Patent Publication Number: US-2005125935-A1

Title: Cleaning machine for cleaning a surface

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a cleaning machine for cleaning a surface.  
      2. Background Information  
      It is know to have cleaning machines for cleaning a surface. One example of a cleaning machine is an extractor that distributes water and detergent cleaning solution to a cleaning surface and substantially simultaneously extracts it along with the dirt on the carpet in a continuous operation. This machine generally uses one or two tanks for holding the cleaning solution and one tank for containing the extracted or recovered dirt and cleaning solution. When using this extractor, the majority of this water is recovered and then discarded. Such an arrangement has several disadvantages. One is that at least two tanks are used which together provide about twice the tank volume that is need to hold the actual volume. Another is that the user has to carry the recovery tank when full to the sink for disposal of the recovered solution and then refill the solution tank(s).  
      To overcome these disadvantages, the extractor can be designed to recycle the extracted cleaning solution for reuse. This solution would eliminate the additional recovery tank and the disposal of the recovered cleaning solution in the tank several times during the cleaning of the surface with the extractor. Further, this solution reduces significantly the number of times the user has to stop and refill the solution tank(s).  
     SUMMARY OF THE INVENTION  
      The foregoing and other facets of the present invention will be readily apparent from the following description and the attached drawings. In one aspect of the invention, a cleaning apparatus for cleaning a surface in which cleaning solution is distributed to the surface and substantially simultaneously extracted along with the dirt on the surface in a continuous operation as it moves along the surface is provided. The cleaning apparatus includes a housing and a liquid distribution system operatively associated with the housing. The liquid distribution system includes a fluid source providing a supply of the cleaning solution and a distributor fluidly connected to the fluid source for distributing the cleaning solution to the surface. A liquid recovery system is operatively associated with the housing and includes a suction nozzle and a recovery tank removably mounted to the housing and in fluid communication with the suction nozzle. A suction source is in fluid communication with the suction nozzle for applying suction to draw the cleaning solution and dirt from the surface through the suction nozzle and into the recovery tank. A filter system is provided on the housing and in fluid communication with the recovery tank for filtering the recovered cleaning solution to be reused and distributed to the surface by the distributor. An indicator device, operatively connected to one of the liquid distribution system and the liquid recovery system, indicates to a user that none of the recovered cleaning solution is flowing to the distributor.  
      In another aspect of the invention, a cleaning apparatus for cleaning a surface in which cleaning solution is distributed to the surface and substantially simultaneously extracted along with the dirt on the surface in a continuous operation as it moves along the surface is provided. The cleaning apparatus includes a housing and a liquid distribution system operatively associated with the housing. The liquid distribution system includes a fluid source providing a supply of the cleaning solution and a distributor fluidly connected to the fluid source for distributing the cleaning solution to the surface. A liquid recovery system is operatively associated with the housing and includes a suction nozzle and a recovery tank removably mounted to the housing and in fluid communication with the suction nozzle. A suction source is in fluid communication with the suction nozzle for applying suction to draw the cleaning solution and dirt from the surface through the suction nozzle and into the recovery tank. A filter system is provided on the housing and in fluid communication with the recovery tank for filtering the recovered cleaning solution to be reused and distributed to the surface by the distributor. The filter system includes a first filter provided on the recovery tank for filtering particles from the cleaning solution and dirt, and a second filter provided on the recovery tank and positioned downstream from the first filter. The second filter filters particles from the cleaning solution and dirt of a smaller size than the particles filtered from the first filter.  
      In still another aspect of the invention, a cleaning apparatus for cleaning a surface in which cleaning solution is distributed to the surface and substantially simultaneously extracted along with the dirt on the surface in a continuous operation as it moves along the surface is provided. The cleaning apparatus includes a housing and a liquid distribution system operatively associated with the housing. The liquid distribution system includes a fluid source providing a supply of the cleaning solution and a distributor fluidly connected to the fluid source for distributing the cleaning solution to the surface.  
      A liquid recovery system is operatively associated with the housing and includes a suction nozzle and a recovery tank removably mounted to the housing and in fluid communication with the suction nozzle. A suction source is in fluid communication with the suction nozzle for applying suction to draw the cleaning solution and dirt from the surface through the suction nozzle and into the recovery tank. A filter system is provided on the housing and in fluid communication with the recovery tank for filtering the recovered cleaning solution to be reused and distributed to the surface by the distributor. A pump is fluidly connected between the recovery tank and the distributor for drawing the cleaning solution from the recovery tank to the distributor, wherein the pump has an outlet in fluid communication with the suction source such that the suction from the suction source is used to prime the pump. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The invention will now be described, by way of example, with reference to the attached drawings, of which:  
       FIG. 1  is a side elevation of a cleaning machine of the present invention schematically illustrating the general arrangement of its operating elements;  
       FIG. 2  is a partially broken away front plan view of the cleaning machine of  FIG. 1  without the handle;  
       FIG. 3  is a cross sectional view of the bottom portion of the suction nozzle, the distributor and related elements with the cleaning machine moving in the forward direction; and  
       FIG. 4  is a view similar to  FIG. 3  except that the cleaning machine is moving in the rearward direction.  
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      Referring to the drawings,  FIG. 1  depicts the general arrangement of the cleaning machine in the form of an extractor  60  according to one embodiment of the present invention. The extractor  60  comprises an upright handle  62  pivotally connected to the rear portion of the floor-engaging portion or base  64  that moves and cleans along a surface  74  such as a bare or hard floor.  
      A combined air/water separator and recovery tank  80  removably sets atop the base  64 . The recovery tank  80  comprises a front wall  82 , rear wall  84 , top wall  86 , bottom wall  88 , and side walls  87 ,  89  ( FIG. 2 ). Before the extractor  60  is used for cleaning the surface  74 , the recovery tank  80  is filled with cleaning solution such as clean water mixed with detergent. Two laterally displaced front wheels  65 L and  65 R and two larger laterally displaced rear wheels  66  (the left wheel  66 L being shown in  FIG. 1 ) are rotatably attached to the base  64 . A motor/fan assembly  90  is mounted to the base  64  and is used to provide the suction power. The motor/fan assembly includes a motor  92  and a fan  94  located upstream that has an inlet  130  in fluid communication with an outlet  132  formed in the rear wall  84  of the tank near its top wall  86 . The fan  94  also includes an outlet  93  in fluid communication with the atmosphere for expelling the air. A suitable motor/fan assembly  90  is shown in U.S. Pat. No. 5,500,977; the disclosure of which is incorporated by reference.  
      A floor suction nozzle  70  is mounted to the front portion of the base  64  and includes front and rear portions  72 ,  73  ( FIGS. 3 and 4 ) that extend across the width of the base  64  as also seen in  FIG. 2 . Referring to  FIGS. 3 and 4 , a cleaning fluid distributor  76  is positioned within the suction nozzle  70  near its bottom portion for distributing the cleaning solution to the surface  74 . The distributor  76  extends across the width of the suction nozzle  70  and includes vertical front and rear walls  100 ,  102 , respectively, defining a chamber  104 . A solution tube  106  is fluidly connected to the distributor  76  at an inlet  108  formed in its rear wall  102  and supplies a flow of cleaning solution to the distributor  76 . The cleaning solution from the solution tube  106  strikes the front wall  100  and travels down to the surface  74  while fanning out into the narrow chamber  104  across the width of the suction nozzle  70  as seen in  FIG. 2 . The rear wall  102  of the distributor  76  is spaced opposite from the rear portion  73  of the suction nozzle  70  to define a rear suction flow path  112 . Likewise, the front wall  100  of the distributor  76  is spaced opposite from the front portion  72  of the suction nozzle  70  to define a front suction flow path  114 .  
      As seen in  FIG. 3 , a front squeegee member  116  is mounted to the front side of the front portion  72  of the suction nozzle  70  and extends down to the surface  74 . A similar rear squeegee member  118  is mounted to the rear is side of the rear portion  73  of the suction nozzle  70  and also extends down to the surface  74 . Each of the squeegee members includes bumps  120 F,  120 R formed along the outer surface of the bottom edges. The bumps  120  raise the leading squeegee member to allow air and liquid to flow between the bumps  120 . Yet, the trailing squeegee member bends out and cleanly wipes the floor with its inside straight edge to keep liquid in the high suction area of its adjacent flow path. Such a squeegee design with the bumps is shown in U.S. Pat. No. 3,520,012; the disclosure of which is incorporated herein by reference.  
      Further, when the base  64  is moved in the forward or rearward direction, the leading squeegee member bends a sufficient distance over the inlet of its adjacent flow path to cover and close the inlet thereby substantially blocking suction from the flow path. In particular, when the base  64  moves forward as shown in  FIG. 3 , the front squeegee member  116  bends over inlet  122  of the front flow path  114  closing it, while the rear squeegee member  118  bends away from inlet  124  of the rear flow path  112  so that is open. When the base  64  moves rearward as shown in  FIG. 4 , the rear squeegee member  118  bends over the inlet  124  of the rear flow path  112  closing it, while the front squeegee member  116  bends away from the inlet  122  of the front flow path  114  so that it is open. Thus, the distributor  76  always distributes the cleaning solution ahead of the open front flow path  114  or rear flow path  112  in both the forward and rearward direction of movement of the base  64 , and the closing of the leading flow path reduces the cross sectional area of the suction nozzle  70  at its inlet thereby creating extra suction power to the trailing flow path to extract and transport the cleaning solution and dirt.  
      The motor/fan assembly  90  generates suction to extract the air and soiled liquid from the surface and draws it through the front or rear flow path of the suction nozzle  70  to inlet  128  formed in the front wall of the recovery tank  80  near its top wall where separation of the air and liquid occurs. Gravity slows upward travel of the liquid and air thereby aiding their separation. In addition, a concaved curved wall or rib  126  extending down from the top wall  86  of the recovery tank  80  further slows the air and liquid down to aid their separation and also directs the liquid to the bottom wall  88  of the recovery tank  80 . The separated air then travels through the outlet  132  of the recovery tank, where it is expelled to atmosphere via the outlet  93  of the fan  94 .  
      The recovery tank  80  includes an outlet or drain  134  formed in its bottom wall  88  that is fluidly connected to an air turbine driven pump  136  via solution tube  144 . A screen  138  is fixed over the drain  134  to prevent dirt from accidentally being flushed into the drain  134  when the recovery tank  80  is being cleaned. Above the screen  138  are two large area filter screens  140 ,  142  removably mounted to the recovery tank  80  and extending across it for filtering the cleaning solution for reuse. Filter  140  is a coarse filter, which removes large particles from the cleaning solution. Filter  142 , located below or downstream from the coarse filter, is a fine filter that removes particles smaller than that from the coarse filter  140 . Thus, cleaning solution is rid of a substantial amount of dirt and other particles as it exits the drain  134  to be reused.  
      Air turbine driven pump assembly  136  draws the cleaning solution under pressure from the recovery tank  80  to the distributor  76  via solution tubes  106 ,  144 . The air turbine driven pump assembly  136  comprises an air driven turbine portion  146  and a centrifugal liquid cleaning solution supply pump portion  148  attached thereto and sharing a common rotating shaft  150 . In operation, vacuum is applied to the air turbine discharge port  152 , which fluidly communicates with the fan  94 , thereby causing clean atmospheric air to enter turbine inlet ports  154 , 156  passing through and thereby driving turbine  146 . As the turbine  146  rotates, pump impeller (not shown) is also rotated via shaft  150  thereby drawing the filtered cleaning solution into pump chamber via solution tube  144  from the recovery tank and discharging the cleaning solution from the pump discharge port  158 , under pressure, to solution discharge valve  160  via solution tube  106 . Further details of the air turbine driven pump are disclosed in the above-mentioned U.S. Pat. No. 5,500,977. A trigger switch  162 , pivotally mounted in the upper portion of the handle  62 , operates the solution discharge valve  160 . In particular, a user squeezes the trigger switch  162  to distribute the cleaning solution to the surface  74 . The solution discharge valve  160  can be one of several types such as, for example, a solenoid valve or umbrella valve.  
      To ensure that the air turbine driven pump assembly  136  is quickly primed, a bypass tube  164  fluidly connects the pump discharge port  158  to an inlet  166  in the recovery tank  80  above the level of cleaning solution in the recovery tank  80 , so that suction from the motor /fan assembly  90  draws the air out of the pump  136 , which primes it. Since the cleaning solution is always being pumped, even with the solution discharge valve  160  closed, the turbine  146  is always under a load and therefore cannot over revolve.  
      An indicator light  168  is provided on the base  64  to inform the user when the recovery tank  80  is out of cleaning solution or that the filter screens are clogged. The light  168  is controlled by a pressure switch  170  provided in the solution tube  106 . In particular, the light  168  is electrically coupled to the pressure switch  170  and includes leads L that are electrically connected to a power source (not shown). When the cleaning solution flows through the discharge port  158  of the pump portion  148  and the solution tube  106 , the pressure caused by the flow of cleaning solution opens the pressure switch  170 , which cuts the power to the light  168  thereby turning or keeping it off. However, when the cleaning solution does not flow through the pump discharge port  158  and solution tube  106 , the absence or lack of pressure closes the pressure switch  170 , which allows power from the power source to turn the light  168  on.  
      In operation, a user fills the recovery tank  80  with cleaning solution. The user then pivots the handle  62  in an incline position while moving the extractor  60  over the surface  74  to clean it. The extractor  60  distributes the cleaning solution to the surface and substantially simultaneously extracts it along with the dirt on the surface in a continuous operation. The soiled cleaning solution is extracted from the surface by the suction nozzle  70  and transported into the recovery tank  80  where the liquid and air are separated. The extracted liquid is filtered and reused as cleaning solution as previously mentioned.  
      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.  
      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.