Tank assembly for a floor treatment machine

Abstract

A collection tank assembly for a wet floor treatment machine such as a wet vacuuming, wet carpet cleaning or wet floor scrubbing machine, comprises a tank chamber 18, an inlet port (32, fig 2) and a suction separator port (34, fig 2) provided in an upper region of the chamber and configured to be attached to a vacuum suction drive which in use draws air-entrained liquid into the chamber. A baffle 40 is disposed between a base of the tank and the suction port and arranged so as to impede ingress of liquid from the chamber into the suction port. Preferably a periphery of the baffle provides an entire barrier between the base of the tank and the top of the tank, along the side wall.

Description

The present invention relates to the field of floor treatment machines and in particular wet vacuuming machines, wet carpet cleaning machines or wet floor scrubbing machines. These machines typically include a waste water collection tank for collecting dirty water from the floor surface being cleaned, and a suction drive I vacuum motor in fluid communication with the tank, via a suction port typically located in an upper region of the collection tank. The present invention seeks to provide an improved collection tank assembly for use in such machines. In known waste water collection tanks, the vacuum motor provides suction which causes an airflow to enter the tank chamber via the inlet port. The airflow, comprising dirt and dirty liquid, is lifted from a floor cleaning process, for example by a squeegee tool of a floor treatment machine. The velocity of the airflow decreases rapidly as it enters the low-pressure chamber and liquid is deposited in the collection tank. A suction shut-off valve, such as a float valve, is usually provided to close the suction port when the liquid collecting within the tank reaches a threshold level, thereby stopping further airflow entering the chamber and preventing liquid from reaching the vacuum motor. However, before the threshold liquid level is reached, liquid ‘sloshing’ within the tank may enter the open suction port and may reach the vacuum motor. The problem of sloshing liquid entering the vacuum motor is particularly prevalent in upright scrubber dryer machines with the waste water tank mounted on a handle portion which can be tilted away from an upright position during use. Such machines are more susceptible to liquid entering the vacuum motor if the handle is manoeuvred quickly, or the machine comes to a sudden stop, for example when knocking into a wall. Liquid entering the vacuum motor can significantly reduce its life expectancy and cause premature failure. Furthermore, any liquid that enters the vacuum motor is normally expelled, resulting in dirty liquid on a cleaned floor area. A known solution for reducing the likelihood of liquid entering a vacuum motor is to 5 increase the capacity of the waste water collection tank, thereby providing additional space for liquid to slosh around in. However this solution is not sufficiently effective at preventing liquid from entering the vacuum motor and furthermore, providing an oversized tank results in an increased overall size of the machine. 10 The present invention seeks to provide an improved, compact waste liquid collection tank assembly, which minimises the risk of liquid within the tank reaching the vacuum motor, and / or dirty liquid being expelled onto a cleaned floor. According to one aspect of the invention there is provided a collection tank assembly for a wet floor treatment machine, the assembly comprising; a tank, comprising an internal chamber defined by a base, a top, and a side wall; an inlet port provided in an upper region of the chamber; a suction port provided in the upper region of the chamber, the suction port configured to be in fluid communication with a vacuum suction drive which in use draws air-entrained liquid via the inlet port and into the chamber for collection of said liquid therein; wherein a baffle is provided in the upper region of the chamber, wherein the baffle has a wall disposed and configured so as to impede collected liquid from freely flowing or sloshing up the chamber side wall and into the suction port. The tank assembly of the present invention reduces the risk of any sloshing liquid with 15 the tank from reaching the vacuum motor via the suction port, thereby minimising the risk of damage to the vacuum motor. Furthermore, a compact tank assembly is enabled, as less space is required above the liquid level line to allow for water ‘sloshing’ around without entering the vacuum motor. The baffle wall may inwardly skirt the upper region of the chamber. The baffle may be provided with an orifice which communicates between the upper and lower chamber regions. The orifice may be centrally located in the baffle. The baffle wall may have a downwards tapered configuration, and may have a generally frustoconical shape. The baffle wall may have a concave profile. The configuration of the baffle of the present invention optimises the coverage of the baffle, and therefore optimises the protection provided to the suction port. The inlet port may bypass the baffle to allow entrained liquid to directly enter the lower region of the chamber. The inlet port may penetrate downwards through the baffle wall. The coverage of the baffle is thereby maximised, without impeding entry of dirty liquid into the chamber. A float valve assembly may be provided in the chamber, arranged to close the suction port when the collected liquid in the chamber reaches a predetermined level. The float valve assembly may be accommodated in the baffle orifice. The coverage of the baffle is thereby maximised, without impeding entry of dirty liquid into the chamber, and whilst ensuring that the float shut-off operates as intended, to close off the suction valve when the liquid reaches a threshold level. The baffle may have a peripheral rim which is seated in the top of the chamber. The tank assembly may further comprise a lid forming the top of the chamber, a separator, provided between the baffle and the lid; and seals, for providing sealing between the tank and the baffle, between the baffle and the separator, and between the separator and the lid. The seals may comprise a baffle seal comprising an annular seal of U-shaped crosssection, located around the baffle peripheral rim, wherein an upper region of the baffle seal provides sealing between the baffle flange and a separator flange at a periphery of the separator; and a lower region of the baffle seal provides sealing between the baffle flange and an edge of the tank side wall. Providing a single baffle seal which acts to seal against two other components of the assembly can reduce costs and complexity of assembly. The seals may comprise an inlet port seal around the inlet port, and a suction port seal around the suction port; wherein the inlet port seal provides sealing against an edge of a lid inlet port, provided in the lid and aligned with the inlet port, and the suction port seal provides sealing against an edge of a lid suction port, provided in the lid and aligned with the suction port. The seals may be configured such that, in a first sub-assembly comprising the tank, the separator, and the lid and not including the baffle, a first leak path is provided between the tank and the separator. The first leak path may comprise a gap between the tank and the separator. The first leak path would result in an insufficient vacuum being created within in the chamber on actuation of the vacuum motor. Effective operation of a machine with the baffle omitted is thereby prevented. The seals may also be configured such that in a second sub-assembly comprising the tank, the baffle, and the lid and not including the separator, a second leak path is provided between the baffle and the lid. The second leak path may comprise a gap between the baffle and the lid. The second leak path would also result in an insufficient vacuum being created within in the chamber on actuation of the vacuum motor. Effective operation of a machine with separator omitted is thereby prevented. According to a further aspect of the invention there is provided a wet vacuuming machine, a wet carpet cleaning machine or a wet floor scrubbing machine, comprising a collection tank assembly as claimed in any one of the preceding claims, and a vacuum suction drive in fluid communication with the suction port. The machine will typically have a floor-facing working tool such as a nozzle, scrubbing brush or another agitator. There may be a clean water reservoir adapted to feed water onto a floor (with detergent) or carpet to effect cleaning. The dirty liquid may be lifted by airflow induced to flow through the floor-facing nozzle or work head, which entrains the liquid into the airflow. The air-entrained liquid (and dirt particles) are dumped into the collection tank in the low-pressure chamber provided therein. The chamber gradually fills with liquid and dirt as the airflow leaves the tank through the suction port. The machine may comprise a scrubber dryer machine wherein the tank assembly is mounted to a handle portion of the machine. The handle portion may be adapted in use to be pivotable forwards or backwards about a first axis and from side to side about second, perpendicular axis. The axes may be provided by a Cardan joint. The tank assembly of the present invention is of particular benefit for use in scrubber dryer machines in which the collection tank is located on an upright handle portion. During use, the handle may be tilted up and down or laterally left and right. The collection tank is therefore often tilted away from an upright orientation during use, causing the liquid level to be closer to suction port on one side of the tank, thereby increasing the risk of sloshing water entering the suction port. Following is a description by way of example only of one mode for putting the invention into effect. In the drawings: Figure 1 is an exploded view of components of a tank assembly in accordance with the present invention; Figures 2, 3 and 4 are sectional front views of the tank assembly with components fully assembled; Figure 5 is sectional partial front view of the components of the tank assembly prior to assembly; Figure 6 is a sectional partial front view of the tank assembly with components fully assembled; Figure 7 is a sectional partial front view of a sub-assembly with a baffle omitted; Figure 8 is a sectional partial front view of a sub-assembly with a separator omitted; and Figure 9 is a side view of a floor treatment machine in accordance with the present invention. Referring to figures 1 to 4, a tank assembly in accordance with the present invention is indicated generally as 2. The tank assembly 2 comprises a waste water tank 10, a tank lid 30, a baffle 40, a separator 70, and a float valve assembly 60. The waste water tank 10 comprises a base 16 and a side wall 12. An interior tank chamber 18 is defined within the tank 10; the chamber is defined within the base 16, the side wall 12, and a top of the tank provided by the lid 30. The chamber 18 has a generally upper region 24 and a generally lower region 26. The separator 70 is provided in the upper region 24 of the chamber 18, and comprises an inlet port 20, and a suction separator port 28. The inlet port 20 communicates with an inlet channel 22 which extends into the chamber 18. The suction separator port 28 communicates with a suction drive I vacuum motor (not shown). The float valve assembly off 60 extends from the separator 70 towards the lower region 26 of the chamber 18. The separator 70 and float valve assembly 60 may be provided as a sub-assembly, for simplicity of assembly I disassembly of the tank assembly 2. The float valve assembly 60 comprises a buoyant riser float ball 62 enclosed within a float enclosure 66, and a closure ball 64 which communicates with the riser float ball 62 via an elongate member 68. The baffle 40 is formed as a single piece or integrally formed component for ease of manufacture, and ease of assembly / disassembly of the tank assembly 2. The baffle 40 includes a generally concave wall of a generally frustoconical shape. The baffle wall inwardly skirts the upper region 24 of the chamber 18, and extends inwardly from a baffle outer perimeter or periphery 42, towards a baffle mid-region 44. The baffle mid-region 44 may be disposed towards a radial centre (with respect to a longitudinal axis X of the chamber as indicated in figures 2 and 3) of the chamber 18. Moving towards the mid-region 44, the baffle 40 extends and tapers downwardly (in the orientation of figures 2 and 3), i.e. towards the base 16 of the tank 10, such that a distance between the baffle inner region 44 and the tank base 16 is less than a distance between the baffle outer periphery 42 and the base 16. The outer periphery 42 of the baffle 40 forms an entire barrier between the base 16 of the tank 10 and the top of the tank 10 along the side wall 12, i.e. all of the baffle periphery 42 is in contact with the side wall 12 of the tank. There are no gaps I fluid pathways between the baffle periphery 42 and the side wall 12, and therefore no liquid can flow along the side wall 12 from the lower region 26 of the chamber 18 towards the top of the tank 10, i.e. collected liquid is impeded from freely flowing or sloshing up the chamber side wall 12 and into the suction separator port 28. The baffle 40 comprises an aperture 48 through which the inlet channel 22 of the separator 70 extends. The inlet port 20 therefore effectively penetrates downwards through the baffle wall and thereby bypasses the baffle 40, such that liquid entrained in the airflow entering via the inlet port 20 may directly enter the lower region 26 of the chamber 18. 5 The baffle 40 further comprises a centrally located orifice 50, which communicates between the upper and lower chamber regions 24, 26. The float valve assembly 60 extends through the orifice 50. In use, actuation of the vacuum suction drive causes suction, via the suction separator port 28 (and a corresponding port 34 in the tank lid 30), which creates a vacuum within the chamber 18. The vacuum acts to draw an airflow into the chamber 18 via the inlet 10 port 20 (and a corresponding port 32 in the tank lid 30). The airflow has typically been lifted from a wet floor surface during a cleaning process, for example by a squeegee of a floor treatment machine, and comprises dirt and dirty liquid, such as water and possibly detergent. In figure 2, suction is indicated generally by the dashed arrows, and the airflow I liquid path by the solid arrows. As the airflow enters the low-pressure tank chamber 18 via the inlet port 20, its velocity decreases rapidly, and liquid particles are then deposited in the chamber 18. Over time, the deposited liquid begins to fill the chamber 18 from the base 16. The liquid level rises toward the upper region 24 of the chamber 18, towards the suction drive motor via the suction separator port 28. Figures 2 and 3 show liquid within the chamber 18 respectively at a first level L1 and at second level L2. The riser float ball 62 is urged upwardly within the float enclosure 66 by the rising liquid within the chamber 18; the rising of the float ball 62 causes the closure ball 64 to rise correspondingly. When the liquid reaches a threshold level, as shown in figure 3, the closure ball 64 acts to close the suction separator port 28 and thereby prevent liquid from reaching the suction drive. Before the liquid reaches the threshold level, i.e. as shown in figure 2, the suction separator port 28 is open, i.e. is not blocked by the closure ball 64. Liquid within the chamber 18 is often not still, and often sloshes (i.e. splashes, or is displaced), around within the chamber 18, for example as a result of rapid manoeuvring of a floor treatment machine to which it is mounted, or by the machine being brought to a sudden stop. The baffle 40 acts to deflect liquid sloshing within chamber 18 away from the suction separator port 28. Sloshing liquid contacts an underside surface 46 of the baffle 40 and is urged back towards the lower region 26 of the chamber 18. The potential for ingress of liquid into the suction drive via the suction separator port 28 is thereby reduced. Figure 4 shows the tank assembly 2 tilted at an angle 8 away from a horizontal orientation H. The tank assembly 2 could for example be mounted to a handle portion of a walk-behind wet scrubbing machine, wherein in use, the handle portion can be pivoted forwards or backwards about a first axis, and from side to side about a second, perpendicular axis. The pivoting of the handle portion about the first and second axes may for example be enabled by a Cardan joint. The liquid in the chamber 18 is at a level L, and sloshing liquid is indicated generally by the dashed arrow. The liquid level L has not yet caused the float valve assembly 60 to shut off the suction separator port 28. However, the tilting of the tank assembly 2 causes the liquid to be closer to the suction separator port 28 on one side of the chamber 18 (i.e. the right hand side in the figure). Liquid within the chamber 18 would therefore be required to slosh, or be displaced, to a lesser degree to reach the separator suction port 28 than if the tank assembly 2 were in an upright orientation. The baffle 40 is therefore particularly beneficial for use in tank assemblies which may not be maintained in an upright orientation during use. Figures 5 and 6 illustrate sealing arrangements for the tank assembly 2. An inlet port seal 72 is provided annularly around a periphery of the inlet port 20 of the separator 70. An annular suction port seal 74 is provided to seal the separator suction port 28. (The inlet port seal 72 and suction port seal 74 are also indicated in figure 1). A baffle seal 52, comprising an annular seal with a U-shaped cross-sectional form, is provided around a rim 54 provided at the outer periphery of the baffle 40. On assembly of the components of the tank assembly 2, the baffle 40 is inserted into the tank 10 such that rim 54 rests (via baffle seal 52) on an annular edge 14 of the side wall 12 of the tank 10. The separator 70 is placed onto the baffle 40 such that the float valve assembly 60 extends through baffle opening 50, the inlet channel 22 extends through baffle aperture 48, and an underside 78 of a flange 76 at a periphery of the separator 70 rests on the baffle rim 54 (via baffle seal 52). The tank lid 30 is placed on the separator 70 such that the inlet port 32 of the lid aligns with the inlet port 20, and suction port 34 of the lid aligns with the suction separator port 28. The tank assembly 2 is secured together, for example by latching mechanisms provided on the tank 10 and the lid 30. After assembly, the baffle 40 is therefore fixed in place in relation to the other components of the tank assembly 2. When the components are assembled together correctly as illustrated in Figure 6, various sealing locations are created. The inlet port seal 72 provides sealing between the inlet port 20 and the corresponding inlet port 32 of the lid 30. The suction port seal 74 provides sealing between the suction separator port 28 and the corresponding suction port 34 of the lid 30. An upper region of the baffle seal 52 provides sealing between the baffle 40 and the underside surface 78 of the separator flange 76. A lower region of the baffle seal 52 provides sealing against the tank side wall edge 14. Therefore, when the components are correctly assembled, the seals 72, 74 and 52 act to prevent air leaking into the tank chamber 18, and to prevent liquid from leaking out of the chamber 18. Correct operation of the tank assembly 2 is thereby enabled on actuation of the vacuum suction drive. The seals are configured so as to discourage or prevent use of the tank assembly 2 when a component has been omitted from the assembly. Specifically the seals are configured such that if the baffle 40, or the sub-assembly comprising the separator 70 and float valve assembly 60, are omitted from the assembly, the sealing required for correct operation of the tank assembly 2 will not be provided. Referring to figure 7, if the tank 10, separator 70 and tank lid 30 are assembled together without the baffle 40, a gap 80 is present between the separator 70 and the tank 10. The gap 80 provides a leak path, indicated generally at A, between the separator 70 and the tank 10. Therefore if the baffle 40 is not installed, when the vacuum suction drive is actuated, air will be drawn into the chamber 18 via the leak path A, a sufficient vacuum will not be created within the chamber 18, and waste liquid will not be drawn into the chamber via the inlet port 20. Effective operation of a floor treatment machine without the baffle 40 being installed is thereby prevented. Referring to figure 8, on assembly of the tank 10, baffle 40, and tank lid 30, without the separator 70, a gap 82 is present between the baffle 40 and the tank lid 30. The gap 82 provides a leak path, indicated generally at B, between the baffle 40 and the tank lid 30. Therefore if the sub-assembly comprising the separator 70 and the float valve assembly 60 is not installed, actuation of the vacuum suction drive will cause air to be drawn into the chamber via the leak path provided at B, a sufficient vacuum will not be created within the chamber 18, and waste liquid will not be drawn into the chamber 18 via the inlet port 20. Effective operation of a machine without the separator 70 including the float valve assembly 60 off being installed is thereby prevented. Figure 9 shows a floor treatment machine 100 in accordance with the present invention. The machine 100 comprises an upright handle portion 102, comprising an elongate stem 104 and a main body 106. The collection tank assembly 2 is attached to the handle portion 102. The stem 104 of the handle portion 102 is pivotably connected to a base portion 108 comprising a work head 110.

Claims

1. A collection tank assembly for a wet floor treatment machine, the assembly comprising;a tank, comprising an internal chamber defined by a base, a top, and a side wall, and having an upper region and a lower region;an inlet port provided in the upper region of the chamber;a suction port provided in the upper region of the chamber, the suction port configured to be in fluid communication with a vacuum suction drive which in use draws air-entrained liquid via the inlet port and into the chamber for collection of said liquid therein;wherein a baffle is provided in the upper region of the chamber, wherein the baffle has a wall disposed and configured so as to impede collected liquid from freely flowing or sloshing up the chamber side wall and into the suction port.

2. A collection tank assembly as claimed in claim 1 wherein the baffle wall inwardly skirts the upper region of the chamber.

3. A collection tank assembly wherein the baffle is provided with an orifice which communicates between the upper and lower regions of the chamber.

4. A collection tank assembly as claimed in claim 3 wherein the orifice is centrally located in the baffle.

5. A collection tank assembly as claimed in any of the preceding claims wherein the baffle wall has a downwards tapered configuration.

6. A collection tank assembly as claimed in any of the preceding claims wherein the baffle wall has a generally frustoconical shape.

7. A collection tank assembly as claimed in any of the preceding claims wherein the baffle wall has a concave profile.

8. A collection tank assembly as claimed in any of the preceding claims wherein the inlet port bypasses the baffle so that the entrained liquid may directly enter the lower region of the chamber.

9. A collection tank assembly as claimed in any of the preceding claims wherein the inlet port penetrates downwards through the baffle wall.

10. A collection tank assembly as claimed in any of the preceding claims wherein a float valve assembly is provided in the chamber, arranged to close the suction port when the collected liquid in the chamber reaches a predetermined level.

11. A collection tank assembly as claimed in claim 3 and claim 10 wherein the float valve assembly is accommodated in the baffle orifice.

12. A collection tank assembly as claimed in any of the preceding claims wherein the baffle has a peripheral rim which is seated in the top of the chamber.

13. A collection tank assembly as claimed in claim 12, further comprising:a lid forming the top of the chamber;a separator, provided between the baffle and the lid; andseals, for providing sealing between the tank and the baffle, between the baffle and the separator, and between the separator and the lid.

14. A collection tank assembly as claimed in claim 13, wherein the seals comprise a baffle seal comprising an annular seal of U-shaped cross-section, located around the baffle peripheral rim, wherein;an upper region of the baffle seal provides sealing between the baffle flange and a separator flange at a periphery of the separator; anda lower region of the baffle seal provides sealing between the baffle flange and an edge of the tank side wall.

15. A collection tank assembly as claimed in any one of claims 10 to 12, wherein the seals comprise an inlet port seal around the inlet port, and a suction port seal around the suction port; wherein;the inlet port seal provides sealing against an edge of a lid inlet port, provided in the lid and aligned with the inlet port; andthe suction port seal provides sealing against an edge of a lid suction port, provided in the lid and aligned with the suction port.

16. A collection tank assembly as claimed in any one of claim 10 to 14 wherein theseals are configured such that:in a first sub-assembly comprising the tank, the separator, and the lid and not including the baffle, a first leak path is provided between the tank and the separator; and / orin a second sub-assembly comprising the tank, the baffle, and the lid and not including the separator, a second leak path is provided between the baffle and the lid.

17. A wet vacuuming machine, a wet carpet cleaning machine or a wet floor scrubbing machine, comprising a collection tank assembly as claimed in any one ofthe preceding claims, and a vacuum suction drive in fluid communication with the suction port.

18. A machine as claimed in claim 17 comprising a scrubber dryer machine wherein the collection tank assembly is mounted to a handle portion of the machine.

19. A machine as claimed in claim 18 wherein the handle portion is adapted in use to be pivotable forwards or backwards about a first axis and from side to side about second, perpendicular axis.

20. A machine as claimed in claim 19 wherein the axes are provided by a Cardan joint.

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