Patent Description:
A robotic vacuum cleaner forms of a self-propelling unit provided with a drive arrangement comprising a control system configured to control a movement of the robotic vacuum cleaner along a surface to be cleaned. The control system may comprise one or more sensors providing input to assist in controlling the movement of the robotic vacuum cleaner. A vacuum producing unit of the robotic vacuum cleaner is arranged in fluid communication with an opening of a nozzle inlet facing the surface to be cleaned. Debris sucked or otherwise propelled into the opening is directed into a debris receptacle of the robotic vacuum cleaner. The debris receptacle is emptied, or replaced, when filled with debris to a certain degree.

Since a robotic vacuum cleaner is to move freely about a surface to be cleaned it would be limited in its movements by an electric cord. Thus, a robotic vacuum cleaner is battery powered and the cleaning capability of a robotic vacuum cleaner has to be designed with the capacity of the on-board battery in mind. Accordingly, the drive arrangement, the capacity of the vacuum producing unit, the use of various rotating brushes, etc. affect consumption of electric power and thus, the design of a robotic vacuum cleaner.

Thus, the vacuum, or suction, produced by the vacuum producing unit should be produced with as low electric energy consumption as possible while maintaining good cleaning efficiency.

Also, todays cleaners assume likewise spreading of particles over the length of the nozzle width and are thereby having openings in the nozzle to allow for this. This may reduce the overall cleaning performance since opening up the nozzle leads to air leakage.

It is an object of the present invention to provide a robotic vacuum cleaner, a nozzle and a method having potential to effectively clean fine dust and particles as well as cleaning larger debris than dust, such larger particles and small stones, into the robotic vacuum cleaner.

<CIT> discloses a robotic vacuum cleaner according to the preamble of independent claim <NUM> having potential to produce a suction force sufficient to draw also larger debris than dust, such as sand and small stones, into the robotic vacuum cleaner with low energy consumption.

The robotic vacuum cleaner has a nozzle inlet comprises the base portion extending at the first level extending substantially in parallel with the surface to be cleaned. The channel formed between distance members has the delimiting surface extending at the second level, a larger air flow is produced in the channel by the vacuum producing unit. The larger airflow and space provided in the channel assists in drawing debris larger than dust into the opening.

The present invention is described in the independent claims.

According to an aspect of the invention, a robotic vacuum cleaner comprising a housing, a drive arrangement being configured to drive the vacuum cleaner along a surface to be cleaned, a vacuum producing unit, a debris receptacle, and a nozzle inlet arranged in a portion of the housing facing the surface to be cleaned. The nozzle inlet comprises a frame structure forming an opening, the opening being arranged in fluid communication with the debris receptacle and the vacuum producing unit being arranged in in fluid communication with the opening. The frame structure has a leading edge portion and opposite thereto a trailing edge portion, the leading edge portion and the trailing edge portion border to the opening. The frame structure comprises a base portion extending substantially in parallel with the surface to be cleaned. The first level is arranged closer to the surface to be cleaned than the second level.

Since the nozzle inlet comprises the base portion extending at the first level and the channel formed between the distance members has the delimiting surface extending at the second level, a larger air flow is produced in the channel by the vacuum producing unit than at the base portion and the distance members at the first level.

It is understood that the first level is arranged closer to the surface to be cleaned than the second level in use of the robotic vacuum cleaner. The robotic vacuum cleaner may be a self-propelling unit. The drive arrangement may comprise one or more wheels, of which at least one wheel is directly or indirectly driven by an electric drive motor. The drive arrangement may further comprise a control system configured to control the electric drive motor to move the robotic vacuum cleaner about the surface to be cleaned. The control system may comprise one or more sensors to provide input assisting in controlling the movement of the robotic vacuum cleaner. The at least one sensor may be of one or more different kinds, such as e.g. an infrared sensor, a laser sensor, an ultrasonic sensor, or a contact sensor. The vacuum producing unit may comprise a fan driven by an electric fan motor. The opening may be arranged in fluid communication with the debris receptacle via a debris conduit system. The vacuum producing unit may be arranged in fluid communication with the opening via the debris conduit system and optionally also the debris receptacle, i.e. the vacuum producing unit in some embodiments may create a suction from the opening of the nozzle inlet via the debris conduit system to the debris receptacle. In use of the robotic vacuum cleaner the leading edge portion of the frame structure travels ahead of the trailing edge portion in most cleaning situations. The robotic vacuum cleaner may comprise one or more rotatable brushes assisting in propelling debris towards, or into, the opening of the nozzle inlet. The rotatable brushes may be driven by one or more electric brush motors.

Besides controlling the drive motor, the control system may also control the fan motor and/or the one or more brush motors. The robotic vacuum cleaner may comprise one or more rechargeable batteries configured to power the drive arrangement including the control system and the various electric motors.

According to the invention robotic vacuum cleaner comprises a housing. The robotic vacuum cleaner comprises a drive arrangement being configured to drive the vacuum cleaner along a surface to be cleaned. The robotic vacuum cleaner comprising a vacuum producing unit, a debris receptacle. The robotic vacuum cleaner comprising a nozzle arranged in the housing facing the surface to be cleaned. The nozzle comprises a front edge, and a suction opening. The suction opening being arranged in fluid communication with the debris receptacle and the vacuum producing unit. The front edge comprises an aperture.

The opening is elongated extending in a direction perpendicular to the drive direction of the robotic vacuum cleaner, and the aperture is arranged adjacent to one end of the elongated opening.

The aperture is arranged at the right or left side of the nozzle.

One aperture is arranged at the right side of the nozzle. A second aperture is arranged at the left side of the nozzle.

A side brush is arranged at one end of the nozzle. The aperture is arranged at the same end.

The aperture is arranged adjacent to the end of the bristles of the side brush.

<FIG> illustrate a top view and a perspective bottom view of a robotic vacuum cleaner <NUM> according to embodiments. The robotic vacuum cleaner <NUM> comprises a housing <NUM>, a drive arrangement <NUM> configured to drive the vacuum cleaner <NUM> along a surface to be cleaned, a vacuum producing unit <NUM> (schematically illustrated), a debris receptacle <NUM>, and a nozzle <NUM> arranged in a portion of the housing <NUM> facing the surface to be cleaned.

The drive arrangement <NUM> ensures that the robotic vacuum cleaner is a self-propelling unit. The drive arrangement <NUM> comprises two wheels <NUM> driven by electric drive motors <NUM>, (schematically illustrated). The drive arrangement <NUM> comprises non-driven supporting wheels <NUM>. The drive arrangement <NUM> also comprises a control system <NUM> (schematically illustrated) configured to control the electric drive motors <NUM>. The control system <NUM> comprises sensors <NUM> assisting in controlling the movement of the robotic vacuum cleaner <NUM>.

The debris receptacle <NUM> is arranged in the housing <NUM>. One side portion <NUM> of the debris receptacle <NUM> forms an outer surface portion of the robotic vacuum cleaner <NUM>. Thus, the debris receptacle <NUM> is easily accessible and removable by a user for emptying thereof. The nozzle <NUM> is elongated and extends in parallel with a rotation axis of the two driven wheels <NUM>. Thus, the nozzle extends across a travelling direction of the robotic vacuum cleaner <NUM> for broad cleaning coverage.

The nozzle <NUM> comprises a frame structure <NUM> forming an opening <NUM>. The opening <NUM> is arranged in fluid communication with the debris receptacle <NUM> and the vacuum producing unit <NUM> is arranged in fluid communication with the opening <NUM>. Thus, the vacuum producing unit <NUM> may produce a suction force at the opening <NUM> to transport debris from an area around the opening <NUM> via a debris conduit system to the debris receptacle <NUM>.

The robotic vacuum cleaner <NUM> comprises a rotatable side brush <NUM> comprising bristles <NUM> extending radially to a rotation axis <NUM> of the rotatable side brush <NUM> and extending substantially in parallel with the surface to be cleaned. The bristles <NUM> extend to, and beyond, a lateral portion <NUM> of the housing <NUM> and over a side portion <NUM> of the nozzle <NUM>. The bristles <NUM> have been illustrated schematically in <FIG>. In practice the bristles <NUM> may be considerably thinner than illustrated and the rotatable side brush <NUM> may be provided with a considerably larger number of bristles <NUM> than illustrated. The robotic vacuum cleaner <NUM> comprises a rotatable elongated brush roll <NUM> arranged inside the housing <NUM> and extending along the nozzle <NUM> including the side portion <NUM> of the nozzle <NUM>.

<FIG> illustrates the nozzle <NUM> of the robotic vacuum cleaner <NUM> shown in <FIG> in greater detail. In these embodiments, the nozzle <NUM> is comprised in a removable lid <NUM> configured to be positioned in the housing of the robotic vacuum cleaner <NUM>. In alternative embodiments, the nozzle <NUM> may be formed directly in the housing.

As mentioned above, the nozzle <NUM> comprises a frame structure <NUM> forming an opening <NUM>. The frame structure <NUM> has a leading edge portion (front edge) <NUM> and opposite thereto a trailing edge portion <NUM>. The leading edge portion <NUM> and the trailing edge portion <NUM> border to the opening <NUM>. The frame structure <NUM> comprises a base portion <NUM>, which in use of the robotic vacuum cleaner extends substantially in parallel with the surface to be cleaned at a first level.

The leading edge portion <NUM> comprises at least two distance members <NUM> forming there between a channel <NUM> to the opening <NUM>. In these embodiments the leading edge portion <NUM> comprises five distance members <NUM>, <NUM>'. In alternative embodiments the leading edge portion may comprise less than five distance members, e.g. three or four distance members, or more than five distance members, e.g. <NUM> - <NUM> distance members, alternatively no distance members.

<FIG> illustrates a partial enlargement of the nozzle <NUM> shown in <FIG>. The channel <NUM> has a delimiting surface <NUM> extending at a second level substantially in parallel with the first level. In use of the robotic vacuum cleaner the first level is arranged closer to the surface to be cleaned than the second level.

If no distance members are used the delimiting surface <NUM> extends all along the leading edge portion <NUM>.

In this embodiment, each distance member <NUM> has a substantially triangular cross section extending substantially in parallel with the first plane. Each distance member <NUM> extends between the first level and the second level with a top <NUM> of the substantially triangular cross section facing outwardly from the opening <NUM> and a base <NUM> of the substantially triangular cross section extending in parallel with the opening <NUM>. Side surfaces <NUM> of the distance members <NUM> extend substantially from the top <NUM> to the base <NUM> of the substantially triangular cross section. At least a portion of the side surfaces <NUM> extend substantially perpendicularly to the base portion <NUM> and to the delimiting surface <NUM> of the channel <NUM>.

The trailing edge portion <NUM> forms part of the base portion <NUM> and part of the side portion <NUM> of the nozzle <NUM>. In these embodiments the side portion <NUM> extends at the second level. Accordingly, at the base portion <NUM> the trailing edge portion <NUM> extends at the first level and at the side portion <NUM> the trailing edge portion <NUM> extends at the second level. In alternative embodiments the entire trailing edge portion <NUM> may extend at the first level.

It is clearly visible in <FIG> that the delimiting surface <NUM> extends at a different level than the base portion <NUM>, i.e. at the second level. Also at a lateral end <NUM> of the nozzle inlet <NUM> and at the trailing edge portion <NUM> of the side portion <NUM>, the side portion <NUM> may extend at the second level. Alternatively, the lateral end <NUM> and the trailing edge portion <NUM> of the side portion <NUM> may extend at the first level. As also clearly visible in <FIG>, the leading edge portion <NUM> comprises a number of portions extending at the second level, namely delimiting surfaces <NUM> of channels formed between the distance members <NUM> as well at end portions of the opening <NUM> next to the outer distance members <NUM>'.

The nozzle <NUM> comprises at least one cross brace <NUM> extending from at least one of the distance members <NUM> to the trailing edge <NUM>. The at least one cross brace <NUM> forms part of the base portion <NUM> and extends at the first level.

The substantially triangular cross section of two adjacent distance members <NUM> reduce the cross section of the channel <NUM> formed there between towards the opening <NUM>. Thus, one of the side surfaces <NUM> of a first of the at least two distance members <NUM> and one thereto opposing side surface <NUM> of a second of the at least two distance members <NUM> forms a funnel towards the opening <NUM>.

A bottom surface <NUM> of each of the distance members <NUM> forms a smooth transition between the second level and the first level.

<FIG> illustrates an enlargement of the encircled area V of <FIG> with the rotatable side brush removed for the sake of clarity. As discussed in connection with <FIG>, the robotic vacuum cleaner <NUM> comprises a rotatable elongated brush roll <NUM> arranged inside the housing <NUM> and extending along the nozzle inlet <NUM>. The rotatable elongated brush roll <NUM> comprises radially extending members <NUM>', <NUM>" extending from inside the housing <NUM> at least to the first level. In these embodiments, a first radially extending member <NUM>' of the radially extending members comprises a resilient lip and a second radially extending member <NUM>" of the radially extending members comprises bristles. Alternatively, all radially extending members <NUM>', <NUM>" may comprise resilient lips or bristles.

In use of the robotic vacuum cleaner <NUM>, the base member <NUM> at the first level may extend at a distance of less than <NUM> from the surface to be cleaned. In use of the robotic vacuum cleaner <NUM>, the base portion <NUM> may be that part of the nozzle <NUM>, which extends closest to the surface to be cleaned. In use of robotic vacuum cleaner <NUM>, the nozzle <NUM> may form part of the housing <NUM> or alternatively, may be attached to the housing <NUM>, and wherein the base portion <NUM> may extend closest to the surface to be cleaned of the nozzle <NUM> and the housing <NUM>.

<FIG> illustrates a robotic vacuum cleaner <NUM> moving along a wall. The enlarged portion illustrates a particle <NUM> in front of the robotic vacuum cleaner which is too large to enter between the leading edge portion/front edge and the surface to be cleaned. The particle <NUM> will stay in front of the leading edge portion. During turning of the robotic vacuum cleaner the particle will move relative to the leading edge portion towards the outside of the robotic vacuum cleaner. An aperture <NUM> (as described in Fig above) is arranged at the end of the nozzle. Since the aperture <NUM> provides a larger opening the particle may pass and enter the nozzle and further to the dust receptacle.

A second particle <NUM> is also illustrated. This particle is moved be the bristles of the side brush towards the nozzle <NUM>. If the particle is too big to enter between the leading edge portion/front edge and the surface to be cleaned. The particle <NUM> will stay in front of the robotic vacuum cleaner or leading edge portion.

The aperture <NUM> provides a larger opening and the particle may pass and enter the nozzle and further to the dust receptacle.

<FIG> illustrates the bottom side of a robotic vacuum cleaner, such as one described above. The robotic vacuum cleaner <NUM> comprises a nozzle having a front edge <NUM> and an opening <NUM>. Inside the opening, a rotatable brush <NUM> may be arranged. The robotic vacuum cleaner also comprises a side brush <NUM>. The front edge comprises an aperture <NUM>.

<FIG> illustrates the front of a robotic vacuum cleaner, such as one described above, eg in <FIG>. The front shows sensors <NUM> connected to a control system as described above. The front edge <NUM> comprises a first section S1 arranged with one distance to the surface to be cleaned, and a second section S2 with a second distance to the surface to be cleaned which is higher than the first distance. The second section S2 comprise an aperture (<NUM>). The second section S2 thereby provides a larger opening for allowing larger particles to enter the nozzle and the robotic vacuum cleaner.

<FIG> illustrates a robotic vacuum cleaner, such as one described above from above and a moving pattern during cleaning. The robotic vacuum cleaner comprises a side brush arranged at the side always facing the outside of the turning. A particle <NUM> is trapped in front of the robotic vacuum cleaner because it is too large to pass between the front edge and the surface to be cleaned. When turning the robotic vacuum cleaner the particle <NUM> will move relative the robotic vacuum cleaner, along the front edge towards the outside of the turn. By having an aperture <NUM> with a height larger than the height over the rest of the front edge the particle <NUM> may pass the aperture and thereby be cleaned.

<FIG> illustrates front of a robotic vacuum cleaner <NUM>, such as one described above. The robotic vacuum cleaner in this embodiment do not have a side brush, however sensors, drive means, control means etc are similar to a robotic vacuum cleaner as described above, e.g. in <FIG>. The robotic vacuum cleaner comprises a front edge <NUM> having a first section S1 and a second section S2. In this embodiment the first section mainly extends between two parts of the second section. The second section comprises an aperture, in this embodiment each part of the second section comprises an aperture <NUM>. The second section and the aperture <NUM> is arranged in each end of the opening <NUM> (see <FIG>).

<FIG> illustrates front of a robotic vacuum cleaner <NUM>, such as one described above. The figure illustrates a preferred moving path of a robotic vacuum cleaner of the claimed type, especially when no side brush is attached to the robotic vacuum cleaner. A particle <NUM> trapped in front of the robotic vacuum cleaner due to that its size is too big to pass between the front edge and the surface to be cleaned, eg pass in the first section S1. An S-form moving pattern may make it possible to clean even these larger particles. When turning the robotic vacuum cleaner the particle <NUM> will move along the front edge towards the outside of the turn. By having an aperture large enough to allow the particle <NUM> to pass the particle <NUM> will be cleaned.

If the moving pattern of the robotic vacuum cleaner during cleaning is based on turning always in the same direction, e. g spiral cleaning, it may be enough with only one aperture arranged at the side always facing the outside of the curve. If the moving pattern during cleaning is turning at both left and right, e.g. random cleaning, it is preferred to arrange one aperture at each side of the robotic vacuum cleaner, e.g. both sides of the elongated opening.

The robotic vacuum cleaner (<NUM>) according to the invention comprises a housing (<NUM>). The robotic vacuum cleaner comprising a drive arrangement (<NUM>) being configured to drive the vacuum cleaner (<NUM>) along a surface to be cleaned. The robotic vacuum cleaner comprising a vacuum producing unit (<NUM>), a debris receptacle (<NUM>). The robotic vacuum cleaner comprising a nozzle arranged in the housing (<NUM>) facing the surface to be cleaned. The nozzle comprises a front edge, and a suction opening (<NUM>). The suction opening (<NUM>) being arranged in fluid communication with the debris receptacle (<NUM>) and the vacuum producing unit (<NUM>). The front edge comprises an aperture (<NUM>).

The opening is elongated extending in a direction perpendicular to the drive direction of the robotic vacuum cleaner. The aperture is arranged adjacent to one end of the elongated suction opening.

The aperture is arranged at the right or left side of the nozzle and/or right or left side of the elongated suction opening.

A side brush (<NUM>) is arranged at one end of the nozzle The aperture is arranged at the same end.

This invention should not be construed as limited to the embodiments set forth herein. A person skilled in the art will realize that different features of the embodiments disclosed herein may be combined to create embodiments other than those described herein, without departing from the scope of the present invention, as defined by the appended claims. Although the invention has been described with reference to example embodiments, many different alterations, modifications and the like will become apparent for those skilled in the art. Therefore, it is to be understood that the foregoing is illustrative of various example embodiments and that the invention is defined only by the appended claims.

Claim 1:
A robotic vacuum cleaner (<NUM>) comprising a housing (<NUM>), a drive arrangement (<NUM>) being configured to drive the vacuum cleaner (<NUM>) along a surface to be cleaned, a vacuum producing unit (<NUM>), a debris receptacle (<NUM>), and a nozzle (<NUM>) arranged in a portion of the housing (<NUM>) facing the surface to be cleaned, wherein the nozzle (<NUM>) comprises an elongated suction opening (<NUM>), the suction opening (<NUM>) being arranged in fluid communication with a the debris receptacle (<NUM>) and the vacuum producing unit (<NUM>) being arranged in fluid communication with the suction opening (<NUM>), wherein a front edge (<NUM>) being arranged along one side of the elongated suction opening (<NUM>),and between the front edge and the surface to be cleaned an air channel (<NUM>) is created, wherein a side brush (<NUM>) is arranged at one end of the nozzle, characterised in that, the front edge (<NUM>) comprises an aperture (<NUM>), which is arranged at the same end of the nozzle where the side brush (<NUM>) is arranged.