WO2008121034A1

WO2008121034A1 - Vacuum cleaner nozzle and a method for vacuum cleaning

Info

Publication number: WO2008121034A1
Application number: PCT/SE2007/000953
Authority: WO
Inventors: Håkan MIEFALK; Anders Haegermarck; Johann Zita; Tommy Lindquist
Original assignee: Aktiebolaget Electrolux
Priority date: 2007-03-29
Filing date: 2007-10-29
Publication date: 2008-10-09

Abstract

The invention relates to a vacuum cleaner nozzle comprising an air inlet opening on a bottom side and being attachable to a vacuum cleaner having a vacuum source to draw air together with debris and dust through the inlet opening to the vacuum cleaner for collecting the debris in a debris separator in the vacuum cleaner. The vacuum cleaner nozzle (4) comprises a separate debris separator (7, 8), which is connected in series, in respect of the air flow through the nozzle and the vacuum cleaner, with the debris separator in the vacuum cleaner. The invention also relates to a method for vacuum cleaning of a surface.

Description

VACUUM CLEANER NOZZLE AND A METHOD FOR VACUUM CLEANING

The present invention relates to a vacuum cleaner nozzle comprising an air inlet opening on a bottom side and being attachable to a vacuum cleaner having a vacuum source to draw air together with debris and dust through the inlet opening to the vacuum cleaner for collecting the debris in a debris separator in the vacuum cleaner.

The invention also relates to a method for vacuum cleaning.

Background of the invention

When vacuum cleaning, use is made of some form of debris separator, which separates the debris and dust from the air flow. As a debris separator it is most common to use a so called filter bag, which filters the air such that the debris is trapped inside the filter bag. When the filter bag is full it normally is replaced by a new one, but it is also conceivable to empty the filter bag and accordingly recycle the filter bag one or several times. However, it is also conceivable to use a debris separator in form of a cyclone, in which the air flow is rotated in a housing such that the debris is forced to the periphery of the housing and eventually is deposited at the bottom of the housing or in a separate debris collector.

One problem with debris separators is of course that they tend to get filled by debris, which necessitate replacement or emptying. Another problem which affect filter bags is that the small pores in the filter bag can be clogged long before the bag is actually full, which will lead to increased air flow resistance through the filter bag and accordingly decreased suction capacity of the vacuum cleaner. Such clogging of the pores is particular common if the debris contains large quantities of a specific small fraction, such as is the case when cleaning carpets or the like by means of a cleaning powder. In such a case the cleaning powder is distributed over the carpet and subsequently, after a predetermined acting time, is sucked up together with debris and dirt by means of a vacuum cleaner. Moreover, when removing debris by means of a vacuum cleaner, the debris and dust can adhere to the surfaces inside the air passages in the vacuum cleaner, e.g. inside the hose of a canister type of vacuum cleaner or a central vacuum cleaner or inside the air passages of a stick type of vacuum cleaner, especially when the debris is somewhat wet. Such wet debris can be for example cleaning powder, which has been applied to a carpet for absorb- .

ing spilled liquids or the like, or a liquid cleaning agent, which is used for e.g. carpet cleaning.

In WO 2006/106278 is disclosed a surface cleaning apparatus comprising a rotary brush which optionally can be connected to an external suc- tion creating means such as a vacuum cleaner. The surface cleaning apparatus comprises a battery powered electric motor, which operates an internal suction creating means. During use, the rotary brush is sweeping debris into a first separator compartment, the internal suction creating means draws an air flow through a first inlet aperture in the bottom side to a cyclone separator, which deposits debris in a second separator compartment, and the external suction creating means draws an airflow through a second inlet aperture in the bottom side to a debris separator in an external vacuum cleaner. Accordingly, there is provided three parallel pathways for the debris. There are several disadvantages with such an apparatus. First of all it is very complicated and will therefore be expensive to manufacture, for instance due to the additional electric motor, the battery pack and the internal suction creating means. Moreover, since there are three parallel pathways for the debris, essentially the same composition of the debris can be collected in three different places. This has only to effect that it will be more laborious for the user since he or she will have to empty debris from three different places instead of only one as is the case for most vacuum cleaners.

Summary of the invention

One object of the invention is to overcome the above disadvantages associated with prior art vacuum cleaners and provide a vacuum cleaner nozzle, which will improve the debris collecting characteristics of the vacuum cleaner. At least this object is achieved by a vacuum cleaner nozzle according to claim 1.

The invention also relates to a method for vacuum cleaning, having essentially the same object as above. At least this object is achieved by a method according to claim 14.

Accordingly, the basis of the invention is the insight that the above object may be achieved by arranging a debris separator in a vacuum cleaner nozzle, which is connected in series with the debris separator in the actual vacuum cleaner, i.e. the whole air flow, which is flowing to the debris separator in the vacuum cleaner, will also pass through the debris separator in the nozzle. Within this general idea, the invention may be implemented in many different ways. In one embodiment the debris separator in the nozzle is a cyclone or cyclone like debris separator. In this way the debris separator can be arranged to be used on a continuous basis such that the debris will be divided into different fractions having different density, wherein high density materials, such as particulate and wet materials, will be deposited in the first debris separator in the vacuum cleaner nozzle, whereas low density materials such as dust will be deposited in the second debris separator in the vacuum cleaner. However, the debris separator in the nozzle can also be arranged as an auxiliary debris separator, which is used only occasionally when needed, e.g. for vacuum cleaning of heavy contaminated places or for removing e.g. cleaning powder from a carpet. In such an embodiment, the debris separator also may comprise a filter bag. The debris separator can be fixed or releasable arranged in the nozzle.

If the debris separator is fixed and is adapted for intermittent or occasionally operation, the nozzle preferably can be provided with a control means for directing the air flow to or past the debris separator as desired. A releasable debris separator is beneficial in so far as it is easier to empty and it can be removed when it is not in use, which will make the nozzle smaller.

In a hereinafter illustrated and described embodiment of the invention, the vacuum cleaner nozzle is provided with a debris separator comprising a cyclone housing and a releasable debris collector, wherein the air flow is caused to rotate inside the cyclone housing such that at least the heavier de- bris is forced outwards to the periphery of the housing and eventually is removed from the cyclone housing, through an opening in a wall thereof, to the debris collector. However, also embodiments where both the cyclone housing and the debris collector are fixed in the nozzle, or in other words, permanently arranged in the nozzle, are possible and one such embodiment will also be described hereinafter. These embodiments have the advantage that the respective parts will not get lost.

A debris collector, which is fixedly arranged in the vacuum cleaner nozzle, can be provided with a closable opening for enabling emptying thereof. In order to easy see when the debris collector is full and needs empty- ing, it can preferably be transparent or have a transparent window or the like.

The vacuum cleaner nozzle can be of any kind. E.g. nozzles for ordinary vacuum cleaning or, as in the hereinafter described and illustrated em- bodiments, a vacuum cleaner nozzle which comprises a rotary brush and, besides being used for ordinary vacuum cleaning, can be used for distributing a cleaning agent such as cleaning powder over a carpet, agitating of the cleaning powder by means of the brush in between the carpet fibres, and subsequent removing of the cleaning powder from the carpet by means of the rotating brush and the air flow through the nozzle.

In one such embodiment of a nozzle for carpet cleaning according to the invention and when using a cleaning powder, the debris collector of the debris separator is made as a releasable unit, which is replaced by a cleaning powder container in the distribution stage. After a predetermined acting time, the cleaning powder container is removed and replaced by the debris collector. The cleaning powder container and the debris collector are made such that at the same time as mounting them onto the vacuum cleaner nozzle, the air flow is automatically redirected such that in the cleaning powder distribu- tion stage, no air is drawn through an air inlet opening in the bottom side adjacent the rotating brush. Instead the air is drawn through an auxiliary air inlet on the upper side of the vacuum cleaner nozzle such that the air is passed through the cyclone housing and a turbine wheel, which drives the rotary brush for agitating of the powder into the carpet. In the powder recovery stage, when the debris collector is mounted onto the vacuum cleaner nozzle, the air flow is redirected such that it flows in through the air inlet opening on the bottom side, into the cyclone housing in which the main part of the cleaning powder is separated and transferred to the debris collector where it is deposited, through the turbine wheel such that the brush is rotated, and subse- quently to the vacuum cleaner where any remaining debris and dust in the air flow is deposited in the debris separator of the vacuum cleaner.

However, it is also possible to arrange the debris separator including the debris collector as a fixed unit in a nozzle for carpet cleaning with a cleaning powder. According to one embodiment, in addition to a fixed cyclone housing and debris collector, also the cleaning powder container is fixed, or in other words, permanently included in the nozzle. The nozzle of this embodiment comprises further a control member, a first air channel from an air inlet opening in the bottom side adjacent the rotating brush and a second air channel from an auxiliary air inlet on the upper side of the vacuum cleaner nozzle. The two air channels can lead to one and the same air inlet of the cyclone housing, or lead to a first and a second air inlet of the cyclone housing, respectively. The control member is operable to, in a cleaning powder distri- bution stage, close the first air channel and open the second air channel such that no air is drawn through the air inlet opening in the bottom side of nozzle housing. Instead the air is drawn through the auxiliary air inlet such that the air travels through the cyclone housing and a turbine wheel, which drives the rotary brush for agitating of the powder into the carpet. Furthermore, the control member is operable to, in the powder recovery stage, to open the first air channel and to close the second air channel whereby the air flow is redirected such that it flows in through the air inlet opening on the bottom side of the nozzle housing. Form there, the air flow continues into the cyclone housing in which the main part of the cleaning powder is separated and transferred to the debris collector where it is deposited, and further through the turbine wheel such that the brush is rotated, and subsequently to the vacuum cleaner where any remaining debris and dust in the air flow is deposited in the debris separator of the vacuum cleaner. According to one embodiment of the inven- tion having air channels with one respective air inlet in the cyclone housing, the air channels are opened and closed by opening and closing the corresponding air inlet in the cyclone housing.

It has appeared that placing a debris separator in form of a cyclone separator immediately before the turbine wheel, is very beneficial for the driv- ing of the turbine wheel, since then the air flow will already have a rotational motion when reaching the turbine wheel, which will increase the rotational speed of the turbine wheel.

It is to be understood, however, that a vacuum cleaner nozzle being adapted for carpet cleaning and having a debris separator, could be formed in many different ways. For example, the rotary brush can be electrically driven, or the vacuum cleaner nozzle can be without any powder dispensing facility and instead the powder is dispensed by hand. Instead of using a cleaning agent in form of a powder, it would be conceivable to use a wet or liquid cleaning agent if the vacuum cleaner nozzle is provided with a debris separa- tor in form of a cyclone. A cyclone can in fact separate liquids and avoid that any of the liquid will stick to the air passages in the vacuum cleaner or that electrical equipment inside the vacuum cleaner will be damaged. One requirement is however that the cyclone and any debris collector is liquid tight. It is also to be understood that although hereinafter is described and illus- trated a vacuum cleaning nozzle adapted for carpet cleaning, the invention is universally applicable to all kinds of vacuum cleaning nozzles. Brief description of the drawings

An embodiment of the invention will now be described with reference to the drawings, in which:

Fig 1 is a perspective view of a canister type of vacuum cleaner hav- ing a hose and tube, in the end of which a vacuum cleaner nozzle according to a first example embodiment of the invention is mounted;

Fig 2 is a perspective view of the vacuum cleaner nozzle according to fig 1 in an enlarged scale, being provided with a debris collector; Fig 3 is a perspective view according to fig 2 with the debris collector released; Fig 4 is a perspective view according to fig 3 with an upper part of the vacuum cleaner nozzle removed;

Fig 5 is a cross section through the vacuum cleaner nozzle along the line V-V in fig 2, showing the air flow through it with the debris collector mounted;

Fig 6 is a cross section according to fig 5 along the line Vl-Vl in fig 2;

Fig 7 is a perspective view of the vacuum cleaner nozzle having the debris collector replaced by a cleaning powder container; Fig 8 is a perspective view from the bottom side of the cleaning powder container and a cleaning powder refill container to be inserted therein;

Fig 9 is a cross section through the vacuum cleaner nozzle according to fig 7, showing the air flow through it with the cleaning powder container mounted.

Fig 10 is a perspective view of a vacuum cleaner nozzle according to a second example embodiment having a fixed debris collector and a fixed cleaning powder container;

Fig. 11 is a perspective view of the vacuum cleaner nozzle according to Fig. 10 with an upper part of the vacuum cleaner nozzle removed;

Figs. 12a -12c are cross sectional views of the vacuum cleaner nozzle according to Fig. 10, showing the operation of the vacuum cleaner according to the second example embodiment; and Fig. 13 is a perspective view of the vacuum cleaner nozzle according to a second example embodiment showing the debris collector in an open position. Detailed description of preferred embodiments of the invention

In fig 1 is illustrated a vacuum cleaner 1 of a so called canister type having a vacuum cleaner body accommodating a, not shown, suction gener- ating fan and a debris separator, normally in form of a filter bag, through which the air flow is filtered such that the debris will be collected inside the filter bag. The vacuum cleaner is provided with a hose 2 and a tube 3, in the end of which is mounted a vacuum cleaner nozzle 4. As customary, the vacuum cleaner nozzle comprises an elongated air inlet opening 5 in a bottom side, as is evident from fig 6 and 7, to allow drawing of an air flow together with debris and dust from the area of a floor 6, or the like, to be cleaned. The air flow is drawn through the nozzle, the tube and the hose to the debris separator inside the vacuum cleaner body, in which the debris is separated from the air flow. However, according to the invention, the illustrated vacuum cleaner nozzle is provided with a separate debris separator, comprising a cyclone housing 7 and a debris collector 8, as is illustrated in fig 2. The debris collector is provided with a transparent window 9 to allow for a user to see when the debris collector needs to be emptied. The debris collector 8 is also releasable from the vacuum cleaner nozzle 1 , as is shown in fig 3, i.a. for facilitate emptying of the debris collector. When the debris collector is removed, three openings 10, 11 and 12 are visible in the vacuum cleaner nozzle. The opening 10 is a debris outlet from the cyclone housing 7 to the debris collector 8. The opening 11 is an air outlet opening being in connection with the air inlet opening 5 on the bottom side of the vacuum cleaner nozzle. The opening 12, finally, is an air inlet opening into the cyclone housing 7. When the debris collector is mounted on the vacuum cleaner nozzle an air passage 13 (fig 3 and 5) in a rear side of the debris collector, connects the air outlet opening 11 with the air inlet opening 12, such that the air flows from the air inlet opening 5 in the bottom of the vacuum cleaner nozzle, through the air outlet opening 11, through the air passage 13 and into the cyclone housing through the air inlet opening 12. Inside the cyclone housing 7, the air flow is twisted around the inner periphery of the cyclone housing from the inlet end at the air inlet opening 12 to the debris outlet end at the debris outlet 10, through which the debris is thrown into the debris collector 8. Now reference is made to figs 4-6 for a description of the function of the vacuum cleaner nozzle in a suction stage. In the perspective view of fig 4 the vacuum cleaner nozzle is shown with an upper part 14 removed such that a partially cut through lower part of the cyclone housing 7 and a cyclone chamber 15 are visible, whereas fig 5 and 6 are cross sectional views along the lines V-V and Vl-Vl, respectively, in fig 2. In the cyclone chamber 15, the air flow is twisted in a clockwise direction, as seen in fig 4, during operation. After the air has been transferred by twisting to the debris outlet end of the cyclone housing 7, and the debris has been thrown out through the debris outlet opening 10, the air flows inwards and flows in an inner twisting flow back towards the inlet end of the cyclone housing 7. The air flow is illustrated by arrows in the drawings. In the air inlet end of the cyclone housing 7 is provided an air outlet tube 16, which extends a distance into the cyclone chamber 15, and into which the air flows. The air outlet tube 16 extends through an end wall 17. On the other side of the end wall 17 is provided a turbine wheel 18, which is rotary journalled by means of a rotary shaft 19. The air flow from the air outlet tube 16 exits in the centre of the turbine wheel 18, which is hollow inside, flows in a radial direction inside the turbine wheel and exits via openings between fins 20 provided around the periphery of the turbine wheel. The outflow of air past the fins 20, causes the turbine wheel to rotate, in the illustrated embodiment in a clockwise direction as seen in fig 4. By arranging the rotational movement of the turbine wheel to be in the same direction as the twisting motion of the air flow inside the cyclone chamber and arranging the turbine wheel immediately after the cyclone chamber, the efficiency of the turbine wheel can be increased since the air flow momentum is utilized to drive the turbine wheel.

In an end opposite the turbine wheel 18, the rotary shaft 19 is provided with a belt disc 21 , such that the rotational motion of the rotary shaft 19 drives a rotary brush 22, provided adjacent the air inlet opening 5, via a drive belt 23 and a corresponding belt disc 24 in the end of the brush 22. After the air has exit the openings in the periphery of the turbine wheel 18, it is guided, by means of a passage 25 in the upper and lower part of the vacuum cleaner nozzle, to an outlet opening 26 and further to the tube 3.

Now reference is made to the perspective view of fig 7 and the cross section in fig 9 taken along the line IX-IX in fig 7, in which the vacuum cleaner nozzle is shown with the debris collector 8 replaced by a cleaning powder container 27. The outer shape of the cleaning powder container 27 is such that the air outlet opening 10 is closed by the cleaning powder container while the air inlet opening 12 into the cyclone housing 7 remains open in contact with ambient air. This has to effect that when driving the vacuum cleaner such that an air flow is drawn through the tube 3, no air will be drawn through the air inlet opening 5 in the bottom side of the vacuum cleaner nozzle. However, an air flow is drawn from the outside through the air inlet opening 12 into the cyclone chamber 15 in the cyclone housing 7 and from the cyclone chamber into the turbine wheel 18. Accordingly, the turbine wheel is rotated and drives the rotary brush 22. At the same time a cleaning powder is distributed from the cleaning powder container 27 through holes 28 (fig 8) on the bottom side of the cleaning powder container and distribution holes 29 in the surface of the upper part 14 of the vacuum cleaner nozzle, as is best seen in fig 3 and 4. The distribution holes 29 extends through the upper part 14 into the space where the brush 22 is positioned. In this way the powder will fall down through the air inlet opening 5 onto the surface 6, e.g. a carpet, to be cleaned, while at the same time the brush will rotate and agitate the cleaning powder in between the carpet fibres. However, since no air is drawn through the air inlet opening 5, no cleaning powder will be swept along with the air flow. Instead, all of the cleaning powder, which falls down through the distribution holes 29, will be agitated into the carpet.

In the exemplified embodiment, the cleaning powder container 27 is adapted to accommodate a disposable cleaning powder refill container 30, as is illustrated in fig 8, of e.g. cardboard or plastic, to minimize handling of and contact with the cleaning powder for the user. Before inserting the refill con- tainer 30 into the cleaning powder container 27, a sealing such as a tape strip 31 or the like, can be torn off from the refill container such that an opening for the cleaning powder will be uncovered. To assist discharging of the cleaning powder from the cleaning powder container, the vacuum cleaner nozzle preferably is provided with some kind of discharging means. In the exemplary embodiment the discharging means is an unbalance weight positioned on the rotary shaft 19 such that the vacuum cleaner nozzle will be exposed to vibrations during operation which will facilitate discharging of the cleaning powder through the holes 28 in the bottom side of the cleaning powder container. If desired, the shown vacuum cleaner nozzle can be used as an ordi- nary vacuum cleaner nozzle without having either a debris collector 8 or a cleaning powder container 27 by providing some kind of additional attachment (not shown), which connects the air outlet opening 11 with the air inlet open- ing 12 and closes the debris outlet opening 10. In this way air can be drawn trough the air inlet opening 5 to the vacuum cleaner 1 without separating any debris in the vacuum cleaner nozzle. Instead all the debris is separated in the debris separator in the vacuum cleaner alone. With reference to Figs. 10 - 13, a second embodiment of the invention will be described, which differs from the first described embodiment in that both the debris collector 8 and the cleaning powder container 28 are permanently fixed in the vacuum cleaner nozzle.

With reference to Fig. 11, a control member 32 is arranged around the cyclone housing at one end thereof, wherein a first air inlet 12'of the cyclone housing 7 and a second air inlet 12^" of the cyclone housing are located under the control member. The fist air inlet 12^' is visible in Fig. 11 and the second air inlet 12", which in Fig. 11 is in hidden under the control member, can be seen in Fig. 12a. Both the first and the second air inlets 12^', 12^" are rectan- gular, however, the dimensions of the second air inlet 12" are larger than the dimensions of the first air inlet 12^'. The control member 32 comprises a collar element which is provided with a first opening 33 and a second opening 34. The first opening 33 comprises a rectangular aperture and the second opening 34 comprises several small through holes. The control member is ar- ranged rotatable around the cyclone housing and can be rotated by operating a handle 36. The control member 32 is movable between a first position, where the aperture of the first opening 33 is aligned with the first air inlet 12^' and the second air inlet 12" is closed by a portion of the collar element, wherein an auxiliary air inlet is formed, and a second position, where the holes of the second opening 34 are aligned with the second air inlet 12^" and the first air inlet 12' is closed by a portion of the collar element.

The cleaning powder container 28 comprises an opening for introducing cleaning powder into the cleaning powder container 28, and a pivotable lid 35, wherein the opening is closable by the pivotable lid 35, c.f. Figs. 10 and 13. Furthermore, the clearing powder container comprises several small distribution holes 39 at bottom side thereof for dispensing a cleaning powder to, for example, a carpet. In this embodiment, the distribution holes 39 are open constantly, such that cleaning powder will fall out through these holes 39 as long a there is any cleaning powder in the container. However, the skilled person realizes that embodiments are possible, where these distribution holes 39 are sealable. The distribution holes are arrange to distribute the cleaning powder in front of a rotary brush 22 of the nozzle 4. The debris collector 8 according to this embodiment is an integral part of the cyclone housing 7, and the debris collector 8 and the cyclone housing include a common lid 37. The debris collector 8 and the cyclone housing each have an open end, which is closable by the common lid 37. The common Hd 37 is provided with a sealing strip in order to enable closing of the open ends in a substantially air tight manner. The lid is held in a closed position by a locking member 38 comprising snap-in elements, which are releasable by operating a bottom 40 of the locking member 38.

Now, with reference to Figs. 12a - 12c, the operation of the vacuum cleaner nozzle according to the second embodiment will be described.

In Fig. 12a, the control member 32 is in the second position, i.e. where an auxiliary air inlet is formed by the holes of the second opening 34 being aligned with the second air inlet 12^", and where the first air inlet 12^' is closed by a portion of the collar element. Furthermore, the cleaning powder container 28 is filled with a cleaning powder agent. Thus, the nozzle 4 is in a cleaning powder distributing stage.

In this second position of the control member 32, when driving the vacuum cleaner such that an air flow is drawn through the tube 3, no air will be drawn through the air inlet opening 5 in the bottom side of the vacuum cleaner nozzle. However, an air flow is drawn from the outside through the several small holes of the second opening 34 of the control member 32 and further through the second air inlet opening 12" into the cyclone chamber 15 in the cyclone housing 7 and from the cyclone chamber into the turbine wheel 18. Accordingly, the turbine wheel 18 is rotated and drives the rotary brush 22. At the same time a cleaning powder is distributed from the cleaning powder container 28 through the distribution holes 39 on the bottom side of the cleaning powder container 28. Since no air is drawn through the air inlet opening 5, no cleaning powder will be swept along with the air flow. When moving the vacuum cleaner nozzle backwards towards the operator as illus- trated by the arrow in Fig. 12a, the distributed powder will be clearly visible on the carpet. When moving the nozzle forwards away from the operator, i.e. opposite the direction of the arrow in Fig. 12a, the rotating brush 22 will agitate the cleaning powder in between the carpet fibres.

The several small holes of the second opening prevent that any larger items are sucked in through the second opening 34 and also that an operator accidentally puts his fingers into the cyclone. After all the powder in the cleaning powder container 28 has been distributed on the carpet and it is time to recover the powder again, the control member is operated as shown in Fig. 12b by rotating it from the described second position to a first position shown in Fig. 12 c, i.e. where the aperture of the first opening 33 is aligned with the first air inlet 12^', and the second air inlet 12" is closed by a portion of the collar element. As also can been seen in Fig. 12c, there is no cleaning powder in the cleaning powder container 28, such that no powder can be distributed though the constantly open holes 39. Thus, the nozzle 4 is now in a powder recovery stage or suction stage. When driving the vacuum cleaner such that an air flow is drawn through the tube 3, no air will be drawn through the auxiliary air inlet comprising the second air inlet opening 12 ^'on the upper side of the vacuum cleaner nozzle 4. However, an air flow is drawn through the air inlet opening 5 in the bottom of the vacuum cleaner nozzle 4, from where the air flow continues to the aperture of the first opening 33 of the control member 32 and further through the first air inlet opening 12^' and into the cyclone housing 7. Inside the cyclone housing 7, the airflow is twisted around the inner periphery of the cyclone housing from the inlet end at the air inlet opening 12^' to the debris outlet end at the debris outlet 10, through which the debris is thrown into the debris collector 8. After the air has been transferred by twisting to the debris outlet end of the cyclone housing 7, and the debris has been thrown out through the debris outlet opening 10, the air flows inwards and flows in an inner twisting flow back towards the inlet end of the cyclone housing 7. The air flow is illustrated by arrows in the drawings. In the air inlet end of the cy- clone housing 7 is provided an air outlet tube 16, which extends a distance into the cyclone chamber 15, and into which the air flows. The outlet tube 16 is provided with a net 41 for preventing that larger debris accidentally should follow the air stream into a turbine wheel 18 instead of being thrown into the debris collector 8. The air outlet tube 16 extends through an end wall 17. The turbine wheel 18, which is rotary journalled by means of a rotary shaft 19, is provided oh the other side of the end wall 17. The air flow from the air outlet tube 16 exits in the centre of the turbine wheel 18, which is hollow inside, flows in a radial direction inside the turbine wheel and exits via openings between fins 20 provided around the periphery of the turbine wheel. The outflow of air past the fins 20, causes the turbine wheel to rotate, in the illustrated embodiment in a clockwise direction as seen in fig 4. By arranging the rotational movement of the turbine wheel 18 to be in the same direction as the twisting motion of the air flow inside the cyclone chamber and arranging the turbine wheel immediately after the cyclone chamber, the efficiency of the turbine wheel can be increased since the air flow momentum is utilized to drive the turbine wheel. The exit of the air stream from the nozzle according to the second embodiment corresponds to the exit of the air in the first described embodiment, c.f. Fig. 4. Thus, with reference to Fig. 4, in an end opposite the turbine wheel 18, the rotary shaft 19 is provided with a belt disc 21 , such that the rotational motion of the rotary shaft 19 drives the rotary brush 22, provided adjacent the air inlet opening 5, via a drive belt 23 and a corresponding belt disc 24 in the end of the brush 22. After the air has exit the openings in the periphery of the turbine wheel 18, it is guided, by means of a passage 25 in the upper and lower part of the vacuum cleaner nozzle, to an outlet opening 26 and further to the tube 3. Any remaining smaller dust particles are then separated in a main separating unit of the vacuum cleaner (not shown),

Consequently, due to the two air inlets 12^', 12^" of the cyclone housing 7, which are alternately closed and opened, the cyclone separator is operable in two different modes depending on which of the air inlets are opened. This is further enhanced by the different sizes of the air inlet openings 12^', 12^" in combination with the corresponding openings 33 and 34 of the control member 32. Thus, due to the many holes of opening 34 and the larger size of the second air inlet 12", the area of a flow passage into the cyclone chamber 15 in the second position of the control member 32 is larger than a corresponding flow passage in the first position of the control member 32. Thereby, in the second position of the control member, a high air flow is achieved into the cyclone chamber 15, which causes a quick rotation of the turbine wheel 18 and consequently also of the rotary brush 22, whereby a strong massaging effect is provided. In the first position of the control member, the flow passage into the cyclone chamber 15 is narrower, wherein the speed distribution in the air stream is altered such that a the cyclone chamber is able to operate with a higher separation efficiency. Thus, the cyclone separator of the nozzle according to the invention is able to alter a flow passage leading into the cyclone chamber 15 such that an air stream passing there through is altered. After substantially all cleaning powder has been reconverted or when the debris collector 8 is full, the debris collector can be emptied by pushing the button 40 of the locking member 38, c.f. Fig 13. Then the lid 37 can be swung open so that powder and debris which has been deposited in the de- bris collector 8 can be removed therefore. Finally, the cyclone chamber 15 can be cleaned if necessary. Finally, the lid 37 can be swung back into engagement with the snap-in elements of the locking member 38.

Claims

1. A vacuum cleaner nozzle comprising an air inlet opening (5) on a bottom side and being attachable to a vacuum cleaner (1) having a vacuum source to draw air together with debris through the inlet opening to the vacuum cleaner for collecting the debris in a debris separator in the vacuum cleaner, characterized in that the vacuum cleaner nozzle (4) comprises a separate debris separator (7, 8), which is connected in series, in respect of the air flow through the nozzle and the vacuum cleaner (1), with the debris separator in the vacuum cleaner.

2. A vacuum cleaner nozzle according to claim 2, characterize d in that the debris separator comprises a cyclone or cyclone-like separator (7, 8), to achieve a first separation of debris from the air flow in the debris separator in the nozzle and subsequently a second separation of debris in the debris separator in the vacuum cleaner.

3. A vacuum cleaner nozzle according to claim 1 or 2, characterize d in that the vacuum cleaner nozzle (4) is adapted for carpet cleaning.

4. A vacuum cleaner nozzle according to any of the preceding claims, characterized in that the vacuum cleaner nozzle (4) comprises a rotary brush (22).

5. A vacuum cleaner nozzle according to claim 4, characterize d in that the rotary brush (22) is driven by a turbine wheel (18) and that the turbine wheel is located immediately after, in respect of the air flow, the cyclone separator (7, 8).

6. A vacuum cleaner nozzle according to any of the preceding claims, characterized in that the debris separator comprises a debris collector (8), which is releasable.

7. A vacuum cleaner nozzle according to claim 6, characteri- z e d in that the debris collector (8) is replaceable by a container (27) for a carpet cleaning powder when distributing the powder over a carpet to be cleaned.

8. A vacuum cleaner nozzle according to claim 7, characterize d in that the air flow is automatically redirected between the powder distributing stage, when the powder container (27) is mounted on the vacuum cleaner nozzle (4) and no air is drawn through the air inlet opening (5), and a powder recovery stage when the debris collector (8) is mounted on the vacuum cleaner nozzle and air is drawn through the air inlet opening.

9. A vacuum cleaner nozzle according to any of the claims 1- 5, characterized in that the debris separator including a debris collector (8), is permanently arranged in the nozzle.

10. A vacuum cleaner nozzle according to claim 9, characterize d in that a container for a carpet cleaning powder (27), is permanently arranged in the nozzle.

11. A vacuum cleaner nozzle according to claim 10, characterize d in that the vacuum cleaner nozzle further comprises a control member which is operable to, in a powder distribution stage, direct the air flow such that no air is drawn through the air inlet opening (5), and in a powder recovery stage, direct the air flow such that air is drawn is drawn though the air inlet opening (5).

12. A vacuum cleaner nozzle according to claim 11,characteri- z e d in that the vacuum cleaner nozzle further comprises a first air channel from the air inlet (5) and a second air channel from an auxiliary air inlet on the upper side of the vacuum cleaner nozzle, wherein the first air channel is in fluid communication with a first air inlet of the cyclone housing and wherein the second air channel is in fluid communication with a second air inlet of the cyclone housing.

13. A vacuum cleaner nozzle according to claim 12, characterize d in that the control member comprises a valve member which is operable to direct the air flow, in the powder distributing stage, by closing the first air inlet of the cyclone housing and opening the second air inlet of the cyclone housing, and in the powder recovery stage, by opening the first air inlet of the cyclone housing and closing the second air inlet of the cyclone housing.

14. A method for vacuum cleaning of a surface, comprising the steps of: providing a vacuum cleaner (1) comprising a vacuum source, a debris sepa- rator and a vacuum cleaner nozzle (4); generating a vacuum in the vacuum source for drawing an air flow through an inlet opening (5) in a bottom side of the nozzle; providing a debris separator (7, 8) in the vacuum cleaner nozzle connected in series, in respect of the air flow through the nozzle and vacuum cleaner, with the debris separator in the vacuum cleaner.

15. A method according to claim 14, comprising the further step of: providing a debris separator in form of a cyclone (7) or cyclone-like separator in the vacuum cleaner nozzle (4), for a first separation of debris in the debris separator in the vacuum cleaner nozzle; and separating any residual debris from the air flow in the debris separator in the vacuum cleaner.

16. A method according to claim 14 or 15, comprising the further step of: taking up cleaning powder, which has been distributed over a carpet to be cleaned, by means of the vacuum cleaner nozzle (4) for collecting at least the main part of the cleaning powder in the debris separator (7, 8) in the vacuum cleaner nozzle.

17. A method according to claim 16, comprising the further step of: releasing a debris collector (8) of the debris separator from the vacuum cleaner nozzle (4) and replacing it with a cleaning powder container (27) when distributing the cleaning powder over the carpet to be cleaned.