GB2435406A

GB2435406A - Indicating operating mode of liquid heating device

Info

Publication number: GB2435406A
Application number: GB0604011A
Authority: GB
Inventors: Peter H Wright
Original assignee: Otter Controls Ltd
Current assignee: Otter Controls Ltd
Priority date: 2006-02-28
Filing date: 2006-02-28
Publication date: 2007-08-29
Also published as: CN201115609Y; GB0604011D0

Abstract

A liquid heating vessel capable of functioning in at least two modes, comprises indication means such as illumination means 28, 30 that is capable of illuminating at least part of the liquid heating vessel with a first colour when the liquid heating vessel operates in a first mode and a second colour when the liquid heating vessel operates in a second mode. A corresponding boil control and illumination circuit are also provided. The illumination means 28,30 may comprise light emitting diodes. The operating modes of the vessel may comprise heating water to boiling and to a lower temperature such as for making coffee, respectively.

Description

Liquid Heating Vessel comprising an indicator Means, a Boil Control for

a Liquid Heating Means, and an Jilumination Circuit for a Liquid Heating Means The present invention relates to a liquid heating vessel comprising an indicator means, a boil control for a liquid heating means, and an illumination circuit for a liquid heating means.

It is a preferred feature in modern liquid heating vessels to provide multiple heating modes, such that, for example, in one mode the liquid heating vessel is operable to boil the liquid contained within the vessel. A second heating mode may be provided where the liquid is heated to a predetermined temperature below boiling point. It is believed by some that the flavour of coffee or various herbal teas are improved by using water heated to below boiling point.

As is well known, such liquid heating vessels generally comprise element protectors and boil controls to provide an overtemperature protection such that the element is de-energized when the liquid in the vessel boils.

Known liquid heating vessels include boil control mechanisms that have been modified to allow a user to select a mode that switches off power to the element when the liquid inside the heating vessel reaches a preset temperature. Such arrangements are described at length in GB2409341.

However, it can be difficult for users to know in which heating mode the liquid heating vessel is functioning. This can be particularly problematic because, for example, particular teas or coffees may be spoiled if water of the wrong temperature is poured thereon.

The present invention seeks to improve on the foregoing mentioned arrangements.

According to a first aspect of the present invention there is provided a liquid heating vessel capable of functioning in at least two heating modes, said liquid heating vessel comprising first indication means arranged to activate in response to operation of the liquid heating vessel in said first mode, and second indication means arranged to activate in response to operation of the liquid heating vessel in said second mode.

Preferably said first and second indication means comprise an illumination means that is operable to illuminate in a first colour when the liquid heating vessel functions in the first mode and a second colour when the liquid heating vessel functions in the second mode. Alternatively, it is also preferred that the illumination means is operable to cause illumination of differing intensity dependent upon the mode selected.

Preferably the indicator means is operable to generate first and second sounds, said first sound being generated when the liquid heating vessel functions in a first mode, and said second sound being generated when the liquid heating vessel functions in the second mode.

It is preferred that the illumination means comprises at least first and second lighting means, which are preferably first and second light emitting diodes (LEDs). It is also preferred that the first and second LEDs are connected in parallel.

Preferably the first and second LEDs have different striking voltages.

It is also preferred that one of the LEDs is connected in series with a switching means. it is most preferred that the switching means is a reed switch.

Preferably the liquid heating vessel incorporates a boil control that carries a magnet. It is preferred that when the magnet is brought into proximity with the switching means (in the preferred embodiment a reed switch) it causes a switching action. It is preferred that, when power is supplied, the first LED is operable to light when the switch means is open, and that the switching action causes the second LED to illuminate.

It is preferred that the LEDs are powered from the mains. In a most preferred embodiment, mains power is first supplied to a capacitor. In this arrangement the LED is operable to remain lit after mains power has been cut off.

According to a second aspect of the present invention there is provided a boil control for a liquid heating element, said boil control being operable to function in at least two different modes, and comprising means for controlling the output of an indicator circuit based on the mode of operation.

Preferably said indicator circuit is an illumination circuit.

Preferably the means for control is operable to change the colour of the light output by the illumination circuit dependent upon the mode of the liquid heating vessel.

It is preferred that means for control comprises a magnet, said magnet being operable to interact with a switch (such as a reed switch) in the illumination circuit.

According to a third aspect of the present invention there is provided an illumination circuit for a liquid heating device comprising a first light emitting means capable of emitting light of a first colour and a second light emitting means capable of emitting light of a second colour, wherein the first light emitting means is operable to activate when the liquid heating device is in a first operating mode, and the second light emitting device is operable to activate when the liquid heating device is in a second operating mode.

Preferably the light emitting means comprises one or more LEDs.

In a preferred arrangement the illumination circuit is controlled by the operation of the liquid heating vessel. Particularly, it is preferred that the illumination circuit is disposed within a liquid heating device that comprises a boil control, and that said boil control is operable to control the illumination circuit.

In order that the present invention be more readily understood, specific embodiments thereof will now be described with reference to the accompanying drawings, in which: Figure 1 shows an example of a suitable LED switching mechanism; Figure 2 shows a graph plotting current against LED voltage for the arrangement of figure 1; Figures 3 5 show an example of a boil control suitable for use in a liquid heating apparatus; and Figure 6 shows an example of the mechanism of figure 1 and the boil control of figures 3 to 5 located within a liquid heating vessel.

Figures 3 to 5 show a side view of a boil control element 12 that is operable to be fitted within a liquid heating vessel 10. GB2409341 describes the above boil control 12 in depth, and it will be apparent from reading the above reference how to incorporate such a device within a liquid heating vessel 10.

From figures 3 to 5 it will be apparent that a rocking lever 14 comprises two V' shaped groove 16 through each of which a lug 18 protrudes (only one of the lugs 18 and one of the V' shaped grooves are shown in the figures -the other being at the opposite side). Accordingly it will be appreciated that the rocking lever 14 is operable to be moved into one of the three positions shown in each of figures 3 to 5.

The end of the rocking lever 14 remote from the V' shaped groove 16 carries a push rod 20. This push rod 20 is arranged so as to be able to interact with a thermal actuator 22; in this case a snap-acting, dished, bi-metal disk.

In the shown example, when the thermal actuator 22 is in its normal' state the bi-metal is shown curving upwards. When the thermal actuator 22 is heated above a specified temperature the thermal actuator 22 will undergo a snap transformation, and this will result in the dished shape curving downwards.

Figure 3 shows the boil control 12 in the "off" state. In this state, the rocking lever 14 is in a central position and the lugs 18 are each located at the apex of the associated V' slots 16.

Figure 4 shows the boil control 12 in a first of its two on' modes. In this position the rocking lever 14 has been rotated (right hand end downwards as illustrated in the figure) so that the lugs 18 are at the upper end of their respective V' slots 16. In this arrangement the push rod 20 is still well clear of the thermal actuator 22.

Figure 5 shows the boil control 12 in the second of its two on' states.

In this position the rocking lever 14 has been rotated (right hand end upwards in shown in the figure) so that the lugs 18 are at the lower end of their respective V' slots 16. This position causes the push rod 20 to be brought into close proximity with the thermal actuator 22. The effect of this is that when the thermal actuator 22 undergoes a snap transformation at a preset temperature, the thermal actuator 22 pushes onto the push rod 20, and causes the rocking lever 14 to revert back to the off' position. This action switches off the boil control 12 and thereby de-energises the heating element, without the liquid in the vessel 10 having been heated to its boiling point. In effect, the thermal actuator 22 operates to switch off the boil control 12 before the liquid in the vessel has reached a sufficient temperature to cause the boil control to operate of its own volition.

Figure 1 shows an example of an illumination mechanism suitable for use with the above boil control 12. Power is received by a capacitive power supply unit 26 and then fed to the LED arrangement. This arrangement comprises a first and a second set of LEDs 28, 30. The first and second sets of LEDs 28, 30 are arranged in parallel with one another. The second set of LEDs 30 is in series with a switch 32. in this example the switch is a reed switch.

The first and second sets of LEDs 28, 30 arc coloured differently, and are used to show the mode of operation. The two sets of LEDs 28, 30 have different striking voltages. For example, the first LED may have an operating voltage of 6.9V, whereas the second LED has an operating voltage of 4V.

This arrangement is illustrated in figure 2. The second set of LEDs 30, which are in series with the reed switch 32, have a lower operating voltage than the first set of LEDs 28.

As will be appreciated, when the reed switch 32 is open power will only flow through the first (higher voltage) LEDs 28. However, when the reed switch 32 is closed, the lower voltage LEDs 30 are placed in parallel with the higher voltage LED set 28. Accordingly the second set of LEDs 30 acts similarly to a Zener diode, and drops the supply voltage to its own level, such that there is insufficient power for the first LED set 28 (ie the higher voltage set) to illuminate. However, as there is sufficient power for the second set of LEDs 30 to illuminate the effect for a user is that the illumination colour of the liquid heating vessel 10 changes. For example, the first set of LEDs might be red, whilst the second set 30 may be green.

It is particularly preferred to include a capacitive power supply unit 26 so that illumination may continue even if the illumination circuit 13 is removed from a fixed power supply. This arrangement is particularly advantageous in a cordless kettle. When the kettle is removed from its power unit (typically a base unit) the illumination circuit 13 is still powered for as long as sufficient charge is retained in the capacitor 26.

Figure 6 shows a schematic of the boil control 14 and the illumination circuit 13 within the body of a liquid heating vessel 10. The illumination circuit 13 is shown in dotted lines.

The rocking lever 14 of the boil control 12 carries a magnet 34. When the rocking lever 14 is moved to the second of the on' positions, the magnet 34 is brought into proximity of the reed switch 32 in the illumination circuit 13. Therefore the reed switch 32 is caused to close and power is operable to flow through the second set of LEDs 30. Hence the liquid heating vessel 10 is caused to be illuminated in a particular colour (green, for example).

When the rocking lever 14 of the boil control 12 is pushed into either the off switch or the first of the on' positions the magnet 34 is too far away from the reed switch 32 to cause the switch to close. Therefore current is only able to flow through the first LED set 28.

Therefore, when the liquid heating vessel 10 is activated in the first mode, the illumination circuit causes the first LED set 28 to light, and hence the liquid heating vessel is illuminated in a different colour (red, for example).

The preferred source of illumination is a series of discrete LEDs, or lamps, spaced from each other. However, any type of illumination that is suitable for use in a liquid heating vessel may be used. In a preferred arrangement the illumination means is configured so as to illuminate the interior of the liquid heating means. However, in other preferred embodiments, the lights may be positioned to illuminate all, or a portion, of the exterior of the liquid heating apparatus. Alternatively, the lights may be positioned to be visible from the exterior of the liquid heating vessel. The lamps or LEDs may be placed in any suitable position in the liquid heating device, preferably within a housing. Said housing may be flush with an exterior wall of the liquid heating device, or may project into the interior of the vessel.

It will also be appreciated that while the invention has been described with reference to the boil control disclosed in GB2409341, the present invention may be incorporated into any liquid heating device that comprises a dual operating mode.

It is to be appreciated that the above described specific description is made for information purposes only and should not be used to limit the scope of the invention, which is set out in the accompanying claims. For example, the invention may use first and second sound generators instead of, or as well as, first and second lighting means. In this embodiment different sounds are used when a particular heating mode is selected.

Claims

Claims 1. A liquid heating vessel capable of functioning in at least

two heating modes, said liquid heating vessel comprising first indication means arranged to activate in response to operation of the liquid heating vcssel in said first heating mode, and second indication means arranged to activate in response to operation of the liquid heating vessel in said second heating mode.

2. A liquid heating vessel according to claim 1, wherein said first and second indication means comprise an illumination means.

3. A liquid heating vessel according to claim 2, wherein the illumination means comprises at least first and second lighting means.

4. A liquid heating vessel according to claim 3, wherein the lighting means are light emitting diodes.

5. A liquid heating vessel according to claim 3 or 4, wherein the first and second lighting means are connected in parallel.

6. A liquid heating vessel according to any of claims 3 to 5, wherein the first and second lighting means have different striking voltages.

7. A liquid heating vessel according to any of claims 3 to 6 wherein one of the lighting means is connected in series with a switching means.

8. A liquid heating vessel according to any preceding claim, wherein the liquid heating vessel incorporates a boil control that carries a magnet.

9. A liquid heating vessel according to claim 8, wherein the switching means is caused to switch when the magnet is brought into proximity therewith.

1 0. A boil control for a liquid heating element, said boil control being operable to function in at least two different heating modes, and comprising means for controlling the output of an indicator circuit based on the mode of operation.

11. A boil control for a liquid heating element according to claim 10, wherein the indicator circuit comprises an illumination circuit.

12. A boil control for a liquid heating element according to claim 10 or 11, wherein the means for control is operable to change the colour of the light output by the illumination circuit dependent upon the mode of the liquid heating vessel.

13. A boil control for a liquid heating clement according to any of claims to 12, wherein the means for control comprises a magnet.

14. A boil control for a liquid heating element according to claim 13, wherein the magnet is operable to interact with a switch in the illumination circuit.

15. An illumination circuit for a liquid heating device comprising a first light emitting means capable of emitting light of a first colour and a second light emitting means capable of emitting light of a second colour, wherein the first light emitting means is operable to activate when the liquid heating device is in a first operating mode, and the second light emitting device is operable to activate when the liquid heating device is in a second operating mode.

16. An illumination circuit for a liquid heating device according to claim 15, wherein the illumination circuit is controlled by the operation of the liquid heating vessel.

17. An illumination circuit for a liquid heating device according to claim or 16, wherein the illumination circuit is disposed within a liquid heating device that comprises a boil control, and that said boil control is operable to control the illumination circuit.