Patent Publication Number: US-10327609-B2

Title: Surface cleaning apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of co-pending U.S. application Ser. No. 14/504,776 entitled SURFACE CLEANING APPARATUS and filed on Oct. 2, 2014, now allowed, which was a continuation of U.S. application Ser. No. 12/846,144 entitled SURFACE CLEANING APPARATUS which was filed on Jul. 29, 2010 and which issued as U.S. Pat. No. 8,869,348 on Oct. 28, 2014, the entirety of which is hereby incorporated by reference. 
    
    
     FIELD 
     The specification relates to a surface cleaning apparatus and preferably an upright surface cleaning apparatus having an anti-rotation locking mechanism. The surface cleaning apparatus may also comprise an alignment mechanism. 
     INTRODUCTION 
     The following is not an admission that anything discussed below is prior art or part of the common general knowledge of persons skilled in the art. 
     Various types of surface cleaning apparatus are known. Typical upright vacuum cleaners include an upper section, including an air treatment member such as one or more cyclones and/or filters, drivingly mounted to a surface cleaning head. An up flow conduit is typically provided between the surface cleaning head and the upper section. In some such vacuum cleaners, a spine, casing or backbone extends between the surface cleaning head and the upper section for supporting the upper section. The air treatment member or members and/or the suction motor may be provided on the upper section. 
     Surface cleaning apparatus having a rotational connection between the upper section and the surface cleaning head that can be rotatably secured in position are known. U.S. Pat. No. 7,503,098 (Stein) discloses a connection arrangement between a vacuum cleaner and a suction tool that includes a pivot element pivotably connected to the suction tool and a rotation element rotatably coupled to the pivot element. A suction wand, hose, handle or other part of the vacuum cleaner is removably connected to a connection end of the rotation element. Coupling ends of the pivot and rotation elements are inserted one in the other, and respectively have circumferential grooves that form a circumferential channel therebetween. Plural partial ring segment elements are received in the circumferential channel to form a connection ring that rotatably secures the pivot and rotation elements. The ring segment elements are inserted into or removed from the channel through a selectively coverable opening in the rotation element or the pivot element. A catch cooperates with a detent to hold a vertically pivoted, rotationally centered rest position of the components. 
     SUMMARY 
     The following introduction is provided to introduce the reader to the more detailed discussion to follow. The introduction is not intended to limit or define the claims. 
     According to one broad aspect, a surface cleaning apparatus such as an upright vacuum cleaner may comprise an upper section comprising a support structure. The support structure is moveable between a storage position and an angled or declined or floor cleaning position. In the storage position the upper section preferably is in a generally upright or vertical orientation and the vacuum cleaner may be free-standing or self-supporting so that it can stand in a closet or other storage location without leaning, tipping or falling over. In addition, the upper section is rotatable relative to the surface cleaning head about a longitudinally extending axis (i.e., it may rotate about an axis extending through the upper section). The vacuum cleaner comprises an anti-rotation locking mechanism that retains the support structure in a given orientation and inhibits changes in orientation once the support structure is in the storage position. In accordance with this aspect, the anti-rotation locking mechanism is automatically engaged when the support structure is moved in the storage position by a user, and is automatically disengaged when a user moves the support structure into the floor cleaning position, allowing the user to freely change the orientation of the support structure and maneuver the vacuum cleaner during use. 
     The stability of a vacuum cleaner in the storage position may depend on the orientation of the support structure relative to the surface cleaning head. A vacuum cleaner may be stable when the support structure is in a particular orientation (for example when it is centered relative to the surface cleaning head so that the centre of gravity of the upper section lies generally above the centerline extending from the front to the back of the surface cleaning head) and may be unstable in another orientation (for example when the support structure is rotated to the left or right such that the centre of gravity of the upper section no longer overhangs the centre line). Absent a locking or securing mechanism, a support structure that is initially placed in a stable orientation may move or rotate into an unstable orientation when released by the user. Accordingly an advantage of this aspect is that the upper section will be automatically secured in a stable storage position when the upper section is moved into the storage position. Further, a user does not have to actuate a foot pedal or other lock release member to move the upper section to a floor cleaning position. A user may forget that there is a lock release that has to be actuated and may force the upper section into a floor cleaning position, thereby breaking the surface cleaning apparatus. 
     According to another broad aspect, a surface cleaning apparatus such as an upright vacuum cleaner may comprise an upper section, comprising a support structure that is moveable between a storage position and a floor cleaning position. In accordance with this aspect, the vacuum cleaner comprises an anti-rotation locking mechanism that is automatically engaged when the support structure is moved in the storage position by a user and an alignment mechanism. The alignment mechanism comprises a guiding or directing apparatus that assists to align the support structure relative to the surface cleaning head when the upper section is moved to the storage position. The alignment of the support structure may be done using a separate apparatus, or may use components that are common with the anti-rotation locking mechanism. It will be appreciated that the first aspect may optionally utilize the alignment mechanism. 
     An advantage of this aspect is that the anti-rotation locking mechanism may be damaged if the user tries to move the upper section to the storage position when the components of the anti-rotation locking mechanism are out of alignment. Further, if the anti-rotation locking mechanism is capable of locking the upper section in more then one orientation, then the upper section could be placed in the storage position with the upper section secured in an unstable orientation. The alignment mechanism would assist to ensure that the upper section is placed in the storage position in a stable orientation. 
     In any aspect, the support structure may comprise a bendable or pivotal construction that is drivingly connected to a surface cleaning head and/or a cleaning unit that is optionally removably mounted to the support structure. In some embodiments, the cleaning unit may be removed from the support structure while remaining in airflow communication with the surface cleaning head. In other embodiments, the cleaning unit may be removed from the support structure and from airflow communication with the surface cleaning head and be capable as being used as a separate cleaning unit. 
     In accordance with one aspect, there is provided an upright surface cleaning apparatus having a front, a rear and opposed lateral sides may comprise a surface cleaning head having a dirt inlet, an upper section moveably mounted to the surface cleaning head between an floor cleaning position and a storage position, an air flow path extending from the dirt inlet to a clean air outlet with a suction motor and a treatment member provided in the air flow path and, an anti-rotation locking mechanism automatically operably engaged when the upper section is moved into the storage position and automatically operably disengaged when the upper section is moved into the floor cleaning position. 
     In any embodiment, the upper section may comprise a rotational coupling member having a longitudinally extending member and the upper section is rotatably mounted about the longitudinal axis and the longitudinal axis extends through a portion of the air flow path. 
     In any embodiment the rotational coupling member may comprise a portion of the air flow path. 
     In any embodiment the rotational coupling member may comprise an up flow duct. 
     In any embodiment the suction motor and the treatment member may be provided in a cleaning unit and the cleaning unit may be removably mounted to the upper section. 
     In any embodiment the upper section may have an absence of a housing defining a recess for receiving the cleaning unit. 
     In any embodiment the cleaning unit may be useable in a first configuration wherein the cleaning unit is mounted on the upright surface cleaning apparatus and at least one additional configuration wherein the cleaning unit is removed from the upright surface cleaning apparatus and attached in air flow communication with the surface cleaning head or wherein the cleaning unit is removed from the upright surface cleaning apparatus and removed from air flow communication with the surface cleaning head and useable as a portable surface cleaning apparatus. 
     In any embodiment the upper section may be rotationally mounted to the surface cleaning head and the storage position may include a particular orientation of the upper section and the apparatus may further comprise an alignment mechanism comprising a first cooperating alignment member associated with the surface cleaning head and a second cooperating alignment member associated with the upper section, the first and second cooperating alignment members guide the upper section to the particular orientation when the upper section is moved into the storage position. 
     In any embodiment the anti-rotation locking mechanism and the alignment mechanism may utilize common components. 
     In any embodiment the anti-rotation locking mechanism may comprise a pair of spaced apart engagement members and complimentary locking members. 
     In any embodiment the spaced apart engagement members maybe provided on the lateral sides. 
     In any embodiment the engagement members may be moveably mounted and biased to a disengaged position, each engagement member having an engaging end and the engaging ends are secured together. 
     In any embodiment the engaging ends may be secured together by a connector that extends around a portion of the fluid flow path. 
     In any embodiment the connector may engage the complimentary locking members. 
     In any embodiment the anti-rotation locking mechanism may further comprise a cam member provided on the surface cleaning head and drivingly associated with the engagement member and the complimentary locking members may comprise receiving members provided on the upper section and the engagement members may be moveable longitudinally to cooperate with the receiving members. 
     In any embodiment the alignment mechanism may comprise a portion of at least one of the receiving members. 
     In any embodiment the complimentary locking members may comprise a cam member. 
     According to another broad aspect, an upright surface cleaning may have apparatus a front, a rear and opposed lateral sides and may include a surface cleaning head having a dirt inlet. The surface cleaning apparatus may include an upper section moveably mounted to the surface cleaning head between a floor cleaning position, in which the upright surface cleaning apparatus is useable for cleaning a floor, and a storage position. The upper section may be rotatably coupled to the surface cleaning head whereby rotation of the upper section relative to the surface cleaning head is enabled. A cleaning unit may be removably mounted to the upper section. The cleaning unit may include an air treatment member, a suction motor and a clean air outlet. An air flow path may extend from the dirt inlet to the clean air outlet and may include the air treatment member and the suction motor. An anti-rotation locking mechanism may inhibit rotation of the upper section when the upper section is in the storage position. The cleaning unit may be removable while the upper section is in the storage position. 
     In any embodiment, the surface cleaning apparatus may have at least two operating modes including:
         a first operating mode in which the cleaning unit is mounted to the upper section and is in airflow communication with the dirty air inlet and the flexible hose comprises a portion of the airflow path between the cleaning unit and the dirty air inlet; and   a second operating mode in which the cleaning unit is removed from the upper section and is in airflow communication with the dirty air inlet and the flexible hose comprises a portion of the airflow path between the cleaning unit and the dirty air inlet.       

     In any embodiment, when the surface cleaning apparatus is in the first operating mode the cleaning unit may be supported by the upper section. 
     In any embodiment, the upper section may be movable between the storage position and the floor cleaning position when the surface cleaning apparatus is in the first operating mode or the second operating mode. 
     In any embodiment, the surface cleaning apparatus may be changeable between the first operating mode and the second operating mode without interrupting the airflow communication between the dirty air inlet and the cleaning unit. 
     In any embodiment, the surface cleaning apparatus may be operable in a third operating mode in which the cleaning unit is detached from the upper section and is not in air flow communication with the surface cleaning head and is operable as a hand vacuum cleaner. 
     In any embodiment, the upper section may include a rigid airflow conduit, and wherein the cleaning unit may be supported on the rigid airflow conduit when mounted to the upper section. 
     In any embodiment, the cleaning unit may be vertically removable from the upper section when the upper section is in the storage position. 
     In any embodiment, the cleaning unit may be removable in the absence of adjusting a configuration of the upper section. 
     In any embodiment, the anti-rotation locking mechanism may include a first abutment member and a second abutment member spaced apart from the first abutment member. The first and second abutment members may each extend laterally outward from one of the surface cleaning head and the upper section. The other of the surface cleaning head and the upper section may include a stop member having a first stop face and a second stop face spaced apart from the first stop face, when the upper section is in the storage position the first abutment member abuts the first stop face and the second abutment member abuts the second stop face, and when the upper section is in the floor cleaning position the first abutment member is spaced apart from the first stop face and the second abutment member is spaced apart from the second stop face. 
     In any embodiment, the first and second abutment members and the stop member may include an alignment mechanism whereby contact between at least one of the abutment members and the stop member guides the upper section to a storage rotational orientation when the upper section is moved from the floor cleaning position into the storage position. 
     In any embodiment, the upper section may be rotatably coupled to the surface cleaning head by a rotational coupling member and the rotational coupling member comprises a portion of the air flow path. 
     In any embodiment, the first and second abutment members may be provided on opposed sides of the upper section and the stop member is provided on the surface cleaning head. 
     In any embodiment, the upper section may include a rotational coupling member having a longitudinally extending member that comprises a portion of the airflow path and extends along a longitudinal axis, whereby the longitudinal axis extends through a portion of the airflow path. 
     In any embodiment, the air flow path may include a flexible hose having a downstream end coupled to the cleaning unit. 
     In any embodiment, the anti-rotation locking mechanism may be operable in both the first and second operating modes. 
     In any embodiment, the air treatment member may include at least a first cyclone chamber having an air inlet, an air outlet and a dirt outlet, and at least a first dirt collection chamber in communication with the dirt outlet. 
     In any embodiment, the first dirt collection chamber may be external the first cyclone chamber. 
     In any embodiment, the first cyclone chamber may include a cyclone axis about which air within the first cyclone circulates and the first dirt collection chamber is disposed at least partially axially between the first cyclone chamber and the suction motor. 
     In any embodiment the first cooperating alignment member may comprise first and second abutment members provided on opposed sides of the upper section and the second cooperating alignment member may comprise a stop member provided on the surface cleaning head. 
     In any embodiment the stop member may comprise a cowling surrounding a portion of the upper section when the upper section is in the storage position. 
     In any embodiment the cowling may be fixedly mounted to the surface cleaning head. 
     In any embodiment the first and second abutment members may be integrally formed with a part of the upper section. 
     In any embodiment the anti-rotation locking mechanism may comprise abutment members having abutment surfaces that are fixedly mounted to the upper section and to the surface cleaning head. 
     In accordance with another aspect, there is provided, an upright surface cleaning apparatus having a front, a rear and opposed lateral sides may comprise a surface cleaning head having a dirt inlet, an upper section that is moveably mounted to the surface cleaning head between an floor cleaning position and a storage position. The surface cleaning head may be rotationally mounted to the surface cleaning head and the upper section is moveable into the storage position when the upper section is in a particular orientation. An air flow path may extend from the dirt inlet to a clean air outlet with a suction motor and a treatment member provided in the air flow path. The upright surface cleaning apparatus may also comprise an anti-rotation locking mechanism automatically that is operably engaged when the upper section is moved into the storage position and an alignment mechanism comprising a first cooperating alignment member associated with the surface cleaning head and a second cooperating alignment member associated with the upper section. The first and second cooperating alignment members may guide the upper section to the particular orientation when the upper section is moved into the storage position. 
     An embodiment in accordance with this aspect may use any one or more of the optional embodiments discussed with respect to the first aspect. 
    
    
     
       DRAWINGS 
       In the detailed description, reference will be made to the following drawings, in which: 
         FIG. 1  is a side elevation view of an upright surface cleaning apparatus; 
         FIG. 2  is a side elevation view of the upright surface cleaning apparatus of  FIG. 1  in an alternate configuration; 
         FIG. 3  is a side elevation view of the upright surface cleaning apparatus of  FIG. 1  in a further alternate configuration; 
         FIG. 4  is a front isometric view of a coupling portion of the upright surface cleaning apparatus of  FIG. 1  in a storage position; 
         FIG. 5  is a front isometric view of a coupling portion of the upright surface cleaning apparatus of  FIG. 1  in a floor cleaning position; 
         FIG. 6  is a side elevation view of the coupling portion in the orientation of  FIG. 4 ; 
         FIG. 7  is a partial section view of the coupling portion in the orientation of  FIG. 4 ; 
         FIG. 8  is a side elevation view of the coupling portion of in the orientation of  FIG. 5 ; 
         FIG. 9  is a partial section view of the coupling portion in the orientation of  FIG. 8 ; 
         FIG. 10  is an exploded view of the coupling portion of  FIG. 4 ; 
         FIG. 11  is a front isometric view of an alternate embodiment of a coupling portion in a floor cleaning position; 
         FIG. 12  is a front isometric view of the alternate embodiment of the coupling portion of  FIG. 11  in the storage position; 
         FIG. 13  is a side elevation view of the alternate embodiment of the coupling portion in the orientation of  FIG. 12 ; 
         FIG. 14  is a side elevation view of the alternate embodiment of the coupling portion in the orientation of  FIG. 11 ; and, 
         FIG. 15  is a front isometric view of the alternate embodiment of the coupling portion of  FIG. 11  in a misaligned orientation. 
     
    
    
     DESCRIPTION OF VARIOUS EXAMPLES 
     Various apparatuses or methods will be described below to provide an example of each claimed invention. No example described below limits any claimed invention and any claimed invention may cover processes or apparatuses that are not described below. The claimed inventions are not limited to apparatuses or processes having all of the features of any one apparatus or process described below or to features common to multiple or all of the apparatuses described below. It is possible that an apparatus or process described below is not an embodiment of any claimed invention. 
     The following description describes various embodiments of an upright surface cleaning apparatus, for example an upright vacuum cleaner, carpet extractor or the like. The upright surface cleaning apparatus generally comprises an upper section that is movably connected to a surface cleaning head. The upper section (also referred to as a support structure, backbone or handle) is moveable between a storage position and a floor cleaning position. Preferably, in the floor cleaning position the upper section can be pivoted and rotated relative to the surface cleaning head. When moved into the storage position, the upper section is preferably guided into a particular storage orientation, relative to the surface cleaning head, and is automatically locked in place by an anti-rotation locking mechanism. Moving the upper section from the storage position to the floor cleaning position may automatically unlock the anti-rotation locking mechanism, enabling rotation of the upper section when in use. A cleaning unit, preferably containing a suction motor and an air treatment member, is optionally removably attached to the upper section. It will be appreciated that the upright surface cleaning apparatus may be of various designs known in the art. For example, it may use various structures for the surface cleaning head and the upper section, it may use various air treatment members and may have various attachments and options known in the art. 
       FIGS. 1-3  exemplify an upright surface cleaning apparatus. In the present example the upright surface cleaning apparatus is an upright vacuum cleaner  100  comprising an upper section  110  movably connected to a surface cleaning head  120  via a coupling portion  136 . The term coupling portion  136  is used to generally describe elements of the vacuum cleaner  100  that are associated with region where the upper section  110  is joined to the surface cleaning head  120  and is not limited to any particular embodiment or assembly of parts. The coupling portion  136  may include multiple structural components or portions of both the upper section  110  and the surface cleaning head  120  as well as additional elements described in more detail below. 
     As exemplified, the surface cleaning head  120  comprises a dirt inlet  122  for sucking in dirt from the surface being cleaned and a pair of rear wheels  123 , located behind the dirt inlet  122 , for rollably engaging the surface being cleaned. In some examples, the surface cleaning head may include additional support wheels. The surface cleaning head  120  has a front end  190 , a rear end  192  and opposed lateral sides  194 ,  196  (see  FIG. 4 ). 
     The upper section  110  is movably connected to the surface cleaning head  120  such that the upper section  110  can be moved between an upright, storage position (as exemplified in  FIG. 1 ) and an angle or declined or floor cleaning position (as exemplified in  FIG. 8 ). Preferably, the upper section  110  is pivotally mounted to surface cleaning head  120 . In the present example, the upper section  110  is both pivotally and rotatably connected to the surface cleaning head  120  so that the upper section  110  can be both pivoted and rotated relative to the surface cleaning head  120  while the surface cleaning head  120  travels along a surface being cleaned (for example a floor). 
     The vacuum cleaner  100  also comprises a suction motor and an air treatment member for drawing dirty air from the floor, removing at least a portion the entrained dirt and exhausting clean (or at least relatively cleaner) air into the surrounding environment. In the present example the suction motor and treatment member are combined to within a generally self-contained cleaning unit  126 . As exemplified in  FIGS. 1-3 , the cleaning unit  126  is a removably mounted portable surface cleaning apparatus, preferably a hand vacuum cleaner, wherein the cleaning unit optionally has a nozzle that may be an open sided air flow chamber for directly engaging a surface to be cleaned. It will be appreciated that the portable surface cleaning apparatus may be of any construction and may use any particular air treatment member (e.g. one or more cyclones comprising one or more cyclonic cleaning stages and/or one or more filters). It will also be appreciated that the upper section to which the portable surface cleaning apparatus is removably attached may be of any particular design and is preferably bendable between the upper end  197  and the lower end  198  of the upright structure (e.g., about pivot  199 ). Further, the cleaning unit  126  may alternately, or in addition, include an open sided nozzle that may selectively receive an auxiliary cleaning tool (for example a flexible hose, a cleaning wand, an air powered brush apparatus, a crevice tool or any other suitable attachment or combination thereof). 
     In other examples, the cleaning unit  126  need not be a portable surface cleaning apparatus having a dirty air inlet for cleaning a surface. Instead it may be a cleaning unit  126  that is fixedly attached to the upper section  110 . For example, it may comprise a housing that houses a suction motor and one or more air treatment members (e.g., one or more cyclones with one or more filters). Such a cleaning unit does not have a dirty air inlet adapted to clean a floor. Instead, it is configured to receive dirty air conveyed from the surface cleaning head  120 , as described below. In other examples, it will be appreciated that the suction motor may be provided in the surface cleaning head. 
     Vacuum cleaner  100  also comprises a fluid flow path  128  (also referred to as an air flow path or air flow conduit) that operatively connects the dirty air inlet  122  (also referred to as a dirt inlet, an air inlet or a suction inlet) on the surface cleaning head  120  with a clean air outlet  124  (also referred to as an exhaust) downstream of the suction motor, e.g., on the cleaning unit  126 . As exemplified in  FIGS. 1-3 , the fluid flow path  128  comprises a lower flexible hose  128   a , a rigid conduit  128   b , an upper flexible hose  128   c  and a cleaning unit attachment member  128   d  that cooperate to create a continuous air flow conduit extending from the surface cleaning head  120  to the cleaning unit  126 . The fluid flow path  128  may also comprise other portions of the upper section  110 , for example the rotational coupling member  142  described below. In other examples, the fluid flow path  128  may comprise a different combination of flexible and rigid conduits or may be formed form a single type of conduit (i.e. all flexible or all rigid). 
     In accordance with a first aspect, the cleaning unit  126  is removably mounted to the upper section  110  and the upright vacuum cleaning is operable in at least two configurations and optionally in three configurations. In a first configuration the cleaning unit  126  is mounted to upper section  110 , in a second configuration the cleaning unit  126  is removed from the support structure but remains in air flow communication with the surface cleaning head  120  and in a third configuration the cleaning unit  126  is detached from the upper section  110  and does not remain in air flow communication with the surface cleaning head  120 . 
     In the first configuration, as exemplified in  FIG. 1 , the vacuum cleaner  100  can be operated with the cleaning unit  126  mounted to the lower portion of the upper section  110  using the attachment member  128   d . In this configuration the cleaning unit  126  is supported by the upper section  110  and the vacuum cleaner  100  can be operated as an upright vacuum cleaner. In some examples, a portion of the load of the cleaning unit is optionally also supported by a mount bracket  129 , which receives and supports another part of cleaning unit  126 , such as optional rear wheel of the cleaning unit  126  when the cleaning unit is a hand vacuum cleaner. 
     In a second configuration, as exemplified in  FIG. 2 , the surface cleaning unit is detached from the upper section  110  but remains in fluid communication with the surface cleaning head  120  via, e.g., flexible hose  128   c  and attachment member  128   d . In this configuration, the cleaning unit  126  may be carried by the user (or rested on the floor or other surface) while still serving as the vacuum or suction source for the vacuum cleaner  100 . 
     In a third configuration, as exemplified in  FIG. 3 , the cleaning unit  126  is detached from the upper section  110  and from fluid communication with surface cleaning head  120 . The cleaning unit  126  may have a nozzle and be a portable surface cleaning apparatus, such as a hand vacuum cleaner. As exemplified in  FIG. 3 , the cleaning unit  126  may be uncoupled from the attachment member  128   d  (which remains attached to the upper section  110 ) and can be used independently as a portable cleaning apparatus or a hand vacuum using nozzle  127  as a dirt inlet. 
     In some examples, the upper section  110  may include a housing, recess, casing or shell that surrounds at least a portion of the cleaning unit  126  when the cleaning unit  126  is mounted on the upper section  110 . In other preferred examples, as exemplified in  FIGS. 1-3 , upper section  110  has an absence of a housing defining a recess for receiving the cleaning unit  126  so that the cleaning unit  126  is not retrained within a recess (or cavity or void) in an outer housing or other portion of the upper section  110 . For example, no molded plastic shell may be provided that houses operating components of the vacuum cleaner and includes a recess for receiving the cleaning unit  126 . 
     In accordance with a second aspect, which may be used by itself or with any one or more other aspects, the upper section is rotationally mounted to the surface cleaning head and is moveable between a storage position and a floor cleaning position. The storage position includes one or more particular orientations of the support structure relative to the surface cleaning head that are stable and desirable for storage purposes. In some instances, the support structure may tend to rotate from the desired orientation into another orientation when a user releases the handle of support structure. To inhibit unwanted rotation of the support structure relative to the surface cleaning head, the upright vacuum cleaning includes an anti-rotation locking mechanism that locks (or fixes or otherwise secures) the orientation of the support structure relative to the surface cleaning head. It will be appreciated that the anti-rotation locking mechanism may secure the upper section in only one position or alternately in more than one position provided that each such position is stable. The anti-rotation locking mechanism is automatically engaged when the upper section  110  is moved to the storage position and automatically disengaged when the upper section is moved to a floor cleaning position. 
     In accordance with a third aspect, which may be used by itself or with any one or more other aspects, the upper section is rotationally mounted to the surface cleaning head and is moveable between a storage and a floor cleaning position. The storage position includes one or more particular orientations of the support structure relative to the surface cleaning head that are stable and desirable for storage purposes. To inhibit unwanted rotation of the support structure relative to the surface cleaning head, the upright vacuum cleaning includes an anti-rotation locking mechanism that locks the orientation of the support structure relative to the surface cleaning head and an alignment mechanism to guide the upper section  110  into the storage position. 
     In some examples, as exemplified in  FIG. 1 , the cleaning unit  126  may contain a majority of the mass of the vacuum cleaner  100  which can result in the centre of gravity of the entire vacuum cleaner  100  (including the mass of the upper section  110  and the cleaning unit  126 ) being located within the cleaning unit  126 . A schematic representation of the centre of gravity  130  of the vacuum cleaner  100  is illustrated in  FIG. 1  for illustrative purposes only and is not intended to precisely define the location of the centre of gravity of the vacuum cleaner  100 . The vacuum cleaner  100  also defines a pivot axis plane  132 , which is defined as the vertical plane that extends perpendicular to the horizontal axis of rotation  133  of the pivot connection between the upper section  110  and the surface cleaning head  120 . 
     In the example illustrated, when the vacuum cleaner  100  is in the storage position (as shown in  FIG. 1 ) the centre of gravity  130  of the vacuum cleaner  100  is in front of, or forward of, the pivot axis plane  132  and above the surface cleaning head  120 . In this particular orientation, the vacuum cleaner  100  is in a generally stable condition. That is, in the absence of an external force (for example a force applied by a user) the vacuum cleaner  100  will tend to stay in the storage position instead of leaning, tipping or falling toward the floor. In this example, the vacuum cleaner  100  will tend to stay in the storage position until the user applies an external force. In other examples, the centre of gravity  130  may be located on, or behind, the pivot axis plane  132 . In these examples, the upper section  110  of the vacuum cleaner  100  may tend to fall out of the storage position if not adequately secured using a pivot-locking or restraining apparatus, for example a pin, a clip, a friction fit, a foot activated lever or a resilient biasing means. If desired, any known pivot-locking apparatus may be used in any embodiment. 
     In some examples, alternately or in addition to positioning the centre of gravity  130  in a front-back position (i.e. relative to the pivot axis plane  132 ), moving the upper section  110  into the storage position may also include registering the centre of gravity  130  in the side-to-side direction (i.e. relative to a centre-line plane  134  exemplified in  FIG. 4  that is perpendicular to the pivot axis plane  132 ). Registering or orienting the centre of gravity  130  relative to the centre-line plane  134  when storing the vacuum cleaner  100  may be advantageous because if the centre of gravity  130  is outside the centre-line plane  134 , or too far from the centre line plane  134 , when the vacuum cleaner  100  is in the storage position the vacuum cleaner  100  may tend to be unbalanced or unstable and may tip over in the lateral or sideways direction. 
     A vacuum cleaner  100  that is prone to tipping over when in the storage position (forward, backward or laterally) or an upper section  110  that tends to fall from the storage position into the floor cleaning position without user intervention may pose a safety hazard and may damage itself or other items when it falls. Positioning or orienting the centre of gravity  130  within the centre-line plane  134  or a range thereof, and optionally in front of the pivot axis plane  132 , may reduce the likelihood that the vacuum cleaner  100  will tip or fall over when in the storage position. In some examples, the proper positioning of the centre of gravity  130  is achieved using an alignment mechanism described below. 
     In addition to properly locating or aligning the centre of gravity  130 , when the vacuum cleaner is in the storage position it is preferred to lock (or otherwise secure) the upper section  110  in a fixed rotational position or orientation relative to the surface cleaning head  120  so that the upper section  110  will not auto-rotate (thereby moving the centre of gravity  130  out of the centre-line plane  134 ) when placed in the storage position and released by the user. The upper section  110  is positioned in the proper rotational position by using an anti-rotation locking mechanism. With the centre of gravity  130  properly located and locked in position, as described above, the vacuum cleaner  100  may be considered stable when in its storage position and may be able to resist small impacts without tipping, for example being accidentally bumped or jostled by a user. 
     Preferably, for ease of use, the anti-rotation locking mechanism automatically engages or activates when the upper section  110  is pivoted into the storage position, and, more preferably, also automatically disengages or deactivates when the upper section  110  is pivoted into the floor cleaning position. 
     Referring to  FIGS. 4-10 , a first example of a coupling portion  136  used to connect the upper section  110  to the surface cleaning head  120  is illustrated comprising an anti-rotation locking mechanism  140 , a mounting member  141  and a rotational coupling member  142 . 
     As exemplified in  FIGS. 4-10 , to enable the desired range of movement when the vacuum cleaner  100  is in use (i.e. when the upper section  110  is in a floor cleaning position) the mounting member  141  is pivotally connected to the surface cleaning head  120  so that it can pivot about pivot axis  133  between the storage position (as illustrated in  FIG. 4 ) and a floor cleaning position (as illustrated in  FIG. 8 ). In the example illustrated in  FIGS. 4-10  the pivot axis  133  coincides with the axis of rotation of the wheels  123  of the surface cleaning head  120 . In other examples (as exemplified in  FIG. 10 ), the pivot axis  133  may be separate from the axis of rotation of the wheels  123 . The pivot connection between the upper section  110  and the surface cleaning head  120  may be any type of suitable pivot joint, including a pin joint, an axle or a bearing. 
     In addition to pivoting about the pivot axis  133 , the rotational coupling member  142  is rotatably coupled to the mounting member  141  so that the rotational coupling member  142  can rotate relative to the mounting member  141 . The rotatable connection between the rotational coupling member  142  and the mounting member  141  can be any suitable rotatable joint or coupling known by those skilled in the art. 
     In some examples the rotational coupling member  142  is a portion of the upper section  110  and is integrally formed therewith. In other examples, the rotational coupling member  142  is a separate member that is coupled or connected to a lower end of the upper section  110 . Accordingly, in some examples, elements or features described as being part of the rotation coupling member  142  may form part of the upper section  110 . 
     As exemplified in  FIGS. 4-10 , the rotational coupling member  142  comprises a longitudinally extending member  144 , an optional elbow  146  and an upper end  147  upstream from the longitudinally extending member  144 . Other examples may include elbows  146  having a greater or smaller bend, or may not include an elbow portion at all (i.e. the rotational coupling member  142  may be a straight member). Elbow  146  assists in positioning upper section at an angle forward of plane  132  (i.e., at an angle of greater than 90° from the horizontal). The rotational coupling member  142  may be a separate element from the up flow duct or may be part thereof. 
     The longitudinally extending member  144  of the rotational coupling member  142  defines a longitudinal axis  148 , about which the rotational coupling member  142  can rotate (see  FIG. 7 ). As shown in this embodiment, it is preferred that at least a portion of the longitudinal axis  148  lies within, or extends through a portion of the air flow path  128 . The longitudinally extending member  144  also comprises a hollow tube-like or pipe-like configuration having an inner diameter that is slightly larger than the outer diameter of a portion of the mounting member  141 . Accordingly, at least a portion of the mounting member  141  is telescopingly received within the longitudinally extending member  144  of the rotational coupling member  142  providing support for and allowing relative rotation of the rotational coupling member  142 . The upper end  147  is configured to be connected a portion of the upper section  110 , for example rigid conduit  128   b.    
     In the present example, the rotational coupling member  142  also comprises, and cooperates with the hollow portion of the mounting member  141  to define, an up flow conduit or up flow duct that forms part of the fluid flow path  128 . In other examples, the air flow or fluid flow path  128  may be entirely or at least partially separate from the coupling portion  136 . 
     To secure the rotational coupling member  142  (and the rest of the upper section  110  attached thereto) in the desired storage position, in which the centre of gravity  130  is properly registered, an anti-rotation locking mechanism  140  is operable to selectively fix the rotational position of the rotational coupling member  142  relative to the mounting member  141  and the surface cleaning head  120 . As exemplified in  FIGS. 4-10 , a first example of the anti-rotation locking mechanism comprises a locking ring  150 , a pair of support posts  152 , a pair of engagement members, for example locking pins  154 , that are movably received within a respective support post  152  and a pair of receiving members  156 . 
     The locking ring  150  is a generally annular ring having an internal opening that is sized and shaped to slidingly receive a portion of the mounting member  141  (and/or a portion of the rotational coupling member  142  in some examples). While the locking ring  150  is slidable relative to the mounting member  141  in the longitudinal direction (i.e. along the longitudinal axis  148 ), the locking ring  150  is also connected to the locking pins  154  received within the support posts  152 , which prevents the locking ring  150  from rotating relative to the mounting member  141 . The locking ring  150  is moveable between an engaged or locked position, shown in  FIGS. 4, 6 and 7 , and a disengaged or unlocked position, shown in  FIGS. 5, 8 and 9 . 
     While shown as being generally circular in the present example, it is understood that the locking ring  150  may be of any shape and is preferably complimentary to the mounting member  141  and/or rotational coupling member  142 . The locking ring  150  has an upper face  158 , an opposed lower face  160  and a pair of upwardly extending projections  162 , extending from its upper face  158 . In the example shown, the locking ring  150  comprises two, upward facing projections (also referred to as studs, protrusions or bosses) located on opposed sides of the vacuum cleaner  100 , e.g. that are spaced approximately 180° apart and preferably on the opposed lateral sides of the vacuum cleaner. In other examples, the locking ring  150  may comprises a greater or fewer number of upwardly extending projections and the projections may be spaced in any suitable arrangement around the periphery or edge of the locking ring. 
     In addition to sliding along the rotational coupling member  142 , the locking ring  150 , and the upward facing projections  162 , are designed to engage with complimentary locking members  168  of the receiving members  156 . In the present example, the receiving members  156  comprise portions of a generally continuous annular flange  164  that extend from the longitudinally extending member  144  (or other portion of the upper section  110 ). The annular flange  164  comprises an upper face  165 , a lower face  166  and a pair of notches  168  (also referred to as gaps, cut-outs or recesses) defined in the lower face  166  comprise the complimentary locking members. The number and location of the notches  168  formed in the lower face  166  of the receiving member  156  is preferably based on the number, size and position of the corresponding projections  162  on the locking ring  150 . In the present example, the locking ring  150  comprises two upward facing projections  162  and each receiving member  156  comprises a corresponding notch  168 . The notches  168  are sized to receive the upward facing projections  162  so that when the locking ring  150  is moved to the engaged or locked position the projections  162  are received within their respective notches  168  and the locking ring upper face  158  abuts the flange lower face  166 . 
     With the projections  162  substantially received with the notches  168 , the angular position of the rotational coupling member  142  is fixed relative to the locking ring  150  and therefore relative rotation between the rotational coupling member  142  and the mounting member  141  is inhibited. As exemplified, the notches  168  may extend through only a portion of the receiving member  156 , thereby forming a recess or blind-holes in the flange lower face  166 . In other examples, the notches  168  may have a different depth (i.e. extending more or less into the receiving member  156 ) or may comprise through-holes or apertures that extend completely through the receiving member  156 , connecting the upper and lower flange faces  165 ,  166 . 
     In the present example, the locking ring  150  is supported by two, spaced apart engagement members, the locking pins  154  that are slidably received within respective support posts  152 . The support posts  152  are pivotally connected to the surface cleaning head  120  and preferably secured to the mounting member  141  so that the angular position of the support posts  152  automatically changes with the position of the mounting member  141  as the vacuum cleaner  100  is moved from the storage position to the floor cleaning position, and vice versa. This connection between the support posts  152  and the mounting member  141  may be created using any suitable means known in the art. In one example of this connection, as best exemplified in  FIG. 10 , each support post  152  includes an integral mounting flange  171  that is connected to a complimentary landing flange  143  portion of the mounting member  141 . The mounting flanges  171  are connected to the landing flanges  143  so that they will move in unison, and both the landing flanges  143  and the mounting flanges  171  are pivotally connected to the surface cleaning head  120  using pins  121 . The mounting flanges  171  may be connected to the landing flanges  143  using a press fit, an adhesive, a mechanical fastener or any other suitable fastening means known in the art. In this example, when the coupling portion  136  is assembled, the pins  121  extend outward, beyond the mounting flanges  171  and serve as the axles that rotatably support the rear wheels  123 . In other examples, the pins  121  may be separate from the axles supporting the rear wheels  123 . 
     Each support post  152  also comprises a generally planar upper face  170  that generally opposes a portion of the locking ring lower face  160 . In use, upward movement of the locking ring  150  may be limited by the contact between the locking ring upper face  158  and the flange lower face  166 , and downward movement of the locking ring  150  may be limited by contact between the upper faces  170  of the support posts  152  and portions of the locking ring lower face  160 . 
     Each locking pin  154  (also referred to as an engagement member) is movably mounted to the surface cleaning head  120  (via support posts  152  as described above) and comprises an upper or engagement end. The engagement ends of both locking pins  154  are joined and secured together by the locking ring  150 . In other examples, the engaging ends of the locking pins  154  may be secured together by a connector other than the locking ring  150 . The locking ring maintains the alignment of the engagement end with the notches and assists to cause the locking pins  154  to move concurrently. It will be appreciated that a pair of arcuate connectors may be used or other alignment members that are provided on rotational coupling member  142  may be used. In another embodiment, a locking ring  150  may not be used and the engagement end of locking pins may directly engage notches  158 . 
     Each locking pin  154  also comprises a lower end  172  that functions as a cam follower for engaging a cam member or cam surface  174  on the surface cleaning head  120 . The support posts  152  and locking pins  154  are positioned relative to the cam surface  174  such that the lower ends  172  of the locking pins  154  are drivingly associated with the cam surfaces  174 . 
     Based on the profile of the cam surface  174 , the position of the pins  154  changes as the upper section  110  is pivoted between the storage and floor cleaning positions. In the floor cleaning position, the cam surface  174  is shaped so that the pins  154  may automatically move downward, which results in the locking ring  150  moving downward (away from the receiving member  156 ) toward the unlocked or disengaged position, as shown in  FIGS. 5, 8 and 9 . Preferably, the locking pins  154  are biased to the unlocked position as exemplified by  FIG. 9  due to gravity and/or a biasing member, such as spring  176 . When the upper section is pivoted toward the storage position the lower ends  172  of the locking pins  154  are automatically driven upward by the cam surface  174 , which results in the locking ring  150  moving upward (toward the receiving member  156 ). 
     As exemplified in  FIGS. 4-10 , the lower ends  172  of the locking pins  154  are preferably rounded or curved to enable the lower end  172  to smoothly slide along the cam surface  174 . In other examples, the lower end  172  may have sharp corners or may comprise additional rolling or sliding elements for engaging the cam surface  174 . 
     Preferably, each support post  152  also comprises a spring  176  (or any other suitable biasing means) for biasing the pins  154  downward, toward the unlocked or disengaged position. The inclusion of the springs  176  may increase the likelihood that the pins  154  and locking ring  150  automatically move from the locked position to the unlocked position when the upper section  110  is tilted from the storage position to the floor cleaning position. To facilitate the automatic engagement/disengagement of the anti-rotation locking mechanism  140 , the springs  176  exert a continuous, downward biasing force urging the locking pins  154 , and therefore the locking ring  150 , toward the unlocked position. The downward biasing force may also maintain the driving contact between the lower end  172  of the locking pin  154  and the cam surface  174  on the surface cleaning head  120 , which supplies a reaction force, opposing the biasing force of the springs  174 . When the upper section  110  is tilted from the storage position, toward the floor cleaning position, the support posts  152  pivot relative to the surface cleaning head  120  which causes the lower end  172  of the locking pins  154  to be urged downward by the spring  176  and to move forward along the cam surface  174 . The profile of the cam surface  174  is designed so that as the pin  154  moves along the cam surface  174 , the pin  154  slides downward, resulting in a corresponding downward movement of the locking ring  150 . This automatic downward movement of the locking ring  150  operatively or functionally disengages the upward facing projections  162  from their respective notches  168  which enables the relative rotation between the rotational coupling member  142  and the mounting member  141 , desired during use. It will be appreciated that cam surface  174  may be of various configurations and that pin  154  need not always contact the cam surface  174 . 
     In the present example, each spring  176  is retained at its upper end at the top, or upper end, of the support post  152  while the lower end of the spring  176  rests on a shoulder  178  formed at the connection between the lower end  172  and a narrower, neck portion of the locking pin  154 . In other examples, the spring  176 , or other biasing means, may be engage in the pin  154  and the support post  152  in any suitable manner, including adhesive connections, tabs or clips. 
     Referring to  FIGS. 11-15 , another example of a coupling portion  136 , comprising another example of an anti-rotation locking mechanism is illustrated. This example of a coupling portion may be used with the vacuum cleaner  100  to connect the upper section  110  to a surface cleaning head  120 . For clarity and ease of description, features of this example that are generally the same as features described with respect to the previous example will be denoted using the same reference numeral, while features of the present example that are analogous to, but structurally different than features of the previous example will be denoted using the references numerals from  FIGS. 1-10 , particularly  FIGS. 4-10 , indexed by 100. 
     As exemplified in  FIGS. 11-15 , the coupling portion  236  comprises a rotational coupling member  242  that is rotatably mounted on a mounting member  141 . The mounting member  241  is pivotally connected to the surface cleaning head  220 , using any method described above, so that it pivots about a pivot axis  233  between a storage position (as shown in  FIGS. 12 and 13 ) and a floor cleaning position (as shown in  FIGS. 11 and 14 ). As mentioned above, in this example the pivot axis  233  is spaced apart from the axis of rotation of the wheels  223 . Other features of the surface cleaning head  220  may also be different than the features of surface cleaning head  120 , but surface cleaning head  220  performs the same general functions as the surface cleaning head described above, and comprises wheels  223  for rolling across a surface and a dirt inlet  222  for sucking in dirt and other debris. 
     As described above, the mounting member  241  is a hollow, tube-like member that forms part of the air flow passage  128  (e.g., air flows therethrough or a hose of the like that transports air passes therethrough). The rotational coupling member  242  telescopingly receives a portion of the mounting member  241  (like rotational coupling member  142 ) and comprises a longitudinally extending member  244 , an elbow  246  and an upper end  247  that is connected to, or forms part of the upper section  110 . The longitudinally extending member  244  defines a longitudinal axis  248 , about which the rotational coupling member  242  rotates when in use. 
     As exemplified, the anti-rotation locking mechanism  240  comprises a stop member or receiving member, for example cowling  282 , and a pair of engaging members, for example abutment members  284 , each abutment member having a forward facing abutment surface. The cowling  282  is an upstanding portion of the surface cleaning head  220  (either integral with or attached to, e.g., fixedly mounted thereto by screws, welding an adhesive or the like) preferably having a curved inner surface  286  extending between and optionally terminating at a pair of spaced, rearward facing stop faces  288 . In other examples the stop faces  288  may be connected directly to the surface cleaning head  220  and/or may be separate from the cowling  282  or a cowling may not be provided. 
     If a cowling is provided, then the cowling is shaped such that the abutment members  284  may be moved forwardly to contact stop faces  288 . It will be appreciated that cowling need not be shaped to match the shape of coupling  136  provided it has a recess for coupling  136  to be received at least partially therein. The curvature of the inner surface  286  of the cowling  282  is preferably configured to match the shape, curvature and profile of the mounting member  241 , the rotational coupling member  242  and the intersection between said elements. If the coupling between the mounting member  241  and the rotational coupling member  242  results in a smooth, continuous surface having a constant diameter then the inner surface  286  of the cowling  282  may have a complimentary, smooth surface. If, as exemplified, the coupling between the mounting member  241  and the rotational coupling member  242  creates a non-uniform or stepped curved surface, the inner surface  286  of the cowling  282  may have a complimentary curved surface having the appropriate shoulders, ridges and recesses for achieving a substantially flush or uniform fit of the at least a portion of the mounting member  241  and rotational coupling member  242  within the cowling  282  when in the storage position. 
     The rearward facing edges of the cowling  282  comprise the cowling stop faces  288 . As exemplified, the stop faces  288  are generally planar edges or surfaces of the cowling  282  that serve as stops or barriers for engaging the abutment surfaces or other portions of the corresponding abutment members  284  of the rotational coupling member  242 . In other examples, the stop faces  288  of the cowling  282  may be of any suitable, complimentary profile selected to match the profile of the abutment members  284  or the abutment surfaces thereon, including having a curved surface or providing a recess for receiving a portion of a respective abutment member. 
     The rotational coupling member  242  comprises a pair of abutment members  284  spaced around its periphery, preferably at the lateral sides of the vacuum cleaner  100 , for engaging the cowling  282  when in the storage position. 
     As exemplified, the two abutment members  284  are spaced on substantially opposing lateral sides of the rotational coupling member  242 , separated by approximately 180°. In other examples, the spacing of the abutment members  284  may spacing of the abutment members may be greater or less than 180°, and the arc length subtended by the curved inner surface  286  of the cowling  282 , may be selected to match the abutment member  284  spacing, or vice versa. 
     As exemplified in  FIGS. 12 and 13 , when the upper section of the vacuum cleaner  100  is in the storage position, the rotational coupling member  242  is at least partially received within the cowling  282  and each abutment member  284  is engaged by its respective stop face  288 . In this configuration, rotation of the rotational coupling member  242  (and the upper section attached thereto) relative to the mounting member  241  is prevented by the engagement of the abutment members  284  with their respective stop faces  288 . 
     For example, rotation of the rotational coupling member  242  in the clockwise direction (when viewed in  FIG. 12 ) is prevented by the interference between the left (relative to the front-back orientation defined above) abutment member  284  and its corresponding stop face  288 . Similarly, rotation of the rotational coupling member  242  in the counter-clockwise direction is inhibited by the interference between the right abutment member  284  and its corresponding stop face  288 . This anti-rotation locking effect is created automatically when the rotational coupling member  242  is received within or seated within the cowling  282  in the storage position and is automatically disengaged or released when the rotational coupling member  242  is pivoted rearwardly into the floor cleaning position, thereby disengaging the abutment members  284  from the stop faces  288  (as shown in  FIGS. 11 and 14 ). 
     The abutment members  284  may be integrally formed with the rotational coupling member  242  or may be separate elements that are attached to the rotational coupling member  242  using known means. 
     While the anti-rotation locking mechanisms  140 ,  240  inhibit rotation of the upper section  110  of the vacuum cleaner  100  when the vacuum cleaner  100  is in the storage configuration, in some examples it may also be desirable to provide a mechanism to ensure that the upper section  110  is properly aligned with the surface cleaning head  120  (i.e. the centre of gravity  130  is in its desired position) before locking the upper section  110  in place. 
     In accordance with this aspect, which may be used by itself or with any one or more other aspects, the upper section is rotationally mounted to the surface cleaning head and is moveable between a storage position and a floor cleaning position. The storage position includes a particular orientation of the support structure relative to the surface cleaning head and the upright vacuum cleaning includes an alignment mechanism for guiding or aligning the upper section in the desired orientation. 
     Referring to  FIGS. 4-10 , a first example of an alignment mechanism  138  for guiding the upper section  110  toward a middle or centre orientation or position in which the center of gravity  130  lies in the centre-line plane  134  is provided. In this example, portions of the anti-rotation locking mechanism  140  also comprise elements of the alignment mechanism  138  on the vacuum cleaner  100 . In other examples, the anti-rotation locking mechanism  140  and the alignment mechanism  138  may be partially or completely separate. 
     As exemplified, the alignment mechanism  138  comprises the driving relationship between the upward facing projections  162  on the locking ring upper face  158  and an alignment cam surface  180  formed by a portion of the flange lower face  166 . 
     When the upper section  110  is moved toward the storage position, locking pins  154  are driven upward by cam surface  174  on the surface cleaning head  120 , which drives the locking ring  150  upward and moves the projections  162  into the notches  168  as described above. However, if the upper section  110  is not orientated properly or is not “centred” (i.e. not facing directly forward so that the centre of gravity  130  lies within the centre-line plane  134 ), then the upward facing projections  162  will not be properly aligned with their respective notches  168 . In the absence of an aligning mechanism, if the projections  162  are moved upward when not properly aligned with the notches  168 , the projections  162  would contact and interfere with a portion of the flange lower face  166 , possibly preventing the upper section  110  from fully reaching the storage position, and possibly preventing the anti-rotation locking mechanism  140  from properly engaging (i.e. the projections  162  may not enter their respective notches  168 ). 
     To help orient the upper section  110 , the vacuum cleaner  100  comprises the alignment mechanism  138 . As exemplified, the alignment mechanism  138  comprises a pair of alignment cam surfaces  180  located on opposing sides of each notch  168 . 
     Each alignment cam surface  180  extends at an angle or incline, extending generally upwardly from the flange lower face  166  toward the notch  168 . If the upper section  110  is not centred when it is pivoted toward the storage position, then when the locking ring  150  moves upward each upward facing projection  162  will contact a respective alignment cam surface  180 . As the upper section  110  is moved, the upward force applied by the locking ring  150  will increase (as the spring compression increases) and the angled nature of the alignment cam surfaces  180  will guide or urge the projections  162  upward, along the alignment cam surface  180  toward the notches  168 . Movement of the projections  162  upward, along the alignment cam surface  180  profile will cause the upper section  110  to automatically rotate toward the centered position, and will lead to the projections  162  being aligned with their respective notches  168 . Once aligned with their respective notches  168 , the rotational force exerted on the projections  162  by the alignment cam surfaces  180  will decrease while the upward force exerted by the springs  176  will urge, snap or click the projections  162  into their respective notches  168 , automatically locking the centered upper section  110  in place. 
     The length, width, slope and profile of each alignment cam surface  180  may be selected based on the size and configuration of the projections  162  and notches  168 . Also, while each pair of alignment cam surfaces  180  is shown as being symmetrical (about the notch  168 ) it is understood that in some examples, each alignment cam surface  180  may have a unique configuration. Further, only a single cam surface may be used to guide the coupling member  142  in a particular direction. 
     A second example of an alignment mechanism is exemplified in  FIGS. 11-15 . In this example, the first cooperating alignment member comprise abutment members  284  provided on opposed sides of the upper section  110  and the second cooperating alignment member comprises a stop member provided on the surface cleaning head, namely stop faces  288  In this example, abutment members  284  and stop faces  288  are also elements in the alignment mechanism  238 . As exemplified, non-uniform engagement between the abutment members  284  and the stop faces  288 , as the rotational coupling member  242  is pivoting toward the storage positions (as opposed to when it is already in the storage position as described above with respect to the anti-rotation locking mechanism), provides the alignment function of the alignment mechanism  238  and is used to ensure that the upper section  110  of the vacuum cleaner  100  is in the “centered” orientation (as defined above) when it reaches the storage position. 
     In this example, the abutment members  284  and cowling stop faces  288  are positioned symmetrically about the longitudinal axis  248 , relative to the front of the vacuum cleaner. When the upper section  110  is centered and pivoting toward the storage position, the left and right abutment members  284  engage their respective stop faces  288  at the same, or substantially the same time. However, when the upper section is not centred, one abutment member  284  will engage its stop face  288  before the second abutment member  284  engages its respective stop face  288 . 
     For example, if the upper section  110  is rotated slightly clockwise relative to its centre position when it is moved toward the storage position, (when viewed in  FIG. 11 ) the left abutment member  284  will contact the left stop face  288  before the right abutment member  284  will contact the right stop face  288 . The contact between the left abutment member  284  and stop face  288  will create a reaction force acting on the left abutment member  284  which will produce an unbalanced rotational force (or torque) on the rotational coupling member  242 . 
     This torque will lead to rotation of the rotational coupling member  242  (and the upper section attached thereto) in the counter-clockwise direction until a matching or balancing reaction force or torque is generated on the right side of the rotational coupling member  242 . In this example, a suitable balancing reaction force or torque will be created when the upper section  110  is pivoted to a position that causes engagement between the right abutment member  284  and the right stop face  288 . As the upper section is pivoted toward the storage position, the magnitude of the unbalanced reaction force may increase causing an automatic rotation or alignment of the rotational coupling member  242 . 
     In some examples, the rotational force exerted on the left abutment member  284  may lead to an over-rotation of the upper section  110  (i.e. past the centre position), leading to an upper section  110  that is misaligned and rotated slightly in the counter-clockwise direction, for example. In such examples, as the upper section  110  continues to be pivoted forward by the user, the right abutment member  284  will be positioned forward of the left abutment member  284  and will contact the right stop face  288  before the left abutment member  284  engages the left stop face  288 . An unbalanced rotational force will then be created in the clockwise direction, moving the rotational coupling member  242  toward the centred position. Alternating contact between the left and right abutment members  284  can iteratively drive the rotational coupling member  242  toward the desired, aligned orientation. 
     When the upper section  110  is properly oriented, the magnitude of the forces exerted on the left and right abutment members  284  will be substantially equal which will keep the upper section  110  in the centred position. 
     When the upper section  110  is fully pivoted into the storage position, rotation of the upper section  110  relative to the surface cleaning head  120  is inhibited by the anti-rotation locking mechanism  140 . 
     In some examples, as exemplified in  FIG. 15 , the rotational coupling member  242  may be rotated in the counter-clockwise direction to such an extent that the right abutment member  284  is rotated to a position in which it will not engage the right stop face  288  when the upper section is pivoted forward. Accordingly, the abutment member  284  will contact the curved inner surface  286  of the cowling  282 . This interference between the abutment member  284  and the inner surface  286  of the cowling  282  may prevent the rotational coupling member  242  from being properly or adequately received within the cowling  282  and may prevent the upper section  110  from reaching the storage position. In response to the interference described above, the user may pivot the upper section rearward and manually rotate the upper section to a position that is closer to the centred position and in which the abutment members  284  can engage their respective stop faces  288 . Having rotated the upper section to an appropriate position, the user may then pivot the upper section forward and utilized the auto-aligning and auto-locking features of the alignment mechanism  238  and anti-rotation locking mechanism  240 . Accordingly, this interference will warn a user that the upper section is not correctly aligned. 
     Preferably, the alignment mechanism may be configured to correct the alignment if the upper section is out of alignment by 10°, preferably by 15°, more preferably by 25° and most preferably by 40°. 
     It will be appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments or separate aspects, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment or aspect, may also be provided separately or in any suitable sub-combination. 
     Although the invention has been described in conjunction with specific embodiments thereof, if is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention.