Floor cleaner

Abstract

A floor cleaner comprises a cleaning head (16, fig 1) and a liquid tank (20, fig 1). The liquid tank defines a liquid retaining volume 22, and the liquid retaining volume is in fluid communication wit

Description

TECHNICAL FIELD The present invention relates generally to floor cleaners and more particularly to a floor cleaner configured to collect a cleaning liquid from a floor surface during cleaning. BACKGROUND Different types of floor cleaner are each designed for cleaning various types of floor surfaces. For example, a dry vacuum cleaner may be designed for cleaning carpet or other dry flooring surfaces using vacuum suction and / or a rotating brush assembly. Wet floor cleaners are designed to clean floor surfaces with the help of a cleaning liquid. A wet floor cleaner may include means for removing the cleaning liquid from the floor surface during cleaning. For example, a wet floor cleaner may include an extraction pump to help remove dirty cleaning liquid from the floor surface using vacuum suction. The extraction pump may be arranged downstream of a liquid tank configured for capturing the dirty cleaning liquid and storing it for subsequent disposal. Use of a wet floor cleaner typically involves moving the cleaner along the floor surface being cleaned, for example in a forwards and backwards motion and / or side to side. However, moving the floor cleaner could cause the liquid in the tank to move, which in some examples may result in waves or swells in the liquid. Such movement of the liquid in the tank could increase the risk of introducing liquid to an inlet of the downstream extraction pump. Exposing the extraction pump to the cleaning liquid may be detrimental to the longevity of such a pump. For example, an extraction pump may include electronic connections and circuitry, and exposing these to liquids could cause short circuits and damage to the extraction pump. It is against this background that the present invention has been developed. SUMMARY In a first aspect of the present invention there is provided a floor cleaner comprising a cleaning head and a liquid tank. The liquid tank defines a liquid retaining volume, and the liquid retaining volume is in fluid communication with, and downstream of, the cleaning head. The floor cleaner further comprises an extraction pump. The extraction pump is in fluid communication with, and downstream of, the liquid retaining volume. The extraction pump is configured to apply vacuum pressure to the liquid retaining volume to draw fluid from the cleaning head to the liquid retaining volume. The floor cleaner further comprises a baffle arrangement defining an inlet for receiving fluid from the liquid retaining volume, an outlet for providing air to the extraction pump, and a baffle volume defined between the inlet and the outlet. The baffle arrangement further comprises one or more baffle walls arranged between the inlet and the outlet to define a tortuous fluid flow path between the inlet and the outlet. The baffle arrangement further comprises one or more drain apertures providing fluid communication between the baffle volume and the liquid retaining volume to allow liquid intercepted by the baffle walls to return to the liquid retaining volume. It will be appreciated that fluid received by the baffle arrangement via the inlet may comprise both liquids and gases. As such, the baffle arrangement is preferably configured to receive both liquids and gases. The liquid may be a cleaning liquid that is used to aid in cleaning a floor surface using the floor cleaner. In some examples the liquid may comprise water, and in some examples the liquid may additionally comprise a cleaning product. The gas may comprise air, for example. The baffle arrangement is configured to separate the liquid from the gas in the fluid received by the baffle arrangement, to help ensure that gas, i.e. air, is provided to the extraction pump whilst the flow of liquid to the extraction pump is obstructed. As such, the or each baffle wall is preferably configured to partially obstruct, i.e. to provide an obstacle for, the fluid entering the baffle arrangement via the inlet. When the fluid is intercepted by the or each baffle wall, the fluid is slowed down and the liquid is separated from the gas by gravity. If liquid covers the outlet defined by the baffle arrangement, i.e. the primary outlet, such liquid may effectively seal the outlet. In such an example, the vacuum pressure applied by the extraction pump may draw liquid covering the outlet towards, and potentially into, the extraction pump. Accordingly, in some examples, the baffle arrangement may further define a separate auxiliary outlet for providing air to the extraction pump. The provision of an auxiliary outlet in addition to the primary outlet helps to reduce or substantially eliminate the risk of drawing liquid into the extraction pump. The auxiliary outlet provides a second path for providing air to the extraction pump so that the suction of liquid covering the primary outlet is broken (or not even initiated), and air from the auxiliary outlet is provided to the extraction pump instead. Movement of the floor cleaner in use may cause waves or swells in the liquid retained in the liquid retaining volume. In outlier situations, such waves or swells could enter the baffle arrangement and cover an outlet. Accordingly, in some examples, the outlet and the auxiliary outlet may be provided in generally opposed positions about the baffle arrangement. This may help to ensure that at least one of the outlets is uncovered at all times, minimising the risk of drawing liquid towards the extraction pump as described previously. In preferred examples, the outlet may be provided in a back half of the baffle arrangement and the auxiliary outlet may be provided in an opposing front half of the baffle arrangement, or vice versa. For example, in use, the floor cleaner may be moved along an axis of movement in a general forward-to-b ackward motion. The front and back halves of the baffle arrangement may be defined in relation to their relative position on the axis of movement, in use. Forward-to-backward motion, or backward-to-forward motion, may cause liquid within the liquid retaining volume to move. In outlier cases, such as when the liquid retaining volume is very full, and / or when the floor cleaner is reclined at more than 75 degrees from a vertical axis, the movement of liquid within the liquid retaining volume may cause a wave or swell of liquid that enters the baffle arrangement and covers one of the outlets, as described previously. Providing the outlet and auxiliary outlet in the back half and front half of the baffle arrangement (or vice versa), i.e. in generally opposed positions about the baffle arrangement, helps to ensure that even in such outlier cases, at least one of the outlets is uncovered to continue providing air to the extraction pump. In some examples, the baffle arrangement may comprise a plurality of drain apertures providing fluid communication between the baffle volume and the liquid retaining volume. Providing a plurality of drainage apertures may help to ensure that liquid intercepted by the baffle walls is quickly and efficiently returned to the liquid retaining volume. The plurality of drainage apertures may also help to ensure that there are one or more other drain apertures facilitating drainage from the baffle volume if one of the drain apertures is blocked, for example by dirt or debris entrained in the cleaning liquid. In some examples, the plurality of drain apertures may be distributed around a periphery of the baffle volume. Providing the drain apertures around the periphery of the baffle volume may further help to ensure that liquid is drained quickly and efficiently from the baffle volume. In particular, this arrangement may help to ensure that liquid is drained from the baffle volume when the floor cleaner is inclined in different orientations in use. In some examples, the tortuous fluid flow path defined between the inlet and the outlet may change direction at least twice through at least 90 degrees. Such a configuration helps to ensure that the baffle arrangement intercepts liquid in the fluid received from the liquid retaining volume via the inlet. Accordingly, configuring the baffle arrangement in this way helps to separate liquid from air in the fluid. The direction changes help to slow down the flow of fluid and thereby restrict the movement of liquid in the fluid from the inlet to the outlet. In some examples, the tortuous fluid flow path defined between the inlet and the outlet may change direction at least once through at least 90 degrees, and at least once through 180 degrees so that the baffle arrangement intercepts liquid in the fluid received from the liquid retaining volume via the inlet. Such a configuration helps to separate liquid from air in any fluid received from the liquid retaining volume via the inlet. Further such a configuration ensures that any liquid in the fluid flow path would have to completely change direction to reach the outlet, and may in some examples have to travel against the effects of gravity to reach the outlet. In some examples, the tortuous fluid flow path defined between the inlet and the outlet may change direction at least twice through at least 180 degrees so that the baffle arrangement intercepts liquid in the fluid received from the liquid retaining volume via the inlet. Configuring the baffle arrangement with a tortuous fluid flow path that changes direction at least twice through at least 180 degrees helps to ensure that liquid in the fluid is separated from air because any liquid in the fluid flow path would have to completely change direction to reach the outlet. Additionally, in some examples such a configuration may mean that any fluid would have to travel against the effects of gravity to reach the outlet. Further, in some examples, the or each direction change may result in a tortuous fluid flow path that specifically directs the fluid towards the or each drainage aperture. In such an example, the liquid in the fluid is motivated by gravity to flow through the drainage aperture, rather than against gravity and further along the flow path towards the outlet. In preferred examples, the inlet of the baffle arrangement may be configured to receive fluid flowing in an upwards direction, for example a substantially vertical direction. As such, in some examples an initial portion of the tortuous fluid flow path may direct fluid in an upwards, i.e. substantially vertical, direction. This initial stage may help to initially separate some liquid from gas in the fluid flow path, because the liquid is more dense than the gas. In some examples, the floor cleaner may be configured such that the baffle arrangement is situated above the liquid retaining volume in use. Configuring the floor cleaner such that the baffle arrangement is situated above the liquid retaining volume when the floor cleaner is in an “in use” orientation means that liquid in the baffle volume is assisted by gravity to return to the liquid retaining volume, in use. In preferred examples, the floor cleaner may be configured such that, in use, the liquid tank may be situated above the cleaning head, and the baffle arrangement may be situated above the water retaining volume defined by the liquid tank. In some examples, the baffle volume may be at least partially defined by a baffle floor. The or each drain aperture may be provided in the baffle floor. Providing the or each drain aperture in the baffle floor facilitates particularly effective gravity-assisted drainage of liquid from the baffle volume to the liquid retaining volume. The baffle floor may extend transverse to the or each baffle wall. For example, the or each baffle wall may be arranged substantially vertically, and the baffle floor may be substantially horizontal. In some examples, the baffle floor may define at least part of a ceiling of the liquid retaining volume. As such, the or each drain aperture in the baffle floor may provide a particularly short, direct path for draining liquid from the baffle volume back into the water retaining volume. In some examples, the baffle arrangement may comprise two or more separable parts. Forming the baffle arrangement of two or more separable parts may be advantageous for cleaning and / or maintenance of the baffle arrangement. For example, in preferred examples the baffle arrangement may be formed of two or more parts that are separable to facilitate access to the baffle volume. Providing access to the baffle volume means that any dirt or debris trapped in the baffle volume can be cleared in a simple manner. It will be appreciated that unless otherwise stated, the baffle arrangement of the floor cleaner may comprise two or more separable parts in any of the examples described herein. That is to say, the provision of a baffle arrangement comprising two or more separable parts is not necessarily, or inextricably, dependent on any of the other features described herein. In some examples, the baffle arrangement may comprise a first part defining the baffle floor and a second part defining a baffle ceiling. For the avoidance of doubt, the first and second parts may be separable from one another in preferred examples. As such, the baffle arrangement may be referred to as having a “horizontal split” between the first and second parts. Configuring the baffle arrangement in this way may be particularly advantageous for providing access to the baffle volume. For example, in examples where the or each drainage aperture is provided in the baffle floor, configuring the baffle arrangement with a horizontal split may provide advantageous access to each drainage aperture for simple removal of any dirt or debris. The first and second parts of the baffle arrangement are preferably releasably attached to one another. For example, the first and second parts of the baffle arrangement may be attached together by means of a snap-fit or press-fit connection. In some examples, the first part of the baffle arrangement may define at least one baffle wall. Additionally or alternatively, the second part of the baffle arrangement may define at least one baffle wall. Such a configuration simplifies assembly of the baffle arrangement because the or each baffle wall is arranged between the inlet and the outlet simply by attaching the first and second parts of the baffle arrangement together. This configuration reduces the number of separate parts required to form the baffle arrangement, again simplifying manufacture and reducing cost. In preferred examples, the first part of the baffle arrangement may define a plurality of baffle walls. Additionally or alternatively, the second part of the baffle arrangement may define a plurality of baffle walls. This may provide improvements in ease of manufacturing. In some examples, the baffle arrangement may form at least part of a lid of the liquid tank. Configuring the floor cleaner such that the baffle arrangement forms at least part of a lid of the liquid tank simplifies manufacture and assembly of the floor cleaner by reducing the number of separate parts required for manufacture and assembly, thereby also reducing cost. In some examples, the baffle arrangement may be detachably fixed to the liquid tank. Such a configuration may advantageously facilitates cleaning, maintenance, or replacement of the baffle arrangement and / or liquid tank. In some preferred examples, the floor cleaner may comprise a seal arranged between the baffle arrangement and an internal surface of the liquid tank. As such, the baffle arrangement may be sealed to the internal surface of the liquid tank, and may thereby form at least part of a lid of the liquid tank. In some examples, the seal may be formed on the baffle arrangement in an overmoulding process. For example, the baffle arrangement, or parts of the baffle arrangement may be formed by injection moulding. The seal may be applied to the baffle arrangement, or to part of the baffle arrangement, in a secondary injection moulding process after the baffle arrangement, or part of the baffle arrangement, has been formed. As such, the seal may be referred to as an overmoulded seal. Configuring the baffle arrangement with an overmoulded seal may provide a particularly effective and robust seal between the baffle arrangement and the liquid tank. This may advantageously help to maintain the vacuum pressure applied by the extraction pump. In some examples, the baffle arrangement may additionally or alternatively comprise one or more mechanical interlocks configured to mechanically fix the seal to the baffle arrangement. In some examples, the extraction pump may be an air-based pump, such as a vacuum pump, for example a vacuum pump comprising an electric motor driving a turbine vane arrangement. The presently described baffle arrangement is particularly advantageous for air-based pump systems, where the inlet is open to ingress. It will be appreciated that any features described herein in connection with an example are equally applicable to any other example described herein. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic perspective view of a floor cleaner comprising a cleaning head, a liquid tank, and an extraction pump; Figure 2 is a schematic flow diagram showing fluid flow paths from a floor surface to the extraction pump via the liquid tank; Figure 3 is a more detailed schematic flow diagram generally illustrating a baffle arrangement provided in the flow path between the extraction pump and a liquid retaining volume defined by the liquid tank; 5 Figure 4 is a schematic side-on cross-sectional view of the baffle arrangement; Figure 5 is a schematic cross-sectional plan view of the baffle arrangement; and Figure 6 is a schematic exploded view of the baffle arrangement and the liquid tank. DETAILED DESCRIPTION Figure 1 shows a schematic perspective view of a floor cleaner 10. The floor cleaner 10 is configured to clean a floor surface 12 with the help of a cleaning liquid 14. The cleaning liquid 14 wets the floor surface 12 to soften and / or loosen dirt on the surface 12. Accordingly, the floor cleaner 10 may be referred to as a wet floor cleaner 10. In some examples, the floor cleaner 10 may comprise an on-board cleaning liquid tank and means for supplying the cleaning liquid 14 to the floor surface 12. The cleaning action is performed by a cleaning head 16 of the floor cleaner 10. Accordingly, in some examples the cleaning head 16 may include motor-driven cleaning elements, such as brushes or pads (not shown), for agitating dirt on the floor surface 12 to help with cleaning. As will be described in more detail with reference to Figures 2 to 6, the floor cleaner 10 also includes an extraction pump 18 (not shown in Figure 1) to help collect cleaning liquid 14 and dirt from the floor surface 12. The extraction pump 18 provides a vacuum pressure to draw dirt and dirty cleaning liquid 14 into the floor cleaner 10 via the cleaning head 16. As such, the extraction pump 18 is in fluid communication with the cleaning head 16. In preferred examples, the extraction pump 18 may be an air-based pump, such as a vacuum pump comprising an electric motor driving a turbine vane arrangement. As will now be described with reference to the remaining figures, the floor cleaner 10 further comprises a liquid tank 20 for retaining cleaning liquid 14 and dirt that is sucked into the floor cleaner 10 via the cleaning head 16. Whilst only shown schematically in Figure 2, the liquid tank 20 of the floor cleaner 10 defines a liquid retaining volume 22 for storing liquid that is drawn into the floor cleaner 10 via the cleaning head 16. Accordingly, the liquid retaining volume 22 is in fluid communication with the cleaning head 16. Arrows 241, 24g in Figure 2 indicate the fluid flow path from the cleaning head 16 to the liquid retaining volume 22. It will be appreciated that as used herein, the term “fluid” is intended to refer to both liquids and gases. In Figure 2, the solid arrows 241, 261, 281 indicate a flow path for liquid, i.e. cleaning liquid 14, and the dashed arrows 24g, 26g, 28g indicate a flow path for gas, i.e. air. As shown in Figure 2, fluid, i.e. liquid and gas, is provided to the liquid retaining volume 22 by means of the fluid communication between the cleaning head 16 and the liquid retaining volume 22. As indicated by the dashed arrows 26g, 28g in Figure 2, the liquid retaining volume 22 is also in fluid communication with the extraction pump 18. The extraction pump 18 is configured to draw fluid from the cleaning head 16 to the liquid retaining volume 22 by applying a vacuum pressure to the liquid retaining volume 22. As indicated by the arrows 241, 24g in Figure 2, the liquid retaining volume 22 is provided downstream of the cleaning head 16, and the extraction pump 18 is provided downstream of the liquid retaining volume 22, as indicated by arrows 26g and 28g. Notably, the liquid retaining volume 22 is configured for retaining liquid, and the extraction pump 18 is configured to apply a vacuum pressure to the liquid retaining volume 22 by evacuating gas, i.e. air, from the liquid retaining volume 22. As described by way of background, allowing liquid to enter or come into contact with the extraction pump 18 may be detrimental to the longevity of the extraction pump 18, and movement of the floor cleaner 10 may increase the risk of liquid entering the extraction pump 18. The floor cleaner 10 therefore comprises a baffle arrangement 30 provided between the liquid retaining volume 22 and the extraction pump 18. As described in more detail later with reference to Figures 3 to 6, the baffle arrangement 30 is configured to ensure that air alone, and no liquid, is provided to the extraction pump 18 by separating any cleaning liquid 14 from the air in the baffle arrangement 30. Air provided to the extraction pump 18 from the baffle arrangement 30 is indicated by arrow 28g in Figure 2, and liquid returned to the liquid retaining volume 22 from the baffle arrangement 30 is indicated by arrow 281. It should be noted that in normal use, the fluid in the baffle arrangement 30 may not comprise liquid and may simply comprise air that is drawn into the baffle arrangement 30 from the liquid retaining volume 22 under vacuum pressure caused by the extraction pump 18. However, the baffle arrangement 30 is provided to ensure that in outlier cases, such as when the liquid retaining volume 22 is nearing capacity or when movement of the floor cleaner 10 causes waves / swells in the liquid in the tank 20, any fluid that is motivated along a fluid flow path towards the extraction pump 18 is first intercepted by the baffle arrangement 30, which subsequently separates the liquid from the air. Figure 3 shows a more detailed schematic diagram of the flow paths between the cleaning head 16 and the extraction pump 18 in the floor cleaner 10. For reference, in some examples the liquid tank 20 and the baffle arrangement 30 may be detachable from a main body 32 of the floor cleaner 10 (shown more clearly in Figure 1). This may be advantageous for maintenance of the liquid tank 20 and baffle arrangement 30, and for emptying the liquid tank 20 when at the tank is at full capacity. The floor cleaner 10 may therefore comprise junction components 34 for providing fluid communication between the main body 32 and the detachable parts of the floor cleaner 10. Referring more specifically to the baffle arrangement 30, as shown schematically in Figure 3 the baffle arrangement 30 defines an inlet 36 for receiving fluid from the liquid retaining volume 22 and an outlet 38 for providing air to the extraction pump 18. The baffle arrangement 30 comprises a baffle volume 40 defined between the inlet 36 and the outlet 38. Accordingly, the inlet 36 facilitates fluid communication between the liquid retaining volume 22 and the baffle volume 40, and the outlet 38 facilitates fluid communication between the baffle volume 40 and the extraction pump 18. The baffle arrangement 30 will now be described in more detail with reference to Figures 4, 5 and 6. Figure 4 shows an example of the baffle arrangement 30 in more detail in a side-on cross-sectional view, Figure 5 shows a schematic cross-sectional plan view of the baffle arrangement 30, and Figure 6 shows a schematic exploded view of an example of a baffle arrangement 30 and a liquid tank 20 of the floor cleaner 10. As shown most clearly in the cross-sectional view of Figure 4, the baffle arrangement 30 comprises a baffle wall 42 arranged between the inlet 36 and the outlet 38 of the baffle arrangement 30. In preferred examples the baffle arrangement 30 may comprise a plurality of baffle walls 42. The baffle walls 42 define a tortuous fluid flow path 44 between the inlet 36 and the outlet 38, indicated by the dashed arrow line in Figure 4. In particular, the baffle walls 42 partially obstruct fluid flowing through the baffle volume 40. This reduces the velocity of the fluid flow between the inlet 36 and the outlet 38 and results in the separation of liquid and air. For example, when the flow is intercepted by the walls 42 and decelerated, the denser liquid is influenced primarily by gravity, whereas the comparatively less dense air continues to be influenced primarily by the vacuum pressure applied by the extraction pump 18. As such, liquid in the fluid in the baffle volume 40 is motivated downwards, whereas the air is drawn through the outlet 38 towards the extraction pump 18, thereby separating the liquid from the air, ensuring only air is introduced to the extraction pump 18. In preferred examples, the tortuous fluid flow path 44 defined between the inlet 36 and the outlet 38 changes direction at least twice through at least 90 degrees. As shown in Figure 4, particularly advantageous configurations of the baffle arrangement 30 prescribe a tortuous fluid flow path 44 that changes direction at least twice through at least 180 degrees. This means that the flow of liquid would need to completely change direction twice to progress from the baffle volume 40 towards the extraction pump 18. In preferred examples, the baffle walls 42 may be arranged in a substantially vertical orientation as shown in Figure 4. With such a configuration, any liquid in the fluid entering the baffle volume 40 would have to completely change direction against the influence of gravity in order to traverse the baffle walls 42 and progress towards the extraction pump 18. Liquid intercepted by the baffle walls 42 is drained from the baffle volume 40 via one or more drain apertures 46. Each drain aperture 46 provides fluid communication between the baffle volume 40 and the liquid retaining volume 22. This ensures that liquid is returned to the liquid retaining volume 22 and does not accumulate in the baffle volume 40. In preferred examples the baffle arrangement 30 may comprise a plurality of drain apertures 46 as shown most clearly in Figure 5, to aid with swift removal of liquid from the baffle volume 40. With reference to Figure 5, in preferred examples the drain apertures 46 may be distributed around a periphery of the baffle volume 40. Providing the drain apertures 46 around the periphery of the baffle volume 40 further contributes to efficient drainage of liquid from the baffle volume 40, and helps to ensure that drainage can be achieved when the floor cleaner 10 is inclined in a plurality of different orientations in use. In some particularly advantageous examples, the baffle walls 42 may prescribe a tortuous fluid flow path 44 that specifically directs incident fluid towards the drain apertures 46, as shown in Figure 4 for example. For example, where the fluid flow path 44 changes direction at least twice through at least 180 degrees, the baffle walls 42 may direct the fluid flow towards the drain apertures 46. Such a configuration is particularly effective for ensuring that liquid does not progress further towards the extraction pump 18, and is quickly drained from the baffle volume 40 instead. Referring also to the schematic exploded view in Figure 6, in preferred examples the floor cleaner 10 may be configured such that the baffle arrangement 30 is situated above the liquid retaining volume 22 in use. Further, as shown in Figure 4, the drain apertures 46 may be provided in a baffle floor 48 that defines at least part of the baffle volume 40. It will be appreciated that in such examples, any liquid in the baffle volume 40 is motivated by gravity to return to the liquid retaining volume 22 following a short, direct fluid flow path through the baffle floor 48. As previously described, the baffle arrangement 30 comprises an outlet 38 for providing fluid communication between the baffle volume 40 and the extraction pump 18. In some outlier situations there may exist a risk that liquid could cover the outlet 38 and effectively form a seal such that the suction from the extraction pump 18 could draw liquid along a flow path towards and potentially into the extraction pump 18. By way of example, an outlier situation may include use of the floor cleaner 10 when the liquid tank 20 is nearing capacity and the floor cleaner 10 is inclined at, or near to, an inclination limit of the cleaner 10. In such outlier situations, the floor cleaner 10 may be particularly susceptible to liquid waves or swells entering the baffle volume 40 in use. In some advantageous examples, the baffle arrangement 30 may therefore comprise a separate auxiliary outlet 50 for providing air to the extraction pump 18. If one of the outlets 38, 50 is covered by liquid in the baffle volume 40, air may still be provided to the extraction pump 18 via the other outlet 38, 50. This ensures that the liquid covering the outlet 38, 50 is not sucked towards the extraction pump 18, because the vacuum pressure is applied via the other, uncovered, outlet 38, 50 instead. To best ensure that at least one of the outlets 38, 50 remains uncovered throughout use of the floor cleaner 10, the outlet 38 and auxiliary outlet 50 are preferably provided in generally opposed positions about the baffle arrangement 30. For example, with reference to a forward-to-b ackward axis of motion 52 (indicated in Figures 1 and 4), the outlet 38 and auxiliary outlet 50 may be separately provided in opposed front and back portions of the baffle arrangement 30 in some examples. This configuration may be particularly advantageous because the main direction of movement of a floor cleaner 10 typically approximates movement along the forward-to-backward axis of motion 52, meaning that swells or waves in the liquid in the liquid tank 20 are most likely to occur towards one of the front or back of the liquid tank 20 in use. Referring now primarily to Figures 4 and 6, in some examples the baffle arrangement 30 may comprise two or more separable parts. For example, as shown in Figure 4, the baffle arrangement 30 may comprise a first part 54 defining the baffle floor 48 and a second part 56 defining a baffle ceiling 58. The baffle arrangement 30 may therefore be assembled and disassembled with a horizontal split, as shown in Figure 6 for example. This advantageously facilitates simple access to the baffle volume 40, and in particular to the baffle floor 48 and drainage apertures 46, for cleaning and maintenance operations such as unblocking a drain aperture 46. In some examples, the separable parts 54, 56 of the baffle arrangement 30 may additionally define the or each baffle wall 42. For example, as shown in Figure 4, the first part 54 of the baffle arrangement 30 may define a baffle wall 42, and the second part 56 of the baffle arrangement 30 may also define a baffle wall 42. Accordingly, the baffle walls 42 may be arranged in the baffle volume 40 simply by arranging the first and second separable baffle parts 54, 56 together when assembling the baffle arrangement 30. As shown in Figure 6, the baffle arrangement 30 may be detachably fixed to the liquid tank 20. Again, this may be advantageous for maintenance of the baffle arrangement 30 and the liquid tank 20. In some examples the baffle arrangement 30 may form at least part of a lid of the liquid tank 20. For example, the liquid tank 20 and the baffle arrangement 30 may be removed from the floor cleaner main body 32 together, and the baffle arrangement 30 may therefore help to ensure that liquid in the tank 20 is not spilled. To help seal the baffle arrangement 30 to other parts of the floor cleaner 10, such as the liquid tank 20 for example, the baffle arrangement 30 may comprise a seal 60 extending around an outer surface of the baffle arrangement 30, as shown most clearly in the cross-sectional view of Figure 4. It will be appreciated that the above description and accompanying figures are provided merely as an example of the present invention. Many alternatives to the examples described above are therefore possible without departing from the scope of the invention as defined in the appended claims. For example, it will be appreciated that the cleaning head 16 may comprise any suitable means for cleaning a floor surface 12, and the invention is not limited to any particular configuration of the cleaning head 16. Further, the fluid flow paths of the floor cleaner 10 referred to herein may be defined by tubing or any other suitable fluid conduit. It will be appreciated that the specific configuration of conduits which define the fluid flow paths are immaterial to the function and advantages of the baffle arrangement 30. The description provided herein serves to demonstrate a plurality of possible examples of the present invention. Features described in relation to any of the examples above may be readily combined with any other features described with reference to different examples without departing from the scope of the invention as defined in the appended claims.

Claims

1. A floor cleaner comprising:a cleaning head;a liquid tank defining a liquid retaining volume, wherein the liquid retaining volume is in fluid communication with, and downstream of, the cleaning head;an extraction pump, wherein the extraction pump is in fluid communication with, and downstream of, the liquid retaining volume, the extraction pump being configured to apply vacuum pressure to the liquid retaining volume to draw fluid from the cleaning head to the liquid retaining volume; anda baffle arrangement defining an inlet for receiving fluid from the liquid retaining volume, an outlet for providing air to the extraction pump, and a baffle volume defined between the inlet and the outlet;the baffle arrangement further comprising one or more baffle walls arranged between the inlet and the outlet to define a tortuous fluid flow path between the inlet and the outlet;the baffle arrangement further comprising one or more drain apertures providing fluid communication between the baffle volume and the liquid retaining volume to allow liquid intercepted by the baffle walls to return to the liquid retaining volume.

2. The floor cleaner of Claim 1, wherein the baffle arrangement further defines a separate auxiliary outlet for providing air to the extraction pump.

3. The floor cleaner of Claim 2, wherein the outlet and the auxiliary outlet are provided in generally opposed positions about the baffle arrangement.

4. The floor cleaner of any preceding claim, wherein the baffle arrangement comprises a plurality of drain apertures providing fluid communication between the baffle volume and the liquid retaining volume.

5. The floor cleaner of Claim 4, wherein the drain apertures are distributed around a periphery of the baffle volume.

6. The floor cleaner of any preceding claim, wherein the tortuous fluid flow path defined between the inlet and the outlet changes direction at least twice through at least 90 degrees so that the baffle arrangement intercepts liquid in the fluid received from the liquid retaining volume via the inlet.

7. The floor cleaner of any preceding claim, wherein the tortuous fluid flow path defined between the inlet and the outlet changes direction at least once through at least 90 degrees, and at least once through 180 degrees so that the baffle arrangement intercepts liquid in the fluid received from the liquid retaining volume via the inlet.

8. The floor cleaner of any preceding claim, wherein the tortuous fluid flow path defined between the inlet and the outlet changes direction at least twice through at least 180 degrees so that the baffle arrangement intercepts liquid in the fluid received from the liquid retaining volume via the inlet.

9. The floor cleaner of any preceding claim, wherein the floor cleaner is configured such that the baffle arrangement is situated above the liquid retaining volume in use.

10. The floor cleaner of any preceding claim, wherein the baffle arrangement comprises two or more separable parts.

11. The floor cleaner of any preceding claim, wherein the baffle volume is at least partially defined by a baffle floor, and wherein the or each drain aperture is provided in the baffle floor.

12. The floor cleaner of Claim 11, wherein the baffle arrangement comprises a first part defining the baffle floor and a second part defining a baffle ceiling.5 13. The floor cleaner of Claim 12, wherein the first part of the baffle arrangementdefines at least one baffle wall and / or wherein the second part of the baffle arrangement defines at least one baffle wall.

14. The floor cleaner of any preceding claim, wherein the baffle arrangement forms 10 at least part of a lid of the liquid tank.

15. The floor cleaner of any preceding claim, wherein the baffle arrangement is detachably fixed to the liquid tank.15 16. The floor cleaner of any preceding claim, wherein the extraction pump is avacuum pump, preferably comprising an electric motor driving a turbine vane arrangement.

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