GB2448155A

GB2448155A - A riser rail assembly

Info

Publication number: GB2448155A
Application number: GB0706546A
Authority: GB
Inventors: Robin Edward Brash
Original assignee: Triton PLC
Current assignee: Triton PLC
Priority date: 2007-04-04
Filing date: 2007-04-04
Publication date: 2008-10-08
Also published as: IE20080162A1; GB0706546D0

Abstract

A riser rail assembly 10 for an electric shower system comprising a hollow member 12 for supporting a shower head, a water inlet 14, a water outlet 18 and a heating element 26 disposed within the hollow member 12 to heat water flowing from the water inlet 14 to the water outlet 18. A plurality of heating elements may be provided. Baffles 28 may be provided within the hollow member. A control means, which may be a solenoid valve 24, may be provided to control the flow of water in the hollow member. A thermal cut-out operated by a sensor 32 at the water outlet may also be provided.

Description

Title: A Riser Rail Assembly

Description of Invention

The present invention relates generally to a riser rail assembly for a shower system, and particularly, although not exclusively, to a riser rail assembly for an electric shower system.

The term "riser rail" is well known in the field of shower systems, and refers to a wall-mountable rail on which a bracket for a shower head is disposed, usually slidably, so that the shower head can be positioned at a desired height by a user.

Typically, electric shower systems use a control box which can be mounted on a wall adjacent or near a riser rail, which supports a shower head attached to an outlet of the control box by a flexible hose. The control box has an inlet, usually on one of its side walls, through which cold water from a mains supply is passed to a heating can, which comprises a small container having an inlet and an outlet for water and housing a coiled heating element, to heat water passing through the container from the inlet to the outlet. The control box also includes other components such as electrically-operated valves, control circuitry and the like, to allow the temperature and pressure of water supplied by the shower system to be controlled by a user.

Control boxes of this type can be unsightly, as they are often large and bulky.

Moreover, when installed, pipes supplying water to the control box tend to be visible, due to the positioning of the water inlet. The heating elements in shower systems of this type are also prone to failure, as they are tightly coiled, which increases the likelihood of "hot spots" forming, at points where the element bends, as thermal insulation between an inner part of the element (usually a length of resistive wire which heats up as electric current passes through it) and its outer wall may be of a reduced thickness at those points.

Thus, the inner part of the element, and the surrounding area, are heated to a high temperature at those points, which can encourage the formation of scale on the outer wall, and lead to the eventual failure of the inner part, and thus of the entire element.

According to the present invention, there is provided a riser rail assembly for an electric shower system comprising a hollow member for supporting a shower head, a water inlet, a water outlet and a heating element disposed within the hollow member to heat water flowing from the water inlet to the water outlet.

In this way, water is heated as it passes through the riser rail, obviating the need for a separate heating can assembly.

Part of the riser rail may define a heating chamber in which water can be heated by the element, an outlet of the heating chamber being disposed above an inlet thereof such that, in use of the assembly, a column of water is present in the heating chamber.

This reduces the risk of the heating element "boiling dry", and thus being damaged.

The water inlet may be a pipe housed within the hollow member, with an open end extending outwardly of a first end thereof.

The pipe may be positioned off-centre within the hollow member.

The pipe may be positioned towards a part of the hollow member which, in use, is located towards a rear of the riser rail assembly.

The water outlet may be disposed towards the first end of the hollow member.

The water outlet may be disposed towards a part of the hollow member which is generally opposite the part in which the pipe is positioned.

The first end of the hollow member may, in use, be an upper end of the assembly.

In this way, water entering the riser rail assembly passes downwardly through the water inlet and upwardly through the hollow member to the water outlet.

Thus, there is always a standing column of water within the hollow member, which prevents the heating element from boiling dry.

The heating element may be generally straight.

Alternatively, the heating element may be non-linear over at least a portion of its length.

The heating element may extend within the hollow member in a longitudinal direction.

The heating element may be positioned off-centre within the hollow member.

The heating element may be positioned towards a part of the hollow member which, in use, is located towards a front of the riser rail assembly.

A plurality of heating elements may be provided.

The assembly may further comprise a baffle disposed within the hollow member.

A plurality of baffles may be provided.

The baffle may be integral with or connected to the pipe, to simplify manufacture of the assembly.

The positioning of the pipe and the heating element ensures that sufficient space is provided between the heating element and the pipe for water to flow around the heating element to be heated, and allows mixing of heated and unheated water to take place. The baffle causes turbulence in the water which encourages further mixing of heated and unheated water, thus producing a generally uniform water temperature at the outlet.

A control means may be associated with the water inlet for controlling the flow of water in the hollow member.

The control means may be provided at an end of the pipe distal from the open end.

In this way, components downstream of the pipe are protected from mains water pressure, as the control means is able to withstand such pressure.

Thus, the components downstream of the pipe can be of a lower specification, and thus less expensive.

The control means may comprise a solenoid valve.

The control means may further comprise a stabiliser, to regulate water flow within the hollow member.

A thermal cut-out may be provided to disconnect an electricity supply from the heating element in an over-temperature condition.

The thermal cut-out may comprise a sensor.

The sensor may be positioned towards the first end of the assembly to detect the temperature of water at the outlet.

The sensor may be positioned within the hollow member at a part generally opposite the pipe, to minimise any cooling effect caused by the pipe.

The thermal cut-out may be a two-stage unit.

A longitudinal gap may be provided between the heating element and the water outlet.

In this way, an "air break" is provided adjacent the heating element, so that in the event that the heating element boils dry, the air in the air break will be heated, eventually triggering the thermal cut- out to disconnect the electricity supply to the element.

According to a second aspect of the invention, there is provided a shower system comprising a riser rail assembly according to any of the preceding paragraphs.

Specific and non-limiting embodiments of the invention will now be described, by way of example only, by reference to the accompanying drawings, of which: Figure 1 is a perspective view of a riser rail assembly; Figure 2 is a somewhat schematic vertical cross-sectional view of a riser rail assembly; and Figure 3 is a somewhat schematic horizontal cross sectional view of a riser rail assembly.

Referring to the Figures, a riser rail assembly is shown generally at 10, and comprises a riser rail 12, configured for supporting a shower head (not shown), which in this example is an elongate hollow tube of generally circular cross-section, although it could be of any other suitable cross-section. The riser rail 12 houses a water inlet pipe 14, of copper or any other suitable material, which extends outwardly of an upper end of the riser rail 12 through a closure member 15 for attachment to a mains water supply, by means of a connector 16 of known type. Although the water inlet pipe is shown in the Figures as extending upwardly, those skilled in the art will readily understand that it could extend in other directions, for example to one side of the riser rail 12. A water outlet 18 is also provided towards an upper end of the riser rail assembly 10, through which water may pass from the riser rail assembly 10 to a shower head (not shown) by means of a hose (not shown) attached to a connector 20 of known type. Towards a lower end of the riser rail assembly 10 there is provided an end cap 22, which closes that end of the riser rail 12.

Turning now to Figure 2, there is shown a somewhat schematic cross-sectional view of the riser rail assembly 10. The end cap 22 houses a control means in the form of a solenoid valve 24, to control the flow of water from the water inlet pipe 14 into the end cap 22. With the solenoid valve 24 in its "open" condition, water is able to flow through the water inlet pipe 14, into the end cap 22 and through the interior of the riser rail 12 to the water outlet 18. A stabiliser valve (not shown) is provided "downstream" of the solenoid valve 24 to control water flow into the interior of the riser rail 12 in response to user commands, and to regulate the flow of water to compensate for fluctuations in pressure in the mains supply.

As well as allowing a user of the assembly 10 to control the flow of water, the solenoid valve 24 serves to protect components of the assembly 10 downstream of it from mains water pressure. Thus, by positioning the solenoid valve 24 in the end cap 22, at a lower end of the water inlet pipe 14, rather than further downstream, only the water inlet pipe 14 and the solenoid valve 24 need to be able to withstand mains water pressure, meaning that less highly-specified (and thus less expensive) components can be used downstream of the solenoid valve 24.

Additionally, the solenoid valve 24 prevents back siphoning' of water, which occurs when external water enters the mains system. For example, in the event of a temporary drop in mains water pressure, if a shower head was dropped in a full bath, it is possible that water from the bath could enter the mains system through the shower head. The presence of the solenoid valve at the lower end of the water inlet pipe 14 prevents such a situation from arising.

A further advantage of the positioning of the solenoid valve 24 towards a lower end of the assembly 10 is that the user controls for the assembly 10 can be positioned at a convenient height, for example at the lower end of the riser rail 12, without having to route long lengths of electrical wiring through the assembly 10, which simplifies the design of a shower system using the assembly 10, and reduces its overall cost.

As well as the water inlet pipe 14, the riser rail 12 also houses two electric heating elements 26, operative to heat water as it passes through the interior of the riser rail, which are located in an off-centre position, towards a "front" part of the riser rail 12. Thus, part of the riser rail 12 defines a heating chamber in which water may be heated by the heating elements 26. The water inlet pipe 14 is located in an off-centre position towards a "rear" part of the riser rail 12, and this positioning (shown in more detail in the cross-sectional view of Figure 5) ensures that there is sufficient space around the heating elements 26 to allow water to circulate freely around and between them, thus encouraging uniform heating of the water. In this example, the heating elements 26 are generally elongate and straight, with a circular cross-section, and this offers numerous advantages over the coiled elements used in heating cans of known electric showers. As the elements 26 are straight, the likelihood of hot spots' forming is greatly reduced, thus reducing the likelihood of scale formation and extending their lifespan. The use of straight elements 26 also makes it easier to predict and control the flow of water than in heating cans, as straight elements do not cause as much deflection of the water as coiled elements.

Additionally, as the elements 26 are disposed within the riser rail, they can generally be longer than the coiled elements used in known heating cans, meaning that they require less power to heat a given volume of water to a given temperature. This gives rise to reduced operating costs, as well as increasing the lifespan of the elements 26.

Nevertheless, the applicants envisage that elements which are non-linear over at least a portion of their length could be used. For example, somewhat sinusoidally curved elements could be used, to increase their overall length, and thus their heating effect, for a given supply voltage and current. The elements could be coiled around one another, to increase their heating effect.

Although the figures show an assembly including two elements, it will be understood by those skilled in the art that more or fewer elements could equally be employed.

Disposed within the riser rail 12 are transverse baffles 28, which deflect water as it passes through the heating chamber of the riser rail 12, to create turbulence which promotes mixing of water heated by the elements 26 with cooler water which has not been in close contact with them. In this way the temperature of water at the outlet can be made more uniform, reducing the problem of unmixed streams of hot and cold water at the outlet that can occur in existing electric showers.

The baffles 28 can be attached to the interior of the riser rail 12, but are preferably soldered, welded or otherwise attached to the water inlet pipe 14, before it is inserted into the riser rail 12, for ease of manufacture. In this example, four baffles 28 are provided, but it will be appreciated that the number of baffles may vary, depending upon, for example, the length of the riser rail 12, the expected water pressure or the number, shape and configuration of heating elements provided. The baffles 28 are shown in the Figures as being generally circular, but it will be understood that any other suitable shape could be used.

A thermal cut-out unit 30 is provided on the closure member 15, and has a sensor 32 positioned within an upper part the riser rail 12, towards a "front" part of the riser rail 12 where it can easily be accessed for maintenance purposes. The sensor 32 is positioned generally diametrically opposite the water inlet pipe 14, to minimise any cooling effect caused by it, and is operative to sense the temperature of water or air within the riser rail 12, with the thermal cut-out unit 30 being operative to disconnect the electricity supply to the heating elements in the event of an over-temperature condition which could result in damage to the assembly 10 or injury to a user. In this example, the thermal cut-out unit 30 is a two-stage unit, in that once a first threshold temperature (for example, 57 C) is detected by the sensor 32, the thermal cut-out unit 30 disconnects the electricity supply temporarily, until the temperature has dropped below the first threshold temperature. If, however, the temperature detected by the sensor 32 reaches a second, higher threshold (for example 90 C), the thermal cut-out unit 32 will disconnect the supply more permanently, with it being necessary to reset the unit 32 manually before the electricity supply can be restored.

As wilt be seen from Figure 2, a longitudinal air break' or gap, shown generally at 34, is provided between upper ends of the heating elements 26 and the water outlet 18, which provides a fail-safe mechanism, such that in the event that the elements boil dry, the air in the gap above the heating elements 26 is be heated, eventually reaching the threshold temperature at which the thermal cut-out unit disconnects the electricity supply to the heating elements 26.

Such a situation is unlikely to arise, however, because of the configuration of the heating chamber formed by the riser rail 12. The heating chamber has an inlet, associated with the end cap 22, and an outlet, disposed towards its upper end in a region adjacent the water outlet 18 of the riser rail assembly 10.

In this way, in use of the assembly 10, there is always a standing column of water in the heating chamber of the riser rail 12. Thus, the heating elements 26 should never be completely dry, and in the event that water stops flowing through the riser rail 12, the heating elements 26 heat this standing column of water such that steam will be produced, with the steam subsequently rising and triggering the thermal cut-out unit 30.

Moreover, a shower system using the assembly 10 will include control means to control the operation of the assembly 10, which includes means to prevent the operation of the heating elements 26 when there is no water flowing through the riser rail 12. Such means may be associated, for example, with means controlling the operation of the solenoid valve 24, so that the heating elements cannot operate unless the solenoid valve 24 is in its open condition.

In use, water passes through the water inlet pipe 14, through the solenoid valve 24 and into the end cap 22. It then passes upwardly through the interior of the riser rail 12, where it is heated by the heating elements 26 whilst being deflected by the transverse baffles 28 to ensure mixing of heated and unheated water, such that water at a substantially uniform temperature exits the riser rail 12 through the outlet 18.

In an alternative embodiment, two elongate hollow tubes could be provided, with a first (front) tube acting as a riser rail for mounting a shower head bracket, water being directed downwardly through the second (rear) tube and into the first, riser rail, tube, where it is heated as is passes upwardly, the heated water then being directed downwardly through a water outlet tube disposed within the riser rail, to exit through a water outlet at a lower part of the riser rail. Alternatively, heating elements may be provided in the second (rear) tube, with water entering through an inlet at a lower part of the tube and being heated as it passes upwardly through the tube, before passing into an outlet pipe in the riser rail connected to an outlet at a lower end thereof.

In a further alternative embodiment, a single elongate hollow tube is used as a riser rail, with a water inlet being provided at a lower part thereof. Water entering the riser rail is heated by heating elements contained within it as is rises, before descending through an outlet pipe disposed within the riser rail, and exiting through an outlet provided at a lower part of the riser rail.

Although the heating elements 26 have been described as being elongate, the applicants envisage that thick film heating elements or similar devices could also be used to heat water. In that case, the elements could be disposed around the outside of a heating tube disposed within the riser rail 12, with suitable insulation, such as an air gap or rock wool, being provided to ensure that the riser rail does not become dangerously hot.

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 riot 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.

Claims

Claims 1. A riser rail assembly for an electric shower system

comprising a hollow member for supporting a shower head, a water inlet, a water outlet and a heating element disposed within the hollow member to heat water flowing from the water inlet to the water outlet.
2. A riser rail assembly according to claim 1 wherein part of the riser rail defines a heating chamber in which water can be heated by the element, an outlet of the heating chamber being disposed above an inlet thereof such that, in use of the assembly, a column of water is present in the heating chamber.
3. A riser rail assembly according to claim I or claim 2 wherein the water inlet comprises a pipe housed within the hollow member, with an open end extending outwardly of a first end thereof.
4. A riser rail assembly according to claim 3 wherein the pipe is positioned off-centre within the hollow member.
5. A riser rail assembly according to claim 3 or claim 4 wherein the pipe is positioned towards a part of the hollow member which, in use, is located towards a rear of the riser rail assembly.
6. A riser rail assembly according to any of claims 3 to 5 wherein the water outlet is disposed towards the first end of the hollow member.
7. A riser rail assembly according to claim 6 wherein the water outlet is disposed towards a part of the hollow member which is generally opposite the part in which the pipe is positioned.
8. A riser rail assembly according to claim 3 wherein the first end of the hollow member in use, is an upper end of the assembly.
9. A riser rail assembly according to any of the preceding claims wherein the heating element is generally straight.
10. A riser rail assembly according to any of claims I -8 wherein the heating element is non-linear over at least a portion of its length.
11. A riser rail assembly according to any of the preceding claims wherein the heating element extends within the hollow member in a longitudinal direction.
12. A riser rail assembly according to any of the preceding claims wherein the heating element is positioned off-centre within the hollow member.
13. A riser rail assembly according to any of the preceding claims wherein the heating element is positioned towards a part of the hollow member which, in use, is located towards a front of the riser rail assembly.
14. A riser rail assembly according to any of the preceding claims comprising a plurality of heating elements.
15. A riser rail assembly according to any of the preceding claims comprising a baffle disposed within the hollow member.
16. A riser rail assembly according to claim 15 comprising a plurality of baffles disposed within the hollow member.
17. A riser rail assembly according to claim 15 or claim 16, as appendant directly or indirectly to claim 3 wherein the baffle or baffles is or are integral with or connected to the pipe.
18. A riser rail assembly according to any of the preceding claims wherein a control means is associated with the water inlet for controlling the flow of water in the hollow member.
19. A riser rail assembly according to claim 18 wherein the control means is provided at an end of the pipe distal from the open end.
20. A riser rail assembly according to claim 18 or claim 19 wherein the control means comprises a solenoid valve.
21. A riser rail assembly according to any of claims 18 -20 wherein the control means comprises a stabiliser, to regulate water flow within the hollow member.
22. A riser rail assembly according to any of the preceding claims wherein a thermal cut-out is provided to disconnect an electricity supply from the heating element in an over-temperature condition.
23. A riser rail assembly according to claim 22 wherein the thermal cut-out comprises a sensor.
24. A riser rail assembly according to claim 23 wherein the sensor is positioned towards the first end of the assembly to detect the temperature of water at the outlet.
25. A riser rail assembly according to claim 23 or claim 24 wherein the sensor is positioned within the hollow member at a part generally opposite the pipe.
26. A riser rail assembly according to any of claims 22 -25 wherein the thermal cut-out is a two-stage unit.
27. A riser rail assembly according to any of the preceding claims wherein a longitudinal gap is provided between the heating element and the water outlet.
28. A shower system comprising a riser rail assembly according to any of the preceding claims.
29. A riser rail assembly substantially as hereinbefore described with reference to and as shown in the accompanying drawings.
30. A shower system substantially as hereinbefore described with reference to and as shown in the accompanying drawings.
31. Any novel feature or novel combination of features described herein and/or in the accompanying drawings.