Patent Publication Number: US-2023148809-A1

Title: Handheld extraction cleaner

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application claims the benefit of U.S. Provisional Application No. 63/280,176, filed Nov. 17, 2021, which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     Extraction cleaners can be embodied as upright units or portable, hand-carriable units. Handheld extraction cleaners include a cleaning solution supply tank and a recovery tank. These extraction cleaners typically have a suction source including a vacuum motor that powers an impeller to create low pressure on one side of the impeller and higher pressure on the other side thereof. The recovery tank is typically positioned between the low pressure side of the impeller and a suction nozzle to remove fluid from a surface and deposit it in the recovery tank. 
     A noted problem with handheld extraction cleaners is that, due to their compact and portable nature, space is at a premium. Accordingly, the supply tank and recovery tank necessarily have a limited capacity. Agitators may be undersized or eliminated altogether. It is also often necessary to hold the extraction cleaner at a particular angle to minimize the likelihood of liquid entering the suction source or leaking out of the suction nozzle. 
     BRIEF SUMMARY 
     Aspects of the disclosure relate to a handheld extraction cleaner having a fluid delivery system for storing cleaning fluid and delivering the cleaning fluid to the surface to be cleaned and a recovery system for removing the spent cleaning fluid and debris from the surface to be cleaned and storing the spent cleaning fluid and debris. 
     According to one aspect of the disclosure, the handheld extraction cleaner includes a supply tank, a suction nozzle, a recovery tank, and a vacuum motor, all of which are carried by a unitary body having a carry handle, where the recovery tank is viewable by a user holding the carry handle and operating the extraction cleaner. The recovery tank includes a tank body defining a collection chamber, the tank body having a first side portion and a second side portion, wherein the first side portion of the recovery tank is disposed laterally outwardly of a first lateral side of a housing of the unitary body and the second side portion of the recovery tank is disposed laterally outwardly of the second lateral side of a housing of the unitary body. 
     In this and other embodiments, the recovery tank has a level viewing window located on at least one, and optionally both, of the side portions of the tank. 
     In this and other embodiments, the recovery tank improves cleaning liquid drainage and usable tank volume in multiple orientations. The side portions and bottom of the recovery tank have a shape tending to direct dirty liquid away from an inlet of the tank and toward an outlet of the tank. 
     In this and other embodiments, the recovery tank has a drain plug that automatically seals an outlet of the tank when the recovery tank is mounted to a tank receiver of the unitary body. 
     In this and other embodiments, the extraction cleaner includes an integrated modular recovery assembly including at least the suction nozzle and the recovery tank, where the integrated modular recovery assembly is removable from a housing of the body as a single module, such that the suction nozzle is removable simultaneously with the recovery tank. 
     According to another aspect of the disclosure, the handheld extraction cleaner includes a supply tank, a suction nozzle, a recovery tank, and a vacuum motor, all of which are carried by a unitary body having a carry handle, where the recovery tank has a drain plug that automatically seals an outlet of the tank when the recovery tank is mounted to a tank receiver of the unitary body. 
     In this and other embodiments, the extraction cleaner has an auto-close feature for the recovery tank, wherein the plug is automatically moved to the closed position by the mounting of the recovery tank in the tank receiver. The auto-close feature can comprise a blocker on a housing of the unitary body that is positioned to push the plug to the closed position as the recovery tank is seated in the tank receiver. 
     According to yet another aspect of the disclosure, the handheld extraction cleaner includes a suction nozzle, a recovery tank, and an agitator, all of which are carried by a unitary body having a carry handle. The agitator is disposed rearwardly of the suction nozzle and forwardly of the recovery tank, wherein the agitator slides out from a first lateral side of the unitary body. 
     In this and other embodiments, the agitator has a handle to facilitate removal of the agitator from an agitator receiver. Optionally, the agitator is exchangeable with a different agitator. 
     According to still another aspect of the disclosure, the handheld extraction cleaner includes a supply tank, a suction nozzle, a recovery tank, and a vacuum motor, all of which are carried by a unitary body having a carry handle, where the suction nozzle comprises a cleaning angle guide skid to orient the extraction cleaner at a predetermined cleaning angle for efficient extraction with respect to a surface to be cleaned. 
     In this and other embodiments, the cleaning angle guide skid can include a front ski and side skis behind the front ski, the front ski extending across a front of the suction nozzle and substantially the width of a nozzle inlet of the suction nozzle, and the side skis extending rearwardly of the nozzle inlet and disposed on either side of an agitation element carried by the unitary body. 
     According to a further aspect of the disclosure, the handheld extraction cleaner includes a supply tank, a recovery tank, and a vacuum motor, all of which are carried by a unitary body having a carry handle, where the supply tank is a non-removable part located rearwardly of the recovery tank, the vacuum motor, and the carry handle. 
     In this and other embodiments, the supply tank has a pivotable fill cap disposed at a rearward end of the carry handle. 
     In this and other embodiments, the unitary body comprises a housing that partially wraps around the supply tank while leaving a portion of the supply tank exposed to form an exterior surface of the extraction cleaner, the exposed portion of the supply tank forming a viewing window that permits a user to ascertain the liquid fill level inside the supply tank. 
     In this and other embodiments, the supply tank is located rearwardly of one or more of a suction nozzle, an agitator, a pump, and a battery. Optionally, the pump and/or battery is disposed below the carry handle. 
     These and other features and advantages of the present disclosure will become apparent from the following description of particular embodiments, when viewed in accordance with the accompanying drawings and appended claims. 
     Before the embodiments of the invention are explained in detail, it is to be understood that the invention is not limited to the details of operation or to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention may be implemented in various other embodiments and of being practiced or being carried out in alternative ways not expressly disclosed herein. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including” and “comprising” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items and equivalents thereof. Further, enumeration may be used in the description of various embodiments. Unless otherwise expressly stated, the use of enumeration should not be construed as limiting the invention to any specific order or number of components. Nor should the use of enumeration be construed as excluding from the scope of the invention any additional steps or components that might be combined with or into the enumerated steps or components. Any reference to claim elements as “at least one of X, Y and Z” is meant to include any one of X, Y or Z individually, and any combination of X, Y and Z, for example, X, Y, Z; X, Y; X, Z; and Y, Z. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings: 
         FIG.  1    is a perspective view of a handheld extraction cleaner according to one aspect of the disclosure; 
         FIG.  2    is a cross-sectional perspective view of the handheld extraction cleaner, taken through line II-II of  FIG.  1   ; 
         FIG.  3    is a side view of the handheld extraction cleaner in one example of a normal use position; 
         FIG.  4    is a view showing a fluid delivery system of the handheld extraction cleaner, with components of the fluid delivery system shown in isolation, the fluid delivery system including a supply tank; 
         FIG.  5    is a close-up sectional view of a rear portion of the handheld extraction cleaner, taken through line II-II of  FIG.  1   , showing the supply tank; 
         FIG.  6    is a sectional view showing a recovery system of the handheld extraction cleaner, taken through line VI-VI of  FIG.  1   , the recovery system including a recovery tank; 
         FIG.  7    is a rear perspective, partially-exploded view of the handheld extraction cleaner, showing removal of a tank assembly from a tank receiver, movement of a recovery tank drain plug to an open position, and movement of a supply tank fill cap to an open position; 
         FIG.  8    is a front perspective, partially-exploded view of the handheld extraction cleaner, showing removal of a nozzle cover and an agitator from the tank assembly; 
         FIG.  9    is a close-up sectional view taken through line VI-VI of  FIG.  1   , showing the drain plug of the recovery tank in an open position; 
         FIG.  10    is a close-up sectional view taken through line VI-VI of  FIG.  1   , showing the drain plug of the recovery tank in an intermediate position between the open and closed positions; 
         FIG.  11    is a close-up sectional view taken through line VI-VI of  FIG.  1   , showing the drain plug of the recovery tank in a closed position; 
         FIG.  12    is a first perspective view of the drain plug; 
         FIG.  13    is a second perspective view of the drain plug; 
         FIG.  14    is a plan view of a tank outlet of the recovery tank; 
         FIG.  15    is a top perspective view of the handheld extraction cleaner, generally from the perspective of a user holding the handheld extraction cleaner in an operative or normal use position, such as illustrated in  FIG.  3   , for example; 
         FIG.  16    is a cross-sectional view taken through line XVI-XVI of  FIG.  3   , showing an exemplary liquid level in the recovery tank when the extraction cleaner is operating on a horizontal surface; 
         FIG.  17    is a view similar to  FIG.  16    showing the liquid level in the recovery tank when the extraction cleaner is tipped to one side; 
         FIG.  18    is a side perspective view of the handheld extraction cleaner, showing a flared side portion and viewing window of the recovery tank; 
         FIG.  19    is a bottom perspective view of the handheld extraction cleaner, showing the removal of the agitator; 
         FIG.  20    is a perspective view of the agitator from  FIG.  19   ; 
         FIG.  21    is a perspective view of an alternative agitator for the handheld extraction cleaner; 
         FIG.  22    is a cross-sectional view taken through line XXII-XXII of  FIG.  1   , showing the agitator latched within an agitator receiver of the extraction cleaner and a guide skid of the extraction cleaner; 
         FIG.  23    is a bottom view of a forward portion of the extraction cleaner; 
         FIG.  24    is a close-up, side view of the handheld extraction cleaner in one example of a normal use position; and 
         FIG.  25    is a cross-sectional view taken through line XXV-XXV of  FIG.  1   , showing an orientation of the guide skid relative to an agitator. 
     
    
    
     DETAILED DESCRIPTION 
     The invention relates generally to extraction cleaners, and more particularly to a portable, handheld extraction cleaner which applies cleaning fluid to a surface and then extracts the applied fluid therefrom. 
       FIG.  1    is a perspective view of a handheld extraction cleaner  10  according to one embodiment of the disclosure. As illustrated herein, the extraction cleaner  10  is adapted to be handheld and portable, and can be easily carried or conveyed by hand. The hand-carriable extraction cleaner  10  can have a unitary body  12  provided with a carry handle  14  attached to the unitary body  12 , and is small enough to be transported by one user (i.e. one person) to the area to be cleaned. 
     For purposes of description related to the figures, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” “inner,” “outer,” and derivatives thereof shall relate to the extraction cleaner  10  as oriented in  FIG.  1    from the perspective of a user behind the extraction cleaner  10 , which defines a rear end of the extraction cleaner  10 , and carrying the extraction cleaner  10  by the handle  14 , which defines an upper end of the extraction cleaner  10 . When used in referring to a direction, the term “longitudinal” refers to a direction generally extending along the length of the extraction cleaner  10 , between a forward end  58  and a rearward end  60  of the housing  15 , and the terms “transverse” or “lateral” refer to a direction generally perpendicular to the longitudinal direction. However, it is to be understood that the invention may assume various alternative orientations, except where expressly specified to the contrary. The use of directional terms should not be interpreted to limit the invention to any specific orientation. 
     The unitary body  12  can include a housing  15  that carries various components and functional systems of the extraction cleaner  10 , including a fluid delivery system for storing cleaning fluid and delivering the cleaning fluid to the surface to be cleaned and a recovery system removing the spent cleaning fluid and debris from the surface to be cleaned and storing the spent cleaning fluid and debris. In being carried by the unitary body  12  or housing  15  of the unitary body  12 , the various components and functional systems are conveyed along with the body  12  as it is transported by the user to or from an area to be cleaned and during operation. Such components and systems can be removable or non-removable from the body  12  or housing  15 . The term “debris” as used herein may include dirt, dust, soil, hair, and other debris, unless otherwise noted. The term “cleaning fluid” as used herein primarily encompasses liquids, and may include steam unless otherwise noted. 
     Referring additionally to  FIG.  2   , the recovery system can include a working air path through the body  12 , and may include a dirty air inlet and a clean air outlet. The working air path can be formed by, among other elements, a suction nozzle  16  defining the dirty air inlet, a suction source  18  in fluid communication with the suction nozzle  16  for generating a working air stream, a recovery tank  20  for separating and collecting fluid and debris from the working airstream for later disposal, and exhaust vents  22  in the housing defining the clean air outlet. The recovery system can further include a separator  24  for separating liquid and entrained debris from the working airstream. The separator  24  can be formed in a portion of the recovery tank  20 , or, as illustrated herein, can be separate from the recovery tank  20 . The separated fluid and debris can be collected in the recovery tank  20 . 
     The fluid delivery system can include a supply reservoir or supply tank  26  for storing a supply of fluid. The fluid can comprise one or more of any suitable cleaning fluids, including, but not limited to, water, compositions, concentrated detergent, diluted detergent, etc., or mixtures thereof. For example, the fluid can comprise a mixture of water and concentrated detergent. 
     The fluid delivery system can include a flow control system  28  for controlling the flow of fluid from the supply tank  26  to at least one fluid distributor  30 . In one embodiment, described in further detail below, the flow control system  28  of the fluid delivery system can comprise a pump  32 , which pressurizes the system. Optionally, a heater (not shown) can be provided for heating the cleaning fluid prior to delivering the cleaning fluid to the surface to be cleaned. In yet another example, cleaning fluid can be heated using exhaust air from a motor-cooling pathway for the suction source  18 . 
     The suction source  18 , which may be a motor/fan assembly, is provided in fluid communication with the suction nozzle  16  via the separator  24 . As shown, the motor/fan assembly includes a vacuum motor  34  and a fan  36  driven by the vacuum motor  34 . An inlet of the fan  36  is in fluid communication with air outlet of the separator  24 . 
     An agitator can be provided adjacent to the suction nozzle  16  for agitating the surface to be cleaned so that the debris is more easily ingested into the suction nozzle  16 . As shown, the agitator comprises a brush  38 . The brush  38  can be provided at a forward portion of the unitary body  12 , rearward of the suction nozzle  16 . The brush  38  is stationary, i.e. fixedly mounted and non-rotating. In another embodiment, the agitator for the handheld extraction cleaner  10  can comprise a powered, rotating brushroll. 
     Referring to  FIG.  1   , the extraction cleaner  10  can include at least one user interface (UI)  40  through which a user can interact with the extraction cleaner  10  to operate and control the extraction cleaner  10 . The UI  40  can be electrically coupled with electrical components, including, but not limited to, circuitry electrically connected to various components of the fluid delivery and collection systems of the extraction cleaner  10 . The UI  40  can include one or more input controls  42 ,  44 , which can comprise a button, trigger, toggle, key, switch, touch screen, or the like, or any combination thereof. The UI  40  can include at least one status indicator  46  that conveys information about an event or change related to the operation of the extraction cleaner  10  or its operating environment, including operational status, diagnostic information, and/or various error and fault codes. 
     The UI  40  can be provided on the body  12  at a forward end of the carry handle  14 . The input controls  42 ,  44  can conveniently be provided above the handle  14 , at a forward end thereof, for operation of the controls by a thumb of the user&#39;s hand that is gripping the carry handle  14 . Likewise, the status indicator  46  can be provided above the handle  14 , at a forward end thereof so that a user can conveniently see the status indicator  46  in a typical operational position of the extraction cleaner  10 . 
     In the embodiment shown herein, one input control  42  is a power input control that controls the supply of power to the vacuum motor  34 , another input control  44  is a dispensing input control that controls the supply of power to the pump  32  or otherwise controls dispensing of cleaning fluid via the flow control system  28 . Thus, suction and fluid delivery can be implemented individually, or in combination, by operation of the input controls  42 ,  44 . The power input control  42  can comprise a toggle switch that allows the user to change the power setting between “off” and “on” states. The fluid input control  44  can comprise a momentary switch that is only engaged while it is being depressed. 
     In the embodiment shown, the input controls  42 ,  44  can comprise buttons in register with switches on a printed circuit board (PCB)  48  ( FIG.  2   ). The PCB  48  can include one or more LEDs that illuminate the status indicator  46 , for example via at least one light pipe  50 . 
     Electrical power can be provided by a source of mains electricity or by a battery or battery pack. In the present embodiment, the extraction cleaner  10  comprises a rechargeable battery  52 . The status indicator  46  can display a battery life or charge status of the battery  52 . In another exemplary arrangement, the battery  52  can comprise a user replaceable battery. In yet another embodiment, the extraction cleaner  10  can comprise a power cord that is pluggable into a household outlet for corded operation. 
     With a rechargeable battery  52 , a charging port  54  can be provided on the housing  15  and can be electrically coupled with the battery  52 . In the illustrated embodiment, the charging port  54  is provided on one side of the body  12 , at a forward end of the carry handle  14  and below the UI  40 . A recharging cable (not shown) couples with the charging port  54  and can be plugged into a suitable electrical outlet for recharging the battery  52 . In an alternative embodiment, the extraction cleaner  10  can have charging contacts on the housing  15 , and a docking station (not shown) can be provided for docking the extraction cleaner  10  for recharging the battery  52 . 
       FIG.  3    is a side view of the handheld extraction cleaner  10  from  FIGS.  1 - 2   . The suction nozzle  16  is disposed at a forward end  58  of the body  12  while the supply tank  26 , is disposed at a rearward end  60  of the body  12 . The recovery tank  20  can be disposed on the housing  15  behind the suction nozzle  16  and in front of the suction source  18 , shown in phantom line in  FIG.  3   . The battery  52 , shown in phantom line in  FIG.  3    can be disposed forwardly of the supply tank  26  and behind the suction source  18 . The pump  32 , shown in phantom line in  FIG.  3   , is disposed below the battery  52 , and also behind the suction source  18 . The carry handle  14  extends in the longitudinal direction between the UI  40  and the supply tank  26 , and is disposed above the battery  52  and pump  32 . The carry handle  14  includes a hand grip portion and a finger receiving area, which can be a closed volume, e.g. a closed loop handgrip. The majority of the carry handle  14  and the closed volume can be disposed behind the suction source  18 . This arrangement of component parts of the extraction cleaner  10  offers a compact unit with a balanced weight-in-hand for the user, and a comfortable carrying and operational position. Other arrangements of component parts for the extraction cleaner  10  are possible. 
     In  FIG.  3   , the handheld extraction cleaner  10  is shown in one example of an operative or normal use position relative to a surface S to be cleaned. In the operative or normal use position, the extraction cleaner  10  is held with the forward end  58 , particularly the suction nozzle  16  and brush  38 , against the surface to be cleaned. The user may hold and manipulate the cleaner  10  via the carry handle  14 . With the suction source  18 , which can constitute the heaviest component of the extraction cleaner  10 , disposed between the carry handle  14  and the forward end  58 , more of the weight of the cleaner  10  can be supported by the surface S to cleaned, and less by the user. 
     The carry handle  14  may define a handle axis H along which the carry handle  14  is longitudinally extended. In the operative or normal use position, the handle axis H may be generally horizontal, or inclined from the horizontal, with “horizontal” being defined as parallel to the surface to be cleaned S. Having a substantially horizontal handle axis H positions the user&#39;s hand and wrist in an ergonomic position with more grip strength for holding the extraction cleaner  10  at an optimal cleaning angle. 
     The handheld extraction cleaner  10  can rest in a stable manner on the surface S in a horizontal position, without leakage from either tank  20 ,  26 . In a self-standing or at rest position, the extraction cleaner  10  can be supported on a substantially flat resting surface  62  on a bottom of the body  12 . With the resting surface  62  lying on surface to be cleaned S, the forward end  58  is supported away from the surface S. A user can therefore set the extraction cleaner  10  down in a stable position, upon a shelf or a countertop, for example, without having the suction nozzle  16  or brush  38  in contact with the surface S, and any residual fluid or dirt on the brush  38  will not transfer to the surface S. Heavy components (relative to the weight of other components of the cleaner  10 ) such as the pump  32  and battery  52  can be disposed above the resting surface  62 , which increases stability in the horizontal position. 
     It is noted that, while the extraction cleaner  10  is shown and described in  FIG.  3    in relation to a horizontal surface S to be cleaned, the extraction cleaner  10  may also be used to clean angled surfaces, such as stairs, upholstered furniture, car seats, and the like. Therefore, it is understood that various use orientations are possible. 
       FIG.  4    is a schematic view of the fluid delivery system of the handheld extraction cleaner  10 , shown in isolation from the other components of the cleaner  10 . As discussed above, the fluid delivery system illustrated herein includes the supply tank  26 , the pump  32 , the fluid distributor  30 , and optionally additional conduits, ducts, tubing, hoses, connectors, etc. fluidly coupling the components of the fluid delivery system together and providing a supply path from the tank  26  to the fluid distributor  30 . For example, a first conduit  64  can connect an outlet of the supply tank  26  with an inlet of the pump  32  and a second conduit  66  can connect an outlet of the pump  32  with an inlet of the fluid distributor  30 . The conduits  64 ,  66  can comprise flexible tubing as shown in  FIG.  4   , but it is understood that any of the conduits can comprise molded rigid conduits, or a combination of conduits, ducts, tubing, hoses, connectors, etc. 
     In one example, the pump  32  can be a centrifugal pump. In another example, the pump  32  can be a diaphragm or membrane pump. In still another example, the pump  32  can be a manually actuated spray pump. In yet another configuration of the fluid delivery system, the pump  32  can be eliminated and the flow control system  28  can comprise a gravity-feed system having a valve fluidly coupled with an outlet of the supply tank  26 , whereby when valve is open, fluid will flow under the force of gravity to the distributor  30 . However, the use of a pump offers the advantage of orienting the supply tank  26  and fluid distributor  30  relative to other components on the body  12  to provide a more balanced weight in hand as well as providing more consistent fluid flow rate compared to a gravity fed system. 
     The fluid distributor  30  can include at least one distributor outlet  68  for delivering fluid to the surface to be cleaned. The outlet  68  can be positioned to deliver fluid directly to the surface to be cleaned, outwardly in front of the suction nozzle  16  so that the user can clearly see where fluid is being applied. See, for example, line CF in  FIG.  3    representing one possible spray path for the distributor  30 . In another embodiment, the outlet  68  can deliver fluid onto the brush  38 . In yet another embodiment, the outlet  68  can deliver fluid behind the suction nozzle  16  and brush  38 . 
     The distributor  30  can comprise any structure, such as a nozzle or spray tip. Multiple distributors  30  can also be provided in other embodiments of the extraction cleaner  10 . As illustrated in the figures, the distributor  30  can comprise one spray tip provided on the front of the body  12  that distributes cleaning fluid to the surface to be cleaned in front of the suction nozzle  16 . 
       FIG.  5    is a close-up sectional view showing the supply tank  26 . The supply tank  26  shown is a non-removable blow-molded part, and includes a hollow tank body  70  defining a supply chamber  72  for holding a supply of cleaning liquid. In being non-removable, the supply tank  26  is not intended to be removed from the body  12 , and is refillable in place on the body  12 . This can eliminate potential leakage points, since that tank  26  does not need to be repeatedly coupled and uncoupled to the fluid pathway of the extraction cleaner  10 . 
     The tank body  70  can include a fill opening  74  through which cleaning liquid can be poured into the supply chamber  72 . The fill opening  74  can be provided at the rearward end of the body  12 , rearward of the handle  14 , and is accessible to a user when the housing  15  is resting on a surface. A fill cap  76  selectively closes the fill opening  74 . 
     The fill cap  76  can be pivotally coupled to the housing  15  of the cleaner body  12  by a hinge  78  or other rotating connection, and can be opened to expose the fill opening  74 . The pivotable coupling ensures the fill cap  76  will not completely separate from the cleaner body  12  during filling. In another aspect, the fill cap  76  can be pivotally coupled with the tank body  70 . 
     The fill cap  76  can fit over the fill opening  74  when closed to seal the fill opening  74  for a fluid-tight closure, such that the supply tank  26  does not leak when the fill cap  76  is closed. One example of a closed position of the fill cap  76  is shown in  FIG.  5   . One example of an open or fill position of the fill cap  76  is shown in  FIG.  7   . 
     In one configuration, the fill cap  76  can be a snap-on cap providing a fluid-tight engagement with the fill opening  74  when snapped onto the tank body  70 . The cap  76  can include a depending lip  80  with a snap  82  that extends from an inward side of the lip  80 , and the tank body  70  can include an outwardly extending bead  84 , with the snap  82  fitting tightly onto the bead  84  when cap  76  is closed. A seal  86  can be provided on an inner side of the cap  76  that confronts the fill opening  74  when the cap  76  is closed to further provide a leak-proof engagement between the fill opening  74  and the fill cap  76 . 
     The fill cap  76  can be opened by lifting the lip  80  of the fill cap  76 , which can be spaced from the tank body  70  in the closed position so that a user can fit a finger between the tank body  70  and an underside of the lip  80 . When the fill cap  76  is open, liquid from a liquid source, such as a container, bottle, faucet, hose, vessel, etc. can be poured into the tank body  70  through the fill opening  74 . 
     The tank body  70  can include a tank outlet  88  in fluid communication with the first conduit  64 . A mesh screen insert  90  can be provided between the tank outlet  88  and the conduit  64  to prevent particulates of a certain size from entering the pump  32 . 
     A first check valve  92  ( FIG.  4   ) is provided on the tank body  70  to allow ambient air into the supply tank  26  to displace dispensed liquid. The check valve  92  can be, for example, an umbrella valve sealing at least one vent hole formed in the tank body  70 . As liquid is pumped out of the supply tank  26 , negative pressure inside the supply tank  26  opens the check valve  92 , drawing ambient air into the supply chamber  72  to equalize pressure. Once pressure equalizes, the check valve  92  closes. 
     A second check valve  94  is provided on the tank body  70  for relieving positive pressure or off-gassing caused by some cleaning liquids. With some formulations of cleaning liquids, excess gas is generated inside the supply tank  26  due to reactions between various additives or off-gassing from peroxide formulations, for example. The check valve  94  can be, for example, an umbrella valve selectively sealing at least one vent hole in the tank body  70 . As excess gas forms in the supply tank  26 , positive pressure inside the supply tank  26  opens the check valve  94 , thereby venting the excess gas into the surrounding atmosphere. Once pressure equalizes, the check valve  94  closes. 
     Referring to  FIG.  7   , the tank body  70  can define at least a portion of the rearward end  60  of the cleaner  10 , and the structure of the tank body  70  is configured for added rigidity and robustness to withstand accidental drops of the extraction cleaner  10 . A portion of the housing  15  can wrap around the tank body  70 , while leaving a portion of the tank body  70  exposed to form an exterior surface of the extraction cleaner  10 . The exposed portion can form a viewing window  91  that permits a user to ascertain the liquid fill level inside the supply tank  26 . In the embodiment shown, a left rear portion  93  of the housing  15  and a right rear portion  95  of the housing  15  can wrap around corresponding sides of the tank body  70 , with a space in between the housing portions  93 ,  95  defining the viewing window  91 . Optionally, the tank body  70  can have an indicia marking (not shown) associated with the viewing window  91 , which may, for example indicate a fill line for the supply tank  26 . While the viewing window  91  is illustrated as being centered at the rearward end  60  of the housing  15 , in some aspects, the viewing window  91  may be offset to one side of the housing or the other. In other aspects, the housing portions  93 ,  95  wrap entirely around the tank body  70  and the viewing window  91  is formed by a cut-out in the housing  15  adjacent the tank body  70 . 
     In one embodiment, the supply tank  26  can be a blow-molded part made from a transparent or translucent material, with the user able to see through the tank body  70  at the exposed portion or viewing window  91  to ascertain the liquid fill level inside the supply tank  26 . In another embodiment, the viewing window  91  can be formed by inserting a transparent or translucent cover into a corresponding window opening in exposed portion of the tank body  70 . 
       FIG.  6    is a sectional view showing the recovery system of the handheld extraction cleaner  10 . As discussed above, the recovery system illustrated herein includes the suction nozzle  16 , the separator  24 , the recovery tank  20 , the suction source  18 , the exhaust vents  22  ( FIG.  2   ), and optionally additional conduits, ducts, tubing, hoses, connectors, etc. fluidly coupling the components of the recovery system together and providing a recovery path from a nozzle inlet  96  to the exhaust vents  22 . 
     In one configuration, working air separated from liquid and debris by the separator  24  can travel through a diffuser conduit  98  before reaching an inlet  100  of the suction source  18 . The diffuser conduit  98  has a gradually-increasing cross-sectional area to decrease the speed of the working air and increase its pressure. The diffuser conduit  98  can have an outlet port  102  in fluid communication with the inlet  100  of suction source  18 . 
     An air pathway  104  can connect an outlet  106  of the separator  24  with an inlet  108  of the diffuser conduit  98 , and can be formed by various conduits, ducts, housings, connectors, etc. fluidly coupling the outlet  106  and inlet  108  together and providing an air path from the separator  24  to the diffuser conduit  98 . To improve air/liquid separation and sound attenuation, the pathway  104  can be a tortuous air pathway  104 , and may include baffles, guides, and other air-turning features that direct the working air and increase the length of the pathway  104 . In one example, the air pathway  104  can include a baffle  110  blocking a lower portion of the conduit inlet  108  so that working air is forced to flow around and over the baffle  110  to enter the inlet  108 . 
     The recovery tank  20  comprises a hollow tank body  112  defining a collection chamber  114  for holding a recovered liquid and debris, with a tank inlet  116  that is in fluid communication with the separator outlet  106  and a tank outlet  118  formed in the tank body  112  for emptying any liquid or debris in the recovery tank  20  that may be collected in the collection chamber  114 . The tank outlet  118  can be closed by a drain plug  120  or other closure feature. 
     The tank inlet  116  to the recovery tank  20  can be formed as an opening  122  through a baffle wall  124  separating the collection chamber  114  from the tortuous air pathway  104 , with debris and liquid that is separated from the working airstream transferrable into the recovery tank  20  through the opening  122 . Other configurations for the tank inlet  116  are possible. 
     The baffle wall  124  can surround the opening  122  on multiple sides to block liquid from passing back through the tank inlet  116  when the extraction cleaner  10  is tipped sideways. In one configuration, the baffle wall  124  can surround the opening  122  on right and left sides, so that if the extraction cleaner  10  is tipped to the side, the baffle wall  124  keeps liquid out of the air pathway  104 . Optionally, in some configurations, the baffle wall  124  can also surround the opening  122  on forward and/or rearward sides. A portion of the baffle wall  124  may extend under the separator outlet  106 , and may be disposed at a downward angle when the extraction cleaner  10  is in the orientation of  FIG.  3    to direct liquid back toward the tank inlet  116 . 
       FIG.  7    is a partially-exploded view of the handheld extraction cleaner  10 , illustrating the removal of the recovery tank  20  from the housing  15 . The recovery tank  20  can form a modular recovery assembly  126  with the suction nozzle  16  that is removable from the housing  15  as a single unit or module, such that the recovery tank  20  and the suction nozzle  16  are removed simultaneously as a unit. At least one of the brush  38 , the separator  24  ( FIG.  6   ), the diffuser  98 , or any combination thereof, may also form part of the modular recovery assembly  126 . In other embodiments of the extraction cleaner  10 , the recovery tank  20  can be removed by itself, e.g. without removing the suction nozzle  16 , etc. At least one of the carry handle  14 , supply tank  26 , fluid distributor  30 , or any combination thereof, may remain with the unitary body  12  when the modular recovery assembly  126  is removed, as can be seen in  FIG.  7   . 
     Referring to  FIGS.  7 - 8   , the modular recovery assembly  126  can be attached to a front of the housing  15  via a module receiver  128  at a forward side  130  of the housing  15 . The receiver  128  includes the working air inlet  100  in fluid communication with the suction source  18  ( FIG.  6   ). With the mounting of the recovery assembly  126  to the receiver  128 , the outlet port  102  automatically mates with the inlet  100  of suction source  18 . While referred to herein as a “module” receiver  128 , in embodiments where the recovery tank  20  is removable by itself, the receiver  128  may be configured to mount the recovery tank  20  alone to the unitary body, and may be located elsewhere on the housing  15 , such as on a bottom side of the housing  15 . 
     Latches  132  or other suitable structures can secure the recovery assembly  126  with the receiver  128 . In the embodiment shown, the latches  132  are carried by the recovery assembly  126 , however it is also possible for the latches  132  to be provided on the housing  15 . Other mounting arrangements for the recovery assembly  126  are possible. 
     In the embodiment shown, a pair of latches  132  are provided, and may be disposed on opposing lateral sides of the recovery assembly  126 . Providing opposing latches  132  may allow a user to pinch the latches  132  between a thumb and at least one other finger (e.g. an index and middle finger) to de-latch and pull the recovery assembly  126  off the housing  15 . 
     Referring to  FIG.  6   , the suction nozzle  16  can include a front cover  134  and a rear cover  136  defining a narrow suction pathway  138  therebetween, with an opening forming the nozzle inlet  96  at a lower end thereof. The suction pathway  138  is in fluid communication with the separator  24  leading to the recovery tank  20 . The front cover  134  can optionally include a transparent or translucent window, or can be formed by a transparent or translucent material, so the user can see liquid being taken up through the suction nozzle  16  and/or determine if the suction nozzle  16  is clogged. 
     Referring to  FIG.  8   , the rear cover  136  can optionally define a portion of the recovery tank  20  and/or separator  24 . An opening  140  from the suction pathway  138  to the separator  24  can be formed in the rear cover  136 . 
     In some embodiments, the front cover  134  can be removable for cleaning clogs and the like in the suction pathway  138 . For example, the front cover  134  may be removably coupled with the rear cover  136  by a snap-fit connection.  FIG.  8    shows one example of the front cover  134  removed from the rear cover  136 . Alternatively, the front and rear covers  134 ,  136  can be fixedly attached together in a non-separable configuration. 
     When the recovery assembly  126  (or recovery tank  20 ) is removed as shown in  FIG.  7   , the drain plug  120  can be opened to drain the recovery tank  20 . Referring to  FIGS.  9 - 11   , the drain plug  120  is moveable between an open position ( FIG.  9   ) in which the plug  120  is at least partially spaced from the tank outlet  118  to form a drain path to empty dirty liquid in the recovery tank  20  and a closed position ( FIG.  11   ) in which the plug  120  seals the tank outlet  118 . 
     The drain plug  120  can include a stem  142  and a cap  144  with a perimeter seal  146 . The stem  142  can be offset on the cap  144  to define a drain passage  148  below the stem  142 , e.g., oriented toward the bottom of the plug  120  when the plug  120  is open as shown in  FIG.  9   . 
     In some embodiments, the drain plug  120  slides between the open and closed positions. In the closed position the stem  142  of the drain plug  120  is pushed into the tank body  112  and the cap  144  seals the tank outlet  118 . In the open position, a user can grip the cap  144  to pull the drain plug  120  out, and liquid and/or debris can drain through the drain passage  149 . 
     To slide the drain plug  120  between the open and closed positions, the recovery tank  20  can include a rail system. As can be seen in  FIG.  12 - 14   , the tank body  112  and stem  142  can have interacting surfaces that allow the drain plug  120  to slide smoothly into and out of the tank outlet  118 . In one configuration, the stem  142  has top rails  150 ,  152 ,  154  and side rails  156 ,  158 , and the tank body  112  has a top guide  160 , side guides  162 ,  164 , and a bottom guide  166 . In addition to providing a smooth sliding motion, the rail system can orient the drain plug  120  in the tank body  112  and prevent the drain plug  120  from rotating once installed in the tank body  112 . 
     The cap  144  has a generally flat head  168  with an outwardly extending flange  170  that is larger than the head  168 . The head  168  is sized to fit within the tank outlet  118  with at least some portion of the flange  170  extending over and outwardly of a rim  172  of the tank outlet  118 . When the plug  120  is closed, the flange  170  meets the rim  172  and acts as a stop for the plug  120  to limit the distance the plug  120  may be inserted into the tank outlet  118 . 
     In certain embodiments, a portion of the flange  170  may be oversized to form pull tabs  174  on the cap  144 . Providing opposing pull tabs  174  may allow a user to pinch the cap  144  between two fingers (e.g. a thumb and index finger) to pull the drain plug  120  out. Other portions of the flange  170 , e.g. portions other than the pull tabs  174 , may generally have an outer dimension substantially equal to an outer dimension of the tank outlet  118 . 
     The perimeter seal  146  can comprise a gasket surrounding an outer perimeter of the head  168 , and may be sized to be compressed by an interior surface  176  of the tank outlet  118  to ensure a leak-free seal when the drain plug  120  is closed. 
     The recovery tank  20  can have a manually releasable latching mechanism for releasably latching the drain plug  120  in the closed position. The manually releasable latching mechanism can include a snap-fit connection, with the tank body  112  and drain plug  120  having snap-fit parts which are pushed together to interlock the drain plug  120  to the tank body  112 . Providing the snap-fit parts as integral attachment features on the drain plug  120  and the tank body  112  provides rapid closure and latching of the drain plug  120 . Where the tank body  112  and drain plug  120  are plastic, the snap-fit parts can be integrally formed therewith. 
     The snap-fit connection can include a snap-lock receiver on the tank body  112  or drain plug  120 , and a snap-lock element on the other, the snap-lock element being engageable with the snap-lock receiver to retain the drain plug  120  in the closed position on the tank body  112 . Referring to  FIGS.  9  and  11   , the snap-lock element can include a cantilevered finger  182  projecting from the cap  144  of the drain plug  120 , the finger  182  having a bead  184  at one end thereof. The snap-lock receiver can include a lug  186  on the bottom guide  166  or in another suitable location on the tank body  112  for engagement with the bead  184 . In certain embodiments, the finger  182  is more elastic than the lug  186 , and the finger  182  is elastically deformed briefly as it is pushed past the lug  186 . When the drain plug  120  is pushed into the tank outlet  119 , the finger  182  snaps around the lug  186 , with the bead  184  seated behind the lug  186  to latch the drain plug  120  in place. The finger  182  can be spaced below the stem  142  so that the bottom guide  166  is disposed between the stem  142  and finger  182  when the drain plug  120  is closed. In order to provide feedback for the user to recognize that the drain plug  120  is latched in the closed position, movement of the bead  184  past the lug  186  can produce an audible “click” or other sound. Upon application of a sufficient force, the drain plug  120  can be pull back out of the tank outlet  118 , with the finger  182  flexing to move the bead  184  under and past the lug  186 . As will be evident to those skilled in the art, other manually releasable latching mechanisms may be used. 
     The drain plug  120  can be prevented from being pulled completely out of the tank body  112  by a stopper  188 . The stopper  188  can be any feature or structure that prevents or inhibits physical separation of the drain plug  120  from the tank body  112 , such as a lip, flange, rib, or other member that interferes with a corresponding feature of the tank body  112 . The stopper  188  can, for example, include a lip on the bottom of the stem  142  that prevents the drain plug  120  from sliding completely out of the tank body  112  during normal use of the tank  20 . As can be seen in  FIG.  9   , in the open position the stopper  188  can engage an edge of the bottom guide  166  to stop further sliding movement of the drain plug  120 . The stopper  188  may be provided at or near a terminal end of the stem  142  to permit the drain plug  120  to extend sufficiently far to allow a large drain passage  148  to be established when the drain plug  120  is opened. As will be evident to those skilled in the art, other structures for preventing/inhibiting separation of the drain plug  120  from the tank body  112  may be used. 
     In some configurations, the stopper  188  can prevent the drain plug  120  from being removed from the tank body  112  by the user. In other configurations the drain plug  120  can, upon application of sufficient force, be pulled completely out of the tank body  112  by overcoming the engagement of the stopper  188  with the tank body  112 . The drain plug  120  can thereafter be inserted back into the tank body  112 . 
     The recovery tank  20  can have a manually releasable latching mechanism for releasably latching the drain plug  120  in the open position. The manually releasable latching mechanism can include a detent  190  on the tank body  112  and a boss  192  on the stem  142  of the drain plug  120 . As the drain plug  120  slides into the tank body  112 , the boss  192  and/or stem  142  is sufficiently elastic to allow the boss  192  to pass under the detent  190  with an applied force, while the stopper  188  prevents the plug  120  form sliding completely out of the tank body  112 . The engagement between the boss  192  and detent  190  in this position prevents the plug  120  from sliding back into the tank outlet  118 . In order to provide feedback for the user to recognize that the drain plug  120  is latched in the open position, movement of the boss  192  past the detent  190  can produce an audible “click” or other sound. Upon application of a sufficient force, the drain plug  120  can be pushed back into the tank outlet  118 , with the boss  192  and/or stem  142  flexing to move the boss  192  under and past the detent  190  in order to move the drain plug  120  to the closed position ( FIG.  11   ). As will be evident to those skilled in the art, other manually releasable latching mechanisms may be used. 
     In one configuration, the extraction cleaner  10  is provided with an auto-close feature for the recovery tank  20 , wherein the plug  120  is automatically moved to the closed position by the mounting of the recovery tank  20  in the receiver  128 . The auto-close feature eliminates the possibility of the recovery tank  20  being installed on the housing  15  with the drain plug  120  open by automatically closing the plug  120  when the recovery tank  20  is installed on the housing. This feature has the benefit of closing the plug  120  using the motion of assembly, e.g. the motion of the recovery tank  20  being installed on the housing  15 , thereby ensuring a leak-free experience. 
     One embodiment of the auto-close feature is shown in  FIG.  10 - 11   , and includes a blocker  194  on the housing  15  that pushes the plug  120  to the closed position ( FIG.  11   ), if not already in the closed position, by the mounting of the recovery tank  20  in the receiver  128 . The blocker  194  depends within or adjacent to the receiver  128  and can comprise an engagement face  196  that overlaps at least a portion of drain plug  120  when the recovery tank  20  is assembled with the receiver  128 . As shown in  FIG.  10   , the blocker  194  can overlap a portion of the cap  144  and can press against the cap  144  as the tank  20  is seated with the receiver  128  to slide the drain plug  120  closed.  FIG.  11    shows the tank  20  fully seated within the receiver  128  with drain plug  120  closed. 
     During mounting of the recovery tank  20 , the drain area may be hidden to the user on the bottom, rear side of the tank  20 , and so the position of the drain plug  120  may be overlooked. The blocker  194  thereby automatically closes the drain plug  120  if it is left open when the recovery tank  20  is installed on the housing  15 . Additionally, the blocker  194  can prevent the drain plug  120  from opening while the recovery tank  20  is on the housing  15 , thereby preventing unintended removal of the plug  120  without first removing the whole tank  20  or module  126  from the housing  15 . 
     Other configurations for auto-close feature are possible depending on the configurations of the recovery tank  20 , drain plug  120 , and receiver  128 . For example, if the drain plug  120  pivots between open and closed positions, the auto-close feature can be configured to pivot the drain plug  120  to the closed position upon mounting the recovery tank  20  to the receiver  128 . 
     Referring to  FIG.  15   , an example of a user&#39;s perspective of the extraction cleaner  10  during operation is shown. Generally, during operation a user will grasp the extraction cleaner  10  by the carry handle  14  and engage the forward end  58  with the surface to be cleaned. The recovery tank  20  can be configured such that, in this use position, the user can view the fullness or fill level of the recovery tank  20 . The recovery tank  20  can further be configured to be equally viewable by a right-handed user and a left-handed user. A right-handed user may, for example tend to hold the extraction cleaner  10  in an orientation where they see more of the left side of the extraction cleaner  10  and a left-handed user may, for example, tend to hold the extraction cleaner  10  in an orientation where they see more of the right side of the extraction cleaner  10   
     In one configuration, the recovery tank  20  has a tank body  112  with side portions  198 ,  200  that extend outwardly with respect to the housing  15  so as to be visible from the user&#39;s perspective during operation. The housing  15  has a first lateral side  202  and a second lateral side  204 , which can comprise left and right lateral sides, respectively, (as viewed from the use position shown in  FIG.  15   ) and the tank body  112  can have a first side portion  198  which is disposed laterally outwardly with respect to the first lateral side  202  of the housing  15  and a second side portion  200  which is disposed laterally outwardly with respect to the second lateral side  204  of the housing  15 . In one aspect, the first and second lateral sides  202  and  204  define a lateral footprint of the forward end of the housing  15  and the first and second side portions  198  and  200  extend outwardly beyond the lateral footprint defined by the first and second lateral sides  202  and  204 . In another aspect, the first and second lateral sides  202  and  204  define first and second vertical planes that intersect the first and second side portions  198  and  200 , respectively. 
     The flared side portions  198 ,  200  can be disposed substantially in front of the carry handle  14 . The recovery tank  20 , and flared side portions  198 ,  200 , are thus located closer to the forward end  58  of the extraction cleaner  10  than the rearward end  60  ( FIG.  3   ) so that a user has a clear view of the tank  20  and its fill level. 
     The side portions  198 ,  200  of the tank body  112  can extend or flare outwardly relative to a longitudinal centerline of the extraction cleaner  10 , which in some configurations of the extraction cleaner  10  may be defined by the handle axis H. Optionally, the side portions  198 ,  200  can extend in opposing directions relative to the longitudinal centerline. In the embodiment shown, the side portions  198 ,  200  are mirror images of each other and can be equal in volume, although it is understood that differences in shape, volume, etc. of the side portions  198 ,  200  is possible. 
     With flared side portions  198 ,  200  on both lateral sides  202 ,  204  of the housing  15 , the recovery tank  20  is equally viewable by a right-handed user and a left-handed user, and a user can observe the recovery tank  20  even if the extraction cleaner  10  is tipped sideways. The flared shape of the recovery tank  20  can also increase the collection capacity of the tank body  112 . The flared side portions  198 ,  200  allow the volume of collected liquid to spread out laterally, which can reduce the height of collected liquid. 
     Another benefit to having flared side portions  198 ,  200  on both sides of the recovery tank  20  is an increase in volume available on each side of the tank  20  when the extraction cleaner  10  is tipped sideways.  FIGS.  16 - 17    are cross-sectional views taken through line XVI-XVI of  FIG.  3    showing a liquid level indicated by phantom line L for a given volume of liquid in the tank  20  when the extraction cleaner  10  is in two different exemplary orientations.  FIG.  16    shows the liquid level L when the extraction cleaner  10  is in the orientation of  FIG.  3    and operating on a horizontal surface S to be cleaned.  FIG.  17    shows the liquid level L for the same volume of liquid when the extraction cleaner  10  is tipped to the left. In the tipped position, a greater portion of the liquid moves into the space defined by the first side portion  198 . When the extraction cleaner  10  is tipped to the right, a greater portion of the liquid can move into the space defined by the second side portion  200 . When tipped, the liquid level L does not rise up to the height of the tank inlet  116 , but rather spreads into the corresponding side portion  198 ,  200 . Therefore, there is less likelihood of ingestion of liquid into the air pathway  104 . 
     To help prevent the liquid from reaching the air pathway  104 , the baffle wall  124  in the tank  20  can block the liquid when the extraction cleaner  10  is tipped sideways. Below a certain level of liquid and at certain degrees of tip, liquid in the tank  20  cannot reach the tank inlet  116 . With the provision of the flared side portions  198 ,  200  and/or the baffle wall  124 , the recovery tank  20  does not require an in-tank float-style shut off. In other words, the recovery tank  20  is a float-less tank. 
     Various shapes for the flared side portions  198 ,  200  are possible. Referring to  FIGS.  16 - 18   , one embodiment of the first side portion  198  is disclosed. It is understood that the second side portion  200  may have the same or a similar configuration. 
     The tank body  112  can have a tank side wall  206  and the first side portion  198  can extend outwardly from the tank side wall  206 . The tank side wall  206  can be flush with or recessed to the first lateral side  202  of the housing  15 , such that the tank side wall  206  is disposed substantially in line with or laterally inwardly of the first lateral side  202 . At a bottom end thereof, the flared side portion  198  can turn back in toward the housing  15 , and can meet a bottom wall  208  of the tank body  112 . 
     Referring to  FIG.  16   , the first side portion  198  can include at least an upper wall  210 , an outer wall  212 , and a lower wall  214 . One or more of these walls can be angled so that the first side portion  198  has a contour that can encourage liquid to move toward the tank outlet  118 , which is closed by the drain plug  120  in  FIG.  16   . For example, the upper and lower walls  210 ,  214  can taper toward the outer wall  212  so that the first side portion  198  has a double beveled contour when viewed from the front or from the rear. With a contour that tapers downwardly and toward the center of the tank  20 , liquid is encouraged to move downwardly along the walls  210 - 214  and toward the tank outlet  118 . Referring to  FIG.  18   , the first side portion  198  can include a front wall  216  at a forward end of the outer wall  212  and a rear wall  218  at a rearward end of the outer wall  212 . These walls  216 ,  218  can also be angled to encourage liquid to move downwardly along the walls  216 ,  218 . 
     The bottom wall  208  can also have a shape which improves cleaning liquid drainage and usable tank volume, such as by sloping rearwardly toward the tank outlet  118  when the extraction cleaner  10  is at rest on the resting surface  62  ( FIG.  3   ), which directs dirty liquid away from the tank inlet  116  and toward the tank outlet  118 . Similarly, when the recovery assembly  126  is removed and rested on a surface, the recovery assembly  126  is supportable on a bottom edge of the plug  120  and the brush  38 , and the bottom wall  208  is oriented to slope rearwardly toward the tank outlet  118 . 
     A level viewing window  220 ,  222  can be located on one or both side portions  198 ,  200  of the recovery tank  20  with the viewing windows  220 ,  222  providing information to the user on the fill level within the recovery tank. With viewing windows  220 ,  222  on both lateral sides  202 ,  204  of the housing  15 , a user can be informed of the fill level regardless of whether the extraction cleaner  10  is held in their right or left hand, and even if the extraction cleaner  10  is tipped sideways. 
     The viewing windows  220 ,  222  can be a transparent or translucent portion of the recovery tank  20  through which the fill level in the recovery tank  20  can be visually determined. In one embodiment, the recovery tank  20  can be a blow-molded part made from a transparent or translucent material, with the viewing windows  220 ,  222  comprising molded features in the tank body  112 . In another embodiment, the viewing windows  220 ,  222  can be formed by inserting a transparent or translucent cover into a corresponding window opening in the tank body  112 . 
     Various configurations for the viewing windows  220 ,  222  are possible. Referring to  FIG.  17   , one embodiment of the first viewing window  220  is disclosed. It is understood that the second viewing window  222  may have the same or a similar configuration. 
     In the exemplary embodiment in  FIG.  18   , viewing window  220  is located on two walls  210 ,  212  of the tank body  112 , and wraps around a corner  224  between the two walls  210 ,  210 . Locating the viewing window  220  on the upper wall  210  and outer side wall  212  of the side portion  198  places the viewing window  220  in the user&#39;s line of sight, with a user being able to see the viewing window  220  from a centered perspective shown in  FIG.  15    or when the extraction cleaner  10  is tilted sideways for cleaning an angled surface.  FIG.  18    shows an example of a user&#39;s perspective of the extraction cleaner  10  during operation, where the user has tilted the extraction cleaner  10  sideways. 
     The viewing window  220  can be recessed into the walls  210 ,  212 . In an embodiment where the viewing window  220  is a molded feature in the tank body  112 , a beveled edge  226  can serve as a transition between the walls  210 ,  212  and the recessed window  220 . 
     Optionally, the tank body  112  can have indicia markings associated with the viewing window  220 . One exemplary embodiment of such indicia markings is shown in  FIG.  18   , where the viewing window  220  has a border marking  228  in a contrasting color to the tank body  112  that draws a user&#39;s attention to the viewing window  220 . Observing a fill level within the border marking  228  can signal to the user that a fill quantity in the recovery tank  20  is approaching a maximum level and/or is within a recommended range for emptying the tank  20 . The viewing window  220  can also have a maximum fill line  230  that indicates a recommended maximum fill quantity in the recovery tank  20 . The border marking  228  can wrap around the corner  224  and the maximum fill line  230  extend along the corner  224 , and preferably above the corner  224 . It is understood that the second viewing window  222  may have the same or similar indicia markings. 
     Referring to  FIG.  15   , in addition to the recovery tank  20 , the suction nozzle  16 , distributor  30 , user interface  40 , brush  38 , or any combination thereof, may be in the line of sight of the user during normal operation of the extraction cleaner  10 . In the exemplary embodiment, the user interface  40  is not symmetrical about the handle axis H, but is convenient for use by a right-handed or left-handed user. Gripping the carry handle  14  in one hand, whether left or right, allows both input controls  42 ,  44  to be actuated by the thumb of that same hand. The end of the carry handle  14  toward the user interface  40  can have a recessed thumb rest  232  for the user&#39;s thumb, so that the thumb of the hand gripping the carry handle  14  has a “home” or resting space, and does not accidentally bump the input controls  42 ,  44 . The input controls  42 ,  44  can be different in size, shape, color, tactile elements, and the like, so that a user can distinguish between them by sight or by feel. 
     In one embodiment, the carry handle  14  is elongated along the handle axis H, and has a first lateral handle side on a first side of handle axis H and a second lateral handle side on a second side of the handle axis H. The input controls  42 ,  44  can be on opposing sides of the handle axis H. For example, the first input control  42  can be spaced from the handle axis H on the first side thereof and the second input control  44  can be spaced from the handle axis H on the second side thereof. In the illustrated configuration, the first input control  42  is spaced from the first lateral handle side of the carry handle  14  and the second input control  44  is spaced from the second lateral handle side of the carry handle  14 . 
     Referring to  FIGS.  19  and  20   , in some embodiments of the extraction cleaner  10 , the brush  38  is removably mounted on the body  12  for cleaning and/or replacement of the brush  38 . Optionally, the brush  38  can be exchanged for another agitator. In some embodiments, multiple agitators can be provided with the handheld extraction cleaner  10  and can be interchangeably mounted to the body  12 . One example of another brush  234  is shown in  FIG.  21   . It is noted that although  FIG.  19    shows the extraction cleaner  10  upside down, one of the advantages of this design is that extraction cleaner  10  does not have to be tipped over to remove the brush  38 . The brush  38  can be removed, for example, when the extraction cleaner  10  is in a normal operative position. 
     Each of the brushes  38 ,  234  can have a brush mount  236  configured to fit within a brush receiver  238  and an agitation element  240  supported by the brush mount  236 . Alternatively, one brush mount  236  can be interchanged among different agitation elements. The brush mount  236  can be constructed of a polymeric material such as acrylonitrile butadiene styrene (ABS), polypropylene or styrene, or any other suitable material such as plastic, wood, or metal. 
     In the embodiment of the brush  38  shown in  FIGS.  19 - 20   , the agitation element  240  is a plurality of bristles  242 . The pattern, shape and type of bristles  242  can vary from the pattern, shape, and type shown herein. The bristles  242  can be constructed of nylon, or any other suitable synthetic or natural fiber. The bristles  242  may be arranged in a plurality of tufts or in a unitary strip. The bristle tufts can be arranged in a single or multiple rows, optionally with the tufts staggered between rows to maximize the density of bristles on the brush mount  236 . 
     In the embodiment of the brush  234  shown in  FIG.  21   , the agitation element  240  is a plurality of tines  244 . The tines  244  can be pliant, i.e. flexible or resilient, in order to bend readily by contact with the surface to be cleaned, yet remain undeformed by normal use of the apparatus  10 . Optionally, the tines  244  can be formed of an elastomer, such as ethylene propylene diene monomer (EPDM) rubber, thermoplastic elastomer (TPE), or thermoplastic polyurethane (TPU). The tines  244  can be arranged in a single or multiple rows, optionally with the tines  244  staggered between rows to maximize the density of tines  244  on the brush mount  236 . Other types of agitation elements  240  are possible, such as paddles, flails, wires, elongated teeth or short nubs, microfiber material, or a scrubbing material, such as a non-woven or open cell foam scrubbing material. 
     The brush receiver  238  can comprise any structure suitable to mount the brush  38 . For example, in the exemplary embodiment, the receiver  238  comprises a substantially closed pocket on the extraction cleaner  10 , with a side-facing opening  246  through which the brush  38  can be installed and removed, and a downward-facing opening  248  through which the agitation elements  240  can project to engage a surface to be cleaned. 
     For removal of the brush  38  as a unit with the suction nozzle  16  and the recovery tank  20 , the brush receiver  238  is preferably part of the modular recovery assembly  126 . As shown herein, in one embodiment the brush receiver  238  can be defined by portions of the suction nozzle  16  and recovery tank  20 , with the brush  38  thereby generally disposed behind the suction nozzle  16  and forward of the tank  20 . Other locations for the brush receiver  238  are possible. 
     To facilitate insertion and removal of the brush  38 , a handle  250  can be provided at the end of brush  38 . The handle  250  can be coupled with, such as by being integrally formed with or otherwise joined to, the brush mount  236 . The handle  250  provides a convenient place to grip the brush  38  during insertion or removal. When installed on the extraction cleaner  10 , an end surface  252  of the brush mount  235  bearing the handle  250  can form an exterior surface of extraction cleaner  10 , and can be substantially continuous with an exterior side surface  254  of the suction nozzle  16 . 
     In some embodiments, the brush  38  slides into and out of the brush receiver  238 . The brush mount  236  and brush receiver  238  can have interacting surfaces that allow the brush  38  to slide smoothly into and out of the receiver  238 . In one configuration, the brush mount  236  can include rails  256 ,  258  and the receiver  238  has rail guides  260 ,  262  that receive the rails  256 ,  258 . 
     The brush  38  can be removable through the exterior side surface  254  of the suction nozzle  16 , and the rails  256 ,  258  and guides  260 ,  262  can extend generally parallel to the nozzle inlet  96 . This arrangement of component parts of the extraction cleaner  10  allows the user to remove the brush  38  without needing to tip the cleaner  10  over and/or without the use of tools, and/or can offer a compact unit with the brush  38  disposed closely to the nozzle inlet  96 . 
     The extraction cleaner  10  can have a manually releasable latching mechanism for releasably latching the brush  38  within the receiver  238 . The manually releasable latching mechanism can include a snap-fit connection, with the brush mount  236  and brush receiver  238  having snap-fit parts which are pushed together to interlock the brush  38  to the brush receiver  238 . Providing the snap-fit parts as integral attachment features on the brush mount  236  and receiver  238  provides rapid mounting and latching of the brush  38 . Where the brush mount  236  and receiver  238  are plastic, the snap-fit parts can be integrally formed therewith. 
       FIG.  22    is a cross-sectional view showing the brush  38  latched within the receiver  238 . The snap-fit connection can include a snap-lock receiver on the brush mount  236  or brush receiver  238 , and a snap-lock element on the other, the snap-lock element being engageable with the snap-lock receiver to retain the brush  38  in the receiver  238 . The snap-lock element can include a cantilevered finger  264  projecting from the brush mount  236 , the finger  264  having a bead  266  at one end thereof. The snap-lock receiver can include a lug  268  in a suitable location on the brush receiver  238  for engagement with the bead  266 . In certain embodiments, the finger  264  is more elastic that the lug  268 , and the finger  264  is elastically deformed briefly as it is pushed past the lug  268 . When the brush  38  is pushed into the receiver  238 , the finger  264  snaps around the lug  268 , with the bead  266  seated behind the lug  268  to latch the brush  38  in place. In order to provide feedback for the user to recognize that the brush  38  is latched in place, movement of the bead  266  past the lug  268  can produce an audible “click” or other sound. Upon application of a sufficient force, the brush  38  can be pulled back out of the receiver  238  using the handle  250 , with the finger  264  flexing to move the bead  266  under and past the lug  268 . Alternatively, in some embodiments, the finger  264  may be carried by the received  238  and the lug  268  may be carried by the brush  38 . As will be evident to those skilled in the art, other manually releasable latching mechanisms may be used. 
     Referring to  FIGS.  22 - 25   , the suction nozzle  16  can have a cleaning angle guide skid  270  to orient the extraction cleaner  10  at a predetermined cleaning angle for efficient extraction with respect to a surface S to be cleaned. For example, the predetermined cleaning angle may be an angle in which the nozzle inlet  96  is sufficiently flat adjacent to and/or against the surface S for efficient extraction, when the nozzle inlet  96  is sealed with the surface S, and/or when the distance between the surface S and the nozzle inlet  96  is small.  FIG.  24    shows the extraction cleaner  10  in one non-limiting example of an optimal cleaning position in which the nozzle inlet  96  is substantially flat against the surface S. The optimal cleaning position for efficient extraction may vary depending on the relative disposition of the components of the cleaner  10 , such as but not limited to the body  12 , carry handle  14 , suction nozzle  16 , and nozzle inlet  96 . A user may not understand the angle for optimal extraction, and may not intuitively tip the extraction cleaner  10  far enough forward. The cleaning angle guide skid  270  provides a structural element that encourages the user to naturally orient the cleaner  10  at an optimal angle for efficient extraction. As an added benefit, the cleaning angle guide skid  270  can help the extraction cleaner  10  glide over the surface S, which helps the user the move the extraction cleaner  10  smoothly over the surface. 
     The guide skid  270  can include one or more skis, lips, runners, gliding surfaces, skids, or the like surrounding the nozzle inlet  96  and/or the brush  38 , and which may at least partially support the forward end  58  of the extraction cleaner  10  on the surface to be cleaned. In one embodiment, the guide skid  270  can include at least a front ski  272  and side skis  274 ,  276  behind the front ski  272 . The skis  272 - 276  can have substantially flat contact surfaces, or may be slightly tapered or curved to help the suction nozzle  16  glide over the surface for easy movement of the cleaner  10  in a back and forth direction across the surface to be cleaned. Thus, the skis  272 - 276  of the guide skid  270  allow the suction nozzle  16  to glide over the surface S in a similar manner as a ski so that a user can pass or glide the extraction cleaner smoothly over a surface. While various configurations for the skis  272 - 276  are possible, the skis  272 - 276  can preferably have smoothly curved or angled surfaces, edges, corners, and the like, to reduce sliding friction. 
     In certain embodiments, the side skis  274 ,  276  can project in a direction transverse to that of the front ski  272 . With multiple skis  272 - 276  projecting in multiple directions around the periphery of the suction nozzle inlet  96 , the user is guided to positon the cleaner  10  at an optimal angle for efficient extraction, particularly one in which the suction nozzle inlet  96  is flat or nearly flat against the surface to be cleaned. 
     The front ski  272  can comprise an elongated, slender runner that extends substantially the width of the nozzle inlet  96  across the front of the suction nozzle  16 . In the embodiment shown, the front ski  272  can project from a forward edge of the front nozzle cover  134 . Where the nozzle cover  134  and front ski  272  are plastic, the front ski  272  can be integrally formed with the nozzle cover  134 . 
     In certain embodiments, the guide skid  270  can further include intermediate skis  278 ,  280  that extend alongside the lateral ends of the nozzle inlet  96  and which can substantially bridge a gap between the front ski  272  and side skis  274 ,  276 . In the embodiment shown, the intermediate skis  278 ,  280  can be defined by bottom surfaces of the front nozzle cover  134 . Where the nozzle cover  134  and intermediate skis  278 ,  280  are plastic, the intermediate skis  278 ,  280  can be integrally formed with the nozzle cover  134 . 
     The side skis  274 ,  276  can comprise elongated, slender runners that extend rearwardly of the nozzle inlet  96  and are disposed on either side of the agitation element  240  of the brush  38 . This extends the guiding action of the cleaning angle guide skid  270  to the brush  38  as well as the nozzle inlet  96 , thereby ensuring that both the brush  38  and the suction nozzle  16  are positioned at an optical cleaning position. 
     The first side ski  274  is generally on the first lateral side  202  of the housing  15 , and can project laterally outwardly of the exterior side surface  254  of the suction nozzle  16 . The second side ski  276  is generally on the second lateral side  204  of the housing  15 , and can project from an exterior side surface  282  of the suction nozzle  16  that is diametrically opposed to the exterior side surface  254 . 
     The first side ski  274  can be defined by a bottom surface of the brush handle  250 . The handle  250  thereby forms a portion of the guide skid  270 , making a separate ski surface on that side of the extraction cleaner  10  unnecessary, as the brush  38  itself can carry the ski  274 . This offsets the handle  250  of the brush  38 , placing the handle  250  closer to the nozzle inlet  96  of the suction nozzle  16 . Where the brush mount  236  and side ski  274  are plastic, the side ski  274  can be integrally formed with the brush mount  236 . 
     In the embodiment shown, the second side ski  276  can project from a side of the rear nozzle cover  136 . Where the nozzle cover  136  and side ski  276  are plastic, the side ski  276  can be integrally formed with the nozzle cover  136 . In certain embodiments, the handle  250  and ski  276  can be generally the same in size and shape, but can be different in color, tactile elements, and the like, so that a user can distinguish where the brush  38  is disposed. 
     It is noted that nozzle inlet  96  can be single opening extending substantially the width of the suction nozzle  16 , or a plurality of smaller openings  284  separated by dividers  286  as shown in  FIG.  22   , the dividers  286  serving the reinforce the suction nozzle  16 . The dividers  286  can be flush with or recessed with respect to the guide skid  270 . 
     An inclined peripheral wall  288  can extend around the nozzle inlet  96 , the inclined peripheral wall  288  extending from the guide skid  270  downwardly and inwardly toward the openings  284 . The peripheral wall  288  surrounding the nozzle inlet  96  may therefore project slightly with respect to the guide skid  270 . In other embodiments, the wall  288  surrounding the nozzle inlet  96  may not project relative to the guide skid  270 , and may for example be flush with the guide skid  270 . 
     Referring to  FIGS.  24 - 25   , the side skis  274 ,  276  may generally lie within a common plane P, thereby being flush with each other. At least a portion of the front ski  272  may lie in the same plane P. In the embodiment shown, the intermediate skis  278 ,  280  can lie within the plane P, and the front ski  272  may turn upwardly away from the plane P. The peripheral wall  288  surrounding the nozzle inlet  96  extend below the plane P. 
     The agitation element  240 , such as bristles  242 , may extend below the guide skid  270 , such as with tips  290  of the bristles  242  in particular extending below the side skis  274 ,  276 , e.g. below the plane P. With the guide skid  270  pressed against the surface S, the agitation element  240  can dig into the surface S, providing enhanced scrubbing action. 
     In certain embodiments, the agitation element  240  is angled with respect to the guide skid  270  so as to resist movement on a forward stroke of the extraction cleaner  10  and to ease the resistance on a backward stroke of the extraction cleaner  10 . For example, the agitation element  240  can define an agitation element axis B that intersects the plane P at an oblique angle A. The agitation element axis B can be defined by the bristles  242 , a tuft of bristles  242 , or a hole  292  supporting a tuft of bristles  242 . In the case of the brush  234  shown in  FIG.  21   , the agitation element axis B can be defined by one of the tines  244 , such that at least one of the tines  244 , and alternatively multiple tines  244 , are disposed at an oblique angle to the plane P, e.g. to the side skids  274 ,  276 . 
     Referring to  FIG.  25   , in the embodiment shown, the brush mount  236  includes holes  292  that support tufts of bristles  242  (not shown in  FIG.  25    for clarity). At least one of the holes  292 , alternatively multiple holes  292 , can define the bristle axis B at a center of the hole  292 . 
     To the extent not already described, the different features and structures of the various embodiments of the invention, may be used in combination with each other as desired, or may be used separately. That one handheld extraction cleaner  10  is illustrated herein as having all of these features does not mean that all of these features must be used in combination, but rather done so here for brevity of description. Furthermore, while the extraction cleaner  10  shown herein is handheld, some features of the invention can be useful on a conventional upright or stick cleaner. Still further, the extraction cleaner  10  can additionally have steam delivery capability. Thus, the various features of the different embodiments may be mixed and matched in various extraction cleaner configurations as desired to form new embodiments, whether or not the new embodiments are expressly described. 
     The above description relates to general and specific embodiments of the disclosure. However, various alterations and changes can be made without departing from the spirit and broader aspects of the disclosure as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents. As such, this disclosure is presented for illustrative purposes and should not be interpreted as an exhaustive description of all embodiments of the disclosure or to limit the scope of the claims to the specific elements illustrated or described in connection with these embodiments. Any reference to elements in the singular, for example, using the articles “a,” “an,” “the,” or “said,” is not to be construed as limiting the element to the singular. 
     Likewise, it is also to be understood that the appended claims are not limited to express and particular components or methods described in the detailed description, which may vary between particular embodiments that fall within the scope of the appended claims. With respect to any Markush groups relied upon herein for describing particular features or aspects of various embodiments, different, special, and/or unexpected results may be obtained from each member of the respective Markush group independent from all other Markush members. Each member of a Markush group may be relied upon individually and or in combination and provides adequate support for specific embodiments within the scope of the appended claims. 
     Further aspects of the disclosure are provided by the subject matter of the following clauses: 
     A handheld extraction cleaner including a unitary body including a carry handle, a supply tank carried by the unitary body, at least one fluid distributor, a working air path through the unitary body, a suction nozzle defining an inlet to the working air path, a suction source in fluid communication with the suction nozzle, a recovery tank including a tank body defining a collection chamber, an inlet opening to the collection chamber, the inlet opening in fluid communication with the suction nozzle, an outlet opening from the collection chamber, and a plug moveable between a closed position in which the plug seals the outlet opening and an open position in which the plug is at least partially spaced from the outlet opening to form a drain path to empty dirty liquid in the recovery tank, a recovery tank receiver provided on the unitary body to mount the recovery tank to the unitary body, and an auto-close feature, wherein the plug is automatically moved to the closed position when the recovery tank is mounted in the recovery tank receiver. 
     The handheld extraction cleaner according to any preceding clause wherein the plug is slidably mounted in the outlet opening, wherein the plug does not separate from the outlet opening in the open position. 
     The handheld extraction cleaner according to any preceding clause wherein the suction nozzle and the recovery tank form a modular recovery assembly that is removable from the unitary body as a single module, such that the suction nozzle is removed simultaneously with the recovery tank. 
     The handheld extraction cleaner according to any preceding clause wherein the modular recovery assembly comprises an agitator disposed rearwardly of the suction nozzle and forwardly of the recovery tank. 
     The handheld extraction cleaner according to any preceding clause wherein the carry handle and the at least one fluid distributor are separate from the modular recovery assembly so that the modular recovery assembly is removable from the unitary body without removing the carry handle and without removing the at least one fluid distributor. 
     The handheld extraction cleaner according to any preceding clause wherein the auto-close feature comprises a blocker on a housing of the unitary body that is positioned to push the plug to the closed position as the recovery tank is seated in the tank receiver. 
     A handheld extraction cleaner including a unitary body including a unitary body including a carry handle, a first lateral side, and a second lateral side, a fluid delivery system including a supply tank carried by the unitary body and at least one fluid distributor, a recovery system including a working air path through the unitary body, a suction nozzle defining an inlet to the working air path, a suction source in fluid communication with the suction nozzle, and a recovery tank carried by the unitary body, and an agitator disposed rearwardly of the suction nozzle and forwardly of the recovery tank, wherein the agitator slides out from the first lateral side of the unitary body. 
     The handheld extraction cleaner according to any preceding clause comprising an agitator receiver disposed between the suction nozzle and the recovery tank, wherein the agitator slides into and out of the agitator receiver. 
     The handheld extraction cleaner according to any preceding clause wherein the agitator has a handle to facilitate removal of the agitator from the agitator receiver. 
     A handheld extraction cleaner including a unitary body including a carry handle, a first lateral side, and a second lateral side, a fluid delivery system including a supply tank carried by the unitary body and at least one fluid distributor, a recovery system including a working air path through the unitary body, a suction nozzle defining an inlet to the working air path, a suction source in fluid communication with the suction nozzle, and a recovery tank carried by the unitary body, an agitator disposed rearwardly of the suction nozzle and forwardly of the recovery tank, and a cleaning angle guide skid to orient the extraction cleaner at a predetermined cleaning angle for efficient extraction with respect to a surface to be cleaned. 
     The handheld extraction cleaner according to any preceding clause wherein the cleaning angle guide skid comprises a front ski and side skis behind the front ski, the front ski extending across a front of the suction nozzle and substantially the width of a nozzle inlet of the suction nozzle, and the side skis extending rearwardly of the nozzle inlet and disposed on either side of an agitation element of the agitator. 
     A handheld extraction cleaner including a unitary body including a carry handle, a recovery system including a working air path through the unitary body, a suction nozzle defining an inlet to the working air path, a suction source in fluid communication with the suction nozzle, and a recovery tank carried by the unitary body, and a fluid delivery system including a supply tank carried by the unitary body and at least one fluid distributor, wherein the supply tank is a non-removable part located within a housing of the unitary body, and wherein an exposed portion of the supply tank forms an exterior surface of the extraction cleaner, the exposed portion of the supply tank comprising a viewing window that permits a user to ascertain the liquid fill level inside the supply tank. 
     The handheld extraction cleaner according to any preceding clause wherein the housing partially wraps around the supply tank while leaving a portion of the supply tank exposed to form the exposed portion. 
     The handheld extraction cleaner according to any preceding clause wherein the handheld extraction cleaner includes a vacuum motor, wherein the supply tank is located rearwardly of the recovery tank, the vacuum motor, and the carry handle. 
     The handheld extraction cleaner according to any preceding clause wherein the supply tank has a pivotable fill cap disposed at a rearward end of the carry handle. 
     The handheld extraction cleaner according to any preceding clause wherein supply tank is located rearwardly of one or more of the suction nozzle, an agitator, a pump, and a battery.