GB2531069A

GB2531069A - Drainage unit

Info

Publication number: GB2531069A
Application number: GB1417987.3A
Authority: GB
Inventors: Martin Powell Timothy
Original assignee: BATHROOM BRANDS IP HOLDINGS Ltd
Current assignee: BATHROOM BRANDS IP HOLDINGS Ltd
Priority date: 2014-10-10
Filing date: 2014-10-10
Publication date: 2016-04-13
Also published as: GB201417987D0

Abstract

A drainage unit for a bath wherein the drainage unit controls water flow in dependence upon the fluid level in the bath. The drainage unit 80 comprises a plug housing 82 which fits within a plug hole 66 of bath 50. The plug housing 80 defines a first chamber 84 with an outlet aperture 86. A drain pipe 88 is fluidly connected to the outlet aperture 86 and comprises a length of pipe which extends away from the outlet aperture 86 to a position which in use, when the drainage unit 88 is coupled to a bath unit or the like, is at a predetermined height that corresponds to a desired maximum water level in the bath 50, above the level of the outlet aperture 86. A later embodiment relates to a drainage unit (200 figure 6) which comprises a movable tube (202 figure 6) open at both ends and which extends upwards from the bath orifice 66 by a predetermined amount which corresponds to a desired maximum fluid level in the bath.

Description

DRAINAGE UNIT

The present disclosure relates to a drainage unit.

In particular the present disclosure relates to a drainage unit for a bath, or the like.

Background

A cross-section of a typical bath unit, for a human to wash in, is shown in Figure 1. The bath comprises a base 20 and side walls 22, with a drain plug 24 being provided in the base 20. Although not shown in the figures, a drainpipe will be connected to the drain plug 24 for the removal of water from the bath. An overflow 26 is provided in the wall 22 of the bath. The base 20 and walls 22 are defined by a shell which, because of the nature of the manufacturing process for such units, is usually smooth on its wet" side, and rough on its "dry' side. Hence the "dry" side is normally hidden from view by a panel 28. The base 20 is supported by legs 32 which extend from the base 20 to the floor 34 upon which the bath unit sits. Typically the bath may be 550mm high, with an internal depth of around 400mm. Hence the gap between the base 20 and the floor, as created by provision of the legs 32, may be typically 150mm. The gap is advantageous as it may be utilised for piping and waste pipe connections. Additionally baths rely on a framework or legs 32 to angle and stabilise the bath, and angle them such that water will drain from the plughole 24.

A duct or pipe may lead from the overflow 26 to the same waste pipe which leads from the plug hole. Hence, if the plug hole is closed (for example with a plug), the water level in the bath will rise as far as the overflow 26, then then flow through the overflow 26 to the waste pipe, thereby restricting the overall depth of the water.

In the interests of water conservation, the height of overflow 26 is generally lower in modern baths than earlier models. However, the height of the bath walls may still remain the same, partly in the interests of aesthetics, and partly to shield the user from drafts and view whilst sitting in the bath. As this can be unsatisfying for the user, they may deliberately block the overflow orifice 26 to raise the level of the bath water, and hence risk bath water flowing over the top of the bath walls and causing water damage to the floor of the bathroom, and any part of the building structure that may be below the bathroom.

In some instances the duct leading from the overflow 26 may be formed as part of the wall of the bath, which adds to complexity of the manufacturing process. Additionally the overflow duct can be difficult to clean, leading to customer dissatisfaction.

Additionally, since the bath must be elevated above the floor on which is it supported to allow space for a drain pipe, the level of the floor 34 must be significantly lower than the height of the base 20, which may result a person stepping into or out of the bath over balancing and falling. This is a common problem, especially for children and the elderly.

Hence a drain arrangement which prevents accidental blockage of an overflow, and which enables a bath geometry which is easy for people to step into and out of, is highly desirable.

Summary

According to the present disclosure there is provided apparatus and a method as set forth in the appended claims. Other features of the invention will be apparent from the dependent claims, and the description which follows.

Accordingly there may be provided a drainage unit for a bath, or the like, wherein the drainage unit is configured to control fluid flow in dependence upon the fluid level in the bath, or the like.

The drainage unit may further comprise a plug housing which is configured to fit within a plug hole of a bath, or the like, and defines a first chamber with an outlet aperture; and a drain pipe which is in flow communication with the outlet aperture and comprises a length of pipe which extends away from the outlet aperture to a position which, in use, when the drainage unit is coupled to a bath or the like, is at a predetermined height, which corresponds to a desired maximum fluid level in the bath, above the level of the outlet aperture.

The drain pipe may further comprise an inverted "U" inflexion portion at its highest point which corresponds to the desired maximum fluid level in the bath; and extends from the inflexion portion downwards to a flow exit.

The flow may comprise a second chamber provided in the plug housing, the second chamber comprising an inlet for flow communication with the inflexion portion; and an outlet for flow communication with a fluid drain downstream of the flow exit.

The second chamber may be located underneath the first chamber.

The first chamber and second chamber may be fixed to one another.

A valve port may be provided between the first chamber and second chamber which permits selective flow communication between the first chamber and the second chamber; and the plug section may be movable between a first position in which the valve port is covered by the plug section such that the first chamber and second chamber are fluidly isolated from one another, such that fluid entering the first chamber flows along the drain pipe via the inflexion before being delivered to the flow exit via the second chamber; and a second position in which the plug section is spaced apart from the valve port such that the first chamber and second chamber are in fluid communication with one another, such that fluid entering the first chamber bypasses the drain pipe and inflexion portion and flows directly to the flow exit via the second chamber.

The plug housing may comprise a filter upstream of the first chamber, the filter being sized to prevent the passage of objects above a predetermined size.

The filter may be removable from the drainage unit.

The drainage unit may comprise a removable tube, open at both ends, which extends upwards from the bath orifice by a predetermined amount which corresponds to a desired maximum fluid level in the bath.

There may also be provided a bath unit comprising: a bath defined by a fluid retaining shell comprising an orifice; and a drainage unit according to the present disclosure, wherein the plug housing is located in the orifice. The bath unit may comprise a base layer is provided on the underside of the bath shell for seating the bath directly on a floor.

The drainage unit may extend downwards in a direction away from the fluid retaining shell such that, in use, it extends below floor level.

The bath may be defined by: a base and side walls; and the walls are angled at substantially 100 deg (A; D)to the underside of the base.

The base of the bath may be configured such that, when the bath is mounted on a floor, the base directs fluid to the orifice.

The base of the bath may be at an angle (C) of at least 1.2 deg to the underside of the base layer.

The shell may comprise material having a thickness of substantially 4mm, and a curved transition wall which has a radius (BE) of substantially 50mm between the walls and the base.

The shell may comprise a material having a thickness of substantially 5mm, and a curved transition wall which has a radius (B,E) of substantially 50mm between the walls and the base.

The bath may be substantially 1700 mm long along its top edge, and 335mm high from the underside of the base layer to the top edge of the bath.

The base layer may be substantially 25mm to 35mm thick.

The ratio of bath height to the thickness of the base layer may be at least 9 but no more than 12.

There may also be provided a bath unit installation comprising: a bath unit according to the present disclosure located on a floor wherein the drainage unit extends through the floor beneath the bath unit.

There may also be provided a method of installing a drainage unit according to the present disclosure comprising the steps of providing a bath having a plug hole; and coupling the drainage unit to the plug hole.

The method may further comprise the steps of: providing a floor for supporting the bath; and providing a thin base layer between the bath and the floor such that the drainage unit extends downwards in a direction away from the base of the bath and base layer.

The method may further comprise the steps of: providing an aperture in the floor; and locating the drainage unit in the floor aperture for coupling to a flow outlet.

Thus there is provided a drainage unit which provides a failsafe means of regulating water level in a bath, and which enables a bath unit which is inherently lower off the ground than a bath unit known from the related art.

Brief Description of the Drawings

Examples of the present disclosure will now be described with reference to the accompanying drawings, in which: Figure 1 shows a conventional bath unit, as previously discussed; Figure 2 shows a cross-section of an example of a bath unit for use with a

drainage unit according to the present disclosure;

Figure 3 shows a plan view of the bath unit shown in Figure 2; Figure 4 shows a side view of the bath unit and drainage unit shown in Figures 2, 3; Figure 5 shows an end view of the bath unit and drainage unit shown in Figures 2, 3, 4; and Figure 6 shows an alternative example of a drainage unit according to the

present disclosure.

Detailed Description

Figure 2 shows a cross section of an example of a bath unit 50 for use with a drainage unit 80 according to the present disclosure, and as shown in Figures 3 to 5, and in Figure 6. However, the drainage unit of the present disclosure may also be used in conjunction with other bath geometries and bath unit installations, not limited to the type or shapes shown in the figures. The drainage units of the present disclosure are configured to control fluid flow in dependence upon the fluid level in the bath, or whatever fluid retaining installation they are fitted to and/or form a part of.

The bath unit 50 comprises a bowl, cavity or basin 52 defined by a fluid retaining shell 54 which comprises a base 56 and side walls 58. That is to say, the bowl 52 is the shaped fluid retaining "bath" part in which a user may stand or sit when using the bath unit 50. A panel or frame 60 extends around the outside of the bath unit 50 and is spaced apart from the sheet material which defines the side walls 58. There may be provided a cavity 62 between the panel 60 and walls 58. A shelf 64 extends around the top edge of the side walls 58 by a distance "S" which may be, for example, about 50 to mm in width. In one example the shelf S may have a width of about 70mm. The shelf 64 extends from the top edge of the side walls 58 to the panel 60, and may be integrally formed as such. The bowl/bath 52 is provided with an orifice 66, which is usually referred to as a plughole. The base 56 of the bath 52 is configured such that when the bath 52 is mounted on a floor, for example the floor of a bathroom in which the bath sits and upon which users of the bath will walk and stand, the base 56 directs fluid to the orifice 66. This configuration may be defined based upon an assumption that the floor 34 will be approximately level (i.e. horizontal). Notably, the bath unit of the present disclosure does not comprise an overflow orifice, akin to the overflow orifice 26 of the related art, in the base 56 or walls 58 of the bath unit, as described in relation to Figure 1.

The bath unit 50 may be provided with a means for supplying water to the bath unit, for example one or more taps, and/or a shower head, which may be fixed relative to the bath unit, or moveable relative to it. At least part of the bath unit 50 may be enclosed with a shower screen.

The drainage unit 80, and bath unit 50 to which the drainage unit 50 may be coupled, will now be described in more detail with reference to Figures 3, 4 and 5. Figure 3 shows a plan view of the bath unit presented in Figure 2. Figure 4 shows a side view, that is to say along a long side of the bath unit, without a panel 60 so that the shape of the fluid retaining shell 54 which forms the bath 52 can be seen, as well as the drainage unit 80 of the present disclosure. Figure 5 shows an end view, that is to say along a shorter side of the bath unit 50, of the bath unit and drainage unit shown in Figure 2, and also, for clarity, omits the detail of the panel 60.

The figures show a bath unit installation comprising the bath unit 50 located on a floor 34. A thin base layer 70 is provided on the underside of the bath shell 54, that is to say, on the underside of the base 56, for seating the bath 52 directly on the floor 34.

The walls 58 are angled at an angle (AD) of substantially 100 degrees to the underside of the base layer 70 and/or base 56. That is to say, in a normal installation the walls 58 are at an angle (A,D) of substantially 100 degrees to the horizontal.

The bath unit may] of course, be provided in a number of different sizes. For example, however, the bath 52 may be substantially 1700mm long along its open side (that is to say the top edge) and 335mm high from the underside of the base layer 70 to the top edge of the bath 52.

The base layer 70 may also be provided in a number of thicknesses. By way of non limiting example, it may be provided as having a thickness of substantially 35mm. The base 56 of the bath 52 is angled at about, or at least, 1.2 degrees (C) to the underside of the base layer 70. That is to say, the base 56 of the bath 52 is angled at about, or at least, 1.2 degrees (C) to the horizontal direction.

Since the base 56 of the bath 52 is at an angle to be horizontal, the base layer 70 may vary along its length, being of greater thickness distal to the orifice (plughole) 66, and have a minimum thickness proximate to the orifice 66. That is to say, since the base 56 is angled to direct water towards the plughole 66, and since the base 56 is formed of the shell 54, the base layer 70 provides a thin layer of support between the underside of the bath unit 50 and the floor 34 upon which it is mounted, regardless of the shape and contours of the shell 54. Hence, any form or shape given to the base 56 is accommodated by the base layer 70 such that the base 56 of the bath unit 50 may be seated level and steady on a floor 34.

The ratio of the bath height to the thickness of the base layer may be at least 9 but no more than 12.

A curved transition wall (or "transition region") is provided between the base 56 and side walls 58, identified on the figures as regions having a radius of B, E. In examples where the thickness of the shell 54 is substantially 4mm, the curved transition walls have a radius B,E of substantially 50mm between the walls 58 and the base 56.

In examples where the thickness of the shell 54 is substantially 5mm, the curved transition walls have a radius B,E of substantially 50mm between the walls 58 and the base 56.

The drainage unit 80 is coupled to the orifice (plughole) 66 which extends down through, and in a direction away from, the base 56 and base layer 70 such that, in use, it extends below the level of the floor 34. The drainage unit 80 comprises a plug housing 82 which is configured to fit within the bath orifice 66. The drainage unit 80 defines a first chamber 84 with an outlet aperture 86 which is coupled to, and in flow communication with, a drainpipe 88.

The drainpipe 88 comprises a length of pipe which extends away from, and upwards from, the base 56 and base layer 70 by a predetermined amount which corresponds to a desired maximum fluid level in the bath unit 50. That is to say the drain pipe 88 is in flow communication with the outlet aperture 86 and comprises a length of pipe which extends away from the outlet aperture 86 to a position which, when the drainage unit 88 is coupled to the bath unit, is at a predetermined height above the level of the outlet aperture 86 which corresponds to a desired maximum fluid level in the bath 50.

The drainpipe 88 comprises an inverted "U" inflexion portion 90 at its highest point which corresponds to the desired maximum fluid level in the bath. The drainpipe 88 leading to the inflexion 90 may be sized such that the inflexion 90 is close to the top of the wall 58 of the bath 52. The drainpipe 88 extends from the inflexion portion 90 towards a flow exit 92. The flow exit 92 is coupled to a fluid drain duct 93 (shown in Figure 5) which extends away from the bath unit to transport waste water to, for example, an appropriate drain system in the building in which the bath unit is provided.

A second chamber 94 is provided upstream of the flow exit 92. The second chamber 94 comprises an inlet 96 for flow communication with, that is to say for receiving fluid from, the inflexion portion 90, and an outlet 98 for flow communication with the drain 93 downstream of the flow exit 92.

The second chamber 94 is located underneath the first chamber 84. The first chamber 84 and second chamber 94 are fixed to one another and fixed relative to the bath unit 52. A valve port 102 is provided between the first chamber 84 and second chamber 94 which permits selective flow communication between the first chamber 84 and second chamber 94.

The plug housing 82 is moveable between a first position in which the valve port 102 is covered by the plug housing 82 such that the first chamber 84 and second chamber 94 are fluidly isolated from one another, such that fluid entering the first chamber 84 flows along the drainpipe 88 via the inflexion 90 before being delivered to the flow exit 92 via the second chamber 94.

Hence in operation, when the plug housing 82 is in the first position, water will flow through the orifice 66 into the drainpipe 88 and the bath shell 54 of the bath unit 50 will fill up to the level of the inflexion section 90. No water will flow over the inflexion 90 towards the flow exit 92 until the water level in the bath unit 50 reaches the height of the inflexion 90. Once the water level in the bath unit 50 and drainage unit reaches above the level of the inflexion section 90, water will begin to flow through the drainpipe 88 into the second chamber 94 and out through the flow exit 92, although the level of the water in the bath will remain constant. The drainage unit 80, which includes the plug hole orifice 66, drain pipe 88 and chambers 84,94, inlet 96, outlet 98, valve port 102 and flow exit 92, is configured to have a flow capacity, that is to say a maximum volume flow rate achievable through the drainage unit 80, equal to or greater than the anticipated flow rate from taps and/or a shower unit which supply water to the bath unit 50. Thus, for example, if a user is bathing with the plug housing 82 in the first position, the water level in the bath will reach a level dictated by the height of the inflexion point before beginning to drain away at the rate at which water is added to the bath unit 50. Regardless of whether the user allows water to continue to flow (for example to shower whilst sitting in a depth of water, or to add water to alter the temperature of the bath) or discontinues the flow of water into the bath, the bath level will remain constant.

The plug housing 82 is moveable from the first position, described above, to a second position in which the plug housing 82 is spaced apart from the valve port 102 such that the first chamber 84 and second chamber 94 are in fluid communication with one another, such that fluid entering the first chamber 84 bypasses the drainpipe 88 and the inflexion portion 90 and flows directly to the flow exit 92 and duct 93 via the second chamber 94.

Thus when the plug housing 82 is in a second position, such that the valve port 102 between the first chamber 84 and the second chamber 94 is open such that the first chamber 84 and second chamber 94 are in fluid communication with one another, water will flow from the bath bath 52 through the orifice 66 through the first chamber 84 and into the second chamber 94 before exiting the flow exit 92 and draining away via the duct 93. The drainage unit 80 is configured to have a flow capacity, that is to say a maximum volume flow rate achievable through the drainage unit 80, equal to or greater than the anticipated flow rate from taps and/or a shower unit which supply water to the bath unit 50. Hence with the plug section in the second position, water will drain from the bath unit 50 without reaching any significant height inside the bath 52. Thus, for example, if a user is showering with the plug housing 82 in a second position, water will drain away rather than collecting around his or her feet.

The plug housing 82 comprises a filter 110 upstream of the first chamber 84, the filter being sized to prevent the passage of objects of a predetermined size. The filter is removable from the drainage unit 80 (i.e. the plughole 66) and may be placed back in the plughole 66. The filter 110 may be provided as a mesh or grill.

An alternative example of a bath installation according to the present disclosure is shown in Figure 6. Features common to the example shown in Figures 2-5 and Figure 6 are described using the same reference numerals.

The example shown in figure 6 differs from the example of figures 2 to 5 in that it comprises a different drainage unit 200 to that shown in the preceding example. In the Figure 6 example, a tube 202 is provided with a seal 204 configured to seal against the orifice 66 in the base 56 of the bath unit 50. Hence, when the drainage unit 200 is in place in the plughole 66, the water level may rise in the bath 52 until it reaches the open end of the tube 202. Having reached this height the water will drain through the tube 202 and into a flow exit 92 coupled to the underside of the bath unit 50. Should the user not want to have a high volume of water in the bath, the tube 202 can be removed such that water flows directly out of the orifice 66. That is to say, the drainage unit in this example comprises a removable tube 202, which is open at both ends, which extends upwards from the bath orifice by a predetermined amount which corresponds to a desired maximum fluid level in the bath unit 50. Tubes 202 of different lengths corresponding to different water heights may be provided as pad of the bath unit.

The drainage unit 200 and flow exit 92, are configured to have a flow capacity, that is to say a maximum volume flow rate achievable through the drainage unit 200 and flow exit 92, equal to or greater than the anticipated flow rate from taps and/or a shower unit which supply water to the bath unit 50.

Hence with the tube 202 in place in the orifice 66, the water level in the bath will reach a level dictated by the height of the tube 202 before beginning to drain away at the rate at which water is added to the bath unit 50. Regardless of whether the user allows water to continue to flow (for example to shower whilst sitting in a depth of water, or to add water to alter the temperature of the bath) or discontinues the flow of water into the bath, the bath level will remain constant.

Without the tube 202 in place in the orifice 66, water will drain from the bath unit 50 without reaching any significant height inside the bath 52. Thus, for example, if a user is showering without the tube 202, water will drain away rather than collecting around his or her feet.

The drainage unit 80 according to the present disclosure as illustrated by way of example in Figures 3 to 5, and/or the drainage unit 200, according to the present disclosure as illustrated by way of example in Figure 6, may be provided separately to the bath shell 52, 54. The drainage units 80, 200 may be used in conjunction with baths or the like, for example alternative fluid retaining systems including hand wash basins, shower trays/units, and baths which differ from that of the present disclosure, including conventional baths. The drainage units 80,200 may also be retrofitted to existing fluid retaining systems. Depending on the system to which it is fitted, the drainage unit 200 may be located entirely above floor level.

The drainage unit 80 may be installed on a bath, where the bath has a base which comprises an orifice/plug hole, by a method which comprises coupling the drainage unit 82 to the orifice/plug hole such that at least pad of the drainage unit 80 extends downwards in a direction away from the base of the bath, although, as described above, parts of the drainage unit may also extend along the base of the bath, and up the side of the bath. The installation may further comprise the step of providing an aperture in the floor 34 and locating at least part of the drainage unit 80 in the floor aperture which is sized to provide space for coupling the drainage unit to the flow outlet 92 and/or duct 93.

Hence a bath unit 50 as herein described, comprising a drainage unit 80, may be installed by providing a bath comprising the bath 52 defined by the fluid retaining shell 54, providing the floor 34 for supporting the bath unit 50 and providing the thin base layer 70 between the bath and the floor 34. This method further comprises the step of angling the base 56 of the bath 52 at about, or at least, 1.2 degrees (C), to the horizontal such that fluid in the bath 52 is directed towards the orifice 66. A drainage unit 80 may be coupled to the orifice 66 such that the drainage unit 80 extends downwards in a direction away from the base 56 and base layer 70. An aperture is provided in the floor 34 in which the drainage unit is located, which also provides space for coupling the drainage unit 80 to a flow outlet 92 and/or duct 93.

A drainage unit according to the present disclosure is advantageous over configurations of the related art for a number of reasons.

The drainage unit of the present disclosure provides a failsafe means of regulating water level in a bath. It also obviates the need for a dedicated over flow orifice (i.e. orifice 26 shown in related art Figure 1), which simplifies bath manufacture and, for the end user, makes cleaning of the bath easier.

The drainage unit also enables a bath unit configuration which is inherently lower off the ground than a bath unit known from the related art which is thus easier for someone to step into and out of the bath unit, and hence lowering the risk of the bather falling as they enter or exit the bath.

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

CLAIMSA drainage unit for a bath, or the like, wherein the drainage unit is configured to control fluid flow in dependence upon the fluid level in the bath, or the like.
2 A drainage unit as claimed in claim 1 comprising a plug housing (82) which is configured to fit within a plug hole (66) of a bath, or the like, and defines a first chamber (84) with an outlet aperture (86); and a drain pipe (88) which is in flow communication with the outlet aperture (86) and comprises a length of pipe which extends away from the outlet aperture (86) to a position which, in use, when the drainage unit (88) is coupled to a bath or the like, is at a predetermined height, which corresponds to a desired maximum fluid level in the bath, above the level of the outlet aperture (86).
3 A drainage unit (80) as claimed in claim 1 or claim 2 wherein: the drain pipe (88) comprises an inverted "U" inflexion portion (90) at its highest point which corresponds to the desired maximum fluid level in the bath; and extends from the inflexion portion (90) downwards to a flow exit (92).
4 A drainage unit (80) as claimed in claim 3 wherein the flow exit (92) comprises a second chamber (94) provided in the plug housing (82), the second chamber (94) comprising an inlet (96) for flow communication with the inflexion portion (90); and an outlet (98) for flow communication with a fluid drain downstream of the flow exit (92).
A drainage unit (80) as claimed in claim 4 wherein the second chamber (94) is located underneath the first chamber (84).
6 A drainage unit (80) as claimed in claim 4 or claim 5 wherein the first chamber (84) and second chamber (94) are fixed to one another.
7 A drainage unit (80) as claimed in any one of claims 4, 5 or 6 wherein a valve port (100) is provided between the first chamber (84) and second chamber (94) which permits selective flow communication between the first chamber (84) and the second chamber (94); and the plug section (82) is movable between a first position in which the valve port (102) is covered by the plug section (82) such that the first chamber (84) and second chamber (94) are fluidly isolated from one another, such that fluid entering the first chamber (84) flows along the drain pipe (88) via the inflexion (90) before being delivered to the flow exit (92) via the second chamber (94); and a second position in which the plug section (82) is spaced apart from the valve port (102) such that the first chamber (84) and second chamber (94) are in fluid communication with one another, such that fluid entering the first chamber (94) bypasses the drain pipe (88) and inflexion portion (90) and flows directly to the flow exit (92) via the second chamber (94).
8 A drainage unit (80) as claimed in any one of claims 1 to 7 wherein the plug housing (82) comprises a filter (110) upstream of the first chamber (84), the filter being sized to prevent the passage of objects above a predetermined size.
9 A drainage unit (80) as claimed in claim 8 wherein the filter is removable from the drainage unit (80).
A drainage unit (80) as claimed in claim 1 wherein the drainage unit (200) comprises a removable tube (202), open at both ends, which extends upwards from the bath orifice (66) by a predetermined amount which corresponds to a desired maximum fluid level in the bath (50).
11 A bath unit (50) comprising a bath (52) defined by a fluid retaining shell (54) comprising an orifice (66); and a drainage unit (80) as claimed in any one of claims 1 to 9, wherein the plug housing (82) is located in the orifice (66).
12 A bath unit (50) as darned in claim 11 wherein a base layer (70) is provided on the underside of the bath shell (52, 54) for seating the bath directly on a floor (34).
13 A bath unit as claimed in claim 12 wherein the drainage unit (80) extends downwards in a direction away from the fluid retaining shell (54) such that, in use, it extends below floor (34) level.
14 A bath unit (50) as claimed in any one of claims 12 to 13 wherein the bath (52) is defined by: a base (56) and side walls (58); and the walls (58) are angled at substantially 100 deg (A; D) to the underside of the base (56).
A bath unit (50) as claimed in claim 14 wherein the base (56) of the bath (52) is configured such that, when the bath (52) is mounted on a floor, the base (36) directs fluid to the orifice (66).
16 A bath unit (50) as claimed in any one of claims 14 to 15 wherein the base (56) of the bath (52) is at an angle (C) of at least 1.2 deg to the underside of the base layer (70).
17 A bath unit (50) as claimed in any one of claims 11 to 16 wherein the shell (54) comprises material having a thickness of substantially 4mm, and a curved transition wall which has a radius (BE) of substantially 50mm between the walls (58) and the base (56).
18 A bath unit (50) as claimed in any one of claims 11 to 16 wherein the shell (54) comprises a material having a thickness of substantially 5mm, and a curved transition wall which has a radius (BE) of substantially 50mm between the walls (58) and the base (56).
19 A bath unit (50) as claimed in any one of claims 11 to 18 wherein the bath (52) is substantially 1700 mm long along its top edge, and 335mm high from the underside of the base layer (70) to the top edge of the bath (52).
A bath unit (50) as claimed in any one of claims 11 to 18 wherein the base layer (70) is substantially 25mm to 35mm thick.
21 A bath unit (50) as claimed in any one of claims 11 to 20 wherein the ratio of bath height to the thickness of the base layer (70) is at least 9 but no more than 12.
22 A bath unit (50) installation comprising a bath unit (50) according to any one of claims 11 to 21 located on a floor (34) wherein the drainage unit (80) extends through the floor beneath the bath unit (50).
23 A method of installing a drainage unit (80) according to any one of claims 1 to 9 comprising the steps of providing a bath having a plug hole; and coupling the drainage unit to the plug hole.
24 A method of installing a drainage unit (80) as claimed in claim 23, the method further comprising the steps of providing a floor (34) for supporting the bath; and providing a thin base layer (70) between the bath and the floor (34) such that the drainage unit (80) extends downwards in a direction away from the base of the bath and base layer (70).
A method of installing a drainage unit (80) as claimed in claim 23 or claim 24 the method further comprising the steps of: providing an aperture in the floor (34); and locating the drainage unit (80) in the floor aperture for coupling to a flow outlet (92).
26 A drainage unit (80) substantially as hereinbefore described and/or as shown in Figures 2 to 6.
27 A bath unit (50) substantially as hereinbefore described and/or as shown in Figures 2 to 6.
28 A bath unit installation substantially as hereinbefore described and/or as shown in Figures 2 to 6.
29 A method of installing a drainage unit (80) substantially as hereinbefore described and/or as shown in Figures 2 to 6.