Abstract:
A vacuum cleaner nozzle having a housing with a downward facing opening, a brush roll rotatably mounted to the housing at the downward facing opening, and a brush roll cleaner mounted to the housing. The brush roll cleaner includes a longitudinal bar extending along a longitudinal axis of the brush and pivotally connected to the housing at a pivot axis, an edge connected the longitudinal bar at a spaced location from the pivot axis and extending along to the longitudinal axis of the brush, and an arm extending from the longitudinal bar. The arm is configured to transmit a force to rotate the brush roll cleaner from a first position in which the edge does not contact the brush roll, to a second position in which the edge contacts the brush roll to remove debris from the brush roll as the brush roll rotates.

Description:
[0001]    This application is a continuation of U.S. application Ser. No. 14/354,449, filed Apr. 25, 2014, which is a national stage of International Application PCT/EP2012/071319, filed Oct. 26, 2012, which claims priority to International Application PCT/EP2011/068743, filed Oct. 26, 2011. This application claims priority to and the benefit of the foregoing applications, and the foregoing applications are incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates to a nozzle for a vacuum cleaner comprising a rotatable member and a cleaning arrangement for removing articles entangled to the rotatable member. The invention is intended for battery powered vacuum cleaners as well as mains-operated vacuum cleaners. The nozzle according to the present invention is further envisaged for robotic vacuum cleaners. 
       BACKGROUND OF THE INVENTION 
       [0003]    In vacuum cleaning nozzles provided with a rotatable member, i.e. a rotatable brush roll, it is known that threads, lint, human or animal hairs or any other fibrous material tend to cling or wrap around adhere to the brush roll during operation of the vacuum cleaner. This may impair the functioning of the cleaning nozzle. In WO2009/117383A2 it is disclosed a cleaning nozzle for a vacuum cleaner provided with a rotary brush having projecting friction surfaces and one or more cleaning members for removing debris that has been wrapped around the rotary brush. The cleaning members are positioned adjacent the rotary brush and are adapted to move between a resting position and a cleaning position, and are arranged to clean the rotary brush during rotation of the brush. Debris that has been collected on a rotary brush is often difficult to remove because it has wrapped tightly around the brush roll and intertwined the bristles. Therefore, a significant force is needed to be able to thread off the entangled threads by means of a cleaning member pressing against a friction member. Such a force may be applied manually by a user of the vacuum cleaner. The electrical vacuum cleaner or motor brush head need to be capable of providing the necessary power to obtain rotation of the brush roll when such force is applied. 
         [0004]    A drawback with the disclosed design is that it is difficult for a user to detect whether the brush roll needs to be subject to a cleaning action, since the rotary brush only is visible via a downward-facing opening of the nozzle where dirt and debris are received. 
       SUMMARY OF THE INVENTION 
       [0005]    In a first aspect, there is provided a vacuum cleaner nozzle having a housing having a downward facing opening, a brush roll mounted to the housing at the downward facing opening and having a plurality of bristles extending therefrom, the brush roll being rotatable relative to the housing around a longitudinal axis of the brush roll, and a brush roll cleaner mounted to the housing. The brush roll cleaner includes a longitudinal bar extending along the longitudinal axis of the brush and pivotally connected to the housing at a pivot axis, an edge connected to the longitudinal bar, the edge being spaced from the pivot axis and extending along to the longitudinal axis of the brush, and an arm extending from the longitudinal bar, the arm being configured to transmit a force to rotate the brush roll cleaner from a first position in which the edge does not contact the brush roll, to a second position in which the edge contacts the brush roll to remove debris from the brush roll as the brush roll rotates. 
         [0006]    In various aspects, the foregoing vacuum cleaner nozzle may further include a push button mounted on an outer face of the housing and operably connected to the arm, such that application of a pressing force on the push button moves the brush roll cleaner from the first position to the second position. The push button may be behind the longitudinal bar. 
         [0007]    In other aspects, the pivot axis may be above and behind the longitudinal axis of the brush, the edge may be a sheet member extending from the longitudinal bar, the edge may be steel, the edge may be the distal edge of a resilient sheet extending from the longitudinal bar, the edge may be a sharp edge, and the edge may be a sharp steel edge formed by punch pressing, shearing or machining the steel. 
         [0008]    The brush roll cleaner may include a protruding part extending from the longitudinal bar and sized to contact the plurality of bristles in advance of the edge as the brush roll rotates. 
         [0009]    The arm may be located proximal to one end of the longitudinal bar. 
         [0010]    In other aspects, at least a portion of the housing may be transparent to allow the brush roll to be seen therethrough. The nozzle also may include one or more lights configured to illuminate the brush roll. Such lights may be configured to be activated by movement of the brush roll cleaner to the second position. 
         [0011]    In still other aspects, the brush roll may include a support surface that the edge is configured to contact when the brush roll cleaner is in the second position. Such a support surface may have at least one helical surface extending along the longitudinal axis of the brush roll. Such a support surface may have a first length extending along the longitudinal axis of the brush roll, and the edge may have a second length extending along the longitudinal axis of the brush roll, and the first length and the second length are the same. The support surface may be provided on a radially projecting portion of the brush roll. The radially projecting portion may have radial ribs having pockets between adjacent pairs of radial ribs. 
         [0012]    In another aspect, there is provided a vacuum cleaner nozzle having a housing having a downward facing opening, a brush roll mounted to the housing at the downward facing opening and having a plurality of bristles extending therefrom, the brush roll being rotatable relative to the housing around a longitudinal axis of the brush roll, and a brush roll cleaner mounted to the housing. The brush roll cleaner includes a longitudinal bar extending along the longitudinal axis of the brush and pivotally connected to the housing at a pivot axis, a sharpened steel edge connected to the longitudinal bar, the edge being spaced from the pivot axis and extending along to the longitudinal axis of the brush, an arm extending from the longitudinal bar at a location proximal to one end of the longitudinal bar, the arm being configured to transmit a force to rotate the brush roll cleaner from a first position in which the edge does not contact the brush roll, to a second position in which the edge contacts the brush roll to remove debris from the brush roll as the brush roll rotates, and a push button mounted on an outer face of the housing and operably connected to the arm, such that application of a pressing force on the push button moves the brush roll cleaner from the first position to the second position. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The various aspects of the invention, including its particular features and advantages, will be readily understood from the following detailed description and the accompanying drawings, in which: 
           [0014]      FIG. 1  illustrates a vacuum cleaner according to an embodiment, 
           [0015]      FIG. 2  illustrates a nozzle with a brush roll comprising a projecting cleaning surface in accordance with an embodiment, 
           [0016]      FIG. 3  illustrates the nozzle from underneath, 
           [0017]      FIG. 4 a - d    illustrate a cleaning arrangement for the brush roll of the nozzle according to embodiments, 
           [0018]      FIG. 5  illustrates a push button and a linking mechanism connected to the cleaning arrangement according to an embodiment, 
           [0019]      FIGS. 6 a  and 6 b    is a side view of the cleaning arrangement and the brush roll according to an embodiment, 
           [0020]      FIGS. 7 a  and 7 b    illustrate alternative arrangements in order to protect the cleaning arrangement and the brush roll with bristles from unnecessary wear when the cleaning arrangement is in a resting mode, and 
           [0021]      FIG. 8  shows details of the cleaning arrangement. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0022]    The present invention will now be described more fully with reference to the accompanying drawings, in which example embodiments are shown. However, this invention should not be construed as limited to the embodiments set forth herein. Throughout the following description similar reference numerals have been used to denote similar elements, parts, items or features, when applicable. 
         [0023]      FIG. 1  illustrates a vacuum cleaner  2  of an upright model comprising a nozzle  1  provided with a rotatable member  3 , like a brush roll, for picking up particles from a surface to be cleaned according to an embodiment of the present invention. The nozzle  1  is further provided with a cleaning arrangement for removing articles entangled to the rotatable member  3 . The nozzle  1  comprises a cover  12  that at least partly is made of transparent material such that the rotatable member  3  may be visible through the nozzle cover  12 . 
         [0024]    Thereby, the user is able to see if there are a lot of articles like hair entangled to the rotatable member  3 . The user initiates cleaning of the rotatable member  3  by pushing a push button  6  on the nozzle  1 . 
         [0025]      FIG. 2  shows a nozzle  1  according to an embodiment more in detail. The cleaning arrangement comprises a cleaning member  5  and a support surface  4  provided on a radially projecting member  13  of the rotatable member  3 . In the embodiment shown, two projecting members  13  are helically arranged along a longitudinal axis of the rotatable member  3 . Other possible alternatives may be a single helically arranged projecting member  13 , or more than two helically arranged projecting members  13 . The cleaning member  5  is movable between a resting position in which the cleaning member  5  is arranged at a distance from the support surface  4  and a cleaning position. The cleaning position may be arranged stepwise or gradually, thus enabling the cleaning member  5  to approach the support surface during cleaning action. This might be advantageous for example if a thick layer of entangled articles are present, or if the power available for driving the rotatable member  3  is limited. A push button  6 , connected via a linking mechanism  7  shaft to a cleaning member  5 , is provided to move the cleaning member  5  between the resting position and the cleaning position. 
         [0026]    In a cleaning position, a resilient sheet member  5   a  of the cleaning member  5  co-operates with the support surface  4  during rotation of the rotatable member  3  to remove any entangled articles from the rotatable member  3 . The resilient sheet member  5   a  is capable of providing a resilient contact with the support surface  4  in the cleaning position during rotation of the rotatable member  3 . Thereby, the possible slow down of the rotational speed of the rotatable member  3  due to the cleaning action will be limited if there is a lot of entangled articles to be removed. The nozzle  1  comprises a cover  12  that at least partly is made of transparent material such that the rotatable member  3  may be visible through the nozzle cover  12 . The transparency enables a user to see if a cleaning action is needed or not. 
         [0027]      FIG. 3  illustrates the nozzle  1  from underneath. When the push button  6  is pressed down, the nozzle  1  is prevented from tilting by one or more protruding parts  8  provided underneath the nozzle  1 . The protruding part (-s)  8  is arranged on the nozzle  1  at a surface turned towards the surface to be cleaned. 
         [0028]    With further reference to  FIGS. 2 and 3 , in a further embodiment of the present invention, the nozzle  1  comprises lighting means arranged at the rotatable member  3  for illuminating at least parts of the rotatable member. The lighting means may be embodied in the form of small lamps or light emitting diodes (LEDs)  15  arranged at the interior of the nozzle  1 . The LEDs  15  may for instance be arranged at a respective end of the longitudinally extending rotatable member  3  as shown in  FIG. 2  or any where at the interior of the nozzle  1  mounted to the nozzle housing. In an embodiment, the LEDs  15  arranged to illuminate the rotatable member  3  when the vacuum cleaner  2  is in operation. Thus, the LEDs will turn on when a user starts the vacuum cleaner. However, a number of different embodiments are envisaged. For instance, the LEDs  15  may be electrically connected to the push button  6 , in which case the LEDs  15  are arranged to illuminate the rotatable member  3  once a pressing force is applied to the push button  6  in order to move the cleaning member  5  to the cleaning position. Thus, the user initiates cleaning of the rotatable member  3  by pushing the push button  6  on the nozzle  1 , thereby making the LEDs  15  illuminate the rotatable member  3  so that the user better can see articles entangled to the rotatable member  3 . In an embodiment, the LEDs  15  are turned on when the push button  6  is fully pressed into an end position. In a further embodiment the LEDs  15  are turned on when the push button  6  is pressed into an intermediate position. 
         [0029]      FIGS. 4 a - b    illustrate a resting mode and a second cleaning mode of the cleaning arrangement for a brush roll of the nozzle according to an embodiment. The cleaning member  5  is pivotally arranged via a longitudinal bar  5   b  above the rotatable member  3  such that the cleaning member  5  is pivoted from the resting position above the rotatable member  3  to a cleaning position adjacent the support surface. The length of the cleaning member  5  is preferably the same as the length of the brush roll that is covered by the support surface  4 . Two radially projecting members  13  are helically arranged along a longitudinal axis  10  of the rotatable member  3 . The cleaning member  5  comprises a longitudinal bar  5   b  holding a resilient sheet member  5   a.  The cleaning member  5  is arranged along a longitudinal axis  10  of the rotatable member  3 . The resilient sheet member  5   a  has preferably a thickness in the range of 0.2-0.8 mm. It is of importance to choose a suited material for the resilient sheet member  5   a.  The material will, over time, get worn and loose its original tearing ability. To be wear resistant relatively hard spring steel may be used. The edge of the cleaning member  5  that will be in contact with the support surface need to be relatively sharp in order to effectively remove entangled articles. By shearing, or punch pressing the spring steel, one of the edges of the sheared surface will be rounded while the other will have an edge burr. By punch pressing the cleaning member  5  one edge of the cut surface will be sharper than the other. By shearing, or punch pressing, there will be as mentioned above, an edge burr at the cleaning member  5  edge. If the edge burr is minimized this will create a sharp edge suited for cleaning entangled articles from the brush roll. As an alternative to the above mentioned edge burr, the edge of the cleaning member  5  may be sharpened by machining. Thereby, improved tolerance of the sharp edge is achieved. 
         [0030]      FIG. 4 c    illustrates a rotatable member  3  shown as a brush roll provided with a support surface  4  with a plurality of segments  4   a,    4   b,    4   c.  Each of the segments  4   a,    4   b,    4   c  are arranged at an individual radius in relation to the longitudinal axis  10 . The radius of the segments is in the shown embodiment gradually changed whereby the segments form a continuous support surface  4 . Alternatively, the radius may be changed in steps whereby three separate support surfaces with different radius are provided. The radius of the segment  4   a  is chosen to enable cleaning contact between the cleaning member, when in a cleaning position, and the surface segment  4   a.  The radius of the segment  4   c  is chosen to enable a small distance between the cleaning member  5 , when the cleaning member  5  is in cleaning position, and the segment  4   c.  The segment  4   b  is provided with a gradually changing radius providing a smooth transition from the radius of segment  4   a  to the radius of segment  4   c.    
         [0031]    In  FIG. 4 d    the cleaning member  5  is seen during cleaning of the rotatable member  3  of  FIG. 4 c   . The resilient sheet member  5   a  of the cleaning member  5  will be in resilient contact with the support surface in a single contact point at segment  4   a.  If the resilient sheet member  5   a  is enabled to flex enough, a certain amount of contact may also be achieved at segment  4   c.  However, although some cleaning interaction may be performed at segment  4   c,  the majority of force applied to the cleaning member will be transferred to segment  4   a.  By such an arrangement, at least the most part of the force applied to the cleaning member  5  is focused to the contact with segment  4   a.  Contact in a single point, or at least in a limited area, ensure efficient cleaning while still not disturbing the normal cleaning operation. 
         [0032]    A problem during cleaning of the brush roll is that entanglement around the brush roll seems not to be evenly spread along the length of the brush roll. Instead, entanglement is of greatest magnitude in the middle segment of the brush roll. Such uneven distribution of the entangled articles is disadvantageous from a brush roll cleaning perspective because cleaning of the top layers of entanglement are performed for each revolution of the brush roll, i.e. the more the layers of entangled articles at a specific segment the longer the total cleaning time. Therefore, the brush roll cleaning time is dependent on the maximum layers of entanglement at one specific segment of the brush roll. Therefore it is more beneficial if the total entanglement is spread out along the length of the brush roll. As seen from the  FIGS. 4 a   -d, the rotatable member  3  comprises radial ribs  9  arranged perpendicular to the longitudinal axis  10  of the rotatable member  3 . The radial ribs  9  extend from the rotatable member  3  to the projecting member creating multiple pockets  11  along the rotatable member  3 . The multiple pockets  11  hinder entangled hairs etc. 
         [0033]    from wandering towards the middle segment. Thereby, a greater distribution of the entangled articles along the length of the brush roll is achieved, and the total brush roll cleaning time is reduced. Each pocket  11  catches and hinder particles like hair from wandering along the length of the brush roll. 
         [0034]      FIG. 5  illustrates the push button  6  and the linking mechanism  7  connected to the cleaning arrangement according to an embodiment. The cleaning member  5  is moved from the resting position to the cleaning position by applying a pressing force to a push button  6  provided on the nozzle  1  at a surface turned towards a user. The cleaning member  5  is connected via a linking mechanism  7  shaft to the push button  6  on the nozzle  1 . 
         [0035]      FIGS. 6 a  and 6 b    is a detailed side view of the cleaning arrangement and the brush roll according to an embodiment. In  FIG. 6 a   , the cleaning member  5  is shown in a resting position. There is no contact between the resilient sheet member  5   a  and any parts of the rotating brush roll. In  FIG. 6 b   , the cleaning member has been pivoted into a cleaning position. The resilient sheet member  5   a  is brought in the near vicinity of the rotating brush roll and a resilient contact is obtained between the resilient sheet member  5   a  and a support surface  4 . The sharp edge of the resilient sheet member  5   a  will remove any articles entangled to the brush roll. 
         [0036]      FIGS. 7 a  and 7 b    illustrate alternative arrangements in order to protect the brush roll from unnecessary wear when the cleaning arrangement is in a resting mode. The cleaning member  5  is designed to be protected from wear during normal vacuum cleaning, and also to help in minimizing the wear of the bristles during brush roll cleaning. Hard particles like small stones or the like cleaned up by the rotatable member  3  may contribute to wear of the cleaning member  5 , and especially of the sharp edge. As seen in the drawings particles are prevented from contact with the cleaning member  5  by a protruding part  8  arranged faced to the rotatable member  3 . Further, the protruding part  8  delimits wear of bristles on the brush roll due to contact between the bristles and the edge of the cleaning member  5 . The bristles will first be in contact with the protruding part  8 . Thereby, the bristles are bent before they get in contact with the edge and wear of the bristles are limited. 
         [0037]      FIG. 8  show details of the cleaning arrangement. The resilient sheet member  5   a  of the cleaning member  5  when positioned in a cleaning position meets a tangent of a segment of the support surface  4  at an angle a which is in the range of 40°-90°. 
         [0038]    When in use, the cleaning arrangement works as follows. During brush roll cleaning the cleaning member  5  will interact and apply pressure on a support surface  4  provided on a rotatable brush roll provided in the nozzle  1  of a vacuum cleaner. During the cleaning process, the motor fan of the vacuum cleaner is also turned on. The support surface  4  is the only area of the brush roll, apart from the bristles, that will be in contact with the cleaning member  5  during a cleaning process. For a full revolution of the brush roll, the entire support surface  4  will have been in contact with the cleaning member  5  and therefore will any entangled article be exposed to the cleaning interaction in between these parts. Entangled articles will get torn into smaller pieces by the tearing, or friction, caused by the cleaning member  5  at the support surface. These torn articles may be separated from the brush roll by the airflow of the vacuum cleaner in combination with centrifugal force due to the rotational movement of the brush roll and will end up in the dust container or dust bag of the vacuum cleaner. The bristles of the brush roll will flex below the cleaning member  5  during brush roll cleaning. Since it is the pressure that the cleaning member  5  applies on the surface of the support surface  4  that generates the majority of the tearing friction, the bristles will not be exposed to the same wear as the entangled articles. Further, since the resilient sheet member  5   a  is able to flex, a consistent interaction in between the resilient sheet member  5   a  and the support surface  4  during brush roll cleaning is achieved, which in turn will lower the tolerances. The brush roll cleaning performance is dependent on the rotational speed of the brush roll; the higher speed, the faster brush roll cleaning. Further on the speed is closely related to the torque; an increased torque will decrease the speed. It is therefore important to find a state were the applied torque is high enough for efficient brush roll cleaning whilst at the same time low enough to not decrease the speed too much.