Patent Publication Number: US-10307028-B2

Title: Cleaner head for a vacuum cleaner

Description:
REFERENCE TO RELATED APPLICATION 
     This application claims the priority of United Kingdom Application No. 1602546.2, filed Feb. 12, 2016, the entire contents of which are incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The present invention relates to a cleaner head for a vacuum cleaner. 
     BACKGROUND OF THE INVENTION 
       FIGS. 1 to 3  illustrate a known cleaner head  1  for a vacuum cleaner. The base of the cleaner head  1  comprises a suction inlet  2 , a front plate  3  located forward of the suction inlet  2 , and a rear plate  4  located rearward of the suction inlet  2 . Each of the two plates  3 , 4  is inclined or ramped relative to the horizontal. When the cleaner head  1  is placed onto a carpeted surface, the two plates  3 , 4  penetrate the piles of the carpet. As a result, the air that is drawn into the suction inlet  2 , which passes beneath each of the plates  3 , 4 , penetrates more deeply into the carpet. When the cleaner head  1  is pushed forwards, the ramped surface of the front plate  3  helps to flatten the piles of the carpet. As a result, the front plate  3  moves relatively smoothly over the piles of the carpet. The rear plate  4 , on the other hand, presents a vertical surface to the piles and therefore tends to dig into the piles. As a result, a greater push force is required in order to manoeuvre the cleaner head  1  forwards. Moreover, as the cleaner head  1  is pushed forwards, the cleaner head  1  may skip over the carpet as the rear plate  4  first digs into the piles and then, with sufficient push force, jumps clear of the piles. Skipping of the cleaner head  1  is likely to worsen the cleaning performance since the cleaner head  1  is momentarily lifted from the carpet. The same behaviour is observed when the cleaner head  1  is pulled rearwards. 
     SUMMARY OF THE INVENTION 
     According to certain aspects, the present invention provides a cleaner head for a vacuum cleaner comprising: a suction inlet; a front blade located forward of or at the front of the suction inlet and arranged to pivot about a first axis; and a rear blade located rearward of or at the rear of the suction inlet and arranged to pivot about a second axis different to the first axis, wherein each blade pivots between a deployed position and a retracted position, each blade projects downwardly when in the deployed position, and the blades are coupled together such that (i) when one of the blades is in the deployed position the other of the blades is in the retracted position, and (ii) moving one of the blades from the deployed position to the retracted position causes the other of the blades to move from the retracted position to the deployed position. 
     Each blade projects downwardly when in the deployed position. Consequently, when used on a carpeted surface, the deployed blade penetrates the piles of the carpet. Air drawn into the suction inlet via the deployed blade then penetrates deeply into the carpet. The blades are coupled together such that, when one of the blades is in the deployed position, the other of the blades is in the retracted position. Consequently, when the cleaner head is manoeuvred forwards or rearwards, only one of the blades is deployed at any one time. As a result, the cleaner head is easier to manoeuvre and is less likely to skip over the carpeted surface. Since only one blade is deployed at any one time, it is possible to employ blades that penetrate more deeply into the carpet. By contrast, if the plates of the cleaner head of  FIGS. 1 to 3  were to penetrate more deeply into the carpet, the force required to manoeuvre the cleaner head may become excessive and/or skipping of the cleaner head may become frequent. In addition to improving the manoeuvrability of the cleaner head, each blade may help to create a partial seal between the cleaner head and the carpet when in the retracted position. As a result, more of the air drawn into the suction inlet occurs at the deployed blade, thus improving the cleaning performance. 
     The front blade may move to the deployed position when the cleaner head is manoeuvred forwards, and the rear blade may move to the deployed position when the cleaner head is manoeuvred rearwards. Moreover, when the direction of travel of the cleaner head over a cleaning surface (such as a carpeted surface) is reversed, the cleaning surface may apply a force to the deployed blade that causes the deployed blade to move towards the retracted position. As a consequence of the coupling between the blades, the retracted blade in turn moves towards the deployed position. As the retracted blade moves towards the deployed position, the cleaning surface may apply a force to the retracted blade that causes the retracted blade to move fully to the deployed position. The blades of the cleaner head thus move automatically between the deployed and retracted positions as the cleaner head is manoeuvred forwards and rearwards. This then has the advantage that a user is not required to adjust the setting of the cleaner head for forward or rearward movement. 
     When in the deployed position, the front blade may have a ramped front-facing surface and the rear blade may have a ramped rear-facing surface. This then has the advantage that, as the cleaner head is manoeuvred forwards and rearwards over a carpeted surface, the deployed blade is able to deflect and flatten the piles of the carpet. As a result, the deployed blade is able to move relatively smoothly over the piles. 
     When in the deployed position, the front blade may have a vertical rear-facing surface and the rear blade may have a vertical front-facing surface. This then has the benefit that a relatively poor seal is formed between the deployed blade and the cleaning surface. Consequently, more of the air drawn into the suction inlet occurs at the deployed blade. Furthermore, dirt-laden air drawn beneath the deployed blade may have a relatively clear path to the suction inlet and thus dirt carried by the air is less likely to be deposited back onto the cleaning surface. 
     When in the retracted position, the rear-facing surface of the front blade and the front-facing surface of the rear blade may be horizontal. As a result, a partial seal may be created between the horizontal surface of the retracted blade and the cleaning surface. This then has the benefit that less air is drawn into the suction inlet via the retracted blade and thus more air is drawn into the suction inlet via the deployed blade, where it is most desired. 
     The cleaner head may comprise a planar front plate located forward of the front blade and a planar rear plate located rearward of the rear blade. The front blade then projects downwardly beyond plane of the front plate when in the deployed position, and the rear blade projects downwardly beyond the plane of the rear plate when in the deployed position. When the cleaner head is manoeuvred forwards over a carpeted surface, the rear plate may sit on top of and gently crush the piles of the carpet so as to form a partial seal. Equally, when the cleaner head is manoeuvred rearwards, the front plate may sit on top of and gently crush the piles of the carpet so as to form a partial seal. This then has the benefit that less air is drawn into the suction inlet via the retracted blade and thus more air is drawn into the suction inlet via the deployed blade. The deployed blade projects downwardly beyond the corresponding plate. As a result, the corresponding plate does not adversely affect the flow of air that is drawn into the suction opening via the deployed blade, i.e. the front plate does not adversely affect the flow of air beneath the front blade during forward movement, and the rear plate does not adversely affect the flow of air beneath the rear blade during rearward movement. 
     The front blade may be flush with the front plate when in the retracted position, and the rear blade may be flush with the rear plate when in the retracted position. This then has the advantage that each blade, when in the retracted position, contributes to the partial seal that is formed between the cleaner head and the cleaning surface. As a result, a more effective seal may be achieved. 
     The front blade may pivot forward and the rear blade may pivot rearward when moving from the deployed position to the retracted position. This then has the benefit that the size of the suction inlet is unchanged by the movement of the blades, and thus the same cleaning performance may be achieved in both forward and rearward directions. 
     The front and rear blades may be coupled together by a bracket that is attached to each blade. More particularly, the bracket may comprise two arms and a bridge. One arm is then fixedly attached at one end to the front blade, and is pivotally attached at the opposite end to the bridge. The other arm is then fixedly attached at one end to the rear blade, and is pivotally attached at the opposite end to the bridge. The use of a bracket to couple the blades, particularly the one described here, provides a relatively simple arrangement for ensuring that, as one blade moves from the deployed position to the retracted position, the other blade is caused to move from the retracted position to the deployed position. 
     According to certain aspects, the present invention also provides a cleaner head for a vacuum cleaner comprising: a suction inlet; a front blade located forward of or at the front of the suction inlet and arranged to pivot about a first axis; and a rear blade located rearward of or at the rear of the suction inlet and arranged to pivot about a second axis different to the first axis, wherein each blade pivots between a deployed position and a retracted position, each blade projects downwardly when in the deployed position, and moving the cleaner head over a cleaning surface in a forward direction causes the front blade to move to the deployed position and the rear blade to move to the retracted position, and moving the cleaner head over the cleaning surface in a rearward direction causes the rear blade to move to the deployed position and the front blade to move to the retracted position. 
     According to certain aspects, the present invention further provides a cleaner head for a vacuum cleaner comprising: a suction inlet; a front blade located forward of or at the front of the suction inlet and arranged to pivot about a first axis; and a rear blade located rearward of or at the rear of the suction inlet and arranged to pivot about a second axis different to the first axis, wherein each blade pivots between a deployed position and a retracted position, the blades are configured such that when one of the blades is in the deployed position the other of the blades is in the retracted position, and, when in the deployed position, the front blade has a ramped front-facing surface and the rear blade has a ramped rear-facing surface. 
     According to certain aspects, the present invention additionally provides a cleaner head for a vacuum cleaner comprising: a main body having a suction inlet located in a base of the main body; a front blade located forward of or at the front of the suction inlet and arranged to pivot about a first axis; and a rear blade located rearward of or at the rear of the suction inlet and arranged to pivot about a second axis different to the first axis, wherein each blade pivots between a deployed position and a retracted position, the blades are configured such that when one of the blades is in the deployed position the other of the blades is in the retracted position, each blade projects downwardly beyond the base of the main body when in the deployed position, and each blade is flush with the base of the main body when in the retracted position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order that the present invention may be more readily understood, an embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: 
         FIG. 1  is a perspective view of a known cleaner head; 
         FIG. 2  is an underside view of the cleaner head of  FIG. 1 ; 
         FIG. 3  is a sectional slice through the centre of the cleaner head of  FIG. 1 ; 
         FIG. 4  is a perspective view of a cleaner head in accordance with the present invention; 
         FIG. 5  is a underside view of the cleaner head of  FIG. 4 ; 
         FIG. 6  is an exploded view of the cleaner head of  FIG. 4 ; 
         FIG. 7  is a sectional slice through the centre of the cleaner head of  FIG. 4  in which blades of the cleaner head are in (a) a first configuration and (b) a second configuration; and 
         FIG. 8  a sectional slice through the centre of the cleaner head of  FIG. 4  during use on a carpeted surface in which (a) illustrates the cleaner head during forward movement, (b) illustrates the cleaner head shortly after the direction of travel of the cleaner head has been reversed, and (c) illustrates the cleaner head during rearward movement. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The cleaner head  10  of  FIGS. 4 to 8  comprises a main body  11 , a front blade  12 , a rear blade  13 , a pair of brackets  14  and a pair of covers  15 . 
     The main body  11  comprises a suction inlet  20  located in the base of the main body  11 . The suction inlet  20  is rectangular in shape and opens into a suction cavity  21  located above the suction inlet  20 . The main body  11  comprises a neck-like portion  18  for attachment to a vacuum cleaner (not shown). A channel  22  extends through the neck-like portion  18  from the suction cavity  21  to a suction outlet  23  located at the end of the neck-like portion  18 . During use, suction applied at the suction outlet  23  by the vacuum cleaner causes dirt-laden air to be drawn into the suction cavity  21  via the suction inlet  20 . From there, the dirt-laden air is carried to the vacuum cleaner via the channel  22 . 
     The base of the main body  11  comprises a front plate  30  located forward of the suction inlet  20  and a rear plate  31  located rearward of the suction inlet  20 . Each of the plates  30 , 31  is planar and extends horizontally. 
     The front and rear blades  12 , 13  are located within the suction cavity  21 , with the front blade  12  located at the front of the suction cavity  21  and the rear blade  13  located at the rear of the suction cavity  21 . Each blade  12 , 13  comprises an elongate body  40  and a pair of pivot pins  41 . The front blade  12  additionally comprises a stop arm  42 . The body  40  of each blade  12 , 13  has a cross-sectional shape that resembles a teardrop. Consequently, the body  40  may be regarded as having a cylindrical portion and a triangular or prismatic portion. The pivot pins  41  extend outwardly from the ends of the body  40 . The stop arm  42  of the front blade  12  extends outwardly along the length of the body  40 . 
     The pivot pins  41  of each blade  12 , 13  are received within corresponding holes  19  in the side walls of the main body  11  of the cleaner head  10 . As a result, each blade  12 , 13  is pivotally attached to the main body  11 . The front blade  12  pivots about a first axis  43 , and the rear blade  13  pivots about a second axis  44  that is different but parallel to the first axis  43 . 
     Each blade  12 , 13  pivots between a deployed position and a retracted position.  FIG. 7( a )  illustrates the cleaner head  10  with (a) the front blade  12  in the deployed position and the rear blade  13  in the retracted position, and  FIG. 7( b )  illustrates the cleaner head  10  with the front blade  12  in the retracted position and the rear blade  13  in the deployed position. When in the deployed position, each blade  12 , 13  projects downwardly, which is to say that the triangular portion of the blade  12 , 13  is directed downwards. Moreover, the blade  12 , 13  projects downwardly beyond the base of the main body  11 . So, for example, when the front blade  12  is in the deployed position, the blade  12  projects downwardly beyond the plane of the front plate  30 . When in the deployed position, each blade  12 , 13  may be said to have a front-facing surface  50 , 60 , a rear-facing surface  51 , 61 , and a working edge  52 , 62  at the meeting of the two surfaces. The front-facing surface  50  of the front blade  12  and the rear-facing surface  61  of the rear blade  13  are ramped. More specifically, the front-facing surface  50  of the front blade  12  extends upwardly from the working edge  52  in a direction towards the front of the main body  11 , and the rear-facing surface  61  of the rear blade  13  extends upwardly from the working edge  62  in a direction towards the rear of the main body  11 . The rear-facing surface  51  of the front blade  12  and the front-facing surface  60  of the rear blade  13  extend vertically. When in the retracted position, each blade  12 , 13  projects forwards (front blade) or rearwards (rear blade), which is again to say that the triangular portion of the blade  12 , 13  is directed forwards or rearwards. Moreover, each blade  12 , 13  is flush with the base of the main body  11 . So, for example, when the front blade  12  is in the retracted position, the rear-facing surface  51  of the front blade  12  lies in the same plane as that of the front plate  30 . 
     The stop arm  42  of the front blade  12  contacts the main body  11  when the front blade  12  is both in the deployed position and the retracted position. The stop arm  42  thus prevents movement of the front blade  12  beyond these two positions. As noted below, the two blades  12 , 13  are coupled together and thus the stop arm  42  also acts to prevent movement of the rear blade  13  beyond the deployed and retracted positions. 
     The two blades  12 , 13  are coupled together such that (i) when one of the blades  12  is in the deployed position, the other of the blades  13  is in the retracted position, and (ii) when one of the blades  12  moves from the deployed position to the retracted position, the other of the blades  13  is caused to move from the retracted position to the deployed position. The blades  12 , 13  are coupled together by the two brackets  14 . One of the brackets  14  is used to couple the blades  12 , 13  on one side of the main body  11 , and the other of the brackets  14  is used to couple the blades  12 , 13  on the opposite side of the main body  11 . Each bracket  14  comprises two arms  70 , 71  and a bridge  72 . One arm  70  is fixedly attached at one end to a pivot pin  41  of the front blade  12 , and is pivotally attached at the opposite end to the bridge  72 . The other arm  71  is fixedly attached at one end to a pivot pin  41  of the rear blade  13 , and is pivotally attached at the opposite end to the bridge  72 . The bridge  72  then extends between and is pivotally attached to the two arms  70 , 71 . When the front blade  12  moves from the deployed position to the retracted position, the arm  70  attached to the front blade  12  pivots about the first axis  43 . The bridge  72  is then pushed rearwards by the arm  70 , which in turn causes the other arm  71  to pivot about the second axis  44 . As a result, the rear blade  13  moves from the retracted position to the deployed position. Similarly, when the rear blade  13  moves from the deployed position to the retracted position, the arm  71  attached to the rear blade  13  pivots about the second axis  44 . The bridge  72  is then pushed forwards by the arm  71 , which in turn causes the other arm  70  to pivot about the first axis  43 . As a result, the front blade  12  moves from the retracted position to the deployed position. 
     The covers  15  are attached to the main body  11  so as to cover the brackets  14  and the ends of the blades  12 , 13 . 
     Use of the cleaner head  10  on a carpeted surface  80  will now be described with reference to  FIG. 8 . 
       FIG. 8( a )  illustrates the cleaner head  10  when moving in a forward direction. The front blade  12  is in the deployed position and the rear blade  13  is in the retracted position. Suction generated at the suction outlet  23  causes air to be drawn into the suction cavity  21  via the suction inlet  20 . The air that is drawn in at the front of the cleaner head  10  is forced to pass beneath the front blade  12 . The front blade  12 , being in the deployed position, penetrates deeply into the piles of the carpet  80 . As a result, the air penetrates deeply into the carpet  80  and picks up more of the dirt. The rear blade  13  and the rear plate  31  present a planar surface that sits on top of and gently crushes the piles of the carpet  80 . A partial seal is therefore created between the carpet  80  and that part of the cleaner head  10  located rearward of the suction inlet  20 . As a result, less air is drawn in at the rear of the cleaner head  10  and thus more air is drawn in at the front of the cleaner head  10 , where it is most desired during forward movement. As the cleaner head  10  moves forwards, the piles of the carpet  80  apply a force on the front blade  12  that acts in a rearward direction. However, the stop arm  42  prevents the front blade  12  from pivoting rearwards beyond the deployed position. The ramped, front-facing surface  50  of the front blade  12  deflects and flattens the piles of the carpet  80 . The front blade  12  therefore moves relatively smoothly over the carpet  80 . The rear blade  13  and the rear plate  31  continue to present a planar surface that sits on top of the carpet  80 . As a result, movement of the cleaner head  10  is not unduly impeded by the rear blade  13  or the rear plate  31 . 
       FIG. 8( b )  illustrates the cleaner head  10  shortly the direction of travel of the cleaner head  10  has been reversed. When the direction of the cleaner head  10  is reversed and begins to moves rearwards, the piles of the carpet  80  apply a force on the front blade  12  that acts in a forward direction. As a result, the front blade  12  begins to move from the deployed position to the retracted position. Owing to the coupling between the two blades  12 , 13 , the rear blade  13  also begins to move from the retracted position to the deployed position. As the rear blade  13  moves from the retracted position, the rear blade  13  catches on the piles of the carpet  80 . Consequently, in addition to applying a force on the front blade  12 , the piles of the carpet  80  apply a force on the rear blade  13 . The carpet  80  therefore pushes the front blade  12  up to the retracted position and pulls the rear blade  13  down to the deployed position. 
       FIG. 8( c )  illustrates the cleaner head  10  when moving in a rearward direction. The front blade  12  is now in the retracted position and the rear blade  13  is in the deployed position. The rear blade  13  penetrates deeply into the piles of the carpet  80 . As a result, the air that is drawn in at the rear of the cleaner head  10  penetrates deeply into the carpet  80 . The front blade  12  and the front plate  30  present a planar surface that sits on top of and gently crushes the piles of the carpet  80 . A partial seal is therefore created between the carpet  80  and that part of the cleaner head  10  located forward of the suction inlet  20 . As a result, less air is drawn in at the front of the cleaner head  10  and thus more air is drawn in at the rear of the cleaner head  10 , where it is most desired during rearward movement. As the cleaner head  10  moves rearwards, the ramped, rear-facing surface  61  of the rear blade  13  deflects and flattens the piles of the carpet  80 . The rear blade  13  therefore moves relatively smoothly over the carpet  80 . The front blade  12  and the front plate  30  continue to present a planar surface that sits on top of the carpet  80 . As a result, rearward movement of the cleaner head  10  is not unduly impeded by the front blade  12  or the front plate  30 . 
     In comparison to the cleaner head  1  of  FIGS. 1 to 3 , the cleaner head  10  described above and illustrated in  FIGS. 4-8  is capable of achieving a better cleaning performance. In particular, when the cleaner head  10  is manoeuvred forwards, the front blade  12  penetrates the carpet  80  and a partial seal is created rearward of the suction inlet  20  between the cleaner head  10  and the carpet  80 . As a consequence of the partial seal, more air is drawn beneath the front blade  12  and thus more dirt is carried by the air into the suction inlet  20 . Similarly, when the cleaner head  10  is manoeuvred rearwards, the rear blade  13  penetrates the carpet  80  and a partial seal is created forward of the suction inlet  20  between the cleaner head  10  and the carpet  80 . As a result, more air is drawn beneath the rear blade  13 . With the cleaner head  1  of  FIGS. 1 to 3 , on the other hand, air is drawn equally beneath the front plate  3  and the rear plate  4  during both forward and rearward movement of the cleaner head  1 . As a result, the air passing beneath each plate  3 , 4  has a lower flow rate and thus less dirt is carried by the air into the suction inlet  2 . 
     In contrast to the cleaner head  1  of  FIGS. 1 to 3 , the cleaner head  10  described above is easier to manoeuvre and is less likely to skip over the carpeted surface  80 . In particular, when the cleaner head  10  is manoeuvred forwards or rearwards, the trailing blade (i.e. the rear blade  13  during forward movement or the front blade  12  during rearward movement) moves to the retracted position and does not unduly impede movement of the cleaner head  10 . By contrast, when the cleaner head  1  of  FIGS. 1 to 3  is manoeuvred forwards or rearwards, the trailing plate  3  or  4  tends to dig into the piles of the carpet. As a result, a greater force is required to manoeuvre the cleaner head  10 . Additionally, the cleaner head  1  is more likely to skip over the carpet as the trailing plate  3  or  4  digs into the piles and then, with sufficient force, jumps clear of the piles. 
     Since the trailing blade  12  or  13  moves to the retracted position and does not unduly impede movement of the cleaner head  10 , it is possible to employ blades  12 , 13  that penetrate more deeply into the carpet  80 . By contrast, if the plates  3 , 4  of the cleaner head  1  of  FIGS. 1 to 3  were to penetrate more deeply into the carpet, the force required to manoeuvre the cleaner head  1  may become excessive and/or skipping of the cleaner head  1  may become frequent. 
     In embodiment described above, the front and rear blades  12 , 13  are located in the suction cavity  21 . A seal  45  is then provided between each blade  12 , 13  and the main body  11  of the cleaner head  10 . As a result, dirt-laden air is prevented from being drawn through the relatively tight space between the blades  12 , 13  and the main body  11 . Since the blades  12 , 13  are located in the suction cavity  21 , the blades  12 , 13  may be regarded as delimiting the front and rear edges of the effective suction inlet (i.e. that part of the suction inlet  20  through which air is drawn). The front blade  12  pivots forwards as it moves from the deployed position to the retracted position, and the rear blade  13  pivots rearwards. As a result, the size of the effective suction inlet is unchanged; this can be seen in  FIGS. 7 and 8 . 
     When in the deployed position, the rear-facing surface  51  of the front blade  12  and the front-facing surface  60  of the rear blade  13  extend vertically. As a result, a relatively sharp working edge  52 , 62  is achieved for each blade  12 , 13 . This then has the benefit that a relatively poor seal is formed between the deployed blade  12  or  13  and the carpet  80 . Consequently, more of the air that is drawn into the suction inlet  20  occurs at the deployed blade  12  or  13 . Furthermore, as can be seen in  FIGS. 8( a ) and 8( c ) , the dirt-laden air drawn beneath the deployed blade  12  or  13  has a relatively clear path to the suction inlet  20  and thus dirt carried by the air is less likely to be deposited back onto the carpet  80 . 
     Rather than locating the blades  12 , 13  in the suction cavity  21 , the blades  12 , 13  may be located outside of the suction cavity  21 . Accordingly, in a more general sense, the front blade  12  may be said to be located forward of or at the front of the suction inlet  20 , and the rear blade  13  may be said to be located rearward of or at the rear of the suction inlet. Where the blades  12 , 13  are located outside of the suction cavity  21 , the blades  12 , 13  are ideally located close to the suction inlet  20  such that a relatively short path is taken by the air as it moves from beneath the deployed blade  12  or  13  to the suction inlet  20 . The reason for this is that, as the length of the path taken by the air increases, there is an increasing likelihood that dirt carried by the air may be deposited back onto the carpet  80 . 
     Each blade  12 , 13  projects downwardly when in the deployed position and pivots through an angle of around 90 degrees when moving to the retracted position. As a result, the front blade  12  projects forward and the rear blade  13  projects rearward when in the retracted position. Moreover, each blade  12 , 13  is flush with the corresponding plate  30 , 31  when in the retracted position. This then has the advantage that each blade  12 , 13 , when in the retracted position, contributes to the partial seal that is formed between the cleaner head  10  and the carpeted surface  80 . In spite of this advantage, each blade  12 , 13  may pivot through a smaller or larger angle. A smaller angle would mean that each blade  12 , 13  continues to project downwardly to some degree when in the retracted position, whilst a larger angle would mean that each blade  12 , 13  projects upwardly. Irrespective of the angle through which the blades  12 , 13  pivot, each blade  12 , 13  nevertheless moves away from the deployed position. As a result, movement of the cleaner head  10  is easier in comparison to an arrangement in which both blades  12 , 13  are fixed in the deployed position. 
     The blades  12 , 13  of the cleaner head  10  move automatically between the deployed and retracted positions as the cleaner head  10  is manoeuvred forwards and rearwards. This then has the advantage that a user is not required to adjust the setting of the cleaner head  10  for forward or rearward movement. The two blades  12 , 13  are coupled together using a pair of brackets  14 , which is a relatively simple arrangement for ensuring that, as one blade  12  moves from the deployed position to the retracted position, the other blade  13  moves from the retracted position to the deployed position. Conceivably alternative means may be used for coupling the two blades  12 , 13  together whilst achieving the same effect. Moreover, rather than coupling the two blades  12 , 13  together, each blade  12 , 13  may be configured for independent movement. However, in order to achieve the advantages described above, the two blades  12 , 13  should ideally be configured such that moving the cleaner head  10  in a forward direction causes the front blade  12  to move to the deployed position and the rear blade  13  to move to the retracted position, and moving the cleaner head  10  in a rearward direction causes the rear blade  13  to move to the deployed position and the front blade  12  to move to the retracted position. 
     The front plate  30  located forward of the front blade  12 , and the rear plate  31  located rearward of the rear blade  13  have the advantage of providing a better seal between the cleaner head  1  and the carpeted surface  80 . In particular, each plate  30 , 31  along with its corresponding retracted blade  12 , 13 , gently crush and from a partial seal with the carpet  80 . In spite of this advantage, the front and rear plates  30 , 31  may be omitted, ramped or located at a different height to the retracted blade  12 , 13 .