Surface cleaning apparatus

A surface cleaning apparatus comprises a body including a rear compartment, a forward compartment and an intermediate compartment arranged between the rear and forward compartments. An elongate rotatable brush arrangement is positioned within and extends across the forward compartment. An electric motor is positioned in the rear compartment for driving the rotatable brush arrangement and the electric motor.

FIELD OF THE INVENTION

This invention relates to a surface cleaning apparatus, such as for a floor or upholstery, incorporating an elongate rotatable brush arrangement and an electric motor for rotating the brush.

BACKGROUND OF THE INVENTION

Current surface cleaning devices conventionally employ suction means. One of the drawbacks of such suction means is that the fans used to generate suction are relatively inefficient, i.e. typically 10 to 12 percent efficient in use, with the result that such apparatus tends not to be easily portable. This is especially the case where the apparatus incorporates batteries for powering the motor. It is therefore not practical to incorporate batteries of sufficient power in a readily portable suction cleaner in order to provide the degree of suction required for effective cleaning.

It is conventional to provide a surface cleaning apparatus, such as for sweeping, in which an elongate brush arrangement, sometimes known as a brush bar, is supported for rotation in a housing which is adapted to be propelled at least in a forwards direction. The brush arrangement generally extends transversely of the housing and is adapted to contact a surface beneath it. The brush arrangement is arranged to be rotated by friction resulting from propelling the housing across a floor. The housing can be provided with wheels which contact the surface. One of the drawbacks of such a construction is that the friction drive is not very effective.

It is also conventional to provide one or more auxiliary brush arrangements extending outwardly from one or two front corners of the housing. The auxiliary brush arrangement is provided for rotation about an axis inclined to the vertical and is provided with radial bristles. An auxiliary brush arrangement of this kind is described in GB-A-1 547 286. The auxiliary brush arrangement is freely rotatable and relies for its rotation on contact with the floor or a skirting board of a room during propulsion of the apparatus across the floor. Such means of rotation is unreliable and results in particles of dust and/or dirt on the floor being flicked towards the elongate rotating brush assembly for collection by the apparatus. Furthermore, contact of the circular auxiliary brush arrangement with the floor or a skirting board results in bristles of the auxiliary brush arrangement which extend outwardly sideways from the housing undergoing angular rotation effectively in a backwards direction. This means that an auxiliary brush means extending outwardly from a front right hand corner of the housing, as viewed from above and behind the apparatus, would be rotated in a clockwise direction and would flick dust and or dirt around behind it in the direction of the elongate rotating brush arrangement. This is not very satisfactory.

In current vacuum cleaner attachments, it is conventional to employ a flexible cleaning strip intended for cleaning hard floor surfaces, for example tiles, marble or linoleum. The flexible strip is intended to increase air speed and mechanically gather particles to assist performance. On a forward stroke the flexible strip will push particles forward. When the vacuum cleaner attachment is pulled in a rearward direction, the gathered particles are left behind by the strip and are extracted by the suction. A disadvantage is that the flexible strip can gather particles on the rearward side, away from the suction, when the attachment is pulled in a rearward direction. However, the action of the suction itself causes the majority of the particles on the rearward side of the flexible strip to pass under the flexible strip and be removed.

Conventional flexible cleaning strips used to clean hard floor surfaces can wear out relatively quickly due to the constant contact with the hard floor surface when in use. Flexible strips used on devices, for example, for washing hard floor surfaces are known to wear out relatively quickly without the benefit of a lubricating cleaning solution which reduces friction between the flexible strip and the floor.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a surface cleaning apparatus which overcomes, or at least ameliorates, at least some of the problems of known apparatus.

In an embodiment, the invention provides a surface cleaning apparatus, comprising a body having a forward compartment and rear compartment; an elongate rotatable brush extending across the forward compartment; an electric motor in the rear compartment; a belt connecting the motor and rotatable brush; and a handle movable between an upright position and steering positions by rotation about an axis transverse to the axial direction of the handle, said handle being further rotatable around a second axis in said steering positions, wherein said second axis of rotation is offset from the axial direction of the handle.

In another embodiment, the invention comprises a surface cleaning apparatus, comprising a body having a forward compartment and rear compartment; an elongate rotatable brush extending across the forward compartment; an electric motor in the rear compartment; a belt connecting the motor and rotatable brush; and an intermediate compartment comprising a removable tray, wherein at least one side of the removable tray forms a wall of said body.

In other embodiments, the invention further comprises an auxiliary brush extending from the forward compartment. The auxiliary brush can be driven by the electric motor used to drive the elongate rotatable brush, such as by connecting the auxiliary brush to the elongate rotatable brush with a gear drive. In still other embodiments, the invention can comprise a body with a removable side wall to allow access to the intermediate compartment. The removable side wall can also include a cover. Alternatively, the entire intermediate compartment can be a removable tray. The walls of the removable tray can form one or more walls of the body of the apparatus. In an embodiment, the belt connecting the motor to the elongate rotatable brush passes through the intermediate compartment, preferably on the side of the compartment remote from a removable side wall.

In yet other embodiments, the wall between the forward and intermediate compartments can be inclined rearwardly, such as at an angle of about 15° to about 20°. The forward compartment can also have a movable portion to expose the bristles of the elongate rotatable brush. The wall between the rear and intermediate compartments can seal the rear compartment off from the intermediate compartment. The rear compartment can also be provided with ground-engaging wheels.

DETAILED DESCRIPTION OF THE INVENTION

The surface cleaning apparatus shown inFIGS. 1 and 2comprises a body1, suitably moulded of one or more plastic materials, and having effectively three compartments.

A rear compartment3houses an electric motor5and a rechargeable battery pack7. The battery pack7may be connected to a main power supply (not shown) for recharging the battery pack. The battery pack may either be connected to the main supply whenever the apparatus is not in use or at suitable times when the battery pack has become depleted. Switch means (not shown) is provided to permit a user to energise and de-energise the motor5as desired. As an alternative to a rechargeable battery pack, the apparatus could employ disposable batteries or be main powered (i.e., adapted to use standard household alternating current).

A forward compartment9houses an elongate rotatable brush arrangement11. For convenience a forward wall of the forward compartment is arcuate and extends around the periphery of the brush arrangement11. The bottom of the forward compartment is open at13to allow the bristles of the brush arrangement to contact a floor, carpet or the like over which the surface cleaning apparatus is to be moved. The rear of the forward compartment is a rearwardly inclined wall15which allows debris, such as dust, dirt and the like, to be propelled up the wall due to rotation of the brush arrangement11and to pass over the wall into an intermediate compartment17which will be described in more detail hereinafter. The wall15extends upwardly to about the same height as the top of the brush arrangement11and is angled rearwardly (i.e. away from the forward compartment) at an angle of about 18 degrees. The precise angle is not important, but the inclination facilitates the passage of the debris up and over the wall and at the same time facilitates retention of the debris within the intermediate compartment17. The brush arrangement extends substantially the entire width of the forward compartment and is provided with two helically arranged rows of bristles. The two rows are diametrically opposed and each row is in the form of a pair of separate helices which twist in opposite directions and meet substantially midway between the ends of the brush arrangement.

The intermediate compartment17is positioned between the wall15and a wall21which encloses the electrical components5,7in the rear compartment3, the wall21protecting the components in the rear compartment from the ingress of debris. The intermediate compartment17also has a lower wall or bottom, an upper wall or top, and side walls formed by the outer wall of the body1. Debris therefore accumulates within the intermediate compartment17. The intermediate compartment is provided with a removable closure to facilitate the removal of debris. For example, one of the walls, such as a side wall, the upper wall or the lower wall, can be removed in order that the debris can be emptied from the intermediate compartment, the removed wall being replaced once the compartment has been emptied. Ideally, side wall23is removable for emptying purposes. The wall15provides the advantage that debris does not readily escape from the intermediate compartment17and, even if the body is inclined such that the forward compartment is below the intermediate compartment, the debris does not escape from the intermediate compartment.

In another embodiment, intermediate compartment17is a removable tray as shown inFIG. 9. In such an embodiment, side wall23can be separately removable from the intermediate compartment17, or a side wall73and intermediate compartment17can be part of a single component as shown inFIG. 9. Intermediate compartment17can also incorporate additional structural portions of body1, such as a portion83of the top wall of body1. The top wall portion83and side wall73(or separately removable side wall23) can be made of a transparent plastic material to allow for visual inspection of the amount of dirt collected in intermediate compartment17. The bottom of removable tray17can serve as part of the bottom wall of body1, or body1can have a separate bottom wall that tray17rests on when inserted into body1.

In an embodiment, the removable tray serving as intermediate compartment17is separated from forward compartment9by at least one wall85formed by a side of intermediate compartment17. A separate wall15(seeFIG. 2) that is not attached to intermediate compartment17can also be present. Similarly, intermediate compartment17is separated from rear compartment3by a wall87that is integral to the intermediate compartment17and/or a separate wall21.

Returning toFIGS. 1 and 2, in an embodiment the brush arrangement11is rotated by motor5, such as by way of toothed rollers25,27attached to the motor and to the brush, respectively, and by way of a toothed belt29, for example of elastomeric material, extending around the two rollers. The toothed belt29is enclosed within a tunnel31where it passes through the intermediate compartment17in order to prevent the ingress of debris into the rear compartment3. The tunnel31may pass through the intermediate compartment17at any convenient point. However, particularly in the event side wall23and/or intermediate compartment17is removable for emptying purposes, the tunnel may be arranged at that side of the intermediate compartment17remote from the side wall23.

A handle33is attached to the body1in the region of the rear compartment3, the body being formed with a recess35beneath the handle to allow the handle to be gripped while maintaining a low profile for the surface cleaning apparatus. The handle33may be in two parts, a first part37which is secured to the body1and a second part39which can be removed from the first part and replaced by a longer handle part41as shown inFIG. 3. The longer handle part41is provided with swivel means43to allow the handle part41to rotate about the axis thereof relative to the body1and with pivot means45to allow the handle part to pivot about an axis transverse to the axial direction of the handle part to enable the surface cleaning apparatus to be steered by the user. As an alternative to interchangeable handles, the handle part41may be removably engageable with the handle part33. In such a case, the handle part33is arranged such that the swivel means43functions only in certain positions of the handle part33in order that movement can be inhibited when the handle part33is used alone.

FIGS. 10–12depict another embodiment for connecting a handle33to body1.FIG. 10shows handle33in an upright position. From this upright position, handle33can be rotated around an axis transverse to the axial direction of the handle.

Rotating handle33around the axis transverse to the axial direction of the handle places the handle in a sweeping position, such as that shown inFIG. 11. Sweeping positions can be discrete positions along the axis of rotation, but preferably handle33will be able to smoothly rotate to any position along the arc of rotation. The term “sweeping position” will be used to refer to any position within this continuous arc other than upright positions.

FIG. 11shows a handle33pivotably attached to body1at attachment joint230. In a sweeping position, handle33can be pivoted around attachment joint230. In the embodiment shown inFIG. 11, the axial direction of handle33does not coincide with the pivot axis at attachment joint230. As a result, handle33may be rotated around attachment joint230, but the axis of rotation does not coincide with the axial direction of the handle. Instead, rotation around attachment joint230causes handle33to rotate into an offset position, as shown inFIGS. 12a–c.FIG. 12ashows a handle rotated to the left around attachment joint230, whileFIG. 12cshows a handle rotated to the right. Handle33is offset from its original axis in bothFIGS. 12aand12c.The offset created by rotating handle33around attachment joint230allows for ease of movement of the sweeper when attempting to move the sweeper around a corner or obstacle.

If handle33is returned to the upright position, handle33cannot rotate around attachment joint230. Body1includes collar235. When handle33is in the upright position, the attachment joint230is contained within collar235of body1. In this position, attachment joint230cannot rotate, as collar235constrains the movement of handle33. From the upright position, the only available direction of rotation for handle33is rotation between the upright and sweeping positions. When handle33is rotated down into a sweeping position, handle33can be rotated around attachment joint230by up to 90 degrees to either the right or left. However, in sweeping positions close to the upright position, rotation about attachment joint230may be constrained by collar235.

FIGS. 12aand12cdepict rotation of handle33by 90 degrees around attachment joint230. The resulting offset of handle33from its original axis can be expressed as an angular offset that corresponds to the plane angles indicated inFIGS. 12aand12c.The amount of angular offset is determined by the axis of rotation for attachment joint230relative to the axial direction of the handle. In an embodiment, rotation of handle33by 90 degrees around attachment joint230results in an angular offset of 30 degrees relative to the original axis of handle33.

As will be apparent particularly fromFIG. 3, the bristles of the brush arrangement11extend outwardly from the aperture in the forward compartment9. In order to remove stubborn debris and/or to revitalise carpet the lower front region of the forward compartment may be chamfered, or the front region of the forward compartment may be movable (including removable), to increase the exposure of the bristles in this region. In this way, the forward part of the apparatus may be inclined relative to the surface to be cleaned, thereby increasing contact between the bristles and a surface to be cleaned and, on some surfaces, increasing the depth to which the bristles penetrate and clean the surface.

Although not shown, an auxiliary rotary brush may be provided at that side of the brush arrangement11which incorporates the roller27and the belt29. Such an auxiliary brush is described, for example, in GB-A-1 547 286. Such an auxiliary brush is able to sweep debris into the path of the brush arrangement11which might otherwise be missed due to the lack of bristles in the region of the roller27. The auxiliary brush may be driven by any suitable means, such as gearing from the brush arrangement11or by friction with the surface to be swept, and is suspended from and extends outwardly beyond the body1. The auxiliary brush may comprise a cylindrical body rotatable about an axis which is inclined to the vertical by about 10 degrees so as to extend outwardly beyond the body1. Bristles protrude radially outwardly from the periphery of the cylindrical body, but need not be perpendicular to the axis of rotation and may preferably be at an angle of about 80 degrees to the axis of rotation so as to form a cone which increases in cross-section with increasing distance from the body1.

Although not shown, the front part of the forward compartment9may be removed to expose the bristles at the front of the apparatus. This effectively increases the aperture in the forward compartment which would seriously impair the effectiveness of a suction cleaner, but in the present invention can effectively be used to assist in the sweeping of stairs, cleaning upholstery and carpets in vehicles and the like operations where a greater exposed area of bristles can be useful. As an alternative to removing the front part of the compartment9, the front part may be movable, for example pivotable or slidable, relative to the remainder of the compartment in order to expose the bristles.

Although not shown, the rear compartment3may be provided with ground-engaging wheels in order to assist mobility of the surface cleaning apparatus. The ground-engaging wheels may, for example, be formed externally in the side regions of the rear compartment3or may be provided within recesses formed at least partly beneath the rear compartment3.

Although the illustrated embodiments of the present invention are intended primarily for domestic use, the surface cleaning apparatus can also be used outdoors or in workshops if desired. However, it may be preferable to provide a more rugged design specifically adapted for such use.

In use of the surface cleaning apparatus according to the invention, as shown inFIGS. 1 and 2, the apparatus is placed upon a surface to be swept, such as a carpet, and the switch operated to energise the motor and consequently to rotate the brush arrangement to sweep debris from the surface and then propel the debris up and over the inclined wall15and into the intermediate compartment17where it is temporarily stored. As the surface cleaning apparatus is moved over the surface with the brush arrangement11rotating, any further debris is similarly swept from the surface and propelled up and over the wall15and into the intermediate compartment17. The surface cleaning apparatus is extremely portable and can be employed wherever it may be required. For example, it can be used to sweep stairs without the need for electrical leads or suction hoses. The shape of the apparatus with the rounded shape of the rear compartment as illustrated facilitates movement of the apparatus over stairs, but ground engaging wheels may be provided to further facilitate such sweeping operations.

When the intermediate compartment17is to be emptied, one wall of the compartment is removed as explained above and the debris can readily be discharged. The removable wall is then replaced. Alternatively, the intermediate compartment may be in the form of a tray which can be removed and emptied so as to discharge debris.

When the surface cleaning apparatus is not in use it can be stored, for example either in a cupboard or the like or plugged into a main supply in order to recharge the battery7.

Thus the surface cleaning apparatus of the present invention incorporates an electrically driven brush arrangement. The brush arrangement is not driven by frictional forces between the surface cleaning apparatus and the surface over which it is to be moved. Thus, efficiency of the apparatus is not dependent on the nature of the frictional contact. Further, the apparatus does not rely on suction means to draw the debris into a storage chamber. Thus, efficiency of the apparatus is not dependent on the effectiveness of suction means and the substantial power drain of suction means on the rechargeable battery is avoided. The provision of the motor at the rear of the apparatus eliminates the need for increased height should the motor be positioned over the compartment for collecting dust and the like and also provides effective full width cleaning which would not be possible if the motor was to be positioned within the compartment for collecting debris. In such a position, debris is likely to accumulate around the motor and cause blockages. In an embodiment, the invention overcomes this problem by passing the drive means for the brush arrangement at least partly through the debris compartment.

Referring toFIGS. 4,5and6, apparatus102for cleaning a surface104by sweeping comprises a housing106, suitably of moulded plastic materials, and effectively having three compartments. A rear compartment108houses an electric motor110and a rechargeable battery pack112. The battery pack112may be connected to a main power supply (not shown) for recharging the battery pack. The battery pack may either be connected to the main supply whenever the apparatus is not in use or at suitable times when the battery pack has become depleted. Switch means113is provided to permit a user to energise and de-energise the motor110as desired. As an alternative to a rechargeable battery pack, the apparatus could employ disposable batteries or be main powered.

A forward compartment114houses a transversely-arranged elongate rotatable brush arrangement116, with bristles118. Such elongate rotatable brush arrangement116is sometimes known as a brush bar. The bottom of the forward compartment114is open at120to allow the bristles118of the elongate brush arrangement116to contact a floor, carpet or the like over which the apparatus is to be propelled. The rear of the forward compartment is a rearwardly inclined wall122which allows debris, such as dust, dirt and the like to be propelled up the wall due to rotation of the brush arrangement116and to pass over the wall into an intermediate compartment124. The front of the forward compartment is provided with a cover (not shown) which may be removable if desired. Debris accumulating in the intermediate compartment124can be removed by opening a cover126. The wall122extends upwardly to about the same height as the top of the elongate brush arrangement116and may be angled rearwardly (i.e. away from the forward compartment) such as at an angle of about 18 degrees. The precise angle is not important, but the inclination facilitates the passage of the debris up and over the wall122and at the same time facilitates retention of the debris within the intermediate compartment124.

The elongate brush arrangement116is rotated by the motor110by way of toothed rollers128,130attached to the motor and to the brush arrangement, respectively, and by way of a toothed belt131, for example of elastomeric material, extending around the two rollers. The toothed belt131is enclosed within a tunnel132where it passes through or alongside the intermediate compartment124in order to prevent the ingress of debris into the rear compartment108.

An auxiliary brush means134is provided extending outwardly from the housing106at the right hand side of the elongate rotatable brush arrangement116as viewed from above and behind the apparatus102. The auxiliary brush means134is of substantially circular form and is supported for rotation about an axis136, which may be vertical or inclined to vertical, such as at an angle of about 10 degrees to vertical. The auxiliary brush means134has a body138provided with radial bristles140which are inclined at an acute angle to the axis of rotation136so as to effectively form a conical arrangement increasing in cross-section with increasing distance from the body138.

The auxiliary brush means134is rotatably driven from the rotating elongate brush arrangement116by a gear wheel142at the end of the elongate brush arrangement116which meshes with a further gear wheel144on the body138of the auxiliary brush means134. The auxiliary brush means134is caused to be rotated in an anti-clockwise direction denoted by arrow146, as viewed from above and behind the apparatus102. During such rotation of the auxiliary brush means134, a peripheral region thereof rotates from a sideways-directed position148(FIG. 6) outside the housing106to an opposed sideways-directed position150covered by the housing106, through a forwardly-directed position152.

The apparatus102is provided with a handle154by means of which it can be propelled at least in a forwards direction156. Wheels158and160are provided to enable or assist manual propulsion of the apparatus across the surface104to be swept, such as a floor, stairway or upholstery. The handle154could be longer, or be of a different shape or form, as required.

The rotating auxiliary brush means134does not rely on contact with the surface104for its rotation and therefore provides more efficient sweeping of edge regions of the surface104regardless of the nature of the surface104. Furthermore, the direction of rotation146of the auxiliary brush means134ensures that debris is swept positively by the auxiliary brush arrangement134into a position ahead of the rotating elongate rotating brush assembly116, ready to be picked up by the elongate brush arrangement116.

If desired, instead of or in addition to the auxiliary brush means134provided extending outwardly from the right hand side of the housing106, a similar auxiliary brush means (not shown) could likewise be provided extending outwardly from the left hand side of the housing106and driven from the opposite end of the elongate brush arrangement116. Such additional or alternative auxiliary brush means differs from the auxiliary brush means134only in that it is caused to rotate in a clockwise, rather than anti-clockwise, direction as viewed from above and behind the apparatus102.

Instead of the apparatus102being provided with a battery or main powered electric motor110to drive the elongate brush arrangement116and hence the auxiliary brush means134, a known form of friction drive means (not shown), resulting from propulsion of the apparatus102along the surface104, may be utilised to effect rotation of the elongate brush arrangement116and hence rotation of the auxiliary brush means134.

An alternative embodiment of apparatus according to the present invention is shown inFIG. 7. Such alternative embodiment comprises an upright vacuum cleaner apparatus102A, having a housing106A with wheels158A and160A, a rotating elongate brush arrangement116A and an auxiliary brush means134A. The apparatus102A is constructed in substantially similar manner to the apparatus102ofFIGS. 4,5and6, with the main exception that instead of the debris-collecting compartment124ofFIG. 5, a debris-collecting container124A, which may include a bag, is provided between a handle154A and the housing106A and connected by a well-known form of suction arrangement (not shown) to the housing106A.

A further embodiment of apparatus102B according to the present invention is shown inFIG. 8. Here the housing106B incorporates components similar to those of the housing106ofFIGS. 4,5and6including wheels158B and, in particular, an elongate rotating brush arrangement116B with an auxiliary rotating brush means134B driven therefrom. However, no debris-collecting compartment is provided inside the housing106B. Instead, the housing106B is provided with a tubular portion162which is demountable on, or may be fixed to, a debris-receiving flexible hose164connected to a well-known form of suction vacuum cleaner166, which may be of cylinder form, mounted on wheels168. Electrical wiring170can be incorporated in the hose164by means of which main electrical power can be supplied from the vacuum cleaner166, and through a connector172and wiring174in the tubular portion162, to an electric motor110B where provided in the housing106B for driving the elongate rotating brush arrangement116B and the auxiliary brush means134B. Of course, such wiring170would be unnecessary where the elongate brush arrangement116B and the auxiliary brush means134B driven therefrom, is caused to be rotated by the friction means previously described. Alternatively, the elongate brush arrangement116B and the auxiliary brush means134B may be caused to be rotated by means of a (rechargeable) battery or an air turbine driven by air passing along the tubular portion162. The housing106B with its included components could be provided as an accessory for existing vacuum cleaners of cylinder form.

In some embodiments, the sweeper also includes a cleaning strip. The cleaning strip assembly2as shown inFIG. 13comprises an elongate support member4comprising a flexible material, for example rubber or a plastic material, with a substantially circular cross-section. Formed integral with the elongate member4are a series of spaced apart flexible tabs6. Also formed integral with the elongate member4is a flexible strip8positioned along substantially the entire length of the elongate member. The thickness of the flexible strip8decreases progressively towards an edge furthest from the elongate member. The flexible strip need not be integral with the elongate support member4. As an alternative, the support member4may be formed with a recessed groove extending in the axial direction and the flexible strip8may be formed with a projection of complementary configuration to retain the flexible strip in the groove. The groove and the projection may conveniently be substantially T-shaped.

The flexible strip may have any convenient length, for example in the range from 2.5 to 8 mm. However, a length of substantially 4.5 mm has been found to be particularly suitable.

The flexible tabs6and the flexible strip8are positioned on the elongate member substantially at an angle relative to each other of approximately 45 degrees. The flexible tabs and flexible strip extend in a generally radial direction from the elongate member, and are directed, in use, towards the lower face of the body of the surface cleaning apparatus.

The elongate member of the cleaning strip assembly is housed within a cavity in the underside of the wall15of the surface cleaning apparatus so as to be rotatable about the axis of the elongate member.FIG. 15depicts an embodiment of a surface cleaning apparatus that incorporates a cleaning strip assembly. The cleaning strip assembly is oriented such that the flexible strip is nearest to the front of the surface cleaning apparatus and the flexible tabs are nearer to the rear of the surface cleaning apparatus. The cavity has an open face through which the flexible strip and the flexible tabs protrude. As shown inFIG. 15, the cavity has a first major wall28, the rear wall in use, which is substantially upright, and a second major wall. The second major wall30, the front wall in use, is inclined away from the rear wall at a nominal angle of 60 degrees. The inner face of the cavity, opposite the opening32, is in the form of a concave curved surface wherein the curvature complements the curvature of the elongate member. The elongate member is retained within the cavity by retaining tabs attached to the rear wall of the cavity at the open face of the cavity. The cavity in the wall15is shaped such that excessive rotation of the elongate member in either direction is prevented by the walls of the cavity engaging the flexible tabs or flexible strip.

Lateral movement of the elongate member may be inhibited by any suitable means. For example a cover for part of the drive mechanism may be provided with a protrusion which extends sufficiently to cover the end of the elongate member. Removal of the cover then exposes the end of the elongate member and allows it to be removed, for example for replacement.

FIG. 14shows an alternative embodiment of the cleaning strip assembly in which the flexible strip has a first section10and a second section12positioned close to a first end14and to a second end16, respectively, of the elongate member4at which material of the flexible strip is absent such that an isolated portion20of the flexible strip is provided at the ends14,16of the elongate member. In use, the isolated portions20, in conjunction with restraining pins18provided on the ends14,16of the elongate member, impinge on retaining tabs of the cavity, such that the ends of the elongate member are prevented from being pulled towards each other during flexure of the elongate member.

The cleaning strip assembly2is used to ensure that efficient cleaning of surfaces, for example hard floor surfaces, is achieved. As shown inFIG. 15A, when the surface cleaning apparatus is pushed forward24over a surface104to be cleaned, the flexible tabs6of the cleaning strip respond to movement of the apparatus by being dragged backwards by friction with the floor causing the elongate member4to rotate about its axis. Rotation of the elongate member brings the flexible strip8into contact with the floor. Continued forward movement of the surface cleaning apparatus results in the flexible strip being held in contact with the surface and particles of dirt103on the surface to be cleaned are gathered together and pushed forward along with the movement of the surface cleaning apparatus. Excessive rotation of the elongate member4, when the surface cleaning apparatus is pushed forwards24, is prevented by the rear face of the flexible strip engaging on the retaining tabs22which retain the elongate member within the cavity32of the wall15. Further rotation is also prevented by the flexible tabs6engaging the rear wall28of the cavity32.

FIG. 15Bshows, when the surface cleaning apparatus is moved in a rearward direction26, the flexible strip8responds to movement of the apparatus by being dragged towards the front of the surface cleaning apparatus by friction with the surface104to be cleaned. In dragging the flexible strip forwards, the elongate member4of the cleaning strip assembly is rotated such that the flexible tabs6are brought into contact with the floor104. The flexible tabs6are also dragged towards the front of the surface cleaning apparatus so resulting in continued rotation of the elongate member and the subsequent lifting of the flexible strip clear of the floor. Excessive rotation of the elongate member is prevented by the flexible strip engaging the inclined front wall30of the cavity32in wall15and being stopped from further forward movement. When the surface cleaning apparatus is pulled in a rearward direction, the particles of dirt gathered together by the flexible strip during use in the forward direction are swept from the surface by the brush arrangement and propelled up and over the wall15and into the intermediate compartment17. As the flexible strip is clear of the floor, additional particles of dirt can pass between adjacent flexible tabs and are not prevented from passing under the flexible strip.

The surface cleaning apparatus is extremely portable and can be employed wherever it may be required. For example, it can be used to sweep stairs without the need for electrical leads or suction hoses. The shape of the apparatus with the rounded shape of the rear compartment as illustrated facilitates movement of the apparatus over stairs, but ground engaging wheels may be provided to further facilitate such sweeping operations.

When the surface cleaning apparatus is not in use, it can be stored, for example either in a cupboard or the like or plugged into a main supply in order to recharge the battery7.

Thus the illustrated surface cleaning apparatus incorporating the cleaning strip assembly of the present invention incorporates an electrically driven brush arrangement. The brush arrangement is not driven by frictional forces between the surface cleaning apparatus and the surface over which it is to be moved. Thus, efficiency of the apparatus is not dependent on the nature of the frictional contact. Further, the apparatus does not rely on suction means to draw the debris into a storage chamber. Thus, efficiency of the apparatus is not dependent on the effectiveness of suction means and the substantial power drain of suction means on the rechargeable battery is avoided. The provision of the motor at the rear of the apparatus eliminates the need for increased height should the motor be positioned over the compartment for collecting dust and the like and also provides effective full width cleaning which would not be possible if the motor was to be positioned within the compartment for collecting debris. In such a position, debris is likely to accumulate around the motor and cause blockages. The illustrated apparatus overcomes this problem by passing the drive means for the brush arrangement at least partly through the debris compartment.

Although the cleaning strip assembly described hereinbefore is shown as comprising an elongate member with a substantially circular cross-sectional area having attached thereto at least one tab and a strip member, it should be appreciated that the cleaning strip assembly may take other embodiments and the moving of the strip member relative to a floor may be achieved by other methods rather than by rotation of the elongate body of the cleaning strip assembly.

FIG. 16shows another embodiment of a cleaning strip assembly202which comprises an elongate member204of rigid material, for example plastic material, which is attached to a flexible strip208, for example of a plastic or rubber material, positioned along substantially the entire length of the elongate member204. The thickness of the flexible strip208decreases progressively towards an edge furthest from the elongate member. The thickness of the flexible strip is less than that of the elongate body such that a shoulder portion210is formed either side of the flexible strip where it is attached to the elongate member.

The flexible strip is directed, in use, towards the lower face of the body of the surface cleaning apparatus.

The elongate member of the cleaning strip assembly is housed within the cavity (not shown) in the underside of the wall15of the surface cleaning apparatus so as to be movable in a substantially upright plane relative to the floor. The cavity also contains an arm212fixed at one end to a pivot pin214which can rotate about a fixed axis within the cavity. In use, the fixed axis of the pivot pin214is substantially parallel to the surface of the floor. The end of the arm212furthest from the pivot pin is positioned beneath a shoulder portion210of the cleaning strip assembly. Also attached to the pivot pin214within the cavity are a number of flexible tabs206. The free end of each tab206, in use, is in contact with the floor104.

The cavity has an open face through which the flexible strip and the flexible tabs protrude. The elongate member204is retained within the cavity by means of the arm212positioned below the shoulder portion210of the cleaning strip assembly.

As shown inFIG. 16A, when the surface cleaning apparatus is pushed forward as shown by the arrow24over a surface104to be cleaned, the flexible tabs206of the cleaning strip assembly are dragged backwards by friction with the floor causing the arm212to pivot about the fixed axis of the pivot pin214towards the floor. Pivoting of the arm away from the shoulder portion210of the cleaning strip assembly allows the elongate member of the cleaning strip assembly to lower and bring the flexible strip208into contact with the floor. Particles of dirt103on the surface to be cleaned are gathered together by the flexible strip and pushed forward along with the movement of the surface cleaning apparatus.

FIG. 16Bshows, when the surface cleaning apparatus is moved in a rearward direction as shown by the arrow26, the flexible tabs are dragged toward the front of the surface cleaning apparatus by friction with the surface104to be cleaned. In dragging the flexible tabs forward, the arm212pivots away from the floor about the fixed axis of the pivot pin214. The arm212, positioned under the shoulder210of the cleaning strip assembly, urges the cleaning strip assembly in a substantially upward direction such that the flexible strip208is lifted clear of the floor.

When the surface cleaning apparatus is pulled in a rearward direction, the particles of dirt gathered together by the flexible strip during use in the forward direction are swept from the surface by the brush arrangement. As the flexible strip is clear of the floor, additional particles of dirt can pass between adjacent flexible tabs and are not prevented from passing under the flexible strip.

FIG. 17shows a further embodiment of the cleaning strip assembly, wherein the cleaning strip assembly comprises an elongate member204of rigid material, for example plastics material, which is attached to a flexible strip208positioned along substantially the entire length of the elongate member. The thickness of the flexible strip208decreases progressively towards an edge furthest from the elongate member. The thickness of the flexible strip is less than that of the elongate body such that a shoulder portion210is formed either side of the flexible strip where it is attached to the elongate member.

The cavity also contains a first arm212fixed at one end to a pivot pin214which can rotate about a first fixed axis within the cavity. The end of the first arm212furthest from the pivot pin214is positioned beneath a shoulder portion210of the cleaning strip assembly. Also attached to the pivot pin within the cavity are a number of flexible tabs206. The free end of each tab206, in use, is in contact with the floor104.

Attached to the elongate body204is a second arm216which connects the cleaning strip assembly202to a second pivot pin218within the cavity in the wall of the surface cleaning apparatus. The elongate member of the cleaning strip assembly is housed within the cavity of the surface cleaning apparatus so as, when in use, to be pivotably moved on the second arm216relative to the floor about an axis of the second pivot pin218substantially parallel with the surface of the floor.

The cavity comprises an open face through which the flexible strip and the flexible tabs protrude. The elongate member is retained within the cavity by means of the first arm212positioned below the shoulder portion210of the cleaning strip assembly and by means of the second arm216attaching the cleaning strip assembly to the second pivot pin218.

When the surface cleaning apparatus is pushed forward24over a surface104to be cleaned, the flexible tabs206of the cleaning strip assembly are dragged backwards by friction with the floor causing the first arm212to pivot towards the floor about the axis of the first pivot pin214. Pivoting of the first arm212allows the elongate member of the cleaning strip assembly to pivot on the second arm216about the axis of the second pivot pin218and so bring the flexible strip208into contact with the floor. As described hereinabove, particles of dirt103on the surface to be cleaned are gathered together by the flexible strip and pushed forward along with the movement of the surface cleaning apparatus.

When the surface cleaning apparatus is moved in a rearward direction the flexible tabs are dragged towards the front of the surface cleaning apparatus by friction with the surface104to be cleaned. In dragging the flexible tabs forward, the first arm212pivots away from the floor about the axis of the first pivot pin214. The first arm, positioned under the shoulder210of the cleaning strip assembly, urges the cleaning strip assembly in a substantially upward direction such that the flexible strip is lifted clear of the floor and pivots, via the second arm213, about the axis of the second pivot pin218.

When the surface cleaning apparatus is pulled in a rearward direction, the particles of dirt gathered together by the flexible strip during use in the forward direction are swept from the surface by the brush arrangement. As the flexible strip is clear of the floor, additional particles of dirt can pass between adjacent flexible tabs and are not prevented from passing under the flexible strip.

It should be understood that an alternative to the flexible tabs described hereinabove could be a friction wheel220, as shown inFIG. 18, whereby movement of the friction wheel220relative to the floor can be used to cause an arm212beneath the shoulder portion210of the cleaning strip assembly to be moved thus raising and lowering the cleaning strip assembly as described hereinabove.

It should be understood that electronic or other means may be used in place of frictional means to determine the movement of the surface cleaning apparatus and for controlling the positioning of the flexible strip.