Patent Publication Number: US-8966711-B2

Title: Cleaner head for a surface treating appliance

Description:
REFERENCE TO RELATED APPLICATIONS 
     This application claims the priority of United Kingdom Application No. 1103366.9, filed Feb. 28, 2011, the entire contents of which are incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The present invention relates to a cleaner head for a surface treating appliance. In its preferred embodiment, the present invention relates to a cleaner head for a vacuum cleaning appliance. 
     BACKGROUND OF THE INVENTION 
     Vacuum cleaners are generally supplied with a range of tools for dealing with specific types of cleaning. The tools include a cleaner head for general on-the-floor cleaning. The cleaner head comprises a main body which engages with a floor surface. The main body has a lower surface comprising a suction opening through which, in use, dirt and dust is drawn into the cleaner head from the floor surface. 
     It is useful for the main body to be pivotably connected to the remainder of the cleaner head so that the suction opening can remain in close proximity to the floor surface as the cleaner head is maneuvered over the floor surface. 
     For example, JP 11-155786 describes a cleaner head having a main body and a conduit assembly connected to the main body for conveying an air flow away from the main body. The main body comprises a suction opening located in a lower surface of the main body, and which lies in a suction plane. The conduit assembly is connectable to a wand of a vacuum cleaner, which has a handle which is manipulated by the user to maneuver the floor tool over the floor surface. The conduit assembly comprises a generally tubular front conduit having a circular air inlet which is connected to the rear of the main body for rotation about a first axis which extends rearwardly from the main body parallel to the suction plane and through the bore of the front conduit. An air outlet extends from midway along the upper surface of the front conduit to the rear of the front conduit. The conduit assembly further comprises a rear conduit which is connected to the front conduit for pivotal movement relative to the front conduit about a second axis which is orthogonal to the first axis and parallel to the suction plane. Opposing recesses are provided on the internal surface of the front conduit lying adjacent the front of the air outlet for receiving the ends of a shaft located on the upper surface of the front of the rear conduit. With the ends of the shaft received within the recesses, the rear conduit can move within the front conduit and about the second axis between raised and lowered positions. 
     Through combinations of a rotation of the front conduit about the first axis and a rotation of the rear conduit about the second axis, the conduit assembly is able to adopt different configurations relative to the main body to facilitate the maneuvering of the main body over a floor surface, and between and beneath items of furniture. However, as the pivoting connection between the front and rear conduits is located within an airflow path passing through the conduits, there is a risk of air leaking around the connection, reducing the pick-up performance of the cleaner head. The presence of such a connection within the airflow path can disrupt the air flow through the conduit assembly, which can generate turbulence and noise. 
     SUMMARY OF THE INVENTION 
     In a first aspect the present invention provides a cleaner head for a surface treating appliance, comprising a main body having a fluid port located at the rear of the main body, a front conduit comprising a front section connected to the main body for rotation relative thereto about a first axis extending rearwardly from the main body and through the fluid port and the front section, a rear elbow section and at least one first connector, and a rear conduit comprising a front elbow section moveable within or about the rear elbow section of the front conduit, a rear section and at least one second connector connected to said at least one first connector to enable the rear conduit to pivot relative to the front conduit about a second axis which is orthogonal to the first axis and which lies outside a fluid flow path passing through the front conduit and the rear conduit. 
     As the connectors for connecting together the front conduit and the rear conduit lie outside a fluid flow path passing through the conduits, the connectors may have any desired configuration without requiring any seals for preventing fluid from leaking between the connectors. In a preferred embodiment, the front conduit comprises a pair of arms which extend towards the rear conduit, and the rear conduit comprises a shaft which is received between the arms. A bolt, pin or other connecting member may be provided for connecting the shaft to the arms so that the shaft can rotate relative to the arms. Alternative, the connectors may be connected together by means of a snap-fit connection. A relatively simple seal may then be provided between the elbow sections to prevent fluid from leaking between the elbow sections. 
     The front section of the rear conduit is preferably inserted into the rear section of the front conduit. As the rear conduit is inserted into the front conduit, at least the front section of the rear conduit has a greater cross-sectional area that the rear section of the front conduit. In a preferred embodiment, the cleaner head is used as part of a cleaning appliance in which fluid flows from the front conduit to the rear conduit. As the fluid flow enters the rear conduit, the fluid flow does not impinge on the front end of the rear conduit, which would disrupt the fluid flow through the conduits and generate noise, but instead passes into a region having a greater cross-sectional area. 
     The elbow sections preferably have substantially the same curvature so that a seal may be readily maintained between the elbow sections as the rear conduit is moved relative to the front conduit. For example, an annular sealing member may be located on the outer surface of the rear elbow section of the front conduit for engaging the inner surface of the front elbow section of the rear conduit as the rear conduit is pivoted relative to the front conduit. Alternatively, a sealing member may be disposed on the inner surface of the front elbow section for engaging the outer surface of the rear elbow section. The inner surface of the front section of rear conduit preferably has a diameter which is only slightly greater than that of the outer surface of the rear section of the front conduit so that the rear section of the front conduit can guide the movement of the front section of the rear conduit relative thereto as the rear conduit is pivoted and with minimal wobbling of the rear conduit relative to the front conduit to minimize the risk of fluid leaking between the conduits. Preferably, the inner surface of the front elbow section of the rear conduit slides over the outer surface of the rear elbow section of the front conduit as the rear conduit pivots relative to the front conduit. 
     The front end of the front elbow section of the rear conduit preferably moves between the front end and the rear end of the rear elbow section of the front conduit as the rear conduit pivots between raised and lowered positions relative to the front conduit. In this case, the curvature of the elbow sections can determine the extent to which the rear section can pivot relative to the front section. The curvature of each elbow section is preferably at least 60°, and in a preferred embodiment each elbow section has a generally 90° curvature. When the cleaner head is located on a substantially horizontal surface, the rear section of the rear conduit may then move between a relatively horizontal position and a relatively vertical position as the rear conduit pivots relative to the front conduit. 
     The front section of the front conduit is preferably also horizontal when the rear conduit is in a lowered position relative to the front conduit. This can enable a conduit assembly comprising the front and rear conduits to have a relatively low profile when the rear conduit is in a lowered position. Each conduit preferably comprises a curved intermediate section located between the front section and the rear section thereof, with each intermediate section preferably having a curvature in the range from 40 to 50° to allow the conduit assembly to have a low profile. 
     Each conduit may comprise a number of tubes or pipes which are connected together and each provide a respective section of the conduit. Alternatively, each conduit may be a single tube or pipe providing the different sections of the conduit. 
     The cleaner head preferably comprises a chassis for supporting the front conduit on a surface. The chassis is preferably connected to the front conduit for rotation therewith about the first axis. The chassis may extend about the front conduit, and about the connectors for connecting together the front and rear conduits to inhibit the ingress of dirt between the connectors. 
     The chassis preferably comprises a body, and a pair of wheels supported by the body. Contact between the rear conduit and the chassis may limit the movement of the rear conduit away from the lowered position. The body may comprise a recessed portion for receiving the rear conduit with pivoting movement thereof about the second axis so that the chassis does not inhibit movement of the rear conduit until the rear conduit has reached, or moved beyond, the desired raised position. This can allow the chassis to be located adjacent the rear conduit, and so allow the conduit assembly to be relatively compact to minimize the length of the cleaner head. 
     The cleaner head may comprise a shield member for inhibiting the ingress of dirt into the body of the chassis through the recess when the rear conduit is not in the raised position. The shield member preferably moves with the rear conduit as it pivots between the raised and lowered positions. For example, the shield member may be connected to the rear conduit. Alternatively, the shield member may be pivotably connected to the body of the chassis, and may be biased towards the rear conduit. The shield member may be pivotable about a third axis which intersects orthogonally the first axis. The shield member is preferably disposed between the recessed portion of the body and the rear conduit. 
     The shield member and the recessed portion of the body may each have a curved outer surface, with the curvature of the outer surface of the shield member preferably being substantially the same as the curvature of the recessed portion of the body. The wheels of the chassis are preferably dome-shaped, and preferably have a substantially spherical curvature. The curvature of the outer surface of the wheels is preferably substantially the same as the curvature of the outer surface of the recessed portion of the body so that the outer surfaces of the body and the wheels of the chassis are located on the surface of a common sphere. The third axis, about which the shield member pivots relative to the body of the chassis, preferably passes through the center of this sphere. As the shield member becomes exposed as the rear conduit moves away from the raised position, the similar curvatures of the shield member and the body of the chassis means that the emergence of the shield member does not disrupt unduly the spherical appearance of the chassis. 
     The cleaner head may be used with any cleaning or surface treating appliance that carries fluid to and/or from a surface, e.g. wet/dry vacuum cleaners, polishing/waxing machines and carpet shampoo machines. 
     In a second aspect, the present invention provides a conduit assembly for a cleaner head of a surface treating appliance, the conduit assembly comprises a front conduit, a rear conduit pivotably connected to the front conduit for movement between a raised position and a lowered position, and a chassis for supporting the front conduit, the chassis comprising a body and a pair of wheels rotatably connected to the body, the body having a recessed portion for receiving the rear conduit as the rear conduit moves towards the raised position, the chassis further comprising a shield member for covering a gap formed between the rear conduit and the recessed portion of the body as the rear conduit moves away from the raised position. 
     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 
       An embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: 
         FIG. 1  is an exploded view of a cleaner head; 
         FIG. 2  is a top view of the cleaner head, with a rear conduit of the cleaner head in a lowered positioned; 
         FIG. 3  is a side view of the cleaner head with the rear conduit in the lowered position, and with a chassis of the cleaner head removed to reveal a front conduit of the cleaner head; 
         FIG. 4  is a side sectional view along line A-A in  FIG. 2 ; 
         FIG. 5  is a top view of the cleaner head, with the rear conduit in a raised positioned; 
         FIG. 6  is a side view of the cleaner head with the rear conduit in the raised position, and with a chassis of the cleaner head removed to reveal a front conduit of the cleaner head; and 
         FIG. 7  is a side sectional view along line B-B in  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1 to 4  illustrate an embodiment of a cleaner head for a surface treating appliance. In this embodiment, the cleaner head  10  is arranged to be connectable to a wand or hose of a cylinder vacuum cleaning appliance. The cleaner head  10  comprises a main body  12  and a conduit assembly  14  connected to the main body  12 . The main body  12  comprises substantially parallel side walls  16 ,  18  extending forwardly from opposite ends of a rear section  20  of the main body  12 , and a moveable section  22  located between the side walls  16 ,  18  of the main body  12 . In this embodiment the moveable section  22  is rotatably connected to the main body  12  for rotation about an axis which extends generally orthogonally between the side walls  16 ,  18  of the main body  12 . 
     The moveable section  22  comprises an upper wall  24 , a lower plate, or sole plate  26 , and two side walls  28  which connect the sole plate  26  to the upper wall  24 . The side walls  28  are located between the side walls  16 ,  18  of the main body  12 , with each side wall  28  being located adjacent and substantially parallel to a respective one of the side walls  16 ,  18  of the main body  12 . In use, the sole plate  26  faces the floor surface to be cleaned and engages the surface of a carpeted floor surface. 
     With particular reference to  FIGS. 3 and 4 , the sole plate  26  comprises a leading section  30  and a trailing section  32  located on opposite sides of a suction opening  34  through which a dirt-bearing air flow enters the cleaner head  10 . The suction opening  34  is generally rectangular in shape. The sole plate  26  comprises two working edges  36 ,  38  on opposing long sides of the suction opening  34  for agitating the fibers of a carpeted floor surface as the cleaner head  10  is maneuvered over such a surface. To prevent the working edges  36 ,  38  from scratching or otherwise marking a hard floor surface as the cleaner head  10  is maneuvered over such a surface, the cleaner head  10  comprises surface engaging support members which serve to space the working edges  36 ,  38  from a hard floor surface. In this embodiment, the cleaner head  10  comprises a plurality of surface engaging support members which are each in the form of a rolling element, preferably a wheel. A first pair of wheels  40  is rotatably mounted within a pair of recesses formed in the leading section  30  of the sole plate  26 , and a second pair of wheels  42  is rotatably mounted within a pair of recesses formed in the trailing section  32  of the sole plate  26 . 
     During use, a pressure difference is generated between the air passing through the cleaner head  10  and the external environment. This pressure difference generates a force which acts downwardly on the cleaner head  10  towards the floor surface. When the cleaner head  10  is located on a carpeted floor surface, the wheels  40 ,  42  are pushed into the fibers of the carpeted floor surface under the weight of the cleaner head  10  and the force acting downwardly on the cleaner head  10 . The thickness of the wheels  40 ,  42  is selected so that the wheels  40 ,  42  will readily sink into the carpeted floor surface to bring at least the working edges  36 ,  38  of the sole plate  26  into contact with the fibers of the floor surface. 
     As the cleaner head  10  is pulled backwards over a carpeted floor surface by a user, there is a tendency for the user to raise the rear section  20  of the main body  12  of the cleaner head  10 . However, the rotatable connection of the moveable section  22  to the main body  12  allows the sole plate  26  to pivot relative to the main body  12  to maintain the working edges  36 ,  38  in contact with the floor surface. Clockwise rotation of the moveable section  22  relative to the main body  12  is restricted through the abutment of upwardly facing surfaces  44  located on the moveable section  22  with downwardly facing surfaces  46  located towards the front of the side walls  16 ,  18  of the main body  12 . Anticlockwise rotation of the moveable section  22  relative to the main body  12  is restricted through the abutment of the upper surface  48  of the trailing section  32  of the sole plate  26  with the bottom surfaces  50  of the side walls  16 ,  18  of the main body  12 . 
     The cleaner head  10  further comprises an agitator assembly for agitating dirt and dust located on the floor surface. In this example the agitator assembly comprises a rotatable brush bar  60  which is mounted within an agitator chamber  62  of the moveable section  22  of the main body  12 . The agitator chamber  62  is partially defined by the upper wall  24  of the moveable section  22 . The upper wall  24  is preferably formed from transparent material to allow the user to see whether the agitator chamber  62  has become blocked. The brush bar  60  is driven by a motor (not shown) located in the rear section  20  of the main body  12 . The motor may be electrically connected to a terminal located in the conduit assembly  14  for connection with a conformingly profiled terminal located in a duct of the cleaning appliance to enable electrical power to be supplied to the motor. Alternatively, the motor may be driven by power supplied from a battery located in the rear section  20  of the main body  12 . 
     The brush bar  60  is connected to the motor by a drive mechanism located, at least in part, within a drive mechanism housing  66  so that the drive mechanism is isolated from the air passing through the suction passage. One end of the brush bar  60  is connected to the drive mechanism to enable the brush bar  60  to be driven by the motor, whereas the other end of the brush bar  60  is rotatably supported by an end cap (not shown) removably connected to the side wall  18  of the main body  12 . The drive mechanism comprises a drive pulley which is connected to a drive shaft rotated by the drive motor, and a driven pulley which is connected to the drive pulley by a belt. A drive dog is mounted on one side of the driven pulley for connection to the brush bar  60 . 
     The brush bar  60  comprises an elongate body  70 . The brush bar  60  is rotated about the longitudinal axis of the elongate body  70  by the drive mechanism. The elongate body  70  bears two different types of bristles for agitating dirt and dust from the floor surface as the brush bar  60  is rotated by the motor. Each of the different types of bristles protrudes from the suction opening  34  in the sole plate  26  by respective different amounts as the brush bar  60  is rotated by the motor. In this embodiment, the brush bar  60  comprises relatively short, preferably relatively stiff, bristles  72 , and relatively long, preferably relatively soft, bristles  74 . The relatively short bristles  72  are arranged in two angularly spaced, helical rows extending along the body  70 . Within each row, the relatively short bristles  72  are arranged in a series of clusters or tufts regularly spaced along the row. The relatively long bristles are arranged in two continuous helical rows, with each row being angularly spaced from a row of tufts formed from the relatively short bristles  72 . 
     The length of the relatively short bristles  72  is chosen so that, as the brush bar  60  is rotated, the tips of these bristles  72  protrude outwardly beyond a first plane containing the suction opening  34 , but not beyond a second plane containing the lowermost extremities of the wheels  40 ,  42 . The relatively long bristles  74  protrude radially outwardly from the body  70  beyond the relatively short bristles  72  so that the relatively long bristles  74  protrude beyond both the first plane and the second plane during rotation of the brush bar  60 . 
     When the cleaner head  10  is located on a carpeted floor surface the wheels  40 ,  42  sink between the fibers of the carpet so that the bottom surface of the sole plate  26  engages the fibers of the carpet. As both the relatively short bristles  72  and the relatively long bristles  74  protrude from the suction opening  26  as the brush bar  60  rotates, both of the different types of bristles are able to agitate dirt and dust from the floor surface. When an air flow is generated through the cleaner head  10 , by operation of a fan unit of a vacuum cleaning appliance to which the cleaner head  10  is connected, this dirt and dust becomes entrained within the air flow and is conveyed into the cleaner head  10  through the suction opening  34 . 
     When the cleaner head  10  is moved from the carpeted floor surface on to a hard floor surface, the sole plate  26  becomes spaced from the hard floor surface by the wheels  40 ,  42 . As the tips of the relatively short bristles  72  do not protrude beneath the plane containing the lowermost extremities of the wheels  40 ,  42 , these bristles do not come into contact with the hard floor surface, thereby preventing scratching or other marking of the hard floor surface by these bristles. However, as the relatively long bristles  74  protrude beyond this plane, these bristles engage, and are swept across, the hard floor surface with rotation of the brush bar  60  to dislodge dirt and dust from the floor surface to become entrained within the air flow. 
     The suction opening  34  provides an opening through which dirt, dust particles and other debris is swept into the agitator chamber  62  by the rotating bristles  72 ,  74  of the brush bar  60 . In this example, the motor and drive mechanism are arranged to rotate the brush bar  60  in such a direction that the bristles  72 ,  74  sweep dirt and dust rearwardly, that is, over the rear working edge  38 , into the agitator chamber  62 . The agitator chamber  62  is bounded by a curved front section  76  of the upper wall  24 , the sole plate  26 , the side walls  28 , and a curved inner wall  78  connected to the upper wall  24 . The front section  76  of the upper wall  24  and the inner wall  78  are in the form of a section of a cylinder, which is substantially co-axial with the rotational axis of the brush bar  60 . The lower end of the inner wall  78  is spaced from the upper surface  80  of the sole plate  26  to define a dust outlet  82  from the agitator chamber  62 . In this example the lower end of the inner wall  78  is generally straight, and extends substantially the entire length of the agitator chamber  62  so that the height of the dust outlet  82  is substantially constant along the length of the agitator chamber  62 . 
     An exhaust port  84  is formed in the rear section  85  of the upper wall  24 . In this example the exhaust port  84  is located midway between the side walls  28 . A dust channel  86  extends between the dust outlet  82  of the agitator chamber  62  and the exhaust port  84  to convey dust and debris to the exhaust port  84 . The dust channel  86  is generally in the shape of a curved funnel having a relatively wide mouth and a relatively narrow outlet. The dust channel  86  defines part of an air flow path which extends through the cleaner head  10 , and along which air is drawn by the motor and fan unit of a vacuum cleaning appliance to which the cleaner head is attached. The air flow path extends from the suction opening  34 , through the dust outlet  82  of the agitator chamber  62  and through the dust channel  86  to the exhaust port  84 . 
     The rear section  20  of the main body  12  includes an air channel  88  passing centrally therethrough for conveying an air flow from the moveable section  22  of the main body  12  to the conduit assembly  14 . The air channel  88  comprises an inlet port  90  for receiving the air flow from the exhaust port  84 , and an outlet port  92 . A sealing member  94  is located between the rear section  20  and the moveable section  22  of the main body  12  to maintain an air tight seal between the exhaust port  84  and the inlet port  90  as the moveable section  22  pivots relative to the rear section  20 . The outlet port  92  is generally circular, and is oriented so that when the cleaner head  10  is located on a hard floor surface with the upper surface  48  of the trailing section  32  of the sole plate  26  abutting the bottom surfaces  50  of the side walls  16 ,  18  of the main body  12 , the outlet port  92  is substantially orthogonal to the second plane containing the lowermost extremities of the wheels  40 ,  42 . 
     The conduit assembly  14  is connected to the rear section  20  of the main body  12 . The conduit assembly  14  comprises a front conduit  100  for receiving the air flow from the outlet port  92  of the main body  12 , and a rear conduit  102  for receiving the air flow from the front conduit  100 . The rear conduit  102  is connectable to the wand or hose of a vacuum cleaning appliance for receiving the air flow from the conduit assembly  14 . 
     The front conduit  100  comprises a front section  104  which is connected to the main body  12 . The front section  104  is generally cylindrical in shape. The front section  104  is inserted into the outlet port  92 , and is connected to the outlet port  92 , for example by a C-clip or a snap-fit connection, so that the front conduit  100  is able to rotate relative to the main body  12 . An annular sealing member  106  is located between the front section  104  and the outlet port  92  to maintain an air tight seal between the main body  12  and the conduit assembly  14 . The front conduit  100  is rotatable relative to the main body  12  about a first axis A, indicated in  FIGS. 2 and 4 , which extends rearwardly from the main body  12  and centrally through the outlet port  92  and the front section  104  of the front conduit  100 . The first axis A is substantially orthogonal to the rotational axis of the brush bar  60 . 
     The front conduit  100  further comprises a rear elbow section  108  from which the air flow enters the rear conduit  102 . The rear elbow section  108  has a generally 90° curvature, and extends about a second axis B indicated in  FIGS. 3 and 4 . The second axis B is orthogonal to the first axis A. The rear elbow section  108  is connected to the front section  104  by a curved intermediate section  110 . The intermediate section  110  has a smaller curvature than the rear elbow section  108 , and in this embodiment the angle of curvature is around 40°. 
     The rear conduit  102  comprises a front elbow section  112  into which the rear elbow section  108  of the front conduit  100  is inserted. The elbow sections  108 ,  112  preferably have substantially the same curvature, and so the front elbow section  112  has a generally 90° curvature. The front elbow section  112  also extends about a second axis B indicated in  FIGS. 3 and 4 . An annular sealing member  114  is located about the outer periphery of the rear elbow section  108  of the front conduit  100  for forming an air tight seal with the inner surface of the front elbow section  112  of the rear conduit  102 . 
     The rear conduit further comprises a rear section  116  which is connectable to a wand or hose of a vacuum cleaning appliance. The rear section  116  is generally cylindrical in shape. The front elbow section  112  is connected to the rear section  116  by a curved intermediate section  118 . As above, the intermediate section  118  has a smaller curvature than the front elbow section  112 , and in this embodiment the angle of curvature is around 50°. 
     The rear conduit  102  is connected to the front conduit  100  so that the rear conduit  102  can pivot relative to the front conduit  100 . The rear conduit  102  is moveable relative to the front conduit  100  between a lowered position, as illustrated in  FIGS. 2 to 4 , in which the rear section  116  of the rear conduit  102  is generally parallel to the front section  104  of the front conduit  100 , and a raised position, as illustrated in  FIGS. 5 to 7 , in which the rear section  116  of the rear conduit  102  is generally orthogonal to the front section  104  of the front conduit  100 . When the rear conduit  102  is in the lowered position, the rear elbow section  108  of the front conduit  100  is substantially fully surrounded by the front elbow section  112  of the rear conduit  102 . In this lowered position of the rear conduit  102 , the front end of the front elbow section  112  of the rear conduit  102  abuts against the outer wall of the intermediate section  110  of the front conduit  100 . 
     The rear conduit  102  is connected to the front conduit  100  so that the rear conduit  102  can pivot relative to the front conduit  100  about the second axis B. In this example, the front conduit  100  comprises a pair of arms  120  which extend rearwardly towards the rear conduit  102  from the intermediate section  110  of the front conduit  100 . The rear conduit  102  comprises a shaft  122  which is received between the arms  120 , and which is secured to the arms  120  by a pin or rod (not shown) which is inserted through apertures formed in the arms  120  and the shaft  122  so that the shaft  122  is rotatable about the second axis B. Of course, the connections between the front conduit  100  and the rear conduit  102  may be reversed, so that the arms  120  are located on the rear conduit  102  and the shaft  122  is located on the front conduit  100 . 
     The pivoting connection between the front conduit  100  and the rear conduit  102  is thus located external of an air flow path passing through the conduit assembly  14 . This means that the connection between the front conduit  100  and the rear conduit  102  can be made in any desired manner without concern of any leakage of air from around or between components of this connection. As the rear conduit  102  moves from the lowered position to the raised position, the inner surface of the front elbow section  112  of the rear conduit  102  slides over the outer surface of the rear elbow section  108  of the front conduit  100 , with the seal between the front and rear conduits  100 ,  102  being maintained by the annular sealing member  114  located about the periphery of the front conduit  100 . 
     The conduit assembly  14  further comprises a chassis for supporting the conduit assembly  14  on a floor surface. The chassis is connected to the front conduit  100  so that the chassis rotates with the front conduit  100  as it is rotated about the first axis A. The chassis extends about the front conduit  100 , and may be connected to the front conduit  100  by, for example, a snap fit connection which retains the chassis in a fixed angular position relative to the front conduit  100 . 
     The chassis comprises a body  124 , and a pair of wheels  126  supported by the body  124  for rotation relative to the body  124 . In this embodiment each wheel  126  is domed-shaped, and rotates about a respective axis of rotation. The axes of rotation are non-parallel and lie in a common plane which is parallel to the outlet port  92  of the main body  12 . The axes of rotation are tilted relative to the second axis B so that the wheels  126  converge beneath the body  124  to engage a floor surface. The wheels  126  have a substantially spherical curvature, and are arranged so that the surfaces of the wheels  126  are coincident with a common sphere. The first axis A passes through the center of this sphere, so that a surface of the sphere remains in contact with the floor surface as the conduit assembly  14  is rotated about the first axis A. The upper surface of the body  124  of the chassis has a similar curvature to the wheels  126  so that this surface of the body  124  is also coincident with this sphere. 
     As illustrated in  FIG. 7 , abutment of the intermediate member  118  of the rear conduit  102  against the body  124  of the chassis limits in one direction the pivoting movement of the rear conduit  102  relative to the front conduit  100 . To allow the rear conduit  102  to be raised to the position shown in  FIGS. 5 to 7  while allowing the chassis to be located adjacent the rear conduit  102 , the body  124  of the chassis includes a recessed portion  128  located adjacent the rear conduit  102 . As the rear conduit  102  is pivoted towards the raised position, the rear conduit  102  moves into the recess defined by the body  124  of the chassis. The recess thus allows the rear conduit  102  to move freely towards the raised position shown in  FIGS. 5 and 7 , and is shaped so that the rear conduit  102  does not abut the chassis until the rear section  116  of the rear conduit  102  is substantially vertical. 
     To inhibit the ingress of dirt into the body  124  of the chassis through the recess when the rear conduit  102  is not in the raised position, the chassis comprises a shield member  130  which is disposed beneath the recessed portion  128  of the body  124 . The shield member  130  is arranged to cover the gap formed beneath the body  124  of the chassis and the rear conduit. The shield member  130  is pivotably connected to the body  124 . As illustrated in  FIG. 1 , the shield member  130  comprises a pair of lugs  132  which are each located within an aperture  134  formed in a respective side surface of the body  124  to allow the shield member  130  to pivot about a third axis C indicated in  FIGS. 2 and 4 , which passes through the center of the sphere defined by the body  124  and the wheels  126 , and intersects orthogonally the first axis A. 
     The shield member  130  is biased towards the rear conduit  102 . In this embodiment, a torsion spring (not shown) or other resilient element is provided between the body  124  and the shield member  130  for urging the shield member  130  towards the rear conduit  102 . The biasing force of the resilient element is selected so that the resilient element does not impede unduly the pivoting movement of the rear conduit  102  relative to the front conduit  100 , and thus relative to the chassis. Due to the biasing force acting on the shield member  130 , the shield member  130  moves with the rear conduit  102  as it pivots between its raised and lowered positions to keep covered the gap between the rear conduit  102  and the body  124  of the chassis. 
     The shield member  130  preferably has a curved outer surface, with the curvature of the outer surface of the shield member  130  being substantially the same as the curvature of the upper surface of the body  124  of the chassis. This can both enable the shield member  130  to be positioned immediately beneath the upper surface of the body  124  when the rear conduit  102  is in its raised position, and cause minimal disruption to the external, spherical appearance of the chassis when the shield member  130  is exposed as the rear conduit  102  is pivoted away from its raised position. 
     In use, the rear section  116  of the rear conduit  102  may be connected to the wand of a vacuum cleaning appliance. The vacuum cleaning appliance is switched on to operate a fan unit which draws an air flow through the main body  12  and the conduit assembly  14  of the cleaner head  10 . The cleaner head  10  is located on a floor surface or other surface to be treated, and is maneuvered forwards and backwards over that surface using the wand of the appliance. As the cleaner head  10  is maneuvered forwards and backwards, the rear conduit  102  pivots relative to the front conduit  100  about the second axis B so that the cleaner head  10  maintains a flat profile with the cleaning surface, and the moveable section  22  of the main body  12  pivots relative to the rear section  20  to maintain the sole plate  26 , or the wheels  40 ,  42  of the sole plate, in contact with the floor surface. Steering of the cleaner head  10  is achieved by rotating the wand, which in turn causes the conduit assembly  14  to rotate about the first axis A so that the cleaner head  10  moves to the right or left in response to clockwise or anticlockwise rotation of the wand of the cleaning appliance. 
     As the cleaner  10  is maneuvered forwards and backwards, the wheels  126  of the chassis rotate to provide a rolling support for the conduit assembly  14 . In response to steering of the cleaner head  10 , the front conduit  100 , and therefore the chassis, rotates about the first axis A. As the chassis rotates, one of the two wheels  126  maintains contact with the floor surface and thus continues to provide rolling support for the conduit assembly  14 . As the surfaces of the wheels  126  are coincident with a common sphere, the center of which is coincident with the first axis A, the wheels  126  continue to support the front conduit  100  at the same height above the floor surface so that no lifting of the cleaner head  10  occurs and a flat profile with the floor surface is maintained.