Floor treatment machine having an airflow outlet

Abstract

A floor treatment machine 10 is disclosed, comprising a base portion 11 provided with at least one rotatable floor-facing work head 29A, 29B having a generally vertical axis of rotation and drive means for rotating the work head around its generally vertical axis of rotation A, B. The machine 10 further comprises an air flow outlet 49 configured to introduce a flow of air 55 on to the floor surface in an air flow direction having a component directed towards the lateral centre of the base portion 11. Preferably, the air flow 55 may originate from the exhaust air of an associated suction motor 19. Fig. 3

Description

[0001] The present invention concerns the field of floor treatment machines such as scrubbers, finishers or polishers. Floor scrubbers typically have rotating work heads equipped with bristles for working the floor to remove dirt. Finishers may have stiffer bristles with which to pare down a floor surface, such as a wooden surface. Polishers are typically equipped with relatively soft cleaning pads for polishing floor surfaces such as wooden, polymer (e.g., Lino) or concrete / ceramic surfaces.

[0002] The present invention in particular concerns floor treatment machines having at least one floor-facing work head. These work heads typically have generally vertical axes of rotation. Where there are two work heads, they are typically arranged to be counter rotating (such as described in US8887348B2 and US9826874B2), although floor treatment machines with two co-rotating heads (i.e. where the heads both rotate in the same direction, either both clockwise or both counterclockwise) have also been proposed.

[0003] However, a dirt and fluid deflection tendency may be displayed by co-rotating machines, as schematically shown in Fig. 1, whereby one of the cleaning brushes may cause water (or other liquid) and / or dirt etc. present on the surface being cleaned to be flicked outside of the machine's intended cleaning path, for example when the machine is used to clear puddles of water from the floor. Fig. 1 is a top plan schematic view of the base or deck shown generally at 1 of a floor treatment machine provided with two co-rotating brush heads 3, 5 and a suction squeegee blade 7, the latter located behind the heads 3, 5 in the usual direction of travel T of the machine for suctioning dirt and fluid from the floor surface under the action of a suction source in the form of a vacuum motor 9. Due to its direction of rotation, the outer or leading edge of the outwardly rotating brush 5 - that is, the brush in which the leading edge (i.e. front half of the brush, in the usual processing / travel direction T) rotates from the centre of the machine towards the outer lateral side of the machine, as shown by the rotation arrow R - tends to displace standing water W (or other liquid / dirt etc.) beyond the machine's immediate cleaning area, in particular, to a position laterally of the base portion 1 as shown in the figure, reducing overall efficiency and creating the potential for incomplete water / liquid removal, resultant from the outward rotation of brush 5 naturally causing the water to be propelled outwardly.

[0004] This fluid deflection effect may also be observed in single head floor processing machines, where again the leading edge of the rotating work head may act to deflect dirt or water on the floor surface laterally of the footprint of the base of the machine.

[0005] Embodiments of the present invention seek to overcome or ameliorate the problems associated with the prior art.

[0006] According to an aspect of the present invention, there is provided a floor treatment machine comprising a base portion provided with at least one rotatable floor-facing work head having a generally vertical axis of rotation, the machine further comprising drive means for rotating the work head around its generally vertical axis of rotation, and wherein the machine further comprises an air flow outlet configured to introduce a flow of air on to the floor surface in an air flow direction having a component directed towards the lateral centre of the base portion.

[0007] Preferably, the generally vertical axis of rotation diverges from 0° to 15° from strictly vertical, more preferably from 0° to 10° from strictly vertical, and still more preferably from 0° to 5° from strictly vertical.

[0008] Preferably, the air flow outlet is further configured such that the air flow direction also has a component directed forwardly of the base portion.

[0009] Preferably, the floor treatment machine further comprises a suction inlet and associated vacuum source for suctioning dirt and fluid from the floor surface, wherein the air flow outlet is in fluid communication with an exhaust port of the vacuum source such that the flow of air comprises exhaust air from the vacuum source.

[0010] Preferably, the suction inlet is provided at a rear side of the base portion, behind the at least one rotatable floor-facing work head.

[0011] Preferably, the suction inlet comprises a squeegee blade.

[0012] Preferably, the floor treatment machine further comprises a waste liquid collection tank in fluid communication with the vacuum source, into which tank waste liquid is drawn from the suction inlet by means of the vacuum source.

[0013] Preferably, the air flow outlet is configured to introduce the flow of air to a position adjacent a lateral side of the base portion.

[0014] Preferably, said at least one rotatable floor-facing work head is a single such work head, wherein the air flow outlet is configured to introduce the flow of air to a position adjacent a lateral side of the base portion towards which a leading edge of the single work head rotates.

[0015] Preferably, the leading edge of the single work head comprises the front half of the single work head, in the usual processing direction of the machine.

[0016] Preferably, the rotational axis of the single work head may be slightly tilted away from the vertical in a direction which has a transverse component so that a side region of the single work head is biased into enhanced contact with the floor so as to provide machine propulsion predominantly in a forward working direction; still more preferably, the tilt may also have an additional rearward component so that the single work head is biased into contact with the floor in a region rearwardly and to the side region of the work head, whereby in use rotation of the work head through the biased region provides propulsion predominantly in a forward direction, along with enhanced contact of the rearward region.

[0017] Also preferably, said at least one rotatable floor-facing work head may instead comprise a plurality of such work heads, wherein the air flow outlet is configured to introduce the flow of air to a position adjacent a lateral side of the base portion towards which a leading edge of at least one of the plurality of work heads rotates.

[0018] Preferably, the leading edge of the at least one of the plurality of work heads comprises the front half of the at least one of the plurality of work heads in the usual processing direction of the machine.

[0019] Preferably, said at least one rotatable floor-facing work head may comprise a first and second such work heads and the drive means comprises one or more motors configured to rotate the first and second work heads in the same rotational direction around their respective generally vertical axes of rotation such that a leading edge of the first work head rotates from a first lateral side of the base portion towards the lateral centre of the base portion and a leading edge of the second work head rotates from the lateral centre of the base portion towards a second lateral side of the base portion and wherein the air flow outlet is configured to introduce the flow of air to a position adjacent the second lateral side of the base portion.

[0020] Preferably, the leading edge of the first and second work heads comprises the front half of the first and second work heads, respectively, in the usual processing direction of the machine.

[0021] Preferably, the first and second work heads are arranged side by side and define therebetween a sagittal plane which is vertical with respect to the floor, and wherein a corrective measure is applied to at least one of the first and second work heads, which measure acts to neutralize any net force generated by the co-rotation of the first and second work heads so as to prevent drift of the machine, or which measure acts to modify a net force created by the co-rotation so as to provide a net propulsive force in a direction of use.

[0022] Preferably, the corrective measure introduces a bilateral asymmetry as between the orientation of the rotational axes of the first and second work heads.

[0023] Preferably, the bilateral asymmetry is in the orientation of the rotational axis of one of the first and second work heads with respect to the other.

[0024] Preferably, a sagittal plane is defined between the first and second work heads and the rotational axis of one of the first and second work heads is inclined towards the sagittal plane more than the other.

[0025] Preferably, the rotational axis of one of the first and second work heads is essentially vertical and the rotational axis of the other of the first and second work heads is inclined towards or away from the sagittal plane so as to prevent machine drift.

[0026] Preferably, the rotational axes of both the first and second work heads are inclined rearwardly in a minus Z direction, preferably by the same amount.

[0027] Preferably, the co-rotating first and second work heads are arranged so that in use no net drift of the machine occurs due to the rotating first and second work heads.

[0028] Preferably, one of the first and second work heads has an essentially vertical axis of rotation, and the other of the first and second work heads is tilted inwards towards the sagittal plane and away from the vertical.

[0029] Preferably, the co-rotating first and second work heads are arranged so that in use a net forwards propulsion is provided by the rotating first and second work heads.

[0030] Preferably, the co-rotating first and second work heads have axes which are both tilted, with one work head axis tilted away from the sagittal plane and the other tilted towards the sagittal plane, wherein the degree of tilt of one of the first and second work heads is greater than the other, so as to produce a net propulsive force which induces travel in the desired working direction of use.

[0031] Also preferably, the at least one rotatable floor-facing work head may instead comprise a first and second such work heads and the drive means comprises one or more motors configured to rotate the first and second work heads in opposite rotational directions around their respective generally vertical axes of rotation such that a leading edge of the first work head rotates from a lateral centre of the base portion towards a first lateral side of the base portion and a leading edge of the second work head rotates from the lateral centre of the base portion towards a second lateral side of the base portion and wherein the air flow outlet is configured to introduce the flow of air to a position adjacent the first lateral side of the base portion.

[0032] Preferably, the floor treatment machine further comprises a second air flow outlet configured to introduce a flow of air on to the floor surface in an air flow direction having a component directed towards the lateral centre of the base portion and wherein the second air flow outlet is configured to introduce the flow of air to a position adjacent the second lateral side of the base portion.

[0033] Preferably, the leading edge of the first and second work heads comprises the front half of the first and second work heads, respectively, in the usual processing direction of the machine.

[0034] In any of the foregoing arrangements, the machine is preferably provided with one or more floor-engaging wheels for supporting at least part of the weight of the machine when in use.

[0035] Preferably, the wheels are connected to a lower region of the handle portion, so that the wheels take at least part of the weight of the handle portion.

[0036] Preferably, the wheel or wheels are connected to the base portion via a linkage which substantially decouples the weight of the base portion from the wheels.

[0037] Preferably, the floor treatment machine is configured so that the weight of the base portion is essentially supported by the at least one work head.

[0038] Preferably, the floor treatment machine is a hand-guided, walk-behind machine, and includes a generally upright handle portion connected to the base portion to guide the base portion and which is reclinable up / down with respect to the base portion.

[0039] Preferably, the handle portion is also pivotable from side to side with respect to the base portion.

[0040] Preferably, the floor treatment machine is configured as a wet scrubbing machine comprising a cleaning liquid reservoir and a conduit for delivering cleaning fluid to the region of the at least one work head so as to permit wet cleaning.

[0041] Preferably there are two work heads. Each work head may be driven by an associated electric motor, with an optional reduction transmission acting between motor and work head.

[0042] Preferably, the generally vertical axis of rotation of the at least one work head diverges from 0° to 15° from strictly vertical, more preferably from 0° to 10° from strictly vertical, and still more preferably from 0° to 5° from strictly vertical.

[0043] Preferably, the at least one work head comprises a plurality of work heads, and the orientation of the rotational axis of a first of the plurality of work heads relative to vertical is different to the orientation of the rotational axis of a second of the plurality of work heads relative to vertical, in magnitude and / or direction of divergence.

[0044] The machine is preferably a hand-guided, walk-behind machine which may preferably include a generally upright handle portion which is reclinable up / down with respect to the base portion. The handle portion may also be movable transversely (from side to side) with respect to the base portion.

[0045] The machine may preferably be provided with one or more floor-engaging wheels for supporting at least part of the weight of the machine when in use. The wheel or wheels may be preferably provided to the rear of the work heads. The wheels may preferably be connected to a lower region of the handle portion, so that the wheels support at least part of the weight of the handle portion.

[0046] The wheel or wheels may preferably be connected to the base portion via a linkage which substantially decouples the weight of the base portion from the wheels. Thus, in this optional configuration, the weight of the base portion is essentially supported by the work heads; in particular, in this optional configuration, the weight of the motor(s) and any transmission is taken by work heads which are thereby kept in intimate contact with the underlying floor being cleaned.

[0047] In a preferred configuration having plural co-rotating work heads, the co-rotating work heads as hereinbefore described are arranged so that in use no net drift of the machine occurs due to the rotating work heads.

[0048] Preferably, one work head may have an essentially vertical axis of rotation, and the other work head may be tilted inwards towards the sagittal plane and away from the vertical.

[0049] In an alternative configuration the co-rotating work heads as hereinbefore described are arranged so that in use a net forwards propulsion (most preferably in the plus Z-direction) is provided by the rotating work heads. In this case, the co-rotating work heads may have axes which are both tilted, with one work head axis tilted away from the sagittal plane and the other tilted towards the sagittal plane. The degree of tilt of one work head may be greater than the other, so as to produce a net propulsive force which induces travel in the desired working direction of use.

[0050] In another aspect of the invention, the machine is configured as a wet scrubbing machine, comprising a cleaning liquid reservoir and a conduit for delivering cleaning fluid to the region of the work heads so as to permit wet cleaning. The machine may be provided with a squeegee collector with an associated suction drive for entraining waste liquid from the floor surface behind the work heads. There may be a waste liquid collection tank in fluid communication with the suction drive, into which tank waste liquid is drawn from the squeegee collector by means of the suction drive. The reservoir and tank may each be mounted on the handle portion, or elsewhere on the machine, such as the base portion. The squeegee collector is typically trailed behind the work heads, spanning the width (cleaning / scrubbing path) of the work heads.

[0051] 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. Figure 1 is a top plan view schematically illustrating a dirt / fluid deflection tendency, observable in the prior art; Figures 2A and 2B are front and rear perspective views of a first embodiment of a floor treatment machine in accordance with the present invention; Figures 3 and 4 are front and rear perspective views of the configuration of the base of the of the scrubbing machine of Figs. 2A and 2B, and Figure 5 is a top plan view thereof; Figure 6 is a top plan view schematically illustrating the re-direction of standing water according to the present embodiment; Figure 7 is a three-quarter perspective front view of the configuration of a deck of the scrubbing machine of the first embodiment, according to a first modification; Figure 8 is a front view of the deck of Figure 7; Figure 9 is a front view of the deck in which the left and right hand work heads' axes of rotation have both been adjusted (left hand axis tilted away from the centre plane, right hand axis tilted inwards towards the centre plane) in accordance with a second modification of the first embodiment of the invention; Figure 10 is a side view of the deck viewed facing the right hand side, showing the rearward tilt of the right hand work head; Figure 11 is a side view of the deck viewed facing the left hand side of the deck, showing the rearward tilt of the right hand work head; Figures 12A and 12B are front and rear perspective views of a second embodiment of a floor treatment machine in accordance with the present invention; and Figures 13 and 14 are front and rear perspective views of the configuration of the deck of the machine of Figs. 12A and 12B.

[0052] A first embodiment of a floor treatment machine in accordance with the invention is shown in figures 2A and 2B. The machine 10 includes a base or deck portion 11, motor housings 13A, 13B, support wheels 15A, 15B and a squeegee suction collector 17, with the figures omitting illustration of hosing placing the squeegee 17 into fluid communication with an associated suction source (vacuum motor 19 - see Fig. 3), for clarity of illustration. There is an upstanding handle portion 21, with superstructure 23 in which is provided a cleaning fluid reservoir and waste liquid collection tank. An upper region of the handle portion 21 is provided with a cross bar 25 and is provided with controls such as an on / off work head actuation lever. The handle portion 21 is movable relative to the deck 11 to enable it to adopt, in use, a partially reclined position with the squeegee suction collector 17 resting on the floor surface and the working direction in which the machine 10 is predominantly moved forward by an operator shown as arrow 27. The deck 11 is provided with first and second work brush-carrying work heads 29A, 29B to scrub the floor as a result of rotation of the work heads in the direction of the arrows 31. Cleaning liquid delivered to the floor assists in the cleaning effect. The dirty cleaning fluid is then collected behind the work heads 29A, 29B by the squeegee collector 17 and discharged into the waste tank (not shown) in the superstructure 23 supported by the handle portion 21.

[0053] An arrangement of the work heads 29A, 29B on the deck 11 is shown as 33 in figure 3. The axes Y, X and Z indicate vertical, transverse and forward-backward working directions respectively (+Z being the usual working direction of travel as indicated by arrow 27). The deck 11 has a plan form in the general shape of a C as shown in the figure. An upper surface region of the deck 11 is provided with first and second transversely spaced apart transmission units 35A, 35B. An upper back region of each transmission unit is provided with associated upstanding cylindrical electric motor units 37A, 37B which are enclosed by their respective motor housings 13A, 13B (per figure 2A). The motor units 37A, 37B each have a depending rotor with a splined end (not visible) which engages with a corresponding recess in its transmission unit. Each transmission includes a generally vertically oriented drive shaft, an upper end of which is visible as 39A, 39B in figure 3. An opposite end of each drive shaft (not visible) depends from the underside of the deck 11 and is provided with a hub unit (not visible) to which is mounted a co-axial work head unit 29A, 29B.

[0054] Each work head unit comprises a generally disc-shaped upper region 41A, 41B (visible via cut-away portion in Fig. 4) made of structural plastics material and a corresponding lower region 43A, 43B which is provided with an annular array of floor facing bristles. The motors and transmissions are arranged so as to rotate both work head units 29A, 29B in the same direction, so that they co-rotate (in this example, in a clockwise direction as seen from above). The work head units 29A, 29B support the weight of the deck 11, transmission units 35A, 35B, motors 37A, 37B and the motor housings 13A, 13B or ancillary items. The handle portion 21 is attached to an axle of the pair of spaced apart wheels 15A, 15B (visible in Fig. 2B). Thus, the weight of the handle portion is supported by the wheels 15A, 15B. The squeegee suction collector 17, in a work configuration, rests under its own weight on the floor surface, behind and spanning the work heads.

[0055] The deck 11 is further provided with a vacuum motor 19 and associated housing 45 defining an air intake 47 and air outlet 49. The squeegee suction collector 17 is placed in fluid communication with the air intake 47 via a suitable hose (omitted, for clarity of illustration) in order to suction dirt and / or fluid (e.g. water) from the floor surface behind the work head units 29A, 29B in the direction of travel 27.

[0056] According to the present embodiment, a further hose or duct 51 extends from the air outlet 49 of the vacuum motor housing 45, with the duct 51 terminating in an exhaust nozzle 53 located adjacent the outer lateral side of the base, in particular adjacent the outer lateral side of the outwardly-rotating brush unit 29B (that is, the brush unit in which the leading edge - i.e. the front half of the brush unit, in the usual processing / travel direction 27 of the floor processing machine - rotates from the lateral centre of the deck 11 towards an outer lateral side of the deck 11), and positioned so as to introduce the flow of exhaust air 55 adjacent the outer lateral side of the deck 11 onto the floor surface in a direction having components directed both inwardly of the deck 11 (i.e. towards the lateral centre of the deck 11, in a -X direction parallel to the X-axis shown in Fig. 3) and forwardly of the deck 11 in the travel direction 27 (in a +Z direction parallel to the Z-axis shown in Fig. 3). Hence, when the vacuum motor 19 is intaking air, the excess air output is redirected from the vacuum motor 19 through the ducting 51 mounted to the deck 11, and out of the exhaust nozzle 53, to the right side of the brush unit 29B, in the present embodiment.

[0057] Consequently, fluid or dirt on the floor surface deflected outwardly of the path of the deck 11 by the rotation of the outwardly-rotating brush unit 29B - i.e. fluid / dirt deflected as shown by arrows 57, 59 - is redirected both inwardly and forwardly of the deck 11 by the air flow 55 as shown by arrow 61, thusly back in to the cleaning path of the deck 11 to a position at which it may be scrubbed and suctioned by the work head units 29A, 29B and trailing squeegee unit 17 in the usual way.

[0058] As a result, cleaning efficiency is improved, as an operator does not need to make multiple passes to collect standing fluid or dirt misdirected by the outwardly rotating brush unit 29B. Instead, standing fluid or dirt which would otherwise end outside of the cleaning path of the deck 11 is redirected to a position more centrally and forward of the deck 11, allowing it to be collected as normal as the deck 11 is pushed further in the cleaning direction 27, as per the schematic illustration of Fig. 6.

[0059] Optionally, the present embodiment may be adapted to obviate unwanted propulsion (drift) which may be created by the co-rotating work heads. In particular, as the work heads co-rotate, there is a bilateral asymmetry which may cause a net force to act inducing the machine to drift (also known as torque steering). The first embodiment may optionally include modifications to counteract this effect, described in the following in connection with Figs. 7 to 11, which modified embodiments are also embodiments of the present invention (Figs. 7 to 11 omit illustration of the ducting 51 and nozzle 53, for ease of illustration). These modifications involve tilting the rotational axes of the first and / or second work head units from a strictly vertical condition.

[0060] In a first modification, the co-rotating work heads are used in a configuration in which there is no net propulsive force causing drifting or unintended propulsion of the machine. The two work heads are arranged to rotate clockwise, as shown in figure 7 by the circular arrows. There is a mid-sagittal plane C (dot-dashed vertical line) between the two sides of the deck, as shown in figure 8. Right hand work head 29A rotation axis B is parallel to the sagittal plane C, so is precisely vertical and perpendicular to the floor. Thus, the right-hand work head 29A exerts essentially uniform brush pressure on the underlying floor.

[0061] Left hand axis A of the work head 29B is angled with respect to the sagittal plane C (and thus with respect to the vertical rotation axis B) in an amount of 0.5° so as to converge slightly towards with the upper end of plane C. The left-hand work head 29B is thus inclined so as to be raised slightly at an outside edge region and depressed slightly at its opposite inner edge region. In this way the inner edge of the work head (with associated brush bristles) urges more strongly against the floor, producing in use a reaction which counters the torque steer provoked by co-rotation of both work heads. Thus, the co-rotating work heads are effectively balanced to produce no unwanted drift. Although precise values for axis angles are given here (and below) a certain amount of trial and error may be necessary to achieve the desired effects, as these may depend upon variables such as the floor finish and materials, base portion weight, the work head treatment brush stiffness and the rotational speed of the brushes.

[0062] In a second, alternate modification of the first embodiment (see figure 9) co-rotating work heads shown either side of a vertical mid-sagittal plane C are arranged to provide forward propulsion. In this case the right hand work head 29A rotation axis B is inwards tilted by 2.0° to 2.5° to converge towards an upper end region of the sagittal plane C. Left hand work head 29B rotation Axis A is tilted away from the upper end region of plane C by 0.5° to 1.0°. This results in the work head 19 and its associated scrubbing face being tilted up at the outer edge region thereof, and the inner edge of the work head being correspondingly depressed (and biased against the underlying floor). Conversely, the outer edge region of the other work head is depressed so as to be biased against the floor. The inner edge region of the work head is correspondingly tilted up. The tilt of axis B from the vertical is greater than that of axis A, typically by +1.5°. Both work heads (with associated brushes) are tilted in such a way as to invoke a propulsive reaction in the plus Z direction, by the biasing of the regions of the work head which draws the brush backward over the floor surface. The difference in the amount of biasing ensures that the net force is forwards, and not skewed left or right (plus or minus X).

[0063] As shown in figures 10 and 11 the axes A and B are both also rearwardly tilted away from the vertical Y axis in the minus Z direction, so that respective front-end regions of the work heads 29A, 29B are raised and the rear end regions of the work heads are correspondingly depressed. The amount of rearward tilt is the same for both axes and is typically 4.5° to 5.0°. The work head bristles are thus urged and compressed onto the floor surface at the rear end regions of both work heads. Thus, both work heads 29A, 29B have bristles occupying the rear half of the work head undersides that are urged against the floor and thus produce an enhanced reaction force. This ensures a good scrubbing effect across the complete span of the two work head brushes.

[0064] From the forgoing it will be appreciated that the axes of one or both of the work heads 29A 29B need not be strictly vertical, and instead may be angled somewhat relative to vertical, to provide, for example and without limitation, drift cancellation or forward propulsion effects. Divergence from vertical may also be observed, for example, owing to manufacturing tolerances. Hence, a "generally vertical" axis of rotation is to be understood as not requiring a strictly vertical axis, and instead may mean a divergence of from 0° to 15° from strictly vertical, more preferably from 0° to 10° from strictly vertical, and still more preferably from 0° to 5° from strictly vertical. And, the orientation of the rotational axis of the first work head relative to vertical may be different to the orientation of the rotational axis of the second work head relative to vertical, in magnitude and / or direction of divergence.

[0065] The preferable use of one or two the support wheels and self-supporting work heads to share the weight of the machine ensures that directional stability is good, while excellent maneuverability is maintained so that the machine can be steered to make sharp turns 'on a sixpence' about the support wheels.

[0066] In addition to twin-head machines, the present invention may beneficially be applied to floor treatment machines having more than two cleaning heads, for example, three or more heads, as well as to floor treatment machines having a single head.

[0067] A single-head floor treatment machine 10 according to a second embodiment of the present invention is shown in Figures 12 to 14, with like features given like reference numerals. Similar to the first embodiment, the machine 10 includes a base or deck portion 11, a motor housing 13 housing a drive motor (not visible) for driving the single work head 29, support wheels 15A, 15B and a squeegee suction collector 17, with the figures omitting for clarity of illustration hosing which places the squeegee suction collector 17 into fluid communication with an associated suction source (vacuum motor 19 - see Fig. 13). There is a handle portion 21, shown here in a partially-reclined "in use" position to facilitate guiding of the deck portion 11 by an operator, with superstructure 23 in which is provided a cleaning fluid reservoir and waste liquid collection tank. An upper region of the handle portion is provided with a cross bar 25 and is provided with controls such as an on / off work head actuation lever. The handle portion 21 is movable relative to the deck 11 from a generally upright storage position (akin to fig. 2A of the first embodiment) to the partially reclined position of figures 12A and 12B, with the squeegee suction collector 17 resting on the floor surface and the working direction in which the machine 10 is moved forward by an operator shown as arrow 27. The deck 11 is provided with a single work brush-carrying work head 29 to scrub the floor as a result of rotation of the work head in the direction of the arrow 31. Cleaning liquid delivered to the floor assists in the cleaning effect. The dirty cleaning fluid is then collected behind the work head 29 by the squeegee collector 17 and discharged into the waste tank (not shown) in the superstructure 23 supported by the handle portion 21.

[0068] The deck 11 is shown in greater detail in figures 13 and 14. The axes Y, X and Z indicate vertical, transverse and forward-backward working directions respectively (+Z being the usual working direction of travel), as indicated by arrow 27. Analogous to the first embodiment, an upper surface region of the deck 11 is provided with a transmission unit and associated upstanding cylindrical electric motor unit (not shown) enclosed by the housing 13, with the motor unit having a depending rotor with a splined end (not visible) which engages with a corresponding recess in its transmission unit. The transmission includes a generally vertically oriented drive shaft (not visible) which depends from the underside of the deck 11 and is provided with a hub unit (not visible) to which is co-axially mounted the work head unit 29, which carries an annular array of floor facing bristles. The work head unit supports the weight of the deck 11 and associated items. The handle portion 21 is attached to an axle of the pair of spaced apart wheels 15A, 15B. Thus, the weight of the handle portion is supported by the wheels 15A, 15B. The squeegee suction collector 17, in a work configuration, rests under its own weight on the floor surface, behind and spanning the work heads.

[0069] The deck is further provided with a vacuum motor 19 and associated housing 45, the housing providing an air intake 47 and air outlet 49. The squeegee suction collector 17 is placed in fluid communication with the air intake 47 via a suitable hose (omitted, for clarity of illustration) in order to suction dirt and / or fluid (e.g. water) from the floor surface behind the work head unit in the direction of travel 27.

[0070] According to the present embodiment, a further hose or duct 51 extends from the air outlet 49 of the vacuum motor 45, with the duct terminating in an exhaust nozzle 53 located adjacent the outer lateral side of the base, in particular adjacent the outer lateral side of the rotating brush unit 29, being the lateral side towards which the leading edge (i.e. the front half, in the direction of travel 27) of the brush unit 29 rotates. The exhaust nozzle 53 is positioned so as to introduce the flow of exhaust air 55 adjacent the outer lateral side of the deck 11 (and brush unit 29) onto the floor surface in a direction having components directed both inwardly of the deck 11 (i.e. towards the lateral centre of the deck 11, in a -X direction parallel to the X-axis shown in Fig. 13) and forwardly of the deck 11 in the travel direction 27 (in a +Z direction parallel to the Z-axis shown in Fig. 13).

[0071] Consequently, dirt or fluid on the floor surface which tends to be deflected in a direction out of the path of the deck 11 by the rotation of the brush unit 29 - i.e. dirt / fluid deflected as shown by arrow 57 in figure 13 - is redirected by air flow 55 both inwardly and forwardly of the deck 11 as shown by arrow 61, back in to the cleaning path of the deck 11 in the cleaning direction 27, to a position at which it may be scrubbed by the work head 29 and suctioned by the trailing squeegee unit 17 in the usual way.

[0072] Consequently, cleaning efficiency is improved, as an operator does not need to make multiple passes to collect standing fluid or dirt misdirected by the outwardly rotating brush unit 29. Instead, standing fluid or dirt which would otherwise end outside of the cleaning path of the deck 11 is redirected to a position more centrally and forward of the deck 11, allowing it to be collected as normal as the deck 11 is pushed further in the cleaning direction, analogous to the schematic illustration of Fig. 6.

[0073] Also analogous to the first embodiment described above, the axis of the work head 29 of the second embodiment need not be strictly vertical, and in modifications also being embodiments of the present invention may instead be angled somewhat relative to vertical, to provide, for example and without limitation, drift cancellation or forward propulsion effects.

[0074] For example, in a modification also being an embodiment of the present invention, the rotational axis of the work head 29 may be slightly tilted away from the vertical in a direction which has a transverse component so that a side region of the work head 29 is biased into enhanced contact with the floor so as to provide machine propulsion predominantly in the forward working direction 27; preferably, the tilt may also have a rearward component so that the work head 29 is biased into contact with the floor in a region rearwardly and to the side region of the work head 29, whereby in use rotation of the work head through the biased region provides propulsion predominantly in a forward direction 27, along with enhanced contact of the rearward region. As with the modifications of the first embodiment described above, a certain amount of trial and error may be necessary to achieve the desired effects, as these may depend upon variables such as the floor finish and materials, base portion weight, the work head treatment brush stiffness and the rotational speed of the brushes. However, by way of illustration, the transverse tilt may for example be in an amount of 1 to 3 degrees away from the vertical and the rearward tilt may for example be in an amount of 1 to 3 degrees.

[0075] Divergence from vertical may also be observed, for example, owing to manufacturing tolerances.

[0076] Again, therefore, a "generally vertical" axis of rotation is to be understood as not requiring a strictly vertical axis, and instead may mean a divergence of from 0° to 15° from strictly vertical, more preferably from 0° to 10° from strictly vertical, and still more preferably from 0° to 5° from strictly vertical.

[0077] As will be appreciated from the above discussion, the first embodiment (and analogously, the second embodiment) is arranged to redirect excess air output from the vacuum motor, to an outer lateral side of the outwardly rotating brush unit 29B. When the vacuum motor 19 is intaking air, the excess air output is redirected from the vacuum motor 19 through the ducting 51, which is mounted to the deck 11, and out of the exhaust 55. When the brush motors 37A, 37B are co-rotating and the machine 1 is pushed forward in the travel direction 27 e.g. over excess water on the ground, the majority of the water within the cleaning path is picked up. But, a small percentage of the water is pushed (57, 59) to an outer lateral side of the machine 1 by the rotation of the outwardly rotating brush 29B. However, the exhaust air 55 redirects this water back into the cleaning path of the machine 10.

[0078] In the above-described embodiments, by using the exhaust air from the vacuum unit, weight, complexity and cost of the floor processing machine may be reduced as no additional air source is required. However, this need not be the case and, in other embodiments, the floor processing machine 10 may be provided with a separate air source such as a dedicated air pump to supply a re-directing airflow 55, either instead of the exhaust air from the vacuum motor 19, or to supplement the exhaust air flow provided by the vacuum motor exhaust. Still further, usage of a dedicated air pump also enables the invention to be applied to embodiments of floor scrubbing machines which do not themselves have a vacuum motor 19 e.g. a simple floor scrubber device without vacuum squeegee and associated vacuum pump.

[0079] Although the forgoing embodiments are described as having one or more clockwise rotating (as viewed from above) work head units 29, this need not be the case, and the invention may equally be applied to embodiments having one or more counter-clockwise rotating (as viewed from above) work head units.

[0080] The above-described first embodiment is a co-rotating machine, however according to further embodiments the invention may also be applied to machines where the work heads counter-rotate i.e. rotate in different directions, in particular where both of the counterrotating work heads rotate outwardly i.e. with their leading edges rotating from a lateral centre of the base or deck 11 towards respective lateral sides of the base. In this case, it is preferable to provide two airflow streams 55, one on either lateral side of the base, for example using twin ducting 51 and exhaust nozzles 53 arrangements analogous to those of the first embodiment, both in fluid communication with the exhaust air from the vacuum motor (where present) and / or with air supplied from one or more dedicated separate air sources.

Claims

1. A floor treatment machine comprising a base portion provided with at least one rotatable floor-facing work head having a generally vertical axis of rotation, the machine further comprising drive means for rotating the work head around its generally vertical axis of rotation, and wherein the machine further comprises an air flow outlet configured to introduce a flow of air on to the floor surface in an air flow direction having a component directed towards the lateral centre of the base portion.

2. The floor treatment machine of claim 1, wherein the air flow outlet is further configured such that the air flow direction also has a component directed forwardly of the base portion.

3. The floor treatment machine of claim 1 or claim 2, wherein the floor treatment machine further comprises a suction inlet and associated vacuum source for suctioning dirt and fluid from the floor surface, wherein the air flow outlet is in fluid communication with an exhaust port of the vacuum source such that the flow of air comprises exhaust air from the vacuum source.

4. The floor treatment device of claim 3, wherein the suction inlet is provided at a rear side of the base portion, behind the at least one rotatable floor-facing work head.

5. The floor treatment device of claim 3 or claim 4, wherein the suction inlet comprises a squeegee blade.

6. The floor treatment machine of any one of claims 3 to 5, further comprising a waste liquid collection tank in fluid communication with the vacuum source, into which tank waste liquid is drawn from the suction inlet by means of the vacuum source.

7. The floor treatment machine of any one of the preceding claims, wherein the air flow outlet is configured to introduce the flow of air to a position adjacent a lateral side of the base portion.

8. The floor treatment machine of claim 7, wherein said at least one rotatable floor-facing work head is a single such work head, wherein the air flow outlet is configured to introduce the flow of air to a position adjacent a lateral side of the base portion towards which a leading edge of the single work head rotates.

9. The floor treatment machine of claim 7, wherein said at least one rotatable floor-facing work head comprises a plurality of such work heads, wherein the air flow outlet is configured to introduce the flow of air to a position adjacent a lateral side of the base portion towards which a leading edge of at least one of the plurality of work heads rotates.

10. The floor treatment machine of claim 9, wherein said at least one rotatable floor-facing work head comprises a first and second such work heads and the drive means comprises one or more motors configured to rotate the first and second work heads in the same rotational direction around their respective generally vertical axes of rotation such that a leading edge of the first work head rotates from a first lateral side of the base portion towards the lateral centre of the base portion and a leading edge of the second work head rotates from the lateral centre of the base portion towards a second lateral side of the base portion and wherein the air flow outlet is configured to introduce the flow of air to a position adjacent the second lateral side of the base portion.

11. The floor treatment machine of claim 9, wherein said at least one rotatable floor-facing work head comprises a first and second such work heads and the drive means comprises one or more motors configured to rotate the first and second work heads in opposite rotational directions around their respective generally vertical axes of rotation such that a leading edge of the first work head rotates from a lateral centre of the base portion towards a first lateral side of the base portion and a leading edge of the second work head rotates from the lateral centre of the base portion towards a second lateral side of the base portion and wherein the air flow outlet is configured to introduce the flow of air to a position adjacent the first lateral side of the base portion.

12. The floor treatment machine of claim 11, further comprising a second air flow outlet configured to introduce a flow of air on to the floor surface in an air flow direction having a component directed towards the lateral centre of the base portion and wherein the second air flow outlet is configured to introduce the flow of air to a position adjacent the second lateral side of the base portion.

13. The floor treatment machine of any one of the preceding claims, wherein the generally vertical axis of rotation of the at least one work head diverges from 0° to 15° from strictly vertical, more preferably from 0° to 10° from strictly vertical, and still more preferably from 0' to 5° from strictly vertical.

14. The floor treatment machine of claim 13, wherein the at least one work head comprises a plurality of work heads, and the orientation of the rotational axis of a first of the plurality of work heads relative to vertical is different to the orientation of the rotational axis of a second of the plurality of work heads relative to vertical, in magnitude and / or direction of divergence.

15. The floor treatment machine of any one of the preceding claims, wherein the floor treatment machine is a hand-guided, walk-behind machine, and includes a generally upright handle portion connected to the base portion to guide the base portion and which is reclinable up / down with respect to the base portion.

16. The floor treatment machine of claim 15, wherein the handle portion is also pivotable from side to side with respect to the base portion.

17. The floor treatment machine of any one of the preceding claims, being configured as a wet scrubbing machine comprising a cleaning liquid reservoir and a conduit for delivering cleaning fluid to the region of the at least one work head so as to permit wet cleaning.

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