Patent Publication Number: US-11375869-B2

Title: Steam mop with viewable tank

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. patent application Ser. No. 15/671,209, filed Aug. 8, 2017, now U.S. Pat. No. 10,085,610, issued Oct. 2, 2018, which is a continuation of U.S. patent application Ser. No. 15/009,220, filed Jan. 28, 2016, now U.S. Pat. No. 9,737,189, issued Aug. 22, 2017, which is a continuation of U.S. patent application Ser. No. 13/788,976, filed Mar. 7, 2013, now U.S. Pat. No. 9,398,836, issued Jul. 26, 2016, which claims the benefit of U.S. Provisional Patent Application No. 61/608,676 filed Mar. 9, 2012, all of which are incorporated herein by reference in their entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     The invention relates generally to a surface cleaning apparatus with steam delivery. Devices such as steam mops and handheld steamers are configured for cleaning a wide variety of common household surfaces such as bare flooring, including tile, hardwood, laminate, vinyl, and linoleum, as well as countertops, stove tops and the like. Typically, steam mops comprise at least one liquid tank or reservoir for storing water that is fluidly connected to a selectively engageable pump or valve. The outlet of the pump or valve is fluidly connected to a steam generator, which comprises a heating element for heating the liquid. The steam generator produces steam, which can be directed towards the surface to be cleaned through a distributor nozzle or a manifold located in a foot or cleaning head that engages the surface to be cleaned. Steam is typically applied to the backside of a cleaning pad that is attached to the cleaning head. Steam eventually saturates the cleaning pad and the damp pad is wiped across the surface to be cleaned to remove dirt, dust, and debris present on the surface. Additionally, auxiliary liquids such as fragrances, detergents or other additives can be supplied via the liquid tank for distribution through the surface cleaning apparatus to improve cleaning efficacy or to provide other sensory benefits. 
     During use, the liquid contained in the reservoir is eventually depleted and must be replenished. However, it can be difficult for a user to ascertain the liquid level within the reservoir prior to or during use. The position of the reservoir on the housing, the user&#39;s viewing perspective relative to the reservoir and the opacity of the reservoir walls can all hinder a user&#39;s ability to visually ascertain the liquid level within the reservoir. Likewise, the cleaning pad is generally hidden from view when it is mounted beneath the foot or cleaning head. Additionally, in some instances, the damp cleaning pad may not entirely remove soil on the surface to be cleaning surface. 
     BRIEF SUMMARY OF THE INVENTION 
     In one aspect, the invention relates to a steam mop having a viewable supply tank. 
     In another aspect, the invention relates to a steam mop including a housing comprising a foot assembly movable along a surface to be cleaned and an upright handle assembly coupled with the foot assembly, a steam generator, a supply tank receiver provided on the upright handle assembly, a supply tank removably coupled with the supply tank receiver and fluidly coupled with the steam generator via the supply tank receiver, a fluid distributor fluidly coupled with an outlet of the steam generator, and a cleaning pad mounted to the foot assembly and positioned to contact the surface to be cleaned, wherein the upright handle assembly comprises a cover over the supply tank receiver, and the cover comprises a cutout through which a portion of the supply tank is visible from an exterior of the steam mop. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings: 
         FIG. 1  is a front perspective view of a surface cleaning apparatus in the form of a steam mop according to a first embodiment of the invention. 
         FIG. 2  is an exploded view of an upper handle portion of the steam mop of  FIG. 1 . 
         FIG. 3  is an exploded view of a lower body portion of the steam mop of  FIG. 1 . 
         FIG. 3A  is a schematic view of the fluid delivery system of the steam mop of  FIG. 1 . 
         FIG. 4  is a partial plan view of the lower body portion of the steam mop with a portion of the housing removed for clarity. 
         FIG. 5  is a partial exploded front perspective view of the steam mop, showing the first and second liquid supply tanks detached from the lower body portion of the steam mop. 
         FIG. 5A  is a close up view of section  5 A of  FIG. 5 . 
         FIG. 6  is a partial exploded rear perspective view of the steam mop, showing the first and second liquid supply tanks detached from the lower body portion of the steam mop. 
         FIG. 6A  is a close up view of section  6 A of  FIG. 6 . 
         FIG. 7  is a cross-sectional view of the steam mop of  FIG. 1  taken along line  7 - 7 . 
         FIG. 8  is a partial exploded view of a pinch valve assembly according to the invention. 
         FIG. 9  is a cross-sectional view of the steam mop of  FIG. 1  taken along line  9 - 9 . 
         FIG. 10  is a partial exploded view of the foot assembly of the steam mop of  FIG. 1 . 
         FIG. 11  is a perspective view of a steam mop according to a second embodiment of the invention. 
         FIG. 12  is a rear perspective view of the foot of the steam mop of  FIG. 11 . 
         FIG. 13  is an exploded view of the foot of the steam mop of  FIG. 11 . 
         FIG. 14  is a partial cut-away view of the steam mop of  FIG. 11  taken along line  14 - 14 , with the agitator shown in a first position. 
         FIG. 15  is a side view of the steam mop of  FIG. 11 , with the agitator shown in a first position. 
         FIG. 16  is a side view of the steam mop of  FIG. 11 , with the agitator shown in a second position. 
         FIG. 17  is a front perspective view of a surface cleaning apparatus in the form of a steam mop according to a third embodiment of the invention. 
         FIG. 18  is a schematic view of a fluid delivery system of the steam mop of  FIG. 17 . 
         FIG. 19  is a partially exploded view of an upper handle assembly of the steam mop of  FIG. 17 . 
         FIG. 20  is a cross-sectional view through line  20 - 20  of the steam mop of  FIG. 17 . 
         FIG. 21  is an exploded view of a foot assembly of the steam mop of  FIG. 17 . 
         FIG. 22  is an exploded view of a coupling joint of the steam mop of  FIG. 17 . 
         FIG. 23  is a partial cut-away view of the foot assembly of  FIG. 21 , showing the coupling joint in an upright position. 
         FIG. 24  is a cross-sectional view through line  24 - 24  of the steam mop of  FIG. 23 , showing the coupling joint in an upright position. 
         FIG. 25  is a partial cut-away view similar to  FIG. 23 , showing the coupling joint in a reclined position. 
         FIG. 26  is a cross-sectional view similar to  FIG. 24 , showing the coupling joint in a reclined position. 
         FIG. 27  is a side view of the steam mop of  FIG. 17 , with an agitator assembly shown in a first use position. 
         FIG. 28  is a view similar to  FIG. 27 , with the agitator assembly shown in a second non-use position. 
         FIG. 29  is an exploded view of the agitator assembly of  FIG. 27 . 
         FIG. 30  is a partial cut-away view of the steam mop of  FIG. 17  taken along line  30 - 30 , with the agitator shown in a use position. 
         FIG. 31  is a bottom perspective view of a foot assembly according to a fourth embodiment of the invention. 
         FIG. 32  is a partially exploded view of the foot assembly of  FIG. 31 . 
         FIG. 33  is a close-up view of a steam delivery pathway for the foot assembly of  FIG. 31 , illustrating an agitator assembly in a use position. 
         FIG. 34  is a close-up view similar to  FIG. 33 , illustrating the agitator assembly in a non-use position. 
     
    
    
     DESCRIPTION OF EMBODIMENTS OF THE INVENTION 
     Referring to the drawings, and in particular to  FIGS. 1-2 , a surface cleaning apparatus according to a first embodiment of the invention comprises a steam mop  10  having a housing with an upright handle assembly  12  and a foot assembly  14 . A cleaning pad  15  can be selectively received on the foot assembly  14  for wiping a surface to be cleaned. 
     The foot assembly  14  is swivelably mounted to the handle assembly  12  via a coupling joint  16 . The handle assembly  12  can pivot from an upright, stored position, in which the handle assembly  12  is oriented substantially vertical relative to the surface to be cleaned, to a reclined, use position, in which the handle assembly  12  is pivoted rearwardly relative to the foot assembly  14  to form an acute angle with the surface to be cleaned. The coupling joint  16  can comprise a ball joint, or a universal or a Cardan joint, as further disclosed in U.S. Pat. No. 8,458,850, U.S. Pat. No. 4,971,471 and Chinese Patent No. CN2482956, which are incorporated herein by reference in their entirety. The coupling joint  16  is configured to permit the handle assembly  12  to rotate about more than one axis relative to the foot assembly  14 . In one embodiment, the handle  12  is configured to rotate up and down as well as side to side, relative to the foot assembly  14 . The coupling joint  16  can also be configured to accommodate one or more fluid delivery conduits passing therethrough. Moreover, the coupling joint  16  can comprise a modified Cardan joint where a portion of the joint comprises a steam delivery manifold as more fully disclosed in U.S. Pat. No. 8,926,208, which is incorporated herein by reference in its entirety. 
     The handle assembly  12  comprises an upper handle portion  18  and a lower body portion  20 . A grip portion  22  at the distal end of the upper handle portion  18  is engageable by a user for directing the steam mop  10  across the surface to be cleaned. A grip insert  24  nests between opposed inboard recesses (not shown) formed in an upper handle front housing  28  and an upper handle rear housing  30 . The grip insert  24  is secured between the housings via conventional fasteners (not shown). A trigger  32  is pivotally mounted to support ribs (not shown) the upper handle front housing  28 . A portion of the trigger  32  protrudes through an aperture in the grip insert  24  where it is accessible for selective engagement by a user. The trigger  32  is operably connected to an upper push rod  40  that is slidably mounted within a cavity  42  formed between the upper handle front housing  28  and the upper handle rear housing  30 . 
     Referring to  FIG. 3 , a bottom end  44  of the upper push rod  40  is in register with a lower push rod  46  that is slidably mounted within a cavity  48  formed in the lower body portion  20 . A lower end  54  of the lower push rod  46  is in register with a mechanical plunger valve  56  that is fluidly connected to a liquid delivery system mounted in the lower body portion  20 . An actuator arm  58  projects outwardly from the side of the lower push rod  46  for selectively engaging a micro-switch  60  that is operably connected to a steam delivery system  66  ( FIG. 3A ).  FIG. 4  is a partial plan view of the steam mop with a portion of the lower body hidden and the interconnecting wiring removed to more clearly show the engagement between the lower push rod  46 , plunger valve  56  and micro-switch  60 . 
     The lower body portion  20  comprises elongated, mating front and rear enclosures  62 ,  64  that form a central cavity therebetween for mounting components of the steam mop  10 , such as a portion of the liquid and steam delivery system  66  ( FIG. 3A ) of the steam mop. A stepped portion  68  at the top of the front and rear enclosures can be inserted within a corresponding socket  70  in the bottom of the upper handle portion  18  (see  FIG. 2 ). The upper handle portion  18  and lower body portion  20  can be fastened together via mechanical fasteners to form the entire upright handle assembly  12 . A badge  72  including a BISSELL® brand logo or other artwork can be prominently displayed within a corresponding pocket  74  near the top of the front enclosure. The badge  72  can be fastened within the pocket  74  via conventional fastening means such as screws, adhesive, or double-sided tape or welding, for example. The rear enclosure  64  also includes a power cord exit aperture  76  and cord wraps  78  for storing the wrapped power cord (not shown) when the steam mop  10  is not in use. 
     Referring to  FIGS. 3 and 3A , the liquid and steam delivery system  66  is adapted to store a primary liquid and an optional auxiliary cleaning liquid, heat the primary liquid to generate steam, meter the flow of the auxiliary cleaning liquid into the steam flow path, and mix the steam and auxiliary cleaning liquid prior to delivering the steam and liquid mixture onto the cleaning surface as will be described in detail hereinafter. The fluid distribution system comprises a water tank assembly  80  and separate auxiliary liquid supply tank assembly  82  that are adapted for fluid connection to a corresponding water tank receiver  84  and auxiliary receiver  86 , respectively. 
       FIGS. 5-6  are partially exploded front and rear perspective views of the steam mop showing the water tank assembly  80  and auxiliary liquid supply tank  82  removed from the front enclosure  62 . The water tank assembly  80  comprises an enclosed liquid reservoir  88  that is configured to hold a predetermined amount of liquid. The reservoir  88  is defined by a front wall  90  with a stepped upper portion  92 , a rear wall  94 , a flat bottom wall  96 , and an angled top wall  98 . A cylindrical recess  100  is formed in the rear wall  94  to nest the auxiliary liquid supply tank assembly  82 . The reservoir  88  further comprises a threaded neck  102  on the bottom wall  96 , which defines the liquid outlet  104 , and also provides an aperture for refilling the reservoir. A one-way valve assembly  106  is removably secured to the threaded neck  102  and mates with the water tank receiver  84 . The one-way valve assembly  106  can be selectively removed to re-fill the reservoir  88 . A bleeder valve  108  is provided on the reservoir  88 , which is illustrated as an elastomeric duckbill check valve, comprises an inlet  110  and a selectively sealable outlet  112  that is adapted to deform and open to equalize pressure between ambient atmosphere and the volume inside the liquid reservoir  88 . The bleeder valve  108  is inserted into a hole  114  within a recessed vent channel  116  on the rear wall  94  so that the outlet  112  is positioned inside the liquid reservoir  88 . The bleeder valve  108  is adapted to vent ambient atmospheric air surrounding the steam mop  10  through the inlet  110  and through the selectively sealable outlet  112 , into the reservoir  88  when liquid inside the reservoir  88  is displaced and released through the liquid outlet  104  and introduced to the downstream components of the steam delivery system during use. 
     A trapezoidal-shaped side cutout  118  is formed at each side of the reservoir  88 . Each side cutout  118  extends rearwardly from the front wall  90  and is defined by three interconnected, faceted walls and an open back. Each side cutout  118  is defined by a substantially horizontal lower wall  120 , a substantially vertical middle wall  122 , a substantially angled upper wall  124  and an open back formed between the distal ends of the lower wall  120  and upper wall  124 . A reservoir grip  128  is formed between the middle walls  122  of the side cutouts  118  and the portion of the front wall  90  spanning therebetween. Because the width of the reservoir grip  128  is less than the full width of the entire reservoir  88 , it provides a comfortable interface that a user can easily grasp while removing, transporting and reinstalling the water tank assembly  80  to the handle assembly  12 . Additionally, a portion of the auxiliary liquid supply tank assembly  82  is visible through the side cutouts  118 , which permits a user to easily ascertain the liquid fill level inside the auxiliary liquid supply tank  82 . 
     A cosmetic crown  130  comprises a front wall  132  with a projection  134  on the backside for engaging a corresponding indentation  136  on the stepped upper portion  92  of the reservoir  88 . The crown  130  further comprises a cylindrical rear wall  140  with angled locator ribs  142  at each end. The crown  130  is designed to slide downwardly and fit snugly over the top of the reservoir  88  so that the front wall  132  mates with the stepped upper portion  92  and the projection  134  seats within the indentation  136  on the reservoir while the cylindrical rear wall  140  and angled locator ribs  142  engage a corresponding inwardly stepped portion on the back of the reservoir  88 . The crown  130  can be fastened to two horizontally oriented screw bosses  144  that are located at the top of the reservoir  88 . The crown  130  is preferably molded from opaque, colored plastic material and can be textured, painted or plated for desired aesthetic effect. Additionally, a U-shaped bezel  146  is configured to be fastened to the top of the crown  130  for enhancing the aesthetic appearance of the water tank assembly  80 . The bezel  146  is preferably molded out of an opaque, colored plastic and can optionally be painted or chrome plated, utilizing a variety of commonly known post-molding finishing processes, such as electroplating for example. 
     Referring to  FIGS. 5A and 6A , the crown  130  further comprises recessed retention tracks  148  on the inner surface thereof, at the ends of the cylindrical rear wall  140 . Retainer tabs  150  protrude inwardly from the retention tracks  148 , towards the central axis A of the tank. The tabs  150  each include an angled lead-in portion  154  at a lower portion thereof. The retention tracks  148  and retainer tabs  150  are configured to engage a corresponding pair of T-ribs  156  on the front enclosure  62 . Each T-rib  156  comprises a vertical stand-off  158  that is connected to a front face  160 , which is perpendicular to the stand-off  158  and spaced from the front enclosure  62 . The front face  160  comprises an outer hook  162 , which extends outwardly from the stand-off  158 , away from the central axis of the tank, and an inner hook  164 , which extends inwardly from the stand-off portion  158 , towards the central axis A of the tank. Detent bumps  166  are formed along the backside of the outer hooks  162  to secure the retainer tabs  150  of the water tank assembly  80  to the front enclosure  62 . 
     Referring to  FIGS. 5-6 , the auxiliary liquid supply tank assembly  82  is configured to hold a predetermined amount of auxiliary cleaning liquid, such as a liquid sanitizing agent such as accelerated hydrogen peroxide, or a disinfectant agent, detergent, fragrance or other liquid surface treatment. The auxiliary liquid supply tank  82  comprises a substantially cylindrical auxiliary reservoir  168  with a flat bottom wall  170  with a threaded neck  172  that defines an auxiliary liquid outlet  174 . A second one-way valve assembly  106  is removably secured to the threaded neck  172  and mates with the auxiliary receiver  86 . The one-way valve assembly  106  is configured to release liquid through the auxiliary liquid outlet  174  into the auxiliary receiver  86  when the valve  106  is actuated and it can be selectively removed to re-fill the auxiliary reservoir  168  through the threaded neck  172 . The auxiliary reservoir  168  further comprises an angled top wall  178  and a flat, vertical back wall  180 . A recessed vent valve seat  184  is formed at an upper portion of the back wall  180  and is fluidly connected to a recessed vertical vent channel  186 . A bleeder valve  108 , illustrated as an elastomeric duckbill valve, is mounted within the valve seat  184  and is adapted to vent ambient atmospheric air through the vent channel  186  and into the auxiliary reservoir  168  when liquid therein is released through the liquid outlet  174  during use, as previously described. A check valve  188 , which is illustrated as an elastomeric umbrella valve, is mounted to the outer surface of the valve seat  184 , adjacent to the bleeder valve  108 . The check valve  188  comprises a resilient circular sealing flap  190  for selectively sealing a vent hole  191  in the back wall  180  of the reservoir. However, when excess gas is generated inside the auxiliary reservoir  168  due to potential reactions between various additives or off-gassing from peroxide formulations, for example, the pressurized gas can flow through the vent hole  191  and momentarily deform the resilient sealing flap  190 , thereby venting the excess gas past the flap  190  and through the vent channel  186 , into surrounding atmosphere. 
     Referring to  FIG. 5-6A , the auxiliary reservoir  168  further comprises depressions at both sides that extend forwardly from the back wall  180  and define auxiliary tank retention tracks  194  for engaging inner hooks  164  of the T-ribs  165  on the front enclosure  62 . Retainer tabs  196  protrude outwardly from each auxiliary tank retention track  194 , away from the central axis of the tank. The retainer tabs  196  each include an angled lead-in portion  198  at a lower portion thereof for sliding over the top edge of the T-ribs  165 . When the auxiliary liquid supply tank  82  is fully seated on the front enclosure  62 , detent bumps  200  along the backside of the inner hooks  164  engage the retainer tabs  196  and retain the auxiliary tank  82  to the front enclosure  62 . 
     Referring to  FIGS. 3, 5 and 7 , the water tank assembly  80  and auxiliary liquid supply tank assembly  82  are adapted for fluid connection to a corresponding water tank receiver  84  and auxiliary receiver  86 , which are both mounted to the front enclosure  62 . Both tanks  80 ,  82  are at least partially supported by the front enclosure  62  when the tanks are mounted to the steam mop  10 . The water tank receiver  84  comprises a groove  202  that wraps around the perimeter of a D-shaped tank support platform  204 . The groove  202  engages a corresponding tongue  206  on the inner surface of a front cover  208  and the front enclosure  62 , thus forming a robust tongue and groove joint that secures the water tank receiver  84  between the front enclosure  62  and the front cover  208 . 
     Similarly, the auxiliary receiver  86  is secured to the front enclosure  62 , above the water tank receiver  84 , by a receiver cover  210  that is fastened to the front enclosure  62 . The receiver cover  210  comprises a pair of vertically spaced grooves  212  that engage a pair of corresponding tongues  214  formed around the perimeter of the auxiliary receiver  86 . The auxiliary receiver  86  comprises a platform  216  for partially supporting the auxiliary liquid supply tank  82  thereon. The platform  216  further comprises at least one aperture  218  for mounting at least one lens  220  therein. Alternatively, lens  220  can be mounted adjacent to either or both of the water supply tank  80  and the auxiliary liquid supply tank  82  on one or a combination of the front enclosure  62 , lower body portion  20 , or the water tank receiver  84 , for example. 
     The shape and material of the lens  220  can be selected to provide the desired optical characteristics. The lens material can be transparent or translucent and adapted to transmit electromagnetic waves, especially visible light waves. For example, the lens  220  can comprise polycarbonate or acrylic plastic material. The lens material can be tinted, textured, or coated to exhibit various visual properties and appearances or to filter or diffuse the emitted light. The lens  220  can also be formed in a convex or concave shape to distribute or focus the light beams as desired. 
     In one embodiment, shown in  FIG. 3 , the platform  216  comprises two adjacent apertures  218  and the lenses  220  are press fit into the apertures  218  from beneath the platform  216 . Mounting features (not shown) on the bottom surface of each lens  220  are adapted to mount light source therein, such as Light Emitting Diodes (LED)  222  shown in  FIG. 3 . The LEDs  222  are mounted in an orientation to emit electromagnetic waves upwardly, through the lenses  220 . A horizontal lap-joint  224  ( FIG. 7 ) between a flange  226  on the lens  220  and the platform  216  wall prevents liquid on the top surface of the auxiliary receiver  86  from leaking past the lens  220  and contacting the LED  222  mounted thereunder. Alternatively, the lens  220  can include a seal that is adapted to shield the LED  222  from liquid, or the lens  220  can be welded or glued to the platform  216  to create a hermetic seal therebetween. In yet another embodiment, the entire receiver  86  can be formed out of transparent or translucent plastic and can comprise at least one integral lens formed therein. 
     Each LED  222  is electrically connected within a control circuit, which can comprise an intermediate Printed Circuit Board (PCB)  228  and a downstream power source, such as a battery pack or a power cord associated with a power outlet, for example, and can be energized and illuminated when power is supplied from the power source. For example, the LEDs  222  can be configured to illuminate as soon as the power cord is plugged into a power outlet. Accordingly, the LEDs  222  can provide an indication of the functional status of the steam mop  10 , such as whether it is ready for use. Optionally, the PCB  228  can include additional conventional control circuitry components configured to vary the appearance of the LEDs  222 , such as a multivibrator circuit that is adapted to flash or gradually pulse the LEDs  222  on and off. Moreover, the LEDs  222  can comprise a single color, such as super bright white, or, alternatively, the LEDs  222  can comprise tri-color or RGB LEDs (red, green, blue). The tri-color or RGB LEDs can be connected to suitable control circuit components on the PCB  228 , such as relays and timers commonly known in the art, that are configured to fade the LEDs  222  through a predetermined color sequence or to gradually morph from one color to another. Furthermore, the LEDs  222  can selected to not only emit light wavelengths in the visible spectrum, but also the non-visible, ultraviolet spectrum, which can be beneficial for activating reactive chemistry stored within the auxiliary liquid supply tank  82  or for enhancing cleaning performance or for sanitizing either of the water tank  80  or auxiliary liquid supply tank  82 , for example. In one embodiment, hydrogen peroxide can be stored in the auxiliary liquid supply tank  82  and the LEDs  222  can be configured to transmit wavelengths in the ultraviolet spectrum through the tank walls to activate the hydrogen peroxide therein for enhanced performance such as accelerated and/or improved stain removal and brightening of the surface to be cleaned, including for example, grout between floor tiles. Alternatively, the light transmitted by the LEDs  222  can include UVC wavelengths for sanitizing the auxiliary liquid supply tank  82  and fluid contained therein. 
     In another embodiment, an elongate light pipe or light guide can be substituted for or be incorporated in conjunction with the lens  220 . The light pipe can be mounted to the front enclosure  62  with a distal end in communication with a remote light source and a proximal end in communication with either of the auxiliary liquid supply tank  82  or the water supply tank  80 . The light pipe can comprise a transparent plastic material suitable for optic components such as acrylic or polycarbonate. The light pipe can be adapted to transmit light from the remote light source, through the light pipe, and to emit light through the proximal end thereof to illuminate either of the auxiliary liquid supply tank  82  or water tank  80  and to emit light through said tank walls. 
     In yet another embodiment, a fiber optic cable containing one or more optical fibers can replace the lens  220 . The fiber optic cable can be mounted with one end in communication with the auxiliary liquid supply tank  82  and the other end in communication with a remote light source to transmit light from the light source to the auxiliary liquid supply tank  82 . In one example, the light source can comprise at least one LED that is located remotely from either of the auxiliary liquid supply tank assembly  82  or the water tank assembly  80 . For example, the LED can be mounted near the badge  72  and the fiber optic cable can be routed inside the lower body portion  20  to an aperture in the front enclosure  62  adjacent to either of the auxiliary liquid supply tank  82  or the water tank assembly  80  to transmit light from the LED to either of the auxiliary liquid supply tank  82  or the water tank assembly  80 . 
       FIG. 8  shows a partial exploded view of a pinch valve assembly  238  that is mounted to the front cover  208  and front enclosure  62  for selectively restricting liquid flow through a flexible tube  240  that is fluidly connected to the outlet of the auxiliary receiver  86 . The pinch valve assembly  238  comprises a rotatable knob  242  that is mounted to the front cover  208  and coupled to a cam  244  on the backside thereof. The cam  244  is a generally disk-shaped member with a raised ramp  246  around its perimeter. The ramp  246  gradually increases in height in a clockwise direction from a low point  248  at the top of the cam  244  to a high point  250  near the bottom, approximately 180 degrees apart from the low point  248  around the circumference. The ramp  246  is in register with the proximal end of a T-shaped plunger  252  that is oriented transversely between the front cover  208  and the front enclosure  62 . The plunger  252  comprises an elongate plunger rod  254  connected to a tube clamp  256  portion at a distal end thereof. The plunger rod  254  further comprises a proximal end  258  that is in sliding register with the ramp  246 . The tube clamp  256  comprises holes  260  near both ends that form bushing sleeves, which are adapted to slide axially along corresponding guide bosses  262  on the front enclosure  62 . The backside of the tube clamp  256  is in register with flexible tubing  240  fluidly connecting the outlet of the auxiliary receiver  86  to a downstream fluid fitting  266  ( FIGS. 3 and 9 ). 
     A user can selectively rotate the knob  242  between at least one of an “open” position, which permits auxiliary liquid to flow through the flexible tubing  240  and a “closed” position, which prevents auxiliary fluid from flowing through the flexible tubing  240 . The “open” position corresponds to the knob  242  being rotated clockwise until an internal rib (not shown) abuts a clockwise stop  268  on the front cover  208 , preventing the knob from further rotation. In this “open” position, the proximal end  258  of the plunger rod  254  is in register with the lowest point  248  of the ramp  246  and so the tube clamp  256  at the distal end of the plunger  252  does not compress the flexible tubing  264 . Accordingly, the tubing  264  is unrestricted and in an un-pinched condition. Conversely, when the knob  242  is rotated counter-clockwise until the internal rib (not shown) abuts a counter-clockwise stop  270 , which corresponds to the “closed” position, the ramp  246  engages the proximal end  258  of the plunger rod  254  and gradually forces the plunger  252  inwardly along the guide bosses  262 . As the proximal end  258  of the plunger rod  254  slides up the ramp  246  to the highest point  250 , the tube clamp  256  is forced against the flexible tubing  240  thereby compressing the tubing  240  until it is entirely pinched closed. Thus, a user can rotate the knob  242  to selectively pinch the flexible tubing  240  to meter the flow of liquid from the auxiliary liquid supply tank  82  to the downstream fluid delivery system. Although not shown in the figures, the knob  242  can comprise detents, which provide discreet “open” and “closed” positions at the respective limits of knob  242  rotation as well as additional discreet intermediate positions corresponding to cam positions that gradually compress or “pinch” the flexible tubing  240  to restrict the internal liquid flow path therein. Alternatively, the knob  242  can omit detents, rendering it entirely variable and adapted to provide infinite metering adjustability. 
     Referring now to  FIGS. 3, 3A and 9 , a pump  272 , steam generator  274 , and a pressure relief valve  276  are mounted within the central cavity  48  between the front and rear enclosures  62 ,  64  and fluidly connected via conventional tubing and fluid fittings. An inlet of the pump  272  is coupled with the water tank receiver  84  and an outlet of the pump  272  is fluidly connected to the steam generator  274  via one branch of a Y-shaped connection tube  278 . Another branch of the Y-shaped connection tube  278  couples the outlet of the pump  272  with the pressure relief valve  276 . The steam generator  274  is electrically coupled with the power cord and can be selectively energized by plugging the cord into a power outlet. The pump  272  is selectively electrically coupled with the power cord via the micro-switch  60  that is operably connected to the trigger  32  mounted in the grip  22  portion. The pump  272  can comprise a conventional solenoid pump. The PCB  228  can be configured to control the duty cycle of the pump  272  and for incorporating various electromagnetic compatibility (EMC), electromagnetic interference (EMI) and radio frequency interference (RFI) filtration components into the pump circuit as necessary. Upon energizing the steam generator  274 , the pump  272  can be selectively activated to distribute steam by depressing the trigger  32 , which actuates the micro-switch  60  electrically connected to the pump  272 . 
     Alternatively, the pump  272  can be replaced by a valve (not shown) to permit liquid to flow from the water tank assembly  80  into the steam generator  274  by gravity, and, subsequently, onto the cleaning surface. 
     The steam generator  274  comprises a heating element for heating liquid that passes into the steam generator  274  from the pump  272 . For example, the steam generator  274  can comprise a flash steam heater or a boiler for generating steam. An outlet of the steam generator  274  is fluidly connected to a fluid fitting  266  that is mounted in a lower neck portion  284  of the rear enclosure  64 . The top of the fluid fitting  266  comprises a steam inlet barb  286  and a liquid inlet barb  288 , which are fluidly connected to a steam outlet barb  290  and an adjacent liquid outlet barb  292  at the bottom of the fluid fitting  266 . The outlet of the steam generator  274  is fluidly connected to the steam inlet barb  286  via flexible tubing  280 . The auxiliary receiver  86  outlet is fluidly connected to the liquid inlet barb  288  via flexible tubing  240 . 
     The lower neck portion  284  of the rear enclosure  64  is adapted for insertion into the coupling joint  16  of the foot assembly  14  to swivelably connect the handle assembly  12  to the foot assembly  14 . The coupling joint  16  is configured to rotate back and forth about horizontal axis “Z”, which extends laterally through the sides of the steam mop  10 , and from side to side about axis “Y”, which is orthogonal to axis “Z” and extends horizontally from the front to back, through the middle of the steam mop  10 . 
       FIG. 10  is an exploded perspective view of the foot assembly  14 . The coupling joint  16  comprises a center pivot ball  298  that is cradled between a front pivot  300  and a rear pivot  302 . The center pivot ball  298  is adapted for side-to-side rotation, between the front and rear pivots  300 ,  302  about axis “Y” ( FIG. 1 ) as will be described hereinafter. The upper portion of the center pivot ball  298  comprises a cylindrical neck  304  that is joined to a partial spherical wall  306  with an open bottom, which forms the lower portion of the center pivot ball  298 . The spherical wall  306  comprises a front hole  308  and a rear hole  310  that are adapted to rotatably receive a front pivot boss  312  that protrudes inwardly from the front pivot  300  and a rear pivot boss  314  that protrudes inwardly from the rear pivot  302 . The front and rear holes  308 ,  310  are configured to rotate freely about the front pivot boss  312  and the rear pivot boss  314 , respectively, when the front and rear pivots  300 ,  302  are fastened together around the center pivot ball  298 . The diameters of the corresponding front hole  308  and front pivot boss  312  can be a different size relative to the diameters of the rear hole  310  and rear pivot boss  314  to prevent misassembly of the coupling joint  16 . 
     The front pivot  300  further comprises axial pivot arms  316  that protrude outwardly from the sides of the front pivot  300 , along axis “Z” ( FIG. 1 ). The pivot arms  316  are rotatably received in corresponding cradle ribs  318  in a base housing  320 . The pivot arms  316  are rotatably retained to the cradle ribs  318  by corresponding support ribs (not shown) in a cover housing  321 , when the cover housing  321  is fastened to the base housing  320 . Accordingly, the coupling joint  16  is adapted to rotate upwardly and downwardly about the pivot arms  316 , which lie along axis “Z”. 
     A semi-circular tab  322  protrudes off the front of the cylindrical neck  304  and is configured to engage a corresponding notch  324  on the cover housing  321  of the foot assembly  14  when the handle  12  is in the upright, storage position. When the handle  12  is returned to the upright storage position, the tab  322  is received within the notch  324  to prevent the center pivot ball  298  from pivoting from side to side about the front and rear pivot bosses  312 ,  314 , which lie along axis “Z”. 
     Referring to  FIG. 9 , the center pivot ball  298  further comprises a hollow steam passageway  326  for transmitting steam therethrough, and liquid passageway  328  for transmitting liquid therethrough. The steam passageway  326  extends through a steam receiver port  330 , which is formed within the neck  304  and a coaxial steam outlet port  332 , which is formed at a lower portion of the center pivot ball  298 , inboard of the partial spherical wall  306 . Likewise, the liquid passageway  328  is located adjacent to the steam passageway  326  and extends through a liquid receiver port  334 , adjacent to the steam receiver port  330  in the neck  304  and an associated liquid outlet port  336  adjacent to the steam outlet port  332 . 
     A flexible steam outlet tube  338  fluidly connects the steam outlet port  332  to a first inlet barb  340  on a distributor nozzle  342  that is fastened to the base housing  320 . Likewise, a flexible liquid outlet tube  344  fluidly connects the liquid outlet port  336  to a second inlet barb  346  on the distributor nozzle  342 , downstream from the first inlet barb  340 . The steam outlet tube  338  and liquid outlet tube  344  pass through the open bottom of the center pivot ball  298  and corresponding slots (not shown) in the front pivot  300  and rear pivot  302 . The distributor nozzle  342  includes an internal conduit (not shown) that merges the internal fluid flow paths from the first and second inlet barbs  340 ,  346  into a single distributor outlet  348 , which is aligned with an aperture  350  formed in the base housing  320 . An O-ring seal  352  is compressed between the distributor nozzle  342  and the aperture  350  to prevent fluid leakage. Alternatively, the coupling joint  16  can comprise a conventional Cardan joint with a flexible steam conduit routed therethrough to fluidly connect the steam outlet port  332  to the distributor nozzle  342 , as is commonly known in the art. 
     Referring to  FIGS. 9 and 10 , the base housing  320  further comprises a bottom wall with a plurality of separable fasteners  351  formed integrally around the perimeter thereof for selectively mounting the cleaning pad  15  thereon. The separable fasteners  351  can comprise spear-like protuberances that are adapted to engage and selectively retain a cleaning pad  15 . The protuberances can be substantially similar to those disclosed in U.S. Pat. No. 3,708,833 to Ribich et al., which is incorporated herein by reference in its entirety. Alternatively, other suitable fastening means commonly known in the art can be used such as hook and loop fasteners, elastic straps, elastic drawstring, or resilient retention members having a plurality of outwardly radiating slits for retaining the cleaning pad  15 , for example. The cleaning pad  15  can comprise a dry, microfiber fabric, or any other suitable cleaning material that is preferably washable for reuse, and can additionally include a backing material to provide structure. Alternatively, the cleaning pad  15  can comprise a generally flat disposable pad or sheet. The cleaning pad  15  can optionally comprise an encapsulated formulation as disclosed in U.S. Pat. No. 8,927,480, which is incorporated by reference herein in its entirety. 
     The back of the neck  304  comprises a keyed channel  354  that receives a complimentary keyed protrusion (not shown) on the lower neck portion  284  of the rear enclosure  64 . A slot  358  in the keyed portion  354  is adapted to selectively receive a spring-biased locking latch  360  that is resiliently mounted to the lower, back portion of the rear enclosure  64 . 
     Upon mounting the foot assembly  14  to the handle assembly  12 , the steam outlet barb  290  and liquid outlet barb  292  on the fluid fitting  266  are configured to sealingly engage the steam receiver port  330  and the liquid receiver port  334  in the center pivot ball  298  of the foot assembly  14 . Accordingly, a continuous fluid path is formed from the water tank assembly  80  and auxiliary liquid supply tank assembly  82  to the distributor nozzle  342  and through the distributor outlet  348 . 
     In operation, a user prepares the steam mop  10  by pouring auxiliary liquid, like detergent for example, through the threaded neck  172  before securing the one-way valve assembly  106  thereto and mounting the auxiliary liquid supply tank  82  to the front enclosure  62 . The user mounts the auxiliary tank  82  by sliding the retention tracks  194  past the inner hooks  164  of the T-ribs  156  until the detent bumps  166  clear the top edge of the retainer tabs  196  and thus secure the auxiliary liquid supply tank  82  to the front enclosure  62 . When the auxiliary tank  82  is properly seated, the bottom wall  170  is at least partially supported by the platform  216  and lies adjacent to the lens  220  while the one-way valve  106  simultaneously engages the auxiliary receiver  86  and delivers auxiliary cleaning liquid to the downstream liquid supply system through the flexible tubing  240 , which is connected to the outlet of the auxiliary receiver  86 . 
     Next, a user fills the water tank assembly  80  in the same manner by first removing the one-way valve assembly  106  from the threaded neck  102  and then filling the reservoir  88  with water. The user then secures the one-way valve assembly  106  to the threaded neck  102  and installs the water tank assembly  80  onto the front enclosure  62  by sliding the retention tracks  148  over the outer hooks  162  of the T-ribs  156  until the detent bumps  166  engage the top of the retainer tabs  150 , thus securing the water tank assembly  80  to the front enclosure  62 . When the water tank assembly  80  is properly seated, the bottom wall  96  is at least partially supported by the water tank receiver  84  while the one-way valve  106  simultaneously engages the water tank receiver  84  and delivers liquid to the downstream liquid supply system through a second flexible tube (not shown), which is connected to the outlet of the water tank receiver  84 . 
     Next, a user selectively depresses the trigger  32  to distribute fluid through the apparatus onto the cleaning surface. A portion of the trigger  32  pushes the upper push rod  40 , which slides downwardly within cavity  42  and forces the lower push rod  46  downwardly within cavity  48 . The lower end  54  of the lower push rod  46  actuates the plunger valve  56  that is fluidly connected to the auxiliary liquid supply tank  82  and the actuator arm  58 , which is also on the lower push rod  46 , simultaneously actuates a micro-switch  60  that is electrically connected to the pump  272  for selectively energizing the pump  272 . Water from the water tank assembly  80  flows through the one-way valve assembly  106  and water tank receiver  84 . The pump  272  conveys the water into the steam generator  274  where the water is converted at least partially into steam. Next, the pump  272  forces steam through steam passageway  326  and associated steam outlet tube  338 , into a first inlet barb  340  and through the distributor nozzle  342  where liquid from the auxiliary liquid supply tank  82  mixes with the steam and is distributed through the distributor outlet  348  and aperture  350  in the base housing  320  and onto the backside of the cleaning pad  15  for distribution onto the surface to be cleaned. 
     Liquid from the auxiliary liquid supply tank  82  flows through the one-way valve assembly  106 , through the auxiliary receiver  86 , through the plunger valve  56  (when it is actuated by the lower push rod  46 ), and downstream flexible tubing  240  that can be selectively restricted or variably metered by adjusting a pinch valve  238 . To increase the flow of auxiliary liquid, the user can rotate the knob  242  of the pinch valve  238  counter-clockwise to decrease engagement between the associated cam  244  and plunger  252 , and thus reduce the level of compression between the plunger  252  and the tubing  240 . Conversely, a user can maximize auxiliary liquid flow by rotating the knob  242  to the clockwise stop  268 , which corresponds to the position in which the plunger rod  254  is in register with the lowest point of the ramp  246  on the cam  244  so that the flexible tubing  240  is in an unrestricted an un-pinched condition. 
     Alternatively, if a user wants to reduce the flow of auxiliary cleaning liquid, the user can rotate the knob  242  counter-clockwise which forces the cam  244  against the plunger  252  to gradually pinch the flexible tubing  240  and thus restrict flow of auxiliary cleaning fluid therethrough. Moreover, to completely block the flow of the auxiliary cleaning liquid, the user can rotate the knob  242  to the counter-clockwise stop  270  so that the high point  250  of the ramp  246  forces the plunger  252  inwardly to pinch the flexible tubing  240  entirely closed to block the flow of liquid therethrough. 
     When the knob  242  is rotated to a position so that the flexible tubing  240  is at least partially un-pinched, the liquid from the auxiliary liquid supply tank  82  flows through the flexible tubing  240 , into the liquid passageway  328  and through the liquid outlet port  336  in the coupling joint  16 , through the second inlet barb  346  of the distributor nozzle  342  whereupon it mixes with the steam flowing through the first inlet barb  340 , and whereupon steam and liquid mixture is distributed simultaneously through the distributor outlet  348  onto the cleaning pad  15 , which is wiped across the surface to be cleaned. 
     When the steam mop  10  is energized, electricity flows through the control circuit and is delivered to LEDs  222 , which are mounted in the receiver platform  216 . Each LED  222  illuminates and light waves are emitted upwardly through the lenses  220 , which are also mounted in the auxiliary receiver  86  platform  216 . Light is transmitted and dispersed through the lenses  220  and through the at least partially transparent bottom wall  170  of the auxiliary liquid supply tank  82 , the fluid contained therein and the outer walls of the auxiliary reservoir  168 . Accordingly, the auxiliary liquid supply tank  82  is illuminated so that a user can see the contents of the auxiliary liquid supply tank  82 . Additionally, the illuminated, glowing auxiliary liquid supply tank  82  provides a pleasing aesthetic effect. 
     A surface cleaning apparatus according to a second embodiment of the invention is shown in  FIGS. 11-16 . Because many of the components of this embodiment are similar to the previous embodiment, like features are indicated with the same reference numeral bearing a prime (′) symbol. Any of the previously described features, including LED illumination components, can be incorporated into the following embodiment of the invention. 
     The surface cleaning apparatus comprises a steam mop  400  with an upright handle assembly  12 ′ that is substantially similar to the previous embodiment. The upright handle assembly  12 ′ is swivelably mounted to a foot assembly  402  through a coupling joint  16 ′. A cleaning pad  15 ′ can be selectively received on the foot assembly  402  for wiping a surface to be cleaned. The coupling joint  16 ′ can comprises a multi-axis Cardan joint as shown in the figures, but can alternatively comprise a ball joint to swivelably connect the foot assembly  402  to the upright handle assembly  12 ′. The coupling joint  16 ′ is adapted to pivotally connect the foot assembly  402  to the handle assembly  12 ′ and defines a first axis, “Z”, which is generally perpendicular to the axis defining the direction of travel D of the steam mop  10 . The handle  12 ′ can be pivoted from front-to-back with respect to the foot assembly  402  about axis “Z”. The coupling joint  16 ′ further defines a second axis, “Y”, which is generally parallel to the axis defining the direction of travel D of the steam mop  400 , and about which the handle  12 ′ can be pivoted from side-to-side with respect to the foot assembly  402 . Accordingly, the coupling joint  16 ′ is configured to permit the foot assembly  402  to swivel multi-axially with respect the handle assembly  12 ′. The upright handle assembly  12 ′ comprises an upper handle portion  18 ′ and a lower body portion  20 ′. 
     A steam distribution system is mounted within the handle assembly  12 ′, the foot assembly  402  or a combination thereof, and can be substantially similar to the steam distribution system  66  described for the first embodiment and schematically shown in  FIG. 3A , with the exception that the steam distribution system is only provided with a single tank assembly, water tank assembly  80 ′. Thus, in this embodiment, the auxiliary liquid supply tank assembly  82 , plunger valve  56 , the pinch valve  238 , the fluid fitting  266 , and other components associated with the auxiliary supply of liquid can be eliminated. As such, the fluid distributor nozzle  342 ′ ( FIG. 13 ) need only receive steam via the steam outlet tube  338 ′. The upper handle portion  18 ′ has a grip  22 ′, a trigger  32 ′, a handle tube  404  and a push rod arrangement as discussed above for the first embodiment slidably mounted within the handle tube  404  and configured to actuate steam distribution as previously described. Other bare floor steam cleaners with similar fluid distribution control systems are disclosed in US2010/0287716 and WO2011019814, which are incorporated herein by reference in their entirety. 
     Referring to  FIGS. 12 and 13 , the foot assembly  402  further comprises a base housing  406  and a cover housing  408  attached to the base housing  406  via fasteners (not shown). The base housing  406  preferably comprises a translucent material that can further optionally comprise a colored tint. The coupling joint  16 ′ is pivotally mounted at a rearward portion of the foot assembly  402  between the base housing  406  and the cover housing  408 . A portion of the coupling joint  16 ′ protrudes through an opening  410  in the cover housing  408 . A lower portion of the coupling joint  16 ′ is pivotally supported by mating cradle ribs (not shown) that are formed inside the base housing  406  and along the sides of the opening  410  in the cover housing  408 . The cradle ribs pivotally attach the coupling joint  16 ′ to the foot assembly  402 . An upper portion of the coupling joint  16 ′ is further configured to detachably receive the lower neck portion  284 ′ of the lower body portion  20 ′ as is commonly known in the art. 
     The cover housing  408  further comprises a viewing window  412  through the top of the cover housing  408  and located on each side of the opening  410  that accommodates the coupling joint  16 ′. Each window  412  comprises a trapezoidal cutout  414  bounded by a substantially vertical wall  416  that extends downwardly from the top surface of the cover housing  408 . The vertical wall  416  defines the perimeter of the viewing window  412  for viewing the base housing  406 , cleaning pad  15 ′ and steam condensation therebetween. The vertical wall  416  mates against a flat top surface  420  of the base housing  406 , which is formed of a transparent or translucent material. The distributor nozzle  342 ′ is mounted to an aperture  350 ′ on the base housing  406 . Steam channels (not shown) on the bottom of the base housing  406  are configured to guide steam from the distributor nozzle  342 ′, evenly across the base housing  406 , and past the translucent viewing windows  412 . Accordingly, a user can look through the viewing windows  412  observe the condensation of the steam vapor while using the steam mop  400  on the surface to be cleaned. Moreover, a user can easily confirm whether a cleaning pad  15 ′ is installed beneath the base housing  406  prior to using the steam mop  400 . Although the viewing windows  412  have been described as being integral to a translucent base housing  406 , it is also contemplated that separate, transparent viewing windows could be fastened to corresponding cutouts in an opaque base housing in an alternate configuration to achieve similar results. 
     A movable agitator assembly  422  is provided on a rear portion of the steam mop foot assembly  402 ; however, the invention is equally applicable to cleaning attachments for canister and upright steam mops and on wet mops, for example. As illustrated herein, the movable agitator assembly  422  is pivotally coupled to a rear portion of the foot assembly  402  and is configured for movement between a first position shown in  FIG. 15  and a second position shown in  FIG. 16 . In the first position, the movable agitator assembly  422  is in a use position and contacts the surface to be cleaned to provide enhanced, localized agitation of the surface to be cleaned whereas, in the second position, the movable agitator assembly  422  is in a non-use position and does not contact the surface to be cleaned. 
     The movable agitator assembly  422  comprises an agitator support frame  424  with support arms  426  extending perpendicularly from the ends thereof. The bottom of the support frame  424  is adapted to receive an agitator element  428  that is separate from the cleaning pad  15 ′. The support frame  424  can include separable fasteners (not shown) such as hook and loop fasteners, for example, that are configured to detachably secure an agitator element  428  to the support frame  424 . Alternatively, the agitator element  428  can be permanently affixed to the support frame  424 . 
     The agitator element  428  is configured to be attached or otherwise supported by the support frame  424  and extends substantially across the width of the support frame  424 , which partially spans the back portion of the base housing  406 . The agitator element  428  can comprise a variety of materials that are configured to agitate the surface to be cleaned. The agitator element  428  can comprise materials that are dissimilar from the cleaning pad  15 ′. Moreover, the thickness of the agitator element  428  can optionally be greater than the thickness of the cleaning pad  15 ′ to ensure that the agitator element  428  contacts the surface to be cleaned when the movable agitator assembly  422  is in the first, in-use position. For example, the agitator element  428  can comprise an elongated strip of scouring pad material, a tufted bristle block, an elastomeric block with spaced projections or nubs, a non-woven material, a micro-fiber material, a cellulose sponge, a strip of open cell melamine resin foam, such as Basotect®, which is commercially available from BASF Corp., or any other materials suitable for agitating a soiled surface to be cleaned without damaging said surface. The agitator element  428  can comprise a combination of materials with different textures. Moreover, the agitator element  428  can be pre-moistened or coated with a cleaning composition to enhance cleaning performance of the agitator assembly  422 . 
     The movable agitator assembly  422  further comprises a mounting assembly  430  for pivotally mounting the support frame  424  to the foot assembly  402 . The mounting assembly  430  can comprise a pair of spaced brackets  432  defined by mating cradle ribs (not shown) that can be formed in the cover housing  408  and base housing  406 . Alternatively, the spaced brackets can comprise individual bearing components that are affixed to either or a combination of the base housing  406  and the cover housing  408 . A pivot pin  436  extends inwardly from the distal end of each support arm  426 . Each pivot pin  436  is rotatably coupled with a corresponding bracket  432  by a pivot coupling (not shown), to hingedly connect the pin  436  to the mating cradle ribs. 
     The movable agitator assembly  422  can be pivoted between a non-use position as shown in  FIG. 16 , in which the agitator element  428  is spaced from the surface to be cleaned F, and a use position, as shown in  FIGS. 11, 12, 14 and 15 , in which the agitator element  428  contacts the surface to be cleaned F. A torsion spring  440  can be mounted around each pivot pin  436  with the free ends being compressed between the support arm  426  and base housing  406  such that the torsion spring  440  is configured to bias the support frame  424  upwardly relative to the base housing  406  toward the non-use position shown in  FIG. 16 . 
     The foot assembly  402  can further comprise an actuator assembly  442  for adjusting the position of the movable agitator  422  with respect to the surface to be cleaned. As best shown in  FIGS. 13 and 14 , a spring-loaded latch  444  can be provided at the rear of the foot assembly  402 . The latch  444  slides vertically through an opening in the cover housing  408 . The latch  444  further comprises a catch  446  at an upper portion thereof for engaging a hook  448  on the bottom of each support arm  426 . A compression spring (not shown) biases the latch  444  upwardly so the catch  446  is forced towards the hook  448 . The catch  446  can be disengaged from the hook  448  by depressing a foot pedal  450  on the upper portion of the latch  444 , which slides the latch  444  vertically downwardly relative to the surface to be cleaned and moves the catch  446  downwardly away from the hook  448 . The torsion spring  440  is then free to push the support arm  426  upwardly, thereby pivoting the support frame  424  and agitator element  428  upwardly to the non-use position, shown in  FIG. 16 , in which the agitator element  428  is spaced from the surface to be cleaned F. 
     In the use position, the agitator element  428  is positioned rearwardly of the base housing  406 . A user can selectively pivot the agitator element  428  into the use position to clean heavily soiled areas on the surface to be cleaned. With the agitator element  428  in the use position, a user can make one or more reciprocal cleaning strokes to scrub the soiled area. To move the agitator element  428  from the use position to the non-use position, the latch  444  can be pressed downwardly to release the catch  446  from engagement with the hook  448 , whereby the support frame  424  and associated agitator element  428  will be forced to pivot upwardly to the non-use position by the torsion spring  440 . The support arms  426  pivot about the pivot pins  436  and are rotated about the pivot couplings until the support arms  426  rest against an upper surface of the cover housing  408 . A first stop  452  is provided on the cover housing  408 , to provide a secure location for the support arms  426  to come to rest against the cover housing  408  in the non-use position. Two spaced second stops  454  are provided on the base housing  406  against which the support arms  426  will rest in the use position. The stops  452 ,  454  are configured so that when the support frame  424  is in the use position, the bottom of the support frame forces the agitator element  428  against the surface to be cleaned, thereby compressing the agitator element to some extent. The stops  452 ,  454  prevent damage to the movable agitator assembly  422  and foot assembly  402  when moving between the use and non-use positions. 
     In operation, the steam mop is prepared for use in substantially the same manner as previously described. Likewise, the function of the steam mop  400  is substantially similar to details previously disclosed herein, with the exception of the steam distribution system, movable agitator assembly  422  and viewing window  412 , which will be described hereinafter. 
     During operation, when a user encounters a heavily soiled area, the user can lock the agitator element  428  and support frame  424  into the use position by manually rotating the support frame  424  downwardly so the pivot pins  436  rotate within the pivot couplings in the spaced brackets  432 . The bottom of the support arms  426  eventually contact the second stops  454 , which limit the downward rotation of the support frame  424 . As the support frame  424  rotates, the torsion spring  440  is compressed between the support arms  426  and the base housing  406 . The hooks  448  on the bottom of the support arms  426  engage a catch  446 , which locks the support frame  424  in the in use position thereby forcing the agitator element  428  into contact with the surface to be cleaned and compressing the agitator element  428  slightly between the support frame  424  and the surface to be cleaned. A user can then resume reciprocal forward and backward cleaning strokes, applying downward force to the foot assembly  402  and wiping the cleaning pad  15 ′ and scrubbing the agitator element  428  across the surface to be cleaned while selectively distributing steam to the surface to be cleaned. To release the agitator element  428  and support frame  424  from the use-position into the non-use position, the user depresses the foot pedal  450  downwardly, which forces the spring loaded latch  444  downwardly away from hook  448  and releases the catch  446  portion of the latch  444  from the corresponding hook  448  on the support arm  426 . The torsion spring  440  forces the support arm  426  upwardly and the support frame  424  rotates about the pivot couplings in the brackets  432  into the non-use position so the agitator element  428  is lifted off the surface to be cleaned F. When the user releases the foot pedal  450 , the compression spring (not shown) forces the latch  444  upwardly. When the support frame  424  is in the non-use position, the tops of the support arms contact a first stop  452  on the cover housing  408 . 
     Steam channels (not shown) on the bottom of the base housing  406  are configured to guide steam through an outlet in the distributor nozzle  342 ′, evenly across the base housing to the backside of the cleaning pad  15 ′, including past the translucent viewing windows  412 . Accordingly, a user can look through the viewing windows  412  and observe the condensation of the steam vapor while using the steam mop  400  on the surface to be cleaned in addition to easily confirming whether the cleaning pad  15 ′ is in place beneath the base housing  406 . 
     A surface cleaning apparatus, illustrated as a steam mop  500 , according to a third embodiment of the invention is shown in  FIGS. 17-30 . Because many of the components of this embodiment are similar to the previous embodiments, like features are indicated with the same reference numerals. Any of the previously described features can be incorporated into the following embodiment of the invention. The coupling joint  16  swivelably mounts the handle assembly  12  to the foot assembly  14  and is configured to permit the handle assembly  12  to rotate about more than one axis relative to the foot assembly  14  when the handle assembly  12  is in the reclined use position. As shown herein, the coupling joint  16  can comprise a universal or Cardan joint, and can be configured to permit the foot assembly  14  to swivel multi-axially relative to the handle assembly  12 . In this embodiment, the coupling joint  16  is configured to rotate back and forth about horizontal axis Z, which extends laterally through the sides of the steam mop  500 , and from side to side about axis Y, which is orthogonal to axis Z and extends horizontally from the front to back, through the middle of the steam mop  500 . The steam mop  500  differs from the previous embodiments with respect to the supply tank  80  and steam delivery system, the coupling joint  16 , the viewing windows  412 , and the movable agitator assembly  422 , as will be described in greater detail below. 
       FIG. 18  is a schematic view of a steam delivery system  66  for the steam mop  500 . The steam delivery system  66  can be substantially similar to the steam distribution system  66  described for the second embodiment, with the exception of a filter assembly  502 , as described in greater detail below. The steam delivery system  66  includes a steam generator  274  producing steam from liquid, at least one supply tank  80  for storing a supply of liquid, a filter assembly  502  for filtering the liquid passing out of the supply tank  80  to prevent foreign particulates and debris from entering the steam generator  274 , a flow controller  272  for controlling the flow of liquid between the supply tank  80  and the steam generator  274 , a distributor nozzle  342  in fluid communication with the steam generator  274  for delivering steam to the surface to be cleaned. 
     The liquid in the supply tank  80  can comprise one or more of any suitable cleaning liquids, including, but not limited to, water, compositions, concentrated detergent, diluted detergent, etc., and mixtures thereof. For example, the liquid can comprise a mixture of water and concentrated detergent. The steam delivery system  66  can further include multiple supply tanks, such as one tank containing water and another tank containing a cleaning agent as described above for the first embodiment. 
     The flow controller  272  can comprise a pump which distributes liquid from the supply tank  80  to the steam generator  274 . An actuator, such as the trigger  32 , can be provided to actuate the pump  272  and dispense liquid to the steam generator  274 . The trigger  32  can be operably coupled to the pump  272  such that pressing the trigger  32  will activate the pump  272 . The pump  272  can be electrically actuated, such as by providing electrical switch between the pump and a power source that is selectively closed when the trigger  32  is actuated, thereby activating the pump  272 . In use, the generated steam is pushed out of the outlet of the steam generator  274  by pressure generated within the steam generator  274  and, optionally, by pressure generated by the pump  272 . The steam flows out of the distributor nozzle  342  to the cleaning pad  15 . 
     A controller  504  having a user interface may be operably coupled with various components of the steam mop  500 , such as the steam generator  274  and/or pump  272 , to implement one or more cycles of operation, such as, but not limited to, light steam distribution, medium steam distribution, and heavy steam distribution. The user interface may include operational controls such as dials, lights, switches, and displays enabling a user to input commands, such as a cycle of operation, to the controller and receive information. The steam generator  274 , pump  272 , and controller  504  can be electrically coupled to a power source, such as a power cord  506  plugged into a household electrical outlet. 
       FIG. 19  is a partially exploded view of the upper handle assembly  12 . The filter assembly  502  can be incorporated with the supply tank  80 , such that the two are removable as one unit from the steam mop  500 . The steam mop  500  comprises a tank receiver  508  for receiving the supply tank  80  and filter assembly  502 . The tank receiver  508  comprises a platform  510  having a valve seat  512  for fluidly coupling with the supply tank  80  and filter assembly  502  with the steam delivery system  66  ( FIG. 18 ) when seated within the tank receiver  508 . The tank receiver  508  can further be defined by a front cover  514  of the steam mop  500 , which forms a pocket  516  for insertion supply tank  80  and filter assembly  502 . Hand grips  518  can be provided on the supply tank  80  for aiding the user in lifting the supply tank  80  and filter assembly  502  as a unit away from the steam mop  10 . The front cover  514  includes cutouts  520  through which a portion of the supply tank  80  is visible, which permits a user to easily ascertain the liquid fill level inside the supply tank  80 . 
       FIG. 20  is a cross-sectional view through the supply tank  80  and filter assembly  502 . The supply tank  80  comprises a tank body  522  having an outlet port  524  on the bottom of the tank body  522 . The outlet port  524  can also act as a fill inlet for the supply tank  80  when the supply tank  80  is removed from the handle assembly  12  for filling. A bleeder valve  526  is provided on the tank body  522  and is adapted to vent ambient atmospheric air into the tank body  522  when liquid inside the supply tank  80  is dispensed during use. At least a portion of the supply tank  80  can be formed of a transparent or tinted translucent material, which permits a user to view the contents of the supply tank  80 . 
     The filter assembly  502  comprises a filter housing  528  removably mounted to the bottom of the supply tank  80 , a filtration medium  530  provided in the filter housing  528 , and a valve assembly  532 . The filter housing  528  can include an upper casing  534  and a lower casing  536  which together define a chamber in which the filtration medium  530  is received. The upper casing  534  has an inlet port  538  adapted to mate with the outlet port  524  of the supply tank  80 . A seal  540  can be positioned between the ports  524 ,  538  to seal the interface therebetween when the filter assembly  502  is mounted to the supply tank  80 . 
     The filtration medium  530  can comprise a granular substance such as a mixed bed ion exchange resin or polymer, which can further comprise cross-linked polystyrene beads, for example, that are configured to purify and decontaminate liquid from the supply tank  80 . Accordingly, the lower casing  536  may be provided with a plurality of internal walls  542  that form a frame work for holding the filtration medium  530  and which can provide a labyrinthine structure for liquid from the supply tank  80  to pass through. 
     The lower casing  536  can further include a lower surface adapted to rest on the platform  510  and a hollow neck  544  protruding from the lower surface that defines an outlet  546  of the filter assembly  502  which receives the valve assembly  532 . The valve assembly  532  is adapted to move to a closed position to seal the outlet  546  of the filter assembly  502  when the supply tank  80  is removed from the steam mop  500 . When the supply tank  80  and filter assembly  502  are seated in the tank receiver  508 , the neck  544  is at least partially received within the valve seat  512  and the valve assembly  532  is adapted to automatically move to an open position to open the outlet  546  of the filter assembly  502 . 
     A filter latch  548  selectively latches the filter assembly  502  to the supply tank  80  and can comprise a latch body  550  that is slidably mounted with a latch cavity  552  formed in the rear of the filter housing  528  and a spring  554  biasing the latch  548  toward a closed position shown in  FIG. 20 . The latch body  550  includes an upper latching tab  556  which is selectively received by a latch receiver  558  formed in the rear of the tank body  522 , and a user-engageable lever  560  for selectively actuating the filter latch  548 . With the supply tank  80  and filter assembly  502  removed from the steam mop  500  as a unit, by pressing down on the lever  560 , the latching tab  556  moves out of the latch receiver  558 , allowing the filter housing  528  to be slid forwardly and off the supply tank  80 . As shown in  FIG. 19 , the supply tank  80  has recessed grooves  562  formed in the tank body  522  for receiving corresponding rails  564  on the filter housing  528  to slidably mount the filter assembly  502  to the bottom of the supply tank.  80 . 
       FIG. 21  is an exploded view of the foot assembly  14 . As in the second embodiment, the foot assembly  14  includes a base housing  406  and a cover housing  408  attached to the base housing  406  via fasteners (not shown). The foot assembly  14  is further provided with one or more viewing windows  412  which allow the user to view the cleaning pad  15  without having to flip the foot assembly  14  over. In the present embodiment, the viewing windows  412  are provided as light transmissive window panes  566  mounted to the foot assembly  14 . Each window pane has a top wall  568  and a peripheral side wall  570 , with at least the top wall  568  being formed of a light transmissive material. The top wall  568  has an upper peripheral ledge  572  and the side wall  570  includes an outwardly extending flange  574  having a lower peripheral ledge  576  along the outer edge of the flange  574 . 
     The housings  406 ,  408  are provided with aligned window cutouts  578 ,  580 , respectively, and the window panes  566  are mounted between the housings  406 ,  408  at the cutouts  578 ,  580 . The cutout  578  on the base housing  406  has a groove  584  that extends around the perimeter of the cutout  578 . The lower ledge  576  of the window pane  566  is seated in the groove  584  to retain the window pane  566  on the base housing  406 . The cutout  580  on the cover housing  408  has a downwardly-depending rim  586  which engages the upper ledge  572  on the top wall  568  of the window pane  566 . 
     The distributor nozzle  342  is aligned with an aperture  350  on the base housing  406 . Various steam channels (not shown) on the bottom of the base housing  406  are configured to guide steam from the distributor nozzle  342 , evenly across the base housing  406 , and past the viewing windows  412 . Accordingly, a user can look through the viewing windows  412  observe the condensation of the steam vapor while using the steam mop  500  on the surface to be cleaned. Moreover, a user can easily confirm whether a cleaning pad  15  is installed beneath the base housing  406  prior to using the steam mop  500 . 
     The coupling joint  16  comprises an upper handle connector  590  and a lower foot connector  592 , and can accommodate a fluid conduit  338  which extends through the coupling joint to the distributor nozzle  342 . The foot assembly  14  comprises a cradle formed by mating cradle halves  598 ,  600  formed in the base housing  406  and the cover housing  408  for accommodating the coupling joint  16 . The upper handle connector  590  pivotally couples with the lower foot connector  592  and defines the second axis of rotation Y about which the foot assembly  14  can rotate. The foot connector  592  in turn pivotally couples with the foot assembly  14  and defines the first axis of rotation Z about which the foot assembly  14  can rotate. 
       FIG. 22  is an exploded view of the coupling joint  16 . The handle connector  590  comprises an upper tubular portion  602  which defines a socket  604  which slidably receives the lower neck portion  284  of the handle assembly  12  ( FIG. 17 ). A lower pivot portion  606  extends downwardly from the tubular portion  602  and has aligned pivot arms  608  protruding from the front and rear of the pivot portion  606  and having blind holes  610  formed therein. 
     The foot connector  592  comprises front and rear holders  612 ,  614  which can be mirror images of each other, in general. Each holder  612 ,  614  comprises an upper extension  616  with an outwardly facing receiver  618  having a bore  620  formed therethrough. Each holder  612 ,  614  further comprises a lower extension  622  that depends from the upper extension  616 . The lower extensions  622  are curved in opposing directions, and mate together to form pivot arms  624  which are rotatably received in the corresponding cradle  598 ,  600  formed in the foot assembly  14  ( FIG. 21 ). Detent springs  632  can be mounted in the cradle  598  for engaging detent slots (not shown) in the bottom of the pivot arms  624  for retaining the handle connector  590  in an upright, storage position. 
     The foot connector  592  can be coupled to the handle connector  590  by sliding the bores  620  on the front and rear holders  612 ,  614  over the pivot arms  608  of the handle connector  590 , and securing the connectors  590 ,  592  together using one or more fasteners  626 . The blind holes  610  in the pivot arms  608  receive the fasteners  626 . A cap  628  can be fitted over the front fastener  626  to hide the front fastener  626  from view. Additional fasteners  630  can be provided for coupling the front and rear holders  612 ,  614  together. 
     The coupling joint  16  can be provided with a detent mechanism for selectively preventing the coupling joint  16  from rotating side-to-side, such as when the steam mop  500  is in a stored position (shown in  FIG. 17 ). The detent mechanism can include a detent bar  634  mounted within the coupling joint  16 , which comprises a central frame  636  with two pivot shafts  638  protruding outwardly from the central frame  636 . Stop arms  640  protrude downwardly from the pivot shafts  638 . A detent protrusion  642  extends upwardly from the central frame  636 . The detent bar  634  is received between the front and rear holders  612 ,  614 , with the pivot shafts  638  positioned in the space between the lower extensions  622  and the stop arms  640  extending out of the pivot arms  624 . The bottom of the handle connector  590  is provided with a detent  644  which receives the detent protrusion  642  on the detent bar  634  when the steam mop  500  is in a stored position. Springs  646  are positioned between the central frame  636  and the rear holder  614  to bias the detent protrusion  642  away from the detent  644 . 
     Referring to  FIG. 21 , in additional to the detent bar  634 , the detent mechanism comprises spring-biased stops  648  mounted within the housings  406 ,  408  of the foot assembly  14 . The base housing  406  can be provided with pockets  650  for receiving the stops  648 , with a slot  652  formed in a forward end of each pocket  650  for allowing a nose  654  of the corresponding stop  648  to slide forwardly and rearwardly. A spring  656  is received in the pocket  650  and biases the stop  648  forwardly so that the nose  654  protrudes through the slot  652 . 
       FIG. 23-26  illustrate the movement of the coupling joint  16  between an upright storage position and a reclined use position. The coupling joint  16  enables the steam mop  500  to move between the upright storage position, shown in  FIGS. 23 and 24 , and the reclined use position, one example of which is shown in  FIGS. 25 and 26 . In the reclined use position, the handle assembly  12  can be moved about the axis Z and Y of the coupling joint  16 . The detent mechanism selectively prevents the handle assembly  12  from rotating side-to-side when the handle assembly  12  is in the storage position. However, the detent mechanism is also configured with a cushion or override feature that allows the handle assembly  12  to rotate from side-to-side even if the detent protrusion  642  is locked in the detent  644  to prevent side-to-side movement, but only when an excessive side load or impact is applied to the handle assembly  12  or foot assembly  14 , for example. The override feature can prevent breakage or damage of the coupling joint  16 , handle assembly  12  and foot  14 . 
     In the reclined use position shown in  FIGS. 25 and 26 , the coupling joint  16  is rotated rearwardly about axis Z with respect to the foot assembly  14  or clockwise as shown in the orientation of  FIG. 26 . The coupling joint  16  initially rotates around the stationary detent bar  634 , which draws the detent  644  in the handle connector  590  away from the detent protrusion  642  on the detent bar  634 , thereby allowing the handle connector  590  to rotate side-to-side about axis Y. During this time, the detent bar  634  remains essentially stationary, since the stop arms  640  are engaged with the stops  648  in the foot  14 . 
     When the coupling joint  16  reaches a predetermined angle of recline, the inner surface of the front holder  612  contacts the central frame  636  on the detent bar  634  and forces the detent bar  634  to rotate clockwise with the coupling joint  16  about the pivot shafts  638  while compressing the springs  646  slightly. Though compressed, the springs  646  push the detent protrusion  642  away from the detent  644  and thus prevent the detent protrusion  642  from inadvertently re-engaging the detent  644  when the handle is reclined. The clockwise rotation of the detent bar  634  while engaged with the front holder  612  also draws the stop arms  640  away from the stops  648 . 
     To return the handle assembly  12  to the upright storage position, shown in  FIGS. 23 and 24 , the coupling joint  16  is rotated forwardly about axis Z with respect to the foot assembly  14  or counterclockwise as shown in the orientation of  FIG. 24 . The initial rotation of the coupling joint  16  immediately draws the front holder  612  away from the central frame  636 , which leaves the detent bar  634  free to rotate counterclockwise under the biasing influence of the springs  646 . This brings the stop arms  640  on the detent bar  634  into engagement with the stops  648  in the foot assembly  14  and temporarily holds the detent bar  634  in place. Further rotation of the coupling joint  16  brings the detent  644  in the handle connector  590  into engagement with the detent protrusion  642  on the detent bar  634 . The final engagement of the handle connector  590  with the detent bar  634  can rotate the detent bar  634  further about the pivot shafts  638 , which will partially depress the stops  648  by partially compressing the springs  656 . 
     The partially depressed stops  648  and springs  656  provide a cushion or override feature that allows the detent mechanism to be overridden if a side load or impact load is applied to the handle assembly  12  or foot assembly  14  that exceeds a predetermined value. For example, if the steam mop  500  is dropped on an edge of the foot assembly  14  or is knocked over onto the handle assembly  12 , the override feature permits the detent protrusion  642  to be forced out of the detent  644 , which frees the handle assembly  12  to rotate side-to-side from an upright detented position, which can prevent breakage or damage of the coupling joint  16 , handle assembly  12  and foot  14 . In a situation where the detent mechanism is overridden, a force or impact is applied to the handle assembly  12 , for example, that urges the handle connector  590  to rotate side-to-side about the Y axis and the detent protrusion  642  is forced against the side of the detent  644 . If the force or impact exceeds a pre-determined value, the detent protrusion  642  will slide out of the detent  644  recess because the cushion or override feature allows the detent bar  634  to flex or rotate forwardly about the Z axis, or counter-clockwise as shown in  FIG. 26  to release the detent protrusion  642  from the detent  644 . As the detent bar  634  rotates, the stop arms  640  further depress the stops  648  and springs  656  rearwardly into the pocket  650  from a previously partially depressed position. The stops  648  move rearwardly to a position that allows the detent bar  634  to rotate forwardly and permit the protrusion  642  to slide out of the detent  644 , thereby freeing the upright detented handle assembly  12  to rotate from side-to-side. 
       FIG. 27-28  illustrate the movement of the agitator assembly  422  between a first use position and a second non-use position. The movable agitator assembly  422  is provided on a rear portion of the foot assembly  14  is configured for movement between a first position shown in  FIG. 27  and a second position shown in  FIG. 28 . In the first position, the agitator assembly  422  is in a use position and contacts the surface to be cleaned F to provide enhanced, localized agitation of the surface to be cleaned whereas, in the second position, the agitator assembly  422  is in a non-use position and does not contact the surface to be cleaned F. 
       FIG. 29  is an exploded view of the agitator assembly  422 . The agitator assembly  422  comprises an agitator support frame  658  with support arms  660  extending perpendicularly from the ends thereof. A cavity  662  is provided in the bottom of the support frame  658  and is adapted to receive a floating plate  664  that is configured to automatically adjust to different floor surface features, carpet pile heights, etc. An agitator element  666  is coupled to the bottom of the plate  664  and is separate from the cleaning pad  15 . The agitator element  666  can comprise a variety of materials that are configured to agitate the surface to be cleaned; as shown herein, the agitator element  666  comprises a plurality of bristles projecting from the bottom of the plate  664 . The plate  664  can include retention features for detachably retaining the plate  664  to the cavity  662 . The retention features have been illustrated as snaps  665  around the perimeter of the plate  664  for engaging a retainer rim (not shown) inside the cavity  662 . Thus, the plate  664  and associated agitator element  666  can be removed from the cavity  662  for cleaning, replacement or for exchanging they type of agitator element  666  by pulling the plate  664  downwardly, which forces the snaps  665  around the lip (not shown) and releases the plate  664  from the cavity  662 . Alternatively, separable fasteners (not shown) such as hook and loop fasteners, for example, can be configured to detachably secure an agitator element  666  to the support frame  658 . Alternatively, the agitator element  666  can be permanently affixed to the plate  664 . 
     The plate  664  can freely move up and down within the cavity  662 , or float, along the floor surface during operation, thereby permitting the agitator element  666  to automatically adjust to the type of floor surface below the foot assembly  14 , such as carpet, including different carpet pile heights, or bare floor. A biasing element  668  can bias the plate  664  downwardly toward the surface to be cleaned. As shown herein the biasing element  668  comprises multiple springs between the bottom of the cavity  662  and the top of the plate  664 . The biasing element  668  can be affixed to the plate  664 , such that the plate  664 , biasing element  668  and agitator element  666  can be removed from the cavity  662  as a sub-assembly. 
     A mounting assembly pivotally mounts the support frame  658  to the foot assembly  14 . The mounting assembly can comprise a pair of spaced bearing brackets  670  formed in the base housing  406 . A pivot pin  672  couples each support arm  660  to the corresponding bearing bracket  670 . A torsion spring  674  can be mounted around each pivot pin  672  with the free ends being compressed between the support arm  660  and base housing  406  such that the torsion spring  674  is configured to bias the support frame  660  upwardly relative to the base housing  406  toward the non-use position shown in  FIG. 28 . 
     The foot assembly  14  can further comprise an actuator assembly for adjusting the position of the agitator assembly  422  with respect to the surface to be cleaned F. The actuator assembly comprises a latch  676  and a spring  678  for biasing the latch  676  toward a latched position. The latch  676  has a catch  680  at a lower portion thereof for engaging the support arm  660 , a pivot shaft  682  for pivotally attaching the latch  676  to the foot  14 , and an actuator in the form of a foot pedal  684  provided on the latch  676 . A latch receiver  686  is provided in the base housing  406  for receiving the latch  676 , with the foot pedal  684  extending vertically through an opening in the cover housing  408 . The catch  680  engages a hook  688  on the bottom of each support arm  660 . The spring  678  biases the latch  676  upwardly so the catch  680  is forced towards the hook  688 . 
     The brackets  670  have upper and lower stops  690 ,  692  to provide a secure location for the support arms  660  to come to rest in the non-use and use positions. The stops  690 ,  692  prevent damage to the movable agitator assembly  422  and foot assembly  14  when moving between the use and non-use positions. 
     In the use position shown in  FIG. 27 , the agitator element  666  is positioned rearwardly of the base housing  406 . A user can selectively pivot the agitator element  666  into the use position to clean heavily soiled areas on the surface to be cleaned. With the agitator element  666  in the use position, a user can make one or more reciprocal cleaning strokes to scrub the soiled area. To move the agitator element  666  from the use position to the non-use position shown in  FIG. 28 , the catch  680  can be disengaged from the hook  688  by depressing the foot pedal  684  on the upper portion of the latch  444 , as indicated in  FIG. 30 , which pivots the latch  676  downwardly about an axis defined by the pivot shaft  682  relative to the surface to be cleaned and rotates the catch  680  away from the hook  688 . The torsion springs  674  are then free to push the support arms  660  upwardly, thereby pivoting the support frame  658  and agitator element  666  upwardly to the non-use position, shown in  FIG. 28 , in which the agitator element  666  is spaced from the surface to be cleaned F. 
     A foot assembly  14  for a surface cleaning apparatus according to a fourth embodiment of the invention is shown in  FIGS. 31-34 . The foot assembly  14  can optionally be used in place of the foot assembly  14  of the third embodiment shown in  FIG. 17 . Because many of the components of this embodiment are similar to the third embodiments, like features are indicated with the same reference numerals. The foot assembly  14  differs from the third embodiment with respect to the movable agitator assembly  422 ; in this embodiment, steam can optionally be delivered via the agitator assembly  422  as well as through the aperture  350  in the base housing  406  to improve cleaning performance. One or more steam orifices  700  are provided on the agitator assembly  422  and can selectively receive steam from the steam generator  274  ( FIG. 19 ). The steam orifices  700  can be formed in the plate  664  holding the agitator element  666 . The cleaning pad  15  is not shown in  FIG. 31  in order to clearly illustrate steam distribution from the aperture  350 . 
       FIG. 32  is a partially exploded view of the foot assembly  14  of  FIG. 31 . The steam distributor  342  is provided with a first outlet port  694  directed toward the cleaning pad  15  and a second outlet port  696  in fluid communication with one or more steam orifices  700  on the agitator assembly  422 , as shown in  FIG. 32 . 
       FIG. 33  is a close-up view of a steam delivery pathway for the foot assembly  14  of  FIG. 31 , illustrating the agitator assembly  422  in a use position. A valve  698  optionally controls the delivery of steam to the agitator assembly  422  and is integrated with the actuator assembly such that the valve  698  is open to deliver steam to the agitator assembly  422  when the agitator assembly  422  is in the use position as shown in  FIG. 33 , and the valve  698  is closed to shut off the delivery of steam when the agitator assembly  422  is in the non-use position, as shown in  FIG. 34 . The valve  698  has an inlet coupled with the second outlet port  696  via a first fluid conduit  702  and an outlet coupled with the agitator assembly  422  via a second fluid conduit  706 . 
     A valve actuator  708  links the open or closed condition of the valve  698  with the movement of the agitator assembly  422  between the use and non-use positions, such that the valve  698  is open when the agitator assembly  422  is in the use position ( FIG. 33 ) and closed when the agitator assembly  422  is in the non-use position ( FIG. 34 ). One example of the valve actuator  708  illustrated in the figures comprises a cam  710  operably coupled with the actuator assembly and a cam follower  712  coupled with the valve  698 . 
     The cam  710  can be operably coupled with the actuator assembly via a gear train as shown here or other suitable mechanical linkage such that as the agitator assembly  422  pivots between the use and non-use positions, the cam  710  will likewise rotate. The gear train shown herein comprises a first gear  714  coupled with the cam  710  and a second gear  716  coupled with the agitator assembly  422  and that is enmeshed with the first gear  714 . 
     The first gear  714  coupled with the cam  710  can be coupled together in any suitable manner that will transmit rotation of the gear  714  to the cam  710 . For example, the first gear  714  and cam  710  can be fixed to a common rotatable shaft (not shown), such that movement of the first gear  714  by the second gear  716  will rotate the shaft and cam  710 . 
     The second fluid conduit  706  can extend through a hollow space in the first gear  714  and cam  710  such that the rotation of first gear  714  and the cam  710  will not disturb the fluid conduit  706 . The second fluid conduit  706  can further extend through the support arms  660  of the agitator assembly  422  to fluidly communicate steam to the steam orifices  700  ( FIG. 31 ). 
     The second gear  716  is fixed to the agitator assembly  422  for movement therewith, such that as the agitator assembly  422  pivots between the use and non-use positions, the second gear  716  will likewise rotate. As illustrated, the second gear  716  is mounted on one of the pivot pins  672  that pivotally couple the support arms  660  of the agitator assembly  422  to the base housing  406 . 
     When the agitator assembly  422  is rotated between the use and non-use positions, the profile of the cam  710  is used to transform the rotational movement to linear movement of the cam follower  712  to open or close the valve  698 . The cam  710  shown herein is configured to have a profile that will extend the cam follower  712  to open the valve  698  when the agitator assembly  422  is in the use position, as shown in  FIG. 33 , and that will depress the cam follower  712  to close the valve  698  when the agitator assembly  422  is in the non-use position, as shown in  FIG. 34 . 
     While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation, and the scope of the appended claims should be construed as broadly as the prior art will permit. For example, it will be apparent that the invention is not limited to steam mop floor cleaning machines of various configurations, but is equally applicable to, for example, extraction cleaning machines having fluid delivery and recovery tanks. Representative examples of extraction cleaning machines are disclosed in U.S. Pat. Nos. 5,500,977 and 6,658,692, which are incorporated by reference herein in their entirety. In addition, although the invention has been described in connection with a steam mop, the invention is also equally applicable to wet mops having a fluid delivery tank as disclosed, for example, in U.S. Pat. No. 7,048,458, which is also incorporated by reference herein in its entirety. Moreover, the aforementioned actuator can be omitted and the agitator assembly can be manually movable between a non-use position and a use position as described above. Moreover, the movable agitator can be positioned exteriorly of the foot assembly  402  as disclosed herein, or it can be positioned inboard of the perimeter of the foot assembly  402 .