WO2009010732A2

WO2009010732A2 - Controls for electrical appliances

Info

Publication number: WO2009010732A2
Application number: PCT/GB2008/002404
Authority: WO
Inventors: Antonio Martin Gaeta; Peter Hallam Wright; Robert Henry Hadfield; David Andrew Smith
Original assignee: Otter Controls Limited
Priority date: 2007-07-17
Filing date: 2008-07-11
Publication date: 2009-01-22
Also published as: GB0713883D0; WO2009010732A3

Abstract

A thermal control (10) for an electrical heating appliance comprises a switching mechanism arranged to be actuated by thermally responsive actuating means so to as to change the heating state of the vessel, and by further actuating means, which may comprise a mechanical, electrical or electronic actuator (17,18). The actuator may be controlled remotely of the appliance. The control may further include means for controlling additional functions of the appliance. The additional functions may be manually controlled independently from a heating state of the appliance. The means for controlling the additional functions may be integrated with the control, or may be added to the control during installation.

Description

Controls for Electrical Appliances Field of the Invention

[0001] The present invention relates to controls for electrical appliances, and to actuators for such controls.

Background of the Invention

[0002] Liquid heating vessels such as kettles normally include one or more thermal controls, which act to switch off or reduce heating power automatically in response to certain conditions, such as the liquid reaching a predetermined temperature or state, and/or a dry boil conditions. Currently available controls for liquid heating vessels fall onto two main classes: mechanical controls, and electronic controls. In one type of mechanical control, a mechanical actuator, such as a steam or dry boil sensitive bimetal, acts on a mechanism that opens a switch, thus disconnecting a heater. The user can also manually actuate the mechanism so as to close or open the switch. Typically, the mechanism includes a bistable trip lever actuable manually or by a bimetal. Examples of such mechanical controls include the X5, Z5, and Al series controls currently available from Otter Controls Ltd. The vast majority of controls currently sold are mechanical controls, as they are cost-effective and extremely reliable.

[0003] In electronic controls for liquid heating vessels, the temperature of the liquid or of part of the vessel is sensed by an electrical or electronic sensor, for example a thermistor. A processor infers the condition of the vessel from the output of the sensor, and actuates an electrical or electronic switch, such as a triac, so as to disconnect power from a heater. A user interface, such as one or more buttons, sends an electrical or electronic input to the processor, which connects or disconnects power to the heater accordingly. Early proposals for electronic controls are disclosed in GB-A-2228634 and GB-A-2185161; examples include the Russell Hobbs Millennium M2 kettle. Electronic controls offer greater flexibility than mechanical controls, but are more expensive.

[0004] Currently available controls for liquid heating vessels may have additional control functions other than switching the vessel off when the liquid contents have boiled, or when the vessel has boiled dry. One type of control is a bi-temperature or 'bi-temp' control, which is selectively operable to heat the liquid up to boiling, or to a preset temperature below boiling. Examples of bi-temp controls include the Al 4 control currently available from Otter Controls Ltd; also the control described in WO-A-05/059670.

[0005] Controls for liquid heating vessels may additionally or alternatively have a 'keep- warm' function, in which the liquid is maintained around a predetermined temperature after having been heated up to a target temperature (which may be boiling temperature or a temperature below boiling). Although such additional functions may be desirable, they add to the complexity of the liquid heating vessel and it becomes difficult to provide a user- actuable selector which is able to select the desired function(s) while being simple and intuitive for the user. [0006] Patent publication EP-A- 1797799 discloses a control with a single manually operable actuator for energising a main heater and for switching off a keep warm heater. [0007] Patent publication GB-A-2391389 discloses a kettle with a rotary switch for switching on the heating element. [0008] Remote power control systems are known, in which an appliance is connected to a power outlet via a remotely controlled switch or a timer switch. However, safety problems arise when the appliance is a high-power heating appliance such as a kettle or a sandwich toaster, which are not designed for unattended operation. In particular, there is a risk of the appliance or its contents overheating while unattended. Such arrangements typically do not meet the relevant safety standards for unattended appliances, such as EN 60335-1 or IEC 62151.

Statements of the Invention

[0009] According to one aspect of the present invention, there is provided a thermal control for a liquid heating vessel, in which a mechanical thermal control mechanism is actuated by an electrical or electronic actuator, such as an electromagnetic actuator. The actuator may be a user-controlled actuator, or an actuator controlled by a sensor. The user-controlled actuator may be controlled by a remote control. The remote control may additionally control other, non-thermal functions of the vessel. The mechanism may additionally be manually mechanically actuable by a user. [0010] According to another aspect of the present invention, there is provided a control arrangement for a liquid heating vessel, comprising an mechanical control having at least two stable states and a toggle mechanism arranged to toggle the mechanical control between said at least two stable states. Preferably, the mechanical control is actuable between said at least two stable states substantially independently of said toggle mechanism. [0011] According to another aspect of the present invention, there is provided a liquid heating vessel controllable by a remote control unit removably mountable on a part of the vessel. The remote control unit may rechargeable when mounted on the vessel.

[0012] According to another aspect of the present invention, there is provided a liquid heating vessel controllable by a remote control unit for audio or audiovisual equipment. [0013] According to another aspect of the present invention, there is provided a liquid heating vessel controllable by a remote control unit arranged to receive status information from the vessel.

[0014] According to another aspect of the invention, there is provided a switching control apparatus for an electric heating appliance, comprising a local user interface and a remote user interface both for controlling the switching state of the appliance, wherein the local user interface is able to override the remote user interface so as to switch off the appliance. [0015] According to another aspect of the present invention, there is provided a switching control apparatus for an electric heating appliance, comprising a local user interface and a remote user interface both for controlling the switching state of the appliance, arranged to selectively disable the remote user interface such that only the local user interface is able to control the switching state of the appliance. [0016] According to another aspect of the invention, there is provide a thermal control for an electrical heating appliance, the control being arranged to control a heating function of the appliance, the control having a plurality of discrete states that are redundant with respect to the heating function but indicate the previous heating state of the vessel. [0017] According to another aspect of the present invention, there is provided a thermal control for a liquid heating vessel, comprising a switching mechanism arranged to be actuated by thermally responsive actuating means so to as to change the heating state of the vessel, and is further arranged to be actuated by further actuating means so as to change the heating state of the vessel, wherein the control further includes means for controlling additional functions of the vessel. The additional functions may be controlled independently from the heating state of the vessel. The means for controlling the additional functions may be integrated with the control, or may be added to the control during installation. The actuator may be a manual actuator, or an electrical, electromagnetic, electromechanical or electronic actuator. [0018] In one embodiment, the switching mechanism has a plurality of stable states each corresponding an active heating state of the vessel, but corresponding to different states of one or more additional functions of the vessel. In another embodiment, the switching mechanism has a plurality of stable states each corresponding to an inactive or reduced heating state of the vessel, but corresponding to different states of one or more additional functions of the vessel. The active heating state may comprise heating the liquid to boiling. [0019] The additional functions may include additional heating functions, such as a keep warm function. Alternatively or additionally, the additional functions may include functions relating to the state of liquid in the vessel, such as a boiling indicator function. Alternatively or additionally, the additional functions may include functions indicating the operational state of the vessel, such as a visual or audible indication.

[0020] According to another aspect of the invention, there is provided a thermal control for a liquid heating vessel, coupled to an actuator such that the actuator has more stable positions than the thermal control has stable states. In one embodiment, at least one position of the actuator holds the thermal control in an otherwise unstable position, which may correspond to a fully off state of the vessel. In another embodiment, each of a plurality of positions of the actuator corresponds to the same stable state of the thermal control. [0021] According to another aspect of the present invention, there is provided a thermal control for a liquid heating vessel, the thermal control being able in isolation to adopt any one of a plurality of discrete control positions but being prevented from adopting at least one of the control positions by the coupling of the control to an actuator. [0022] According to another aspect of the present invention, there is provided a thermal control for a liquid heating vessel, the control being arranged to control a heating function of the vessel and having at least first and second discrete stable states each arranged to activate the heating function, and at least one other stable control state, the control being coupled to an actuator such that the control may be actuated directly from the first to the second stable control state without passing through any other stable control state.

[0023] According to another aspect of the present invention, there is provided a thermal control for a liquid heating vessel, the control being arranged to control a heating function of the appliance and having at least three discrete stable control states, the control being coupled to a actuator such that the control may be actuated directly from any of the stable control states to any other of the stable control states. [0024] According to another aspect of the present invention, there is provided a thermal control for a liquid heating vessel, arranged to control at least three independently switchable functions of the vessel.

Brief Description of the Drawings

[0025] Embodiments of the present invention will now be described with reference to the accompanying drawing identified below.

[0026] Figure 1 is a schematic diagram of a liquid heating vessel of a type in which some embodiments of the invention may be provided.

[0027] Figure 2 is a schematic diagram of an embodiment comprising a liquid heating vessel including a remote control.

[0028] Figure 3 is a schematic diagram of an embodiment comprising a liquid heating vessel including a remote control and an intermediate module.

[0029] Figure 4 is a block diagram illustrating the functional arrangement of a liquid heating vessel having a mechanical control and a remote control. [0030] Figures 5a and 5b are respectively a diagram of a liquid heating vessel incorporating a thermal control and an actuator, and a close-up view of the arrangement of the actuator and of the control, in a first embodiment.

[0031] Figures 6a and 6b are respectively a diagram of a liquid heating vessel incorporating a thermal control and an actuator, and a close-up view of the arrangement of the actuator and of the control, in a second embodiment.

[0032] Figures 7a and 7b are respectively a diagram of a liquid heating vessel incorporating a thermal control and an actuator, and a close-up view of the arrangement of the actuator and of the control, in a third embodiment.

[0033] Figures 8a and 8b are schematic diagrams of the arrangement of an actuator and a control in first and second variants of a fourth embodiment.

[0034] Figure 9 is schematic diagram of the arrangement of an actuator and a control in a fifth embodiment.

[0035] Figure 10 is a schematic diagram of a first mechanism suitable for interfacing an actuator to a control in embodiments of the invention. [0036] Figure 11 is a schematic diagram of a second alternative mechanism suitable for interfacing an actuator to a control in embodiments of the invention. [0037] Figures 12a to 12h are schematic diagrams of a third alternative mechanism suitable for interfacing an actuator to a control in embodiments of the invention.

[0038] Figures 13a to 13c are schematic diagrams of a fourth mechanism suitable for interfacing a reciprocating drive means to a rotary actuator in embodiments of the invention. [0039] Figures 14a and 14b are respectively front elevation and perspective views of a control and rotary actuator in a first embodiment, in a manual off position.

[0040] Figures 15a and 15b are respectively front elevation and perspective views of a control and rotary actuator in a first embodiment, in a first manual on position.

[0041] Figures 16a and 16b are respectively front elevation and perspective views of a control and rotary actuator in a first embodiment, in a first auto off position.

[0042] Figures 17a and 17b are respectively front elevation and perspective views of a control and rotary actuator in a first embodiment, in a second manual on position.

[0043] Figures 18a and 18b are respectively front elevation and perspective views of a control and rotary actuator in a first embodiment, in a second auto off position. [0044] Figures 19a to 19d show user selectable states of a rotary actuator in different specific embodiments relating to the first embodiment.

[0045] Figure 20 shows a user-actuable pivoting lever connected to the rotary actuator.

[0046] Figures 21a and 21b are respectively front elevation and perspective views of a control and rotary actuator in a second embodiment, in a manual off position. [0047] Figures 22a and 22b are respectively front elevation and perspective views of a control and rotary actuator in a second embodiment, in an auto off position.

[0048] Figures 23a to 23c show user selectable states of a rotary actuator in different specific embodiments relating to the first embodiment.

Detailed Description of the Embodiments

[0049] In the following description, similar features are indicated using the same reference numerals; this may apply between different embodiments, and between broad and specific disclosures of similar features.

[0050] Figure 1 shows schematically a jug kettle with a control, as an example of a liquid heating vessel to which embodiments of the invention may be applied. In this example, the kettle is a cordless kettle comprising a kettle body 15 and a power base 16 having respective body and base cordless connectors 3 and 4, preferably 360° cordless connectors. The power base 16 is connectable by a power cord 2 to an electrical power outlet (not shown). [0051] The kettle body 15 comprises a reservoir 5 for containing water to be heated, and a base section 6, as well as a spout 7, a lid 8 and a handle 9. Water is heated by an element plate 12 forming the base of the reservoir 5, and including a heating element on the underside (i.e. facing towards the base section 6). The element plate 12 may be fitted into an aperture in the kettle body 15, for example using the Easifix (RTM) fitting as described in WO 99/17645. The element may comprise a sheathed element, such as a mechanical or diecast element and/or a thick film element. The element plate may be substantially as described in WO 06/83162. [0052] The base section contains a thermal control 10 for controlling the operational state of the kettle, as will be described in more detail below. A steam tube 14 carries steam from the top of the reservoir 5 to the control 10, for sensing by a steam sensor within the control 10 so as to detect boiling. Alternatively, the control 10 may detect boiling by sensing the temperature of water within the reservoir, for example by means of a thermal sensor in contact with the underside of the element plate 12. A manual actuator 11 may be connected to the control 10 to enable a user to control the kettle.

[0053] The kettle body 15 and/or the base 16 preferably include a safety cut-out that switches off heating power in response to an overheat condition, such as a dry boil protector. Preferably, the safety cut-out cannot be overridden by user actuation of the control, but can be reset when the appliance is no longer overheated. [0054] It should be noted that the configuration shown in Figure 1 is only one of many different configurations to which embodiments of the invention may be applied. For example, the jug kettle may be a filter kettle, in which the kettle body 15 includes a filter reservoir that dispenses filtered water into the main heating area of the kettle body 14. Alternatively, the reservoir may have a manual dispensing function without a filtering function, so that a measured quantity of water can be dispensed from the reservoir.

Electrical/Electronic Actuator

[0055] In the embodiments described in the sections below, an electrically or electronically controlled actuator is arranged to actuate a mechanical appliance control. The actuator may operate electrically, electromagnetically, or electromechanically for example. The actuator may be controlled automatically, or by a user. The actuator may have a wired or wireless controller, such as a sensor or a user interface. Automatically Controlled Actuator

[0056] In some embodiments, the actuator is controlled automatically, for example by means of a sensor within the vessel 15. The sensor may be a steam sensor arranged at the top of the reservoir 5, connected to the actuator adjacent the control 10. Such an arrangement removes the need for a steam tube 14; instead, a wireless or low voltage signal is sent to the actuator. The sensor may be a bimetal low voltage (e.g. 5 or 12 V) switch. In this way, a low voltage circuit may be made from the actuator to the sensor, thus avoiding the safety concerns of routing a mains circuit to the top of the reservoir 5. Alternatively, the sensor may be a scale detection sensor or element delamination sensor.

User Controlled Actuator

[0057] In other embodiments, the actuator is controlled by an electrical or electronic user interface 1, comprising a user input device such as a button, switch or touch-sensitive sensor, and/or a display device for displaying or indicating information to the user. The user interface 1 may be permanently attached to or integrated with the liquid heating vessel; as an example, Figure 1 shows the user interface 1, mounted in the handle 9 of the kettle. Alternatively, the user interface 1 may be movably mounted so that its position or configuration can be altered to suit the user. For example, the display device may be pivotable and/or rotatable, preferably about a substantially vertical axis of the vessel in its upright position, so that it is more easily visible when the vessel 15 is separated from or connected to the base 16.

[0058] Alternatively, as shown in Figure 2, the user interface 1 may be provided as a remote control, connected wirelessly to the actuator, for example by an infrared (IR), sonic, ultrasonic or radio frequency (RF) link. Known wireless technologies and/or protocols may be used for the wireless link, such Bluetooth®, or IR signalling protocols similar to those used in remote control devices for audiovisual equipment; in this way, the vessel may be controlled by a suitably programmed remote control device for audio or audiovisual equipment. For example, a person watching television need not get up to switch on the kettle, but may instead switch on the kettle using an existing television IR remote control, provided there is a line of sight to the kettle, or using an RF remote control. Where the actuator is remotely controlled by sonic signals, the user may switch on the kettle without the need for a remote control device, simply by whistling for example. [0059] The use of a remote control user interface 1 for a liquid heating vessel has ecological advantages. For example, users often fill a kettle and set it to heat up or boil, in the expectation of needing hot water for cooking or making beverages in the near future. Much energy is wasted as the water cools down before it is needed, or is kept warm for too long. With a remote control, the user may switch on the kettle shortly before hot water is needed, while performing other tasks.

[0060] The user interface 1 may control additional heating features of liquid heating vessel, such as selecting a 'keep warm' feature to maintain the liquid around a predetermined temperature, and/or setting the temperature to which the liquid is heated, such as 100°C for tea, or 80°C for tea.

[0061] The user interface 1 may control auxiliary features of the liquid heating vessel not directly involving heating, such as lighting effects. In a reservoir kettle, such as a filter kettle or an 'ECO' kettle as described in EP-A-1289395, the user interface may control a valve for admitting water or other liquid from a reservoir into a heating chamber. The user interface may control other functions, such as lid opening mechanisms, spout flaps, filling aids and pouring aids.

[0062] The user interface 1 may be programmable and include a timer, so that the user can set desired actions at specific times. The link to the user interface 1 may be bidirectional, so that information regarding the status of the vessel 15 may be sent from the vessel 15 to the user interface 1. The status may be displayed and/or user to trigger a further control signal by the user interface 1. For example, the user interface 1 may be programmed to activate a 'keep warm' mode or a prolonged boil or simmer mode after the liquid has reached the required temperature. In the prolonged boil or simmer mode, the user may set the duration of this mode; for example, the user may set a 1 minute prolonged boil for sterilization, or a 10 minute simmer for cooking, where the vessel 15 is suitable for cooking foods in water or other liquid. A first alert may be sent to the user interface 1 when the liquid has reached boiling, and the interval timer may then be started by a further user actuation, for example after the user has added the food to the liquid. When the interval has expired, the user is alerted again to drain the cooked food. [0063] As another example, the control 10 may detect whether the vessel 15 is connected to the base 16, or whether power is available, and indicate this status to the user interface 1 so that the user knows whether heating functions are available. As another example, the control 10 may indicate the level of liquid in the vessel, so that the user knows whether heating can be activated, or the vessel needs to be refilled. Other status or condition indications may include the sensed water temperature, the estimated time to reach target temperature (sub- boil or boil), whether the vessel needs descaling, whether the vessel has dry boiled, time since last filling etc.

[0064] The user interface 1 may be removably mountable on the vessel 15 and/or the power base 16, and may be rechargeable by an electrical or inductive coupling thereto.

[0065] The control 10 may only be operable by means of the user interface 1, such that if the user interface 1 is removed, the control 10 is not manually operable; this may provide an advantageous child safety feature. Alternatively, the user interface 1 may be mountable over the manual actuator 11, so that the latter is only accessible when the user interface 1 is removed. For example, the user interface 1 may provide touch-sensitive control, but may be removed if the user prefers mechanical control. Alternatively, the control 10 may be manually actuable independently of the user interface 1.

[0066] In an alternative embodiment shown in Figure 3, the remote control user interface 1 may be arranged to communicate with an intermediate module Ia that communicates in turn with the control 10. The intermediate module Ia may act as a relay between the remote control 1 and the control 10, and may provide additional functions as described below. [0067] The intermediate module Ia may communicate wirelessly with the control 10, using a similar or different form of wireless communication to that used by the user interface 1. However, the intermediate module Ia may be a fixed installation and therefore may communicate with the control 10 using a wired connection, such as via mains signalling; this is particularly advantageous since the vessel must be connected to the mains in order to operate.

[0068] The intermediate module Ia may be arranged to communicate with one or more additional electrical devices other than the liquid heating vessel, such as lighting, heating or other devices. The intermediate module Ia may be a control hub for a wireless domestic control system.

[0069] The intermediate module may include a control program, so as to implement the control logic described below. The intermediate module Ia may be reprogrammable, for example by loading an updated control program via a local network connection or via the Internet.

[0070] Figure 4 shows, as functional blocks, the components of a remote controlled appliance having a mechanical appliance control 10 in an embodiment of the invention. The control 10 is actuated (e.g. switched) by a mechanical actuator mechanism 36 that can be actuated by a mechanical interface 11. The mechanical actuator mechanism may form part of the manual interface 11 or the mechanical appliance control 10, and need not be provided as a discrete component.

[0071] The remote control 1 communicates wirelessly with a remote receiver Ib, optionally via the intermediate module Ia. Control logic 13, such as a processor, controls the actuator mechanism 36 via an electromechanical interface 17, 18. The electromechanical interface 17, 18, which may include solenoids or magnets as described herein, and optionally the control logic 13, may be integrated with the mechanical appliance control 10, so that the control 10 may be supplied as a unitary component to the appliance manufacturer. Alternatively, the electromechanical interface 17, 18 may be fitted to a conventional mechanical appliance control 10 to provide an electrical or electronic actuator interface thereto. The remote control 1 may also be supplied to the manufacturer together with the control 10, so that an existing design of appliance for use with a completely manual control may be upgraded for use with the remote control 1. [0072] Manual actuation via the manual interface 11 may be performed independently of the electromechanical interface 17, 18, for example as described in the embodiments above. In at least some embodiments, local manual actuation may take priority or precedence over remote actuation, such as via the electromechanical interface 17, 18. For example, the manual interface 11 may be actuable to switch off the appliance regardless of the state of the electromechanical interface 17, 18. This arrangement is advantageous where a safety standard for an unattended appliance requires a visible local 'off switch to be provided on the appliance. Alternatively, an additional 'off switch' may be connected to the appliance, for example in the vessel 15, the base 16, or in the power cord 2.

[0073] The appliance may have a safety lock feature, whereby the appliance can be switched off locally but not switched on locally, or can only be switched on locally by performing an additional operation. The safety lock feature may be provided as a selectable mode, or as a permanent feature. For example, the additional 'off switch may be actuated locally to switch off, but not to switch on; switching on can only be performed via the remote control 1, or locally by an operation that is not easily performed by a child, such as resetting the additional off switch with a special tool such as a screwdriver. The safety lock feature may prevent a child from accidentally switching on the appliance locally, but may allow the child to switch off the appliance in an emergency.

[0074] The appliance may be provided with means to selectively disable and enable operation by the remote control 1 ; this provides an additional safety to prevent accidental switching on of the appliance, for example when the user intends to leave the appliance unattended for a long period of time. Operation by the remote control may be disabled automatically, for example if the remote control 1 has not been operated for a predetermined period of time; this functionality may be implemented in the control logic 13. [0075] The appliance may be provided with a local indicator, such as a visible indicator, arranged to indicate whether remote control is enabled and/or is in use. For example, an LED may be illuminated when remote control is enabled, and may flash when a remote control signal is received. This allows a local user to determine the status of the remote control without having access to the remote control interface 1 itself.

Actuator Interface to Mechanical Control

[0076] Preferably, the above embodiments allow electrically or electronically controlled actuation of a mechanical thermal control. New modes of user actuation may be implemented without abandoning the cost and reliability advantages of mechanical controls. [0077] Specific embodiments of mechanisms for interfacing an electrical or electronic actuator to a mechanical control will now be described. In some embodiments, the movement of the mechanical control is substantially unimpeded by the actuator. In other words, the mechanical control can still be mechanically actuated substantially without interference from the actuator, but the actuator provides an additional or alternative means for actuating the mechanical control. [0078] The same reference numerals will be used for functionally similar parts between the different embodiments.

Actuator - First embodiment

[0079] In the first embodiment, as shown in Figures 5a and 5b, the control 10 is an A12 control of the type currently available from Otter Controls Ltd. The control 10 has a bistable trip lever 33 that is actuable by a steam sensing bimetal and by a dry boil bimetal within the control 10 to move from an 'on' position' to an 'off position. The trip lever 33 is coupled to switch contacts so as to close the switch in the 'on' position and open the switch in the 'off position. The switch is connected between a power supply and the heating element. Mechanical thermal controls of this type are well known in the art and need not be described further herein. [0080] An actuating member 17 is arranged about a distal end of the trip lever 33. The actuating member 17 has a lower portion 17b arranged to abut a portion of the trip lever 33 when in the 'on' position, as shown in Figure 5b, and an upper portion 17a arranged to abut a portion of the trip lever 33 when in the 'off position. In this case, the actuating member 17 contacts a laterally projecting pin on the distal end of the trip lever 33, but the upper and lower portions 17a, 17b need not necessarily contact the same portion of the trip lever 33. [0081] The upper portion 17a is spaced from the lower portion 17b such that, when the actuating member 17 moves upwards so as to overcome the bias of the trip lever 33 into the 'on' position, the portion of the trip lever 33 is able to travel into the 'off position without being impeded by the upper portion 17a. The actuating member 17 may also be driven downwards, so that the upper portion 17a abuts a portion of the trip lever 33 when in the 'off position and overcomes the bias so as to move the trip lever 33 into the 'on' position without impedance from the lower portion 17b. In other words, the connection between the actuating member 17 and the trip lever 33 exhibits a form of 'lost motion', with the trip lever 33 disconnecting from the actuating member 17 as it travels between bistable states. Additionally, if the trip lever 33 is already in the 'on' position when the actuating member 17 is driven downwardly, or is already in the 'off position when the actuating member 17 is driven upwardly, the actuating member 17 does not contact the trip lever 33, or at least does not apply significant force to the trip lever 33, thereby avoiding jamming of the actuator. [0082] The actuating member 17 is actuated by electrically or electronically controlled drive means, examples of which are described below. Preferably, the drive means is arranged to return the actuating member 17 to an intermediate position when not activated, and the upper and lower portions 17a and 17b are arranged so that neither impedes the trip lever 33 when the actuating member 17 is in the intermediate position. For example, a push-pull solenoid as the drive means may return to an intermediate position when not activated. [0083] Alternatively, the actuating member 17 may be able to move freely when the drive means is not activated, so as not to impede the movement of the trip lever 33.

Actuator - Second embodiment

[0084] In the second embodiment, as shown in Figures 6a and 6b, the control 10 is an X5 control of the type currently available from Otter Controls Ltd. The X5 control is designed for immersed elements, rather than underfloor elements of the type shown in Figure 1 , and is therefore mounted in the side of the vessel, under the handle. Although the X5 mechanism differs substantially from that of the Al 2 control, it includes a bistable trip lever 33 actuable by integral steam sensing and dry boil sensing bimetals. [0085] Figure 6a shows schematically the connection of the actuating member 17 to drive means 18, which may be a push-pull solenoid providing a linear motion selectively upward or downward. As shown in Figure 6b, the actuating member 17 is arranged to actuate the trip lever using spaced apart upper and lower portions 17a, 17b, similarly to the arrangement in the first embodiment.

Actuator - Third embodiment

[0086] In the third embodiment, as shown in Figures 7a and 7b, the control 10 is a Z5 control of the type currently available from Otter Controls Ltd. The Z5 control has an integrated steam sensing bimetal, but no dry boil sensing, and is designed for installation in a variety of different positions; Figure 7a shows an installation at the top of the handle of a vessel, so as to sense steam at the top of the vessel without requiring a steam tube. [0087] The control has a bistable trip lever 33 that moves substantially horizontally, in the orientation shown in Figures 7a and 7b. The actuating member 17 is driven substantially horizontally, and includes spaced apart portions 17a and 17b as in the first and second embodiments.

Actuator - Fourth embodiment

[0088] In the fourth embodiment, as shown in Figures 8a and 8b, the control 10 is an Al 2 control of the type currently available from Otter Controls Ltd, shown here end on, facing the distal end of the trip lever 33. hi this embodiment, the trip lever 33 is actuated electromagnetically rather than electromechanically. A magnet 19 is mounted on the trip lever 33, with poles oriented generally vertically. An electromagnet 20 is arranged in close proximity to the magnet 19, so as to apply upward or downward force on the magnet 19 according to the polarity of the current to the electromagnet 20. The magnet 19 may alternatively be of magnetic but unmagnetised material. [0089] When the distal end of the trip lever 33 is down, in the 'on' position', the electromagnet 20 may be energized with a first polarity to repel the magnet 19 sufficiently to overcome the bias of the trip lever 33 and move it into the 'off position. When the distal end of the trip lever 33 is up, in the 'off position, the electromagnet 20 may be energized with a second polarity to attract the magnet 19 sufficiently to overcome the bias of the trip lever 33 and move it into the 'on' position. When the electromagnet 20 is not energized, the trip lever is able to move between its 'on' and 'off positions without interference by the magnetic actuating system.

[0090] In the variant of Figure 8a, the electromagnet 20 is positioned under the magnet 19, and attracts or repels the magnet 19 according to the polarity of the current. This arrangement is convenient in that it does not interfere with the mounting of the control 10 on the element plate 12.

[0091] In the variant of Figure 8b, the electromagnet 20 has poles arranged above and below the magnet 19. This arrangement gives better magnetic coupling than the first variant, but is more difficult to assemble. [0092] In a variant of the fourth embodiment, the actuator may operate electrostatically, such that the trip lever is actuated by means of a variable electrostatic field rather than a magnetic field.

Actuator - Fifth embodiment

[0093] In the fifth embodiment, as shown in Figure 9, the control 10 is an Al 2 control of the type currently available from Otter Controls Ltd, shown from the side. As shown in Figure 9, the trip lever 33 pivots about a pivot point 21.

[0094] First and second actuating members 17a, 17b are arranged under the trip lever 33 at either side of the pivot point 21. The actuating members 17a, 17b are coupled to respective drive means (not shown), which may be solenoids. When the trip lever 33 is in the 'on' position, as shown in Figure 9, the second actuating member 17b can be driven upwardly so as to push the trip lever 33 into the 'off position. When the trip lever 33 is in the 'off position, the first actuating member 17a can be driven upwardly so as to push the trip lever 33 into the 'on' position. This arrangement is advantageous in that the actuating mechanism can be assembled entirely below the control 10, and may be mounted on a sub-base portion forming the bottom of the base section 6. Although two drive means may be required, these can be simple single action solenoids, rather than push-pull solenoids.

Alternative Driving Mechanisms

[0095] Figure 10 shows a first alternative driving mechanism for coupling drive means 18 to actuating member 17 in the first to third embodiments. In this case, the actuating member 17 is pivotally mounted about an axis 17c extending substantially perpendicular to the plane of Figure 8, and includes a projecting portion 17d extending to the opposite side of the axis 17c from the portions 17a and 17b. A lug 24 is rotatably mounted about an axis 24a extending substantially perpendicular to the plane of Figure 10, and is rotatably driven by the drive means 18.

[0096] When the lug 24 is rotated clockwise from the position shown in Figure 10, it strikes the projecting portion 17d and rotates the actuating member 17 anticlockwise, so as to move the end of the trip lever 33 upwards. As the trip lever 33 moves out of its bias into the opposite bistable position, the lug 24 slips past the projecting portion 17d so that the drive means 18 disengages from the actuating member 17. [0097] When the lug 24 is rotated anticlockwise from the position shown in Figure 10, it strikes the projecting portion 17d and rotates the actuating member 17 clockwise, so as to move the end of the trip lever 33 downwards. As the trip lever 33 moves out of its bias into the opposite bistable position, the lug 24 then slips past the projecting portion 17d so that the drive means 18 disengages from the actuating member 17. [0098] Figure 11 shows a second alternative driving mechanism that is similar to the first alternative, but the actuating member 17 is dispensed with and the lug 24 strikes the end of the trip lever directly. This arrangement is simpler than the second driving arrangement, but may be more difficult to design so that the lug 24 is able to slip past the end of the trip lever 33, due to the comparatively large radius of the trip lever 33. [0099] Figures 12a to 12h show a third alternative driving mechanism that allows a single action solenoid, as drive means 18, to toggle the actuating member 17 between two positions, while allowing the actuating member 17 to move freely when not activated. A reciprocating part 25, coupled for example to a solenoid as said driving means 18, has a pusher pin 26 pivotally mounted thereto. The rotation of the distal end of the pusher pin 26 is constrained by a wall 27 shaped so that the pusher pin 26 is substantially aligned with the direction of reciprocation when in the rest position shown in Figures 12a and 12d, but is able to pivot in the actuated positions shown in Figures 12c and 12f. [00100] The actuating member 17 is pivotally mounted, and has a cam surface 17d facing towards the pusher pin 26 in the direction of reciprocation. The rotational position of the actuating member 17 in the rest position shown in Figures 12a and 12d is governed by the bistable position of the trip lever 33 (not shown). When the drive means is actuated, the pusher pin 26 moves into contact with the cam surface 17d, as shown in Figures 12b and 12e, and contacts one side or the other of the cam surface 17d, depending on the rotational position of the actuating member 17. As the reciprocating part is driven further, the pusher pin 26 pushes the contacted side of the cam surface 17d and rotates the actuating member 17 into the opposite rotational position, thereby driving the trip lever 33 to its opposite bistable position. When the drive means 18 (such as a solenoid) is deactivated, the mechanism returns to its rest position; for example, from the position of Figure 12c to that of Figure 12d, or from the position of Figure 12f to that of Figure 12a. [00101] For further clarification, Figure 12g is a perspective view of the mechanism in the position of Figure 12d, while Figure 12h is a perspective rear view of the same position.

[00102] Aspects of the above driving mechanisms can be combined; for example, the actuating member 17 of the second alternative driving mechanism may be actuated by an electromagnet 20 similar to that of the fourth embodiment, rather than by the lug 24, so that the actuating member 17 acts as intermediate pivot between the electromagnet 20 and the trip lever 33.

[00103] Alternatively, the actuating member 17 may be rotated by a stepper motor that provides precise position control. The stepper motor may 'freewheel' when not activated, so that the actuating member 17 can rotate freely and allow movement of the mechanical control independently of the actuator.

[00104] Figures 13a to 13c show a fourth alternative driving mechanism for coupling linear drive means 18 to a rotating actuating member 17. In this case, the driving means 18 reciprocates a shaft 22 carrying a rack gear 23 for engaging a pinion 21 connected to rotating actuating member 17. At the extreme end of travel of the shaft 22 as shown in Figures 13a and 13c, the rack gear 23 disengages from the pinion 21 so as to disconnect the drive means 18 from the actuating member 17. However, the rack gear 23 re-engages with the pinion 21 when the shaft 22 is driven in the opposite direction, as shown in Figure 13b. When disengaged from the rack 23, the pinion 21 rotates freely so that the actuating member 17 can be actuated manually.

[00105] In another alternative, the driving means 18 may be mounted in the power base 16, and may drive one or more actuating members that project from the base 16 into the vessel 15 so as to actuate the control 10. Preferably, the actuating members are arranged to actuate the control 10 regardless of the relative rotational orientation of the vessel 15 and the base 16, for example as described in WO-A-05/059670. Manual Rotatable Actuator

[00106] In the embodiments of this section, the manual actuator 11 is connected to an actuating mechanism allowing selection of different states of the control 10. The actuating mechanism may additionally or alternatively be actuated by an electrically or electronically controlled actuator, as described above.

Manual Rotatable Actuator - First embodiment

[00107] A first embodiment of a manual actuator is shown with reference to Figures

14-17. In this embodiment, the control 10 is an A14 control available from Otter Controls Ltd, but the invention is not limited to this control. Nevertheless, the functions of the A14 control will be outlined with reference to the drawings, to assist understanding of the embodiment. The control 10 is shown mounted on a display base 30 carrying the manual actuator 11; however, it will be understood that the control 10 will in practice be mounted in the base section 6 of a liquid heating vessel such as a kettle, for example as shown in Figure 1. [00108] The control 10 is mounted in use to the underside of the element plate 12, by means of a mounting bracket (not shown). The control 10 includes a pair of overheat sensors 31, comprises snap-acting dished bimetallic discs, which contact the underside of the element plate 12 in their normal position. A sub-boil sensor 32, shown floating in the drawings, is mounted on the underside of the element plate 12, for example as disclosed in WO-A-07/045869. The sub-boil sensor 32, also comprising a snap-acting dished bimetallic disc, is set to be triggered when the liquid in the reservoir 5 reaches a predetermined sub- boil temperature, such as 80°C The control 10 also includes a steam sensor, not visible in the drawings but positioned within a lower portion of the control close to the manual actuator 11. [00109] The control 10 has a bistable trip lever 33 which is arranged to pivot about a substantially horizontal axis between two stable positions, to which it is biased by a bistable biasing means such as a spring. In the 'off position, in which the end of the trip lever 33 closest to the manual actuator 11 is pivoted upwards, the trip lever is arranged to open switching contacts so as to disconnect power to the element plate 12. In the 'on' position, in which the end of the trip lever 33 closest to the manual actuator 11 is pivoted downwards in the figures, the trip lever allows the switching contacts to close so as to connect power to the element plate 12. The trip lever 33 is pivotable by manual actuation from the 'off position to the 'on' position, and is actuable by any of the steam sensor and the overheat sensors 21 to move from the 'on' position to the 'off position.

[00110] A bistable rocker arm 34 is mounted pivotally, about a substantially vertical axis, on the trip lever. The rocker arm 34 is pivotable between two stable positions to which it is biased by a bistable biasing means such as a spring. In the 'sub-boil' position, in which the end of the rocker arm 34 closest to the manual actuator is moved to the left in the figures, the trip lever 33 can be actuated by the sub-boil sensor 32 so that it is switched into the 'off position when the predetermined sub-boil temperature is reached. In the 'boil' position, in which the end of the rocker arm 34 closest to the manual actuator is moved to the right in the figures, the trip lever 33 cannot be actuated by the sub-boil sensor 32, but is instead actuated by the steam sensor when boiling is reached.

[00111] A contact member 35 is loosely mounted on the trip lever 33, and includes a cam follower that is traversed by a cam surface of the rocker arm 34. In the 'sub-boil' position of the rocker arm 34, the cam surface presses the cam follower against the trip lever 33 so that the contact member is secured against the trip lever 33 and a contact portion of the contact portion is held up towards the sub-boil sensor 32. When the sub-boil sensor 32 trips, it presses the contact portion of the contact member 35 downwards and thereby moves the trip lever 33 into the 'off position. In the 'boil' position of the rocker arm 34, the cam follower is released by the cam surface and the contact member 35 is held loosely by the trip lever 33, such that the contact portion drops downwards and cannot be contacted by the sub- boil sensor so as to move the trip lever 33 into the 'off position.

[00112] The mechanism described above enables the control to adopt any one of four stable states: off/sub-boil, on/sub-boil, off/boil and on/boil; in the following description, the corresponding states of the control selection mechanism (i.e. the trip lever 33 and rocker arm 34) are referenced as A, B, 1 and 2 respectively, and are shown in Figures 15, 16, 17 and 18 respectively.

[00113] The manual actuator 11 comprises a rotatably mounted knob connected via a crank connector 36, the distal end of which is movable within a horizontal slot in the distal end of the rocker arm 34. As shown in Figure 18a, the rotational positions labelled A, B, 1 and 2 correspond to the states of the control mechanism as described above.

[00114] To switch on the control in sub-boil mode, the user rotates the manual actuator 11 to position B; when the sub-boil sensor 32 trips, the manual actuator rotates automatically to position A. To switch on the control in boil mode, the user rotates the manual actuator 11 to position 2; when the steam sensor trips, the manual actuator moves automatically to position 1.

[00115] The inventors have recognized that this type of control selection mechanism involves some operational redundancy, since different stable positions of the mechanism relate to the same operational state; for example, the off/boil and the off/sub-boil positions both relate to the 'off state of the liquid heating vessel. These positions are not totally redundant, since they indicate whether the vessel was previously heated to boiling or to the sub-boiling temperature; hence, these positions may be coupled to an indicator that differentiates between the two positions, or a manual actuator may serve as the indicator. Hence, the indicator may indicate the previous operational state of the vessel.

[00116] One alternative approach would be to design a control mechanism that has only three states: off, on/boil and on/sub-boil. However, such a tri-stable mechanism is difficult to achieve with the common trip lever arrangement that has been widely accepted in the technical field. [00117] Instead, additional functions may be assigned to the off states, so that the different off states provide different functions, or one provides a function that the other does not. The additional functions may be controlled by switches, solenoids, magnets, motors and/or mechanical couplings actuated by the corresponding state of the control 10 and/or the position of the manual actuator 11. [00118] The additional functions may include: a. a keep warm mode in which a low heating power is supplied so as to keep the liquid in the vessel at or around a predetermined temperature; b. a low power/low noise mode in which a lower power is supplied to the element plate 12 e.g. 2kW rather than 3kW; c. a steam tube isolation feature to close off the entrance of the steam path, so as to isolate the steam tube 14 from the control 10; d. a dispensing feature for a filter kettle or dispensing kettle, whereby water is dispensed into the heating area; e. a lock feature; for example, the manual actuator 1 1 can only be moved out of an off state by performing another action, such as pushing or pulling the manual actuator, or pressing a release button in or around the manual actuator; f. a timer feature, which preserves a control state for a predetermined period, such as a prolonged boil in which the liquid is boiled for a predetermined period such as 1 minute, or a lighting effect which is kept on only for a predetermined period such as 5 minutes; g. a boiling indicator mode e.g. an audible or visible signal is given when boil is detected; h. a scale indicator mode e.g. an audible or visible signal is given when excess scale deposit is detected; i. a lighting feature e.g. lighting indicating the operational state of the vessel and/or aesthetic or 'mood' lighting; j. an audio feature e.g. indicating the operational state of the vessel with an acoustic signal, or switching on a music player or radio integrated with the vessel; k. a standby mode, for example in which heating cannot be manually selected until the temperature of the liquid has fallen below a predetermined threshold;

or any other function requiring electrical power or a mechanical linkage, but not involving heating at full power.

[00119] For example, in one embodiment with reference to Figure 19a, the different positions of the manual actuator 1 1 correspond to different states of the control 10 as follows:

1 Red lighting effect

2 Heat to boiling, then return automatically to state 1

A Blue lighting effect

B Heat to predetermined sub-boiling temperature, then return automatically to state A

[00120] In an alternative embodiment with reference to Figure 19a, one of the positions of the manual actuator 11 corresponds to a 'fully off state, with no functions enabled, for example:

1 Off

2 Heat to boiling, then return automatically to state 1 A Keep warm B Heat to predetermined sub-boiling temperature, then return automatically to state A

[00121] Alternatively or additionally, an additional selectable state is added by means of the manual actuator 11 , which is able to adopt a stable state that holds the control mechanism in a position that is in itself not stable for the control mechanism; for example, it does not correspond to one of the bistable states for the trip lever 33 and/or the rocker arm 34. This additional state is referenced as '0' and is illustrated in Figures 14a, 14b and 19b. The manual actuator 11 may be moved manually from state A or from state 1 to state 0. The manual actuator 11 is releasably held at state 0 by a suitable mechanism, such as a small spring-loaded ball bearing that sits in a recess at the rotational position corresponding to state 0.

[00122] This additional state 0 is preferably a 'fully off state. At first sight, this appears to compound the problem since there are now three 'off states. However, where additional functions are assigned to the other 'off states 1 and A, there is a need for the 'fully off state 0 in which the additional functions are not selected.

[00123] Advantageously, a lock feature such as described above may be applied to position 0, so that the vessel can be locked in a fully off position.

[00124] In one specific embodiment, with reference to Figure 19b, the different positions of the manual actuator 1 1 correspond to different states of the control 10 as follows:

0 Off position

1 Keep warm (close to boiling)

2 Heat to boiling, then return automatically to state 1

A Keep warm (at predetermined sub-boiling temperature) B Heat to predetermined sub-boiling temperature, then return automatically to state A

[00125] In this embodiment, the sub-boil function is enabled. A keep warm mode is activated when the manual actuator 11 is in either of positions 1 and A, but the keep warm temperature is set at close to boiling and at the predetermined sub-boiling temperature respectively; this may be done using separate keep warm heating circuits, different configurations of the same keep warm heating circuits, or different thermostat settings for the same keep warm circuits. The user may switch off either keep warm mode by manually returning the manual actuator to the 0 position. Hence, the two additional 'off states of the control are used for two different keep warm functions appropriate to the two heating functions of the control.

[00126] Alternatively or additionally, some of the functions of the control may be disabled, so that states of the control mechanism may be used for selecting alternative functions. For example, the control mechanism described above may be used where the control 10 does not include the sub-boil sensor 32 and the contact member 35. [00127] In one specific embodiment, also with reference to Figure 19b, the different positions of the manual actuator 11 correspond to states of the control 10 as follows:

0 Off position

1 Lighting effect on

2 Heat to boiling with lighting effect on, then return automatically to state 1 A Keep warm on

B Heat to boiling, then return automatically to state A

[00128] In this embodiment, the sub-boil function is disabled. A keep warm circuit is energized when the manual actuator is in position A, for example by means of a switch that is closed by the control mechanism in state A. A lighting circuit is energized when the manual actuator is in position 1 and in position 2, optionally with different lighting effects in positions 1 and 2, for example by means of lighting switches that are closed by the control mechanism in states 1 and 2.

[00129] Alternatively or additionally, the manual actuator may prevent at least one of the states of the control mechanism from being selected. In this way, only the required number of states need be provided to the user, without the need to redesign the control mechanism itself. [00130] In one specific embodiment, with reference to Figure 19c, the manual actuator is only able to select states 0, 1 and 2, and is prevented from rotating anticlockwise past position 0. The positions of the manual actuator may correspond to states of the control as follows:

0 Off position 1 Keep warm

2 Heat to boiling, then return automatically to state 1 The keep warm mode may be switched off manually by rotating the manual actuator 11 from position 1 to position 0. In this specific embodiment, the control 10 may not include the sub-boil sensor 32 and the contact member 35.

[00131] In another specific embodiment, with reference to Figure 19d, the manual actuator is only able to select states 0, A and B, and is prevented from rotating clockwise past position 0. The positions of the manual actuator may correspond to states of the control as follows:

0 Off position A Lighting effect B Heat to boiling, then return automatically to state 1

The lighting effect may be switched off manually by rotating the manual actuator 1 1 from position A to position 0. In this specific embodiment, the control 10 may not include the sub-boil sensor 32 and the contact member 35.

[00132] Each of the embodiments described above may be implemented using the same design of control 10, optionally omitting components such as the sub-boil sensor 32 and the contact member 35. This leads to efficiencies in the manufacture of the control 10, since the same control design may be used to satisfy many different installation requirements. [00133] In the above embodiments, the manual actuator 11 comprises a rotatable knob. However, other types of rotatable manual actuator may be used. Alternatively, the manual actuator 11 may comprise a member moveable in two dimensions, such as joystick- type mechanism. For example, a user-actuable member may be fixed to the rocker arm 34 so as to project out of the base section 6. Preferably, the member or joystick is moveably directly between any two stable positions of the manual actuator 11; for example, between position B and position 2, which may be advantageous for example if the user changes his or her mind about which heating mode is desired. Alternatively, the manual actuator 11 may be a rotatable member, such as a knob, that can be rotated through 360°, for example directly between position B and position 2. [00134] Figure 20 shows an alternative form of manual actuator 11, in the form of a pivoting lever which drives a crank 36 via a rotating rack 40 and a pinion 42. This alternative form of manual actuator may be applied to any of the manual rotatable actuator embodiments, with the pinion 42 replacing the rotatable member 11 in those embodiments. The pivoting lever pivots about a substantially horizontal axis 44. In this way, the user may select the state of the control using an up-and-down motion, which may be more convenient than a rotary motion, particularly for users with poor motor skills. [00135] The pivoting lever may adopt different stable pivotal positions corresponding to one or more of the positions labelled 0, 1 , 2 A and B in the embodiments described herein.

[00136] In an alternative to the manual actuator 11, an electrically or electronically controlled actuator as described above may actuate the bistable rocker arm 34 directly, without the need for an intermediate mechanism such as the crank connector 36.

Manual Rotatable Actuator - Second Embodiment

[00137] In the second embodiment, as shown in Figures 21a, 21b, 22a and 22b, the control 10 has no sub-boil heating mode and has only two stable states, 'off and 'on'. Like parts to those of the first embodiment will be referred to by the same reference numerals. The control shown in Figures 21a, 21b, 22a and 22b is the Al 2 control available from Otter Controls Ltd, but the second embodiment is also applicable to other types of control. [00138] Briefly, the control 10 lacks the sub-boil mechanism of the first embodiment, so there is no sub-boil sensor 32, bistable rocker arm 34 or contact member 35. However, the trip lever 33 is actuable by any of the steam sensor and the overheat sensors 31 to move from the 'on' position to the 'off position, as in the first embodiment. The manual actuator 11 is connected via the crank connector 36, the distal end of which is movable within a horizontal slot in the distal end of the trip lever 33.

[00139] Hence, as shown in Figure 23a, the manual actuator 11 has three positions corresponding to stable states of the control 10: position 0, corresponding to the 'off state, and positions B and 2, both corresponding to the 'on' state in which the control 10 closes a switch so as to heat the contents of the vessel to boiling. Unlike the first embodiment, position 0 corresponds to a stable state of the control 10, and the manual actuator 11 moves from position B or 2 to position 0 automatically when the trip lever 33 is moved to the off state; in that respect corresponds to both positions 1 and A of the first embodiment. Preferably however, position 0 is assigned to a 'fully off state of the control 10, and so is labelled 0. [00140] There is redundancy between positions B and 2, since they both correspond to the same state of the control 10. However, unlike aspects of the first embodiment, the redundant states are 'on' states rather than 'off states. Different additional functions may be assigned to positions B and 2, or one additional function may be assigned to one of those positions, but not to the other. The additional function or functions may be selected from the list described above with reference to the first embodiment, as appropriate. [00141] In one specific embodiment, the positions of the manual actuator 11 may correspond to states of the control 10 as follows:

0 Off B Heat to boiling with lighting

2 Heat to boiling, no lighting

[00142] In another specific embodiment, the positions of the manual actuator 11 may correspond to states of the control 10 as follows:

0 Off position B Low power heating (e.g. 2kW)

2 High power heating (e.g. 3kW)

[00143] In another specific embodiment, the positions of the manual actuator 11 may correspond to states of the control 10 as follows:

0 Off position B Heat to boiling with active boiling indication

2 Heat to boiling without active boiling indication

[00144] Unlike in the first embodiment, the manual actuator 11 effectively provides additional stable control positions: there are only two stable positions of the control 10, but three stable positions of the manual actuator. However, as in the first embodiment, additional stable positions of the manual actuator 11 may be provided that do not correspond to stable states of the control 10. In the specific embodiment shown in Figure 23b, stable positions A and 1 may be provided between positions 0 and B, and positions 0 and 2 respectively. These additional positions provide further 'off states of the control 10 that may be used to select additional functions, such as keep warm functions. Preferably, the manual actuator 11 can be moved automatically by the trip lever 33 from position B to position A, and from position 2 to position 1 , and may then be moved manually to position 0.

[00145] In an alternative embodiment, the coupling between the manual actuator 11 and the control 10 may be such that positions A and 1 still correspond to the stable 'off state of the control 10. For example, the slot in the distal end of the trip lever may allow sufficient play in the vertical direction such that the trip lever is not moved out of its stable

'off state when the manual actuator is in position A or 1. hi an alternative embodiment, illustrated in Figure 23c, the manual actuator 1 1 only has a number of positions corresponding to the states of the control; for example, the manual actuator 11 can only be rotated between positions 0 and 2, corresponding to 'on' and 'off states of the control 10 respectively.

Additional Features

[00146] Additional features may be provided to any of the embodiments described above. For example, a counter may be coupled to the manual actuator 1 1 and/or the control mechanism to count the number of times the manual actuator 11 is manually operated, or the number of times the manual actuator 11 automatically changes position. The counter may provide a visual indication of the total count, or an alert may be indicated when the counter reaches a predetermined number, for example as a reminder to performance maintenance, such as a descaling operation.

Alternative Embodiments

[00147] Embodiments of the invention may be applied to other types of liquid heating vessel, such as Turkish tea makers (caydanhk), samovars, urns, moka makers and the like, including vessels designed for heating liquids other than water, such as electric saucepans and milk frothers. [00148] Some aspects of the present invention are not limited to liquid heating vessels, but may be applied to other types of liquid heaters such as flow-through heaters, including hot water dispensers, coffee makers and the like. Furthermore, some aspects of the invention may be applied to other types of portable domestic electrical heating appliances, such as toasters, sandwich toasters, waffle irons, crepe makers, electric frying pans, irons and the like. In particular, a remote control as described above may be implemented in these appliances, preferably with one or more of the safety features outlined above. Aspects of the invention are also applicable to fixed electrical installations such as saunas, ovens and steam generators.

[00149] The embodiments described above are illustrative of rather than limiting to the present invention. Alternative embodiments apparent on reading the above description may nevertheless fall within the scope of the invention.

Claims

1. A control apparatus for a domestic electrical appliance, comprising a mechanical switching control and an electrically or electronically controlled actuator arranged to actuate the mechanical control.

2. The apparatus of claim 1, wherein the mechanical switching control comprises a mechanical switch having a plurality of stable states including at least one 'off state.

3. The apparatus of claim 2, wherein the switch comprises a trip lever, the mechanical control comprising at least one mechanical sensor arranged to move said trip lever to said at least one 'off state.

4. The apparatus of claim 3, wherein the mechanical sensor comprises a bimetal.

5. The apparatus of any one of claims 2 to 4, wherein the actuator is arranged to move the switch from one to another of said stable states.

6. The apparatus of claim 5, wherein the actuator is arranged to toggle the switch between two of said stable states.

7. The apparatus of any one of claims 1 to 6, wherein the mechanical control is mechanically actuable substantially independently of said actuator.

8. The apparatus of claim 7, wherein the mechanical control is manually actuable substantially independently of said electrical or electronic actuator.

9. The apparatus of claim 7, wherein the mechanical control is automatically actuable substantially independently of said electrical or electronic actuator.

10. The apparatus of any one of claims 7 to 9, wherein the actuator comprises an actuating member arranged to actuate the mechanical control, the actuating member being coupled to an electrical or electronic drive means such that the mechanical control is substantially unimpeded by the actuating member when the drive means is inactive.

11. The apparatus of any one of claims 7 to 10, wherein the actuating member is arranged to exhibit lost motion with respect to the mechanical control.

12. The apparatus of any one of claims 7 to 11, wherein the actuating member comprises first and second actuating portions spaced apart so as to allow movement of the mechanical control independently of the actuating member.

13. The apparatus of any one of claims 7 to 12, wherein the actuator comprises a plurality of discrete actuating members each arranged to actuate a different part of the mechanical control.

14. The apparatus of any preceding claim, wherein the actuator is magnetically coupled to the mechanical control.

15. The apparatus of claim 14, wherein the actuator comprises an electromagnet coupled directly or indirectly to a magnetic or magnetisable portion of the electromechanical control.

16. The apparatus of any one of claims 1 to 13, wherein the actuator is electrostatically coupled to the mechanical control.

17. The apparatus of any one of claims 7 to 9, wherein the actuator comprises a rotary actuating member arranged to actuate the mechanical control.

18. The apparatus of any one of claims 7 to 9, wherein the actuator comprises a pivotal lever arranged to actuate the mechanical control.

19. The apparatus of any preceding claim, including means for controlling the actuator automatically.

20. The apparatus of claim 19, wherein the means for controlling the actuator automatically comprises a sensor.

21. The apparatus of claim 20, wherein the sensor is coupled to the actuator by a low voltage connection.

22. The apparatus of claim 20, wherein the sensor is coupled to the actuator wirelessly.

23. The apparatus of any one of claims 1 to 18, including a user interface for controlling the actuator.

24. The apparatus of claim 23, wherein the user interface is movably mounted with respect to the appliance.

25. The apparatus of claim 24, wherein the user interface is pivotable and/or rotatable with respect to the appliance.

26. The apparatus of claim 25, wherein the user interface is pivotable and/or rotatable with respect to a substantially vertical axis of the appliance in an upright position thereof.

27. The apparatus of claim 23, wherein the user interface comprises a remote control separate or separable from the appliance.

28. The apparatus of claim 27, wherein the remote control is mountable on the appliance.

29. The apparatus of claim 28, wherein the remote control is rechargeable when mounted on the appliance.

30. The apparatus of claim 28 or 29, wherein the mechanical control is manually mechanically actuable only when the remote control is separated from the appliance.

31. The apparatus of any one of claims 27 to 29, wherein the remote control is further arranged to control audio or audiovisual equipment.

32. The apparatus of any one of claims 23 to 31, wherein the user interface is arranged to control an additional function of the vessel.

33. The apparatus of claim 32, wherein the additional function comprises a lighting function.

34. The apparatus of claim 32, wherein the additional function comprises an additional heating function of the appliance.

35. The apparatus of any one of claims 23 to 34, wherein the user interface is arranged to receive information on the status of the appliance.

36. A switching control apparatus for an electric heating appliance, comprising a local user interface and a remote user interface both for controlling the switching state of the appliance, wherein the local user interface is able to override the remote user interface so as to switch off the appliance.

37. Apparatus according to claim 36, wherein the local user interface is arranged to control the switching state of the appliance mechanically.

38. Apparatus according to claim 36 or 37, wherein the remote user interface is arranged to switch on the appliance after the appliance is switched off by the local user interface, without further actuation of the local user interface.

39. Apparatus according to any one of claims 36 to 38, wherein the local user interface is not operable so as to switch on the appliance.

40. The apparatus of any one of claims 36 to 39, including a safety cut-out responsive to overheating of the appliance to switch off heating of the appliance in precedence over the local user interface and the remote user interface.

41. A switching control apparatus for an electric heating appliance, comprising a local user interface and a remote user interface both for controlling the switching state of the appliance, arranged to selectively disable the remote user interface such that only the local user interface is able to control the switching state of the appliance.

42. The apparatus of claim 41, arranged to selectively disable the remote user interface automatically.

43. The apparatus of claim 42, arranged to selectively disable the remote user interface in response to inactivity of the remote control interface for a predetermined interval.

44. The apparatus of any one of claims 41 to 43, including an indicator local to the appliance, arranged to indicate whether the remote user interface is disabled.

45. The apparatus of any one of claims 41 to 44, including an indicator local to the appliance, arranged to indicate whether the remote user interface is being actuated.

46. A control apparatus for an electrical appliance, comprising a mechanical control having at least two stable states and a toggle mechanism arranged to toggle the mechanical control between said at least two stable states.

47. The apparatus of claim 46, wherein the mechanical control is actuable between said at least two stable states substantially independently of said toggle mechanism.

48. A domestic electrical appliance comprising the apparatus of any one of claims 1 to 47.

49. A liquid heating appliance comprising the appliance of claim 48.

50. A liquid heating vessel comprising the appliance of claim 49.

51. The vessel of claim 50, wherein the vessel is a cordless vessel having a cordless base.

52. The vessel of claim 51, wherein the vessel includes a 360° cordless connector for connection to the cordless base.

53. The vessel of claim 51 or 52, wherein the mechanical switching control and the actuator are provided in the vessel body.

54. The vessel of claim 51 or 52, wherein the mechanical switching control is provided in the vessel body and the actuator is provided in said base.

55. The vessel of claim 54 when dependent on claim 52, wherein the actuator is arranged to actuate the control regardless of the rotational orientation of the cordless connector.

56. The vessel of any one of claims 50 to 55, wherein the vessel includes an element plate.

57. The vessel of claim 56, wherein the element plate includes a sheathed heating element.

58. The vessel of claim 56, wherein the element plate includes a thick film heating element.

59. A liquid heating vessel controllable by a remote control unit removably mountable on a part of the vessel.

60. The vessel of claim 59, wherein the remote control unit is rechargeable when mounted on the vessel.

61. A liquid heating apparatus controllable by a remote control unit further arranged to control audio or audiovisual equipment.

62. A liquid heating apparatus controllable by a remote control unit arranged to receive status information from the vessel.

63. A control for a domestic electrical heating appliance, the control being arranged to control a heating function and an additional function of the appliance, the control having a plurality of discrete states that are redundant with respect to the heating function but correspond to different states of the additional function.

64. The control of claim 63, wherein said plurality of redundant discrete states each correspond to an active state of the heating function.

65. The control of claim 63, wherein said plurality of redundant discrete states each correspond to an inactive state of the heating function.

66. The control of any one of claims 63 to 65, wherein said control has a further plurality of redundant discrete states each corresponding to another state of the heating function.

67. The control of claim 66, wherein said further plurality of redundant discrete states each correspond to different states of a second additional function of the vessel.

68. The control of any one of claims 63 to 67, wherein said heating function comprises heating of the liquid at full heating power.

69. The control of any one of claims 63 to 68, wherein said appliance is a liquid heating appliance and the additional function comprises one or more of: a keep warm function, a lower power heating function, a locking function, a steam path isolating function, a dispensing function, a timing function, a boiling indicator function, a scale deposit indicator function, a lighting function, an audio function and a standby function.

70. The control of any one of claims 63 to 69, coupled to an actuator having at least one stable position that does not correspond to any of the discrete states of the control.

71. A control for an electrical heating appliance, the control being arranged to control a heating function of the appliance, the control having a plurality of discrete states that are redundant with respect to the heating function but indicate the previous heating state of the vessel.

72. A switching control for an electrical heating appliance, the control being able to adopt any one of a plurality of discrete stable control states, and being coupled to an actuator having a second plurality of stable positions, the second plurality being greater in number than the first plurality.

73. The switching control of claim 72, wherein at least one of the stable positions of the actuator does not correspond to any of the stable control states of the control.

74. The switching control of claim 72, wherein one of the stable control states of the control corresponds to more than one of the stable positions of the actuator.

75. The switching control of claim any one of claims 72 to 74, wherein each of said discrete stable control states corresponds to an active state of at least one of a plurality of functions of the appliance, and at least one of the stable positions of the actuator corresponds to an inactive state of each of said plurality of functions.

76. The switching control of any one of claims 72 to 75, wherein said appliance is a liquid heating appliance and the functions are selected from a group comprising a heating function, a keep warm function, a lower power heating function, a locking function, a steam path isolating function, a dispensing function, a timing function, a boiling indicator function, a scale deposit indicator function, a lighting function, an audio function and a standby function.

77. A switching control for a domestic electrical appliance, the control being able in isolation to adopt any one of a plurality of discrete control positions but being coupled to an actuator such that the control is unable to adopt at least one of said control positions.

78. A switching control according to claim 77, wherein the at least one control positions that the control is unable to adopt correspond to redundant control states of the control.

79. A switching control for a domestic electrical appliance, the control having at least first and second discrete stable states each arranged to activate the heating function, and at least one other stable control state, the control being coupled to an actuator such that the control may be manually actuated directly from the first to the second stable control state without passing through any other stable control state.

80. A switching control for a domestic electrical appliance, the control having at least three discrete stable control states, the control being coupled to an actuator such that the control may be actuated directly from any of the stable control states to any other of the stable control states.

81. The switching control of any one of claims 72 to 80, wherein the actuator is a mechanical actuator.

82. The switching control of any one of claims 72 to 80, wherein the actuator is an electrically or electronically controlled actuator.

83. The switching control of any one of claims 72 to 82, wherein the actuator is manually actuable.

84. The switching control of any one of claims 72 to 82, wherein the actuator is automatically actuable.

85. A control according to any one of claims 63 to 84, wherein each of said states corresponds to a respective stable position of a mechanism of the control.

86. The switching control of claim 85, wherein said mechanism includes a mechanical trip lever actuable by one or more sensors.

87. The thermal control of claim 86, wherein said mechanical trip lever is actuable by any one of a plurality of sensors.

88. The switching control of claim 86 or 87, wherein said sensor(s) comprise at least one thermal sensor.

89. The switching control of any one of claims 86 to 88, wherein said mechanism further includes a bistable mechanical member moveable relative to the trip lever.

90. The switching control of any one of claims 85 to 89, further including a rotatable actuator coupled to the control mechanism.

91. The switching control of claim 90, wherein the rotatable actuator comprises a rotatable crank member, the distal end of the crank member being coupled to the control mechanism.

92. The switching control of claim 91, wherein the distal end of the crank member is retained within a slot in the control mechanism.

93. The switching control of any one of claims 90 to 92, including a pivotal lever coupled to the rotatable actuator.

94. A switching control for a liquid heating vessel, arranged to control at least three independently switchable functions of the vessel.

95. An electrical appliance including a control according to any one of claims 63 to 94.

96. A liquid heating appliance comprising an appliance as claimed in claim 95.

97. A liquid heating vessel comprising an appliance as claimed in claim 96.