Floor treatment machine

Abstract

The present invention relates to the field of floor treatment machines for cleaning floors. The invention relates in particular to wet scrubbing machines with work heads provided with brushes for agitating the floor surface. The invention provides a floor treatment machine comprising: a deck portion provided with at least one floor-facing work head which is provided with a floor treatment surface disposed on a floor-facing underside of the work head, the deck portion being adapted for translational movement over the floor surface in a cleaning direction, wherein the deck portion carries at least one drive motor assembly for rotating the work head via a hub unit, the hub assembly providing a connection between the work head and the motor assembly; wherein the machine is provided with at least one reservoir for storing a cleaning liquid and an associated fluid distribution system for delivering cleaning liquid via the hub from a location above the hub to the underside region of the work head, the fluid distribution system comprising at least one inlet for receiving the cleaning liquid from the reservoir, at least one liquid distribution system outlet for dispensing the liquid onto the floor under the work head, wherein the distribution system comprises a fixed upper portion which serves as an outskirt within which a motor drive shaft rotates, and a lower hub portion which serves as an outskirt of the drive shaft, and which is attached to the drive shaft so as to rotate therewith, wherein the liquid distribution system inlet is provided in the fixed upper portion, and the liquid distribution system outlet is provided disposed at a lower region of the hub portion, which portion projects through the work head and faces the floor thereunder, and wherein at least one fluid flow path is provided between the inlet and outlet extending via the upper fixed portion and the lower hub portion, the arrangement being such that in use cleaning liquid passes into the inlet and passes through the lower rotating hub portion and is ejected therefrom to assist the floor treatment action.

Description

[0001] Floor treatment machine

[0002] The present invention relates to the field of floor treatment machines for cleaning floors. The invention relates in particular to wet scrubbing machines with floor-facing work heads provided with brushes for agitating the floor surface.

[0003] It is known that a possible way to optimise the use of liquid such as water, cleaning solution and / or a mix thereof when cleaning floors using floor treatment machines is by feeding the liquid to the centre region of the annular brushes of the floor treatment machines. As compared to directly spraying the floor in front of the work heads. The centrifugal delivery of the liquid through the brushes minimises overall liquid usage, results in no messy spray-off and increases efficiency by reducing the time-consuming operations of refilling the floor treatment machine with liquid.

[0004] There are existing floor treatment machines which are adapted to feed the liquid to the centre of the brushes. These machines are provided with hollow drive shafts and axial through-shaft liquid delivery systems. The liquid is fed down the centre of the drive shaft towards the floor surface to be treated. In some of these machines, the top portion of the axial through-shaft needs to be clear for liquid input, this means that the drive shaft and the motor are mounted onto the machine so that drive shaft axis and the motor axis are offset with respect to each other. In this offset arrangement, the transmission can be achieved by using a motor with a gearbox transmission arrangement.

[0005] A potential drawback of existing floor treatment machines with liquid fed through the drive shaft is that they require drive shafts with large diameters (and correspondingly large bearings) to allow for the liquid to pass through; thus, this can result in a machine with a bulky design. Further, the offset arrangement between the shaft axis and the motor axis restricts the options of the type of gearbox arrangements which can be fitted onto these floor treatment machines.

[0006] Thus, it would be desirable to provide improved floor treatment machines which address one or more of these issues. According to one aspect of the present invention, there is provided a floor treatment machine comprising: a deck portion provided with at least one floorfacing work head which is provided with a floor treatment surface disposed on a floor-facing underside of the work head, the deck portion being adapted for translational movement over the floor surface in a cleaning direction, wherein the deck portion carries at least one drive motor assembly for rotating the work head via a hub unit, the hub assembly providing a connection between the work head and the motor assembly.

[0007] The machine may be provided with at least one reservoir for storing a cleaning liquid and an associated fluid distribution system for delivering cleaning liquid via the hub from a location above the hub to the underside region of the work head. The fluid distribution system may comprise at least one inlet for receiving the cleaning liquid from the reservoir, and a fluid distribution system outlet or outlets for dispensing the liquid onto the floor under the work head.

[0008] The fluid distribution system may comprise a fixed upper portion which serves as an outskirt within which a motor drive shaft rotates. There may be a lower hub portion which serves as an outskirt or sleeve of the drive shaft, and which is attached to the drive shaft so as to rotate therewith.

[0009] The fluid distribution system inlet may be provided in the fixed upper portion, and the fluid distribution system outlet may be disposed at a lower region of the hub portion, which lower portion projects through the work head and faces the floor thereunder. A fluid flow path may be provided between the inlet and outlet extending via the upper fixed portion and the lower hub portion. The arrangement may be such that in use cleaning liquid passes into the inlet and passes through the lower rotating hub portion and is ejected therefrom to assist the floor treatment action - typically floor cleaning.

[0010] The fluid flow path may comprise one or more vertically extending channels formed in the outskirt of the hub portion. There are preferably two or more said vertical channels. The channels may be straight or curved, axial or helical in the hub portion. The hub portion is typically generally cylindrical in form, such as in the form of an annular sleeve.

[0011] The fixed upper portion may comprise a collar provided with (or partially defining) an internal manifold for receiving cleaning liquid or fluid from the inlet. The hub portion’s channels are fed by the manifold.

[0012] The manifold may comprise an annular groove or chamber provided in the collar. The groove or chamber may open onto an upper end face of the hub portion. One or more manifolds may be provided entirely within the hub portion.

[0013] The fluid flow channels may have upper ends which are aligned with the groove or chamber. The inlet in the collar may comprise a generally radially oriented spigot, or an axially oriented vertical spigot, which feeds into the manifold. The manifold accumulates cleaning liquid for distribution by the flow channels.

[0014] The liquid flow paths may comprise one or more channels extending between the upper end face of the hub portion and a lower end region of the portion which faces the floor to be treated.

[0015] Seals may be provided to seal between the collar and the hub portion. There may be one circular inner seal inset within the annular groove and another circular outer seal outside the annular groove. The seals may be toroidal or annular, but of course seals having alternative profiles or shapes may of course be provided instead. The profiles of any seal seats may also be tailored to the particular interface structure. Instead of, or in addition to, seals as described above, other methods of sealing may be used. For example, fine tolerances may be relied upon, and / or the use of low-friction bearing materials (such as PTFE). Greases or other lubricants may be used to provide an enhanced seal whilst permitting free rotation of the hub relative to the fixed upper portion of the liquid distribution system.

[0016] An outer region of the hub portion is preferably engaged with, and carries, the work head. Typical hubs have a configuration well known in the art. A connection between the hub portion and the work head may comprise a multifaceted male member which is received by a corresponding seat member. The hub portion may be mounted co-axially with the drive motor rotor, or offset from the motor rotor where a transmission unit is present. The drive shaft may be an extension of a drive rotor, or may be an extension of the rotor, or may be driven by a gear train.

[0017] The hub portion may comprise a generally cylindrical body portion and an axial bore for receiving a distal end region of a motor drive shaft. The lower distal end of the hub portion may be provided with a face which includes one or more axially directed cleaning fluid outlets. The outlets may be splayed somewhat, so as to produce a frusto-conical curtain of cleaning liquid under the work head. Other outlet configurations are of course possible.

[0018] The fluid distribution system and / or associated feed reservoir rely upon gravity feed to dispense cleaning liquid from the outlet. In this case the reservoir outlet is preferably disposed so as to be vertically spaced apart from the fluid distribution system inlet. Alternatively, the system and / or reservoir may be pressurised to above atmospheric pressure so as to dispense liquid from the outlet under pressure. In this case one or more pumps may be provided to pressurise the system and / or reservoir. The pump may increase air pressure in the reservoir, or may be positioned to act on liquid downstream of the reservoir so as to draw liquid from the reservoir and dispense it under pressure from the outlet(s).

[0019] One fluid distribution system inlet may be in fluid communication with a liquid detergent source. This may be gravity fed or under pressure. The inlet may be dedicated to the liquid detergent (or other floor treatment chemical), or may receive a solution of cleaning liquid (typically water) and detergent. The liquid detergent feed is preferably controllable by an operator, by means of an actuator, such as a squeezable bladder or an electric pump. By varying the amount of detergent, the richness of the cleaning liquid solution dispensed can be adjusted. The detergent from the dedicated inlet may be mixed with cleaning liquid from another inlet within the fluid distribution system before it is dispensed.

[0020] Alternatively, the respective inlet conduits may be kept separate so that detergent liquid and cleaning liquid are dispensed in parallel, but separately.

[0021] Mixing cleaning liquid and detergent may occur in a manifold formed in the hub portion fed by the inlets, or in a manifold provided in the fixed upper portion. Mixing may be enhanced by providing an inlet in which is fed a gas, such as air, so as to aerate the cleaning liquid and / or detergent. Increasing the proportion of air in the cleaning liquid can help reduce water use, and thus reduce the need for reservoir refilling at a tap.

[0022] The work head will typically be disc-shaped, with an underside provided with a surface treatment attachment. These may be an annular scrubbing brush, or a polishing pad, or grinding features. The work head may be driven to rotate in a preferred direction continuously, or may be configured and arranged to oscillate back and forth through a limited arc.

[0023] In a preferred configuration there are two rotatably driven work heads disposed side-by-side, preferably transversely disposed with respect to the working direction. The work heads may be adapted to counter rotate with respect to one another, so as to make the machine directionally stable when pushed (or propelled) over a floor surface. The work heads may each have a vertical axis of rotation. Alternatively, the axes may be set to converge or diverge transversely slightly so as to induce propulsion by scrubbing brush rotation.

[0024] A squeegee suction collector may be disposed behind the work head or heads. The collector is preferably adapted to entrain used cleaning liquid collected on the floor and to convey and discharge liquid into a waste liquid tank in the machine. This arrangement of scrubbing brush, application of cleaning liquid and collection of waste liquid is known as a scrubber-dryer.

[0025] When user-guided, the machine may have an upstanding handle portion attached to the deck portion via a pivoting connection. The pivoting connection may permit up / down (to provide a handle height adjustment) and / or side-to-side pivoting (to provide deck steering) of the handle with respect to the deck portion. In the latter case a universal joint can be used to provide the two pivots which permit steering of the machine by twisting the handle portion.

[0026] Alternatively, the machine may be configured as a treatment robot with selfpropulsion, guidance system and no vertical handle portion.

[0027] The machine may be adapted and configured so that, during use, the weight of the machine is taken at least in part by the work head or head. The weight of the machine however may be shared between the work heads or heads and one or more support wheels or castors. Alternatively, the machine weight can be taken entirely by the work head or heads. In which case ancillary wheels may be deployable to selectively engage with the floor and facilitate wheeling of the machine between jobs, or to prevent the brush becoming flattened during storage by the machine weight.

[0028] The inlet in the collar may comprise a generally radially oriented spigot which feeds into the manifold. This may be fed by a flexible tube from the cleaning liquid reservoir. It may be gravity fed or pumped. The collar may have an upper proximal region which is fixed to a motor housing.

[0029] The manifold may comprise an annular groove or chamber in the collar. The groove may open onto a proximal end face of the second portion. The groove may overlap proximal ends of one or more fluid conduits provided in the second portion, so that in use as the second portion rotates with respect to the collar each fluid conduit can be fed by liquid from the groove, i.e. fluid communication is maintained during use. The one or more fluid conduits typically extend between the upper end face (where the collar is located) and a distal end region of the second portion which faces the floor to be treated (where the cleaning liquid is delivered to the floor surface).

[0030] The one or more fluid conduits are may each be formed within sidewalls of the second portion. Two or more annular or toroidal elastomer seals may be provided, operative between the collar and the proximal face of the lower hub portion. One inner seal may be inset from the annular groove and the other outer seal may be outside the annular groove. In this way the second portion can rotate with respect to the collar / f i rst portion with the mating faces sealed.

[0031] The hub portion in accordance with the invention thus serves to deliver cleaning liquid to the floor surface, within the confines of the annular curtain provided by the work head underside treatment surface. This surface is typically an annular array of floor scrubbing bristles, with a central portion occupied by the hub mounting. Delivering into the core of the work head provided the best delivery for cleaning and avoids waste and splashing of cleaning fluid.

[0032] The hub unit may comprise a generally cylindrical body portion with an axial bore for receiving a distal end region of the drive shaft. The shaft may be splined to engage with an interior region of the cylindrical body, and retained by a bolt or clip.

[0033] The distal end of the hub or second portion may be provided with a face which includes one or more axially directed cleaning liquid outlets. The fluid conduits deliver (in some embodiments) two diametrically opposed jets of cleaning fluid, which when the hub rotates causes a curtain of liquid to form, depending from the floor-facing lower face of the hub portion.

[0034] The (or each) drive motor assembly may comprise a motor with drive shaft that is directly driven, or may comprise a transmission or gearbox acting between the motor rotor and a drive shaft which carries the hub portion. There may be a single motor with a transmission which is adapted to drive multiple drive shafts with work heads via respective hubs with fluid distribution systems.

[0035] For the sake of simplicity and weight reduction, it is preferred that the electric motor has a rotor which serves as the driveshaft (or where the drive shaft is a co-axial extension of the rotor) and which directly drives the hub and carries the fluid distribution system.

[0036] There may be a motor for each work head, of a single motor which drives two or more work heads. The work heads may be adapted to counter rotate with respect to one another, so as to provide a balanced scrubbing action. However, the work heads may co-rotate (rotate in the same direction) or may oscillate rather than fully rotate.

[0037] The work heads may each have a generally vertical axis of rotation. By inclining the co-rotation axes inwardly or outwardly slightly (transversely) a net propulsion forwards or backwards can be induced. Alternatively, a separate propulsion system may be provided, such as a drive wheel or wheels. Alternatively, the machine may have no propulsion system and rely upon a user pushing or pulling the machine entirely manually.

[0038] The liquid delivered to the floor surface is typically a water-based liquid cleaning solution, which may include detergent and other additives. It could however comprise another solvent or simple water or another treatment liquid such as a polish, wax or grinding paste. As described elsewhere, the liquid could be aerated with a gas, such as air. The liquid may be a heated liquid, or heated further to form steam or a vapour.

[0039] The machine may have a guide handle portion for steering and guiding the machine, however, ride-on machines may be made in accordance with the invention.

[0040] Following is a description by way of example only and with reference to the figures of the drawings of modes for putting the present invention into effect.

[0041] In the drawings:

[0042] Figure 1 is a side view of a floor scrubbing machine in accordance with a first embodiment of the present invention.

[0043] Figure 2 is a schematic cross-sectional view of a work head and drive motor assembly in accordance with the present invention.

[0044] Figure 3 is a schematic perspective three quarter view showing the drive motor and a fluid distribution system in accordance with the invention. Figure 4 is a longitudinal section through the fluid distribution system of Figure 3.

[0045] Figure 5 is a top section through a collar region of the fluid distribution system of Figure 3.

[0046] Figure 6 is an exploded perspective view of a motor transmission and hub assembly in accordance with a second embodiment of the invention.

[0047] Figure 7 is a three quarter view of a cross-sectioned transmission and hub assembly of figure 6.

[0048] Figure 8 is a three quarter perspective view of the assembly of figures 6 and 7, with the collar and drive shaft having been sectioned to leave a 90 degree arc.

[0049] First embodiment

[0050] In Figure 1 a floor scrubbing machine in accordance with the first embodiment of the invention is shown generally as 100 sitting on floor surface 110. The machine has a deck portion 101 having an upper front region provided with a motor housing 102. A generally vertical, slightly rearwardly reclined handle portion 103 has a lower end region which is attached to the deck portion via a two-way (up / down, side to side) pivot, preferably a universal (or Cardan) joint.

[0051] An upper end region of the handle portion 104 is provided with a hand grip with operating controls. A mid-region of the handle portion is provided with a housing 106 for a cleaning liquid reservoir (internal, not visible) and a waste liquid collection tank (also not visible). The waste liquid collection tank is fed by a squeegee collector 107 which is disposed behind the deck portion 101 . The squeegee collector is resting on the floor and with a rear supporting wheel 112. A suction turbine motor (not shown) is provided which draws waste water from the squeegee’s collector via a hose 109. A cleaning liquid delivery tube 111 feeds from the reservoir to an upper rear region of the housing and then inside the housing. An underside of the deck portion is provided with a two generally disc-shaped floor scrubbing work heads 23 which are disposed side by side (one partially visible in figure 1 , best seen in figure 2). As shown in figure 2 each work head comprises a generally disc-shaped member formed with a central bore 25a. A lower surface 23b of the work head is provided with an array of bristles 25b which together form a generally annular, floor-facing a scrubbing brush 25.

[0052] In figure 2 an upstanding cylindrical electric motor is shown as 2. The motor has a vertical rotor axis (dashed lines). As is best shown in figure 3, a hub portion 10 is carried by the rotor 4 for rotation therewith and is fixed to the rotor by an axial retaining bolt 16 received in a threaded bore of the rotor. An annular collar 8 is fixed to the lower face 2a of the motor housing, with the rotor being a sliding fit in a central bore of the collar. Thus, when the motor rotor rotates, the collar remains fixed while the hub portion 10 rotates coaxially. The hub has a mid-region 26 formed with facets an defining an octagonal shape. This mid-region is received in a corresponding octagonal seat 28 (see fig. 2) in the work head. In this way hub torque is transferred to the work head.

[0053] An upper annular face of the hub is juxtaposed a lower face 8b of collar 8. Two O-ring seals 9, 11 are fixed to the underside of the collar so as to form an interface seal. As is best shown in figure 5, the collar is formed with an internal co-axial annular chamber 20. A radial spigot 18 feeds into the chamber in the direction of the arrow and liquid is distributed around the chamber. The spigot is itself fed by the cleaning liquid delivery tube 111 , discussed above. The seals prevent leakage of cleaning liquid at the interface of the stationary collar and rotating hub.

[0054] A wall portion of the hub is provided with two axially extending diametrically opposed bores 22, 24 (see fig. 4). These bores extend from an upper face of the hub portion to diametrically opposed outlets 22b, 24b provided in an annular bottom face 10b of the hub portion. Thus, cleaning liquid accumulated in the collar manifold chamber 20 flows down into the bores and is ejected down from the hub outlet nozzles (22b, 24b) onto an underlying floor surface skirted by the work head brush. As the hub rotates a circular curtain of fluid is directed to the floor surface under the hub. At the outlet bores constriction nozzles may be provided to cause effects such as liquid spraying or focussing of the cleaning liquid delivery.

[0055] The spigot, collar and hub together form an embodiment of a liquid distribution system. The system may rely upon gravity feed of the cleaning liquid from the reservoir. A pump may also be provided. The cleaning fluid may comprise water, typically with a detergent. Other specialist liquids may be used in particular circumstances, such as solvents for oily dirt or deposits. In practice there are preferably two work heads which are disposed transversely spaced apart, with the squeegee collector trailed behind the wheels to collect waste liquid with entrained detritus.

[0056] Second embodiment

[0057] Figure 6 shows a transmission assembly 200 which comprises a generally cylindrical electric motor 202 and a reduction gearbox 201 . A drive shaft 204 depends from an underside of the gear box, at a right angle with respect to the motor orientation. Four mounting legs (two visible as 236 in figure 6) extend downwardly from corner regions of the gearbox. A mounting plate 230 has one side with a generally circular cut-out 231 and a mouth 234. There are two radially projecting ears 232 formed with mounting holes. The plate has another side with a neck portion 233 at 90 degrees with respect to the cut-out 231 . The neck portion has a distal end region provided with two spaced apart further mounting holes 235. The mounting holes are aligned so as to receive the mounting legs of the gearbox. The said one side of the mounting plate is formed with three circumferentially spaced holes 237.

[0058] The collar 208 has a generally annular form, with three threaded bores 212 formed in an upper surface thereof. The bores are aligned with the holes 237 and receive three corresponding bolts 213 so as to fix the mounting plate and collar 208 together (as visible in figure 7). The collar is provided with a radially extending spigot 218 which serves as an inlet for cleaning liquid / solution. The spigot distal end is formed with an annular rim 238 which helps retain a flexible cleaning liquid supply tube on the spigot. As will be seen from figure 7, the spigot feeds into vertical conduit bore 239 formed in the collar. The underside region of the collar is accommodated in an annular seat 240 formed in a hub member 226. The hub has a central upper bore 241 , with a lower shoulder feature 242 and a lower bore 248. The upper bore region of the hub receives the distal lower end of drive shaft 204. The locking bolt 216 is inserted upwards to be seated in the lower bore against the shoulder feature 242. A shoulder region 243 of the drive shaft abuts an upstanding annular nose 244 of the centre of the hub. The annular under surface of the collar is spaced apart from the upper surface of the annular seat in the hub, thereby to define an annular chamber 220 for cleaning / solution. The chamber is fed by the vertical inlet bore 239. An inner toroidal seal 209 is seated between the hub nose 244 and the inner surface of the collar, in opposing grooved channels. Similarly, and further toroidal seal 249 is seated between an outside surface of the collar and an inner face of outer annular wall 245 of the hub. A sidewall portion of the hub is formed with a vertically extending conduit 224. The conduit feeds from the annular chamber 220 to an outlet orifice 246 in the lower end face of the hub. The hub has a waist region 247 which is formed with a multifaceted circumferential surface, as per the hub of the first embodiment (see fig. 5). The waist region can thereby be securely engaged in a corresponding multi-faceted hub seat formed in a work head brush (23, 25 as per figure 2). Such engagements are known in the art and not described further herein.

[0059] The four mounting legs of the gearbox are placed in the mounting holes of the mounting plate, and fixed in threaded bores on a work head deck of the scrubbing machine. In use, the work head is driven to rotate by the hub on the drive shaft. The drive shaft has a generally vertical axis of rotation, ensuring that the work head and brush rotate on the floor in a plane parallel to the floor. By modifying the spacing provided by each leg between the gearbox and the deck, the drive shaft axis can be shifted slightly from the vertical, thereby to provide differential pressure across each work head. This differential pressure can be used to promote or effect propulsion by the brush or brushes during rotation (i.e. during the cleaning operation). In use, the spigot 218 receives liquid cleaning solution, under gravity feed or active pressure, from a reservoir. The solution enters the fixed collar and fills the chamber 220. The solution travels down the vertical conduit 239, which is rotating with the engaged drive shaft and hub. Solution projects from the end face of the hub lower face via the outlet orifice 246, creating a liquid curtain of cleaning fluid withing the hub and annular brush array 25, promoting efficient cleaning and avoiding waste of cleaning liquid.

[0060] In summary, the present invention relates to the field of floor treatment machines for cleaning floors. The invention relates in particular to wet scrubbing machines with work heads provided with brushes for agitating the floor surface. The invention provides a floor treatment machine comprising: a deck portion provided with at least one floor-facing work head which is provided with a floor treatment surface disposed on a floor-facing underside of the work head, the deck portion being adapted for translational movement over the floor surface in a cleaning direction, wherein the deck portion carries at least one drive motor assembly for rotating the work head via a hub unit, the hub assembly providing a connection between the work head and the motor assembly; wherein the machine is provided with at least one reservoir for storing a cleaning liquid and an associated fluid distribution system for delivering cleaning liquid via the hub from a location above the hub to the underside region of the work head, the fluid distribution system comprising at least one inlet for receiving the cleaning liquid from the reservoir, at least one liquid distribution system outlet for dispensing the liquid onto the floor under the work head, wherein the distribution system comprises a fixed upper portion which serves as an outskirt within which a motor drive shaft rotates, and a lower hub portion which serves as an outskirt of the drive shaft, and which is attached to the drive shaft so as to rotate therewith, wherein the liquid distribution system inlet is provided in the fixed upper portion, and the liquid distribution system outlet is provided disposed at a lower region of the hub portion, which portion projects through the work head and faces the floor thereunder, and wherein at least one fluid flow path is provided between the inlet and outlet extending via the upper fixed portion and the lower hub portion, the arrangement being such that in use cleaning liquid passes into the inlet and passes through the lower rotating hub portion and is ejected therefrom to assist the floor treatment action.

Claims

Claims1 . A floor treatment machine comprising: a deck portion provided with at least one floor-facing work head which is provided with a floor treatment surface disposed on a floor-facing underside of the work head, the deck portion being adapted for translational movement over the floor surface in a cleaning direction, wherein the deck portion carries at least one drive motor assembly for rotating the work head via a hub unit, the hub assembly providing a connection between the work head and the motor assembly; wherein the machine is provided with at least one reservoir for storing a cleaning liquid and an associated fluid distribution system for delivering cleaning liquid via the hub from a location above the hub to the underside region of the work head, the liquid distribution system comprising at least one inlet for receiving the cleaning liquid from the reservoir, a fluid distribution system outlet or outlets for dispensing the liquid onto the floor under the work head, wherein the fluid distribution system comprises a fixed upper portion which serves as an outskirt within which a motor drive shaft rotates, and a lower hub portion which serves as an outskirt of the drive shaft, and which is attached to the drive shaft so as to rotate therewith, wherein the fluid distribution system inlet is provided in the fixed upper portion, and the fluid distribution system outlet is provided disposed at a lower region of the hub portion, which portion projects through the work head and faces the floor thereunder, and wherein at least one fluid flow path is provided between the inlet(s) and outlet(s) extending via the upper fixed portion and the lower hub portion, the arrangement being such that in use cleaning liquid passes into the inlet and passes through the lower rotating hub portion and is ejected therefrom via the outlet to assist the floor treatment action.

2. A machine as claimed in claim 1 wherein the fluid flow path comprises one or more vertically extending channels formed in the outskirt of the hub portion.

3. A machine as claimed in claim 2 wherein there are two or more said vertical channels.

4. A machine as claimed in any of the preceding claims wherein the fixed upper portion comprises a collar provided with (or partially defining) an internal manifold for receiving cleaning fluid from the inlet, and wherein the hub portion channels are fed by the manifold.

5. A machine as claimed in claim 4 wherein the manifold comprises an annular groove or chamber provided in the collar.

6. A machine as claimed in claim 5 wherein the groove or chamber opens onto an upper end face of the hub portion.

7. A machine as claimed in claim 5 or 6 wherein the fluid flow channel or channels have upper ends which are aligned with the groove or chamber.

8. A machine as claimed in any of claims 4 to 7 wherein the inlet in the collar comprises a generally radially oriented spigot, or an axially oriented vertical spigot, which feed into the manifold,9. A machine as claimed in any of the preceding claims wherein the fluid flow paths comprise one or more channels extending between the upper end face of the hub portion and a lower end region of the portion which faces the floor to be treated.

10. A machine as claimed in any of claims 5 to 9 wherein one or more seals are provided between the collar and the mating hub portion.

11. A machine as claimed in any of the preceding claims wherein an outer region of the hub portion is engaged with, and carries, the work head.

12. A machine as claimed in claim 11 wherein the hub portion comprises a generally cylindrical body portion and an axial bore for receiving a distal end region of a motor drive shaft.

13. A machine as claimed in any of the preceding claims wherein the lower distal end of the hub portion is provided with a face which includes one or more axially directed cleaning liquid outlets.

14. A machine as claimed in claim 11 wherein a connection between the hub portion and the work head comprises a multi-faceted male member which is received by a corresponding seat member.

15. A machine as claimed in any of the preceding claims wherein the hub portion is mounted co-axially with the drive motor rotor.

16. A machine as claimed in claim 15 wherein the drive shaft is an extension of, or is connected to, a drive rotor.

17. A machine as claimed in any of the preceding claims wherein there are two rotatably driven work heads disposed side-by-side, preferably transversely disposed with respect to the working direction.

18. A machine as claimed in claim 17 wherein the work heads are adapted to counter rotate with respect to one another.

19. A machine as claimed in claim 18 wherein the work heads each have a generally vertical axis of rotation.

20. A machine as claimed in any of the preceding claims wherein a squeegee suction collector is disposed behind the work head or heads, the collector being adapted to entrain used cleaning liquid collected on the floor and to convey and discharge the liquid and entrained dirt into a waste liquid tank in the machine.21 . A machine as claimed in any of the preceding claims wherein the machine has a handle portion attached to the deck portion via a pivoting connection.

22. A machine as claimed in claim 21 wherein the pivoting connection permits up / down and / or side-to-side pivoting of the handle with respect to the deck portion.

23. A machine as claimed in any of the preceding claims wherein the machine is configured as a treatment robot with self-propulsion, guidance system and no vertical handle portion.

24. A machine as claimed in any of the preceding claims and adapted so that during use the weight of the machine is taken at least in part by the work head or heads.

25. A machine as claimed in claim 24 wherein the weight of the machine is shared between the work heads or heads and one or more support wheels or castors.

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