Patent Document

BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a cleaning machine having a control system for cleaning a surface.  
           [0003]    2. Background Information  
           [0004]    It is know to have cleaning machines for cleaning a surface. One example of a cleaning machine is a carpet extractor distributes cleaning solution to a cleaning surface and substantially simultaneously extracts it along with the dirt on the carpet in a continuous operation. It would be desirable to control certain cleaning operations of the extractor distributed based on certain operating characteristics of the extractor. For example, when cleaning the surface using such an extractor, less cleaning solution is distributed on areas of the cleaning surface in which the extractor moves very quickly over.  
           [0005]    Likewise, extractors with agitators do not agitate those areas of the cleaning surface as much since less time is spent agitating those areas. The same situation applies to the degree of suction. Also, it would be desirable to vary the mix ratio of detergent and clean water in the cleaning solution to compensate for the change in speed of the extractor moving over the surface. Thus, it would be desirable to uniformly clean the surface using these cleaning functions irrespective of the speed of the extractor as it moves along a surface. Also, these or other cleaning functions could be controlled based on the extractor speed or other operating characteristics of the extractor.  
           [0006]    Hence, it is an object the present invention to provide a cleaning machine that controls certain cleaning operations of the extractor based on certain operating characteristics of the extractor.  
           [0007]    It is another object of the present invention to provide a cleaning machine that more uniformly cleans the cleaning surface.  
         SUMMARY OF THE INVENTION  
         [0008]    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 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 cleaning apparatus includes a base assembly that moves along the surface. A liquid distribution system is associated with the base assembly and includes a source providing a supply of cleaning solution to a distributor fluidly connected to the source. A liquid recovery system is also associated with the base assembly and includes a suction nozzle having an inlet located at the front portion of the base assembly. 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. The cleaning apparatus further includes a detecting device for detecting the speed of the cleaning apparatus as it moves along the surface and producing a speed signal representing the speed of the cleaning apparatus relative to the surface. A controller, operatively connected to the detecting device and the liquid distribution system, controls the amount of cleaning solution distributed to the surface based on the speed signal.  
           [0009]    In another aspect of the invention, a 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 cleaning apparatus includes a base assembly that moves along the surface. A liquid distribution system is associated with the base assembly and includes a source providing a supply of cleaning solution to a distributor fluidly connected to the source. A liquid recovery system is also associated with the base assembly and includes a 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. An agitator is operatively connected to the base assembly The cleaning apparatus further includes a detecting device for detecting the speed of the cleaning apparatus as it moves along the surface and producing a speed signal representing the speed of the cleaning apparatus relative to the surface. A controller, operatively connected to the detecting device and the agitator, controls the speed of the agitator agitating the surface relative to the base assembly based on the speed signal.  
           [0010]    In still another aspect of the invention, a method for cleaning a surface with a carpet extractor is provided and includes the steps of moving the carpet extractor along the surface, detecting an operating characteristic of the carpet extractor, distributing a predetermined amount of cleaning solution from the carpet extractor based on the operating characteristic of the carpet extractor, and recovering the cleaning solution and dirt form the surface using the carpet extractor.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    The invention will now be described, by way of example, with reference to the attached drawings, of which:  
         [0012]    [0012]FIG. 1 is a perspective view of a carpet extractor embodying the present invention;  
         [0013]    [0013]FIG. 2 is a schematic view of the fluid distribution system and control system of the embodiment shown in FIG. 1;  
         [0014]    [0014]FIG. 3 is an exploded view of the speed sensor of the present invention of the embodiment of FIG. 1;  
         [0015]    [0015]FIG. 4 is a partial left side view of the base of the carpet extractor of FIG. 1 showing the speed sensor of FIG. 3; and  
         [0016]    [0016]FIG. 5 is a schematic view of the fluid distribution system and control system of a second embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0017]    Referring to the drawings, FIG. 1 depicts a perspective view of an 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 or bare floor. 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 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 suction motor/fan assembly  81  (FIG. 2) of the 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 is in fluid communication with the recovery tank  80  for transporting air and liquid into the recovery tank  80 . The floor suction nozzle  124  assembly is extends forwardly down to the front portion of the base assembly  64 . 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 . The suction nozzle  124  has an inlet  138  located forwardly adjacent the front end of the base assembly  64 . Further details of the above mentioned elements of the carpet extractor are disclosed in co pending application having Ser. No. 10/165,731; the disclosure being incorporated herein by reference.  
         [0018]    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). An electric motor  73  with gear assembly drives the gear train on the brush. One such suitable electric motor is disclosed as best illustrated in FIG. 24 in co-pending patent application Ser. No. 09/956,297; the entire disclosure of which is incorporated by reference. Other brush assemblies could be also used such as, for example, a horizontal brush roll or a vibrating or oscillating type brush assembly.  
         [0019]    The supply tank assembly  76  comprises a clean water supply tank  620  and a detergent supply tank  622  adhesively mounted to 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 .  
         [0020]    With reference to FIG. 2, the carpet extractor  60  includes a solution hose  794  that fluidly connects the outlet 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 of the water tank  620  to an inlet  812  of a pressure actuated shut off valve  804 . The outlet of the detergent tank  622  is fluidly connected to the inlet  523  of a mixing valve  796  via a suitable flexible hose  798 .  
         [0021]    The pressure actuated shut off valve  804  is fluidly connected between the clean water tank  620  and the mixing valve  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 the inlet  521  of the mixing valve  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 valve  796  so that fluid could flow the opposite direction if desired.  
         [0022]    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, clean water or detergent is prevented from flowing through it. Various types of pumps can be used such as a gear pump or centrifugal pump.  
         [0023]    The 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 . Both of the shut off valves  800 ,  820  are in the form of a solenoid valve, however, other electrical actuated valves could be also used.  
         [0024]    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 valve  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  81 , pump  808 , and brush motor  73 . Alternatively, a separate switch could be incorporated to turn on and off the brush motor independent of the main power switch. The water or detergent mixed with water cleaning solution from the tanks  620 ,  622  flows to their associated shut off valves  800 ,  820 . The cleaning liquid distributor  792  evenly distributes the cleaning liquid to each of the rotary scrub brushes  72 . The scrub brushes  72  then spread the cleaning liquid onto the carpet (or bare floor), scrub the cleaning liquid into the carpet and dislodge embedded soil. A solution discharge valve  877  allows 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.  
         [0025]    As is commonly known, a user pivots the handle  62  in an incline position while moving the carpet extractor  60  over the surface to clean it. The carpet extractor  60  distributes the cleaning solution to the carpeted surface using the brushes  72  and substantially simultaneously extracts it along with the dirt on the carpet in a continuous operation. In particular, soiled cleaning liquid is extracted from the carpet 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  81 , which draws air from the recovery tank  80  and exhausts the air to the carpeted surface.  
         [0026]    A user interface module  200  is provided on the handle  62  to allow the user to select additional options on the extractor  60  to clean the surface. These options include distributing an amount of cleaning solution based on the speed of the base assembly  64  moving across the cleaning surface, controlling the speed of the scrub brushes  72  scrubbing the surface, and controlling the suction motor  81  to vary the amount of suction based on the speed of the base assembly  64  moving across the surface. Other options can also be incorporated into module. The module  200  can be in the form of a touch screen having touch sensors to select the options, or the module could comprise pushbuttons, rotary switches, or other suitable means to select the options. A controller  202  is electrically connected to the module  200  for receiving a signal from the module  200  representing the selected option.  
         [0027]    A speed sensor  204  is also electrically connected to the controller  202  and outputs a signal representative of the speed of the base assembly  64  with respect to the cleaning surface. FIG. 3 shows in more detail the speed sensor  204  and related parts. The speed sensor  204  includes a hall sensor  206  secured to an arm  210  and positioned spacedly adjacent a magnetic disk  222  mounted to the rear extractor wheel  66 L by screws  208  or other suitable means such as for example, adhesive. The magnetic disk  222  can also be keyed to securely fit into a complimentary configured axle. The magnetic disk  222  has a multiple of alternating pie-shaped segments of opposite polarity such as the north and south segments  224 ,  226  as shown. As the wheel  66 L rotates when rolled over the cleaning surface, the magnetic disk  222  rotates with it. The arm  210  includes axles  227  with rollers  228  that ride on the magnetic disk  222  to ensure clearance between the hall sensor  206  and the magnetic disk  222 .  
         [0028]    As seen in FIG. 4, the rear extractor wheel  66 L includes an axle  67  that slidably extends through an opening in the arm  210  and rotates within the opening. The arm  210  is further positioned in a recess  211  of the frame or body  84  so that the arm  210  and hall sensor  206  remain stationary while the axle  67  rotates as the base assembly  64  moves along the cleaning surface. The hall sensor  206  is electrically connected to the controller  202 . Alternatively, the hall sensor  206  can be mounted on the body  84 .  
         [0029]    As the magnetic disk rotates, the hall sensor  206  breaks into the positive gauss of the magnetic field of the North Pole thereby causing the hall sensor  206  to output a pulsed signal, which is representative of the rotation speed of the wheel  66 L, to the controller  202 . Optionally, a commonly known RC network can adjust the signal to a proportional output voltage type before it is inputted into the controller. The speed sensor  204  can also be an infrared or optical sensor or other suitable type of sensor.  
         [0030]    The outputs of the controller  202  are electrically connected to the pump  808 , the mixing valve  796 , brush motor  73 , and suction motor  81 . Additional outputs of the controller  202  can be incorporated and electrically connected to other devices on the extractor  60  such as one for controlling the amount of pressure exerted by the brush assembly  70  on the cleaning surface. Also, other devices that detect an operating characteristic of the carpet extractor  60  can be electrically connected to additional inputs of the controller  202 .  
         [0031]    The controller  202  first determines what option was selected by comparing the option signal outputted by the module  200  and data stored in the controller  202 . If the controller  202  receives the option signal representing distributing an amount of cleaning solution based on the speed of the base assembly  64  moving across the cleaning surface, the controller  202  compares the speed signal from the speed sensor  204  with data stored in it. The controller  202  then outputs a pulse width modulated control signal to the pump  808 , which controls the amount of cleaning solution flowing to the distributor  792  based on that speed signal. For this option, the controller  202  is programmed to control the pump  808  so that the amount of cleaning solution flowing to the distributor  792  increases in proportion to the speed of the base assembly  64  moving along the surface. A driver  232  is electrically connected between an output of the controller and power switching device  234 , which is electrically connect to he pump  808 . Upon receiving the control signal from the controller, the driver  232  adjust the voltage to a proper value for input to the power switching device  234  which switches on and of the controls of the motor in the pump  808  thereby controlling the amount of cleaning solution flowing to the distributor  792 .  
         [0032]    If the controller  202  receives the option signal representing setting the speed of the brushes  72  scrubbing the cleaning surface based on the speed of the base assembly  64  moving across the cleaning surface, the controller  202  compares the speed signal from the speed sensor  204  with data stored in it.  
         [0033]    The controller  202  then outputs a pulse width modulated control signal to the brush motor  73 , which controls the speed of the brushes  72  scrubbing the cleaning surface based on the speed signal. A driver  236  is electrically connected between an output of the controller  202  and power switching device  238 , which is electrically connect to the brush motor  73 . For this option, the controller  202  is programmed to control the brush motor  73  so that the rotary speed of the brushes  72  scrubbing the cleaning surface increases in proportion to the speed of the base assembly  64  moving along the cleaning surface. Upon receiving the control signal from the controller  202 , the driver adjust the voltage to the proper value for input to the power switching device  238 , which switches on and of the controls of the brush motor  73  thereby controlling the rotational speed of the brushes  72  scrubbing the cleaning surface.  
         [0034]    If the controller  202  receives the option signal representing setting the speed of the suction motor  81  based on the speed of the base assembly  64  moving across the cleaning surface, the controller  202  compares the speed signal from the speed sensor  204  with data stored in it. The controller  202  then outputs a pulse width modulated control signal to the suction motor  81 . A driver  240  is electrically connected between an output of the controller  202  and power switching device  242 , which is electrically connect to the suction motor  81 . For this option, the controller  202  is programmed to control the suction motor  81  so that the speed of the suction motor  81  generating suction increase in proportion to the speed of the base assembly  64  moving along the cleaning surface. Upon receiving the control signal from the controller  202 , the driver  240  adjust the voltage to the proper value for input to the power switching device  242 , which switches on and off the controls of the suction motor  81  thereby controlling the amount of suction generation or power related to the speed of the suction motor  81 .  
         [0035]    If the controller  202  receives the option signal representing setting of the mixing valve  796  based on the speed of the base assembly  64  moving across the cleaning surface, the controller  202  compares the speed signal from the speed sensor  204  with data stored in it. The controller  202  then outputs a pulse width modulated control signal to the mixing valve  244 . A driver  244  is electrically connected between an output of the controller  202  and valve controller  246 , which is electrically connect to the mixing valve  796 . For this option, the controller  202  is programmed to control the mixing valve  796  so that the proportion of detergent in cleaning solution increases in proportion to the speed of the base assembly  64  moving along the cleaning surface. Upon receiving the control signal from the controller  202 , the driver  244  adjusts the voltage to the proper value for input to the valve controller  246 , which controls the mixing valve  796  to adjust the mixing ratio of detergent and water.  
         [0036]    In a second embodiment of the invention as shown in FIG. 5, two pumps  248 ,  250  are used to draw the cleaning solution to the distributor  792 . Components from the previous embodiment shown in FIGS. 1 through 4, which are identical in structure and have identical functions will be identified by the same reference numbers. In this embodiment, one pump  248  for the clean water tank  620  is fluidly connected between the clean water tank  620  and distributor  792 . The other pump  250  for the detergent tank  622  is fluidly connected via conduit  260  between a Tee  252  provided in the conduit  256  connecting the water pump  248  and clean water tank  620 . The pumps  248 ,  250  are gear pumps but they can be also centrifugal pumps or other suitable type pumps. The controller  202  is electrically connected to each of the pumps  248 ,  250  at one or more of its outlets. A check valve  258  is provided in the conduit  256  connecting the outlet of the water pump  248 .  
         [0037]    If the controller  202  receives the option signal representing controlling the pumps  248 ,  250  to pump the amount of detergent and/or clean water based on the speed of the base assembly  64  moving across the cleaning surface, the controller  202  compares the speed signal from the speed sensor  204  with data stored in it. The controller  202  then outputs pulse width modulated control signal(s) to the pumps  248 ,  250 . For this option, the controller  202  is programmed to control the pumps  248 ,  250  so that the proportion of detergent in cleaning solution increases in proportion to the speed of the base assembly  64  moving along the cleaning surface. Also, the pumps  248 ,  250  can control the amount of mixed cleaning solution based on the speed of the base assembly  64  moving across the surface, if the user selected such an option signal. Further, if desired, the user can increases or decrease the amount of cleaning solution on the module  200  irrespective of the speed of the base assembly  64  across the cleaning surface. The controller  202  can be a microprocessor or an analog circuit. The power switching devices can be field effect transistors, triacs or other suitable power switching devices.  
         [0038]    In addition to speed, the speed sensor  204  could also detect the forward or rearward direction of movement of the extractor  60  and output such a signal to the controller  202 . In this situation, the controller  202  compares the signal with stored data and outputs one or more control signals to the various devices (such as the brush motor  73 , suction motor  81 , and pump  808  or pumps  248 ,  250 ) to control their functions. For example, if the speed sensor  204  outputs a signal indicating that the extractor  60  is moving in the rearward direction, the controller sends a control signal to the valve controller  246  to control the mixing valve  796  to allow only clean water to flow to the distributor  792 . If the second embodiment is used in this example, upon the speed sensor  204  detecting the rearward direction of the extractor  60 , the controller  202  sends a control signal to the detergent pump  250  to turn it off to allow only clean water to flow to the distributor  792 . Additionally, upon the speed sensor  204  detecting the rearward direction of the extractor  60 , the controller  202  sends a control signal to the brush motor  73  to reverse the rotational direction of the brushes  72  agitating the surface so that the brushes  72  scrub the surface of the cleaning path in both the clockwise and counter clockwise direction when the extractor  60  is moved forward and rearward over the cleaning path.  
         [0039]    Optionally, a speed sensor can be operatively associated with the brush assembly  70  and controller  202  to detect the speed of the brushes  72  (or brush roll) agitating the surface and output a speed signal representative of that agitating speed to the controller  202 . The controller  202  compares the signal with stored data and outputs one or more control signals to the various devices (such as the valve controller  246 , brush motor  73 , suction motor  81 , and pump  808  or pumps  248 ,  250 ) to control their functions as previously described based on the speed of the brush assembly  70  agitating the surface.  
         [0040]    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.  
         [0041]    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.

Technology Category: 1