WO1998027851A1

WO1998027851A1 - Liquid heating vessels

Info

Publication number: WO1998027851A1
Application number: PCT/GB1997/003527
Authority: WO
Inventors: John Crawshaw Taylor
Original assignee: Strix Limited
Priority date: 1996-12-23
Filing date: 1997-12-23
Publication date: 1998-07-02
Also published as: GB9917382D0; GB2336292A; GB2336292B

Abstract

An electric liquid heating vessel (2; 50) has a single liquid level indicator (18; 54) arranged generally centrally at a rear portion of the vessel (2; 50) such that the level of liquid (24) indicated by the liquid level indicator (18; 54) may be seen from either side of the vessel. The liquid level indicator (18; 54) may comprise e.g. a tube (28) in fluid communication with the interior of the vessel or a tansparent window (56) in the wall of the vessel. Also disclosed are means (74) to illuminate the liquid level indicator (18; 54) or any other suitable level indicator.

Description

Liσuid Heatinσ Vfisspls

This invention relates to electric liquid heating vessels, and more particularly liquid heating vessels having liquid level indicators for indicating the level of liquid inside the vessel.

In liquid heating vessels, such as kettles and hot- water jugs, it is very useful to be able to tell at a glance how much liquid there is in the vessel and therefore whether or not the vessel needs to be filled before it is operated. Also, whilst filling the vessel, it is useful to be able to know the liquid level in the vessel and particularly when the maximum level has been reached. Accordingly such vessels have been fitted with level indicators .

One form of indicator consists merely of transparent window in the side of the vessel through which the level of liquid inside the vessel may be seen. Commonly, such level indicators have a graduated scale on them which may be calibrated to show the volume of liquid in the vessel, or may simply be a nominal liquid level or merely a maximum and minimum liquid level for safe operation of the vessel. Another form of indicator comprises a separate, self-contained gauge which is mounted to the wall of the liquid heating vessel or the rear handle or cover of the vessel and which is in fluid communication with the inside of the vessel at one end. As mentioned above, a level indicator is of particular use whilst the vessel is being filled or indeed handled by a user. Thus, it has been usual to provide two level indicators, one on each side of the vessel in order that the liquid level may be ascertained regardless of which hand is used to pick up the vessel, i.e. an indicator is provided for both left-handed and right-handed users. According to one aspect of the present invention there is provided a liquid heating vessel comprising a single liquid level indicator arranged generally centrally at a rear portion of the vessel such that the level of liquid indicated by the liquid level indicator may be seen from either side of the vessel .

By providing a liquid level indicator centrally at the rear of the vessel, only a single indicator is needed, rather than one on each side as was previously known, since the level of liquid inside the vessel may be seen from either side. This reduction in the number of indicators required confers benefits in styling and manufacturing costs . The provision of a liquid level indicator in such a location is made easier in light of recent developments whereby the electrical power controls for electrical liquid heating vessels are more commonly now being located beneath the base of the liquid vessel, rather than the traditional location at the rear of the vessel. In one preferred embodiment, the liquid level indicator is provided in, or mounted to a portion of the handle of the vessel . The indicator may comprise a tube mounted to or in the vessel, the lower end of the tube being in liquid communication with the inside of the vessel.

In another preferred embodiment, the indicator may be provided in or mounted to a wall of the vessel. Most preferably, the indicator comprises a transparent portion of the wall through which a user may see directly the level of liquid in the vessel.

Preferably the liquid level indicator is graduated and most preferably indicates the maximum and/or minimum levels of liquid which are prescribed for safe operation of the vessel. Means may be provided to facilitate reading of the liquid level in the indicator. For example, as is already known, a float, usually in the form of a brightly coloured plastics bead, may be provided in the indicator. Such floats are not entirely satisfactory, since after time the float can become stuck in its tube, particularly in hard water areas where it may accrete lime deposits. Furthermore, the float may not be seen satisfactorily in poor light. Moreover a float cannot be used with the transparent window type of level indicator.

Preferably, therefore, means are provided to illuminate the liquid level indicator. By illuminating the level indicator, the contrast between it and the liquid's meniscus will be improved, making the level of liquid in the vessel more readily apparent, particularly in poor lighting conditions. Since there are no moving parts such as a float, the lime accretion problems associated with the float arrangement are overcome. Furthermore, a more aesthetic design may be achieved, for example if the illuminating means is chosen to have a colour which complements the colour of the vessel or indicator.

The provision of an illuminating means arranged to illuminate a liquid level indicator is novel and advantageous in its own right and is applicable to liquid level indicators wherever they are arranged on the vessel, not just to those arranged centrally at a rear portion thereof. Accordingly, from a second aspect the invention provides a liquid heating vessel comprising a liquid level indicator and means arranged to illuminate the indicator. In a particular preferred embodiment, where the level indicator comprises a cavity in fluid communication with the interior of the vessel for receiving a column of fluid, the illuminating means is arranged to transmit light into the liquid itself through the level indicator, preferably by arranging the illuminating means at the lower end of the indicator. This allows light to pass into the bottom of the liquid which then acts as a light pipe to highlight its meniscus .

In another embodiment, the backdrop to a column of liquid may be illuminated to provide contrast with the liquid meniscus.

In a third preferred embodiment the level indicator comprises a transparent portion of the vessel wall and the means to illuminate the indicator is arranged to illuminate the viewing window of the level indicator so as to provide a good contrast with the meniscus of the liquid behind. The illuminating means may be conveniently located at the upper or lower end of the level indicator.

In a fourth arrangement, the main body of the liquid may be illuminated so as to highlight its meniscus against a viewing window.

The illuminating means may be mounted in any convenient location in the vessel, for example under the handle thereof. Preferably, however, it is mounted to the level indicator. This not only facilitates mounting of the illuminating means, but also maximises light transmission to the liquid. Preferably, therefore the level indicator is provided with mounting means for the illuminating means, most preferably at its lower end. Such a level indicator is believed to be novel in its own right and from a further aspect, the invention provides a level indicator for a liquid heating vessel comprising means for mounting means for illuminating the indicator. For example, the mounting means may comprise a resilient clip formed in the indicator, or bore into which the illuminating means may be push fitted during assembly. The clip or the bore may be integrally formed, e.g. moulded with the indicator. The illuminating means may comprise a standard filament type bulb, or a light emitting diode, but preferably it comprises a neon bulb. Neon bulbs are preferred since they are relatively inexpensive whilst being long-lasting and generating little heat. They are also especially suited to use with mains voltages for prolonged periods of time. The illuminating means may be lit only while the vessel is heating, by connecting it in parallel with the heating element, downstream of the control of the vessel, or whenever a power supply is connected to the vessel, by connecting it across the power supply upstream of the control. "Power on" neon indicators are already provided in certain vessels, so this neon could act also to illuminate the liquid level indicator, avoiding the need for a further neon.

Preferably the liquid heating vessel is of the electric cordless type whereby the electrical power is supplied to the vessel via a cordless base. This arrangement has the advantage that no electrical connection is required at the rear of the vessel, thereby further increasing the space available for locating the indicator.

Certain preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:

Fig. 1 shows an electrically powered cordless liquid heating vessel having a level indicator arranged in a handle portion,-

Fig. 2 shows an exploded view of the level indicator of Fig. 1 and its mounting;

Fig. 3 shows another embodiment comprising a jug- type kettle having a level indicator formed as part of the vessel wall;

Fig. 4 shows a further embodiment of the invention;

Fig. 5 shows an enlarged sectional view of the detail A of Fig. 4; Fig. 6 is a front elevation of a level indicator incorporating means for mounting a neon bulb;

Fig. 7 is a top view of the level indicator of Fig. 6 ;

Fig. 8 is a side view of the level indicator of Figs . 6 and 7 ; and

Fig. 9 shows an enlarged sectional view of a further embodiment of the invention.

Referring first to Fig. 1, an electrically powered liquid heating vessel in the form of a "traditional" kettle 2 is shown. The kettle 2 is of metal, is generally circular in section and has an upper mounted handle 4, an openable lid 6 and a pouring spout 8. The kettle may be filled with water via the opening covered by the lid 6 or via the spout 8. Electrical power to the element of the vessel (not shown) is supplied from a cordless base 10 via a cordless connector 12 of the type allowing electrical connection to be made between the base unit and the vessel at substantially any orientation such as is described in International Patent application WO 95/08524. In a particularly advantageous arrangement, a control unit for the vessel is also provided under the base of the vessel together with the connector and is of the type generally described in International Patent application WO 95/34188. The vessel may be switched on or off via means of a switch 14 mounted at the base 16 of the vessel. A liquid level indicator 18 is mounted in an aperture 20 formed in a lower portion of the handle 4 which extends over the rear of the vessel . The level indicator 18 includes a transparent window 22 through which the water level 24 inside the level indicator may be seen. Since the transparent window 22 extends around the sides of the handle portion 4, the water level 26 in the level indicator may easily be seen by a user from either side of the vessel.

Referring now to Fig. 2 in more detail, the level indicator 18 comprises a tube 28 having an opening 30 to which is mounted the transparent window 22. The window 22 is graduated by means of a series of marks 32 running down its centre. The tube 28 is vented at its upper end through a silicone plug 34. At its lower end, the tube 28 is in fluid communication with the inside of the vessel 36 through a pipe 38, extending through a silicone seal 40 which is mounted in a hole 42 formed in the wall of the vessel body. The handle portion 4 (which is a downward extension of a handle moulding part) is placed over the level indicator so that only the transparent window 22 is visible through the handle aperture 20. When the vessel is filled with water, water passes into the level indicator 18 through the pipe 38 in order that its level may be seen and judged against the graduation marks 32. (See Fig. l)

Fig. 3 shows a second embodiment of the invention in which it is applied to a plastics "jug" style kettle 50. In such a kettle, the handle 52 is arranged extending along the rear of the vessel. In this embodiment, the level indicator 54 consists merely of a transparent window 56 provided in the vessel wall. The window 56 extends partially around to the sides of the vessel in order that the liquid level within the vessel is easily visible from either side of the vessel through the transparent window 56.

Referring now to Fig. 4, there is shown a further embodiment of the invention. In this embodiment, a metal bodied vessel 60 has a moulded plastics handle 62. The handle moulding 62 extends around the rear part of the vessel 60, and has a liquid level indicator 64 arranged against the outer surface of the vessel body 60.

Fig. 5 shows an enlarged partial sectional view of region A of Fig. 4. As can be seen, the level indicator 64 comprises a moulding 66 which communicates with the interior of the vessel via an opening 68 in the vessel wall 60. The level indicator 64 is visible through a window 70 provided in the handle moulding 62. At least a portion 72 of the rearward facing surface of the indicator moulding 64 is transparent to allow the liquid level to be seen.

A neon bulb 74 is mounted in bore 76 formed in a light transmitting portion 78 of the indicator moulding 64. Electrical connection to the bulb 74 is made via wires 80, the other ends of which are omitted for clarity. The neon bulb 74 may, for example, be connected across the element, so as to illuminate only whilst the liquid in the vessel is being heated or it may be connected across the electrical supply so as to illuminate as long as the vessel is connected to the supply.

The neon bulb 74 emits light mainly in a radial direction. This light therefore passes into the end portion 78 of the level indicator and into the liquid in the indicator, which acts as a light pipe, to highlight its meniscus. Since the end portion 78 is integral with the main body of the level indicator 60, the number of boundaries through which the light must pass and hence wherefrom it may be scattered, is minimised.

Figs. 6, 7 and 8 are front, top and side views respectively of an embodiment of a further liquid level indicator 80 in accordance with the invention. The overall construction of the indicator 80 is generally the same as the indicator 64 in the embodiment of Figs. 4 and 5, apart from the manner in which the neon bulb is mounted, so it may also be used in conjunction with Figs . 4 and 5 to give further details of the indicator 64 of that embodiment. The indicator 80 is moulded from acrylic and is generally elliptical in shape. As can be seen from Fig. 7, the indicator has a centrally moulded liquid receiving cavity 82 and a cosmetic faςade 84 formed around the cavity 82. The faςade is frosted in appearance and carries markings 86 representing degrees of filling of the vessel. An elliptical transparent window 88 is provided (e.g. by polishing) over the cavity 82 to allow the level of liquid in the indicator to be viewed. As in the earlier embodiment, a moulding 90 is provided at the lower end of the level indicator extending from the liquid receiving cavity 82 for communication with the interior of the liquid heating vessel, and an integral extension 92 provided for mounting a neon bulb or other suitable illuminating means. In this embodiment, however, rather than having a bore into which the bulb is pushed, the extension is formed as a resilient clip 94.

Fig. 9 shows an enlarged sectional view of a further embodiment which is similar to that shown in Fig. 3 in that the level indicator 96 comprises a transparent plastics window 98 which insert moulded into the rear of the main body moulding of a plastics jug kettle. A handle 52 is located to the rear of the main body. The indicator 96 has a downward extension 100 which has a clip 102 for receiving a neon 74. Light is transmitted from the neon 74 into the transparent downward extension 100 and thus into the transparent window 98 which acts therefore as a light guide. This illumination of the window 98 will act to increase the contrast of the liquid's meniscus against the window. In all the above embodiments, not only is the indicator aesthetic, but it is more easily read by a user.

Although the present invention has been described in terms of two specific embodiments where a user can see the liquid itself, it will be understood by those skilled in the art that various modifications may be made within the scope of the invention. For example, in the embodiment of Fig. 3, the level indicator may be formed as a tube mounted to the vessel wall and in fluid communication with the interior of the vessel. It will also be appreciated that illumination may be provided with any of the level indicators described, not just those for which a neon is explicitly shown. For example, a neon may be provided under the tube 28 in the embodiment of Fig 2 to illuminate the liquid therein, particularly the meniscus.

Also, an illuminated level indicator may be provided in any suitable location in the vessel . For example illuminated windows such as those shown in Figs . 3 and 9 may be provided in one or both side walls of the vessel. Furthermore, the invention is applicable both to metal and plastics walled vessels with top mounted or rear mounted handles . For example the plastics vessel of Fig. 3 could equally be metallic.

Claims

1. An electric liquid heating vessel comprising a single liquid level indicator arranged generally centrally at a rear portion of the vessel such that the level of liquid indicated by the liquid level indicator may be seen from either side of the vessel.

2. A liquid heating vessel as claimed in claim 1, wherein said liquid level indicator is provided substantially in or on a handle portion of the vessel.

3. A liquid heating vessel as claimed in claim 1, wherein said liquid level indicator is provided in or on a wall of said vessel.

4. A liquid heating vessel as claimed in claim 1, 2 or 3 , wherein said liquid level indicator comprises a tube in fluid communication with the interior of the vessel.

5. A liquid heating vessel as claimed in claim 3, wherein said liquid level indicator comprises a transparent portion of a wall of said vessel.

6. A liquid heating vessel as claimed in any preceding claim, wherein said vessel comprises a control for the vessel mounted under the vessel.

7. A liquid heating vessel as claimed in any preceding claim, wherein electrical power is supplied to the vessel via a cordless electrical connection.

8. A liquid heating vessel as claimed in any preceding claim comprising means arranged to illuminate the liquid level indicator.

9. An electric liquid heating vessel comprising a liquid level indicator and means arranged to illuminate the indicator.

10. A liquid heating vessel as claimed in claim 8 or 9, wherein the illuminating means is mounted to the indicator.

11. A liquid level indicator for a liquid heating vessel comprising means for mounting means for illuminating the indicator.

12. Apparatus as claimed in any of claims 8 to 11, wherein the illuminating means is arranged at the lower end of the indicator.

13. Apparatus as claimed in claim 10, 11 or 12 wherein the mounting means for the illuminating means comprises a resilient clip.

14. Apparatus as claimed in claim 10, 11 or 12 wherein the mounting means for the illuminating means comprises a bore into which the illuminating means may be push fitted.

15. Apparatus as claimed in any of claims 10 to 14 wherein the mounting means for the illuminating means is integrally moulded with the indicator.

16. Apparatus as claimed in any of claims 9 to 15, wherein the indicator comprises a cavity for containing a column of liquid.

17. Apparatus as claimed in any of claims 10 to 15, wherein the indicator comprises a window in the vessel wall .

18. Apparatus as claimed in any of claims 8 to 17 wherein the illuminating means comprises a neon indicator.

19. A liquid heating vessel substantially as hereinbefore described with reference to the accompanying drawings .

20. A liquid level indicator substantially as hereinbefore described with reference to the accompanying drawings .