Cleaning device with an improved housing

Abstract

A cleaning device for cleaning a vertical surface (50) when moving in a forward direction (R) comprises: a pick-up unit (100) and a housing (300\). The pick-up unit (100) includes a cleaning roller (110) to pick-up dirt from the surface (50), a scraper (122) to take off the picked-up dirt from the cleaning roller (110) during rotation of the cleaning roller (110), and a channel (162) for carrying away the wet dirt. The housing (300) provides a closure for the cleaning device and a support for the pick-up unit (100). The housing (300) comprises a first portion (310) in the forward direction (R) and a second portion (320) opposite to the forward direction (R). The pick-up unit (100) is arranged between the first portion (310) and the second portion (320), wherein the first portion (310) is adapted to accommodate at least partially the scraper (122) and the channel (162), and wherein the first portion (310) leaves a gap of predetermined height (H) to the surface (50) which is greater than a radius of the cleaning roller (110).

Description

[0001] The present invention relates to a cleaning device and a method for manufacturing a cleaning device and, in particular, to a cleaning robot, a spring-loaded scraper for the cleaning robot, a floating cleaning unit for the cleaning robot, a channel system of the cleaning robot, and a housing structure for the cleaning robot.BACKGROUND

[0002] Conventional cleaning devices and particularly cleaning robots include fixed scrapers to pick up dirt from a cleaning roller. In addition, sewage water channels are provided to transport sewage into a tank. However, the fixed scrapers provide an insufficient scraping effect on the cleaning roller, especially if the dirt is wet. Therefore, there is a demand for alternative scrapers that improve the pick-up efficiency of (wet) dirt from a cleaning roller.

[0003] Conventional cleaning devices may further have a cleaning unit which is either fixedly mounted to the cleaning device or have a suction unit that is floatingly mounted to the cleaning device. The conventional cleaning devices may further have cleaning rollers that are fixedly mounted to their housings and may comprise textiles pads and rotating pads for cleaning a surface. However, also these arrangements, provide only insufficient cleaning results, because there is no balanced pressure applied on the surface to be cleaned. The pressure is either too high or too low or is applied only on one side, which results in turn into insufficient cleaning results. Therefore, there is a further demand for improved cleaning units that provides better cleaning results.

[0004] Conventional cleaning robots have dirty water channel systems to transport the wet dirt or sewage from the cleaning roller to a tank. However, the dirty water channel systems provide acceptable results only for particular situations such as for horizontal surfaces. In particular, the conventional water channel systems are insufficient for cleaning robots that shall clean also vertical surfaces and that shall make turns on the vertical surfaces. In conventional cleaning devices, the sewage is only transported into the sewage tanks for particular orientations like on top of a horizontal surface. Therefore, there is further demand for cleaning devices that can clean vertical surfaces while transporting continuously the sewage reliably into the tank and thus achieve a high cleaning effect - even on vertical surface or underneath a horizontal surface.

[0005] Other conventional cleaning robots rely only on vacuum suction systems for the transport of the sewage from a cleaning roller to the tank. These cleaning robots need a suction system at the cleaning roller, which makes the cleaning device more costly and more error prone. Therefore, also for these cleaning devices, there is a demand for improvement for the sewage transport of sewage, which should be transported continuously and reliably, also on vertical surface or underneath a horizontal surface.

[0006] Other conventional cleaning robots have a housing with high side walls to clean also near a surface frame. When the conventional cleaning devices relies on a suction system, the high side walls prevent a high suction effect. Thus, conventional cleaning devices have to compromise both effects: high suction effect and a possible cleaning close frames of a window or a door or other obstacles. One conventional solution is to completely uncover the cleaning roller, which may allow a cleaning close to a frame. However, these devices are still not suitable to clean vertical surfaces when moving up and down the surfaces, because the sewage transport is not possible, or a suction system is needed. An alternative conventional solution is a complete enclose of the cleaning roller in the housing, which, however, makes the cleaning device not usable for a clean near frames or other obstacles.

[0007] Therefore, there is a demand for a cleaning device which, on the one hand, provides a sufficiently high cleaning efficiency and, on the other hand, is able to clean the proximity of frames (e.g., of windows).SUMMARY OF THE INVENTION

[0008] At least some of the above-mentioned problems are solved by a cleaning device according to claim 1 and a method for manufacturing a cleaning device according to claim 15. The dependent claims refer to further advantageous realizations for the subject matters of the independent claims.

[0009] The present invention relates to a cleaning device for cleaning a vertical surface when moving in a forward direction, wherein the cleaning device comprises: a pick-up unit with a cleaning roller to pick-up dirt from the surface, a scraper to take off the picked-up dirt from the cleaning roller during rotation of the cleaning roller, and a channel for carrying away the wet dirt; and a housing providing a closure for the cleaning device and a support for the pick-up unit, wherein the housing comprises a first portion in the forward direction and a second portion opposite to the forward direction.

[0010] The pick-up unit may be arranged between the first portion and the second portion (or rear portion). The first portion may be adapted to accommodate at least partially the scraper and the channel. The first portion leaves a gap (clearance) of predetermined height to the surface which is greater than a radius of the cleaning roller. The gap may be open at the forward side of the housing, e.g. over a complete lateral width (perpendicular to a moving direction). Thus, the cleaning device may move partially over an obstacle in front of the cleaning device.

[0011] Optionally, the gap of predetermined height is in a range from 10 mm to 50 mm or between 20 mm and 30 mm or between 20 mm and 40 mm or about 25 mm.

[0012] Optionally, the cleaning device comprises a sensor unit adapted to detect an obstacle. The sensor unit may include at least one of the following sensors: optical sensor, a mechanical sensor, a switch, a light gate, an ultrasonic sensor, a current sensor for an electric current consumed by a drive unit for the cleaning roller. The obstacle may be one of the following: a frame, an edge of the surface, a decoration element, a window handle, a door handle, a strip, an edge of the surface.

[0013] Optionally, the cleaning device comprises: a drive unit for moving the cleaning device; and a control unit for controlling the drive unit based on the sensor data from the sensor unit to clean the vertical surface close to the obstacle.

[0014] Optionally, the cleaning roller is exposed at the gap of predetermined height to allow the roller to get in touch with the obstacle.

[0015] Optionally, when the sensor unit includes the current sensor, the control unit may be configured to detect or to confirm the obstacle based a detection of amplitude changes of the electric current values or a comparison of the electric current values with one or more thresholds.

[0016] Optionally, when the sensor unit includes the mechanical sensor which is adapted to measure pressure values exerted onto the pick-up unit from the obstacle, the control unit may be is configured to detect or to confirm the obstacle based on the pressure values received from the mechanical sensor.

[0017] Optionally, when the mechanical sensor or the sensor unit includes a mechanical switch, the control unit may be configured to cause one or more of the following: to reverse the cleaning device (e.g. when the cleaning roller has lost contact with vertical surface or the obstacle is hit), to perform a turn of the cleaning device, to turn off the pick-up unit (e.g. when the edge was detected as obstacle, or the cleaning roller has lost contact with vertical surface).

[0018] Optionally, the cleaning device comprises: a mounting for the pick-up unit adapted to press the pick-up unit with a predetermined pressure on the surface to enable a floating pick-up unit. The first portion and the second portion of the housing are adapted to provide a guidance for the floating pick-up unit (e.g. by a sliding edge).

[0019] Optionally, the housing provides between the first portion and the second portion a recess for the pick-up unit (e.g. when viewed from a lateral side). The recess may be open on one lateral side. The pick-up unit may comprise a support frame mounted to the housing by the mounting and providing a support for the cleaning roller. The support frame may close flush the open lateral side of the recess. The support frame may form a sliding edge with the housing to enable a linear movement of the pick-up unit.

[0020] Optionally, the cleaning device comprises a main tank for sewage arranged on a lateral side of the cleaning roller to allow the pick-up unit to pick-up wet dirt from the surface and to collect the sewage. The open lateral side of the recess in the housing is opposite to the side where the main tank is arranged.

[0021] Optionally, the cleaning device comprises a second scraper, a holding structure, and at least one biasing device. The second scraper takes off the picked-up dirt from the cleaning roller during rotation of the cleaning roller. The holding structure holds the scraper and the second scraper. The holding structure is configured to allow a movement (e.g. a linear movement) of each of the scraper and the second scraper towards the cleaning roller. The at least one biasing device exerts a bias force on the linear movement of the scraper and the second scraper towards the cleaning roller.

[0022] Optionally, the cleaning device include again a vacuum unit to generate a vacuum in a vacuum chamber, wherein the vacuum and the vacuum chamber may be adapted to hold the cleaning device at the vertical wall and / or to hold the cleaning device underneath a horizontal wall.

[0023] Optionally, this cleaning device include again a suction unit and a suction channel. The control unit can be adapted to control the suction unit and the drive unit based on the sensor data to move up and down the vertical wall or underneath a horizontal wall.

[0024] Further embodiments relate to a cleaning device for a vertical surface. The cleaning device comprises: a cleaning roller configured to rotate to pick-up dirt from the surface; a first scraper configured to take off dirt in a first angular range of the cleaning roller; a second scraper configured to take off dirt in a second angular range of the cleaning roller; and a holding structure to hold the first scraper in the first angular range and the second scraper in the second angular range.

[0025] The first angular range includes a first angle with the surface between 90° and 180°, preferably between 125° and 145° or about 135°. The second angular range includes a second angle with the surface between 0° and 90°, preferably between 20° and 40° or about 30°. The first angle and the second angle are measured in a same coordinate frame.

[0026] The definition of the "cleaning device for a vertical surface" shall be construed in that the cleaning device is suitable and designed to move up and down vertical surfaces and not only along horizontal surfaces. Therefore, the cleaning device shall be able to move up on vertical surfaces while cleaning the vertical surface. However, the cleaning device may also clean horizontal surfaces from underneath or from above and also usual floors. It is understood that the cleaning device could also clean inclined surfaces. The vertical direction shall be understood as the direction of gravity.

[0027] The "surface" may be any surface on which a cleaning robot can be moved and may be made of various materials including glass, stone, tiles, ceramics, carpet or carpeting, wood etc.

[0028] Although the term "scraper" shall be construed broadly, a scraper should be distinguished from a sealing element, which does not scrape or remove dirt form the cleaning roller but seals a contact to the cleaning roller. The sealing is achieved, e.g., by moisture (which is not removed) on the cleaning roller. The cleaning roller is driven by a motor and may rotate during cleaning in a forward direction, i.e. it supports a forward motion of the cleaning device.

[0029] It is further understood that scrapers take off dirt in angular ranges, not only at one particular angle. The angular ranges may depend on an applied pressure onto the cleaning roller and / or a stiffness of the cleaning roller and may cover a range of 5° or 10° or 20°.

[0030] The term "dirt" can refer to dry dirt and / or wet dirt which can be collected as sewage. Thus, the "dirt" may include all kinds of dirt which can be picked up by a cleaning robot. The term "lateral" shall refer to the axial direction (either the left-hand side or right-hand side) of the cleaning roller that has a rotational axis. This axis defines the axial direction. The "radial" direction may thus be defined with respect to the radius of the cleaning roller.

[0031] Optionally, the holding structure is configured to allow a movement of the first scraper and / or of the second scraper towards the cleaning roller. The movement is at least one of the following: a linear movement, a pivotal movement, a curved movement, a circular movement (e.g. along a circular section). Therefore, the scrapers may change its position and / or its orientation with respect to the cleaning roller. The path of the movement may at least partially go in a radial direction.

[0032] Optionally, the cleaning device comprises at least one biasing device to exert a bias force for the linear movement of one or both of the two scrapers towards the cleaning roller (e.g. a pressure is applied by the scrapers).

[0033] Optionally, the bias force exerted by the at biasing device is in the range of 15 N to 30 N or about 22 N.

[0034] Optionally, the first scraper and the second scraper include at least one of the following: a plate-shaped scraper, a roller scraper, a rigid scraper, a curved scraper, a V-shaped scraper, or any other shape which is suitable to remove (wet) dirt from the cleaning roller. The first scraper and / or the second scraper may include each a scraping strip at an edge to contact the cleaning roller and to take off the picked-up dirt from the cleaning roller. This edge may be of particular advantage for plate-shaped scraper(s). The roller scraper may include (each) a roller which may be configured to counter rotate to the cleaning roller to take off dirt from the cleaning roller.

[0035] The term "plate-shaped" may be understood in that it forms essentially a planar element having two opposite surfaces, which may be flat or plane, but may also be curved. The plate-shaped scraper can also be bent or curved but may provide a certain stiffness in order to apply a predetermined pressure on the cleaning rollers. The roller scraper is a rotatable roller that gets into contact with the cleaning roller. The roller scraper may rotate in an opposite rotational direction when compared to the cleaning roller in order to provide an effective pick-up effect of dirt. The roller scraper may also rotate faster than the cleaning roller to clean the cleaning roller effectively. Optionally, the rotational speeds may be adjusted in accordance with the needs.

[0036] According to embodiments, the cleaning device may also have scrapers of different types, e.g. one scraper may be formed as a plate-shaped scraper and one as a roller scraper or one may be formed as a V-shaped scraper or as a pivoting scraper. Each scraper design has its own advantages. For example, scrapers that move linearly need only a little assembly space, whereas roller scrapers may need more space. On the hand, the scraping effect of the roller scraper can be controlled by adjusting its rotational speed compared to the rotational speed of the cleaning roller. V-shaped scrapers may be very stable.

[0037] Optionally, the holding structure comprises respective sliding chambers for each of the one or more plate-shaped scrapers to move back and forth in the respective sliding chamber. The sliding chamber may provide lateral support to keep each of the one or more plate-shaped scrapers in its angular position with respect to the rotating cleaning roller. This sliding chamber does not need to be a closed chamber, but it may provide a guidance or an alignment, e.g., for a linear movement of the scraper.

[0038] The cleaning roller may again be configured to pick-up wet dirt from the surface and the cleaning device may optionally comprise a first channel for carrying away the (wet) dirt from the first scraper and a second channel for carrying away the (wet) dirt from the second scraper. When both channels are provided, the first channel may be utilized when the cleaning device moves in a first direction, and the second channel may be utilized when the cleaning device moves in a second direction, opposite to the first direction. Depending on the orientation of the cleaning device, both channels can transport the (wet) dirt simultaneously.

[0039] Optionally, the holding structure extends partially around the cleaning roller to provide a collecting space for sewage between a surface of the cleaning roller and the holding structure. The first channel may be formed as a first U-shaped recess of the collecting space adjacent to the first (plate-shaped) scraper to guide wet dirt into the first channel. Likewise, the second channel may be formed as a second U-shaped recess of the collecting space adjacent to the second (plated-shaped) scraper to guide wet dirt into the second channel.

[0040] Optionally, each of the (plate-shaped) scrapers define a respective angle with respect to a surface of the cleaning roller, wherein for multiple plate-shaped scrapers the respective angles can be different or equal. The angles may be predetermined angles to provide the advantage of taking off different type of dirt (e.g. moisture, solid dirt, surface dirt, deeper dirt, etc.).

[0041] Optionally, the cleaning device further comprises a vacuum unit to generate a vacuum in a vacuum chamber. The vacuum and the vacuum chamber may be adapted to hold the cleaning device at the vertical surface and / or to hold the cleaning device underneath a horizontal surface during cleaning (in an upside-down position).

[0042] The cleaning device may be configured to move during cleaning predominantly in a forward direction. Then, optionally, the vacuum unit is arranged, with respect to the forward direction, after the cleaning roller.

[0043] Optionally, each of the at least one biasing device includes as source for the biasing force a spring or an elastic material with an elasticity exerting the biasing force when compressed. The spring can be a spiral spring, leaf spring, or another spring. Possible elastic material may be rubber, a sponge, etc.

[0044] Optionally, the cleaning device comprises further one or more or all of the following: a housing with a suction unit and a suction channel; a drive unit for moving the cleaning device; a sensor unit providing sensor data; a control unit for controlling the drive unit based on the sensor data up and down the vertical surface or underneath a horizontal surface.

[0045] Therefore, according to embodiments, the cleaning device can be a cleaning robot that is configured to autonomously clean the surface.

[0046] The cleaning device may again be configured to move during cleaning predominantly in a forward direction. Then, the cleaning device may comprise a wetting system at at least one of the following positions: at one or more circumferential positions around the cleaning roller to wet the cleaning roller, at one or more front portions of the housing with respect to the forward direction to wet the surface in front, at one or more lower portions of the housing to wet the surface underneath the cleaning device.

[0047] The optional wetting system may include one or more spray nozzles, which may be activated or deactivated depending on the moving direction. Likewise, optionally, the nozzles may be controllable to adjust an amount of water according to the needs.

[0048] Further embodiments relate to a cleaning device for a surface with a pick-up unit, a mounting, and a vacuum unit. The pick-up unit is configured to pick-up wet dirt from the surface. The pick-up unit may include a cleaning roller, a motor for the cleaning roller, at least one scraper, and a main tank for collecting the wet dirt as sewage. The mounting is configured to secure the pick-up unit and is adapted to press the pick-up unit with a predetermined pressure on the surface. The vacuum unit is adapted to generate a vacuum in a vacuum chamber. The vacuum and / or the vacuum chamber are adapted to hold the cleaning device at a vertical wall or underneath a horizontal wall.

[0049] Optionally, the vacuum unit is adapted to hold the cleaning device at the surface while the mounting presses the pick-up unit against the surface with the predetermined pressure.

[0050] Optionally, the mounting is adapted to permanently press the pick-up unit with the predetermined pressure on the surface.

[0051] Optionally, the cleaning device is configured to move, during cleaning, predominantly in a forward direction and the vacuum unit is arranged, with respect to the forward direction, behind the cleaning roller.

[0052] Optionally, the mounting includes one or more springs or elastic elements to exert the predetermined pressure against the surface.

[0053] Optionally, the cleaning device further comprises a housing accommodating the vacuum unit. The housing may be adapted to hold the mounting and may provide a sliding edge to provide a guidance for the pick-up unit. The one or more springs of the mounting may provide a same linear spring force to press the pick-up unit homogenously onto the surface away from the housing.

[0054] Optionally, the one or more springs include four springs each being arranged at a respective corner portion of the pick-up unit.

[0055] Optionally, the housing comprises a rear portion located behind the pick-up unit (e.g. with respect to the forward direction). The rear portion includes one or more of the following: a sponge cleaning element, a textile pad, a vibrating textile pad, a rubber cleaning element, a flexible roller element.

[0056] Optionally, the pick-up unit further comprises: a supplemental tank fluidly connected with the main tank and extending parallel to the cleaning roller. The pick-up unit may further include a valve, or a pump formed along the fluid connection between the main tank and the supplemental tank. The valve (or the pump) is configured to allow sewage to flow only from the main tank to the supplemental tank.

[0057] Further embodiments relate to a cleaning device for a vertical surface that comprises: a cleaning roller configured to rotate to pick-up wet dirt from the vertical surface; at least one scraper, wherein each of the at least one scraper is configured to take off the picked-up dirt from the cleaning roller during rotation of the cleaning roller; a first channel for carrying away the wet dirt; and a second channel for carrying away the wet dirt.

[0058] The first channel and / or the second channel may form a suction port. Alternatively, or in addition, the first channel and / or the second channel may be formed oblique relative the vertical surface.

[0059] Optionally, the cleaning device further comprises a main tank for collecting the wet dirt as sewage arranged on a lateral side of the cleaning roller. The main tank may comprise a first termination opening connected to the first channel and / or a second termination opening connected to the second channel. The first termination opening and / or the second termination opening may be spaced from an outer wall of the main tank to prevent a backflow of sewage during turns on the vertical surface or during upside-down movements of the cleaning device.

[0060] Optionally, the first termination opening and / or the second termination opening are (both) spaced from all walls of the main tank by at least a minimum distance to provide sufficient room for the sewage to flow around the first termination opening and to flow around the second termination opening during operation or during the turns on the vertical surface and / or during the upside-down movements of the cleaning device.

[0061] Optionally, the main tank and / or the positions of the first termination opening and of the second termination opening are adapted to allow a volume of sewage in a range of 10 cm3 to 50 cm3 or a range of 20 cm3 to 30 cm3 to flow around the first termination opening and the second termination opening for turns in any or at least one orientation of the cleaning device.

[0062] Optionally, the cleaning device comprises a supplemental tank fluidly connected with the main tank and extending parallel to the cleaning roller. The cleaning device may comprise further a valve formed along the fluid connection between the main tank and the supplemental tank. The valve may be configured to allow sewage to flow only from the main tank into the supplemental tank.

[0063] Optionally, the cleaning device comprises a pump arranged between the main tank and the supplement tank to pump the sewage from the main tank to the supplemental tank.

[0064] Optionally, the cleaning device is configured to move during cleaning predominantly in a forward direction. The supplement tank may be arranged in front of the cleaning roller with respect to the forward direction. The fluid connection with the valve may be formed at an upper corner of the main tank. The valve may be a check valve. The upper side can be defined as the side opposite to the surface to cleaned.

[0065] Optionally, when the cleaning device comprises a drive unit configured to move the cleaning device forward, backward and / or to make turns with the cleaning device, the control unit may be configured to control the drive unit to make preferentially turns to the lateral side where the main tank is arranged. This will ensure that during each turn sewage can be transported from the cleaning roller or from the first channel and / or from the second channel into the main tank. However, the cleaning device can also make turns in the other direction, but if both turns are possible the control unit may choose the preferred turning direction. If the preferred turning direction is not possible or is for some reasons difficult or not safe, the cleaning device can also make turns in the opposite (not preferred) direction.

[0066] Optionally, when the first channel is formed as a first U-shaped recess adjacent to the first scraper and the second channel is formed as a second U-shaped recess adjacent to the second scraper, a depth of the first U-shaped recess continuously increases while a depth of the second U-shaped recess continuously decreases along an axial extension of the cleaning roller.

[0067] Optionally, the increasing depths of the first the first channel and / or of the second channel are adapted to carry away the wet dirt by gravity during a movement (vertical or horizontal) at the vertical surface.

[0068] Further embodiments relate to cleaning devices including all or most of the features of the cleaning devices as described before. The defined limitations may relate to various aspects of one cleaning device. However, the present invention shall not be limited to the overall system, but the respective aspects defined in the enclosed claims.

[0069] Although the various embodiments define different feature combinations, it is understood that the cleaning device may comprise the various components only once, even though the components may have different functions in the different embodiments (e.g. implemented by the control unit). For example, the cleaning device may comprise only one of the following components: pick-up unit, cleaning roller, sensor unit (with possibly multiple sensors), suction unit, vacuum unit, drive unit, housing, wetting system, etc.

[0070] Embodiments relate also to methods of manufacturing or of operating the cleaning device as described in this disclosure. The methods of operating the cleaning devices, or at least part thereof, may also be implemented in software, or as a computer program product. Therefore, embodiments relate also to a computer program or computer program product or a machine-readable storage device having a program code for performing the method, when the computer code is executed on a processor.

[0071] It is understood that all functions (e.g. provided by the control unit) may be implemented by additional method steps. Likewise, all operational modes (functions) can be implemented in the control unit and define thus optional limitations for the control unit.BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Various embodiments of the present invention will be described in the following by way of examples only, and with respect to the accompanying drawings, in which: Fig. 1depicts an embodiment for a cleaning device with scrapers. Fig. 2depicts an embodiment for the cleaning device with a spring-loaded pick-up unit. Fig. 3depicts a cross-sectional view through the cleaning device according to embodiments showing further details. Fig. 4A, 4Bdepict an embodiment for the cleaning device with oblique channels. Fig. 5A, 5Bdepict a back view and a cross-sectional view of the cleaning device with oblique channels shown in Fig. 3. Fig. 6A-6Eillustrates advantageous aspects of embodiments for the cleaning of vertical surfaces. Fig. 7A,7Billustrates advantageous aspects of embodiments for the cleaning of horizontal surfaces. Fig. 8depicts an embodiment for the cleaning device with an improved housing. DETAILED DESCRIPTION

[0073] Various examples will now be described more fully with reference to the accompanying drawings in which some examples are illustrated.

[0074] Accordingly, while examples are capable of various modifications and alternative forms, the illustrative examples in the figures will herein be described in detail. It should be understood, however, that there is no intent to limit examples to the particular forms disclosed, but on the contrary, examples are to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure. Like numbers refer to like or similar elements throughout the description of the figures.

[0075] It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," etc.).

[0076] The terminology used herein is for the purpose of describing illustrative examples only and is not intended to be limiting. As used herein, the singular forms "a," "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises," "comprising," "includes" and / or "including," when used herein, specify the presence of stated features, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components and / or groups thereof.

[0077] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which examples belong. It will be further understood that terms, e.g., those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0078] Fig. 1 depicts a cross-sectional view through a cleaning device which is suitable and designed for cleaning a vertical surface 50 or in an upside-down position, wherein the vertical direction refers to the direction opposite to gravity. The surface 50 may be any surface of materials such as glass, stone, tiles, ceramics, carpet or carpeting, wood etc. It is understood that the device may also clean horizontal surfaces (from underneath or from above or a floor) and likewise inclined surfaces.

[0079] The cleaning device comprises: a cleaning roller 110, two scrapers 120 and a holding structure 130 and the cross-section of Fig. 1 is selected perpendicular to an axial direction of the cleaning roller 110. The cleaning roller 110 is configured to rotate to pick-up dirt from the surface 50, wherein a motor 190 may drive the rotation. The two scrapers 120 are configured to take off the picked-up dirt from the cleaning roller 110 during rotation of the cleaning roller 110. The holding structure 130 holds the two scrapers 120 so that each of the two scrapers 120 are in contact with cleaning roller 110. The cleaning device further includes one or more tanks 180, 181 to collect the dirt. The dirt can be wet dirt so that the collected dirt can be sewage (not shown in Fig. 1).

[0080] According to embodiments the two scrapers 120 comprise a first scraper 121 configured to take off dirt in a first angular range 111 of the cleaning roller 110, and a second scraper 122 configured to take off dirt in a second angular range 112 of the cleaning roller 110. The first angular range 111 may include a first angle 113 measured with respect to the surface 50 which is between 90° and 180°, preferably between 125° and 145° or about 135°. The second angular range 112 may include a second angle 114 (measured with respect to the surface 50) which is between 0° and 90°, preferably between 20° and 40° or about 30°. The first angle 113 and the second angle 114 can be measured in a same coordinate frame (in the same direction) and may differ by at least 10° or 30° or 60°.

[0081] According to embodiments the first scraper 121 and / or the second scraper 122 is at least one of the following: a plate-shaped scraper, a roller scraper (or a scraper roller), a rigid scraper, a curved scraper, a V-shaped scraper, etc. Fig. 1 show exemplary only the plate-shaped scraper, but embodiments shall not be limited only on the depicted scrapers. The plate-shaped scrapers 121, 122 may comprise each a scraping strip 125 at an edge to contact the cleaning roller 110, which is adapted to take off the picked-up dirt from the cleaning roller 110 and which may be unitarily formed with the scraper 121, 122 (same material).

[0082] The cleaning device may be movable in a preferred forward direction R and the cleaning roller 110 may rotate in the forward direction R (anti clockwise in Fig. 1). In accordance with the rotational direction D, the scraping strips 125 may be formed plate-like or V-shaped to receive an upper surface of the cleaning roller 110 to remove the dirt therefrom. The at least one roller scraper may include each a roller which is configured to counter rotate to the cleaning roller 110 to take off dirt from the cleaning roller 110, wherein a rotational speed of the roller scraper may be predetermined or adjustable to the needs (e.g. amount of dirt).

[0083] According to embodiments, each of the at least one plate-shaped scrapers 120 define a respective angle with respect to a surface of the cleaning roller 110, wherein for multiple plate-shaped scrapers 120 the respective angles can be different or equal to each other. These angles can be predetermined or may be different to provide the advantage of taking off different type of dirt (e.g. moisture, solid dirt, surface dirt, deeper dirt, etc.).

[0084] According to embodiments the holding structure 130 allows a movement L of the first scraper 121 and / or of the second scraper 122 towards the cleaning roller 110. The movement L may be at least one of the following: a linear movement, a pivotal movement, a curved movement, or any other suitable movement.

[0085] The cleaning device may further comprise at least one biasing device 140 to exert a biasing force to press the scrapers 120 onto the cleaning roller 110 along the movement L. For example, a biasing device 140 may be formed for each scraper and the biasing force may act in the radial direction (towards the cleaning roller 110). The bias force exerted by the biasing device 140 may be in the range of 15 N to 30 N or about 22 N. According to embodiments, each of the biasing devices 140 includes as source for the biasing force a spring or an elastic material with an elasticity exerting the biasing force when compressed. The spring(s) 140 can be spiral springs, leaf spring, etc. and the elastic material can be rubber, a sponge, etc.

[0086] Thus, the scrapers 120 according to embodiments should be distinguished from conventional sealing elements, which are designed to prevent an air flow along the surface of the cleaning roller 110. Due to the applied pressure by the biasing device 140, the cleaning roller 110 may be deformed by the scrapers 120 resulting in a possibly insufficient sealing effect towards the cleaning roller 110. Therefore, the scrapers 120 may provide only an insufficient or no sealing effect. If there is a need for a sealing, additional sealing elements can be formed which differ from the scrapers 120.

[0087] According to embodiments also a mixture of two different scrapers is possible. For example, one rotating or roller scraper may be combined with a linearly moving scrapper. The different scrapers may provide different advantages. For example, it may be of advantage to use plate-shaped scrapers 121, 122 is only a limited installation space is available - in particular, when combined with the linear movements L. On the other hand, the roller scraper may provide a more effective removal of dirt from the cleaning roller 110, e.g. by adjusting by its rotational speed accordingly.

[0088] As depicted in Fig. 1, according to embodiments, the holding structure 130 extends partially around the cleaning roller 110 to provide a collecting space 115 for the sewage between a surface of the cleaning roller 110 and the holding structure 130. The cleaning device may further comprise a first channel 161 for carrying away the (wet) dirt from the first scraper 121. The first channel 161 may be formed as a first U-shaped recess of the collecting space 115 (directly) adjacent to the first plate-shaped scraper 121 to guide wet dirt into the first channel 161. The U-shaped recess of the first channel 161 may comprise a (variable) first channel depth C1 in the axial direction perpendicular to the drawing plane.

[0089] The cleaning device may further comprise a second channel 162 for carrying away the (wet) dirt from the second scraper 122. The second channel 162 may also be formed as a second U-shaped recess of the collecting space 115 (directly) adjacent to the second plated-shaped scraper 122 to guide wet dirt into the second channel 162. The U-shaped recess of the second channel 162 may comprise a (variable) second channel depth C2 in the axial direction perpendicular to the drawing plane.

[0090] Fig. 2 depicts an exploded view on an embodiment of the cleaning device with a spring-loaded (biased) pick-up unit 100, a mounting 150, a housing 300, and a vacuum unit 600. The housing 300 may comprise a cover portion 330 (shown at the top) and a base portion 340 (shown in the middle), which can be closed by the cover portion 330. The pick-up unit 100 (shown at the bottom) can be mounted to the base portion 340 in a respective opening or recess.

[0091] Again, the cleaning device is able to clean surfaces 50, which particularly extend vertically. Again, the pick-up unit 100 is configured to pick-up wet dirt from the surface 50, as it was described in more detail in Fig. 1. The pick-up unit 100 includes again a cleaning roller 110, a motor 190 to rotate the cleaning roller 110, at least one scraper (not visible in Fig. 2), and a main tank 180 for collecting the wet dirt as sewage. Optionally, the pick-up unit 100 includes an additional, supplementary tank 181.

[0092] According to embodiments the mounting 150 secures the pick-up unit 100 to the housing 300 in spring-loaded way and comprises mounting elements 151 and springs 155. The mounting elements 151 allow relative movement between the housing 300 and the pick-up unit 100 up to a maximal separation and the springs 155 press the pick-up unit 100 with a predetermined pressure away from the housing 300 (or its base portion 340) on the surface 50 (not shown in Fig. 2) to exert a (predetermined) pressure with the cleaning roller 110 on the surface 50. According to embodiments the mounting 150 comprises four springs 155, each being arranged at a respective corner portion of the pick-up unit 100. Therefore, the pick-up unit 100 is suspended in a floating manner to provide a balanced pressure.

[0093] Alternatively, or in addition, one or more of the springs 155 can be replaced by any kind of elastic elements that are able to exert the predetermined pressure against the surface 50.

[0094] Therefore, according to embodiments, a homogenous (or balanced) pressure can be applied equally on all sides or positions and may not change, even when cleaning vertical surfaces 50 or in an upside-down position. For example, the springs 155 of the mounting 150 can provide a same linear spring force to press the pick-up unit 100 homogenously onto the surface 50. Likewise, the pick-up unit 100 can float even over uneven surfaces. However, as long as the desired effect is achieved, embodiments shall not be limited on a particular number of springs 155 or elastic elements.

[0095] The housing 300 may accommodate, inter alia, the vacuum unit 600 which generate a vacuum in a vacuum chamber connected to vacuum holding pads 650. The vacuum unit 600 comprises exhaust ports 610 which couple to openings in the housing 300 to exhaust air when generating the vacuum. As already set out, embodiments of the vacuum unit 600 hold the cleaning device at the (vertical) surface 50 or in an upside-down position even under the pressure applied by cleaning roller 110 onto the surface 50. The vacuum holding pads 650 may hold rear part of the housing 300 tightly on the surface 50. Therefore, the vacuum unit 600 may be arranged behind the cleaning roller 110, wherein relative locations (e.g. in the rear) can be defined with respect to the predominantly used forward moving direction R of the cleaning device.

[0096] Embodiments ensure the holding force onto the surface 50 by controlling the vacuum unit 600 to produce a stronger adhesive force than the pressure force applied by the cleaning roller 110. In other words, the vacuum unit 600 is adapted to hold the cleaning device at the surface 50 while the mounting 150 presses the pick-up unit 100 against the surface 50.

[0097] According to embodiments, the housing 300 includes a frame structure to support all components the cleaning device. For example, the cleaning device may comprise one or more of the following optional components: a suction unit 200 and a suction channel 210, a drive unit 400 for moving the cleaning device, a sensor unit 700 for detecting objects / obstacles in the surrounding and providing respective sensor data, a control unit 500 for controlling the drive unit 400 based on the sensor data up and down the vertical surface or underneath a horizontal surface.

[0098] According to embodiments the components (e.g. the control unit 500, the drive unit 400, the sensor unit 700, the suction unit 200) in the housing 300 can be placed at various locations. The depicted positions of the components in the drawings of this disclosure represent merely possible examples and embodiments shall not be limited on the location shown here in Fig. 2 and the other figures.

[0099] Optionally, the pick-up unit 100 comprises a support frame 170 which may be suspended by the mounting 150 to the housing 300. This support frame 170 may provide a guidance (e.g. by its edge 175) for the relative movement between the housing 300 and the pick-up unit 100. The pick-up unit 100 or the base portion 340 of the housing 300 may include one or more of the following optional components: a sponge cleaning element, a textile pad, a vibrating textile pad, a rubber cleaning element, a flexible roller element.

[0100] Fig. 3 depicts a cross-sectional view through an assembled cleaning device as shown in Fig. 2 in an exploded view. The cleaning device may again include a drive unit 400, the control unit 500, and the vacuum unit 600. In addition, the cleaning device includes as optional components a sensor unit 700, and a wetting system 800. The cleaning device may move during cleaning predominantly in a forward direction R. In this moving direction, under normal conditions, the cleaning process may be most efficiently. Moreover, the cleaning device is again designed to clean especially wet dirt, for which the wetting system 800 may be utilized.

[0101] The wetting system 800 may include one or more nozzle devices 801, 802, 803 to wet the surface 50 before and / or during the cleaning. For example, a first nozzle device 801 may be arranged at one or more front portions of the housing 300 to wet the surface 50 in the forward direction R, i.e. before the cleaning device will arrive at that position. A second nozzle device 802 may be arranged at one or more lower portions of the housing 300 to wet the surface underneath the cleaning device, e.g. just before the cleaning roller 110. The second nozzle device 802 may likewise partially wet the cleaning roller 110. The second nozzle device 802 may face the surface 50 to be cleaned. A third nozzle device 803 may be arranged at one or more circumferential positions around the cleaning roller 110 to wet the cleaning roller 110 from a position inside the collecting space 115 for sewage.

[0102] According to embodiments, not all nozzle devices 801, 802, 803 may be activated at all times. Likewise, not all nozzle devices 801, 802, 803 may be present. According to the needs and / or the moving direction, only some of the nozzle devices 801, 802, 803 can be activated. Likewise, the amount of water for every nozzle device 801, 802, 803 may be adjusted in accordance with the needs (e.g. the degree and kind of dirt).

[0103] The sensor unit 700 may detect obstacles and / or the degree and / or the kind of dirt. The sensor unit 700 may provide respective sensor data to the control unit 500. For this, the sensor unit 700 includes at least one of the following sensors: optical sensor, a mechanical sensor, a switch, a light gate, an ultrasonic sensor, a current sensor for an electric current consumed by a drive unit 400 for the cleaning roller 110. The obstacle may be one of the following: a frame, an edge of the surface, a decoration element, a window handle, a door handle, a strip. The control unit 500 may control the drive unit 400 based on sensor data received from the sensor unit 700 to clean the (vertical) surfaces 50 even close to the obstacle and based on the needs (e.g. degree and kind of dirt).

[0104] The cleaning device comprises again a vacuum unit 600 to generate a vacuum in a vacuum chamber, wherein the vacuum and the vacuum chamber are again adapted to hold the cleaning device at the vertical surface and / or to hold the cleaning device underneath a horizontal surface 50 in an upside down position.

[0105] Therefore, according to embodiments, the control unit 400 may control one or more or all of the following: the motor 190 for the cleaning roller 110, the suction unit 200, the drive unit 400 the vacuum unit 600, the wetting unit 800 other components of the cleaning device.

[0106] The control unit 400 may move of the cleaning device during cleaning predominantly or preferably in the forward direction R to optimize the cleaning process. However, the control unit 400 may also move the cleaning device backward (e.g. if the forward direction R is blocked).

[0107] The vacuum device 600 may be arranged, with respect to the forward direction R, after the cleaning roller 110, where the amount of dirt is expected to be less so that the vacuum device 600 can provide a stronger holding force. Again, the control unit 400 may control the vacuum unit 600 to generate sufficient vacuum to hold the cleaning device even at vertical surfaces 50 during the cleaning process.

[0108] The functions provided by the control unit 500 may be implemented by software installed in the control unit 500. The control unit 500 may comprise a storage device for storing instructions (as software) and a processor which is configured to read the instructions from the storage device to provide the functions as described in this disclosure.

[0109] Figs. 4A and 4B depict an embodiment of the pick-up unit 100 of the cleaning device for vertical surfaces 50. The cleaning device comprises a main tank 180 and Fig. 4A shows a 3d view on the side with main tank 180, where the main tank 180 is shown without a lateral lid or cover to expose the interior of the main tank 180. Fig. 4B shows a side view on the side of the main tank 180.

[0110] The cleaning device comprise comprises again the cleaning roller 110 configured to rotate to pick-up wet dirt from the surface 50 and at least one scraper 120 (see Fig. 1). The scraper(s) 120 take(s) off again the picked-up wet dirt from the cleaning roller 110 during rotation of the cleaning roller 110. The pick-up unit 100 includes a first channel 161 for carrying away the wet dirt, and a second channel 162 for carrying away the wet dirt.

[0111] The main tank 180 collects the wet dirt as sewage and is arranged on a lateral side of the cleaning roller 110, e.g. on the right-hand side with respect to the forward direction R. The main tank 180 comprises a first termination opening 186 connected to the first channel 161 and a second termination opening 187 connected to the second channel 162.

[0112] The first termination opening 186 and the second termination opening 187 release the sewage from the first and second channels 161, 162 into the main tank 180 and they are spaced from at least one wall of the main tank 180 by a minimum distance dmin (see Fig. 4A). This minimum distance dmin is selected to prevent a backflow of sewage during turns on the exemplary vertical surface and / or during upside-down movements of the cleaning device. According to embodiments, the first termination opening 186 and the second termination opening 187 are both spaced from all walls of the main tank 180 by at least the minimum distance dmin to provide sufficient room for the sewage to flow around the first termination opening 186 and / or the second termination opening 187 during various movements of the cleaning device such as turns on the vertical surface 50 and / or upside-down or horizontal movements.

[0113] This may also limit the dimensions (height, width, depth) of the main tank 180 to have enough space available for collecting sewage while preventing the backflow into the first and second channels 161, 162. For example, the main tank 180 and / or the positions of the first termination opening 186 and of the second termination opening 187 may allow a volume of sewage in a range of 10 cm 3< to 50 cm 3< or in a range of 20 cm 3< to 30 cm 3< to flow around the first termination opening 186 and around the second termination opening 187 for turns in any orientation of the cleaning device.

[0114] According to embodiments, a supplemental tank 181 is fluidly connected with the main tank 180 and extends parallel to the cleaning roller 110. Optionally, a valve 183 is formed along the fluid connection between the main tank 180 and the supplemental tank 181. The valve 183 may allow sewage to flow only from the main tank 180 to the supplemental tank 181. Alternatively, or in addition, the cleaning device comprises a pump arranged between the main tank 180 and the supplement tank 181 to pump the sewage from the main tank 180 to the supplemental tank 181.

[0115] According to embodiments, the supplement tank 181 is arranged in front of the cleaning roller 110 with respect to the forward direction R. Accordingly, the fluid connection with the valve 183 or pump may be formed at an upper corner of the main tank 180, wherein the upper side may be the side opposite to the surface 50 to be cleaned. The valve may be a check valve. The pump may be controlled by the control unit 500.

[0116] According to embodiments, the drive unit 400 (see Fig. 3) of the cleaning device can be controlled to move forward, to move backward and to make turns. Advantageously, the control unit 500 (see Fig. 3) controls the drive unit 400 to make preferentially turns to the lateral side of the forward direction R where the main tank 180 is arranged. In Fig. 4A this would be right turns. If both turns would be possible in a given situation, the control unit 500 may select the preferred turning direction in controlling the drive unit 400. On the other hand, if the preferred turning direction is not possible or is for some reasons difficult or not safe, the cleaning device can also make turns in the opposite (not preferred) direction.

[0117] Due to the relative arrangement of the main tank 180 and the supplemental tank 181, this "turning policy" of embodiment will trigger at turns a sewage flow from the main tank 180 into the supplemental tank 181, because the sewage sooner or later be in contact will the valve 183 and the water pressure in the main tank 180 will press the sewage into the supplemental tank 181. Therefore, the main tank 180 cannot overflow. When a pump is installed between the main tank 180 and the supplemental tank 181, the control unit 500 may control the pump accordingly to ensure that a maximal amount of sewage will not be exceeded in the main tank 180. For example, the pump could be activated when the orientation of the cleaning device is such that the fluid connection to the supplemental tank 181 is "under sewage".

[0118] Fig. 5A and Fig. 5B depict the pick-up unit 100 in a back view so that the forward direction R goes into the drawing plane. Fig. 5A shows an overview and Fig. 5B shows again a cross-section view (parallel to the surface 50) through the motor 190 and the second channel 162 with the second termination port 187 (cp. Fig. 4A).

[0119] According to embodiments the second termination opening 187 is spaced from all walls of the main tank 180. It has a first distance d1 to a lower wall, a second distance d2 to a side wall, a third distance d3 to an upper wall, and a fourth distance d4 to an inner wall (towards the cleaning roller 110). The main tank 180 and the second termination opening 187 are formed so that each of the first to fourth distances d1, d2, d3, d4 is greater than the minimal distance dmin. Same applies to the first termination opening 186 which is not shown in Fig. 5B.

[0120] According to embodiments, this minimal distance ensures that a sufficient volume of sewage, as set out before, can flow around the first terminal opening 186 and the second terminal opening 187 without entering the first channel 161 or the second channel 162.

[0121] According to embodiments, the first channel 161 and / or the second channel 162 can be formed as suction ports (not shown) or as U-shaped recesses defining oblique channels. As set out in detail with Fig. 1, the first scraper 121 can take off the wet dirt from the cleaning roller 110 at one position and the second scraper 122 can take off the wet dirt of the cleaning roller 110 at another position. The first channel 161 and the second channel 162 were formed as U-shaped recesses adjacent to the respective first scraper 121 and second scraper 122. The first channel depth C1 of the first U-shaped recess may continuously increase while the second channel depth C2 of the second U-shaped recess may continuously decreases along an axial extension of the cleaning roller 110. Both channels 161, 162 are thus relative oblique with each other.

[0122] Alternatively, or in addition, the first channel 161 and / or the second channel 162 may be formed as oblique channels relative to the surface 50 (see Fig. 5B). This inclination may ensure the sewage will flow to the main 180 due gravity. For example, in the situation depicted in Fig. 5B, the cleaning device may move in an upside-down orientation underneath the surface 50 in the forward direction R. The sewage collected by the second channel 162 will then flow towards the main tank 180 due to the gravity.

[0123] The first channel 161 may be tilted in the opposite direction implying that the first channel 161 can transport the sewage gravity-driven when the cleaning device clean a horizontal surface 50 from top. Thus, the first channel 161 may carry away the wet dirt from the first scraper 121 when the cleaning device moves with a first orientation (e.g. on a horizontal surface). Similarly, the second channel 162 may carry away the wet dirt from the second scraper 122 when the cleaning device moves with a second orientation (e.g. underneath a horizontal surface).

[0124] According to embodiments, the first channel 161 and / or the second channel 162 are formed or oriented to allow a gravity-driven flow for any movement in space. For this, embodiments orient the U-shaped recesses with increasing / decreasing depth in an oblique manner when viewed from all directions (from front, back, top, bottom). Therefore, the inclinations may differ from the embodiment shown in the figures. Therefore, the first channel 161 may carry away the wet dirt when the cleaning device moves in a first direction, and the second channel 162 may carry away the wet dirt from the second scraper 122 when the cleaning device moves in a second direction.

[0125] Alternatively, or in addition, the flow of the sewage can be driven by a suction device so that the inclination (oblique orientation) may not be needed to ensure a transport of the sewage.

[0126] According to further embodiments, the holding structure 130 (see Fig. 1), which holds the first scraper 121 and the second scraper 122, may form part of the first channel 161 and / or the second channel 162.

[0127] Fig. 6A to Fig. 6E illustrate advantageous aspects of the cleaning device with oblique channels as implemented in embodiments when moving with the cleaning device on vertical surfaces.

[0128] First, Fig. 6A shows schematically the cleaning device in a side view on the surface 50 moving in the left side direction (forward direction R). The cleaning robot includes a pick-up unit 100 with the cleaning roller 110 and a first scraper 121 and a second scraper 122 which are configured to take off the picked-up dirt from the cleaning roller 110. The cleaning roller 110 is formed between the first scraper 121 and the second scraper 122. A rear portion 320 (second portion) of the cleaning device may include, inter alia, the drive unit 400 and the vacuum unit 600 to move and hold the cleaning device on the exemplary vertical surface 50 to be cleaned. The cleaning device is shown in the horizontal orientation with the surface 50 below (in the direction of gravity) the cleaning device. The cleaning roller 110 rotates in the anticlockwise rotation direction D when viewed in the depicted side view which supports the forward motion R on the surface 50.

[0129] Fig. 6B shows the orientation of the first channel 161 and of the second channel 162 in a top view on the cleaning device, wherein the cleaning roller 110 is arranged between the first channel 161 and of the second channel 162 that may be formed as suction ports or as U-shaped recesses. The depths of the U-shaped recesses defining the first channel 161 and of the second channel 162 may again continuously increase or decrease to carry away the wet dirt by gravity from the cleaning roller 110 towards the main tank 180.

[0130] As will be described in more details in the following, the recesses are oriented or arranged in the pick-up unit 100 to allow a gravity-driven transport of sewage even movements on the vertical surfaces. Concretely, the first channel 161 may carry away the wet dirt from the first scraper 121, when the cleaning device moves in a first direction, and the second channel 162 can carry away the wet dirt from the second scraper 122, when the cleaning device moves in a second direction, opposite to the first direction.

[0131] Fig. 6C illustrates an exemplary vertical movement in an upward direction, i.e. the gravity direction G is opposite to the forward direction R (see right illustration in Fig. 6C). During this motion, the second channel 162 is inclined towards the main tank 180 and allows the sewage to flow itself (by gravity) into the main tank 180. No pumps are needed. The first channel 161 may be inclined in the opposite direction.

[0132] On the left-hand side, Fig. 6C shows the top view (in the direction of gravity) and the bottom view (against the direction of gravity) of the moving cleaning device. Thus, the main tank 180 is located on the left-hand side in the top view and on the right-hand side in the bottom view. According to embodiments, the first channel 161 as well as the second channel 162 are also inclined in both views. With respect to the axial axis of the cleaning roller 110, the first channel 161 has a first inclination angle 163 and second channel 162 has a second inclination angle 164. As already set out, the first channel 161 and the second channel 162 may be inclined in all viewing directions. In other words, they are oblique in all spatial directions. This implies that the first channel 161 and the second channel 162 may also be inclined in the direction out / into the drawing plan. Therefore, the first inclination angle 163 and second inclination angle 164 are measured slightly out of the drawing planes.

[0133] By comparing the top view and the bottom view, the first channel 161 is inclined oppositely compared to the second channel 162 (see also Fig. 6B). This will ensure that even in an upside-down movement (underneath a horizontal surface) one of the two channels 161, 162 will always allow a gravity-driven flow of sewage (e.g. the second channel 162 is the situation shown in Fig. 6C).

[0134] Fig. 6D illustrates a vertical movement in the downward direction, where the forward direction R is in the direction of gravity G. The right-hand side shows again a view onto the surface 50, the left-hand side shows the top view (in the direction of gravity) and the bottom view (against the direction of gravity). Thus, compared to Fig. 6C, the situation in Fig. 6D is exactly opposite. Although the first and second channels 161, 162 are still oblique in the 3D space, for the depicted downward movement the first channel 161 may always allow a gravity-driven flow of sewage because it is inclined by the first inclination angle 163 towards the main tank 180.

[0135] However, since the main tank 180 is exemplary arranged only on one side, there is a preferred turning direction to ensure that sewage will be transported to the main tank 180 and not the other way around. Accordingly, drive unit will make preferentially turns to the lateral side of the forward direction R where the main tank 180 is arranged. In the depicted embodiment the preferred turning direction are right turns.

[0136] Fig. 6E illustrates a side movement along a vertical surface. Again, the gravity acts in the way that the sewage from the cleaning roller 110 will flow under gravity to the main tank 180. Fig. 6E also illustrates the preferred turning direction which ensures that both channels 161, 162 will be emptied during this turn, since the main tank 180 is below the cleaning roller 110 and both channels 161, 162.

[0137] Fig. 7A and Fig. 7B illustrate horizontal movements. Again, the cleaning device moves in the forward direction R while the cleaning roller 110 rotates in the direction D.

[0138] Fig. 7A shows the example of a movement above the surface 50. The top view shows a side view onto the cleaning device, a front view is shown in the middle, and a back view is shown at the bottom. The forward direction R is perpendicular to the direction of gravity G. The oblique channels 161, 162 still ensure that sewage will flow into the main tank 180, wherein in the depicted situation the first channel 161 has an inclination angle 163 that allows the sewage to flow into the main tank 180. The second channel 162 in inclined in the opposite direction 164 allowing the sewage flow in the upside-down situation.

[0139] Fig. 7B shows the upside-down movement where the cleaning device moves underneath the surface 50. Again, the top view shows a side view onto the cleaning device, and below a front view and a back view are shown. The forward direction R is again perpendicular to the direction of gravity G. The oblique channels 161, 162 again ensure that sewage flows into the main tank 180, wherein in the depicted situation the second channel 162 has now an inclination angle 164 that allows the sewage to flow into the main tank 180 (see back view). The first channel 161 is now inclined in the opposite direction 163.

[0140] Fig. 8 depicts an embodiment for the cleaning device with an improved housing 300. Again, the cleaning device is suitable to clean a vertical surface 50 when moving in a forward direction R. However, the surface 50 may comprise objects or obstacles 55 such as: a frame, an edge of the surface, a decoration element, a window handle, a door handle, a strip, or others. The cleaning device may again comprise a pick-up unit 100 with the cleaning roller 110 to pick-up dirt from the surface 50, a (first) scraper 121 to take off the picked-up dirt from the cleaning roller 110 during rotation of the cleaning roller 110, and a channel 161 for carrying away the wet dirt (see Fig. 1). Again, optionally, a second scraper 122 may be present to clean another angular region of the cleaning roller 110.

[0141] According to embodiments, the housing 300 provides a closure for the cleaning device and a support for the pick-up unit 100 and comprises a first portion 310 in the forward direction R and a second portion 320 opposite to the forward direction R. The pick-up unit 100 is arranged between the first portion 310 and the second portion 320. Furthermore, the first portion 310 is adapted to accommodate at least partially the scraper 121 and the channel 161 and leaves a gap (or clearance) of predetermined height H to the surface 50 which is greater than a radius of the cleaning roller 110. In Fig. 8, the gap is "filled" with the obstacle 55, whereas in Fig. 1 the gap is an empty space before the cleaning roller 110 (no obstacle is shown).

[0142] According to embodiments, the predetermined height H of the gap is in a range from 10 mm to 50 mm or between 20 mm and 30 mm or about 25 mm. The predetermined heigh H can be selected freely, it should be larger than the clearance behind the cleaning roller 110.

[0143] According to embodiments, the cleaning device comprises again one or more sensor units 700 which is adapted to detect obstacles 55 and to provide respective sensor data to the control unit 500 (see Fig. 3). The sensor unit 700 may include at least one of the following sensors: optical sensor, a light gate, a mechanical sensor, an ultrasonic sensor, a current sensor for an electric current consumed by a drive unit for the cleaning roller 110, a radar sensor, a LIDAR sensor, ultrasonic sensor, other obstacle detection sensors (suitable to detect obstacles).

[0144] According to embodiments, the cleaning device comprises again a drive unit 400 for moving the cleaning device and the control unit 500 may again control the drive unit 400. For example, based on the sensor data from the sensor unit 700, the control unit 500 controls the drive unit 400 to clean the vertical surface 50 close to the obstacle 55. For example, the cleaning roller 110 may be exposed at the gap of predetermined height H to allow the cleaning roller 110 to get in touch with the obstacle 55 (e.g. to partially clean to the obstacle 55).

[0145] According to embodiments, when the sensor unit 700 includes the (electric) current sensor, the control unit 500 may detect or confirm the obstacle 55 based on a detected change in an electric current value or based on a comparison of the electric current values with one or more thresholds. For example, when the cleaning roller 110 gets into touch with an exemplary window frame, the roll resistance of the cleaning roller 110 may increase which may in turn correlate to an increase electric current consumption of the motor 190 that drives the cleaning roller 110. The electric current sensor can detect this increase and may infer from this, that the cleaning roller 110 had hit an obstacle.

[0146] Since the surface 50 may be subject of different degrees of contaminations, the rolling resistance will always be fluctuating within an acceptable range. Thus, only when the current value exceeds a minimal threshold, an obstacle may have been hit. Other thresholds may be associated with different types of obstacles which may result in different increases in the rolling resistances. A change in the rolling resistance may also be an indication of a different material of the surface (e.g., glass vs. metal, or wooden vs. carpet, or different carpeting). Embodiment will also take into account these changes and may change the cleaning.

[0147] According to embodiments, when the sensor unit 700 includes the mechanical sensor (e.g. a switch or pressure sensor), the control unit 500 may detect or confirm the obstacle 55 based on a trigger of the mechanical sensor. For example, a mechanical switch can be activated when the obstacle 55 moves under the first portion 310 of the housing 300. The mechanical sensor may be arranged in a front portion of housing 300 to detect the obstacle in good time before the obstacles 55 hits the cleaning roller 110.

[0148] According to embodiments, the mechanical switch may turn off the pick-up unit 100 when the cleaning roller 110 has lost contact with vertical surface 50 (e.g. beyond an edge) and / or the control unit 500 may move the cleaning device backwards to get again contact with the surface 55.

[0149] According to embodiments, the sensor unit 700 can comprise a light gate, which may provide the same functions as the mechanical switch. Again, light gate can be arranged in a front portion of the housing 300. For example, a transmitter of the light gate can be arranged on one lateral side and the receiver on an opposite lateral side of the cleaning device.

[0150] According to embodiments the housing 300 can also provide a guidance for the pick-up unit 100 along the sliding edge 175. Again, the pick-up unit 100 may be suspended by a spring-loaded mounting 150 that provides a pressure of the cleaning roller 110 onto the surface 50. For this movable mounting 150, the housing 300 and the support frame 170 provide the sliding edge 175 along which die pick-up unit 100 can linearly move while exerting the pressure onto the surface 50.

[0151] It is understood that the control unit 500 may comprise one or more controllers arranged at difference positions in or at the cleaning device. Each of the controller(s) can be dedicated for one or more functions. Alternatively, or in addition, all functions can be implemented into one central control unit.

[0152] According to embodiments, all operational functions described in this disclosure can be implemented in a method for controlling the cleaning device. Similarly, all functions can be implemented by software installed in the one or more controllers which are thus configured to provide the respective functions.

[0153] These methods may be implemented in software or as a computer program product. Therefore, embodiment relate also to a computer program product or a machine-readable storage device having a program code for performing the method, when the computer program is executed on a processor. A person of skill in the art would readily recognize that steps of various above-described acts may be performed by programmed computers. Embodiments are also intended to cover program storage devices, e.g., digital data storage media, which are machine or computer readable and encode machine-executable or computer-executable programs of instructions, wherein the instructions perform some or all of the acts of the above-described methods, when executed on the computer or processor.

[0154] The description and drawings merely illustrate the principles of the disclosure. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described or shown herein, embody the principles of the disclosure and are included within its scope.

[0155] Furthermore, while each embodiment may stand on its own as a separate example, it is to be noted that in other embodiments the defined features can be combined differently, i.e. a particular feature descripted in one embodiment may also be realized in other embodiments. Such combinations are covered by the disclosure herein unless it is stated that a specific combination is not intended.

[0156] Although the invention has been illustrated and described in detail by way of preferred embodiments, the invention is not limited by the examples disclosed, and other variations can be derived from these by the person skilled in the art without leaving the scope of the invention. It is therefore clear that there is a plurality of possible variations. It is also clear that embodiments stated by way of example are only really examples that are not to be seen as limiting the scope, application possibilities or configuration of the invention in any way. In fact, the preceding description and the description of the figures enable the person skilled in the art to implement the exemplary embodiments in concrete manner, wherein, with the knowledge of the disclosed inventive concept, the person skilled in the art is able to undertake various changes, for example, with regard to the functioning or arrangement of individual elements stated in an exemplary embodiment without leaving the scope of the invention, which is defined by the claims and their legal equivalents, such as further explanations in the description.List of reference signs

[0157] 50surface, wall (e.g. vertical) 55obstacle (e.g. window frame) 100pick-up unit 110cleaning roller 111, 112angular ranges 113, 114angles 115collecting space for sewage 120,121,122scraper(s) 125scraping strip 130holding structure 135sliding chamber (of scraper) 140biasing device (e.g. springs) 150mounting (of pick-up unit) 155spring(s) for mounting 161,162transport units for sewage (e.g. channel or suction ports) 163, 164inclination angles of channels 170support frame of pick-up unit 180main tank 181supplemental tank 183valve 186first termination opening 187second termination opening 190motor for cleaning roller 200suction unit 210suction channel 300housing (e.g. rectangular in a top view) 310first portion (front portion) 320second portion (rear portion) 330cover portion 340base portion 400drive unit 500control unit 600vacuum unit (to hold the cleaning unit) 650vacuum holding pads 700sensor(s) 800wetting system (water dispensing unit) 801, 802,803nozzle devices Rforward direction Drotation direction of cleaning roller Gdirection of gravity Hheight of housing Llinear movement C1, C2channel depths dminminimal distance d1, d2, ...distances (clearances)

Claims

1. A cleaning device for cleaning a vertical surface (50) when moving in a forward direction (R), the cleaning device comprising: a pick-up unit (100) with a cleaning roller (110) to pick-up dirt from the surface (50), a scraper (122) to take off the picked-up dirt from the cleaning roller (110) during rotation of the cleaning roller (110), and a channel (162) for carrying away the wet dirt; and a housing (300) providing a closure for the cleaning device and a support for the pick-up unit (100), the housing (300) comprises a first portion (310) in the forward direction (R) and a second portion (320) opposite to the forward direction (R), the pick-up unit (100) being arranged between the first portion (310) and the second portion (320), wherein the first portion (310) is adapted to accommodate at least partially the scraper (122) and the channel (162), and wherein the first portion (310) leaves a gap at a forward side of the housing (300) of predetermined height (H) to the surface (50) which is greater than a radius of the cleaning roller (110).

2. The cleaning device according to claim 1, wherein the gap of predetermined height (H) is in a range from 10 mm to 50 mm or between 20 mm and 30 mm or about 25 mm.

3. The cleaning device according to claim 1 or claim 2, further comprising a sensor unit (700) adapted to detect an obstacle (55), wherein the sensor unit (700) includes at least one of the following sensors: optical sensor, a mechanical sensor, a switch, a light gate, an ultrasonic sensor, a current sensor for an electric current consumed by a drive unit for the cleaning roller (no), and wherein the obstacle (55) is one of: a frame, an edge of the surface, a decoration element, a window handle, a door handle, a strip.

4. The cleaning device according to claim 3, further comprising: a drive unit (400) for moving the cleaning device; and a control unit (500) for controlling the drive unit (400) based on the sensor data from the sensor unit (700) to clean the vertical surface close to the obstacle (55).

5. The cleaning device according to claim 3 or claim 4, wherein the cleaning roller (110) is exposed at the gap of predetermined height (H) to allow the roller (110) to get in touch with the obstacle (55).

6. The cleaning device according to claim 4 or claim 5, wherein the sensor unit (700) includes the current sensor, and wherein the control unit (500) is configured to detect or to confirm the obstacle (55) based a detection of amplitude changes of the electric current values or a comparison of the electric current values with one or more thresholds.

7. The cleaning device according to any one of claims 4 to 6, wherein the sensor unit (700) includes the mechanical sensor which is adapted to measure pressure values exerted onto the pick-up unit (100) from the obstacle (55), and wherein the control unit (500) is configured to detect or to confirm the obstacle (55) based on the pressure values received from the mechanical sensor.

8. The cleaning device according to any one of claims 4 to 7, wherein the mechanical sensor (700) includes a mechanical switch to turn off the pick-up unit (100) when the cleaning roller (110) has lost contact with vertical surface (50), and / or the control unit (500) is configured to drive back and / or to turn off the pick-up unit (100) when the edge was detected as obstacle (55) and / or the cleaning roller (110) has lost contact with vertical surface (50).

9. The cleaning device according to any one of claims 1 to 8, further comprising: a mounting (150) for the pick-up unit (100) adapted to press the pick-up unit (100) with a predetermined pressure on the surface (50) to enable a floating pick-up unit (100), wherein the first portion (310) and the second portion (320) are adapted to provide a guidance for the floating pick-up unit (100).

10. The cleaning device according to claim 9, wherein the housing (300) provides between the first portion (310) and the second portion (320) a recess for the pick-up unit (100), the recess being open on one lateral side, the pick-up unit (100) further comprising: a case (170) mounted to the housing (300) by the mounting (150) and providing a support for the cleaning roller (no), wherein the case (170) closes flush the open lateral side of the recess.

11. The cleaning device according to claim 10, further comprising: a main tank (180) for sewage arranged on a lateral side of the cleaning roller (110) to allow the pick-up unit (100) to pick-up wet dirt from the surface (50), wherein the open lateral side of the recess is opposite to the side where the main tank (180) is arranged.

12. The cleaning device according to any one of claims 1 to 11, further comprising: a second scraper (120; 121) to take off the picked-up dirt from the cleaning roller (110) during rotation of the cleaning roller (no); a holding structure (130) to hold the scraper (122) and the second scraper (120; 121), the holding structure (130) being configured to allow a movement of each of the scraper (122) and the second scraper (120; 121) towards the cleaning roller (no); and at least one biasing device (140) to exert a bias force on the linear movement of the scraper (122) and the second scraper (120; 121) towards the cleaning roller (110).

13. The cleaning device according to any one of claims 1 to 12, further comprising: a vacuum unit (600) to generate a vacuum in a vacuum chamber, the vacuum and the vacuum chamber being adapted to hold the cleaning device at the vertical wall and / or to hold the cleaning device underneath a horizontal wall.

14. The cleaning device according to any one of claims 1 to 13, further comprising a suction unit (200) and a suction channel (210) wherein the control unit (500) is further adapted to control the suction unit (200) and the drive unit (400) based on the sensor data to move up and down the vertical wall or underneath a horizontal wall.

15. Method for manufacturing a cleaning device according to any one of claims 1 to 14.

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