[go: up one dir, main page]

WO2024213882A1 - Appareils de chauffage de liquide avec surveillance de température de liquide - Google Patents

Appareils de chauffage de liquide avec surveillance de température de liquide Download PDF

Info

Publication number
WO2024213882A1
WO2024213882A1 PCT/GB2024/050951 GB2024050951W WO2024213882A1 WO 2024213882 A1 WO2024213882 A1 WO 2024213882A1 GB 2024050951 W GB2024050951 W GB 2024050951W WO 2024213882 A1 WO2024213882 A1 WO 2024213882A1
Authority
WO
WIPO (PCT)
Prior art keywords
liquid
temperature
liquid heating
appliance
electrical
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/GB2024/050951
Other languages
English (en)
Inventor
Raymond DOYLE
Marc Gibson Collinson
Richard Brandon Fumagalli
Colin Peter Moughton
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Strix Ltd
Original Assignee
Strix Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from GB2305461.2A external-priority patent/GB2629136A/en
Application filed by Strix Ltd filed Critical Strix Ltd
Publication of WO2024213882A1 publication Critical patent/WO2024213882A1/fr
Anticipated expiration legal-status Critical
Pending legal-status Critical Current

Links

Classifications

    • A—HUMAN NECESSITIES
    • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47J—KITCHEN EQUIPMENT; COFFEE MILLS; SPICE MILLS; APPARATUS FOR MAKING BEVERAGES
    • A47J27/00—Cooking-vessels
    • A47J27/21—Water-boiling vessels, e.g. kettles
    • A47J27/21008—Water-boiling vessels, e.g. kettles electrically heated
    • A47J27/21058—Control devices to avoid overheating, i.e. "dry" boiling, or to detect boiling of the water
    • A47J27/21083—Control devices to avoid overheating, i.e. "dry" boiling, or to detect boiling of the water with variable operating parameters, e.g. temperature or boiling period
    • A—HUMAN NECESSITIES
    • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47J—KITCHEN EQUIPMENT; COFFEE MILLS; SPICE MILLS; APPARATUS FOR MAKING BEVERAGES
    • A47J27/00—Cooking-vessels
    • A47J27/21—Water-boiling vessels, e.g. kettles
    • A47J27/21008—Water-boiling vessels, e.g. kettles electrically heated
    • A47J27/2105—Water-boiling vessels, e.g. kettles electrically heated of the cordless type, i.e. whereby the water vessel can be plugged into an electrically-powered base element
    • A—HUMAN NECESSITIES
    • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47J—KITCHEN EQUIPMENT; COFFEE MILLS; SPICE MILLS; APPARATUS FOR MAKING BEVERAGES
    • A47J27/00—Cooking-vessels
    • A47J27/21—Water-boiling vessels, e.g. kettles
    • A47J27/21008—Water-boiling vessels, e.g. kettles electrically heated
    • A47J27/21058—Control devices to avoid overheating, i.e. "dry" boiling, or to detect boiling of the water
    • A47J27/21091—Control devices to avoid overheating, i.e. "dry" boiling, or to detect boiling of the water of electronic type

Definitions

  • the present invention relates to a liquid heating appliance.
  • an electrical heater is typically arranged to heat liquid stored within a liquid heating vessel of the appliance.
  • Control units may be provided in order to control the provision of electrical power to the electrical heater, e.g. to initiate or terminate a heating operation.
  • power is typically provided to the cordless liquid heating vessel via a power base connected to a mains supply of electricity.
  • Said control units often include a switch for removing the supply of electrical power from the appliance when a particular temperature or condition is sensed within the appliance, thereby switching off the electrical heater.
  • the control unit may be arranged to disconnect the power supply when the liquid inside the liquid heating vessel has reached boiling temperature.
  • the residual heat of the electrical heater will continue to heat the liquid even after the electrical heater is switched off, there is an overshoot if the electrical heater is switched off only in reaction to the liquid reaching the boiling temperature. This overshoot results in wasted energy, and hence results in unnecessary electricity costs over the lifespan of the appliance.
  • a liquid heating appliance for heating liquid to a boiling temperature, comprising: a liquid heating vessel; an electrical heater for heating liquid contained within the liquid heating vessel, and an electrical power supply circuit arranged to power the electrical heater; detection means arranged to detect when the liquid contained within the liquid heating vessel is approaching boiling point but has a liquid temperature below its boiling temperature that corresponds to an early cut-off temperature; and an electrical control unit comprising control circuitry arranged to interrupt the electrical power supply circuit, thereby deactivating the electrical heater, in response to the detection means detecting that the liquid temperature corresponds to the early cut-off temperature, wherein the liquid heating vessel is configured such that residual heat of the electrical heater causes the liquid temperature to continue to rise to the boiling temperature after the electrical heater has been deactivated at the early cut-off temperature.
  • the electrical heater can be deactivated early, and yet, as a result of the residual heat of the electrical heater (e.g. the heating element), the temperature of the liquid will continue to rise.
  • the electrical heater e.g. the heating element
  • the liquid can still be boiled, but the amount of active heating is reduced. This can result in a significant energy saving over the life span of the appliance.
  • the appliance comprises an electronic temperature sensor configured to provide liquid temperature data.
  • the electronic temperature sensor is a thermistor.
  • the appliance comprises a processor and the electronic temperature sensor is configured to provide liquid temperature data to the processor.
  • the appliance comprises a display assembly configured to indicate to a user of the appliance that the liquid temperature has reached the boiling temperature when the electronic temperature sensor detects that the liquid has reached boiling point due to the residual heat.
  • the display assembly may receive the liquid temperature data directly from the electronic temperature sensor and display the liquid temperature data as received.
  • the liquid temperature data may accurately reflect the current liquid temperature
  • the appliance preferably uses a processor to assess when the liquid temperature has reached the boiling temperature based on the liquid temperature data provided by the electronic temperature sensor.
  • the processor that receives the liquid temperature data from the electronic temperature sensor is configured to control the display assembly based on the liquid temperature data.
  • the display assembly is configured to indicate to a user of the appliance that the liquid temperature has reached the boiling temperature when it is determined by the processor, based on the liquid temperature data, that the liquid has reached the boiling temperature due to the residual heat remaining in the electrical heater after it has been deactivated.
  • the liquid temperature data may lag behind the ‘true’ current liquid temperature but a suitable algorithm running on the processor can calculate the current liquid temperature before it is displayed.
  • the display assembly may indicate that boiling temperature has been reached by illuminating lights on a temperature scale or changing the colour of illumination. However, it is desirable for the boiling temperature to be displayed as a number so that a user feels confident that the boiling temperature has actually been detected. It is therefore preferable that the display assembly is configured to display a liquid temperature value (e.g. a current liquid temperature value) based on the liquid temperature data provided by the electronic temperature sensor.
  • the processor that receives the liquid temperature data from the electronic temperature sensor may be configured to convert the received liquid temperature data to a temperature value to be displayed. This is particularly relevant in the case of the present invention because the liquid heating appliance will sound different to a conventional liquid heating appliance.
  • a conventional liquid heating appliance will not deactivate its heating element until after the liquid has boiled and so the liquid in the appliance will boil for a few seconds (e.g. typically less than 10 seconds). Users are accustomed to the sound which this period of boiling produces. Since the liquid heating appliance of the present invention deactivates the heating element at an early cut-off temperature, the liquid will more gently reach its boiling temperature and so the appliance will be quieter. As a result of not hearing what they are used to, the user may not initially have confidence that the liquid has boiled.
  • the display assembly comprises an alphanumeric display (such as a LCD or LED screen) and a processor for controlling the alphanumeric display.
  • the same processor may be configured to obtain the liquid temperature data provided by the electronic temperature sensor (as mentioned above) and to control the alphanumeric display to display the current liquid temperature value.
  • the display assembly may comprise a printed circuit board (PCB) and an alphanumeric display, e.g. mounted on the PCB.
  • the display assembly may comprise a 7-segment alphanumeric display which may be controlled by a processor included on the PCB.
  • the electrical control unit further comprises a trip lever for allowing a user to manually interrupt the electrical power supply circuit.
  • the detection means may be configured to operate the trip lever upon detecting that the liquid contained within the liquid heating vessel has reached the early cut-off temperature. This provides a visual and/or audible indication to a user that the power supply has been cut-off early (i.e. saving energy) but the user can be assured by the display (as described above) that the liquid temperature continues to rise until boiling has been attained.
  • the detection means comprises an electronic detection means arranged to detect that liquid within the liquid heating vessel has reached the early cut-off temperature and to operate a switch or the trip lever to interrupt the electrical power supply circuit upon said detection.
  • the electronic detection means may comprise an electronic temperature sensor (e.g. a thermistor), for example arranged to measure (directly or indirectly) the temperature of liquid within the liquid heating vessel.
  • an electronic temperature sensor e.g. a thermistor
  • the electronic temperature sensor may be mounted on the electrical control unit to contact the electrical heater (e.g. a heat diffuser plate thereof) or to extend into the liquid heating vessel (e.g. by passing through the heat diffuser plate to contact the liquid contained in the liquid heating vessel).
  • the appliance may further comprise a processor or control circuit and preferably the electronic temperature sensor is configured to provide a measurement signal representative of the temperature of liquid within the liquid heating vessel (e.g. liquid temperature data) to the processor or control circuit.
  • the appliance may also comprise a relay or TRIAC configured to interrupt the electrical power supply circuit, for example connected to the processor or control circuit.
  • the processor or control circuit may be included on the PCB of the display assembly discussed above.
  • the processor or control circuit may be provided with the display assembly in the cordless liquid heating vessel.
  • a discrete processor or control unit may be provided, for example at any suitable location in the appliance.
  • the display assembly is housed in a side wall or handle of the liquid heating vessel.
  • the liquid heating appliance is a cordless appliance.
  • the electrical control unit comprises a control body defining a cordless electrical adapter part for mating with a corresponding base electrical connector part, e.g. of a corresponding power base stand, to receive a supply of electrical power.
  • the control body may be a monolithic (e.g. moulded) plastics material body.
  • the cordless electrical adapter part and corresponding base electrical connector part may be of the type that can be mated regardless of their relative angular orientation, or at least through a wide angular range (e.g. at least 340° and preferably up to 360°). Suitable cordless connectors of this “360° type” are described in W095/08024 and WO01/28294, and are available as the Strix P72 or P76 connector parts.
  • the liquid heating appliance is a cordless appliance comprising a power base stand, and the liquid heating vessel is arranged to be seated on the power base stand.
  • the power base stand may comprise the corresponding base electrical connector part.
  • This base electrical connector part may include tabs for electrical connection to a mains power supply cable, or the mains power supply cable may be integrated with the connector part.
  • the base electrical connector part is mounted centrally on the power base stand.
  • the power base stand may comprise the display assembly. This may help to isolate the display assembly from steam which is generated by the liquid heating vessel.
  • the processor or control circuit receiving the liquid temperature data may be provided with the display assembly in the power base stand.
  • the cordless electrical adapter part located in the electrical control unit may comprise at least two mating conductors, for connecting to the live and neutral poles of the power supply circuit. An additional earth connection may also be present.
  • the cordless electrical adapter part is a 3-pole connector part (e.g. for mating with a Strix P72).
  • the cordless electrical adapter part is a 5-pole connector part (e.g. for mating with a Strix P76).
  • Such 5-pole connector parts provide for electronic signal connection as well as electrical power connection.
  • the electrical power supply circuit of the liquid heating appliance is arranged to receive (e.g. from the base electrical connector part) an electrical current of between 3 and 15 amps.
  • the appliance may include a wireless (e.g. radio-frequency) or physical connection to communicate the liquid temperature data provided by the electronic temperature sensor to the components in the power base stand.
  • the cordless electrical adapter part includes a physical electrical connection to communicate the liquid temperature data provided by the electronic temperature sensor to the power base stand.
  • the cordless electrical adapter part may comprise two or three terminals for supplying electrical power to the cordless liquid heating vessel and one or two further terminals for communicating the liquid temperature data to the base electrical connector part.
  • the cordless electrical adapter part may comprise five terminals (e.g. a 5-pole cordless connection as described in WO01/28294, the contents of which are hereby incorporated by reference).
  • the liquid heating appliance comprises an electrical power socket for receiving an electrical power cord for connecting to a mains electrical power supply.
  • the liquid heating appliance comprises an integrated power cord.
  • the liquid heating appliance may comprise a heat diffuser plate arranged in thermal communication with the electrical heater.
  • the electrical control unit is arranged to be mounted to an underside of the heat diffuser plate.
  • the electrical control unit comprises a mount plate for mounting the electrical control unit to the underside of the heat diffuser plate.
  • the mount plate is preferably metal.
  • the mount plate is preferably substantially flat.
  • an electronic temperature sensor is arranged to indirectly detect a temperature corresponding to the early cut-off temperature
  • the detected temperature may be the temperature of the electrical heater or the temperature of the heat diffuser plate.
  • the electronic temperature sensor may protrude through the heat diffuser plate to contact the base of the liquid heating vessel or even protrude into the liquid heating vessel to be in contact with the liquid contained therein.
  • the appliance comprises liquid volume estimation means configured to estimate a volume of the liquid contained within the liquid heating vessel.
  • liquid volume estimation means may use the/an electronic temperature sensor to estimate the liquid volume based on the initial rate of temperature rise, e.g. as known from WO01/56436.
  • the liquid volume estimation means comprises a processor configured to: obtain liquid temperature data from a/the electronic temperature sensor whilst the liquid is being heated, use the liquid temperature data to measure the temperature gradient, and estimate the liquid volume based on the temperature gradient.
  • the liquid volume estimation means comprises one or more weight sensors (e g. in the liquid heating vessel or elsewhere in the appliance e g. in the power base stand of a cordless appliance) configured to measure the weight of the liquid contained within the liquid heating vessel.
  • weight sensors e g. in the liquid heating vessel or elsewhere in the appliance e g. in the power base stand of a cordless appliance
  • the liquid volume estimation means comprises one or more weight sensors (e g. in the liquid heating vessel or elsewhere in the appliance e g. in the power base stand of a cordless appliance) configured to measure the weight of the liquid contained within the liquid heating vessel.
  • the display assembly is configured to display the estimated liquid volume based on the measured weight.
  • the estimated liquid volume is provided to the display assembly directly or indirectly (e.g. via a/the processor).
  • the estimated liquid volume may be displayed in addition to the indication of boiling temperature (e.g. current temperature value), for example at the start and/or end of a boiling cycle, to give reliable and instant user feedback on the amount of water being boiled.
  • the liquid heating appliance comprises a/the processor configured to set the early cut-off temperature based on the estimated liquid volume.
  • the liquid volume is therefore taken into account when setting an appropriate value for the early cut-off temperature, as the amount of residual heat required to raise the liquid temperature to boiling temperature depends on the volume of liquid contained in the liquid heating vessel.
  • the liquid heating appliance comprises a/the processor programmed with an anti-lag function which is dependent on liquid volume, and is configured to account for time lag between liquid temperature data (e.g. provided by an electronic temperature sensor) and the (e.g. actual) liquid temperature, wherein the processor is configured to estimate the current liquid temperature based on liquid temperature data, the anti-lag function, and the estimated liquid volume.
  • the estimated liquid volume may be provided by any suitable type of liquid volume estimation means (e.g. using an electronic temperature sensor and/or one or more weight sensors).
  • the Applicant has recognised that the liquid temperature data, depending on how it is obtained, may not represent the actual liquid temperature within the liquid heating vessel and the anti-lag function can account for the time lag.
  • the time lag can be different for an electronic temperature sensor mounted in direct contact with liquid in the liquid heating vessel as compared to an electronic temperature sensor mounted in contact with the electrical heater.
  • the extent of the time lag is can also be dependent on the liquid volume.
  • the electronic temperature sensor may not be in direct contact with the liquid contained in the liquid heating vessel.
  • the electronic temperature sensor may be mounted in contact with the heated base of the liquid heating vessel. This arrangement may be advantageous for simplifying construction of the liquid heating appliance, however, since the electronic temperature sensor is not able to directly measure the liquid temperature, this arrangement may lead to a time lag between changes in the measured liquid temperature data, and changes in the actual liquid temperature.
  • the anti-lag function can be developed (e.g. based on experimental data) having liquid volume as a variable. As such, if the volume of liquid in the liquid heating vessel is known, the anti-lag function can be used to compensate for the time lag, reducing the risk of overboil.
  • the display assembly is configured to display the estimated current liquid temperature as the liquid temperature value.
  • the displayed liquid temperature value can be relied upon as a true representation of the liquid temperature inside the liquid heating vessel.
  • the detection means comprises a thermomechanical actuator e.g. snapaction bimetallic element arranged to detect that some liquid within the liquid heating vessel has been converted into steam at the early cut-off temperature and to operate a switch or the trip lever to interrupt the electrical power supply circuit upon said detection.
  • the snap-action bimetallic element may be arranged to operate at a predetermined temperature of 70-80 °C.
  • the thermomechanical actuator is comprised in the electrical control unit.
  • the detection means comprises a thermomechanical actuator as discussed above (preferably comprised in the electrical control unit) wherein the appliance comprises: an outlet for allowing liquid to be poured from the liquid heating vessel; a steam pipe configured to direct steam produced in the vessel to reach the thermomechanical actuator; and a baffle configured to restrict steam from exiting the vessel via the outlet.
  • thermomechanical actuator can detect the presence of steam in the vessel much earlier than in a standard kettle and hence detect that liquid in the liquid heating vessel has a liquid temperature below its boiling temperature that corresponds to the early cut-off temperature. This means that the thermomechanical actuator operates to interrupt the electrical power supply circuit when liquid in the vessel is at the early cut off temperature below its boiling temperature.
  • the baffle comprises a partition extending below a minimum liquid fill line of the vessel. This prevents any steam which is produced on the opposite side of the partition from the outlet from escaping through the outlet. In these embodiments, substantially all of the steam produced in the vessel is forced into the steam pipe. This ensures that the thermomechanical actuator operates at the early cut off temperature.
  • the appliance comprises a steam chamber housing the thermomechanical actuator.
  • the steam chamber houses the electrical control unit when the electrical control unit and thermomechanical element are integrated.
  • the steam chamber may be located at or close to the base of the vessel.
  • the appliance comprises a steam guiding member (which is preferably provided on the electrical control unit) which is configured to guide steam away from the display assembly.
  • a display assembly housing is provided which at least partially surrounds the display assembly to restrict steam from reaching the display assembly.
  • the display assembly is housed in a side wall or handle of the vessel. This means that the display assembly can be positioned away from the electrical control unit in the steam chamber and is not exposed to steam.
  • the electrical control unit comprises: a first set of electrical tabs connected to the electrical heater to form the electrical power supply circuit, wherein the control circuitry is arranged to interrupt the electrical power supply circuit, thereby deactivating the electrical heater, in response to the thermomechanical actuator detecting steam when the liquid temperature corresponds to the early cut-off temperature; and a second set of electrical tabs connected to the display assembly to form a bypass electrical power supply circuit. Since the display assembly is powered by this bypass electrical power supply circuit, it can indicate the liquid temperature to the user even after the main electrical power supply circuit to the heater has been interrupted. Furthermore, the bypass electrical power supply circuit can provide freedom for the display assembly to be positioned independently of the electrical control unit.
  • the display assembly receives liquid temperature data from a remote temperature sensor, for example from an electronic temperature sensor positioned in or under the heated base of the vessel (e.g. integrated with the electrical control unit).
  • the electronic temperature sensor may be connected to the display assembly by a temperature signal wire or wireless connection may even be used.
  • the display assembly it is preferable for the display assembly to be co-located with the electronic temperature sensor.
  • the bypass electrical power supply circuit comprises the electronic temperature sensor and the display assembly is configured to indicate to a user of the appliance that the liquid temperature has reached the boiling temperature when the electronic temperature sensor detects that the liquid has reached the boiling temperature.
  • the bypass electrical power supply circuit that provides for “overshoot” liquid temperature sensing and display is therefore independent of the electrical control unit that provides for disconnection of the electrical heater at the early cut off temperature.
  • the bypass electrical power supply circuit further comprises a rechargeable power source for the display assembly. This means that the display assembly can continue to indicate the liquid temperature even if the appliance comprises a cordless liquid heating vessel that is lifted from its power base stand.
  • the appliance is a cordless appliance and the display assembly is housed in the power base stand.
  • the display assembly can therefore remain powered regardless of whether the main electrical power supply circuit to the heater has been interrupted.
  • the display assembly may receive liquid temperature data from an electronic temperature sensor positioned in the cordless liquid heating vessel, for example from an electronic temperature sensor positioned in or under the heated base of the vessel (e.g. integrated with the electrical control unit).
  • the electronic temperature sensor may transmit the liquid temperature data through signal connections provided by the cordless electrical connector set to a processor located in the power base stand and configured to control the display assembly.
  • a method of heating liquid contained within a liquid heating vessel to a boiling temperature comprising: activating an electrical heater by completing an electrical power supply circuit to the electrical heater; detecting when the liquid contained within the liquid heating vessel is approaching boiling point but has a liquid temperature below its boiling temperature that corresponds to an early cut-off temperature; and interrupting the electrical power supply circuit, thereby deactivating the electrical heater, in response to detecting that the liquid temperature corresponds to the early cut-off temperature, such that residual heat of the electrical heater causes the liquid temperature to continue to rise to the boiling temperature after the electrical heater has been deactivated at the early cut-off temperature
  • the method further comprises: determining that the liquid has reached the boiling temperature due to the residual heat and displaying to a user of the appliance that the liquid temperature has reached the boiling temperature.
  • the method comprises obtaining liquid temperature data using an electronic temperature sensor. It may be determined that the liquid has reached the boiling temperature based on the obtained liquid temperature data.
  • the method further comprises displaying to a user a liquid temperature value based on the obtained liquid temperature data.
  • the method comprises measuring or estimating a volume of the liquid contained within the liquid heating vessel.
  • the method may comprise setting the early cut-off temperature based on the measured or estimated volume.
  • the method comprises: obtaining liquid temperature data from an electronic temperature sensor whilst the liquid is being heated, using the liquid temperature data to measure the temperature gradient, and estimating the liquid volume based on the temperature gradient.
  • the method further comprises using an anti-lag function which is dependent on liquid volume, and is configured to account for time lag between liquid temperature data and the (e.g. actual) liquid temperature, to estimate the current liquid temperature based on the liquid temperature data, the anti-lag function, and the measured or estimated liquid volume.
  • an anti-lag function which is dependent on liquid volume, and is configured to account for time lag between liquid temperature data and the (e.g. actual) liquid temperature, to estimate the current liquid temperature based on the liquid temperature data, the anti-lag function, and the measured or estimated liquid volume.
  • a liquid heating appliance for heating liquid to a target temperature, comprising: a liquid heating vessel; an electrical heater for heating liquid contained within the liquid heating vessel, and an electrical power supply circuit arranged to power the electrical heater; a processor; an electronic temperature sensor configured to provide, to the processor, liquid temperature data for liquid contained within the liquid heating vessel; and liquid volume estimation means configured to estimate a liquid volume contained within the liquid heating vessel, wherein the processor is programmed with an anti-lag function, the anti-lag function being dependent on the liquid volume and configured to account for time lag between the liquid temperature data and the (e.g. actual) temperature of liquid contained within the liquid heating vessel, wherein the processor is configured to estimate a current liquid temperature based on the liquid temperature data, the anti-lag function, and the estimated liquid volume.
  • the Applicant has recognised that the liquid temperature data, depending on how it is obtained, may not represent the actual liquid temperature within the liquid heating vessel and the anti-lag function can account for the time lag.
  • This can allow the target temperature to be detected more rapidly and/or accurately
  • the time lag can be different for an electronic temperature sensor mounted in direct contact with liquid in the liquid heating vessel as compared to an electronic temperature sensor mounted in contact with the electrical heater.
  • the extent of the time lag can also be dependent on the liquid volume.
  • the electronic temperature sensor may not be in direct contact with the liquid contained in the liquid heating vessel.
  • the electronic temperature sensor may be mounted in contact with the heated base of the liquid heating vessel. This arrangement may be advantageous for simplifying construction of the liquid heating appliance, however, since the electronic temperature sensor is not able to directly measure the liquid temperature, this arrangement may lead to a time lag between changes in the measured liquid temperature data, and changes in the actual liquid temperature.
  • the anti-lag function can be developed (e.g. based on experimental data) having liquid volume as a variable. As such, if the volume of liquid in the liquid heating vessel is known, the anti-lag function can be used to compensate for the time lag. In some embodiments, the anti-lag function may be an empirical model built from experimental data comparing the liquid temperature data to a measured (e.g. actual) temperature of liquid contained within the liquid heating vessel, for different liquid volumes.
  • the target temperature is a temperature below the boiling temperature. In some embodiments, the target temperature is an early cut-off temperature. In some embodiments, the target temperature is the boiling temperature In various embodiments, the target temperature may be pre-programmed and/or set by a user input.
  • liquid volume estimation means may use the electronic temperature sensor to estimate the liquid volume based on the initial rate of temperature rise, e.g. as known from WO01/56436.
  • the liquid volume estimation means may comprise the processor (or another processor), and the processor is configured to: obtain liquid temperature data from the electronic temperature sensor whilst the liquid is being heated, use the liquid temperature data to measure the temperature gradient, and estimate the liquid volume based on the temperature gradient. This means that the liquid volume can be estimated using the existing electronic temperature sensor, although an estimation is not possible until heating is taking place and the temperature gradient can be measured.
  • the liquid volume estimation means comprises one or more weight sensors (e.g. in the liquid heating vessel or elsewhere in the appliance e.g. in the power base stand of a cordless appliance) configured to measure the weight of the liquid contained within the liquid heating vessel.
  • weight sensors e.g. in the liquid heating vessel or elsewhere in the appliance e.g. in the power base stand of a cordless appliance
  • Using weight sensors to estimate the liquid volume may have the advantage that the liquid volume can be estimated before the liquid has begun to be heated As such the liquid volume can be estimated more quickly. Further, the use of weight sensors may result in a more accurate estimated liquid volume.
  • the appliance comprises a display assembly configured to indicate the current liquid temperature to a user of the appliance.
  • the display assembly may also be configured to indicate the estimated liquid volume.
  • the liquid heating appliance comprises a power base stand, wherein the liquid heating vessel is a cordless liquid heating vessel arranged to be seated on the power base stand, wherein the power base stand is configured to provide power to the liquid heating vessel (e.g. to the power supply circuit), and wherein the power base stand comprises the processor. This may help to isolate the processor from steam which is generated by the liquid heating vessel.
  • the power base stand comprises all control and processing electronics (e.g. processor, display, weight sensor(s)).
  • the liquid heating appliance comprises a cordless liquid heating vessel arranged to be seated on a power base stand, the electronic temperature sensor being located in the cordless liquid heating vessel and the processor being located in the power base stand.
  • the liquid temperature data can be transmitted to the processor via a cordless connector set (for example, as described in WO01/28294).
  • the power base stand may further include (the) one or more weight sensors configured to measure the weight of the liquid contained within the cordless liquid heating vessel and to provide weight data to the processor for estimation of the liquid volume.
  • the power base stand may further include a/the display assembly configured to indicate to a user of the appliance at least one of: the current liquid temperature and the estimated liquid volume.
  • a/the display assembly configured to indicate to a user of the appliance at least one of: the current liquid temperature and the estimated liquid volume.
  • Fig.1 shows a schematic view of a liquid heating appliance in accordance with a first embodiment of the present invention
  • Fig. 2 shows a perspective view of the appliance of Fig. 1 ;
  • Fig. 3 shows a flow diagram illustrating a method according to an embodiment of the invention
  • Fig. 4 shows an exemplary graph of liquid temperature plotted against time
  • Fig. 5 shows a side view of a liquid heating appliance in accordance with a second embodiment of the present invention
  • Fig. 6 shows a side view of the liquid heating appliance of Fig. 5 in use
  • Fig. 7 shows a perspective view of the steam chamber of the liquid heating appliance of Fig. 5;
  • Fig. 8 shows an exploded view of the display assembly housed in the liquid heating appliance of Fig. 5;
  • Fig. 9 shows a side view of a liquid heating appliance in accordance with a third embodiment of the present invention.
  • Fig. 10 shows a schematic diagram of the electrical power supply circuits of the liquid heating appliance of Fig. 9;
  • Fig .11 shows a schematic view of a liquid heating appliance in accordance with a fourth embodiment of the present invention.
  • Fig. 12 shows a perspective view of the appliance of Fig. 11 ;
  • Fig. 13 shows a cut-through view of the power base stand of the liquid heating appliance of Fig. 11 ;
  • Figs. 14 and 15 show measured temperature plotted against actual liquid temperature for different sensor placements and liquid volumes
  • Fig. 16 shows a flow diagram illustrating a method according to an embodiment of the invention.
  • FIG. 1 shows a schematic view of a liquid heating appliance 2 in accordance with an embodiment of the present invention.
  • the liquid heating appliance 2 is in the form of a kettle.
  • the liquid heating appliance 2 may be in any appliance suitable for heating a liquid, e g. in the form of a milk heating and frothing appliance.
  • the liquid heating appliance 2 comprises a cordless liquid heating vessel 4 and a power base stand 6.
  • the cordless power base stand 6 is shaped to receive the liquid heating vessel 4 thereon.
  • the liquid heating vessel 4 comprises a heated base 8 which defines a liquid chamber 10 which receives a liquid to be heated.
  • the heated base 8 is heated by a heating element 12 and includes a heat diffuser plate.
  • the liquid heating vessel 4 comprises a cordless electrical adapter part 14 (hereinafter “adapter 14”) arranged to mate with a corresponding base electrical connector part 16 (hereinafter “connector 16”) which is provided on the power base stand 6.
  • the adapter 14 is part of an electrical control unit 18 which controls the supply of electrical power to the heating element 12.
  • the power base stand 6 comprises a power cable 20 which may be plugged into a suitable power source, e.g. a mains electric power supply.
  • the power cable 20 may be suitably electrically connected to the base electrical connector part 16.
  • the liquid heating vessel 4 comprises a temperature sensor 22, which in the illustrated embodiment is a thermistor.
  • the temperature sensor 22 protrudes through the heated base 8 and into the liquid chamber 10 such that the liquid temperature can be directly measured.
  • the temperature sensor 22 may not protrude into the liquid chamber 10 and may therefore not directly measure the liquid temperature.
  • the temperature sensor may be mounted beneath and against the heated base 8 and may be configured to measure the temperature of the heated base 8 as being indicative of the liquid temperature.
  • the heating element 12 is shown schematically here and it should be appreciated that the temperature sensor 22 may be mounted so as to avoid contact with the heating element 12 and may even be mounted in a cut-out in the heat diffuser plate so as to be shielded from direct heating by the element 12.
  • FIG. 2 shows an external view of the liquid heating appliance 2 of Figure 1.
  • the liquid heating appliance 2 comprises a display assembly 21 comprising a 7-segment display 24 which is controlled by a printed circuit board (PCB) 26 on which the display 24 is mounted.
  • the PCB 26 includes a processor which is configured to receive liquid temperature data from the temperature sensor 22, and to control the display 24 to display the current liquid temperature to a user.
  • the processor is further connected to the electrical control unit 18 (not shown in Figure 2) and comprises a controller which is configured to instruct the electrical control unit 18 to control the supply of electrical power to the heating element 12.
  • the controller for the heating element 12 may be provided by a separate processor.
  • the user fills the liquid chamber 10 with the liquid to be heated and provides an input to begin the heating process.
  • This input may be provided in any suitable and known way, such as via an input button or lever provided on the liquid heating appliance.
  • the controller instructs the electrical control unit 18 to provide electrical power to the heating element 12 in order to activate (e g. turn on) the heating element 12.
  • the liquid inside the liquid chamber 10 is heated by the heating element 12.
  • the temperature sensor 22 measures the liquid temperature over time and generates a time series of liquid temperature data. This liquid temperature data is sent to the processor for analysis.
  • the processor analyses the time series of liquid temperature data to calculate the temperature gradient.
  • the temperature gradient can be used to estimate the liquid volume in the liquid chamber 10 since a larger volume of liquid will have a shallower temperature gradient. This is illustrated by the graph of Figure 4. This estimation could be done in any known way.
  • the processor e.g. a memory of the processor
  • the processor may be programmed with a plurality of exemplary temperature gradient and liquid volume pairs, and the processor may match the calculated temperature gradient to the closest exemplary temperature gradient, and hence to the paired exemplary liquid volume.
  • the processor selects an early cut-off temperature.
  • This selection could be made in any suitable way, for example, the processor (e g. a memory of the processor) may be programmed with a plurality of liquid volume and early cut-off temperature pairs. These pairs are known to result in the liquid temperature still reaching boiling point when the heating element 12 is deactivated at the early cut-off temperature.
  • the processor may match the estimated liquid volume to the closest exemplary liquid volume.
  • the paired early cut-off temperature is then selected as the early cut-off temperature.
  • a selection of experimental volume and cut-off temperature pairs are shown below in table 1.
  • the controller instructs the electrical control unit 18 to cut off the supply of electrical power to the heating element 12 to deactivate (e.g. turn off) the heating element.
  • the temperature sensor 22 continues to monitor the liquid temperature, and, at step 37, when the temperature sensor 22 detects that the liquid temperature has reached the boiling temperature, this is indicated to the user via the display 24.
  • this indication may simply be via a light or other visual indication means, or via an audible indication means such as a speaker playing a sound such as a beep to indicate that the liquid has reached its boiling temperature.
  • the current liquid temperature (which is the boiling temperature at step 37) is indicated to the user using the 7- segment display 24.
  • steps 34 and 35 are replaced by a single step in which the processor simply compares the liquid temperature data to an early cut-off temperature that is preprogrammed (e.g. stored in a memory). For example, it can be seen from Table 1 that a preset early cut-off temperature of 98.5 °C has been found to allow different volumes of liquid to reach boiling point using the residual heat from a 2.2 kW or 3 kW heating element.
  • the controller instructs the heating element to turn off when the temperature sensor detects that the liquid temperature is equal to the early cut off temperature without any volume estimation taking place.
  • Figure 5 shows a cut-through view of a liquid heating appliance 102 in accordance with a second embodiment of the invention.
  • the liquid heating appliance 102 also comprises a cordless liquid heating vessel 104 and a power base stand 6.
  • the power base stand 6 is shaped to receive the liquid heating vessel 104 thereon.
  • the liquid heating vessel 104 comprises a heated base 108 which defines a liquid chamber 110 which receives a liquid to be heated.
  • the heated base 108 is heated by a sheathed heating element 12 attached to a heat diffuser plate.
  • the cordless liquid heating vessel 104 comprises a cordless electrical adapter part 14 (hereinafter “adapter 14”) arranged to mate with a a corresponding base electrical connector part 16 (hereinafter “connector 16”) which is provided on the power base stand 6.
  • the adapter 14 is part of an electrical control unit 118 which controls the supply of electrical power to the heating element 12.
  • the power base stand 6 comprises a power cable which may be plugged into a suitable power source, e.g. a mains electric power supply.
  • the power cable may be suitably electrically connected to the base electrical connector part 16.
  • the cordless electrical control unit 118 comprises a thermomechanical actuator 41 , supported by a moulded plastics control body 46.
  • the thermomechanical actuator 41 is a snap-action bimetallic actuator set to operate at a predetermined temperature.
  • the thermomechanical actuator 41 is arranged to detect the temperature of steam generated by liquid (e.g. water) boiling within the liquid heating chamber 110 and conveyed via a steam pipe 43 extending from the top of the chamber 110 to the electrical control unit 118, as is known in the art.
  • the electrical control unit 118 comprises a trip lever 44 that is pivotally mounted on the control body 46.
  • a distal end of the trip lever 44 is arranged to be operated by the thermomechanical actuator 41 , while a proximal end of the trip lever 44 is arranged to operate an electrical switch (not shown in Figure 5) which connects the heating element 12 to the power supply.
  • the trip lever 44 also includes a manual switch extension 45 that protrudes out of the side of the vessel 104 for a user to manually switch on and off the power supply to the heating element 12.
  • thermomechanical actuator 41 is arranged such that its operation at the predetermined temperature causes the trip lever 44 to pivot so as to open the electrical switch, thereby disrupting the supply of electrical energy to the heating element 12. This allows the heating element 12 to be switched off when a steam temperature is detected by the thermomechanical actuator 41 that is representative of liquid within the liquid heating vessel 104 approaching boiling.
  • the present invention aims to deactivate the heating element 12 at an early cut-off temperature which is lower than the boiling point of the liquid being heated, but sufficiently close to the boiling temperature that the liquid temperature will continue to rise to the boiling temperature after the heating element 12 has been deactivated.
  • this objective is achieved by trapping steam inside the chamber 110. Although steam is of course produced when water boils, some steam is produced when the overall liquid temperature is approaching boiling point. In a conventional kettle with a steam pipe 43 and a thermomechanical actuator 41 , this small amount of steam is not sufficient to trip the actuator 41 since most of the steam escapes from the spout 48. Therefore, the thermomechanical actuator 41 is not tripped until the water is fully boiling.
  • the applicant has realised that by blocking the spout 48, the steam is trapped inside the chamber 110. As such, even before the liquid has reached its boiling point, there is enough steam trapped inside the chamber 110 for a sufficient amount of steam to travel down through the steam pipe 43 and trip the thermomechanical actuator 41. As such, the heating element 12 is deactivated as known in the art, but this deactivation happens at an early cut-off temperature which is below the boiling temperature, saving energy.
  • the spout 48 is blocked using a baffle 50.
  • the baffle 50 is formed as a curved wall (e.g. cylindrical section) which extends from the top of the vessel 104, close to the spout 48, to a point below the minimum fill line 52, and contacts the wall of the vessel 104 on either side of the spout 48 such that a fluid channel is formed which allows liquid which is contained in the chamber 110 to exit the vessel 104 via the spout when the vessel 104 is sufficiently tilted, as shown in Figure 6.
  • the baffle 50 extends below the minimum fill line 52, steam which rises from the liquid on the side of the baffle distal from the spout 48 cannot escape via the spout 48.
  • the baffle 50 may take any shape which is suitable for providing the functionality described above.
  • the liquid heating appliance 102 also comprises a temperature sensor 22 (as shown in Figure 5), which in the illustrated embodiment is a thermistor.
  • the temperature sensor 22 protrudes through the heated base 108 and into the liquid chamber 110 such that the liquid temperature can be directly measured.
  • the temperature sensor 22 may not protrude into the liquid chamber 110 and may therefore not directly measure the liquid temperature.
  • the temperature sensor may be mounted beneath and against the heated base 108 and may be configured to measure the temperature of the heated base 108 as being indicative of the liquid temperature.
  • the liquid heating appliance 102 also includes a display assembly 21 comprising a 7-segment display 24 (shown in Figure 8) which is controlled by a printed circuit board (PCB) 26 on which the display 24 is mounted.
  • the PCB 26 includes a processor which is configured to receive liquid temperature data from temperature sensor 22, and to control the display 24 to display the current liquid temperature to a user.
  • the electrical control unit 118 is arranged below the heated base 108, which is particularly suitable when it is integrated with a cordless electrical adapter part 14 as shown.
  • the electrical control unit 118 could be separate from the cordless electrical adapter part 14 and could be positioned elsewhere in the liquid heating vessel 104, for example along a side wall of the liquid chamber 110 or in the handle.
  • the liquid heating vessel 104 may not be cordless at all, in which case the electrical control unit 118 may take any suitable position next to the liquid chamber 110 so as to detect the liquid temperature with the temperature sensor 22 and receive power from a mains power supply cord.
  • the display assembly 21 is not housed inside the steam chamber 54. Instead, as shown for the appliance 202 in Fig. 9, the display assembly 21 is positioned in a side wall of the liquid heating vessel 204.
  • This appliance 202 has many features in common with the first and second embodiments, including the cordless liquid heating vessel 204 being seated on a power base stand 6 with a cordless electrical adapter part being arranged to mate with a corresponding base electrical connector part as previously described.
  • the appliance 202 may also use a steam baffling arrangement, as described in relation to the second embodiment, to detect when the liquid contained within the liquid heating vessel is approaching boiling point but has a liquid temperature below its boiling temperature that corresponds to an early cut-off temperature.
  • an electrical control unit 118 as previously described may be mounted in the base of the vessel 204.
  • the electrical control unit 118 in the third embodiment comprises second set of electrical tabs, connected to the electrical adapter part separately from a first set of electrical tabs that electrically connect to the electrical heater to form a primary electrical power supply circuit.
  • the second set of electrical tabs can electrically connect to the display assembly 21 in a bypass electrical power supply circuit. This is described in more detail with reference to Fig. 10.
  • FIG 10 shows a schematic diagram of the electrical power supply circuits of the appliance 202 of Figure 9.
  • the appliance 202 comprises a primary electrical power circuit 60 (represented by dashed lines in Figure 10) and an auxiliary electrical power circuit 62 (represented by solid lines).
  • control unit 118 of the appliance 202 comprises a cordless electrical adapter part 14 that can connect to a corresponding base electrical connector part 16, which supplies AC current to the electrical components of the vessel 204 when the vessel 204 is positioned on the power base stand 6.
  • the control unit 118 further comprises a pair of switches 64a, 64b and a first pair of fixed electrical tabs 29a, 29b. Each tab 29a, 29b is connected to the cordless electrical adapter part 14 via a respective one of the switches 64a, 64b.
  • the electrical heating element 12 is connected across the first pair of tabs 29a, 29b, thereby completing the primary electrical power circuit 60.
  • the thermomechanical actuator 41 is arranged to open the switches 64a, 64b when the predetermined temperature is sensed. This causes the electrical heating element 12 to be disconnected from the electrical power supply provided by the base electrical connector part 16, thereby turning off the heater 12
  • the control unit 118 further comprises a second pair of fixed electrical tabs 33a, 33b, each connected to the cordless electrical adapter part 14. Unlike the first pair of fixed electrical tabs 29a, 29b, each of the second pair of fixed electrical tabs 33a, 33b is connected directly to the cordless electrical adapter part 14, rather than via a switch.
  • a display assembly 21 is connected across the second pair of fixed electrical tabs 33a, 33b, thereby completing the auxiliary electrical power circuit 62, which is in parallel with the primary electrical power circuit 60. Owing to the arrangement described above, when the thermomechanical actuator 41 operates to open the switches 64a, 64b so as to disconnect the electrical heating element 12 from the power source provided by the base electrical connector part 16, the supply of electrical power to the auxiliary electrical power circuit 62 is not disrupted.
  • the display assembly 21 optionally comprises a rechargeable power source 72 that is directly connected to the second pair of fixed electrical tabs 33a, 33b.
  • the rechargeable power source 72 is arranged to store electrical energy received from the power supply of the base electrical connector part 16 when the vessel 204 is arranged on the power base stand 6. This means that, after the vessel 204 has been lifted away from the power base stand 6, such that the cordless electrical adapter part 14 and the base electrical connector part 16 are no longer connected, the rechargeable power source 72 can provide electrical power to the other components of the display assembly 21 . Therefore, the display assembly 21 can continue to operate even after the vessel 204 has been removed from the power base stand 6.
  • the display assembly 21 comprises a processor 74, an electronic alphanumeric display 76, and a thermistor 78 acting as the liquid temperature sensor, each of which is arranged to receive electrical power from the rechargeable power source 72.
  • the thermistor 78 may pass through a side wall of the liquid heating chamber to directly contact liquid contained therein.
  • the electronic alphanumeric display 76 is visible on the side of the liquid heating vessel 204.
  • the auxiliary electrical power circuit 62 ensures that the display 76 can indicate to a user that the liquid temperature continues to rise and has reached the boiling temperature after the thermomechanical actuator 41 has operated to interrupt the primary electrical power circuit 60. If the rechargeable power source 72 is included in the display assembly 21, then the display 76 can continue to indicate the liquid temperature even after the vessel 204 has been removed from the power base stand 6.
  • FIG 11 shows a schematic view of a cordless liquid heating appliance 302 in accordance with a fourth embodiment of the present invention.
  • Figure 12 shows perspective view of the liquid heating appliance 302.
  • the liquid heating appliance 302 shown in Figures 11 and 12 is a variant of the liquid heating appliance 2 shown in Figures 1 and 2.
  • the liquid heating appliance 302 is in the form of a kettle.
  • the liquid heating appliance 302 may be any appliance suitable for heating a liquid, e.g. in the form of a milk heating and frothing appliance.
  • the liquid heating appliance 302 comprises a cordless liquid heating vessel 4 and a power base stand 6.
  • the cordless power base stand 6 is shaped to receive the liquid heating vessel 4 thereon.
  • the liquid heating vessel 4 comprises a heated base 8 which defines a liquid chamber 10 which receives a liquid to be heated.
  • the heated base 8 is heated by a heating element 12 and includes a heat diffuser plate
  • the liquid heating vessel 4 comprises a cordless electrical adapter part 14 (hereinafter “adapter 14”) arranged to mate with a corresponding base electrical connector part 16 (hereinafter “connector 16”) which is provided on the power base stand 6.
  • the adapter 14 is part of an electrical control unit 18 which controls the supply of electrical power to the heating element 12.
  • the power base stand 6 comprises a power cable 20 which may be plugged into a suitable power source, e.g. a mains electric power supply.
  • the power cable 20 may be suitably electrically connected to the base electrical connector part 16.
  • the liquid heating vessel 4 comprises a temperature sensor 22, which in the illustrated embodiment is a thermistor (e.g. NTC thermistor).
  • the temperature sensor 22 is mounted beneath and against the heated base 8 and is configured to measure the temperature of the heated base 8 as being indicative of the liquid temperature.
  • the heating element 12 is shown schematically here and it should be appreciated that the temperature sensor 22 may be mounted so as to avoid contact with the heating element 12 and may even be mounted in a cut-out in the heat diffuser plate so as to be shielded from direct heating by the element 12. In other embodiments (such as that shown in Figures 1 and 2), the temperature sensor 22 may protrude through the heated base 8 and into the liquid chamber 10 such that the liquid temperature can be directly measured.
  • the power base stand 6 comprises a pair of weight sensors 60 which are configured to measure the weight of the liquid heating vessel 4.
  • FIG 12 shows an external view of the liquid heating appliance 302 of Figure 11 .
  • the liquid heating appliance 302 comprises a display assembly 21 provided on the power base stand 6.
  • the display assembly 21 comprises a temperature display 21a, and a fill level display 21 b.
  • the fill level display 21b is configured to display the number of cups of liquid which are present inside the liquid heating vessel by illuminating cup icons.
  • the fill level display may display the volume of liquid inside the liquid heating vessel 4 in other units (e.g. millilitres, fluid ounces, etc.)
  • the power base stand 6 further comprises a plurality of user input elements 62, a power on/off input element 62a, and a temperature adjustment input element 62b. A user can select a temperature of 100 °C when it is desired to heat liquid to boiling.
  • Figure 13 shows a cut-through perspective view of the power base stand 6 of the liquid heating appliance 302.
  • the weight sensors 60 can be seen in Figure 13.
  • the temperature display 21a comprises a 7-segment display 24, and that the fill level display 21 b comprises a plurality of LEDs 25
  • the 7-segment display 24 and the LEDs 25 are controlled by a printed circuit board (PCB) 26 on which they are mounted.
  • the PCB 26 includes a processor (not shown) which is configured to receive liquid temperature data transmitted via the adapter 14 and connector 16 from the temperature sensor 22, and liquid heating vessel weight data from the weight sensors 60.
  • the adapter 14 and connector 16 may be a 5-pole connector set of the “P76” type available from Strix. Based on this data, the processor is configured to control the temperature display 21a to display the current liquid temperature to a user, and to control the fill level display 21b to display the current fill level to a user.
  • the processor may be configured to calculate an estimated liquid temperature based on the liquid temperature data from the temperature sensor 22, and to control the temperature display 21a to display the estimated liquid temperature to a user. This is discussed in greater detail below with reference to Figures 13 - 15.
  • the processor is further connected to the electrical control unit 18 (not shown in Figure 13) and comprises a controller which is configured to instruct the electrical control unit 18 to control the supply of electrical power to the heating element 12.
  • the controller for the heating element 12 may be provided by a separate processor. It can thus be seen that, other than the temperature sensor 22, all the control and processing electronics are in the power base stand 6.
  • the temperature sensor 22 is not in direct contact with the liquid, but rather is mounted below the heated base 8. This arrangement may be advantageous for simplifying construction of the liquid heating appliance 302. However, since the temperature sensor 22 is not able to directly measure the liquid temperature, this arrangement may lead to a time lag between changes in the measured temperature, and changes in the actual liquid temperature.
  • This issue is exemplified by the plots of Figures 14 and 15.
  • Figure 14 shows the temperature measured by a temperature sensor (“NTC”) in direct contact with water being heated plotted against the actual water temperature for different water volumes.
  • Line 1 shows the target, where the measured temperature corresponds to the actual water temperature.
  • Lines 250, 500, 1000, and 1700 each represent the data gathered when the volume of water in the liquid heating vessel 4 was 250ml, 500ml, 1000ml, and 1700ml respectively. It can be seen from Figure 14 that for each of the different volumes, the lines are close to the target line, and so the measured temperature is tracking reliably with the actual temperature.
  • Figure 15 shows the temperature measured by a temperature sensor (“NTC”) mounted below the heated base 8 plotted against the actual water temperature for different water volumes.
  • Line 1 shows the target, where the measured temperature corresponds to the actual water temperature.
  • Lines 250, 500, 1000, and 1700 each represent the data gathered when the volume of water in the liquid heating vessel 4 was 250ml, 500ml, 1000ml, and 1700ml respectively. It can be seen from Figure 15 that, for each of the different volumes, the lines are further from the target line 1 when compared with the plot of Figure 14. For higher liquid volumes (see lines 1000, and 1700) the measured temperature is initially much higher (up to 15 degrees higher) than the actual temperature.
  • an anti-lag function can be developed (e.g. based on experimental data) having liquid volume as a variable. As such, if the volume of liquid in the liquid heating vessel 8 is known, the anti-lag function can be used to compensate for the time lag, reducing the risk of overboil
  • the user fills the liquid chamber 10 with the liquid to be heated and provides an input to begin the heating process.
  • This input may be provided in any suitable and known way.
  • the input may comprise selecting a target temperature (e g. boiling) using the temperature adjustment input element 62b, and then starting the heating cycle using the power on/off input element 62a.
  • the liquid volume present in the liquid chamber 10 is determined using the weight sensors 60.
  • the processor is pre-programmed with an anti-lag function configured to take liquid volume as a variable. As such, based on this determination, the liquid volume is input into the antilag function.
  • the weight sensors 60 may be omitted from the liquid heating appliance 302, and the liquid volume may be estimated based on the temperature gradient as explained in relation to steps 32, 33, and 34 of the method illustrated in Figure 3.
  • the processor selects an early cut-off temperature.
  • This selection could be made in any suitable way, for example, the processor (e.g. a memory of the processor) may be programmed with a plurality of liquid volume and early cut-off temperature pairs. These pairs are known to result in the liquid temperature still reaching boiling point when the heating element 12 is deactivated at the early cut-off temperature.
  • the processor may match the estimated liquid volume to the closest exemplary liquid volume.
  • the paired early cut-off temperature is then selected as the early cut-off temperature.
  • a selection of experimental volume and cut-off temperature pairs are shown above in table 1.
  • the controller instructs the electrical control unit 18 to provide electrical power to the heating element 12 in order to activate (e.g. turn on) the heating element 12.
  • the liquid inside the liquid chamber 10 is heated by the heating element 12.
  • the temperature sensor Whilst the liquid is being heated, at step 85, the temperature sensor generates liquid temperature data and sends this data to the processor.
  • the processor inputs the liquid temperature data into the anti-lag function to calculate the current estimated liquid temperature.
  • the processor controls the temperature display 21a to display the current estimated liquid temperature.
  • the controller instructs the electrical control unit 18 to cut off the supply of electrical power to the heating element 12 to deactivate (e.g. turn off) the heating element.
  • the temperature sensor 22 continues to monitor the liquid temperature, and the processor continues to calculate the estimated liquid temperature using the anti-lag function, and, at step 37, when the estimated liquid temperature has reached the target temperature (e.g. boiling temperature), this is indicated to the user via the display 21a.
  • this indication may simply be via a light or other visual indication means, or via an audible indication means such as a speaker playing a sound such as a beep to indicate that the liquid has reached its boiling temperature.

Landscapes

  • Engineering & Computer Science (AREA)
  • Food Science & Technology (AREA)
  • Cookers (AREA)

Abstract

L'invention concerne un appareil de chauffage de liquide permettant de chauffer du liquide jusqu'à une température d'ébullition, comprenant : un récipient de chauffage de liquide ; un dispositif de chauffage électrique pour chauffer le liquide contenu au sein du récipient de chauffage de liquide et un circuit d'alimentation électrique agencé pour alimenter le dispositif de chauffage électrique ; des moyens de détection agencés pour détecter le moment où le liquide contenu au sein du récipient de chauffage de liquide approche du point d'ébullition, mais a une température de liquide inférieure à sa température d'ébullition qui correspond à une température de coupure précoce ; et une unité de commande électrique comprenant une circuiterie de commande agencée pour interrompre le circuit d'alimentation électrique, pour ainsi désactiver le dispositif de chauffage électrique, en réponse à la détection par les moyens de détection du fait que la température de liquide correspond à la température de coupure précoce. Le récipient de chauffage de liquide est conçu de telle sorte que la chaleur résiduelle du dispositif de chauffage électrique provoque la poursuite de l'élévation de la température de liquide jusqu'à la température d'ébullition après que le dispositif de chauffage électrique a été désactivé à la température de coupure précoce. Un ensemble d'affichage peut être conçu pour indiquer à un utilisateur de l'appareil que la température du liquide a atteint la température d'ébullition.
PCT/GB2024/050951 2023-04-13 2024-04-11 Appareils de chauffage de liquide avec surveillance de température de liquide Pending WO2024213882A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
GB2305461.2A GB2629136A (en) 2023-04-13 2023-04-13 Liquid heating appliance
GB2305461.2 2023-04-13
CN202310540091.7A CN118787224A (zh) 2023-04-13 2023-05-12 具有提前切断温度的液体加热器具
CN202310540091.7 2023-05-12

Publications (1)

Publication Number Publication Date
WO2024213882A1 true WO2024213882A1 (fr) 2024-10-17

Family

ID=90825682

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB2024/050951 Pending WO2024213882A1 (fr) 2023-04-13 2024-04-11 Appareils de chauffage de liquide avec surveillance de température de liquide

Country Status (1)

Country Link
WO (1) WO2024213882A1 (fr)

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2261362A (en) * 1991-11-05 1993-05-19 Strix Ltd Water heating vessel
WO1995008024A1 (fr) 1993-09-17 1995-03-23 Beloit Technologies, Inc. Procede d'orientation des fibres
WO2001028294A2 (fr) 1999-10-11 2001-04-19 Strix Limited Appareils electriques sans fil
WO2001056436A2 (fr) 2000-02-01 2001-08-09 Strix Limited Appareils chaufffants electriques
US20110259871A1 (en) * 2010-04-23 2011-10-27 Wing Chung Li Intelligent electric kettle
CN106889881A (zh) * 2015-12-17 2017-06-27 广东美的生活电器制造有限公司 水壶及其加热控制方法
CN110037548A (zh) * 2019-04-29 2019-07-23 九阳股份有限公司 一种电水壶的显温方法
CN110074664A (zh) * 2019-04-29 2019-08-02 英特卡机电(惠州)有限公司 智能感应水沸腾温度并延时断电的电热水壶及方法
WO2020067056A1 (fr) * 2018-09-25 2020-04-02 株式会社カリタ Bouilloire électrique
US20200268190A1 (en) * 2017-09-12 2020-08-27 Breville Pty Limited A liquid heating appliance for making a beverage and associated method, power management system and microcontroller readable medium

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2261362A (en) * 1991-11-05 1993-05-19 Strix Ltd Water heating vessel
WO1995008024A1 (fr) 1993-09-17 1995-03-23 Beloit Technologies, Inc. Procede d'orientation des fibres
WO2001028294A2 (fr) 1999-10-11 2001-04-19 Strix Limited Appareils electriques sans fil
WO2001056436A2 (fr) 2000-02-01 2001-08-09 Strix Limited Appareils chaufffants electriques
US20110259871A1 (en) * 2010-04-23 2011-10-27 Wing Chung Li Intelligent electric kettle
CN106889881A (zh) * 2015-12-17 2017-06-27 广东美的生活电器制造有限公司 水壶及其加热控制方法
US20200268190A1 (en) * 2017-09-12 2020-08-27 Breville Pty Limited A liquid heating appliance for making a beverage and associated method, power management system and microcontroller readable medium
WO2020067056A1 (fr) * 2018-09-25 2020-04-02 株式会社カリタ Bouilloire électrique
CN110037548A (zh) * 2019-04-29 2019-07-23 九阳股份有限公司 一种电水壶的显温方法
CN110074664A (zh) * 2019-04-29 2019-08-02 英特卡机电(惠州)有限公司 智能感应水沸腾温度并延时断电的电热水壶及方法

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
AMAZON.DE: "Fityou Electric Kettle Gooseneck, Temperature Control, 1200 W, 1 L High Capacity, Quick Cooking, LED Digital Screen, Celsius/Fahrenheit Conversion, for Specialty Coffee and Tea", 25 April 2022 (2022-04-25), amazon.de, pages 1 - 8, XP093171002, Retrieved from the Internet <URL:https://www.amazon.de/Fityou-elektrischer-Temperaturregelung-Fahrenheit-Umwandlung-Spezialit%C3%A4tenkaffee/dp/B09YQWF3N7/ref=sr_1_6?__mk_de_DE=%C3%85M%C3%85%C5%BD%C3%95%C3%91&crid=BFJ17GNRFBFO&dib=eyJ2IjoiMSJ9.KMj6jO_ChdG5WKr9N3EIdwZMgNmVHY6-XQReJqmuPHWEkFZiaVT1lrNdtc_gjpd_td8kV91hJToW9RYHE5nQHtdHl> [retrieved on 20240605] *
DMOFWHI: "Amazon.com DmofwHi Electric Kettle ([deg.F]/[deg.C]), 1.5L Electric Hot Water Kettle, 1200W Electric Tea Kettle", 3 September 2022 (2022-09-03), XP093171440, Retrieved from the Internet <URL:https://www.youtube.com/watch?v=7aJsval0pWE> [retrieved on 20240606] *

Similar Documents

Publication Publication Date Title
EP1858297B1 (fr) Applications électriques sans fil
AU2008101189B4 (en) Improved temperature sensor for an electric heating appliance
EP2661994B1 (fr) Récipient chauffant pour liquide et commande
US7805867B2 (en) Device for generating steam
CN108720550A (zh) 烹饪用锅具及烹饪控制方法
WO2024213882A1 (fr) Appareils de chauffage de liquide avec surveillance de température de liquide
KR101329247B1 (ko) 조리용기의 존재를 검출하는 전기 조리기구
GB2629136A (en) Liquid heating appliance
EP3527114B1 (fr) Dispositif de préparation de boisson présentant une fonctionnalité de détection de cuisson et de niveau
EP0783861A1 (fr) Appareil à chauffage éléctrique
US20220287499A1 (en) Multi-functional slow cooker with temperature control features
WO2008138268A1 (fr) Bouilloire/grille-pain combinés et bouilloire électrique sans cordon
US7342329B2 (en) Power supply for electrical domestic appliances and domestic appliances for co-action with such a power supply
JP5113139B2 (ja) 電気湯沸かし器
GB2387765A (en) Cordless electrical appliances
AU2010292990B2 (en) Electric kettle
GB2629134A (en) Liquid heating appliance
WO2024213881A1 (fr) Appareil de chauffage de liquide avec circuit d&#39;alimentation électrique de dérivation
AU2010200571B2 (en) Improved temperature sensor for an electric heating appliance
AU2013200269B2 (en) Improved temperature sensor for an electric heating vessel
WO2014096768A1 (fr) Réchauffeurs de liquide
AU2015264889A1 (en) Improved temperature sensor for an electric heating vessel

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 24720557

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 2024720557

Country of ref document: EP

NENP Non-entry into the national phase

Ref country code: DE

ENP Entry into the national phase

Ref document number: 2024720557

Country of ref document: EP

Effective date: 20251113

ENP Entry into the national phase

Ref document number: 2024720557

Country of ref document: EP

Effective date: 20251113

ENP Entry into the national phase

Ref document number: 2024720557

Country of ref document: EP

Effective date: 20251113

ENP Entry into the national phase

Ref document number: 2024720557

Country of ref document: EP

Effective date: 20251113

ENP Entry into the national phase

Ref document number: 2024720557

Country of ref document: EP

Effective date: 20251113