WO2009138736A2

WO2009138736A2 - Liquid heating vessels

Info

Publication number: WO2009138736A2
Application number: PCT/GB2009/001189
Authority: WO
Inventors: Peter Hallam Wright; Antonio Martin Gaeta; Robert Henry Hadfield
Original assignee: Otter Controls Limited
Priority date: 2008-05-12
Filing date: 2009-05-12
Publication date: 2009-11-19
Also published as: EP2320773A2; WO2009138736A3; CN102026566A

Abstract

A liquid heating vessel (1) has a fluorescent water level indicator (10), or other part, and a source (20,22) of UV light for energising the fluorescent part. Also disclosed is a water level indicator that remains level as the vessel is tilted. Also disclosed is a water level mark that remains tangential to the water level as the vessel is tilted about a horizontal axis.

Description

Liquid Heating Vessels

Field of the Invention

The present invention relates to liquid heating vessels, and particularly but not exclusively to electric water heating vessels such as kettles and the like.

Background to the Invention

Electric water heating vessels, such as kettles and the like, are often designed with a transparent or translucent 'water window' so that the water level within the vessel can be easily seen. In some types of vessel, the entire wall of the vessel is made of glass or polycarbonate. It is also known to provide a light source within the kettle to illuminate the contents of the vessel so that the water level can be seen more easily and to illuminate any markings on the vessel wall against which the water level can be measured.

However, such a light source typically does not illuminate a transparent wall or water window very well, since most of the light passes through. Illumination may be improved by making the wall portions translucent so as to scatter more light, but then the interior of the vessel can no longer be seen clearly. Illumination may be improved by increasing the power of the light source, but this uses more energy and may just increase the overall brightness rather than making the water level easier to see.

Easy measurement of water level is desirable in a heating vessel, since it would help to avoid overfilling, which wastes both electricity and water and therefore has an adverse effect on the environment. However, it is difficult to judge water level when filling a conventional kettle, since the kettle is typically held at an angle so that markings on the side of the vessel do not give an accurate level indication.

The Kenwood JK470 Clearsense™ kettle has a transparent polycarbonate body with angled level markings to assist the user to judge the water level when filling, but the angled level markings are only accurate for one angle of inclination.

Patent publication GB-A-2332522 proposes improving the visibility of a level indicator of a kettle by illuminating the liquid in the proximity of the level indicator. This document also discloses making a level-indicating float of fluorescent material, but it is apparent that phosphorescent material is meant since the aim is to maintain the visibility of the float after a light source has been deactivated.

Electric water heating vessels, such as kettles and the like, generally have high power ratings (e.g. in the range 2-3 kW) and are used on a daily basis in the domestic environment. As such, they are responsible for a significant fraction of domestic energy consumption. It is becoming ever more important to save energy, so as to reduce demand on scarce energy resources and to protect the environment. Moreover, the environmental impact of electric water heating vessels goes beyond their energy consumption; other considerations include the energy required to manufacture and transport the vessel, the raw materials needed for the vessel, and the amount of water wasted when using the kettle. Moreover, it would be desirable to convert existing vessels to reduce their environmental impact, rather than requiring users to replace an existing vessel with a more environmentally friendly one, which incurs the environmental cost of manufacturing a complete new vessel. One problem is that users often heat more water than they need, so that a significant amount of energy is wasted heating water that is never used, or at least is allowed to cool so that it must be reheated before it is used.

One solution to this problem would be to encourage users to measure the quantity of water required before it is heated, for example by filling a teapot with cold water and then filling the kettle with water from the teapot. However, most users are reluctant to perform additional operations unless some means is provided to facilitate them.

Another solution is proposed in patent publication WO-Al-01/93733, in which a kettle has a chamber for heating water and a reservoir located within the chamber and having a user-operable valve for releasing water into the chamber. However, this merely replicates the problem within the kettle itself; the user must still judge how much water is to be heated, and fill the chamber to the appropriate level from the reservoir. Another problem is that a seal is required to seal the reservoir after filling, to prevent water from spilling out.

Another problem is that thermal transfer between the heating element and the liquid to be heated may not be efficient. In conventional immersed element kettles, thermal transfer is relatively efficient because the element is substantially surrounded by liquid. In conventional 'under floor' element kettles, the heating element is arranged on the underside of the reservoir floor of the kettle and heat maybe lost to the surroundings.

Statements of the Invention

According to one aspect of the present invention, there is provided a liquid heating vessel having a portion arranged to emit visible light when energised by an energy source. The energy source may comprise a source of ultraviolet (UV) radiation arranged to energise the portion, and the portion may comprise a fluorescent material that emits visible light when energised by the UV radiation.

The fluorescent material may be applied as a coating to the portion, or included as an additive to the material from which the portion is made. The fluorescent material may be invisible to naked eye without the UV light source. The fluorescent material may be distributed evenly over the portion, or selectively for example to form a marking, pattern or indicium on the portion. The fluorescent material may be a preformed structure that is moulded into the portion during manufacture. The fluorescent material may comprise a fluorescent dye, such as a dye that emits light predominantly in the blue region.

The portion may comprise a wall portion of the vessel, such as window within a translucent or opaque vessel body. Alternatively, the wall portion may comprise part or all of a wall of the vessel. The wall portion may be transparent or translucent. The wall portion may be made substantially of glass, polycarbonate or other heat-resistant substantially transparent material.

Alternatively, the portion may comprise any externally visible part of the vessel; for example, the portion may comprise part of a handle of the vessel. Alternatively, the portion may comprise a level gauge that is distinct from but interconnected to the liquid within the main vessel body.

The UV source may emit little or no visible light, to increase the contrast of the fluorescent material. The UV source may be arranged to emit predominantly in the UVA frequency range. The UV source may comprise one or more UV LEDs; the LEDs may emit within a frequency range of 360-400 nm. Alternatively, the UV source may comprise a fluorescent lamp, a mercury vapour lamp, or an incandescent lamp, preferably with a filter such as a doped envelope to reduce emission of visible light.

The UV source may be controlled to provide variable energisation of the portion. The UV source may be switched on and off, or its intensity varied, according to the state of the vessel. For example, the UV source may be switched on or off in response to the heating state of the vessel or in response to a dry boil condition of the vessel. Alternatively, the spatial distribution of the UV illumination may be varied, for example to produce a scanned image or a variable marking. The UV source may illuminate the portion through a mask to define the area of the portion that is illuminated. According to another aspect of the invention, there is provided a liquid heating vessel having a liquid level indicator that remains substantially upright as the vessel is tilted. The liquid level indicator may comprise a moveable member mounted in a wall of the vessel, or within the vessel. The moveable member may be suspended within the vessel, or may be a buoyant member secured to a lower part of the vessel. According to another aspect of the invention, there is provided a liquid heating vessel having a liquid level indicator comprising at least one curved marking on the wall of the vessel. The curved marking may follow a parabolic curve.

According to another aspect of the invention, there is provided a liquid heating vessel having a liquid reservoir arranged to dispense liquid into the heating part of the vessel, wherein the liquid reservoir is disposed towards the back of the vessel, away from a dispensing outlet of the heating part.

According to another aspect of the invention, there is provided a liquid heating vessel having a liquid reservoir arranged to dispense liquid into the heating part of the vessel, wherein the liquid reservoir is vertically elongate. According to another aspect of the invention, there is provided a liquid heating vessel having a liquid reservoir arranged to dispense liquid into the heating part of the vessel in response to actuation of a trigger or button or button in a handle of the vessel.

According to another aspect of the present invention, there is provided a liquid heating vessel having a liquid reservoir that dispenses liquid into the heating part of the vessel sufficiently slowly so as not to affect the filling accuracy of the reservoir, but sufficiently large to allow a heating chamber to be energised immediately the reservoir is filled to the required level.

Brief Description of the Drawings

Embodiments of the invention will now be described with reference to the drawings identified below.

Figures 1 to 3 are side elevation views of a kettle in a first embodiment, respectively upright, tilted forward by 10°, and tilted forward by 20°.

Figures 4 to 6 are front elevation views of the kettle of the first embodiment, respectively upright, tilted to one side, and tilted to the other side. Figures 7 and 8 are schematic views of a kettle of a second embodiment, respectively tipped forward and upright, including a rotating water window as a level indicator.

Figures 9 to 11 are schematic views of a kettle of a third embodiment, respectively upright, tipped forward by 10°, and tipped forward by 20°.

Figure 12 is a schematic view of a vessel having a level indicator applied thereto. Figure 13 is a schematic view of a sliding level indicator.

Figure 14 is a schematic view showing possible positions of a UV source in the kettle.

Figures 15 and 16 are perspective diagrams showing alternative configurations of a kettle handle.

Figures 17 to 19 are perspective, partially cut-away and further cut-away views of a kettle including a dispensing reservoir activated by an actuator on the lid.

Figure 20 is a perspective view of another embodiment of a kettle including a dispensing reservoir activated by a trigger or button under the handle.

Figure 21 is a partially cut-away view of another embodiment of a kettle including a dispensing reservoir having an open orifice in communication with the heating chamber.

Figure 22 is an exploded view of a kettle showing a dispensing reservoir as a separate part from the kettle body. Detailed Description of Embodiments

Each of the embodiments involves, by way of example, a kettle 1 having a base 2 and a body 3; the base contains an electric heater and an associated connector and control (not shown) for supplying and controlling electrical power to the heater. The body 3 is for containing liquid such as water and comprises a heating chamber 4 for containing liquid to be heated. Preferably, at least part of the body 3 is transparent or translucent, such that the user may observe the quantity of water in the heating chamber 4. Water is dispensed out of the kettle 1 from the heating chamber 4, for example through a spout 7.

The kettle 1 also has a handle 9, normally at the opposite side from the spout 7, and a lid 8.

Preferably, the electric heater is arranged on the underside of a heating element plate in the base of the heating chamber 4, but the electric heater may alternatively be immersed within the reservoir.

The base 2 may be a corded base, which has an electrical power cord connected directly thereto, or may be a cordless base removably connectable to a power base by means of cordless connectors, most preferably by 360° cordless connectors such as CS4 and CP7 connectors as supplied by Otter Controls Ltd and/or as described in patent publication WO 94/06185.

Level Indicator Embodiments of the invention may advantageously include a level indicator that indicates the volume of water in the reservoir. The level indicator may comprise a series of markings indicating the water level corresponding to different numbers of cups.

Level Indicator- First Embodiment

As shown in Figures 1 to 6, in a first embodiment the kettle 1 includes a level indicator comprising a rod 10 suspended centrally from the lid 8 by a universal joint or gimbal 12 that allows the rod 10 to remain substantially vertical as the kettle 1 is tilted, provided the rod 10 is not impeded by the side wall of the body 3. The rod 10 carries markings, preferably indicating progressive integral multiples of a constant volume, such as a standard cup. In the example shown in Figure 1, the water level 11 reaches the second marking from the lower end of the rod 10, indicating a volume of two cups. As shown in Figures 2 to 6, the water level 11 remains at this marking despite the tilting forward or sideways of the kettle 1, so that the rod 10 continues to provide a reliable level indication. It should be noted that the internal shape of the reservoir is designed so that the water level 11 remains at a substantially fixed height below the gimbal 12 as the kettle 1 is tilted through a range of angles.

In an alternative embodiment, the rod 10 may be attached to the floor of the heating chamber 4 and be sufficiently buoyant to remain upright when water is present in the heating chamber.

Level Indicator - Second Embodiment

As shown in Figures 7 and 8, in a second embodiment the level indicator comprises a self-levelling water window 15 that rotates as the kettle 1 is tilted for filling, so that the markings remain horizontal. In this way, the indicator provides a more accurate indication of liquid level as the kettle 1 is filled. The water window 15 may be mounted internally or externally of the body 3. The water window 15 may be weighted to rotate automatically under gravity or may be manually rotatable, for example to be set at a preferred filling angle. The water window 15 may comprise a transparent or translucent member in front of or behind a water window in the kettle 1, and is preferably circular or has a partial circular section to allow rotation thereof. The water window 15 may be retrofitted to an existing kettle having a water window. The kettle 1 may include illumination to make the water window 15 more visible.

Level Indicator - Third Embodiment

As shown in Figures 9 to 11, in a third embodiment the level indicator comprises a fixed water window 17 comprising a series of curved volume markings indicating different multiples of a constant volume, such as a standard cup. Each marking comprises a line curved in such a way that, when the heating chamber 4 contains the corresponding volume of liquid, the liquid level 11 is tangential to the marking over a range of angles of tilt about an axis perpendicular to the plane of the handle 9 and the spout 7, in other words tilt forwards and backwards, but not from side to side. The range of angles may be at least up to 20° of inclination, and optionally up to 30° or even 45°, limited only by the extent of the markings on the water window . The curvature of each marking and the spacing between adjacent markings depends on the internal shape of the heating chamber 4, but the lines may be approximately parabolic. The markings in this embodiment are at the side of the kettle and are therefore suitable for indicating the water level as the kettle is tipped forward or back. Alternatively or additionally, there may be similarly curved marking at the front or back of the kettle, suitable for indicating the water level as the kettle is tilted from side to side.

Level Indicator - Alternative Embodiments

Alternatively, as shown in Figure 12, the level indicator may comprise one or more stickers or other markers 16 that can be added to the water window or gauge of an existing kettle 1, to indicate a preferred filling level for a particular use. For example, a user may require a kettle either to make a single cup of tea, or a pot of tea. The user may then add stickers to their existing kettle indicating the required volumes for the single cup, and for the pot. Alternatively, as shown in Figure 13, the level indicator may comprise a sliding indicator 18 attached to a water window or gauge, that may be adjusted by the user so as to indicate the required filling level.

Where the level indicator requires electrical power, this may be provided from the source of electricity for heating, from a rechargeable battery or capacitor, or from a non-rechargeable battery. Where the kettle 1 is cordless, the rechargeable battery or capacitor may be carried within the kettle 1 when separated from the cordless base, so that the level indicator may operate when the kettle 1 is removed from the cordless base.

Alternatively, the level indicator may comprise a simple mechanical device, such as a float that only becomes visible as the predetermined level is reached. The float may also close off a filling aperture. The float may be carried on a steam tube for conveying steam from above the water in the heating chamber 4 to a steam sensor in the base 2, the steam tube extending through the water in the heating chamber 4.

Fluorescent Illumination rn the level indicator embodiments described above, the level markings may be made of a fluorescent material that emits visible light when illuminated by ultraviolet (UV), thereby being more visible to the user. The fluorescent material may be substantially invisible to the user when not illuminated.

For example, the level markings may be applied as a coating containing fluorescent material. In one example, the coating is an epoxy coating including a silane adhesion promoter and a fluorescent dye. In all but the first embodiment of the level indicator, the coating may be applied to the outer surface of the body 3, so as to avoid tainting the liquid within the reservoir.

Alternatively, the dye may be included as an additive to the material from which the level markings are made, and may for example be included in a pre-formed structure that is moulded into part of the kettle; for example, the rod 10 in the first embodiment above may have fluorescent rings moulded into it to form markers. In the second and third embodiments, the markings may be coated onto the outside of or moulded into the water window 15, 17.

The kettle 1 includes at least one UV source arranged to illuminate the fluorescent material. For example, the UV source 20 may be arranged to illuminate the interior of the heating chamber 4 diffusely with UV so that some of the UV light is absorbed by markings on the water window 17, causing the markings to fluoresce so that they are more clearly visible.

Various alternative positions of the UV source 20 are shown in Figure 14. The UV source 20 may illuminate the water level 11 from above or below. The UV light may reflect off the water surface so that, if the source 20 is above the water level 11, then the markings are brighter above the water level and if the light source 20 is below the water level 11, the markings are brighter below the water level 11. If the source 20 illuminates the markings below the water level 11, then the light emitted by the fluorescence may be scattered within the water so that the water is illuminated with visible light and the water level 11 is more easily discernable.

Alternatively, the UV source may illuminate the markings along a transparent wall of the body 3, for example using the wall as a light guide. As another alternative, the UV source may be arranged to illuminate the markings from the outside of the reservoir, for example from the inner side of the handle 9 or the lid 8 or from a cordless base. The UV source may illuminate markings in a sight glass in fluid communication with the heating chamber 4. The sight glass may include a fluorescent float.

A UV source may be provided to illuminate fluorescent material arranged in parts of the kettle 1 other than water level markings, such as the lid 8 or the handle 9. For example, a UV source 22 as shown in Figure 14 may be arranged to illuminate the interior of the handle 9, part of which contains fluorescent material. In one example shown in Figure 15, the handle 9 comprises a core 9b arranged as a UV light guide and containing fluorescent material, the interior of which is illuminated by the UV source 22, surrounded by a transparent outer portion 9a, through which the fluorescent core 9b is visible. Alternatively or additionally, one or more portions or facets on the outside of the handle 9 may be coated with fluorescent material. In another alternative or additional feature, the core 9b may be in communication with the interior of the heating chamber 4 and arranged to act as a sight glass, so that the water level can be seen within the handle 9. In another example shown in Figure 16, the handle 9 comprises a transparent portion 9a in which are embedded bubbles 9c or other shapes of fluorescent material; the UV source illuminates the outer portion 9a, for example by emitting UV light into the end of the handle 9, which acts as a light guide. The fluorescent material embedded within the handle 9 may take the form of a 2D or 3D shape or logo, for example. The parts of the kettle 1 that contain fluorescent material need not be transparent or be visible through a transparent portion. For example, the wall of the reservoir may be made of translucent material including a fluorescent dye, and the fluorescence may be visible through the translucent material.

The UV source 20, 22 may be arranged in other parts of the kettle 1, for example: a) through the base of the heating chamber 4; b) through the side of the heating chamber 4; c) above or below the water level 11; d) through a central light guide within the heating chamber 4; e) through the rod 10 in the first embodiment; f) through a steam tube for conveying steam from the top of the heating chamber 4 to a control in the base 2; g) through an external part of the handle 9.

The kettle 1 may include one or more of the UV light sources described above. The UV light source(s) are preferably diffuse, and may include a diffuser. The UV source may be a 'black light' that emits little or no visible light, to increase the contrast of the fluorescent material.

The UV source may be arranged to emit predominantly in the UVA frequency range, rather than the shorter wavelength UVB range, so as to minimize the risk to the user from UV leakage.

The UV source may comprise one or more UV LEDs; the LEDs may emit within a frequency range of 360-400 nm; examples include LEDs that emit at 370 nm and 400 nm. The LEDs are low power, preferably less than 20 mW. The power required for illumination may be significantly lower than that required in conventional liquid heating vessels, because only the fluorescent parts need to be illuminated with UV light, and these have a high contrast with other parts that do not fluoresce.

Alternatively, the UV source may comprise a fluorescent lamp, similar to a small fluorescent lamp used for lighting applications, but with different phosphors or no phosphor, so as to emit UV light. The lamp may have a nickel oxide doped glass envelope, for example of Wood's glass, to block most of the visible light.

Alternatively, the UV source may be a mercury vapour lamp, possibly with a doped glass envelope; these lamps are suitable for higher power applications.

Alternatively, the UV source may be an incandescent lamp, preferably with a filter such as a doped envelope to reduce emission of visible light, although these are less efficient than other types of UV source.

The UV source(s) may be controlled to provide variable illumination, and may be switched on and off, or their intensity varied, according to the state of the kettle. For example, a UV source may be switched on or off in response to the heating state of the vessel, in response to a dry boil condition of the vessel 1, or to indicate various other status information, such as just boiled, keep warm mode, kettle overfilled, descaling required, change filter cartridge, tea mode or boil mode. The UV source may be controlled to vary the parts of the kettle that are illuminated, for example to produce a scanned image or a variable marking such as a message indicating the nature of the status information, or to show a pattern or logo. Alternatively, the UV source may illuminate the portion through a mask to define the area of the portion that is illuminated. In either case, an area of the kettle used to display the illuminated pattern may contain the fluorescent material substantially evenly, or with a pattern or texture.

To produce a scanned image, the UV source may be moveable by a motor, or the light emitted therefrom may be scanned by a moveable mirror or refractor. The dye may be of the type used as an optical brightener in paper or textiles; these absorb UV light and fluoresce in the blue part of the spectrum.

Alternative means may be used to cause parts of the kettle to emit light. For example, wavelengths other than UV may be used to induce fluorescence. Electrofluorescent materials may be used, stimulated by capacitative coupling with the liquid in the vessel; this may allow only markings below the liquid level to emit light, for example.

Dispensing Reservoir

In the following embodiments, the kettle body 3 includes a dispensing reservoir 5, fillable by the user, for containing water to be dispensed into the heating chamber 4. hi the embodiment shown in Figures 17 to 19, the dispensing reservoir 5 comprises a vertically elongate chamber arranged at the handle side of the body 3, within a water window that indicates the water level in the heating chamber 4. Thus, as can be seen in

Figures 17 and 18, level markings for both the heating chamber 4 and the dispensing reservoir 5 are visible from the handle side of the kettle 1. The vertically elongate shape of the dispensing reservoir 5 enhances the accuracy with which the water level within the dispensing reservoir 5 can be determined.

The user-operable actuator comprises a push button 6 in the lid 8, connected via a rod to a valve 25 in the bottom of the reservoir 5, so that pushing the button 6 opens the valve and dispenses water into the heating chamber 4.

The dispensing reservoir 5 is fillable through a filling aperture 13 behind the spout 7 but at the spout side of the kettle. A passage 14 leads from the filling aperture 13 to the handle side of the kettle 1, where it empties into the dispensing reservoir 5. Hence, when water is dispensed from the heating chamber 4 through the spout 7, water cannot escape from the dispensing reservoir 5 through the filling aperture 13. The user may also fill the heating chamber 4 directly through the spout 7. In an alternative shown in Figure 20, the actuator 6 comprises a trigger or button located under the handle 9.

In another alternative shown in Figure 21, there is no user-operable actuator; instead, water flows out of the dispensing reservoir 5 through a small orifice 24, sufficiently small to allow the dispensing reservoir 5 to be filled to the required level accurately, but large enough not to require the user to wait for sufficient water to be dispensed before switching on the kettle 1. The orifice 24 may include a one-way valve to prevent water from flowing back from the heating chamber 4 into the dispensing reservoir 5.

As shown in Figure 22, the reservoir 5 and passage 14 may be formed as a unitary part that is insert moulded into the body 3 during manufacture. Part or all of the dispensing reservoir 5, actuator 6 or filling aperture 13 may be fluorescent and able to be illuminated by an ultraviolet source, as described above.

Thick Film Element

The majority of currently available 'under floor' elements are sheathed elements, in which a heating resistance wire is wound around a core and packed within a metal sheath that is bonded to the underside. Another type of under floor element is a thick film element, in which heating resistance tracks are printed onto an electrically insulating layer on the underside of the element. Thick film elements typically require

5-15% less energy than sheathed elements to boil a given volume of water. Hence, the above embodiments preferably include a thick film element so as further to reduce the energy requirements of the kettle 1.

Alternative Embodiments

The above embodiments illustrate, but do not limit, the present invention. For example, the present invention is not limited to kettles, but may be applied to other domestic liquid heating vessels. Alternative embodiments, which may occur to the skilled reader on reading the above description, may also fall within the scope of the invention.

Claims

1. A liquid heating vessel comprising a fluorescent portion and means for exciting the fluorescent portion to emit visible light.

2. The vessel of claim 1, wherein said fluorescent portion comprises a liquid level indicator.

3. The vessel of claim 2, wherein the fluorescent portion comprises one or more level markings against which the liquid level is discernible from outside the vessel.

4. The vessel of any preceding claim, wherein said fluorescent portion comprises a transparent or translucent surface of the vessel.

5. The vessel of claim 1, wherein said fluorescent portion comprises a handle portion of the vessel.

6. The vessel of any preceding claim, wherein the means for exciting the fluorescent portion comprises an ultraviolet light source.

7. The vessel of claim 6, wherein the ultraviolet light source comprises one or more ultraviolet LEDs.

8. The vessel of claim 6 or 7, wherein the ultraviolet source is arranged to emit substantially no visible light.

9. The vessel of any one of claims 6 to 8, wherein the ultraviolet source is arranged to emit ultraviolet light predominantly in the UVA range.

10. The vessel of any one of claims 6 to 9 when dependent on claim 5, wherein the handle portion includes a light guide for guiding the ultraviolet light onto said fluorescent portion.

11. The vessel of any preceding claim, including means for controlling the excitation of the fluorescent portion.

12. The vessel of claim 11, wherein said excitation is controlled according to the status of the vessel.

13. A liquid heating vessel having a liquid level indicator arranged to rotate relative to the body of the vessel about a substantially horizontal axis.

14. The vessel of claim 13, wherein the indicator is arranged to rotate to remain substantially level as the vessel is tilted.

15. The vessel of claim 13 or claim 14, wherein the indicator is arranged to rotate about perpendicular substantially horizontal axes.

16. The vessel of any one of claims 13 to 15, wherein the indicator is rotatably suspended from an upper part of the vessel.

17. A liquid heating vessel having a liquid level indicator slidably mounted relative to the body of the vessel.

18. A liquid heating vessel having a liquid level mark arranged so that the liquid level of a predetermined volume of liquid is substantially tangential to said mark regardless of the inclination of the vessel about a horizontal axis, within a predetermined range of said inclination.

19. The vessel of claim 18, wherein said range of inclination is up to at least 20 degrees of inclination.

20. The vessel of claim 19, wherein said range of inclination is up to 30 degrees of inclination.

21. The vessel of claim 20, wherein said range of inclination is up to 45 degrees of inclination.

22. A liquid heating vessel having a liquid reservoir arranged to dispense liquid into the heating part of the vessel, wherein the liquid reservoir is disposed towards the back of the vessel, away from a dispensing outlet of the heating part.

23. A liquid heating vessel having a liquid reservoir arranged to dispense liquid into the heating part of the vessel, wherein the liquid reservoir is vertically elongate.

24. A liquid heating vessel having a liquid reservoir arranged to dispense liquid into the heating part of the vessel, wherein the liquid reservoir has an opening towards the lower end thereof, arranged to dispense liquid into the heating part at a rate sufficiently low to allow the dispensing reservoir to be filled to the required level accurately, but sufficiently high not to require the user to wait for sufficient liquid to be dispensed before heating the liquid in the heating part.

25. The vessel of claim 24, wherein the opening comprises a one-way valve.

26. A liquid heating vessel having a liquid reservoir arranged to dispense liquid into the heating part of the vessel in response to actuation of a trigger or button under a handle of the vessel.

27. The liquid heating vessel of any preceding claim, having a thick film heating element.

28. The liquid heating vessel of any preceding claim, having a cordless power base.

29. The liquid heating vessel of claim 28 when dependent on any one of claims 1 to 12, wherein the source is able to emit ultraviolet light when the vessel is separated from the power base.