System with cleaner head and heating arrangement

Abstract

Disclosed is a system comprising a cleaner head. The cleaner head comprises a roller and is configured to apply a fluid to the roller. The system comprises a heating arrangement configured to cause heating of at least one of the roller and fluid applied to the roller. The heating arrangement comprises a first electrically conductive element and an electronic circuit configured to generate an oscillating electric current in the first electrically conductive element to generate at least one of an oscillating magnetic field and an oscillating electric field, such that the at least one of the oscillating magnetic field and the oscillating electric field causes heating of at least one of the roller and fluid applied to the roller.

Description

[0001] SYSTEM WITH CLEANER HEAD AND HEATING ARRANGEMENT

[0002] BACKGROUND

[0003] Appliances for cleaning or treating surfaces may comprise a cleaner head that is in contact with a surface to be cleaned or treated in use. Some appliances utilise liquids, such as water, to clean or treat a surface. Such liquids may be utilised alongside a roller, mop, wipe, or other component for applying a wiping force to the surface.

[0004] SUMMARY

[0005] A first aspect of the present invention provides a system comprising: a cleaner head comprising a roller, wherein the cleaner head is configured to apply a fluid to the roller; and a heating arrangement configured to cause heating of at least one of the roller and fluid applied to the roller, the heating arrangement comprising: a first electrically conductive element; and an electronic circuit configured to generate an oscillating electric current in the first electrically conductive element to generate at least one of an oscillating magnetic field and an oscillating electric field, such that the at least one of the oscillating magnetic field and the oscillating electric field causes heating of at least one of the roller and fluid applied to the roller.

[0006] By causing heating of the at least one of the roller and fluid applied to the roller, the system may cause the roller to dry, such as by causing a rate of evaporation of fluid applied to the roller to increase. Drying the roller may, in turn, limit pathogen growth, such as bacterial, fungal and / or viral growth, on the roller. Alternatively, or in addition, the system may be configured to heat the roller and / or fluid applied to the roller to a sufficient temperature to at last partially sterilise the roller.

[0007] Using the at least one of the oscillating magnetic field and the oscillating electric field to cause heating of at least one of the roller and fluid applied to the roller may allow the roller to be heated absent a direct electrical connection to the roller, such as an electrical connection to a heating element in the roller. In this way, the roller may be provided without a slip ring for passing an electrical current to the roller as it rotates. This may provide a simpler, lighter, cheaper, and / or more reliable roller construction. The cleaner head may also be easier to clean, repair and / or upgrade. For instance, it may be simpler to clean, replace or upgrade the roller if there are fewer direct electrical connections to the roller.

[0008] Moreover, providing the at least one of the oscillating magnetic field and the oscillating electric field to cause heating of at least one of the roller and fluid applied to the roller may be more efficient than other contactless heating arrangements, for example, passing heat to the roller from a heat generating component (e.g., a heater or heat exchanger) located away from the roller.

[0009] Providing the fluid to the roller may improve an ability of the cleaner head, and particularly the roller, to clean a surface. Optionally, the fluid applied to the roller is water, or a water-based solution. Optionally, the fluid applied to the roller is a cleaning fluid, such as a fluid comprising a detergent.

[0010] It will be appreciated that the heating arrangement may be configured to cause heating of the fluid indirectly by causing heating of the roller. Alternatively, the heating arrangement may be configured to cause heating of the roller indirectly by causing heating of the fluid.

[0011] Heating the fluid may cause a rate of evaporation of the fluid to increase, such as after the cleaner head has been used to clean a surface.

[0012] Optionally, the electronic circuit is configured to generate the oscillating electric current in the first electrically conductive element to generate the oscillating electric field, such that the oscillating electric field interacts with fluid applied to the roller to cause dielectric heating of the fluid applied to the roller.

[0013] Causing dielectric heating of the fluid applied to the roller may provide an efficient way of increasing a rate of evaporation of the fluid applied to the roller, such as to dry the roller. Such heating of the fluid may also, or alternatively, provide an efficient way of at least partially sterilising the fluid and / or the roller of certain pathogens.

[0014] Optionally, the heating arrangement comprises a second electrically conductive element spaced from the first electrically conductive element.

[0015] Optionally, the second electrically conductive element is electrically connected to the electronic circuit so that the first and second electrically conductive elements form a pair of electrodes. In this way, the electronic circuit may be configured to generate an oscillating electric current through the pair of electrodes to generate the oscillating electric field between the pair of electrodes. This arrangement may provide a stronger electric field in an area between the first and second electrically conductive elements than when the second electrically conductive element is not a part of the electronic circuit, which may in turn provide more efficient dielectric heating of the dielectric fluid. Optionally, the second electrically conductive element is electrically connected to ground.

[0016] Optionally, the electronic circuit is configured to generate the oscillating electric current in the first electrically conductive element to generate the oscillating magnetic field, such that the oscillating magnetic field interacts with the second electrically conductive element to cause inductive heating of the second electrically conductive element, for instance by causing the generation of correspondingly oscillating eddy currents in the second electrically conductive element.

[0017] Causing inductive heating of the second electrically conductive element may provide a versatile and efficient way to heat the at least one of the roller and fluid applied to the roller, without requiring a direct electrical connection to the second electrically conductive element. This provides an effective way of transferring power from a stationary structure to a rotary structure. For instance, inductively heating the second electrically conductive element may allow the second electrically conductive element to be located in a location in which it might otherwise be difficult to provide power, such as in the roller. This may provide versatility in the location of the second electrically conductive element. Moreover, by employing inductive heating of the second electrically conductive element, the heating arrangement may be able to cause heating of the second electrically conductive element whilst the second electrically conductive element is in motion, thereby improving a versatility of the heating arrangement and / or the cleaner head.

[0018] Optionally, the first electrically conductive element is formed by a coil of electrically conductive material. Optionally, a level of inductance and resistance in the electronic circuit is determined by a geometry of the coil. The coil of electrically conductive material may provide a stronger oscillating magnetic field in a space comprising the coil compared, for example, to a single length of the electrically conductive element extending in one direction across the same space and carrying the same current. This may provide an efficient and effective heating arrangement. The coil may be shaped as a flat coil. A flat coil may be more compact than, for example, a cylindrical coil.

[0019] Optionally, the coil extends across at least 30% of a length of the roller in an axial direction along an axis of rotation of the roller. Optionally, the coil extends across at least 40%, at least 60%, at least 80%, or at least 100% of the length of the roller in the axial direction. Increasing the amount by which the coil extends across the length of the in the axial direction may provide a more uniform distribution of the oscillating magnetic field across the roller, which may in turn provide more uniform generation of eddy currents in the second electrically conductive element and thus heating of the roller, particularly when the second electrically conductive element is located in the roller. Reducing a length of the coil may reduce a power consumption of the coil. This may provide heating of only a part of the second electrically conductive material, or a part of the roller. This may, in turn, lead to a local hot-spot on the roller that may provide improved cleaning compared to a nonheated roller, while reducing power consumption compared to heating a greater surface area of the roller.

[0020] Optionally, the first electrically conductive element comprises two or more coils of electrically conductive material. This may provide versatility in the position and orientation of the coils in the cleaner head, for instance to make better use of space inside the cleaner head. When two or more coils of electrically conductive material are provided, the coils combined may extend across at least 80% of the length of the roller in the axial direction. Optionally, a first coil may be arranged to cause heating of a corresponding first portion of the second electrically conductive material, and a second coil may be arranged to cause heating of a corresponding second portion of the second electrically conductive material. For instance, the first and second coils may extend across different parts of the roller in the axial direction, such as respective first and second halves of the roller in the axial direction. Optionally, in a first mode, the first coil may be operated to cause heating of the first portion to form a hot-spot on the roller in the region of the first portion, and the second coil may not be operated. This may provide improved cleaning from the first portion while reducing power compared to heating both the first and second portions. Optionally, in a second mode, the first and second coils may be simultaneously operated to cause heating of the respective first and second portions. This may provide improved drying of the roller after use, and / or improved cleaning over a larger area of a surface to be cleaned by the roller than when heating only the first portion.

[0021] Optionally, the heating arrangement is located in the cleaner head. This may provide a self- contained heating arrangement and / or cleaner head. Optionally, the heating arrangement is configured to be operable while the cleaner head is used to clean a surface. Locating the heating arrangement in the cleaner head and heating the at least one of the roller and the fluid applied to the roller while the cleaner head is used to clean a surface may improve a cleaning effect provided by the cleaner head, such as improved stain removal. Optionally, the heating arrangement is configured to be operable at a same time as fluid is applied to the roller and / or while the roller is rotating. Optionally, the cleaner head is configured to cause rotation of the roller at a same time as the heating arrangement is heating the at least one of the roller and fluid applied to the roller.

[0022] Optionally, the cleaner head is configured to cause heat to be exchanged between the first electrically conductive element and fluid to be applied to the roller. In this way, heat generated in the first electrically conductive element by virtue of the oscillating electric current passed through the first electrically conductive element can be transferred to the fluid, thereby simultaneously cooling the first electrically conductive element and preheating the fluid. This may provide an effective and energy-efficient cleaning head. Optionally, when the first electrically conductive element comprises the coil of electrically conductive material, the coil may be formed by a hollow conduit. Optionally, the fluid to be applied to the roller is passable through the hollow conduit to cause the transfer of heat between the fluid and the coil. Optionally, the coil is housed in a sealed housing, and the fluid to be applied to the roller is passable through the sealed housing to cause a transfer of heat between the fluid and the coil.

[0023] Optionally, the first and / or second electrically conductive element is located external to the roller. This may provide a simple roller that is easy to manufacture. This may also allow the heating arrangement to be used with existing rollers, such as rollers normally provided for cleaner heads that do not comprise such a heating arrangement. This may improve an ease of repair or replacement of the roller.

[0024] Optionally, the heating arrangement is configured to heat the at least one of the roller and / or liquid applied to the roller to a temperature of up to 40 °C, up to 50 °C, up to 60 °C, up to 70 °C, up to 80 °C, up to 90 °C, or greater than 90 °C. Higher temperatures may improve a cleaning effect provided by the cleaner head, while lower temperatures may be reached more quickly and with less power, which may be particularly advantageous when drying the roller. Optionally, the heating arrangement is configured to heat the at least one of the roller and liquid applied to the roller to generate steam, which may provide effective cleaning.

[0025] Optionally, the heating arrangement comprises a temperature sensor arranged to determine a temperature of the roller and / or liquid applied to the roller. Optionally, the heating arrangement is configured to control heating of the roller and / or the liquid applied to the roller based on a temperature sensed by the temperature sensor. Such closed-loop control of heating may provide an accurate heating arrangement that can continuously adjust heating to reach a set temperature of the roller and / or liquid in the roller.

[0026] Optionally, the system comprises a dock configured to receive the cleaner head, the dock comprising at least one of the first electrically conductive element and the second electrically conductive element. Providing the first and / or the second electrically conductive element in the dock, rather than the cleaner head, may lead to a simpler and / or lighter cleaner head. The heating arrangement may be configured to cause heating of the at least one of the roller and fluid applied to the roller when the cleaner head is docked in the dock. This may provide a convenient arrangement for heating the at least one of the roller and fluid applied to the roller, such as to dry the roller, when the cleaner head is not in use. Optionally, the temperature sensor is located in the dock. Optionally, the roller is positioned close to, or in contact with, the temperature sensor when the cleaner head is docked in the dock. Alternatively, or in addition, the temperature sensor or another temperature sensor is located in the cleaner head.

[0027] Optionally, the electronic circuit is configured to receive power from a power supply to the dock. This may provide a cleaner head with reduced power draw. For instance, the dock may be connected to mains electricity, and so may be able to cause heating of the at least one of the roller and fluid applied to the roller, using the electronic circuit, without requiring power from a power supply to the cleaner head. This may be particularly beneficial when the cleaner head receives power from a battery, such as a battery of a floorcare cleaning appliance comprising the cleaner head.

[0028] By receiving power from the power supply to the dock, (e.g., rather than from the power supply to the cleaner head), the electronic circuit may be configured to generate the oscillating electric current without requiring an inverter or other electronic circuitry to convert DC power to AC power, which may provide a simpler heating arrangement that is cheaper to manufacture. This may be of particular benefit, for instance, when the power supply to the dock provides an alternating current (AC) to the dock, while the power supply to the cleaner head, such as the battery of the floorcare cleaning appliance, provides a direct current (DC) to the cleaner head. In such a case, the cleaner head and / or the heating arrangement may be provided absent an inverter, leading to a simple and cost- effective cleaner head and / or dock.

[0029] Optionally, the dock comprises the electronic circuit. This may provide a simple arrangement for supplying power to the electronic circuit from the power supply to the dock. Optionally, the cleaner head comprises the electronic circuit. In this case, the electronic circuit may be configured to receive power from the power supply to the dock when the cleaner head is docked in the dock. Optionally, when the cleaner head comprises the electronic circuit, the electronic circuit is configured to receive power from a power supply to the cleaner head when the cleaner head is not docked in the dock, and to receive power from the power supply to the dock when the cleaner head is docked in the dock. In either case, the cleaner head and / or the dock may comprise an electrical interface for connecting the electronic circuit to the power supply to the dock when the cleaner head is docked in the dock. Such an arrangement may allow the electronic circuit to be configured to provide efficient heating with a particular arrangement of the first and / or second electrically conductive elements in the cleaner head, while allowing the dock to be used with different cleaner heads, which may provide a versatile system.

[0030] Optionally, the cleaner head is configured to cause rotation of the roller when the cleaner head is docked in the dock. This may provide more uniform heating of the at least one of the roller and fluid applied to the roller when the cleaner head is docked in the dock.

[0031] Optionally, the dock comprises the first electrically conductive element and the cleaner head comprises the second electrically conductive element. Providing the first electrically conductive element in the dock, rather than in the cleaner head, may provide a simpler cleaner head with reduced weight, which may improve manoeuvrability of the cleaner head. This may also provide a compact arrangement in the cleaner head. For instance, particularly when the first electrically conductive element is formed by a coil of electrically conductive material, providing the first electrically conductive element in the dock may free up space in the cleaner head for other components, or may allow a smaller cleaner head to be provided.

[0032] Optionally, the roller comprises the second electrically conductive element. Providing the second electrically conductive element in the roller may provide a compact heating arrangement. Providing the second electrically conductive element in the roller may also permit retro-fitting of the roller to an existing cleaner head, such as to provide the cleaner head with roller-heating functionality. Optionally, the roller comprises a pile on an outer surface of the roller, the pile configured to receive and retain fluid applied to the roller. Optionally, the second electrically conductive element is located inwardly of the pile. Providing the second electrically conductive element inwardly of the pile may allow the pile to be heated from an inner surface of the pile. In this way, heat may be conducted through the pile from the inner surface to an outer surface of the pile. This may provide a temperature gradient, in use, that is higher at the inner surface of the pile than the at the outer surface of the pile. Because fluid closer to the inner surface of the pile is less exposed to air than fluid at the outer surface, increasing the temperature of the fluid closer to the inner surface of the pile may improve evaporation of that fluid, while still providing sufficient heat for evaporation of the fluid more exposed to air at the outer surface. This, in turn, may allow more efficient and effective drying of the roller and / or heating of fluid in the pile, particularly compared to heating the roller and / or the fluid by simply passing heated air across the roller. This may also increase a temperature at the inner surface of the pile compared to passing heated air across the roller, which may improve sterilisation of the pile at the inner surface of the pile, such as by increasing a number of pathogens that are sterilised at the inner surface.

[0033] The pile may be configured to contact a surface to be cleaned. The pile may comprise a microfibre layer, which may retain fluid on the roller for cleaning. Retaining water in the pile may improve an ability of the pile to clean the surface to be cleaned. Heating the pile and / or the fluid in the pile may further improve an ability of the pile to clean the surface. Alternatively, or in addition, the heating arrangement may be configured to heat the fluid (e.g., by heating the pile) to increase a rate of evaporation of the fluid from the pile. This may cause the pile to dry, and / or may at least partly sterilise the pile during or after use.

[0034] Optionally, the roller comprises a roller base, and the second electrically conductive element is provided on the roller base. Optionally, the second electrically conductive element comprises a layer of metallic material, such as aluminium or steel. Providing the second electrically conductive element as a layer of metallic material may provide an efficient heating arrangement that is simple to manufacture. Optionally, the roller base is polymeric, and the roller comprises the layer of metallic material on the roller base. Optionally, the second electrically conductive element is the roller base. For instance, the roller base may be formed of an electrically conductive material, such as aluminium or steel.

[0035] Optionally, the layer of metallic material is provided outwardly of the roller base and / or inwardly of the pile, relative to an axis of rotation of the roller. Optionally, the layer of metallic material has a thickness of between 0.05mm and 0.2 mm, such as between 0.08 and 0.02 mm, such as 0.1 mm. Providing a thinner layer of metallic material may reduce a size of the roller, which may allow the roller to be more readily retrofitted to an existing cleaner head. Optionally, the second electrically conductive element forms the roller base, or a part of the roller base. This may similarly improve an ability to retrofit the roller to an existing cleaner head, particularly when the roller base formed by the second electrically conductive element is the same or a similar size as a roller base of an existing cleaner head.

[0036] Optionally, the second electrically conductive element extends circumferentially around the roller. Providing the second electrically conductive element extending circumferentially around the roller may provide uniform heating of the roller. Optionally, the second electrically conductive element extends around a full circumference of the roller. For instance, when the second electrically conductive element comprises a layer of metallic material, the layer of metallic material may form a cylindrical surface encircling the roller base of the roller, where provided. Increasing a degree to which the second electrically conductive element extends around the circumference of the roller may provide more uniform heating of the second electrically conductive element and the roller, particularly when the roller is rotating.

[0037] Optionally, the second electrically conductive element extends up to 20%, such as up to 40%, up to 50%, up to 70%, up to 90%, or up to 100% of the length of the roller in the axial direction of the roller. Optionally, the second electrically conductive material is located centrally along the roller in the axial direction. In this way, when the heating arrangement is operated, the second electrically conductive material generates heat at a central location along the roller in the axial direction. In particular, when the second electrically conductive element extends, for example, along less than 100%, and particularly less than 70%, less than 50%, or less than 30% of the length of the roller in the axial direction, operation of the heating arrangement may generate a localised “hot-spot” on the roller, which may improve a cleaning effect of the roller at that hot-spot while reducing power required to heat the roller (compared to heating a full length of the roller). Optionally, the second electrically conductive material is located closer to one side of the roller than the other, so that the part of the roller that is heated (the hot-spot) is located closer to the one side of the roller than the other side. This may provide a hot-spot that is offset from a centre of the roller in the axial direction. Optionally, the second electrically conductive material may extend from an end of the roller in the axial direction by a length that is up to or greater than 50% of the length of the roller from an end of the roller in the axial direction. This may be to provide heating of one half of the roller. The cleaner head may comprise an indicator, such as a physical marking, to indicate to the user the location of the heated part of the roller so that, for instance, a user can readily align the heated part of the roller with a stain to be removed on a surface to be cleaned. This may improve an ease of use of the roller.

[0038] Optionally, the roller comprises a layered cylindrical structure comprising, in order extending away from an axis of rotation of the roller, the roller base, the second electrically conductive element on the roller base, and the pile on the second electrically conductive element. Optionally, the roller base is coupled to a mover configured to cause rotation of the roller base, and thus the roller, in use.

[0039] Optionally, the dock comprises the heating arrangement. Providing the heating arrangement, including the first and second electrically conductive elements and the electronic circuit, in the dock may allow the cleaner head to be provided without the first and second electrically conductive elements and the electronic circuit. This, in turn, may provide a simpler and / or lighter cleaner head, while still providing an efficient way to heat the roller when the cleaner head is docked. Such an arrangement may also provide versatility in the types of roller that can be heated. For instance, the dock may be provided to heat rollers of existing cleaner heads absent the electronic circuit and the first and second electrically conductive elements, without requiring replacement of the rollers and / or other components of such cleaner heads. Providing the heating arrangement in the dock, rather than the cleaner head, may provide more configuration options for a user. For instance, a cleaner head absent the heating arrangement may provide a lower-cost option for a user, and the dock may be provided as an optional extra to provide the roller and / or fluid heating functionality described above when the cleaner head is docked in the dock. Moreover, the dock may be connected to mains electricity, and so may be able to power the electronic circuit (and so heat the roller and / or fluid applied to the roller) without draining power from a power supply to the cleaner head, such as from a battery of a floorcare cleaning appliance comprising the cleaner head. This may improve a capacity of such a battery.

[0040] It will be appreciated that, when the first and second electrically conductive elements are configured as a pair of electrodes to enable dielectric heating of fluid in the roller, the pair of electrodes may be located in the dock. The cleaner head may be configured to be docked in the dock so as to position the roller relative to the pair of electrodes such that the electric component of the electromagnetic field generated between the pair of electrodes causes dielectric heating of the fluid on the roller.

[0041] Optionally, the electronic circuit is configured to generate the oscillating electric current at a frequency of greater than 100 kHz. This may provide efficient heating of the at least one of the roller and the fluid applied to the roller. For instance, where the second electrically conductive element is provided as a layer of metallic material, the frequency of the electric current generated may depend on the thickness of the layer of metallic material. A lower frequency may increase a “skin depth” of an electric current induced in the second electrically conductive element by the oscillating magnetic field. Providing an oscillating electric current at a frequency of greater than 100 kHz may provide efficient heating of a thin layer of metallic material, such as a layer of metallic material having a thickness of up to 0.1 mm, up to 0.2 mm, up to 0.3 mm, up to 0.4 mm, or up to 0.5 mm. The electronic circuit may be configured to generate a higher frequency electric current (e.g., up to or greater than 1 Mhz) in the first electrically conductive element to provide efficient heating of a thinner layer of metallic material (e.g., up to 0.05 mm or up to 0.01 mm thickness). Conversely, the electronic circuit may generate a lower frequency electric current (e.g., less than 100 kHz) to provide more efficient heating of a thicker layer of metallic material (e.g., up to or greater than 1 mm thickness), or to increase a skin depth of the current induced when the second electrically conductive element forms a whole or a significant part of the roller base, where provided.

[0042] Optionally, the system comprises an air moving device configured to move air across the roller when the heating arrangement is operated to cause heating of the roller. The causing of air to move across the roller may increase a rate of evaporation of fluid applied to the roller. This may, for instance, be by reducing a saturation of air around the roller, such as by replacing humid air around an outer surface of the roller with ambient, lower-humidity air, thereby increasing a potential for vaporisation of the fluid. Increasing a rate at which the air is moved across the roller may increase turbulence in the air around the roller, and / or reduce a size of a boundary layer of air moving across the roller, which may also improve evaporation of fluid from the roller. Optionally, the air moving device is configured to cause air to flow over the roller in a direction substantially aligned with an axis of rotation of the roller.

[0043] Optionally, the cleaner head comprises the air moving device. Providing the air moving device in the cleaner head may allow the air moving device to operate while the cleaner head is in use. Optionally, the dock comprises the air moving device. This may provide a simpler and / or lighter cleaner head, and / or a more efficient dock.

[0044] Optionally, the system comprises a floorcare cleaning appliance, the floorcare cleaning appliance comprising the cleaner head. Optionally the roller is configured to contact the floor to clean the floor. Optionally, the appliance comprises a fluid distribution system configured to supply the fluid to the roller. Optionally, the fluid distribution system comprises a reservoir configured to store the fluid, and one or more fluid paths through which the fluid is flowable from the reservoir to the roller. Optionally, the reservoir and / or the one or more fluid distribution paths are located in the cleaner head. Optionally, the fluid distribution system comprise a fluid distribution path through the hollow tube of the coil and / or the housing of the coil, where provided, to permit pre-heating of the fluid passed through the fluid distribution system towards the roller. A second aspect of the present invention provides a cleaner head comprising: a roller, the cleaner head configured to apply a fluid to the roller; and a heating arrangement configured to cause heating of at least one of the roller and fluid applied to the roller, the heating arrangement comprising: a first electrically conductive element; a second electrically conductive element spaced from the first electrically conductive element; and an electronic circuit configured to generate an oscillating electric current in the first electrically conductive element such that an oscillating electromagnetic field is generated between the first and second electrically conductive elements, and the oscillating electromagnetic field causes heating of at least one of the roller and fluid applied to the roller.

[0045] The cleaner head of the second aspect of the present invention may comprise and / or benefit from any of the optional features and / or advantages of the first aspect of the present invention when the cleaner head of the first aspect of the present invention comprises the heating arrangement. Similarly, the system of the first aspect of the present invention may comprise the cleaner head of the second aspect of the present invention.

[0046] A third aspect of the present invention provides a cleaning appliance comprising: a cleaning head comprising a roller, wherein the cleaner head is configured to apply a fluid to the roller; and a heating arrangement configured to cause heating of at least one of the roller and fluid applied to the roller, the heating arrangement comprising: a first electrically conductive element; a second electrically conductive element spaced from the first electrically conductive element; and an electronic circuit configured to generate an oscillating electric current in the first electrically conductive element to generate an oscillating magnetic field, such that the oscillating magnetic field interacts with the second electrically conductive element to cause inductive heating of the second electrically conductive element to cause heating of at least one of the roller and fluid applied to the roller.

[0047] Optionally, the first electrically conductive element is formed by a coil of electrically conductive material. Optionally, the coil is formed by a hollow conduit and arranged such that the fluid to be applied to the roller is passable through the hollow conduit to cause the transfer of heat between the fluid and the coil. Optionally, the coil is housed in a sealed housing and arranged such that the fluid to be applied to the roller is passable through the sealed housing to cause a transfer of heat between the fluid and the coil. Optionally, the coil of electrically conductive material is shaped as a flat coil. The coil of electrically conductive material extends across at least 30% of a length of the roller in an axial direction along an axis of rotation of the roller.

[0048] Optionally, the first electrically conductive element comprises two or more coils of electrically conductive material. Optionally, the two or more coils of electrically conductive material in combination extend across at least 80% of the length of the roller in the axial direction. A first coil is arranged to cause heating of a corresponding first portion of the second electrically conductive material, and a second coil may be arranged to cause heating of a corresponding second portion of the second electrically conductive material. The first and second coils extend across different parts of the roller in the axial direction, such as respective first and second halves of the roller in the axial direction. The electronic circuit is configured to selectively generate an oscillating electric current in the first and / or second coils.

[0049] Optionally, the heating arrangement is located in the cleaner head. The cleaner head is configured to cause heat exchange between the first electrically conductive element and fluid to be applied to the roller. The heating arrangement comprises a temperature sensor arranged to determine a temperature of the roller and / or liquid applied to the roller.

[0050] Optionally, the cleaning appliance further comprises a dock configured to receive the cleaner head, the dock comprising at least one of the first electrically conductive element and the second electrically conductive element. The heating arrangement is configured to cause heating of the at least one of the roller and fluid applied to the roller when the cleaner head is docked in the dock. The dock comprises the first electrically conductive element and the cleaner head comprises the second electrically conductive element. The second electrically conductive element extends circumferentially around the roller. The roller comprises a roller base, and the second electrically conductive element is provided on the roller base. Optionally, the roller comprises a pile on an outer surface of the roller, the pile configured to receive and retain fluid applied to the roller, wherein the second electrically conductive element is located inwardly of the pile.

[0051] Optionally, the cleaning appliance further comprising an air moving device configured to move air across the roller when the heating arrangement is operated to cause heating of the roller.

[0052] BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure l is a perspective view of a system comprising a floorcare cleaning appliance;

[0054] Figure 2 is a cutaway view of a cleaner head of the floorcare cleaning appliance of Figure;

[0055] Figure 3 is a schematic side-on cross-sectional view of the cleaner head of Figure 2;

[0056] Figure 4 is a schematic top-down view of the cleaner head of Figures 2 and 3;

[0057] Figure 5 is a schematic side-on cross-sectional view of an alternative cleaner head and dock;

[0058] Figure 6 is a schematic side-on cross-sectional view of a further alternative cleaner head;

[0059] Figure 7 is a schematic side-on cross-sectional view of a further alternative cleaner head and dock; and

[0060] Figure 8 is a schematic top-down view of a further alternative cleaner head.

[0061] DETAILED DESCRIPTION

[0062] Figure 1 shows a first system 1 comprising a floorcare cleaning appliance 10, a dock 160 and a heating arrangement 190. The dock 160 and the heating arrangement 190 will be described in more detail below, with respect to Figure 3. The floorcare cleaning appliance

[0063] 10 comprises a main unit 11, a wand 12 releasably connected to the main unit 11, and a cleaner head 100 releasably connected to the wand 12. The cleaner head 100 can instead be releasably connected to the main unit 10, depending on a user’s preference. The main unit

[0064] 11 houses a power supply in the form of a battery 20, an airflow generator 21, and a control module 22. Power can be provided from the battery 20 to the airflow generator 21, and to the cleaner head 100 via a terminal (not shown) of the main unit 10, under control of the control module 22. Further details of the main unit 10 are not pertinent to the present invention, and will not be discussed here for sake of brevity.

[0065] Figure 2 shows a top-down cutaway view of the cleaner head 100 of Figure 1, viewed along a depth D direction of the cleaner head 100. The cleaner head 100 comprises a roller rotatably 114 mounted in the cleaner head such as to rotate around a rotational axis R that is substantially parallel to a width direction W of the cleaner head 100. The cleaner head 100 also comprises a roller drive 142 (shown as a dashed box in Figure 2) located inside the roller 114 and configured to drive rotation of the roller 114.

[0066] The cleaner head 100 comprises a pump 132, a liquid tube 134, a reservoir 138, and a reservoir inlet 136. The pump 132 is fluidically connected between the liquid distribution tank 130 and the liquid tube 134, the liquid tube extending from the pump 132 to the reservoir inlet 136. The reservoir 138 is generally cuboidal in form and is elongate along an axis parallel to the rotational axis R of the roller 14. The reservoir 138 comprises eight reservoir outlets 139, although between 6 to 10 reservoir outlets are also envisaged. The reservoir outlets 139 are spaced substantially evenly along a length of the reservoir 138 along an axis parallel to a rotational axis R of the roller 114, which is substantially parallel to a width direction W of the cleaner head 100. The reservoir outlets 136 comprise generally circular apertures formed in a reservoir outlet surface 137, which is a base surface of the reservoir 138.

[0067] The cleaner head 100 also comprises control circuitry 140 configured to drive the pump 132 and the roller 114, in use. Figure 3 shows a schematic diagram of a side-on cutaway of the cleaner head 100, viewed along the width direction W, when the cleaner head 100 is docked in the dock 160. The roller 114 comprises a roller base 120, an electrically conductive element in the form of a metallic layer 156 on the roller base, and a pile 122 on the metallic layer 156. The roller base 120 is generally cylindrical (with a cylindrical base surface) and hollow in form, and is formed from an electrically insulating material. An interior of the roller base 120 is provided with fixing mechanisms for releasably fixing the roller 114 to the roller drive 142 and rotatably mounting the roller 114 in the cleaner head 100. Details of such fixing mechanisms are not pertinent to the present invention, and so will not be described here for sake of clarity.

[0068] The metallic layer 156 extends circumferentially around the roller base 120 and has a thickness of around 0.1 mm. The metallic layer 156 extends along a full length of the roller 114 in the width direction W, but in other examples may extend only partially along the length of the roller 114. The pile 233 extends circumferentially around the metallic layer 156. The pile 122 is a microfibre pile with a density of between 46,500 and 85,250 fibres / cm2. In an alternative embodiment, the roller 114 may further include a bristle pile arranged over the microfibre pile, where the bristle pile may be formed of a stiffer material, such as nylon or Polyethylene terephthalate (PET). The pile 122 has a thickness T of around 5 mm to 7 mm, for example, around 6.7 mm in a particular embodiment.

[0069] The dock 160 comprises an electrically conductive element in the form of a coil 150 of electrically conductive material, an electronic circuit 154, and an air moving device in the form of a fan 262. The coil 150 is sealed in a coil housing 152 to fluidically isolate the coil 150 from liquid on the roller 114, in use.

[0070] The structure of the coil 150 is shown in Figure 4, which is a top-down schematic view of the cleaner head 100 docked in the dock 160 when viewed along the depth D dimension of the cleaner head 100. The cleaner head 100 and roller 114 shown as dashed boxes, for clarity. It can be seen that the coil 150 is a “flat” coil extending in a planar winding pattern across a planform of the roller 114 parallel to the rotational axis R when the cleaner head 100 is docked in the dock 160. The coil 150 extends across more than 60% of a width and length of the roller in the width W and length L dimensions when the cleaner head 100 is docked in the dock 160.

[0071] The coil 150 is electrically connected to the electronic circuit 154 to form an RLC, or “resonant” circuit, where the coil forms a resistive (R) and inductive (L) portion of the RLC circuit, and the electronic circuit 154 comprises one or more capacitors (C). The electronic circuit 154 is electrically connected to mains power and is configured to generate a Radio Frequency (RF) oscillating electric current in the coil 150. This causes an oscillating magnetic field 158 to be generated around the coil 150 at the same frequency as the oscillating electric current. The dashed circles in Figure 3 show an example shape of the oscillating magnetic field 158. The coil 150 is positioned relative to the roller 114 when the cleaner head 100 is docked in the dock 160 so that the oscillating magnetic field 158 causes the generation of eddy currents in the metallic layer 156 in the roller 114, thereby to cause inductive heating of the metallic layer 156. In particular, the oscillating magnetic field 158 induces an electromotive force (EMF) in the metallic layer 156, which acts as a conductor. This, in turn, causes circulating electric currents (eddy currents) to flow in closed loops within the metallic layer 156. According to Joule’s law, the eddy currents are subject to the electrical resistance of the metallic layer 156 which causes heat to be generated in the metallic layer 156. This heating of the metallic layer 156, in turn, causes heating of the pile 122 and the liquid in the pile 122, in use, largely due to conductive heat transfer between the metallic layer 156 and the pile 122 and / or the liquid in the pile 122. The electronic circuit 154, the coil 150 and the metallic layer 156 together form the heating arrangement 190, which is configured to heat the pile 122 and liquid applied to the pile 122 from the liquid distribution tank 130, in use.

[0072] In use, the cleaner head 100 is attached to the main unit 10, and a user can remove the cleaner head 100 from the dock 160 to use the floorcare cleaning appliance 10. Power is supplied from the battery 20 of the main unit 10 via looming (not shown) to the cleaner head 100, and in particular to the control circuitry 140, the roller drive 142, and the pump 132. When the cleaner head 100 is in use to clean a surface, the pump 132 is controlled by the control circuitry 140 to drive distribution of liquid from the liquid distribution tank 130 to the reservoir 138 via the liquid tube 134 and the reservoir inlet 136. The liquid is then delivered to the roller 114 via the reservoir outlets 136. The liquid pools in the reservoir 138 and is gradually distributed to the roller 114 by simply falling from the reservoir outlets 136 and onto the roller 114.

[0073] After cleaning the surface to be cleaned, the cleaner head 100 can be docked in the dock 160 to allow the heating arrangement 190 to heat the pile 122 and leftover liquid on the pile 122 as described above. In this way, the heating arrangement 190 can aid drying of the pile 122 by increasing a rate of evaporation of liquid on the pile 122. This may reduce a growth of pathogens (e.g., bacteria and fungi) in the pile and, if the temperature is high enough, may at least partly sterilise the pile 122 and / or liquid of certain pathogens. For instance, the pile 122 may be sterilised of certain pathogens by raising a temperature of the pile 122, using the heating arrangement 190, as described above, to 63 °C for 30 minutes, or 72°C for 15 seconds, for example.

[0074] The cleaner head 100 is docked in the dock 160 in such a way as to permit rotation of the roller 114 in the cleaner head 100. The cleaner head 100, and in particular the control circuitry 140, is configured to cause rotation of the roller 114 at a same time as the electronic circuit 154 generates the oscillating electric current in the coil 150 and the metallic layer 156. The cleaner head 100 comprises detection circuitry (not shown) for detecting when the cleaner head 100 is docked in the dock 160. The detection circuitry detects that the cleaner head 100 is docked when electrical power is received by the cleaner head 100 from the dock 160 (which in turn is connected to mains electricity, as noted above). In other examples, the detection circuitry may comprise a sensor, such as a near- field-communication sensor, for detecting when the cleaner head 100 has been docked in a suitable dock 160.

[0075] When the detection circuitry determines that the cleaner head 100 is docked in the dock 160, the cleaner head 100 initiates a drying process involving operating the heating arrangement 190 while simultaneously operating the roller drive 142 to cause the roller 114 to rotate. Causing rotation of the roller 114 during heating causes each part of the metallic layer 156 to pass through the oscillating magnetic field 158, providing uniform heating of the metallic layer 156 and liquid in the pile 122 of the roller 114. The dock 160 also operates the fan 162 to blow air across the pile 122 when the heating arrangement 190 is being used to heat the pile 122. Moving air across the pile 122 increases a rate of evaporation of fluid from the pile 122, and can also carry heat across the pile to provide uniform heating of the pile 122.

[0076] It will be appreciated that the temperature and / or rate of heating of the pile 122 and / or liquid in the pile 122 will vary with parameters including a power consumption of the electronic circuit 154, dimensions of the coil 150, a thickness of the metallic layer 156, an electrical efficiency of the electronic circuit 154, a relative position of, and distance between, the coil 150 and the metallic layer 156, and a rate of rotation of the roller 114.

[0077] Figure 5 shows a second system 2 comprising a cleaner head 200 and heating arrangement 290. The cleaner head 200 is substantially the same as the cleaner head 100 of the first system, and is removably attached to a corresponding main unit (not shown, for brevity) in a similar way to the cleaner head 100 of the first system 1. In particular the cleaner head 200 comprises a roller 214 comprising a cylindrical roller base 220, a metallic layer 256 on the roller base 220, and a pile 222 on the metallic layer 256. The cleaner head 200 is similarly configured to apply liquid to the roller 214 in the same way as the cleaner head 100 of the first system 1.

[0078] The heating arrangement 290 of the second system 2 is also substantially the same as the heating arrangement 190 of the first system 1 described above, except that the heating arrangement 290 in the second system 2 is contained in the cleaner head 100. Specifically, the heating arrangement 290 comprises the metallic layer 256 in the roller 214, as well as a coil 250 and an electrical circuit 254, each located in the cleaner head 100. In this case, the system 2 is provided without a dock, and the electronic circuit 254 is configured to receive power from a battery of the main unit to which the cleaner head 200 is attached.

[0079] The second system 2 otherwise operates in the same way as the first system 1 described above in that the electronic circuit 254 generates a RF oscillating electric current in the coil 250, which in turn generates an oscillating magnetic field 258 around the coil 250. In addition to heating the roller 214 to dry the roller 214 after the cleaner head 200 has been used to clean a surface, the heating arrangement 260 of the second system 2 is also able to heat the roller 214 while the cleaner head 200 is in use to clean a surface, and in particular while the roller 214 is rotating. This allows heating of the liquid that is to be applied to the surface, which improves a cleaning effect of the cleaner head 200. As with the cleaner head 100 of the first system 1, a temperature and rate of heating depends on various parameters.

[0080] Figure 6 shows a third system 3, which similarly comprises a cleaner head 300, a roller 314 in the cleaner head 300 and a heating arrangement 390. The roller 314 of the third system 3 is the same as the rollers 114, 214 of the first and second systems 1, 2, and comprises a roller base 320, a metallic layer 356 on the roller base 320, and a pile 322 on the metallic layer 356. The cleaner head 300 of the third system 3, however, comprises a metal plate 350 instead of a coil of electrically conductive material. The metal plate 350 is elongate and extends along a width of the roller 314 in the width direction W, specifically 80% of the width of the pile 314.

[0081] The metal plate 350 is electrically connected to an electronic circuit 354 of the cleaner head 300, which here comprises a RF amplifier. The electronic circuit 354 is configured to generate a RF oscillating electric current the metal plate 350. This causes the metallic layer 356 to generate a RF wave between the metal plate 350 and the metallic layer 356. In particular, the metal plate 350 is positioned so that an oscillating electric field 358, indicated by double-headed arrows in Figure 6, is generated between the metal plate 350 and the metallic layer 356. In this way, the metal plate 350 and the metallic layer 356 form a pair of electrodes, with the metallic layer 356 acting as a “ground” electrode.

[0082] The pile 322 is disposed between the metal plate 350 and the metallic layer 356 such that the electric field 358 interacts with the liquid in the pile 322 to cause dielectric heating of the liquid in the pile. In particular, when RF electromagnetic waves generated from the metal plate 350 encounter the liquid in the pile 122, the waves interact with polar molecules within the liquid. The polar molecules have positively and negatively charged ends (dipoles). The rapidly oscillating electric field 358 of the RF waves causes the dipoles to attempt to align themselves with the changing field. As the electric field 358 rapidly changes direction, the polar molecules within the liquid attempt to follow these changes. This constant reorientation of the molecules results in friction, which generates heat within the liquid. The heat generated through this friction causes the temperature of the liquid to rise.

[0083] Thus, in contrast to the cleaner heads 100, 200 of the first and second systems 1, 2, the liquid in the pile 322 is heated directly. The electronic circuit 354, the metal plate 350 and the metallic layer 356 thereby form the heating arrangement 390 configured to heat the pile 322 and liquid applied to the pile 322.

[0084] The cleaner head 300 of the third system 3 shown in Figure 6 is configured to cause the roller 314 to rotate while the liquid is dielectrically heated, and in particular while the cleaner head 300 is in use. This ensures that the entire circumference of the pile 352, and thus liquid distributed through the pile 352, passes through the electromagnetic field 358 to be heated, metallic layer 356

[0085] As with the heating arrangements 190, 290 of the first and second systems 1, 2, a temperature and rate of heating of the liquid in the pile 352 depends on various parameters. Dielectrically heating the liquid may be more efficient than inductively heating the metallic layer 156. On the other hand, the LC (resonant) circuits provided in the inductive heating arrangements of Figures 1 to 5 may have a lower cost than the RF amplifier provided in the dielectric heating arrangement of Figure 6.

[0086] Figure 8 shows a fourth system 4 comprising a cleaner head 400, a roller 414 in the cleaner head 400, and a dock 460 into which the cleaner head 400 is docked. The roller 414 of the fourth system 4 comprises an electrically insulating roller base 420 and a pile 422 on an outer surface of the roller base 420. In contrast to the rollers 114, 214, 314, of the first to third systems 1, 2, 3, there is no layer of metallic material between the roller base 420 and the pile 422 in the fourth system 4. The fourth system 4 comprises a dock 460, which comprises first and second metal plates 450, 456. The first and second metal plates 450, 456 are each connected to an electronic circuit 454 in the dock 460, so that the first and second metal plates 450, 456 form a pair of electrodes in the electronic circuit 454. The electronic circuit 454 comprises a RF amplifier configured to generate a RF oscillating electric current in the first and second metal plates 450, 456 so that an oscillating electric field 458 is generated between the first and second metal plates 450, 456. It will be appreciated that the second metal plate 456 need not be connected to the electronic circuit 454, and may instead be connected to ground, as in the second system 2 described above.

[0087] The first and second metal plates 450, 456 are located in a lower surface of the base 460, and are positioned so that, when the cleaner head 400 is docked in the dock 460, a part of the pile 422 of the roller 414 is positioned in the electric field generated between the first and second metal plates 400, 456. This causes dielectric heating of liquid in the pile 422 in a similar way as described above.

[0088] The electronic circuit 454 and the first and second metal plates 450, 456 thereby form the heating arrangement 490 configured to heat the pile 422 and liquid applied to the pile 422. In this way, the heating arrangement 490 of the fourth system 4 is located in the dock 460, rather than in the cleaner head 400, or rather than having one or more components in the cleaner head 400. The dock 460 of the fourth system 4 is connected to mains electricity, and also comprises an air moving device in the form of a fan 462.

[0089] The cleaner head 400 is docked in the dock 460 in such a way as to permit rotation of the roller 414 in the cleaner head 400. The cleaner head 400 is, in particular, configured to cause rotation of the roller 414 at a same time as the electronic circuit 454 generates the oscillating electric current in the first and second metal plates 450, 456. This permits uniform heating of the liquid in the pile 422 of the roller 414. The cleaner head 400 comprises a detection circuit (not shown), as in the first system 1, which causes simultaneous operation of the heating arrangement 460 with rotation of the roller 414. The fan 462 is configured to blow air across the pile 422 to aid evaporation of the liquid in the pile 422. Figure 8 shows a top-down schematic view of a cleaner head 500 of a fifth system 5, the cleaner head 500 comprising a heating arrangement 560 having first and second electrically conductive coils 550a, 550b. The first and second electrically conductive coils 550a, 550b overly respective first and second axial halves 515a, 514b of a roller 514 of the cleaner head 500 and are each electrically connected to an electronic circuit 554. Aside from having two coils 550a, 550b instead of one, the cleaner head 500 and components thereof (including the heating arrangement 560, the roller 514 and electronic circuit 554) are of the same construction as the cleaner head 200 and respective components thereof of the second system 2. The heating arrangement 560 of the fifth system 5 is operable in a first mode, in which the electronic circuit 554 provides an oscillating electric current to the first electrically conductive coil 550a, but not to the second electrically conductive coil 550b, to cause inductive heating of the first half 514a of the roller 514. The heating arrangement 560 is also operable in a second mode, in which the electronic circuit 554 simultaneously provides an oscillating electric current to each of the first and second electrically conductive coils 550a, 550b to cause simultaneous heating of each of the respective first and second halves 514a, 514b of the roller 514.

[0090] It will be appreciated that variations and modifications may be made to the abovedescribed first to fourth systems 1, 2, 3, 4 without departing from the scope of the invention as defined by the appended claims. For instance, in the first and second systems 1, 2, which are configured to inductively heat a respective layer 156, 256 of metallic material in a respective roller 114, 214, the respective layer 156, 256 of metallic material may instead be a layer of any other suitable electrically conductive material. Moreover, the respective layer may be of any other suitable thickness, such as a thickness of less than 0.1 mm, or up to 0.2 mm, or up to 0.5 mm. In other such examples, instead of providing a layer of metallic material, the roller base 150, 250 may itself be formed of an electrically conductive material and the pile 122, 222 may be provided on top of the roller base 150, 250. It will be appreciated that changes in the configuration of an inductive heating arrangement described above may be accompanied by changes in parameters such as a frequency or power draw of an associated electronic circuit. In some examples, though not shown in the figures, instead of providing the layer 356 of metallic material in the roller 320 in the third system 3, the cleaner head 300 may comprise the first metal plate 350 and a second metal plate in a similar arrangement to the first and second metal plates 450, 456 of the dock 460 of the fourth system 4. Such first and second metal plates in the third system 3 may be located in the cleaner head 300 such that the electric field 358 generated between the first and second metal plates interacts with liquid in the pile 322, in use, to cause dielectric heating of the liquid in the pile 322.

[0091] It will also be appreciated that the second and third systems 2, 3 described above, which are illustrated absent a dock, may, in some examples, comprise a respective dock into which the respective cleaning head 200, 300 can be docked. The electronic circuit 154, 254, 354, 454, in any of the above-described systems 1, 2, 3, 4 may also receive power from any suitable source, such as from either a battery of a main unit of a respective floorcare cleaning appliance, or from a mains electricity connection to a respective dock. In the first and second systems 1, 2, where the electronic circuit 254, 354 is located in a respective cleaner head 200, 300, an electrical interface may be provided in the respective cleaner head and / or a respective dock to power the respective electronic circuit 254, 354 from a mains electricity connection to the respective dock.

[0092] In some examples, though not shown in the Figures, the coil housing 152 of the first system 1 may be fluidically connected to the liquid tube 134 so that liquid is passable through the coil housing 152, in thermal contact (direct or otherwise) with the coil 150, before being passed to the reservoir inlet 136 and the pile 122. This allows heat generated in the coil 150 to be passed to the fluid passing through the liquid tube 134, thereby cooling the coil 150 and pre-heating the fluid before it is passed to the roller 150. In other examples, the coil comprises a hollow conduit that is fluidically connected to the liquid tube 134 so that fluid is flowable through the hollow conduit towards the reservoir inlet 136. This may similarly provide cooling of the coil 150 and pre-heating of fluid to be passed to the roller 150.

[0093] An embodiment of a cleaning appliance in accordance with this disclosure can be described in the following clauses. 1. A cleaning appliance comprising: a cleaning head comprising a roller, wherein the cleaner head is configured to apply a fluid to the roller; and a heating arrangement configured to cause heating of at least one of the roller and fluid applied to the roller, the heating arrangement comprising: a first electrically conductive element; a second electrically conductive element spaced from the first electrically conductive element; and an electronic circuit configured to generate an oscillating electric current in the first electrically conductive element to generate an oscillating magnetic field, such that the oscillating magnetic field interacts with the second electrically conductive element to cause inductive heating of the second electrically conductive element to cause heating of at least one of the roller and fluid applied to the roller.

[0094] 2. The cleaning appliance of clause 1 wherein the first electrically conductive element is formed by a coil of electrically conductive material.

[0095] 3. The cleaning appliance of clause 2 wherein the coil is formed by a hollow conduit and arranged such that the fluid to be applied to the roller is passable through the hollow conduit to cause the transfer of heat between the fluid and the coil.

[0096] 4. The cleaning appliance of clause 2 wherein the coil is housed in a sealed housing and arranged such that the fluid to be applied to the roller is passable through the sealed housing to cause a transfer of heat between the fluid and the coil.

[0097] 5. The cleaning appliance of clause 2 wherein the coil of electrically conductive material is shaped as a flat coil.

[0098] 6. The cleaning appliance of clause 2 or 5 wherein the coil of electrically conductive material extends across at least 30% of a length of the roller in an axial direction along an axis of rotation of the roller.

[0099] 7. The cleaning appliance of clause 1 wherein the first electrically conductive element comprises two or more coils of electrically conductive material. 8. The cleaning appliance of clause 7 wherein the two or more coils of electrically conductive material in combination extend across at least 80% of the length of the roller in the axial direction.

[0100] 9. The cleaning appliance of clause 7 wherein a first coil is arranged to cause heating of a corresponding first portion of the second electrically conductive material, and a second coil may be arranged to cause heating of a corresponding second portion of the second electrically conductive material.

[0101] 10. The cleaning appliance of clause 9 wherein the first and second coils extend across different parts of the roller in the axial direction, such as respective first and second halves of the roller in the axial direction.

[0102] 11. The cleaning appliance of clause 10 wherein the electronic circuit is configured to selectively generate an oscillating electric current in the first and / or second coils.

[0103] 12. The cleaning appliance of any one of clauses 1-11 wherein the heating arrangement is located in the cleaner head.

[0104] 13. The cleaning appliance of any one of clauses 1-12 wherein the cleaner head is configured to cause heat exchange between the first electrically conductive element and fluid to be applied to the roller.

[0105] 14. The cleaning appliance of anyone of clauses 1-13 wherein the heating arrangement comprises a temperature sensor arranged to determine a temperature of the roller and / or liquid applied to the roller.

[0106] 15. The cleaning appliance of clause 1 further comprising a dock configured to receive the cleaner head, the dock comprising at least one of the first electrically conductive element and the second electrically conductive element. 16. The cleaning appliance of clause 15 wherein the heating arrangement is configured to cause heating of the at least one of the roller and fluid applied to the roller when the cleaner head is docked in the dock.

[0107] 17. The cleaning appliance of clause 16 wherein the dock comprises the first electrically conductive element and the cleaner head comprises the second electrically conductive element.

[0108] 18. The cleaning appliance of clause 17, wherein the second electrically conductive element extends circumferentially around the roller.

[0109] 19. The cleaning appliance of clause 18 wherein the roller comprises a roller base, and the second electrically conductive element is provided on the roller base.

[0110] 20. The cleaning appliance of any one of clauses 1-18 wherein the roller comprises a pile on an outer surface of the roller, the pile configured to receive and retain fluid applied to the roller, wherein the second electrically conductive element is located inwardly of the pile.

[0111] 21. The cleaning appliance of any one of clauses 1-20 further comprising an air moving device configured to move air across the roller when the heating arrangement is operated to cause heating of the roller.

[0112] Other variations and modifications within the scope of the appended claims will be evident to the skilled person.

Claims

CLAIMS1. A system comprising: a cleaner head comprising a roller, wherein the cleaner head is configured to apply a fluid to the roller; and a heating arrangement configured to cause heating of at least one of the roller and fluid applied to the roller, the heating arrangement comprising: a first electrically conductive element; and an electronic circuit configured to generate an oscillating electric current in the first electrically conductive element to generate at least one of an oscillating magnetic field and an oscillating electric field, such that the at least one of the oscillating magnetic field and the oscillating electric field causes heating of at least one of the roller and fluid applied to the roller.

2. The system of claim 1, wherein the electronic circuit is configured to generate the oscillating electric current in the first electrically conductive element to generate the oscillating electric field, such that the oscillating electric field interacts with fluid applied to the roller to cause dielectric heating of the fluid applied to the roller.

3. The system of claim 1 or claim 2, wherein the heating arrangement comprises a second electrically conductive element spaced from the first electrically conductive element, and wherein the electronic circuit is configured to generate the oscillating electric current in the first electrically conductive element to generate the oscillating magnetic field, such that the oscillating magnetic field interacts with the second electrically conductive element to cause inductive heating of the second electrically conductive element.

4. The system of any one of claims 1 to 3, wherein the heating arrangement is located in the cleaner head.

5. The system of any one of claims 1 to 4, wherein the heating arrangement is configured to be operable while the cleaner head is used to clean a surface.

6. The system of any one of claims 1 to 3, comprising a dock configured to receive the cleaner head, the dock comprising the first electrically conductive element.

7. The system of claim 6, wherein the electronic circuit is configured to receive power from a power supply to the dock.

8. The system of claim 6 or claim 7, wherein the cleaner head is configured to cause rotation of the roller when the cleaner head is docked in the dock.

9. The system of any one of claims 6 to 8, wherein the heating arrangement comprises a second electrically conductive element spaced from the first electrically conductive element, and wherein the dock comprises the first electrically conductive element and the cleaner head comprises the second electrically conductive element.

10. The system of claim 3 or claim 9, wherein the roller comprises the second electrically conductive element.

11. The system of claim 10, wherein the roller comprises a pile on an outer surface of the roller, the pile configured to receive and retain fluid applied to the roller, and wherein the second electrically conductive element is located inwardly of the pile.

12. The system of any one of claims 9 to 11, wherein the second electrically conductive element extends circumferentially around the roller.

13. The system of any one of claims 6 to 8, wherein the dock comprises the heating arrangement.

14. The system of any one of claims 1 to 13, wherein the electronic circuit is configured to generate the oscillating electric current at a frequency of greater than 100 kHz.

15. The system of any one of claims 1 to 14, wherein the system comprises an air moving device configured to move air across the roller when the heating arrangement is operated to cause heating of the roller.

16. The system of any one of claims 1 to 15, comprising a floorcare cleaning appliance, the floorcare cleaning appliance comprising the cleaner head.

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