slab, which then turns at about 90 degrees into a pipe run. At this point, it is often desirable to have a rodding access point.

The inventive unit provides simplicity for an installer, whilst also reducing environmental impact, reduced health and safety risk, reduction in wasted products or off-cuts, reduced transportation burden, reduced product handling burden, reduced chance of installation errors (and therefore reduced chance of leakage/failure of pipe system).

Optionally, the access pipe portion comprises at its open end, a connection zone arranged to facilitate connecting of a further pipe to the access pipe portion. In combination, the features of (a) the end cap retaining means features and (b) the connection zone provide versatility -i.e. the option for an installer of either being able to a) provide rodding access to the junction or b) connect a further pipe onto the open end of the rodding access pipe portion. This is particularly useful in large installation projects, i.e. installations requiring multiple junctions. The time and resource saving is magnified.

Optionally, the connection zone comprises a blank section of pipe. The blank section allows easier connection to a further pipe. The blank section is a section without protrusions, such as end cap retaining means, lugs, eyelets hooks, loops etc. This allows for easier connection to a further pipe.

Optionally, the length of the connection zone is 10mm or longer than 10mm. The connection zone is optionally a blank section of pipe. This allows easy connection using known techniques (e.g. via a ring coupling). A connection zone of 10mm will allow such coupling. In other cases (couplings from different manufacturers vary), a connection zone of 15mm may be needed. In yet further cases, a connection zone of 20mm or about 40mm may be provided.

Optionally, the access pipe portion comprises the end cap retaining means. Conveniently, the end cap retaining means is located at or on the access pipe portion, since this is close to the end cap, which is being retained.

Optionally, the end cap retaining means is arranged to facilitate retaining the end cap by exerting a force on the end cap in a line substantially parallel to a longitudinal axis of the access pipe portion. The end cap retaining means acts (in terms of its force applied) in a direction parallel to the longitudinal axis of the access pipe portion. The end cap is therefore pulled towards the closed position -this is more efficient than a traditional ring clamp coupling because a better seal is provided as the end cap is engaged in the line of the exerted force. In contrast, the usual ring clamp exerts force at 90 degrees compared to exerted force exerted on the end cap from the pipe. The inventive unit is no longer reliant solely upon a friction force to hold the cap in position. The inventive unit is no longer reliant upon an out-of-line force to hold the cap in position.

For the purpose of this specification, a lug is any projecting part by which anything is held or supported.

Optionally, the end cap retaining means comprises one or more securing lugs arranged to receive end cap securing means, such as a bolt, the end cap securing means being arranged to secure the end cap to the access pipe portion. The securing lug and bolt system provides a more secure end cap mounting than a ring clamp. A better seal is provided. In particular, the bolt in combination with the push fit end cap aligns with the rodding access pipe portion and pulls the end cap towards the closed position -this is better than a ring clamp because a better seal is provided as the end cap is engaged in the line of the exerted force. In contrast, the usual ring clamp exerts force at 90 degrees compared to exerted force exerted on the end cap from the pipe. The inventive unit is no longer reliant solely upon a friction force to hold the cap in position. The inventive unit is no longer reliant upon an out-of-line force to hold the cap in position.

Further optionally, the bolt has a longitudinal axis and, in use, is arranged parallel to the longitudinal axis of the access pipe portion such that the end cap is urged to close the open end of the access pipe portion in line with the longitudinal axes. The securing mechanism (bolt) being in line with the force on the end cap from within the pipe provides a more secure end cap mounting.

Optionally, the end cap retaining means comprises a first thread on the access pipe portion, the first thread being configured to engage with a second thread on the end cap, which is optionally a flat push fit end cap. The end cap retaining means comprises a first thread on the access pipe portion, which is arranged to threadably engage with a second thread on the end cap.

Optionally, in one example the first thread comprises an internal thread (i.e. within the access pipe portion). In this case the first thread may extend from the open end of the access pipe portion.

Instead, in another example, the first thread may comprise an external thread (i.e. on the outer surface of the access pipe portion). In this case the first thread may extend from the open end of the access pipe portion.

Or, in yet another example, the first thread may comprise an external thread (i.e. on the outer surface of the access pipe portion), but in this case, in order to provide the connection zone at the end of the access pipe section, the first thread may not extend from the open end of the access pipe portion; instead, the first thread may be formed only after the connection zone (e.g. at least 10mm, or 20mm, or 40mm etc.) from the open end of the access pipe portion.

In examples in which the first thread comprises an internal thread, the first thread may also extend from a location spaced from the open end of the access pipe portion.

In further examples, any combination of internal and external threads may be provided.

Optionally, the end cap comprises a push fit end cap, optionally a flat push fit end cap, arranged to friction fit into the open end of the access pipe portion.

The end cap is substantially flat (as opposed to a bowl type end cap). There are cost and environment benefits to minimising the end cap shape towards a flat shape. In other embodiments, other end cap shapes could be provided. Due to the better sealing of the end cap, the inventive unit is able to be used with a generally flat end cap as opposed to the bowl type end caps used in conventional apparatus.

Optionally, the or each securing lug is just over 10mm from the open end. Having the securing lugs as close as possible to the open end, whilst leaving enough space for connecting another pipe, allows for a shorter bolt or bolts, which efficiently achieves the sealing.

Optionally, the rodding branch unit further comprises attachment means arranged to facilitate attachment, such as by hanging or suspension, of the unit to a structure, such as a ceiling or floor or wall. This feature allows for easy hanging from a structure such as a floor/ceiling/wall.

Further optionally, the attachment means is arranged to facilitate attachment of the unit in more than one configuration, such as in a first orientation and in a second orientation, and optionally wherein the relative orientation of the unit relative to the structure in the first orientation compared to the second orientation is 90 degrees. This feature adds further versatility -allows for both horizontal or vertical mounting and use. This is useful in most large installations. Otherwise, bespoke pipe runs are often created from multiple small cast components.

Optionally, the attachment means comprises one or more fixing lugs, and optionally wherein each fixing lug is arranged to receive a fixing rod. Fixing lugs (or eyelets or hooks or loops etc.) provide for easy hanging of pipes.

Optionally, the fixing lugs are spaced apart. The fixing lugs being spaced apart provides a more stable mounting.

Optionally, at least one of the one or more fixing lugs are just over lOmm from the open end. The fixing lugs are spaced from the open end, which helps to provide a stable fixing point. The fixing lugs are provided immediately after the connection zone or blank portion. They are spaced from the end to allow space for a connecting pipe. The fixing lugs remove the need for other fixing components. Other fixing components are usually in the form of other cast components, e.g. a bracket and a threaded rod. We save resource and environmental resource. If a further connecting pipe is being used, there may be no need to immediately provide a further hanging point for the further pipe (as would usually be required) until further down on the pipe run.

Optionally, at least one of the one or more fixing lugs are over 100 mm from the point where the inlet pipe portion meets the access pipe portion. The fixing lugs are spaced from where the inlet pipe portion, the outlet pipe portion and the access pipe portion meet. This allows for easy hanging of the unit. Optionally the hanging lug is at least 100mm from the junction of the pipe portions. The fixing lugs are located such that they are not too close to the core hole from above and also easily accessible to install.

The fixing lug spacing is chosen/configured such that the fixing lugs are spaced apart enough to offer stable hanging points, i.e. not too close together (when in the horizontal hanging configuration).

Optionally, the unit comprises a web between the inlet pipe portion and the access pipe portion. The web is located at the junction between the inlet pipe portion and the access pipe portion. The web is provided for casting (and strength). Further optionally, the unit comprises a fixing lug within the web, which fixing lug can be used when rodding branch unit is placed horizontally, in addition to or instead of, one or more of the other fixing lugs.

Optionally, the unit is a cast metal unit. It is a one-piece unit. In other embodiments, the unit may be steel or plastic material.

Optionally, the outlet pipe portion and the access pipe portion are aligned with each other.

Optionally, the angle between the outlet pipe portion and the inlet pipe portion is about 90 degrees, or is about 45 degrees. The unit is particularly suitable for approximately 90 degree bends, e.g. soil pipes coming through a floor. It will be apparent to the person skilled in this field that in other examples, other angles and configurations could be developed within the scope of this invention.

In some examples, the inlet, outlet and access pipe portions have the same inner diameter. In other examples, any one or more of the inlet, outlet and access pipe portions have different inner diameters. In one example, the access pipe portion has an inner diameter of about 100mm. In one example, the access pipe portion has an inner diameter smaller than the inner diameter of the other portions.

According to another aspect, the invention provides a pipe system containing multiple pipes joined using the rodding branch unit of any preceding aspect.

Drawings -brief description

Embodiments of the inventions will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows an underfloor pipe system constructed using a rodding branch unit according to an aspect of the invention; Figure la is a close-up view of part of the system of Figure 1; Figure lb is a close-up view of another part of the system of Figure 1; Figure 2a is a view from one side of a rodding branch unit according to an aspect of the invention; Figure 2b is a plan view of the rodding branch unit of Figure 2a; Figure 2c is a view from another side of the rodding branch unit of Figure 2a; Figure 2d is an end view of part of the system of the rodding branch unit of Figure 2a; Figure 2e is a perspective view of the rodding branch unit of Figure 2a; Figure 3a is a view from one side of a rodding branch unit according to another aspect of the invention; Figure 3b is a plan view of the rodding branch unit of Figure 3a; Figure 3c is a view from another side of the rodding branch unit of Figure 3a; Figure 3d is an end view of part of the system of the rodding branch unit of Figure 3a; Figure 3e is a perspective view of the rodding branch unit of Figure 3a; and Figure 4 shows the rodding branch unit of Figure 2a installed under a floor.

Description

Referring to figures 1, la and 1 b, there is shown a pipe network that is installed in a multi-floor building space. The building space incudes a ground floor 4 separated from a basement 6 by a floor 8. In this example the pipe network is arranged to carry waste drainage water from the ground floor area to the basement via the pipe network 2. The pipes and other elements that make up the pipe network are generally circular in cross-section in the examples listed in the specification. Other conventional pipe shapes and profile may be envisaged by the skilled person.

The pipe network 2 includes a first pipe 10a, which is oriented substantially vertically and passes from the ground floor 4 to the basement 6 via a hole 14 in the floor 8. The pipe network 2 also includes a second pipe 10b, which is oriented substantially horizontally, i.e. at about 900 relative to the first pipe 10a.

The pipe network 2 further includes a third pipe 10c, which is arranged substantially horizontally and at about 45° relative to the second pipe 10b. The pipe network 2 further includes a fourth pipe 10d, which is arranged substantially horizontally and at a further 45° relative to the third pipe 10c.

Waste water travels from the first pipe 10a through the second pipe 10b through the third pipe 10c and then through the fourth pipe 10d in sequence. Underfloor elements of the pipe network 2, including the second pipe 10b, third pipe 10c and fourth pipe 10d are suspended from the ceiling of the basement, i.e. from the floor 8 in a conventional manner -in this embodiment, the suspension is achieved via fixing rods embedded in the floor 8 and fixed to the pipes of the pipe network.

It is desirable to have rodding access at certain points within the pipe network 2. The pipe network includes a rodding branch unit 20 according to an embodiment of the invention, which is suitable for joining the first pipe 10a to the second pipe 10b, since the first and second pipes are substantially perpendicular to each other. This first embodiment of the rodding branch unit is shown in closer detail in figure la and figures 2a to 2e and will be referred to as the 900 rodding branch unit 20 for ease of reference.

Another embodiment of the invention provides a rodding branch unit 50, which is suitable for joining the third pipe 10c to the fourth pipe 10d since the pipes at about 45° relative to each other. For ease of reference, this will be referred to at the 45° rodding branch unit in the specification.

In some embodiments, a tolerance is built into the unit to allow for slight deviation; the units described above can be used to join pipes at almost 90 degrees, or almost 45 degrees relative to each other.

In further embodiments, the unit may be designed to join pipes at any other desired angles, e.g. 10, 20, 30, 40, 50, 60, 70, 80, 100, 110, 120, 130 degrees etc. Or, any other desired angle. The inlet pipe portion, the outlet pipe portion and the access pipe portion are in the same plane in the above-described embodiments. In other embodiments, the inlet pipe portion, the outlet pipe portion and the access pipe portion may be not be in the same plane -e.g. the inlet pipe portion may be offset out of the plane of the outlet pipe portion and the access pipe portion.

It will be apparent to the skilled person that other embodiments of rodding branch unit can be provided to allow for a different amount of relative orientation between input and output pipes. It will also be apparent to the skilled person that the invention can be applied to any other configuration of pipe network, other than that shown in figure 1.

Referring to figures 2a to 2e, the 90° rodding branch unit 20 is shown in further detail. The 900 rodding branch unit 20 is arranged to join the first pipe 10a to 30 the second pipe 20b and to allow access to the junction between the two pipes. The unit 20 comprises an inlet pipe portion 22 arranged to be attached to the first pipe 10a. The inlet pipe portion 22 has a generally circular cross-section tube profile and has an open end 24 to which the first pipe 10a can be easily joined by conventional means. In this embodiment there is a straight, plain section of pipe extending from the open end 24. The straight, plain section of pipe is suitable for attaching to the first pipe via a conventional ring coupling. The inlet pipe portion 22, after the straight section, comprises a bent section leading into a further straight section of pipe.

The unit 20 further comprises an outlet pipe portion 26. The further straight section of the inlet pipe portion 22 merges with the outlet pipe portion 26. The outlet pipe portion 26 is oriented at about 900 relative to the inlet pipe portion 22 in this embodiment. The outlet pipe portion 26 is arranged to be attached to the second pipe 10b. The outlet pipe portion 26 also comprises a straight, plain section of pipe, which makes it easy to attach the second pipe 10b via a conventional coupling. In this example, the plain sections of pipe are about 40mm long on both the inlet pipe portion 22 and the outlet pipe portion 26. In other examples, the plain sections of pipe may only need to be 10mm long in order to accommodate a coupling suitable for attaching the relevant portion to a pipe.

The outlet pipe portion 26 leads drainage water flowing from the inlet pipe portion 22 along a first direction. The unit 20 further comprises an access pipe portion 28 that extends opposite to said first direction. The access pipe portion 28 is parallel to the outlet pipe portion 26; it is formed effectively as a single pipe section as can be seen from figures 2a to 2e. The access pipe portion 28 is a generally elongate section of pipe. In this embodiment, the inlet pipe portion 22 forms an acute angle with the access pipe portion 28. From the point at which the inlet pipe portion meets the access pipe portion 28, the access pipe portion 28 extends about 160mm further to an open end 30. The access pipe portion is arranged to provide access to the unit 20 and in particular to the junction where the inlet pipe portion 22 meets the outlet pipe portion 26. At this junction, because of the change of direction of water flow through the pipe network, blockages can occur and it is important to be able to quickly clear blockages at this junction.

In this embodiment, the inner diameters of the inlet pipe portion 22, the outlet pipe portion 26 and the access pipe portion 28 are identical -they are all 100mm. In other embodiments, the portions may have different inner diameters, e.g. 150mm, 200mm, 400mm etc. In yet further embodiments, the inner diameters of the different portions may not be identical to each other.

For example the access pipe portion may be of a smaller inner diameter than the outlet pipe portion 26. In such an example, the access pipe portion may need to be a certain minimum inner diameter, for example 75mm in order to provide effective rodding access to the junction. Beyond providing that effective access, the access pipe portion 28 need not be any larger.

The open end 30 of the access pipe portion 28 needs to be covered in normal use. An end cap 32 is used to cover the open end 30 of the access pipe portion 28. In this example, the end cap 32 is a push fit end cap. In this example, the end cap 32 is a flat end cap. It will be apparent to the skilled person that in other examples, the end cap may not be a push fit end cap, and may not be flat. A flat end cap saves resource (in terms of material) relative to a non-flat, e.g. a bowl-shaped, or cylindrical, end cap.

The end cap is usually formed separately from the unit 20.

In this embodiment, the access pipe portion 28 further comprises end cap retaining means. In this embodiment the end cap retaining means comprises securing lugs 34. In this embodiment the securing lugs 34 comprises a pair of lugs arranged 1800 apart on opposite sides of the access pipe portion 28.

Each securing lug 34 projects outwardly from an outer surface of the access pipe portion 28. In this embodiment, each securing lug 34 comprises a generally U or C shaped securing lug. Each prong of the securing lug is approximately pyramid shaped. Each securing lug 34 is arranged to receive end cap securing means. In this embodiment the end cap securing means comprises a bolt 36 for each securing lug. The bolt is able to pass through a channel in the securing lug in between the prongs of the securing lug 34 as shown in figure 2e. The bolt can then have a washer attached to its end in order to secure it against the prongs of the lug 34. The end cap 32 that is to be attached to the unit 20 has bolt holes formed therein in this embodiment and the bolt holes are arranged to receive the bolt 36. In other embodiments, other arrangements for attaching the bolt 36 to the end cap 32 will be apparent to the skilled person For example, the bolt may be permanently attached to the end cap.

The bolt 36 is secured to the end cap 32 via a conventional washer in this 15 embodiment.

The bolt 36 has a longitudinal axis and cooperates with the other bolt 36 on the opposite side of the unit 20 to provide a retaining force to retain the end cap 32 to close the open end 30 of the access pipe portion 26. The retaining force is aligned with the longitudinal axis of the bolt 36 and also the longitudinal axis of the access pipe portion 28. As a result, an efficient closing mechanism for the open end of the access pipe portion is provided.

In a further embodiment, the end cap retaining means comprises only a single 25 securing lug. The corresponding end cap securing means may comprise a single bolt in such an embodiment.

In this example, the end of the access pipe portion 28 comprises a connection zone 38 arranged to facilitate connecting of a further pipe (if desired) to the 30 end of the access pipe portion. The connection zone 38 is in the form of a blank section of pipe in this example. The blank section of pipe comprises a plain, straight pipe section, which can be used to connect the access pipe portion 28 to a further pipe if the end cap is not in place. The connection zone 38 in this example extends for about 40mm and there are no lugs, or other protrusions in this connection zone 38 such that easy connection via a conventional coupling to a further pipe can be achieved if the end cap is not required to be in place. In other embodiments the connection zone may be shorter, for example about 10mm in length. The connection zone 38 is similar to connection zones (blank, straight sections) at the ends of the inlet pipe portion and the outlet pipe portion that are used to facilitate joining inlet and outlet pipes thereto.

In yet further embodiments, alternatively or additionally to comprising one or more lugs, the end cap retaining means comprises a thread provided on the access pipe portion and arranged to correspond with a corresponding thread provided on an end cap. The thread may be an internal thread on the inner surface of the access pipe portion 28. In that case the thread may extend from the open end of the access pipe portion.

Or, the thread may be an external thread provided on an outer surface of the access pipe portion. In that case, if the option to attach a further pipe to the access pipe portion is not required, then the thread may extend from the open end. Otherwise, if a connection zone 38 is to be retained on the outer surface of the access pipe portion, then the external thread on the outer surface of the access pipe portion may extend only once the connection zone has expired, i.e. there is a plain portion of pipe extending form the open end of the access pipe portion followed by the external thread.

Having the end cap retaining means in the form of a thread still retains the benefit of the retaining force being in line with the longitudinal axis of the access pipe portion and therefore in line with the pressure or force exerted on the end cap in use.

The unit 20 further comprises attachment means arranged to facilitate attachment of the unit to the floor 8. In this case the unit 20 is hung or suspended from the floor 8 as shown in figure 1 and figure 1 a. In other embodiments the unit 20 itself may not be suspended from the floor but sufficient securing may be achieved by the pipes that it joins together being sufficiently secured to an adjacent structure, such as the floor 8. For example, the second pipe 10b may be sufficiently secured to the floor which means that the unit 20 itself does not need to be secured.

However in this particular example, the unit 20 is secured to the underside of the floor 8. The attachment means comprises, in this example, multiple fixing lugs projecting from an outer surface of the unit. In some embodiments, only a single fixing lug may be provided. In other embodiments, no fixing lug is provided.

The unit 20 comprises a web 40 formed between the access pipe portion 20 and the inlet pipe portion 22. The web 40 is best seen in figure 2e. The web 40 provides strength to the structure of the unit 20.

The attachment means comprises multiple fixing lugs 42a, 42b as seen in figures 2a to 2e. The fixing lugs 42a are provided as a pair on opposite sides of the outer surface of the access pipe portion 28 in between the securing lugs 34 in this particular example. The fixing lugs 42a, similarly to the securing lugs 34 are provided just beyond the connection zone, in this embodiment. This is to achieve an advantageous balance so that the connection zone 38 can be kept clear and also so that the fixing lugs 42a are spaced at sufficient distance from the inlet pipe portion 22 such that an installer can easily attach a fixing mechanism to the fixing lug 42a. In use, as can be seen in figure 1 and figure 1 a, a fixing rod 44a is attached in a conventional manner to one of the fixing lugs 42a (the one on the same side of the unit as the inlet pipe portion 22). In this example, each fixing lug 42a comprises a projection extending from an outer surface of the access pipe portion 28. Each fixing lug has a hole formed therein to which a fixing rod 44a can be attached. In other embodiments suitable forms of fixing lug or fixing hook or fixing loop or other suitable attachment means will be apparent to the skilled person.

In this example, the attachment means also comprises a further fixing lug 42b formed via an aperture within the web 40. When the unit is mounted in a different orientation, then this fixing lug 42b can also be used for fixing the unit to a nearby structure via a fixing rod. This further fixing lug 42b may also be used to attach the unit 20 to a nearly wall, e.g. a vertical wall.

In this example, the pair of fixing lugs 42a, or at least one of the fixing lugs 42a, is spaced by at least 100mm from the closest part of the inlet pipe portion 22 -this is so that an installer has easy access to the fixing lug 42a when hanging the unit 20.

In this embodiment the unit 20 is formed as a single piece of cast metal; in this embodiment cast iron. In other embodiments the single piece may be another cast metal, or cast steel, or a single piece plastics material. Formation as a single piece provides the advantage of off-site manufacture of a complex part of the pipe system, and an associated resource saving, in terms of volume of material required and also installation complexity and time.

Referring to figures 3a to 3e another embodiment of the invention comprises the 45° rodding branch unit 50. From the figures 3a to 3e, it will be appreciated that the 45° rodding branch unit is substantially similar to the 90° rodding branch unit other than it is intended to join together inlet and outlet pipes (i.e. the third pipe 10c and the fourth pipe 10d in figure 1) that are in the same plane and oriented at about 45° relative to each other. The unit 50 has an inlet pipe portion 52 having an open end 54, an outlet pipe portion 56, and access pipe portion 58 having an open end 60, and end cap retaining means in the form of securing lugs 64 arranged to secure an end cap 62. The securing lugs 64 cooperate with bolts 66 as previously described in relation to the first embodiment. The access pipe portion 58 includes a connection zone 68.

A web 70 is provided between the inlet pipe portion and the access pipe portion. Fixing lugs 72a are formed on the access pipe portion as a pair on opposite sides. A fixing lug 72b is provided within the web 70. Features of the unit 50 are generally similar to the features of the unit 20 of the first embodiment. A difference is the shape of the inlet pipe portion 52 as can be seen from figures 3a to 3e compared to figures 2a to 2e. In particular, the inlet pipe portion 52 comprises a generally straight section of pipe with no bend. No bend is required in this embodiment. Therefore the inlet pipe portion 52 is able to be formed slightly shorter than the inlet pipe portion 22. In general, in both described embodiments the inlet pipe portion, outlet pipe portion and access pipe portion are as compact as possible whilst providing effective connection zones on each, and also to allow sufficient space for securing lugs and fixing lugs that are easy to use. The units 20, 50 are generally shorter and more compact than prior art equivalent sections of separate pipe that are cut and joined together. As can be seen in figure 1 b, the unit 50, in the example shown, is suspended in a different configuration to the unit 20. Since the unit 20 is differently orientated relative to the floor 8, different fixing lugs are used. The pair of fixing lugs 72a are both used in conjunction with fixing rods 74a as shown in figure 1 b. Although not shown, it will be apparent to the skilled person that in another scenario, the fixing lug 72b formed within the web 70 may also have a fixing rod (not shown) attached it within the configuration shown in figure lb for attaching the unit 50 to the floor 8.

In other embodiments, the unit 20 may be used in a similar role to the unit 50 in the underfloor pipe network. For example if the second pipe 10b is to be attached to the fourth pipe 10b (without the third pipe 10c in between) then the 900 rodding branch unit 20 can be used in a different configuration, and different fixing lugs used to secure it to the floor 8. The inlet pipe portion 22 would then be attached to the second pipe 10b, whilst the outlet pipe portion 26 would be attached to the fourth pipe 10b. Rodding access would still be conveniently provided by the unit 20 at the junction.

The units 20, 50 have further utility. In particular, in some scenarios, instead of rodding access, it is desirable to attach a further length of pipe to the junction between an incoming pipe and an outgoing pipe. Rodding access may be provided further along the pipe network instead of at the junction. In that scenario, the inventive unit allows an easy, efficient mechanism for attaching a further pipe. The connection zone 38 on the unit 20 or the connection zone 68 on the unit 50 is specially designed to allow for easy coupling of a further pipe using standard couplings. In particular, the blank portion of the pipe at the end of the access pipe portion allows for this.

Advantageously, in the embodiment described so far, the securing lugs 34, 64 are provided just after the connection zones 38, 68. This allows for the best possible securing of the cap balanced with the option to easily attach a further pipe in the event that an end cap is not required. Conventional pipe networks simply do not offer this option.

Figure 4 shows the 90° rodding branch unit 20 attached to the floor 8. As can be seen in figure 4, in order to join two pipes and provide good rodding access, the inventive unit 20 in addition to two couplings 80 is used. The couplings are standard ring clamp couplings that are used to attach, in a conventional manner, ends of the inlet pipe portion and the outlet pipe portion to adjoining pipes. The couplings 80 are usually separate cast metal pieces.

The couplings 80 work by applying a clamping force on both pipes (i.e. the pipes to be joined together) towards the centre line of the pipes. Therefore a force is applied in a direction perpendicular to the direction of flow through the pipes (i.e. the longitudinal axis of the pipe).

It will be appreciated that the unit of the present invention greatly simplifies the installation process for installing on site of a secure, efficient pipe junction having good rodding access.

Various modifications may be made to the present invention without departing from its scope. In particular, different forms of securing lugs or fixing lugs may be used as will be apparent to the skilled person. For example, lugs may be in the form of hooks or loops.

The end cap retaining means (e.g. securing lug or lugs) may not be provided on the access pipe portion in other embodiments. For example, the end cap retaining means (e.g. securing lug or lugs) may instead (or additionally) be provided on the outlet pipe portion (in such an embodiment, longer bolts may be used to connect the end cap to the end cap retaining means). In another example, the end cap retaining means (e.g. securing lug or lugs) may instead (or additionally) be provided on the inlet pipe portion On such an embodiment, offset or angled or bent end cap securing means may be provided. In summary, the end cap retaining means may be provided on any of the inlet pipe portion, the outlet pipe portion or the access pipe portion, or any combination thereof (e.g. partly on any one or more of the above-mentioned portions).

It will be apparent to the skilled person that the unit can be attached to a structure other than a floor, e.g. a wall, ceiling or any other stable structure.

When used in this specification and claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Although certain example embodiments of the invention have been described, the scope of the appended claims is not intended to be limited solely to these embodiments. The claims are to be construed literally, purposively, and/or to encompass equivalents.

Claims

Claims 1. A rodding branch unit arranged to join a first pipe and a second pipe and allow access to the junction, the unit comprising: an inlet pipe portion arranged to be attached to the first pipe; an outlet pipe portion arranged to be attached to the second pipe; and an access pipe portion arranged to provide access to the unit, the access pipe portion having an open end; wherein the unit further comprises end cap retaining means arranged to facilitate retaining an end cap on the open end.
2. The rodding branch unit of claim 1 wherein the access pipe portion comprises at its open end, a connection zone arranged to facilitate connecting of a further pipe to the access pipe portion.
3. The rodding branch unit of claim 1 or claim 2 wherein the connection zone comprises a blank section of pipe.
4. The rodding branch unit of claim 2 or claim 3 wherein the length of the connection zone is lOmm or longer than lOmm.
5. The rodding branch unit of any preceding claim wherein the access pipe portion comprises the end cap retaining means.
6. The rodding branch unit of any preceding claim wherein the end cap retaining means is arranged to facilitate retaining the end cap by exerting a force on the end cap in a line substantially parallel to a longitudinal axis of the access pipe portion.
7. The rodding branch unit of any preceding claim wherein the end cap retaining means comprises one or more securing lugs arranged to receive end cap securing means, such as a bolt, the end cap securing means being arranged to secure the end cap to the access pipe portion.
8. The rodding branch unit of claim 7 when dependent on claim 6 wherein the bolt has a longitudinal axis and, in use, is arranged parallel to the longitudinal axis of the access pipe portion such that the end cap is urged to close the open end of the access pipe portion in line with the longitudinal axes.
9. The rodding branch unit of any of claims 5 to 8 wherein the end cap retaining means comprises a first thread on the access pipe portion, the first thread being configured to engage with a second thread on the end cap, which is optionally a flat push fit end cap.
10. The rodding branch unit of any of claims 1 to 8 wherein the end cap comprises a push fit end cap, optionally a flat push fit end cap, arranged to friction fit into the open end of the access pipe portion.
11. The rodding branch unit of any of claims 7 to 10 wherein the or each securing lug is just over lOmm from the open end. 20
12. The rodding branch unit of any preceding claim comprising attachment means arranged to facilitate attachment, such as by hanging or suspension, of the unit to a structure, such as a ceiling or floor or wall, and optionally wherein the attachment means is arranged to facilitate attachment of the unit in more than one configuration, such as in a first orientation and in a second orientation, and optionally wherein the relative orientation of the unit relative to the structure in the first orientation compared to the second orientation is 90 degrees.
13. The rodding branch unit of claim 11 wherein the attachment means comprises one or more fixing lugs, and optionally wherein each fixing lug is arranged to receive a fixing rod.
14. The rodding branch unit of claim 13 wherein the fixing lugs are spaced apart.
15. The rodding branch unit of claim 13 or claim 14 wherein at least one of the one or more fixing lugs are just over lOmm from the open end.
16. The rodding branch unit of any of claims 13 to 15 wherein at least one of the one or more fixing lugs are over 100 mm from the point where the inlet pipe portion meets the access pipe portion.
17. The rodding branch unit of any preceding claim comprising a web between the inlet pipe portion and the access pipe portion.
18. The rodding branch unit of claim 17 comprising a fixing lug within the web.
19. The rodding branch unit of any preceding claim wherein the outlet pipe portion and the access pipe portion are aligned with each other.
20. The rodding branch unit of any preceding claim wherein the angle between the outlet pipe portion and the inlet pipe portion is about 90 degrees, or is about 45 degrees.