Wet vacuum cleaner, cleaning tray, and cleaning method

Abstract

The present invention provides a cleaning tray for a wet floor cleaner for receiving a head of the wet floor cleaner. The cleaning tray has at least one brush channel for receiving the bottom of the outer periphery of a roller brush. At least one raised protrusion having an upstream sloping surface and a steeper downstream sloping surface is disposed along the brush channel. The protrusion adds turbulence for improved cleaning results and allows for controlled flow of cleaning fluid around the brush and cleaning tray to ensure complete immersion of the brush and cleaning of all areas of the cleaning tray itself. The present invention also provides a cleaning method using the cleaning tray.

Description

[Technical field]

[0001] This invention relates to wet vacuum cleaners, and in particular to cleaning the roller brushes used in the heads of wet vacuum cleaners. [Background technology]

[0002] Wet vacuum cleaners are known that have two counter-rotating brushes in the cleaning head (often known as a "nozzle"). Suction is applied to at least the space between the brushes to draw liquid from the floor that is applied to the floor by the vacuum cleaner. The brushes come into contact with the floor and perform a scrubbing action.

[0003] Wet vacuum cleaners are difficult to clean after use. Cleaning after use is a must to avoid bacterial growth and unpleasant odors after use, both of which are perceived by users as unhygienic.

[0004] To overcome this problem, some wet vacuum cleaners are equipped with a cleaning tray that is used to rinse the appliance after use. For example, EP 2 672 872 discloses a tray for cleaning the roller brushes of a wet cleaning vacuum cleaner.

[0005] Most known wet vacuum cleaners are connected to a mains power source, and the known use of trays does not work with battery-powered appliances, as the available suction power is not sufficient to achieve a satisfactory cleaning result. Summary of the Invention [Problem to be solved by the invention]

[0006] Thus, there is a need for an improved wet vacuum cleaning tray that can be used especially with battery powered appliances, and there is also a need for improved cleaning results for the appliances and the trays. [Means for solving the problem]

[0007] The invention is defined by the claims.

[0008] According to an embodiment of the present invention, there is provided a cleaning tray for a wet floor cleaner, the cleaning tray receiving a head of the wet floor cleaner. The head includes a roller brush. The cleaning tray includes: A base for supporting the head; a brush channel formed in the base for receiving a bottom portion of a periphery of the roller brush; at least one raised protrusion disposed along the brush channel for protruding into the roller brush when the cleaning tray is in use, the at least one raised protrusion including an upstream sloped surface and a downstream sloped surface, the upstream sloped surface being disposed such that a periphery of the roller brush rides up onto the upstream sloped surface when rotated, the downstream sloped surface being steeper than the upstream sloped surface; and a suction area facing the downstream sloped surface.

[0009] The cleaning tray has at least one brush channel for receiving a roller brush. There is at least one protrusion that functions as a turbulence generating element. The turbulence promotes mixing of the debris with the cleaning liquid, thereby allowing the debris to be more effectively removed during the cleaning cycle when the cleaning tray is used. The rotation of the roller brush generates a negative pressure at the location of the downstream inclined surface, which draws the cleaning liquid towards it. This effectively transports the cleaning liquid within the tray, in particular so that the entire roller brush (as well as the entire area of ​​the cleaning tray) is exposed to the flow of cleaning liquid when in use. The negative pressure is increased because the outer periphery of the roller brush may not be in contact with the downstream inclined surface due to the rotation speed and the inertia of the tufts (which prevent the tufts from immediately deforming radially outwards to the location of the downstream inclined surface). Thus, a cavity is formed behind the downstream inclined surface, generating a negative pressure.

[0010] It is noted that "upstream" and "downstream" refer to the rotation of the roller brush, i.e., the outer periphery of the rotating roller brush first contacts the upstream surface.

[0011] The upstream inclined surface is preferably smoothly inclined. It may be straight, concave or convex, or may have multiple sections, each with a different convex, concave or straight shape. It does not present an obstacle to the flow of the cleaning liquid, and therefore does not impede the passage of the cleaning liquid being carried by the roller brush, but provides a guide surface. The transition between the upstream and downstream inclined surfaces is particularly turbulent.

[0012] The cleaning tray, for example, includes a set of raised protrusions, each having an upstream sloped surface and a downstream sloped surface.

[0013] The use of multiple raised protrusions controls the flow of cleaning fluid around the roller brush and cleaning tray, preventing cleaning fluid (e.g., delivered by the head of a wet floor cleaner) from collecting in only localized areas of the roller brush, thereby ensuring cleaning of the entire surface of the roller brush.

[0014] By way of example, there may be protrusions near each end of the brush channel, and thus near the four corners of the cleaning tray if there are two brush channels. Additionally, the protrusions may be at intermediate positions along the brush channels.

[0015] The or each raised protrusion may be, for example: a height in the range of 1 mm to 10 mm, and / or It is parallel to the length of the brush channel and has a length in the range of 1 mm to 50 mm.

[0016] This height is measured from the bottom of the brush channel. Even relatively small protrusions can create enough turbulence to promote collection of debris from the roller brush during cleaning.

[0017] The or each raised projection has an apex at a junction between the upstream and downstream sloped surfaces that has an angle of greater than 90 degrees.

[0018] The rapid change in direction of the surface against which the roller brush is driven creates the desired turbulence and negative pressure.

[0019] For example, the radius of curvature of the apex is less than 2 mm.

[0020] Sharp corners cause abrupt changes in the flow area, thereby creating significant turbulence in the flow.

[0021] The brush channels may include two or more sets of raised protrusions that may be distributed along the length of the roller brush, such as near the ends, to provide a turbulent cleaning effect along the length.

[0022] For example, the brush channel may include two or more sets of raised protrusions, with at least two different shapes of raised protrusions within a set. The use of different designs of protrusions allows for more precise control of the desired flow pattern. The different shapes of protrusions may have different widths and / or heights.

[0023] The cleaning tray may further include a flow guide within the brush channel that provides a flow path across the brush channel to the suction area.

[0024] The use of flow guides can further control the flow of cleaning liquid around the tray. It helps to direct the cleaning liquid to the corners of the tray, especially when there is a large amount of cleaning liquid. At the end of the cleaning cycle, when there is a small amount of cleaning liquid, it helps to direct the remaining cleaning liquid to the center of the tray where it is picked up by the suction airflow. Thus, the flow guides further help to obtain a clean and dry tray.

[0025] The flow guide may, for example, include two side projections that converge towards each other along the flow path.

[0026] Thus, the flow guide defines a channel that narrows towards the suction region, e.g., the height of the side projections ranges from 1 mm to 6 mm.

[0027] The two side projections form part of a V-shape with a vertex angle in the range of, for example, 40 degrees to 120 degrees.

[0028] The cleaning tray may include opposed side walls, one of the side walls having an opening (or pair of openings) through which the roller brush (or both roller brushes) may be received transversely parallel to their axis of rotation.

[0029] This allows the brush or both brushes to be removed from the cleaning head, and therefore from the cleaning tray, when cleaning is complete but the cleaning head remains in the cleaning tray. The roller brush (or both brushes) are then exposed to ambient air to dry thoroughly. The openings also allow air flow around the cleaning head to dry thoroughly.

[0030] The cleaning tray receives a head of a wet floor cleaner that includes, for example, a pair of roller brushes. The cleaning tray includes a pair of brush channels with a suction area between the pair of brush channels.

[0031] The present invention also provides a wet floor cleaner, comprising: Housing and at least one rotating brush extending across the width of the housing; a cleaning head including at least a suction channel for providing suction to a space adjacent to the at least one rotating brush; a pump for providing suction to a suction channel of the cleaning head; a supply system for supplying a cleaning fluid to the cleaning head; and the cleaning tray described above.

[0032] The delivery system may be a second pump that is part of the cleaner, or there may be a separate external fluid source. In the latter case, the delivery system is a conduit that receives the cleaning fluid from the external fluid source and delivers it to the cleaning head.

[0033] The cleaning head further includes a support wheel arrangement for mounting the housing with minimal spacing from the floor surface to be cleaned, and in the case of a system having two rotating brushes, a drive arrangement is also provided for driving the first and second rotating brushes in opposite rotational directions.

[0034] The present invention also provides a method for cleaning a roller brush of a cleaning head of a wet floor cleaner when the cleaning head is attached to a cleaning tray, the cleaning head including at least one rotating brush and at least a suction channel for providing suction to a space adjacent to the at least one rotating brush. The method includes: In the initiation cycle, supplying a relatively large amount of cleaning liquid to the cleaning head and driving the roller brush at a relatively slow rotational speed without providing suction; supplying a relatively small amount of cleaning fluid to the cleaning head and driving the roller brush at a relatively high rotational speed to apply a first level of suction; In the intermediate cycle, supplying a relatively large amount of cleaning liquid to the cleaning head and driving the roller brush at a relatively slow rotational speed without providing suction; supplying a relatively small amount of cleaning liquid to the cleaning head and driving the roller brush at a relatively high rotational speed without providing suction; supplying a relatively small amount of cleaning liquid to the cleaning head, driving the roller brush at a relatively high rotational speed, and applying a second level of suction that is lower than the first level of suction; In the final cycle, supplying a maximum amount of cleaning liquid to the cleaning head and driving the roller brush at a relatively slow rotational speed without providing suction; driving the roller brush at a relatively high rotational speed and applying suction without the supply of cleaning fluid.

[0035] It should be noted that the terms "relatively large," "relatively small," "relatively slow," and "relatively fast" refer to individual cycles. For example, the "relatively large amount (large amount)" in the intermediate cycle does not have to be the same as the "relatively large amount (large amount)" used in the start cycle. It only has to be larger than the "relatively small amount (small amount)" in the intermediate cycle.

[0036] The method provides a three cycle cleaning method. The first cycle submerges the brush using a slow rotation speed and a large amount of cleaning fluid (such as water). Using high suction and high roller drive speed, residue is removed without spreading the dirt in the tray. This can be thought of as a pre-wash to remove coarse soils.

[0037] The mid-cycle has a spin period where no suction is used and only a small amount of cleaning fluid is used to remove dirt from the brushes.

[0038] In the final cycle, the most cleaning liquid is provided to soak and reach all areas of the cleaning tray at a low brush speed. This can be thought of as a rinse cycle. After this, the cleaning liquid is removed by applying suction.

[0039] The cleaning method has been found to be particularly effective and allows for low power operation.

[0040] The intermediate cycle may be carried out two or more times.

[0041] The final step of the termination cycle may include driving the roller brush at a relatively high rotational speed and applying a second level of suction, followed by applying the first level of suction without the application of cleaning fluid.

[0042] Thus, if a large amount of cleaning liquid remains, a low level of suction is used initially to prevent leakage, and then the suction is increased to remove substantially all of the remaining water and residue.

[0043] The method is applied, for example, with the cleaning head attached to the cleaning tray described above.

[0044] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter. [Brief description of the drawings]

[0045] For a better understanding of the present invention and to show more clearly how it may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings in which:

[0046] [Figure 1] FIG. 1 shows a known layout of a wet floor cleaner head. [Diagram 2] FIG. 2 shows another known layout for achieving a smaller, more compact cleaning head. [Diagram 3] FIG. 3 shows a cross-sectional view of one of the rear support wheels of the cleaning head of FIG. [Figure 4] FIG. 4 shows an example of a cleaning tray. [Diagram 5] FIG. 5 shows the protrusions in more detail. [Figure 6] FIG. 6 shows the flow guide in more detail. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0047] The present invention will now be described with reference to the drawings.

[0048] It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the devices, systems, and methods, are for purposes of illustration only and are not intended to limit the scope of the invention. These and other features, aspects, and advantages of the devices, systems, and methods of the present invention will become better understood from the following description, the appended claims, and the accompanying drawings. It should be understood that the figures are schematic representations only and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the figures to indicate the same or similar parts.

[0049] The present invention provides a cleaning tray for a wet floor cleaner for receiving a head of the wet floor cleaner. The cleaning tray has at least one brush channel for receiving the bottom of the outer periphery of a roller brush. At least one raised protrusion having an upstream sloping surface and a steeper downstream sloping surface is disposed along the brush channel. The protrusion adds turbulence for improved cleaning results and allows for controlled flow of cleaning fluid around the brush and cleaning tray to ensure complete immersion of the brush and cleaning of all areas of the cleaning tray itself. The present invention also provides a cleaning method using the cleaning tray.

[0050] Accordingly, the present invention is directed to a cleaning tray for cleaning the head of a wet floor cleaner.First, the general construction of an exemplary cleaner head having a pair of parallel roller brushes will be described.

[0051] Figure 1 shows an underside view of a known layout of a wet floor cleaner head 10. The head includes a housing 12. The housing 12 supports a first, front brush 14 and a second, rear brush 16. A set of four support wheels 18 are arranged in a rectangular configuration behind the rear brush 16.

[0052] The primary direction of movement of the cleaning head when in use is parallel to the length of the cleaning head and perpendicular to the width of the housing as described above. The primary direction of movement is indicated by the large arrow. This movement serves to roll the brush across the floor.

[0053] FIG. 2 shows another known layout for achieving a smaller, more compact cleaning head, which may be more suitable for example for battery powered devices.

[0054] The head 10 again includes a housing 12 which supports a first, forward brush 14 and a second, rearward brush 16 .

[0055] The housing 12 has a width W between a first side wall 20 and a second side wall 22, and a length L that is parallel to the intended primary direction of movement of the cleaning head over the floor to be cleaned.

[0056] The first rotating brush 14 and the second rotating brush 16 each extend across the width of the housing between the first side wall 20 and the second side wall 22, have parallel axes of rotation and are aligned longitudinally. A suction channel is provided for providing suction to at least the space 24 between the first rotating brush 14 and the second rotating brush 16. The suction force is applied throughout the volume of the housing.

[0057] This definition of width and length of the cleaning head applies throughout this text.

[0058] The support wheel arrangement in this design includes a first support wheel 30 in the space 24 between the first and second rotating brushes, and a second support wheel 32 in the space 24 between the first and second rotating brushes. The outer surfaces of the wheels are approximately flush with the sidewall.

[0059] Mounting the first and second support wheels between the rotating brushes saves space. In the length direction, behind the first and second rotating brushes there is a third support wheel 34 (alternatively it can be in front of them) and alongside the third support wheel 34 there is a fourth support wheel 36.

[0060] Figure 3 shows a cross section of one of the rear support wheels 34, 36 of the cleaning head of Figure 2, and also shows the further back support wheel 30 (behind the plane of the cross section). It shows that the first rotating brush 14 and the second rotating brush 16 are driven in opposite rotational directions so as to move upwards when facing each other in the space 24. A suction channel 40 provides suction to at least the space 24 between the first and second rotating brushes.

[0061] The rotating brushes are driven by a drive including a single motor and a belt drive for driving the two rotating brushes, or each rotating brush may have its own motor attached to its respective rotating brush core.

[0062] The cleaning head also comprises a fluid supply (not shown) for supplying cleaning liquid (i.e. water and optionally a cleaning agent) to the first and / or second rotating brushes. The cleaning liquid is supplied to the rotating brush 16 at the rear of the cleaning head from a reservoir formed, for example, in the main housing of the vacuum cleaner.

[0063] The vacuum cleaner itself has a first pump (fan) to provide suction to the cleaning head, and a second pump to provide the cleaning fluid.

[0064] The mounting of the support wheels by the housing defines a minimum spacing S between the bottom surface of the housing and the floor surface. This minimum spacing can be, for example, in the range of 1.5 mm to 3 mm. The rotating brush protrudes below the floor level (if no floor is present) so that the tufts are deformed by the presence of the floor. This creates a recess in the floor, which is part of the water collection and cleaning function and provides brush torque control.

[0065] Figure 3 also shows the front and rear spoilers 42. These maintain air pressure within the housing to prevent air or water from being blown out of the system, which could make it difficult to pick up dirt from the floor, and they also direct water sprayed against the housing back to the brushes.

[0066] After use, it is known to attach the cleaning head to a cleaning tray and apply a cleaning program. The present invention is particularly concerned with the design of the cleaning tray and the cleaning cycle to achieve optimal cleaning of the brushes. By making the cleaning cycle more efficient, it can be performed with less power, which is of particular interest for battery-powered vacuum cleaners.

[0067] FIG. 4 shows a cleaning tray 50 for a wet floor cleaner for receiving the head 10 of the wet floor cleaner.

[0068] The cleaning tray includes a base 52 for supporting the head. To securely position the cleaning head in the cleaning tray, a mounting area 54 is provided for engagement with the cleaning head.

[0069] The cleaning tray 50 includes a pair of brush channels 56 formed in the base. These are arcuate recesses (having a cylindrical shape that generally matches the cylindrical shape of the outer periphery of the roller brush). In use, the outer periphery of the roller brush contacts the brush channels and deforms the tufts to facilitate cleaning. For example, the radius of the brush channels is smaller than the outer diameter of the roller brush, in the range of 1 mm to 3 mm.

[0070] Thus, each brush channel is for receiving the bottom of the periphery of a corresponding roller brush.

[0071] Between the brush channels 56 are suction areas 58 over which the suction nozzles of the cleaning head are positioned when placed in the cleaning tray.

[0072] The present invention provides raised protrusions on one or both of the brush channels. One raised protrusion is sufficient to significantly affect the flow of cleaning fluid during cleaning. However, Figure 4 shows an example using six protrusions of two different designs.

[0073] The front brush channel has two larger protrusions 60 near each end and two smaller protrusions 62 more centrally.

[0074] The rear brush channel has two larger protrusions 64 near each end and one in the middle.

[0075] The protrusions at the ends of the brush channel become more effective as the cleaning tray fills with water. As the water is removed, the protrusions at the ends of the brush channel become less effective as they are cleared away from the center. Thus, the more central protrusions continue to generate turbulence (see below) until all the water is removed.

[0076] FIG. 5 shows one projection 60 in more detail in a cross section perpendicular to the longitudinal axis of the brush channel 56. The depth of the brush channel is, for example, 3 mm or less. As can be seen from the brush 14 in FIG. 5, the projection 60 is intended to protrude into the tufts of the roller brush when the cleaning tray is used. The raised projection includes an upstream inclined surface 70 arranged such that the outer periphery of the roller brush 14 rides up on the upstream inclined surface when rotated. The upstream inclined surface is smoother so that the usable radius of the roller brush gradually decreases than a steeper surface. However, it may be straight, concave or convex, or have sections with different curvatures. The downstream inclined surface 72 is steeper than the upstream inclined surface. The downstream inclined surface faces the suction area 58. At the junction between the inclined surfaces 70, 72 there is an apex 74.

[0077] For example, the angle of the upstream sloped surface may range from 20 degrees to 40 degrees (relative to a straight line between the rear and front of the projection that contacts the brush channel), and for example, the angle of the downstream sloped surface may range from 60 degrees to 90 degrees. For purposes of this angle definition, each sloped surface is approximated as a straight plane between the apex and the front or rear.

[0078] The protrusions act as turbulence generating elements. Turbulence promotes mixing of the debris with the liquid, thereby allowing for more effective removal of debris during the cleaning cycle. The rotation of the roller brush generates a negative pressure at the location (downstream of) the downstream inclined surface, which draws the cleaning liquid towards it. This effectively transports the cleaning liquid within the tray, particularly so that the entire roller brush is exposed to the flow of cleaning liquid when in use. The negative pressure is increased because the outer periphery of the roller brush may not be in contact with the downstream inclined surface due to the speed of rotation and the inertia of the tufts (which prevent the tufts from readily deforming radially outwards to meet the downstream inclined surface).

[0079] The turbulence and negative pressure creates a current of water-laden particles that circulates within the tray.

[0080] For example, the height of the protrusions (in the radial direction of the roller brush) ranges from 1 mm to 10 mm, and the length parallel to the length of the brush channel ranges from 1 mm to 50 mm. Relatively small protrusions can generate sufficient turbulence to facilitate collection of debris from the roller brush during cleaning.

[0081] For example, the angle of the apex 74 is 90 degrees or more, which allows the surface against which the roller brush is driven to change direction rapidly, thereby creating the desired turbulence and negative pressure. For example, the radius of curvature of the apex 74 is less than 2 mm.

[0082] For example, the protrusions are formed as an integral part of the tray.The pressure differential created by the angled surface is designed to control the flow of cleaning fluid to spread the cleaning fluid along the length of the brush.

[0083] The protrusions near the corners of the tray are located on either side of the wheel, thus protecting the area near the wheel, which is highly sensitive to contamination, mainly fibrous materials that easily wrap around the shaft of the wheel. The protrusions provide a barrier function and reduce this contamination by creating turbulence near the wheel.

[0084] Returning to FIG. 4, the forward brush channel 56 additionally includes a flow guide 80 that provides a flow path from the brush channel 56 to the suction area 58 .

[0085] The use of flow guides allows for more control of the flow of cleaning liquid around the tray. They help direct cleaning liquid to the corners of the tray, especially when there is a large amount of cleaning liquid. They also direct the reduced cleaning liquid to the center of the tray where it is picked up by the suction flow at the end of the cleaning cycle. Thus, the flow guides 80 further aid in obtaining a clean and nearly dry tray.

[0086] The flow guide 80 includes two side projections 82 that converge toward each other along the flow path toward the suction region 58. For example, the height of the side projections 82 ranges from 1 mm to 6 mm. They form part of a V-shape with an apex angle ranging from 40 degrees to 120 degrees.

[0087] FIG. 6 shows the flow guide 80 more clearly.

[0088] 4, the cleaning tray is also shown to have opposed side walls 90, 92. One of the side walls, 92, has a pair of openings 94 through which the roller brushes are received transversely and parallel to their axes of rotation.

[0089] This allows the brush to be removed from the cleaning head, and therefore from the cleaning tray, when cleaning is complete but the cleaning head remains in the cleaning tray. The roller brush is then exposed to ambient air to dry thoroughly. The opening also allows air flow around the cleaning head to dry thoroughly.

[0090] The present invention also provides a method of using a cleaning tray.

[0091] The method includes three types of cycles. The cycle characteristics are shown in the table below. Cycle 1 is the start cycle, cycles 2 and 3 are the middle cycles, and cycle 4 is the end cycle. Each cycle has multiple steps.

[0092] Each step includes the rotational speed of the roller brush ("RPM"), the suction power ("Fan Power"), the rate at which the cleaning fluid is dispensed ("Pump Speed"), and a duration ("Time"). The product of the duration and the rate at which the cleaning fluid is dispensed gives the amount of cleaning fluid used ("Water Volume"). [Table 1]

[0093] As shown, in the initiation cycle, A relatively large amount of cleaning liquid (52 ml) is supplied to the cleaning head, and the roller brush is driven at a relatively slow rotational speed (2500 rpm) without the supply of suction, and then A relatively small amount of cleaning fluid (9 ml) is applied to the cleaning head, the roller brush is driven at a relatively high rotational speed (4500 rpm) and a first level of suction power (100 W) is applied.

[0094] In the mid-cycle, A relatively large amount of cleaning liquid (50 ml, then 41 ml for the second iteration of the intermediate cycle) is supplied to the cleaning head and the roller brush is driven at a relatively slow rotational speed (2500 rpm) without the supply of suction, Then, a small amount of cleaning liquid (11 ml) is supplied to the cleaning head, and the roller brush is driven at a relatively high rotation speed (4500 rpm) without the supply of suction force. Thereafter, a relatively small amount of cleaning liquid (4 ml) is applied to the cleaning head, the roller brush is driven at a relatively high rotational speed (4500 rpm), and a second level of suction force (60 W) higher than the first level of suction force is applied.

[0095] In the final cycle, A maximum amount of cleaning fluid (61 ml, i.e., the most delivered at any step) is delivered to the cleaning head and the roller brush is driven at a relatively slow rotational speed (2500 rpm) without the delivery of suction; Thereafter, the roller brush is driven at a relatively high rotation speed (4500 rpm) and suction power (60 W, 100 W) is applied without supplying cleaning liquid.

[0096] The purpose of each of the 11 steps is explained below.

[0097] Step 1 In this step, fill the tray with cleaning solution at low RPM, enough to soak but not squirt water out the sides or front. Step 2 A vacuum is applied to enhance airflow while the brushes spin at high RPM, removing dirt all along the way without spreading it around in the tray. Step 3 Fill the tray with enough water to soak using a slow brush RPM, creating turbulence to release dirt from corners and edges. Step 4 The brushes spin at high RPMs, which removes dirt from the brushes and rinses the tray (and sight glass). Step 5 A low airflow will remove the dirty water from the tray, it's not necessary to reach a good dryness or cleanliness yet. Step 6 This is a repeat of step 3, filling the brush with enough water to submerge it, but at a slower brush RPM, which creates turbulence that releases dirt from corners and edges. Step 7 This is a repeat of step 4, spinning at a higher brush RPM, which loosens dirt from the brush and rinses the tray and window. Step 8 This is a repeat of step 5, using low airflow to suck the dirty water out of the tray. Step 9 In this step, the tray is overfilled with water for soaking at a slow RPM, creating turbulence at each corner of the tray and at the nozzle to release any remaining dirt. Step 10 A vacuum is applied with low airflow and high roller brush RPM to remove most of the water and dirt without expelling additional water filled from the tray with increased RPM. Step 11 Vacuum is applied with high airflow and high roller brush RPM to remove all remaining water and dirt.

[0098] The method is seen to provide a three cycle cleaning method (with intermediate cycles repeated at slightly different times). The first cycle uses a slow rotation speed and a large amount of cleaning solution to soak the brush. Using high suction and high roller drive speed, residue is removed without spreading the dirt in the tray. This can be thought of as a pre-wash to remove coarse soils.

[0099] The mid-cycle has a spin period where no suction is used and only a small amount of cleaning fluid is used to remove dirt from the brushes.

[0100] In the final cycle, the most cleaning liquid is provided to soak and reach all areas of the cleaning tray at a low brush speed. This can be thought of as a rinse cycle. After this, the cleaning liquid is removed by applying suction and using a high brush rotation speed.

[0101] Although the cleaning head housing is shown as generally rectangular with side walls 20, 22 parallel, the side walls may be non-parallel, for example with a triangular or trapezoidal housing. The first and second brushes may be the same length (across the width of the head) or may be different lengths. The cleaning tray is designed to mate with the cleaning head.

[0102] In the above embodiment, there is a pair of roller brushes. However, the present invention may be applied to cleaning heads with a single roller brush, such as a roller brush in front of a squeegee. The ability of one or more protrusions to spread water along the length of the roller brush and achieve flow control may also be applied to cleaning a cleaning head with a single roller brush.

[0103] Variations of the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and singular elements do not exclude a plurality.

[0104] The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0105] It should be noted that when the term "adapted to" is used in the claims or description, it is intended to be equivalent to the term "configured to."

[0106] Any reference signs in the claims should not be construed as limiting the scope.

Claims

1. A cleaning tray for a wet floor cleaner, the cleaning tray receiving a head of the wet floor cleaner, the head including a roller brush, the cleaning tray including: A base for supporting the head; a brush channel formed in the base for receiving a bottom portion of a periphery of the roller brush; at least one raised protrusion disposed along the brush channel for protruding into the roller brush when the cleaning tray is in use, the at least one raised protrusion including an upstream sloped surface and a downstream sloped surface, the upstream sloped surface being disposed such that the outer periphery of the roller brush rides up onto the upstream sloped surface when rotated, the downstream sloped surface being steeper than the upstream sloped surface; a suction area facing the downstream inclined surface; Includes a cleaning tray.

2. 10. The cleaning tray of claim 1 including a set of raised protrusions, each having an upstream sloping surface and a downstream sloping surface.

3. The or each raised projection may be a height in the range of 1 mm to 10 mm, and / or A cleaning tray according to claim 1 or 2, having a length parallel to the length of the brush channel in the range of 1 mm to 50 mm.

4. 4. A cleaning tray according to any preceding claim, wherein the or each raised projection has an apex at an angle of 90 degrees or greater at the junction between the upstream and downstream sloped surfaces.

5. The cleaning tray of claim 4 , wherein the apex has a radius of curvature of less than 2 mm.

6. 6. A cleaning tray according to any one of the preceding claims, wherein the brush channel comprises two or more sets of raised protrusions, with at least two different shapes of raised protrusions within said set.

7. 7. The cleaning tray of claim 1, further comprising a flow guide within the brush channel to provide a flow path across the brush channel to the suction area.

8. The cleaning tray of claim 7 , wherein the flow guide includes two side projections that converge toward each other along the flow path.

9. The cleaning tray of claim 8, wherein the two side projections form part of a V-shape with a vertex angle in the range of 40 degrees to 120 degrees.

10. 10. A cleaning tray according to any one of the preceding claims, including opposed side walls, one of the side walls having an opening through which the roller brush is received transversely parallel to its axis of rotation.

11. 11. A cleaning tray according to any one of claims 1 to 10 adapted to receive a head of a wet floor cleaner comprising a pair of roller brushes, the cleaning tray comprising a pair of brush channels, the suction area being between the pair of brush channels.

12. Housing and at least one rotating brush extending across the width of the housing; a suction channel for providing suction to at least a space adjacent the at least one rotating brush; and a pump for providing suction to the suction channel of the cleaning head; a supply system for supplying a cleaning fluid to the cleaning head; A cleaning tray according to any one of claims 1 to 11; Wet floor cleaners, including:

13. 1. A method for cleaning a roller brush of a cleaning head of a wet floor cleaner when the cleaning head is attached to a cleaning tray, comprising: The cleaning head includes at least one rotating brush and a suction channel for providing suction to at least a space adjacent to the at least one rotating brush. said method comprising: In the initiation cycle, supplying a relatively large amount of cleaning liquid to the cleaning head and driving the roller brush at a relatively slow rotational speed without providing suction; supplying a relatively small amount of cleaning fluid to the cleaning head and driving the roller brush at a relatively high rotational speed to apply a first level of suction; Including, In the intermediate cycle, supplying a relatively large amount of cleaning liquid to the cleaning head and driving the roller brush at a relatively slow rotational speed without providing suction; supplying a relatively small amount of cleaning liquid to the cleaning head and driving the roller brush at a relatively high rotational speed without providing suction; supplying a relatively small amount of cleaning liquid to the cleaning head and driving the roller brush at a relatively high rotational speed to apply a second level of suction that is lower than the first level of suction; Including, In the final cycle, supplying a maximum amount of cleaning liquid to the cleaning head and driving the roller brush at a relatively slow rotational speed without providing suction; driving the roller brush at a relatively high rotational speed and applying the suction force without a supply of cleaning liquid; A method comprising:

14. 14. The method of claim 13, wherein a final step of the termination cycle includes driving the roller brush at a relatively high rotational speed and applying the second level of suction, followed by applying the first level of suction without a supply of cleaning fluid.

15. 15. The method according to claim 13 or 14, wherein the cleaning head is applied while mounted in a cleaning tray according to any one of claims 1 to 11.

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