A power base for receiving removable appliance portion thereon

Abstract

A power base (4) for receiving a removable appliance portion thereon. The power base (4) comprises an upper portion (8) configured to receive a removable appliance portion thereon in use and a lower portion (10) separate from the upper portion (8). The power base (4) comprises a weight sensor (34) arranged between an upper portion (8) and a lower portion (10). The power supply base (4) further comprises a power supply cable (12) configured to supply power to the power supply base (4) and a cable fixing device (28) configured to fix the power supply cable (12) to the lower portion (10).

Description

Technical Field

[0001] The present disclosure relates to a power base and an electrical appliance including the power base. Background Art

[0002] Some prior art countertop water heating appliances include a device for measuring the weight of the water contained in the appliance. The measured weight can be used to provide an indication to the user about how much water is in the appliance. This can allow the user to determine, for example, whether the appliance needs to be refilled before operation. Some water heating appliances are in the form of cordless liquid heating appliances, which include a removable appliance part, such as a liquid heating container, which is removably seated on a power base. In such an example, the power base may include a weight sensor capable of measuring the weight of the removable appliance part when the removable appliance part is seated thereon. By knowing the weight of the removable appliance part without any contents therein, the weight of the contents can be determined.

[0003] The applicant has recognized that in some prior art examples, the weight sensor may not always accurately measure the weight of the removable appliance part, and therefore may provide an inaccurate indication of the contents of the removable appliance part. Specifically, the applicant has recognized that in the prior art appliances, various forces may play a role in distorting the measured weight. For example, cordless appliances are generally included in a cordless electrical connector in a power base and a corresponding cordless electrical adapter in the removable appliance part. Such connectors and adapters generally include elastic biased electrical contacts, which apply force to the other of the connector and the adapter when the connector and the adapter are mated together. Such force may affect the weight measured by the weight sensor, depending on the positioning of the removable appliance part relative to the power base. In a similar manner, the power supply cable generally extending from the power base may be relatively inflexible, and therefore, when arranged in at least some positions, it may apply a vertical force to the power base, which may distort the measured value obtained from the weight sensor arranged in the power base. Summary of the invention

[0004] The present disclosure aims to solve or at least alleviate at least one of the above problems. When viewed from a first aspect, the present disclosure provides a power base for receiving a removable appliance part thereon, the power base comprising:

[0005] an upper portion configured to receive a removable appliance portion thereon in use;

[0006] a lower portion, which is separated from the upper portion and arranged below the upper portion;

[0007] a weight sensor disposed between the upper portion and the lower portion;

[0008] a power supply cable configured to supply power to the power base; and

[0009] A cable fixture is configured to secure a power supply cable to the lower portion.

[0010] The applicant has appreciated that the particular structure of the power base according to the first aspect of the present disclosure can facilitate a more accurate measurement of the weight of a removable appliance part received on the power base in use. Thus, the power base is able to more accurately determine the weight of the contents of the removable appliance part.

[0011] Specifically, the cable fixing device that acts to fix the power supply cable to the lower part can advantageously prevent any force from the power supply cable from being transmitted to the weight sensor, which would otherwise affect the weight measured by the weight sensor. When the removable appliance part is seated on the upper part, the weight of the removable appliance part is transmitted through the upper part to the weight sensor arranged between the upper part and the lower part. Since the power supply cable is fixed to the lower part, any force applied by the power supply cable will be applied to the lower part and may not affect the output of the weight sensor because the weight sensor is arranged between the lower part and the upper part. Fixing the power supply cable in this way isolates it from any force applied to the power base.

[0012] Because the power base is configured to receive the removable appliance part during use, the removable appliance part can be considered to be a physically separate component from the power base, which can be placed on the power base during use. The power base can be a power base for providing power to any suitable removable appliance part. The power base can be configured to provide inductive power to the removable appliance part. In this way, the power base can include an induction heater, such as an induction heater in the form of an induction coil. In such an embodiment, the removable appliance part can include a susceptor configured to generate heat when subjected to a magnetic field generated by the induction heater.

[0013] However, in one group of embodiments, the power base includes a cordless electrical connector for providing an electrical connection to the removable appliance part when the removable appliance part is seated on the power base, wherein the cordless electrical connector extends from the upper part and is positioned to cooperate with the corresponding cordless electrical adapter on the removable appliance part when the removable appliance part is received on the upper part. As described above, the cordless electrical connector, and in fact the corresponding adapter in the removable appliance part, can include at least one elastic biasing component acting between the connector and the adapter. The elastic biasing component can, for example, be an elastic biasing electrical contact. When the removable appliance part is seated on the power base, at least one elastic biasing component can generate a force acting between the connector and the adapter. The arrangement of the weight sensor between the upper part and the lower part, combined with the cordless connector extending from the upper part, advantageously means that the force generated between the connector and the adapter when the appliance part is seated on the upper part will not affect the weight measured by the weight sensor. Therefore, the power base can more accurately measure the weight of the removable appliance part.

[0014] In embodiments where the cordless electrical connector is configured to mate with a corresponding cordless electrical adapter on an appliance part, the power base may be considered a cordless power base as it provides an electrical connection to the appliance part in a cordless manner.

[0015] Since the removable appliance part is received on the power base, ie sits or stands on the power base, during use, the power base may be considered a power base stand.

[0016] The power base can be configured to receive any suitable removable appliance part. In some embodiments, the removable appliance part is a liquid heating container. The liquid heating container may include a chamber for receiving a liquid (e.g., water). Therefore, a measurement of the weight of the removable appliance part may indicate the weight of the liquid contained in the chamber. In such an embodiment, the liquid heating container may include a heating element configured to heat the contents of the liquid heating container, such as the contents of the chamber.

[0017] The cable fixture for securing the power supply cable to the lower portion may take any suitable form. In one set of embodiments, the cable fixture is integrally formed with the lower portion. For example, the cable fixture may include at least one cable securing feature integrally molded with the lower portion. The cable securing feature may, for example, include a latch that may be used to retain the power supply cable against the lower portion. Providing an integrally formed cable fixture may reduce the total number of components required to manufacture the power base and may simplify assembly of the power base.

[0018] However, it is not necessary for the cable fixture to be integrally formed with the lower part. Therefore, in one set of alternative embodiments, the cable fixture comprises a clamping element configured to be attached to the lower part so as to fix the power supply cable to the lower part. The clamping element may be attached to the lower part in any suitable manner. For example, the clamping element may be attached to the lower part using at least one (e.g. two) screws. In one set of embodiments, the clamping element and / or the lower part may include at least one retaining feature configured to attach the clamping element to the lower part. For example, the clamping element may include a latching feature configured to engage the lower part in a manner that holds the clamping element against the lower part. The use of such a retaining feature may reduce the number of components required to manufacture the power base and may also reduce the time required to assemble the power base. In addition, by using a separate clamping element, the molding of the lower part may be less complicated compared to an integrally formed cable fixture, which may therefore reduce the cost of the lower part and may reduce the cost of the power base.

[0019] In some embodiments, the cable fixture may be shaped to appropriately secure the power supply cable against the lower portion. For example, the clamping element may be shaped to receive the power supply cable therein. For example, the clamping element may include a curved portion shaped to extend at least partially around the power supply cable. Such a curved portion may increase the amount of contact between the clamping element and the power supply cable, which may hold the power supply cable in a more stable manner. In one set of embodiments, the lower portion includes a cable receiving portion, which is integrally formed in the lower portion and is shaped to receive the power supply cable. The cable receiving portion may have a shape corresponding to the shape of the power supply cable. For example, if the power supply cable has a substantially circular (e.g., circular) cross-section, the cable receiving portion may be circular, or at least have a curved portion that follows a circular profile. The cable receiving portion may include an opening in a wall of the lower portion into which the power supply cable may be inserted. The size of the cable receiving portion may be set to be substantially the same as the power supply cable, such as the same size. Providing the cable receiving portion may minimize the amount by which the power supply cable can move relative to the lower portion, thereby preventing force from being transferred from the power supply cable to other parts of the power base.

[0020] The cable fixture may secure the power supply cable in any suitable manner.In one set of embodiments the cable fixture is configured to retain the power supply cable against the lower portion.

[0021] The cable fixture is configured to secure the power supply cable to the lower portion of the power base. In one set of embodiments, the cable fixture is configured to secure the power supply cable to the lower portion in such a way that at least the portion of the power supply cable secured to the lower portion cannot move relative to the lower portion. This arrangement may help ensure that any forces applied by the power supply cable (e.g. due to bending of the power supply cable) are applied substantially (e.g. only) to the lower portion and not to any other part of the power base.

[0022] The lower part to which the power supply cable is fixed is arranged below the upper part. The lower part can be arranged to be placed on a work surface in use. The lower part can be arranged to be placed directly on the work surface. The work surface can, for example, include a work surface. In other embodiments, the lower part can be an intermediate part arranged between the upper part and another lower part arranged below the lower part. In any case, by fixing the power supply cable to the lower part separated from the upper part, the force applied by the power supply cable can be prevented from being transferred to the upper part.

[0023] The lower portion may include a single molded body. However, in some embodiments, the lower portion includes a first sub-portion arranged to be placed on a work surface and a second sub-portion attached to the first sub-portion. The first sub-portion may be shaped to receive the upper portion and allow the upper portion to move relative to the first sub-portion. The second sub-portion may function to enclose the bottom of the lower portion and may therefore be considered a lower cover. Providing the first sub-portion and the second sub-portion may facilitate assembly of the power base.

[0024] The cordless electric connector can be formed integrally with the upper part. However, in one group of embodiments, the cordless electric connector is mounted to the upper part. The cordless electric connector can be arranged so that there is a minimum gap, for example 8mm, between the surface below the cordless electric connector and the bottom side facing the cordless electric connector (for example the surface of the lower part). This minimum gap can prevent an electrical short circuit from occurring in the cordless electric connector when water enters the space between the upper part and the lower part. Therefore, this can improve the safety of the power base. The minimum gap required may depend on the type of connector used in the power base and the power base design. In other embodiments, the minimum gap can be, for example, 6mm or 10mm.

[0025] The weight sensor may have any suitable form. In one set of embodiments, the weight sensor includes a plurality of sub-sensors spatially distributed between the upper portion and the lower portion. The plurality of sub-sensors may be spatially distributed around an axis extending through the upper portion and the lower portion. In an embodiment comprising a cordless electrical connector, the axis may extend through the center of the cordless electrical connector. The plurality of sub-sensors may, for example, include at least three sub-sensors, for example at least four sub-sensors.

[0026] The plurality of sub-sensors may be spatially distributed in any suitable manner. In one set of embodiments, the plurality of sub-sensors are spatially evenly distributed between the upper portion and the lower portion. For example, the plurality of sub-sensors may be distributed equiangularly around an axis extending through the lower portion and the upper portion. The axis may be a central axis, such as an axis extending through the cordless electrical connector (where the cordless electrical connector is included). Distributing the sub-sensors evenly in this manner may mean that in embodiments where the power base is configured to receive the appliance portion regardless of angular orientation, the weight of the removable appliance portion may still be accurately measured. Such an arrangement may also advantageously allow for embodiments where the center of mass of the appliance portion is not aligned with an axis extending through the center of the cordless electrical adapter of the removable appliance portion.

[0027] In one set of alternative embodiments, the weight sensor comprises a single weight sensor arranged between the upper portion and the lower portion. The single weight sensor may be, for example, centrally arranged between the upper portion and the lower portion. For example, the single weight sensor may be arranged below and aligned with the cordless electrical connector (if included). The overall cost of the power base may be reduced by providing a single weight sensor. Using a single weight sensor may reduce the measurement accuracy of the weight of the appliance portion, however, this arrangement is still useful in embodiments where approximately cups of water are needed rather than exact volumes.

[0028] The weight sensor may take any suitable form capable of measuring the weight of the removable appliance portion. In one set of embodiments, the weight sensor comprises at least one strain gauge. In embodiments where the weight sensor comprises a plurality of sub-sensors, each sub-sensor may comprise a strain gauge. The output of the strain gauge may indicate the weight of the appliance portion when seated on the power base during use. In other embodiments, any other suitable device may be used to measure weight. For example, a force sensitive resistor may be used. Applicants also recognize that the weight sensor need not be electrical / electronic. Therefore, in some embodiments, the weight sensor may be non-electrical and may, for example, comprise a mechanical scale. Such a mechanical scale may comprise an elastic element (e.g., a spring) in combination with a weight indicator (e.g., a dial).

[0029] The weight sensor can be arranged at any suitable position between the upper part and the lower part. In one set of embodiments, the weight sensor is arranged between the upper part and the lower part in such a way that all downward vertical forces applied to the upper part are applied by the weight sensor. The upper part and the lower part can have any suitable form / arrangement relative to each other so that the vertical force is applied in this way. When it is arranged to apply all downward vertical forces by the weight sensor, the upper part can be regarded as floating on / resting on the weight sensor. In other words, the upper part can be seated on the weight sensor so that all downward vertical forces are applied by the weight sensor. The upper part can be directly seated on the weight sensor. However, in some embodiments, at least one intermediate member can be arranged between the upper part and the weight sensor. In other embodiments, only a portion of the weight of the removable appliance part is transferred to the weight sensor. The power base can be configured to take this into account when providing an indication of the weight of the removable appliance part, such as using a suitable control circuit.

[0030] In some embodiments, the upper part and the lower part can be elastically biased toward each other, or elastically biased away from each other. In some embodiments, at least one elastic biasing member (e.g., a spring) can be arranged between the upper part and the lower part. At least one elastic biasing member can be arranged to push the upper part in a direction away from the lower part, or pull the upper part in a direction toward the lower part. In this way, at least one elastic biasing member can prevent the upper part from moving freely relative to the lower part (at least when there is no removable appliance part sitting on the power base), which can help prevent rattling in the power base. Since the force from at least one elastic biasing member acts between the upper part and the lower part, this may not be affected by the force applied by the power supply cable, and therefore may not affect the accuracy of the measurement performed by the weight sensor. In embodiments in which at least one elastic biasing member is arranged to push the upper part in a direction away from the lower part, the spring force provided by the at least one elastic member can be set to be lower than the weight of the upper part plus the minimum weight of the appliance. In this way, when the appliance part is seated on the upper part, it will overcome the spring force provided by the at least one elastic biasing member and apply the force to the weight sensor. The at least one elastic biasing member can be formed integrally with at least one of the upper part and the lower part. In other embodiments, the at least one elastic biasing member can be a component separated from the upper part and the lower part. In some embodiments, the at least one elastic biasing member includes a plurality of elastic biasing members. The at least one elastic biasing member can be in the form of a leaf spring or a coil spring, for example. The weight sensor or the control circuit connected thereto can be configured to take into account the spring force applied by the at least one elastic member when measuring the weight of the removable appliance part.

[0031] In one set of embodiments, the upper part and the lower part together include a retaining device, which is configured so that in at least one angular position of the upper part relative to the lower part, the upper part can move vertically relative to the lower part, and is also prevented from separating from the lower part when moving only in the vertical direction. For example, the retaining device may include a bayonet fitting, which includes at least one protruding pin and at least one corresponding slot, such as an L-shaped slot, which is arranged to receive the protruding pin. The size of the L-shaped slot and the pin can be designed to facilitate a small range of vertical movement between the upper part and the lower part during use of the power base. This can allow the upper part to move vertically, thereby applying force to the weight sensor during use. The amount of vertical movement can be, for example, 1.5mm-2.5mm, such as 2mm. The vertical movement of the upper part can help avoid interference between the parts of the power base.

[0032] In one set of embodiments, the upper portion and the lower portion together define a housing of the power base. The upper portion can, for example, define a top portion of the housing, and the lower portion can define a side (e.g., periphery) and a bottom portion of the housing. In any embodiments herein, the upper portion and the lower portion can be molded (e.g., injection molded) plastic bodies. In some embodiments in which the upper portion and the lower portion together define the housing, a power supply cable extends from the housing. For example, the power supply cable can extend through a side wall of the housing. The side wall can, for example, be defined by a lower portion of the power base. Of course, in other embodiments, the power supply cable can enter the power base (e.g., the housing of the power base) at the bottom side of the power base.

[0033] The lower portion may be configured to rest directly on a work surface. In one set of embodiments, the lower portion includes a plurality of feet arranged to rest on the work surface. The plurality of feet may be integrally formed with or attached to the lower portion. The plurality of feet may include a contact portion having a high coefficient of friction to prevent the lower portion from sliding on the work surface. For example, the plurality of feet may include a rubber portion arranged to contact the work surface.

[0034] The presence of a weight sensor in the power base may indicate to the user the volume of liquid within the removable appliance portion. In one set of embodiments, the power base further comprises an indicator device configured to provide an indication relating to the weight measured by the weight sensor. The indicator device may, for example, comprise an electronic display, such as a liquid crystal display (LCD) or a light emitting diode (LED) display. The electronic display may, for example, provide an indication of the volume of liquid within the appliance portion. The volume may be indicated as a number of cups of a predetermined volume, or an actual measurement of the volume, such as in milliliters, liters, fluid ounces, etc. The volume may be determined based on the weight measured by the weight sensor.

[0035] The power base may include control circuitry, for example in the form of an electronic controller. The electronic controller may be connected to a weight sensor and an indicator device (where included). The electronic controller may be configured to determine the weight of the contents (e.g., liquid) of the removable appliance portion and may convert the weight to a volume. This conversion may be based on an expected density of the material contained within the removable appliance portion.

[0036] Determination of the weight of the contents of the removable appliance part may be achieved by appropriate calibration of the electronic controller, which may involve measuring the weight of the removable appliance part when its contents are empty (e.g., without water). This calibration may be performed in the factory using a single removable appliance part, and the empty weight of the removable appliance part may then be used in the electronic control circuitry for multiple power bases. Additionally, or alternatively, the calibration may be performed by the user of the power base.

[0037] To determine the weight of the contents of the removable appliance part, the power base, such as the electronic control circuit therein, can be configured to subtract the weight of the empty removable appliance part from the measured weight when the removable appliance part is received on the power base. The difference is the weight of the contents (e.g., liquid) within the removable appliance part.

[0038] The provision of a weight sensor may also allow a more complex indication to be provided. This may be particularly relevant when the removable appliance part is in the form of a liquid heating vessel. In one set of embodiments the power base is for receiving a removable appliance part in the form of a liquid heating vessel, and wherein the power base further comprises control circuitry configured to:

[0039] determining a first amount of liquid within the removable appliance portion using a weight sensor while the removable appliance portion is positioned on the power base;

[0040] detecting when a removable appliance part has been removed from a power base and subsequently placed back on the power base; and

[0041] After detecting, a second amount of liquid within the removable appliance portion is determined using the weight sensor.

[0042] Determining the amount of liquid within the removable appliance part at different points in time while the removable appliance part is seated on the power base may allow analysis of how a user operates the appliance including the power base.

[0043] In another set of embodiments, the control circuit is further configured to determine whether the difference between the first amount of liquid and the second amount of liquid is less than a threshold value. When the difference is less than the threshold value, this may indicate that the user has only dispensed a small volume of liquid from the removable appliance portion. The dispensing of a small amount of liquid may be considered an uneconomical use of the appliance. In another set of embodiments, the control circuit is configured to send a signal for triggering a user alarm device in response to determining that the difference is less than the threshold value, the user alarm device being configured to alert the user that overfilling has occurred.

[0044] Thus, the power base is able to provide feedback to the user about how effectively they are using the appliance of which the power base forms a part. The indicator means (where provided) may be a user alert means. In some embodiments, the user alert means is separate from the indicator means.

[0045] In another set of embodiments the power base is a removable appliance part for receiving a liquid heating vessel and wherein the power base further comprises a control circuit configured to:

[0046] determining that the removable appliance portion has been operated while seated on the power base;

[0047] detecting when a removable appliance portion has been removed from a power base and subsequently placed back on the power base;

[0048] After the detection, determining the amount of liquid remaining in the removable appliance portion using a weight sensor; comparing the amount of liquid remaining to a first threshold; and

[0049] If the remaining amount of liquid is greater than a first threshold, a signal is sent to trigger a user alarm device, and the user alarm device is configured to warn the user that overfilling has occurred.

[0050] The determination that the removable appliance part has been operated can be the determination that the removable appliance part has been operated to heat the liquid content therein. The detection of this can be determined by detecting the power transmission through the cordless electrical connector, which can indicate that the removable appliance part has been operated. Of course, any other device for detecting the operation of the removable appliance part can be used. The first threshold value can correspond to 200ml, for example. Of course, the exact threshold value amount can depend on the volume of the removable appliance part, and therefore can be greater than or less than 200ml. In other embodiments, the threshold value can be based on the percentage change of the liquid in the removable appliance part. In the most economical case, after operating the removable appliance part and removing it from the power base, its entire contents will be used, and therefore when the removable appliance part is subsequently placed back on the power base, the amount of liquid in the removable appliance part can be zero. However, in reality, since it is usually difficult to fill the removable appliance part with the exact amount of liquid required, it can be expected that even when the user fills the removable appliance part in an economical manner, a small amount of liquid may still exist in the removable appliance part. Thus, when only a small amount of liquid remains in the removable appliance portion, the first threshold is non-zero but still relatively small, which can prevent repeated indications of overfilling. Nevertheless, the above embodiments can provide an indication to the user when the user overfills the removable appliance portion with more water than they actually need during use.

[0051] Although described above in the context of liquids, the power base can be used with a removable appliance portion containing materials other than liquids (e.g., food). Therefore, the above embodiments can also be used to determine the weight of food materials within the removable appliance portion rather than the weight of liquid.

[0052] In one set of embodiments, the control circuit is configured to use a weight sensor to determine when a removable appliance part has been removed from the power base and placed back on the power base. Using a weight sensor as a means of detecting when a removable appliance part has been removed from the power base can reduce the number of components required to perform the above steps.

[0053] In some embodiments, the power base includes a control circuit configured to control the operation of the power base. The control circuit can perform the above functions. In another set of embodiments, the control circuit is configured to:

[0054] using a weight sensor to determine the weight of the contents of the removable appliance portion;

[0055] comparing the weight to a maximum fill threshold; and

[0056] If the weight is greater than the maximum filling threshold, a signal is sent for triggering a user alarm device arranged to alert the user that overfilling has occurred.

[0057] In this case, the power base may be able to provide an indication that too much material (e.g., water) has been inserted into the removable appliance part. This may prevent the user from operating the removable appliance part in a manner that may cause damage to the removable appliance part and / or create a safety hazard.

[0058] In another set of embodiments, the control circuit is configured as:

[0059] using a weight sensor to determine the weight of the contents of the removable appliance portion;

[0060] comparing the weight to a minimum fill threshold; and

[0061] If the weight is less than a minimum fill threshold, a signal is sent for triggering a user alarm device arranged to alert a user that underfill has occurred.

[0062] In this case, the power base may be able to provide an indication that too little material (e.g., water) has been added to the removable appliance part. This may prevent the user from operating the removable appliance part in a manner that may cause damage to the removable appliance part and / or create a safety hazard.

[0063] The power base can have any suitable form. In some embodiments, the power base can be suitable for receiving an appliance part in a single orientation. However, in one set of embodiments, the power base is configured to receive a removable appliance part substantially independently of the angular orientation of the removable appliance part relative to the power base (e.g., independently of the angular orientation of the removable appliance part). In such an embodiment, the appliance part can have a generally circular cross-section. Therefore, the upper portion of the power base can have a generally circular (e.g., circular) cross-section. Such an upper portion can define an upper circular receiving portion on which the appliance part can be seated. The lower portion can have any shape capable of receiving the upper portion. In a further embodiment, wherein the power base includes a cordless electrical connector, the cordless connector can include a 360-degree cordless connector, which is arranged to mate with a corresponding adapter at any angular orientation.

[0064] The cordless power cable can be directly connected to the cordless electrical connector (when included). For example, the power cable can include a live core, a neutral core and a ground core (when provided), which can be connected to corresponding live terminals, neutral terminals and ground terminals on the cordless electrical connector. In other embodiments, the cordless power cable can be indirectly connected to the cordless electrical connector via at least one electrical component in the power base. A weight sensor can be connected to the electrical component. The electrical component can include a control circuit, such as an electronic controller.

[0065] The present disclosure is not limited to providing only a power base. Therefore, when viewed from a second aspect, the present disclosure provides an electrical appliance, comprising:

[0066] A power base according to any of the above embodiments; and

[0067] A removable appliance portion is configured to sit on the power base.

[0068] The removable appliance portion may include any suitable appliance portion in which it is desired to measure the weight of its contents. For example, the removable appliance portion may include a food mixer or blender in which it is desired to know the amount of food / liquid in the mixer or blender. The electrical appliance may be a household electrical appliance. The electrical appliance may be a countertop electrical appliance. In one set of embodiments, the removable appliance portion is a liquid heating container. In such embodiments, the electrical appliance may be a cordless electric kettle suitable for heating water. In other embodiments, the liquid heating container may be a milk frother configured to heat milk and froth the milk. The removable appliance portion may be seated on a power base and removed from the power base by the user of the appliance (e.g., for filling the removable appliance portion with water). Therefore, the power base and the removable appliance portion are physically separate components.

[0069] As described above with respect to the power base, an indication device may be arranged on the power base to provide an indication related to the weight measured by the weight sensor. In some embodiments, the removable appliance portion includes an indication device configured to provide an indication related to the weight measured by the weight sensor. In such an embodiment, there may be a data connection between the power base and the removable appliance portion, which facilitates data transmission between them. The data connection may facilitate the transmission of data including the weight measured by the weight sensor from the power base to the removable appliance portion for indication on the indication device.

[0070] As previously described, the power base may include a weight sensor that includes a plurality of sub-sensors that are appropriately spaced apart to accurately indicate the weight of the removable appliance portion when the center of mass of the removable appliance portion is not necessarily aligned with the centerline of the removable appliance portion. In other embodiments, the removable appliance portion is constructed so that its center of mass is substantially aligned with the centerline extending through the removable appliance portion, and wherein the weight sensor in the power base includes a single weight sensor.

[0071] In such an embodiment, since the center of gravity is substantially aligned with the center line extending through the utensil, the angular position of the removable utensil part relative to the power base has less influence on the weight measurement, and therefore only a single weight sensor can be used, rather than a weight sensor including multiple sub-sensors. The removable utensil part can be constructed in any suitable manner so that its center of gravity is substantially aligned with its center line. For example, the components in the removable utensil part can be properly arranged, thereby displacing the center of gravity accordingly. For example, in an embodiment in which the removable utensil part is in the form of a liquid heating appliance, the removable utensil part can include a heating element (such as a resistive heating element) and a heat diffusion plate. The heating element can be shaped so that there is a gap at one end thereof. The heating element can be arranged in the removable utensil part so that the gap is located on one side of the removable utensil part, which is otherwise heavier than the relative side of the removable utensil part. For example, the gap can be arranged on one side of the removable utensil part including a handle, otherwise the handle moves the center of gravity away from the center of the removable utensil part. The gap may be arranged between the cold tails of the heating element, ie between the terminals of the heating element.

[0072] Similarly, the heat diffuser plate may include a cutout, and this may also be arranged so that the cutout is on a side of the removable appliance portion that is otherwise heavier than the opposite side. This is just one example of how the removable appliance portion can be constructed so that its center of gravity is substantially aligned with the centerline. In some embodiments, the center of mass is completely aligned with the centerline.

[0073] The centre line of the removable appliance part may extend through the centre of a cordless electrical adapter arranged on the base of the removable appliance part.

[0074] In an embodiment of the second aspect of the present disclosure, the removable appliance portion may include a cordless electrical adapter configured to cooperate with a cordless electrical connector on a power base (if provided). In other embodiments, the removable appliance portion may be configured to sit on the power base, but no electrical connection may be formed between them. Instead, the power base may include an induction heater, and the removable appliance portion may include a susceptor configured to heat the contents of the removable appliance portion.

[0075] According to a third aspect of the present disclosure, there is provided a power base for receiving a removable appliance part thereon, the power base comprising:

[0076] an upper portion configured to receive a removable appliance portion thereon in use;

[0077] a lower portion separate from the upper portion, arranged below the upper portion, and arranged to be placed on a work surface in use;

[0078] a weight sensor disposed between the upper portion and the lower portion;

[0079] a power supply cable configured to supply power to the power base; and

[0080] A cable fixture is configured to secure a power supply cable to the lower portion.

[0081] The features of any embodiments of the first and second aspects of the present disclosure may be equally applied to the third aspect of the present disclosure.

[0082] In any of the above embodiments, where a liquid is described, the liquid may include water, milk, or any other liquid that may be heated or processed in any other suitable manner by the removable appliance portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] Some preferred embodiments of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0084] Figure 1 A perspective view of a cordless electrical appliance according to an embodiment of the present disclosure is shown, including a power base according to an embodiment of the present disclosure;

[0085] Figure 2 Shows Figure 1 A perspective view of the power base standalone shown in FIG.

[0086] Figure 3 An exploded view of the power base shown in the previous figure is shown;

[0087] Figure 4 showing a view of the underside of the power base shown in the previous figures;

[0088] Figure 5 Shows Figure 1 A cross-sectional view of the cordless electrical appliance shown in ;

[0089] Figure 6 A cross-sectional view of a cordless electrical appliance according to another embodiment of the present disclosure is shown, including a power base according to another embodiment of the present disclosure;

[0090] Figure 7 Shows the included Figure 6 a view of the underside of a heat diffuser plate and heating element in a removable appliance portion of the appliance shown in;

[0091] Figure 8 Shows Figure 6 A view of the underside of the power base shown in FIG.

[0092] Fig. 9 Shows Figure 6A perspective view of a power base shown in , with the upper portion separated from the power base;

[0093] Fig.10 showing a perspective view of a lower portion of a power base including an integrated cable fixture;

[0094] Fig.11 shows the steps that may be performed by the control circuit in the power base;

[0095] Fig.12 An embodiment of a power base including a user alert device is shown;

[0096] Fig.13 shows a perspective view of a cordless electrical appliance according to another embodiment of the present disclosure, wherein the removable appliance portion includes an indicator device;

[0097] Fig.14 shows a cross-sectional view of a cordless electrical appliance including an induction heater and a susceptor according to an embodiment of the present disclosure; and

[0098] Fig.15 An exploded view of another embodiment of a power base is shown, the power base including a resilient biasing member acting between upper and lower portions thereof. DETAILED DESCRIPTION

[0099] Figure 1 A perspective view of a cordless electrical appliance 2 according to an embodiment of the present disclosure is shown. In the depicted embodiment, the cordless electrical appliance 2 comprises a power base 4 according to an embodiment of the present disclosure and a removable appliance part 6. In the depicted embodiment, the removable appliance part 6 is in the form of a liquid heating container, however any other suitable removable appliance part may be used.

[0100] Figure 2 Shown separately Figure 1 . As shown in the figure, the power base 4 includes an upper part 8 and a lower part 10, which together define the main housing of the power base 4. The power supply cable 12 extends into the main housing defined by the upper part 8 and the lower part 10. The cordless power connector 14 extends upward from the upper part 8 so as to be connected to the power supply cable 12. Figure 1The power base 4 includes an indicator device 16, such as a LCD or LED display. The indicator device 16 can be used to provide an indication of the weight measured by the weight sensor provided in the power base 4. The weight can be expressed as the volume of the liquid contained in the removable appliance part 6. The indicator device 16 can also be used to indicate the operating mode or state of the removable appliance part 6 when it is seated on the power base 4.

[0101] Figure 3 Shown is an exploded view of the power base 4 discussed above and shown in the previous figure. The upper part 8 of the power base 4 has a circular cross section so that the removable appliance part 6 is properly received, and the bottom of the removable appliance part also has at least a corresponding circular cross section. The upper part 8 includes a hole 18 for receiving the cordless electrical connector 14 at its center. The upper part 8 includes a circumferentially extending skirt 20 extending around its periphery. The skirt 20 includes at least one L-shaped groove 22 therein. The size of the L-shaped groove 22 is set to receive a pin (not visible in this figure) protruding radially inward on the lower part 10. The engagement between the pin and the L-shaped groove 22 prevents the upper part 8 from separating from the lower part 10 during the normal use of the power base 4. The L-shaped groove 22 also allows the upper part 8 to move vertically relative to the lower part 10. The L-shaped groove 22 and the pin (not shown) form a retaining device. The cordless electrical connector 14 is fixed to the upper part 8 using a bracket 24.

[0102] The lower portion 10 includes a first sub-portion 10A and a second sub-portion 10B. The second sub-portion 10B serves to enclose the bottom side of the power base 4 and can therefore be considered a lower cover. The first sub-portion 10A and the second sub-portion 10B can be attached together by any suitable means, such as by friction fittings. Figure 3 As can be seen in the figure, the first sub-section 10A includes a cable receiving portion 26 formed integrally therewith. The cable receiving portion 26 is shaped and sized to receive the power supply cable 12. A cable fixing device 28 in the form of a clamping element is also included. In the depicted embodiment, the cable fixing device 28 is configured to be attached to the first sub-section 10A, thereby fixing the power supply cable 12 in place using two screws.

[0103] The first subsection 10A includes a plurality of feet 30. The second subsection 10B includes a plurality of openings 32 shaped to receive the feet 30 so that the feet 30 extend therethrough. Thus, when assembled, the feet 30 are positioned to rest on a work surface, such as a countertop.

[0104] In the described embodiment, the power supply cable 12 includes three cores, a live core 12A, a neutral core 12B and a ground core 12C. Each of the cores 12A, 12B, 12C can be directly connected to a corresponding terminal on the cordless electrical connector 14. In other embodiments, although not shown, the power supply cable 12 can be connected to an intermediate electrical component, such as an electronic controller.

[0105] In the depicted embodiment, the power base 4 includes a weight sensor 34, which includes four sub-sensors 34A, 34B, 34C, 34D. Although four sub-sensors are shown, it should be understood that any suitable number of sub-sensors may be used. The first sub-portion 10A of the lower portion 10 includes a sensor receiving portion 36, on which the four sub-sensors 34A-34D are seated. In the illustrated embodiment, the feet 30 are positioned directly below the sensor receiving portion 36. This can help ensure that the lower portion 10, particularly the first sub-portion 10A, has sufficient rigidity when the removable appliance portion 6 is seated thereon. This can help ensure that the sub-sensors 34A-34D provide accurate weight measurements.

[0106] The first sub-portion 10A may also include an opening 38 in which the indicator device 16 may be mounted. The indicator device 16 may be configured to output a measurement of the volume of the contents of the removable appliance portion 6 when the removable appliance portion 6 is seated on the power base 4. The volume may be determined directly from the weight measured by the weight sensor 34. Appropriate electronic control circuitry (not shown) may be provided to determine the weight, and thereby the volume of the contents of the removable appliance portion, and provide an appropriate output on the indicator device 16.

[0107] Figure 4 1 shows a view of the underside of the assembled power base 4 with the second subsection 10B removed. This view more clearly shows each of the four legs 30 of the first subsection 10A. The outer wall 40 of the first subsection 10A includes a cutout 42 through which the power supply cable 12 extends. Figure 4 As shown, when assembled, the power supply cable 12 is received in the cable receiving portion 26 and fixed in place using the cable fixing device 28. As shown in this figure, the power supply cable 12, such as the live core 12A, the neutral core 12B and the ground core 12C, can be directly connected to the cordless electrical connector 14.

[0108] As will be appreciated by those skilled in the art, by securing the power supply cable 12 to the lower portion 10, i.e. the first sub-portion 10A, a force applied by the cable portion 44 outside the power base 4 is not transferred to the cable portion 46 inside the power base. Instead, the force is applied directly to the first sub-portion 10A, i.e. the lower portion. Therefore, the force may have a small effect, or no effect, on any reading of the weight sensor 34. The portion of the power supply cable 12 below the cable fixture 28, within the cable receiving portion 26, may be held therein so that it cannot move relative to the lower portion 10. This arrangement may be used to prevent force from being transferred from the power supply cable 12 to any portion of the power base 4 other than the lower portion 10.

[0109] Figure 5 A side cross-sectional view of a removable appliance portion 6 and a power base 4 is shown. As can be seen in this cross section, the removable appliance portion 6 includes a cordless electrical adapter 48 configured to mate with the cordless electrical connector 14 on the power base 4 when it is seated on the power base 4 during use. In the depicted embodiment, the removable appliance portion 6 is in the form of a liquid heating container that includes a liquid receiving chamber 50 heated by a heating element 52 (e.g., a sheathed electric heating element). The heating element 52 is electrically connected to the cordless electrical adapter 48 so that it is electrically connected to the power base 4 when the removable appliance portion 6 is seated on the power base 4.

[0110] As in Figure 5 As can be seen in the figure, the skirt 20 of the upper part 8 rests on each of the sub-sensors 34A-34D, although only the sub-sensors 34A, 34C are visible in this figure. The upper part 8 is sized so that there is a small gap 54 between the skirt 20 and the first sub-section 10A, i.e. around the skirt 20 and the first sub-section 10A. In this way, the upper part 8 can move vertically freely relative to the first sub-section 10A of the lower part 10.

[0111] As will be appreciated by those skilled in the art, in the embodiment shown in the figure, the upper portion 8 rests completely on the weight sensor 34, specifically on the sub-sensors 34A-34D. Like this, when the removable appliance portion 6 is seated on the upper portion 8, all the weight of the removable appliance portion 6 is transmitted downwardly through the weight sensor 34. In other words, all vertical downward forces are transmitted through the weight sensor 34. Any forces interacting between the cordless electrical connector 14 and the cordless electrical adapter 48 have negligible or no effect on the measured weight.

[0112] The power base 4 may include a control circuit 35, such as Figure 5As shown. The control circuit 35 can be connected to the weight sensor 34 and the indicator device 16. The control circuit 35 can be in the form of a controller including a processor. The control circuit 35 can process the measurement value from the weight sensor 34 and convert the measurement value into the volume of the liquid contained in the removable appliance part 6.

[0113] As will be appreciated by those skilled in the art, the power base 4 of the above-described embodiments may advantageously provide a more accurate measure of the weight of the removable appliance portion 6, and thereby the contents thereof.

[0114] Figure 6 1 shows an embodiment of a cordless appliance 102 according to another embodiment of the present disclosure. A power base 104 according to another embodiment of the present disclosure is also depicted. Unlike the power base 4 in the previous embodiment, which includes a weight sensor 34 and a plurality of sub-sensors 34A-34D, in Figure 6 In the illustrated embodiment, the power base 104 includes a single weight sensor 134. The single weight sensor 134 is still disposed between the upper portion 108 and the lower portion 110 (specifically, the first sub-portion 110A of the lower portion 110).

[0115] The upper portion 108 includes a skirt 120 similar to the above-described embodiments. However, since there is only a single weight sensor 134, the skirt 120 includes a tab 156 that rests on a flange 158 on the first sub-portion 110A. As such, when the removable appliance portion 106 is seated on the power base 104, some of the force transmitted through the upper portion 108 will be transmitted directly to the lower portion 110, particularly the first sub-portion 110A, rather than through the weight sensor 134. However, the control circuit / electronics to which the weight sensor 134 may be connected may be configured to take this into account. For example, the skirt 120 may be constructed and the weight sensor 134 arranged so that, for example, 20% of the force is transmitted through the weight sensor 134. Any measured force may then be scaled up to reflect the actual force, and thereby the weight of the removable appliance portion 106. However, this may not work particularly well when the removable appliance portion 106 has a center of gravity that is not substantially aligned with the centerline of the removable appliance portion 106.

[0116] Thus, in some embodiments, the removable implement portion 106 can be specifically configured to have a center of gravity aligned with its centerline. Figure 6, the center of gravity of a typical removable appliance portion 106 in the form of a liquid heating appliance is usually located away from the center line (indicated by the dotted line 164) and towards the position of the handle 166 of the removable appliance portion 106. The black cross 160 indicates the usual center of gravity of such a removable appliance portion. However, in the depicted embodiment, the removable appliance portion 106 is modified so that the center of gravity is closer to the center line 164. In the depicted embodiment, the center of gravity of the removable appliance portion 106 is indicated by a black cross 162, which is substantially aligned with the center line 164. The movement of the center of gravity 162 of the removable appliance portion 106 is achieved by some modifications in the depicted embodiment.

[0117] First, the control electronics 168 in the removable appliance portion 106 can be moved to a position where they are as far away from the handle 166 as possible within the confines of the removable appliance portion 106. Figure 6 As can be seen in FIG. 1 , the control electronics 168 are located on the far right hand side of the removable appliance portion, away from the handle 166 .

[0118] Second, the heating element 152 and the heat diffuser plate 170 may be configured such that the amount of weight on the side of the centerline 164 proximate to the handle 166 is reduced. Figure 7 The heating element 152 and heat diffuser plate 170 of the removable appliance portion 106 are shown separately. As shown here, the heating element 152 follows a circular shape with a void 174 where the cold end 172 is provided for electrical connection to the heating element 152. In the space adjacent to the void 174, the heat diffuser plate includes a corresponding cutout 176. As a result of this arrangement, the weight of the heating element 152 and heat diffuser plate 170 assembly is Figure 7 is smaller on the left hand side than on the right hand side. Return to reference Figure 6 By arranging the heating element 152 and the heat diffusion plate 170 in such a manner that the gap 174 and the cutout 176 are located on the side of the centerline 164 near the handle 166, Figure 6 The weight of the removable appliance portion on the left hand side of the centerline 164 shown can be reduced. As a result, the center of gravity 162 can be moved closer to the centerline 164. Of course, any other components of the removable appliance portion 106 can be rearranged so as to more closely align the center of gravity 162 with the centerline 164. Having the center of gravity 162 as close as possible to the centerline 164 of the removable appliance portion 106 can allow the power base 104 to include a single weight sensor 134 because the amount of force applied to the weight sensor 134 by the upper portion 108 will be substantially the same regardless of the angular orientation of the removable appliance portion 106 relative to the power base.

[0119] Figure 8 Shows Figure 61. A view of the bottom side of the power base 104 shown in FIG. The power base 104 is the same as the power base 4 of the first embodiment described above, except that a single weight sensor 134 is provided instead of multiple sub-sensors. As such, the power supply cable 112 of this embodiment is secured to the first sub-portion 110A in the same manner using a cable fixture.

[0120] Fig. 9 A view of the power base 104 described above is shown. As can be more clearly seen in this figure, the upper portion 108 includes a plurality of tabs 156, which when assembled rest on a flange 158 of the lower portion 10. A single weight sensor 134 can also be seen. The tabs 156 and the single weight sensor 134 can be equiangularly distributed around the flange 158.

[0121] Fig.10 A view of the bottom side of a lower portion 210 according to another embodiment of the present disclosure is shown. As depicted, in this embodiment, a cable fixture 228 is formed integrally with the lower portion 210, unlike the previous embodiments in which the cable fixture is in the form of a separate clamping element attached to the lower portion. The cable fixture 228 can take any suitable form. In the depicted embodiment, as will be appreciated by those skilled in the art, when the power supply cable is pushed against the cable fixture 228, the cable fixture 228 will initially shift to allow the power supply cable to move into the cable receiving portion 226. Once in the cable receiving portion 226, the cable fixture 228 can press against the power supply cable and hold it therein. Forming the cable fixture 228 integrally with the lower portion can reduce the number of separate components that must be manufactured and assembled.

[0122] Fig.11 A flow chart showing steps that may be performed by a control circuit may be present in any of the embodiments described herein. For ease of reference, reference will be made to Figures 1 to 5 These steps are described with reference to the electrical appliance 2 shown. In step S1, the control electronics determine a first amount of liquid in the removable appliance part 6 using the weight sensor 34. Then, in step S2, the control electronics detect when the removable appliance part 6 has been removed from the power base 4, for example in order to pour heated liquid from the removable appliance part 6, and subsequently placed back on the power base 4. After this detection, in step S3, the second amount of liquid in the removable appliance part 6, i.e. the remaining amount, is determined using the weight sensor 34. Thereafter, in step S4, the difference between the first amount and the second amount can be determined, and the difference can be compared with a threshold value. If the difference is less than the threshold value, i.e. only a small amount has been poured out, a signal can be sent to a user alarm device in step S5 to indicate that overfilling has occurred.

[0123] In step S2 , detection of the removable appliance part 6 being lifted off and placed back onto the power base 4 may be achieved using the weight sensor 34 .

[0124] Fig.12 A perspective view of a power base 302 according to another embodiment is shown. The power base 302 is substantially the same as the first embodiment described above, except that the power base 302 also includes a user alert device 378. The user alert device 378 may include, for example, three lights, such as three light emitting diodes (LEDs). Each of the LEDs may have a different color, such as red, yellow, and green. The user alert device 378 may be in addition to the indicator device 316. The user alert device 378 may be used to provide a user alert device similar to the above-described first embodiment. Fig.11 Outputs associated with the steps shown. For example, if it is determined that overfilling occurs, the red user alarm device 378 can be illuminated. On the contrary, if overfilling is not detected, the green user alarm device 378 can be illuminated.

[0125] Fig.13 A perspective view of an electrical appliance 402 is shown, wherein, in addition to the indicator device 416 disposed on the power base 404, or alternatively, an indicator device 480 can be disposed on the removable appliance portion 406. The indicator device 480 can similarly include an LCD display or an LED display. The indicator device 480 can also provide an indication related to the weight measured by the weight sensor in the power base 404, such as the liquid volume in the removable appliance portion 406. Otherwise, the electrical appliance 402 is the same as the above-described appliance 2.

[0126] Fig.14 A side sectional view through an electrical appliance 502 according to another embodiment of the present disclosure is shown. In this embodiment, a power base 504 includes an induction heater 582, and a removable appliance portion 506 includes a susceptor 584. The susceptor 584 is arranged to heat the contents of a liquid chamber 550. The induction heater 582 may include an inductive coil. In addition to the cordless electrical connector being removed, the power base 504 is otherwise similar to the power base 4 described above in terms of its including a weight sensor and the relative arrangement of the upper and lower portions. When the removable appliance portion 506 is seated on the power base 504 (specifically the upper portion 508 of the power base 504), gravity is transmitted downward to the weight sensor 534. Although not shown in the figure, the power base 504 includes a power supply cable fixed to the lower portion 510 of the power base 504.

[0127] Fig.15An exploded view of a power base 604 according to another embodiment of the present disclosure is shown. The power base 604 is the same as the power base 4 described above, except that the power base 604 shown in this embodiment includes at least one resilient biasing member 635A, such as a plurality of resilient biasing members 635A-635D disposed between the upper portion 608 and the lower portion 610. The at least one resilient biasing member 635A-635D can be used to urge the upper portion 608 away from the lower portion 610. The upper portion 608 can be prevented from completely separating from the lower portion 610 due to the engagement between the L-shaped slot 622 and the pin. The at least one resilient biasing member 635A-635D can function to prevent the upper portion 608 from rattling relative to the lower portion 610. Although the resilient biasing members 635A-635D are depicted as being used to push the upper portion 608 away from the lower portion 610, it is contemplated that, alternatively, the resilient biasing members may be used to pull the upper portion 608 toward the lower portion 610. At least one resilient biasing member 635A-635D may be integrally formed with at least one of the upper portion 608 and the lower portion 610. As depicted, the at least one resilient biasing member 635A-635D may be in the form of a coil spring. However, the at least one resilient biasing member 635A-635D may take any other suitable form. Although four resilient biasing members 635A-635D are shown, any number of resilient biasing members may be used.

[0128] Although the present disclosure has been described in detail in conjunction with only a limited number of embodiments, it should be readily understood that the present disclosure is not limited to the embodiments so disclosed. On the contrary, the present disclosure may be modified to incorporate any number of variations, changes, substitutions, or equivalent arrangements not heretofore described but commensurate with the scope of the present disclosure. In addition, although various embodiments of the present disclosure have been described, it should be understood that aspects of the present disclosure may include only some of the described embodiments. Therefore, the present disclosure should not be considered to be limited by the foregoing description, but only by the scope of the appended claims.

Claims

1. A power base for receiving a removable appliance portion thereon, the power base comprising: an upper portion configured to receive the removable appliance portion thereon in use; a lower portion, the lower portion being separated from the upper portion and arranged below the upper portion; a weight sensor disposed between the upper portion and the lower portion; a power supply cable configured to supply power to the power base; and A cable fixture is configured to secure the power supply cable to the lower portion.

2. The power base according to claim 1 further includes a cordless electrical connector for providing an electrical connection to the removable appliance part when the removable appliance part is seated on the power base, wherein the cordless electrical connector extends from the upper part and is positioned to cooperate with a corresponding cordless electrical adapter on the removable appliance part when the removable appliance part is received on the upper part.

3. A power base according to any preceding claim, wherein: The cable fixture is integrally formed with the lower portion.

4. The power base according to claim 1 or 2, wherein: The cable fixture device comprises a clamping element configured to be attached to the lower part in order to secure the power supply cable to the lower part.

5. A power base according to any preceding claim, wherein: The lower portion includes a cable receiving portion integrally formed therein and shaped to receive the power supply cable.

6. A power base according to any preceding claim, wherein: The cable fixture is configured to retain the power supply cable against the lower portion.

7. A power base according to any preceding claim, wherein: The cable fixing device is configured to fix the power supply cable to the lower portion in such a manner that the power supply cable cannot move relative to the lower portion at least at a portion of the power supply cable fixed to the lower portion.

8. A power base according to any preceding claim, wherein: The weight sensor includes a plurality of sub-sensors spatially distributed between the upper portion and the lower portion.

9. The power base according to claim 8, wherein: The plurality of sub-sensors are spatially uniformly distributed between the upper portion and the lower portion.

10. A power base according to any preceding claim, wherein: The weight sensor includes at least one strain gauge.

11. A power base according to any preceding claim, wherein: The weight sensor is arranged between the upper portion and the lower portion in such a manner that all downward vertical forces applied to the upper portion are applied through the weight sensor.

12. A power base according to any preceding claim, wherein: The upper portion and the lower portion together define a housing of the power base.

13. The power base of claim 12, wherein: The power supply cable extends from the housing.

14. A power base as claimed in any preceding claim, further comprising indicator means configured to provide an indication relating to the weight measured by the weight sensor.

15. A power base according to any preceding claim, wherein: The power base is for receiving a removable appliance part in the form of a liquid heating vessel, and wherein the power base further comprises a control circuit configured to: determining a first amount of liquid within the removable appliance portion using the weight sensor while the removable appliance portion is positioned on the power base; detecting when the removable appliance portion has been removed from the power base and subsequently placed back onto the power base; and After the detecting, a second amount of liquid within the removable appliance portion is determined using the weight sensor.

16. The power base of claim 15, wherein: The control circuit is also configured to determine whether a difference between the first amount of liquid and the second amount of liquid is less than a threshold value.

17. The power base of claim 16, wherein: The control circuit is configured to send a signal for triggering a user alert device in response to determining that the difference is less than the threshold value, the user alert device being arranged to alert a user that overfilling has occurred.

18. A power base according to any preceding claim, wherein: The control circuit is configured to use the weight sensor to determine when the removable appliance portion has been removed from the power base and returned to the power base.

19. A power base according to any preceding claim, wherein: The power base is configured to receive a removable implement portion substantially regardless of an angular orientation of the removable implement portion relative to the power base.

20. An electrical appliance comprising: A power base according to any preceding claim; and A removable appliance portion is configured to sit on the power base.

21. The electric appliance according to claim 20, wherein: The removable appliance part is a liquid heating container.

22. The electrical appliance according to claim 20 or 21, wherein: The removable appliance portion comprises an indication device configured to provide an indication related to the weight measured by the weight sensor.

23. An electrical appliance according to claim 20, 21 or 22, wherein: The removable implement portion is configured such that its center of gravity is substantially aligned with a centerline extending through the removable implement portion, and wherein the weight sensor in the power base comprises a single weight sensor.

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