Abstract:
A portable cleaning apparatus for cleaning a surface is provided and includes a housing. A distributor is operatively connected to the housing for distributing solution to the surface. A first solution container is mounted to the housing and contains a first solution. The first solution container has a bottom portion with an outlet portion fluidly connected to the distributor for supplying a flow of a first solution to the distributor. A second solution container with an outlet is provided in the first solution container and contains a second solution. The outlet of the second solution container is fluidly connected to the distributor for supplying a flow of a second solution to the distributor. In at least one aspect of the invention, the second solution container is design and constructed to transfer the weight of the first solution above the second solution container to the second solution in the second solution container to produce substantially the same hydrostatic head at both the outlet of the first solution container and the outlet of the second solution container.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a solution distribution arrangement for a portable cleaning machine.  
         [0003]     2. Background Information  
         [0004]     It is known to have floor cleaning units that have a liquid distribution system for dispensing detergent to wash the floor and/or clean water to rinse the floor. Often when washing the floor, detergent from one supply tank is automatically mixed with clean water and then the mixed cleaning solution is distributed on the floor. It is desirable to maintain a constant mix ratio between the detergent and clean water, especially in a gravity flow system for its low cost benefits. However, as the level of the water and detergent lowers during the application of cleaning solution in a gravity flow system, the flow rates out of the tanks will decline and at disproportional rates from each other due to the different tank volumes. This is due to the different hydrostatic heads caused by the different levels of water and detergent in their respective tanks. These variable flow rates produces a variable mixing ratio. One solution is to pump the fluids from their respective tanks at a pressure that is much higher than the hydrostatic head, thus making the effect of the liquid level on flow rate insignificant. However, the pump is an added cost, consumes power, and is subject to failure.  
         [0005]     It is an object of the present invention to provide a cleaning machine with clean water and detergent containers having a low cost and reliable automatic mixing system in which the mixing ratio of clean water and detergent is constant irrespective of the levels of clean water and detergent in their respective containers.  
       SUMMARY OF THE INVENTION  
       [0006]     The foregoing and other objects of the present invention will be readily apparent from the following description and the attached drawings. In one aspect of the invention, a portable cleaning apparatus for cleaning a surface in which cleaning solution is dispensed to the surface and substantially simultaneously extracted along with the dirt on the surface in a continuous operation is provided. The portable cleaning apparatus includes a housing and a distributor operatively connected to the housing for distributing cleaning solution to the surface. A first solution container is removably mounted to the housing and fluidly connected to the distributor for supplying a flow of cleaning solution to the distributor. A recovery tank is removably mounted to the housing and a suction nozzle is secured to the housing and in fluid communication with the recovery tank for transporting the cleaning solution and dirt from the surface into the recovery tank. A suction source is in fluid communication with the suction nozzle and recovery tank for drawing the cleaning solution and dirt from the surface through the suction nozzle and to the recovery tank. A second solution container is provided inside the first solution container for supplying a flow of cleaning solution to the distributor.  
         [0007]     In another aspect of the invention, a portable cleaning apparatus for cleaning a surface is provided and includes a housing. A distributor is operatively connected to the housing for distributing solution to the surface. A first solution container is mounted to the housing and contains a first solution. The first solution container has a bottom portion with an outlet portion fluidly connected to the distributor for supplying a flow of a first solution to the distributor. A second solution container is provided in the first solution container and contains a second solution. The second solution container has an outlet fluidly connected to the distributor for supplying a flow of a second solution to the distributor. The second solution container is design and constructed, to transfer the weight of the first solution above the second solution container to the second solution in the second solution container to produce substantially the same hydrostatic head at both the outlet of the first solution container and the outlet of the second solution container.  
         [0008]     In still another aspect of the invention, a portable cleaning apparatus for cleaning a surface is provided and includes a housing. A distributor is operatively connected to the housing for distributing solution onto the surface. A first solution container having a bottom portion is mounted to the housing and fluidly connected to the distributor for supplying a flow of a first solution to the distributor. A second solution container is provided inside the first solution container for supplying a second solution to the distributor. The second solution container having a bottom portion, wherein the bottom portion of the second solution container having a fill opening for filling the second solution container with solution. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]     The invention will now be described, by way of example, with reference to the attached drawings, of which:  
         [0010]      FIG. 1  is a perspective view of a carpet extractor embodying the present invention;  
         [0011]      FIG. 2  is a schematic view of the fluid distribution system of the embodiment shown in  FIG. 1  with portions broken away for illustrative purposes;  
         [0012]      FIG. 3  is a sectional view of taken along line  3 - 3  of  FIG. 1 ; and  
         [0013]      FIG. 4  is a vertical sectional view the solution release valve in the clean water tank. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0014]     Referring to the drawings,  FIG. 1  depicts a perspective view of a cleaning apparatus in the form of a upright carpet extractor  60  according to one embodiment of the present invention. The upright carpet extractor  60  comprises an upright handle assembly  62  pivotally connected to the rear portion of the floor-engaging portion or base assembly  64  that moves and cleans along a surface  74  such as a carpet  74 . The base assembly  64  includes two laterally displaced wheels  66  (only the left wheel  66 L being shown) rotatably attached thereto. A supply or solution tank assembly  76  is secured upon a bottom base  624  and removably mounted to the handle portion  62  of the extractor  60 . A combined air/water separator and recovery tank  80  with carrying handle  332  removably sets atop a motor/fan assembly  90  (FIG. 3. from co pending application having Ser. No. 10/165,731 and publication no. 20030226230; the disclosure being incorporated herein by reference) of base assembly  64  and is surrounded by a hood portion  82 . A floor suction nozzle assembly  124  is removably mounted to the hood portion  82  of the base assembly  64  and in fluid communication with the recovery tank  80  for transporting air and liquid into the recovery tank  80 . The floor suction nozzle assembly  124  includes a front plate secured to a rear plate that in combination define dual side ducts  130 ,  132  separated by a tear drop shaped opening  134 .  
         [0015]     As depicted in  FIG. 2 , the base assembly  64  includes a brush assembly  70  having a plurality of rotating scrub brushes  72  for scrubbing the surface. A suitable brush assembly  70  is taught in U.S. Pat. No. 5,867,857, the disclosure which is incorporated herein by reference. Brush assembly  70  is operated by a suitable gear train (or other known means). A suitable air turbine driven gear train is taught in U.S. Pat. No. 5,443,362, the disclosure of which is incorporated by reference. Other brush assemblies could be used such as, for example, a horizontal brush roll or fixed brush assembly.  
         [0016]     The supply tank assembly  76  comprises a clean water supply tank  620  and a smaller detergent supply container  622  provided in the clean water supply tank  620  as depicted in  FIG. 1 . The supply tank assembly  76  includes a combination carrying handle and tank securement latch  78  providing a convenient means for carrying the tank and/or securing the tank to the extractor handle assembly  62 . The clean water tank  620  has a cap  720  (FIG. 27 from co pending application having Ser. No. 10/165,731 and publication no. 20030226230) covering a top opening for filling the corresponding clean water tank  620  with clean water. The clean water tank  620  has a bottom wall  713  with an outlet opening  541 , which receives a solution release valve  746  as seen in  FIG. 4 .  
         [0017]     Referring to  FIG. 3 , the detergent container  622  is a flexible container in the form of a bladder. The material of the bladder is composed of vinyl that is chemical resistance to the detergent. However, other suitable flexible material can be used. A mounting member  211  is secured to the outer side of the bottom wall  713  and covers an opening  543  formed in the bottom wall  713  of the clean water tank  620 . The mounting member  211  has a flat attaching portion  213  that is attached to the bottom wall  713  by a pair of screws  215  threaded into bosses  217  formed in the bottom wall  713 . Seals  219  are inserted around the screws  215  and sandwiched between the mounting member  211  and bottom wall  713  to prevent the fluid in the clean water tank  620  from leaking. Other suitable means can be used to secure the mounting member  211  to the bottom wall  713 , such as, for example, by adhesives or welding.  
         [0018]     The mounting member  211  has a neck  221  extending upwardly therefrom over which a bottom neck  223  of the bladder  622  fits tightly around it and is adhesively secured. An elastic band or clamp  225  fits snugly around the neck  223  of the bladder for additional securement. The neck  221  surrounds a solution release valve  746  provided in the mounting member and a fill opening  227  formed in the mounting member  211  for filling the detergent container  622  with liquid detergent. A threaded cap  231  is removably secured to the fill opening  227 . Alternatively, the neck  221  can be integrally formed with the bottom wall  713  of the clean water tank  620  with the outlet opening  545  and fill opening  227  being formed in the bottom wall  713  to eliminate the mounting member  211 .  
         [0019]     The solution release valve  746  is normally in the closed position. However, when the tank assembly  76  is positioned in the handle  62 , the solution release valves  746  in the clean water tank  620  and detergent container  622  open permitting clean water from the clean water supply tank  620  and detergent from the detergent supply container  622  to flow to mixing Tee  796 . Upon removal of the tank assembly  76  from the handle  62 , the solution release valves  746  close prohibiting liquid from flowing out of the clean water tank  620  and detergent container  622 .  
         [0020]     As seen in  FIG. 3 , the solution release valve  746  is incorporated into an opening  545  of the mounting member  211  for the detergent container  622 . The other solution release valve  746  is incorporated into outlet  541  of the bottom plate  713  of the clean water tank  620  as seen in  FIG. 4 , which is of similar construction. Thus, only the one for the detergent tank  622  will be described in more detail. The solution release valve  746  comprises a valve body  742  having an elongate plunger  744  extending coaxially upward therethrough. The plunger  744  having an outside diameter less than the inside diameter of the valve body  742  is provided with at least four flutes  745  (FIG. 27 from co pending application having Ser. No. 10/165,731 and publication no. 20030226230) to maintain alignment of the plunger  744  within the valve body  742  as the plunger  744  axially translates therein and permits the passage of fluid therethrough when the plunger  744  is in the open position.  
         [0021]     A valve body  742  having a vertically extending bore  756  (FIG. 27 from co pending application having Ser. No. 10/165,731 and publication no. 20030226230) slidingly receives therein the upper shank portion of the plunger  744 . An elastomeric circumferential seal  748  circumscribes plunger  744  for sealingly engaging valve body  742 . The seal  748  is urged against the valve body  742  by action of the compression spring  752 , circumscribing plunger  744 . The spring  752  is positioned between the body  742  and the seal  748 . The solution release valve  746  is normally in the closed position. However, as the supply tank assembly  76  is placed upon the support shelf  743  of the handle  62 , the pin  738  of the reservoir  721  (FIG. 27 from co pending application having Ser. No. 10/165,731 and publication no. 20030226230) aligns with plunger  744 , thereby forcing plunger  744  upward to separate the seal  748  from the valve body  742 , compressing spring  752 , and opening the valve body  742  permitting detergent from the detergent supply container  622  to flow through bore  756  of the valve body  742  into the reservoir  721 . Upon removal of supply tank assembly  76  from the support shelf  743 , the energy stored within compression spring  752  urges the seal  748  down against the valve body  742  to close the valve  746 .  
         [0022]     An elastomeric tank seal  500  has an annular groove  501  that receives the edge  503  of the opening  545  of the mounting member  211  to secure it to the edge  503 . For the solution release valve  746  of the clean water tank  620 , the tank seal  500  has the annular groove  501  receiving the edge  571  of the outlet opening  541  of the bottom wall  713  as seen in  FIG. 4 . Upper and lower annular ribs  505 ,  507  formed on the outer surface of the valve body  742  secure the elastomeric seal  500  to the valve body  742 . In particular, the lower rib  507  engages the underside of a lip  509  on the seal and the upper rib extends over and engages the top edge  511  of the outlet opening. The cap  231  is threadily secured around a complimentary threaded downwardly depending neck portion  233  of the fill opening  227  of the mounting member  211 . A seal  235  is sandwiched between the cap  231  and bottom end of the neck portion  233  to prevent fluid from leaking from the detergent container  622 . Alternatively, the neck portion  233  can depend downwardly from the outlet opening  545 , so that a threaded cap can be received thereon and also mount a solution release valve through the outlet opening  545  to eliminate the fill opening  227 . Further details of such a cap and solution valve arrangement are shown in U.S. Pat. No. 6,167,586; the disclosure of which is hereby incorporated by reference.  
         [0023]     In operation, the detergent container  622  is filled with liquid detergent and the clean water tank  620  is filled with the clean water above the height of the detergent. In this arrangement, the weight of the water above the detergent container or bladder is transferred through the bladder wail  623  to the liquid detergent. The bladder wall  623  is designed to be flexible enough to collapse and allow this weight transfer. The equal weight produces approximately the same hydrostatic head at both the outlet  541  for the water and outlet  545  for the liquid detergent. Also, as water level drops due to the clean water flowing out of the clean water tank  620 , the pressures at each of the outlets changes by the same amount as long as the water level is above the detergent container  622 . This constant pressure ratio in turn causes the flow rates to change at generally the same amount and thus substantially reduces the variation of the detergent to water mixing ratio in mixing Tee  796 .  
         [0024]     With continue reference to  FIG. 2 , the carpet extractor  60  includes a solution hose  794  that fluidly connects outlet opening  541  of the clean water tank  620  to a shut off valve  800  used for selectively turning on and off the flow of clean water. Another solution hose  790  fluidly connects the outlet opening  541  of the water tank  620  to an inlet  812  of a pressure actuated shut off valve  804 . A solution hose  798  fluidly connects the outlet opening  545  of the detergent container  622  to an inlet  523  of the mixing Tee  796 . A second shut off valve  820  is used for selectively turning on and off the flow of mixed water and detergent cleaning solution through distributor  792 . Both shut off valves  800 ,  820  are fluidly connected to the distributor  792  through their respective solution hoses  794 ,  876 . The shut off valves  800 ,  820  are in the form of solenoid valves, however, other types of valves also could be used.  
         [0025]     The pressure actuated shut off valve  804  is fluidly connected between the clean water tank  620  and the mixing Tee  796  for turning off and on the flow of water. This shut off valve  804  is opened and closed by outside pressure via a conduit  806  connected between it and the outlet  807  of a pump  808  through a Tee  817 . The valve  804  includes a pressure port  822  fluidly connected to the outlet  807  of a pump  808 . The outlet of the valve  814  is fluidly connected to an inlet  521  of the mixing Tee  796  via hose  815 . It should be known that clean water tank  620  could be fluidly connect to the outlet  814  of the valve  804  with the inlet  812  of the valve  804  being fluidly connect to the mixing Tee  796  so that fluid could flow the opposite direction if desired.  
         [0026]     In operation, when the pressure at the pressure port  822  is below a predetermined value such as between 7 to 10 psi, the valve  804  opens to allow water to flow in both directions. Such a pressure value at the pressure port  822  occurs when the main shut off valve  820  is opened and the pump  808  is turned on. The pump  808  also pressurizes the water mixed with detergent to draw it to the distributor  792 . When the pressure exceeds a second predetermined value such as between 20 to 30 psi, the valve  804  closes. This would occur if the main shut off valve  820  is closed and the pump is turned on. Thus, with the valve  804  closed, the cleaning solution is prevented from flowing through it. Various types of pumps can be used such as a piston pump, gear pump or centrifugal pump.  
         [0027]     Outlet  525  of the mixing Tee  796  is fluidly connected via flexible hose  823  to the inlet of the pump  808 , which provides pressure to draw the cleaning solution to the distributor  792 , when it is turned on. A relief valve  809  is fluidly connected across the pump  808  to limit the pressure at the outlet  807  of the pump  808  to a predetermine value. The outlet  807  of the pump  808  is fluidly connected to the main shut off valve  820  via flexible hoses  825 ,  874  and  876 .  
         [0028]     The valves  800 ,  820  are operated by a trigger switch  821  as depicted in  FIG. 1 . The trigger switch  821  is pivotally connected to the upper handle portion  358  approximately near a closed looped handgrip  824 . Slide switch  858  is used to select one of the shut off valves  800 ,  822  to be opened and closed by the trigger switch  821 . Slide switch  856  is the main power switch, which turns on and off the suction motor  90  (FIG. 3 from co pending application having Ser. No. 10/165,731 and publication no. 20030226230) and pump  808 . The cleaning solution containing the clean water or water mixed with detergent flows to their associated shut off valves  800 ,  820 . The cleaning liquid distributor  792  evenly distributes the cleaning solution to each of the rotary scrub brushes  72 . The scrub brushes  72  then spread the cleaning solution onto the carpet (or bare floor), scrub the cleaning liquid into the carpet and dislodge embedded soil. A solution discharge valve  877  allows the mixed detergent and clean water to flow through an integrally formed nipple  218  and a detachable solution tube  216  to a hand-held cleaning attachment (not shown) and dispense by typical spray means.  
         [0029]     As is commonly known, a user turns on the carpet extractor  60  and pivots the handle  62  in an incline position while moving the carpet extractor  60  over the surface to clean it. The user squeezes the trigger switch  821  so that the carpet extractor  60  distributes the cleaning solution to the surface and substantially simultaneously extracts it along with the dirt on surface in a continuous operation. In particular, soiled cleaning solution is extracted from the surface by the suction nozzle  124  and transported into the recovery tank  80  where the liquid and air are separated. A vacuum is created in the recovery tank  80  by the suction motor, which draws air from the recovery tank  80  and exhausts the air to the surface  74 . Further details of the carpet extractor are disclosed in co pending application having Ser. No. 10/165,731 and publication no. 20030226230; the disclosure being incorporated herein by reference.  
         [0030]     The present invention has been described by way of example using the illustrated embodiments. Upon reviewing the detailed description and the appended drawings, various modifications and variations of the embodiments will become apparent to one of ordinary skill in the art. All such obvious modifications and variations are intended to be included in the scope of the present invention and of the claims appended hereto. For example, the mixed detergent and clean water cleaning solution can flow from the clean water tank and detergent container by gravity alone, without the use of the pump, to the distributor.  
         [0031]     In view of the above, it is intended that the present invention not be limited by the preceding disclosure of the embodiments, but rather be limited only by the appended claims.