Patent Publication Number: US-2022234055-A1

Title: Air treatment apparatus

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/594,396, filed Oct. 7, 2019, which itself claims priority from co-pending U.S. Provisional Patent Application No. 62/748,840, filed on Oct. 22, 2018, which is herein incorporated by reference in its entirety. 
    
    
     FIELD 
     The field of disclosure relates generally to surface cleaning apparatus, docking stations to empty a surface cleaning apparatus, such as a robotic surface cleaning apparatus, and also air treatment apparatus for a surface cleaning apparatus. 
     INTRODUCTION 
     Various types of robotic surface cleaning apparatus are known. Robotic vacuum cleaner may have a docking station that charges the robotic vacuum cleaner when the robotic vacuum cleaner is connected to the docking station. Also, a docking station may have means to empty a dirt collection chamber of a robotic surface cleaning apparatus. 
     In addition, surface cleaning apparatus that use a cyclonic cleaning stage that comprises a plurality of cyclones in parallel are known. 
     SUMMARY 
     In accordance with a first aspect of this disclosure, a cyclonic array for a surface cleaning apparatus or a docking station for a robotic surface cleaning apparatus comprises a plurality of cyclones is parallel. In accordance with this aspect, the cyclones (which have an axis of rotation that is at an angle to the vertical and, optionally, the axis is oriented generally horizontally) are arranged such that dirt exiting the dirt outlets of the cyclones travels directly to a dirt chamber. Accordingly, the cyclones may be of varying length or the cyclones may be staggered in the direction of the axis of rotation such that an upper cyclone positioned above a lower cyclone has an outlet that is rearward of the rear end of the lower cyclone. 
     For example, a plurality of cyclones, which are in parallel, may be oriented such that, in operation, some of the cyclones are positioned above other cyclones and the dirt outlets (which may be provided in the sidewall) of the upper cyclones are positioned so as to not overlie the lower cyclones. These cyclones may have the same length but may be staggered so that the dirt outlet end of the upper cyclones is rearward of the dirt outlet end of the lower cyclones. Alternately, or in addition, the lower cyclones may be shorter so that that the dirt outlet end of the upper cyclones is rearward of the dirt outlet end of the lower cyclones. 
     In accordance with this aspect, there is provided a cyclone array which may be used for a surface cleaning apparatus or a docking station for a robotic surface cleaning apparatus, the cyclone array having a top, a bottom and spaced apart lateral sides, the cyclone array comprising:
         (a) a plurality of cyclones arranged in parallel, the plurality of cyclones comprising a first upper cyclone and a first lower cyclone, each cyclone having a cyclone axis of rotation, a front end, an axially spaced apart rear end, an air inlet, an air outlet and a dirt outlet; and,   (b) at least one dirt collection chamber in communication with the dirt outlets, wherein, when the cyclone array is oriented with the top above the bottom, the cyclone axes extend at an angle to the vertical and at least a first upper cyclone is positioned above a first lower cyclone and the dirt outlet of the first upper cyclone is spaced axially rearwardly from the rear end of the first lower cyclone.       

     In any embodiment, a length of the first upper cyclone between the front end and the rear end of the first upper cyclone may be the same as a length of the first lower cyclone between the front end and the rear end of the first lower cyclone. 
     In any embodiment, a plane that is transverse to the cyclone axis of rotation of the first upper cyclone may be located at the front end of the first upper cyclone and the front end of the first lower cyclone may be located adjacent the plane and a length of the first upper cyclone between the front end and the rear end of the first upper cyclone may be longer than a length of the first lower cyclone between the front end and the rear end of the first lower cyclone. 
     In any embodiment, the dirt outlet of the first upper cyclone and the dirt outlet of the first lower cyclone may face a floor of a common dirt collection chamber. Optionally, the floor may comprise an openable door. 
     In any embodiment, the dirt outlet of the first upper cyclone and the dirt outlet of the first lower cyclone may be provided in a sidewall of the cyclones. 
     In any embodiment, the air inlet and the air outlet may be provided at the front end of the cyclones and the dirt outlet is provided at the rear end of the cyclones. 
     In any embodiment, when the cyclone array is oriented with the top above the bottom, the cyclone axes may extend generally horizontally. 
     In any embodiment, the plurality of cyclones may comprise a first plurality of upper cyclones and a second plurality of lower cyclones. 
     In accordance with another aspect, a docking station of a surface cleaning apparatus, such as a robotic surface cleaning apparatus is provided with a docking port that is removably connectable to the surface cleaning apparatus, an air flow path extending from the docking port to at least one air treatment member. When the surface cleaning apparatus is docked at the docking station, an air stream containing dirt collected in the surface cleaning apparatus is drawn through the docking port into the docking station where the air is treated to remove the collected dirt and a clean air stream is emitted from the docking station. The air stream may be produced by a motor and fan assembly in the surface cleaning apparatus and/or a motor and fan assembly (a suction motor) in the docking station. Accordingly, the docking station may be used to empty the surface cleaning apparatus. 
     The docking station may use one or more air treatment members. In one embodiment, the docking station uses a first stage momentum separator and a second stage cyclonic unit, which may comprise a plurality of cyclones in parallel. The cyclonic stage may be arranged with the cyclones disposed such that the cyclone axis of rotation is generally horizontal, generally vertical or at angle to the horizontal and/or vertical plane. In other embodiments, the docking station can use a first stage cyclonic unit rather than a first stage momentum separator. Accordingly, in these embodiments, the docking station can comprise two cyclonic stages. 
     In embodiments wherein the first stage comprises a momentum separator, the momentum separator may have a screen as part or all of an upper wall thereof and/or part or all of a vertical wall. In either case, a facing wall may be provided spaced from and facing the screen. Therefore, a flow channel may be provided between the screen and the facing wall. The facing wall may be spaced from the screen by 2-40, 4-25, 8-15 or 10 mm/m 3  per minute of air flow. If the flow channel extends upwardly (e.g., generally vertically) then the flow channel may define a second stage momentum separator. 
     The screen may have a surface area (flow area) that is 2-100, 10-100, 20-50 or any in between range (e.g., 5-10 or 30) times the cross sectional flow area of the docking port in a direction of flow through the docking port. 
     In any embodiment, two or more of the cyclonic stage, the momentum separator and the second stage momentum separator may be emptied concurrently (e.g., they may have a common, openable bottom door). 
     In accordance with this embodiment, there is provided an apparatus including the cyclone array wherein the apparatus has a flow path from an air inlet to an air outlet wherein air travels along an exterior of the cyclones as the air travels from the rear end of the cyclones to the air inlets at the front end of the cyclones. 
     In accordance with this embodiment, there is also provided a surface cleaning apparatus including the cyclone array. The cyclone array may be a second cyclonic cleaning stage. 
     In accordance with this embodiment, there is also provided a docking station for a robotic surface cleaning apparatus including the cyclone array. 
     In accordance with this embodiment, there is also provided an air treatment apparatus, which may be used for a surface cleaning apparatus or a docking station for a robotic surface cleaning apparatus, comprising:
         (a) an air flow path extending from an air treatment apparatus air inlet to an air treatment apparatus air outlet; and,   (b) a momentum separator positioned in the air flow path, the momentum separator having an upper wall, a lower wall and a sidewall extending between the upper and lower walls,   wherein a momentum separator air inlet is provided in an inlet portion of the sidewall, the momentum separator air inlet facing an opposed portion of the sidewall that is opposed to the inlet portion of the sidewall and the inlet portion of the sidewall comprises a side screen.       

     In any embodiment, air exiting the momentum separator air inlet may be directed generally horizontally towards the opposed portion of the sidewall. 
     In any embodiment, air exiting the momentum separator air inlet may be directed generally horizontally and downwardly towards the opposed portion of the sidewall. 
     In any embodiment, air exiting the momentum separator air inlet may be directed generally downwardly. 
     In any embodiment, the opposed portion of the sidewall may be generally planar. 
     In any embodiment, the momentum separator air inlet may have an outlet port and the outlet port may extend in a plane that is generally parallel to the opposed portion of the sidewall. 
     In any embodiment, the inlet portion of the sidewall may extend in a plane that is generally parallel to the opposed portion of the sidewall. 
     In any embodiment, the lower wall may comprise an openable door. 
     In any embodiment, the side screen may comprise a majority of the inlet portion of the sidewall. 
     In any embodiment, the side screen may comprise over 50%, over 60%, over 70%, over 80%, over 90% of the inlet portion of the sidewall. 
     In any embodiment, the upper wall may also comprise an upper screen. Optionally, the upper screen may comprise a majority of the upper wall. The upper screen may comprise over 50%, over 60%, over 70%, over 80%, over 90% of the upper wall. 
     In any embodiment, the air treatment apparatus may further comprise an end wall spaced from and facing the side screen wherein an up flow chamber is positioned between the end wall and the side screen. 
     In any embodiment, the momentum separator may have a bottom openable door. 
     In any embodiment, the up flow chamber may have a bottom openable up flow chamber door. 
     In any embodiment, the lower wall may comprise an openable momentum separator door and the momentum separator door and the up flow chamber door are concurrently openable. 
     In accordance with this embodiment, there is also provided an air treatment apparatus, which may be used for a surface cleaning apparatus or a docking station for a robotic surface cleaning apparatus, comprising:
         (a) an air flow path extending from an air treatment apparatus air inlet to an air treatment apparatus air outlet;   (b) a momentum separator positioned in the air flow path, the momentum separator having an upper wall, a lower wall, a sidewall extending between the upper and lower walls and a momentum separator air inlet, the upper wall comprises an upper screen; and,   (c) an upper end wall spaced from and facing the upper screen wherein an airflow chamber is positioned between the upper end wall and the upper screen.       

     In any embodiment, air exiting the momentum separator air inlet may be directed generally horizontally towards the sidewall. 
     In any embodiment, air exiting the momentum separator air inlet may be directed generally horizontally and downwardly towards the sidewall. 
     In any embodiment, air exiting the momentum separator air inlet may be directed generally downwardly. 
     In any embodiment, the air treatment apparatus may further comprise a deflector positioned on the upper wall. 
     The air treatment apparatus of claim  31  wherein the lower wall comprises an openable door. 
     In any embodiment, the upper screen may comprise a majority of the upper wall. The upper screen may comprise over 50%, over 60%, over 70%, over 80%, over 90% of the upper sidewall. 
     In any embodiment, the sidewall may also comprise a side screen. The sidewall may comprise first and second opposed sidewalls and the side screen comprises a majority of the first sidewall. The side screen may comprise over 50%, over 60%, over 70%, over 80%, over 90% of the first sidewall. Optionally or in addition, the air treatment apparatus may further comprise an end wall spaced from and facing the side screen wherein an up flow chamber may be positioned between the end wall and the side screen. 
     In any embodiment, the momentum separator may have a bottom openable door. 
     In any embodiment, the up flow chamber may have a bottom openable up flow chamber door. 
     In any embodiment, the lower wall may comprise an openable momentum separator door and the momentum separator door and the up flow chamber door are concurrently openable. 
     In accordance with this aspect, there is also provided a docking station for a robotic surface cleaning apparatus comprising:
         (a) a first stage air treatment chamber;   (b) a second stage cyclone array having a top, a bottom and spaced apart lateral sides, the cyclone array comprising:
           (i) a plurality of cyclones arranged in parallel, the plurality of cyclones comprising a first upper cyclone and a first lower cyclone, each cyclone having a cyclone axis of rotation, a front end having an air inlet and an air outlet and an axially spaced apart rear end having a dirt outlet; and,   (ii) at least one dirt collection chamber in communication with the dirt outlets,   
           wherein, when the cyclone array is oriented with the top above the bottom, at least a portion of a first upper cyclone is positioned above a first lower cyclone and the dirt outlets are arranged in a staggered configuration whereby dust exiting the dirt outlet of the first upper cyclone is not obstructed by the first lower cyclone.       

     In any embodiment, at least a portion of the dirt outlet of the first upper cyclone may be spaced rearwardly from the rear end of the first lower cyclone. 
     In any embodiment, a length of the first upper cyclone between the front end and the rear end of the first upper cyclone may be the same as a length of the first lower cyclone between the front end and the rear end of the first lower cyclone. 
     In any embodiment, a plane that is transverse to the cyclone axis of rotation of the first upper cyclone may be located at the front end of the first upper cyclone and the front end of the first lower cyclone may be located adjacent the plane and a length of the first upper cyclone between the front end and the rear end of the first upper cyclone may be longer than a length of the first lower cyclone between the front end and the rear end of the first lower cyclone. 
     In any embodiment, when the cyclone array is oriented with the top above the bottom, the cyclone axes may extend at an angle to the vertical, e.g., at about a 45° to the vertical. 
     In any embodiment, the plurality of cyclones may comprise a first plurality of upper cyclones and a second plurality of lower cyclones. Optionally, the plurality of cyclones may comprise a first plurality of upper cyclones and a second plurality of lower cyclones. 
     In any embodiment, the dirt outlet of the first upper cyclone and the dirt outlet of the first lower cyclone may face a floor of a common dirt collection chamber. Optionally, the floor may comprise an openable door. 
     In any embodiment, the at least one dirt collection chamber may comprise a single common dirt collection chamber and dirt exiting the dirt outlet of the first upper cyclone and dirt exiting the dirt outlet of the first lower cyclone may travel downwardly to a floor of the common dirt collection chamber. Optionally the floor may comprise an openable door. 
     In any embodiment, dirt exiting the dirt outlet of the first upper cyclone and dirt exiting the dirt outlet of the first lower cyclone may travel downwardly to an openable floor of the at least one dirt collection chamber. 
     In any embodiment, the dirt outlet of the first upper cyclone and the dirt outlet of the first lower cyclone may be provided in a sidewall of the cyclones. 
     In any embodiment, when the cyclone array is oriented with the top above the bottom, the cyclone axes may extend generally horizontally. 
     In any embodiment, air exiting the cyclones may travel downwardly. 
     In any embodiment, the first stage air treatment chamber may have a dirt collection region with an openable bottom door. 
     In any embodiment, the first stage air treatment chamber may have a dirt collection region with an openable bottom door. 
     In any embodiment, the at least one dirt collection chamber may have an openable bottom door and the bottom openable door of the at least one dirt collection chamber may be concurrently openable with the bottom openable door of the first stage air treatment chamber. 
     In any embodiment, when the cyclone array is oriented with the top above the bottom, the dirt outlet of the first upper cyclone may be positioned above the dirt outlet of the first lower cyclone. 
    
    
     
       DRAWINGS 
       The drawings included herewith are for illustrating various examples of articles, methods, and apparatuses of the teaching of the present specification and are not intended to limit the scope of what is taught in any way. 
       In the drawings: 
         FIG. 1  is a front perspective view of one embodiment of an air treatment apparatus; 
         FIG. 2  is a side cross-sectional view along line  2 - 2 ′ in  FIG. 1  of the air treatment apparatus of  FIG. 1 ; 
         FIG. 3  is a perspective side cross-sectional view along line  2 - 2 ′ in  FIG. 1  of the air treatment apparatus of  FIG. 1 ; 
         FIG. 4A  is a side cross-sectional view along line  2 - 2 ′ in  FIG. 1  of a momentum separator located inside of the air treatment apparatus of  FIG. 1 , according to some embodiments; 
         FIG. 4B  is a side cross-sectional view along line  2 - 2 ′ in  FIG. 1  of the momentum separator according to some other embodiments; 
         FIG. 4C  is a side cross-sectional view along line  2 - 2 ′ in  FIG. 1  of the momentum separator according to still other embodiments; 
         FIG. 5  is a perspective view of the momentum separator of  FIG. 3 ; 
         FIG. 6  is another perspective view of the momentum separator according to an example embodiment; 
         FIG. 7A  is a schematic, side cross-sectional view along line  2 - 2 ′ in  FIG. 1  of the momentum separator according to another example embodiment; 
         FIG. 7B  is a schematic, perspective view of the momentum separator of  FIG. 7A ; 
         FIG. 7C  is a schematic, perspective view of the momentum separator according to still yet another example embodiment; 
         FIG. 8  is a side perspective view of the air treatment apparatus of  FIG. 1 , showing a lower wall of the air treatment apparatus being removed; 
         FIG. 9  is a perspective view from below of the air treatment apparatus of  FIG. 1 , 
         FIG. 10  is a schematic, perspective view of a housing body for the momentum separator according to an alternative example embodiment; 
         FIG. 11  is a top-down cross-sectional view along line  11 - 11 ′ in  FIG. 3  of the air treatment apparatus of  FIG. 1 ; 
         FIG. 12  is a side perspective view of a cyclone array located inside of the air treatment apparatus of  FIG. 1 , according to an example embodiment; 
         FIG. 13  is a rear perspective view of the cyclone array of  FIG. 12 ; 
         FIG. 14  is a rear perspective cross-sectional view along line  14 - 14 ′ in  FIG. 12  of the cyclone array of  FIG. 12 ; 
         FIG. 15  is a front perspective cross-sectional view along line  15 - 15 ′ in  FIG. 1  of the air treatment apparatus of  FIG. 1 ; 
         FIG. 16A  is a perspective side cross-sectional view along line  2 - 2 ′ in  FIG. 1  of the cyclone array of  FIG. 12 ; 
         FIG. 16B  is a partially cut away rear perspective view of the cyclone array of  FIG. 12 ; 
         FIG. 16C  is a vertical cross-sectional view along line  14 - 14  in  FIG. 12  from the rear of the cyclone array of  FIG. 12 ; 
         FIG. 17  is a bottom-up cross-sectional view along line  17 - 17 ′ in  FIG. 13  of the cyclone array of  FIG. 12 ; 
         FIG. 18  is a perspective view of another embodiment of the air treatment apparatus; 
         FIG. 19  is a side cross-sectional view along line  19 - 19 ′ in  FIG. 18  of the air treatment apparatus of  FIG. 18 ; 
         FIG. 20  is a side perspective cross-sectional view along line  19 - 19 ′ in  FIG. 18  of the air treatment apparatus of  FIG. 18 ; 
         FIG. 21  is another side perspective cross-sectional view along line  19 - 19 ′ in  FIG. 18  of the air treatment apparatus of  FIG. 18 ; 
         FIG. 22  is a bottom-up perspective cross-sectional view along line  22 - 22 ′ in  FIG. 18  of the air treatment apparatus of  FIG. 18 ; 
         FIG. 23  is a side perspective view of the air treatment apparatus of  FIG. 18  with a bottom wall of the air treatment apparatus being removed; 
         FIG. 24  is bottom-up perspective view of the air treatment apparatus of  FIG. 18 ; 
         FIG. 25  is a perspective view of the air treatment apparatus of  FIG. 18  showing a top lid and a top screen of the air treatment apparatus being removed; 
         FIG. 26  is a perspective view of a cyclone array of the air treatment apparatus of  FIG. 18 ; 
         FIG. 27  is a cross-sectional view along line  27 - 27 ′ in  FIG. 26  of the cyclone array of  FIG. 26 ; 
         FIG. 28  is a partially exploded view of the air treatment apparatus of  FIG. 18 . 
         FIG. 29  is a rear vertical cross-sectional view of a cyclone array according to an alternative example embodiment; 
         FIG. 30  is a side cross-sectional view of the cyclone array of  FIG. 29  along the section line  30 - 30 ′ of  FIG. 29 ; 
         FIG. 31  is a side cross-sectional view of an alternate cyclone array of the configuration of  FIG. 29 ; 
         FIG. 32A  is a side elevation view of another embodiment of the air treatment apparatus with a bottom door in an open configuration; 
         FIG. 32B  is a cross-sectional view along line  32 B- 32 B′ in  FIG. 32A  of the air treatment apparatus of  FIG. 32A  with the bottom door in a closed configuration; 
         FIG. 32C  is a cross-sectional view along line  32 C- 32 C′ in  FIG. 32A  of the air treatment apparatus of  FIG. 32A  with the bottom door in the closed configuration; 
         FIG. 32D  is a cross-sectional view along line  32 B- 32 B′ in  FIG. 32A  of the air treatment apparatus of  FIG. 32A  with the bottom door in the open configuration; 
         FIG. 33A  is a cross-sectional view along line  32 B- 32 B′ in  FIG. 32A  of the air treatment apparatus of  FIG. 32A  according to another example embodiment; and, 
         FIG. 33B  is a cross-sectional view along line  33 B- 33 B′ in  FIG. 33A  of the air treatment apparatus of  FIG. 33A . 
     
    
    
     DESCRIPTION OF VARIOUS EMBODIMENTS 
     Various apparatuses or processes will be described below to provide an example of an embodiment of each claimed invention. No embodiment described below limits any claimed invention and any claimed invention may cover processes or apparatuses that differ from those 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. Any invention disclosed in an apparatus or process described below that is not claimed in this document may be the subject matter of another protective instrument, for example, a continuing patent application, and the applicants, inventors or owners do not intend to abandon, disclaim or dedicate to the public any such invention by its disclosure in this document. 
     The terms “an embodiment,” “embodiment,” “embodiments,” “the embodiment,” “the embodiments,” “one or more embodiments,” “some embodiments,” and “one embodiment” mean “one or more (but not all) embodiments of the present invention(s),” unless expressly specified otherwise. 
     The terms “including,” “comprising” and variations thereof mean “including but not limited to,” unless expressly specified otherwise. A listing of items does not imply that any or all of the items are mutually exclusive, unless expressly specified otherwise. The terms “a,” “an” and “the” mean “one or more,” unless expressly specified otherwise. 
     As used herein and in the claims, two or more parts are said to be “coupled”, “connected”, “attached”, or “fastened” where the parts are joined or operate together either directly or indirectly (i.e., through one or more intermediate parts), so long as a link occurs. As used herein and in the claims, two or more parts are said to be “directly coupled”, “directly connected”, “directly attached”, or “directly fastened” where the parts are connected in physical contact with each other. As used herein, two or more parts are said to be “rigidly coupled”, “rigidly connected”, “rigidly attached”, or “rigidly fastened” where the parts are coupled so as to move as one while maintaining a constant orientation relative to each other. None of the terms “coupled”, “connected”, “attached”, and “fastened” distinguish the manner in which two or more parts are joined together. 
     Some elements herein may be identified by a part number, which is composed of a base number followed by an alphabetical or subscript-numerical suffix (e.g.  112   a , or  112   1 ). Multiple elements herein may be identified by part numbers that share a base number in common and that differ by their suffixes (e.g.  112   1 ,  112   2 , and  112   3 ). All elements with a common base number may be referred to collectively or generically using the base number without a suffix (e.g.  112 ). 
     In embodiments described herein, there is provided an air treatment apparatus. The air treatment apparatus may be used in combination with a surface cleaning apparatus, such as a hard floor cleaning apparatus and/or a vacuum cleaner e.g., an upright surface cleaning apparatus, a canister surface cleaning apparatus, a robotic surface cleaning apparatus, a hand vac, a stick vac and/or an extractor). For example, in at least some embodiments, the air treatment apparatus can be used as a “docking station” to facilitate quick emptying of a surface cleaning apparatus from dust or debris that has collected therein during cleaning operation. 
     In the example applications described herein, the air treatment apparatus may be used as a “docking station” for a robotic surface cleaning device. In particular, an air inlet (docking port) of the air treatment apparatus may be removably coupleable to a port or outlet of the robotic cleaning device. The port or outlet may be, for example, in fluid communication with a dust collecting chamber of the robotic device. A motor and fan assembly drives the flow of air through the air inlet and into the air treatment apparatus. As air is drawn into the air inlet of the air treatment apparatus, debris located inside of the dust collecting chamber is drawn out of the dust collecting chamber and transferred with the air stream into the air treatment apparatus. The air treatment apparatus may accordingly proceed to treat the incoming stream of air to separate dust and debris therefrom. Once some or all of the dust has been transferred out of the robotic device, the air treatment apparatus may be independently cleaned-out. In this manner, the air treatment apparatus facilitates safe and fast emptying of the robotic surface cleaning device without requiring dismantlement (or opening) of the robotic device each time it is desired to empty out dust and debris. 
     General Description of a Robot Docking Station 
     Referring now to  FIGS. 1 to 3 , a first embodiment of an air treatment apparatus  100  is illustrated. As shown, the air treatment apparatus  100  may include a housing body  104 , an air treatment apparatus air inlet  108  (also referred to as a dirty air inlet  108 ), and an air treatment apparatus air outlet  112  (referred to as a clean air outlet  112 ). The air treatment apparatus air inlet  108  may be the inlet of a docking station or may be downstream thereof. For example, if the air treatment apparatus  100  is removable from the docking station for emptying, then the air treatment apparatus air inlet  108  may be the inlet of a docking station. 
     The air treatment apparatus air inlet  108  is configured to accommodate an incoming stream of dirty air that includes, for example, coarse and fine dust, solid debris as well as other air-borne containments. Airflow received by the air inlet  108  travels into the air treatment apparatus  100  and passes through one or more separating stages that are configured to separate the flow of air from the air-borne containments. Relatively cleaner may then exit the air treatment apparatus  100  through the air outlet  112 . In at least some embodiments, a suction device (i.e., suction motor) may connect to the air outlet  112  and may generate a suction force to drive the flow of air between the air inlet  108  and the air outlet  112  (e.g., suction motor  324  of  FIG. 18 ). 
     Referring to  FIG. 1 , the air inlet  108  may optionally fluidly connect to the air treatment apparatus  100  via an inlet conduit  116 . The inlet conduit  116  may extend at a distance from the air treatment housing body  104  to allow a surface cleaning apparatus to “dock” at the air treatment apparatus  100  from a distance. For example, a robotic cleaning device may dock at the air treatment apparatus  100  without necessarily being in abutting engagement with the apparatus  100 . 
     The air treatment apparatus air outlet  112  may also fluidly connect to the air treatment apparatus  100  via an air outlet conduit  120 . Alternately, the air outlet conduit  120  may extend from the housing body  104  to allow other devices (i.e., a suction motor) to couple to the air outlet  112  at a spaced distance (e.g., it may be connected to a conduit similar to the conduits used for a built in vacuum system such that the air outlet is exterior to the dwelling). For instance, as exemplified in  FIG. 18 , the air outlet conduit  120  may extend from the housing body  104  to connect to suction motor  324 . Alternately, air treatment apparatus  100  may include a suction motor and the outlet  112  may be a clean air outlet. For example, a suction motor may be included in air treatment apparatus  100  of  FIG. 33A . 
     As exemplified in  FIGS. 2 and 3 , the inlet conduit  116  may extend into the housing body  104  along an inlet conduit axis  140  between an upstream end  144  and a downstream end  148 . The downstream end  148  includes an outlet port  152 , which is in fluid communication with a separator which may be a first stage separator  124  with a second stage separator  132  (e.g., one or more cyclones) downstream thereof. Accordingly, the first stage separator  124  is positioned in the flow path to receive dirty air travelling upwardly through the inlet conduit  116  and exiting through the outlet port  152 . As exemplified in  FIG. 32B , a transverse passage  530  may be positioned below handle  532  and above the first stage separator  124  and the second stage separator  132 . 
     Optional Air Treatment Members for a Docking Station 
     As exemplified in  FIGS. 2 and 3 , air treatment apparatus  100  may include a first stage separator  124 , and a second stage separator  132  positioned in the airflow path downstream from the first stage separator  132 . In the exemplified embodiments of  FIGS. 2-28 , the first stage separator  124  comprises a momentum separator  128 , and the second stage separator  132  comprises a cyclone array  136 . The momentum separator  128  and the cyclone array  136  may be both located within the housing body  104  of the air treatment apparatus  100 . Alternatively, as exemplified in  FIGS. 32A-32D  and  FIGS. 33A-33B , the air treatment member  100  may include a first stage separator  124  comprising a cyclone  502 , and the second stage separator  132  may comprise the cyclone array  136 . Accordingly, the first stage separator  124  can comprise a first cyclonic stage, and the second stage separator  132  can comprise a second cyclonic stage. 
     It will be appreciated that each of the momentum separator and/or cyclone in the first stage separator, and the cyclone array  136  in the second stage separator, as disclosed herein, may be used by itself (e.g., in a surface cleaning apparatus). It will also be appreciated that the momentum separator and/or the cyclone, and the cyclone array may be used in the same surface cleaning apparatus. In some embodiments, the air treatment apparatus can include one or more of the momentum separator, cyclone and cyclone array. 
     Momentum Separator 
     The following is a description of momentum separators that may be used in a docking station as exemplified herein (alone or in combination with one or more other air treatment members), or which may be used by themselves or in combination with one or more other air treatment members in a surface cleaning apparatus. The other air treatment member may be a cyclonic array as discussed subsequently. 
     Referring to  FIGS. 2-6 , which exemplify an embodiment of a momentum separator  128  which can be used as a first stage separator  124  in the air treatment apparatus  100 . 
     As exemplified, the momentum separator  128  may comprise a momentum separator chamber  154  which is bounded by an upper wall  156  (also referred to as top wall  156 ), a lower wall  160  (also referred to as a bottom wall  160 ), a sidewall  164  which extends between the upper wall  156  and the lower wall  160 , and an end wall  172  that extends between a top portion  174  (or a top wall  174 ) of the housing body  104  and the lower wall  160  of the momentum separator  128 . The momentum separator chamber  154  is also bounded, on either side, by lateral walls  178  that extend laterally between the sidewall  164  and the end wall  172  of the housing body  104 , as well as vertically between the top housing wall  174  and the bottom wall  160  of the momentum separator. In this example, the end wall  172  faces and is distally opposed from the sidewall  164 . It will be appreciated that several of the walls may form part of the housing body  104 . In this example, lateral walls  178  and end wall  172  form part of housing body  104 . 
     As exemplified, one or more walls of the momentum separator chamber  154  may comprise porous walls, e.g., part or all of one or more of the walls may be partially or fully porous. The porous wall or porous section of a wall is configured to have openings and to be generally air permeable such that air may exit the momentum separator  128  by flowing outwardly through the openings in the porous wall or porous section. The porous wall or porous section may comprise, for example, a screen, a mesh, a net, a shroud, or any other air permeable medium that is configured to pass air flow, while separating (or filtering) the air flow from dust, dirt and other solid debris. The openings in the porous wall may be selected to inhibit dirt of a predetermined size from exiting the momentum separator. 
     In at least some embodiments, the porous section of a wall may comprise a majority of a wall. For example, the porous portion of a wall may have a surface area that is between 40-100%, 50-100%, 60-100%, 70-100%, 80-1200% or 90-100%, or anywhere in between, of the total surface area of the porous wall. 
     The surface area of the porous portion(s) that define the air exit of the momentum separator may also be expressed relative to the opening area of a momentum separator air inlet  182 . For example, in some cases the one or more porous wall sections may have a surface area (screen area) that is 2-100, 10-100, 20-50 or any in between range (e.g., 5-10 or 30) times the opening area of the momentum separator air inlet  182  (i.e., the cross-section area of the inlet  182  in a direction transverse to the direction of air flow through the inlet  182 ). An advantage of using a larger porous portion(s) area is that the greater surface area for air to exit the momentum separator  128  produces a reduced flow rate of air through the porous portion(s), thereby reducing the likelihood that dirt may get pushed through the porous portion(s), which would reduce the separation efficiency of the momentum separator. Accordingly, this can facilitate the filtering of dust, dirt and other air-borne containments from the exiting air stream. 
     Another advantage of using a large air exit is to avoid generating a wind tunnel like effect as air exits the momentum separator  128 . In particular, where a large volume of air exits the momentum separator  128  through a small porous portion, the air flow may experience a sudden increase in flow velocity, which results in air-borne containments being less likely to become separated from the exiting stream of air and to therefore clog the openings. 
     The momentum separator  128  may include any number of porous walls, or walls which include porous sections. For instance,  FIGS. 2-6  exemplify an embodiment of the momentum separator  128  in which the sidewall  164  of the momentum separator has a porous section defined by a side screen  176 . The side screen  176  provides an outlet for air which enters via outlet port  152  to exit from the momentum separator (see arrow A in FIG.  3 ). Dust particles, which do not pass through the side screen  176 , may collect on the lower wall  160  of the momentum separator  128 . 
     Optionally, in addition or in alternative to the side screen  176 , the upper wall  156  of the momentum separator  128  may also comprise a porous wall and may include a top screen  180  which is generally air permeable. Accordingly, air can exit the momentum separator  128  by flowing upwardly and outwardly through the top screen  180 . 
     An advantage of using the combination of a top screen  180  and a side screen  176  is that an even larger surface area is provided for air to exit the momentum separator  128 . Accordingly, this generates a further reduction in the velocity of the outgoing air stream, which in turn, facilitates the separation of dust and debris from the stream of air. In at least some embodiments, including both the top screen  180  and the side screen  176  can reduce outgoing airflow velocity by as much as 50% as compared to using only the side screen  176 . 
       FIGS. 19-22  exemplify a further embodiment wherein only the upper wall  156  of the momentum separator  128  include a porous section (e.g., a top screen  180 ). 
       FIGS. 7A-7B  exemplify a further alternative embodiment in which the momentum separator includes one or more screens (or porous sections) that are recessed from the momentum separator chamber walls. In this embodiment, the momentum separator  128  includes an end screen  158 , as well as lateral screens  186 . An advantage of this configuration is that air flow may exit through five different screens. Again, this may ensure that the velocity of the exiting air stream is minimized, which in turn, helps the dis-entrainment of air borne contaminants. 
       FIG. 7C  shows still a further alternative embodiment wherein air, incoming into the momentum separator  128 , is bounded by screens from each side (i.e.,  6  screens in total). The screens may be, for example, suspended inside of the momentum separator chamber. This configuration maximizes the surface area available for air to exit the momentum separator  128 . Accordingly, the velocity of the air exiting the momentum separator  128  is reduced to a minimum, which generates optimal conditions for separation of air-borne dust and dirt. 
     It will be appreciated that the configurations illustrated in  FIGS. 2-6, 7A-7C , and  19 - 22  have only been provided herein by way of example. In other embodiments, the momentum separator  128  may include any number or arrangement of porous wall sections and/or screens. 
     Referring now back to  FIGS. 2-3 and 9 , wherein the porous wall section is provided on a sidewall (e.g., side screen  176 ), an up flow chamber  188  can be provided for air exiting the momentum separator  128 , through the side screen  176 . The up flow chamber  188  is positioned between the side screen  176  and an end wall  192  (otherwise known as a blocking or facing wall) of the air treatment apparatus  100 . Air entering the up flow chamber  188  flows upwardly in a plane parallel to the inlet conduit axis  140 . In embodiments wherein the air treatment apparatus  100  includes a second stage separator  132 , air that is carried through the upflow chamber  188  may flow downstream to the second stage separator  132 . In this manner, the up flow chamber  188  acts as a conduit between the first stage separator  124  and the second stage separator  132 . It will be appreciated that in other embodiments, chamber  188  may be oriented other than vertically. 
     As exemplified in  FIG. 11 , the end wall  192  may be laterally spaced from, and facing, the side screen  176  to form the up flow chamber  188 . More specifically, a lateral spacing distance  196  separates the end wall  192  from the side screen  176 . The lateral spacing distance  196  can be configured to be any suitable distance. In various embodiments, the lateral spacing distance  196  can be 2-40, 4-25, 8-15 or 10 mm/m 3  per minute of airflow. An advantage of using a smaller (or narrower) lateral spacing distance  196  is that a wind tunnel-like effect is generated inside the up flow chamber  188 . Accordingly, air entering the up flow chamber  188  may travel with increased speed downstream to the second stage separator  132 . Alternatively, an advantage of using a larger (or widened) spacing distance  196  is that air entering the up flow chamber  188  may experience a reduction in velocity, which in turn, facilitates the separation of dust and other air borne debris from the incoming air stream, thereby allowing the passage to function as a momentum separator. Accordingly, the passage may comprise a second stage momentum separator and, in such a case, the momentum separator  128  may be considered a first stage or primary momentum separator. Also, in such an embodiment, chamber  188  may extend generally vertically to enable separated dirt to fall downwardly under the influence of gravity to collect on the bottom wall or floor of the chamber  188 . 
     In embodiments wherein the upper wall  156  of the momentum separator  128  includes a top screen  180 , air exiting through the top screen  180  may also flow into a side-flow chamber  208 . As exemplified in  FIGS. 6 and 19 , the side-flow chamber  208  may be positioned between the top screen  180 , the upper end wall (or upper portion)  174  of the housing body  104 , and the end wall  172  of the housing body  104 . Air entering the side flow chamber  208  deflects off of the upper wall  174  and the end wall  172  and is directed laterally towards a further downstream air treatment member. 
     In various cases, as best exemplified by  FIG. 6 , the upper wall  174  of the housing body  104  faces, and is vertically spaced from, the top screen  180  by a vertical spacing distance  212  to form the side-flow chamber  208 . Similar to the lateral spacing distance  196 , the vertical spacing distance  212  can be any suitable distance, such as 2-40, 4-25, 8-15 or 10 mm/m 3  per minute of airflow. A smaller vertical spacing distance  212  may tend to induce a wind tunnel like effect that results in an increase in airflow velocity inside of the side-flow chamber  208 . Conversely, a wider (or larger) vertical spacing distance  212  may induce a reduction in air stream velocity, which in turn, may help separate particles of dust and dirt from the airflow. 
     Referring to  FIG. 10 , there is shown an alternative embodiment of a portion of the housing body  104  that surrounds the momentum separator  128 . In this example, the housing body  104  includes rounded edges or corners  162 , which facilitate smoother flow of air inside side-flow chamber  208 . 
     Momentum Separator with a Generally Horizontal Air Inlet 
     Optionally, as exemplified in  FIGS. 2-6 , a momentum separator as discussed herein may have a momentum separator air inlet  182  that directs an air flow to enter the momentum separator generally horizontally. Alternately, or in addition, the momentum separator air inlet  182  may be provided external to the momentum separator chamber  154 . Accordingly, as exemplified in  FIGS. 2-6 , momentum separator air inlet  182  may be provided in an upwardly extending sidewall that provides all or part of the air outlet of the momentum separator (e.g., part or all of sidewall  164  may be a screen  176 ). 
     The momentum separator may be used in a surface cleaning apparatus, such as a robotic surface cleaning apparatus or a hand vac. The momentum separator may use any of the features and/or dimensions of momentum separator  128  and is also exemplified herein as part of a docking station. 
     As the air stream enters momentum separator chamber  154 , the velocity of the air stream may decrease and entrained dirt will fall towards the bottom of the momentum separator chamber  154 . 
     Optionally, the wall opposed to the wall having the momentum separator air inlet  182  (e.g., end wall  172 ) may be solid. Therefore, air entering the momentum separator chamber  154  cannot continue in a generally linear direction but must change direction and exit the momentum separator chamber  154  on the same side as it entered the momentum separator chamber  154 . Accordingly, the air stream will undergo a 180° change in direction that will further enhance the extent to which entrained dirt will become dis-entrained. 
     As exemplified in  FIG. 3 , the sidewall  164  includes an inlet portion  168 . The inlet portion  168  includes a momentum separator air inlet  182 , which is configured to receive air from the inlet conduit  116 . In the illustrated embodiment, the momentum separator air inlet  182  is the same as the outlet port  152  of the inlet conduit  116 . In other embodiments, the outlet port  152  may be separate from the momentum separator air inlet  182 , for example if an upstream air treatment member is provided. 
     The momentum separator air inlet  182  is optionally situated at an elevated section of the inlet portion  168  along the sidewall  164  (e.g., above the midpoint, in the upper third, or in the upper quarter of the sidewall  164 ). Accordingly, air enters into the momentum separator  128  from a raised position above any dirt that may have collected in the momentum separator chamber  154  (provided the momentum separator chamber  154  has been emptied when a fill line has been reached) and will therefore tend to not re-entrain dirt that has already been collected. Upon entry to the momentum separator chamber  154 , the air stream will experience a reduction in velocity, which facilitates the separation of air borne dust and dirt from the airflow. In various embodiments, air entering the momentum separator  128  may experience a reduction of velocity by as much as 25 to 100 times the original velocity of the air as it exits the outlet port  152  and/or the momentum separator air inlet  182 . Dust and dirt, which becomes dis-entrained from the airflow inside of the momentum separator  128 , i.e., as a result of the velocity reduction, may collect on top of the lower wall  160  of the momentum separator  128 . 
     In the example embodiment shown in  FIGS. 2 and 3 , the downstream end  148  of the inlet conduit  116  is curved to re-direct airflow, into the momentum separator chamber  154 , in a generally horizontal direction towards the end wall  172  of the housing body  104 . To this end, the momentum separator air inlet  182  may extend in a plane that is generally parallel to the end wall  172 . 
       FIG. 4A  shows an alternative embodiment of the downstream end  148 . In this embodiment, rather than being curved, the downstream end  148  is configured with a sharp right degree angle. An advantage of this configuration is that the airflow experiences an abrupt change in direction, which may result in a further reduction in airflow velocity. The reduction in airflow velocity may facilitate separation of air-borne dust and debris from the air stream. 
       FIG. 4B  shows a further alternative embodiment for the downstream end  148 . In this case, the downstream end  148  is downwardly sloped and is configured to re-direct air into the momentum separator  128  in a generally horizontal and downward direction, i.e., towards the mid or lower portion of end wall  172 . In this embodiment, the airflow experiences an even more abrupt change in flow direction, which, accordingly, may result in a further reduction in the air stream velocity. This may again help to facilitate the separation of air-borne dust and debris from the airflow. 
       FIG. 4C  shows still yet a further alternative embodiment for the downstream end  148 . In this alternative embodiment, the downstream end  148  is now increasingly downwardly sloped and is configured to re-direct air in a generally downward direction. As such, the air stream experiences yet a more extreme reduction in flow velocity, which may further facilitate the process of dis-entraining air-borne dust and debris therefrom. 
     In other embodiment not shown, the downstream end  148  may be configured to re-direct air entering the momentum separator  128  in any one of a number of other suitable directions (for example, generally horizontally and upwardly, etc.) 
     Momentum Separator with a Vertical Air Inlet 
     Optionally, as exemplified in  FIGS. 19-28 , a momentum separator as discussed herein may have a momentum separator air inlet  182  that directs an air flow to enter the momentum separator generally vertically. Alternately, or in addition, the momentum separator air inlet  182  may be provided internal to the momentum separator chamber  154 . 
     The momentum separator may be used in a surface cleaning apparatus, such as a robotic surface cleaning apparatus or a hand vac. The momentum separator may use any of the features and/or dimensions of momentum separator  128  and is also exemplified herein as part of a docking station. 
     As exemplified in  FIGS. 19-28 , optionally, the inlet conduit  116  may extend upwardly and in a generally vertical direction, along inlet conduit axis  140 , and at least partially into the momentum separator  128 . In this configuration, air may exit the conduit  116 , via the outlet port  182 , in a generally upward or vertical direction. In other cases, the inlet conduit outlet port  356  may be configured to direct the dirty air into the momentum separator chamber  360  in any suitable direction 
     As further exemplified, optionally, if the air exits outlet port  182  vertically or generally vertically, then a deflecting member (or deflector)  388  may be provided, e.g., on the upper wall  156 . The deflecting member  388  is preferably positioned such that an incoming stream of dirty air, exiting the outlet port  182 , impacts the deflector  388 . The air stream is accordingly forced to change direction quickly, and in turn, experience a sudden reduction in velocity. This may help to facilitate separation of solids and other air-borne debris from the incoming stream of air. In addition, if the upper wall  156  comprises or consists of a screen, then the deflector may prevent the incoming air stream being directed directly at the screen. 
     The deflector  388  may have any suitable shape. In the illustrated embodiment, the deflector  388  has a generally concave shape (see  FIGS. 21 and 22 ) which re-directs incoming airflow in a direction that is generally horizontal and downward. 
     Single Cyclone 
     The following is a description of a single cyclone that may be used by itself or in combination with other air treatment members in a docking station as exemplified herein, or which may be used by itself or in combination with other air treatment members in a surface cleaning apparatus. Accordingly, as exemplified in  FIGS. 32A-32D and 33A-33B , a cyclone or cyclone unit  502  may be used in place of the momentum separator  128  discussed previously herein. Accordingly, the first stage separator  124  may comprise or consist of a first cyclone stage, and, if provided, the second stage separator  132  may define a second cyclone stage (e.g., cyclone array  136 ). 
     As exemplified, cyclone  502  may include a cyclone bin assembly  504  comprising a cyclone chamber  506  and a separate dirt collection chamber  508 . Dirt collection chamber  508  is external to the cyclone chamber  506  and is in communication with the cyclone chamber  506 , via a dirt outlet  510 , to receive dirt and debris exiting the cyclone chamber  506 . Cyclone chamber  506  includes an air inlet  182  for receiving a flow of dirty air, and an air outlet  518  through which clean air may exit the chamber  506 . 
     As exemplified, cyclone chamber  506  may also include a cyclone chamber side wall  580  which extends between the first and second cyclone ends. In some cases, lateral walls  178  and end wall  172  may define the cyclone chamber sidewall  580  (e.g.,  FIGS. 32A-32D ). In other cases, the cyclone chamber  506  may include a separate cyclone sidewall  580 , which is recessed inwardly from lateral walls  178  and end wall  172  (e.g.,  FIG. 33A ). 
     Cyclone chamber  506  extends along cyclone axis of rotation  550  between a first cyclone end  506   a  and a second cyclone end  506   b  and may be of various designs and orientations. In the embodiment exemplified in  FIGS. 32A-32D , upper wall  156  may define the first cyclone end  506   a , while lower wall  160  may define the second cyclone end  506   b . Accordingly, with the upper wall  156  is positioned over the lower wall  160 , the cyclone axis  550  may be oriented generally vertically. However, in other cases, the cyclone axis  550  may be oriented in any other direction. For example, the cyclone axis  550  may be vertically offset (e.g., ±20°, ±15°, ±10°, or ±5° from the vertical). 
     The dirt outlet  510  may have any suitable shape or configuration. For instance, in the embodiment exemplified in  FIGS. 32B-32D , the dirt outlet  510  may comprise one or more openings (e.g., slots or perforations) formed on separating wall  376   a.    
     In the embodiment of  FIG. 33A-33B , a plate  560  or lower wall  560  is supported spaced from the lower wall  160  by a support member  555 , which may extend generally parallel to cyclone axis  550 . In other cases, the plate  560  may be supported inside of the housing  104  in any other manner known in the art. As exemplified, the dirt outlet  510  may be formed as a gap between the plate  560  and cyclone chamber sidewall  580 . 
       FIGS. 32A-32D  exemplify an embodiment wherein cyclone  502  is configured as a uniflow cyclone (e.g., a cyclone with unidirectional airflow). In this configuration, air inlet  182  and air outlet  518  are positioned at axially opposite ends of the cyclone chamber  506 . In the exemplified embodiment, air inlet  182  is located proximal the second cyclone end  506   b  (e.g., lower wall  160 ), while air outlet  518  is located at the first cyclone end  506   a  (e.g., upper wall  156 )  368 . In this embodiment, the dirt outlet  510  is provided at the upper end of the cyclone chamber. 
       FIGS. 33A-33B  exemplify an alternate configuration wherein the cyclone air inlet  182  and air outlet  518  are positioned at the same end of the cyclone chamber  506  (e.g., proximal the first cyclone end  506   a ). In this embodiment, the dirt outlet  510  is provided in a lower end of the cyclone chamber. 
     In various cases, the cyclone chamber  506  can also be configured as an inverted cyclone. In other words, dirty air may enter from the bottom of the cyclone chamber  506  and exit from the lower end of cyclone chamber  506 . 
     Cyclone air inlet  182  and air outlet  518  may have any suitable configuration. For instance, in the exemplified embodiments, air inlet  182  comprises a tangential opening on the cyclone sidewall  580 , while cyclone air outlet  518  may be defined by an opening on the top wall  156  and may comprise an outlet passage  524 . 
     Optionally, a screen  512  may be positioned over the cyclone air outlet  518 . Screen  512  may help to prevent dirt and debris (e.g., hair, larger particles of dirt) from exiting cyclone chamber  506  via the air outlet  518 . As exemplified, screen  512  can include one or more air permeable regions  514 , which permit the flow of air through the screen  512  to the air outlet  518 . The permeable regions  514  can comprise, for example, a mesh material. In some cases, the mesh material may be self-supporting (e.g., metal mesh). In other cases, non-permeable frame members  516  can be used as support frame for the mesh material. The non-permeable frame members  516  may surround the permeable regions  514 . 
     In the exemplified embodiment of  FIGS. 32B-32C , the screen  512  is configured as a generally frusto-conical shaped member. In other cases, the screen  512  may be configured as a conical shaped member ( FIGS. 33A-33B ), or may have any other suitable shape (e.g., cylindrical). 
     In operation, dirty air may flow into the cyclone chamber  506  via the air inlet  182  and cyclonically flow inside cyclone chamber  506  about cyclone axis  550 . Air may then exit the cyclone chamber  506  from the air outlet  518 . In the exemplified embodiments, air exiting the cyclone chamber  518  may enter the side flow chamber  208  and continue toward the second (downstream) stage separator  132  (e.g., cyclone array  136 ). 
     As cyclonic flow is induced inside of cyclone chamber  506 , dirt may be ejected from the cyclone chamber  506  into the dirt collection chamber  508 , via the dirt outlet  510 . 
       FIGS. 32B-32D  exemplify a first embodiment of the dirt collection chamber  508 . In this embodiment, the dirt chamber  508  is provided externally to the cyclone chamber  506 . As exemplified, the dirt collection chamber  508  is located between a first partition wall  376   a  and a second partitioning wall  376   b . The first partition wall  376   a  separates dirt chamber  508  from the cyclone chamber  506 . Second partition wall  376   b  separates dirt chamber  508  from dirt chamber  276  of the second stage cyclone array  136 . In some cases, as exemplified in  FIG. 32C , the first partition wall  376   a  may comprise a portion of the cyclone sidewall  580 . As exemplified, the dirt chamber  508  extends generally parallel to cyclone axis  550 , and spans the axial length of cyclone chamber  506 . In other embodiments, the dirt chamber  508  may extend only part of the way along the axial length of cyclone chamber  506  and/or may be oriented at an angle to the cyclone axis  550 . In still other cases, the dirt chamber  508  may be located at any other suitable location relative to cyclone chamber  506 . For instance, as exemplified in  FIG. 33A , the dirt chamber  508  may be located axially below the cyclone chamber  506 . In this configuration, dirt particles may fall by gravity into dirt collection chamber  508 . 
     Cyclone Array 
     The following is a description of a cyclone array that may be used by itself or in combination with one or more additional air treatment members that may be located upstream and/or downstream from the cyclone array. The cyclone array may be used in a surface cleaning apparatus, such as a robotic surface cleaning apparatus or a hand vac or a docking station. The cyclone array is exemplified herein as part of a docking station. 
     In accordance with this aspect some, and preferably all, of the cyclones in a cyclone array have a dirt outlet that is positioned such that dirt exiting the dirt outlet is not directed towards another cyclone in the array. Accordingly, dirt exiting the cyclone array may travel unimpeded to a dirt collection chamber. Optionally, this design is utilized when the cyclones have a cyclone axis of rotation that is at an angle (non-zero angle) to the vertical, such as about 75°, 60°, 45° (e.g., as exemplified in  FIGS. 32B and 33A ), 30°, 15° or 0° (i.e., generally horizontal as exemplified in  FIGS. 12 to 13 ) in operation. Accordingly, if the dirt outlet is provided in a sidewall of the cyclone, the dirt outlet may directly face the floor of a dirt collection chamber or a passage to a dirt collection chamber (i.e., no significant intervening structure is located between the dirt outlet and the floor of a dirt collection chamber or a passage to a dirt collection chamber). This may be achieved by shortening some of the cyclones as exemplified in  FIGS. 16 and 30  such that a dirt outlet end of an upper cyclone does not overlie a lower cyclone or staggering the cyclones in the direction of the cyclone axis of rotation such that an upper cyclone does not overlie a lower cyclone. 
     Alternately, or in addition, in accordance with this aspect the cyclone array may be configured to enable air to flow between or along the cyclones. For example, a plurality of housings  216  may be provided wherein each housing has, e.g., 2 or more cyclones, and the housings  216  are spaced apart from each other to enable air to flow therebetween. Alternately, the cyclone may themselves be spaced apart to enable air to flow therebetween. 
     The cyclones may be provided in a single housing such that a single manifold or header distributes air to each of the cyclones. Alternately, a plurality of such headers may be provided. In the embodiment of  FIGS. 2 and 3 , a single header  296  is provided. The header may be upstream from a single airflow path from, e.g., momentum separator  128 . Alternately, as optionally exemplified in  FIGS. 12 to 13 , a plurality of flow paths may be provided from up flow chamber  188  and side-flow chamber  208  to the header  296 . 
     Referring to  FIGS. 2-17  and  FIGS. 19-28 , as exemplified, the second stage separator  132  may comprise a cyclone array  136 . The cyclone array  136  may include one or more cyclones  221 . For instance, cyclone array  136  may include six cyclones ( FIGS. 2-17 ), or ten cyclones ( FIGS. 19-28 ). 
     Each cyclone  221  may include a cyclone chamber  260  that extends, along a cyclone axis of rotation  244 , between a first cyclone end  248  and an axially opposed second cyclone end  252 . The axial extension between the first cyclone end  248  and the second cyclone end  252  defines the axial length  280  of the cyclone. A cyclone sidewall  270  may extend between the first and second cyclone ends. 
     As discussed previously, the cyclone axis of rotation  224  may be oriented in various directions. For instance,  FIGS. 2-17  exemplify an embodiment wherein each cyclone  221  has a cyclone axis  224  that is oriented generally horizontally. In other words, the first cyclone end  248  is positioned forward of the second cyclone end  252 .  FIGS. 32B-32D  exemplify a further embodiment wherein each cyclone has a cyclone axis  224  that is oriented at an angle to the horizontal plane (e.g., a 45°).  FIGS. 19-28  exemplify still a further alternative embodiment wherein each cyclone  221  has a cyclone axis  224  that is oriented generally vertically. In this embodiment, the first cyclone end  248  is positioned on top of the second cyclone end  252 . 
     While the exemplified embodiments illustrate each cyclone  221 , in the cyclone array  136 , as being oriented in the same direction, and in a generally parallel configuration, in other cases, different cyclones  221  in cyclone array  136  may have cyclone axis oriented in different directions. 
     Each cyclone unit  221  may have one or more air inlets  256  for receiving a flow of air, and a cyclone outlet  264  for an outflow of air. 
     The cyclone air inlets  256  and air outlet  264  may be located at any suitable position along the axial length of each cyclone  221 . In the exemplified embodiments, the air inlet  256  and air outlet  264  are positioned at the first cyclone end  248  ( FIG. 16A ). In other cases, however, the cyclone unit  221  may be configured as a uniflow cyclone, whereby the inlet  256  and outlet  264  are positioned at opposite axial ends of the cyclone chamber  260 . 
     The cyclone air inlet  256  and outlet  264  may also have any suitable shape or configuration. For instance, as exemplified, each cyclone air inlet  256  may comprise a tangential inlet, and the cyclone  221  may include one or more air inlets  256  positioned circumferentially around the outer perimeter of the cyclone unit  221 . The cyclone air outlet  264  may comprise a central opening located in the first cyclone end  248 , and may be surrounded by the one or more air inlets  256 . 
     In operation, as exemplified in  FIGS. 16 and 27 , dirty air flows into the cyclones  221  via air inlets  256 , and enters the cyclone chamber  260 . Inside of the cyclone chamber  260 , air is induced to swirl around the cyclone axis  244 , which in turn, facilitates the separation of the finer particles of dust and debris from the airflow. Cleaner air exits the cyclone chamber  260  via the cyclone air outlet  264 . Air which exits through the air outlet  264  may continue downstream to the air treatment apparatus air outlet  120 , and in some cases, may continue further downstream to a suction device (i.e., a suction motor  324  of  FIG. 18 ) in communication with the air outlet  120 . 
     Dirt and debris, which becomes separated from the airflow inside of the cyclone chamber  260 , exits the cyclone through one or more dirt outlets  268 . In the exemplified embodiments, the dirt outlets  268  are provided at the second cyclone end  252 , and are configured as apertures (e.g., slot or gap) on the cyclone sidewall  270 . As exemplified in  FIG. 16A , the dirt outlets  268  may have any suitable width  274 . For example, in some cases the dirt outlets  268  may have a width  274  of 5 mm, 7 mm, or 10 mm. A greater width  274  may allow more dirt to exit the cyclone chamber  260 . 
     In various embodiments, the cyclones  221  inside of the cyclone array  136  may be arranged into one or more “sets”. For instance, as exemplified in  FIGS. 2-27, and 32B-32D , the cyclone array  136  may comprise a first cyclone set  236  and a second cyclone set  240 . 
     In the embodiment of  FIGS. 2-16, and 32B-32D , the first cyclone set  236  corresponds to an upper cyclone row, and the second cyclone set  240  corresponds to a lower cyclone row. Alternatively, as exemplified in  FIGS. 20-27 , the cyclone array  136  is may be arranged generally vertically, and the first set  236  can correspond to a front column of cyclones, and the second cyclone set  240  can correspond to a rear column of cyclones (e.g.,  FIG. 26 ). 
     In other cases, cyclone array  136  may include more than two cyclone sets. For example,  FIGS. 29-31  exemplify embodiments wherein the cyclone array  136  includes three cyclone rows  702   a ,  702   b  and  702   c.    
     In the exemplified embodiments, each cyclone set  236  and  240  can include one or more cyclones  221 . For instance,  FIGS. 2-16  exemplify an embodiment wherein each cyclone set includes three cyclones  221 .  FIGS. 20-27  exemplify an embodiment wherein each cyclone set includes five cyclones  221 . 
     The cyclone sets may be spaced apart (e.g., vertically or horizontally, as the case may be), by any desired distance. For instance, in  FIG. 16A , the upper and lower cyclone rows  236 ,  240  are spaced apart such that the lower air inlets of the upper cyclone row are spaced from the upper air inlets of the lower cyclone row. In addition, the lower cyclone is spaced from lower wall  290  of the apparatus. Accordingly, as exemplified in  FIG. 27 , gaps  602  may be formed between adjacent cyclones  221  to allow for air to flow from, e.g., the front column set  236  to the rear column set  240 . 
     As exemplified, in  FIG. 26 , in some cases, the cyclones  221  may be held in configuration at least by a mounting bracket  452  (see for example  FIG. 26 ). Mounting bracket  452  may define a lower wall of a header for the cyclone inlets. Accordingly, air may travel from the momentum separator  128  through side flow channel  208  to the cyclone air inlets. 
     It will be understood that gaps  602  may be provided in embodiments wherein the cyclone array  136  is oriented generally horizontally with the cyclones  221  in the upper cyclone row  236  and lower cyclone row  240  positioned one on top of the other such that the upper cyclones  236  fully overly the lower cyclones  240  (e.g., the upper and lower cyclones may have the same diameter and the cyclone axes of rotation may be located in a vertical plane extending through the upper and lower cyclones). Alternatively, as exemplified in  FIG. 29 , gaps  602  may be provided if the cyclone array  136  is horizontally staggered (e.g., first cyclone row  236  may be positioned inwardly with respect to the lower cyclone row  240 , or the first cyclone row  236  may be positioned outwardly with respect to the second cyclone row  240 ). 
     In the embodiment exemplified in  FIGS. 2-17  (e.g., the cyclones  221  have a generally horizontal cyclone axis configuration), the array of cyclones  136  may be provided in a single housing or, alternately, as exemplified in  FIGS. 12 and 13 , each column of cyclones may be provided in a discrete housing  216 . As exemplified in  FIGS. 12 to 13 , each cyclone housing  216  includes a top  220 , a bottom  224 , and spaced apart lateral sides  228  that extend between the top  220  and the bottom  224 . 
     An advantage of using discrete housings is that an airflow path may be provided between adjacent housings. As exemplified, the discrete housings  216  may be spaced apart by gaps  232  formed between opposing lateral sides  228  of each housing  216 . Each gap may form part of an airflow path. 
     Each cyclone housing  216  may comprise one or more cyclones. In the illustrated embodiment, each cyclone housing comprises one upper cyclone  236  positioned above, and in parallel to, one lower cyclone  240 . 
     Air-flowing from the up flow chamber  188  and/or the side-flow chamber  208  (see  FIG. 2 ) travels to the air inlets  256  by flowing along the exterior of the top  220  of cyclone housings  216 , from the rear end of the cyclone housings  192  (which as exemplified in the end wall of up flow chamber  188 ) to the front end  248   a ,  248   b  of the cyclones where header  296  is located (see  FIGS. 14 to 16 ). In addition, air flows between gaps  232  between adjacent cyclone units (i.e., when viewed from the rear, between the left lateral wall  228  of one cyclone housing  216  and the right lateral wall  228  of another cyclone housing  216 ). The gap  232  may have a width of 4 mm, 8 mm, or 10 mm. Gaps having a larger width may accommodate a greater (and slower) flow of air. Conversely, gaps having a narrower width may accommodate a smaller (and faster) flow of air. 
     In other embodiments, any other airflow path may be used to provide air to header. For example, the air may travel above the cyclone housings and/or between the cyclone housings and/or laterally beside the outer cyclone housing and/or below the cyclone housings. 
     It will be appreciated that, in one aspect, the cyclones may be of various configurations provided the cyclones have a dirt outlet that permits dirt to exit in a direction such that dirt exiting the dirt outlet is not impeded from collecting on a lower end of the dirt collection chamber by another cyclone in the array. Accordingly, the cyclone air inlet or outlets may be provided at various locations and the dirt outlet may also be provided at various locations. For example, the cyclones may be in a staggered configuration and/or the cyclone axis of rotation may be at an angle to the horizontal. 
       FIG. 16  exemplifies one embodiment of the staggered configuration. In this embodiment, the first cyclone end  248 , of each of the upper cyclones  236  and lower cyclones  240  are located along a common plane. The common plane is transverse to the cyclone axis of rotation  244 . Further, the axial length  280  of the upper cyclones  236  extends beyond the axial length  280  of the lower cyclones  240 . Accordingly, this arrangement results in the dirt outlets  268  of the upper cyclones  236  being spaced axially rearwardly (i.e., staggered), along cyclone axis  244 , from the second cyclone end  252  of the lower cyclones  240 . 
     The dirt outlet  268  of the upper cyclones  236  may be staggered rearwardly of the second cyclone end  252 , of the lower cyclone  240 , by any suitable staggering distance  288 . For example, the staggering distance  288  may be 4 mm, 6 mm, 8 mm, 10 mm or more. A greater staggering distance  288  can reduce the possibility that lower cyclones  240  obstructing dirt exiting the dirt outlet  268  of the upper cyclones  236 . Conversely, a smaller staggering distance  288  can allow for a more compact cyclone array configuration. 
       FIGS. 29-30  exemplifies the same staggered arrangement as  FIG. 16 , using three cyclone rows. In the exemplary embodiment of  FIG. 30 , the cyclone array  136  includes six cyclones  221   a ,  221   b ,  221   c ,  221   d ,  221   e , and  221   f  that are arranged in a generally circular geometry. The staggered configuration is achieved by the progressive shortening of the axial cyclone length  280  of cyclone units  221  in separate rows. 
     For example, cyclones  221   c  and  221   d  may have a length  280  of 50 mm, cyclones  221   a  and  221   f  may have a length  208  of 38 mm, and cyclones  221   b  and  221   e  may have a length  280  of 44 mm. In some cases, the cyclone units may also each have a diameter of 5 mm. 
     In other embodiments, a staggered configuration can be achieved using cyclones of equal length  280 . For instance, as exemplified in  FIG. 31 , the length  280  of cyclones  221  in different row is generally equal. However, each sequentially lower row of cyclones has a first cyclone end  248  which is located forward of the first cyclone end of the cyclones of the row immediately there above. Accordingly, this generates a staggered configuration between dirt outlets  268 . 
       FIGS. 33A-33E  exemplify a further staggered configuration using cyclones  221 , in different rows, of equal length. In this embodiment, the cyclone axis  240  of each cyclone row is oriented at an angle, such that the lower cyclone row does not obstruct the dirt outlet of an upper cyclone row. It will be appreciated that the cyclones may be of differing lengths. 
     As exemplified in  FIG. 27 , in embodiments wherein the cyclone array is oriented in a generally vertical direction, the cyclones may also be staggered (e.g., some cyclones may be longer than the others so that the lower ends of some cyclones are positioned lower than the lower ends of other cyclones in the array, or the cyclones may b have the same length with the lower ends of some of the cyclones positioned lower than the lower ends of other cyclones in the array). Alternately, the dirt outlets may be positioned to not directly face another cyclone. 
     In the embodiment exemplified in  FIGS. 2-17 , the dirt outlet  268  of each cyclone  221  is oriented downwardly and face a common dirt collection chamber  276 , which is in communication with each of the dirt outlets  268  (see  FIG. 10 ). The dirt outlets  268  of cyclones in the upper row  236  and the lower row  240  are arranged in a staggered configuration. The staggered configuration may be configured such that dust exiting the dirt outlet  268 , of the top cyclone row  236 , is not obstructed from entering the dirt collection chamber  276  by the bottom cyclone row  240 . For example, the dirt outlets  268  of cyclones in the upper row  236  are rearward of the dirt outlets of the lower row  240  such that all of the dirt outlets directly face the floor of the dirt collection chamber  276 . As such, dirt exiting the cyclones thought the dirt outlets  268  may collect in the dirt collection chamber  276 . It will be appreciated that each cyclone set may have its own dirt collection chamber. 
     The dirt may travel downwardly to the floor of the dirt collection chamber  276  in a portion of the dirt collection chamber  276  that is a single contiguous space or channel, or in separate channels. As exemplified in  FIG. 2  the dirt collection chamber may have a front wall  292  and a rear wall  192 . Air exiting all of the cyclones travels downwardly between the front wall  292  and the rear wall  192  of the dirt collection chamber. 
     Alternately, as exemplified in  FIGS. 16A, 16B, 16C and 17 , the dirt outlets of the lower cyclones may travel to the floor of the dirt collection chamber  276  by a forward channel and the dirt outlets of the upper cyclones may travel to the floor of the dirt collection chamber  276  by a rearward channel. The forward channel may be defined by front wall  292  and intermediate wall  252  and the rearward channel may be defined by intermediate wall  252  and rear wall  192 . The intermediate wall  252  may be an extension downwardly of the ear wall of the lower cyclone may continue part way or all the way to the floor  272  of the dirt collection chamber  276 . 
     As exemplified, linking or connecting walls  284  may extend between the lower ends of adjacent lateral walls  228  to define part of a top of the dirt collection chamber. Accordingly, lateral walls  228  and rear wall  192  of cyclone housings  216  and front wall  292  may be considered to define a plurality of vertical passages that extend from the dirt outlets of the cyclones of each cyclone unit to a common volume of the dirt collection chamber  276  that is positioned below linking walls  284 . 
     Front wall  292  may be an exterior wall of the apparatus. Alternately, a front wall  298  may be provided forward of front wall  292 . As shown in  FIG. 16A , front wall  292  may extend upwardly and be located between the upper and lower cyclones to isolate the dirt collection chamber from header  296 . 
     Emptying of the Air Treatment Member 
     The following is a description of emptying the air treatment member that may be used by itself in any surface cleaning apparatus or in any combination or sub-combination with any other feature or features described herein. 
     As exemplified in  FIGS. 8, 28, and 32D , in various embodiments, the lower wall  160  of the first stage separator  124  may comprise an openable door  184 . The openable door  184  facilitates emptying of the first stage separator  124  from solid debris and other containments that have accumulated therein. In embodiments wherein the first stage separator  124  comprises a momentum separator  128  (e.g.,  FIGS. 2-17 ), openable door  184  may allow emptying of dirt collected on the bottom of the separator  128 . Openable door  184  also allows access to the top screen  180  and/or the side screen  176  of the momentum separator  124  (i.e., for cleaning or de-briding). Alternatively, where the first stage separator  128  comprises a cyclone unit  502  (e.g.,  FIG. 32D ), openable door  128  facilitates cleaning of the cyclone  502  and/or the screen  522 . 
     Optionally, as exemplified, lower wall  160  may form a common wall between the first stage separator  124  and the cyclone dirt chamber  276 . Accordingly, door  184  can allow concurrent emptying of dirt that has accumulated in both the first stage separator  124  and the dirt collection chamber  276 . Alternatively, or in addition, the dirt collection chamber  276  may have a separate openable door  272  from the first stage separator. In particular, this may allow for separate and independent emptying of the dirt collection chamber  276 . 
     In the embodiment of  FIGS. 2-17 , openable door  184  can also allow for concurrent emptying of the up flow chamber  188 . In addition, or in the alternative, the up flow chamber  188  may include a separate bottom openable door  204 . 
     As exemplified in the embodiment of  FIG. 33A , the dirt collection chamber  508  may be located below the cyclone chamber  506 . In this configuration, the openable door  184  may also move plate  560  so that opening the dirt collection chamber  508  also opens the first stage dirt collection chamber  508  and optionally the second stage dirt collection chamber  276 . In still other cases, each dirt chamber may have a separable open door. 
     The door  184  may be openable in any manner known in the art. For example,  FIG. 8  exemplifies an embodiment whereby the openable door  184  is axially removably (e.g., detachable) from the housing body  104 . Alternately,  FIGS. 32A and 32D  exemplify another embodiment wherein the openable door  184  is moveably mounted to housing body  104  between a closed position ( FIG. 32B ) and an open position ( FIG. 32D ). For instance, in the exemplified embodiment, the openable door  184  is pivotally connected to the housing body  104  by hinge  526  and moves, along an axis of rotation, between the open and closed position ( FIG. 32D ). 
     The openable door  184  can also be held in the closed position in any suitable manner. As exemplified in  FIGS. 32B and 32D , the openable door  184  can be held in the closed position by a releasable latch  542 . 
     In some embodiments, the top wall  174  of the apparatus  100  can also form a removable (or openable) top lid  408 , which can be detached from the body housing  104  (e.g.,  FIG. 25 ). This configuration allows for immediate access to the top screen  180 , which can be removed and independently cleaned of dust, and debris, which has accumulated thereon. As explained in further detail herein, removing the top lid  408  may also provide access to the cyclone array  136 . The top lid  408  may be removably or detachably mounted to the housing body  304  in any suitable manner, or may be moveably mounted between an open and closed position to the housing  104 . In at least some embodiments, each compartment of the air treatment apparatus  100  may also have a separate top lid portion. 
     Removable Components 
     Any one or more of the removable components may have any or more of the features of the first stage momentum separator, second stage momentum separator and the cyclone array discussed herein. 
     Alternately, or in addition, as exemplified in  FIG. 8 , the dirt collection chamber  276  may comprise a removable tray, which may be removed when openable door  272  is opened or removed. 
     In at least some embodiments, one or more components comprising the air treatment apparatus  100  may be configured for separate or joint removal from the air treatment apparatus  100  (i.e., for maintenance or cleaning). By way of non-limiting examples, the following components may be separately or jointly removed: (a) the momentum separator  128 ; (b) the cyclone array  136 ; (c) the combination of the momentum separator  128  and the cyclone array  136 ; (d) the combination of the momentum separator  128 , the cyclone array  136 , and the dust collecting chamber  276 ; (e) the momentum separator  128  and the dust collecting chamber  276  (without the cyclone array  136 ); (f) the combination of any one of (a) to (e), and one or both of the side screen  176  and the top screen  180 . 
     While the above description provides examples of the embodiments, it will be appreciated that some features and/or functions of the described embodiments are susceptible to modification without departing from the spirit and principles of operation of the described embodiments. Accordingly, what has been described above has been intended to be illustrative of the invention and non-limiting and it will be understood by persons skilled in the art that other variants and modifications may be made without departing from the scope of the invention as defined in the claims appended hereto. The scope of the claims should not be limited by the preferred embodiments and examples, but should be given the broadest interpretation consistent with the description as a whole.