GB2332522A

GB2332522A - Liquid level indication device

Info

Publication number: GB2332522A
Application number: GB9725139A
Authority: GB
Inventors: Robert Andrew O'neill; John William George Preece; Charles Frazer Kilby
Original assignee: Otter Controls Ltd
Current assignee: Otter Controls Ltd
Priority date: 1997-11-27
Filing date: 1997-11-27
Publication date: 1999-06-23
Also published as: GB2332522A9; GB9725139D0

Abstract

A level indication device for a liquid container such as an electric kettle (1) or hot water jug comprises a sight glass (8) which is located in a recess in the outer wall of the container and connected so that the liquid level is the same in the sight glass (8) as in the container, and a light source (15) is provided at one end of the sight glass (8) to illuminate the liquid inside the liquid chamber (8) and the surrounding walls of the liquid chamber (8) so as to make the liquid level easier to see. The light source (15) may be powered partly by a battery or capacitor. A reflective float (9) may be provided. There may be light sources of different colours.

Description

2332522 1 AN INDICATION DEVICE

Field of the Invention:

The present invention relates to an indication device, and particularly but not exclusively to an indication device for indicating the level of liquid in a liquid container such as a domestic kettle or hot water jug for example.

Backzround of the Invention:

Kettles and hot water jugs are commonly used in the home to heat water in order to make tea or coffee. Such water heating appliances can be either corded or cordless, the latter comprising a vessel which is adapted to be set down on a base which serves to supply power from the mains supply to a heating element of the vessel via mated connector parts of the vessel and base.

It is known to provide liquid containers with a sight glass which allows the user to see the liquid level therein. Kettles and hot water jugs are also known wherein the sight glass comprises a separate member which is let into the outer wall of the vessel and provides a columnar chamber connected to the interior of the vessel such that the height of the water level in the chamber is indicative of the water level in the kettle.

Due to the limited visibility of a relatively small column of water, the water level in such kettles cannot always be seen clearly. It is known to provide a brightly coloured float in the water chamber, but this still may not provide the desired visibility of the water level.

is 2 Accordingly, it is desirable to improve the visibility of the liquid level in a liquid container, such as for example a kettle or hot water jug.

Summary of the Invention:

According to one aspect of the present invention, there is provided an indication device for indicating the amount of liquid in a liquid container, said device being adapted to be installed in or on a wall of said container so as to permit a liquid level to be viewed which is indicative of the amount of liquid in said container, and a light source being provided in said device to illuminate at least said liquid level.

By providing a light source in the indication device of the invention, the visibility of the liquid level that is to be viewed can be much improved. Also, by using a light source, the visibility of the liquid level remains constant and is not substantially affected by the level of ambient illumination which might otherwise make it difficult to see.

In an exemplary embodiment of the invention which is described in detail hereinafter, the indication device comprises an elongate, narrow liquid container which is adapted to be received in an accommodating vertical recess in the external wall of a water heating vessel, the container having a spigot at one end (its lower end in use) which is adapted to fit sealingly into an aperture in the vessel wall so as to enable the container to fill as the vessel is filled and having an opening at its other (upper) end for the avoidance of air locks as the vessel is filled and emptied. The container develops a vertical column of water ill- -- 3 as the vessel is filled and it is the level of the upper end of this column which enables the amount of liquid in the vessel to be judged. The light source is provided at the bottom of the vertical column of water and comprises a light emitting diode (LED) or a miniature bulb. The light source illuminates both the container and the column of water within it.

A float may be provided within the device and may advantageously be made reflective for better visibility. The visibility of other parts of the device may also be enhanced by provision of suitably reflective or diffusing surfaces, printing or coatings. For example, level markings may be made more visible in this way.

With the indication device of the invention incorporated into an electric kettle or hot water jug for example, the light source is preferably powered from the power supply of the appliance, namely the mains supply. However, in order to power the light source, at least for a short time, after the appliance is disconnected ftom the mains, a battery is preferably provided, preferably a rechargeable battery. Alternatively, a capacitor may be used instead of a battery. The capacitor/battery could be arranged to be recharged when the appliance was connected to the mains supply. These options have benefits since it is normal to disconnect the power supply from such an appliance before taking it to the tap for filling, at which time enhanced visibility of the water level is useful. If the appliance has other electronic functions, for t 4 example an audible warning of boiling, then the same power supply continuation system could be used for such features.

The light source may emit coloured light and different colours may be emitted in dependence upon the condition of the appliance. For example, the light source may emit light of a first colour (eg. red) when the appliance is first switched on, and light of a second colour (eg. green) when the desired water temperature is reached and the appliance switches off. The emission of light of different colours simplifies the use of the appliance and improves its appearance and attraction.

According to another aspect of the present invention, there is provided a liquid container comprising a sight glass arranged to indicate the amount of liquid in said container, and a light source for illuminating said sight glass to improve the visibility of the liquid level in the container.

The above and other features of the present invention will become clear is from consideration of the following detailed description of an exemplary embodiment of the present invention given with reference to the accompanying drawings. Description of the Drawinp-s,:

Fig. 1 shows a kettle incorporating a sight glass; Fig. 2 shows a sight glass moulding embodying the present invention; and Fig. 3 shows the sight glass moulding of Fig. 2 with an inserted LED.

1 Detailed Descrii3tion of the Embodiments:

Referring to Fig. 1, a kettle I comprises a lid 2, a handle 3 and a spout 4. The kettle I may be of the cordless type aforementioned which has to be placed on a base station (not shown) for connecting the kettle I to a power supply for powering a heating element inside the kettle 1, or may alternatively be of a corded type. The kettle I comprises a sight glass moulding 5 which is located in a recess in the wall of kettle I and is arranged to indicate a water level 6 corresponding to the amount of water 7 inside the kettle 1.

The sight glass moulding 5 is formed of clear (transparent) plastics and comprises a tubular water chamber 8 which is arranged to guide a float 9 along the sight glass moulding 5. The water chamber 8 is connected to the inner volume of kettle I so that the level of the water in the water chamber 8 is indicative of the amount of water in the kettle 1. A scale 10 is provided along the sight glass moulding 5 for indicating the number of cups that are associated with the water level 6. The scale 10 also comprises markings I I in the form of vertical and horizontal lines on the sight glass moulding 5 to assist the visibility of the water level in relation to the indicated number of cups.

As is explained in more detail in connection with Figs. 2 and 3, a light source is provided below the lower end of the sight glass moulding 5. The light source illuminates the sight glass moulding 5, the water chamber 8, the water therein and the float 9.

6 In the kettle I shown, the sight glass moulding 5 has a rectangular shape and is arranged centrally between the handle 3 and the spout 5. However, the sight glass moulding 5 may be provided at any desired position, in any desired shape and any appropriate size. For example, the sight glass moulding 5 may have an oval shape. Also, there may be more than one sight glass moulding 5, for example on opposite sides of the kettle. The float 9 and the water chamber 8 are not necessarily required, and the kettle I may only comprise the sight glass moulding 5 together with the light source.

Referring now to Figs. 2 and 3, the sight glass moulding 5 is shown in more detail. On the lower end of the rear 12 of the sight glass moulding 5, a spigot 13 is provided which sealingly engages an aperture in the kettle wall to enable the chamber 8 to fill as the kettle I is filled. An opening (not shown) is provided at the other end of the sight glass moulding to avoid air lock as the chamber 8 fills and/or empties.

Below the inlet 13, a cavity 14 is provided in the sight glass moulding 5 transversely to the inlet 13. An LED 15 is placed in the cavity for illuminating the bottom end of the water chamber 8 (Fig. 3). Conductors 16 extend out of the cavity 14 and are connected to a power supply. The LED 15 may be separated from the water chamber 8 by a transparent wall therebetween.

When the kettle I is connected to a power supply, the LED 15 may be powered via that power supply. Additionally, the LED 15 may be connected to a battery or a capacitor which supplies power to the LED 15 when the 7 kettle 1 is not connected to its power supply. The batterylcapacitor may be arranged to be recharged by the power supply when the kettle 1 is placed on the base station. If the kettle 1 has any other electronic functions, for example an audible warning of boiling, then the same internal power supply continuation system used for these functions can be used for the LED 15. The electrical components for performing this function could for example be housed in the handle of the kettle 1, and connections to the light source(s) in the indication device could be provided via channels formed in the kettle wall and not accessible by the contents of the kettle.

Though the illustrated embodiment uses only one LED 15 as the light source, additional light sources may be used. For example, several light sources may be used such that the colour of the illumination of the sight glass depends on the state of operation of the kettle 1. The light source may for example emit light of a first colour when the kettle is in a rest state, light of a second colour when water is being heated, and light of a third colour when the water is boiling and/or when the kettle has switched off. Also, the LED 15 may not be arranged at the bottom end but at the top end of the sight glass moulding 5. Alternatively, one or more longitudinal light sources may be provided along the sight glass moulding 5 or even inside the water chamber 8.

A clear (transparent) plastics material is preferably used for the sight glass moulding 5, and the effect can be enhanced by use of reflective or difflusing surfaces, printing or coatings to improve the visibility of specific parts 1 8 of the sight glass. For example, the level markings I I may be made to stand out in this way, and/or the float 9 may be made reflective for better visibility.

The indication device is described hereinbefore with reference to a kettle. However, the indication device may be used for other types of liquid containers. For example, it can well be used for the water container of a coffee-maker.

Having thus described the present invention by reference to an exemplary embodiment, it is to be understood that modifications and variations such as will occur to those of appropriate knowledge and skill may be made without departure from the scope of the invention.

1 9

Claims

CLAIMS:

1. An indication device for indicating the amount of liquid in a liquid container, said device being adapted to be installed in or on a wall of said container so as to permit a liquid level to be viewed which is indicative of the amount of liquid in said container, and means enabling the provision of a light source in said device for illuminating at least said liquid level.

2. The indication device of claim 1, comprising a plastics moulding defining an elongate chamber adapted for communication with the internal volume of said container such that the level of liquid in said chamber corresponds to the amount of liquid in said container.

3. The indication device of claim 2, wherein said plastics moulding has a connector at one end for engagement with an aperture in the wall of said container for admitting liquid from the container to said chamber, and a vent opening is provided at the other end of said moulding.

4. The indication device of claim 2 or 3, wherein a cavity is provided at one end of said moulding for accommodating said light source.

The indication device of any of claims 2 to 4, further comprising a float provided in said chamber to be illuminated by said light source.

1 6. The indication device of claim 5, wherein said float comprises a light- reflective material.

7. The indication device of any preceding claim, wherein indicia are provided in or on said device and their visibility is arranged to be enhanced by said light source.

8. The indication device of any preceding claim, wherein reflective and/or diffusive surfaces are provided in the device to enhance its visual effect.

9. The indication device of any preceding claim in combination with a light source in the device.

is 10. The indication device of claim 9, wherein said device has a plurality of different coloured light sources.

11. A liquid container provided with an indication device as claimed in claim 9 or 10, said container including means for powering said light source(s).

12. The container of claim I I configured as an electrically powered liquid heating container and wherein the or each said light source is connected to a 11 rechargeable battery or a capacitor, said rechargeable battery or capacitor being arranged to be recharged when said container is connected to a power supply and to power said light source (at least for a limited period) when said container is disconnected from said power supply.

13. The container of claim 11 or 12, wherein a plurality of light sources of different colours are provided and the arrangement is such that different ones of said light sources are illuminated depending on the condition of the container.

14. A liquid container comprising: a sight glass arranged in a wall of said liquid container to indicate the liquid level in said liquid container; and a light source for illuminating said sight glass to improve the visibility of the liquid level.

15. An indicator device substantially as hereinbefore described with reference to Figures 2 and 3 of the accompanying drawings, or a liquid container incorporating such an indicator device.