Patent Description:
Various proposals have been made in respect of autonomous surface cleaning apparatus, which are driven automatically and do not require to be propelled by a user across a surface to be cleaned. Essentially, such an apparatus comprises a body or chassis supported on wheels or tracks which are driven by an on-board battery pack and guided by a control system which navigates the apparatus around a room so that the floor or floor covering can be cleaned. For cleaning, such an apparatus typically also incorporates a cleaner head having a suction opening communicating with a dirt or dust collection device so that dirt and dust can be sucked up from the surface to be cleaned and stored in a receptacle for disposal.

When such autonomous surface cleaning apparatus are cleaning a surface it can be challenging for them to manoeuvre themselves sufficiently close to any walls to ensure that the edges of the surface are thoroughly cleaned by the cleaner head. To improve their edge cleaning capability, many autonomous surface cleaning apparatus are provided with one or more rotating side brushes whose bristles extend out beyond the periphery of the apparatus with the intention that of sweeping any dirt or debris away from an edge and into the path of the cleaner head. An example of such an apparatus is shown in <CIT>. However, relying on the sweeping action of such side brushes is not a particularly effective approach for edge cleaning as dirt and debris can often bypass.

As an alternative to side brushes, some autonomous surface cleaning apparatus are provided with one or more suction nozzles that can project out beyond the periphery of the apparatus with the intention of using the suction of the apparatus to capture dirt or debris that is present at an edge. An example of such an apparatus is shown in <CIT>. Whilst the application of suction can improve the effectiveness with which small dirt and debris is captured during edge cleaning, without an agitator it is typically difficult for these suction nozzles to effectively capture larger debris. In addition, such suction nozzles typically cannot get as close to the edge of a wall or other vertical surface as is possible with the bristles of a brush.

According a first aspect there is provided an autonomous surface cleaning apparatus. The apparatus comprises a body, a drive system carried by the body and configured to move the autonomous surface cleaning apparatus across a surface, and a cleaning assembly disposed at a front of the body. The cleaning assembly comprises a housing defining a suction chamber having a suction chamber opening in a bottom surface of the cleaning assembly and a suction channel extending from the suction chamber to a suction channel opening provided in a first side surface of the cleaning assembly, and a side suction nozzle mounted to an extension and retraction assembly that is arranged to allow the side suction nozzle to be moved between an extended position in which the side suction nozzle extends away from the suction channel opening and a retracted position. The side suction nozzle comprises a first resilient blade and a second resilient blade, the first resilient blade being arranged such that a surface of the first resilient blade is substantially forward facing and the second resilient blade being arranged such that a surface of the second resilient blade is substantially downward facing.

Preferably, when in the retracted position the side suction nozzle does not project away from the suction channel opening. The side suction nozzle may be retracted within the cleaning assembly when in the retracted position, and is preferably retracted behind the first side surface of the cleaning assembly.

Preferably, when in the extended position both the first resilient blade and the second resilient blade extend away from the suction channel opening. The first resilient blade may be arranged to project away a rearmost edge of the suction channel opening when the side suction nozzle is in the extended position. The second resilient blade may be arranged to project away an upper edge of the suction channel opening when the side suction nozzle is in the extended position.

The first resilient blade and the second resilient blade may be arranged such that a transverse axis of the first resilient blade is perpendicular to a transverse axis of the second resilient blade. Preferably, the first resilient blade is arranged to be substantially vertical when the apparatus is disposed on a horizontal surface. Preferably, the second resilient blade is arranged to be substantially horizontal, and is more preferably from <NUM> to <NUM> degrees below horizontal, when the apparatus is disposed on a horizontal surface.

The first resilient blade may be substantially planar. The first resilient blade may have a lower edge that is straight and an upper edge that is at least partially curved so as to meet the lower edge at a point. The second resilient blade may be corrugated. The second resilient blade may be arranged such that ridges and grooves of the second resilient blade extend from a proximal end to a distal end of the second resilient blade.

The first resilient blade and the second resilient blade may each comprise a resilient material such as an elastomer, such as a resilient plastic or rubber. The first resilient blade and the second resilient blade may each comprise a resilient material such as thermoplastic polyurethane (TPU).

The side suction nozzle may further comprise a nozzle base to which the first resilient blade and the second resilient blade are attached, the first resilient blade and the second resilient blade being connected to the extension and retraction assembly by way of the nozzle base. The first resilient blade, the second resilient blade and at least a portion of the nozzle base may be integrally formed. The first resilient blade may only be connected to the second resilient blade by way of the nozzle base.

The extension and retraction assembly may comprise an extension arm that is movably connected to the cleaning assembly and the suction nozzle is attached to a distal end of the extension arm. The extension arm may be arranged to move laterally relative to the cleaning assembly. The extension and retraction assembly may comprise a linear actuator arranged to move the extension arm laterally relative to the cleaning assembly. The linear actuator may comprise a motor arranged to drive a drive member and a driven member that is arranged to be driven by the drive member to cause the extension arm to move laterally relative to the cleaning assembly. The drive member may comprise a pinion mounted to a shaft of the motor and the driven member comprises a rack provided on the extension arm.

The cleaning assembly may further comprises a door that is arranged to move between a closed position when the suction nozzle is in the retracted position and an open position when the suction nozzle is in the extended position. Preferably, the door is arranged to cover covers the suction channel opening when in the in the retracted position and to not cover the suction channel opening in the extended position. The cleaning assembly may comprise a door actuation assembly that is arranged to move the door between the closed position and the open position. The door actuation assembly may comprise a retraction arm that is movably connected to the cleaning assembly with the door then being attached to a distal end of the retraction arm by a hinge. The retraction arm may be arranged to move laterally relative to the cleaning assembly with the door then being arranged such that lateral movement of the retraction arm causes the door to move between the closed position and the open position. The linear actuator of the extension and retraction assembly may then be arranged to move the extension arm in a first direction and to simultaneously move the retraction arm in a second direction. The rack on the extension arm may then be arranged to engage with a first side of the pinion, and the retraction arm may be provided with a rack that is arranged to engage with a second side of the pinion, the second side being diametrically opposite to the first side of the pinion.

Preferably, a plan shape of the cleaning assembly is substantially rectangular. Preferably, the cleaning assembly defines a generally planar front surface and first and second side surfaces that extend rearward from opposite ends of the front surface, the first and second side surfaces being generally planar and substantially perpendicular to the front surface of the cleaning assembly.

The cleaning assembly may be disposed beneath a front surface of the body and project forward of the front surface of the body. The body may define a generally planar front surface and first and second side surfaces that extend rearward from opposite ends of the front surface. The first and second side surfaces may each have a frontmost portion that is generally planar and a rearmost portion that is curved, with the rearmost portions curving inwardly toward one another. The frontmost portions of the first and second side surfaces of the body may be substantially perpendicular to the front surface of the body.

The cleaning assembly may further comprises an agitator disposed within the suction chamber. The apparatus may further comprise an airflow generator for creating an airflow through the suction chamber. The airflow generator may comprise a motor-driven impeller.

The apparatus may further comprise a receptacle configured to receive dirt collected by the cleaning assembly, the receptacle being releasably attached to the body. The apparatus may further comprises a separation system that is configured to separate dirt from an airflow passing through the apparatus and to deposit dirt into the receptacle. The separation system may be disposed an airflow path between an air inlet provided at the suction chamber of cleaning assembly and an air outlet of the apparatus. The apparatus may comprise an inlet duct that extends from the cleaning assembly to the separation system. The inlet duct may be straight and extend in a direction that is parallel to the longitudinal axis of the body. The separation system may be at least partially disposed within the receptacle. The separation system may comprise a cyclonic separator.

An embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:.

There will now be described an autonomous surface cleaning apparatus that provides various advantages over conventional autonomous surface cleaning apparatus. <FIG> are external views of an embodiment of such an autonomous surface cleaning apparatus <NUM> (hereinafter "the apparatus <NUM>"). In this embodiment, the apparatus <NUM> is shown in the context of a robotic vacuum cleaner, although it should be appreciated that this is not essential to the invention and that the invention is applicable to any autonomous surface cleaning apparatus, in a domestic setting or otherwise. <FIG> shows a rear perspective view of the apparatus <NUM> approaching an associated docking station <NUM>, <FIG> shows a front perspective view of the apparatus <NUM>, <FIG> shows a rear perspective view of the bottom of apparatus <NUM>, and <FIG> shows a bottom view of the apparatus <NUM>.

As shown in <FIG>, the apparatus <NUM> has a longitudinal axis (X<NUM>) that extends between the front and the rear of the apparatus <NUM>, a transverse axis (Y<NUM>) that extends in the lateral direction between the left (L) and right (R) sides of the apparatus <NUM>, and a vertical axis (Z<NUM>) that extends substantially vertically relative to the surface on which the apparatus <NUM> travels. For the purpose of this description, terms such as 'front' and 'rear', in the context of the apparatus <NUM>, are used in the sense of its forward and reverse directions during operation. Similarly, the terms 'left' and 'right' will be used with reference to the direction of forward movement of the apparatus <NUM>.

The apparatus <NUM> comprises a body <NUM>, a drive system <NUM> carried by the body <NUM> and configured to move the autonomous surface cleaning apparatus <NUM> across a surface, a cleaning assembly <NUM> disposed at a front of the body <NUM>, and a receptacle <NUM> releasably attached to the body <NUM> and configured to receive dirt collected by the cleaning assembly <NUM>. The apparatus <NUM> further comprises a rechargeable battery system <NUM> carried by the body <NUM> and arranged to provide electrical power to the various systems of the apparatus <NUM>, with battery charging contacts <NUM> disposed on a front surface <NUM> of the body <NUM>. The charging contacts <NUM> are electrically connected to the rechargeable battery system <NUM> and are configured to pass electrical current when in contact with corresponding charging contacts <NUM>, e.g. provided on a docking station <NUM> associated with the autonomous surface cleaning apparatus <NUM>.

In the illustrated embodiment, the body <NUM> defines a generally planar front surface <NUM> that is substantially perpendicular to a bottom or base of the body <NUM> such that the front surface <NUM> is approximately vertical when the apparatus <NUM> is supported on a horizontal surface. The body <NUM> also defines first and second (i.e. left and right) side surfaces <NUM>, <NUM>, at least a portion of which extend rearward from opposite ends of the front surface <NUM>. The first and second side surfaces <NUM>, <NUM> each have a frontmost portion that is generally planar and a rearmost portion that is curved, with the rearmost portions curving inwardly toward one another and toward the longitudinal axis (X<NUM>) of the apparatus <NUM>. The frontmost portions of the side surfaces <NUM>, <NUM> of the body <NUM> are substantially perpendicular to the front surface <NUM> of the body <NUM>, and are therefore parallel to one another. The body <NUM> of the apparatus <NUM> therefore has a plan shape that is generally D-shaped. The term "plan shape" as used herein refers to the outer peripheral shape when viewed from above.

As shown in <FIG>, the body <NUM> of the apparatus <NUM> comprises a chassis <NUM> and an outer shell <NUM> mounted to the chassis <NUM>. The outer shell <NUM> defines the outer surfaces of the body <NUM> and comprises one or more covers that are collectively arranged to cover the chassis <NUM> and form the exterior surfaces of the body <NUM>. In the illustrated embodiment, the outer shell <NUM> comprises a base cover <NUM>, a front cover <NUM> and a pair of rear covers <NUM>.

The drive system <NUM> is mounted to the chassis <NUM> and comprises a pair of differentially drive wheels <NUM> that partially project from the bottom of the body <NUM>. In the illustrated embodiment, the drive system <NUM> is disposed approximately midway between a frontmost portion of the apparatus <NUM> and a rearmost portion of the apparatus <NUM>, with first and second (i.e. left and right) drive wheels <NUM> disposed adjacent to the respective side surface <NUM>, <NUM>.

The cleaning assembly <NUM> is disposed beneath the front surface <NUM> of the body <NUM> and projects forward of the front surface <NUM> of the body <NUM>. This arrangement provides that the cleaning assembly <NUM> is the first part of the apparatus <NUM> to pass over a surface to be cleaned and also provides that the cleaning assembly <NUM> can reach under low objects where the full height of the apparatus <NUM> may not be able to go. In the illustrated embodiment, the cleaning assembly <NUM> comprises a housing <NUM> defining a suction chamber <NUM>, the suction chamber <NUM> having an opening in a bottom surface of the cleaning assembly such that the opening is adjacent to a surface to be cleaned. As shown in <FIG>, the apparatus <NUM> then further comprises an airflow generator <NUM> for creating an airflow through the suction chamber. The airflow generator <NUM> comprises an impeller (not shown) that is driven by a vacuum motor (not shown), with the vacuum motor being driven by electrical power received from the rechargeable battery system <NUM>. An agitator <NUM> is also disposed within the suction chamber <NUM> and is arranged to move or dislodge dirt from a surface to be cleaned, making it easier to collect through the suction chamber <NUM>. In the illustrated embodiment, the agitator <NUM> is provided by a rotatable brush bar.

The plan shape of the cleaning assembly <NUM> is substantially rectangular. The cleaning assembly <NUM> therefore has a generally planar front surface <NUM> and first and second (i.e. left and right) side surfaces <NUM>, <NUM> that extend rearward from opposite ends of the front surface <NUM>. As shown in <FIG>, the housing <NUM> of the cleaning assembly <NUM> then also defines a suction channel <NUM> that extends from the suction chamber <NUM> to a suction channel opening <NUM> provided in the first side surface <NUM> of the cleaning assembly <NUM>. A side suction nozzle <NUM> is then mounted to the housing <NUM> adjacent to the suction channel opening <NUM>. The side suction nozzle <NUM> is mounted to the housing <NUM> by way of an extension and retraction assembly that is arranged to allow the side suction nozzle <NUM> to be moved between an extended position and a retracted position. In the extended position the side suction nozzle <NUM> projects away from the suction channel opening <NUM> and away from the first side surface <NUM> of the cleaning assembly <NUM>, whilst in the retracted position the side suction nozzle <NUM> is retracted within the cleaning assembly <NUM> (i.e. behind the first side surface <NUM> of the cleaning assembly <NUM>).

As shown in <FIG>, the side suction nozzle <NUM> comprises a first resilient blade <NUM> and a second resilient blade <NUM>, the first resilient blade <NUM> being arranged such that a surface <NUM> of the first resilient blade <NUM> is substantially forward facing and the second resilient blade <NUM> being arranged such that a surface <NUM> of the second resilient blade <NUM> is substantially downward facing. In this specific embodiment, the first resilient blade <NUM> is arranged to be substantially vertical when the apparatus <NUM> is supported on a horizontal surface, whilst the second resilient blade <NUM> is arranged to be substantially horizontal. The transverse axis (Y<NUM>) of the first resilient blade is therefore perpendicular to the transverse axis (Y<NUM>) of the second resilient blade. The first resilient blade <NUM> and the second resilient blade <NUM> each comprise a resilient material such as an elastomer, particularly a resilient plastic or rubber. For example, the first resilient blade <NUM> and the second resilient blade <NUM> could comprise a resilient material such as thermoplastic polyurethane (TPU). The side suction nozzle <NUM> allows the apparatus <NUM> to clean close to the edges of vertical surfaces, such as walls, as the apparatus <NUM> can be manoeuvred such that the resilient blades <NUM>, <NUM> of the side suction nozzle <NUM> contact and swipe along these surfaces to ensure that dirt and debris is directed into cleaning assembly <NUM> through the side suction channel <NUM>.

The first resilient blade <NUM> is substantially planar, with a lower edge that is straight and an upper edge that is at least partially curved so as to meet the lower edge at a point (i.e. such that the first resilient blade <NUM> has the shape of a straight back blade). In contrast, the second resilient blade <NUM> is corrugated and is arranged such that ridges and grooves of the second resilient blade extend from a proximal end or base of the blade to a distal end or tip of the blade. In the illustrated embodiment, the second resilient blade <NUM> is arranged to be at an angle (θ<NUM>) of from <NUM> to <NUM> degrees below horizontal when the apparatus <NUM> is supported on a horizontal surface.

The side suction nozzle <NUM> further comprises a nozzle base <NUM> to which the first resilient blade <NUM> and the second resilient blade <NUM> are attached, with the first resilient blade <NUM> and the second resilient blade <NUM> being connected to the extension and retraction assembly <NUM> by way of the nozzle base <NUM>. In the illustrated embodiment, the first resilient blade <NUM>, the second resilient blade <NUM> and the nozzle base <NUM> are integrally formed, with the first resilient blade <NUM> only being connected to the second resilient blade <NUM> by way of the nozzle base <NUM>.

As is illustrated in <FIG> and <FIG>, when in the retracted position the first resilient blade <NUM> and the second resilient blade <NUM> are retracted and retained within the cleaning assembly <NUM> such that they do not project away from the first side surface <NUM> of the cleaning assembly <NUM>, and when in the extended position the first resilient blade <NUM> and the second resilient blade <NUM> extend away from the first side surface <NUM> of the cleaning assembly <NUM>. Specifically, when the side suction nozzle <NUM> is in the extended position the first resilient blade <NUM> projects away a rearmost edge of the suction channel opening <NUM>, whilst the second resilient blade <NUM> projects away an upper edge of the suction channel opening <NUM>.

The extension and retraction assembly is shown in <FIG> and comprises an extension arm <NUM> that is movably connected to the cleaning assembly <NUM>, with the suction nozzle <NUM> being attached to a distal end of the extension arm <NUM>. The extension arm <NUM> is then arranged to move laterally relative to the cleaning assembly <NUM> (i.e. towards and away from the first side surface <NUM> of the cleaning assembly <NUM>). To do so, the extension and retraction assembly further comprises a linear actuator that is arranged to move the extension arm <NUM> laterally relative to the cleaning assembly <NUM>. In the illustrated embodiment, the linear actuator comprises a nozzle motor <NUM> arranged to drive a drive member <NUM> and a driven member <NUM> that is arranged to be driven by the drive member <NUM> to cause the extension arm <NUM> to move laterally relative to the cleaning assembly. Specifically, the drive member <NUM> comprises a pinion mounted to a shaft of the nozzle motor <NUM> and the driven member <NUM> comprises a rack provided on the extension arm <NUM> that is arranged to engage with a first side of the pinion.

The cleaning assembly <NUM> then further comprises a door <NUM> that is arranged to move between a closed position in which the door <NUM> covers the suction channel opening <NUM> when the suction nozzle <NUM> is in the retracted position, and an open position in which the door <NUM> does not cover the suction channel opening <NUM> when the suction nozzle <NUM> is in the extended position. In the illustrated embodiment, the cleaning assembly <NUM> comprises a door actuation assembly that is arranged to move the door <NUM> between the closed position and the open position. The door actuation assembly comprises a retraction arm <NUM> that is movably connected to the cleaning assembly <NUM>, with the door <NUM> being attached to a distal end of the retraction arm <NUM> by way of a hinge <NUM>. The retraction arm <NUM> is arranged to move laterally relative to the cleaning assembly <NUM> (i.e. towards and away from the first side surface <NUM> of the cleaning assembly <NUM>) and the door <NUM> is arranged such that lateral movement of the retraction arm <NUM> causes the door <NUM> to move between the closed position and the open position. The linear actuator of the extension and retraction assembly is then arranged to move the extension arm <NUM> in a first direction and to simultaneously move the retraction arm <NUM> in a second direction. To do so, the retraction arm <NUM> is provided with a rack <NUM> that is arranged to engage with a second side of the pinion <NUM>, the second side of the pinion <NUM> being diametrically opposite to the first side of the pinion <NUM>.

The autonomous surface cleaning apparatus <NUM> further comprises a separation system <NUM> configured to separate dirt from an airflow passing through the apparatus <NUM> and to deposit dirt into the receptacle <NUM>. To do so, the separation system <NUM> is disposed in the airflow path between an air inlet <NUM> provided at the suction chamber <NUM> of the cleaning assembly <NUM> and an air outlet or exhaust <NUM> of the apparatus <NUM>. In the illustrated embodiment, the separation system <NUM> comprises a cyclonic separator that is partially disposed within the receptacle <NUM>. The apparatus <NUM> then comprises an inflow or inlet duct <NUM> that extends from the cleaning assembly <NUM> to the separation system <NUM> within receptacle <NUM>. The inflow duct <NUM> is straight and extends through the body <NUM> in a direction that is parallel to the longitudinal axis (X<NUM>) of the body <NUM>. The apparatus <NUM> also includes a removable filter assembly <NUM> disposed in the airflow path between the separation system <NUM> and the air outlet <NUM> of the apparatus <NUM>. In the illustrated embodiment, the removable filter assembly <NUM> combines both a pre-motor filter and a post-motor filter into a single unit. The filter assembly <NUM> is therefore arranged such that a pre-motor filter of the filter assembly <NUM> is disposed in the airflow path between the separation system <NUM> and the motor of the airflow generator <NUM> and with a post-motor filter of the filter assembly <NUM> is disposed in the airflow path between the motor of the airflow generator <NUM> and the air outlet <NUM> of the apparatus <NUM>.

In the illustrated embodiment, the apparatus <NUM> further comprises a vibration sensor <NUM> configured to detect vibrations of the inflow duct <NUM> caused by dirt impacting the inflow duct <NUM> (i.e. as dirt traverses through the inflow duct <NUM> from the cleaning assembly <NUM> to the separation system <NUM>). The vibration sensor <NUM> is disposed adjacent to an outside of an upper surface of the inflow duct <NUM>. In the illustrated embodiment, the vibration sensor <NUM> comprises a piezoelectric sensing element. The vibration sensor <NUM> is configured to communicate with a control system of the apparatus <NUM> and thereby provide vibration data, with the control system being configured to process the vibration data received from the vibration sensor <NUM> to determine one or more of a volume of dirt, a size of dirt pieces, a mass of dirt pieces and a type of dirt pieces etc..

As shown in <FIG>, when attached to the body <NUM> of the apparatus <NUM> the receptacle <NUM> is partially disposed within a rearward facing recess <NUM> defined by the body <NUM>. The apparatus <NUM> is configured such that the receptacle <NUM> can be removed from the recess <NUM> by moving the receptacle <NUM> in a rearwards direction relative to the body <NUM> (i.e. in a direction that is substantially parallel to the longitudinal axis (X<NUM>) of the apparatus <NUM>), as shown by the arrow in <FIG>. Specifically, the body <NUM> defines a rear opening <NUM> into the recess <NUM> and the body <NUM> is arranged to allow the receptacle <NUM> to be removed from the recess <NUM> by moving the receptacle <NUM> in a rearwards direction through the rear opening <NUM>. This arrangement of the receptacle <NUM> relative to the battery charging contacts <NUM> of the apparatus <NUM> allows for easy removal of the receptacle <NUM> when the apparatus <NUM> is docked with an associated docking station, e.g. during charging of the rechargeable battery system <NUM>. This arrangement also provides that a portion of a side surface <NUM> of the receptacle <NUM> is visible when retained within the recess <NUM> and that by making this visible portion at least partially transparent the fill level of the receptacle <NUM> is then visible during use. In the illustrated embodiment, the receptacle <NUM> is generally cylindrical and the recess <NUM> has a shape that substantially corresponds with the generally cylindrical shape of the receptacle <NUM>. An outer wall of the generally cylindrical receptacle <NUM> is then entirely transparent.

In the illustrated embodiment, the apparatus <NUM> is also configured such that the receptacle <NUM> can be removed from the recess <NUM> by moving the receptacle <NUM> in an upwards direction relative to the body <NUM> (i.e. in a direction that is substantially parallel to the vertical axis (Z<NUM>) of the apparatus <NUM> when supported on a horizontal surface) after the receptacle <NUM> has been released from the body <NUM>. Specifically, the body <NUM> defines both the rear opening <NUM> into the recess <NUM> and an upper opening <NUM> into the recess <NUM>, with the rear opening <NUM> and upper opening <NUM> being combined into a single opening in the illustrated embodiment.

When attached to the body <NUM> a portion of the receptacle <NUM> protrudes from the recess <NUM> beyond the rearmost portion of the body <NUM>. This arrangement provides for a larger receptacle <NUM> without increasing the size of the body <NUM> of the apparatus <NUM>. A lower edge <NUM> of the receptacle <NUM> that is rearmost when attached to the body <NUM>, and that therefore protrudes beyond from the recess <NUM>, is then at least partially chamfered. This chamfering provides that this protruding lower edge <NUM> of receptacle <NUM> will not obstruct or prevent a slight rearward tilt of the apparatus <NUM> that would otherwise prevent it from traversing over low objects it's in path. The body <NUM> then comprises a ledge <NUM> that is flush with a bottom surface of the body <NUM> and that extends partially over a lower end of the recess <NUM> in order to support a portion of the receptacle <NUM> when the receptacle <NUM> is attached to the body <NUM>. However, the ledge <NUM> is arranged such when the receptacle <NUM> is attached to the body <NUM> the ledge <NUM> does not extend beyond a periphery of a bottom surface of the receptacle <NUM>. Specifically, the ledge <NUM> is arranged such that it does not extend beyond a lower corner of the chamfered lower edge <NUM> when the receptacle <NUM> is attached to the body <NUM>. The ledge <NUM> therefore provides support for the receptacle <NUM> when it is attached to the body <NUM> without obstructing or preventing a slight rearward tilt of the apparatus <NUM>.

The apparatus <NUM> then further comprises a retention assembly for retaining the receptacle <NUM> within the recess <NUM>, with the retention assembly comprising a user-actuable release mechanism for releasing the receptacle <NUM> from the retention assembly. In the illustrated embodiment, the retention assembly comprises a moveable upper catch <NUM> provided on the body <NUM> and an upper catch keeper <NUM> provided on the receptacle <NUM>, with the upper catch keeper <NUM> being arranged to be engaged by the upper catch <NUM> when the receptacle <NUM> is maximally disposed within the recess <NUM>. The moveable upper catch <NUM> is arranged to be moved between a first position and a second position, and is arranged to engage the upper catch keeper <NUM> when receptacle <NUM> is maximally disposed within the recess <NUM> with the upper catch <NUM> in the first position and to disengage the upper catch keeper <NUM> when in the second position. The upper catch <NUM> is then biased into the first position by an upper catch spring (not shown) with the user-actuable release mechanism being provided by a receptacle release button <NUM> provided on the body <NUM> that is arranged, when operated by a user, to cause movement of the upper catch <NUM> into the second position against the force of the upper catch spring.

In the illustrated embodiment, the retention assembly further comprises a moveable lower catch <NUM> provided on the body <NUM> and a lower catch <NUM> keeper provided on the receptacle <NUM>, with the lower catch keeper <NUM> being arranged to be engaged by the lower catch <NUM> when the receptacle <NUM> is maximally disposed within the recess <NUM>. As with the upper catch <NUM>, the lower catch <NUM> is arranged to be moved between a first position and a second position, and is arranged to engage the lower catch keeper <NUM> when receptacle <NUM> is maximally disposed within the recess <NUM> with the lower catch <NUM> in the first position and to disengage the lower catch keeper <NUM> when in the second position. The lower catch <NUM> is biased into the first position by a lower catch spring (not shown) with the user-actuable release mechanism being arranged such that operation of the receptacle release button <NUM> by a user causes both movement of the upper catch <NUM> into the second position against the force of the upper catch spring and movement of the lower catch <NUM> into the second position against the force of the lower catch spring. The lower catch <NUM> is also arranged such that, when moved from the first position to the second position, the lower catch <NUM> will push the receptacle <NUM> rearward relative to the body <NUM> to assist removal of the receptacle <NUM>. To do so, the lower catch <NUM> is arranged to extend rearward from the body <NUM> and into the recess <NUM> when in the second position.

In an alternative embodiment, the catches <NUM>, <NUM> and the user-actuable release mechanism of the retention assembly could be provided on the receptacle <NUM> with the catch keepers <NUM>, <NUM> then being provided on the body <NUM>. In such an alternative embodiment, the lower catch <NUM> would then be arranged to extend forward from the receptacle <NUM> when in the second position so to push the receptacle <NUM> way from the body <NUM> of the apparatus <NUM>.

The rechargeable battery system <NUM> comprises a plurality of battery cells disposed at a rear of the body <NUM>, and that are therefore disposed at the opposite end of the body <NUM> relative to the cleaning assembly <NUM>, so as to provide a favourable centre of gravity for the apparatus <NUM>. In the illustrated embodiment, the rearward facing recess <NUM> defined by the body <NUM> is aligned with a longitudinal axis (X<NUM>) of the body <NUM>. The body <NUM> therefore defines a first rearmost portion <NUM> that extends along a first (i.e. left) side the recess <NUM> and a second rearmost portion <NUM> that extends along a second (i.e. right) side of the recess <NUM>. The first rearmost portion <NUM> and the second rearmost portion <NUM> therefore at least partially define the recess <NUM>. The rechargeable battery system <NUM> then comprises a first set of battery cells <NUM> disposed within the first rearmost portion <NUM> and a second set of battery cells <NUM> disposed within the second rearmost portion <NUM>. Consequently, the first set of battery cells <NUM> are carried by the body <NUM> on the first side of the recess <NUM> and the second set of battery cells <NUM> are carried by the body <NUM> on the second side of the recess <NUM>. This arrangement provides that the battery cells <NUM>, <NUM> are disposed at the opposite end of the apparatus <NUM> to the cleaning assembly <NUM> to provide some counterbalance for the weight of the cleaning assembly <NUM>, whilst also providing that the battery cells <NUM>, <NUM> are distributed on either side of the longitudinal axis (X<NUM>) of the apparatus to maintain a favourable centre of gravity. In the illustrated embodiment, the number of battery cells in the first set <NUM> is equal to the number of battery cells in the second set <NUM> so that the battery cells are evenly divided distributed on either side of the longitudinal axis (X<NUM>) of the apparatus <NUM>.

As shown in <FIG>, the battery cells in the first set of battery cells <NUM> are disposed within a first battery housing <NUM> that supports and provides interconnections between the battery cells in the first set of battery cells <NUM>, and the battery cells in the second set of battery cells <NUM> are disposed within a distinct, second battery housing <NUM> that supports and provides interconnections between the battery cells in the second set of battery cells <NUM>. The rechargeable battery system <NUM> then further comprises a cable harness <NUM> that extends between and connects the first battery housing <NUM> and the second battery housing <NUM>, such that the first set of battery cells <NUM> and the second set of battery cells <NUM> are connected together.

The apparatus <NUM> then further comprises a control system <NUM> that is configured to control the operation of the apparatus <NUM>, with the control system <NUM> being illustrated schematically in <FIG>. In particular, the control system <NUM> is responsible for controlling the movement, navigation, cleaning operations, docking, charging, communications etc. of the apparatus <NUM>. The control system <NUM> is therefore implemented as a combination of computer hardware and software and comprises one or more processors <NUM>, such as microcontroller, and a memory <NUM> that provides storage for any data required by the control system <NUM>, such as any computer programs/software applications implemented by the one or more processors <NUM>. The control system <NUM> also comprises one or more transceivers <NUM> for wireless communication with other entities such as a personal computer device (e.g. a user's smartphone, tablet computer etc.) and/or a communications interface device (e.g. a wireless access point, telecommunications base station). The control system therefore includes a communications unit <NUM> that controls communications sent and received through the transceiver(s) <NUM>.

Amongst other operations, the control system <NUM> is responsible for controlling movement of the apparatus within an environment and is therefore provided with a motion control unit <NUM> that controls the drive system <NUM> and a navigation unit <NUM> that receives data from a navigational sensor system <NUM> and uses this data to autonomously navigate the apparatus <NUM> within an environment. In particular, the navigation unit <NUM> is configured to use the data received from the navigational sensor system <NUM> to implement functions such as localization within the environment, mapping of the environment and hazard avoidance.

In the illustrated embodiment, the navigational sensor system <NUM> comprises one or more vision sensors <NUM> that are arranged to capture images of the environment around the apparatus <NUM>, one or more motion sensors <NUM> that are arranged to detect motion of the apparatus <NUM>, a plurality of proximity sensors <NUM>-<NUM> that are arranged to detect the presence of and/or distance to objects, a plurality of cliff sensors <NUM>-<NUM> that are arranged to detect the presence of potential drop, and a plurality of contact or bump sensors <NUM>, <NUM>, <NUM> that are arranged to detect impacts between the apparatus and other objects. In the illustrated embodiment, the vision sensors <NUM> comprise an omnidirectional camera, positioned at the top of the apparatus <NUM>, for providing the apparatus <NUM> with a panoramic view of its surroundings for use in localization etc., and the motion sensors <NUM> comprise an optical flow sensor directed towards the surface on which the apparatus is supported for implementing visual odometry to provide localization compensation for traction slippage etc..

As detailed above, the cleaning assembly <NUM> then has a generally planar front surface <NUM> and first and second (i.e. left and right) side surfaces <NUM>, <NUM> that extend rearward from opposite ends of the front surface <NUM>. The cleaning assembly <NUM> therefore has a first (i.e. left) front corner that is formed where the front surface <NUM> meets the first side surface <NUM> and a second (i.e. right) front corner that is formed where the front surface <NUM> meets the second side surface <NUM>. The navigational sensor system <NUM> then comprises a first forward proximity sensor <NUM> disposed at the front surface <NUM> of the cleaning assembly <NUM> adjacent to the first front corner of the cleaning assembly <NUM>, and a second forward proximity sensor <NUM> disposed at the front surface <NUM> of the cleaning assembly <NUM> adjacent to the second front corner of the cleaning assembly <NUM>. The first and second forward proximity sensors <NUM>, <NUM> are arranged to detect obstacles that are present in the path of the cleaning assembly <NUM> and the apparatus <NUM>. To do so, both the first and second forward proximity sensors <NUM>, <NUM> are angled inwardly towards the longitudinal axis (X<NUM>) of the cleaning assembly <NUM>. In particular, the first and second forward proximity sensors <NUM>, <NUM> are directed inwardly at an acute angle (θ<NUM>) relative to the front surface <NUM> of the cleaning assembly <NUM>. This arrangement of forward proximity sensors <NUM>, <NUM> provides that only two proximity sensors are required in order to monitor for obstacles in the path of the apparatus <NUM> and improves the sensitivity of hazard detection by ensuring that the field of view of the proximity sensors at least partially overlap.

In the illustrated embodiment, the first and second forward proximity sensors <NUM>, <NUM> are directed inwardly at an angle (θ<NUM>) of approximately <NUM> degrees relative to the front surface <NUM> of the cleaning assembly <NUM>. However, those skilled in the art will recognise that the exact angle chosen for the forward proximity sensors (θ2) will depend on the width of the apparatus <NUM>, the size of the field of view of the proximity sensors and their detection range. In the illustrated embodiment, each of the first and second forward proximity sensors <NUM>, <NUM> are provided by a time-of-flight (TOF) sensor, such as an ultrasonic or infrared TOF sensor, and are preferably provided by an invisible infrared laser TOF sensor.

The navigational sensor system <NUM> further comprises a first side proximity sensor <NUM> disposed at the first side surface <NUM> of cleaning assembly <NUM> adjacent to the first front corner of the cleaning assembly <NUM>, and a second side proximity sensor <NUM> disposed at the second side surface of cleaning assembly <NUM> adjacent to the second front corner of the cleaning assembly <NUM>. The first and second side proximity sensors <NUM>, <NUM> are directed laterally away from the apparatus <NUM> and are preferably arranged such that they are directed substantially parallel to the front surface <NUM> of the cleaning assembly <NUM> (i.e. such that an axis of the sensor is substantially parallel to the front surface <NUM> of the cleaning assembly <NUM>). This arrangement of side proximity sensors <NUM>, <NUM> provides that walls or other similar obstacles are detected by the forwardmost corners of the apparatus <NUM> and, when their outputs are combined with those of the forward proximity sensors <NUM>, <NUM>, allows the apparatus <NUM> to accurately detect approaching corners. In the illustrated embodiment, each of the first and second side proximity sensors <NUM>, <NUM> are provided by a time-of-flight (TOF) sensor, such as an ultrasonic or infrared TOF sensor, and are preferably provided by an invisible infrared laser TOF sensor.

In the illustrated embodiment, the navigational sensor system <NUM> further comprises a first forward cliff sensor <NUM> disposed at the bottom surface of cleaning assembly <NUM> adjacent to the first front corner of the cleaning assembly <NUM>, and a second forward cliff sensor <NUM> disposed at the bottom surface of cleaning assembly <NUM> adjacent to the second front corner of the cleaning assembly <NUM>. This arrangement of the forward cliff sensors <NUM>, <NUM> ensures that potential drops are detected by the forwardmost corners of the apparatus <NUM> to prevent the cleaning assembly <NUM> from passing over a drop, thereby minimising the risk of the apparatus <NUM> falling and avoiding wasting energy by running the vacuum motor and/or the agitator whilst over a drop.

In the illustrated embodiment, the navigational sensor system <NUM> also comprises rear cliff sensors <NUM>, <NUM> disposed adjacent to the rearmost bottom edges of the body <NUM>. Specifically, a first rear cliff sensor <NUM> is disposed adjacent to the rearmost bottom edge of the first rearmost portion <NUM> and a second rear cliff sensor <NUM> is disposed adjacent to the rearmost bottom edge of the second rearmost portion <NUM>. These rear cliff sensors <NUM>, <NUM> provide that potential drops are detected by the rearmost edges of the apparatus <NUM> to minimise the risk that the apparatus <NUM> will pass over a drop when moving in reverse. However, as these rear cliff sensors <NUM>, <NUM> are disposed on the rearmost portions of the body <NUM>, these rear cliff sensors <NUM>, <NUM> are closer to the longitudinal axis (X<NUM>) of the body <NUM> than the drive wheels <NUM> due to inward curvature of these rearmost portions <NUM>, <NUM> of the body <NUM>. The navigational sensor system <NUM> therefore also comprises first and second side cliff sensors <NUM>, <NUM> that are each disposed immediately behind and parallel with (i.e. longitudinally aligned with) a respective drive wheel <NUM>. These side cliff sensors <NUM>, <NUM> are therefore directly behind each of the drive wheels <NUM> in order to detect drops that may be present immediately behind the drive wheels <NUM> but that may not have been detected by the rear cliff sensors <NUM>, <NUM>.

As shown in <FIG>, the navigational sensor system <NUM> of the illustrated embodiment comprises a pair of front corner sensor assemblies <NUM>, <NUM>, wherein each of these front corner sensor assemblies <NUM>, <NUM> comprises a forward proximity sensor, a side proximity sensor and a forward cliff sensor. Specifically, the navigational sensor system <NUM> comprises a first front corner sensor assembly <NUM> disposed at the first (i.e. left) front corner of the cleaning assembly <NUM> and a second front corner sensor assembly <NUM> disposed at the second (i.e. right) front corner of the cleaning assembly <NUM>. The first front corner sensor assembly <NUM> then includes the first forward proximity sensor <NUM>, the first side proximity sensor <NUM>, and the first forward cliff sensor <NUM>, whilst the second front corner sensor assembly <NUM> includes the second forward proximity sensor <NUM>, the second side proximity sensor <NUM>, and the second forward cliff sensor <NUM>.

As shown in <FIG>, each of the front corner sensor assemblies <NUM>, <NUM> comprises a single circuit board, such that the forward proximity sensor, the side proximity sensor and the forward cliff sensor of a front corner sensor assembly are all mounted to the same circuit board. Specifically, the first front corner sensor assembly <NUM> comprises a first corner sensor circuit board <NUM> on which the first forward proximity sensor <NUM>, the first side proximity sensor <NUM>, and the first forward cliff sensor <NUM> are all mounted, and the second front corner sensor assembly <NUM> comprises a second corner sensor circuit board <NUM> on which the second forward proximity sensor <NUM>, the second side proximity sensor <NUM>, and the second forward cliff sensor <NUM> are all mounted. Combing three sensors onto a single circuit board simplifies the manufacture and assembly of the apparatus <NUM>.

The first corner sensor circuit board <NUM> and the second corner sensor circuit board <NUM> are both rigid-flex circuit boards. The term "rigid-flex circuit board" as used herein refers to a single circuit board that is hybrid of a flexible and rigid circuit board and that therefore comprises one or more flexible portions that provide an interconnect between rigid portions. The use of a rigid-flex circuit board simplifies the manufacture and assembly of these circuit boards as it provides that electronic components, including the individual sensors, can be mounted thereon when the circuit board is in a flat configuration with the circuit board then being subsequently reconfigured so that the sensors mounted thereon are at the required, different orientations. Each of the first corner sensor circuit board <NUM> and the second corner sensor circuit board <NUM> comprise a first rigid portion <NUM> on which the forward proximity sensor is mounted, a second rigid portion <NUM> on which the forward cliff sensor is mounted, a third rigid portion <NUM> on which the side proximity sensor is mounted, a first flexible portion <NUM> connecting the first rigid portion <NUM> to the second rigid portion <NUM>, and a second flexible portion <NUM> connecting the second rigid portion <NUM> to the third rigid portion <NUM>.

The first front corner sensor assembly <NUM> then further comprises a first corner circuit board frame <NUM> on which the first corner sensor circuit board <NUM> is mounted, with the first circuit board frame <NUM> being arranged to hold the first corner sensor circuit board <NUM> in a fixed configuration such that the relative positions of the sensors are fixed in the required orientations. Correspondingly, the second front corner sensor assembly <NUM> comprises a second corner circuit board frame <NUM> on which the second corner sensor circuit board <NUM> is mounted, with the second corner circuit board frame <NUM> being arranged to hold the second corner sensor circuit board <NUM> in a fixed configuration such that the relative positions of the sensors mounted thereon are fixed in the required, different orientations. The first corner sensor circuit board <NUM> is then mounted to the chassis <NUM> of the apparatus <NUM> by way of the first circuit board frame <NUM>, and the second corner sensor circuit board <NUM> is mounted to the chassis <NUM> of the apparatus <NUM> by way of the second circuit board frame <NUM>.

As noted above, the navigational sensor system <NUM> includes a plurality of contact or bump sensors that are arranged to detect impacts between the apparatus <NUM> and other objects. In the illustrated embodiment, the contact sensors include a plurality of forwardmost contact sensors <NUM> that are disposed behind a forward bumper <NUM> that is mounted to the front surface <NUM> of the cleaning assembly <NUM>, with each of the forwardmost contact sensors <NUM> then being arranged to detect displacement of the forward bumper <NUM> relative to the cleaning assembly <NUM>.

The forward bumper <NUM> is arranged to be displaceable relative to the cleaning assembly <NUM> in response to a force applied as a result of an impact on the bumper <NUM>. Specifically, the forward bumper <NUM> comprises a plurality of rigid segments <NUM> that are collectively arranged to extend laterally along the front surface <NUM> of the cleaning assembly <NUM>, with each of the plurality of rigid segments <NUM> being displaceable relative to the other of the plurality of rigid segments <NUM> in response to an applied force. To do so, the plurality of rigid segments <NUM> are connected by flexible joints <NUM>, and preferably resilient flexible joints. In the illustrated embodiment, these the flexible joints <NUM> are provided by living hinges. The term "living hinge" as used herein refers to a flexible joint made from the same material as rigid parts that it joins together. A forwardmost contact sensor <NUM> is then disposed beneath each of the plurality of rigid segments <NUM>, with each forwardmost contact sensor <NUM> being arranged to detect displacement of a corresponding rigid segment <NUM> of the forward bumper <NUM>. In the illustrated embodiment, each of the rigid segments <NUM> comprises a projection <NUM> that extends inwardly from the forward bumper <NUM> and that is arranged to contact the respective forwardmost contact sensor <NUM> when the rigid segment <NUM> is displaced longitudinally towards the body <NUM> of the apparatus <NUM>. This arrangement of the forward bumper <NUM> and the forwardmost contact sensors <NUM> provides that the forwardmost contact sensors <NUM> can be activated independently of one another, which in turn provides that the location of an impact on the forward bumper <NUM> can be accurately determined based on which of the forwardmost contact sensors <NUM> are activated by the impact.

In addition to extending along the front surface <NUM> of the cleaning assembly <NUM> the forward bumper <NUM> extends over and around the first and second front corners of the cleaning assembly <NUM>, and partially along both the first and second (i.e. left and right) sides <NUM>, <NUM> of the cleaning assembly <NUM>. Specifically, a first (i.e. left) end rigid segment 1114a of the bumper <NUM> extends around the first front corner of the cleaning assembly <NUM> and a second (i.e. right) end rigid segment 1114b of the bumper <NUM> extends around a second front corner of the cleaning assembly <NUM>. The first end rigid segment 1114a of the bumper <NUM> is arranged to be displaced by a force applied to the first front corner of the bumper <NUM> and the second end rigid segment 1114b of the bumper <NUM> is arranged to be displaced by a force applied to the second front corner of the bumper <NUM>.

The contact sensors also include a first plurality of shell contact sensors 1117a, 1117b disposed behind the outer shell <NUM>, with each of the first plurality of shell contact sensors 1117a, 1117b being arranged to detect longitudinal displacement of the outer shell <NUM> relative to the chassis <NUM>, and a second plurality of shell contact sensors 1118a, 1118b disposed behind the outer shell <NUM>, with each of the second plurality of shell contact sensors 1118a, 1118b being arranged to detect lateral displacement of the outer shell <NUM> relative to both the chassis <NUM> and the cleaning assembly <NUM>. The outer shell <NUM> is therefore arranged to be displaceable relative to the chassis <NUM> in both the longitudinal and lateral directions in response to a force applied as a result of an impact on the outer shell <NUM>. The apparatus <NUM> then further comprises a first biasing assembly <NUM> that is arranged to apply a restoring force to the outer shell <NUM> following a rearward displacement of the outer shell <NUM> in order to return the outer shell <NUM> to its initial longitudinal position with respect to the chassis <NUM>, and a second biasing assembly <NUM>, <NUM> that is arranged to apply a restoring force to the outer shell <NUM> following a lateral displacement of the outer shell <NUM> in order to return the outer shell <NUM> to its initial lateral position with respect to the chassis <NUM>.

In the illustrated embodiment, the first plurality of shell contact sensors 1117a, 1117b are disposed behind the front surface <NUM> of the outer shell <NUM> and are each arranged to detect longitudinal displacement of an adjacent portion of the front surface <NUM> of the outer shell <NUM> toward the chassis <NUM>. Specifically, the first plurality of shell contact sensors comprise a first front shell contact sensor 1117a disposed adjacent to a first front corner of the outer shell <NUM> and a second front shell contact sensor 1117b disposed adjacent to a second front corner of the outer shell <NUM>. This arrangement of shell contact sensors <NUM>, 1117b behind the front corners of the outer shell <NUM> provides that the location of an impact on the front of the outer shell <NUM> can be determined based on which of the front shell contact sensors 1117a, 1117b are activated by the impact.

The first biasing assembly then comprises two biased arms <NUM> that are rotatably mounted on respective pins (not shown) located in the right and left front corners of the chassis <NUM>. The pins extend vertically such that each of the arms <NUM> is rotatable about a vertical axis between a biased and an actuated position. The arms <NUM> extend generally inwards towards the longitudinal axis of the body <NUM>, with front shell contact sensors 1117a, 1117b disposed behind a distal end of the respective arm <NUM>. In their biased position, each arm <NUM> pushes forwardly against the inside of the front surface <NUM> of the outer shell <NUM>, holding the outer shell <NUM> in its initial position forward of the chassis <NUM>. When an impact occurs on the front of the outer shell <NUM>, the outer shell <NUM> is displaced rearwardly against the biasing force of a corresponding torsion spring (not shown), moving at least one of the arms <NUM> to the actuated position in which the distal end of the arm <NUM> activates the respective front shell contact sensors 1117a, 1117b. The arms <NUM> then return to the biased position upon the removal of the longitudinally acting force, returning the outer shell <NUM> to its initial position.

The second plurality of shell contact sensors 1118a, 1118b then comprise at least one shell contact sensor disposed behind the first side surface <NUM> of the outer shell <NUM> and at least one shell contact sensor disposed behind the second side surface <NUM> of the outer shell <NUM>. Specifically, the second plurality of shell contact sensors comprise a first (i.e. left) side shell contact sensor 1118a mounted to the first side <NUM> of the cleaning assembly <NUM> and a second (i.e. right) side shell contact sensor 1118b mounted to the second side <NUM> of the cleaning assembly <NUM>. The frontmost portions of both the first side surface <NUM> and the second side surface <NUM> of the outer shell <NUM> then also extend forward of the front surface <NUM> of the outer shell <NUM> so as to cover these contact sensors provided on the sides <NUM>, <NUM> of the cleaning assembly <NUM>. The first side shell contact sensor 1118a is therefore arranged to detect lateral displacement of the first side surface <NUM> of the outer shell <NUM> towards the cleaning assembly <NUM>, whilst the second side shell contact sensor 1118b is arranged to detect lateral displacement of the second side surface <NUM> of the outer shell <NUM> towards the cleaning assembly <NUM>.

In the illustrated embodiment, the second biasing assembly comprises a centering device <NUM> centrally mounted towards the front of the chassis <NUM> and that is biased into a laterally central position by compression springs <NUM> that are disposed on either lateral side of the centering device <NUM>. The outer shell <NUM> is then mounted to the chassis <NUM> via the centering device <NUM> such that the outer shell <NUM> is held in a laterally central position with respect to the chassis <NUM>. The centering device <NUM> then also functions to return the outer shell <NUM> to the laterally central position following an impact that causes a lateral displacement of the outer shell <NUM> from the central position.

The above described arrangements of the contact sensors allows the apparatus <NUM> to accurately determine the location of a contact made by either of the frontmost portions of the apparatus <NUM>, i.e. by each of the cleaning assembly <NUM> and the front <NUM> of the outer shell <NUM>, whilst also enabling the detection of contacts made by the sides of the cleaning assembly <NUM> and/or the body <NUM> of the apparatus <NUM>. Furthermore, combining the outputs of the contact sensors arranged in this way allows the apparatus <NUM> to more effectively determine a manoeuvre that will avoid obstacles contacted by the apparatus <NUM>.

It will be appreciated that individual items described above may be used on their own or in combination with other items shown in the drawings or described in the description and that items mentioned in the same passage as each other or the same drawing as each other need not be used in combination with each other. In addition, the expression "means" may be replaced by actuator or system or device as may be desirable. In addition, any reference to "comprising" or "consisting" is not intended to be limiting in any way whatsoever and the reader should interpret the description and claims accordingly.

Claim 1:
An autonomous surface cleaning apparatus (<NUM>) comprising:
a body (<NUM>);
a drive system (<NUM>) carried by the body (<NUM>) and configured to move the autonomous surface cleaning apparatus across a surface; and
a cleaning assembly (<NUM>) disposed at a front of the body;
a housing defining a suction chamber (<NUM>) having a suction chamber opening in a bottom surface of the cleaning assembly (<NUM>) and a suction channel (<NUM>) extending from the suction chamber to a suction channel opening provided in a first side surface of the cleaning assembly; and
a side suction nozzle (<NUM>) mounted to an extension and retraction assembly that is arranged to allow the side suction nozzle to be moved between an extended position in which the side suction nozzle extends away from the suction channel opening and a retracted position;
characterised in that the side suction nozzle (<NUM>) comprises a first resilient blade (<NUM>) and a second resilient blade (<NUM>), the first resilient blade being arranged such that a surface of the first resilient blade is substantially forward facing and the second resilient blade being arranged such that a surface of the second resilient blade is substantially downward facing.