Abstract:
A surface-treating appliance includes a main body, a surface-treating head and a support assembly. The support assembly is moveable out of a supporting position in which it supports the main body by a user performing a plurality of steps—for example, by depressing a pedal, then tilting the main body by pulling the handle. This arrangement reduces the likelihood of accidental release of the support assembly from its supporting position. For example, if the user depresses the pedal alone, or only pulls on the handle, the support assembly remains in its supporting position.

Description:
REFERENCE TO RELATED APPLICATIONS 
     This application is a national stage application under 35 USC 371 of International Application No. PCT/GB2007/003500, filed Sep. 14, 2007, which claims the priority of United Kingdom Application No. 0619181.1, filed Sep. 29, 2006, the contents of both of which prior applications are incorporated herein by reference. 
     FIELD OF INVENTION 
     This invention relates to a surface treating appliance, such as a vacuum cleaner. 
     BACKGROUND OF THE INVENTION 
     Surface treating appliances such as vacuum cleaners and floor polishers are well known. The majority of vacuum cleaners are either of the ‘upright’ type or of the ‘cylinder’ type, called canister or barrel cleaners in some countries. A typical upright vacuum cleaner comprises a main body which houses the main components of the vacuum cleaner, such as a motor and fan for drawing dirty air into the machine and some form of separating apparatus for separating dirt, dust and other debris from a dirty airflow drawn in by the fan. The main body also houses filters for trapping fine particles in the cleaned airflow. A cleaner head is rotatably mounted to the lower end of the main body. A supporting wheel is mounted on each side of the lower part of the main body, in a fixed relationship to the main body. In use, a user reclines the main body of the vacuum cleaner and then pushes and pulls a handle which is fixed to the main body of the cleaner. The vacuum cleaner rolls along the floor surface on the supporting wheels. 
     A dirty-air inlet is located on the underside of the cleaner head. Dirty air is drawn into the dust separating apparatus via the dirty-air inlet by means of the motor-driven fan. When the dirt and dust entrained within the air has been separated from the airflow in the separating apparatus, air is conducted to the clean air outlet by a second air flow duct, and via one or more filters, and expelled into the atmosphere. 
     Conventional upright vacuum cleaners have a disadvantage in that they can be difficult to manoeuvre about an area in which they are used. They can be pushed and pulled easily enough, but pointing the cleaner in a new direction is more difficult. It has been proposed to make an upright vacuum cleaner more manoeuvrable by substituting a wide rolling support for the supporting wheels, such as is described in our patent application GB2422094. A support assembly is provided to give further support to the main body when in the vertical position. The support assembly is moveable between a supporting position, in which it supports the main body of the appliance, and a stored position, in which it lies substantially against the main body. The support assembly is released from its supporting position by a user-operable foot pedal. 
     A problem which may be encountered with this type of support assembly is that there is a risk of inadvertent release of the support assembly from its supporting position. For example, if the user accidentally depresses the pedal, or if an object falls on it, the support assembly is brought out of its supporting position. Without the support of the support assembly, the main body has a tendency to tilt backwards and thus the appliance might topple over. 
     SUMMARY OF THE INVENTION 
     The invention provides a surface-treating appliance having a main body, a surface-treating head and a support assembly arranged to be moveable out of a supporting position in which it supports the main body by a user performing both of the following steps: actuating a mechanism on the support assembly and subsequently tilting the main body. 
     The provision of a support assembly that is releasable from its supporting position by a plurality of steps reduces the likelihood of accidental release of the support assembly from its supporting position. If the user depresses the pedal alone, the support assembly remains in its supporting position. 
     Advantageously, the support assembly is arranged to be moveable into a retracted position, where it lies substantially against the main body. The provision of a support assembly that lies substantially against the main body of the appliance when not needed improves the manoeuvrability and range of motion achievable by the appliance in use. 
     Advantageously, the appliance has a rolling support assembly comprising a plurality of rollers arranged relative to one another to define a region into which components of the appliance are mountable, such as the change over valve, and/or at least some of the components of the support assembly when in the retracted position. 
     The invention is particularly suitable for inclusion in upright vacuum cleaners having a wide, ball-like rolling support assembly, but may be applied to more conventional upright cleaners and other domestic appliances. 
     The term “surface treating appliance” is intended to have a broad meaning, and includes a wide range of machines having a head for travelling over a surface to clean or treat the surface in some manner. It includes, inter alia, machines which apply suction to the surface so as to draw material from it, such as vacuum cleaners (dry, wet and wet/dry), as well as machines which apply material to the surface, such as polishing/waxing machines, pressure washing machines, ground marking machines and shampooing machines. It also includes lawn mowers and other cutting machines. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will now be described, by way of example, with reference to the accompanying drawings, in which: 
         FIG. 1  is a side view of a surface-treating appliance constructed according to the invention; 
         FIG. 2  is a rear view of the appliance of  FIG. 1 ; 
         FIG. 3  is a side view of the appliance of  FIGS. 1 and 2  being put into a mode of cleaning by a user; 
         FIG. 4  is an exploded view of components of the support assembly of the appliance of  FIGS. 1 to 3 ; 
         FIG. 5   a  is a plan view of some of the components of  FIG. 4  in a first position; 
         FIG. 5   b  is a sectional view along the line A-A of  FIG. 5   a;    
         FIG. 6   a  is a plan view of the components of  FIG. 5   a  in a second position; 
         FIG. 6   b  is a sectional view along the line B-B of  FIG. 6   a;    
         FIG. 7  is an exploded view of components of the change over valve of the appliance of  FIGS. 1 to 3 ; 
         FIG. 8   a  is a perspective view of the change over valve of  FIG. 7  in a first position; 
         FIG. 8   b  is a perspective view of the change over valve of  FIG. 7  in a second position; 
         FIG. 9   a  is a side view of part of the support assembly of  FIG. 4  and the change over valve of  FIG. 7  in the first position; 
         FIG. 9   b  is a side view of the components of  FIG. 9   a  in an intermediary position; 
         FIG. 9   c  is a side view of the components of  FIG. 9   a  in the second position; 
         FIG. 10  is a perspective view of the appliance in a mode of use; 
         FIG. 11  is a perspective view of part of the appliance including a component of the support assembly; and 
         FIG. 12  is a side view of the appliance being returned to the position of  FIG. 1 . 
     
    
    
     Like reference numerals refer to like parts throughout the specification. 
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to  FIGS. 1 and 2 , the surface treating appliance is shown in the form of a vacuum cleaner and is indicated generally by the reference numeral  1 . The vacuum cleaner  1  comprises a main body  2 , a user-operable handle  3  and a roller assembly  4  for rolling the cleaner along a floor surface. The handle  3  extends upwardly from the rear part of the main body  2 . The main body  2  houses a motor and fan for generating a suction airflow (not visible in these drawings) as well as separating apparatus  5  for separating dirt, dust and other debris from a dirty airflow drawn into the machine by the fan and motor. 
     In this embodiment, the separating apparatus  5  is cyclonic, in which the dirt and dust is spun from the airflow. The cyclonic separating apparatus  5  comprises two stages of cyclone separation arranged in series with one another. The first stage is a cylindrically-walled chamber  6  and the second stage comprises a set  7  of tapering, substantially frusto-conically shaped chambers arranged in parallel with one another. Airflow is directed tangentially into the upper part of a first cyclonic chamber  6  by a duct  8 . Larger debris and particles are removed and collected in the first cyclonic chamber  6 . The airflow then passes through a shroud  9  to the set  7  of smaller frusto-conically shaped cyclonic chambers. Finer dust is separated by these chambers and the separated dust is collected in a common collecting region. 
     The main body  2  also houses filters (not visible in these drawings) for trapping fine particles in the cleaned airflow. These filters remove any fine particles of dust which have not already been removed from the airflow by the separating apparatus. A first filter, called a pre-motor filter, is provided before the motor and fan. A second filter, called a post-motor filter, is provided after the motor and fan. Where the motor for driving the suction fan has carbon brushes, the post-motor filter also serves to trap any carbon particles emitted by the brushes. Clean air is then expelled to the atmosphere. 
     A cleaner head  10  is pivotably mounted to the lower end of the main body  2 , and serves, in use, to treat the floor surface. In this embodiment, it comprises a housing with a chamber for supporting an agitator in the form of a brush bar  11 . The lower, floor-facing side of the chamber has an air inlet slot  12  and the brush bar  11  is rotatably mounted in the chamber such that bristles on the brush bar can protrude through the inlet slot and can agitate the floor surface over which the cleaner head passes. The brush bar  11  is rotatably driven by a dedicated motor  13  positioned on the cleaner head  10 . 
     The roller assembly  4  permits the cleaner to be manoeuvred easily along a floor surface. However, the roller assembly  4  may not provide sufficient support for the cleaner when the main body  2  is in the vertical, or substantially vertical position. To this end, a support assembly  14  is provided. 
       FIG. 4  is an exploded view of the main components of the support assembly  14 . Minor features such as fasteners and washers have been omitted for clarity. The support assembly  14  comprises a stand  15  shaped so as to form two legs  16   a ,  16   b , with a strut  17  therebetween to provide structural strength to the stand  15 . Each of the legs  16   a ,  16   b , has a wheel  18   a ,  18   b  attached to an end portion. The wheels  18   a ,  18   b  aid a user in guiding the cleaner  1  between rooms. In this embodiment, each of the wheels  18   a ,  18   b  is wide and the face furthest from the leg  16   a ,  16   b  is rounded. This gives smooth running on a variety of floor surfaces. Each wheel  18   a ,  18   b  is attached to a respective leg  16   a ,  16   b  by axles  19   a ,  19   b  such that the wheels are outside the legs of the stand  15 . This provides a wide wheel-base for extra stability. 
     The end portion of the stand  15  remote from the wheels  18   a ,  18   b  has outwardly facing pins  20   a ,  20   b , only one of which ( 20   a ) is visible in this drawing. The pins  20   a ,  20   b  are arranged to engage in apertures on a yoke  21  associated with the main body  2  of the cleaner  1  so that the stand  15  is attached to the yoke, and can move pivotably with respect to the main body. 
     The support assembly  14  also comprises a pedal  22 , which is intended to be depressible by the user&#39;s foot. The pedal  22  extends between the legs  16   a ,  16   b  of the stand  15 , above the strut  17 . The pedal  22  has outwardly-facing pins  23   a ,  23   b , which engage with recesses  24   a ,  24   b  on the inwardly-facing surface of the stand  15 , so that the pedal  22  is pivotable with respect to the stand. 
     Another component of the support assembly  14  is an actuator  25 , which is approximately T-shaped. The end of the actuator  25  that corresponds with the foot of the T has outwardly-facing pins  26   a ,  26   b  that are arranged to engage in apertures (not shown) on the main body  2 . Thus, the actuator  25  is pivotable with respect to the main body  2 . Resilient means in the form of a helical spring  27  is also provided between the actuator  25  and the main body  2 , and is biased so that the actuator tends to pivot upwardly, with the arms  28   a ,  28   b  of the T uppermost. Ordinarily, when the support assembly  14  is supporting the main body  2  of the cleaner  1 , the actuator  25  is arranged to bear against a lower surface of the foot pedal  22 , thereby urging it upwardly, so that it stands proud of the stand  15 . Thus, the pedal  22  is conspicuous to the user. 
     The support assembly  14  also comprises a locking member  29 , which is provided to give further support for the cleaner  1 . The locking member  29  comprises two legs  30   a ,  30   b , with a reinforcing strut  31  therebetween. One end portion of each leg  30   a ,  30   b  has an outwardly-facing projection  32   a ,  32   b  that engages in respective apertures (not shown) on the main body  2 , close to the bottom of the hose  33  on the rear of the cleaner  1 . Thus, the locking member  29  is pivotable with respect to the main body  2 . The other end portion of each leg  30   a ,  30   b  has outwardly facing locking-pins  34   a ,  34   b . Ordinarily, when the support assembly  14  is supporting the main body  2  of the cleaner  1 , the locking pins  34   a ,  34   b  engage with co-operating notches  35   a ,  35   b  on the foot pedal  22 . Thus, the foot pedal  22 , being urged into a predetermined position by the sprung actuator  25 , engages the locking member  29  in a position where it provides support for the main body  2  of the cleaner  1 . 
     Other features of the support assembly  14  include a locking pin lever  36 , which is arranged to fit in a recess  37  on an inwardly-facing surface of the stand  15 . The locking pin lever  36  is pivotably attached to the stand  15 , and is resiliently biased with respect to it by means of helical spring  38 . The recess  37  for the locking pin lever  36  communicates with a locking pin groove  39 . A corresponding locking pin groove (not visible in these drawings), is provided on the other side of the stand  15 . The stand  15  also comprises actuator ramps  40   a ,  40   b , only one of which is visible in this drawing. There is also provided on the stand  15  a change over valve pin  41 . These features will be discussed in more detail further in the specification. 
     When the cleaner  1  is in the position shown in  FIGS. 1 and 2 , it can be used in a cylinder mode, in which case the handle  3  may be released and used as a hose and wand assembly in conjunction with the hose  33 . Air is drawn into the cleaner  1  through the end of the wand which can be released from the cleaner for appropriate manipulation. The inlet  12  in the cleaner head  10  is automatically shut off. 
     When the cleaner  1  is to be used in conventional upright mode, the user reclines the main body  2 . In order to do so, the support assembly  14  must be released from the supporting position shown in  FIGS. 1 and 2 . The first step is for the user to depress the pedal  22  with his foot. This is illustrated in  FIGS. 5   a  and  5   b.    
     The action of depressing the pedal  22  moves it out of engagement with the locking pins  34   a ,  34   b . Thus, the weight of the main body  2  bears against the locking member  29 , and the pins  34   a ,  34   b  of the locking member bear against the stand  15 . The locking pin lever  36  resists movement of the pin  34   b , and hence the locking member  29  out of this supporting position. The support assembly  14  maintains its supporting position and continues to support the main body  2 , even though the pedal  22  has been depressed. This is an important safety feature, as it prevents the main body  2  from toppling backwards if the user accidentally depresses the pedal  22 . 
     In order to bring the support assembly  14  out of its supporting position, the user must subsequently apply a turning moment to the main body  2  by pivoting the handle  3  towards him, as illustrated in  FIG. 3 , to bring the main body out of its substantially vertical position. This action causes the main body  2  to bear against the locking member  29  with a force having a greater horizontal component than that experienced by the locking member when the main body  2  is vertical. Consequently, the pin  34   b  of the locking member  29  is urged against the locking pin lever  36 . The force is sufficient to cause the locking pin lever  36  to pivot downwardly in its recess  37  against the force of its spring  38 . This permits the pin  34   b , and hence the pin  34   a , to move out of their supporting position and into the locking pin grooves  39  on the stand  15 . Thus, the support assembly  14  is brought out of its supporting position only when the user is supporting the cleaner  1  himself by means of the handle  3 . 
     As the user continues to recline the main body  2 , the locking pins  34   a ,  34   b  slide along the grooves  39  in the stand  15 . The wheels  18   a ,  18   b  on the stand remain on the floor surface and so, as the main body  2  reclines, the stand  15  is brought closer to the rear of the main body. The action of depressing the pedal  22  and sliding the stand  15  causes the arms  28   a ,  28   b  of the actuator  25  to be pushed under the actuator ramps  40   a ,  40   b  provided on the stand. Over the range of positions up to this point, the actuator  25  applied a spring force to the pedal  22 , as shown in  FIG. 5   b . When the actuator arms  28   a ,  28   b , engage with, and move along the actuator ramps  40   a ,  40   b  on the stand  15 , the actuator  25  ceases to act on the pedal  22  but instead applies a spring force to the stand. Over the range of positions beyond this point, the actuator acts on the stand  15 . The actuator  25  is biased so as to push upwardly against the ramps  40   a ,  40   b , and hence urge the stand  15  upwards, as shown in  FIGS. 6   a  and  6   b . As the stand  15  pivots upwards, it lifts the wheels  18   a ,  18   b  and hence brings the support assembly  14  out of engagement with the floor surface. In the fully retracted position, as shown in  FIG. 3 , the support assembly  14  lies substantially against the main body  2  of the cleaner  1 . 
     In reclining the main body  2  of the cleaner  1 , the user changes the mode of cleaning from the cylinder mode, in which air is drawn through the hose and wand assembly  3 ,  33 , to the upright mode, in which air is drawn through the head  10  of the cleaner. A change over valve  42  is required in order to connect automatically the dust separating apparatus  5  to either the wand and hose  3 ,  33  or the cleaner head  10 , in dependence on the mode of operation. As the user reclines the main body  2  of the cleaner  1 , the change over valve  42  automatically shuts off the air inlet at the distal end of the wand and connects the dust separating apparatus  5  to the cleaner head  10 . The support assembly  14  is arranged to act on the change over valve  42  such that it occupies the correct position for the mode of cleaning. 
     The main components of the change over valve  42  are shown in the exploded view of  FIG. 7 . Minor components, such as seals, springs and fasteners have been omitted for clarity. The change over valve  42  comprises a casing  43  which houses a cylindrical drum  44 . The drum  44  is rotatably mounted in the casing  43  such that it rotates about its longitudinal axis. The drum  44  has an inlet  45  on its circumference and an outlet  46  at one end. The drum  44  defines a fluid flow path. The position of the drum  44  determines the mode of cleaning.  FIGS. 8   a  and  8   b  illustrate the position of the change over valve  42  in the two modes of cleaning. The hose  47 , connected at one end portion of the casing  43  is internal to the cleaner head  10  and so defines the fluid outlet from the air inlet  12  on the cleaner head. The opening  48  at the other end of the casing  43  is arranged to connect with the main hose  33  and so defines the fluid outlet from the hose and wand assembly  3 ,  33 . A wheel  49  is connected to the rotational axis of the drum  44 . Rotation of the wheel  49  causes the drum  44  to move between the positions defining the cleaning modes. A slot  50  in the circumference of the wheel  49  corresponds approximately to the position of the fluid inlet  45  on the circumference of the drum  44 . 
     In the position shown in  FIG. 8   a , the cleaner is in cylinder mode, with the inlet  45  of the drum  44  facing the opening  48 . The cleaner head hose  47  is closed off. Air is drawn through the hose and wand assembly  3 ,  33 , into the change over valve  42  and exits the outlet  46  of the drum  44  into a fluid conduit  51 . The fluid conduit  51  leads to the duct  8  connected to the dirt and dust separating apparatus  5 . 
     In the position shown in  FIG. 8   b , the cleaner is in upright mode, with the inlet  45  of the drum facing the cleaner head hose  47 . The opening  48  that communicates with the hose and wand assembly  3 ,  33  is closed off. Air is drawn through the cleaner head  10  via the inlet  12 , into the change over valve  42  and exits the outlet  46  of the drum  44  into the fluid conduit  51 . 
     Whilst the user is reclining the main body  2  of the cleaner  1 , the stand  15  moves pivotably relative to the main body. The change over valve pin  41  on the stand  15  engages with the slot  50  on the wheel  49  of the change over valve  42 .  FIG. 9   a  illustrates the point at which the change over valve pin  41  enters the opening of the slot  50 . The change over valve pin  41  bears against a wall  50   a  of the slot and induces the wheel  49  to rotate, as shown in  FIG. 9   b . Thus, the pivoting motion of the stand  15  is translated into rotational motion of the drum  44  of the change over valve  42 , in the manner of a Geneva drive. As the user moves the main body  2  into the reclined position, so that the stand  15  is urged upwards, the change over valve  42  is caused to rotate from the cylinder mode to the upright mode. The stand then continues to move into its fully retracted position, as shown in  FIG. 9   c.    
     Another function of the support assembly  14  is to control the locking and release of the cleaner head  10 . When the main body  2  is in the vertical position, with the support assembly  14  in the supporting position, the cleaner head  10  is latched with respect to the main body  2 . This enables the user to tilt the cleaner  1  as a whole onto the wheels  18   a ,  18   b  of the support assembly  14  so that the cleaner can be wheeled from location to location without the cleaner head  10  drooping and obstructing manoeuvrability. The support assembly  14  is arranged to release the cleaner head  10  from this position as it moves into the retracted position so that, as the main body  2  of the cleaner  1  is reclined, the head remains in contact with the surface to be treated. 
     The cleaner head  10  is connected to the main body  2  of the vacuum cleaner  1  in such a manner that the cleaner head  10  remains in contact with a floor surface as the main body is manoeuvred through a wide range of operating positions, e.g. when moved from side-to-side or when the main body is twisted about its longitudinal axis. The yoke  21  connects the main body  2  to the cleaner head  10 . The yoke  21  is mounted to each end of a rotational axis of the roller assembly  4 . The yoke  21  can pivot independently of the main body  2 . At the forward, central part of the yoke  21  there is a joint  52 , which connects to the cleaner head  10 . 
     The main body  2  is rotatably connected to the roller assembly  4 , which lies at the base of the main body. The roller assembly  4  allows the apparatus to be easily pushed or pulled along a surface. The shape of the roller assembly  4  and the connections between the main body  2  and the roller assembly, and the roller assembly and the cleaner head  10 , allow the apparatus to be more easily manoeuvred than traditional vacuum cleaners. 
     The roller assembly  4  comprises a central roller  53  and a pair of outer rollers  54   a ,  54   b , which are arranged relative to each other so as to provide a rolling support surface, but with rotational axes that are spaced from each other. The central roller  53  comprises an elongated and barrel-shaped shell, which shape provides both stability and manoeuvrability. A plurality of ridges  55  are provided around its circumference, to provide extra grip as the cleaner  1  is rolled along a surface to be treated. The outer rollers  54   a ,  54   b  are cap-shaped, having a larger diameter than the maximum diameter of the central roller  53  but a relatively narrow rolling support surface. This arrangement of rollers delimits a region into which components of the vacuum cleaner  10  may be mounted. In this embodiment, the region houses the change over valve mechanism  42  and also provides a space into which components of the support assembly  14  can fold into when the cleaner  1  is being used for upright cleaning. Thus, components of the support assembly  14  are hidden from the user when the support assembly is in the retracted position. This prevents the components from being damaged or tampered with, as well as being more aesthetically pleasing. 
     The arrangement of the pivotal mounting of the yoke  21  and joint  52  allows the main body  2  together with the roller assembly  4  to be rotated about the longitudinal axis  56  of the handle  3 , in the manner of a corkscrew, while the cleaner head  10  remains in contact with the floor surface. This arrangement also causes the cleaner head  10  to point in a new direction as the main body  2  is rotated about its longitudinal axis  56 . 
       FIG. 10  shows the vacuum cleaner in a turning position. The user rotates the main body  2  about its longitudinal axis  56  by means of the handle  3 . This causes the roller assembly  4  to tilt with respect to the floor. The joint  52  associated with the yoke  21  causes the cleaner head  10  to turn whilst remaining in contact with the floor. The extent to which the main body  2  is turned about its longitudinal axis  56  determines the extent to which the cleaner head  10  moves from its forward facing position towards the right or left. The support assembly  14  remains neatly tucked up against the rear of the main body  2  during this range of motions performed by the cleaner  1 . This permits the user easily to manoeuvre the cleaner  1 , even when cleaning under furniture and other low obstructions. 
     When the user wishes to return the cleaner  1  to the vertical position, he pivotally moves the main body  2  back towards the vertical, as indicated by the arrow in  FIG. 12 . As the main body  2  rotates, an arm  57  fixed to the yoke  21  bears against a surface of the stand  15 , as shown in  FIG. 11 . The arm  57  pushes the stand  15  out of its retracted position against the main body  2 . The stand  15  moves away from the main body  2  and, as it does so, pivots downwardly towards the floor surface. 
     The change over valve pin  41  on the stand  15  re-engages with the slot  50  on the wheel  49  of the change over valve  42 . The change over valve pin  41  bears against the other side wall  50   b  of the slot and induces the wheel  49  to rotate in the opposite direction to that when the stand  15  was being retracted. As the user moves the main body  2  from its reclined position back into the vertical position, the change over valve  42  is caused to rotate from the upright mode to the cylinder mode. The motion of the stand  15  and valve  42  is the same as that shown in  FIGS. 9   a  to  9   c , but in reverse. 
     The pins  34   a ,  34   b  of the locking member  29  ride along the grooves  39  in the stand  15  as it moves out of the retracted position and cause the locking member to pivot outwardly from the main body  2 . When moving from the retracted position into the supporting position, the locking pins  34   a ,  34   b  are arranged to move along the upper surfaces of the grooves. Hence the locking pin  34   b  moves over the locking pin lever  36  and into the top end of its groove  39 . As the main body  2  returns to its vertical position, the locking pin  34   b  is prevented from sliding back along the groove  39  by the locking pin lever  36 . 
     The arms  28   a ,  28   b  of the actuator  25  slide along the actuator ramps  40   a ,  40   b  provided on the stand  15 , as the stand moves relative to the main body  2 . The actuator  25  continues to apply an upwardly-directed spring force to the stand  15 , but the force of the yoke arm  57  against the stand overcomes this spring force and prevents the stand from being urged back into the retracted position. When the actuator arms  28   a ,  28   b  reach the ends of the ramps  40   a ,  40   b , the actuator  25  ceases to act on the stand  15 . Therefore, the spring force urging the stand  15  upwards is released. Hence, the stand  15  falls under the influence of gravity towards the floor surface and pivots so that its wheels  18   a ,  18   b  resume engagement with the floor. The actuator  25 , freed from the constraints of the ramps  40   a ,  40   b , pivots upwards under the influence of the spring and re-engages the pedal  22 . The actuator  25  urges the pedal  22  upwards, so that the notches  35   a ,  35   b  on the pedal re-engage with the pins  34   a ,  34   b  of the locking member  29 . In this manner, the cleaner  1  is returned to its vertical position and the support assembly  14  supports the main body of the cleaner. 
     The components may be arranged to produce a click or other sound, to indicate to the user that the appliance has been fully returned to the vertical position. Thus, the user releases the handle  3 , leaving the main body  2  to be supported by the support assembly  14 . 
     Of course, variations may be made without departing from the scope of the invention. For example, the support assembly  14  may be coupled to the brush bar  11 , so that the brush bar, or other agitator, is driveable only as the user reclines the main body  2  for upright cleaning. This prevents the brush bar  11  from being energised when the cleaner is in the vertical position, when it may be stationary for an extended period of time. Thus, excessive wear and tear on the floor surface is prevented. The support assembly may further be arranged to cause the agitator to be driven automatically as the main body  2  is reclined, without the need for selective energisation by the user. Similarly, the support assembly  14  may be arranged automatically to interrupt driving of the agitator when the main body  2  is returned to the vertical position. 
     The provision of a depressible pedal  22  makes the cleaner user-friendly when converting from cylinder-type cleaning to upright cleaning. However, the foot pedal may be replaced by some other user-operable mechanism, such as a handle, lever or catch. 
     It is possible that some users may not acknowledge the presence of the pedal or other user-operable device and may be more familiar with cleaners in which the conversion between cylinder and upright modes is effected by pushing down on the cleaner head  10  itself as the body  2  is reclined. Therefore, the support assembly  14  may be arranged so as to release the cleaner head  10  from its latched position in the event that a downward force over a predetermined limit is applied to the cleaner head. This allows the head  10  to drop down onto the floor surface for upright-type cleaning. When the main body  2  is returned to the vertical position, the support assembly re-sets itself, so that the user can subsequently recline the main body  2  in the correct manner by means of the pedal  22 . This feature prevents the cleaner head  10  from being damaged if the user tries to deploy the cleaner head in the wrong manner. 
     It is also possible that a user may misuse the appliance, or else be unaware of the operation of the support assembly, and may try to move the components manually. The support assembly  14  is arranged to be completely self-resetting when the main body  2  is returned to the vertical position. This feature ensures that the sequence of operations activated by the support assembly does not get out of synchronisation if the cleaner  1  is used incorrectly. 
     While the illustrated embodiment shows a vacuum cleaner in which ducts carry airflow, it will be appreciated that the invention can be applied to cleaners which carry other fluids, such as water and detergents. 
     Separation of dust from the airflow could equally be carried out using other means such as a conventional bag-type filter, a porous box filter, an electrostatic separator or some other form of separating apparatus. For embodiments of the apparatus which are not vacuum cleaners, the main body can house equipment which is appropriate to the task performed by the machine. For example, for a floor polishing machine the main body can house a tank for storing liquid wax 
     The brush bar  11  can be driven in other ways, such as by a turbine which is driven by incoming or exhaust airflow, or by a coupling to the motor which is also used to drive the suction fan. The coupling between the motor and brush bar can alternatively be via a geared coupling. In alternative embodiments the brush bar can be removed entirely so that the machine relies entirely on suction or by some other form of agitation of the surface. For other types of surface treating machines, the cleaner head can include appropriate means for treating the floor surface, such as a polishing pad, a liquid or wax dispensing nozzle etc. The lower face of the cleaner head can include small rollers to ease movement across a surface.