FIELD OF THE INVENTION AND PRIOR ART

The present invention relates to a vacuum cleaning system according to the preamble of claim 1 .

A robotic vacuum cleaner unit is an apparatus that performs a cleaning task by sucking substances such as dust and debris from a floor surface while autonomously moving in an area to be cleaned without being manipulated by a user. Vacuum cleaning systems with a robotic vacuum cleaner unit for autonomous vacuum cleaning of floor surfaces are known in various configurations. One type of such a vacuum cleaning system is disclosed in US 6 076 226 A and comprises a mobile robotic vacuum cleaner unit with its own vacuum source and with a dust collecting compartment for temporarily accommodating dust and debris collected by the robotic vacuum cleaner unit. This previously known vacuum cleaning system also comprises a stationary docking station for the robotic vacuum cleaner unit, wherein a rechargeable battery of the robotic vacuum cleaner unit may be recharged and the dust collecting compartment of the robotic vacuum cleaner unit may be emptied when the robotic vacuum cleaner unit is in a docking position in the docking station.

Another type of vacuum cleaning system with a mobile robotic vacuum cleaner unit is disclosed in US 2005/0055792 A1 and US 2002/0174506 A1 and comprises a mobile main unit with a vacuum source and a dust collecting compartment, wherein the robotic vacuum cleaner unit is connected to the main unit trough a flexible suction hose and moveable in relation to the main unit. SUMMARY OF THE INVENTION

The object of the present invention is to provide a vacuum cleaning system with a robotic vacuum cleaner unit that has a new and favourable design.

According to the invention, this object is achieved by means of a vacuum cleaning system having the features defined in claim 1.

The vacuum cleaning system of the present invention comprises:

- a robotic vacuum cleaner unit, which comprises:

• a driving arrangement capable of moving the robotic vacuum cleaner unit over a floor surface,

• an electronic control device configured to control the driving arrangement to thereby control the movement of the robotic vacuum cleaner unit, and

• a vacuum cleaning nozzle;

- one or more docking stations for the robotic vacuum cleaner unit; and

- one or more flexible suction hoses, each suction hose being connected to a central unit in order to allow vacuum to be generated in the suction hose by a vacuum source included in the central unit, wherein each suction hose is associated with one of said docking stations and storable in a storage space in or adjacent to the associated docking station.

Each suction hose is provided with an end fitting at a front end, this end fitting having a first coupling part that is releasably connectable to a corresponding second coupling part on the robotic vacuum cleaner unit in order to provide fluid communication between the suction hose and the vacuum cleaning nozzle of the robotic vacuum cleaner unit. Said first coupling part is provided with a first suction port and said second coupling part is provided with a second suction port, wherein the second suction port is in fluid communication with the vacuum cleaning nozzle of the robotic vacuum cleaner unit and configured to be in fluid communication with the first suction port when the second coupling part is connected to the first coupling part.

Furthermore, each docking station comprises a holder for the end fitting of the associated suction hose, wherein the end fitting is received in and supported by this holder when the suction hose is in a retracted end position in the suction hose storage space associated with the docking station. The second coupling part on the robotic vacuum cleaner unit is connectable to and disconnectable from the first coupling part on the end fitting of a suction hose when the end fitting is received in the holder of the docking station associated with the suction hose and the robotic vacuum cleaner unit is positioned in a predefined docking position in this docking station.

In the vacuum cleaning system of the present invention, the mobile robotic vacuum cleaner unit is configured to be connected to a vacuum source of a stationary central unit through a flexible suction hose that extends between the robotic vacuum cleaner unit and a stationary docking station, which implies that a much more powerful vacuum source may be used as compared to the case with a conventional robotic vacuum cleaner unit equipped with its own vacuum source. The use of a powerful vacuum source makes it possible to achieve good cleaning efficiency.

Owing to the fact that the robotic vacuum cleaner unit included in the vacuum cleaning system of the present invention does not need to be equipped with any vacuum source or dust collecting compartment, the height and overall size as well as the weight of the robotic vacuum cleaner unit may be reduced as compared to a conventional robotic vacuum cleaner unit equipped with its own vacuum source and its own dust collecting compartment, which in its turn makes it possible for the robotic vacuum cleaner unit to reach into narrow spaces in a space to be cleaned. The reduced weight of the robotic vacuum cleaner unit and the absence of a vacuum source in the robotic vacuum cleaner unit also imply that the power consumption of the robotic vacuum cleaner unit is reduced, which in its turn implies prolonged operating time of the robotic vacuum cleaner unit. Furthermore, the absence of a dust collecting compartment in the robotic vacuum cleaner unit implies that there is no need for any complicated equipment in the docking station for emptying such a dust collecting compartment.

A further advantage with the vacuum cleaning system of the present invention is that the robotic vacuum cleaner unit is easily connectable to different docking stations, which may be installed in different parts of a building to be cleaned by means of the vacuum cleaning system, for instance in different rooms of the building. When the robotic vacuum cleaner unit has been disconnected from the end fitting of the suction hose at a docking station, the robotic vacuum cleaner unit is free to move itself to another docking station and connect itself to the suction hose at the latter docking station.

According to an embodiment of the invention, the first coupling part is rotatably mounted to the end fitting so as to be rotatable about a centre axis of the first suction port and/or the second coupling part is rotatably mounted to the robotic vacuum cleaner unit so as to be rotatable about a centre axis of the second suction port. The first and second coupling parts will hereby form a swivelling joint between the end fitting and the robotic vacuum cleaner unit. This rotatability between the end fitting and the robotic vacuum cleaner unit facilitates the movability of the robotic vacuum cleaner unit over the floor surface to be cleaned.

According to another embodiment of the invention, the robotic vacuum cleaner unit comprises an actuating device that is controlled by the electronic control device of the robotic vacuum cleaner unit, wherein the second coupling part on the robotic vacuum cleaner unit is connectable to and/or disconnectable from the first coupling part on the end fitting of a suction hose by operation of the actuating device when the end fitting is received in the holder of the docking station associated with the suction hose and the robotic vacuum cleaner unit is positioned in the predefined docking position in this docking station. According to one alternative, the second coupling part on the robotic vacuum cleaner unit is configured to be automatically connected to the first coupling part on the end fitting of a suction hose when the robotic vacuum cleaner unit assumes the docking position in the docking station. According to another alternative, the second coupling part on the robotic vacuum cleaner unit is configured to be connected to the first coupling part on the end fitting of a suction hose by operation of the actuating device when the robotic vacuum cleaner unit is in the docking position in the docking station. In both cases, the second coupling part is configured to be disconnected from the first coupling part by operation of the actuating device when the robotic vacuum cleaner unit is to move to another docking station.

According to another embodiment of the invention, said first and second coupling parts form a magnetic coupling, wherein at least one of the first and second coupling parts is provided with magnetic elements in the form of permanent magnets, preferably rare earth magnets, in order to allow the first and second coupling parts to be connected to each other by magnetic attraction. Different types of magnetic hose couplings suitable for the use here in question are available on the market. However, other types of quick-connect couplings could also be used, such as for instance different types of bayonet couplings or couplings with push latch mechanisms.

According to another embodiment of the invention, the above- mentioned actuating device comprises one or more separating elements, preferably in the form of axially moveable pins or plungers, and an actuator, preferably in the form of an electric motor, wherein the separating elements, by operation of the actuator, are moveable between a raised position, in which the separating elements protrude vertically beyond an upper surface of the second coupling part and thereby prevents the second coupling part from coming into contact with or remain in contact with the first coupling part on the end fitting of a suction hose, and a lowered position, in which the second coupling part is allowed to come into contact with and remain in contact with the first coupling part on the end fitting of a suction hose. In this case, the second coupling part is with advantage provided in a seat formed as a depression in an upper surface of the robotic vacuum cleaner unit, wherein this seat has a shape adapted to the shape of the first coupling part to thereby allow the first coupling part, or at least a part thereof, to be received in this seat. Thus, the first coupling part fits into the seat in the upper surface of the robotic vacuum cleaner unit and is configured to be received in this seat when the first coupling part is connected to the second coupling part. The seat ensures that the coupling parts will be properly positioned in relation to each other.

The above-mentioned separating elements are preferably urged towards the lowered position by means of one or more spring members included in the actuating device. In this case, the separating elements are moveable from the lowered position to the raised position by the actuator against the action of a spring force from said spring members and moveable from the raised position to the lowered position under the action of this spring force. However, the separating elements may as an alternative be urged towards the raised position by means of one or more spring members included in the actuating device, wherein the separating elements are moveable from the raised position to the lowered position by the actuator against the action of a spring force from said spring members and moveable from the lowered position to the raised position under the action of this spring force. As a further alternative, the actuator may be configured to move the separating elements from the lowered position to the raised position and also configured to move the separating elements from the raised position to the lowered position.

According to an alternative embodiment of the invention, the magnetic elements of the second coupling part are moveable by the actuating device between a lowered position and a raised position in the robotic vacuum cleaner unit, wherein the second coupling part is connectable to the first coupling part on the end fitting of a suction hose by movement of these magnetic elements from the lowered position to the raised position by means of the actuating device and disconnectable from the first coupling part by movement of these magnetic elements from the raised position to the lowered position by means of the actuating device. In this case, the magnetic elements of the second coupling part are preferably urged towards the lowered position, or alternatively towards the raised position, by means of one or more spring members included in the actuating device. When the magnetic elements of the second coupling part are in the lowered position, they are to be at such a distance from the magnetic elements of the first coupling part that the magnetic attraction between the magnetic elements of the second coupling part and the magnetic elements of the first coupling part is to low to allow the robotic vacuum cleaner unit to pull the end fitting of the suction hose out of its holder in the docking station.

Another embodiment of the invention is characterized in:

- that each docking station comprises a motorized feeding device, which is capable of feeding the suction hose associated with the docking station in a first direction away from the suction hose storage space and in an opposite second direction towards the suction hose storage space; and

- that each docking station comprises an electronic control device, which is configured to control the feeding device of the docking station in dependence on the movement of the robotic vacuum cleaner unit when the suction hose associated with the docking station is connected to the robotic vacuum cleaner unit. The length of the suction hose between the docking station and the robotic vacuum cleaner unit can hereby be automatically adapted to the prevailing position of the robotic vacuum cleaner unit in relation to the docking station, which implies a reduced risk for the robotic vacuum cleaner unit to be obstructed by the suction hose during its movement over the floor surface to be cleaned. According to another embodiment of the invention, a springreturn hose reel is provided in said suction hose storage space, wherein the suction hose is stored on the spring-return hose reel and withdrawable from the spring-return hose reel by the feeding device of the associated docking station against a retracting force from a spring return mechanism of the spring-return hose reel. This is a well-known and reliable manner of storing a suction hose of a central vacuum cleaning system.

According to an alternative embodiment of the invention, said suction hose storage space constitutes an inner space of a vacuum tube that is connected to the central unit in order to allow vacuum to be generated in the vacuum tube by the vacuum source of the central unit, wherein the suction hose is slidably received in said vacuum tube and withdrawable from the vacuum tube by the feeding device of the associated docking station against a retracting force from the vacuum generated in the vacuum tube by the vacuum source of the central unit. This is another well-known and reliable manner of storing a suction hose of a central vacuum cleaning system known under the name Hide-a-Hose.

Further advantageous features of the vacuum cleaning system according to the present invention will appear from the description following below and the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

With reference to the appended drawings, a specific description of embodiments of the invention cited as examples follows below. In the drawings:

Fig 1 is a schematic perspective view of a vacuum cleaning system according to a first embodiment of the present invention, Fig 2 is a schematic lateral view of the vacuum cleaning system of Fig 1 ,

Fig 3 is a schematic and partly cut perspective view of a vacuum cleaning system according to a second embodiment of the invention,

Fig 4 is a schematic and partly cut lateral view of the vacuum cleaning system of Fig 3,

Fig 5 is a perspective view from above of a robotic vacuum cleaner unit included in the vacuum cleaning systems of Figs 1-4,

Fig 6 is a perspective view from below of the robotic vacuum cleaner unit of Fig 5,

Fig 7 is a lateral view of the robotic vacuum cleaner unit of Fig 5,

Fig 8 is a planar view from below of the robotic vacuum cleaner unit of Fig 5,

Fig 9 is a planar view from above of the robotic vacuum cleaner unit of Fig 5,

Fig 10 is a perspective view of a part of a docking station included in the vacuum cleaning systems of Figs 1 -4,

Fig 11 is a perspective view corresponding to Fig 10, as seen with an end fitting of a suction hose received in a holder included in the docking station,

Figs 12a-12c are schematic perspective views of the docking station and the robotic vacuum cleaner unit, as seen at different mutual positions, Fig 13 is a schematic illustration of a feeding device and a suction hose included in the vacuum cleaning systems of Figs 1-4,

Fig 14 is a schematic illustration of feed rollers included in a feeding device of an alternative type,

Fig 15 is a schematic illustration of a feeding device of another alternative type,

Fig 16 is a front view of the docking station and the robotic vacuum cleaner unit,

Fig 17 is a schematic cut through the docking station and the robotic vacuum cleaner unit according to the line A-A in Fig 16,

Fig 18 is a schematic cut through a part of the robotic vacuum cleaner unit according to the line B-B in Fig 16,

Fig 19 is a cut perspective view of a part of the robotic vacuum cleaner unit,

Figs 20a and 20b are perspective views of an actuating device included in the robotic vacuum cleaner unit, as seen with the magnetic elements in a lowered position and a raised position, respectively,

Figs 21 and 22 are exploded perspective views of the actuating device of Figs 20a and 20b, and

Figs 23 and 24 are perspective views illustrating an actuating device of an alternative type. DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

A vacuum cleaning system 1 according to two alternative embodiments of the present invention are illustrated in Figs 1-4. The vacuum cleaning system 1 comprises a mobile robotic vacuum cleaner unit 30 and at least one stationary docking station 20 for the robotic vacuum cleaner unit installed in a room or other type of space to be cleaned by means of the robotic vacuum cleaner unit 30. The vacuum cleaning system 1 preferably comprises several docking stations 20 installed in different rooms or spaces in a building to be cleaned by means of the robotic vacuum cleaner unit 30. If a room or other space with a large floor surface is to be cleaned by means of the robotic vacuum cleaner unit 30, there may be two or more docking stations 20 installed in different parts of the room/space.

Each docking station 20 is associated with a flexible suction hose 2, which is connected to a central unit 3 in order to allow vacuum to be generated in the suction hose 2 by a vacuum source 4 included in the central unit. The vacuum source 4 is very schematically illustrated by broken lines in Figs 2 and 4 and may consist of a conventional vacuum motor or vacuum pump. Each suction hose 2 is connected to the central unit 3 through a system of vacuum tubes 5. The central unit 3 comprises a dust collecting compartment 6 for accommodating dust and debris conveyed to the central unit 3 from the robotic vacuum cleaner unit 30 through the suction hose 2 and the vacuum tubes 5 that are connected to the robotic vacuum cleaner unit. The dust collecting compartment 6 is very schematically illustrated by broken lines in Figs 2 and 4.

The suction hose 2 is storable in a storage space 7 in or adjacent to the associated docking station 20. In the embodiment illustrated in Figs 1 and 2, the suction hose 2 is stored on a spring-return hose reel 8 provided in a suction hose storage space 7 located behind the associated docking station 20, wherein the suction hose 2 is withdrawable from the spring-return hose reel 8 against a retracting force from a spring return mechanism of the spring-return hose reel. Thus, when a part of the suction hose 2 has been withdrawn from the spring-return hose reel 8, this part of the suction hose 2 is rewindable onto the spring-return hose reel 8 by the retracting spring force from the spring return mechanism.

In the embodiment illustrated in Figs 3 and 4, the suction hose storage space 7 constitutes an inner space of a vacuum tube 5’ that is connected to the central unit 3 in order to allow vacuum to be generated in the vacuum tube 5’ by the vacuum source 4 of the central unit, wherein the suction hose 2 is slidably received in this vacuum tube 5’ and withdrawable from the vacuum tube against a retracting force from the vacuum generated in the vacuum tube 5’ by the vacuum source 4 of the central unit 3. Thus, when a part of the suction hose 2 has been withdrawn from the suction hose storage space 7 in the vacuum tube 5’, this part of the suction hose 2 is retractable into the suction hose storage space 7 in the vacuum tube 5’ by the retracting suction force generated in the vacuum tube 5’ by the vacuum source 4 of the central unit 3.

The docking station 20 comprises a motorized feeding device 21 , which is capable of feeding the associated suction hose 2 in a first direction away from the suction hose storage space 7 and in an opposite second direction towards the suction hose storage space 7. Thus, in the embodiment illustrated in Figs 1 and 2, the suction hose 2 is withdrawable from the spring-return hose reel 8 by the feeding device 21 against the retracting force from the spring return mechanism of the spring-return hose reel, and in the embodiment illustrated in Figs 3 and 4, the suction hose 2 is withdrawable from the vacuum tube 5’ by the feeding device 21 against a retracting force from the vacuum generated in the vacuum tube 5’ by the vacuum source 4 of the central unit 3. The feeding device 21 preferably comprises two or more rotatably mounted feed rollers 22, which are in contact with the suction hose 2 on different sides thereof and configured to control the feeding of the suction hose 2 in the above-mentioned first and second directions, wherein the feeding device 21 further comprises at least one reversible electric motor 23 (see Figs 13 and 17) for rotating at least one of the feed rollers 22. The electric motor 23 may be configured to rotate only one of the feed rollers 22, wherein the other feed rollers are idler rollers. Driving torque for rotating the driven feed roller 22 may be transmitted from the electric motor 23 to the driven feed roller 22 through a suitable transmission. One single electric motor 23 may as an alternative be configured to rotate two or more of the feed rollers 22 through a suitable transmission, for instance through a transmission comprising pulleys and an associated drive belt. According to a further alternative, two or more feed rollers 22 may be individually driven by a respective electric motor 23.

The feeding device 21 is with advantage provided with three feed rollers 22 distributed about the circumference of the suction hose 2 in the manner illustrated in Fig 13. However, feeding device 21 may as an alternative be provided with four feed rollers 22 distributed about the circumference of the suction hose 2 in the manner illustrated in Fig 14. Preferably, at least one of the feed rollers 22 is spring-urged towards the suction hose 2 by spring force from a spring mechanism 24 to thereby allow the suction hose 2 to be pinched between the feed rollers 22.

As a further alternative, the feeding device 21 may be provided with two drive belts 25 (see Fig 15), which are in contact with the suction hose 2 on opposite sides thereof and configured to control the feeding of the suction hose 2 in the above-mentioned first and second directions, wherein each drive belt 25 is arranged in an endless loop around two rollers 26. In this case, at least one of the rollers 26 of at least one of the drive belts 25 is driven in rotation by a reversible electric motor. The feeding device 21 may of course also be designed in any other suitable manner, as long as it is capable of feeding of the suction hose 2 in the above-mentioned first and second directions.

The suction hose 2 is provided with an end fitting 10 at a front end, i.e. at the end where the suction hose 2 is to be connected to the robotic vacuum cleaner unit 30. The suction hose 2 is connectable to the robotic vacuum cleaner unit 30 through this end fitting 10. The docking station 20 comprises a holder 27 for the end fitting 10 of the associated suction hose 2, wherein the end fitting 10 is received in and supported by the holder 27 when the suction hose 2 is in a retracted end position in the suction hose storage space 7, as illustrated in Figs 11 and 12a. In the illustrated embodiments, the holder 27 has the form of a tubular sleeve, which extends in horizontal direction from the docking station 20 and which surrounds a rear part of the end fitting 10 when the suction hose 2 is in the retracted end position in the suction hose storage space 7. The holder 27 is provided with guide surfaces 28 (see Figs 10 and 11 ), which co-operate with a guide member 11 on the end fitting 10 in order to guide the end fitting 10 into a predefined resting position in the holder 27 when the rear part of the end fitting 10 is moved into the holder. The holder 27 may of course also be designed in any other suitable manner.

In the illustrated embodiments, the feeding device 21 is arranged in a housing 29 at a lower part of the docking station 20, wherein the holder 27 is fixed to this housing 29 and configured to project in horizontal direction from it.

The docking station 20 also comprises an electronic control device 12 (very schematically illustrated by broken lines in Figs 2 and 4), which is configured to control the feeding device 21 in dependence on the movement of the robotic vacuum cleaner unit 30 when the suction hose 2 is connected to the robotic vacuum cleaner unit. The robotic vacuum cleaner unit 30 comprises a driving arrangement 31 for moving the robotic vacuum cleaner unit over a floor surface and an electronic control device 32 that is configured to control the driving arrangement 31 to thereby control the movement of the robotic vacuum cleaner unit 30. By means of the driving arrangement 31 , the robotic vacuum cleaner unit 30 can move forwards and backwards and rotate. The driving arrangement 31 comprises two or more drive wheels 33a, 33b and one or more reversible electric drive motors 34a, 34b for driving the drive wheels 33a, 33b. In the illustrated embodiment, the driving arrangement 31 comprises first and second drive wheels 33a, 33b arranged on opposite sides of the robotic vacuum cleaner unit 30, a first drive motor 34a for driving the first drive wheel 33a and a second drive motor 34b for driving the second drive wheel 33b. Thus, the drive wheels 33a, 33b are individually driven by the associated drive motors 34a, 34b. Hereby, the robotic vacuum cleaner unit 30 can be driven forwards or backwards in a straight path by propelling the first and second drive wheels 33a, 33b in the same direction and at the same speed. If one of the drive wheels 33a, 33b is propelled forwards at a higher speed than the other drive wheel, the robotic vacuum cleaner unit 30 will turn along an arc to the right or to the left. The robotic vacuum cleaner unit 30 can also be rotated about a vertical axis by propelling the first and second drive wheels 33a, 33b in opposite directions. In the illustrated embodiment, the robotic vacuum cleaner unit 30 also comprises two castors 35a, 35b, which are arranged on opposite sides of the robotic vacuum cleaner unit and which are capable of moving in all directions. The driving arrangement 31 may of course also be designed in any other suitable manner.

The robotic vacuum cleaner unit 30 is provided with at least one rechargeable battery 36, which is configured to supply electric energy to the electronic control device 32 and the drive motors 34a, 34b. The battery 36 is connected to one or more charging contacts 37 on the robotic vacuum cleaner unit 30. The docking station 20 is provided with corresponding charging contacts and a battery charger circuit connected to these charging contacts. When the robotic vacuum cleaner unit 30 assumes the predefined docking position illustrated in Figs 1-4, each charging contact 37 on the robotic vacuum cleaner unit 30 will automatically connect to an associated charging contact in the docking station to thereby allow a recharging of the battery 36 in the robotic vacuum cleaner unit 30.

The robotic vacuum cleaner unit 30 also comprises a vacuum cleaning nozzle 38 with a downwardly facing inlet opening 39, which is in fluid communication with a suction channel 40 in the robotic vacuum cleaner unit 30. Dust and debris may be sucked into the suction channel 40 through the inlet opening 39 of the vacuum cleaning nozzle 38 when the robotic vacuum cleaner unit 30 moves over a floor surface.

The end fitting 10 at the front end of the suction hose 2 is provided with a first coupling part 14a, which is provided with a first suction port 15a and which is releasably connectable to a corresponding second coupling part 14b on the robotic vacuum cleaner unit 30. The first suction port 15a is in fluid communication with the suction hose 2 via a flow channel 16 in the end fitting 10. The second coupling part 14b is provided with a second suction port 15b, which is in fluid communication with the inlet opening 39 of the vacuum cleaning nozzle 38 via the suction channel 40 in the robotic vacuum cleaner unit 30. When the first coupling part 14a is connected to the second coupling part 14b, the first and second suction ports 15a, 15b are configured to be in fluid communication with each other to thereby provide fluid communication between the suction hose 2 and the vacuum cleaning nozzle 38 of the robotic vacuum cleaner unit.

The second coupling part 14b on the robotic vacuum cleaner unit 30 is connectable to and disconnectable from the first coupling part 14a on the end fitting 10 of the suction hose 2 when the end fitting 10 is received in the holder 27 of the docking station 20 and the robotic vacuum cleaner unit 30 is positioned in the predefined docking position in the docking station.

In the illustrated embodiments, the first suction port 15a is facing downwards and the second suction port 15b is facing upwards, wherein the second suction port 15b is provided in an upper surface 42 of a housing 43 of the robotic vacuum cleaner unit 30.

The first and second coupling parts 14a, 14b are preferably configured to form a swivelling joint between the end fitting 10 and the robotic vacuum cleaner unit 30. This may be achieved by having the first coupling part 14a rotatably mounted to the end fitting 10 so as to be rotatable about a centre axis of the first suction port 15a and/or by having the second coupling part 14b rotatably mounted to the housing 43 of the robotic vacuum cleaner unit 30 so as to be rotatable about a centre axis of the second suction port 15b.

The robotic vacuum cleaner unit 30 preferably comprises an actuating device 45 that is controlled by the electronic control device 32 of the robotic vacuum cleaner unit, wherein the second coupling part 14b on the robotic vacuum cleaner unit is connectable to and/or disconnectable from the first coupling part 14a on the end fitting 10 by operation of the actuating device 45 when the end fitting 10 is received in the holder 27 of the docking station 20 and the robotic vacuum cleaner unit 30 is positioned in the predefined docking position in the docking station. In the illustrated embodiments, the second coupling part 14b is configured to be automatically connected to the first coupling part 14a when the robotic vacuum cleaner unit 30 assumes the docking position in the docking station 20 and configured to be disconnected from the first coupling part 14a by operation of the actuating device 45.

The first and second coupling parts 14a, 14b are with advantage configured to form a magnetic coupling, wherein at least one of the first and second coupling parts 14a, 14b is provided with magnetic elements 16a, 16b in the form of permanent magnets, for instance in the form of neodymium magnets, in order to allow the first and second coupling parts 14a, 14b to be connected to each other by magnetic attraction. In the illustrated embodiments, six magnetic elements 16b in the form of permanent magnets are provided in the second coupling part 14b and circumferentially distributed about the second suction port 15b, wherein six magnetic elements 16a of ferromagnetic material are provided in the first coupling part 14a and circumferentially distributed about the first suction port 15a. When the first and second coupling parts 14a, 14b are connected to each other, the magnetic elements 16a of the first coupling part 14a are configured to be aligned with a respective one of the magnetic elements 16b of the second coupling part 14b. The number of magnetic elements 16a, 16b in each coupling part 14a, 14b may of course also be fewer or more than six. Furthermore, the magnetic elements 16a of the first coupling part 14a could be permanent magnets, wherein the magnetic elements 16b of the second coupling part 14a could be of ferromagnetic material.

The above-mentioned actuating device 45 may comprise one or more separating elements 46 and an actuator 47, preferably in the form of an electric motor, wherein the separating elements 46, by operation of the actuator 47, are moveable between a raised position, in which the separating elements 46 protrude vertically beyond an upper surface of the second coupling part 14b and thereby prevents the second coupling part from coming into contact with or remain in contact with the first coupling part 14a, and a lowered position, in which the second coupling part 14b is allowed to come into contact with and remain in contact with the first coupling part 14a. Thus, in this case, the magnetic elements 16a of the first coupling part 14a are disconnected from the magnetic elements 16b of the second coupling part 14b by movement of the separating elements 46 from the lowered position to the raised position. In the illustrated embodiments, the separating elements 46 have the form of axially moveable pins or plungers and are slidably received in a respective bore 48 in a body 49 that is fixed to or forms part of the housing 43 of the robotic vacuum cleaner unit 30 and that surrounds the second coupling part 14b. The second coupling part 14b is with advantage rotatably mounted to this body 49. The separating elements 46 are preferably two or more in number.

The movements of the separating elements 46 between the lowered and raised positions may for instance be achieved by means of a cam mechanism of the type illustrated in Figs 18-22. In this case, the actuating device 45 comprises:

- an annular first cam member 50a with an externally toothed rim 51 and upwardly facing inclined guide surfaces 52a;

- an annular second cam member 50b with downwardly facing inclined guide surfaces 52b configured to co-operate with the guide surfaces 52a on the first cam member, wherein the second cam member 50b is located above the first cam member 50a and the guide surfaces 52b on the second cam member bears against a respective guide surface 52a on the first cam member; and

- an actuator 47 in the form of a reversible electric motor, wherein the actuator 47 is configured to rotate a gear 56, which in its turn is in driving engagement with the toothed rim 51.

The separating elements 46 are fixed to the second cam member 50b. Spring members 54 are clamped between the annular body 49 and the second cam member 50b, wherein the second cam member 50b is urged towards the first cam member 50a by these spring members 54. The first cam member 50a is rotatable in relation to the second cam member 50b by the actuator 47 from a first rotary position (see Fig 20a), in which the second cam member 50b and the separating elements 46 are in a lowered position, and a second rotary position (see Fig 20b), in which the second cam member 50b and the separating elements 46 are in a raised position. When the first cam member 50a is rotated in relation to the second cam member 50b from the first rotary position to the second rotary position, the guide surfaces 52a on the first cam member slide against the corresponding guide surfaces 52b on the second cam member to thereby push the second cam member 50b vertically upwards. When the first cam member 50a is rotated in relation to the second cam member 50b in the opposite direction from the second rotary position to the first rotary position, the second cam member 50b is pushed vertically downwards by the spring force of the spring members 54.

The movements of the separating elements 46 between the lowered and raised positions may as an alternative be achieved by means of a link mechanism of the type illustrated in Figs 23 and 24. In this case, the actuating device 45 comprises:

- a shaft 58, which is rotatably mounted to the housing 43 of the robotic vacuum cleaner unit 30;

- levers 59, which are fixed to the shaft 58 and configured to be pivoted about a centre axis of the shaft 58 by rotation of the shaft, wherein the levers 59 are articulately connected to a respective separating element 46; and

- an actuator 47 in the form of a reversible electric motor, which is configured to rotate the shaft 58.

In this case, the link mechanism is configured to transfer a rotation of the shaft 58 in a first rotary direction into a linear movement of each separating element 46 from the lowered position to the raised position and a rotation of the shaft 58 in the opposite rotary direction into a linear movement of each separating element 46 from the raised position to the lowered position.

The movements of the separating elements 46 between the lowered and raised positions may of course also be achieved in any other suitable manner.

As an alternative to the use of separating elements 46, the magnetic elements 16b of the second coupling part 14b may be moveable by the actuating device 45 between a lowered position and a raised position in the robotic vacuum cleaner unit 30, wherein the second coupling part 14b is connectable to the first coupling part 14a by movement of the magnetic elements 16b from the lowered position to the raised position and disconnectable from the first coupling part 14a by movement of the magnetic elements 16b from the raised position to the lowered position. The movements of the magnetic elements 16b between the raised and lowered positions may for instance be achieved by means of a cam mechanism of the type illustrated in Figs 18-22 or by means of a link mechanism of the type illustrated in Figs 23 and 24, or in any other suitable manner.

In the illustrated embodiments, the second coupling part 14b is provided in a seat 62 formed as a depression in the upper surface 42 of the housing 43 of the robotic vacuum cleaner unit 30, wherein this seat 62 has a shape adapted to the shape of the first coupling part 14a to thereby allow the first coupling part, or at least a part thereof, to be received in this seat 62. When the robotic vacuum cleaner unit 30 approaches the docking position in the docking station 20, the first coupling part 14a is configured to slide against the upper surface 42 of the housing 43 of the robotic vacuum cleaner unit 30 and finally reach a position in alignment with the seat 62 when the robotic vacuum cleaner unit 30 assumes the docking position.

The electronic control device 32 of the robotic vacuum cleaner unit 30 may be configured to control the movement of the robotic vacuum cleaner unit in a space to be cleaned in any suitable and previously known manner. For this purpose, the robotic vacuum cleaner unit 30 is provided with navigation sensors 65, 66, wherein the electronic control device 32 of the robotic vacuum cleaner unit is connected to these navigation sensors 65, 66 and configured to receive sensor signals from them. The robotic vacuum cleaner unit 30 may for instance be configured to move along a predetermined path in a space to be cleaned, wherein the electronic control device 32 may be configured to generate a map of the space. In this case, at least one of the navigation sensors is used for mapping the surrounding space and may for instance have the form of a camera sensor, sonar sensor, lidar sensor, infrared sensor or 3D scanner sensor, wherein the electronic control device 32 is configured to generate said map based on sensor signals from this sensor or these sensors. In the illustrated embodiment, the robotic vacuum cleaner unit 30 is provided with a lidar sensor 65 for mapping the surrounding space. Some of the navigation sensors are used for obstacle detection and may for instance have the form of ultrasonic sensors and/or infrared sensors. In the illustrated embodiment, the robotic vacuum cleaner unit 30 is provided with several ultrasonic sensors 66, which are arranged on different sides of the robotic vacuum cleaner unit and used for obstacle detection.

When the vacuum cleaning system 1 is set up, the electronic control device 32 of the robotic vacuum cleaner unit 30 may be configured to initially learn the position of a docking station 20 in a space to be cleaned by being manually positioned in the docking position in the docking station, whereupon the electronic control device 32 is configured to generate a map of the space starting from the docking station 20. When the robotic vacuum cleaner unit 30 is to move between docking stations 20 in different spaces, the electronic control device 32 is first configured to generate a map of each space starting from the docking station 20 of the space, whereupon a user may mark a connection between the different mapped spaces through a suitable user interface to thereby enable for the electronic control device 32 to manoeuvre the robotic vacuum cleaner unit 30 from a docking station 20 in one space to a docking station 20 in another space.

In order to facilitate the manoeuvring of the robotic vacuum cleaner unit 30 into the correct docking position in a docking station 20, the docking station may be provided with visual markings that are detected by a camera on the robotic vacuum cleaner unit 30.

The electronic control device 12 of each docking station 20 is configured to control the feeding device 21 of the docking station on the basis of control signals from the electronic control device 32 of the robotic vacuum cleaner unit 30 related to the movement of the robotic vacuum cleaner unit in relation to the docking station when the suction hose 2 associated with the docking station 20 is connected to the robotic vacuum cleaner unit 30, to thereby keep the length of the suction hose 2 between the docking station 20 and the robotic vacuum cleaner unit 30 as short as possible, while taking any obstacles between the docking station 20 and the robotic vacuum cleaner unit 30 into account. The electronic control device 32 of the robotic vacuum cleaner unit 30 is configured to take the sensor signals from the navigation sensors 65, 66 into account when generating said control signals. The control signals are transmitted from the electronic control device 32 of the robotic vacuum cleaner unit 30 to the electronic control device 12 of the docking station 20 through a wireless connection.

When the robotic vacuum cleaner unit 30 has been connected to a suction hose 2 at a docking station 20, the electronic control device 32 of the robotic vacuum cleaner unit 30 may initiate a cleaning operation by transmitting a starting signal to the electronic control device 12 of the docking station 20 through a wireless connection, whereupon the electronic control device 12 of the docking station 20, when having received the starting signal, is configured to transmit an activation signal to the central unit 3 in order to effect a starting of the vacuum source 4. The activation signal may be transmitted from the electronic control device 12 of the docking station 20 to the central unit 3 in a conventional manner through a wire or through a wireless connection.

The invention is of course not in any way restricted to the embodiments described above. On the contrary, many possibilities to modifications thereof will be apparent to a person with ordinary skill in the art without departing from the basic idea of the invention such as defined in the appended claims.