Patent Publication Number: US-10786132-B2

Title: Supply tank for an extractor cleaning machine

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 13/600,525, filed Aug. 31, 2012, which claims priority to U.S. Provisional Patent Application No. 61/530,506, filed Sep. 2, 2011, the entire contents of which are hereby incorporated by reference herein. 
    
    
     BACKGROUND 
     The present invention relates to extractor cleaning machines and, more particularly, to supply tanks for extractor cleaning machines. 
     An extractor cleaning machine typically includes a supply tank that dispenses premixed water and detergent for cleaning a surface. Some extractor cleaning machines include two separate tanks for water and for detergent such that the water and detergent are mixed at a preset ratio within the machine. Other extractor cleaning machines include detergent tanks combined with water tanks into a single assembly. These extractor cleaning machines typically include elaborate valve and conduit arrangements to mix the water and detergent at desired ratios during operation. 
     SUMMARY 
     In one embodiment, the invention provides an extractor cleaning machine including a base movable along a surface to be cleaned, and the base includes a distribution nozzle and a suction nozzle. A suction source is in fluid communication with the suction nozzle, and the suction source is operable to draw fluid from the surface through the suction nozzle. A recovery tank is in fluid communication with the suction source and the suction nozzle to receive the fluid drawn through the suction nozzle. The extractor cleaning machine further includes a supply tank including, a first chamber for storing a first fluid, a second chamber for storing a second fluid, and a third chamber in fluid communication with the first chamber and the second chamber to receive the first and second fluids, the third chamber also in fluid communication with the distribution nozzle for supplying a mixture of the first and second fluids to the distribution nozzle. 
     In another embodiment, the invention provides an extractor cleaning machine including a base movable along a surface to be cleaned, and the base includes a distribution nozzle and a suction nozzle. A suction source is in fluid communication with the suction nozzle, and the suction source is operable to draw fluid from the surface through the suction nozzle. A recovery tank is in fluid communication with the suction source to receive the fluid drawn through the suction nozzle. The extractor further includes a supply tank including a first tank including a body for storing a first fluid, a second tank including a body that is at least partially defined by the body of the first tank for storing a second fluid, and a mixing chamber at least partially defined by at least one of the body of the first tank and the body of the second tank. The mixing chamber is in fluid communication with the first tank and the second tank for receiving the first and second fluids. The mixing chamber is also in fluid communication with the distribution nozzle for supplying a mixture of the first and second fluids to the distribution nozzle. 
     In yet another embodiment, the invention provides a supply tank for use with an extractor cleaning machine where the extractor cleaning machine includes a base having a distribution nozzle. The supply tank includes a first chamber for storing a first fluid, a second chamber for storing a second fluid, and a third chamber in fluid communication with the first chamber and the second chamber for receiving the first and second fluids. The third chamber includes an outlet configured to be in fluid communication with the distribution nozzle for supplying a mixture of the first and second fluids to the distribution nozzle. The supply tank further includes a valve operable to control the amount of second fluid being supplied from the second chamber to the third chamber. The first chamber, the second chamber, the third chamber, and the valve are configured to be removable as a single unit from the extractor cleaning machine. 
     Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an extractor cleaning machine according to one embodiment of the invention. 
         FIG. 2  is a partially exploded view of the extractor cleaning machine shown in  FIG. 1 . 
         FIG. 3  is a rear perspective view of a supply tank of the extractor cleaning machine of  FIG. 1 . 
         FIG. 4  is a cross-sectional view of the supply tank taken along lines  4 - 4  of  FIG. 2 . 
         FIG. 5  is another cross-sectional view of the supply tank taken along lines  5 - 5  of  FIG. 1 . 
         FIG. 6  is a perspective view of a rear body portion of the supply tank. 
         FIG. 7  is a perspective view of a sealing member of the supply tank. 
         FIG. 8  illustrates a valve assembly for use with a supply tank according to another embodiment of the invention. 
         FIG. 9  illustrates a valve assembly for use with a supply tank according to another embodiment. 
         FIG. 10  is a cross-sectional view of the valve assembly of  FIG. 10 . 
         FIG. 11  illustrates another embodiment of a supply tank for use with the extractor cleaning machine shown in  FIG. 1 . 
         FIG. 12  illustrates a valve assembly of the supply tank of  FIG. 11 . 
         FIG. 13  illustrates a valve assembly for use with the supply tank shown in  FIG. 11  according to another embodiment of the invention. 
         FIG. 14  is a perspective view of yet another embodiment of a supply tank for use with the extractor cleaning machine shown in  FIG. 1   
         FIG. 15  is a cross-sectional view of the supply tank of  FIG. 14  taken along lines  15 - 15  of  FIG. 14 . 
         FIG. 16  is an enlarged cross-sectional view of a portion of the supply tank of  FIG. 15 . 
         FIG. 17  is a perspective view of a portion of a valve assembly of the supply tank of  FIG. 14 . 
         FIG. 18  is an enlarged view of a portion of the supply tank shown in  FIG. 14 . 
         FIG. 19  is an enlarged cross-sectional view of a portion of the supply tank shown in  FIG. 14 . 
         FIG. 20  is a cross-sectional view of a portion of a supply tank for use with the extractor cleaning machine of  FIG. 1  according to another embodiment. 
         FIG. 21  is a rear side view of the supply tank assembly of  FIG. 20 . 
     
    
    
     DETAILED DESCRIPTION 
     Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. 
       FIG. 1  illustrates an extractor cleaning machine  20  (hereinafter referred to simply as an “extractor”). In the illustrated embodiment, the extractor  20  is an upright extractor operable to clean a surface such as, for example, a floor. In other embodiments, the extractor  20  may be, for example, a canister-type extractor, a handheld extractor, or a portable carpet cleaner. In some embodiments, the extractor  20  may be adapted to clean a variety of surfaces, such as carpets, hardwood floors, tiles, or the like. The extractor  20  distributes or sprays a cleaning fluid (e.g., water, detergent, or a mixture of water and detergent) onto the surface to clean the surface. The extractor  20  then draws the cleaning fluid and dirt off of the surface, leaving the surface relatively clean and dry. 
     The illustrated extractor  20  includes a body having a base or foot  24  and a handle  28  that is pivotally coupled to the base  24 . A suction source is supported by the base  24 , and a recovery tank  36  is coupled to the base  24 . A distributor is supported by the handle  28 , and a supply tank  44  is coupled to the handle  28 . The base  24  is movable along the surface to be cleaned and supports the other components of the extractor  20 . Two wheels  48  (only one of which is shown in  FIG. 1 ) are coupled to the base  24  to facilitate movement of the base  24  along the surface. In the illustrated embodiment, the wheels  48  are idle wheels. In other embodiments, the wheels  48  may be driven wheels. 
     The base  24  includes a distribution nozzle, a suction nozzle  56 , and a brush assembly. The distribution nozzle is coupled to the lower surface of the base  24  to direct cleaning fluid toward the surface. The suction nozzle  56  is also coupled to the base  24  to draw fluid and dirt from the surface back into the recovery tank  36 . The brush assembly is coupled to the lower surface of the base  24  adjacent the nozzle  56  to scrub the surface. In some embodiments, the brush assembly may be electrically or pneumatically rotated to agitate and scrub the surface. 
     The illustrated handle  28  is pivotally coupled to and extends from the base  24 . The handle  28  is pivotable or tiltable relative to the base  24  from the generally vertical storage position shown in  FIG. 1  to an infinite number of generally non-vertical inclined operating positions. Pivoting the handle  28  to an operating position facilitates moving the base  24  along the surface. When the handle  28  is in the upright position, the supply tank  44  is above and over the recovery tank  36 . The handle  28  supports a trigger  64  that is actuatable to spray cleaning fluid from the supply tank  44  through the distribution nozzle and onto the surface. The handle  28  also supports an accessory hose  68  that is connectable to a variety of hand-held tools. 
     The suction source is in fluid communication with the suction nozzle  56  to draw fluid and dirt from the surface through the nozzle  56 . In some embodiments, the suction source includes an electric motor that rotates a fan to generate a vacuum to draw the fluid and dirt through the nozzle  56 . 
     The recovery tank  36  is in fluid communication with the suction source and the suction nozzle  56  to receive and store the fluid and dirt drawn through the nozzle  56 . The illustrated recovery tank  36  is removably coupled to and supported by the base  24 . In other embodiments, the recovery tank  36  may be supported by the handle  28 . 
     The distributor is in fluid communication with the distribution nozzle and transports cleaning fluid from the supply tank  44  to the surface through the distribution nozzle. In some embodiments, the distributor may include a pump, a valve, and conduits connecting the supply tank  44 , the valve, and the pump to transport and control the flow of cleaning fluid to the distribution nozzle. In some embodiments, the distributor may not include the pump such that cleaning fluid is gravity-fed from the supply tank  44  to the distribution nozzle. 
     The supply tank  44  includes a first tank  72  for storing a first cleaning fluid (e.g., water) and a second tank  76  above the first tank  72  for storing a second cleaning fluid (e.g., detergent). In other embodiments, the relative positions of the first tank  72  and the second tank  76  may be reversed. In the illustrated embodiment, the supply tank  44  is supported on the handle  28  to supply the cleaning fluids to the distribution nozzle. The supply tank  44  is removable from the handle  28  to facilitate filling or emptying the tanks  72 ,  76 . In other embodiments, the supply tank  44  may be supported on the base  24 . 
     As shown in  FIGS. 2-4 , the first tank  72  includes a body  80  having a front body portion  84  and a rear body portion  88 . The front and rear body portions  84 ,  88  are coupled together to define a first chamber  92  ( FIG. 4 ) for storing the first cleaning fluid. In the illustrated embodiment, the front body portion  84  is blow molded and the rear body portion  88  is coupled to the front body portion  84  with screws. In other embodiments, the rear body portion  88  may be connected to the front body portion  84  by welding, glue, snaps, or geometric features (e.g., dovetail joints). A first inlet aperture  94  is formed in an upper surface  96  of the body  80  for filling the first tank  72 . The first inlet aperture  94  is covered by a first cap  100  to allow selective access to the first chamber  92 . A handle  98  is coupled to and extends from the front body portion  84 . The illustrated handle  98  includes a latching mechanism  99  to releasably secure the supply tank  44  to the extractor  20 . 
     In the illustrated embodiment, the rear body portion  88  includes two projected areas  102 . In other embodiments, the rear body portion  88  may include fewer or more projected areas. When the tank  44  is coupled to the handle  28 , the handle  28  is located between the projected areas  102  and the projected areas  102  and the handle  28  provide a locating feature that helps the user locate the proper position of the tank  44  to couple the tank  44  to the handle  28 . The projected areas  102  extend outwardly from the supply tank  44  to increase the capacity (e.g., volume) of the first chamber  92 . During manufacture, the sizes of the projected areas  102  may be increased or decreased depending on the desired capacity of the first chamber  92 . Adjusting the sizes of the projected areas  102  on the rear body portion  88  allows the capacity of the first chamber  92  to be easily changed while maintaining the industrial design of the supply tank  44  (i.e., without altering the appearance of the visible portions of the supply tank  44  when the tank  44  is connected to the extractor  20 ). 
     The second tank  76  is coupled to and supported by the first tank  72  such that the first tank  72  and the second tank  76  are removable from the handle  28  as a single unit. In the illustrated embodiment, the second tank  76  is positioned within the first tank  72  such that the supply tank  44  is a tank-in-tank design that separates the second cleaning fluid from the first cleaning fluid. As shown in  FIGS. 4 and 5 , the second tank  76  is formed by a portion of the front body portion  84 , a portion of the rear body portion  88 , and an inner wall  104  extending through the body  80 . The inner wall  104  does not extend entirely across the body  80 , but instead extends to the upper surface  96  to define a relatively small fill neck  106  for filling the first chamber  92  of the first tank  72  through the first inlet aperture  94 . The rear body portion  88  is removable from the front body portion  84  to facilitate positioning and manufacturing the second tank  76  within the first tank  72 . The front body portion  84 , the rear body portion  88 , and the inner wall  104  together define a second chamber  108  for storing the second cleaning fluid. In other embodiments, the second tank  76  may be discrete from, yet permanently coupled or fixed to the body  80  of the first tank  72 . In still other embodiments, the second tank  76  may snap-fit into the first tank  70 , or otherwise releasably coupled to by latches, snaps, or fasteners. A second inlet aperture  110  is formed in the upper surface  96  of the body  80  for filling the second tank  76 . The second inlet aperture  110  is covered by a second cap  112  to allow selective access to the second chamber  108 . 
     As shown in  FIGS. 4-5 , the front and rear body portions  84 ,  88  also define a mixing chamber  116  in a lower portion of the body  80  below and toward the rear of the first and second chambers  92 ,  108  such that the mixing chamber  116  remains at a lowest point of the tank  44  when a user reclines the handle  28 . The first and second chambers  92 ,  108  are in fluid communication with the mixing chamber  116  via a T-shaped recess or groove  120  ( FIG. 7 ) formed in the rear body portion  88 . In other embodiments, the chambers  92 ,  108  may be in fluid communication with the mixing chamber  116  via a tube or conduit. In the illustrated embodiment, a cover  124  is coupled to the rear body portion  88  to substantially cover the T-shaped recess  120  and define two channels  125 ,  126  ( FIG. 4 ) for fluid flow. The channels  125 ,  126  are separated by a dividing wall  127  that extends from the cover  124  to the rear body portion  88 . The mixing chamber  116  is in fluid communication with the distributor and the distribution nozzle via an outlet aperture. An outlet valve  128  is coupled to the outlet aperture to selectively allow fluid flow out of the mixing chamber  116 . In the illustrated embodiment, the outlet valve  128  is a poppet valve that is automatically opened when the supply tank  44  is connected to the extractor  20  and automatically closes when the supply tank  44  is removed. In other embodiments, other suitable valves may also or alternatively be employed. The illustrated outlet aperture and valve  128  are located at a lowest point toward a rear of the supply tank  44  to facilitate emptying or draining the mixing chamber  116  when the handle  28  ( FIG. 1 ) is in a non-vertical, use position. A breather tube may extend from the mixing chamber  116  to a top of the supply tank  44  to evacuate air out of the mixing chamber  116 . 
     Referring to  FIGS. 4 and 6 , the first chamber  92  is in fluid communication with the first channel  125  of the T-shaped recess  120  via two outlets  132  formed in the rear body portion  88 . The outlets  132  are formed near a bottom of the chamber  92  to facilitate draining when the handle  28  ( FIG. 1 ) is in a non-vertical, use position. A plurality of inlets  136  is also formed in a circular pattern on the rear body portion  88  such that the first channel  125  communicates with the mixing chamber  116 . The first cleaning fluid can thereby flow out of the first chamber  92  through the outlets  132 , through the first channel  125  on the rear body portion  88 , and into the mixing chamber  116  through the inlets  136 . 
     As shown in  FIGS. 4 and 5 , a check valve  140  is coupled to the rear body portion  88  and covers the inlets  136 . The check valve  140  allows fluid to flow from the first channel  125  into the mixing chamber  116 , but inhibits fluid from flowing back out of the mixing chamber  116  into the first channel  125 . In the illustrated embodiment, the check valve  140  is an umbrella valve that mounts to a central aperture  144  ( FIG. 6 ) formed in the rear body portion  88  in the center of the inlets  136 . The check valve  140  includes an elastomeric head  148  that covers the inlets  136  and is deflectable to allow fluid flow into the mixing chamber  116 . In other embodiments, other suitable check valves may also or alternatively be employed. In addition, the inlets  136  may be formed in other patterns or the rear body portion  88  may only include a single inlet. 
     Referring back to  FIGS. 4 and 6 , the second chamber  108  is in fluid communication with the second channel  126  of the T-shaped recess  120  via an outlet  152  formed in the rear body portion  88 . The outlet  152  is formed near a bottom of the second chamber  108  to facilitate maximum draining when the handle  28  ( FIG. 1 ) is in a non-vertical, use position. A relatively large-diameter inlet  156  and a relatively small-diameter inlet  160  are also formed in the rear body portion  88  such that the second channel  126  is in fluid communication with the mixing chamber  116 . Although in the illustrated embodiment the inlets  156 ,  160  are circular, in other embodiments the inlets can have other suitable shapes and/or sizes. The second cleaning fluid can thereby flow out of the second chamber  108  through the outlet  152 , through the second channel  126  on the rear body portion  88 , and into the mixing chamber  116  through either or both of the inlets  156 ,  160 . 
     In the illustrated embodiment, the second tank  76  is positioned in an upper portion of the body  80  so that the second chamber  108  is located generally above the first chamber  92  and the mixing chamber  116 . Therefore, the fluid level within the second chamber is above the fluid level in the first chamber  92  even when the handle  28  is in a reclined position relative to the base  24 . Such an arrangement inhibits cross-mixing of fluid between the tanks  72 ,  76 . That is, by positioning the second chamber  108  above the first chamber  92  and the mixing chamber  116 , cleaning fluid within the mixing chamber  116  and water within the first chamber  92  are generally inhibited from flowing back into the second chamber  108  when the extractor  20  is not in operation. In addition, the geometry of the inner wall  104  and the fill neck  106  ( FIG. 5 ) limits the volume of fluid that could be located above the second chamber  108  if the first chamber  92  were completely filled. Cross-flow in the opposite direction (i.e., from the second chamber  108 , through the mixing chamber  116 , and into the first chamber  92 ) is inhibited by the check valve  140 . In other embodiments, the tanks  72 ,  76  may be positioned at relatively the same height, and the supply tank  44  may include multiple check valves to inhibit cross-flow between the tanks  72 ,  76 . 
     As shown in  FIGS. 4-6 , the supply tank  44  also includes a valve assembly  164  coupled to the body  80  of the first tank  72  and extending into the mixing chamber  116 . The valve assembly  164  allows a user to adjust the amount (i.e., flow rate) of second cleaning fluid being supplied from the second tank  76  to the mixing chamber  116  and, ultimately, the distribution nozzle. By adjusting the flow rate of the second cleaning fluid, a user can change the ratio (i.e., concentration) of detergent to water being distributed onto a surface. In the illustrated embodiment, the valve assembly  164  is mounted to and supported by the first tank  72  such that the entire supply tank  44  (e.g., the first tank  72 , the second tank  76 , and the valve assembly  164 ) is removable as a single unit from the extractor  20 . 
     The illustrated valve assembly  164  includes an actuator  168 , an elongated shaft  172 , a sealing member  176 , and a biasing member  180 . The actuator  168  extends from the front body portion  84  of the first tank  72  and is manually rotatable by the user. The elongated shaft  172  extends from the actuator  168  and through the mixing chamber  116  toward the rear body portion  88  of the first tank  72 . Annular seals  184  (e.g., O-rings) are positioned about a portion of the shaft  172  to inhibit fluid leakage out of the mixing chamber  116 . 
     The sealing member  176  is coupled to an end of the elongated shaft  172  opposite the actuator  168 . As shown in  FIG. 7 , the sealing member  176  is formed of an elastomeric material and includes a planar portion  188  and a recessed portion  192 . The planar portion  188  engages an inner surface  196  of the rear body portion  88  to selectively block the large-diameter inlet  156  and the small-diameter inlet  160 . The recessed portion  192  is spaced apart from the inner surface  196  of the rear body portion  88  to selectively allow fluid flow through the inlets  156 ,  160  when the planar portion  188  does not cover the inlets  156 ,  160 . 
     Referring back to  FIGS. 4-6 , the biasing member  180  extends between the front body portion  84  and a flange  200  mounted to the shaft  172 . The biasing member  180  biases the shaft  172  toward the rear body portion  84  to maintain the planar portion  188  of the sealing member  176  in constant engagement with the rear body portion  88 . In the illustrated embodiment, the biasing member  180  is a coil spring. In other embodiments, other suitable biasing members may also or alternatively be employed. 
     In operation, the sealing member  176  selectively blocks the large-diameter inlet  156  and/or the small-diameter inlet  160  to meter the flow rate of the second cleaning fluid that flows into the mixing chamber  116  via gravity. In the illustrated embodiment, the valve assembly  164  has three positions corresponding to three mixing ratios of first cleaning solution to second cleaning solution. A user can switch the valve assembly  164  between the positions by rotating the actuator  168  to change the orientation of the sealing member  176  relative to the inlets  156 ,  160 . In other embodiments, the valve assembly  164  may have fewer or more positions corresponding to different mixing ratios. In the first position (i.e., a super wash or spot wash position), the small-diameter inlet  160  ( FIG. 7 ) is blocked by the sealing member  176  and the large-diameter inlet  156  ( FIG. 7 ) is unblocked such that a relatively large amount of second cleaning fluid can flow into the mixing chamber  116 . In the second position (i.e., a regular wash position), the large-diameter inlet  156  is blocked by the sealing member  176  and the small-diameter inlet  160  is unblocked such that a smaller amount of second cleaning fluid can flow into the mixing chamber  116 . In the third position (i.e., a rinse position), both of the inlets  156 ,  160  are blocked by the sealing member  176  such that the second cleaning fluid cannot flow into the mixing chamber  116 . In other embodiments the tank can include another outlet directly from the first chamber  92  (i.e., fluid from the first chamber  92  does not travel through the mixing chamber  116 ) so that the extractor  20  can be used in a rinse mode without operating the valve  164 . 
     In other embodiments, the rear body portion  88  may only include a single inlet that allows the second cleaning fluid to flow into the mixing chamber  116 . In such embodiments, the valve assembly  164  may be operable to selectively block or unblock the single inlet to change the extractor  20  between a wash mode and a rinse mode. Alternatively, the valve assembly  164  may selectively block or unblock a portion of the single inlet to meter the amount of second cleaning fluid flowing into the mixing chamber  116 . In such embodiments, a user may adjust the concentration of second cleaning fluid being discharged onto a surface by rotating the actuator  168  only a small degree. In still other embodiments, both of the inlets  156 ,  160  could have generally the same diameter, and the sealing member  176  could selectively block both inlets, one inlet, or neither inlet to control the flow rate. 
     By positioning the valve assembly  164  directly on the supply tank  44 , the supply tank  44  can be easily interchanged with a premixed water and detergent supply tank that includes only a single fluid chamber. That is, like a premixed supply tank, the illustrated supply tank  44  only includes a single outlet (e.g., the outlet aperture covered by the outlet valve  128 ) that communicates with the distributor and the distribution nozzle of the extractor  20 . Additional valves and conduits are therefore not needed inside the extractor  20  to mix the cleaning solutions of a two-tank assembly to a desired ratio. Therefore, the manufacturer can produce substantially the same extractor and switch only the tank  44  with a premixed-style tank depending on the type of extractor being supplied to the customer. Furthermore, the illustrated supply tank  44  maintains the first cleaning fluid and the second cleaning fluid in separate chambers  92 ,  108 . Such an arrangement allows a user to easily adjust the detergent concentration being distributed onto a surface for different cleaning situations. 
       FIG. 8  illustrates another embodiment of a valve assembly  300  for use with the supply tank  44 . The illustrated valve assembly  300  includes an actuator  304 , an elongated shaft  308 , and a sealing member  312 . In the illustrated embodiment, the actuator  304  defines a slot  316  and the elongated shaft  308  includes a projection  320  extending into the slot  316 . The slot  316  and the projection  320  provide a cam mechanism that moves the elongated shaft  308  and the sealing member  312  axially relative to the supply tank  44  when the actuator  304  is rotated. As the shaft  308  moves axially, the sealing member  312  blocks or unblocks an inlet in the rear body portion  88  to inhibit or allow the second cleaning fluid to flow into the mixing chamber  116 . In some embodiments, the valve assembly  300  can also control the mix ratio by selectively allowing flow through one or more inlets in the rear body portion  88 . 
       FIGS. 9 and 10  illustrate yet another embodiment of a valve assembly  400  for use with the supply tank  44 . Similar to the valve assembly  300  of  FIG. 9 , the illustrated valve assembly  400  includes an actuator  404 , an elongated shaft  408 , and a sealing member  412 . In the illustrated embodiment, the actuator  404  is a pivotable lever that is coupled to the shaft  408  via a slot  416  and a projection  420 . The slot  416  and the projection  420  provide a cam mechanism that moves the elongated shaft  408  and the sealing member  412  axially relative to the supply tank  44  when the actuator  404  is pivoted. As the shaft  408  moves axially, the sealing member  412  blocks or unblocks an inlet in the rear body portion  88  to inhibit or allow the second cleaning fluid to flow into the mixing chamber  116 . 
       FIG. 11  illustrates another embodiment of a supply tank assembly  500  for use with the extractor  20 . The illustrated supply tank assembly  500  includes a first tank  504 , a second tank  508 , and a valve assembly  512 . The first tank  504  includes a body  516  that defines a first chamber  520  for storing a first cleaning fluid. A first cap  524  is coupled to an upper surface of the first tank  504  to allow selective access to the first chamber  520  through an inlet aperture. The second tank  508  includes a body  528  that defines a second chamber  532  for storing a second cleaning fluid. In the illustrated embodiment, the body  516  of the first tank  504  and the body  528  of the second tank  508  are two discrete bodies that are securely or releasably coupled together. In other embodiments, the first tank  504  and the second tank  508  may be integrally formed as a single piece such that a portion of the body  516  of the first tank  504  defines the second tank  508 . 
     As shown in  FIGS. 11 and 12 , the valve assembly  512  extends through the second tank  508  and is supported by the body  516  of the first tank  504 . The illustrated valve assembly  512  includes an outer tube  536  ( FIG. 13 ), an inner tube  540 , and an actuator  544 . The outer tube  540  extends to a bottom surface  548  of the body  528  of the second tank  508  and defines an opening  552  near the bottom surface  548 . In the illustrated embodiment, a gasket  556  is positioned between the outer tube  540  and the bottom surface  548  to inhibit fluid leakage from the second tank  508 . A sleeve nut  560  is coupled to an upper end of the outer tube  536  to secure the outer tube  536  to the body  528  of the second tank  508 . In the illustrated embodiment, the sleeve nut  560  may be loosened and the valve assembly  512  may be temporarily removed to refill the second tank  508 . 
     The inner, or selector, tube  540  is positioned substantially within the outer tube  536  and defines a cross-hole  564  at substantially the same height as the opening  552  in the outer tube  536 . The inner tube  540  is rotatable relative to the outer tube  536  to selectively move the cross-hole  564  into and out of fluid communication with the opening  552 . When the cross-hole  564  and the opening  552  are aligned, the second cleaning fluid stored within the second chamber  532  can flow into the inner tube  540  through the cross-hole  564  to a fluid conduit  568 . The fluid conduit  568  extends from the second tank  508  to a mixing chamber  572  positioned in a lower portion of the first tank  504 . In some embodiments, the fluid conduit  568  may extend through the first chamber  520 . In other embodiments, the fluid conduit  568  may be coupled to or formed on an outer surface of the first tank  504 . When the cross-hole  564  and the opening  552  are not aligned, the inner tube  540  blocks the second cleaning fluid from flowing out of the second tank  508 . 
     The actuator  544  is coupled to an upper portion of the inner tube  540  to rotate the inner tube  540  relative to the outer tube  536 . In the illustrated embodiment, the actuator  544  is a dial that is manually rotatable by a user. In other embodiments, other suitable actuators may also or alternatively be employed. 
     Referring to  FIG. 11 , the mixing chamber  572  is also in fluid communication with the first chamber via a check valve  576 . The check valve  576  permits fluid to flow from the first chamber  520  into the mixing chamber  572 , but inhibits fluid flow back into the first chamber  520 . In the illustrated embodiment, the supply tank assembly  500  also includes a mushroom, or poppet, valve  580 . The valve  580  is coupled to an outlet aperture of the mixing chamber  572  to selectively allow fluid flow out of the mixing chamber  572 . The valve  580  is automatically opened when the supply tank assembly  500  is connected to the extractor  20  and is automatically closed when the supply tank assembly  500  is removed. In some embodiments, such as the illustrated embodiment, a gasket  584  may be coupled to the valve  580  adjacent the outlet aperture to inhibit fluid leakage when the supply tank assembly  500  is supported on the extractor  20 . 
       FIG. 13  illustrates another embodiment of a valve assembly  600  for use with the supply tank assembly  500  of  FIG. 11 . The illustrated valve assembly  600  includes a threaded shaft  604 , a sealing member  608 , and an actuator  612 . The threaded shaft  604  extends through an internally-threaded support bracket  616  coupled to the body  528  of the second tank  508 . In the illustrated embodiment, the support bracket  616  is secured to the second tank  508  by a sleeve nut  620 . The sleeve nut  620  may be loosened and the valve assembly  600  may be temporarily removed to refill the second tank  508 . In other embodiments, the support bracket  616  may be integrally formed as a single piece with the second tank  508 . The threaded shaft  604  is rotatable relative to the support bracket  616  to move axially within the second tank  508 . A packing seal  624  is positioned between a portion of the shaft  604  and the support bracket  616  to inhibit fluid leakage from the second tank  508 . 
     The sealing member  608  is coupled to an end of the threaded shaft  604  opposite the support bracket  616 . In the illustrated embodiment, the sealing member  608  is a relatively flat disk that blocks or unblocks an outlet aperture  628  formed in the second tank  508  to inhibit or allow fluid flow out of the second chamber  532 . As the threaded shaft  604  is rotated, the sealing member  608  moves axially with the shaft  604  toward or away from the outlet aperture  628  to block or unblock the outlet aperture  628 . When the sealing member  608  tightly engages the bottom surface  552  of the body  528 , the sealing member  608  inhibits fluid from flowing out of the second chamber  532  and into the fluid conduit  568 . When the sealing member  608  is spaced apart from the bottom surface  552 , the sealing member  608  allows fluid flow into the conduit  568 . As such, a user can finely adjust the amount of fluid flowing out of the second tank  508  by rotating the threaded shaft  604  a small degree. In other embodiments, the sealing member  608  may be generally conically-shaped and the outlet aperture  628  may be defined by a generally conically-shaped surface. In such embodiments, the conical sealing member could move into and seal against the conical aperture to allow fine adjustment of the mixing ratio. 
     The actuator  612  is coupled to an upper portion of the threaded shaft  604  to facilitate rotating the threaded shaft  604 . In the illustrated embodiment, the actuator  612  is a dial that is integrally formed with the threaded shaft  604  and manually rotatable by a user. In other embodiments, the actuator  612  may be a separate member that is coupled to the threaded shaft  604 . In further embodiments, other suitable actuators may also or alternatively be employed. 
       FIG. 14  illustrates another embodiment of a supply tank assembly  700  for use with the extractor  20 . The illustrated supply tank assembly  700  includes a first tank  704 , a second tank  706  and a valve assembly  708 . The first tank  704  includes a body  712  having a front body portion  716  and a rear body portion  720 . The front and rear body portions  716 ,  720  are coupled together to define a first chamber  724  for storing a first cleaning fluid. The front body portion  716 , the rear body portion  720 , and an inner wall  722  define a second chamber  723  of the second tank  706  for storing a second cleaning fluid, similar to the second chamber  108  shown in  FIG. 4 . 
     The front and rear body portions  716 ,  720  also define a mixing chamber  728  in a lower portion of the body  712 . The first chamber  724  is in fluid communication with the mixing chamber  728  via a first channel  732  defined between the rear body portion  720  and a cover  736 . A check valve  740  is coupled to the rear body portion  720  adjacent the first channel  732  to selectively allow fluid flow from the first channel  732  into the mixing chamber  728 . The second chamber is in fluid communication with the mixing chamber  728  via a second channel  744  defined between the rear body portion  720  and the cover  736 . An inlet  748  is formed in the rear body portion  720  adjacent the second channel  744  to allow fluid flow from the second channel  744  into the mixing chamber  728 . The valve assembly  708  selectively blocks the inlet  748  to prohibit fluid flow from the second chamber into the mixing chamber  728 . 
     The valve assembly  708  is coupled to the front body portion  716  and extends into the mixing chamber  728 . As shown in  FIGS. 15-18 , the valve assembly  708  includes an actuator  752 , an elongated shaft  756 , a sealing member  760 , and a biasing member  764 . The actuator  752  extends from the front body portion  716  and is manually rotatable by a user. Two ribs  768  extend from the actuator  752  toward a cam surface  772  formed on the front body portion  716 . As shown in  FIGS. 18-19 , the cam surface  772  includes recessed portions  776  and protruding portions  780 . The ribs  768  engage the cam surface  772  and follow the contour of the recessed and protruding portions  776 ,  780  to move the elongated shaft  756  along a longitudinal axis of the shaft  756  relative to the tank body  712 . In the illustrated embodiment, the actuator  752  also includes detents  784  ( FIGS. 16-17 ) formed on the ribs  768 . The detents  784  releasably engage corresponding recesses  788 ,  792  formed in the cam surface  772  to define two discrete operating positions of the valve assembly  708 . In other embodiments, additional recesses may be formed in the cam surface  772  to define three or more operating positions of the valve assembly  708 . 
     Referring back to  FIG. 15 , the elongated shaft  756  extends from the actuator  752  and through the mixing chamber  728  toward the rear body portion  720 . In the illustrated embodiment, the elongated shaft  756  and the actuator  752  are integrally formed as a single piece. In other embodiments, the elongated shaft  756  and the actuator  752  may be separate pieces that are coupled together. Annular seals  796  (e.g., O-rings) are positioned about a portion of the shaft  756  adjacent the mixing chamber  728  to inhibit fluid leakage out of the mixing chamber  728 . 
     The sealing member  760  is coupled to an end of the elongated shaft  756  opposite the actuator  752 . The sealing member  760  may be formed of, for example, an elastomeric material. The sealing member  760  has a planar surface  800  that engages an inner surface  804  of the rear body portion  720  to selectively block fluid flow through the inlet  748 . 
     The biasing member  764  surrounds the elongated shaft  756  and extends between the front body portion  716  and a flange  808  mounted to the shaft  756 . The biasing member  764  biases the shaft  756  toward the rear body portion  720  to maintain engagement between the actuator  752  and the cam surface  772  on the front body portion  716 . In the illustrated embodiment, the biasing member  764  is a coil spring. In other embodiments, other suitable biasing members may also or alternatively be employed. 
     In operation, the valve assembly  708  is movable between a first, or open, position (i.e., a wash position) and a second, or closed, position (i.e., a rinse position) by rotating the actuator  752 . When in the open position, the actuator  752  is positioned such that the ribs  768  engage the protruding portions  780  of the cam surface  772  and the detents  784  sit in the first set of recesses  788  ( FIG. 19 ). In this position, the elongated shaft  756  is moved away from the rear body portion  720  against the force of the biasing member  764 . The sealing member  760  is thereby spaced slightly apart from the rear body portion  720  to allow fluid (e.g., detergent) flow through the inlet  748  to the mixing chamber  728 . When in the closed position, the actuator  752  is positioned such that the ribs  768  engage the recessed portions  776  of the cam surface  772  and the detents  784  sit in the second set of recesses  792  ( FIG. 18 ). In this position, the elongated shaft  756  is moved toward the rear body portion  720  by the biasing member  764 . The sealing member  760  thereby tightly engages the rear body portion  720  to block the inlet  748  and inhibit fluid flow from the second channel  744  into the mixing chamber  728 . 
     In another embodiment, referring to  FIGS. 20 and 21 , the mixing chamber  728  can include a pressure relief valve  800 . In the illustrated embodiment, the pressure relieve valve  800  is an umbrella valve, but in other embodiments, other suitable types of valves can be used. When pressure in the mixing chamber  728  is greater than a predetermined pressure, the valve  800  opens to allow fluid in the mixing chamber  728  to travel into the channel  744  and toward the second chamber  723 . However, the pressure relief valve  800  does not allow fluid to flow in the opposite direction (i.e., from the camber  723  toward the mixing chamber  728 ). The pressure relief valve  800  is particularly suited for extractors that use a pump to pressurize the fluid that flows from the tank  700  to the surface being cleaned. In such extractors, when the extractor is turned off (i.e., the pump is turned off), fluid can flow back through the pump and into the mixing chamber  728 , which can increase the pressure in the mixing chamber  728  above a desirable level. The pressure relief valve  800  can then vent the undesirable pressure to the larger volume chamber  723 . 
     Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of one or more independent aspects of the invention as described.