Abstract:
In a first aspect, the present invention provides a motor, fan and filter arrangement for a vacuum cleaner, comprising: a motor ( 10 ); a fan ( 20 ) connected to an output shaft ( 12 ) of the motor and having an axial intake; and a filter ( 30, 230, 330 ); wherein the fan ( 20 ) is arranged with its axial intake facing the motor ( 10 ); and the motor ( 10 ) is housed within the filter ( 30, 230, 330 ). Such an arrangement makes much more efficient use of space than a conventional arrangement and allows the motor to be positioned within the filter in a reversed direction in comparison to conventional arrangements, so that clear air from the filter can be drawn over the motor before encountering the fan. This also has the beneficial side-effect of cooling the motor with the filtered air. In a second aspect, the present invention also provides vacuum cleaners ( 100, 200, 300 ) comprising such a motor, fan and filter arrangement. Preferred embodiments of such vacuum cleaners are described, including a pivotable stick vac and different hand-holdable vacuum cleaners.

Description:
FIELD OF THE INVENTION 
       [0001]    This application claims priority to European Patent Application No. 07106392.9 filed Apr. 18, 2007. The entire contents of that application are expressly incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    The present invention concerns a motor, fan and filter arrangement for a vacuum cleaner and vacuum cleaners comprising such a motor, fan and filter arrangement. Vacuum cleaners are well known for collecting dust and dirt, although wet-and-dry variants which can also collect liquids are known as well. Typically, vacuum cleaners are intended for use in a domestic environment, although they also find uses in other environments, such as worksites. Generally, they are electrically powered and therefore comprise an electric motor and a fan connected to an output shaft of the motor, an inlet for dirty air, an outlet for clean air and a collection chamber for dust, dirt and possibly also liquids. Electrical power for the motor may be provided by a source of mains electricity, in which case the vacuum cleaner will further comprise an electrical power cable, by a removable and replaceable battery pack, or by one or more in-built rechargeable cells, in which case the vacuum cleaner will further comprise some means, such as a jack plug, for connecting the vacuum cleaner to a recharging unit. When the vacuum cleaner is provided with electrical power from one of these sources, the electric motor drives the fan to draw dirty air along an airflow pathway in through the dirty air inlet, via the collection chamber to the clean air outlet. 
       BRIEF SUMMARY OF THE INVENTION 
       [0003]    Interposed at some point along the airflow pathway, there is also provided some means for separating out dust and dirt (and possibly also liquids) entrained with the dirty air and depositing these in the collection chamber. This separation means may comprise one or more filters and/or a cyclonic separation device. Conventionally, in the event that the separation means comprises a filter, the motor, fan and filter have an arrangement as represented schematically in  FIG. 1 . As may be seen from  FIG. 1 , dirty air which has entered the vacuum cleaner via the dirty air inlet passes from region P to region Q through filter  30 . This separates out dust and dirt (and possibly also liquids) entrained with the dirty air and the filtered material therefore remains in region P. If, as is usually the case, filter  30  is located within the collection chamber itself, the filtered material remaining in region P also accumulates there. The clean air then passes from region Q on the other side of filter  30  to a third region R through a grille  42  formed in a wall  40  on which filter  30  is mounted. Although it may be provided with an additional filter, grille  42  does not generally have a filtering effect. Its primary purpose is instead to prevent users from gaining access to fan  20  mounted on motor output shaft  12  of motor  10 , which draws air through the vacuum cleaner when motor  10  is supplied with electricity through electrical terminals  14 ,  16 . As shown in  FIG. 1 , fan  20  is an impeller, which draws air in axially towards its face and expels air out tangentially, from where the air then passes to the clean air outlet of the vacuum cleaner. An example of a hand-holdable vacuum cleaner having the conventional motor, fan and filter arrangement of  FIG. 1  is described in European patent publication no. EP 1 523 916 A (corresponding U.S. Application No. 10/686,506), also in the name of the present applicant. 
         [0004]    The conventional arrangement of motor, fan and filter described above therefore creates three separate regions, P, Q and R, of which the second region, region Q, is effectively “dead” space. In other words, whereas region P can be used to provide the collection chamber for filtered material as described, and region R houses the motor  10  and fan  20 , region Q only consumes space without fulfilling any purpose. On the one hand, filter  30  should have as large a surface area as possible in order to increase its filtering effect, which tends to increase the size of region Q. This is the reason why just a flat filter located across the face of fan  20  in the location of grille  42  is generally avoided. Whereas this would dispense with region Q altogether, such a small filter would also dramatically reduce the efficiency of the vacuum cleaner by creating a bottleneck in the airflow pathway. Moreover, in order to improve the effectiveness of filter  30  still further, the filter is often also provided with a cylindrical or frusto-conical shape. Such a shape encourages dirty air in region P to swirl around filter  30  before passing therethrough, which has the effect of throwing dust and dirt particles outwardly, away from filter  30 , under the action of centrifugal force in a cyclonic separation. On the other hand, however, if it is necessary to provide filter  30  with a large surface area or such a shape, the alternative solution of inserting fan  20  and possibly also part or all of motor  10  into region  0 , in order to save space and reduce the size of region Q, cannot be contemplated either, since this would impede the outflow of air expelled tangentially from fan  20  towards the clean air outlet of the vacuum cleaner and instead cause the air expelled by the fan to impinge on the inner surface of filter  30 , thereby countering the inflow of clean air through filter  30  and dramatically diminishing the efficiency of the filtering operation once again. 
         [0005]    The conventional arrangement of motor, fan and filter shown in  FIG. 1  is therefore inefficient in its use of space, but no obvious solution how to overcome this problem presents itself. Such an inefficient use of space is particularly undesirable in a compact or hand-holdable vacuum cleaner, where the efficient use of space is of great importance and any wasted space will necessarily add to the overall weight of the vacuum cleaner, without giving any counteracting benefit. 
         [0006]    It is therefore an object of the present invention to provide a motor, fan and filter arrangement for a vacuum cleaner which makes much better use of space than the conventional arrangement shown in  FIG. 1 . It is also an object of the present invention to provide a motor, fan and filter arrangement particularly suitable for use in a compact or hand-holdable vacuum cleaner. A further object of the invention is to provide a vacuum cleaner comprising such a motor, fan and filter arrangement. 
         [0007]    Accordingly, in a first aspect, the present invention provides a motor, fan and filter arrangement for a vacuum cleaner, comprising: a motor; a fan connected to an output shaft of the motor and having an axial air intake; and a filter; wherein the fan is arranged with its axial intake facing the motor; and the motor is housed within the filter. Such an arrangement allows the motor to be positioned within the filter in a reversed direction in comparison to the conventional arrangement, so that clear air from the filter is drawn over the motor before encountering the fan. The fan may thus still be located outside the filter by protruding therefrom on the output shaft of the motor, so that air expelled by the fan remains unimpeded by the filter and may still pass easily to the clean air outlet of the vacuum cleaner. Moreover, since the clean air from the filter is drawn over the motor before it encounters the fan, a beneficial side-effect of cooling the motor with air from the filter is also provided, unlike in the conventional arrangement of  FIG. 1 , where if the motor were to be cooled with air expelled by the fan, the outflow of air from the fan would have to be re-routed in order to pass over the motor. This would require the flow of air to change direction, thereby introducing aerodynamic resistance into the airflow and reducing the overall efficiency of the vacuum cleaner. In contrast, the motor, fan and filter arrangement of the invention does not require the air expelled by the fan to be re-routed, and since the motor is contained within the filter, it makes efficient use of space and is therefore particularly suitable for use in a compact or hand-holdable vacuum cleaner. 
         [0008]    The motor, fan and filter arrangement of the invention also has the significant advantage that whereas the fan in the conventional arrangement of  FIG. 1  is an impeller which expels air out tangentially, the fan in the motor, fan and filter arrangement of the invention can be either an impeller or a propeller, the latter of which expels air out axially from the opposite side to the face towards which air is drawn in axially by the fan. This is because in the conventional arrangement, the rear face of the fan is obstructed by the motor, so the outflow of air from the fan must be directed tangentially, whereas in the motor, fan and filter arrangement of the invention, the rear face of the fan is unobstructed, so that air from the fan can be expelled either tangentially, as in an impeller, or axially, as in a propeller. This gives far greater versatility in overall design of the airflow within a vacuum cleaner comprising such a motor, fan and filter arrangement to direct the air expelled by the fan as desired. 
         [0009]    The motor, fan and filter arrangement of the invention may further comprise an air-permeable housing interposed between the motor and the filter. Thus, if the filter is removable, for example in order to clean or replace it, the housing prevents a user from gaining access to the motor and fan, but air is still able to pass through the housing from the filter to the fan. Alternatively the motor housing may be impermeable to air, in which case the arrangement may further comprise a grille located between the motor and the fan, through which grille the output shaft of the motor passes. Thus, the impermeable housing completely prevents a user from gaining access to the electrical components of the motor, but air may still pass through the grille from the filter to the fan. This alternative is safer for a user than an air-permeable motor housing, but has the countervailing disadvantage that the motor is not cooled by air from the filter. 
         [0010]    Preferably, the output shaft of the motor extends from within the filter and an end of the output shaft is mounted on a bearing located on an opposite side of the fan from the motor. In this way, the axial intake to the fan is not blocked by either the motor or the bearing, which improves the aerodynamic efficiency of the airflow into the fan, and the extended motor output shaft is supported by the bearing, which prevents the extended shaft from vibrating under any potential imbalance in the fan as it rotates. 
         [0011]    In a second aspect, the present invention also provides a vacuum cleaner comprising a motor, fan and filter arrangement according to the first aspect of the invention. Preferably, the vacuum cleaner is a hand-holdable vacuum cleaner which is able to make greatest use of the space savings which such a motor, fan and filter arrangement provides. 
     
    
     
       BRIEF DESCRIPTION OF THE INVENTION 
         [0012]    Further features and advantages of the present invention will be better understood by reference to the following description, which is given by way of example and in association with the accompanying drawings, in which: 
           [0013]      FIG. 1  is a cross-sectional view of a conventional motor, fan and filter arrangement for a vacuum cleaner; 
           [0014]      FIG. 2A  is an isometric view of a motor and fan suitable for use in a motor, fan and filter arrangement according to an embodiment of the invention; 
           [0015]      FIG. 2B  is a plan view of the motor and fan shown in  FIG. 2A ; 
           [0016]      FIG. 2C  is an end elevational view of the motor and fan of  FIG. 2A  looking in the direction of the arrow labelled “Y” in  FIG. 2B ; 
           [0017]      FIG. 2D  is a cross-sectional view of the motor and fan of  FIG. 2A  along the line A-A′ represented in  FIG. 2B ; 
           [0018]      FIG. 3  is an isometric view of a first embodiment of a vacuum cleaner comprising a motor, fan and filter arrangement according to the invention; 
           [0019]      FIG. 4  is close-up isometric view of a central portion of the vacuum cleaner shown in  FIG. 3 ; 
           [0020]      FIG. 5  is an exploded view of the central portion of the vacuum cleaner shown in  FIG. 4 ; 
           [0021]      FIG. 6  is a cross-sectional view through the central portion of the vacuum cleaner shown in  FIG. 4 ; 
           [0022]      FIG. 7  is a perspective view of a second embodiment of a vacuum cleaner comprising a motor, fan and filter arrangement according to the invention; 
           [0023]      FIG. 8  is a perspective view from below of the hand-holdable vacuum of  FIG. 7 ;  FIG. 9  is a perspective view of the underside of the hand-holdable vacuum cleaner of  FIG. 7 ; 
           [0024]      FIG. 10  is an exploded view of the major components of the hand-holdable vacuum cleaner of  FIG. 7 ; 
           [0025]      FIG. 11  is a perspective view of a third embodiment of a vacuum cleaner comprising a motor, fan and filter arrangement according to the invention; 
           [0026]      FIGS. 12A ,  12 B and  12 C are perspective views of the hand-holdable vacuum cleaner of  FIG. 11 , respectively showing the pivotable nose thereof in 180, 360 and 135 degree positions relative to the main axis of the vacuum cleaner; 
           [0027]      FIG. 13  is an exploded view of the major components of the hand-holdable vacuum cleaner of  FIG. 11 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0028]    Firstly referring to  FIGS. 2A to 2D , these show a motor and fan suitable for use in a motor, fan and filter arrangement according to an embodiment of the invention. Motor  10  has an output shaft  12  on which is mounted fan  20 . Electrical power is supplied to motor  10  through electrical contacts  14 ,  16 , so that during operation of the motor, air passes over motor  10  in the direction of the arrows indicated in  FIG. 2A  axially into the intake or “eye”  24  of fan  20 , which is an impeller and which therefore expels the air out tangentially. An end of output shaft  12  remote from motor  10  is mounted on a bearing  22  which supports output shaft  12 , preventing it from vibrating under any potential imbalance in fan  20  as it rotates. As may best be seen in the plan view of  FIG. 2B , motor output shaft  12  has a length sufficiently great to allow the free flow of air around motor  10  into intake  24  unimpeded, and as may further be seen in the end-on view of  FIG. 2C , axial intake  24  of fan  20  has a diameter greater than motor  10 , so that a circumferential portion of intake  24  presents itself completely unobstructed by motor  10 .  FIG. 2B  also indicates by means of the arrow labelled “X” the usual length of a motor output shaft found in a conventional motor and fan arrangement suitable for use in a vacuum cleaner. In such a conventional arrangement, bearing  22  is generally not required because the shorter length of the motor output shaft makes the shaft stiffer and therefore less susceptible to vibration caused by any potential imbalance in the fan as it rotates. A conventional motor may however be adapted for use in a motor, fan and filter arrangement according to the invention by the addition of an extension piece to the shorter motor output shaft thereof and/or a coupling to another shaft which carries the fan. The arrow labelled “X” in  FIG. 2B  also indicates the approximate location of where a grille (not shown) may be located between motor  10  and fan  20 , through which grille output shaft  12  of the motor may pass, thereby screening fan  20  off from access by a user. This grille may be used to supply additional support for the motor output shaft. 
         [0029]    Turning next to  FIG. 3 , there is shown a first embodiment of a vacuum cleaner comprising a motor, fan and filter arrangement according to the invention. This is a compact stick-shaped vacuum cleaner (or “stick-vac”) previously described in more detail in co-pending European patent application no. EP 07102186.9 (corresponding U.S. Application No. 12/069,691), from which the present application claims priority. Vacuum cleaner  100  comprises an upper body portion  50 , a lower body portion  60 , a floorhead  70 , a handle  80  and a dust-filtering portion  90 . Upper body portion  50  is pivotable relative to lower body portion  60  about an axis of dust filtering portion  90 . Floorhead  70  comprises a dirty air inlet and a pair of floor-running wheels  71 ,  72 , whereas handle  80  comprises an electrical on/off switch  81 . Dust filtering portion  90  comprises a tangential entry duct  91 , a dust collection chamber, a clean air outlet, and a motor, fan and filter arrangement according to the invention, which is described in greater detail below in relation to  FIGS. 4 to 6 . During operation of vacuum cleaner  100 , a user activates the motor contained in dust filtering portion  90  by operating electrical on/off switch  81 , which is connected to the motor via electrical wires running inside upper body portion  50 . This causes dirty air to pass from the dirty air inlet of floorhead  70  up a duct located within lower body portion  60  to tangential entry duct  91 , whence it enters the dust collection chamber of dust filtering portion  90 . 
         [0030]    The dust collection chamber may best be seen in  FIG. 4 , where it is labelled by reference numeral  92 . Dirty air entering dust collection chamber  92  via tangential entry duct  91  swirls around a cylindrical coarse filter  93  in a clockwise fashion as indicated by the arrows in  FIG. 4 . Coarse filter  93  surrounds and contains a smaller cylindrical fine filter  30 , so that between them, coarse filter  93  and fine filter  30  act to filter out successively smaller particles of dust and dirt entrained with the dirty air, which therefore start to collect in dust collection chamber  92 . An end face of dust collection chamber  92  comprises a door  94  mounted on a hinge  99  and closed via a series of latches  95 , which are designed to engage with a corresponding lip on a rim of dust filtering portion  90 . When door  94  is closed, a series of first component parts  96  of a filter cleaning mechanism provided on an end face of fine filter  30  engage with a corresponding series of second component parts  97  of the filter cleaning mechanism provided on the inside face of door  94 . The engagement of these first and second component parts  96 ,  97  allows a user to operate the filter cleaning mechanism when the door is closed via a wheel (not visible in  FIG. 4 , but labelled  940  in  FIG. 6 ) located on the outside face of door  94 . A resilient seal  98  made of polyethylene, rubber or a similar elastomeric material provided around the circumference of door  94  ensures that the door closes in an airtight fashion. 
         [0031]    Turning now to  FIG. 5 , there is shown an exploded view of the central portion of the vacuum cleaner of  FIG. 3  indicating how fine filter  30  is contained within coarse filter  93 . Within fine filter  30 , there may also be seen a housing  18  of motor  10 . Housing  18  is made air-permeable by the presence of a plurality of first vents  180  formed in an end face thereof. Thus, clean air passing through fine filter  30  may enter housing  18  via vents  180 .  FIG. 6  shows a cross-section through the central portion of this vacuum cleaner in greater detail. As may be seen in  FIG. 6 , motor output shaft  12  in this embodiment is constructed from an extension piece added to the shorter motor output shaft of a conventional motor. This drawing also shows how a plurality of second vents  181  formed in the opposite end face of housing  18  from the plurality of first vents  180  allows clean air to exit housing  18  and pass around motor output shaft  12  towards fan  20 , which finally directs the clean air back to atmosphere via clean air outlet vents  900   a ,  900   b . Thus, the entire filtering process from the entry of dirty air via tangential entry duct  91  to the exit of clean air via clean air outlets  900   a ,  900   b , including motor  10 , motor housing  18 , fan  20 , fine filter  30 , coarse filter  93 , filter cleaning mechanism  96 ,  97 ,  940  and dust collection chamber  92 , is all contained within the particularly compact, substantially cylindrical body of dust filtering portion  90  of the vacuum cleaner. 
         [0032]      FIG. 7  shows a second embodiment of a vacuum cleaner comprising a motor, fan and filter arrangement according to the invention, which is a hand-holdable vacuum cleaner  200 . As shown in  FIG. 7 , vacuum cleaner  200  comprises a main body portion  260 , a handle  280 , and a dust collection chamber  292  containing a filter assembly  230 , both of which are oriented orthogonally to the longitudinal axis of main body portion  260 , such that in use of the vacuum cleaner, dust collection chamber  292  and filter assembly  230  are held substantially vertically, and dust collects in the bottom of dust collection chamber  292 . The view from below of  FIG. 8  of hand-holdable vacuum cleaner  200  shows how dust collection chamber  292  is emptied. Dust collection chamber  292  comprises a door  294  hinged on an end face thereof, which opens in the direction of the arrow shown in  FIG. 8 . Dust collection chamber  292  is transparent to allow a user to view dust swirling around filter assembly  230  during operation of the vacuum cleaner and also to see when dust collection chamber  292  is full and therefore needs emptying. The view from below of  FIG. 8  also shows a dirty air inlet  270  of the vacuum cleaner  200 . 
         [0033]      FIG. 9  shows filter assembly  230  removed from within dust collection chamber  292  to reveal an air permeable motor housing  218  contained therein. Motor housing  218 , which in turn contains a motor not visible in  FIG. 9 , has a plurality of first vents  280  formed in an end face thereof to allow clean air which has passed through filter assembly  230  to enter the motor housing. The exploded view of  FIG. 10  shows the major internal components of hand-holdable vacuum cleaner  200 . As shown in  FIG. 10 , main body portion  260  and handle  280  are composed from two half-clamshells  261 ,  262 . This reveals how dirty air inlet  270  is placed in fluid communication with dust collection chamber  292  via a duct  273  integrally moulded into lower half-clamshell  262 . Duct  273  is shaped so as to provide a tangential inlet to dust collection chamber  292 . Space within lower half-clamshell  262 , either side of duct  273  is used to house a plurality of rechargeable cells  264 , which are electrically connected via wires  266  to a jack plug charger socket  268 . This allows the bank of cells  264  to be recharged by means of a conventional removable jack plug charger  265  (which does not form part of the vacuum cleaner  200 ). Cells  264  are also electrically connected via wires  282  with an electrical on/off switch  281  mounted in handle  280 . Electrical on/off switch  281  has a cover  284  to insulate it from a user. Cells  264  and on/off switch  281  are also in electrical connection via wires  216  with motor  10 , such that when a user operates on/off switch  281 , motor  10  is activated by cells  264 , causing fan  20  mounted on motor output shaft  12  to begin to rotate and dirty air to start to be drawn up duct  273 . Motor output shaft  12  is supported on a bearing  22  to prevent it from vibrating. Motor  10  itself is contained within a housing  218 . This has a separate end cap  220  for ease of manufacture. Housing  218 ,  220  is in turn contained within filter assembly  230  inside dust collection chamber  292 . The filter assembly  230  has a frusto-conical shape to act in concert with dust collection chamber  292  as a cyclonic separator. 
         [0034]      FIG. 10  also shows door  294  of dust collection chamber  292 , which door is mounted on a hinge  299  and sealed by a resilient seal  298  made of polyethylene, rubber or a similar elastomeric material, in order to ensure that the door  294  closes in an airtight fashion. Thus, during operation of vacuum cleaner  200 , dirty air entering dust collection chamber  292  via duct  273  from dirty air inlet  270  swirls around filter assembly  230  and the clean air which passes therethrough is drawn through air-permeable motor housing  218  by fan  20 , which directs the air through a plurality of holes  291  formed in an end face of the dust collection chamber opposite door  294  before it is expelled from a plurality of clean air outlet vents  290  formed in half-clamshell  261 . In order to allow a user to empty dust collection chamber  292 , half-clamshell  261  is also provided with a hole  263  revealing a spring-loaded release button  244  which acts against the force of a spring  246  to depress a push rod  248 . This in turn pushes door  294  open about hinge  299 . In order to allow a user to close door  294  again once the dust collection chamber has been emptied, door  294  is provided with a latch  250  that engages with a lip formed on the rim of dust collection chamber  292 . 
         [0035]    Finally turning to  FIG. 11 , there is shown a third embodiment of a vacuum cleaner comprising a motor, fan and filter arrangement according to the invention, which is a hand-holdable vacuum cleaner  300 . As shown in  FIG. 11 , vacuum cleaner  300  comprises a main body portion  360 , a handle  380 , and a dust collection chamber  392  designed to contain a filter assembly  330  therein, which is shown removed therefrom in  FIG. 11 . When mounted in dust collection chamber  392 , both filter assembly  330  and dust collection chamber  392  are oriented orthogonally to the longitudinal axis of main body portion  360 , such that in use of the vacuum cleaner, dust collection chamber  392  and filter assembly  330  are held substantially horizontally, and dust collects in the lower side of dust collection chamber  392 . Dust collection chamber  392  is transparent to allow a user to view dust swirling around filter assembly  330  during operation of the vacuum cleaner and also to see when dust collection chamber  392  is full and therefore needs emptying. 
         [0036]      FIG. 11  also shows how dust collection chamber  392  can be emptied by means of a door  394  hinged on an end face thereof.  FIG. 11  also reveals an air permeable motor housing  318  contained inside filter assembly  330 . Motor housing  318 , which in turn contains a motor not visible in  FIG. 11 , has a plurality of vents  380  formed in an end face thereof to allow clean air which has passed through filter assembly  330  to enter the motor housing. 
         [0037]    Vacuum cleaner  300  is able to pivot about the central axis of dust collection chamber  392  in a manner similar to that described in European patent publication no. 1 752 076 A (corresponding U.S. application Ser. No. 11/495,742),also in the name of the present applicant. Thus, as shown in  FIGS. 12A to 12C , vacuum cleaner  300  may be folded as indicated by the arrows in  FIGS. 12B and 12C  from the 180 degree position shown in  FIG. 12A  into the 360 degree position shown in  FIG. 12B , for example for storage or shipping, or into the 135 degree position shown in  FIG. 13C , for example to permit access to awkward corners.  FIG. 12  C also reveals a dirty air inlet  370  of vacuum cleaner  300 . 
         [0038]    The exploded view of  FIG. 13  shows the major internal components of hand-holdable vacuum cleaner  300 . As shown in  FIG. 13 , main body portion  360  is formed from upper and lower components  361  and  362 , respectively, and handle  380  is composed from two half-clamshells  385 ,  386 . Dirty air inlet  370  is placed in fluid communication with dust collection chamber  392  via a duct  373  contained within main body portion  360  and which enters dust collection chamber  392  tangentially. Space within lower body component  362  beneath duct  373  is occupied by a plurality of rechargeable cells  364 , which are electrically connected via wires  366  to a jack plug charger socket  368 . This allows the bank of cells  364  to be recharged by means of a conventional removable jack plug charger  365  (which does not form part of the vacuum cleaner  300 ). Cells  364  are also electrically connected via wires  382  with an electrical on/off switch  381  mounted in handle  380 . Electrical on/off switch  381  has a cover  384  to insulate it from a user. Cells  364  and on/off switch  381  are also in electrical connection via wires  316  with motor  10 , such that when a user operates on/off switch  381 , motor  10  is activated by cells  364 , causing fan  20  mounted on motor output shaft  12  to begin to rotate and dirty air to start to be drawn up duct  373 . Because vacuum cleaner  300  can pivot in the manner described above in relation to  FIGS. 12A to 12C , wires  382  connected to on/off switch  381  terminate in a pair of electrical contacts  388 , which remain in sliding contact with a corresponding pair of conducting tracks  389  mounted on dust collection chamber  392 . Thus, an electrical circuit can always be established between cells  364 , on/off switch  381  and motor  10 , regardless of the angle of orientation of main body  360  relative to handle  380 . 
         [0039]    As can also be seen in  FIG. 13 , a bearing  22  located at the end of motor output shaft  12  remote from motor  10  supports motor output shaft  12  to prevent it from vibrating. Motor  10  itself is contained within housing  318 . This has a separate end cap  320  for ease of manufacture, in which can be seen the vents  380  to allow clean air which has passed through filter assembly  330  to enter the motor housing. Housing  318 ,  320  is in turn contained within filter assembly  330  inside dust collection chamber  392 . The filter assembly  330  has a frusto-conical shape to act in concert with dust collection chamber  392  as a cyclonic separator. 
         [0040]      FIG. 13  also shows door  394  of dust collection chamber  392 , which door has a spring-loaded latch  344  that can be depressed against the force of a spring  346  to open door  394 . Latch  344  engages with a lip formed on the rim of dust collection chamber  392  to allow the door to be closed again. The door is sealed by a resilient seal  398  made of polyethylene, rubber or a similar elastomeric material, in order to ensure that the door  394  closes in an airtight fashion. Thus, during operation of vacuum cleaner  300 , dirty air entering dust collection chamber  392  via duct  373  from dirty air inlet  370  swirls around filter assembly  330  and the clean air which passes therethrough is drawn through air-permeable motor housing  318  by fan  20 , which directs the air through a plurality of holes  391  formed in an end face of the dust collection chamber opposite door  394  before it is expelled from a plurality of clean air outlet vents  390  formed in half-clamshell  385 . To allow a user to adjust the angle of main body  360  relative to handle  380 , half-clamshell  386  is finally also provided with a ratchet wheel  350  having a plurality of teeth formed on the inner circumference thereof. These act to lock main body  360  in one of a plurality of orientations relative to handle  380 . Ratchet wheel  350  is also provided with a spring-loaded release button  352  which can be depressed against the force of a spring  354  to allow a user to disengage the teeth and therefore rotate main body  360  from one orientation into another. Releasing button  352  again relocks main body in the new orientation relative to handle  380 .