GB2580597A - Liquid heating appliances - Google Patents

Abstract

A liquid heating appliance, such as a kettle, comprises a liquid reservoir 2 having a first chamber 24a arranged below a second chamber 24b. The chambers are separated by a partition 22. The appliance further comprises a heating arrangement which, in use, heats liquid contained within the first chamber. First and second valves 26 are arranged in the partition to selectively allow liquid to flow between the first and second chambers. Each valve comprises a floating valve member that can float and mate with a respective valve seat to close the valve. The appliance also comprises a valve actuation arrangement 25 and a liquid outlet in the first chamber. The liquid outlet is in fluid communication with a dispense outlet so as to allow liquid to be dispensed from the first chamber when the first and second valves are closed. The valve actuation arrangement is movable between a first position, in which the floating valve members are free to float so as to mate with their respective valve seats, and a second position, in which it prevents the floating valve members from floating, thereby holding the valves open.

Description

Liquid Heatinq Appliances The present invention relates to liquid heating appliances, in particular to a liquid heating appliance capable of selectively heating a small volume of liquid.

Liquid heating appliances, such as kettles, are common in many households. Kettles can be used to heat volumes, often up to 1.7 I, of water, to boiling. However, users frequently only need to heat a relatively small volume of water to boiling, for example if they are making a single hot drink. Depending on the kettle it can be difficult to accurately fill the kettle with the correct amount of water for a single drink, and as a result kettles are regularly over filled. This overfilling results in more energy being required to heat the volume of water to the desired temperature. As kettles typically have a fixed power output, this ultimately results in a user having to wait a longer period of time for the water to reach the desired temperature. Further, not only does it mean a user has to wait a longer time, the extra energy required to heat the surplus volume of water is often wasted as the surplus water is typically left to cool in the kettle. Kettles are commonly used multiple times a day, by millions of people worldwide, and as a result, the amount of energy wasted in heating unused volumes of water is significant.

One attempt to address the problems described above can be seen in WO 2010/094945. There is disclosed therein an appliance having a water heating chamber divided into first and second heating chambers separated by a partition. A user actuable valve selectively opens and closes fluid communication between the first and second heating chambers. The first chamber is heated directly by a heating element. Depending on the volume of water a user wishes to heat, they can control the user actuable valve either to close the first, lower chamber, such that only the water in the first chamber is heated, or to open the valve such that the water in both the first and second chambers is heated. As seen in Figs. 2c and 2d of WO '945, the user actuable valve comprises a series of apertures arranged in a circle on one side of the partition. The apertures are selectively closed by a user actuated valve plate. -2 -

As will be appreciated by those skilled in the art, in order to operate the appliance disclosed in WO '945, a user must first fill the reservoir with water. They must then operate the user actuable valve depending on the desired mode of operation. If they wish to dispense a smaller volume by only heating the water in the first chamber, they must first open the user actuable valve, allow water to fill the first chamber, and then close the user actuable valve once the first chamber is full. Following operation, once the water has been heated in the first chamber and dispensed, if a user wishes to operate the appliance again to heat only water in the first chamber, they must again open the user actuable valve, allow water to fill the first chamber, and then close the user actuable valve again. Having to open and close the valve every time a volume of heated liquid is required is inconvenient, especially when a user expects to be able to heat a small volume of liquid for a fast operation.

The present invention aims to provide an improved appliance and when viewed from a first aspect the present invention provides a liquid heating appliance comprising: a liquid reservoir comprising a first chamber arranged below a second chamber and separated by a partition extending therebetween, a heating arrangement arranged to heat, in use, liquid contained within the first chamber; a first valve and second valve arranged in the partition to selectively allow liquid to flow between the first and second chambers and wherein each valve comprises a floating valve member arranged to float and mate with a respective valve seat and thereby close the valve in order to prevent the flow of liquid through the valve; a liquid outlet in the first chamber in fluid communication with a dispense outlet provided on the appliance so as to allow liquid to be dispensed from the first chamber when the first and second valves are closed; and a valve actuation arrangement for selectively holding each floating valve member away from the valve seat so as to hold each valve open, wherein the valve actuation arrangement is arranged to be moved between a first position in which the floating valve members are free to float so as to mate with the respective valve seats and a second position in which valve actuation arrangement prevents the floating valve members from floating thereby holding the valves open. -3 -

As will be appreciated by those skilled in the art, the liquid heating appliance may effectively be operated in two different modes. It may be operated in a first mode, with the valve actuation arrangement in the first position, in which it is used to dispense a fixed volume of liquid directly from the first chamber, i.e. a 'hot-cup' mode. As a result, the appliance may quickly heat a smaller volume of liquid when required. The appliance may also operate in a second mode with the valve actuation arrangement in the second position such that it prevents the floating valve members from mating with their respective valve seats. In this mode, liquid will flow between the first and second chambers as liquid in the first chamber is heated by the heating arrangement. The valve actuation arrangement in this second position may be considered to correspond to a 'kettle' mode. A user may select the type of operation, by controlling the position of the valve actuation arrangement, depending on the volume of heated liquid they require.

In use, as the liquid reservoir is filled with liquid, due to the floating valve members in the first and second valves, the liquid will be free to flow from the second chamber into the first chamber via the first and second valves. Providing the reservoir is filled with a sufficient amount of liquid, when the first chamber becomes full of liquid, and with the valve actuation arrangement in its first position, the liquid within the first chamber will cause the floating valve members to float and mate with their respective valve seats. Once all of the floating valve members are mated with their respective seats this will close the first chamber thereby preventing any further liquid from entering or leaving the first chamber. The heating arrangement may then be operated to heat the volume of liquid in the first chamber.

Advantageously, due to the arrangement of the floating valve members, when used in the hot-cup mode, the liquid heating appliance automatically closes off the first chamber when it has been filled with the predefined volume of liquid, and does not require any interaction from a user. This is in contrast to the user actuable valve seen in WO '945 and described above which requires interaction from a user to close the user actuable valve. This therefore simplifies operation of the appliance for the user. -4 -

With the first and second valves closed, in the hot-cup mode of operation, when the heating arrangement is operated, it will cause the temperature of the liquid in the first chamber to increase. As the liquid within the first chamber cannot escape its temperature will continue to rise. As the temperature increases, and eventually reaches boiling, the pressure within the first chamber will increase. This pressure may be used as a means to force the liquid out of the first chamber via the liquid outlet towards the dispense outlet. Of course additional or alternative means for dispensing may be provided, for example a pump arranged to draw the heated water from the first chamber. Irrespective of the means for dispensing, due to the increased pressure resulting from the heated liquid, the increased pressure within the first chamber will hold the floating valve members such that they are mated with their respective seats thereby holding the at least first and second valves closed.

Once all of the liquid has been dispensed from the first chamber, and the steam pressure drops, a pressure disparity is created between the first and second chambers such that the floating valves are forced away from their respective valve seats thereby allowing liquid to refill the first chamber. Again, as the first chamber is filled, the floating valve members will float and mate with the respective valve seats thereby closing the first and second valves thus closing the first chamber. The liquid heating appliance is then immediately ready to be operated in the hot-cup mode again. Accordingly, as will be appreciated by those skilled in the art, the liquid heating appliance according to the present invention is configured to automatically refill and close the first chamber such that it can quickly, and more easily, be operated in the hot-cup mode again.

With the valve actuation arrangement in the second position, i.e. with the appliance operating in the kettle mode, when the heating arrangement is operated, e.g. supplied with electrical power, liquid in the first chamber will be heated and convection currents will develop which result in heated water flowing out of the first chamber into the second chamber, thereby heating the liquid within the second chamber, whilst cooler water from the second chamber flows into the first chamber to be heated therein. After a sufficient time, the entire volume of liquid within the liquid reservoir will reach boiling. -5 -

The Applicant has recognised that the provision of at least the first and second valves helps to promote the development of the convection currents which may improve the efficiency of heating in this mode of operation. The Applicant has found that a single valve may restrict the liquid flow between the first and second heating chambers resulting in inadequate mixing of the liquid in each of the chambers. This may cause the liquid within the first chamber to overheat, without causing heating of liquid in the second chamber. Further, overheating of the liquid in the first chamber may result in a build-up of steam within the first chamber. Where the appliance further comprises a suitable control having dry boil detection arranged to shut off the power to the heating arrangement in the instance where dry boil is detected, the Applicant has found that with only a single valve, it may cause overheating which results in this dry boil detection being triggered which thus stops further operation of the appliance. By providing the first and second valves to promote the development of convection currents this overheating risk may be avoided. Further, the Applicant has found that the stronger the convection currents between the first and second chambers, the quicker the liquid in the chambers is heated.

The liquid heating appliance may comprise a further heating arrangement, for example arranged within the second chamber to provide supplementary heat to the liquid contents thereof. However, the Applicant has recognised that the arrangement of the first and second chambers, with the partition therebetween comprising the first and second valves, means that the heating arrangement arranged to heat the contents of the first chamber may be sufficient to heat liquid in both of the first and second chambers. Therefore, in a set of embodiments, the heating arrangement arranged to heat liquid in the first chamber is the only heating arrangement in the liquid heating appliance. The use of a single heating arrangement, rather than a separate heating arrangement for each of the first and second chambers, may reduce the overall cost and complexity of the liquid heating appliance.

The first and second valves alone may allow sufficient convection currents to develop, when operating in the kettle mode, to heat the liquid within the second chamber in a reasonable time. However, in a set of embodiments, the liquid heating appliance comprises one or more further valves arranged in the partition to selectively allow liquid to flow between the first and second chambers. The liquid -6 -heating appliance may, for example, comprise a third valve, optionally also a fourth valve, optionally also a fifth valve. Of course any number of valves may be provided. Each of the further valves may also comprise a floating valve member arranged to float and mate with a respective valve seat and thereby close the valve in order to prevent the flow of liquid through the valve. In embodiments comprising further valves, e.g. five valves, the valves may be arranged in the partition in any suitable arrangement. For example, in a substantially circular shaped partition, in which five valves are provided, one valve may be provided in the centre of the partition, and the remaining four valves may be equally distributed around a periphery of the partition.

The inclusion of further valves in the partition may further promote the flow of liquid between the first and second chambers and thus further improve the speed and efficiency in which liquid is heated in the first and second chambers when the appliance is operated in the kettle mode of operation. Further, the addition of further valves may allow liquid to fill the first chamber more quickly when the liquid reservoir is initially filled, and following a dispensing operation. The Applicant has also recognised that increasing the number of valves in the partition may advantageously reduce the amount of air which may be trapped in the first chamber when the valves are closed. The trapping of air may, for example, occur due to the shape of the partition and how the appliance is arranged on a surface.

The partition separating the first and second chambers may be substantially horizontal, at least when the liquid heating appliance is arranged on a level surface.

Alternatively, the partition may be arranged at an angle to horizontal, for example in at an angle between 0-10" to the horizontal. In a set of embodiments, however, the partition has a domed shape. In a set of such embodiments, the partition is symmetrical so that the highest point is located substantially at the centre of the partition. In a further set of embodiments, one of the valves is arranged at the highest point of the dome. Arranging one of the valves in this position helps to release trapped air within the first chamber as the first chamber is filled with liquid.

When the valve actuation arrangement is in the second position, i.e. the appliance is in the kettle mode, once the liquid within the first and second chambers has been heated, the liquid may simply be poured out of the liquid reservoir. In a set of -7 -embodiments, however, the liquid reservoir comprises a spout arranged to allow liquid to be poured out of the appliance. The spout may be arranged on/in the second chamber. A spout may allow for more controlled pouring of liquid from the liquid heating appliance. This may be particularly important, for example when pouring boiling water.

In embodiments comprising a spout, preferably one of the first or second valves, or a further valve where provided, is arranged in the partition substantially below the spout. Positioning a valve in this manner means that when the appliance is used in the kettle mode, as the appliance is tilted in order to pour the liquid out of the spout, it is possible to drain substantially all of the liquid out of the first chamber. As will be appreciated by those skilled in the art, without providing a valve below the spout, a portion of liquid may be trapped within the first chamber when the appliance is tilted. This may be undesirable, for example when the entire contents of the liquid reservoir are required.

In a set of embodiments, the liquid heating appliance further comprises a handle, and one of the first or second valves, or a further valve where provided, is arranged in the partition substantially opposite the handle. As will be appreciated by those skilled in the art, when a user empties the contents of the appliance, the handle will typically be the part of the appliance by which it is tilted. Accordingly, by arranging a valve opposite the handle, this may help to ensure that a maximum amount of liquid can be poured from the liquid reservoir in a similar manner as described above with regard to the spout.

When operating the appliance with the valve actuation arrangement in the first position, i.e. in the hot-cup mode, when the liquid in the first chamber is heated sufficiently it may be dispensed out of the liquid outlet directly to the dispense outlet. As discussed above, the liquid within the first chamber may be expelled from the first chamber under pressure, e.g. steam pressure, which increases within the first chamber as the liquid is heated. When the dispensing of the liquid is driven by steam pressure, steam may escape with the liquid as it is dispensed which may cause erratic dispensing of both steam and liquid out of the dispense outlet. This may be dangerous, as the dispensing of steam may cause injury to a user. In a set of embodiments, therefore, the liquid heating appliance further comprises a -8 -dispense chamber arranged between the liquid outlet and the dispense outlet such that liquid first passes via the dispense chamber before passing out of the dispense outlet. The Applicant has recognised that by providing a dispense chamber, as heated liquid passes through the dispense chamber, the heated liquid and steam may separate and thereby allowing the heated liquid to be dispensed in a less erratic manner. This may be safer, and provide a more laminar flow of liquid from the dispense outlet.

The dispense chamber may be arranged within the second chamber, preferably in an upper portion thereof. In a set of embodiments, the dispense chamber comprises a liquid inlet, in communication with the liquid outlet of the first chamber, a first liquid outlet in communication with the dispense outlet, and a second liquid outlet in liquid communication with the second chamber to allow undispensed water to drain back into the second chamber. In a further set of embodiments, the dispense chamber comprises a valve element arranged to selectively close the first or second liquid outlet. In a further set of embodiments, the valve actuation arrangement is further arranged such that when in the first position, the valve actuation arrangement acts on the valve element to close the second outlet, and when in a second position the valve actuation arrangement acts on the valve element to close the first outlet. Accordingly, as will be appreciated by those skilled in the art, when the valve actuation arrangement is in the first position, i.e. in the hot-cup mode, it will also act on the valve element to close the second outlet such that liquid can only escape the dispense chamber via the first outlet to the dispense outlet. Further, when the valve actuation arrangement is in the second position, i.e. in the kettle mode, it will act on the valve element to close the first outlet such that heated liquid cannot escape via the dispense outlet. This helps to protect against the inadvertent dispensing of heated liquid from the dispense outlet when it is not desired which, as will be appreciated, may otherwise be dangerous.

The liquid heating appliance may comprise any suitable arrangement for stopping operation of the heating arrangement, e.g. switching off the power supply, when the temperature of the liquid within either of the first or second chambers reaches a desired temperature. For example, the liquid heating appliance may comprise an electronic controller connected to a thermistor sensitive to the temperature of the liquid in one or both of the first and second chambers. When the electronic -9 -controller detects a certain state has been reached, e.g. when boiling has been reached, the electronic controller may shut off the electrical power supply to the heating element in order to terminate heating. In a set of embodiments, however, the liquid heating appliance comprises a thermomechanical element arranged so as to be sensitive to temperature within the appliance, and arranged to switch off a power supply to the heating arrangement when the thermomechanical element detects a predefined temperature. The predefined temperature may, for example, correspond to a typical minimum temperature of steam. A separate thermomechancial element may be provided for each of the first and second chambers, however, in a set of embodiments the thermomechanical element is arranged so as to be used for both the first and second chambers. The Applicant has recognised that the use of a single thermoechanical element may reduce the cost of manufacture of the appliance. The thermomechanical element may comprise a bimetallic sensor.

In embodiments comprising a dispense chamber, preferably the thermomechanical element is arranged in the dispense chamber, and further the dispense chamber comprises a steam inlet arranged to allow the entry of steam from the second chamber. Accordingly, in such a set of embodiments, with the thermomechanical element arranged in the dispense chamber, the thermomechanical element will be capable of detecting steam passing into the dispense chamber indicating that liquid has been heated and dispensed from the first chamber, i.e. in the hot-cup mode of operation. Further, steam in the second chamber can freely pass into the dispense chamber via the steam inlet and thus the thermomechanical element will also be capable of detecting boiling of the liquid in the second chamber, i.e. when the appliance is operating in the kettle mode of operation.

The valve actuation arrangement may be inherently stable in each of its first and second positions, e.g. due to gravity and/or inherent friction within the arrangement which prevents movement of the valve actuation arrangement without user interaction. In a set of embodiments, however, the valve actuation arrangement comprises a resilient member arranged to hold the valve actuation arrangement in the first position or the second position. The resilient member may be in the form of a bi-stable spring. Such a resilient member will allow a user to select the mode of operation and release the valve actuation arrangement. The use of a resilient member may beneficially resist any movement of the valve actuation arrangement which may, for example, be driven by the floating valve members trying to float within the first chamber when the first chamber is filled with liquid.

In a set of embodiments, the dispense outlet is moveable between a dispensing position and a non-dispensing position, and is coupled to the valve actuation arrangement such that when the dispense outlet is moved into the dispense position, the valve actuation arrangement is moved into its first position, and when the dispense outlet is moved to the non-dispensing position, the valve actuation arrangement is moved into its second position. The dispensing position may, for example correspond to the dispense outlet protruding out from the appliance and the non-dispensing position may correspond to the dispense outlet being retracted away into the appliance. Accordingly, as will be appreciated by those skilled in the art, a user can use the dispense outlet itself as a means to control the type of operation of the appliance which the Applicant has recognised may be a particularly intuitive means for selecting the type of operation. As the dispense outlet may be immediately visible to a user, it may also allow a user to quickly and easily determine the configuration the appliance is in, e.g. by observing the position of the dispense outlet. The dispense outlet may be moveably arranged in any suitable manner. For example, the dispense outlet may comprise a rotatable or pivoting arrangement which comes out of a body the appliance. In a set of potentially overlapping embodiments, the dispense outlet is moveable between a dispensing position and a non-dispensing position, and is coupled to the valve actuation arrangement such that when the valve actuation arrangement is moved into its first position, the dispense outlet is moved into its dispensing position, and when the valve actuation arrangement is moved into its second position, the dispense outlet is moved into its non-dispensing position. Accordingly, the valve actuation arrangement may also be used to move the dispense outlet between its dispensing and non-dispensing positions thereby removing the need for the user to separately operate both the dispense outlet and the valve actuation arrangement.

The spacing of the first and second valves in the partition may impact the strength of the convection currents which may form. In a set of embodiments, the partition has a maximum lateral dimension and the first and second valves are separated by at least 50% of the maximum lateral dimension, preferably by at least 70% of the maximum lateral dimension. The Applicant has recognised that by separating the first and second valves in accordance with this embodiment, helps to promote the development of convection currents when the valve actuation arrangement is in the second position, and the liquid heating appliance is effectively operating in the kettle mode. As will be appreciated by those skilled in the art, the greater the separation of the valves, the stronger the convection currents may be as there is less chance of warmer water escaping the first chamber through the same valve which cooler water is trying to enter the first chamber. As discussed previously, improving the likelihood of stronger convection currents forming may increase the speed and efficiency of which the liquid within the liquid reservoir can be heated.

The heating arrangement may, for example, comprise an underfloor heating arrangement e.g. in the form of a sheathed electrical heating element. Such a sheathed electrical heating element may, for example, be formed in a horseshoe shape with its electrical terminations at each extreme of the horseshoe. As will be appreciated, with such a horseshoe shaped heating element arranged on the underside of the first chamber, the portion of the first chamber proximal to the space between the two ends of the horseshoe shaped heating element, will not be directly heated by the heating element, whereas the rest of the first chamber, particularly the portion immediately next to the heating element, will be heated more directly and thus to a higher temperature. This will result in a temperature differential across the liquid within the first chamber. In a set of embodiments at least one of the valves is arranged immediately above an area between two terminations of the heating element. With the valve arrangement according to this set of embodiments, in use, the temperature of the liquid around the other valve(s) will be higher than the temperature of the liquid around the valve above the terminations. Consequently, convection currents may form such that heated liquid will tend to leave the first chamber via the first valve and liquid will enter the first chamber via the second valve. The separation of the exit and entry of water out of and into the first chamber, further helps to create a strong convection current and thus helps to provide more efficient heating of the liquid.

The floating valve member of each valve may be arranged to float independently of the other valves. In a set of embodiments, however, the floating valve members of the first and second valves, and of any further valve where provided, are connected together. The floating valve members may, for example, be connected together by a series of connecting arms. The connecting arms may themselves float. In such a set of embodiments, the buoyancy of the floating valve members may be provided by the connecting arms, rather than the floating valve members themselves.

Connecting the floating valves together in this manner will form a distributed valve arrangement which may result in each of the floating valve members moving simultaneously together. The Applicant has recognised that simultaneously closing and opening the valves may be beneficial in certain situations. Connecting the floating valves together may also mean that the valve actuation arrangement need only act on, for example, one of the valves in order to hold all of the floating valves open. As will be appreciated, this may simplify the valve actuation arrangement provided in the second heating chamber.

The liquid heating appliance may comprise a heating arrangement within the first heating chamber, e.g. in the form of an immersed heating element, to directly heat the liquid contained therein. In a set of embodiments, however, the liquid heating appliance comprises an underfloor heating arrangement arranged to heat the base of the first chamber. In a further set of embodiments, the liquid heating appliance comprises a sheathed electrical heating element.

The size of the appliance, specifically the volume of the first and second chambers may be dependent on the particular intended use of the appliance. In a set of embodiments, the first chamber has a volume between 50 ml and 500 ml, e.g. 350 ml. Such a volume may correspond to a dispensed volume suitable, for example, for a receptacle such as a mug. This allows a user to heat just enough water for a single mug of heated liquid. As previously discussed, this both speeds up the heating process, and reduces the amount of wasted energy. Providing a first chamber with a volume of for example 350 ml may allow 250 ml of heated liquid to be dispensed when operating in the hot-cup mode. The amount dispensed from the first chamber in the hot-cup mode may be variable and this may be controlled in a number of ways, for example it may be achieved by blocking the flow of liquid after a certain volume has been dispensed or by a variable height weir arrangement.

The liquid heating appliance may be of the corded type, i.e. one which a power cord is either integrally provided with, or which can be directly plugged into the appliance. In a set of embodiments, however, the liquid heating appliance is a cordless heating appliance. In a further set of embodiments, the liquid reservoir is arranged to mate with a corresponding power base. The liquid reservoir may comprise a cordless electrical connector, and the power base may comprise a corresponding cordless electrical adaptor. The cordless electrical adaptor and corresponding cordless electrical connector on the base may be of the type which allows the liquid reservoir to be placed on the power base substantially irrespective of their relative angular orientation.

As will be appreciated by those skilled in the art, the liquid heating appliance may be used to heat any suitable liquid, e.g. water.

Some preferred embodiments of the present invention will now be described, by way of example only, and with reference to the accompanying drawings, in which: Fig. 1 shows a perspective view of a liquid heating appliance in accordance with an embodiment of the invention; Fig. 2 shows a perspective view of the underside of the liquid heating appliance seen in Fig. 1; Fig. 3 shows a partially cut-away view of the liquid heating appliance seen in Fig. 1; Fig. 4 shows the liquid heating appliance seen in Fig. 1 with the reservoir wall removed; Fig. 5 shows a view from above of the arrangement of the valves in the partition between the first and second chambers; Fig. 6 shows an underside view of the components within the first chamber; Fig. 7 shows a detailed view of a baffle arrangement on the partition; Fig. 8 shows a cut-away view of the first chamber with the valve actuation arrangement in the second position; Fig. 9 shows the dispensing chamber with its upper cover removed; Fig. 10 shows the valve actuation arrangement and its associated components; Fig. 11 shows part of the valve actuation arrangement; Fig. 12 shows an underside view of the dispensing chamber; Fig. 13 shows an underside view of the base of the liquid heating appliance along with the relative position of each of the valves; Fig. 14 shows a perspective view of the liquid heating appliance seen in Fig. 1 with the dispensing outlet arranged to dispense liquid into a receptacle; Fig. 15 shows a cut-away view of the first heating chamber with the valve actuation arrangement in the first position; Fig. 16a shows the dispensing chamber with its upper cover removed to reveal its inner components, with the valve actuation arrangement in the first position; Fig. 16b shows part of the valve actuation arrangement and associated bi-stable spring; Fig. 17 shows a perspective view of a liquid heating appliance in accordance with a second embodiment of the present invention, with its dispensing outlet in a non-dispensing position; Figs. 18A-18B show the dispensing outlet in the position seen Fig. 17 Fig. 19 shows the liquid heating appliance seen in Fig. 17 with the dispensing outlet in a dispensing position; Figs. 20A-20B show the dispensing outlet in the position seen in Fig. 19; Fig. 21 shows a cross sectional view through the partition; Fig. 22 shows a perspective view of a power base; and Fig. 23 shows a perspective view of the appliance seen in Figs. 1-16b placed on the power base seen in Fig. 22.

Figures 1 to 13 show a liquid heating appliance, or components thereof, in accordance with an embodiment of the invention. In these views the valve actuation arrangement of the appliance is in a 'second' position which corresponds to a 'kettle' mode. Figure 1 shows a perspective view of the liquid heating appliance, hereinafter the appliance. In the view seen in Figure 1, the outermost cover of the appliance has been removed. The appliance comprises a liquid reservoir 2, a spout 4, a dispensing outlet 6 along with a handle 8 for lifting the appliance. Arranged at the uppermost portion of the liquid reservoir 2 is a dispensing chamber 10 which will be described in more detail with reference to later Figures. The appliance further comprises a water window 12, made from an at least partially transparent material, which enables a user to visually determine the water level within the liquid reservoir 2.

Figure 2 shows a perspective view of the underside of the appliance. As can be seen, the appliance comprises a sheathed electrical heating element 14 arranged to heat the base 16 of the liquid reservoir 2. This sheathed electrical heating element 14 arranged on the base 16 forms an underfloor heating arrangement.

Arranged within the space defined in the centre of the sheathed electrical heating element 14 is a cordless control 18 which comprises a 360° cordless adaptor 20. This cordless control 18 allows the appliance to be mated with a corresponding base connector provided on a power base (not shown), thereby supplying the appliance with electricity.

Figure 3 shows a partially cut-away view of the appliance showing the inside of the liquid reservoir 2. A dome-shaped partition 22 divides the liquid reservoir 2 into a first chamber 24a and a second chamber 24b. Provided in the partition 22 are five valves 26, three of which can be seen in this Figure. Also seen is a valve actuation arrangement 25 which will be described in more detail with reference to later Figures. The dome-shape of the partition 22 can be seen more clearly in Figure 21.

Figure 4 shows a perspective view of the appliance with the outer wall forming the liquid reservoir 2 removed to reveal the inner components of the appliance.

Arranged within, and at the top of, the second chamber 24b is the dispensing chamber 10. A first conduit 28 provides a fluid connection between a fluid outlet 30 of the first chamber 24a and the dispensing chamber 10. In this embodiment, the fluid outlet is provided in the partition 22. The dispensing outlet 6 is connected via a second conduit 32 in fluid communication with the dispensing chamber 10. The dispensing chamber 10 itself will be described in more detail with respect to later Figures. The valve actuation arrangement 25 comprises an elongate rod 42, extending up through the dispensing chamber 10, which is operatively connected to an actuation member 44. The actuation member 44 may be used to control the position of the valve actuation arrangement 25. Arranged at the base of the elongate rod 42 is a cross-shaped member 46 from which five valve actuators 48 extend. This valve actuation arrangement 25 can be seen in more detail in Figure 10.

Figure 5 shows a view from above of the partition 22 and shows the relative arrangement of the valves 26. As shown in this Figure, there are five valves 26 arranged in a cross-shape, with one of the valves 26 arranged in the centre of the partition 22 and the other four valves 26 arranged around the periphery of the partition 22. The cross-shaped member 46 and valve actuators 48 seen in Figure 4 have a complementary arrangement to the valves 26 seen in this Figure.

Figure 6 shows a view from the underneath of the first chamber 24a. with the base 16 removed. As can be seen in this Figure, each of the valves 26 comprises a floating valve member 34 which is constrained by a guide 36. Each guide 36 comprises a star-shaped base 38 from which extend four posts 40. The star-shaped base 38 and four posts 40 together constrain the movement of the floating valve member 34. Constraining the movement of the floating valve members 34 may help to ensure that the floating valve members 34 reliably close the valves 26 when required. If they were not suitably constrained, the floating valve member 34 may rotate, or move away from the respective valve seats and no longer be capable of closing the valves 26. As will be appreciated by those skilled in the art, when the first chamber 24a is filled with liquid, e.g. water, the floating valve members 34 will float upwards within the guides 36.

Figure 7 shows a close-up view of a baffle arrangement 51 associated with one of the valves 26 arranged in the partition 22. In this particular embodiment, each of the valves 26 and associated baffle arrangements 51 are identical. The baffle arrangement 51 comprises a cylindrical protrusion 50, extending from the partition 22. The cylindrical protrusion 50 comprises a hole 52, in its end face, dimensioned to receive the valve actuator 48 of the valve actuation arrangement 25. The cylindrical protrusion further comprises a series of liquid apertures 54 arranged around the protrusion 50 to allow liquid to flow through the valve 26. The baffle arrangement 51 further comprises a plurality of upstanding walls 56 are also arranged around the protrusion 50. Each upstanding wall is spaced away from the protrusion 50 and aligned with one of the apertures 54. The baffle arrangement 51 may be integrally formed with the partition 22. The purpose of the baffle arrangement 51 is to regulate the flow of liquid through the valves 26 as the first chamber 24a is refilled. As mentioned previously, once the liquid from the first chamber 24a has been dispensed, there will be a sudden pressure disparity between the first chamber 24a and second chamber 24b, and liquid from the second chamber 24b will be rapidly drawn through the valves 26. The baffle arrangement 51 acts to restrict the flow of liquid through the valves 26 thereby allowing for a more controlled and thus quieter refilling of the first chamber 24a.

Figure 8 shows a partially cut-away view through the first chamber 24a. In Figures 1-8, the valve actuation arrangement 25 is in a second position in which the valves 26 are held open for 'kettle' mode. As can be seen in this Figure, the valve actuation arrangement 25 is in the second position in which the valve actuators 48 are in contact with the floating valve members 34 thereby holding them away from the valve seats 58. As a result, with the valve actuation arrangement 25 in this position, when the appliance is supplied with electrical power the sheathed heating element 14 (seen in Figure 2), will heat the liquid contained within the first chamber 24a. As the temperature of the water within the first chamber 24a increases, the water will circulate between the first chamber 24a and second chamber 24b via the valves 26 as convection currents arise.

Figure 9 shows a perspective view of the dispensing chamber 10, with its upper cover removed. As will be described later, when the valve actuation arrangement 25 is in its first position, i.e. such that the appliance is in the 'hot cup' mode, water enters the dispensing chamber 10 via the conduit 28 which is in fluid communication with the first chamber 24a. However, with the valve actuation arrangement 25 in the second position shown in this Figure, as also seen in earlier Figures, the appliance effectively operates in the kettle mode whereby heated water circulates between the first chamber 24a and second chamber 24b. As a result, heated water will not pass up through the conduit 28 as there will be insufficient steam pressure to drive this liquid movement. Nonetheless, the dispensing chamber comprises a number of features which prevent undesired dispensing from the dispensing outlet 6, with which it is connected. The dispensing chamber 10 comprises a dispensing outlet 60 and a drain outlet 62. The dispensing chamber 10 further comprises a dispense valve element 64 which comprises a first closure member 66 arranged to close the dispensing outlet 60 and a second closure member 68 arranged to close the drain outlet 62. The dispense valve element 64 is pivotally mounted in the dispensing chamber 10. The actuation member 44 is operatively connected to the dispense valve element 64, such that when the actuation member 44 is in the position seen in Figure 9, i.e. in the kettle mode, the actuation member 44 also moves the dispense valve element 64 into a position whereby the first closure member 66 closes the dispense outlet, whilst at the same time moving the second closure member 68 away from the drain outlet 62.

Accordingly, in this mode of operation, whilst it is unlikely that any liquid would travel up the conduit 28, even if this were to happen, or indeed if any liquid remained in the dispense chamber 10, e.g. due to an earlier interrupted dispensing operation, the liquid would be prevented from exiting the dispensing chamber 10 via the dispense outlet 60 and would instead drain back into the second chamber 24b via the drain outlet 62.

Figure 10 shows a perspective view of the valve actuation arrangement 25 in isolation. As can be seen, the valve actuation arrangement 25 comprises the actuation member 44 which is connected to the dispense valve element 64. The dispense valve element 64 is also connected to a linkage 70, which is connected to the elongate rod 42. The elongate rod 42 is connected to the cross shaped member 46 from which the valve actuators 48 extend. Accordingly, movement of the actuation member 44 will cause movement of both the dispense valve element 64 and the valve actuators 48.

Figure 11 shows a perspective view of the underside of the dispense valve element 64 along with the actuation member 44 and linkage 70. As can be seen in this Figure, the dispense valve element 64 comprises a first axle 74 and second axle 75 for mounting and connecting the linkage 70 and actuation member 44 respectively.

The dispense valve element 64 also comprises a pivot axle 76 about which the dispense valve element 64 is mounted within the dispense chamber 10.

Figure 12 shows an underside view of the dispensing chamber 10 with its upper cover removed. In addition to the dispense outlet 60 and drain outlet 62, the dispensing chamber 10 further comprises a steam inlet 78 in the form of an aperture in the base 80 of the dispensing chamber 10. A cylindrical tube 82, within the dispensing chamber 10, extends from the steam inlet 78 towards a switch 84. The switch 84 comprises a thermomechanical element in the form of a bimetallic sensor 86. Whilst not shown, the switch 84 is electrically connected to the sheathed heating element 14. The bimetallic sensor 86 is arranged such that once it reaches a specific, predefined temperature, it acts within the switch 84 to cut the electrical power supply to the appliance. The switch 84 may be of the Applicant's R48 series. Accordingly, once sufficient steam has been produced, for example indicating that the water is boiling, the bimetallic sensor 86 switches off the appliance. The tube 82 ensures that any steam generated within the second chamber 24b is directed towards the bimetallic sensor 86 such that the bimetallic sensor 86 reliably triggers once the predefined temperature is detected. The extent of the tube 82 into the dispensing chamber 10 also prevents liquid from passing into the dispensing chamber 10, from the first chamber 24a, and immediately back out into the second chamber 24b.

Figure 13 shows a view of the base 16 of the liquid reservoir 2, with the sheathed heating element 14 attached, but with other components removed for clarity, alongside the partition 22 when viewed from underneath. Each of the valves 26 can be seen in the partition 22. As will be appreciated by those skilled in the art, the partition 22 defines the uppermost extent of the first chamber 24a and, in the view shown in this Figure, is separated from the base 16 whereas it is in fact provided above it. The dashed lines with arrows show the relative locations of each of the valves 26 with respect to the base 16.

The sheathed heating element 14 is in the form of a horseshoe shape, the ends of which are defined by the cold tails 86a, 86b which allow an electrical connection to be made to the sheathed heating element 14. As can be seen, there is a portion 88 on the base 16, between these two cold tails 86a, 86b where the sheathed heating element 14 does not extend. As a result, this portion 88 of the base 16 will typically be at a lower temperature than the rest of the base, and as a result a volume of liquid proximal to this portion 88 will typically be heated more slowly than the rest of the liquid within the first chamber 24a which is directly above the sheathed heating element 14. As seen by the arrowed dashed lines, one of the valves is located immediately above the portion 88 between the cold tails 86a, 86b, and at least three of the other valves 26 are located above the sheathed heating element 14 itself. Accordingly, as will be appreciated by those skilled in the art, as liquid is heated in the first chamber 24a, there will be a temperature difference between the liquid located above the portion 88, and to that located above the sheathed heating element 14. As a result, due to the arrangement of a valve 26 proximal to this portion 88, this valve will help to promote the establishment of a convection current as cooler liquid is drawn in via the valve 26 above the portion 88, and hotter water is expelled via the valves 26 above the sheathed heating element 14. As mentioned previously, the Applicant has found that this may help to speed up the heating process of the entire contents of the reservoir 2.

Operation of the appliance in the kettle mode of operation will now be described with respect to Figures 1 to 13. If not already in the position seen in these Figures, the valve actuation arrangement 25 may first be moved into the second position shown by operation of the actuation member 44. In acting on the actuation member 44 in order to move the valve actuation arrangement 25 into the second position, the actuation member 44 will also move the dispense valve element 64 such that the first closure member 66 is moved so as to close the dispense outlet 60 and such the second closure member 68 is moved away so as to open the drain outlet 62. As a result, any liquid within already within the dispense chamber 10, e.g. due to a previously interrupted dispensing operation, will drain back into the second chamber 24b.

Once the valve actuation arrangement 25 is in this second position, the sheathed heating element 14 may be supplied with electrical power. This may be achieved by operation of the switch 84. Preferably, the valve actuation arrangement 25 is moved into the second position, prior to providing the sheathed heating element 14 with electrical power, in order to avoid inadvertent dispensing of heated liquid out of the dispensing outlet 6. However, of course, the switch 84 may be operated, and the valve actuation arrangement 25 may be moved into the second position after a short period of time, e.g. before the liquid within the first chamber 24a gets too hot.

As the temperature of the liquid in the first chamber 24a increases, as the liquid within the second chamber 24b is not directly heated, it will typically be at a lower temperature, at least at the beginning of the heating operation. Accordingly, due to the valves 26 being held open by the valve actuation arrangement 25, heated water will flow out of the first chamber 24a into the second chamber 24b, and cooler water in the second chamber 24b will flow into the first chamber 24a. As described above, the arrangement of the valves 26 in the partition relative to the element helps promote the establishment of a convection current within the liquid reservoir 2.

Liquid will continue to circulate between the first chamber 24a and second chamber 24b until the overall temperature of the liquid is sufficient to generate enough steam -21 -to pass up through the steam inlet 78 in the dispense chamber 10, towards the bimetallic sensor 86 on the switch 84. Once sufficient steam is generated, this will trigger the bimetallic sensor 86 which will act within the switch 84 to cut the electrical power supply to the sheathed heating element 14. A user may then lift the appliance using the handle 8 and pour the heated liquid out of the liquid reservoir 2 via the spout 4.

Figure 14 shows a perspective view of the appliance in a hot-cup mode of operation with the valve actuation arrangement 25 (not visible in this Figure) in a first position, i.e. when it is used to heat and dispense a volume of water from the first chamber 24a. As can be seen, the dispensing outlet 6 has been moved out to a dispensing position and rotated so as to dispense into a receptacle in the form of a mug 90. Whilst not shown, the appliance may comprise a support on which to rest the mug 90 such that it is in an appropriate position for receiving liquid from the dispensing outlet 6. The dispensing outlet 6 may be manually pulled out by a user.

Figure 15 shows a partially cutaway view through the first chamber 24a showing the valve actuation arrangement 25 in the first position. In this position, the valve actuators 48 are lifted away from the floating valve members 34 such that the floating valve members 34 are free to float. When the first chamber 24a is filled with liquid, the floating valve members 34 will float upwards to the position seen in Figure 15 whereby they engage with the respective valve seat 58 so as to close each valve 26 and prevent further flow of liquid into the first chamber 24a.

Figure 16a shows the dispensing chamber 10, with its upper cover removed to reveal its inner components, with the valve actuation arrangement 25 in its first position. In this position, the dispense valve element 64 is moved such that the first closure member 66 is moved away from the dispense outlet 60 and the second closure member 68 is moved towards the drain outlet 62. As a result, the drain outlet 62 is closed, in order to prevent liquid from draining from the dispense chamber 10 back into the second chamber 24b, and the dispense outlet 60 is opened in order to allow liquid to be dispensed via the dispensing outlet 6. The conduit 28, extending from the first chamber 24a, is connected to the dispensing chamber 10 such that water heated in the first chamber 24a can pass into the dispensing chamber 10.

Figure 16b shows a perspective view of the dispense valve element 64 along with the actuation member 44 and linkage 70. Also shown is a bi-stable spring 45. This bi-stable spring 45 has been omitted from earlier Figures for clarity purposes. The bi-stable spring 45 is arranged to act on the actuation member 44 such that the actuation member 44 is held in one of two positions, either the position corresponding to the valve actuation arrangement 25 in its first position, as seen in Figure 16a, or the position corresponding to the valve actuation arrangement 25 in its second position, as seen in Figure 9, so as to hold the valve actuation arrangement 25 in its relative position. As will be appreciated by those skilled in the art, the bi-stable spring 45 may be arranged to act on any part of the valve actuation arrangement 25 in order to hold it in the first or second position.

Operation of the appliance in this second mode of operation will now be described with reference to Figures 14 to 16. If not already in the first position, the valve actuation arrangement 25 may be moved into the first position by pressing down on the actuation member 44. This movement will also move the first closure member 66 away from the dispense outlet 60 and move the second closure member 68 towards the drain outlet 62 as described above. With the valve actuation arrangement 25 in the first position seen in Figure 15, as the liquid reservoir 2 is filled with a liquid, e.g. water, liquid will pass into the first chamber 24a. As the first chamber 24a fills up with liquid, the floating valve members 34 will float upwards, within the guides 36 seen in Figure 6, until they engage with their respective valve seats 58 thereby closing the valves 26. With valve actuation arrangement 25 in the first position, and the valves 26 closed as a result of the first chamber 24a being filled with liquid, when the sheathed heating element 14 is supplied with power, it will begin heating the volume of liquid in the first heating chamber 24a.

As the volume of liquid is heated, the pressure within the first chamber 24a will gradually increase. As the liquid reaches boiling point, there will be enough steam pressure within the first chamber to force the heated liquid up the conduit 28 into the dispensing chamber 10. The sheathed heating element 14 will continue to heat the liquid within the first chamber 24a until all of the liquid has been forced, under steam pressure, up the conduit 28 into the dispensing chamber 10. Whilst there is still liquid within the first chamber 24a, due to the pressure created by the steam each of the floating valve members 34 will be held against each respective seat 58, even though they may no longer be floating on the liquid within the first chamber 24a. This prevents the first chamber 24a from refilling and thus ensures that only the volume of the first chamber 24a is dispensed. Once the liquid is emptied from the first chamber 24a, to the dispensing chamber 10, this is followed by a lot of steam which is sufficient to trigger the steam switch 84 and switch off the heating element. The pressure within the first chamber 24a will then drop and the floating valve members 34 will fall, such that water within the second chamber 24b can refill the first chamber 24a.

Water within the dispensing chamber 10 will pass through the dispensing outlet 60 through the second conduit 32 and be dispensed via the dispense outlet 6 into the mug 90. The dispensing chamber 10 advantageously provides a space for the heated liquid and associated steam to separate such that it is predominantly the heated liquid which passes out through the dispense outlet 6, rather than heated liquid and steam which may cause spluttering of the liquid as it is dispensed. As discussed previously, this may provide for a more laminar flow of liquid out of the dispense outlet 6, and may reduce the amount of dispensed steam which may be dangerous.

Figure 17 shows a perspective view of a liquid heating appliance in accordance with a second embodiment of the present invention. The liquid heating appliance shown is similar to the liquid heating appliance seen in Figures 1-16, except that it has a dispensing arrangement 172, comprising a dispensing outlet not shown in this Figure, which is configured to control the valve actuation arrangement (not shown).

As can be seen in Figure 17, the dispensing arrangement 172 is in a non-dispensing position, i.e. a position corresponding to the liquid heating appliance being used in a kettle mode of operation.

Figure 18A shows a perspective view of the dispensing arrangement 172, in isolation from the rest of the components of the liquid heating appliance, when viewed from the rear, when in the non-dispensing position. The dispensing arrangement 172 comprises a main body 174 to which its components are mounted. A front plate 176, which can be accessed by a user on the outside of the appliance, and from which the dispense outlet extends, is pivotally mounted in the body 174 and is pivotally connected to a linkage 178 via arms 180. The linkage 178 is also pivotally mounted to a mount 182 on the main body 174. Whilst not shown, the linkage 178 is operatively connected within the appliance to the valve actuation arrangement so as to be capable of moving the valve actuation arrangement between its first and second positions, thereby to control the floating valve members. In the position seen in this Figure, the dispensing arrangement 172 holds the valve actuation arrangement in its second position, thereby keeping the valves open so as to be able to operate in the kettle mode of operation.

Figure 18B shows a side view of the dispensing arrangement 172 in the non-dispensing position, and is provided for comparison purposes later with respect to Figure 20B.

Figure 19 shows a perspective view of the liquid heating appliance in accordance with the second embodiment of the present invention with the dispensing arrangement 172 in the dispensing position.

Figure 20A shows a perspective view of the dispensing arrangement 172, in isolation from the rest of the components of the liquid heating appliance, when viewed from the rear, when in the dispensing position. As can be seen in this Figure, the front plate 176 has been pulled out to reveal the dispense outlet 106. Whilst not shown, the dispense outlet 106 will be connected to a conduit in fluid communication with the first chamber in the appliance. As the front plate 176 has been pivoted out, due to the connection between the arms 180 and the linkage 178, and the fact that the linkage 178 is pivotally mounted, a distal end 184 of the linkage 178 has been pivoted upwards. The linkage 178 is appropriately coupled to the valve actuation arrangement such that this movement is sufficient to move the valve actuation arrangement from its second position to its first position.

Figure 20B shows a side view of the dispensing arrangement 172 in the dispensing position. Comparing this Figure to Figure 19B, it can be seen how the distal end 184 of the linkage 178 has been pivoted upwards.

Figure 21 shows a cross sectional, enlarged view through the partition 22. Here it can be seen that the partition 22 is dome shaped with a peak 22a in its centre. One of the valves 26 is located at this peak 22a. As the first chamber 24a is filled with liquid, air will collect in the peak 22a and pass into the second chamber 24b via the valve 26. This arrangement will therefore help to minimise the amount of air trapped in the first chamber 24a.

Figure 22 shows a perspective view of a power base 92 onto which the appliance, seen in earlier Figures, may be placed in order to connect the appliance to an electricity supply. The power base 92 comprises a cordless electrical connector 94 which is arranged to engage with the cordless adaptor 20 provided on the appliance. The cordless electrical connector 94 is electrically connected to a power cable 96 which is connected to a plug 98. The plug 98 may be of any suitable type for connection to an electrical power supply.

Figure 23 shows a perspective view of the appliance placed on the power base 92 in order to supply the appliance with electricity. In this view, an outer cover of the appliance is removed in order to demonstrate how the appliance couples with the power base 92.