Patent Description:
Suction cleaning devices provide motors for establishing flow of air through the device, to transport air and entrained dirt from a suction inlet formed at the floor cleaning head of the cleaner, or from the mouth of a suction hose or cleaning tool connected to the device, to an exhaust outlet for expelling air from the device. The air with entrained dirt is drawn through a separator assembly, removing coarse dirt from the air flow, and a substantial proportion of fine dirt, for storage within a dirt bin. The filtered air is drawn through the motor and is subsequently expelled from the device via the exhaust outlet.

It is common for a floor cleaning head of a cleaner to provide an agitation device driven by a motor, to assist in dislodging dirt from the surface being cleaned, and to guide or sweep the dirt into the suction inlet of the floor cleaning head. The shape and contours of the suction inlet, and the area surrounding the suction inlet, affect the performance of the floor cleaning head in terms of the efficiency of its pick-up (i.e. the ability to gather dirt from the surface being cleaned). A floor cleaner head according to the preamble is already known e.g. from <CIT>.

The present invention seeks to reduce or overcome one or more of the deficiencies associated with the prior art.

According to a first aspect of the invention we provide a floor cleaning head for a suction cleaner, the floor cleaning head providing a housing having a suction inlet, and the housing providing:.

The deflecting surface may be inclined relative to the rotational axis of the agitator. The angle of inclination between the deflecting surface and rotational axis of the agitator is α, wherein α may be defined such that <NUM>° ≤ α ≤ <NUM>°, or <NUM>° ≤ α ≤ <NUM>°, or <NUM>° ≤ α ≤ <NUM>°, or α is around <NUM>°.

The ramp may extend around the periphery of the agitator between a start position rearward of the rotational axis of the agitator, and an end position in front of the rotational axis of the agitator.

The end position may lie below the height of the rotational axis of the agitator.

At the end position of the ramp, the deflecting surface may extend from the side wall between a first edge at which it meets the side wall and at which it is radially offset by a distance D1 from the rotational axis of the agitator, and a second edge away from the side wall, and radially offset by a distance D2 from the rotational axis of the agitator, wherein D2>D1.

At all positions between its start position and end position the radial offset D1 at the first edge of the deflecting surface may be less than the radial offset D2 at the second edge of the deflecting surface.

The ratio of D2:D1 may increase between the start position and the end position.

The ratio of D2:D1 may increase continuously between the start position and end position.

At least a portion of the ramp may lie above the rotational axis of the agitator.

The agitator may be driven, and may be driven at a speed of between 1700rpm and 2500rpm.

The agitator may be formed of a soft fibrous material, and may be formed of fibres having a length of between <NUM> and <NUM>.

The agitator may be a first agitator, and the floor cleaning head may provide a second agitator disposed rearwardly of the first agitator.

Each end of the agitator chamber may provide a respective ramp.

According to a second aspect of the invention we provide a suction cleaner, including:.

The floor cleaning head may be formed in a base portion of the suction cleaner.

Embodiments of the technology will now be described, by way of example only, with reference to the following figures, of which:.

With reference to the drawings, we describe a suction cleaner <NUM> for cleaning a floor surface. The cleaner illustrated in this example embodiment is a floor-standing upright cleaner, although it should be understood that aspects of the invention may be applied to other types of suction cleaner, and in particular other forms of floor-standing cleaners, such as a canister type cleaner, or a cylinder cleaner, for example.

In general terms, and with reference to <FIG> and <FIG>, we describe a suction cleaner <NUM> with a floor cleaning head <NUM> providing a nozzle that defines a suction inlet (or suction inlet) for applying a suction force to a surface being cleaned. A motor (the position of which is indicated generally at <NUM>) creates a suction flow of air through the cleaner <NUM> between the suction nozzle and an exhaust outlet <NUM>. Where the term 'floor cleaning head' is used, it is with reference to the base portion of the suction cleaner <NUM>, generally providing a housing forming the suction inlet. The term floor cleaning head should be construed to cover both an integral base part of a floor-standing suction cleaner, and/or a separate floor cleaning head for use attached to a wand or the like, connected to a suction cleaner.

The suction cleaner <NUM> provides a separator assembly <NUM> for separating dirt from the air flow between the suction inlet and the motor <NUM>, and an exhaust assembly for separating fine contaminants from the air flow between the motor <NUM> and the exhaust outlet <NUM>.

In the embodiment illustrated, the suction cleaner <NUM> comprises an upright body <NUM> providing a handle portion <NUM> including a first user-graspable handle <NUM> to allow a user to operate and steer the device. The floor cleaning head <NUM> provides rollers <NUM> (e.g. wheels) for moving the suction cleaner <NUM> across a surface.

The floor cleaning head <NUM> provides one or more agitators for dislodging dirt from the floor surface and a floor cleaning head outlet from which air and entrained dirt are drawn from the floor cleaning head towards a separator assembly <NUM> via a suction passage <NUM>. The suction passage <NUM> fluidly connects the floor cleaning head <NUM> to an inlet of the separator assembly <NUM>. An outlet of the separator assembly <NUM> fluidly connects the separator assembly <NUM> to the motor <NUM>, via which a suction air flow is generated within the suction cleaner, so as to draw air and entrained dirt through the floor cleaning head <NUM>, to the separator assembly <NUM>, and to draw cleaned air from the separator assembly <NUM>. An exhaust outlet <NUM> vents air from the suction device <NUM>, downstream of the motor <NUM>.

In embodiments, and as shown in <FIG>, the separator assembly <NUM> comprises a housing <NUM> that provides a collecting volume for collecting dirt separated from the incoming air flow. The housing <NUM> also contains a separator, which in embodiments is formed of a first stage cyclonic separator to remove large particles of dirt, and a second stage cyclonic separator for removing smaller particles of dirt from the air flow. In embodiments, the first stage separator provides a mesh shroud for filtering relatively large particles, and the second stage separator provides a plurality of cyclonic separators, each formed as cone shape as is known in the art, for filtering fine dirt particles from the air flow.

In embodiments, the separator assembly <NUM> is mounted on a portion <NUM> of the upright body <NUM> during use, but is detachable from the body <NUM> for the purpose of emptying the dirt from the separator assembly collecting volume. The separator assembly <NUM> may further include a pre-motor filter positioned downstream of the separator stages described above. In embodiments this pre-motor filter is housed within a removable lid portion <NUM> of the housing <NUM>. In this way, the removable lid portion <NUM> may be detached to expose the filter for cleaning. The lid portion <NUM> may further provide a handle <NUM> to allow a user to lift away the housing <NUM> when detached from the upright body <NUM> of the cleaner. A motor inlet <NUM> communicates with the outlet of the separator assembly <NUM> when it is mounted on the upright body <NUM> of the suction cleaner <NUM>.

The body <NUM> further provides a power source, which in embodiments is a rechargeable battery pack <NUM>. The battery pack <NUM> may be rechargeable in situ, or when removed from the body <NUM>, as is known in the art. Alternatively, or in addition, the suction cleaner <NUM> may be provided with a power cable for connection to a mains power source.

The body <NUM> further includes a carrying handle <NUM> configured to enable a user to lift and carry the device <NUM>.

With reference to <FIG>, we now describe aspects of the floor cleaning head <NUM> according to embodiments of the technology. The floor cleaning head <NUM> includes a lead agitator <NUM> and a rear agitator <NUM>, each formed as a rotational agitator disposed widthways of the floor cleaning head. The floor cleaning head <NUM> provides a housing <NUM> having a front end <NUM>, which extends in front of the lead agitator <NUM>, and provides a lower edge defining a front inlet <NUM> between the lower edge and the floor surface.

In embodiments, the floor cleaning head <NUM> is supported on the floor surface by the rollers <NUM> disposed at the rear for the floor cleaning head <NUM>, and by one or more further rollers disposed at or towards the front and/or midsection of the floor cleaning head <NUM>. As shown in <FIG>, a pair of smaller floor-engaging wheels <NUM> is positioned at the front of the floor cleaning head <NUM>, spaced outwardly from the ends of the lead agitator <NUM>. These wheels <NUM> ensure that the floor cleaning head <NUM> sits at a desired ride height above a floor surface, establishing appropriate engagement between the agitators <NUM>, <NUM> and the floor surface or carpet surface, for example.

A suction inlet <NUM> (or nozzle) is formed as an opening in the underside of the housing <NUM>, through which debris is drawn under the motion of the agitators <NUM>, <NUM> and the suction applied via the suction passage <NUM> leading to the suction motor.

In embodiments, the central axis X of the lead agitator <NUM>, around which it rotates, lies above (i.e. higher than) the lower edge of the front end <NUM> of the floor cleaning head housing <NUM>. The leading agitator <NUM> is preferably formed with fibres of a relatively soft material compared to the bristles of the rear agitator <NUM>, such that it is suited to dislodging dirt and debris from a carpet, for example, and moving said debris rearwards towards or into the suction inlet formed behind the lead agitator <NUM>. For example, the body of the lead agitator <NUM> may be formed of uniform soft fibres which are roughly <NUM>-<NUM> in length, preferably between <NUM> and <NUM> (and most preferably around <NUM> in length). The lowermost part of lead agitator <NUM> lies roughly <NUM> from the floor surface, when the suction cleaner <NUM> is used on a hard floor.

The lead agitator <NUM> is driven by an agitator motor (at a position generally indicated at <NUM>) at a speed of between 1700rpm and 2500rpm. In embodiments, each of the agitators <NUM>, <NUM> is driven via a drive belt mechanism, in which a portion of a drive belt is disposed around an end portion of each respective agitator <NUM>, <NUM>, to transfer drive from the motor <NUM>, the motor <NUM> being disposed rearwardly of the rear agitator <NUM>, within a rear portion of the housing <NUM>.

In embodiments, one or both of the lead agitator <NUM> and rear agitator <NUM> are each removable axially from the housing via openings in a side of the housing which in use are sealed with removable end caps <NUM>. The agitators <NUM>, <NUM> may be inserted through the openings, and pushed by a user into contact with an engaging formation <NUM> disposed within the housing on the opposing side of the floor cleaning head <NUM>. Alternatively, one or both of the lead agitator <NUM> and rear agitator <NUM> may be removable downwardly through the underside of the housing.

In embodiments, the rear agitator <NUM> is a bristled roller, having a row of relatively firm bristles <NUM> (i.e. firm compared to the lead agitator <NUM>) extending outwardly from its cylindrical core. Preferably, the bristles are formed in clumps or tufts. Preferably, the rear agitator <NUM> provides multiple rows of bristles which wind around its perimeter in a chevron-style formation, for example. The one or more rows of bristles <NUM> may be interspersed between one or more ridges or flaps formed of a plastic or rubberised material, extending outwardly from the core of the agitator <NUM>. The ridges of material are preferably provided so as to impact the uppermost parts of a carpet surface, for example, to assist in dislodging dirt attached or lodged in the carpet, so that it can readily be swept into the suction inlet by the bristles <NUM> as the agitator rotates.

The rear agitator <NUM> is substantially housed within a suction chamber formed within the housing, to which suction is applied via the suction passage <NUM>. In this way, the rear agitator <NUM> is disposed in the suction flow path formed between the suction inlet <NUM> and the suction passage <NUM>. In embodiments, a rear sealing strip formed of a plastic, rubberised, or a fibrous material, is formed adjacent a rear portion of the suction inlet.

In broad terms, and with reference to <FIG>, we describe aspects of the housing surrounding the lead agitator <NUM>. The floor cleaning head <NUM> provides the housing <NUM> having a suction inlet <NUM>, and the housing <NUM> provides an agitator chamber <NUM> having ends forming a pair of side walls <NUM> disposed on opposing sides of the floor cleaning head <NUM>. A dividing wall lies to the rear of the agitator <NUM>, between the lead agitator <NUM> and rear agitator <NUM>, forming a back part of the agitator chamber <NUM>.

The lead agitator <NUM> is supported between the side walls <NUM> and configured to rotate about a lengthways central rotational axis X. In embodiments of the technology, the lead agitator <NUM> is supported at the respective side walls <NUM> at each end of the agitator, at a position substantially in line with the central rotational axis X, so that the ends of the lead agitator <NUM> are enclosed by the side walls <NUM> (i.e., to prevent ingress of dirt into the chamber inwardly from the direction of the side walls <NUM> or through openings in the side walls <NUM>). In embodiments, at least one of the side walls <NUM> forms an external wall of the floor cleaning head <NUM>.

In embodiments of the technology, the front end of the housing <NUM>, together with the side walls <NUM> and the dividing wall lying rearward of the lead agitator <NUM> surround the lead agitator <NUM>.

In embodiments of the technology, the lead agitator <NUM> is covered substantially along its entire length with a layer of a soft fibrous material (i.e., as opposed to bristles). In this way, the entire width of the chamber between the side walls <NUM> is subject to cleaning via the soft fibrous material on the lead agitator <NUM>.

An end of the agitator chamber <NUM> provides a ramp <NUM> extending around a portion of a periphery of the agitator <NUM> and inwardly from the side wall <NUM>, the ramp <NUM> providing a deflecting surface <NUM> configured to deflect dirt particles inwardly from the side wall <NUM> towards a central portion of the floor cleaning head <NUM>. Preferably, a ramp <NUM> is provided at each end of the agitator chamber <NUM>.

As the lead agitator <NUM> rotates, it is possible for small dirt particles to be lodged on its surface, and be drawn upwards on the surface of the lead agitator <NUM> as it rotates, into the housing <NUM>. While having a few dirt particles drawn into the housing <NUM> does not in itself pose a problem, large numbers of dirt particles may eventually clog the housing <NUM> in proximity to the agitator, inhibiting its ability to rotate, causing excessive power drain when powering the motor <NUM> to drive the agitator. Furthermore, it is undesirable for dirt particles to be entrained on the agitator surface, as they may be flung off the surface in a forward direction as the agitator rotates, for example.

The primary purpose of the ramp <NUM> is to prevent such dirt particles becoming lodged at an end of the agitator chamber <NUM> in this way, by guiding the movement of the particles inwardly of the floor cleaning head <NUM>. In other words, any particle that is rotating with the lead agitator <NUM>, at an end of the agitator, comes into contact with the deflecting surface <NUM> of the ramp <NUM> as the lead agitator <NUM> rotates. The deflecting surface <NUM> is inclined relative to the rotational axis X of the lead agitator <NUM>, offset by an angle α. The angle α of offset between the ramp <NUM> and the rotational axis X of the lead agitator <NUM> is less than <NUM>°, i.e. the ramp is not perpendicular to the axis, or else it would lie flat against the side wall <NUM>. So, in this way, the deflecting surface <NUM> is also angled inwardly from the side wall <NUM> so that any particle hitting it face on is likely to be moved in a direction away from the side wall <NUM>. At a more central position, the particle is likely to be swept backwards by the rotational movement of the lead agitator <NUM>, to the suction inlet <NUM> disposed rearwardly of the lead agitator <NUM>.

In embodiments of the technology, the angle α of inclination between the deflecting surface <NUM> and rotational axis X of the agitator is in the range of <NUM>° to <NUM>°, and preferably between <NUM>° and <NUM>°, and more preferably still between <NUM>° and <NUM>°. In embodiments, the angle α is <NUM>° (or in the region of <NUM>°).

As illustrated in <FIG>, the ramp <NUM> extends around a portion of the periphery of the lead agitator <NUM> (and, consequently, around a portion of the agitator chamber <NUM>) from a start position A which is rearward of the rotational axis X of the lead agitator <NUM>, i.e. behind the axis X in the direction of travel of the suction cleaner <NUM>. A portion of the ramp <NUM> lies above the rotational axis X of the lead agitator <NUM>. The ramp <NUM> may begin at a start position A which is angled at approximately <NUM>° upwards from and to the rear of the axis X, and the ramp <NUM> extends to an end position B in front of the rotational axis X of the lead agitator <NUM>.

In embodiments, the end position B of the ramp <NUM> coincides with the height of the lower edge of the front end <NUM> of the floor cleaning head housing <NUM>. In this way, dirt that is deflected by the ramp <NUM> leaves the end of the ramp at the point where dirt enters the front inlet <NUM> beneath the front end <NUM> of the housing <NUM>, so as to join the incoming passage of dirt into the floor cleaning head <NUM> through the front inlet <NUM>.

In embodiments, and as shown in <FIG>, the end position B of the ramp <NUM> lies in front of the rotational axis X of the agitator, and below the height of the rotational axis X of the agitator. In such a configuration, the rotational direction of motion of dirt leaving the end <NUM> of the ramp <NUM> is such that the dirt has a trajectory with downwards and backwards components. This causes the majority of dirt leaving the end <NUM> of the ramp <NUM> to be swept backwards underneath the rotating lead agitator <NUM> rather than moving forwardly outwards through the front inlet <NUM>.

In embodiments of the technology, at the end position B of the ramp <NUM>, the deflecting surface <NUM> extends from the side wall <NUM> between a first edge <NUM> at which it meets the side wall <NUM> and at which it is radially offset by a distance D1 from the rotational axis of the agitator X, and a second edge <NUM> away from the side wall <NUM>, and radially offset by a greater distance D2 from the rotational axis of the agitator X. In other words, at the end <NUM> of the ramp <NUM>, D2>D1.

In embodiments of the technology, and as illustrated in <FIG>, the distance by which the deflecting surface <NUM> of the ramp <NUM> extends into the agitator chamber <NUM>, from the side wall <NUM>, increases along the length of the ramp <NUM> from the start position A to the end position B. So, in embodiments, at all positions between its start position A and end position B the radial offset D1 at the first edge <NUM> of the ramp <NUM> is less than the radial offset D2 at the second edge <NUM> of the ramp <NUM>. In the embodiment shown, the ratio of D2:D1 increases between the start position A and the end position B. In some embodiments, the ratio of D2:D1 increases continuously between the start position and end position. In other embodiments, the increase may be stepped (i.e. so the ratio or distance does not increase continuously).

The lead agitator <NUM>, as described above, effectively lies at the very front of (or slightly in advance of) the suction inlet <NUM>, and acts to dislodge particles from a carpet surface, for example, in order to transfer those dirt particles back towards and into the suction inlet lying behind it. The dividing wall lies to the rear of the lead agitator <NUM>, under which dislodged particles of dirt are flung by the rotational movement of the lead agitator <NUM>. At either side of the housing, surrounding the lead agitator <NUM>, the separating wall seals to the side wall of the housing, on which the agitator is supported and from which it extends inwardly towards the centre of the floor cleaning head <NUM>.

In embodiments, the lead agitator <NUM> lies largely outside of the suction flow path, separated from the suction chamber by the dividing wall between the two agitators <NUM>, <NUM>. The lead agitator <NUM> preferably sits at a height such that the lowermost surface of the lead agitator <NUM> is raised slightly above the surface being cleaned, where that surface is a flat floor surface. When used on a carpet surface, the lower most portion of the lead agitator <NUM> impacts the carpet surface as the device moves across the carpet. A lower edge of the dividing wall sits at a position raised above the surface being cleaned, so as not to interfere with the carpet surface since doing so would create unwanted friction and drag on the surface, and potentially cause snagging. A row of very fine bristles <NUM> may descend from the lower edge of the separating wall, to inhibit the flow of air between the lowest portion of the lead agitator <NUM> and the suction chamber located behind it. In this way, the fine bristles <NUM> have the effect of defining a front most portion of the suction inlet <NUM>. It should be noted that the fine bristles <NUM> do not directly contact the floor surface; however, they provide an effective screen with the aim of concentrating the suction applied to the floor surface, to the area directly behind the row of bristles <NUM>.

In embodiments, on either side of the floor cleaning head <NUM>, air channels <NUM> are provided in the side walls of the floor cleaning head. The air channels <NUM> are disposed rearwardly of the lead agitator <NUM>, and rearwardly of the dividing wall, so as to be at least partially aligned with the suction inlet <NUM>. The air channels <NUM> provide an opening through the side wall of the housing <NUM>, to allow air to flow inwardly from the sides of the floor cleaning head <NUM>, into the suction inlet <NUM>. This has the effect of drawing fine dirt from the sides of the floor cleaning head <NUM> into the suction inlet <NUM>, and also assists in allowing air flow into the suction flow part when the device is used on a very deep carpet, to ensure the carpet does not entirely block access to the suction inlet <NUM>.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claim 1:
A floor cleaning head (<NUM>) for a suction cleaner (<NUM>), the floor cleaning head providing a housing (<NUM>) having a suction inlet (<NUM>), and the housing providing:
an agitator chamber (<NUM>) having ends forming a pair of side walls (<NUM>) disposed on opposing sides of the floor cleaning head,
characterized in that
the housing further provides an agitator (<NUM>) configured such that each end of the agitator is supported between and enclosed by the side walls and configured to rotate about a lengthways central rotational axis,
wherein an end of the agitator chamber provides a ramp (<NUM>) extending around a portion of a periphery of the agitator and inwardly from the side wall, the ramp providing a deflecting surface (<NUM>) configured to deflect dirt particles inwardly from the side wall towards a central portion of the floor cleaning head.