GB2622852A

GB2622852A - A cleaner head for an appliance

Info

Publication number: GB2622852A
Application number: GB2214354.9A
Authority: GB
Inventors: Haris Md Ishak Nizam; John Saban Elvyn
Original assignee: Dyson Operations Pte Ltd
Current assignee: Dyson Operations Pte Ltd
Priority date: 2022-09-30
Filing date: 2022-09-30
Publication date: 2024-04-03
Also published as: GB202214354D0; WO2024069406A1; CN117796720A; CN220360385U

Abstract

A cleaner head for an appliance includes a liquid distribution tank 34 for storing liquid to be distributed to a surface to be cleaned, a roller 14 for contacting the surface to be cleaned, a reservoir 88 having at least one reservoir inlet 114 for receiving liquid from the liquid distribution tank and a plurality of reservoir outlets 116 for distributing the liquid onto the roller, and a drive component 84 for driving distribution of liquid from the liquid distribution tank to the reservoir. A ratio of an interior volume of the reservoir to a total combined cross-sectional area of the plurality of reservoir outlets is such that, in use, liquid exits the reservoir substantially uniformly from the plurality of reservoir outlets.

Description

A CLEANER HEAD FOR AN APPLIANCE

Field of the Invention

The present invention relates to a cleaner head for an appliance, and to an appliance comprising such a cleaner head.

Background of the Invention

Appliances for cleaning or treating surfaces may comprise a cleaner head that is in contact with the 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.

Summary of the Invention

According to a first aspect of the present invention there is provided a cleaner head for an appliance, the cleaner head comprising: a liquid distribution tank for storing liquid to be distributed to a surface to be cleaned; a roller for contacting the surface to be cleaned; a reservoir having at least one reservoir inlet for receiving liquid from the liquid distribution tank and a plurality of reservoir outlets for distributing the liquid onto the roller; and a drive component for driving distribution of liquid from the liquid distribution tank to the reservoir, wherein a ratio of an interior volume of the reservoir to a total combined cross-sectional area of the plurality of reservoir outlets is such that, in use, liquid exits the reservoir substantially uniformly from the plurality of reservoir outlets.

Obtaining a substantially uniform flow of liquid from the reservoir outlets for example facilitates a relatively uniform application of the liquid onto the roller. In turn, this can enable more uniform distribution of liquid by the roller onto the surface to be cleaned, allowing the surface to be cleaned more efficiently. Such a relatively even deposition of liquid into the surface may be achieved in a simple manner as the substantially uniform flow of liquid may be obtained straightforwardly, for a given configuration of other elements of the cleaner head, due to the ratio of the interior volume of the reservoir to a total combined cross-sectional area of the plurality of reservoir outlets. For example, the flow of liquid from each of the reservoir outlets may vary by less than 10% between different reservoir outlets.

The interior volume of the reservoir in millimetres cubed may be at least 150 times greater than the total combined cross-sectional area of the plurality of reservoir outlets in millimetres squared. This may enable the liquid to flow substantially uniformly from the reservoir outlets without the liquid pressure in the reservoir exceeding a desired limit, such as a limit for safe operation of the cleaner head or a limit for operation of the cleaner head without leaking of the reservoir.

The interior volume of the reservoir in millimetres cubed may be less than 400 times greater than the total combined cross-sectional area of the plurality of reservoir outlets in millimetres squared. This for example allows the liquid to flow substantially uniformly from the reservoir outlets so as to deposit a sufficient quantity of liquid onto the roller for effective cleaning of the surface.

The interior volume of the reservoir in millimetres cubed may be at least 1300 times greater than a cross-sectional area of each of the plurality of reservoir outlets in millimetres squared. This may further improve the uniformity of flow of the liquid from the reservoir outlets by reducing build-up of liquid at reservoir outlets, which may otherwise occur if there is a reservoir outlet with a smaller cross-sectional area relative to the interior volume of the reservoir.

The interior volume of the reservoir in millimetres cubed may be less than 2800 times greater than a cross-sectional area of each of the plurality of reservoir outlets in millimetres squared. This may further improve the uniformity of flow of the liquid from the reservoir outlets by limiting rapid gushing of liquid from reservoir outlets, which may otherwise occur if there is a reservoir outlet with a larger cross-sectional area relative to the interior volume of the reservoir.

The interior volume of the reservoir in millimetres cubed may be at least 900 times greater than a cross-sectional area of the or each at least one reservoir inlet in millimetres squared. This may enable a sufficient flow of liquid into the reservoir from the at least one reservoir inlet to provide for sufficient liquid pressure within the reservoir to aid in subsequent flow of the liquid from the reservoir outlets.

The interior volume of the reservoir in millimetres cubed may be less than 1900 times greater than a cross-sectional area of the or each at least one reservoir inlet in millimetres squared. This may prevent an excessive flow of liquid into the reservoir from the at least one reservoir inlet, reducing the risk of leaks and improving the safety of the cleaner head.

The total combined cross-sectional area of the plurality of reservoir outlets may be at least 2.5 times greater than a total combined cross-sectional area of the at least one reservoir inlet. This for example aids in achieving substantially uniform flow of liquid from the reservoir outlets without excess liquid pressure building up in the reservoir, reducing the risk of leaks or unsafe operation. In addition or alternatively, the total combined cross-sectional area of the plurality of reservoir outlets may be less than 10 times greater than the total combined cross-sectional area of the at least one reservoir inlet. This for example aids in achieving substantially uniform flow of liquid from the reservoir outlets without saturating the roller to excess with the liquid exiting the reservoir, thereby improving operation of the cleaner head by reducing dripping of surplus liquid from the roller onto the surface to be cleaned.

The reservoir may have a single reservoir inlet. This may allow the cleaner head to be fabricated more straightforwardly, and may provide for improved robustness compared to a reservoir with more reservoir inlets. For example, the single reservoir inlet may be provided with liquid from the liquid distribution tank via a single fluid channel, such as a single tube, which can be manufactured in a simple manner. In addition or alternatively, the reservoir may have between 6 and 10 reservoir outlets. This may provide a suitable balance between a sufficient number of reservoir outlets to assist in deposition of liquid onto a sufficient length of the roller to achieve an acceptable level of cleaning, without excessively increasing the complexity of the cleaner head.

The reservoir may be generally cuboidal, and a long axis of the reservoir may be parallel to a rotational axis of the roller. A generally cuboidal shape of the reservoir may be fabricated more straightforwardly than other shapes. Locating the reservoir with a long axis parallel to the rotational axis of the roller is for example an efficient use of space of the cleaner head to provide space for other components within the cleaner head. Furthermore, this may allow the liquid to be distributed in an elongate region for flow of the liquid towards and out of the reservoir outlets, which may themselves be located along a length of the reservoir.

A reservoir inlet surface of the reservoir may comprise the at least one reservoir inlet and a reservoir outlet surface of the reservoir, different from the reservoir inlet surface, may comprise the plurality of reservoir outlets. This may cause the liquid to flow across the interior volume of the reservoir from the at least one reservoir inlet to the plurality of reservoir outlets, enabling the reservoir to at least partially fill with liquid before the liquid exits the reservoir. This aids in generating an appropriate liquid pressure within the reservoir to cause the liquid to be expelled from the reservoir outlets at a desired rate.

The reservoir inlet surface may be a side surface of the reservoir facing the liquid distribution tank and the reservoir outlet surface may be a base surface of the reservoir. Locating the at least one reservoir inlet on the side surface of the reservoir facing the liquid distribution tank for example shortens a path for distributing the liquid from the liquid distribution tank to the at least one reservoir inlet. For example, a shorter tube or other connector can be used to connect the at least one reservoir inlet to the liquid distribution tank. This means that the liquid can be transferred to the reservoir and subsequently to the surface to be cleaned more efficiently than otherwise. Furthermore, by locating the reservoir outlets on a base surface of the reservoir, which for example faces the surface to be cleaned with the cleaner head in use, gravity can aid in the subsequent deposition of the liquid from the reservoir outlets onto the roller, which is for example located at a lower position vertically than the reservoir outlets with the cleaner head in use.

In use, a flow rate of liquid exiting the reservoir may be between approximately millilitres per minute and approximately 35 millilitres per minute. Such a flow rate may be sufficiently high to enable effective cleaning of the surface, without depositing surplus liquid on the surface.

In use, a liquid pressure in the reservoir may be between approximately 13.5 kilopascals (kPa) and approximately 14.5 kilopascals. With this liquid pressure, the liquid may exit the reservoir outlets due to the liquid pressure rather than due to gravity, which can further aid in achieving the substantially uniform flow of liquid from the reservoir outlets.

The cleaner head may comprise a distribution surface for receiving liquid from the plurality of reservoir outlets for distributing the liquid onto the roller. Without a distribution surface, liquid leaving the reservoir via the reservoir outlets is for example deposited onto the roller under pressure and can bounce or splash off or otherwise be ejected from a surface of the roller rather than saturating the roller. This can reduce the efficiency of the cleaner head. Furthermore, the ejected liquid can also escape from the cleaner head and come into contact with the surface to be cleaned, leaving wet spots, or other components of the cleaner head, which may affect safety. However, arranging a distribution surface for example means that the liquid exiting the at least one reservoir outlet is deposited onto the distribution surface before flowing onto the roller. This may result in a lower speed of the liquid as the liquid is distributed from the distribution surface onto the roller compared to direct deposition of the liquid from the at least one reservoir outlet onto the roller. This can reduce splashing of liquid from the roller when the liquid is deposited on the roller, allowing the liquid to penetrate and saturate the roller more readily. This may improve the efficiency of the cleaner head and reduce undesirable wet spots on the surface to be cleaned.

The distribution surface may be substantially parallel to a reservoir outlet surface of the reservoir comprising the plurality of reservoir outlets. Arranging the distribution surface substantially parallel to the reservoir outlet surface may be particularly effective at reducing ejection of liquid from the surface of the roller when the liquid is deposited on the roller from the distribution surface compared to other angles between the distribution surface and the reservoir outlet surface. For example, the distribution surface may be parallel to the reservoir outlet surface within manufacturing tolerances, such as within 5 degrees.

The cleaner head may comprise a reservoir cover to cover the reservoir and a seal located about a periphery of side walls of the reservoir, between the side walls and the reservoir cover. This may more securely contain the liquid within the reservoir and reduce the risk of liquid escaping from the reservoir and damaging other components of the cleaner head.

The seal may comprise silicone. Such a seal is for example hard-wearing and can be easily configured to tightly seal the reservoir.

According to a second aspect of the present invention there is provided a cleaner head for an appliance, the cleaner head comprising: a liquid distribution tank for storing liquid to be distributed to a surface to be cleaned; a roller for contacting the surface to be cleaned; a reservoir having at least one reservoir inlet for receiving liquid from the liquid distribution tank and at least one reservoir outlet for distributing the liquid onto the roller; and a drive component for driving distribution of liquid from the liquid distribution tank to the reservoir, wherein a ratio of an interior volume of the reservoir in millimetres cubed to a total combined cross-sectional area of the at least one reservoir outlet in millimetres squared is between 150 and 400.

This ratio for example assists in obtaining a suitable flow of liquid from the at least one reservoir outlet for wetting the roller in an efficient manner without liquid pressure building up to excess within the reservoir.

The interior volume of the reservoir in millimetres cubed may be between 1300 and 2800 times greater than a cross-sectional area of the or each at least one reservoir outlet in millimetres squared. This may further assist in obtaining an appropriate flow of liquid from the at least one reservoir outlet for effective cleaning of a surface.

The interior volume of the reservoir in millimetres cubed is between 900 and 1900 times greater than a cross-sectional area of the or each at least one reservoir inlet in millimetres squared. This may aid in filling of the reservoir liquid at an appropriate rate that is sufficiently high to provide for efficient cleaning of a surface, without being unsafe or leading to leakages of liquid from the reservoir.

The total combined cross-sectional area of the at least one reservoir outlet may be at least 2.5 times greater than a total combined cross-sectional area of the at least one reservoir inlet and less than 10 times greater than the total combined cross-sectional area of the at least one reservoir inlet. This can further improve the suitability of the flow of liquid from the at least one reservoir outlet for efficient cleaning of a surface, by providing for efficient deposition of the liquid onto the roller without leading to excessive pressure building up in the reservoir.

The cleaner head may comprise a distribution surface for receiving liquid from the at least one reservoir outlet for distributing the liquid onto the roller. As explained with respect to the first aspect, this can reduce splashing liquid from the roller when the liquid is deposited on the roller, which can improve the efficiency of the cleaner head and reduce the deposition of undesirable wet spots on the surface to be cleaned.

The distribution surface may be substantially parallel to a reservoir outlet surface of the reservoir comprising the at least one reservoir outlet. This may be particularly effective at reducing ejection of liquid from the surface of the roller when the liquid is deposited on the roller from the distribution surface compared to other angles between the distribution surface and the reservoir outlet surface. For example, the distribution surface may be parallel to the reservoir outlet surface within manufacturing tolerances, such as within 5 degrees.

According to a third aspect of the present invention there is provided an appliance comprising a cleaner head according to the first or second aspect of the present invention.

The appliance may comprise a main unit, and the cleaner head may be releasably attachable to the main unit. This may enable the functionality of the cleaner head to be selectively provided for the appliance, for example enabling the cleaner head to be swapped for a further cleaner head of different form and/or functionality.

The main unit may comprise a power supply for supplying electrical power to the drive component. This may reduce the need for a separate power supply to be provided in the cleaner head, which may reduce size and/or weight and/or cost of the cleaner head.

Optional features of aspects of the present invention may be equally applied to other aspects of the present invention, where appropriate.

Brief Description of the Drawings

Figure 1 is a perspective view of a cleaner head; Figure 2 is an exploded perspective view of the cleaner head of Figure 1, showing first and second housing portions; Figure 3 is a perspective view of the first housing portion of Figure 2 in isolation; Figure 4 is a bottom plan view of the first housing portion of Figure 3; Figure 5 is an upper plan view of the first housing portion of Figure 3; Figure 6A is a perspective view illustrating a removable cover of a liquid collection tank of the first housing portion of Figure 3, and Figure 6B is a cross-sectional view of a squeegee of the first housing portion of Figure 3; Figure 7 is a perspective view of the second housing portion of Figure 2 in isolation; Figure 8 is a perspective view of the second housing portion of Figure 7 with a wall section removed; Figure 9 is a right side view of the second housing portion of Figure 7; Figure 10 is a schematic view of the cleaner head of Figure 1 with an upper wall and a side wall of its housing removed; Figure 11 is a schematic cross-sectional view taken along a central depth line of the cleaner head of Figure 1; Figure 12 is an enlarged view of the circled region denoted A in Figure 11; and Figure 13 is a schematic illustration of an appliance comprising the cleaner head of Figure 1.

Detailed Description of the Invention

A cleaner head 10 is illustrated in Figures 1 to 2.

The cleaner head 10 comprises a housing 12, a roller 14, and an attachment mechanism 16. The roller 14 is rotatably connected to the housing 12 such that it rotates about a rotational axis R (see Figure 2) that is substantially parallel to a width direction W of the housing 12. The housing 12 comprises a first housing portion 18 and a second housing portion 20 releasably connected to each other.

The first housing portion 18 is illustrated in Figures 3 to 6, and comprises a right side wall 22, a tank assembly 24, a mounting member 26, a catch mechanism 28, and a projection in the form of a guide strip 30. The right side wall 22 is generally elongate in form, and extends generally in a depth direction D of the cleaner head 10. The tank assembly 24 and the mounting member 26 are each fixedly connected to the right side wall 22 (allowing the mounting member 26 to be fixedly connected to the tank assembly 24). The tank assembly 24 and the mounting member 26 extend from the right side wall 22 such that the tank assembly 24 and the mounting member 26 are located within the housing 12 when the cleaner head 10 is assembled. The catch mechanism 28 and the guide strip 30 are generally centrally located along the right side wall 22.

The mounting member 26 is located at a front end 32 of the right side wall 22, with the tank assembly 24 located rearwardly of the mounting member 26. The front end 32 of the right side wall 22 is generally shaped to correspond to the curvature of the roller 14, and has a region of reduced radius such that the roller 14 is partially exposed at the front of the housing 12 when the cleaner head 10 is assembled and the roller 14 contacts the surface to be cleaned.

The tank assembly 24 comprises a liquid distribution tank 34 for storing liquid to be distributed to a surface to be cleaned and a liquid collection tank 36 for collecting liquid from the surface to be cleaned. The liquid collection tank 36 and the liquid distribution tank 34 are fixedly connected to one another. The liquid distribution tank 34 is hollow in form and has a curved rear wall 37, a flat base wall 38, a wheel 40, an inlet 42, and a closure 44. The wheel 40 is disposed in the flat base wall 38. The inlet 42 is covered and closed by the closure 44 in Figures 4 and 5, and has the form of an aperture defined by a neck with an external screw thread that cooperates with an internal screw thread of the closure 44. The inlet 42 is located on the liquid distribution tank 34 such that the inlet 42 is located within an interior volume of the housing 12 when the cleaner head 10 is assembled. The inlet 42 faces in a first direction W along the housing 12 of the cleaner head 10. This first direction is a direction toward a sidewall of the housing 12 when the cleaner head 10 is located on a surface to be cleaned in use.

The closure 44 has the form of a cap that covers the inlet 42, and is removable from the inlet 42 via twisting. The closure 44 comprises a valve member 46 that enables fluidic communication between an interior of the liquid distribution tank 34 and a drive component comprising a pump 84 (see Figure 8).

The liquid distribution tank 34 has an internal volume of around 300m1. The liquid distribution tank 34 extends for substantially the full height direction H of the cleaner head 10, but only extends partially (for a little over 50%) across a width direction W of the housing 12 of the cleaner head 10. The liquid distribution tank 34 is located at a rear end 48 of the right side wall 22, and forms part of a rear surface of the cleaner head 10 when the cleaner head 10 is assembled.

The liquid collection tank 36 comprises a main tank body 50, an upper plate 52, and a removable cover 54 releasably connected to the main tank body 50 via an interference fit. The liquid collection tank 36 further comprises a front wall 56 and a surface contact member in the form of a squeegee 58. The squeegee 58 and removable cover 54 are entirely removable from the main tank body 50. The liquid collection tank 36 is located generally centrally along the right side wall 22, such that the liquid collection tank 36 is located between the liquid distribution tank 34 and the mounting member 26. A bottom surface of the liquid collection tank 36 and a bottom surface of the liquid distribution tank 34 are substantially aligned.

The main tank body 50 is generally cuboidal and hollow in form, and extends across substantially the entirety of the width direction W of the cleaner head 10 when the cleaner head 10 is assembled. An upper region of the main tank body 50 is open such that the hollow interior of the main tank body 50 is accessible via the upper region. The main tank body 50 has an internal volume of around 360m1, giving the liquid collection tank 36 an internal volume 20% greater than the internal volume of the liquid distribution tank 34.

The upper plate 52 is generally solid and planar in form, and is fixedly connected to a rear section of a periphery of the upper region of the main tank body 50 such that the upper plate 52 overlies around 50% of the upper region of the main tank body 50. The removable cover 54 is selectively locatable underneath the upper plate 52 such that the removable cover 54 overlies the upper region of the main tank body 50.

Referring to Figure 6A, the removable cover 54 is generally rectangularly shaped in plan view, and has an outer periphery 60, an inner periphery 62, a sloped surface 64, and a handle in the form of a pull-tab 66, and mounting wings 67.

The sloped surface 64 slopes from the outer periphery 60 to the inner periphery 62 such that the inner periphery 62 is located a lower height relative to the outer periphery 60 when the removable cover 54 is located on the main tank body 50. The pull tab 66 is located on a front periphery of the removable cover 54 and is facing outwardly from an upper surface of the cover 54 (in particular, it is upstanding from the sloped surface 64). The inner periphery 62 defines an elongate slot that acts as a combined inlet/outlet 65 of the liquid collection tank 36. The combined inlet/outlet 65 may be located symmetrically about a center line of the liquid collection tank 36. Due to the sloped surface 64, the combined inlet/ outlet 65 is located at a height lower than a height of the main tank body 50.

The combined inlet/outlet 65 faces in a second direction H along the housing 12 of the cleaner head 10, where the second direction H is different to the first direction Win which the inlet 42 of the liquid distribution tank 34 faces. As shown in Figure 1, the second direction H is substantially orthogonal to the first direction W and to the rotational axis R, and is a direction toward an upper surface of the housing 12 when the cleaner head 10 is located on a surface to be cleaned in use. The mounting wings 67 extend from sides of the outer periphery 60 near a front region of the outer periphery 60, and are shaped and dimensioned to be received between the upper plate 52 and the front wall 56 of the liquid collection tank 36. The pull tab 66 is spaced from the combined inlet/outlet 65 by virtue of its location on the sloped surface 64.

The front wall 56 is arcuate in form, and is shaped to generally correspond to the curvature of the roller 14. A lower region of the front wall 56 is shaped and spaced from the main tank body 50 to define a channel within which the squeegee 58 is received. The channel is open at one end to enable the squeegee 58 to slide into and out of the channel.

The squeegee 58 is formed of a resiliently deformable material, and is shaped such that the squeegee 58 is an extension of the front wall 56 when located within the channel. When located within the channel, the squeegee 58 extends from the front wall 56 such that a surface of the squeegee 58 and a surface of the front wall 56 form a continuous surface. As shown in Figure 6B, a rear portion of the squeegee 58 includes an elongate element 581 extending from a top surface of the squeegee 58. The elongate element 581 includes a first elongate recess 582a and a second elongate recess 582b. Referring to Figure 11, the arcuate front wall 56 ends with a first elongate protrusion 562a. A second elongate protrusion 562b extends from the bottom of the main tank body 50, and is arranged vertically below the first elongate protrusion 562a. To locate the squeegee 58 within the channel, the squeegee 58 is slid relative to the main tank body 50, and the first 562a and second 562b elongate protrusions are received within the first 582a and second 582b elongate recesses respectively. The squeegee 58 extends to a position slightly lower than a lower surface of the main tank body 50 when located within the channel. A vertical gap G (see Figure 3) between the lower surface of the main tank body 50 and the surface to be cleaned is thus formed when the cleaner head is in use. As the roller 14 rotates, the rotational energy from the roller 14 helps to scoop the liquid (from the surface to be cleaned) up along the arcuate front wall 56. The vertical gap G is dimensioned so that it is small enough to prevent dirty liquid from the surface being cleaned to pass beyond the squeegee toward the rear of the cleaner head 10, and large enough to prevent scratching of the surface by the main tank body 50. A height (along the direction H in Figure 1) of this vertical gap G may range from about 0.2mm to 1.5mm.

As previously noted, the mounting member 26 is located at the front end 32 of the right side wall 22. The mounting member 26 is releasably connected to the roller 14 and rotatably mounts the roller 14 within the housing 12. The mounting member 26 is shaped and dimensioned to be received within, and engage with, the roller 14. The mounting member 26 is fixedly connected to the right side wall 22, yet comprises a bearing assembly (not shown) to enable rotation of the roller 14 when connected to the mounting member 26. Further details of the mounting member 26 will be apparent to a person skilled in the art, and so will not be described here for sake of brevity.

The catch mechanism 28 is located substantially centrally along the right side wall 22, above the liquid distribution tank 34. The catch mechanism 28 comprises a depressible button 70 and a hook 72 movable in response to movement of the depressible button 70. The hook 72 is releasably engageable with a corresponding latch (not shown) formed on an underside of an upper wall 74 (see Figure 7) of the second housing portion 20.

The guide strip 30 is elongate in form and extends in the width direction W to a similar extent as that of the liquid collection tank 36. The guide strip 30 is spaced vertically apart from the upper plate 52, and is shaped and dimensioned to be received within a guide channel 94 of the second housing portion 20. The guide strip 30 has a generally T-shaped cross-sectional shape.

The second housing portion 20 is illustrated in Figures 7 to 12. The second housing portion 20 comprises an upper wall 74, a left side wall 76, control circuitry 78, a drive mechanism in the form of a roller drive 80, a pump compartment 82, a pump 84, a liquid tube 86, an intermediate plate 87, a reservoir 88, a distribution surface 90, a mangle 92, and a guide channel 94. The roller 14 is rotatably connected to the second housing portion 20.

A front end of the upper wall 74 is shaped to correspond to the curvature of the roller 14, and a planar portion of the upper wall 74 comprises a notch 96 shaped and dimensioned to receive the depressible button 70 of the catch mechanism 28.

The left side wall 76 is generally elongate in form, and extends in the depth direction D of the cleaner head 10. The outer surface of the left side wall 76 is the same shape as that of the right side wall 22. The left side wall 76 is hollow in form, and defines a compartment 98 within which the control circuitry 78 is housed. The compartment 98 is sealed from any regions within the housing 12 that contain liquid in use. An inner surface of the left side wall 76 comprises a locating feature in the form of a locating ridge 77 that generally corresponds to a side surface of the liquid collection tank 36.

The control circuitry 78 comprises appropriate control circuitry for driving the roller drive 80 and the pump 84. Further details of how the control circuitry 78 drives the roller drive 80 and the pump 84 will be provided hereafter. The control circuitry 78 also comprises a delay component, specifically a delay circuit, the functionality of which will be discussed hereafter.

The roller drive 80 is located at, and fixedly connected to, a front end 100 of the left side wall 76 at a similar position to which the mounting member 26 is connected to the right side wall 22 of the first housing portion 18. The roller drive 80 comprises an appropriate torque generator, such as a motor, for generating a torque to drive rotation of the roller 14. The roller drive 80 is shaped and dimensioned to fit within an interior of the roller 14, such that the roller drive 80 is located internally of the roller 14 with the roller 14 and the roller drive 80 concentric when the cleaner head 10 is assembled. The roller drive 80 is controlled by the control circuitry 78 to operate at a rate of rotation of around 900- 1000rpm in a steady state. Steady state operational speeds in the region of 500- 120Orpm are also envisaged.

The pump compartment 82 is substantially hollow in form, and is shaped and dimensioned to receive the pump 84 therein. The pump compartment 82 is 30 further shaped and dimensioned to correspond to a projected footprint of the liquid distribution tank 34. The pump compartment 82 is located at a rear end 102 of the left side wall 76, and extends partially in the width direction W of the cleaner head 10. The pump compartment 82 has an aperture (not shown) which enables the pump 84 to connect to the valve member 46 of the closure 44 of the liquid distribution tank 34.

The pump 84 is any appropriate pump for driving liquid from the liquid distribution tank 34 to the reservoir 88, as will be discussed in more detail hereafter. The pump 84 is controlled by the control circuitry 78 to operate in a pulsed or cyclical manner, with the pump 84 controlled to be on for a first duration, to be off for a second duration, and so on. In other words, the pump 84 is on (i.e. drives the distribution of liquid) for the first duration to generate each pulse and consecutive pulses are separated by the second duration in which the drive component does not drive the distribution of liquid. The first duration lasts for at least one revolution of the roller 14. The first duration may be 0.25 seconds and the second duration may be 6 seconds, which equates to the first duration being around 4% of the second duration. With a roller speed of between around 900rpm and 1000rpm, the first duration of 0.25 seconds equates to the pump 84 being controlled to be on for between around 3.8 and 4.2 revolutions of the roller 14. With a roller speed of between around 500rpm and 1200rpm, the first duration of 0.25 seconds equates to the pump 84 being controlled to be on for between around 2 and 5 revolutions of the roller 14. In other examples, the pump 84 may be controlled to be off for a duration of between around 3 and 10 seconds. In still other examples, the first duration may be between around 2% and 9% of the second duration. In yet still other examples, there may be a valve for controlling the passage of liquid from the pump 84. For example, the pump 84 may operate continuously, and the valve may be configured or otherwise controlled to open and close in a pulsed or cyclical manner.

Referring to Figure 10, the liquid tube 86 extends from the pump 84 to the reservoir 88 along the intermediate plate 87. The intermediate plate 87 is fixedly connected to the left side wall 76 at a region between the front 100 and rear 102 ends of the left side wall 76, and is vertically spaced apart from the upper wall 74. An upper surface of the intermediate plate 87 comprises a dividing wall 104 and a lower surface of the intermediate plate 87 comprises the guide channel 94 (see Figure 9). The dividing wall 104 extends across the width of the intermediate plate 87, and, together with the upper wall 74 defines a guide region 106 and a reservoir region 108.

The guide region 106 is a hollow cavity that acts to guide the liquid tube 86 from the pump 84 to the reservoir 88, and to guide electrical looming from the attachment mechanism 16 to the control circuitry 78 within the compartment 98.

The liquid tube 86 extends through a gap in the dividing wall 104 to bridge the guide region 106 and the reservoir region 108.

The guide channel 94 extends across the lower surface of the intermediate plate 87 in the width direction W of the cleaner head 10. The guide channel 94 is shaped and dimensioned to receive the guide strip 30 of the first housing portion 18. An end of the guide channel 94 opposite to the left side wall 76 is open such that the guide strip 30 can be slidably received within the guide channel 94.

Referring to Figure 12, the reservoir 88 is at least partly formed by the second housing portion 20 and is defined by the upper surface of the intermediate plate 87 in the reservoir region 108, reservoir side walls 110, and a reservoir cover 91 located between lower surface of the upper wall 74 of the second housing portion 20 and the upper ends of the reservoir walls 110. The reservoir 88 is generally cuboidal in form and is elongate along an axis parallel to a rotational axis of the roller 14. A seal 112 (which may include silicon) is located about a periphery of the reservoir side walls 110, in particular, between the side walls 10, the reservoir cover 91 and the intermediate plate 87. The reservoir side walls 110 are shaped such that the reservoir 88 extends across the width direction W of the cleaner head 10, and has a width in the direction W of around 202mm. The reservoir 88 extends for around 90% of a length of the roller 14 (where the length of the roller 14 extends along the W direction shown in Figure 1), although the reservoir 88 extending for at least 80% of the length of the roller 14 is also envisaged. The reservoir 88 has an interior volume of around 1444mm3. An interior volume of up to around 1571mm3 is also envisaged.

The reservoir 88 has a reservoir inlet 114 and eight reservoir outlets 116, although between 6 to 10 reservoir outlets are also envisaged. The reservoir inlet 114 comprises a circular aperture formed centrally along a rear one of the reservoir side walls 110, in a reservoir inlet surface 115 which is a side surface of the reservoir 88 facing the liquid distribution tank 34. The reservoir inlet 114 is in fluid communication with the liquid tube 86 and receives liquid from the liquid distribution tank 34. The reservoir inlet 114 has a radius in the region of 1.25mm, although radii in the region of 1.00mm to 1.50mm are also envisaged.

The reservoir outlets 116 are spaced substantially evenly along a length of the reservoir 88 along an axis parallel to the rotational axis of the roller 14. Further, they are offset from the reservoir inlet 114 along the axis parallel to the rotational axis of the roller 14. The reservoir outlets 116 comprise generally circular apertures formed in a reservoir outlet surface 117 of the intermediate plate 87 in the reservoir region 108, which is a base surface of the reservoir 88. Each reservoir outlet 116 has a radius of around 1.00mm, and the reservoir outlets 116 are spaced by around 28.00mm along the width direction W of the cleaner head 10. The reservoir outlets 116 cover a length extending to around 90% of a length of the roller 14, although the reservoir outlets 116 covering a length of at least 80% of the length of the roller 14 is also envisaged. The cross-sectional area of the reservoir inlet 114 is larger (e.g. less than 3 times larger) than the cross-sectional area of each reservoir outlet 116. In one example, the reservoir inlet 114 has a radius of around 1.25 times the radius of an individual reservoir outlet 116, whilst the reservoir inlet 114 has a radius of around 0.16 times the combined radius of the reservoir outlets 116. A ratio of a total combined cross-sectional area of the reservoir outlets 116 to a cross-sectional area of the reservoir inlet 114, and a ratio of an interior volume of the reservoir 88 to a total combined cross-sectional area of the reservoir outlets 116 are such that in use, liquid exits the reservoir 88 substantially uniformly from the plurality of reservoir outlets 116. The combined cross-sectional area of the reservoir outlets 116 is around 5 times the cross-sectional area of the reservoir inlet 114. The interior volume of the reservoir 88 is around 1444 times the radius of each individual reservoir outlet 116, and is around 181 times the total combined cross-sectional area of the reservoir outlets 116. Such a configuration of the reservoir 88, in combination with the pulsed delivery cycle of the pump 84 mentioned previously, provides a water flow rate of around 30m1/min in the reservoir 88, alongside a pressure of around 13.5kPa to 14.5kPa in the reservoir 88. Radii of between 0.80mm and 1.20mm are also envisaged for the reservoir outlets 116, as is a spacing of around 25.00mm to 30.00mm between each reservoir outlet 116. Thus, a combined cross-sectional area of the reservoir outlets 116 of between around 2.5 and 10 times the cross-sectional area of the reservoir inlet 114, an interior volume of the reservoir 88 of between 150 to 400 times the combined cross-sectional area of the reservoir outlets 116, an interior volume of the reservoir 88 of between 1300 to 2800 times the individual cross-sectional area of each of the reservoir outlets 116, and an interior volume of the reservoir 88 of between 900 to 1900 times the cross-sectional area of reservoir inlet 114 are also envisaged. Variations in size of the reservoir inlet 114 and the reservoir outlets 116 can lead to water flow rates in the reservoir 88 of between 25m1/min and 35m1/min. In other words, liquid is delivered to the pile 122 of the roller 14 at a rate of between 25m1/min and 35m1/min.

The distribution surface 90 is defined by a protrusion 118 of the second housing portion 20, where the protrusion 118 extends from the lower surface of the intermediate plate 87 underneath the reservoir outlets 116. The protrusion 118 forms a distribution structure comprising the distribution surface 90 for distributing liquid onto the pile 122 of the roller 14. The distribution surface 90 is below the reservoir outlet surface 117 (but non-overlapped by this surface 117) when the cleaner head 10 is located on the surface to be cleaned, in use. The distribution surface 90 is substantially planar in form On other words, substantially flat), and extends substantially parallel to the planar portion of the upper wall 74 (and substantially parallel to the reservoir outlet surface 117 and the surface to be cleaned when the cleaner head is located on this surface, in use). The distribution surface 90 is thus elongate along an axis parallel to a rotational axis of the roller 14 (R, illustrated in Figure 2, which is parallel to the width direction W of the cleaner head 10), with a substantially uniform distance between the edge of the distribution surface 90 and the roller 14 (indicated in Figure 12 using the reference numeral g). The distance g is taken in a direction perpendicular to the rotational axis of the roller 14 (R, shown in Figure 2) and along the depth direction D of the cleaner head (shown in Figure 1), and is very small in the example of Figure 12. However, it is envisaged that the distance between the edge of the distribution surface 90 and the roller 14 may be larger in other cases.

The distribution surface 90 is located around 1.6mm below each reservoir outlet 116 (indicated as a height h in Figure 12, which is parallel to a height direction H of the cleaner head 10 as shown in Figure 1 and represents a distance between a plane including the reservoir outlet surface 117 and a plane including the distribution surface 90). The distribution surface 90s has a depth d in the depth direction D of the cleaner head (in other words, a depth d along a short axis of the distribution surface 90) of around 4.1mm. Distances of around 1.5mm to 1.7mm between the distribution surface 90 and the reservoir outlet surface 117(corresponding to heights h as shown in Figure 12), are also envisaged, as are depths d in the region of 4.0mm to 4.3mm. Although not illustrated, dividers are positioned between adjacent ones of the reservoir outlets 116 along the distribution surface 90. The reservoir outlets 116 are positioned between first and second separating members 119a, 119b that separate the distribution surface 90 from the reservoir outlet surface 117. The dividers are the same as the separating members 119a,119b but positioned between two adjacent reservoir outlets 116 rather than at each end of the reservoir outlet surface 117.

The protrusion 118 also defines a collection surface 123 which is directly beneath the reservoir outlets 116, and is thus overlapped by the reservoir outlet surface 117. The collection surface 123 has a concave curved form, and extends substantially parallel to the planar portion of the upper wall 74. At least a portion of the collection surface 123 is angled with respect to the distribution surface. Liquid deposited on the collection surface 123 by the reservoir outlets 116 is urged by the collection surface 123 towards the distribution surface 90. The distribution surface 90 adjoins the collection surface 123 and is offset from the reservoir outlets 116 horizontally.

The mangle 92 is an elongate protrusion affixed to an underside of the intermediate plate 87, where a part of the mangle 92 is positioned below the distribution surface 90. A thickness TM of the mangle may be around 2mm. The protrusion 118, which in this case forms a distribution structure comprising the distribution surface 90, abuts the mangle 92. The distribution structure transfers liquid to the roller 14 substantially without transfer of the liquid to the mangle 92. The mangle 92 extends forwardly of the distribution surface 90, with a vertical distance v of around 3.4mm between the edge of the distribution surface 90 (facing the roller 14) and the mangle 92. The vertical distance v is in a direction perpendicular to the rotational axis R of the roller 14 and is parallel to a height direction H of the cleaner head 10. Vertical distances v of around between 3.0mm and 4.00mm are also envisaged. As shown in Figure 12, a portion of the roller 14 is located between the edge of the distribution surface 90 and the mangle 92.

The mangle 92 projects at an acute angle 0 of approximately 30 to 60 degrees (see Figure 11) with respect to the distribution surface 90 and relative to an axis of rotation of the roller 14 from a plane passing through the rotational axis of the roller 14 and parallel to the surface to be cleaned when the cleaner head 10 is located on the surface to be cleaned in use. The mangle 92 is dimensioned to extend around 2.5mm into the roller 14 (with such extension labelled E in Figure 12), as will be discussed in more detail hereafter. The mangle 92 is thus at an acute angle 8 (in this case of between approximately 30 to 60 degrees) relative to the distribution surface 90. Penetration depths E of between 2mm and 3mm are also envisaged.

The roller 14 comprises a core 120 and a material for contacting a surface to be cleaned where the material is in the form of a pile 122. The core 120 is generally cylindrical (with a cylindrical base surface) and hollow in form. An interior of the core 120 is provided with fixing mechanisms for releasably fixing the roller 14 to the roller drive 80 and the mounting mechanism 26. Details of such fixing mechanisms are not pertinent to the present invention, and so will not be described here for sake of clarity. A diameter of the core 120 is sufficiently large that the roller drive 80 can be received within the core 120. The pile 122 is a microfibre pile with a density of between 46,500 and 85,250 fibres/cm2. The pile 122 has a thickness T of around 5mm. The roller 14 as a whole has a radius of around 62mm when dry, and around 58mm when wet. The roller 14 has a length of around 226mm, although lengths in the region of 225mm and 227mm are also envisaged. In other words, a surface area of the pile 122 is between 800 and 900 square centimetres.

As previously noted, the cleaner head 10 comprises an attachment mechanism 16. The attachment mechanism 16 comprises a lower portion 124 and an upper portion 126. The lower portion 124 is hingedly mounted to a central region of the upper wall 74 of the second housing portion 20, such that the lower portion 124 can move in a plane defined by the depth D and height H directions of the cleaner head 10. The upper portion 126 is hingedly mounted to the lower portion 124 to enable the upper portion 126 to move relative to the lower portion 124 in a plane defined by the width W and height H directions of the cleaner head 10.

The upper portion 126 comprises a connection formation 128, and looming, which isn't shown for sake of clarity. The connection formation 128 comprises a catch for releasably connecting to either a wand 204 or a main unit 202 of an appliance 200. Details of the catch are not pertinent to the present invention, and will not be described here for sake of brevity. The connection formation 128 is tubular in form and solid, such that there is no airflow path therethrough. The looming provides an electrical connection between the main unit 202 of the appliance 200 and the cleaner head 10.

The cleaner head is shown in an assembled configuration in Figure 1 and in a disassembled configuration in Figure 2.

To assemble the cleaner head 10, the roller 14 is connected to the roller drive 80, and the first 18 and second 20 housing portions are moved toward one another via a sliding motion along the width direction W of the cleaner head 10. The guide strip 30 is received in the guide channel 94 to guide the relative sliding motion. As a result of the sliding motion, the first 18 and second 20 housing portions are brought together and the hook 72 of the catch mechanism 28 engages the latch of the upper wall 74 of the second housing portion 20 to secure the first 18 and second 20 housing portions in place relative to one another. Thus, the first 18 and second 20 housing portions are slidably connected to one another along an axis parallel to the rotational axis R of the roller 14.

Bringing together the first 18 and second 20 housing portions moves the mounting member 26 into contact with the roller 14, such that the roller 14 is rotatably connected to the housing 12 by each of the mounting member 26 and the roller drive 80. The locating ridge 77 locates the tank assembly 24 relative to the second housing portion 20. In particular, the locating ridge 77 defines a recess for receiving a portion (side wall) of the liquid collection tank 36. The valve member 46 of the closure 44 of the liquid distribution tank 34 is brought into contact with the pump 84 such that a fluidic connection is made between the liquid distribution tank 34 and the pump 84. When the first 18 and second 20 housing portions are assembled together, the roller 14 is located at a first end of the housing 12 and the liquid distribution tank 34 is located at a second end of the housing 12 (the first and second ends being opposite to each other along the depth direction D of the housing 12). The liquid collection tank 36 is located between the liquid distribution tank 34 and the roller 14 in the depth direction D of the housing 12. Further, both the inlet 42 of the liquid distribution tank 34 and the combined inlet/outlet 65 of the liquid collection tank 36 are located within an internal volume of the housing 12. Additionally, the liquid distribution tank 34 and the pump 84 are adjacent to one another across the width of the housing 12. In other words, each of the liquid distribution tank 34 and the pump 84 extends partially across the width of the housing 12.

In the assembled configuration, the roller 14 extends along the width of the cleaner head 10 between the right side wall 22 and the left side wall 76 of the respective first 18 and second 20 housing portions, at the front of the cleaner head 10. The reservoir 88 overlies a rear portion of the roller 14. The mangle 92 extends into the pile 122 of the roller 14. The liquid collection tank 36 is located rearwardly of the roller 14, with the front wall 56 spaced slightly from the roller 14 to enable rotation of the roller 14 within the housing 12. The combined inlet/outlet 65 of the liquid collection tank 36 faces toward the upper wall 74 of the cleaner head 10. The mangle 92 is positioned between 3 and 5mm higher (with such a distance labelled m in Figure 11) than the combined inlet/outlet 65 of the liquid collection tank 36. The liquid collection tank 36 extends across the width direction W of the cleaner head 10 to a similar extent to that of the roller 14 between the right side wall 22 and the left side wall 76 of the respective first 18 and second 20 housing portions. The liquid collection tank 36 and the roller 14 may each extend across at least 90% of the width of the housing 12 (i.e. dimension of the housing 12 along the direction W between the opposing side walls 22, 76). The combined inlet/outlet 65 may extend across at least 75% of a width of the liquid collection tank 36.

The liquid distribution tank 34 is located rearwardly of the liquid collection tank 36. The liquid collection tank 36 extends across the width in the direction W (between the opposing side walls 22, 76) of the housing 12 to a greater extent than the liquid distribution tank 34. The pump compartment 82, and hence the pump 84, are located adjacent to the liquid distribution tank 34 across the width W of the cleaner head 10. The attachment mechanism 16 is located centrally on the upper wall 74 such that the attachment mechanism 16 overlies the liquid collection tank 36, and is connected to the upper wall 74 at a point between the roller 14 and the liquid distribution tank 34.

To disassemble the cleaner head 10, a user depresses the depressible button 70 to remove the hook 72 of the catch mechanism 28 from engagement with the latch of the upper wall 74 of the second housing portion 20. At the same time, the user applies a force to separate the first 18 and second 20 housing portions by relative sliding of the first 18 and second 20 housing portions. Sliding motion of the first 18 and second 20 housing portions is constrained by movement of the guide strip 30 along the guide channel 94 to be in a direction parallel to a rotational axis R of the roller 14.

Since the tank assembly 24 is arranged within the first housing portion 18, the tank assembly 24 is releasably connected to the second housing portion 20 when the first 18 and second 20 housing portions are assembled. As the user slides the first 18 and second 20 housing portions away from one another along a connection axis (parallel to the axis of rotation R of the roller 14), the tank assembly 24 is moved along the connection axis and is disconnected from the second housing portion 20. Disconnection of the first 18 and second 20 housing portions breaks the fluidic connection between the liquid distribution tank 34 and the pump 84. Similarly, the connection between the mounting member 26 and the roller 14 is broken, with the mounting member 26 being removed from within an end of the core 120 of the roller 14. The user can continue to separate the first 18 and second 20 housing portions until the guide strip 30 leaves the guide channel 94, and the first 18 and second 20 housing portions are discrete, separated components.

In such a manner, the tank assembly 24, i.e. the liquid distribution tank 34 and the liquid collection tank 36, is removable from the second housing portion 20 by sliding the tank assembly 24 along the width direction W of the cleaner head 10.

The tank assembly 24 is then located separately from electronic components of the cleaner head 10, and the liquid collection tank 36 can be emptied, and the liquid distribution tank 34 can be refilled. The removable cover 54 can be removed from the liquid collection tank 36 to aid with emptying.

Similarly, the roller 14 may then be removed from the second housing portion 20 by sliding the roller 14 along its axis of rotation to separate the roller 14 from the roller drive 80. The roller 14 can then be cleaned by a user.

When desired, the user can reassemble the cleaner head 10 in the manner previously described.

To use the cleaner head 10, the attachment mechanism 16 is used to connect the cleaner head 10 to an appliance 200, as illustrated schematically in Figure 13.

The appliance 200 has a main unit 202, and a wand 204 releasably connected to the main unit 202. The cleaner head 10 can be connected to either of the main unit 202, or to the wand 204, depending on a user's preference. The main unit 202 houses a power supply in the form of a battery 206, an airflow generator 208, and a control module 210. Power can be provided from the battery 206 to the airflow generator 208, and to the cleaner head 10 via a terminal (not shown) of the main unit 202, under control of the control module 210. Further details of the main unit 202 are not pertinent to the present invention, and will not be discussed here for sake of brevity.

The control module 210 determines whether the cleaner head 10 is attached to the main unit 202 based on a current drawn from the terminal in response to a voltage applied to the terminal. When the cleaner head 10 is attached to the main unit 202, either directly or via the wand 204, and a user actuates the main unit 202 by pressing a button or trigger or the like (i.e. sends a trigger signal indicating that the appliance is to be operated), the control module 210 of the main unit 202 causes a first voltage pulse to be sent to the cleaner head 10 via the terminal. As previously noted, the control circuitry 78 comprises a delay circuit. The delay circuit is configured to delay the draw of current by the cleaner head 10 from the terminal in response to the applied voltage. Specific details of the delay circuit are not important, and will be immediately apparent to a person skilled in the art. For example, an RC delay circuit may be utilised. This delay circuit means that, in response to the first voltage pulse, the control module 210 of the main unit 202 does not detect a current profile of the cleaner head 10 within a first time period of around 65-95ps post commencement of the first voltage pulse. The control module 210 of the main unit 202 then causes a second voltage pulse to be sent to the cleaner head 10 via the terminal. The control module 210 of the cleaner head 10 then detects a current profile within a second time period of say 300-350ps post commencement of the second voltage pulse.

Such a current profile, for example no current detected in the first time window and current detected in the second time window, may be distinctive compared to that provided by other cleaner heads, for example other cleaner heads without a delay circuit where a current profile is detected within the first time period by the control module 210 of the main unit 202. Thus the control module 210 can determine when the cleaner head 10 is attached to the main unit 202 based on the delay with which (or the particular one of a plurality of time periods) current is drawn from the terminal in response to the applied voltage. The control module 210 can also determine that a cleaner head other than cleaner head 10 is attached to the main unit 202 based on current being drawn from the terminal in response to the applied voltage in a different particular one of the plurality of time periods. If no current is drawn from the terminal in response to the applied voltage in any of the plurality of time periods, then it can be determined that no cleaner head is attached to the main unit 202. An initial one of the plurality of time periods may have a first duration and a subsequent time period may have a second duration longer than the first duration. The adjacent time periods may be separated from one another by a time gap. For example, the applied voltage may include a plurality of voltage pulses, one for each of the plurality of time periods, where there may be a time gap in between consecutive pulses.

The control module 210 can then take appropriate action in controlling the main unit 202. The control module 210 can operate the airflow generator 208 in either a first mode (in which power Is provided by the main unit 202 to the airflow generator 208 and an airflow is generated) and a second mode (in which power is not provided to the airflow generator 208 and an airflow is not generated). In particular, when the control module 210 determines that the cleaner head 10 is attached to the main unit 202, the control module 210 can control the operational mode of airflow generator 208 to be in the second mode (off), such that no airflow is provided by the main unit 202, as such airflow is not needed for the cleaner head 10. For other cleaner heads, the operational mode of the airflow generator 208 may instead be controlled to provide an airflow where such airflow is appropriate. When it is determined that there is no cleaner head attached to the main unit 202, the control module also controls the airflow generator to operate in the first mode.

Although the cleaner head 10 is detected here by looking at current profiles, other methods of detection, for example including communication from the cleaner head 10 to the control module via a wired and/or wireless connection, that enable the control module 210 to turn off the airflow generator 208 are also envisaged.

With the cleaner head 10 attached to the main unit 202, power is supplied from the battery 206 of the main unit 202 via looming (not shown) to the cleaner head 10, and in particular to the control circuitry 78, the roller drive 80, and the pump 84. With other cleaner heads attached to the main unit 202, power may also be supplied to these cleaner heads from the battery 206. However, power is not provided to the terminal of the main unit 202 when it is determined that no cleaner head is attached to the main unit 202.

The pump 84 drives distribution of liquid from the liquid distribution tank 34. The pump 84 is controlled by the control circuitry 78 to operate in a pulsed or cyclical manner, as noted previously, with the pump 84 controlled to be on for a first duration of 0.25 seconds, to be off for a second duration of 6 seconds, and so on.

In other words, for each pulse, the first duration is around 4% of the second duration. This causes liquid to be moved from the liquid distribution tank 34, through the liquid tube 86, to the reservoir 88. In particular, liquid is driven by the pump 84 via the reservoir inlet 114 to the reservoir 88, and liquid is delivered to the pile 122 of the roller 14 via the reservoir outlets 116. The pressure within the reservoir 88 is such that liquid exits the reservoir 88 through the reservoir outlets 116, and drips onto the distribution surface 90. The configuration of the reservoir 88 and the operation of the pump 84 is such that the liquid flow rate through the reservoir is around 30m1/min. The pump 84, the liquid tube 86, the reservoir 88, and the distribution surface 90 together provide a liquid delivery assembly for delivering liquid to the roller 14 (in particular, the pile 122 of the roller 14).

The liquid pools on the distribution surface 90 and is gradually distributed to the roller 14 by simply falling from the distribution surface 90 onto the pile 122 of the roller 14. The roller 14 is wetted at a rate of around 30m l/m in. With the roller 14 wetted by the liquid, the cleaner head 10 can be moved across a surface to be cleaned by the user. The roller drive 80 is controlled to rotate the roller 14 at around 900-1000rpm. As the roller 14 rotates and is moved across the surface to be cleaned, the roller 14 can impart a wiping force to the surface to be cleaned.

The squeegee 58 contacts the surface to be cleaned and ensures that no dirty liquid from the surface being cleaned passes toward the rear of the cleaner head 10.

The roller 14 causes displacement of liquid (from the surface to be cleaned) into the combined inlet/outlet 65 of the liquid collection tank 36.

In particular, the rotation of the roller 14 and the curved nature of the front wall 56 of the liquid collection tank ensures that dirty liquid, and debris, passes from the surface being cleaned to the interior volume of the cleaner head 10. The roller 14 directs the dirty liquid and debris toward the squeegee 58 and the rotational energy generated via rotation of the roller 14 pushes the dirty liquid and debris upwards along the front wall 56 into the main tank body 50 of the liquid collection tank 36.

Further, as previously noted, the mangle 92 contacts the roller 14, in particular, it extends into the pile 122 of the roller 14. As the roller 14 rotates, the roller 14 is driven so that the roller 14 impinges the mangle 92 from below. In such a manner the pile 122 contacts the mangle 92, the mangle 92 acts to scrape dirty liquid and debris from the pile 122 of the roller 14. Accordingly, the liquid carried by the roller 14 is displaced into the combined inlet/outlet 65 of the liquid collection tank 36 in use. The speed of the roller 14 at the mangle 92 is around 5 to 7 m/s, which has been found to be particularly good for removal of dirty liquid and debris from the pile 122 of the roller 14. Speeds of between around 3m/s to 8m/s are also envisaged. The positioning and shape of the mangle 92 results in dirty liquid and debris being passed rearwardly toward the liquid collection tank 36.

Such dirty liquid and debris is guided by a curved portion 89 of the intermediate plate 87 (adjacent to the mangle 92) and/or the sloped surface 64 of the removable cover 54 through the combined inlet/outlet 65 into the interior of the main tank body 50 of the liquid collection tank 36. For example, the dirty liquid and debris is guided by the curved portion 89 along a curved path towards the liquid collection tank 36. As shown in Figure 12, the curved portion 89 is concave from the perspective of the surface to be cleaned when the cleaner head 10 is located on the surface to be cleaned in use.

With the configuration of the cleaner head 10 described above, the roller 14 (in particular the pile 122 of the roller 14) is maintained at a saturation level of between 25% and 28% in use. Such a saturation level has been found to be effective at cleaning a surface to be cleaned, without the need to distribute excessive levels of liquid onto the surface. Efficient cleaning may also be achieved with a saturation level of between 10% and 30%.

When desired, for example when there is no remaining liquid in the liquid distribution tank 34, the cleaner head 10 can be removed from the main unit 202 of the appliance 200. The cleaner head 10 can then be disassembled in the manner previously described to enable the liquid collection tank 36 to be emptied, and the liquid distribution tank 34 to be refilled.

Whilst particular examples and embodiments have thus far been described, it should be understood that these are illustrative only and that various modifications may be made without departing from the scope of the invention as defined by the claims. For example, the values of various parameters and dimensions described in conjunction with the specific embodiment above may be varied within a reasonable tolerance range that will be apparent to a person skilled in the art without significantly modifying operation of the cleaner head 10.

Claims

Claims 1. A cleaner head for an appliance, the cleaner head comprising: a liquid distribution tank for storing liquid to be distributed to a surface to be cleaned; a roller for contacting the surface to be cleaned; a reservoir having at least one reservoir inlet for receiving liquid from the liquid distribution tank and a plurality of reservoir outlets for distributing the liquid onto the roller; and a drive component for driving distribution of liquid from the liquid distribution tank to the reservoir, wherein a ratio of an interior volume of the reservoir to a total combined cross-sectional area of the plurality of reservoir outlets is such that, in use, liquid exits the reservoir substantially uniformly from the plurality of reservoir outlets.
2. A cleaner head as claimed in any preceding claim, wherein the interior volume of the reservoir in millimetres cubed is at least 150 times greater than the total combined cross-sectional area of the plurality of reservoir outlets in millimetres squared.
3. A cleaner head as claimed in any preceding claim, wherein the interior volume of the reservoir in millimetres cubed is less than 400 times greater than the total combined cross-sectional area of the plurality of reservoir outlets in millimetres squared.
4. A cleaner head as claimed in any preceding claim, wherein the interior volume of the reservoir in millimetres cubed is at least 1300 times greater than a cross-sectional area of each of the plurality of reservoir outlets in millimetres 30 squared.
5. A cleaner head as claimed in any preceding claim, wherein the interior volume of the reservoir in millimetres cubed is less than 2800 times greater than a cross-sectional area of each of the plurality of reservoir outlets in millimetres squared.
6. A cleaner head as claimed in any preceding claim, wherein the interior volume of the reservoir in millimetres cubed is at least 900 times greater than a cross-sectional area of the or each at least one reservoir inlet in millimetres squared.
7. A cleaner head as claimed in any preceding claim, wherein the interior volume of the reservoir in millimetres cubed is less than 1900 times greater than a cross-sectional area of the or each at least one reservoir inlet in millimetres squared.
8. A cleaner head as claimed in any preceding claim, wherein the total combined cross-sectional area of the plurality of reservoir outlets is at least 2.5 times greater than a total combined cross-sectional area of the at least one reservoir inlet and less than 10 times greater than the total combined cross-sectional area of the at least one reservoir inlet.
9. A cleaner head as claimed in any preceding claim, wherein the reservoir has a single reservoir inlet and between 6 and 10 reservoir outlets.
10. A cleaner head as claimed in any preceding claim, wherein the reservoir is generally cuboidal, and a long axis of the reservoir is parallel to a rotational axis of the roller.
11. A cleaner head as claimed in claim 10, wherein a reservoir inlet surface of the reservoir comprises the at least one reservoir inlet and a reservoir outlet surface of the reservoir, different from the reservoir inlet surface, comprises the plurality of reservoir outlets.
12. A cleaner head as claimed in claim 11, wherein the reservoir inlet surface is a side surface of the reservoir facing the liquid distribution tank and the reservoir outlet surface is a base surface of the reservoir.
13. A cleaner head as claimed in any preceding claim, wherein, in use, a flow rate of liquid exiting the reservoir is between approximately 25 millilitres per minute and approximately 35 millilitres per minute.
14. A cleaner head as claimed in any preceding claim, wherein, in use, a liquid pressure in the reservoir is between approximately 13.5 kilopascals and approximately 14.5 kilopascals.
15. A cleaner head as claimed in any preceding claim, comprising a distribution surface for receiving liquid from the plurality of reservoir outlets for distributing the liquid onto the roller, wherein optionally the distribution surface is substantially parallel to a reservoir outlet surface of the reservoir comprising the plurality of reservoir outlets.
16. A cleaner head as claimed in any preceding claim, comprising a reservoir cover to cover the reservoir and a seal located about a periphery of side walls of the reservoir, between the side walls and the reservoir cover.
17. A cleaner head as claimed in claim 16, wherein the seal comprises silicone.
18. A cleaner head for an appliance, the cleaner head comprising: a liquid distribution tank for storing liquid to be distributed to a surface to be cleaned; a roller for contacting the surface to be cleaned; a reservoir having at least one reservoir inlet for receiving liquid from the liquid distribution tank and at least one reservoir outlet for distributing the liquid onto the roller; and a drive component for driving distribution of liquid from the liquid distribution tank to the reservoir, wherein a ratio of an interior volume of the reservoir in millimetres cubed to a total combined cross-sectional area of the at least one reservoir outlet in millimetres squared is between 150 and 400.
19. A cleaner head as claimed in claim 18, wherein the interior volume of the reservoir in millimetres cubed is between 1300 and 2800 times greater than a cross-sectional area of the or each at least one reservoir outlet in millimetres squared.
20. A cleaner head as claimed in claim 18 or claim 19, wherein the interior volume of the reservoir in millimetres cubed is between 900 and 1900 times greater than a cross-sectional area of the or each at least one reservoir inlet in millimetres squared.
21. A cleaner head as claimed in any one of claims 18 to 20, wherein the total combined cross-sectional area of the at least one reservoir outlet is at least 2.5 times greater than a total combined cross-sectional area of the at least one reservoir inlet and less than 10 times greater than the total combined cross-sectional area of the at least one reservoir inlet.
22. A cleaner head as claimed in any one of claims 18 to 21, comprising a distribution surface for receiving liquid from the at least one reservoir outlet for distributing the liquid onto the roller, wherein optionally the distribution surface is substantially parallel to a reservoir outlet surface of the reservoir comprising the at least one reservoir outlet.
23. An appliance comprising a cleaner head as claimed in any preceding claim.
24. An appliance as claimed in claim 23, wherein the appliance comprises a main unit, and the cleaner head is releasably attachable to the main unit.
25. An appliance as claimed in claim 24, wherein the main unit comprises a power supply for supplying electrical power to the drive component.