Patent Publication Number: US-9844307-B2

Title: Cleaning head

Description:
FIELD OF INVENTION 
     The present invention relates to a cleaning head for a vacuum cleaner. In particular the present invention relates to a cleaning head for an upright or stickvac type vacuum cleaner. 
     BACKGROUND OF INVENTION 
     Vacuum cleaning devices are known to comprise motorised cleaning brushes. The motorised cleaning brushes or beater bars are mounted in the cleaning head of a vacuum cleaner in or adjacent to the suction nozzle. The cleaning brushes are configured to rotate within the cleaning head and engage against a surface to be cleaned. Accordingly debris is physically moved and entrained in the inward airflow into the suction nozzle. The cleaning brushes can dislodge ingrained dirt in a textile such as a carpet. This means that the suction power required to clean particularly dirty surfaces may be less. This is particularly useful for cordless vacuum cleaners when energy efficiency can increase battery life. 
     Some cleaning brushes, for example as shown in EP 0 351 224, can clog because debris such as hair can wrap around the cleaning brush rather than being sucked into the vacuum cleaner. According the cleaning head must be examined and the cleaning brush extracted from the cleaning head. This can be a particular nuisance because the user may have to remove large quantities of hair which is unsightly and unhygienic. Furthermore the user may have to invert the cleaning head and/or the vacuum cleaner to remove the cleaning brush which can cause debris partially sucked in to the cleaning head to fall out. 
     Embodiments of the present invention aim to address the aforementioned problems. 
     BRIEF SUMMARY OF THE INVENTION 
     According to an aspect of the present invention there is a cleaning head connectable to a vacuum cleaner comprising: a cassette removeably mountable on the cleaning head; a rotatable bar having projecting cleaning elements engageable with a surface to be cleaned and the rotatable bar is removeably mountable in the cassette; a first cassette mounting assembly coupled to the rotatable bar at a first end with a first spindle; a second cassette mounting assembly coupled to the rotatable bar at a second end with a second spindle; wherein the first and second cassette mounting assemblies have removable cover portions for shielding the first and second spindles from debris and the first cassette mounting assembly is rotatably coupled to and removable with the first spindle. 
     By providing a cassette containing the cleaning brush, the cleaning head is easier to maintain. Furthermore since the bar comprises a cover portion at each end and the first cassette mounting assembly is removable together with the first spindle, the user can easily access the bearing. This means that when hair eventually ingresses adjacent to the bearing, the user can easily dismantle the cleaning head without misplacing parts of the mounting assembly. 
     Preferably the first and second cassette mounting assemblies each comprise a bearing rotatably coupled respectively to the first and second spindles. Preferably the covers are respectively integral with the first cassette mounting assembly and the second cassette mounting assembly. This means that the mounting assemblies can be single removable assemblies which cannot be disassembled further by the user. This makes maintenance more straight forward. 
     Preferably the rotatable bar comprises a fixed flange portion at each end. This means that fibrous material that wraps around the bar is limited in its movement along the bar towards the ends. The projecting flange means that the hair must move up over the flange before being able to ingress the vicinity of the bearing. 
     Preferably the first spindle comprises at least one drive surface. Preferably the drive face is a D-shaped cross section. Preferably the at least one drive surface is engageable with a reciprocal surface in the rotatable bar. This means that the first spindle comprises a flat drive surface which corresponds to the flat side of the “D”. This means that the first spindle does not slip with respect to the bar  222 . 
     Preferably the second spindle is fixed to the bar and the cover is rotatably mounted on the second spindle. 
     Preferably the first or second cassette mounting assemblies comprises a drive gear mounted on the first or second spindle. Preferably the drive gear comprises a plurality of circumferentially spaced drive elements. Preferably each drive element comprises a camming surface and a drive surface. This means that the drive gear will always seat correctly when the cassette is inserted into the cleaning head. 
     Preferably the first cassette mounting assembly comprises a mounting groove for receiving reciprocal mounting ribs on the cassette. Preferably the second cassette mounting assembly comprises a mounting plug for engaging a reciprocal mounting hole in the cassette. This means that the bar is easy for the user to insert and mount in the cassette. Since the first and second cassette mounting assemblies are different, the bar has directionality and the user is not able to insert the bar the wrong way round. 
     Preferably the cover portions comprises an overlapping lip extending over the ends of the rotatable bar. This means that there is a labyrinthine pathway that debris must take in order to jam the bearing. 
     Preferably the cassette is transparent. This means that the use knows when the bar is in operation and when the cassette needs to be removed for maintenance. 
     Preferably the cleaning head comprises a locking mechanism for releasably locking the cassette in the cleaning head. Preferably the cassette is configured to be upwardly releasable from the cleaning head away from a surface to be cleaned. This means that the cassette is easily removable from the cleaning head without dislodging dirt from other parts of the vacuum cleaner. 
    
    
     
       BRIEF DESCRIPTION OF THE INVENTION 
       Various other aspects and further embodiments are also described in the following detailed description and in the attached claims with reference to the accompanying drawings, in which: 
         FIG. 1  shows a perspective view of a cleaning head of a vacuum cleaner; 
         FIG. 2  shows an exploded perspective view of a cleaning head; 
         FIG. 3  shows a perspective view of the cassette; 
         FIG. 4  shows an exploded perspective view of the cassette; 
         FIG. 5  shows an underneath exploded perspective view of the cassette; 
         FIG. 6  shows an underneath plan view of the cassette; 
         FIG. 7  shows a cross sectional side view of the cassette along axis A-A. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a perspective view of a cleaning head  100  for a vacuum cleaner (not shown). The cleaning head comprises a base portion  102  on which an articulated joint  104  is mounted. The articulated joint  104  couples the base portion  102  to a neck portion  106 . The base portion  102  is arranged to move over a surface to be cleaned such as a floor. The neck  106  comprises an attachment mechanism  108  for attaching to a hose (not shown) or extension tube (not shown) of the vacuum cleaner. The cleaning head  100  is connectable to a handheld vacuum cleaner via an extension tube, a canister vacuum cleaner via a hose or directly to an upright or a stickvac vacuum cleaner. The neck  106  comprises an airway which is in fluid communication with a dirty inlet port  110  in the base portion  102 . The neck portion  106  may comprise electrical power and control wires for powering and controlling functionality in the cleaning head  100 . The vacuum cleaner can comprise one or more control buttons (not shown) for actuating a motor to drive the bar  222 . 
     The articulated joint  104  provides at least two degrees of freedom of the base portion  102  with respect to the neck portion  106 . The articulated joint  104  as shown in  FIG. 1  comprises two pivot axes which are mounted perpendicular to each other. The articulated joint  104  is known and will not be discussed in any further detail. 
     The cleaning head  100  comprises a cleaning assembly or cassette  200 . The cassette  200  is removeably mountable in the base portion  102 . The cassette  200  is optionally transparent. This means that the user can see when the cassette  200  is in operation and when the cassette  200  requires maintenance. 
     The cassette  200  will be discussed in further detail with reference to  FIG. 2 , which shows a perspective exploded view of the cleaning head  100 . The cassette  200  and cleaning head  100  comprise a locking mechanism  204  for selectively releasing the cassette  200  from the cleaning head  100 . The locking mechanism  204  comprises a latch  210  (see  FIG. 3 ) and catch  208  arrangement. The cassette  200  comprises a spring biased latch  210  which is coupled to a manually operated release button  206 . The base portion  102  comprises a catch  208  engageable with the latch  210  on the cassette  200 . In some other embodiments the spring biased latch and the manually operated release button can be mounted on the base portion  102  and the catch element is mounted on the cassette  200 . Alternatively the spring biased latch can be mounted on the cassette  200  and the release button is mounted on the base  102 . In other embodiments any suitable locking mechanism can be provided for selectively releasing the cassette  200  from the cleaning head  100 . 
     The cassette  200  is removable from the cleaning head  100  when the release button  206  is depressed. The cassette  200  is upwardly removable from the base portion  102 . This means that when removing the cassette  200  from the base portion  102 , the user lifts the cassette  200  away from the surface to be cleaned (such as the floor). This makes removing the cassette  200  from the base portion  102  easier for the user. Furthermore by allowing the user to vertically lift the cassette  200  from the cleaning head  100 , the user does not need to tip the cleaning head  100  or the vacuum cleaner to access the cassette  200 . This means that accessing and maintaining the cassette  200  is cleaner and less likely to dislodge debris which may be between the dirty air inlet and the dirt container (not shown) in the vacuum cleaner. 
     The cassette  200  is generally linear in construction and extends along a longitudinal axis A-A (as shown in  FIG. 6 ). Turning back to  FIG. 2 , the cassette  200  comprises a first end  214  and a second end  216 . The second end  216  comprises a side rib  218  which projects outwardly from the cassette  200 . The side rib  218  is configured to slide in a reciprocal vertical slot  112 . The vertical slot  112  constrains the movement of the side rib  218  causing the cassette  200  to be moveable in an upwards direction. 
     Turning to  FIG. 3 , the cassette  200  will be discussed in further detail.  FIG. 3  shows a perspective view of the cassette  200 . The cassette  200  comprises a housing  220  and a bar  222  is mounted within the housing  220 . In some embodiments the bar  222  is a cylindrical element. In other embodiments the bar  222  is elongate and substantially cylindrical and comprises ridges and groves. For example the bar  222  can comprise spiral grooves and/or ridges for receiving cleaning brushes or ribs. The bar comprises at least one cleaning element  224 . The at least one cleaning element  224  can be a cleaning brush having a plurality of projecting bristle cleaning elements  226 . Additionally or alternatively the bar  222  comprises any means suitable for cleaning a surface. For example the cleaning element  222  can be a strip of bristles  228 , projecting rubber strip or projecting rubber fingers or a combination of different types of cleaning elements. In some embodiments the cleaning elements  226 ,  228  can comprise bristles having different stiffness. A variable stiffness in the bristles  226 ,  228  means that different types of debris can be picked up by the cassette  200 . 
     The bar  222  is rotatably mounted in the cassette  200  such that the bar  222  is configured to rotate with respect to the cassette  200 . The first end  214  of the cassette  200  comprises a drive gear  230 . The drive gear  230  is configured to mesh with a motor drive gear (not shown) mounted in the base portion  102  when the cassette  200  is seated in the cleaning head  100 . The motor drive gear is an inverse reciprocal shape to the drive gear  230 . The drive gear  230  is configured to transmit rotational movement from a brush motor in the cleaning head  100  to the bar  222 . The brush motor can be selectively operated by the user or controlled automatically. The control and operation of the brush motor is known as will not be discussed in any further detail. 
     The drive gear  230  comprises a plurality of circumferentially spaced drive elements  232 .  FIG. 3  shows three drive elements  232  equally spaced around the drive gear  230 . Each drive element comprises a straight sided drive face  234  and a sloping camming face  236 . In this way each drive element  232  has a saw-tooth profile. The straight sided drive face  234  comprises a flat straight sided face which is configured to engage with an identical straight sided drive face on the motor drive gear. The sloping camming face  236  is configured to engage with an identical reciprocal sloping camming face on the motor drive gear. This means that when the drive gear  230  is inserted against the motor drive gear, the drive elements  232  will either be located between drive elements on the motor drive gear or the sloping camming face  236  will engage the drive elements of the motor drive gear. If the sloping camming face  236  engages a reciprocal drive element on the motor drive gear, the sloped sided face will cam against the motor drive gear. Since the motor will not be operational when the cassette  200  is inserted into the cleaning head  100 , the motor drive gear will be relatively stiff to turn. Accordingly the drive gear  230  will rotate and turn the bar  222  as the sloped sided face  236  cams against the drive elements on the motor drive gear. This means that the drive gear and the motor drive gear will always seat correctly when the cassette  200  is inserted into the cleaning head. 
       FIG. 4  shows an exploded perspective view of the cassette  200 . The bar  222  is removable from the cassette  200  and can be manually disassembled by the user.  FIG. 4  shows the bar  222  removed from the cassette  200 . By removing the bar  222  from the cassette  200 , the user is able to clean the bar  222  and the cassette housing  220 . For example the user is able to more easily remove hair or other fibrous material that may have wrapped around the bar  222 . The bar  222  comprises a first cassette mounting assembly  300  and a second cassette mounting assembly  310  for rotatably mounting the bar  222  in the cassette  200 . 
     The bar  222  and the first and second cassette mounting assemblies  300 ,  310  will be discussed in more detail with respect to  FIG. 5 .  FIG. 5  shows an exploded perspective view of the cassette  200 . The first cassette mounting assembly  300  comprises at least one mounting portion  302  for engaging with the cassette  200 . The at least one mounting portion  302  comprises first and second projecting ribs  302 ,  304 . The mounting ribs  302 ,  304  are configured to slot in a reciprocal groove  306  at the first end  214  of the cassette  200 . The groove  306  is arranged in a plane which is perpendicular to the longitudinal axis A-A of the cassette  200 . In this way the first mounting assembly  300  is configured to slide vertically or perpendicularly away from the longitudinal axis A-A cassette  200  as shown in  FIG. 5 . 
     The second cassette mounting assembly  310  comprises an end plug  312  for engaging in a reciprocal hole  314  in the second end  216  of the cassette. The end plug  312  has a push fit or interference fit with the hole  314 . When removing the bar  222 , the user slides the first cassette mounting assembly  300  out of the groove  306  in the cassette  200  and then pulls the end plug  312  out of the hole  314 . In order to set the bar  222  in the cassette  200 , the user reverses the steps for removing the bar  222  from the cassette  200 . In alternatively embodiments, the first and second mounting assembles  300 ,  310  can comprises any suitable mechanism for mounting the bar  222  to the cassette  200 . For example, the mounting assemblies  300 ,  310  can both have rib-groove mounting arrangements. Alternatively the mounting assemblies  300 ,  310  can have a snap-fit arrangement whereby the mounting assemblies are held in place with resilient retaining elements (not shown). 
     The first cassette mounting assembly  300  comprises a removable first spindle  320 . The drive gear  230  is mounted on the removable drive spindle  320 . In this way when the drive gear  230  turns, so does the first removable spindle  320 . The removable first spindle  320  comprises at least one drive surface engageable with a reciprocal surface in a hole  322  in the bar  222 . In some embodiments the at least one drive surface is the flat side of a D-shaped cross section. The removable first spindle  320  comprises a D-shaped cross section and fits into a reciprocal D-shaped hole  322  in the centre of the bar  222 . The D-shaped cross section ensures that there is positive engagement between the removable spindle  320  and the bar  222  and the drive force from the drive gear is transmitted to the bar  222  without slipping. The flat side  516  of the D-shape of the first spindle can be seen in  FIG. 7 . In other embodiments the spindle  320  and the hole  322  can be any shape to prevent relative movement therebetween. For example, the cross-sectional shape can be star shaped, triangular, or square or any other suitable shape. The removable first spindle  320  is rotatably coupled to the mounting ribs  302 ,  304 . The first cassette mounting assembly  300  comprises a bearing  500  (see  FIG. 7 ) for permitting relative rotation of the first spindle  320  with respect to the mounting ribs  302 ,  304  and the cover portion  400 . In this way the first cassette mounting assembly  300  and the removable first spindle  320  are a single removable assembly. This means that when the user removes the first cassette mounting assembly  300  from the bar, the removable first spindle  320  is also removed. The first cassette mounting assembly  300  is not arranged to be disassemble into separate parts. This means the user is less likely to lose parts of the cassette  200  during maintenance. Otherwise the user would have to reassemble the first spindle  320 , drive gear  230 , the mounting ribs  302 ,  304  and a plurality of washers and clips (not shown) in the right order, which would be difficult and time consuming. 
     The removable first spindle  320  can be rotatably mounted on the first cassette mounting assembly with C-clips. Alternatively other fastening means can be used to keep the components of the first cassette mounting assembly  300  together but allow relative rotational movement between components of the first cassette mounting assembly  300 . 
     By permitting the user to remove the first cassette mounting assembly  300  from the bar  222 , the user is able to remove any hair or other fibrous material that may have ingressed into the vicinity of the bearing  500  at the first end  214  of the bar  222 . Although it may be unlikely that hair may clog the bearing  500 , some hair may eventually wrap around the removable first spindle  320  and jam the bearing at the first end  214  of the bar  222 . In this case by allowing the cassette  200  to be disassembled, the user can more easily maintain the cassette  200 . 
     The second cassette mounting assembly  310  comprises a removable end cap  330 . The removable end cap is rotatably mountable on a fixed second spindle  340 . The fixed second spindle  340  is fixed with respect to the bar  222  such that when the bar  222  rotates, so does the fixed second spindle  340 . The end cap  330  comprises a bearing  510  at the second end  216  of the cassette. This means that the fixed second spindle  340  rotates within the bearing  510  in the end cap  330 . The end cap  330  is removable and this means that the user can take off the end cap  330  can expose the fixed second spindle  340 . This means that the user can remove any hair or other fibrous material that may have wound around the fixed second spindle  340 . 
     The cassette  200  will now be discussed in further detail with reference to  FIGS. 6 and 7 .  FIG. 6  shows an underneath plan view of the cassette  200 .  FIG. 6  shows the longitudinal axis A-A of the cassette  200 . The longitudinal axis of the cassette  200  is also the rotational axis of the bar  222 .  FIG. 7  shows a side cross sectional view of the cassette  200  along the axis A-A. 
     The first and second cassette mounting assemblies  300 ,  310  respectively comprise a first and second cover portion  400 ,  410 . The cover portions  400 ,  410  respectively overlap the first and second ends  214 ,  216  of the bar  222 . The first cover portion  400  overlaps past a first flange  512  at the first end  214  of the bar  222 . Likewise the second cover portion  410  overlaps past a second flange  514  at the second end  216  of the bar  222 . The flanges  512 ,  514  project above the surface of the bar  222 . This means that any fibrous material must move up over the flange  512 ,  514  before it can interfere with the first and second spindles  320 ,  330 . In some embodiments the flanges  512 ,  514  are permanently fixed to the bar  222  so that hair will not slip off the end of the bar  222 . 
     The diameter of the first and second cover portions  400 ,  410  are slightly bigger than the diameter of the flanges  512 ,  514  of the bar  222 . This means that the bar  222  can freely rotate with respect to the first and second cover portions  400 ,  410 . The first cover portion  400  is integral with the with first cassette mounting assembly  300 . The second cover portion  410  is integral with the second cassette mounting portion  410 . In this way the cover portions  400 ,  410  together with the flanges  512 ,  514  provide a labyrinthine pathway that debris and fibrous material must take before it is adjacent to the bearings  500 ,  510  of the first and second ends  214 ,  216 . This means that hair and other fibrous material is less likely to wrap around the removable first spindle  320  or the fixed second spindle  330 . 
     In another embodiment two or more embodiments are combined. Features of one embodiment can be combined with features of other embodiments. 
     Embodiments of the present invention have been discussed with particular reference to the examples illustrated. However it will be appreciated that variations and modifications may be made to the examples described within the scope of the invention.