GB2431445A

GB2431445A - Soil manifold with off centre connection bosses

Info

Publication number: GB2431445A
Application number: GB0521267A
Authority: GB
Inventors: Peter Dark
Original assignee: Wavin BV
Current assignee: Wavin BV
Priority date: 2005-10-19
Filing date: 2005-10-19
Publication date: 2007-04-25
Anticipated expiration: 2025-10-19
Also published as: GB0521267D0; GB2431445B

Abstract

A soil manifold 8 for connecting a waste pipe to a soil stack comprises a housing 15 for connection in-line with the stack, having at least one sidewall 16, 17, 18, 19 with a boss 21, 22, 23 for connecting to a waste pipe. There is a skirt 32 within the housing 15 for deflecting waste entering through the connector, and preventing waste in the stack from flowing back into the waste pipe. The connector bosses 21, 22, 23 are off-radial with respect to the skirt, which may reduce the likelihood of damage to the skirt when a hole saw is used to open up the bosses. It may also reduce the likelihood of blockage by inducing a circumferential flow within the housing.

Description

1 2431445

ROIL MANIFOLD

The present invention relates to a soil manifold.

In certain plumbing systems, it is desirable to connect the wasteflow pipes from a number of units (WC, bath, sink, etc) to a single outflow soil stack. This can be achieved using branch fittings, with each fitting connecting a respective unit to the soil stack. This type of arrangement is inconvenient, however, as each connection must be joined to the soil stack at a different height along the stack. Double branch fittings can be used to make two connections at the same height. Double branch fittings do not accommodate three or more connections, however, and can result in cross-flow i.e. waste water flowing from a branch on one side into a branch on the opposite side of the fitting.

Fittings known as soil manifolds or collar bosses are used to connect waste pipes to a soil stack in a space-saving manner, by enabling several connections to be made at the same level. GB 1 271 971 describes a soil manifold which enables the connection of up to four waste pipes at the same point of a soil stack. This is achieved using a generally cylindrical soil manifold wherein four bosses, used to connect a respective outflow pipe to the soil manifold, are equidistantly spaced around the circumference of the cylindrical soil manifold. Typically, three of the four bosses are supplied closed, and are opened as required using a circular hole saw. Once the required bosses are opened, waste pipes are connected to the manifold by inserting the pipes through the opened bosses, along an axis of the boss. The boss axis aligns radially with a longitudinal axis of the cylindrical manifold. The soil manifold further includes a central skirt within the manifold. The skirt is designed to prevent cross-flow, i.e. waste water flowing out of one connection into a connection opposite. The skirt also serves as a joint to enable a pipe of the soil stack to be inserted into the top of the soil manifold.

There are a number of disadvantages associated with this soil manifold. In particular, as the bosses are so close to the skirt, it is not uncommon for less experienced operators to damage the skirt when opening a boss. Also, when a pipe laid close to a wall is to be connected to the soil manifold, the pipe must nearly always be bent to make the connection with the manifold.

The present invention seeks to provide an improved soil manifold.

According to the present invention, there is provided a soil manifold for cormecting at least one waste pipe to a soil stack, the soil manifold comprising: a housing having a sidewall provided with at least one connector for colmecting a waste pipe to the soil manifold, said at least one connector defining a connector axis; a skirt contained within the housing to deflect waste entering the housing from said at least one connector, the skirt defining a skirt axis; wherein said connector axis is off-radial with respect to the skirt axis.

Embodiments of the invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a schematic view of a plumbing system using an embodiment of a soil manifold according to the present invention; Figure 2 is a perspective view of the embodiment of a soil manifold according to the present invention; Figure 3 is a crosssectional view along the line A-A of Figure 2; Figure 4 is an exploded perspective view of the soil manifold of Figure 2; Figure 5 is a reverseangle exploded perspective view of the soil manifold of Figure 2; Figure 6 is a top plan view of part of the soil manifold of Figure 2 with its cover removed; Figure 7 is a cross-section along the line B-B of Figure 6; and Figures 8, 9 and 10 illustrate variations of the embodiment of Figure 2.

Figure 1 shows an embodiment of a soil manifold according to the present invention in use in a typical application.

A vertical soil stack I comprising two pipes IA, lB is arranged to collect waste water from plumbing systems on a number of different floors in a building. In the illustrated plumbing system, shown generally at 2, a branch fitting 3 having two arms 4, 5, is used to connect two toilets 6, 7 to the upper pipe 1A of the soil stack I. The bottom of the upper soil stack pipe 1A extends out from the bottom of the branch fitting 3 and is inserted into the top of the soil manifold 8. The soil manifold 8, which will be described in greater detail hereinafter, connects outflow pipes 9, 10, 11 from two sink units 12, 13 and a bath 14 to the soil stack I at the same height along the vertical soil stack 1. The bottom of the soil manifold 8 is inserted into the top of the lower pipe 1 B of the soil stack 1. This pipe leads out of the building, either directly or via other plumbing systems which also feed into the soil stack.

The embodiment of the soil manifold 8 according to the present invention shown in Figure 1 will now be described in greater detail, with reference to Figures 2 to 7.

The soil manifold 8 comprises a housing 15 made of a PVC plastics material.

The housing has four straight sidewalls 16, 17, 18, 19 of equal length joining at right- angles, such that the housing 15 has a square cross-section in a horizontal plane. The housing 15 is open at its top and has a bottom wall 20 defining a flat bottom plane. At each internal corner of the housing 9, the bottom wall 20 is indented to form a pair of triangular, angled faces 20A, 20B, such that each internal corner of the housing 15 is profiled. The triangular faces are angled at 20 degrees to the flat bottom plane in the present embodiment, although other angles may be used.

As best seen from Figures 5 and 6, three of the four flat sidewalls 16, 17, 18 of the housing are provided with respective pairs of connectors in the form of protruding bosses 21, 22, 23. Each of the bosses 21, 22, 23 is located laterally off-centre of its respective sidewalls 16, 17, 18. That is, the bosses of each pair are located with a first boss 21A, 22A, 23A to one horizontal side of the centre of the sidewall, and with a second boss 21B, 22B, 23B on the other horizontal side of the centre of the sidewall.

Each boss is of circular cross-section and is provided with dual-sized 40 mm and 50 mm spigots to allow a more flexible range of fittings to be attached to the manifold. The boss spigots are closed and must be opened prior to use, as required, using a hole saw or other suitable means. Each boss defines a respective boss axis perpendicular to the plane of its sidewall 16, 17, 18 along which a waste pipe may be inserted to connect the pipe to the manifold 8. The fourth flat sidewall 19 of the housing 24 is blank and is not provided with any bosses.

An axial tubular extension 24 extends from the bottom wall 20 of the housing and comprises a circular collar 25 connected to a pipe extension 26 by a frustoconical tapering wall 27. The pipe-extension 26 is co-axial with the circular collar 25, and the lower edge of the pipe extension 26, remote from the circular collar 25, is chamfered. The outer diameter of the pipe extension 26 is fractionally smaller than the inner diameter of a pipe of a soil stack to which the soil manifold 8 is to be connected.

The soil manifold 8 further comprises a separate cover 28, which has a flat upper wall 29, provided with a surrounding peripheral first vertical wall 30. As best seen from Figure 4, within the perimeter defined by the first vertical wall 30, and spaced horizontally therefrom, is a second vertical wall 31, which extends from the flat upper wall 29 by a greater distance than the first vertical wall 30. Within the boundary defined by the first and second vertical walls 30, 31 is a skirt 32, which defines a longitudinal skirt axis perpendicular to the plane of the flat upper wall 29. The skirt 32 comprises a hollow inwardly-tapering frustoconical portion 33 having an inwardly- turned end region 33A linking the frustoconical portion 33 to a circular fitting 34. The circular fitting terminates in a turned-in circumferential lip 34A at the end of the circular fitting 34 remote from the frustoconical portion 33.

A mouth 35 of the frustoconical portion defines an aperture in the top of the cover 28 where it meets the flat upper wall 29, and the inner diameter of the circular fitting 34 is fractionally larger than the outer diameter of a pipe of a soil stack to which the soil manifold 8 is to be connected.

The cover 28 and housing 15 fit together as shown in Figures 2 and 3. The upper edges of the sidewalls 16, 17, 18, 19 of the housing 25 are inserted into the gap between the first and second vertical waIls 30, 31 to contact the underside of the flat upper wall 29 of the cover 28.

When the cover 28 is in place, the axis of the skirt 32 of the fitted cover aligns with the axis of the tubular extension 24 of the housing. The boss axes lie in a plane substantially perpendicular to the longitudinal axes of the skirt 32 and tubular extension 24. Furthermore, owing to the off-centre location of the bosses 21, 22, 23 on the sidewalls 16, 17, 18 the axes of the bosses are laterally off-centre with respect to the longitudinal axes of the skirt 32 and tubular extension 24 - rather than aligning with a radius of those axes, the boss axes lie to a lateral side of the skirt and tubular extension axes. That is, the boss axes are off-radial with respect to the skirt and tubular extension axes.

As best seen from Figure 3, when the cover 28 is fitted in place, an annular cavity 36 is formed between the outer faces of the frustoconical portion 33 and circular fitting 34 of the cover 28, and the internal faces of the sidewalls 16, 17, 18 19 of the housing 15. Furthermore, the lower edge of the circular fitting 34 of the cover 28 is vertically spaced from the tapering wall 27 of the housing.

The fitted cover 28 is joined to the housing 15 by solvent welding to form the assembled manifold. Alternatively, a tight seal may be established as a snap-fit between the fitted cover 28 and the housing 15.

The installation of the assembled soil manifold 8 into a plumbing system will now be described. First, the bottom end of an upper pipe 1 A of a soil stack I is inserted into the aperture in the cover 28 of the manifold 8 defined by the mouth 35 of the frustoconical portion 33 of the skirt 32. The insertion is continued until the pipe protrudes into the circular fitting 34 and seats upon the circumferential lip 34A. As the internal diameter of the circular fitting 34 is only fractionally larger than the outer diameter of the upper pipe of the soil stack 1, a friction fit is established therebetween for subsequent solvent welding.

The pipe extension 26 at the bottom of the housing 15 is then inserted into the top end of a lower pipe I B of the soil stack. This insertion is facilitated by the chamfered lower edge of the pipe extension 26. As the exterior diameter of the pipe extension 26 is only fractionally smaller than the interior diameter of the lower pipe I B, a friction fit is established therebetween for subsequent solvent welding.

As will be appreciated, because the axes of the skirt 32 of the fitted cover 28 and of the tubular extension 24 of the housing 15 are aligned, the upper and lower pipes, once connected to the soil manifold 8, will also be aligned. The longitudinal axes of the skirt 32 and tubular extension 24 are thus aligned with a longitudinal axis of the soil stack, permitting the unimpeded flow of waste water from the upper pipe to the lower pipe of the soil stack.

This fitting process could be reversed, and the pipe extension 26 at the bottom of the housing 15 could first be inserted into the top of a lower soil stack pipe, with the bottom of an upper soil stack pipe being inserted into the cover 28 of the soil manifold 8 thereafter, or alternatively, simultaneously. Whatever method is adopted, however, it should be noted that the flat bottom wall 20 of the housing 15 permits the housing 15 to fit flush to the floor of a room, prior to the laying down of screed, which fixes the soil manifold 8 in place.

It is often desirable to fit the soil manifold 8 as close to a backing wall of a room as possible. By mounting the soil manifold with the flat sidewall 19 of the housing 15 flush against a backing wall, a very close fitting may be provided.

Once the soil manifold 8 is fitted in place, outflow pipes of units to be connected to the soil stack 1 are connected to the soil manifold 8 as follows.

Firstly, if the appropriate bosses have not yet been opened, then that action is performed, using a hole saw or other suitable means. It will be appreciated that as the axes of the bosses 21, 22, 23 are off-centre with respect to the axis of the skirt 32 of the cover 28, the likelihood of damage to the skirt 28 by insertion of a hole saw or similar along the axis of a boss is significantly reduced. In the present embodiment, the amount of lateral offset of the bosses 21, 22, 23 from the middle of the sidewalls 16, 17, 18 is such that a hole saw of an appropriate size for the boss does not contact the skirt, even when fully inserted into the housing 15.

Once the bosses have been opened, the outflow pipes 9, 10, 11 of the various units to be connected to the soil stack are inserted into the bosses 21, 22, 23. As each of the bosses is provided with a dual-size spigot, outflow pipes of various diameters may be connected to the manifold.

As will be appreciated, once the bosses have been opened, a path of fluid communication from the boss to the soil stack, via the annular cavity 36, is established.

Waste water from the units connected to the manifold may thus flow from the units into the soil stack 1.

Furthermore, as the bosses are located off-centre, waste water flowing through the outflow pipes into the soil manifold 8 is induced into a radial flow within the housing, which reduces bridging of the annular cavity 36 by debris contained in the waste water. The profiled corners of the housing 15 also reduce the build-up of debris in the annular cavity 36.

As will further be appreciated, the two bosses 21A, 23B of the housing 15 closest to the flat sidewall 19 permit pipes to be connected thereto without need for significant bending of the pipes to make the connection, even when the pipes are located close to a backing wall. This results from the bosses 21 A, 23B themselves being located close to the backing wall, by virtue firstly of their off-centre position on their respective sidewalls and secondly as a result of the close fitting against the backing wall provided by the flat, blank sidewall 19 of the manifold.

Although each of the bosses 21, 22, 23 of the housing 15 are illustrated as being off-centre, not all of the bosses need be so disposed. The present embodiment has been described as having six bosses located in three pairs on the three side-walls - fewer or greater than two bosses may be provided on the sidewalls. Other numbers of bosses may be used, in particular four and eight bosses, and the bosses need not be provided in pairs on sidewalls of the housing 15. Although the skirt 32 has been described as a separate piece, integral with the cover 28, this need not be the case - in particular, the cover and skirt may be formed integrally with the housing 15. Alternatively, the skirt 32 could be integral with the housing 15, with only the cover separate. In that case, holes would need to be provided in the skirt 32 to permit waste water to flow out of the housing. Although the above-described embodiment of a manifold is made of PVC parts joined by solvent welding, other thermoplastics, such as ABS plastic, are equally suitable. Also, other types of materials and/or connections, for example a snap-fit, or a connection employing rubber sealing rings, are equally possible. All that is required is for the connections to be tight enough to prevent odours from emanating from the manifold 8.

Also, the housing 15 of the above-described embodiment is square in crosssection which, amongst other advantages, allows convenient installation into corners.

Other cross-sections are possible, however. For example, a housing 37 of circular cross-section could be employed, with the housing 37 formed such that the axes of the bosses 38, 39, 40, 41 are non-radial, as shown in the variation of the embodiment of Figure 2 shown in Figure 8.

Figure 9 shows a further variation of the embodiment of Figure 2, in which the bosses 42, 43, 44, 45 are mounted centrally on the sidewalls of the housing 46. The bosses 42, 43, 44, 45 are angled in the horizontal plane with respect to the sidewalls, such that the boss axes are angularly offset with respect to the skirt and tubular extension axes. In this variation, the risk of damaging the skirt by opening the bosses is not necessarily reduced. This arrangement does, however, provide the advantage of inducing radial flow within the housing 46.

Figure 10 shows a further variation of the embodiment of Figure 2, wherein the skirt 47 is of substantially square cross-section. Although the skirt 47 is of substantially square cross-section, the housing 52 still has a circular aperture 53 in its cover for a circular cross- section soil stack pipe to be inserted therein. Bosses are provided in pairs 48, 49, 50, 51 on sidewalls of the housing 52, which is also of square cross-section. The bosses 48, 49, 50, 51 are laterally offset from the centres of the sidewalls of the housing by a sufficient amount that their respective axes align with the gap between the skirt 47 and the housing 52. As a result, the risk of damage to the skirt 47 when the bosses are opened is minimised, and waste water entering the manifold is induced into radial flow in the housing 52.

Although the bosses of the above-described embodiment define axes perpendicular to the sidewalls of the housing in a vertical plane, this need not be so.

The soil manifold connections in the above-described embodiment are protruding bosses. Other types of connections, for example recessed sockets, could however equally be used.

It is within the scope of the present invention that the various features of the embodiment, described alternatives and variations may be combined to form other embodiments falling within the scope of the present invention.

Claims

1. A soil manifold for connecting at least one waste pipe to a soil stack, the soil manifold comprising: a housing having a sidewall provided with at least one connector for connecting a waste pipe to the soil manifold, said at least one connector defining a connector axis; a skirt contained within the housing to deflect waste entering the housing from said at least one connector, the skirt defining a skirt axis; wherein said connector axis is off-radial with respect to the skirt axis.

2. A soil manifold according to claim I, wherein said at least one connector is laterally offset with respect to the skirt axis.

3. A soil manifold according to claim 1 or claim 2, wherein said at least one connector is angularly offset with respect to the skirt axis.

4. A soil manifold according to any preceding claim, wherein said sidewall has a middle, and said at least one connector is laterally offset of the middle of said sidewall.

5. A soil manifold according to any preceding claim, wherein said at least one connector is angled with respect to said sidewall of said housing.

6. A soil manifold according to any preceding claim, wherein said at least one connector comprises a plurality of connectors, the sidewall being provided with at least one of said plurality of connectors.

7. A soil manifold according to claim 6, wherein the sidewall is provided with a plurality of connectors of said plurality of connectors.

8. A soil manifold according to claim 6 or 7, wherein the soil manifold further comprises a plurality of sidewalls, each of the sidewalls being provided with at least one connector of said plurality of connectors.

9. A soil manifold according to claim 8, wherein the soil manifold comprises a plurality of sidewalls provided with a plurality of connectors of said plurality of connectors.

10. A soil manifold according to any preceding claim, wherein the soil manifold further comprises at least one blank sidewall not provided with a connector.

11. A soil manifold according to any preceding claim, wherein the sidewall or sidewalls are flat and define a plane parallel to said skirt.

12. A soil manifold according to any preceding claim, wherein the housing has a substantially square cross-section.

13. A soil manifold according to any one of claims I to 7, wherein the housing has a substantially circular cross-section.

14. A soil manifold according to any preceding claim, wherein said at least one connector is closed and arranged to be opened prior to use.

15. A soil manifold according to any preceding claim, wherein said at least one connector has a dual-sized spigot.

16. A soil manifold according to any preceding claim, wherein the housing has a bottom wall defining a flat bottom plane.

17. A soil manifold according to any preceding claim, wherein the housing has at least one profiled corner.

18. A soil manifold according to claim 17 as dependent upon claim 16, wherein the corner is profiled by a face disposed at an angle with respect to the flat bottom plane.

19. A soil manifold according to claim 18, wherein the face is disposed at an angle of 20 degrees with respect to the flat bottom plane.

20. A soil manifold according to any preceding claim, wherein the skirt is separate from the housing.

21. A soil manifold according to claim 20, wherein the skirt is integral with a cover of the soil manifold which is separate from the housing of the soil manifold.

22. A soil manifold according to any one of claims ito 19, wherein the skirt is integral with the housing.

23. A soil manifold according to claim 22, wherein the skirt is provided with apertures.

24. A soil manifold according to any preceding claim, wherein the soil manifold comprises parts made of a thermoplastics material.

25. A soil manifold according to claim 24, wherein the parts are connected by solvent welding.

26. A soil manifold according to any one of claims 1 to 24, wherein the soil manifold comprises parts connected using sealing rings.

27. A soil manifold according to any preceding claim, wherein the skirt has rotational symmetry around the skirt axis.

28. A soil manifold according to claim 27, wherein the skirt has a circular cross-section.

29. A soil manifold according to any one of claims ito 26, wherein the skirt is of square cross-section.

30. A soil manifold according to any preceding claim, wherein the connector axis of said at least one connector lies in a plane which is substantially perpendicular to the skirt axis.

31. A soil manifold substantially hereinbefore described, with reference to the accompanying Figures i to 7.

32. A soil manifold substantially hereinbefore described, with reference to the accompanying Figure 8.

33. A soil manifold substantially hereinbefore described, with reference to the accompanying Figure 9.

34. A soil manifold substantially hereinbefore described, with reference to the accompanying Figure 10.