Field of the Invention

The present invention concerns a floor cleaner. More particularly, but not exclusively, this invention concerns a vacuum cleaner for washing and cleaning a floor with a cleaning liquid, which may be referred to as a wet floor cleaner.

Background of the Invention

Various types of floor cleaner are available. They include “dry” floor cleaners such as vacuum cleaners, and “wet” floor cleaners. Some wet floor cleaners of the prior art apply a cleaning fluid to the floor as part of the cleaning process and include a reservoir for holding such cleaning fluid. Some wet floor cleaners of the prior art include cleaning elements arranged to be in contact with the floor and for agitating the cleaning fluid once applied to the floor. Such cleaning elements may be driven via one or more electric motors. The wet floor cleaner may also include a vacuum pump or fan which removes waste liquid from the floor.

CN206586900U discloses a wet floor cleaner having a cleaner head with a scrubbing device comprising adjacent generally circular cleaning discs which in use are driven to rotate in opposite directions. Cleaning liquid is delivered to the floor via outlets in the cleaner head. A liquid suction device is arranged on the cleaner head and located behind the scrubbing device, and is used for sucking away liquid on the surface to be cleaned. Rotational movement utilising generally round cleaning pads makes it difficult to clean a floor in the region in or near a comer formed by two perpendicular walls. Also the rubbing motion between pad and floor increases with radial distance from the centre of rotation, meaning that floor beneath the centre of rotation will be cleaned less effectively that areas nearer the periphery of the pad.

Other floor cleaners having more than one driven cleaning device, in the form of a pad which is moved over the floor when cleaning, are known. GB389285A discloses a pair of such pads which are rectangular and reciprocate on a straight line path in use, moving in opposite directions as they do so. The pads move left and right, such that the area in the fore-aft direction cleaned by the pads, absent any extra movement caused by the operator of the cleaner, is limited by the length of the pads in the fore-aft direction.

KR20010087031 shows a floor cleaner with square pads which rotate to and fro about spaced apart axes. There is an open area between the pads at which cleaning liquid is sprayed onto the floor. The region of the floor at the gap between the pads does not appear to be covered by the rotating motion of the pads, other than by means of the operator moving the whole floor cleaner laterally over the floor.

In all of the above-described prior art, the cleaning elements in contact with the floor are flat-bottomed remaining co-planar with the surface being cleaned and utilise either rotational movement of pads about a fixed axis or translational reciprocating movement along a straight line path. Dirt will tend to be moved to the exterior of the area being swept out by the pads. That might make it difficult to clean areas near walls or in corners.

The present invention seeks to mitigate one or more of the above-mentioned problems. Alternatively or additionally, the present invention seeks to provide an improved floor cleaner.

Summary of the Invention

The present invention provides a floor cleaner for cleaning a floor. The floor cleaner comprises a reservoir for storing cleaning liquid, and a cleaning head. The cleaning head is arranged to deliver cleaning liquid received from the reservoir to the floor, and to suck used cleaning liquid from the floor. The cleaning head includes at least one driven cleaning elements for engaging and cleaning the floor in combination with the delivered cleaning liquid. The cleaning element is arranged to be driven relative to the cleaning head with a cyclical motion such that during each cycle of motion: (a) there is a time during which a first region of the cleaning element contacts the floor whilst a second region is spaced apart from the floor (b) there is a different time during which the second region of the cleaning element contacts the floor whilst the first region is spaced apart from the floor, and (c) the first and second regions always face towards the floor. In embodiments of the invention, when the cleaner is used to clean a floor, the first and second regions move toward and away from the floor during each cycle, but always face the floor. The cleaning element may have a shape (fixed at least in part and/or deformable / reconfigurable, at least in part) which facilitates such a feature.

In embodiments of the invention, when the cleaner is used to clean a floor, the cleaning element moves over and around the floor, relative to the cleaning head, with a motion that better cleans the floor. Having part only of the cleaning element in contact with the floor allows for greater pressure (and cleaning action) to be applied at the point/region of contact with the floor, in contrast to systems that employ planar cleaning pads which maintain contact with the floor over the entire extent of the side of the pad that faces the floor. Having non-contacting regions always facing the floor lessens the chance of cleaning fluid (whether fresh fluid being delivered to the floor or used fluid on the floor already) being sprayed upwards as might be the case if a cylindrical roller-pad were utilised that rotates about a horizontal axis. Not having all regions of the cleaning element that face always in contact with the floor during use may also lessen wear.

The cleaning element may have a convex surface which comprises the first and second regions, for example being conical in shape or bowl-shaped. Such a convex shape may assist in beneficial pressure distribution as regards the regions of contact between the cleaning element and the floor.

The cyclical motion of the cleaning element may include a component of rotation about a non-horizontal axis, for example about an axis that is more vertical than horizontal in use. The axis may be substantially vertical, for example within 10 degrees of vertical. The rotation of the cleaning element may be about an axis that is spaced apart and/or angled relative to a upright (i.e. substantially vertical) axis of symmetry. The rotation may be eccentric rotation.

It may be that the cleaning element is arranged to be driven such that during each cycle of motion there is a path of contact on the surface of the cleaning element that is defined by the regions of contact between the cleaning element and the floor. In certain embodiments that path may be round, for example circular. The path may be a line have a relatively wide thickness as a result of the cleaning element being resilient or otherwise deformable at the region of contact with the floor.

In embodiments of the invention, particularly ones using a cleaning element with a convex surface which is moved in a way that defines a round path of contact between the cleaning element and the floor, the cleaning element may effectively peel dirt, debris and/or liquid from the floor in a manner similar to the way in which a cloth might be used manually to peel and/or scoop up wet mess from the floor. It is also thought that a simple rotating flat cleaning element, for example with a generally round shape in plan view, will tend to move dirt, debris and liquid on the floor to the periphery of the rotating element, rather than wiping it up or cleaning it effectively. In embodiments of the present invention, the combination of the non-planar nature of the cleaning element and how it is moved in use may result in a better and/or more efficient cleaning action.

The cleaning element may have a notional central axis, for example an axis of symmetry or an upright axis that passes through the centre of mass of the cleaning element and has the minimum moment of inertia. In certain embodiments, the cleaning element may be configured such that during the cyclical motion of the cleaning element it moves such that its notional central axis rotates such about an upright axis, that is fixed relative to the cleaner head. The notional central axis of the cleaning element may be non-parallel with the upright axis. The upright axis may be perpendicular to the floor. The cleaning element may be configured such that during the cyclical motion of the cleaning element the notional central axis of the cleaning element maintains an orientation which is at an acute angle to said upright axis. The cleaning element may be configured such that during the cyclical motion of the cleaning element the notional central axis of the cleaning element maintains an orientation which is at the same angle to said upright axis. In embodiments of the invention, the motion of the cleaning element may be described as a rolling motion. Such a rolling motion may cause little if no rubbing between the floor and the region in contact with the floor. It is preferred however, for there to be some relative rubbing/sliding contact between the cleaning element and the floor. This may be caused by the cleaning head being moved relative to the floor. In certain embodiments, the motion of the cleaning element may cause it to rub against and over the floor, even when the cleaning head is stationary relative to the floor. The combination of a rolling motion and a sliding/rubbing motion may enhance the scrubbing action effected by the cleaning elements.

The cleaning element may comprise, for example have attached to it, a cleaning pad that directly contacts the floor in use. The pad may be an absorbent pad. The pad may be shaped such that its exterior surface when on the cleaning element has a convex surface which comprises the first and second regions that contact the floor. The pad when on the cleaning element may have a shape in the general form of a bowl or a cone. The pad may include a fixing for attaching to a corresponding fixing of the cleaning element. The shape of the pad when not on the cleaning element may be in the general form of a bowl or a cone.

The cleaning element may be mounted to the cleaner head via a flexible mounting. The flexible mounting may act to limit the rotation of the cleaning element about its central axis relative to the cleaner head. For example, the cleaning element may be able to rotate about its central axis and relative to the cleaner head by a few degrees in either direction from its neutral rotational position but is prevented from rotating as far as 20 degrees from its neutral rotational position. The flexible mounting may allow for greater freedom of movement of the cleaning element in directions other than rotation about its central axis relative to the cleaner head. For example, the cleaning element may be able to rotate about an axis transverse to its central axis by more than 5 degrees, and possible at least 10 degrees. The flexible mounting may be a flexible mounting that exerts a returning force urging the cleaning element to a neutral position. The flexible mounting may comprise a flexible membrane which attaches to the cleaning element at or near its periphery.

It will of course be appreciated that features described in relation to one aspect of the present invention may be incorporated into other aspects of the present invention.

Description of the Drawings

Embodiments of the present invention will now be described by way of example only with reference to the accompanying schematic drawings of which:

Figure 1 shows a floor cleaner of a type compatible with embodiments of the invention;

Figure 2 shows a dock capable of receiving the floor cleaner of Figure 1; Figure 3 shows schematically the functions of the floor cleaner of Figure 1; Figures 4 and 5 show a cleaner head for a floor cleaner according to a first embodiment of the invention, and

Figures 6 and 7 show a cleaner head for a floor cleaner according to a second embodiment of the invention. Detailed Description

Embodiments of the present invention relate to a floor cleaner for cleaning a floor. The following description relates to features that are typically present in a given embodiment of the invention, but it will be understood that there may be embodiments not having such features. The skilled person will appreciate that the accompanying claims may be amended to add or remove features now described. The one or more specific embodiments relating to the accompanying Figures are described in detail later.

The floor cleaner comprises a cleaning head including at least one driven cleaning element for engaging and cleaning the floor. The floor cleaner may comprise only two such cleaning elements. In other embodiments, the floor cleaner may comprise more than two cleaning elements.

The floor cleaner may be in the form of a vacuum cleaner. The cleaning head may be arranged to suck dirt from the floor in use. The driven cleaning element(s) may be arranged to engage and clean the floor by means of agitating dirt so that it can be more readily sucked from the floor. For example, the driven cleaning element may comprises one or more brushes, for example arranged around its periphery.

The floor cleaner may be a wet floor cleaner. The floor cleaner may comprise a reservoir for storing cleaning liquid. The cleaning head may be arranged to deliver cleaning liquid, for example received from such a reservoir, to the floor. It may be that the liquid is gravity fed. It is preferred however for the liquid to be pumped, for example under the control of a control unit that forms part of the floor cleaner. The cleaning element(s) may be arranged to engage and clean the floor in combination with delivered cleaning liquid. The cleaning head of the floor cleaner may be arranged to remove used cleaning liquid from the floor, for example via suction. Thus, the cleaning head may be arranged (a) to deliver cleaning liquid received from a reservoir of the floor cleaner to the floor, so that the cleaning element(s) engage and clean the floor in combination with the delivered cleaning liquid, and (b) to suck used cleaning liquid from the floor. The floor cleaner may include a waste tank for receiving used cleaning liquid sucked from the floor by the cleaning head.

The floor cleaner may have its own electrical power supply for driving a motor that is arranged to provide suction, for example by the motor driving a vacuum pump or fan. The floor cleaner may have its own electrical power supply for driving the one or more cleaning elements. The floor cleaner may contain one or more batteries, for example in the form of a rechargeable battery pack.

Each cleaning element may comprise a pad, for example a cleaning pad and/or an absorbent pad. When the floor cleaner is in the form of a wet cleaner, cleaning liquid may be delivered to the floor via the cleaning pad(s) of the cleaning element(s). Used cleaning liquid may be sucked from the floor via the cleaning pad(s) of the cleaning element(s). Each cleaning pad may comprise an open cell foam material, for example which allows liquid to drain therethrough. Each cleaning pad may additionally or alternatively comprise holes or channels in the body of the pad to allow liquid to drain therethrough.

The cleaner head may comprise multiple suction inlets arranged to be adjacent to the floor when the cleaner is in use, the suction inlets being spaced apart from the cleaning elements and being provided to suck used cleaning liquid from the floor. The cleaner head may comprise multiple outlets arranged to be adjacent to the floor when the cleaner is in use, the outlets being spaced apart from the cleaning elements and being provided to deliver cleaning liquid to the floor. It will be appreciated that in some embodiments, liquid may be delivered via the pads and sucked from the floor via a different route, and that in other embodiments, liquid may be sucked from the floor via the pads but delivered to the floor via a different route.

Each cleaning element may be moved relative to the floor with a component of rotational motion, for example about an axis (which itself may move or be stationary relative to the cleaning head) that may be non-parallel to the floor, and/or upright (that is, not necessarily always perfectly vertical or perpendicular to the plane of the floor when in use, but substantially vertical, or at least more vertical than horizontal). Each cleaning element may be moved relative to the floor with a component of translational motion, for example parallel to the floor. Each cleaning element may be moved relative to the floor around a closed path, for example which is fixed in position relative to the cleaning head. Each cleaning element may be arranged to be moved to and fro, in one direction and then in an opposite direction, and/or with an oscillating motion. The oscillating motion may for example include moving the cleaning element with movement along a path or in a given direction, for a period of time, and then moving the cleaning element with an opposite movement, for example for an equal period of time, before reversing the movement again, and repeating. Each cleaning element may be arranged to have cyclical motion, for example with the same set cycle of motion being repeated cyclically.

The cleaning element, and/or the pad associated with the cleaning element, may have a shape that includes a pointed corner. The pointed corner may be rounded. The pointed comer may form an apex. The shape may have at least three pointed comers. The shape may have rotational symmetry. The shape may be a quadrilateral with three edges that are at right angles to at least one of the other two edges. The shape may have two parallel edges. The shape may have one edge that is at an acute angle to the opposite edge, for example a slanted edge. One cleaning element, and/or the pad associated with the cleaning element, may have a shape with a portion (for example a curved portion or a slanted edge) that, in use is adjacent to a correspondingly shaped portion of the shape of another, for example paired, cleaning element/pad.

In the case where there are at least two cleaning elements, one of the cleaning elements may be arranged to be a master cleaning element and another cleaning elements may be arranged to be a slave cleaning element, such that the master cleaning element is arranged to drive the slave cleaning element. The cleaning elements may be arranged to be driven relative to the cleaning head such that as a first of the cleaning elements rotates in a clockwise direction, a second of the cleaning elements rotates in an anticlockwise direction or such that as the first cleaning element moves in one direction, the second cleaning element moves in the opposite direction.

In the case where there are multiple cleaning elements, the cleaning elements (for example the pads of the cleaning elements) are preferably so shaped that the footprint of the area swept out by a first cleaning element and the footprint of the area swept out by a second cleaning element have a shared boundary or overlap. Such a geometry reduces the chance of a region of the floor between the pads not being adequately cleaned. The pads of the cleaning elements may be compressible or deformable to allow for the pads to touch during use, whilst reducing the risk of finger trapping or trapping other foreign objects. For such a reason, the rigid bodies of the cleaning elements may be arranged to always be spaced apart during use. The shape of each cleaning element may be the same. The shape of one cleaning element may be a mirror image of another cleaning element, for example a paired cleaning element.

In the case where the cleaner is a wet floor cleaner, the cleaning head may further comprise a barrier member for retaining cleaning liquid at least partly within a footprint of the cleaning head. The barrier member may for example comprise a squeegee device. The cleaner head may comprise a first barrier member on one side of the foot print of the cleaner head and a second barrier member on an opposite side of the foot print of the cleaner head. The cleaner head may be open (e.g. no barrier member) on the other sides of the footprint of the cleaner head. Each barrier member may be movably mounted on the cleaning head, so that it lifts off from the floor when moved along the floor as the leading barrier member and is nearer to the floor (e.g. in contact with the floor) when moved along the floor as the trailing barrier member. With such an arrangement, a cleaning head may be moved along the floor in such a way that the leading barrier member lifts so that it passes freely over dirt, debris and moisture on the floor, whereas the trailing barrier member, being nearer to the floor (for example in sliding contact with the floor) may sweep such dirt, debris and moisture on the floor. As such, any such dirt, debris and moisture on the floor may be retained within the footprint of the cleaning head and be sucked up from the floor. The cleaning head may be so arranged that used cleaning liquid may be sucked from the floor via a channel forming part of, being adjacent to or otherwise associated with a barrier member. The barrier member may for example comprise a channel for sucking liquid from the floor. The channel may be provided between two walls, which may be arranged next to each other. The walls may each extend along the outer edge of the cleaner head.

The cleaning head may have a generally rectangular footprint having its shortest edge in the fore-aft direction in which a user might typically move the cleaner over the floor. In the case where there are multiple cleaning elements, the cleaning elements (for example the pads of the cleaning elements) may be arranged side by side along the longest edge of the rectangular footprint.

The floor cleaner may be associated with a separate dock for receiving the floor cleaner. Such a dock may comprise a receiving unit for receiving the floor cleaner. Such a dock may comprise a reservoir for containing a liquid, for example to enable the dock to replenish the cleaning liquid stored in the floor cleaner. Such a dock may comprise a reservoir for containing a liquid, for example to enable the dock to received waste water from the floor cleaner. Such a dock may comprise a reservoir for containing a liquid, for example to clean a part of the floor cleaner when docked. The dock may comprise a charging unit, the charging unit arranged to charge a battery of a floor cleaner received in the receiving unit. The cleaning head of the floor cleaner may be configured to be detachable from the rest of the floor cleaner. The cleaning head may therefore be provided separately. The cleaning head may comprise a mechanical connection to facilitate the mounting of the cleaning head to the rest of the floor cleaner. The cleaning head may comprise one or more fluid connectors to facilitate the flow of liquid to and/or from the cleaning head from and/or to the rest of the floor cleaner and/or the provision of suction to the floor region. The cleaning head may comprise a connector that when engaged with a corresponding part of the rest of the floor cleaner facilitates the transmission of motion from a motor housed in the body of the floor cleaner to one or more driven elements of the cleaning head. The cleaning head may comprise an electrical connection.

Each cleaning element may, at least in part, be configured to be detachable from the rest of the cleaning head. The cleaning element may therefore be provided separately. The cleaning element may comprise a mechanical connection to facilitate the mounting of the cleaning element to the cleaning head or a part of the cleaning element to the rest of the cleaning element. The cleaning element may, for example, include a detachable pad, brush assembly or the like. Such parts may be provided separately, for example as consumable parts having a limited useable lifetime compared to the floor cleaner itself. Such parts may be reusable. Such parts may be removable to facilitate cleaning or washing of the parts separately from the rest of the cleaning element.

Figure 1 shows an external view of a floor cleaner 100 according to a first illustrated embodiment of the invention, wherein the floor cleaner comprises a cleaner body 106, a neck 102, a handle 104 and a cleaner head 112.

When in use, the bottom surface of the cleaner head 112 faces the floor surface to be cleaned. The cleaner head 112 is mounted at the base of the cleaner body 106 and is pivotally attached to allow for relative movement between the cleaner head and body 106. The neck 102 is in the form of a long and thin cylindrical shaft which extends upwardly from the cleaner body 106 to the handle 104. The handle 104 is an angled extension of the neck, and allows the user to operate the floor cleaner from a standing position. The cleaner body 106 and handle 104 move together as a relatively rigid body. The handle 104 comprises a user interface which enables the floor cleaner functions to be controlled by the user. The cleaner body 106 comprises a housing which contains a vacuum suction element and two liquid tanks, one 108 for holding the cleaning fluid and the other 110 for containing waste liquid that has been removed from the floor via suction. In use, as the user moves the cleaner 100 over the floor to be cleaned, cleaning liquid from the tank 108 is applied to the floor. Moving parts (described later) of the cleaner head 112 agitate, scrub, or otherwise move over the floor, and in combination with the cleaning liquid clean the floor. Used and dirty liquid is then sucked up back into the waste water tank 110 of the cleaner body 106. The pivoting connection between the cleaner head 112 and the cleaner body 106, allows the user to move the cleaner back and forth over the floor, with the angle of the shaft of the neck 102 relative to the floor changing, while the cleaner head 112 remains parallel to the floor. The cleaner body 106 also comprises a battery (not shown in Figure 1) for powering various parts of the cleaner.

Figure 2 shows an external view of the floor cleaner 100 received into a dock 200, according to the same embodiment of the invention. The dock is arranged so that the cleaner head 112 of the floor cleaner 100 can be rested in the central cavity 202 of the dock 200 while the handle 102 can be propped up by a support arm 204, which allows the floor cleaner to stand upright in the dock. The dock 200 is connected into the mains power by a plug 208. The dock comprises a cleaning liquid tank for replenishing the cleaning liquid stored in the corresponding tank 108 of the floor cleaner, a waste tank for receiving waste water from the corresponding tank 110 of the floor cleaner, and a charging connector for (re-)charging the battery of the floor cleaner with power from the mains. The dock may be mobile and have its own battery unit.

Figure 3 shows a schematic diagram illustrating the function of the floor cleaner 100 of the first embodiment of the invention. The cleaner head comprises a main body 118, one or more cleaning elements 138, a front squeegee arrangement 114 and a rear squeegee arrangement 116. The main body 118 houses a motor 122 which drives the movement of the cleaning elements 138. The motor 122 is powered by a battery 132 housed in the cleaner body 106 (not shown separately in Figure 3). The squeegee arrangements 114, 116 are mounted on the main body 118 of the cleaner head via an attachment 124, which allows the squeegee arrangements to pivot up and down. Figure 3 shows the front squeegee arrangement 114 lifted off from the floor in front of the main body 118 and the rear squeegee arrangement 116 in contact with the floor behind the main body 118.

In use, the user may manually move the cleaner over the floor backwards and forwards in a fore-aft motion, represented by the double headed arrow 125. A connecting mechanism (not shown separately) between the handle 104 and the squeegee arrangements 114, 116 causes each of the two squeegee arrangements to be raised in turn dependent on the direction of movement of the floor cleaner. When the floor cleaner 100 is pushed forwards by the user (to the left in Figure 3), the front squeegee arrangement 114 (being the leading squeegee arrangement at that moment) moves to its raised position, thus allowing the cleaner head to move across the floor and over any dirt, liquid and the like on the floor in the region that was immediately in front of the cleaner head. At the same time the rear squeegee arrangement 116 (being the trailing squeegee arrangement at that moment) moves to its lowered position so that it is in contact with the floor, thus retaining any dirt, liquid and the like within the footprint of the cleaner head. When the floor cleaner 100 is pulled backwards by the user (to the right in Figure 3), the front squeegee arrangement 114 (now the trailing squeegee arrangement) moves to its lowered position and the rear squeegee arrangement 116 (now being the leading squeegee arrangement) moves to its raised position. Such a function allows any cleaning liquid or debris present on the floor in the regions around the cleaner head 112 to be swept over and subsequently collected by the cleaner head, and for the majority of any liquid added to the floor by the cleaner head to be retained within its footprint.

In this embodiment, each squeegee arrangement is formed by a pair of squeegees which are arranged either side of a suction opening 136. Waste liquid or debris present on the floor that is swept over by the cleaner head is collected by the trailing squeegee arrangement and is sucked through the suction opening 136 into the waste liquid tank 110 via a suction conduit 130. Suction is provided by a vacuum suction element 134 which is housed in the cleaner body 106 of the floor cleaner 100 and is powered by the battery 132.

The cleaning elements 138 are comprised of a cleaning element body 120 attached to each of which is a cleaning pad 126 which engages the floor during use. The motor 122 drives the motion of the cleaning elements 138 such that they are able to move relative to the main body 118. The movement and the shape of the cleaning pads, and variations thereof, are described in more detail below in relation to Figure 4 and the subsequent Figures. It should be appreciated that while the drawing in Figure 3 shows schematically what appear to be at least two cleaning elements arranged fore and aft, it is possibly more likely that there will be either one cleaning element per cleaning head, or two cleaning elements per cleaning head arranged side-by-side. Other configurations are of course possible in other embodiments. Cleaning liquid from the cleaning liquid tank 108 is provided to the cleaning pads 126 via a conduit 128 that leads from the tank 108 to the cleaning element 138. The conduit is arranged so as to allow the cleaning liquid to flow at a controlled rate onto the cleaning pads 126, which then deliver the cleaning liquid to the floor. It will be appreciated that the geometry and arrangement of the tanks 108, 110 and conduits 128, 130 is not shown in Figure 3 and will depend on the position of the tanks in the body of the cleaner and the desired configuration of the outlets/inlets for liquid at the underside of the cleaning head. During use, it is possible for the cleaning pads to be kept wet/moist, rather than sodden, such that the floor is made wet, but without significant pools or liquid being deposited on the floor at any given time. The water to be fed to the floor may be warm and may be heated. The floor cleaner may include a water heater for such purposes, for example powered by the battery.

Figure 4 is an exploded view from below of a cleaner head 112 in accordance with the first embodiment of the invention, the cleaner head having two bowl-shaped pads 126 that are rotated eccentrically relative to their central axes. Each pad is associated with a drive mechanism in the form of a ball 146 that rotates about an offset vertical axis. The pads are loosely attached to the cleaner head 112 and have sufficient freedom of movement that they can rotate relative to the cleaner head about orthogonal axes parallel to the floor in use. The cleaning head 112 of the first embodiment of the invention is also shown in Figure 5, which is a compound drawing showing both a partially transparent view from below of the cleaner head (the upper half of Figure 5) and a partially transparent view from the side of the cleaner head (the lower half of Figure 5). There are shown flexible mountings 148 for the pads, which may be in the form of a rubber shroud, a flexible corrugated surround, resilient membrane, springs or the like. The flexible mountings for the pads are arranged to resist, but not necessarily prevent, significant rotation of the pad about an upright axis.

Each ball 146 is arranged to rotate about a circular path which is symmetrical about the central axis of symmetry of the pads and to urge the region of the pad that is in contact with the ball into contact with the floor. The balls 146 roll over the inner surface of the pads 126. As the ball 146 moves around the circular path, a corresponding path of contact is defined between the external surface of the pad 126 and the floor. Other parts of the external surface of the pad are out of contact at any given time. All parts of the pad 126 that contact the floor at any given time will, with the geometry shown in Figures 4 and 5 always be facing towards the floor, even when not contacting the floor. Having such a non-planar pad in rolling contact with the floor has several potential advantages, over a comparable pad that is planar and always in contact with the floor. The pad(s) 126 can be caused to roll as well as sweep over the floor, in use, which can increase the scrubbing action due to greater movement between the pads and the floor (in comparison to the case where the pads merely translate over the floor, as the cleaner itself is translated over the floor). There is movement of the pads in directions that are not exactly parallel to the floor, for example. Having bowl-shaped pads 126 associated with the balls 146 directing pressure between pad and floor at localised areas on the pad, can enhance scrubbing / cleaning action whilst also spreading the wear over the pad.

Figures 6 and 7 illustrate some of the features of the motion of the cleaning elements 338 of a second embodiment that is similar to the cleaning pads described with reference to Figures 4 and 5. The cleaning elements 338 of Figures 6 and 7 are bowl-shaped and deformable to the extent that the weight of the associated floor cleaner will deform the element such that a round area 339 (see Figure 6) on the bottom of the element will be in contact with the floor, the round area possibly extending up to, and possibly slightly beyond, the centre of the cleaning element. The underside of each element is in the form of a cleaning pad 326. The area of contact 339 between cleaning element 338 and floor moves in a circular path 341 around the element (rotating about the centre) as the elements are moved.

Figure 7 shows the cleaning elements 338 in two extreme positions the first in unbroken line at a 0 degrees position (i.e. at the start / end of a given cycle of movement) and the second in broken line at a 180 degrees position (halfway through the cycle). At all times, the central axis 350 of the cleaning element is at an angle (at about ten degrees) to the notional vertical axis (relative to the floor). As a result of the rolling motion, the central axis of the cleaning element 350 rotates about the vertical axis, although the cleaning element 338 itself does not rotate significantly about that vertical axis. The extent of contact between floor and elements during a single cycle (with the cleaner head 312 remaining stationary on the floor for this illustration) is shown by the arrows 352 in Figure 7.

Whilst the present invention has been described and illustrated with reference to particular embodiments, it will be appreciated by those of ordinary skill in the art that the invention lends itself to many different variations not specifically illustrated herein. By way of example only, certain possible variations will now be described.

The floor cleaner may be one which operates independently of a mobile dock. The floor cleaner may be configured to operate with the need for a dock. The floor cleaner may be mains powered for example.

Where in the foregoing description, integers or elements are mentioned which have known, obvious or foreseeable equivalents, then such equivalents are herein incorporated as if individually set forth. Reference should be made to the claims for determining the true scope of the present invention, which should be construed so as to encompass any such equivalents. It will also be appreciated by the reader that integers or features of the invention that are described as preferable, advantageous, convenient or the like are optional and do not limit the scope of the independent claims. Moreover, it is to be understood that such optional integers or features, whilst of possible benefit in some embodiments of the invention, may not be desirable, and may therefore be absent, in other embodiments.