Patent Publication Number: US-2022233037-A1

Title: Surface cleaning apparatus

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 17/458,195, filed on Aug. 26, 2021, which itself is a continuation-in-part of co-pending U.S. patent application Ser. No. 16/270,693, filed on Feb. 8, 2019 and issued as U.S. Pat. No. 11,202,539 on Dec. 21, 2021, which itself is a continuation of U.S. patent application Ser. No. 15/095,941, filed on Apr. 11, 2016 and issued as U.S. Pat. No. 10,258,208 on Apr. 16, 2019, each of which is incorporated herein in its entirety by reference. 
    
    
     FIELD 
     The specification relates to surface cleaning apparatus. In a preferred embodiment, the surface cleaning apparatus comprises a portable surface cleaning apparatus, such as a hand vacuum cleaner or a pod. 
     INTRODUCTION 
     The following is not an admission that anything discussed below is part of the prior art or part of the common general knowledge of a person skilled in the art. 
     Various types of surface cleaning apparatus are known. Surface cleaning apparatus include vacuum cleaners. Currently, a vacuum cleaner typically uses at least one cyclonic cleaning stage. More recently, cyclonic hand vacuum cleaners have been developed. See for example, U.S. Pat. No. 7,931,716 and US 2010/0229328. Each of these discloses a hand vacuum cleaner which includes a cyclonic cleaning stage. U.S. Pat. No. 7,931,716 discloses a cyclonic cleaning stage utilizing two cyclonic cleaning stages wherein both cyclonic stages have cyclone axis of rotation that extends vertically. US 2010/0229328 discloses a cyclonic hand vacuum cleaner wherein the cyclone axis of rotation extends horizontally and is co-axial with the suction motor. In addition, hand carriable cyclonic vacuum cleaners are also known (see U.S. Pat. Nos. 8,146,201 and 8,549,703). 
     SUMMARY 
     This summary is intended to introduce the reader to the more detailed description that follows and not to limit or define any claimed or as yet unclaimed invention. One or more inventions may reside in any combination or sub-combination of the elements or process steps disclosed in any part of this document including its claims and figures. 
     In accordance with one aspect of this disclosure, a hand vacuum cleaner has a uniflow cyclone with a front cyclone air inlet and a rear air cyclone outlet. Accordingly, the cyclone axis extends rearwardly from the front end of the cyclone. The cyclone air inlet may be in an upper portion of the cyclone and may be in an upper portion of the sidewall (e.g., most and preferably essentially all of the inlet opening may be in the sidewall of the cyclone above the axis of rotation of the cyclone). The dirt collection area may be a dirt collection chamber that is external to the cyclone chamber and may be provided below the cyclone chamber. The dirt outlet of the cyclone chamber may be provided in a lower portion of the sidewall of the cyclone near or at the rear end of the cyclone. 
     In accordance with this aspect, there is provided a hand vacuum cleaner having a front end having a dirty air inlet, a rear end, a clean air outlet, an upper end and a bottom, the hand vacuum cleaner comprising:
         (a) a main body comprising an upper end having a dirty air inlet, a lower end, a front end and a rear end, the main body housing a suction motor and fan assembly, the suction motor and fan assembly having a suction motor axis of rotation; and,   (b) a cyclone unit comprising a cyclone having a cyclone axis of rotation, a front end having a cyclone air inlet and a longitudinally spaced apart rear end having a cyclone air outlet, wherein the cyclone air inlet is in an upper portion of the cyclone;   wherein when the hand vacuum cleaner is oriented with the cyclone underneath the upper end, the cyclone axis of rotation is generally horizontal.       

     In some embodiments, when the hand vacuum cleaner is positioned with the bottom on a horizontal surface, the cyclone axis of rotation may be generally horizontal. 
     In some embodiments, when the hand vacuum cleaner is oriented with the cyclone underneath the upper end, the suction motor axis of rotation may be generally horizontal. 
     In some embodiments, when the hand vacuum cleaner is oriented with the cyclone underneath the upper end, the suction motor axis of rotation may be positioned below the cyclone axis of rotation. 
     In some embodiments, the cyclone has a sidewall having an upper portion and a lower portion and a dirt outlet may be provided in the lower portion and is in communication with a dirt collection chamber that is exterior to the cyclone. Optionally, the cyclone air inlet may be provided in the upper portion of the sidewall of the cyclone. 
     In some embodiments, the cyclone axis of rotation may be generally parallel to the suction motor axis of rotation. 
     In some embodiments, the main body may be provided with a handle. 
     In some embodiments, the hand vacuum cleaner further comprises a handle having a hand grip portion that may extend upwardly and forwardly when the hand vacuum cleaner is oriented with the cyclone underneath the upper end. 
     In some embodiments, the lower end of the main body may comprise the bottom. 
     In some embodiments, the cyclone unit may be provided on the front end of the main body. Alternately, or in addition, the cyclone unit may be removably mounted to the main body. 
     In some embodiments, the dirty air inlet may be provided on a front end of the cyclone unit. 
     In some embodiments, the dirty air inlet may comprise an inlet passage that extends longitudinally between an inlet end and an outlet end and has a longitudinal passage axis, the outlet end of the inlet passage communicates with the cyclone air inlet and the inlet passage axis may be positioned between an upper and a lower end of a handle of the hand vacuum cleaner. 
     In some embodiments, the handle may comprise a hand grip portion that extends upwardly and forwardly when the hand vacuum cleaner is oriented with the cyclone underneath the upper end. In some of these embodiments, the suction motor axis of rotation may be positioned below the cyclone axis of rotation when the hand vacuum cleaner is oriented with the cyclone underneath the upper end. 
     In some embodiments, the inlet passage may have a longitudinal passage axis that is linear and all of the longitudinal passage may be positioned above the cyclone axis of rotation when the hand vacuum cleaner is oriented with the cyclone underneath the upper end. 
     In accordance with this aspect, there is also provided a surface cleaning apparatus comprising the hand vacuum cleaner discussed herein, a surface cleaning head and a rigid air flow conduit extending between the surface cleaning head and the hand vacuum cleaner wherein an outlet end of the rigid air flow conduit is removable connectable in air flow communication with the inlet passage. 
     In accordance with this aspect, there is also provided a hand vacuum cleaner having a front end, a rear end, a clean air outlet, an upper end and a bottom, the hand vacuum cleaner comprising:
         (a) a main body comprising an upper end, a lower end, a front end and a rear end, the main body housing a suction motor and fan assembly, the suction motor and fan assembly having a suction motor axis of rotation; and,   (b) an air treatment member having a front end having an air treatment member air inlet and a longitudinally rearwardly spaced apart rear end having an air treatment member air outlet, wherein the air treatment member air inlet is in a longitudinally extending sidewall of the air treatment member; and,   (c) a dirty air inlet comprising an inlet passage that extends longitudinally between an inlet end and an outlet end and has a longitudinal passage axis, the outlet end of the inlet passage communicates with the air treatment member air inlet.       

     In some embodiments, air travels through the air treatment member air outlet in a flow direction and the flow direction may be generally parallel to the suction motor axis of rotation. 
     In accordance with another aspect of this disclosure, a hand vacuum cleaner has an air treatment member with an air flow conduit or passage wherein the conduit is also a handle of the air treatment member. 
     In accordance with this aspect, there is provided a hand vacuum cleaner having a front end having a dirty air inlet, a rear end, a clean air outlet, an upper end and a bottom, the hand vacuum cleaner comprising:
         (a) a main body comprising an upper end, a lower end, a front end, a rear end and a driving handle, the main body housing a suction motor and fan assembly, the suction motor and fan assembly having a suction motor axis of rotation;   (b) an air treatment member comprising an air treatment member handle, a dirt collection region having an openable door and an openable door lock comprising a door release actuator wherein the door is moveable to an open position when the door release actuator is actuated; and,   (c) an air inlet comprises an inlet passage that extends longitudinally between an inlet end and an outlet end and has a longitudinal passage axis and the inlet passage comprises the air treatment member handle.       

     In some embodiments, the driving handle may comprise a portion spaced from the main body whereby a finger receiving area is provided between the driving handle and the main body. 
     In some embodiments, the driving handle may be provided at the rear end of the main body. 
     In some embodiments, the air treatment member handle may comprise a portion spaced from the air treatment member whereby a finger receiving area is provided between the air treatment member handle and the air treatment member. 
     The In some embodiments, the air treatment member handle may be provided above the air treatment member. 
     In some embodiments, the openable door may be provided at the front end of the hand vacuum cleaner. 
     In some embodiments, the openable door may have a lower end that is moveably mounted to the air treatment member and an upper end that may be engaged by the door lock. 
     In some embodiments, the door release actuator may be positioned proximate the air treatment member handle. 
     In some embodiments, the inlet passage may extend generally rearwardly. 
     In some embodiments, the door release actuator may be positioned at a forward end of the inlet passage. 
     In accordance with this aspect, there is also provided a hand vacuum cleaner having a front end having a dirty air inlet, a rear end, a clean air outlet, an upper end and a bottom, the hand vacuum cleaner comprising:
         (a) a main body comprising an upper end, a lower end, a front end, a rear end and a driving handle, the main body housing a suction motor and fan assembly, the suction motor and fan assembly having a suction motor axis of rotation; and,   (b) a cyclone unit comprising a cyclone having a cyclone axis of rotation, a cyclone unit handle, a dirt collection region having an openable door and an openable door lock comprising a door release actuator wherein the door is moveable to an open position when the actuator is actuated;   wherein when a user&#39;s hand is holding the cyclone unit by the cyclone unit handle, the door release actuator is operable by the same hand.       

     In some embodiments, the driving handle may comprise a portion spaced from the main body whereby a finger receiving area is provided between the driving handle and the main body. 
     In some embodiments, the driving handle may be provided at the rear end of the main body. 
     In some embodiments, the cyclone unit handle may comprise a portion spaced from the cyclone unit whereby a finger receiving area is provided between the cyclone unit handle and the cyclone unit. 
     In some embodiments, the cyclone unit handle may be provided above the cyclone unit. 
     In some embodiments, the openable door may be provided at the front end of the hand vacuum cleaner. 
     In some embodiments, the air inlet may comprise an inlet passage that extends longitudinally between an inlet end and an outlet end and the inlet passage comprises the cyclone unit handle. 
     In some embodiments, when the hand vacuum cleaner is positioned with the bottom on a horizontal surface, the cyclone axis of rotation may be generally horizontal. 
     In accordance with another aspect of this disclosure, the air treatment member, e.g., a cyclone unit, may be removably mounted to the rest of the hand vacuum cleaner. The air treatment member may include a dirty air inlet that is connectable to an upper end of a longitudinally extending rigid member (e.g., which may be hollow to enable airflow therethrough) and a surface cleaning head may be provided (preferably removably connected) to a lower end of the longitudinally extending rigid member. When assembled as an upright or stick vacuum cleaner with the hand vacuum cleaner drivingly connected to the surface cleaning head by the longitudinally extending rigid member (e.g., a rigid wand), the handle of the hand vacuum cleaner may be used to steer the surface cleaning head. An advantage of this configuration is that the hand vacuum cleaner may be easily converted to an upright or stick vacuum cleaner. 
     In such a configuration, lateral stresses (i.e., stresses transverse to the longitudinal forward/rearward axis of the hand vacuum cleaner) may occur as the handle of the hand vacuum cleaner is used to steer the surface cleaning head. In order to assist in stabilizing the joint of the air treatment member and the rest of the hand vacuum cleaner, lateral stability members may be provided at the interface of the air treatment member and the rest of the hand vacuum cleaner. For example, one or more pairs of inter-engagement members may be provided which extend in a direction that extends generally between the lower end and the upper end of the hand vacuum cleaner. These lateral stability members may extend continuously or they may have discontinuities and they may extend linearly or otherwise. As the lateral stresses are exerted in a direction that is at an angle between 0-90°, 25-90°, 45-90° or 70-90° to the lateral stability members, and may be generally perpendicular (90°) thereto, the lateral stability members will strengthen the joint of the air treatment member and the rest of the hand vacuum cleaner. Preferably, at least one pair is provided on either lateral side of a center line extending in the longitudinal forward/rearward direction of the hand vacuum cleaner. The lateral stability members may be any members that have sides that abut to resist the lateral stresses and may comprise a longitudinally extending protrusion or spline and a mating groove or abutting longitudinally extending protrusions or splines. 
     In accordance with this aspect, there is provided a surface cleaning apparatus comprising:
         (a) a hand vacuum cleaner having a front end having a dirty air inlet, a longitudinally spaced apart rear end, a clean air outlet, an upper end and a bottom, the hand vacuum cleaner comprising:
           (i) a main body comprising an upper end, a lower end, a front end and a rear end, the main body housing a suction motor and fan assembly, the suction motor and fan assembly having a suction motor axis of rotation;   (ii) an air treatment member removably mounted at the front end of the main body, the air treatment member comprising an upper end, a lower end, a front end and a rear end, the lower end of the air treatment member is rotationally mounted to the lower end of the main body; and,   (III) an air treatment member release lock comprising a release actuator and first and second engagement members wherein the first engagement member is provided on the upper end of the air treatment member and the second engagement member is provided on the upper end of the main body and the release actuator is provided on one of the air treatment member and the main body,   
           (b) a surface cleaning head; and,   (c) a rigid air flow conduit extending between the surface cleaning head and the hand vacuum cleaner wherein an outlet end of the rigid air flow conduit is removably connectable in air flow communication with the inlet passage.       

     In some embodiments, the lower end of one of the air treatment member and the main body may be provided with a transversely extending rod and the lower end of the other of the air treatment member and the main body may be provided with a hook removably connectable with the rod. 
     In some embodiments, the lower end of the air treatment member may be rotationally mounted to the lower end of the main body at a position longitudinally spaced from the first and second engagement members. 
     In some embodiments, the lower end of the air treatment member may be rotationally mounted to the lower end of the main body at a position longitudinally spaced from a position at which the upper end of the air treatment member abuts the upper end of the main body. 
     In some embodiments, one of the air treatment member and the main body may be provided with an outwardly extending protrusion and the other of the air treatment member and the main body may be provided with a groove in which the outwardly extending protrusion is received when the air treatment member is secured to the main body. 
     In some embodiments, the main body may have a driving handle and the dirty air inlet is part of the air treatment member. 
     In some embodiments, the air treatment member may comprise a cyclone unit and the driving handle may be provided at the rear end of the main body and the dirty air inlet may comprise an inlet passage that extends longitudinally between an inlet end provided at a front end of the cyclone unit and an outlet end, and the inlet end may be adapted to receive an accessory cleaning tool. The accessory cleaning tool may comprise a rigid air flow conduit. 
     In some embodiments, the air treatment member may comprise a cyclone unit and the driving handle may be provided at the rear end of the main body and the dirty air inlet may comprise an inlet passage that extends longitudinally between an inlet end provided at a front end of the cyclone unit and an outlet end, and the inlet end may be positioned forward of the cyclone unit. 
     In some embodiments, dirty air inlet may be provided above the air treatment member. 
     In some embodiments, the air treatment member may comprise a dirt collection region having an openable door and the openable door may be provided at the front end of the air treatment member. 
     In some embodiments, when the hand vacuum cleaner is oriented with the air treatment member below the upper end, the cyclone axis of rotation may be generally horizontal. 
     In accordance with this aspect, there is also provided a hand vacuum cleaner having a front end having a dirty air inlet, a longitudinally spaced apart rear end, a clean air outlet, an upper end and a bottom, the hand vacuum cleaner comprising:
         (a) a main body comprising an upper end, a lower end, a front end and a rear end, the main body housing a suction motor and fan assembly, the suction motor and fan assembly having a suction motor axis of rotation;   (b) a cyclone unit removably mounted at the front end of the main body, the cyclone unit comprising an upper end, a lower end, a front end, a rear end and a cyclone axis of rotation, the lower end of the cyclone unit is rotationally mounted to the lower end of the main body; and,   (c) a cyclone unit release lock comprising a release actuator and first and second engagement members wherein the first engagement member is provided on the upper end of the cyclone unit and the second engagement member is provided on the upper end of the main body and the release actuator is provided on one of the cyclone unit and the main body.       

     In some embodiments, the lower end of one of the cyclone unit and the main body may be provided with a transversely extending rod and the lower end of the other of the cyclone unit and the main body may be provided with a hook removably connectable with the rod. 
     In some embodiments, the lower end of the cyclone unit may be rotationally mounted to the lower end of the main body at a position longitudinally spaced from the first and second engagement members. 
     In some embodiments, the lower end of the cyclone unit may be rotationally mounted to the lower end of the main body at a position longitudinally spaced from a position at which the upper end of the cyclone unit abuts the upper end of the main body. 
     In some embodiments, one of the cyclone unit and the main body may be provided with an outwardly extending protrusion and the other of the cyclone unit and the main body is provided with a groove in which the outwardly extending protrusion is received when the cyclone unit is secured to the main body. 
     In some embodiments, the main body may have a driving handle and the dirty air inlet is part of the cyclone unit. 
     In some embodiments, the driving handle may be provided at the rear end of the main body and the dirty air inlet may comprise an inlet passage that extends longitudinally between an inlet end provided at a front end of the cyclone unit and an outlet end, and the inlet end may be adapted to receive an accessory cleaning tool. The accessory cleaning tool may comprise a rigid air flow conduit. 
     In some embodiments, the driving handle may be provided at the rear end of the main body and the dirty air inlet may comprise an inlet passage that extends longitudinally between an inlet end provided at a front end of the cyclone unit and an outlet end, and the inlet end may be positioned forward of the cyclone unit. 
     In some embodiments, the dirty air inlet may be provided above the cyclone unit. 
     In some embodiments, the cyclone unit may comprise a dirt collection region having an openable door and the openable door may be provided at the front end of the cyclone unit. 
     In some embodiments, when the hand vacuum cleaner is oriented with the cyclone below the upper end, the cyclone axis of rotation may be generally horizontal. 
     In accordance with another aspect of this disclosure an air treatment member includes an air flow passage which functions as a handle of the air treatment member. An advantage of this design is that the air treatment member may be provided with a handle that is not an additional part. The air flow passage may be part of the air flow path from a dirty air inlet to the air treatment member air inlet. Alternately or in addition, the air flow passage may be part of an air flow path for a bleed stream and a bleed valve may be provided in the air flow passage. 
     In accordance with this aspect of the disclosure, there is provided a hand vacuum cleaner having a front end, a rear end, an upper end and a bottom, the hand vacuum cleaner comprising:
         (a) a main body comprising an upper end, a lower end, a front end, a rear end and a driving handle, the main body housing a suction motor and fan assembly, the suction motor and fan assembly having a suction motor axis of rotation; and,   (b) an air treatment member, the air treatment member comprising an air treatment member axis and an air treatment member handle wherein the air treatment member handle comprises an air flow passage.       

     In some embodiments, the air flow passage may comprise an inlet passage of the air treatment member. 
     In some embodiments, the inlet passage may extend longitudinally between a dirty air inlet end and an outlet end. 
     In some embodiments, the air treatment member handle may comprise a portion spaced from the air treatment member whereby a finger receiving area is provided between the air treatment member handle and the air treatment member. 
     In some embodiments, the air treatment member handle may be provided above the air treatment member. 
     In some embodiments, the passage may extend generally axially in the direction of the air treatment member axis. 
     In some embodiments, the driving handle may comprise a portion spaced from the main body whereby a finger receiving area is provided between the driving handle and the main body. 
     In some embodiments, the driving handle may be provided at the rear end of the main body. 
     In some embodiments, the air treatment member may be removable from the main body and the air treatment member handle may be removable with the air treatment member. 
     In some embodiments, a bleed valve may be positioned in the air treatment member handle. 
     In accordance with this aspect, there is also provided a hand vacuum cleaner having a front end, a rear end, an upper end and a bottom, the hand vacuum cleaner comprising:
         (a) a main body comprising an upper end, a lower end, a front end, a rear end and a driving handle, the main body housing a suction motor and fan assembly, the suction motor and fan assembly having a suction motor axis of rotation; and,   (b) a cyclone unit, the cyclone unit comprising a cyclone having a cyclone axis of rotation, a cyclone unit handle, wherein the cyclone unit handle comprises an air flow passage.       

     In some embodiments, the cyclone unit handle may comprise an inlet passage of the cyclone unit. 
     In some embodiments, the inlet passage may extend longitudinally between a dirty air inlet end and an outlet end. 
     In some embodiments, the cyclone unit handle may comprise a portion spaced from the cyclone unit whereby a finger receiving area is provided between the cyclone unit handle and the cyclone unit. 
     In some embodiments, the cyclone unit handle may be provided above the cyclone unit. 
     In some embodiments, the passage may extend generally parallel to the cyclone axis. 
     In some embodiments, the driving handle may comprise a portion spaced from the main body whereby a finger receiving area is provided between the driving handle and the main body. 
     In some embodiments, the driving handle may be provided at the rear end of the main body. 
     In some embodiments, the cyclone unit may be removable from the main body and the cyclone unit handle may be removable with the cyclone unit. 
     In some embodiments, when the hand vacuum cleaner is oriented with the upper end positioned above the lower end, the cyclone axis of rotation may be generally horizontal. 
     In some embodiments, a bleed valve may be positioned in the cyclone unit handle. 
     In accordance with another aspect of this disclosure, a surface cleaning apparatus is electrically connectable with an accessory cleaning tool (e.g., a rigid air flow conduit, a crevice tool, a brush or the like) and a circuit electrically connecting the accessory tool with a source or power provided for the surface cleaning apparatus (e.g., AC power from a wall outlet or an on board energy storage member such as one or more batteries) is moved from a circuit open position to a circuit closed position when the accessory tool is mounted in air flow communication with the surface cleaning apparatus. An advantage of this design is that the terminal ends of the electrical outlet of the surface cleaning apparatus are de-energized when they are exposed. In one embodiment, an electrical conductor element of the accessory cleaning tool drives an electrical conductor element of the surface cleaning apparatus to a circuit closed position when the accessory tool is mounted in air flow communication with the surface cleaning apparatus. Accordingly, one or more of the electrical conductor elements of the surface cleaning apparatus may be biased to a circuit open position and may be moveable (e.g., linearly moveable, by contact with the electrical conductor element of the accessory tool). In alternate embodiments, the driving member provided on the accessory cleaning tool may be a non-conductive (e.g., plastic) engagement member (e.g., finger), that engages a member (e.g., a slideable tab of a housing of the electrical conductor elements of the surface cleaning apparatus) to move the electrical conductor elements of the surface cleaning apparatus to a circuit closed position. 
     In accordance with this aspect, there is provided a surface cleaning apparatus comprising:
         (a) an air flow passage extending between a dirty air inlet and a clean air outlet;   (b) a main body housing a suction motor and fan assembly that is positioned in the air flow passage;   (c) an air treatment member positioned in the air flow passage;   (d) an electrical outlet electrically connectable with an accessory cleaning tool; and,   (e) a circuit extending between a source of power and the electrical outlet, the circuit comprising first and second electrical conductor elements, at least the first electrical conductor element is biased to a circuit open position wherein the first electrical conductor element is moved to a circuit closed position when an accessory cleaning tool is connected to the dirty air inlet.       

     In some embodiments, the first and second electrical conductor elements may engage electrical conductors of the accessory tool whereby the first and second electrical conductor elements are electrically connectable with the accessory cleaning tool and at least the first electrical connector conductor may be biased to a circuit open position. 
     In some embodiments, the first and second electrical conductor elements may comprise first and second electrical connector conductors, each of the electrical conductor elements may have an accessory tool contact end and a terminal end contact end, at least the first electrical connector conductor may be biased to a circuit open position and at least one of the accessory tool contact ends may be recessed in the electrical outlet when in the circuit open position. 
     In some embodiments, the circuit may comprise electrically conductive members, each of which extends from the source of power to a terminal end, at least the first electrical conductor element may be moveably mounted from a position in which it contacts one of the terminal ends to a position in which it is spaced from the terminal end. 
     In some embodiments, each of the electrical conductor elements may be moveably mounted from a position in which each of the electrical conductor elements contacts one of the terminal ends to a position in which the electrical conductor elements contacts are spaced from the terminal ends. 
     In some embodiments, the circuit may comprise electrical conductive members, each of which may extend from the source of power to a terminal end, the first and second electrical conductor elements may comprise first and second electrical connector conductors, each of the electrical conductor elements may have an accessory tool contact end and a terminal end contact end, at least the first electrical conductor element may be moveably mounted from a position in which it contacts one of the terminal ends to a position in which it is spaced from the terminal end. 
     In some embodiments, surface cleaning apparatus may further comprise a compression spring positioned between the first electrical conductor element and one of the terminal ends. 
     In some embodiments, the compression spring may be non-conductive. 
     The In some embodiments, the source of power may comprise a power cord. 
     In some embodiments, the circuit further may comprise a main power switch. 
     In some embodiments, the accessory cleaning tool may comprise a rigid air flow conduit. 
     In some embodiments, the surface cleaning apparatus may comprise a hand vacuum cleaner and the electrical outlet is provided adjacent the dirty air inlet. 
     In accordance with this aspect, there is also provided a surface cleaning apparatus comprising
         (a) a suction motor and fan assembly operable on a source of power;   (b) an electrical outlet housing having first and second electrical conductor elements, each of the electrical conductor elements has a first contact end and a second contact end; and,   (c) a circuit including the electrical conductor elements and a main power switch operable between a circuit closed position and a circuit open position, at least the first electrical conductor element is moveable between a circuit closed position and a circuit open position and is biased to the circuit open position wherein the first electrical conductor element is moved to a circuit closed position upon mechanical engagement of a part having an air flow conduit with the electrical outlet housing.       

     In some embodiments, the circuit may comprise electrically conductive members, each of which may extend from the source of power to a terminal end, at least the first electrical conductor element may be moveably mounted from a position in which it contacts one of the terminal ends to a position in which it is spaced from the terminal end. 
     In some embodiments, each of the electrical conductor elements may be moveably mounted from a position in which each of the electrical conductor elements contacts one of the terminal ends to a position in which the electrical conductor elements contacts are spaced from the terminal ends. 
     In some embodiments, the surface cleaning apparatus may further comprise a compression spring positioned between the first electrical conductor element and the one of the terminal ends. 
     In some embodiments, the compression spring may be non-conductive. 
     In some embodiments, the source of power may comprise a power cord. 
     In some embodiments, the first electrical conductor element may be longitudinally moveable in the electrical outlet housing 
     In some embodiments, the surface cleaning apparatus may comprise a hand vacuum cleaner and the electrical outlet housing is provided adjacent a dirty air inlet. 
     In accordance with another aspect of this disclosure, a hand vacuum cleaner is provided with a front openable door of a dirt collection area and the hand vacuum cleaner has a handle that extends upwardly and forwardly when the hand vacuum cleaner is oriented with the upper end above the lower end (e.g., when the hand vacuum cleaner is seated on a horizontal surface). An advantage of this design is that the handle is oriented to permit the user to point the hand vacuum cleaner downwardly to empty the dirt collection area when the door is opened. 
     In accordance with this aspect, there is provided a hand vacuum cleaner having a front end having a dirty air inlet, a rear end, a clean air outlet, an upper end and a bottom, the hand vacuum cleaner comprising:
         (a) a main body comprising an upper end, a lower end, a front end, a rear end and a driving handle, the main body housing a suction motor and fan assembly, the suction motor and fan assembly having a suction motor axis of rotation wherein the driving handle has a hand grip portion that extends upwardly and forwardly when the hand vacuum cleaner is oriented with the upper end above the lower end; and,   (b) an air treatment member comprising a dirt collection region having an openable door provided on a front end of the air treatment member and an openable door lock comprising a door release actuator wherein the door is moveable to an open position when the door release actuator is actuated.       

     In some embodiments, the hand grip portion may be spaced from the main body whereby a finger receiving area is provided between the hand grip portion and the main body. 
     In some embodiments, at least a portion of the finger receiving area may be positioned linearly rearwardly from the air treatment member. 
     In some embodiments, the main body may comprise a suction motor housing and the driving handle has an end that may extend from the suction motor housing. 
     In some embodiments, the main body may comprise a suction motor housing and the driving handle may have an end that extends upwardly and forwardly from the suction motor housing. 
     In some embodiments, the driving handle may be provided at the rear end of the main body. 
     In some embodiments, the inlet passage may extend generally rearwardly. 
     In some embodiments, the inlet passage may be positioned above the openable door. 
     In some embodiments, the dirty air inlet may comprise an inlet passage that extends longitudinally between an inlet end and an outlet end and has a longitudinal passage axis and the longitudinal passage axis interests the driving handle. 
     In some embodiments, the air treatment member may have a front end having an air treatment member air inlet and a longitudinally rearwardly spaced apart rear end having an air treatment member air outlet. 
     In some embodiments, the inlet passage may be positioned above the openable door. 
     In accordance with this aspect, there is also provided a hand vacuum cleaner having a front end having a dirty air inlet, a rear end, a clean air outlet, an upper end and a bottom, the hand vacuum cleaner comprising:
         (a) a main body comprising an upper end, a lower end, a front end, a rear end and a driving handle, the main body housing a suction motor and fan assembly, the suction motor and fan assembly having a suction motor axis of rotation wherein the driving handle has a hand grip portion that extends upwardly and forwardly when the hand vacuum cleaner is oriented with the upper end above the lower end; and,   (b) a cyclone unit comprising a cyclone having a cyclone axis of rotation, a dirt collection region having an openable door provided on a front end of the cyclone unit and an openable door lock comprising a door release actuator wherein the door is moveable to an open position when the actuator is actuated.       

     In some embodiments, the hand grip portion may be spaced from the main body whereby a finger receiving area is provided between the hand grip portion and the main body. 
     In some embodiments, at least a portion of the finger receiving area may be positioned linearly rearwardly from the cyclone unit. 
     In some embodiments, the main body may comprise a suction motor housing and the driving handle has an end that extends from the suction motor housing. 
     In some embodiments, the main body may comprise a suction motor housing and the driving handle has an end that extends upwardly and forwardly from the suction motor housing. 
     In some embodiments, the driving handle may be provided at the rear end of the main body. 
     In some embodiments, the inlet passage may extend generally rearwardly. 
     In some embodiments, the inlet passage may be positioned above the openable door. 
     In some embodiments, the dirty air inlet may comprise an inlet passage that extends longitudinally between an inlet end and an outlet end and has a longitudinal passage axis and the longitudinal passage axis interests the driving handle. 
     In some embodiments, the inlet passage may be positioned above the openable door. 
     In some embodiments, when the hand vacuum cleaner may be oriented with the upper end above the lower end, the cyclone axis of rotation is generally horizontal. 
     In accordance with another aspect of this disclosure, which may be used alone or in combination with any other aspect, a hand vacuum cleaner has a power connection (an accessory power connector) to which an accessory may be removably connected (e.g., a powered floor cleaning tool), and the power connection for the accessory is provided as part of a removable air treatment member or a part of an air treatment member that is moveable with respect to the hand vacuum cleaner. For example, a removeable air treatment member may be removably mounted to a main body of the hand vacuum, wherein the main body houses the suction motor. The air treatment member includes a bin electrical connector while the main body includes a corresponding body electrical connector such that power may be transferred from the body connector to the bin connector, which is electrically connected to the accessory power connector by, electrically conductive members. This may allow the air treatment member to be more easily removed while still allowing for a desirable location for the power connector. For example, the air treatment member may remove forwardly, and the accessory power connector may be on a forward end of the bin. The bin connector may be on an opposite side of the bin. For example, the bin connector may be on a rear of the bin while the accessory power connector is on a front of the bin. The bin may be mounted to the body with a rear of the bin in contact with the body and the front of the bin carrying a nozzle or connection point for an air flow connection between the bin and the accessory. Alternately, the accessory power connector may be on part of the air treatment member that is moveable mounted to the main body or another portion of the air treatment member. For example, a portion of the air treatment member may pivot to an open position to enable the air treatment member to be emptied and the accessory power connector may be on the moveable portion of the air treatment member. 
     In accordance with this broad aspect, there is provided a hand vacuum cleaner comprising an air flow path extending from a dirty air inlet to a clean air outlet; a main body comprising a handle, the main body housing a suction motor and fan assembly that is positioned in the air flow path; and, an air treatment member removably mounted to the main body, the air treatment member having an air treatment chamber that is positioned in the air flow path when the air treatment member is mounted to the main body and a cleaning tool electrical connector; whereby, when a cleaning tool is connected to the air treatment member, the cleaning tool is connected in air flow communication with the air treatment member and the cleaning tool is electrically connected to the air treatment member. 
     In some embodiments, the cleaning tool may be concurrently connectable in air flow communication with the air treatment member and electrically connectable to the air treatment member when the cleaning tool is connected to the air treatment member. 
     In some embodiments, the main body may have a main body electrical connector, and the air treatment member may have an air treatment member electrical connector wherein the air treatment member electrical connector is disconnected from the main body electrical connector when the air treatment member is removed from the main body. 
     In some embodiments, the air treatment member may be concurrently connectable in air flow communication with the main body and electrically connectable to the main body when the air treatment member is mounted to the main body. 
     In some embodiments, the hand vacuum cleaner may comprise an inlet conduit having the dirty air inlet and the cleaning tool electrical connector is provided adjacent the inlet conduit. 
     In some embodiments, the hand vacuum cleaner may comprise an inlet conduit having the dirty air inlet, the inlet conduit is provided at an upper end of the hand vacuum cleaner, the cleaning tool electrical connector is provided adjacent the inlet conduit and the air treatment member electrical connector is provided at a lower end of the air treatment member. 
     In some embodiments, the air treatment member electrical connector may be provided at a lower end of the hand vacuum cleaner. 
     In some embodiments, the inlet conduit may be provided at a front end of the hand vacuum cleaner and the air treatment member may comprise electrical conductors that extend from the air treatment member electrical connector to the cleaning tool electrical connector and at least a portion of the electrical conductors extend along a front end of the air treatment member. 
     In some embodiments, the electrical conductors may also extend along a lower end of the air treatment member. 
     In some embodiments, a rear end of the air treatment member may be openable. 
     In some embodiments, the air treatment member may comprise electrical conductors that extend along a portion of the air treatment member from the air treatment member electrical connector to the cleaning tool electrical connector and the electrical conductors may comprise flat conductors that have a depth in a direction that extends in an outward direction to the portion of the air treatment member and a width in a direction parallel to a wall of the portion of the air treatment member and the width is greater than the depth. 
     In some embodiments, the depth may be 0.01-5 mm, optionally 1-3 mm and the width may be 1-10 mm, optionally 2-7. 
     In accordance with this broad aspect, there is also provided a surface cleaning apparatus comprising an air flow path extending from a dirty air inlet to a clean air outlet with a suction motor and fan assembly positioned in the air flow path; a main body comprising a main body electrical connector; and, an air treatment member removably mounted to the main body, the air treatment member having an air treatment chamber that is positioned in the air flow path when the air treatment member is mounted to the main body, an air treatment member electrical connector and a cleaning tool electrical connector; whereby, when a cleaning tool is connected to the air treatment member, the cleaning tool is connected in air flow communication with the air treatment member and the cleaning tool is electrically connected to the cleaning tool electrical connector and, wherein the air treatment member electrical connector is connectable to the main body electrical connector when the air treatment member is mounted to the main body. 
     In some embodiments, the cleaning tool may be concurrently connectable in air flow communication with the air treatment member and electrically connectable to the air treatment member when the cleaning tool is connected to the air treatment member. 
     In some embodiments, the air treatment member may be concurrently connectable in air flow communication with the main body and electrically connectable to the main body when the air treatment member is mounted to the main body. 
     In some embodiments, the air treatment member may comprise electrical conductors that extend from the air treatment member electrical connector to the cleaning tool electrical connector and at least a portion of the electrical conductors extends along an outer surface of the air treatment member. 
     In some embodiments, the air treatment member may comprise electrical conductors that extend along a portion of the air treatment member from the air treatment member electrical connector to the cleaning tool electrical connector and the electrical conductors may comprise flat conductors that have a depth in a direction that extends in an outward direction to the portion of the air treatment member and a width in a direction parallel to a wall of the portion of the air treatment member and the width is greater than the depth. 
     In some embodiments, the depth may be 0.01-5 mm, optionally 1-3 mm and the width may be 1-10 mm, optionally 2-7. 
     In accordance with this broad aspect, there is also provided a surface cleaning apparatus comprising an air flow path extending from a dirty air inlet to a clean air outlet with a suction motor and fan assembly positioned in the air flow path; a main body comprising a main body electrical connector; an air treatment member having an air treatment chamber that is positioned in the air flow path when the air treatment member is mounted to the main body; a cleaning tool electrical connector; and, electrical conductors that connect the cleaning tool electrical connector to a source of power in the surface cleaning apparatus, and the electrical conductors extend longitudinally and comprise flat conductors that have a depth in a first direction transverse to the longitudinal direction and a width in a second direction transverse to the longitudinal direction, and the width is greater than the depth. 
     In some embodiments, the depth may be 0.01-5 mm, optionally 1-3 mm and the width may be 1-10 mm, optionally 2-7. 
     It will be appreciated that the aspects and embodiments may be used in any combination or sub-combination. 
    
    
     
       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. 
         FIG. 1  is a front perspective view of a surface cleaning apparatus in accordance with at least one embodiment; 
         FIG. 2  is a rear perspective view of the surface cleaning apparatus of  FIG. 1 ; 
         FIG. 3  is a top perspective view of the surface cleaning apparatus of  FIG. 1 ; 
         FIG. 4  is a bottom perspective view of the surface cleaning apparatus of  FIG. 1 ; 
         FIG. 5  is a perspective view of the surface cleaning apparatus of  FIG. 1  mounted to a wand and surface cleaning head in a stickvac configuration; 
         FIG. 5A  is a cross-sectional view taken along line  5 A- 5 A in  FIG. 5 ; 
         FIG. 6  is a cross-sectional view taken along line  6 - 6  in  FIG. 1 , showing an air flow path; 
         FIG. 7  is a front perspective view of the surface cleaning apparatus of  FIG. 1 , with a cyclone unit partially cutaway; 
         FIG. 8  is a front perspective view of the surface cleaning apparatus of  FIG. 1  with the cyclone unit separated from a main body and a pre-motor filter chamber in an open position; 
         FIG. 8A  is the front perspective view of  FIG. 8  with a pre-motor filter in the pre-motor filter chamber; 
         FIG. 9  is a side elevation view of the surface cleaning apparatus of  FIG. 1  with the cyclone unit separated from the main body; 
         FIG. 10  is a rear perspective view of the surface cleaning apparatus of  FIG. 1  with the cyclone unit separated from the main body; 
         FIG. 10A  is the rear perspective view of  FIG. 10  showing the cyclone unit being held by the cyclone unit handle; 
         FIG. 11  is a front perspective view of the surface cleaning apparatus of  FIG. 1  with the cyclone unit separated from the main body; 
         FIG. 12  is a cross-sectional view taken along line  6 - 6  in  FIG. 1 , with an enlargement of a first connector pair in a locked position; 
         FIG. 13  is the cross-sectional view of  FIG. 12 , with the first connector pair in an unlocked position; 
         FIG. 14  is the rear perspective view of  FIG. 10 , with the first connector pair exploded; 
         FIG. 15  is a partial cross-sectional view taken along line  6 - 6  in  FIG. 1 , showing an alternative first connector pair in a locked position; 
         FIG. 16  is the partial cross-sectional view of  FIG. 15  showing the alternative first connector pair in an unlocked position; 
         FIG. 17  is a cross-sectional view taken along line  6 - 6  in  FIG. 1 , showing an airflow path through a bleed valve; 
         FIG. 18  is a front perspective view of the surface cleaning apparatus of  FIG. 1 , with a front cyclone unit wall in an open position; 
         FIG. 19  is the front perspective view of  FIG. 1 , with an exploded cyclone unit lock and lock actuator; 
         FIG. 20  is the front perspective view of  FIG. 1 , with an enlarged and partially cutaway cyclone unit lock in an engaged position; 
         FIG. 21  is the front perspective view of  FIG. 20 , with the cyclone unit lock in a disengaged position; 
         FIG. 22  is a cross-sectional perspective view taken along line  6 - 6  in  FIG. 1 , 
         FIG. 23  is a bottom perspective view of a surface cleaning apparatus with a counterweight stand, in accordance with at least one embodiment; 
         FIG. 24  is a side-elevation view of the surface cleaning apparatus of  FIG. 1  supported on a horizontal surface; 
         FIG. 25  is the front perspective view of  FIG. 20 , with an exploded electrical coupling; 
         FIG. 26  is a perspective view of a surface cleaning apparatus with the cyclone unit separated from the main body, in accordance with another embodiment; 
         FIG. 27  is a partial cross-sectional view of the surface cleaning apparatus of  FIG. 26  with the cyclone unit connected to the main body; 
         FIG. 28  is a perspective view of a surface cleaning apparatus with the cyclone unit separated from the main body, in accordance with another embodiment; 
         FIG. 29  is a perspective view of a surface cleaning apparatus with the cyclone unit separated from the main body, in accordance with another embodiment; 
         FIG. 30  is a perspective view of a surface cleaning apparatus with the cyclone unit separated from the main body, in accordance with another embodiment; 
         FIG. 31  is a bottom perspective view of another hand vacuum cleaner, in accordance with an embodiment; 
         FIG. 32  is a bottom perspective cross sectional view of the hand vacuum cleaner of  FIG. 31 ; 
         FIG. 33  is a rear perspective view of the hand vacuum cleaner of  FIG. 31  with a bin assembly removed; 
         FIG. 34  is a front perspective cross sectional view of the hand vacuum cleaner of  FIG. 31  with the bin assembly removed; 
         FIG. 35  is an expanded view of a portion of the hand vacuum cleaner of  FIG. 31 ; 
         FIG. 36  is a rear perspective view of the bin assembly of the hand vacuum cleaner of  FIG. 31  with a rear door in a first open position; 
         FIG. 37  is a rear perspective view of the bin assembly of the hand vacuum cleaner of  FIG. 31  with a rear door in a second open position; and, 
         FIG. 38  is a front perspective view of a main body of the hand vacuum cleaner of  FIG. 31 . 
     
    
    
     DESCRIPTION OF VARIOUS EMBODIMENTS 
     Numerous embodiments are described in this application, and are presented for illustrative purposes only. The described embodiments are not intended to be limiting in any sense. The invention is widely applicable to numerous embodiments, as is readily apparent from the disclosure herein. Those skilled in the art will recognize that the present invention may be practiced with modification and alteration without departing from the teachings disclosed herein. Although particular features of the present invention may be described with reference to one or more particular embodiments or figures, it should be understood that such features are not limited to usage in the one or more particular embodiments or figures with reference to which they are described. 
     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. 
     Referring to  FIG. 1 , an embodiment of a surface cleaning apparatus  100  is shown. The following is a general discussion of this embodiment which provides a basis for understanding each of the features which is discussed herein. As discussed in detail subsequently, each of the features may be used in other embodiments. 
     In the embodiment illustrated, the surface cleaning apparatus  100  is a hand-held vacuum cleaner, which is commonly referred to as a “hand vacuum cleaner” or a “handvac”. As used herein and in the claims, a hand-held vacuum cleaner or hand vacuum cleaner or handvac is a vacuum cleaner that can be operated one-handedly to clean a surface while its weight is held by the same one hand. This is contrasted with upright and canister vacuum cleaners, the weight of which is supported by a surface (e.g. floor below) during use. Optionally, surface cleaning apparatus  100  could be removably mountable on a base so as to form, for example, an upright vacuum cleaner, a canister vacuum cleaner, a stick vac, a wet-dry vacuum cleaner and the like. Power can be supplied to the surface cleaning apparatus  100  by an electrical cord (not shown) that can be connected to a standard wall electrical outlet. Alternatively, or in addition, the power source for the surface cleaning apparatus can be an onboard energy storage device, including, for example, one or more batteries. 
     As exemplified in  FIGS. 1-4 , the surface cleaning apparatus  100  may comprise a main body  104  having a handle  108 , an air treatment member  112  connected to the main body  104 , a dirty air inlet  116 , a clean air outlet  120 , and an air flow path extending between the inlet  116  and outlet  120 . Surface cleaning apparatus  100  includes a front end  121 , a rear end  122 , an upper end  123 , and a bottom  125 . In the embodiment shown, the dirty air inlet  116  is at the front end  121 . As exemplified, dirty air inlet  116  is the inlet end  124  of an inlet passage  128 . Dirty air inlet  116  may be positioned forward of air treatment member  112  as shown. Optionally, the inlet end  124  can be used as a nozzle to directly clean a surface. Alternatively, the inlet end  124  can be connected or directly connected to the downstream end of any suitable accessory tool such as a rigid air flow conduit (e.g. wand, crevice tool, mini brush or the like) for example. For example,  FIGS. 5 and 5A  show an exemplary surface cleaning apparatus  132  (e.g. a stickvac) including surface cleaning apparatus  100  with connector inlet end  124  directly connected to a wand  136  (e.g., wand outlet end  612  may be removably connectable in air flow communication with inlet connector  128 ) that is pivotally connected to a surface cleaning head  140 . Wand may be securable to connector  128  by any means known in the art such as a locking member or a friction fit. In the illustrated configuration of  FIG. 5 , the surface cleaning apparatus  100  can be used to clean a floor or other surface in a manner analogous to conventional upright-style vacuum cleaners. 
     From the dirty air inlet  116 , the air flow path may extend through an air treatment member  112 . The air treatment member  112  may be any suitable member that can treat the air in a desired manner, including, for example, removing dirt particles and debris from the air. In the illustrated example, the air treatment member is a cyclone unit  112 , which may be of any design. Alternatively or in addition, the air treatment member may comprise one or more of a bag, a filter or other air treating means. 
     Cyclone unit  112  may include one or a plurality of cyclones for separating dirt from the air flow, and one or a plurality of dirt collection regions for receiving dirt separated in the cyclone(s). As exemplified in  FIG. 6 , cyclone unit  112  includes a cyclone or cyclone chamber  160  and an external dirt collection chamber  164 . The cyclone  160  and dirt collection chamber  164  may be of any configuration suitable for separating dirt from an air stream and collecting the separated dirt, respectively. For example, it will be appreciated that in some dirt collection area may be internal of the cyclone chamber, e.g., a dirt collection area may be provided at a longitudinal end of the cyclone chamber. Cyclone  160  may be oriented in any direction. For example, when surface cleaning apparatus  100  is positioned with bottom  125  on a horizontal surface  584 , cyclone axis of rotation  484  may be oriented horizontally as exemplified, vertically, or at any angle between horizontal and vertical. 
     As also exemplified in  FIG. 6 , a suction motor and fan assembly  152  may be mounted within a motor housing portion  156  of the main body  104 . In this configuration, the suction motor and fan assembly  152  is downstream from the cyclone unit  112 , and the clean air outlet  120  is downstream from the suction motor and fan assembly  152 . 
     Optionally, one or more pre-motor filters may be placed in the air flow path between the air treatment member and the suction motor and fan assembly. Alternatively, or in addition, one or more post-motor filters may be provided downstream from the suction motor and fan assembly. 
     As exemplified in  FIG. 6 , main body  104  is shown including a pre-motor filter housing portion  208  that is positioned in the air flow path downstream of cyclone unit  112 . Pre-motor filter housing  208  may be of any construction known in the vacuum cleaner art. As exemplified, filter housing  208  may be bounded by one or more walls, which may be integral with or discrete from the main body exterior walls  212 . Turning to  FIG. 8 , pre-motor filter housing  208  is shown including a filter housing first wall  216  axially opposite a filter housing second wall  220 , and a filter housing sidewall  224  that extends in the direction of the cyclone axis of rotation between the first and second walls  216  and  220 . It will be appreciated that first wall  216  is optional and second wall  220  may be in the form of ribs to hold the filter in place. In the illustrated example, filter housing sidewall  224  is discrete from main body exterior walls  212 , which may provide enhanced sound insulation for air passing through the pre-motor filter housing  208 . In alternative embodiments, filter housing sidewall  224  may be defined in whole or in part by main body exterior walls  212  for a more compact design. 
     Referring back to  FIG. 6 , one or more filters made of or comprising a porous filter media may be positioned within the pre-motor filter housing  208  to filter particles remaining in the air flow exiting the cyclone air outlet  184 , before the air flow passes through the suction motor and fan assembly  152 . In the illustrated embodiments, pre-motor filter housing  208  contains an upstream filter  228  and a downstream filter  232 . The pre-motor filters  228  and  232  may be of any suitable configuration and formed from any suitable materials. Preferably, the pre-motor filters  228  and  232  are made of porous media such as foam, felt, or filter paper. Preferably a foam pre-motor filter is provided upstream of a felt pre-motor filter. 
     Pre-motor filter housing  208  may include a filter housing air inlet and a filter housing air outlet of any suitable design and arrangement within the housing  208 . In the illustrated embodiment, pre-motor filter housing  208  includes a filter housing air inlet  236  formed in filter housing first wall  216 , and a filter housing air outlet  240  formed in filter housing second wall  220 . 
     Still referring to  FIG. 6 , pre-motor filter housing  208  may promote the air flow to broadly distribute across the pre-motor filters  228  and  232  inside. This allows the collected dust particles to be more evenly distributed throughout pre-motor filters  228  and  232  instead of concentrating in a narrow air flow path. An advantage of this design is that the pre-motor filters  228  and  232  will have a greater effective dirt capacity, which allows the pre-motor filters  228  and  232  to be cleaned or replaced less frequently. To this end, pre-motor filter housing  208  may have any structure suitable for broadly distributing the air flow across pre-motor filters  228  and  232 . For example, pre-motor filter housing  208  may provide an upstream header  256 , a downstream header  260 , or both as shown. Headers  256  and  260  may be provided by spacing the pre-motor filters from the filter housing end walls  216  and  220  respectively. In some embodiments, pre-motor filter housing  208  includes spacing members positioned to hold the pre-motor filters  228  and  232  away from the filter housing end walls  216  and  220 . For example, referring to  FIGS. 6 and 8 , filter housing first wall  216  may include upstanding ribs  264  that hold the upstream side  268  of pre-motor filter  228  spaced apart from filter housing first wall  216  to allow air from filter housing air inlet  236  to flow laterally between pre-motor filter  228  and filter housing first wall  216  before penetrating pre-motor filter  228 . The illustrated example also shows filter housing second wall  220  including upstanding ribs  272  that hold the downstream side  276  of pre-motor filter  232  spaced apart from filter housing second wall  220  to allow air exiting pre-motor filter  232  to flow laterally between pre-motor filter  232  and filter housing second wall  220 , to filter housing air outlet  240 . 
     Cyclone with a Unidirectional Flow of Air 
     The following is a description of a cyclone that may be used by itself in any surface cleaning apparatus or in any combination or sub-combination with any other feature or features disclosed including a uniflow cyclone, the positioning of the dirt collection chamber, the orientation of the suction motor, the lateral stability members, the air treatment member handle, the position and orientation of a driving handle, pre-motor filter housing door, air treatment member door actuator, a counterweight stand, electrical coupling members and an accessory power connector. 
     In accordance with this aspect a cyclone comprises a cyclone with a unidirectional flow of air or a “uniflow” cyclone. As discussed in more detail, the uniflow cyclone may be horizontally disposed as opposed to being vertically disposed which is typical in the art. In other words, when held by hand and used to clean a surface, the axis of the cyclone chamber may be closer to horizontal than vertical. 
     In accordance with this aspect, the cyclone air inlet may be at the front end and the cyclone air outlet may be at the rear end. An advantage of this design is that the cyclone inlet may be used to redirect the air from the inlet passage  124  to the cyclone chamber and the air may exit the cyclone and travel linearly to the pre-motor filter. Accordingly, dirty air may travel from the dirty air inlet to the pre-motor filter without passing through any bends, thereby reducing the backpressure created by flow through the vacuum cleaner. 
     Alternately or in addition, in accordance with this aspect, the cyclone air inlet may be in an upper portion of the sidewall  168  of the cyclone. An advantage of this design is that is that it inhibits dirt that may remain in cyclone chamber  160  from exiting or blocking the air inlet when the apparatus is moved to various operating angles. 
     Alternately or in addition, in accordance with this aspect, the dirt collection chamber  164  may be external to the cyclone chamber  160 . Further, the dirt outlet  188  of the cyclone chamber  160  may be at a rear end of the cyclone chamber and/or may be in a lower portion of the cyclone chamber, such as in a lower part of sidewall  168  of the cyclone chamber. An advantage of placing the dirt outlet  188  in a lower portion of the rear end of the cyclone chamber  160  is that, when the handvac is in use with inlet  116  pointed downwardly, dirt will enter the dirt collection chamber  164  and fall forwardly due to gravity thereby preventing outlet  188  from becoming blocked until the dirt collection chamber  164  is full. 
       FIG. 7  exemplifies a cyclone unit including these aspects. As exemplified, cyclone  160  comprises a cyclone sidewall  168  extending axially from a cyclone first end  172  (e.g. front end comprising first end wall  192 ) to a cyclone second end  176  (e.g. rear end comprising second end wall  196 ), a cyclone air inlet  180  which enters cyclone  160  at a front portion of sidewall  168 , a cyclone air outlet  184  provided in cyclone second end wall  196 , and a cyclone dirt outlet  188 . Cyclone sidewall  168  includes an upper wall  169  and a lower wall  171 . As exemplified in  FIG. 6 , dirty air may enter cyclone  160  tangentially at cyclone air inlet  180  (which may be provided in the upper wall  169 ), and swirl (e.g. move cyclonically) through cyclone  160  to separate dirt from the air flow, and then exit cyclone  160  through cyclone air outlet  184 . The separated dirt may exit cyclone  160  through cyclone dirt outlet  188  and deposit into dirt collection chamber  164 . 
     As exemplified a vortex finder  204  may extend axially between cyclone first and second ends  172  and  176 . Vortex finder  204  may have any configuration known in the art. For example, vortex finder  204  may be connected to cyclone second end wall  196  and extend axially towards cyclone first end  172 . Vortex finder  204  may surround cyclone air outlet  184 , so that air exiting cyclone  160  travels downstream through vortex finder  204  to cyclone air outlet  184 . Vortex finder  204  may include filter media  206  (e.g. mesh) to capture large dirt particles (e.g. hair and coarse dust) that remains in the air flow exiting cyclone  160 . 
     It will be appreciated that if cyclone air inlet  180  is located at an upper end of the cyclone  160 , then inlet passage  128  may be located above the central longitudinal axis of cyclone  160  and preferably is located above cyclone  160 . For example, as exemplified in  FIGS. 1, 6 and 7 , cyclone air inlet  180  may be a tangential air inlet so that air entering the cyclone  160  will tend to rotate as the air travels axially through the cyclone  160 , thereby dis-entraining dirt and debris from the air flow, before leaving the cyclone via the air outlet  184 . Further, inlet passage  128  extends longitudinally between passage inlet end  124  (i.e., the dirty air inlet  116 ) and passage outlet end  130  along a longitudinal passage axis  364 , and passage outlet end  130  communicates (e.g. is positioned upstream) of cyclone air inlet  180 . Passage axis  364  may be linear, and all of the longitudinal passage axis  364  may be positioned above cyclone axis of rotation  484  when surface cleaning apparatus  100  is positioned with bottom  125  on a horizontal surface  584 . 
     Cyclone air inlet  180  may be positioned and constructed in any manner suitable for directing air tangentially into cyclone  160 . In the illustrated example of  FIG. 22 , cyclone air inlet  180  is formed as a curved passage extending from a cyclone air inlet upstream end  532  to a cyclone air inlet downstream end  536 . The cyclone air inlet downstream end  536  may be oriented to direct air substantially tangentially to the inner surface of sidewall  168 . As exemplified, cyclone air inlet  180  may be positioned above cyclone axis of rotation  484  and suction motor axis of rotation  540 . For example, cyclone air inlet  180  may be positioned at an upper end  544  of cyclone  160 . This allows gravity to assist with inhibiting dirt inside cyclone  160  from blocking or exiting cyclone air inlet  180 . This is because at least a portion of the cyclone  160  will be positioned below the cyclone air inlet  180  when apparatus  100  is held at various operating angles, so that the dirt inside will tend to fall away from cyclone air inlet  180 . 
     Still referring to  FIG. 22 , cyclone air inlet  180  is formed in cyclone sidewall  168  at cyclone first end  172 , and cyclone air outlet  184  is formed in cyclone second end wall  196  at cyclone second end  176 . As exemplified, air may exit cyclone air outlet  184  in a flow direction  616  that is generally parallel to the suction motor axis of rotation  540 . 
     As exemplified in  FIG. 6 , main body lower end  568  may comprise bottom  125 . In the illustrated example, when bottom  125  is placed on a horizontal surface, cyclone  160  may be oriented horizontally if bottom or base  125  is parallel to the cyclone axis. If will be appreciated that if bottom  125  is oriented at an angle to the horizontal, e.g., so that dirt air inlet  116  points downwardly when bottom  125  is on a horizontal surface, cyclone  160  may not be oriented horizontally when bottom  125  is on a horizontal surface. It will be appreciated that, as referred to herein, cyclone  160  being horizontal relates to the orientation if bottom  125  is parallel to the cyclone axis of rotation  484 . 
     As exemplified in  FIG. 5A , when inlet connector  128  is mounted to a wand  557  (i.e. rigid air flow conduit), the wand axis  559 , the inlet connector axis  364 , and the cyclone axis of rotation  484  may be parallel. An advantage of this embodiment is that This reduces bends in the air flow for improved air efficiency. It will be appreciated that only some of these axes may be parallel. For example, only the inlet connector axis  364  and the cyclone axis of rotation  484  may be parallel. 
     Positioning of the Dirt Collection Chamber 
     The following is a description of a dirt collection chamber that may be used by itself in any surface cleaning apparatus or in any combination or sub-combination with any other feature or features disclosed herein including the uniflow cyclone, the orientation of the suction motor, the lateral stability members, the air treatment member handle, the position and orientation of a driving handle, the pre-motor filter housing door, the air treatment member door actuator, the counterweight stand, the electrical coupling members and the accessory power connector. 
     In accordance with this aspect of the disclosure, a dirt collection chamber for a cyclone chamber may be provided external to and below the cyclone chamber. An advantage of this design is that a cyclone dirt outlet  188  may be provided in a lower portion of the cyclone chamber (e.g., cyclone dirt outlet  188  is provided in lower wall  171 ) such that dirt which remains in the cyclone chamber after termination of operation of the vacuum cleaner may fall into the dirt collection chamber when the vacuum cleaner is held with the cyclone extending horizontally and slightly upwardly. A further advantage is that the width of the vacuum cleaner may be narrower as the dirt collection chamber is not located on the lateral sides of the cyclone chamber. Therefore, as exemplified in  FIG. 18 , the maximum width of a handvac may be determined by the width of the suction motor housing or the width of the cyclone  160 . 
     As exemplified in  FIG. 18 , dirt collection chamber  164  extends around approximately one-half of cyclone  160 . As exemplified, partition wall  556  may circumscribe approximately one-half of cyclone  160 . In other embodiments, dirt collection chamber  164  may extend around less than or greater than one-half of cyclone  160 , and partition wall  556  may similarly circumscribe less than or greater than one-half of cyclone  160 . In alternative embodiments, dirt collection chamber  164  may not surround cyclone  160 . 
     It will be appreciated that cyclone sidewall  168  and dirt collection chamber sidewall  548  may have any construction suitable for separating the cyclone  160  from dirt collection chamber  164  and allowing the passage of dis-entrained dirt therebetween. For example, cyclone sidewall  168  and dirt collection chamber sidewall  548  may be discrete walls that are spaced apart and connected by a dirt outlet passage. As exemplified in  FIG. 18 , dirt collection chamber sidewall  548  is formed at least in part by portions of cyclone sidewall  168  and portions of cyclone unit exterior wall  552 . Similarly, cyclone sidewall  168  as shown is formed at least in part by portions of dirt collection chamber sidewall  548  and cyclone unit exterior wall  552 . Accordingly, the wall portion  556  in common between cyclone  160  and dirt collection chamber  164  may operate as a dividing wall. Sharing a common dividing wall may help reduce the overall size of the cyclone unit  112 , for a more compact design. 
     Returning to  FIG. 22 , cyclone  160  may include any dirt outlet  188  suitable for directing dis-entrained dirt from cyclone  160  to dirt collection chamber  164 . For example, dirt outlet  188  may be formed in or connected to one or more (or all) of cyclone sidewall  168  and cyclone end walls  192  and  196 . In the illustrated embodiment, dirt outlet  188  is formed in cyclone sidewall  168 . Dirt outlet  188  may have any shape and size suitable for allowing dirt particles to pass into dirt collection chamber  164 . In the illustrated embodiment, dirt outlet  188  is formed as a rectangular aperture in wall portion  556 . In alternative embodiment, dirt outlet  188  may be circular, triangular, or another regular or irregularly shaped aperture. As exemplified, cyclone dirt outlet  188  may be bounded in part by cyclone second end wall  196 . 
     It will be appreciated that cyclone dirt outlet  188  may be positioned anywhere at or between cyclone first and second ends  172  and  176 . In the illustrated embodiment, cyclone  160  is a uniflow cyclone and accordingly cyclone dirt outlet  188  is positioned at cyclone second end  176  proximate cyclone air outlet  184 . This allows the dirt and air to travel towards the same end of the cyclone  160  before parting ways—the air exiting through air outlet  184  and the dirt exiting through dirt outlet  188 . 
     In use, the air stream inside cyclone  160  swirls towards cyclone air outlet  184  at cyclone second end  176 , which dis-entrains dirt particles against cyclone sidewall  168 . Under the influence of the rearward air stream, the dirt particles travel towards cyclone second end  176  and exit through cyclone dirt outlet  188  to dirt collection chamber  164 . 
     Referring to  FIG. 18 , dirt collection chamber  164  may have any size and shape suitable to accommodate dirt separated by cyclone  160  during one or more uses. A larger dirt collection chamber  164  can store more dirt to allow apparatus  100  to run longer before emptying dirt collection chamber  164 , but will add bulk and weight to the apparatus  100 . A smaller dirt collection chamber  164  is smaller and lighter, but must be emptied more frequently. 
     Orientation of the Suction Motor 
     The following is a description of the orientation of a suction motor that may be used by itself in any surface cleaning apparatus or in any combination or sub-combination with any other feature or features disclosed herein including the uniflow cyclone, the positioning of the dirt collection chamber, the lateral stability members, the air treatment member handle, the position and orientation of a driving handle, the pre-motor filter housing door, the air treatment member door actuator, the counterweight stand, the electrical coupling members and the accessory power connector. 
     As exemplified in  FIG. 22 , in accordance with this aspect, the axis of rotation of the suction motor may be generally parallel to the cyclone axis of rotation and/or the inlet conduit axis. An advantage of this design is that the air may travel generally rearwardly from the cyclone air outlet to the suction motor air inlet, thereby reducing the backpressure through this portion of the vacuum cleaner due to a reduction in the number of bends in the air flow path. 
     As exemplified in  FIG. 22 , when surface cleaning apparatus  100  is positioned with bottom  125  on a horizontal surface  584 , the suction motor axis of rotation  540  may be generally horizontal. For example, cyclone sidewall  168  may extend generally horizontally between longitudinally spaced apart cyclone end walls  172  and  176 , when surface cleaning apparatus  100  is positioned with bottom  125  on a horizontal surface  584 . As exemplified, suction motor axis of rotation  540  may be generally parallel with cyclone axis of rotation  484 . This allows for fewer bends in the air flow between dirty air inlet  116  and clean air outlet  120 , which can result in reduced backpressure, all other elements remaining the same. 
     As exemplified, the suction motor axis of rotation  540  may be positioned below cyclone axis of rotation  484 . This may provide surface cleaning apparatus  100  with a relatively lower center of gravity for greater stability when surface cleaning apparatus  100  is positioned with bottom  125  on a horizontal surface  584 . In such a case, the pre-motor filter air inlet and outlet  236  and  240  may be axially offset as shown. In the illustrated example, filter housing air inlet axis  248  is located above and spaced apart from filter housing air outlet axis  252 . An advantage of this design is that one or both of the headers may be used to change to elevation at which the air travels rearwardly with without using a conduit with bends. For example, air may travel generally rearwardly (linearly) into the pre-motor filter housing and air may travel generally rearwardly (linearly) out of the pre-motor filter housing, but at a lower elevation. 
     In alternate embodiments, filter housing air inlet and outlet axes  248  and  252  may not be spaced apart (e.g. they may be collinear). 
     In alternate embodiments, it will be appreciated that suction motor and fan assembly  152  may be positioned in main body  104  with its axis of rotation  540  oriented in any direction. 
     Lateral Stability Members 
     The following is a description of the lateral stability members that may be used by itself in any surface cleaning apparatus or in any combination or sub-combination with any other feature or features disclosed herein including the uniflow cyclone, the positioning of the dirt collection chamber, the orientation of the suction motor, the air treatment member handle, the position and orientation of a driving handle, the pre-motor filter housing door, the air treatment member door actuator, the counterweight stand, the electrical coupling members and the accessory power connector. 
     Optionally, the air treatment member may be separable from the main body, such as for emptying, cleaning, or replacing the air treatment member or other internal components of the apparatus, such as the pre-motor filters. 
     In accordance with this aspect the air treatment member  112  is removable mountable to the main body  104  and is provided with lateral stability members. For example, the air treatment member  112  may abut against a front face of the main body  104  (see for example  FIG. 1 ). Optionally, one of the air treatment member  112  and the main body may be receivable in the other. Accordingly, when unlocked, the air treatment member  112  may be removed from the main body  104  by moving it forwardly. During use, a transverse force may be applied to the air treatment member  112 . As exemplified, inlet  116  is provided on the removable air treatment member  112 . Therefore, when used as part of a stickvac and handle  108  is driving connected to a surface cleaning head (see for example  FIG. 5 ), a force may be provided transverse to wand axis  559 . If sufficient pressure is applied, then the air treatment member may break off of the main body or the air tight seal between the air treatment member and the main body may be broken allowing air to bypass the surface cleaning head. The provision of the lateral stability members reinforces the joint of the air treatment member and the main body to resist such transverse forces. 
     The lateral stability members are provided internal of the handvac and may be provided on opposed facing faces of the air treatment member and the main body. The lateral stability members may comprise generally vertically extending inter-engagement members 
     Cyclone unit  112  may be securable to main body  104  in any manner that allows the cyclone unit  112  to be selectively separated and reconnected to main body  104 . For example, cyclone unit  112  and main body  104  may collectively include any releasable engagement members (e.g. latches, snaps, magnets, straps, etc.) suitable for releasably joining the cyclone unit  112  and main body  104 . Further, cyclone unit  112  and main body  104  may collectively include any actuators that allow selective manual release (i.e. by hand) of the releasable engagement member(s). The releasable engagement member(s) and the actuator(s) may be mechanical, electrical, and/or electro-mechanical in nature. 
     As exemplified in  FIGS. 9-11 , main body  104  and cyclone unit  112  are separably connected by a cyclone unit release lock  278 . As exemplified, cyclone unit release lock  278  includes a pair  280  of engagement members  304  and  308 , and a release actuator  328 . The release actuator  328  may be manually user operable (e.g. by hand) for selectably unlocking cyclone unit release lock  278  to allow main body  104  and cyclone unit  112  to separate. 
     In the illustrated example, cyclone unit  112  is also rotationally mounted to main body  104 . For example, cyclone unit  112  may be rotationally mounted to main body  104  at a position longitudinally spaced apart from cyclone unit release lock  278 . This allows cyclone unit  112  to rotationally separate from main body  104  when cyclone unit release lock  278  is unlocked (e.g. by operation of release actuator  328 ). In some embodiments, cyclone unit  112  may be rotationally mounted to main body  104  by a detachable pair  284  of engagement members  312  and  316 . This allows for the option of fully detaching cyclone unit  112  from main body  104 , such as to carry cyclone unit  112  to a garbage bin for emptying or cleaning for example. In alternative embodiments, second pair  284  of engagement members  312  and  316  may provide a permanent rotational connection that is not detachable. It will be appreciated that an alternate connection mechanism may be provided to secure the lower end of the air treatment member  112  and the main body  104  together when cyclone unit release lock  278  is engaged. 
     Cyclone unit release lock  278  and engagement member pair  284  may be positioned at any location on apparatus  100  suitable for securely joining the main body  104  and cyclone unit  112 . For example cyclone unit release lock  278  and engagement member pair  284  may be positioned at opposite ends of apparatus  100 , such as longitudinally spaced at apparatus upper end  288  and lower end  292  as shown. In the illustrated example, first cyclone unit engagement member  304  is positioned on cyclone unit upper end  348  and first main body engagement member is positioned on main body upper end  570 . In alternate embodiments, the lock positions may be reversed. 
     Cyclone unit release lock  278  and engagement member pair  284  may take any form suitable for separably joining main body  104  and cyclone unit  112 . For example, one or both engagement member pairs  280  and  284  may include a first engagement member removably receivable in a second engagement member. As exemplified, first engagement member pair  280  includes a first cyclone unit engagement member  304  and a first main body engagement member  308 , and second engagement member pair  284  includes a second cyclone unit engagement member  312  and a second main body engagement member  316 . 
     Referring to  FIG. 12 , first cyclone unit engagement member  304  and first main body engagement member  308  are shown formed as hooks which are sized and positioned to interlock when the cyclone unit  112  and main body  104  are brought together. Second cyclone unit engagement member  312  is shown formed as a transversely extending rod which is received in hook-like second main body engagement member  316  when the cyclone unit  112  and main body  104  are brought together. As exemplified, cyclone unit lower end  352  is rotationally mounted to main body lower end  568  when second engagement member pair  284  is connected. When connected, cyclone unit release lock  278  and engagement member pair  284  hold cyclone unit  112  in fluid communication with main body  104 , so that an air flow path is formed from dirty air inlet  116  to clean air outlet  120 . A gasket or the like may be provided to form an air tight seal. 
     As exemplified in  FIGS. 12-14 , one or more of engagement members  304 ,  308 ,  312 , and  316  may be movable to facilitate manual disconnection of the cyclone unit  112  from main body  104 . For example, one or more of engagement members  304 ,  308 ,  312 , and  316  may be movable away from the other engagement member of its respective engagement member pair  280  or  284  from a locked position to an unlocked position for disconnecting that engagement member pair  280  or  284 . It will be appreciated that an engagement member  304 ,  308 ,  312 , or  316  may be moveable in any direction. For example, it may be translatable in a linear direction or along a curved path, rotatable about any one or more axes, or combinations thereof. 
     As shown in  FIG. 13 , first cyclone unit engagement member  304  is in the open or unlocked position wherein it has been moved away from the closed or locked position shown in  FIG. 12  in which it engages first main body engagement member  308 , thereby disengaging the first engagement member pair  280 . As exemplified, first cyclone unit engagement member  304  is pivotally mounted to a first engagement member axle  324  for rotation about the first engagement member axis  320  that extends laterally and first cyclone unit engagement member  304  extends substantially rearwardly whereby rotation of first cyclone unit engagement member  304  about first engagement member axis  320  moves the first cyclone unit engagement member  304  substantially vertically. In this example, first cyclone unit engagement member  304  is formed as a lower upwardly facing hook, first main body engagement member  308  is formed as an upper downwardly facing hook, and first cyclone unit engagement member  304  is pivotal about first engagement member axis  320  to move first cyclone unit engagement member  304  downwardly away from first main body engagement member  308  from the locked position ( FIG. 12 ) to the unlocked position ( FIG. 13 ), thereby disconnecting the first engagement member pair  280 . 
     Once the first engagement member pair  280  is disconnected, the cyclone unit  112  and main body  104  may be separated at the apparatus upper end  288 , and then the cyclone unit  112  may be moved relative to the main body  104  to disconnect the second engagement member pair  284  thereby completing the disconnection of the cyclone unit  112  from the main body  104 . 
     Apparatus  100  may include any actuator  328  suitable for disengaging engagement member  304  and  308  to unlock cyclone unit release lock  278 . Actuator  328  may be provided on either of cyclone unit  112  or main body  104 . Preferably, the actuator  328  is manually operable (i.e. by hand) to allow selective disconnection of the engagement members  304  and  308 . In the illustrated embodiment, first main body engagement member  308  is connected to an actuator  328 . Actuator  328  may take any form such as a button as shown, a switch, or a slider for example. Actuator  328  may be connected to first main body engagement member  308  in manner suitable for directing the movement of first main body engagement member  308 . In the illustrated example, first main body engagement member  308  is integrally formed with a distal end of actuator  328 . In alternative embodiments, actuator  328  may be a discrete component that is rigidly or movably connected to first main body engagement member  308  directly or indirectly by way of one or more intermediary components. 
     As exemplified, a proximal end of actuator  328  may be pivotally mounted to cyclone unit  112  by first engagement member axle  324  for rotation about first engagement member axis  320 . In use, a user may depress actuator  328  to rotate actuator  328  and first cyclone unit engagement member  304  downwardly, thereby disconnecting the first engagement member pair  280 . 
     In some embodiments, first cyclone unit engagement member  304  may be biased to the locked position to mitigate the risk of first engagement member pair  280  becoming unlocked during use of apparatus  100 . In the illustrated example, a bias  332  biases first cyclone unit engagement member  304  to the open position. Bias  332  may be formed as a torsional spring, as shown, which is mounted to first engagement member axle  324 . A user may depress actuator  328  to move the first cyclone unit engagement member  304  against the bias of spring  332  and disconnect first engagement member pair  280 . 
     Reference is now made to  FIGS. 15 and 16 , which show apparatus  100  including an alternative first engagement member pair  280 . As exemplified, first cyclone unit engagement member  304  may include an engagement member arm  336  with an engagement member socket  340 , and first main body engagement member  308  may be formed as a peg. In the locked position ( FIG. 15 ), peg  308  may be received in engagement member socket  340  to securely join first engagement member pair  280 . In the unlocked position ( FIG. 16 ) peg  308  may be removed from engagement member socket  340  to disconnect first engagement member pair  280 . As exemplified, engagement member arm  336  may be resiliently bendable (i.e. as a living hinge) for moving first main body engagement member  308  between the locked and unlocked positions. For example, engagement member arm  336  can resiliently bend upwardly to remove peg  308  from engagement member socket  340  ( FIG. 16 ), and vice versa. Preferably, the resiliency of engagement member arm  336  biases first cyclone unit engagement member  304  towards the locked position. 
     Exemplary lateral stability members are shown in  FIGS. 26-30 . As exemplified, air treatment member  112  and main body  104  may collectively include one or more pairs of protrusions and recesses, which mate at the interface between air treatment member  112  and main body  104  when air treatment member  112  is connected to main body  104 . This helps provide a more robust separable connection between air treatment member  112  and main body  104  with enhanced strength and rigidity. Air treatment member rear end  436  and main body front end  432  may be provided with mating protrusions  620  that are receivable in recesses  624 . 
     Protrusions  620  and recesses  624  may have any size, shape, and position which allows the protrusions  620  to be received in the recesses  624  when air treatment member  112  and main body  104  are connected. As exemplified, each of protrusions  620  and recesses  624  may be formed as elongate segments which are continuous or have discontinuities. In the illustrated embodiment, each of protrusions  620  and recesses  624  extend longitudinally downwardly. 
     As exemplified in  FIGS. 26 and 27 , protrusions  620  are formed in cyclone unit upper end  348  (engagement member arm  336 ) and recesses  624  are formed in surface of main body upper end  570  against which engagement member arm  336  abuts. Protrusions  620  are received in recesses  624  when air treatment member  112  is connected to main body  104 . 
       FIG. 28  shows an alternate embodiment, in which cyclone unit upper end  348  includes recesses  624  and main body upper end  570  includes protrusions  620 . 
       FIG. 29  shows another alternate embodiment including protrusions  620  and recesses  624  extending across cyclone rear end wall  176  and filter housing front wall  216 . 
       FIG. 30  shows another embodiment including protrusions  620  extending across cyclone rear end wall  176  and filter housing front wall  216 . When air treatment member  112  is connected to main body  104 , protrusions  620  on cyclone rear end wall  176  contact filter housing front wall  216 , and protrusions  620  on filter housing front wall  216  contact cyclone rear end wall  176 . In this embodiment, protrusion  620  provide rigid beams at the interface between main body  104  and air treatment member  112  which may increase the rigidity and strength of the separable connection. 
     Air Treatment Member Handle 
     The following is a description of an air treatment member handle that may be used by itself in any surface cleaning apparatus or in any combination or sub-combination with any other feature or features disclosed herein including the uniflow cyclone, the positioning of the dirt collection chamber, the orientation of the suction motor, the lateral stability members, the position and orientation of a driving handle, the pre-motor filter housing door, the air treatment member door actuator, the counterweight stand, the electrical coupling members and the accessory power connector. 
     In accordance with this aspect, the air treatment member may include a handle in addition to the main body handle (“driving handle”). This allows a user to hold the main body and the air treatment member simultaneously, with different hands before, during, and after disconnecting the main body from the air treatment member. 
     In one embodiment, the air treatment member handle may for part of an air flow conduit of the air treatment member. Alternately or in addition, the air treatment member handle may extend along the axial direction of the air treatment member and/or may be on an upper portion thereof and/or may provide a gap for receiving fingers of the user. 
     As exemplified in  FIG. 11 , cyclone unit handle  344  is connected to cyclone unit  112  when cyclone unit  112  is disconnected from main body  104 , and driving handle  108  is connected to main body  104  when main body  104  is disconnected from cyclone unit  112 . Cyclone unit handle  344  may have any suitable size, shape, and position on cyclone unit  112  which allows a user to easily grasp the cyclone unit handle  344  by hand to carry the cyclone unit  112  (see  FIG. 10A ). In the illustrated embodiment, cyclone unit handle  344  is formed as a substantially cylindrical member, which extends rearwardly along cyclone unit upper portion  348 . In other embodiments, cyclone unit handle  344  may have a different regular or irregular cross-sectional shape, and may extend along a different portion of cyclone unit  112 , such as along lower portion  352 , or a lateral side  356  for example. As exemplified in  FIG. 6 , cyclone unit handle  344  may include a portion or gap  347  spaced from cyclone unit  112  whereby a finger receiving area  349  is provided between the cyclone unit handle  344  and the cyclone unit  112 . 
     Returning to  FIG. 11 , preferably apparatus  100  is configured to allow the user to take whatever action disconnects the main body  104  from air treatment member  112  while holding air treatment member handle  344  with one hand and holding driving handle  108  with the other hand. For example, cyclone unit handle  344  or driving handle  108  may be positioned proximate (e.g. within finger-reach of) an actuator that releases the connector(s) which hold air treatment member  112  and main body  104  together. This would allow the user to use a finger to operate the actuator while holding the handle  344  or  108  with the remaining fingers of their hand. In the illustrated embodiment, cyclone unit handle  344  and actuator  328  are both located on the cyclone unit upper portion  348  and in close proximity. This allows a user to hold air treatment member  112  by handle  344  while simultaneously operating actuator  328  with the same hand to disconnect air treatment member  112  from main body  104 . The user may also use the same hand to open a front door of the air treatment member as discussed subsequently in more detail. 
     Referring to  FIG. 6 , cyclone unit handle  344  is shown extending along a cyclone unit handle axis  360 . In some embodiments, cyclone unit handle axis  360  may be parallel with and may be coaxial with inlet connector axis  364 . This may promote a compact shape for apparatus  100  in contrast with handles with an axis that extends above the inlet connector axis  364 . 
     As exemplified in  FIGS. 1 and 17 , cyclone unit handle  344  may comprise an air flow passage (e.g. an air flow conduit). This may promote a compact design for apparatus  100  by reducing or eliminating the volume added to apparatus  100  to incorporate cyclone unit handle  344 . For example, an existing air flow conduit may be reshaped and/or repositioned to provide handle functionality. As exemplified in  FIG. 17 , handle  344  is positioned rearward and coaxial with the inlet conduit extending from dirty air inlet  116 . It will be appreciated that if the inlet to the air treatment member chamber (e.g., cyclone chamber  160 ) is rearward of the front of handle  344 , then part of handle  344  form part of inlet conduit  124 . Alternately, or in addition as exemplified in  FIG. 17 , handle  344  may provide part or all of a bleed air conduit  380  having a longitudinal passage axis  390 . Bleed conduit  380  provides a portion of the air flow path between the bleed air inlet  384  and the suction motor and fan assembly  152  and houses bleed valve  388 . The bleed valve  388  may be any suitable valve that known in the art, which typically open automatically in response to low pressure. For example, bleed valve  388  may be a pressure relief valve. Bleed valve  388  may help maintain adequate volumetric air flow through the suction motor and fan assembly  152  during low pressure events to avoid overheating of the suction motor and fan assembly  152 . Low pressure may occur where there is a partial or total blockage in the air flow upstream of the suction motor and fan assembly  152  (e.g. a plastic bag is blocking dirty air inlet  116 ). 
     It will be appreciated that cyclone unit handle  344  is grasped primarily when apparatus  100  is turned off (e.g. when separating, reconnecting, or transporting cyclone unit  112 ) so that there is little or no concern of the bleed air inlet  384  being blocked by a user&#39;s hands when apparatus  100  is turned on. 
       FIG. 17  exemplifies an optional air flow path from bleed air inlet  384  to suction motor and fan assembly  152  which bypasses cyclone  160  and pre-motor filters  228  and  232 . As exemplified, the air flow path may extend rearwardly through bleed valve conduit  380  to filter housing downstream header  260  bypassing filter housing upstream header  256  and pre-motor filters  228  and  232 . In alternate embodiments, the air flow path may extend through pre-motor filters  228  and  232  to filter fine particulates that may be present in the ambient air drawn into bleed air inlet  384 . For example, filter housing upstream header  256  may be positioned downstream of bleed valve  388  in the air flow path from bleed air inlet  384 . 
     Position and Orientation of a Driving Handle 
     The following is a description of a driving handle that may be used by itself in any surface cleaning apparatus or in any combination or sub-combination with any other feature or features disclosed herein including the uniflow cyclone, the positioning of the dirt collection chamber, the orientation of the suction motor, the lateral stability members, the air treatment member handle, the pre-motor filter housing door, the air treatment member door actuator, the counterweight stand, the electrical coupling members and the accessory power connector. 
     In accordance with this aspect, the driving handle is which extends upwardly and forwardly. Driving handle  108  may extend upwardly from the suction motor housing (e.g., an upper surface of the main body that houses the suction motor). Driving handle  108  may terminate at Or above an upper end of the handvac  100 . Accordingly, the inlet conduit axis  364  and/or the handle axis  360  may intersect the driving handle  108 . An advantage of this design is that the weight of the motor is below the hand grip. Further, the driving axis of the handvac when connected to a wand (the wand axis) is at an opposite end of the handle to the suction motor. This provides improved hand weight for a user. 
     As exemplified in  FIG. 6 , driving handle  108  may extend from its lower end  368  to its upper end  372  along a driving handle axis  376 . When surface cleaning apparatus  100  is positioned with bottom  125  on a horizontal surface  584  and the bottom  125  extends horizontally, driving handle axis  376  may extend generally upwardly and forwardly (e.g. at an angle  378  of less than 45 degrees to vertical) to provide a comfortable natural grip during use. 
     As exemplified, driving handle axis  376  may be at an angle to cyclone unit handle axis  360 . For example, axes  360  and  376  may be angularly offset by 30 degrees or more. This reflects that the driving handle  108  and cyclone unit handle  344  may have different functions. For example, the driving handle  108  may be configured to provide a comfortable grip for the user during use, and the cyclone unit handle  344  may be configured with a compact design. 
     In the illustrated embodiment, driving handle  108  includes a portion  377  spaced from main body  104  whereby a finger receiving area  379  is provided between the driving handle  108  and the main body  104 . As exemplified, driving handle  108  may be positioned at main body rear end  434  and longitudinally spaced apart from cyclone unit handle  344 . 
     Pre-Motor Filter Housing Door 
     The following is a description of a pre-motor filter door that may be used by itself in any surface cleaning apparatus or in any combination or sub-combination with any other feature or features disclosed herein including the uniflow cyclone, the positioning of the dirt collection chamber, the orientation of the suction motor, the lateral stability members, the air treatment member handle, the position and orientation of a driving handle, the air treatment member door actuator, the counterweight stand and the electrical coupling members. 
     In accordance with this aspect, a surface cleaning apparatus may have a pre-motor filter chamber which is closed by an openable door that is accessible when the air treatment member is removed from the remainder of the surface cleaning apparatus (as exemplified in  FIG. 6 ). A pre-motor filter may be accessed for cleaning or replacement when the door is opened. The pre-motor filter door may include a handle for user operation. The pre-motor filter chamber may be provided in the removable air treatment member  112  or the main body  104 . The door may be held in a closed position by a part of the surface cleaning apparatus that does not include the pre-motor filter chamber. For example, if the pre-motor filter chamber is provided in the air treatment member, then the door may be held closed by a part of the main body when the air treatment member is attached to the main body. Conversely, if the pre-motor filter chamber is provided in the main body as exemplified in  FIG. 8 , then the door may be held closed by a part of the air treatment member when the air treatment member is attached to the main body. An advantage of this design is that it allows a simpler design for the pre-motor filter door that is free of locking members such as latches. A further advantage is that unintentional user access to the pre-motor filter housing  208  may be prevented while the apparatus  100  is in operation. 
       FIGS. 8, 8A and 11  exemplify an embodiment in which pre-motor filter housing  208  is accessible when air treatment member  112  is disconnected from main body  104 . For example, one of the filter housing walls  216  and  220  (e.g., filter housing upstream wall  216  as exemplified in  FIG. 8 ) may be exposed when air treatment member  112  is disconnected from main body  104 . 
     The openable filter housing wall may be openable in any manner suitable for providing access to clean or replace the pre-motor filters inside. For example, the openable wall may be moveably mounted or removably mounted. Accordingly, filter housing wall  216  or  220  may be pivotally attached to the pre-motor filter housing  208 , slideably attached to the pre-motor filter housing  208 , or removable altogether from the pre-motor filter housing  208 . In the illustrated embodiment, filter housing upstream wall  216  is pivotally attached to pre-motor filter housing  208 . 
     As exemplified in  FIGS. 8A and 11 , filter housing upstream wall  216  is rotatable about a filter-housing wall pivot axis  392  between a closed position ( FIG. 11 ), and an open position ( FIG. 8A ). It will be appreciated that filter housing upstream wall  216  may be rotatable in any manner and direction suitable for moving the filter housing upstream wall  216  generally away from the pre-motor filter housing  208  to provide access to the pre-motor filters  228  and  232  inside. In the illustrated embodiment, filter housing upstream wall  216  is upwardly rotatable about a laterally extending (e.g. horizontal) filter housing wall pivot axis  392  located at an upper end  396  of the pre-motor filter housing  208 . As exemplified, the filter housing wall pivot axis  392  is transverse to (e.g. substantially perpendicular to) the inlet connector axis  364 , the cyclone unit handle axis  360 , and the filter housing air inlet axis  248 . 
     In alternative embodiments, filter housing upstream wall  216  may rotate in a different direction about a different axis. For example, filter housing upstream wall  216  may move laterally outwardly by rotation about a substantially vertical axis positioned proximate a left or right side of the pre-motor filter housing  208 . 
     Still referring to  FIGS. 8A and 11 , the filter housing upstream wall  216  may have any construction suitable for allowing the filter housing upstream wall  216  to rotate about the filter housing wall pivot axis  392 . For example, filter housing upstream wall  216  may be connected to filter housing sidewall  224  by a hinge  404  of any suitable type. In some embodiments, filter housing upstream wall  216  may be resiliently bendable to connect with pre-motor filter housing  208  by a living hinge. 
     Optionally, filter housing upstream wall  216  may be at least partially transparent (e.g., the wall may be made of a transparent material or it may have a window) to provide visibility of the upstream surface  268  ( FIG. 8A ) of the pre-motor filter inside. This would allow the user to inspect the pre-motor filter through the filter housing upstream wall  216 , without opening the pre-motor filter housing  208 , in order to assess whether to clean or replace the pre-motor filter. In alternative embodiments, the filter housing upstream wall  216  may be opaque, and the pre-motor filter may not be visible through the filter housing upstream wall  216 . 
     Still referring to  FIGS. 8A and 11 , the openable filter housing wall is preferably manually user openable (e.g. by hand). This allows the user to selectively open the openable filter housing wall to access the pre-motor filters inside. In the illustrated example, the filter housing upstream wall  216  includes a filter housing handle  408  that is user operable to move the filter housing upstream wall  216  between the open and closed positions. The filter housing handle  408  may have any construction that allows the user to easily grasp and pull the filter housing handle  408  to open the pre-motor filter housing  208 . In the illustrated example, the filter housing handle  408  extends outwardly from an end opposed to the hinged end (in this case lower end  412  of the filter housing upstream wall  216 ). Referring to  FIGS. 11 and 13 , the filter housing handle  408  extends from a filter housing handle inboard end  416  to a filter housing handle outboard end  420 . As exemplified, the filter housing handle inboard end  416  may be connected to an upstream face  424  of the filter housing upstream wall  216 . The filter housing outboard end  420  may include a gripping feature, which may be of any design such a lip  428 . In the illustrated example, lip  428  is curls approximately 90 degrees. 
     As exemplified in  FIG. 13 , the filter housing handle  408  may extend from filter housing upstream wall  216  outwardly towards cyclone unit  112 . In the illustrated example, a front end  432  of main body  104  is connectable to the rear end  436  of cyclone unit  112 , and filter housing handle  408  extends forwardly from filter housing upstream wall  216  towards cyclone unit  112 . As shown, the filter housing handle outboard end  420  extends into a handle recess  440  of cyclone unit  112  outside of cyclone  160  and dirt collection chamber  164 . In this way, the handle may overlap a portion of the cyclone chamber so as to have a longer length in the direction of the cyclone axis. This construction allows the filter housing handle  408  to have a greater dimension  444  between its inboard and outboard ends  416  and  420 , while permitting the filter housing upstream wall  216  to contact at least a portion of cyclone second wall  196  to fluidly connect the cyclone air outlet  184  to the filter housing air inlet  236 . In the illustrated example, the filter housing handle  408  extends from filter housing upstream wall lower end  412 , and cyclone unit handle recess  440  is provided in cyclone unit lower portion  352 . 
     Returning to  FIGS. 8A and 11 , in some embodiments, pre-motor filter housing  208  may be free of locking members, such as latches or clasps, which are operable to secure the openable wall in the closed position. Accordingly, when the main body  104  and cyclone unit  112  are connected together (see, e.g.  FIG. 1 ) filter housing handle  408  extends forwardly from filter housing upstream wall  216  and abuts a part of air treatment member  112 , e.g., rear end wall  196  of the air treatment member. 
     As exemplified in  FIG. 13 , the openable door of the pre-motor filter housing  208  may be held in its closed position by interaction with cyclone unit  112 , when cyclone unit  112  is connected to main body  104 . For example, at least a portion of cyclone unit rear end  436  may contact filter housing upstream wall  216  to hold the filter housing upstream wall  216  in its closed position. In the illustrated example, cyclone second wall  196  is bordered by a peripheral lip  448  which contacts upstream face  424  of filter housing upstream wall  216 , and cyclone air outlet  184  is bordered by a peripheral lip  452  that contacts a peripheral recess  456  of filter housing air inlet  236 . Peripheral lip  452  and recess  456  may form a substantially air tight connection between cyclone air outlet  184  and filter housing air inlet  236 . 
     In some embodiments, a gasket, such as an O-ring (not shown) may be provided and compressed when the air treatment member is attached to provide an air tight seal between the openable door and the rest of the pre-motor filter chamber. 
     Air Treatment Member Door Actuator 
     The following is a description of an air treatment member door actuator that may be used by itself in any surface cleaning apparatus or in any combination or sub-combination with any other feature or features disclosed herein including the uniflow cyclone, the positioning of the dirt collection chamber, the orientation of the suction motor, the lateral stability members, the air treatment member handle, the position and orientation of a driving handle, the pre-motor filter housing door, the counterweight stand, the electrical coupling members and the accessory power connector. 
     The air treatment member may include an openable door that provides access to empty or clean the air treatment member (e.g. to empty or clean a dirt collection region of the air treatment member). In accordance with this aspect, the air treatment member door may be openable by an actuator positioned within finger-reach of the air treatment member handle. This allows for one handed operation of the air treatment member door. 
     Reference is now made to  FIGS. 1 and 18 . In some embodiments, air treatment member  112  includes an openable wall (e.g., a door) to provide access to clean or empty the air treatment member (e.g., cyclone  160  and dirt collection chamber  164 ). Any portion of air treatment member  112  suitable for emptying air treatment member  112  may be openable. 
     In the illustrated example, air treatment member  112  includes an openable front end  472  wherein all of the front end is opeanable. As exemplified, the air treatment member may be a cyclone unit comprising a cyclone and a dirt collection chamber external to the cyclone and may have a front end  472  the includes cyclone first end wall  192 , and dirt collection chamber first end wall  476 . It will be appreciated that, in some embodiments, only a portion of the front end  472  may be openable. 
     The openable door may be openable in any manner suitable for providing access to clean or empty air treatment member  112 , e.g., cyclone  160  and dirt collection chamber  164 . For example, the door may be pivotally attached to the air treatment member  112  which is exemplified in  FIG. 18 , slideably attached to the air treatment member  112 , and/or removable altogether from the air treatment member  112 . 
     As exemplified, cyclone unit front door  472  is rotatable about a cyclone unit wall pivot axis  480  between a closed position ( FIG. 1 ), and an open position ( FIG. 18 ). It will be appreciated that cyclone unit front door  472  may be rotatable in any manner and direction suitable for moving cyclone unit front door  472  generally away from the cyclone unit  112  to provide access to the cyclone  160  and dirt collection chamber  164  inside. In the illustrated embodiment, cyclone unit front door  472  is downwardly rotatable about a laterally extending (e.g. horizontal) cyclone unit wall pivot axis  480  located at a lower portion  352  of the cyclone unit  112 . As exemplified, the cyclone unit wall pivot axis  480  is transverse to (e.g. substantially perpendicular to) the inlet connector axis  364 , the cyclone unit handle axis  360 , and the cyclone axis of rotation  484 . 
     In alternative embodiments, cyclone unit front door  472  may rotate in a different direction about a different axis. For example, cyclone unit front door  472  may move laterally outwardly by rotation about a substantially vertical axis positioned proximate a left or right side of the cyclone unit  112 . In other embodiments, cyclone unit front door  472  may move upwardly by rotation about a substantially horizontal axis positioned proximate cyclone unit lower portion  352 . 
     Still referring to  FIGS. 1 and 18 , the cyclone unit front door  472  may have any construction suitable for allowing the cyclone unit front door  472  to rotate about the cyclone unit wall pivot axis  480 . For example, cyclone unit front door  472  may be connected to cyclone unit  112  by a hinge  486  of any type known in the art. In some embodiments, cyclone unit front door  472  may be resiliently bendable to connect with cyclone unit  112  by a living hinge. 
     Still referring to  FIGS. 1 and 18 , the openable cyclone unit wall is locked in the closed position, and manually user openable (e.g. by hand). This allows the openable cyclone unit wall to remain closed while the apparatus  100  is operating, and allows the user to selectively open the openable cyclone unit wall to empty the cyclone  160  and dirt collection chamber  164  inside when the apparatus  100  is turned off. In the illustrated example, cyclone unit  112  includes a door lock  492 , which inhibits opening of cyclone unit front door  472  when engaged. Door lock  492  is user operable to disengage door lock  492  to thereby permit cyclone unit front door  472  to move to its open position. 
     Door lock  492  may be any type of lock suitable for retaining cyclone unit front door  472  in its closed position, and which is user releasable to permit cyclone unit  112  to open. In some embodiments, door lock  492  may have a manually operable actuator for moving the lock between its engaged and disengaged positions. In the illustrated embodiment, door lock  492  includes an engaging member  496  and an actuator  504 . 
     Preferably, actuator is positioned proximate the air treatment member handle  344  so that a user may operate actuator  504  with the same hand that is used to hold handle  504 . For example, actuator  504  may be located within close proximity (e.g. finger-reach) of handle  344 , e.g., it may be provided on or adjacent handle  344  and may be provided at the end of handle  344  at which the door is located. Accordingly, while holding handle  344 , the user may use their thumb of the same hand to operate actuator  504 , i.e., door release actuator  504  may be operated by the same hand which is holding the cyclone unit  112  for single-handed emptying of cyclone unit  112 . In the illustrated embodiment, unit door release actuator  504  is positioned forward of handle  344  on upper portion  348  (e.g. at a forward end of inlet passage  380 ). In other embodiments, door release actuator  504  may be located on handle  344 , or rearwardly of handle  344 . 
     As exemplified in  FIGS. 20 and 21 , the door release actuator  504  is manually user operable (i.e. by hand) to move the engaging member  496  between its engaged position ( FIG. 20 ) and its disengaged position ( FIG. 21 ). As exemplified, in the engaged position ( FIG. 20 ), door release actuator  504  may engage cyclone unit front door  472  to inhibit movement of front door  472  to its open position. This prevents front door  472  from rotating about its cyclone unit wall pivot axis  480  to its open position. In the disengaged position ( FIG. 21 ), door release actuator  504  releases cyclone unit front door  472  to permit front door  472  to move to its open position. 
     Referring to  FIGS. 19-21 , lock engaging member  496  may be of any construction having an engaged position for retaining the openable cyclone unit wall in its closed position, and a disengaged position for releasing the openable cyclone unit to move to its open position. In the illustrated example, lock engaging member  496  is connected to an exterior of air treatment member  112 . As exemplified, lock engaging member  496  has a front end  508  which is sized and positioned to releasably hook onto a recess  512  formed in cyclone unit front door  472  to retain the front door  472  in its closed position. 
     Lock engaging member  496  may be movable in any suitable manner between its engaged and disengaged positions. For example, lock engaging member  496  may be rotatable as shown, translatable, or combinations thereof. In the illustrated embodiment, lock engaging member  496  is pivotally connected to air treatment member  112  for rotation about a lock engaging member axis  516  ( FIG. 19 ) between its engaged and disengaged positions. As exemplified, in the engaged position, lock engaging member  496  may hook onto front wall lock recess  512 . Lock engaging member  496  may then be rotated about its axis  516  away from cyclone unit front door  472  to unhook from front wall lock recess  512 . Optionally, lock engaging member  496  may be biased to the locked position. For example, a biasing member (e.g. torsional spring, not shown) may bias lock engaging member  496  to rotate toward the closed position. 
     Still referring to  FIGS. 19-21 , door lock  492  may have any door release actuator  504  suitable for moving the lock engaging member  496  between its engaged and disengaged positions. In the illustrated example, door release actuator  504  is formed as a button which is operable to rotate lock engaging member  496  to its unlocked position. As exemplified, door release actuator  504  and lock engaging member  496  may both include abutments  520  and  524 , respectively, which make contact to move lock engaging member  496  when door release actuator  504  is depressed. In this example, when door release actuator  504  is depressed, abutment  520  moves abutment  524  downwardly which teeters lock engaging member  496  to rotate about its lock engaging member axis  516  to its disengaged position. It will be appreciated that door release actuator  504  may be movable in any suitable manner. For example, door release actuator  504  may be rotatable (e.g. pivotal) as shown, or translatable (e.g. slidable). In the illustrated example, door release actuator  504  is rotatably connected to cyclone unit  112  about a lock actuator axis  528  between its raised position ( FIG. 20 ) and its depressed position ( FIG. 21 ). 
     Counterweight Stand 
     The following is a description of a counterweight stand that may be used by itself in any surface cleaning apparatus or in any combination or sub-combination with any other feature or features disclosed herein including the uniflow cyclone, the positioning of the dirt collection chamber, the orientation of the suction motor, the lateral stability members, the air treatment member handle, the position and orientation of a driving handle, the pre-motor filter housing door, the air treatment member door actuator, the electrical coupling members and the accessory power connector. 
     In accordance with this aspect, the apparatus may include a counterweight positioned to adjust the apparatus center of gravity for reducing user-torque required to orient the apparatus at common operating angles. The counterweight may be located at a lower end of the main body to provide a stand for supporting the apparatus on a horizontal surface. The counterweight may be formed by a removable member (e.g. energy storage member), or a permanently attached or integrally molded member (e.g. ribs). 
     As exemplified in  FIG. 23 , apparatus  100  includes a counterweight stand  564 . The counterweight stand  564  may have any configuration suitable for helping to support apparatus  100  on horizontal surface and for influencing the center of gravity of apparatus  100 . As exemplified, counterweight stand  564  may be connected to apparatus lower end  292  for supporting apparatus  100  when apparatus lower end  292  is placed on a horizontal surface (e.g. for storage). In various embodiments, counterweight stand  564  may be connected to main body  104 , air treatment member  112 , or both. In the illustrated embodiment, counterweight stand  564  is connected to main body lower end  568  to define at least a portion of a lower wall of main body  104  for supporting apparatus  100  on a horizontal surface. 
     Counterweight stand  564  may be of any size and weight suitable for providing stable support and for influencing the apparatus center of gravity. For example, counterweight stand  564  may be formed of the same material as main body exterior wall  212  (e.g. plastic), and may be formed as a solid member, a hollow member, a porous member, or a plurality of spaced apart members. In the illustrated embodiment, counterweight stand  564  is formed as a plurality of spaced apart counterweight ribs  572  that are integrally formed with the main body exterior wall  212 . As exemplified, counterweight ribs  572  may be rearwardly extending and laterally spaced apart. This allows the counterweight ribs  572  to be distributed across a large area to form a base that nay itself or with bottom  125  stably support the apparatus  100  on a horizontal surface. The collective weight of ribs  572 , and thus their influence on the apparatus center of gravity, is determined by varying the number, density, spacing, and distribution of the counterweight ribs  572 . In alternative embodiments, counterweight stand  564  may be formed by a hollow member, and the weight of the counterweight stand  564  is determined by the fill density inside the block. In some embodiments, counterweight stand  564  may be formed from a different material than main body exterior wall  212 , such as a material of greater density to provide greater stability and influence on center of gravity. 
     Still referring to  FIG. 23 , the counterweight stand  564  may be integrally formed, permanently connected, or removably connected to apparatus  100 . In the illustrated embodiment, counterweight stand  564  is permanently connected to apparatus  100 . As exemplified, apparatus  100  may be a corded appliance having a power cord connector  576  for permanently or removably receiving a power cord (not shown) that is connectable to an external power source (e.g. wall outlet). Turning to  FIGS. 4 and 24 , another embodiment of apparatus  100  is shown including a counterweight stand  564  formed as an energy storage member  580  (e.g. battery). Energy storage member  580  may be permanently or removably connected to apparatus  100 , and may have a size and weight suitable for helping to support apparatus  100  on a horizontal surface  584  and influencing the center of gravity of apparatus  100 . 
     Electrical Coupling Members 
     The following is a description of a electrical coupling members that may be used by itself in any surface cleaning apparatus or in any combination or sub-combination with any other feature or features disclosed herein including the uniflow cyclone, the positioning of the dirt collection chamber, the orientation of the suction motor, the lateral stability members, the air treatment member handle, the position and orientation of a driving handle, the pre-motor filter housing door, the air treatment member door actuator, the counterweight stand and the accessory power connector. 
     In accordance with this aspect, the apparatus may include an electrical outlet with electrical conductor element(s) that are movable from a circuit closed position to a circuit open position upon removal of an accessory tool such as a wand, crevice tool, mini brush or the like. The accessory tool which is mounted on the apparatus may have a member which engages a driven member on the apparatus. When engaged, the driven member mechanically moves an element of the circuit to open the circuit so that the electrical conductor elements on the apparatus are not live. This allows the electrical outlet to be safe to touch when the accessory tool is disconnected. 
     Referring to  FIG. 1 , connector  128  may be any suitable connector that is operable to connect to, and preferably detachably connect to, a hose, cleaning tool or other accessory tool. Optionally, in addition to providing an air flow connection, connector  128  may also include an electrical connection. Providing an electrical connection may allow accessory tools that are coupled to the connector  128  to be powered by the surface cleaning apparatus  100 . For example, the surface cleaning unit  100  can be used to provide both power and suction to a surface cleaning head, or other suitable accessory tool. In the illustrated embodiment, the connector  128  includes an electrical outlet  144  in the form of a female socket member, and a corresponding male connector member may be provided on the hose, cleaning tool or other accessory tool that is connected to the connector inlet end  124 . In other embodiments, electrical outlet  144  may include male connectors. 
     As exemplified in  FIG. 25 , apparatus  100  includes an electrical circuit  624  between a source of power and electrical conductor elements  588 . The source of power may be an energy storage member  580  (e.g. battery) or a power cord  628  (connectable to an external power outlet), for example. In accordance with this aspect, electrical conductor elements  588  may be de-energized when not connected with a mating electrical coupling (e.g. of a power accessory). This may prevent user injury from being hurt by inadvertent contact with the electrical conductor elements  588 . 
     The electrical circuit  624  may include two or more electrical conductor elements  588 , at least one of which, and preferably two of which, may be movable between a circuit closed position and a circuit open position, and biased to the circuit open position. In the circuit closed position, the electrical conductor element  588  is electrically connected to the source of power. In the circuit open position, the electrical conductor  588  is electrically disconnected from the source of power. Accordingly, at least one of the electrical conductor elements  588  is normally electrically disconnected from the source of power, which may prevent accidental electric shock. In use, the electrical conductor element  588  is moved to the circuit closed position upon attaching an accessory tool to dirty air inlet  116 . 
     In one embodiment, the electrical conductor elements  588  may be moved to the circuit closed position by engagement with the electrical conductor elements of an accessory tool. Accordingly, when the accessory tool is mounted on inlet  116 , the electrical conductor elements of the accessory tool may drive electrical conductor elements  588  to the circuit closed position. 
     As exemplified, electrical conductor elements  588  may be a rigid rod movably mounted in a housing  596  of electrical outlet  144 . Each electrical conductor element  588  extends from a first contact end  640  to a second contact end  644 . The first contact end  640  may be an accessory tool contact end which makes electrical contact with a mating electrical conductor element of an attached accessory tool. The second contact ends  644  may be a terminal end contact end which makes electrical contact with the terminal ends  636  of electrically conductive members  590  when the electrical conductor elements  588  are in a circuit closed position. Accordingly, when an accessory tool is electrically connected to electrical outlet  144  and electrical conductor elements  588  are in the circuit closed position, the conductor element  588  can conduct electricity from the source of power to the connected accessory tool. 
     It will be appreciated that electrically conductive members (e.g., wires)  590  extend from the source of power to terminal ends  636 . One or both of electrical conductor elements  588  may be movable between a circuit closed position, in which second contact end  644  contacts terminal end  636  of an electrically conductive member  590 , and a circuit open position, in which second contact end  644  is spaced apart from the terminal ends  636  of electrically conductive members  590 . For example, one or both of electrical conductor elements  588  may be axially slidable in electrical outlet housing between the circuit open and circuit closed positions. In the illustrated example, electrical conductor elements  588  are rearwardly slideable in rearwardly extending housing channels  604  formed in electrical outlet housing  596 . 
     In some embodiments, the first end  640  of one or both of electrical conductor elements  588  may be recessed into the electrical outlet  144  when in the circuit open position. For example, first end  640  may be positioned rearwardly of electrical outlet front end  608 . 
     Electrical conductor element  588  may be biased to the circuit open position in any manner. For example, electrical outlet  144  includes a biasing member  648  that applies a biasing force urging electrical conductor element  588  toward the circuit open position. In the illustrated example, biasing member  648  is a compression spring positioned between the electrical conductor element  588  and the terminal end  636  of electrically conductive member  590  which urges electrical conductor element  588  forwardly. The force of biasing member  648  may be overcome when connecting an accessory tool to dirty air inlet  116  to move the electrical conductor element  588  rearwardly to the circuit closed position. Preferably, biasing member  648  is substantially non-electrically conductive. For example, biasing member  648  may be formed of (or coated with) plastic, rubber, a non-conductive metal or another substantially non-electrically conductive material. This helps to prevent biasing member  648  from short circuiting electrical circuit  624  or electrically connecting electrical conductor element  588  and terminal end  632  when the electrical conductor element  588  is in the closed position. 
     It will be appreciated that, in an alternate embodiment, electrical conductor elements  588  may be mounted in a moveable (e.g., plastic or other non-conductive material) housing and the housing may have an engagement member that is engaged by, e.g., a protrusion or finger provided on the accessory tool. In this way, the electrical conductor elements of the accessory tool need not be used to drive the circuit  624  to a closed position. 
     In some embodiments, main power switch  650 , which is movable between a circuit closed position and a circuit open position to energize the suction motor, may be part of electrical circuit  642 . The power switch may be manually user operable. In the circuit open position, power switch  650  electrically disconnects electrical terminal end  636  from the power source. In the circuit closed position, power switch  650  electrically connects circuit terminal end  636  with the power source. 
     Accessory Power Connection on Removeable Air Treatment Member 
     The following is a description of an electrical coupling members that may be used by itself in any surface cleaning apparatus or in any combination or sub-combination with any other feature or features disclosed herein including the uniflow cyclone, the positioning of the dirt collection chamber, the orientation of the suction motor, the lateral stability members, the air treatment member handle, the position and orientation of a driving handle, the pre-motor filter housing door, the air treatment member door actuator the counterweight stand and the electrical coupling members. 
     In accordance with this aspect, the surface cleaning apparatus  100  includes a power connector  144  (which may be referred to as an accessory power connector) for an accessory (e.g., a powered floor cleaner head). The power connector  144  for the accessory is provided on a part of the air treatment member that is moveable with respect to another part of the air treatment member and/or the main body of the hand vac. For example, the power connector  144  may be on a removeable bin assembly or air treatment member  112 . The power connector  144  for the accessory may be on a front  121  of the surface cleaning apparatus  100 . 
     An advantage of this aspect is that the accessory power connector  144  may be part or an openable portion of an air treatment member or a removable portion of an air treatment member or an air treatment member that is removable when closed. For example, if the inlet conduit or nozzle of the hand vacuum cleaner is part of a removable air treatment member, the accessory power connector  144  may be part of the removable assembly, thereby enabling the accessory power connector  144  to be provided at a location adjacent the nozzle. 
     As exemplified in  FIGS. 31 to 38 , the surface cleaning apparatus  100  may include an electrical connector  144  for providing power to an upstream attachment (e.g., a surface cleaning head or another cleaning tool). As shown, connector  144  may extend from a front connector end  271  along a connector axis  274  to a rear connector end  275  (see  FIG. 32 ). Connector axis  274  may be parallel to one or more of nozzle axis  364 , cyclone axis  484 , and motor axis  540 . In the illustrated embodiment, connector axis  274  is parallel to nozzle axis  364 , cyclone axis  484 , and motor axis  540 . Part or all of the accessory power connector  144  may extend forwardly of the bin assembly  241 . Accordingly, when a cleaning tool is connected to the air treatment member  112 , the cleaning tool is connected in air flow communication with the air treatment member  112  (e.g., via the inlet  128 ) and (e.g., concurrently) the cleaning tool is electrically connected to the air treatment member  112  (e.g., via connector  144 ). 
     In some embodiments, the surface cleaning apparatus  100  may include one or more electrical conductors or cables  590  which extend from electrical connector  144 , e.g., rearwardly, to electrically couple accessory electrical connector  144  with a source of power (e.g., the power cord  201  in the illustrated example or one or more on board energy storage members). The source of power is in the main body  108 , and the cables  590  extend rearwardly through the bin assembly  241  and further cables  590  extend through the main body to the source of power. 
     The air treatment member  112  and/or bin assembly  241  includes an air treatment member electrical connector  282  to electrically couple the air treatment member  112  and/or bin assembly  241  and the main body  108 . The main body  108  includes a main body electrical connector  283  to be coupled to the air treatment member electrical connector  282  of the air treatment member  112  and/or bin assembly  241  (connectors  282 ,  283  are shown decoupled in  FIG. 34 ), to electrically join the accessory power connector  144  mounted to the removeable air treatment member  112  and/or bin assembly  241  to the source of power in the main body  108  (e.g., to couple the cables  590  in the bin to the cables  590  in the body  108 ). 
     The body electrical connector  283  may extend from or be adjacent to a surface of the main body that abuts a surface of the air treatment member when the air treatment member  112  and/or bin assembly  241  is mounted to the body  108  in air flow communication with the body  108 . Similarly, the bin electrical connector  282  may extend from or be adjacent to a surface of the bin  112  and/or bin assembly  241  that abuts a surface of the body  108  when the air treatment member  112  is mounted to the body  108  in air flow communication with the body  108 . The bin electrical connector  282  may be directed rearwardly from the bin assembly  241 , and the body connector  283  may be directed forwardly from the body  108 . Accordingly, the air treatment member  112  and/or bin assembly  241  is concurrently connectable in air flow communication with the main body  108  and electrically connectable to the main body  108  when the air treatment member  112  and/or bin assembly  241  is mounted to the main body  108 . It will be appreciated that the bin electrical connector  282  and the body electrical connector  283  may be provided at any location which enables the bin electrical connector  282  and the body electrical connector  283  to be electrically connected to each other when the bin  112  and/or bin assembly  241  is mounted to the main body  108 . 
     The accessory power connector  144  and the main body electrical connector  283  may each be a female connector, and the air treatment member electrical connector  282  may be a male connector. However, it will be appreciated that any other combination of male and female connectors may be used, and, in some examples, there may be multiple accessory power connectors  144 , main body connectors  283 , and/or air treatment member connectors  282 . If the accessory power connector  144  and/or the main body connector  283  is a male connector, the surface cleaning apparatus  100  may include a switch to turn off power to the accessory power connector  144  and/or the main body connector  283 . 
     The accessory power connector  144  may be on an openable door of the air treatment member  112 . As exemplified in  FIG. 21 , an air treatment member  112  may have an openable door  472  (e.g., an openable front door or end). In some examples, the accessory power connector  144  is mounted on an openable door such as door  472  of the embodiment shown in  FIG. 21 . 
     As exemplified in  FIG. 32 , the surface cleaning apparatus  100  may include an inlet conduit  128  having the dirty air inlet  116 , and the accessory electrical connector  144  may be provided adjacent the inlet conduit  128 . The inlet conduit  128  may be provided at an upper end  123  of the surface cleaning apparatus  100 . 
     As exemplified in  FIGS. 32 and 33 , the bin electrical connector  282  may be provided at a lower end  125  of the air treatment member  112  and/or the bin assembly  241 . Electrical connectors  144 ,  282  of the air treatment member  112  may be on opposite sides (e.g., lateral sides) of the surface cleaning apparatus. For example, the electrical connectors  144 ,  282  of the air treatment member  112  may be on opposite sides of a vertical line through the centre of gravity and/or on opposite sides of a horizontal line through the centre of gravity. Maneuverability may be facilitated by having the electrical connectors  144 ,  282  on either side of the centre of gravity. 
     It will be understood that the connectors  144 ,  282 ,  283  may be any suitable electrical connectors and may be arranged in any suitable way to permit electrically coupling the accessory to the power source of the main body through the bin assembly. As illustrated, the connectors  144 ,  282 ,  283  may be rigidly mounted, which may facilitate making an electrical connection concurrently when establishing air flow connections. Alternatively, one or more connector  144 ,  282 ,  283  may be a pig tail connector. 
     The electrical conductors or cables  590  may take any suitable path through the bin assembly  241  and/or main body  108 . The air treatment member  112  comprises electrical conductors  590  that extend along or through a portion of the air treatment member  112  from the air treatment member electrical connector  282  to the cleaning tool electrical connector  144 . Optionally at least a portion of the electrical conductors  590  extending along an outer surface  291  of the walls of the cyclone chamber  160  and/or the dirt collection chamber  164 . 
     As illustrated in  FIG. 32 , the air treatment member  112  may comprise electrical conductors  590  that extend along a front end of the bin assembly  241 . For example, the electrical connectors may extend along an outer surface of a front end  121  of the air treatment member  112 . The electrical conductors  590  also extend along a lower end  125  of the air treatment member  112 . The electrical conductors  590  may extend along an outer surface of a bottom end of the dirt collector  164 . The bin assembly  241  includes a cover  298  mounted to the air treatment member  112  to overly that electrical conductors  590  if the electrical conductors extend over outer surfaces of the air treatment member  112  (e.g., outer surfaces of the dirt chamber or cyclone chamber). 
     As illustrated in  FIG. 32 , the conductors  590  extend from the cord  201  up through the handle  108  (i.e., the hand grip portion  219 ), into the motor housing  156  through a grommet  294  to the motor  152  to supply power to the motor  152 . The electrical conductors  590  also extend from the motor  152  out of the motor housing  156  through the grommet  294  then between the motor housing  156  and the outer housing of main body  108 , through a bleed valve housing  296 , out of the bleed valve housing  296  through an aperture and then between the premotor filter housing  208  and the outer housing of the main body  108  to the body connector  283 . It will be appreciated that the electrical conductors  590  in the main body  108  may follow any route through the main body  108 . 
     The body connector  283  couples to the bin connector  282  to supply power to the bin connector  282 . Electrical conductors extend from the bin connecter  282  along, e.g., an outer surface of the walls of the dirt chamber  164  at the bottom end of the dirt chamber  164  to the front of the dirt chamber  164 , and then up an outer surface of the dirt assembly  164  at the front of the dirt chamber  164  and up an outer surface of the walls of the cyclone chamber  160  at a front end of the cyclone chamber  160  to the accessory power connector  144 . Along the outer surfaces of the walls of the dirt chamber  164  and cyclone chamber  160 , the conductors  590  are optionally covered by an outer cover  298  of the bin assembly  241 . 
     If the rear end  133  of the air treatment member  112  is openable, then no electrical conductors may extend across the rear end  133 . For example, the rear end  133  of the air treatment member  112  may include an openable door  300 . The door  300  ( FIGS. 33 to 37 ) may be pivotally secured to the air treatment member  112 , and moveable between an operating position ( FIGS. 33 and 34 ) and an emptying position ( FIGS. 36 and 37 ). As illustrated in  FIG. 35 , the door  300  may be secured by a latch  302  inside the flange  242 . An actuator  303  within the flange  242  may be accessible when the bin assembly  241  and/or air treatment member  112  is removed from the main body  108  (e.g., and not accessible when the bin assembly  241  and/or air treatment member  112  is not removed from the main body  108 ). 
     In the emptying position one or both of the cyclone chamber  160  and the dirt collection chamber  164  may be opened to remove dirt. In some examples, opening the rear door  300  also opens the dirt outlet  188  (e.g., moves one wall defining a part of a perimeter of the dirt outlet  188  away from another wall defining another portion of the perimeter of the dirt outlet  188 ). It will be appreciated that, optionally, the bin connector  282  may be part of the openable rear end  133 . 
     The electrical conductors or cables  590  may be any electrical connector such as wires. Alternately, they may be flat conductors. The electrical conductors  590  may comprise flat conductors that have a height and a width perpendicular to the height, wherein the height and the width are dimensioned in a plane that is perpendicular to an extension direction of the conductor, and the width is the longest distance across the conductor in the plane and the height is perpendicular to the width. The electrical conductors  590  may have a depth (e.g., a height) in a direction that extends in an outward direction to a wall of a portion of the air treatment member  112  and a width in a direction parallel to a wall of the portion of the air treatment member  112  and the width is greater than the depth or height. For example, if as exemplified in  FIG. 32 , the electrical conductors  590  extends along the surface to which reference numeral 292 points in  FIG. 34 , then the height is in the forward direction and the width is in the lateral, side to side, direction). One or more conductor of the surface cleaning apparatus  100  may have a height of 0.01-5 mm, 0.5-5 mm, 0.5-3 mm or 1-3 mm. One or more conductor of the surface cleaning apparatus  100  may have a width of 0.25-15 mm, 1-10 mm, or 2-7 mm. Using a flat conductor may allow for sharper bends in a conduction path. 
     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.