Patent Publication Number: US-9414726-B2

Title: Cleaning appliance

Description:
REFERENCE TO RELATED APPLICATIONS 
     This application claims the priority of United Kingdom Application No. 1016449.9, dated Sep. 30, 2010, the entire contents of which are incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The present invention relates to a cleaning appliance, which in one embodiment is in the form of a vacuum cleaning appliance. 
     BACKGROUND OF THE INVENTION 
     Cleaning appliances such as vacuum cleaners are well known. The majority of vacuum cleaners are either of the “upright” type or of the “cylinder” type (called canister or barrel machines in some countries). Cylinder vacuum cleaners generally comprise a main body which contains a motor-driven fan unit for drawing a dirt-bearing air flow into the vacuum cleaner, and separating apparatus, such as a cyclonic separator or a bag, for separating dirt and dust from the air flow. The dirt-bearing air flow is introduced to the main body through a suction hose and wand assembly which is connected to the main body. The main body of the vacuum cleaner is dragged along by the hose as a user moves around a room. A cleaning tool is attached to the remote end of the hose and wand assembly. 
     For example, GB 2,407,022 describes a cylinder vacuum cleaner having a chassis which supports cyclonic separating apparatus. The vacuum cleaner has two main wheels, one on each side of a rear portion of the chassis, and a castor wheel located beneath the front portion of the chassis which allow the vacuum cleaner to be dragged across a surface. Such a castor wheel tends be mounted on a circular support which is, in turn, rotatably mounted on the chassis to allow the castor wheel to swivel in response to a change in the direction in which the vacuum cleaner is dragged over the surface. 
     EP 1,129,657 describes a cylinder vacuum cleaner which is in the form of a spherical body connected to the suction hose and wand assembly. The spherical volume of the spherical body incorporates a pair of wheels, one located on each side of the body, and houses an electric blower for drawing a fluid flow through the cleaner, and a dust bag for separating dirt and dust from the fluid flow. 
     PCT/GB2010/050418 describes a cylinder vacuum cleaner having a generally spherical rolling assembly connected to the chassis for improving the maneuverability of the vacuum cleaner over a floor surface. The rolling assembly comprises a body and a pair of dome shaped wheels connected to the body. The chassis extends forwardly from the body of the rolling assembly, and includes a pair of wheels for steering the vacuum cleaner and for supporting the rolling assembly as the vacuum cleaner is maneuvered over a floor surface. 
     The chassis also includes a support for supporting cyclonic separating apparatus of the vacuum cleaner. The support is located on an inlet duct for conveying a dirt-bearing air flow to the separating apparatus. To assist with the maneuvering of the vacuum cleaner around objects located on the floor surface, the inlet duct is pivotably connected to the chassis for movement relative to the chassis as the user pulls the vacuum cleaner in different directions over the floor surface. The movement of the duct relative to the chassis actuates a steering mechanism for turning the wheels connected to the chassis. The inlet duct comprises a relatively rigid section connected to the chassis for pivoting movement relative thereto, and a relatively flexible hose located upstream to the rigid section and which tends to flex relative to the rigid section as the duct pivots relative to the chassis. 
     SUMMARY OF THE INVENTION 
     In a first aspect the present invention provides a cleaning appliance of the canister type comprising a cyclonic separating apparatus for separating dirt from a dirt-bearing fluid flow, and a main body comprising a fluid inlet for receiving a fluid flow from the separating apparatus, a system for drawing the fluid flow into the rolling assembly, and a plurality of rolling elements rotatable relative to the main body and which define with the main body a substantially spherical floor engaging rolling assembly, wherein the separating apparatus is mounted on the main body. 
     By mounting the separating apparatus directly on to the main body of the spherical rolling assembly, which term includes a spheroidal rolling assembly, as opposed to mounting the separating apparatus on a support connected to an inlet duct for conveying the fluid flow to the separating apparatus, the overall length of the cleaning appliance may be reduced. 
     The main body preferably comprises a support for supporting the separating apparatus. The support is preferably integral with the main body of the rolling assembly. The main body may be formed from a plurality of sections, in which case the support is preferably integral with one of those sections. 
     The support is preferably separate from the fluid inlet of the main body, and so in a second aspect the present invention provides a cleaning appliance comprising a cyclonic separating apparatus for separating dirt from a dirt-bearing fluid flow, and a main body comprising a fluid inlet for receiving a fluid flow from the separating apparatus, a system for drawing the fluid flow into the rolling assembly, a plurality of rolling elements rotatable relative to the main body and which define with the main body a substantially spherical floor engaging rolling assembly, and a support, separate from the fluid inlet, connected to the main body for supporting the separating apparatus. 
     The support is preferably located on the front of the main body. The support preferably comprises a spigot locatable within a recess formed in a base member of the separating apparatus. When the separating apparatus is mounted on the support, the separating apparatus preferably has a longitudinal axis inclined at an acute angle to the vertical when the cleaning appliance moves over a substantially horizontal floor surface. This angle may be in the range from 30 to 70°. The main body may further comprise one or more additional supports for supporting the side surface of the separating apparatus. 
     The side surface of the separating apparatus is preferably cylindrical, and so these additional supports preferably have support surfaces which have a similar curvature to the side surface of the separating apparatus. 
     The appliance preferably comprises an inlet duct for conveying the dirt-bearing fluid flow to the separating apparatus. The duct preferably passes beneath the support, and preferably passes through a sleeve located between the support and the main body of the rolling assembly. The sleeve is preferably integral with the support and the main body. Alternatively, the support may be connected to a chassis connected to the main body of the rolling assembly. 
     Preferably, at least part of the duct is moveable relative to the support. The appliance preferably comprises a chassis connected to, and preferably integral with, the main body, and the pivoting part of the duct is preferably pivotably connected to the chassis. The appliance preferably comprises a plurality of floor engaging support members connected to the chassis for supporting the rolling assembly as it is maneuvered over a floor surface. Each support member preferably comprises a wheel or other rolling member, such as a caster or ball. 
     The duct preferably comprises an inlet section which is moveable relative to the support, and an outlet section for coupling the inlet section to the separating apparatus. The sleeve preferably extends about a joint between the inlet section and the outlet section of the duct. This joint may comprise one or more sealing members for maintaining a fluid tight seal between the sections of the duct as the inlet section pivots relative to the outlet section. The support may be configured to inhibit pivoting movement of the outlet section with the inlet section. For example, one of the support and the outlet section may comprise a detent which is locatable within a recess of the other of the support and the outlet section. 
     Each of the plurality of rolling elements is preferably in the form of a wheel rotatably connected to a respective side of the main body of the rolling assembly. Each of these rolling elements preferably has a curved, preferably dome-shaped, outer surface. Each of the plurality of rolling elements preferably has an outer surface of substantially spherical curvature. The rotational axes of the rolling elements may be inclined upwardly towards the main body with respect to a floor surface upon which the cleaning appliance is located so that the rims of the rolling elements engage the floor surface. The angle of the inclination of the rotational axes is preferably in the range from 4 to 15°, more preferably in the range from 5 to 10°. As a result of the inclination of the rotational axes of the rolling elements, part of the outer surface of the main body is exposed to enable components of the cleaning appliance, such as user-operable switches for activating the motor or a cable-rewind mechanism, to be located on the exposed part of the main body. In a preferred embodiment, one or more ports for exhausting the air flow from the cleaning appliance are located on the outer surface of the main body. The main body preferably comprises a filter for removing particulates from the fluid flow. The filter is preferably located downstream from the system for drawing the fluid flow into the rolling assembly, which is preferably in the form of a motor-driven fan unit. 
     The cleaning appliance preferably comprises an outlet duct extending from the separating apparatus to the rolling assembly for conveying the fluid flow to the rolling assembly. Preferably, the duct can be disengaged from the separating apparatus to allow the separating apparatus to be removed from the appliance. To facilitate the disengagement of the duct from the separating apparatus, the duct is preferably pivotably connected to the rolling assembly. The duct is preferably connected to the upper surface of the rolling assembly so that it can be moved between a raised position to allow the separating apparatus to be removed from, and subsequently relocated on, the appliance, and a lowered position, in which the duct engages the separating apparatus. In its lowered position, the duct is preferably configured to retain the separating apparatus on the appliance. The duct is preferably formed from a rigid material, preferably a plastics material, and may include a handle. 
     Although an embodiment of the invention is described in detail with reference to a vacuum cleaner, it will be appreciated that the invention can also be applied to other forms of cleaning appliance. 
     Features described above in connection with the first aspect of the invention are equally applicable to the second aspect of the invention, and vice versa. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Preferred features of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: 
         FIG. 1  is a front perspective view, from above, of a vacuum cleaner; 
         FIG. 2( a )  is a front perspective view, from above, of the vacuum cleaner, with a separating apparatus of the vacuum cleaner removed,  FIG. 2( b )  is a side view of the same, and  FIG. 2( c )  is a top view of the same; 
         FIG. 3  is a rear perspective view, from above, of the chassis base plate, wheel assemblies, inlet section of the inlet duct and biasing arrangements of the vacuum cleaner; 
         FIG. 4  is a top sectional view taken along line A-A in  FIG. 2( b ) ; 
         FIG. 5( a )  is a front perspective view, from above, of the vacuum cleaner with the separating apparatus removed and the inlet section of the inlet duct pivoted relative to the chassis; and  FIG. 5( b )  is a top view of the same; 
         FIG. 6( a )  is a side sectional view taken along line C-C in  FIG. 2( c ) , and  FIG. 6( b )  is a magnified view of part of  FIG. 6( a ) ; 
         FIG. 7( a )  is a top view of the separating apparatus, and  FIG. 7( b )  is a sectional view taken along line D-D in  FIG. 7( a ) ; and 
         FIG. 8  is a rear sectional view taken along line B-B in  FIG. 2( c ) . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  illustrates an external view of a cleaning appliance in the form of a vacuum cleaner  10 . The vacuum cleaner  10  is of the cylinder, or canister, type. In overview, the vacuum cleaner  10  comprises separating apparatus  12  for separating dirt and dust from a fluid flow. The separating apparatus  12  is preferably in the form of cyclonic separating apparatus, and comprises an outer bin  14  having an outer wall  16  which is substantially cylindrical in shape. The lower end of the outer bin  14  is closed by curved base  18  which is pivotably attached to the outer wall  16 . A motor-driven fan unit for generating suction for drawing dirt laden fluid into the separating apparatus  12  is housed within a rolling assembly  20  located behind the separating apparatus  12 . The rolling assembly  20  comprises a main body  22  and two wheels  24 ,  26  (see  FIG. 2( a ) ) rotatably connected to the main body  22  for engaging a floor surface. An inlet duct  28  extending beneath the separating apparatus  12  conveys dirt-bearing fluid into the separating apparatus  12 , and an outlet duct  30  conveys fluid exhausted from the separating apparatus  12  into the rolling assembly  20 . The inlet duct  28  is connected to a hose of a hose and wand assembly (not shown) which the user pulls to maneuver the vacuum cleaner  10  over the floor surface. 
     A chassis  32  is connected to the main body  22  of the rolling assembly  20 . In this example, the chassis  32  is integral with part of the main body  22  of the rolling assembly  20 . The chassis  32  is generally in the shape of an arrow head pointing forwardly from the rolling assembly  20 . The chassis  32  comprises side edges  34  which extend rearwardly and outwardly from the front tip  36  of the chassis  32 , shown in  FIGS. 5( b ) and 6( a ) . The front tip  36  of the chassis  32  is located on an axis A extending substantially perpendicular to a vertical plane passing through the center of the rolling assembly  20 . The direction in which the vacuum cleaner  10  moves over a floor surface during a cleaning operation extends along the axis A. The angling of the side edges  34  relative to the axis A can assist in maneuvering the vacuum cleaner  10  around corners, furniture or other items upstanding from the floor surface, as upon contact with such an item these side edges  34  tend to slide against the upstanding item to guide the rolling assembly  20  around the upstanding item. As illustrated in the figures, bumpers or pads  38  may be attached to the side edges  34 . 
     A pair of wheels  40  for engaging the floor surface is connected to the chassis  32 . The wheels  40  are located behind the side edges  34  of the chassis  32 , and in front of the wheels  24 ,  26  of the rolling assembly  20 . As shown in  FIG. 3 , each wheel  40  is mounted on a respective axle  42  fitted to the chassis  32 , for example by press fitting or overmolding, so that the wheel  40  rotates relative to the axle  42 , and thus relative to the chassis  32 . Each axle  42  is aligned along an axis which is substantially perpendicular to the axis A so that the wheels  40  rotate to move the vacuum cleaner  10  in a direction extending along the axis A. 
     The wheels  40  also provide support members for supporting the rolling assembly  20  as the vacuum cleaner  10  is maneuvered over a floor surface by restricting rotation of the rolling assembly  20  about the axis A. For increased support to the rolling assembly  20 , the distance between the points of contact of the wheels  40  with the floor surface is greater than that between the points of contact of the wheels  24 ,  26  of the rolling assembly  20  with that floor surface. 
     As shown in  FIG. 2( b ) , the components of the vacuum cleaner  10  are arranged so that, when the vacuum cleaner  10  is located on a substantially horizontal floor surface F, the center of gravity C of the vacuum cleaner  10  is located within the rolling assembly  20 . The center of gravity C is located in a first vertical plane PL 1  which passes between a second vertical plane PL 2  containing the points of contact between the wheels  24 ,  26  of the rolling assembly  20  and the floor surface, and a third vertical plane PL 3  containing the points of contact between the wheels  40  and the floor surface, preferably substantially mid-way between the two planes PL 2 , PL 3 . This can further enhance the stability of the vacuum cleaner  10  as it is maneuvered over the floor surface. 
     The location of the center of gravity C is indicated above for a situation in which the separating apparatus  12  is connected to the vacuum cleaner  10 , and the separating apparatus  12  is in an unloaded state, and with no hose and wand assembly connected to the vacuum cleaner  10 . 
     To reverse the direction in which the vacuum cleaner  10  is moving over a floor surface, the user may raise the wheels  40  of the chassis  32  from the floor surface, using the hose of the hose and wand assembly so that the vacuum cleaner  10  tilts backwards on to the wheels  24 ,  26  of the rolling assembly  20 . Using the hose, the vacuum cleaner  10  may then be “spun” around the point of contact between the rolling assembly  20  and the floor surface until the vacuum cleaner  10  is facing in the required direction. The hose may then lowered to bring the wheels  40  back into contact with the floor surface, and the vacuum cleaner  10  pulled in the required direction. 
     To enable the vacuum cleaner  10  to be maneuvered smoothly around an object or the corner of a wall during a cleaning operation, part of the inlet duct  28  is connected to the chassis  32  for pivoting movement relative to the chassis  32 , and thus relative to the rolling assembly  20 .  FIGS. 2( a ) to 2( c )  illustrate the vacuum cleaner  10  with the separating apparatus  12  to reveal the inlet duct  28 . The removal of the separating apparatus  12  from the vacuum cleaner  10  is described in more detail below. The inlet duct  28  comprises an inlet section  44  for receiving the dirt-bearing fluid flow from the hose and wand assembly, and an outlet section  46  for coupling the inlet section  44  to the separating apparatus  12  to convey the dirt-bearing fluid flow into the separating apparatus  12 . The inlet section  44  is pivotably connected to the chassis  32 , whereas the outlet section  46  is connected to the main body  22  of the rolling assembly  20  so that the inlet section  44  is pivotable relative to the outlet section  46 . Alternatively, the outlet section  46  may be connected to the chassis  32 . 
     With particular reference to  FIGS. 3, 4, 6 ( a ) and  6 ( b ), in this example the inlet section  44  of the inlet duct  28  comprises a plurality of components. The inlet section  44  comprises a coupling  48  for electrical and/or physical connection to a wand and hose assembly (not shown) for conveying the duct-bearing fluid flow to the inlet duct  28 . The wand and hose assembly is connected to a cleaner head (not shown) comprising a suction opening through which a dirt-bearing fluid flow is drawn into the vacuum cleaner  10 . The coupling  48  is connected to one end of a cylindrical section  50  of the inlet duct  28 . Of course, the section  50  may have an alternative cross-sectional shape, such as an elliptical or polyhedral shape. The other end of the cylindrical section  50  is connected to a curved section  52  of the inlet duct  28 . In this example, the cylindrical section  50  is integral with the curved section  52 , but these two sections  50 ,  52  of the inlet duct  28  may be integrally formed. The curved section  52  is shaped to change the direction in which the fluid flows through the inlet duct  28  by around 90°. The curved section  52  has a fluid outlet  54  which is concentric with, and located immediately below, a fluid inlet  56  of the outlet section  46  of the inlet duct  28 . One or more annular sealing members  58 ,  60  are located between the fluid outlet  54  and the fluid inlet  56  to maintain an air tight seal and a relatively low frictional force therebetween during pivoting movement of the inlet section  44  relative to the outlet section  46 . 
     The inlet section  44  is mounted on a cylindrical spindle  62  extending upwardly from the upper surface of the chassis  32 . The curved section  52  comprises a cylindrical boss  64  depending downwardly therefrom and which is located over the spindle  62  so as to be substantially concentric with the spindle  62 . A plain bearing or sleeve  66  may be located between the spindle  62  and the boss  64  to minimize friction therebetween during rotation of the boss  64  about the spindle  62  and to ensure accurate alignment between the spindle  62  and the boss  64 . Alternatively, the spindle  62  may be formed from a low friction material. The longitudinal axis of the spindle  62  thus defines the pivot axis P about which the inlet section  44  pivots relative to the chassis  32  and the outlet section  46 . The pivot axis P passes through the center of the fluid outlet  54  of the inlet section  44  and the fluid inlet  56  of the outlet section  46 . The pivot axis P is substantially vertical when the vacuum cleaner  10  is located on a horizontal floor surface. As the curved section  52  is shaped with a 90° bend, the longitudinal axis of the cylindrical section  50  is substantially orthogonal to the pivot axis P and so during pivoting movement of the inlet section  44  the cylindrical section  50  sweeps orthogonally about the pivot axis P. 
     The pivoting movement of the inlet section  44  relative to the chassis  32  is guided by a pin or rib  68  depending from the cylindrical section  50 . The rib  68  is moveable within a curved groove or slot  70  which extends about the pivot axis P, and which is formed in a portion of the upper surface of the chassis  32  which is substantially orthogonal to the pivot axis P. 
     The inlet section  44  is pivotable about the pivot axis P by an angle of ±α° from a central, rest position. The angle α is preferably in the range from 15 to 45°, and in this example is around 30°. The inlet section  44  is illustrated in its rest position in  FIGS. 1 to 4, 6 ( a ) and  6 ( b ). In this rest position, the inlet section  44  is aligned along the axis A, that is, with the longitudinal axis of the cylindrical section  50  of the inlet section  44  parallel to the axis A.  FIGS. 5( a ) and 5( b )  illustrate the vacuum cleaner  10  with the inlet section  44  pivoted by around 30° in the angular direction R 1 , indicated in  FIG. 4 , from the rest position. The extent of the pivoting movement of the inlet section  44  away from the rest position is restricted by the abutment of the side of the inlet section  44  with one of a pair of raised walls  72  of the chassis  32 , as illustrated in  FIG. 1 . 
     The inlet section  44  of the inlet duct  28  is biased towards a rest position. Consequently, when the inlet section  44  is pivoted away from the rest position during the maneuvering the vacuum cleaner  10  over a floor surface, for example while the vacuum cleaner  10  is being pulled around an object or piece of furniture, the inlet duct  44  will return automatically to its rest position when the vacuum cleaner  10  has moved away from the object. 
     The inlet section  44  is biased towards its rest position by a biasing system which engages the inlet section  44  to urge the inlet section  44  towards its rest position. With reference now to  FIGS. 3 and 4 , in this example the biasing system comprises a plurality of biasing arrangements  74 ,  76  located on opposite sides of the inlet section  44 . A first biasing arrangement  74  is arranged to urge the inlet section  44  towards the rest position when it moves in angular direction R 1  away from the rest position, and a second biasing arrangement  76  is arranged to urge the inlet section  44  towards the rest position when it moves in angular direction R 2 , opposite to R 1 , away from the rest position. 
     The inlet section  44  comprises a return member for engaging the biasing arrangements  74 ,  76  as the inlet section  44  is pivoted away from the rest position. In this example, the return member is in the form of an arm  78  connected to the curved section  52 , and generally on the opposite side of the curved section  52  to the cylindrical section  50 . 
     The biasing arrangements  74 ,  76  are located beneath the chassis  32 . The vacuum cleaner  10  includes a chassis base plate  80  which is connected to the lower section of the chassis  32 , and the biasing arrangements  74 ,  76  are located within a housing  82  located between the chassis  32  and the chassis base plate  80 . During assembly, the biasing arrangements  74 ,  76  are located within the housing  82 , and the housing  82  is connected to the base plate  80 . The chassis  32  is then connected to the base plate  80 , for example by means of screws or other connectors  84  inserted through apertures in the base plate  80 . The inlet section  44  is then mounted on the chassis  32 . To engage the biasing arrangements  74 ,  76 , the arm  78  of the inlet section  44  extends through a curved slot  86 , indicated in  FIG. 6( a ) , formed in the chassis  32  behind the spindle  62  to enter the housing  82 . 
     With particular reference to  FIG. 4 , the housing  82  extends about the pivot axis P. When the inlet section  44  is in its rest position, the arm  78  is located centrally within the housing  82 , between the biasing arrangements  74 ,  76 . Each biasing arrangement  74 ,  76  is located within a respective compartment of the housing  82 , between which the arm  78  is located when in its rest position. Each biasing arrangement  74 ,  76  comprises a resilient element, in this example in the form of a helical compression spring  88 , and a piston, in this example in the form of a circular disc  90 . The spring  88  urges the disc  90  against an annular seat located at one end of the compartment. The other end of the compartment is closed by a closure member  92  connected to the housing  82 . 
     When the inlet section  44  is pivoted about the pivot axis P in the direction R 1 , for example, the arm  78  enters the compartment housing the biasing arrangement  74 . The biasing force of the spring  88  is selected to allow the arm  78  to move within the compartment towards the closure member  92 , against the biasing force of the spring  88 , without the user having to apply an excessive force to the inlet section  44  using the hose and wand assembly attached thereto. When the user relaxes the force applied to the inlet section  44 , for example when the vacuum cleaner  10  has moved beyond an obstacle on the floor surface, the biasing force of the spring  88  exceeds the force applied to the inlet section  44 . This causes the spring  88  to urge the disc  90  back towards its seat, thereby returning the arm  78  automatically to its rest position. 
     As mentioned above, the outlet section  46  of the inlet duct  28  provides a static coupling between the separating apparatus  12  and the inlet section  44  of the inlet duct  28 . The fluid inlet  56  of the outlet section  46  is mounted on, and supported by, the annular sealing members  58 ,  60  of the inlet duct  28 . The outlet section  46  is removably connected to the main body  22  of the rolling assembly  20  to allow the outlet section  46  to be removed from the vacuum cleaner  10  by the user to allow any blockages within the outlet section  46  to be removed. The removal of the outlet section  46  from the vacuum cleaner  10  also facilitates the removal of blockages from within the inlet section  44  of the inlet duct  28 . As shown in  FIG. 6( b ) , the outlet section  46  comprises a manually operable, resilient catch  100  which extends upwardly from a rear surface of the outlet section  46 . The catch  100  engages a catch face  102  located on the main body  22  of the rolling assembly  20 , or alternatively on the chassis  32 , to retain the outlet section  46  on the main body  22 . To remove the outlet section  46 , the user pulls the catch  100  away from the catch face  102  and lifts the outlet section  46  away from the inlet section  44 . 
     The vacuum cleaner  10  comprises a support  104  for supporting the separating apparatus  12 . The support  104  is connected to, and in this example is integral with, part of the main body  22  of the rolling assembly  20 . The support  104  extends forwardly from the main body  22  so as to extend over the inlet section  44  of the inlet duct  28 . The main body  22 , and therefore the support  104 , is formed from a relatively rigid material, preferably a plastics material, so that, when the separating apparatus is mounted on the support  104 , the support  104  does not deform to such an extent as to engage the upper surface of the inlet section  44 , and thereby interfere with the pivoting movement of the inlet section  44  relative to the chassis  32 . The end of the support  104  which is remote from the main body  22  comprises a spigot  106  which extends upwardly therefrom for location within a recess (not shown) formed in the base  18  of the outer bin  14 . The location of the spigot  106  within the recess ensures correct angular alignment of the separating apparatus  12  relative to the support  104  when it is mounted on the support  104 , so that a fluid inlet  108  of the separating apparatus  12  is located over and against a fluid outlet  110  of the outlet section  46 . The outlet section  46  is provided with a flexible annular seal surrounding the fluid outlet  110  for forming an air tight seal against the periphery of the fluid inlet  108  of the separating apparatus  12 . 
     When the separating apparatus  12  is mounted on the support  104 , the longitudinal axis of the outer bin  14  is inclined to the pivot axis P, in this example by an angle in the range from 30 to 40°. The outer wall  16  of the outer bin  14  is supported by a pair of resilient supports  112  mounted on the main body  22  of the rolling assembly  20 . 
     To provide the vacuum cleaner  10  with a compact appearance, the main body  22  and the support  104  together define a sleeve  114  through which the inlet duct  28  extends. The longitudinal axis of the sleeve  114  is co-linear with the pivot axis P of the inlet section  44 . The inlet section  44  and the outlet section  46  of the inlet duct  28  are located on opposite sides of the sleeve  114 . The sleeve  114  thus surrounds the fluid outlet  54  of the inlet section  44 , the fluid inlet  56  of the outlet section  56 , and the annular sealing members  58 ,  60 . The inner surface of the sleeve  114  comprises a recess  116  for receiving a detent  118  located on the outer surface of the outlet section  46  when the outlet section  46  is mounted on the main body  22 . The recess  116  has substantially the same profile as the detent  118  to inhibit rotation of the outlet section  46  relative to the sleeve  114 , and therefore relative to the separating apparatus  12  and the main body  22 , as the inlet section  44  pivots about the pivot axis P. 
     The separating apparatus  12  is illustrated in  FIGS. 7( a ) and 7( b ) . The specific overall shape of the separating apparatus  12  can be varied according to the size and type of vacuum cleaner in which the separating apparatus  12  is to be used. For example, the overall length of the separating apparatus  12  can be increased or decreased with respect to the diameter of the apparatus, or the shape of the base  18  can be altered. 
     As mentioned above, the separating apparatus  12  comprises an outer bin  14  which has an outer wall  16  which is substantially cylindrical in shape. The lower end of the outer bin  14  is closed by a base  18  which is pivotably attached to the outer wall  16  by means of a pivot  120  and held in a closed position by a catch (not shown) which engages a groove located on the outer wall  16 . In the closed position, the base  18  is sealed against the lower end of the outer wall  16 . The catch is resiliently deformable so that, in the event that downward pressure is applied to the uppermost portion of the catch, the catch will move away from the groove and become disengaged therefrom. In this event, the base  18  will drop away from the outer wall  16 . 
     With particular reference to  FIG. 7( b ) , the separating apparatus  12  further comprises a dust collector  122  located within the outer bin  14 . The dust collector  122  has a generally cylindrical outer wall  124 , and a generally cylindrical inner wall  126  connected to the outer wall  124  at the upper end of the dust collector  122 , and a base  128  which closes the lower end of the inner wall  126 . The outer wall  124  of the dust collector  122  is located radially inwardly of the outer wall  16  and spaced therefrom so as to form an annular chamber  130  therebetween. The outer wall  124  of the dust collector  122  meets the base  18  (when the base  18  is in the closed position) and is sealed against an annular sealing member  132  carried by the base  18 . The fluid inlet  108  is arranged tangentially to the outer bin  14  (as shown in  FIG. 6( a ) ) so as to ensure that incoming dirty fluid is forced to follow a helical path around the annular chamber  124 . 
     A fluid outlet from the annular chamber  130  is provided in the form of a perforated shroud. The shroud has an upper section  134  formed in a frusto-conical shape, a cylindrical section  136  and a skirt  138  depending therefrom. A large number of apertures are formed in the cylindrical section  136 . The skirt  138  tapers outwardly from the cylindrical section  136  in a direction towards the outer wall  16 . 
     The upper section  134  of the shroud is connected to a cyclone pack  140 . The cyclone pack  140  is mounted on the upper end of the dust collector  122 , and comprises a circumferential flange  142  for engaging the upper end of the outer bin  14 . The cyclone pack  140  carries an annular seal  144  for sealing against the outer wall  16  adjacent the upper end of the outer bin  14 . 
     The cyclone pack  140  comprises an annular array of cyclones  146 . The cyclones  146  are arranged in parallel. In the preferred embodiment there are twelve cyclones  146  for this bin diameter arranged in a ring which is centered on a longitudinal axis of the outer bin  14 . Each cyclone  146  has an axis which is inclined downwardly and towards the longitudinal axis. The twelve cyclones  146  can be considered to form a second cyclonic separating unit, with the annular chamber  130  forming the first cyclonic separating unit. In the second cyclonic separating unit, each cyclone  146  has a smaller diameter than the annular chamber  124  and so the second cyclonic separating unit is capable of separating finer dirt and dust particles than the first cyclonic separating unit. It also has the added advantage of being challenged with a fluid flow which has already been cleaned by the first cyclonic separating unit and so the quantity and average size of entrained particles is smaller than would otherwise have been the case. The separation efficiency of the second cyclonic separating unit is higher than that of the first cyclonic separating unit. 
     Each cyclone  146  is identical to the other cyclones  146 , and comprises a cylindrical upper portion having a tangential inlet  148  and a tapering portion depending from the upper portion. The tapering portion of each cyclone  146  is frusto-conical in Shape and terminates in a cone opening  150 . Each tapering portion protrudes through an aperture formed in the upper end of the dust collector  122  so that the cone opening  150  is located in a chamber  152  located between the outer wall  124  and the inner wall  126  of the dust collector  122 . 
     The inner wall  126  and the base  128  of the dust collector  122  form a lower section of a filter housing  154 . An upper section of the filter housing  154  is provided by a generally annular filter housing member  156  mounted on the upper end of the dust collector  122 , and which forms a generally continuous inner wall of the filter housing  154  with the inner wall  126  of the dust collector  122 . The cyclone pack  140  surrounds the filter housing member  156  and defines with the filter housing member  156  a plenum chamber  158  for conveying fluid which has passed through the apertures in the shroud to the inlets  148  of the cyclones  146 . 
     The open upper ends of the cyclones  146  are closed by an annular exhaust manifold. The exhaust manifold comprises an upper section  160  and a lower section  162 . An apertured sealing member  163  may be provided between the cyclone pack  140  and the lower section  162  of the exhaust manifold. The lower section  162  of the exhaust manifold comprises a vortex finder  164  to allow fluid to exit the cyclone  146 . Each vortex finder  164  communicates with a manifold finger  166  defined between the upper and lower sections  160 ,  162  of the exhaust manifold. Each manifold finger  166  is a generally inverted U-shape and extends from the upper end of a respective cyclone  146  to a generally cylindrical exhaust manifold wall  168  formed in the upper section  160  of the exhaust manifold. The wall  168  comprises a plurality of apertures  170  each for receiving fluid from a respective one of the manifold fingers  166 . The wall  168  extends about a bore which is generally co-axial with the outer wall  16 . 
     The apertures  170  convey fluid into the filter housing  154 . A filter assembly  180  is located within the filter housing  154 . The filter assembly  180  is inserted into the filter housing  154  through the bore of the upper section  162  of the exhaust manifold. The filter assembly  180  comprises a body  182  and a filter  184  mounted on the filter body  182 . The filter body  182  is preferably a single-piece item, preferably molded from plastics material, but alternatively the filter body  182  may formed from a plurality of components connected together. The filter body  182  is generally tubular in shape, and comprises an annular body  186 , a set of radially extending elongate spokes  188  connected to the inner surface of the body  186  and depending therefrom. A set of elongate fins  190  is connected between the spokes  188  so that each fin  190  is located between adjacent spokes  188 . The fins  190  are connected to the spokes  188  by connectors  192 . The spokes  188  and the fins  190  together provide a support for supporting the filter  184 . 
     The filter  184  is in the form of a sock filter which extends about the spokes  188  and the fins  190  of the filter body  182 . The upper end of the filter  184  comprises a collar  194 , which is retained within an annular groove formed in the filter body  182 . The lower end of the filter  184  comprises a base or end cap  196  for closing the lower end of the filter  184  for ease of insertion of the filter assembly  180  into the filter housing  154 . 
     The filter  184  further comprises a plurality of tubular filter members of varying levels of filtration for removing dust and other particulates from the fluid flow passing through the filter housing  154 . The filter member having the finest level of filtration is preferably has the largest surface area. Each filter member of the filter assembly  180  is manufactured with a rectangular or tapering shape. The filter members are then joined and secured together along their longest edge by stitching, gluing or other suitable technique so as to form a tubular length of filter material having a substantially open cylindrical shape. An upper end of each cylindrical filter member is then attached to the collar  194 , while a lower end of each filter member is attached to the end cap  196 , for example by over-molding the material of the collar  194  and the end cap  196  during manufacture of the filter assembly  180 . Alternative manufacturing techniques for attaching the filter members include gluing, and spin-casting polyurethane around the upper and lower ends of the filter members. In this way the filter members are encapsulated by polyurethane during the manufacturing process to produce a sealed arrangement which is capable of withstanding manipulation and handling by a user. 
     The filter body  182  comprises an annular sealing member  198  for engaging the air inlet  200  of the outlet duct  30 . With reference to  FIGS. 1 and 2 ( a ), in this example the air inlet  200  of the outlet duct  30  is generally dome-shaped, and enters the filter assembly  180  through the open upper end  202  of the filter body  182  to engage the sealing member  198  and form an air-tight seal therewith. The sealing member  198  may be overmolded with the filter body  182  during assembly, or otherwise attached to the filter body  182 . Alternatively, the sealing member  198  may be integral with the filter body  182 . 
     The outlet duct  30  is generally in the form of a curved arm extending between the separating apparatus  12  and the rolling assembly  20 . The outlet duct  30  is moveable relative to the separating apparatus  12  to allow the separating apparatus  12  to be removed from the vacuum cleaner  10 , and to allow the filter assembly  180  to be removed from the filter housing  154  of the separating apparatus  12 . The end of the tube outlet duct  30  which is remote from the air inlet  200  of the outlet duct  30  is pivotably connected to the main body  22  of the rolling assembly  20  to enable the outlet duct  30  to be moved between a lowered position in which the outlet duct  30  is in fluid communication with the separating apparatus  12 , and a raised position which allows the separating apparatus  12  to be removed from the vacuum cleaner  10 . 
     The outlet duct  30  is biased towards the raised position by a resilient member (not shown) located in the main body  22 . The main body  22  comprises a biased catch  204  for retaining the outlet duct  30  in the lowered position against the force of the resilient member, and a catch release button  206 . The outlet duct  30  comprises a handle  208  to allow the vacuum cleaner  10  to be carried by the user when the outlet duct  30  is retained in its lowered position. Alternatively, the outlet duct  30  may be used to carry the vacuum cleaner  10 . The catch  204  is arranged to co-operate with a finger  210  connected to outlet duct  30  to retain the outlet duct in its lowered position. Depression of the catch release button  206  causes the catch  204  to move away from the finger  210 , against the biasing force applied to the catch  204 , allowing the resilient member to move the outlet duct  30  to its raised position. 
     The rolling assembly  20  will now be described with reference to  FIGS. 6( a )  and  8 . The rolling assembly  20  comprises a main body  22  and two curved wheels  24 ,  26  rotatably connected to the main body  22  for engaging a floor surface. In this embodiment the main body  22  and the wheels  24 ,  26  define a substantially spherical rolling assembly  20 . In this example, the main body  20  comprises an upper section  212  and a lower section  214  connected to the upper section  212 . The support  106  is integral with the upper section  212 , whereas the chassis  32  is integral with the lower section  214 . The wheel  24  is mounted on an axle  216  connected to the lower section  214  of the body  22 , whereas the wheel  26  is mounted on an axle  218  connected to the upper section  212  of the body  22 . The axles  216 ,  218  are arranged so that the rotational axes of the wheels  24 ,  26  are inclined upwardly towards the main body  22  with respect to a floor surface upon which the vacuum cleaner  10  is located so that the rims of the wheels  24 ,  26  engage the floor surface. The angle of the inclination of the rotational axes of the wheels  24 ,  26  is preferably in the range from 4 to 15°, more preferably in the range from 5 to 10° to minimize point contact with a floor surface. 
     Each of the wheels  24 ,  26  of the rolling assembly  20  is generally dome-shaped. Each wheel  24 ,  26  comprises an outer wheel member  220  and an inner wheel member  222  connected to the outer member  220  about the periphery thereof. The outer wheel member  220  and the inner wheel member  222  are preferably connected together using a spin welding technique. A plurality of annular connections is preferably made between the wheel members  220 ,  222 . In this example, the wheel members  220 ,  222  are joined together at three different positions P 1 , P 2  and P 3 , each of which is illustrated in  FIG. 8 . Position P 1  is located at or towards the outer rims of the wheel members  220 ,  222 , position P 3  is located at or towards the center of the wheel members  220 ,  222 , and position P 2  is located generally midway between positions P 1  and P 3 . The inner surface of the outer wheel member  220  and the outer surface of the inner wheel member  222  comprise interengaging features located at each of these positions. For example, one of the wheel members  220 ,  222  may comprises a series of circular grooves each for received a respective raised circular bands formed on the other wheel member  220 ,  222   
     The wheel members  220 ,  222  are formed from a relatively stiff material, preferably from a plastics material. For example, each of the wheels members  220 ,  222  is preferably formed from a glass-filled polypropylene, preferably a 30% glass-filled polypropylene. Alternatively, the wheels members  220 ,  222  may be formed from different plastics material. For example, the outer wheel member  220  may be formed from a 20% glass-filled polypropylene. 
     The inner wheel member  222  is shaped so as to maintain the outer wheel member  220  in a state of tension. This can make the outer surface of the wheels  24 ,  26  relatively stiff, thereby making the wheels  24 ,  26  less prone to deformation, for example due to impact with objects during a cleaning process. 
     The inner wheel member  222  comprises an annular bearing arrangement  224  for rotatably supporting the wheel  24 ,  26  on its axle  216 ,  218 . During assembly, the wheels  24 ,  26  are located over their respective axles  216 ,  218 , and a fastener  226  is connected over the bearing arrangement  224  to retain the wheel  24 ,  26  on its axle  216 ,  218 . 
     The rolling assembly  20  houses a motor-driven fan unit  228 , a cable rewind assembly  230  for retracting and storing within the main body  22  a portion of an electrical cable (not shown) terminating in a plug  232  providing electrical power to, inter alia, the motor of the fan unit  228 , and at least one filter assembly  234 . The fan unit  228  comprises a motor, and an impeller driven by the motor to drawn the dirt-bearing fluid flow into and through the vacuum cleaner  10 . The fan unit  228  is housed in a motor bucket  236 . The motor bucket  236  is connected to the lower section  214  of the main body  22  so that the fan unit  228  does not rotate as the vacuum cleaner  10  is maneuvered over a floor surface. In this example, the filter assembly  234  is located downstream of the fan unit  228 . The filter assembly  234  is cuff shaped and located around a part of the motor bucket  236 . A plurality of perforations is formed in a portion of the motor bucket  236  which is surrounded by the filter assembly  234  to allow air to pass from the motor bucker  236  to the filter assembly  234 . 
     The filter assembly  234  may be periodically removed from the rolling assembly  20  to allow the filter assembly  234  to be cleaned. The filter assembly  234  is accessed by removing the wheel  26  of the rolling assembly  20 . This wheel  26  may be removed, for example, by the user first removing the fastener  226 , and then pulling the wheel  26  from the axle  218 . The filter assembly  234  may then be removed from the rolling assembly  20  by depressing a catch connecting the filter assembly  234  to the motor bucket  236 , and pulling the filter assembly  234  from the rolling assembly  20 . 
     The main body  22  of the rolling assembly  20  further comprises a motor inlet duct  238  for conveying a fluid flow received from the outlet duct  30  to the motor bucket  236 . The motor inlet duct  238  is connected to the upper section  212  of the body  22  of the rolling assembly  20 , and has a fluid inlet  240  and a fluid outlet  242 . The cable rewind assembly  230  is mounted on the side of the motor inlet duct  238  which is opposite to the fluid outlet  242 . An annular seal  244  may be provided between the motor bucket  236  and the motor inlet duct  238 . The fan unit  228  comprises a series of exhaust ducts  246  located around the outer circumference of the fan unit  228 . In the preferred embodiment a plurality of exhaust apertures  246  are arranged around the fan unit  228  and provide communication between the fan unit  228  and the motor bucket  236 . 
     The main body  22  further comprises an air exhaust port for exhausting cleaned air from the vacuum cleaner  10 . The exhaust port is formed towards the rear of the main body  22 . In the preferred embodiment the exhaust port comprises a number of orifices  248  located in a lower section  214  of the main body  22 , and which are located so as to present minimum environmental turbulence outside of the vacuum cleaner  10 . 
     A first user-operable switch  250  is provided on the main body and is arranged so that, when it is depressed, the fan unit  228  is energized. The fan unit  228  may also be de-energized by depressing this first switch  250 . A second user-operable switch  252  is provided adjacent the first switch  250 . The second switch  252  enables a user to activate the cable rewind assembly  230 . Circuitry  254  for driving the fan unit  228 , cable rewind assembly  230  and other auxiliary components of the vacuum cleaner  10  is also housed within the rolling assembly  20 . 
     In use, the fan unit  228  is activated by the user pressing the switch  250 , and a dirt-bearing fluid flow is drawn into the vacuum cleaner  10  through the suction opening in the cleaner head. The dirt-bearing air passes through the hose and wand assembly, and enters the inlet duct  28 . The dirt-bearing air passes through the inlet duct  28  and enters the dirty air inlet  108  of the separating apparatus  12 . Due to the tangential arrangement of the dirty air inlet  108 , the fluid flow follows a helical path relative to the outer wall  16 . Larger dirt and dust particles are deposited by cyclonic action in the annular chamber  130  and collected therein. 
     The partially-cleaned fluid flow exits the annular chamber  130  via the apertures in the shroud and enters the plenum chamber  158 . From there, the fluid flow enters the twelve cyclones  146 , wherein further cyclonic separation removes some of the dirt and dust still entrained within the fluid flow. This dirt and dust is deposited in the dust collector  122  while the cleaned air exits the cyclones  146  via the vortex finders  164  and enters the manifold fingers  166 . The fluid flow then passes into the filter housing  154  through the apertures  170 . Within the filter housing  154 , the air flow flows through the filter  184  of the filter assembly  180 . The support provided by the spokes  188  and fins  190  of the filter body  182  prevents the filter  184  from collapsing as the air flow passes through the filter  184 . The air flow subsequently passes axially through the filter body  182  to be exhausted through the air outlet  202  of the filter assembly  180  and into the dome-shaped air inlet  200  of the outlet duct  30 . 
     The air flow passes through the outlet duct  30 , and enters the main body  22  of the rolling assembly  20  through the fluid inlet  240  of the motor inlet duct  238 . The motor inlet duct  238  guides the fluid flow into the fan unit  228 . The fluid flow is subsequently exhausted through the exhaust apertures  246  in the side of the fan unit  228  and into the motor bucket  236 . The fluid flow leaves the motor bucket  236  through the perforations and passes through the filter assembly  234 . Finally the fluid flow follows the curvature of the main body  22  to the orifices  248  in the main body  22 , from which the cleaned fluid flow is ejected from the vacuum cleaner  10 . 
     Through use, the filter assembly  180  can become clogged, causing a reduction in the filtration efficiency, and so the filter assembly  180  will require periodic cleaning or replacement. In the preferred embodiment the filter assembly  180  is capable of being cleaned by washing. The filter assembly  180  can be accessed by the user for cleaning when the outlet duct  30  is in its raised position. The user removes the filter assembly  180  from the separating apparatus  12  by gripping one of the spokes  188  of the filter body  182 , and pulling the filter assembly  180  from the filter housing  154 . The filter assembly  180  can be washed by rinsing under a household tap and allowed to dry. The filter assembly  180  is then re-inserted into the filter housing  154  of the separating apparatus  12 , the outlet duct  30  is moved to its lowered position and use of the vacuum cleaner  10  can continue. 
     When the outlet duct  30  is in its raised position, the separating apparatus  12  may be removed from the vacuum cleaner  10  for emptying and cleaning. The separating apparatus  12  comprises a handle  250  for facilitating the removal of the separating apparatus  12  from the vacuum cleaner  10 . The handle  250  is connected to the upper section  160  of the exhaust manifold  122 , for example by a screw or a snap-fit connection. To empty the separating apparatus  12 , the user depresses a button  252  located on the upper section  160  of the exhaust manifold for actuating a mechanism for applying a downward pressure to the uppermost portion of the catch on the base  18 . This causes the catch to deform and disengage from the groove located on the outer wall  16  of the outer bin  14 . This enables the base  18  to move away from the outer wall  16  to allow dirt and dust that has been collected in the separating apparatus  12  to be emptied into a dustbin or other receptacle. The mechanism for applying the force to the catch preferably comprises a series of push rods which are moved towards the catch in response to the depression of the button  252 . The arrangement of push rods allows the outer bin  14  to be separated from the cyclone pack  140 .