Abstract:
A carpet cleaning apparatus is disclosed with a loop agitator. The loop agitator comprises a spindle with a plurality of flexible loops attached to the spindle. A blade is provided in close relative proximity to the agitator for severing hair and other fibers that become entangled on the agitator. A de-foaming device is included that automatically dispenses a de-foaming chemical. The de-foaming device comprises at least two electrodes that allow foam to complete a circuit to open a solenoid valve. Negative vacuum pressure is allowed to disburse the de-foaming chemical. The device also comprises a basket with a mesh bag for straining wastewater and removing debris. Wastewater drains into a wastewater tank where an electrode switch is provided for activating a wastewater pump.

Description:
CROSS REFERENCES TO RELATED APPLICATIONS  
       [0001]    This application claims priority of U.S. provisional patent application Ser. Nos. 60/040,484 and 08/070,773, filed on Mar. 7, 1997 and Jan. 8, 1998, respectively. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of Invention  
           [0003]    The present invention relates to a device for cleaning carpets, rugs, floor coverings, window coverings, upholstery, and other material.  
           [0004]    2. Description of Related Art  
           [0005]    Carpet cleaning machines are well known in the art. Numerous machines and devices related to these machines have been developed for domestic and commercial use. Most carpet cleaning devices operate by applying a solution of water and cleaning chemicals to a carpet, agitating the carpet, and vacuuming the solution, dissolved soil, and loose debris into a tank. However, most of these devices have undesirable characteristics or fail to achieve a desired level of performance. For example, most carpet cleaning devices have at least one of the following failings:  
           [0006]    They are heavy requiring a great deal of effort to transport and maneuver;  
           [0007]    They use a large amount of water and leave a large amount of water and cleaning solution in a carpet during a cleaning process;  
           [0008]    Some styles of devices reuse dirty water during cleaning thereby decreasing cleaning efficiency.  
           [0009]    They do not remove objects from wastewater that could damage wastewater removal pumps;  
           [0010]    They do not efficiently eliminate suds in their vacuum ducts;  
           [0011]    The agitators are inefficient and destructive to carpets;  
           [0012]    The agitators become clogged with hair and other objects; and  
           [0013]    They have poor overall cleaning efficiency.  
           [0014]    Although these problems and failings have long been recognized, little has been done to improve existing carpet cleaning devices. Manufacturers and users have come to accept these problems as part and parcel of carpet cleaning devices. What has long been needed is a means for improving carpet cleaning devices to reduce or eliminate these failings.  
         SUMMARY OF INVENTION  
         [0015]    1. Objects of the Invention  
           [0016]    It is an object of the present invention to provide an improved apparatus for cleaning carpets, rugs, floor coverings, window coverings, upholstery, and other materials and objects.  
           [0017]    It is a further object of the present invention to provide a cleaning apparatus that utilizes a rotating agitator with loops or fins of flexible material.  
           [0018]    It is another object of the present invention to provide the rotating agitator described above wherein the loops or fins are mounted at an angle to the direction of rotation.  
           [0019]    It is another object of the present invention to provide a cleaning device that utilizes a removable mesh bag for collecting debris and providing a filter for filtering wastewater.  
           [0020]    It is a further object of the present invention to provide a cleaning device that utilizes an automatically activated pump to remove wastewater from the device.  
           [0021]    It is another object of the present invention to provide an automatic pump described above that is activated when wastewater completes a circuit between at least two electrodes.  
           [0022]    It is a further object of the present invention to provide a cleaning device that utilizes an automatic de-sudser.  
           [0023]    It is another object of the present invention to provide the de-sudser described above that is activated when foam or suds complete a circuit between at least two electrodes.  
           [0024]    It is a further object of the present invention to provide a wastewater removal system that allows wastewater to back flush the automatically activated pump described above.  
           [0025]    It is another object of the present invention to provide the de-sudser described above which utilizes the negative pressure created by a vacuum motor to disperse a de-sudsing substance.  
           [0026]    It is another object of the present invention to provide a cleaning device that is light and easily transported and maneuvered.  
           [0027]    It is another object of the present invention to provide a cleaning device that does not require high pressure or high temperature water lines.  
           [0028]    It is another object of the present invention to provide a cleaning device that is easier and more efficient to operate than prior art devices.  
           [0029]    It is a further object of the present invention to provide a cleaning device that comprises an air duct that directs vacuum motor exhaust through streams of liquid solution.  
           [0030]    It is another object of the present invention to provide a blade in close proximity to a rotating agitator for cutting hair and other fibers before they wind around the agitator.  
           [0031]    It is a further object of the present invention to provide a carpet cleaning apparatus with rigid skid rails for structurally supporting the cleaning apparatus.  
           [0032]    These and other objects of the present invention may be realized by reference to the remaining portions of the specification, claims, and abstract.  
           [0033]    2. Brief Description of the Invention  
           [0034]    The carpet cleaning apparatus of the present invention comprises an agitator with a substantially cylindrical spindle and a plurality of loops attached to the spindle. The loops are adapted to agitate and massage fibers on a carpet or material. A blade is located in close relative proximity to the agitator for cutting hair or other fibers that become entangled on the agitator.  
           [0035]    A vacuum duct is provided for vacuuming wastewater and debris into the apparatus. The duct comprises an automatic de-foaming device that automatically dispenses a de-foaming chemical. The de-foaming apparatus comprises at least two electrodes that allow foam to complete an electrical circuit. When the circuit is completed, a solenoid valve is opened and vacuum pressure in the duct is allowed to draw de-foaming chemical into the duct.  
           [0036]    The present invention also comprises a basket with removable, disposable bag for straining debris from wastewater. The wastewater is allowed to drain into a wastewater tank where it may be pumped out of the device. An electrode switch is provided in the wastewater tank for activating the pump when the wastewater reaches a predetermined level.  
           [0037]    The vacuum motor of the present invention forces air through a duct located near the bottom of the apparatus. A gap is provided near the duct for providing a suction that draws air from the internal cavity of the device. This helps provide air circulation in the internal cavity to cool the internal components. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0038]    [0038]FIG. 1 is a cross sectional side view of the cleaning device of the present invention taken along line  1 - 1  in FIG. 2.  
         [0039]    [0039]FIG. 2 is a partial cross sectional plan view of the cleaning device of the present invention taken along line  2 - 2  of FIG. 1.  
         [0040]    [0040]FIG. 3 is a cross sectional view of the agitator of the present invention taken along line  3 - 3  of FIG. 2.  
         [0041]    [0041]FIGS. 4 a  and  4   b  are schematic representations of the relative orientation of loops or fins of the present invention.  
                                             REFERENCE NUMERALS                                    7   vacuum motor           9   electrode           10   electrode           11   basket           15   switch           16   handle           17   cord           18   hose           19   wastewater line           20   pump           21   valve           22   chemical tank           23   bag           25   switch           26   switch           31   valve           33   agitator           34   loops or fins           35   spindle           37   squeegee elements           38   tank           39   rear lip           50   carpet or material           52   direction of rotation           54   first row of loops           56   second row of loops           60   front lip           62   screen           67   air tube           68   tube           69   air duct           100   device           101   inlet duct           102   blade           103   spray jets           104   holes           106   holes           106   tube           108   side rails           110   exhaust duct           112   skids           114   hinge           116   solid center portion           120   nozzle           121   tube           134   chain drive           135   drive motor                        
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0042]    As seen in FIGS. 1 and 2, the present invention comprises a cleaning device generally indicated by reference number  100 . Device  100  is adapted to utilize external supplies of electricity and water. A cord  17  is attached to an electrical outlet (not shown) and hose  18  is attached to a faucet or other water source (not shown) with a standard faucet adapter that is well known in the art. Cleaning chemicals are preferably added to water in hose  18  by a chemical injector at the point where the cleaning hose connects to the faucet. Injectors and other similar devices are well known in the art and they are commonly used to add cleaning chemicals to water in a predetermined proportion. The water and cleaning chemicals are mixed as they travel through hose  18  and device  100  to form a cleaning solution that is used to clean a carpet or material  50 . A wastewater line  19  is also provided for removing wastewater. Preferably cord  17 , hose  18 , and wastewater line  19  are 50 to 80 feet long.  
         [0043]    A switch  15  is provided on a handle  16  to activate a 24 volt solenoid valve  31  that allows the solution to spray out of spray jets  103 . No pump is needed to spray the solution as the invention utilizes water pressure provided at the faucet. This feature helps reduce the weight, cost, and complexity of device  100 . A tube  68  is provided for allowing electrical wires and hoses to pass through a wastewater tank  38 .  
         [0044]    Device  100  includes a number of innovations that allow it to use less water and cleaning chemicals during cleaning operations. The bottom surface of device  100  is provided with an air duct  69  for directing exhaust air from a vacuum compressor and motor  7  forward towards an agitator  33 . Preferably, air duct  69  directs exhaust air across substantially the length of agitator  33 . As streams of solution exit jets  103 , the solution collides with the turbulent exhaust air thereby dispersing the solution. The streams of solution also are directed towards agitator  33 . As the solution strikes agitator  33 , which is normally rotating, the solution is further dispersed.  
         [0045]    The dispersed solution allows the solution to soak into the fibers of material  50  faster than would otherwise be possible. This results in a number of advantages including the following:  
         [0046]    Less water and cleaning chemicals are needed to clean the material;  
         [0047]    Device  100  does not need to remove as much solution from the material, which allows the device to be smaller, lighter, and less expensive; and  
         [0048]    The backing of the material does not become saturated with water, which allows the material to dry faster, prevents mildew, and prolongs the life of the material.  
         [0049]    Agitator  33  is adapted to rotate on the bottom of device  100  where the agitator is in contact with material  50 . In the preferred embodiment, a drive motor  135  and chain drive  134  are provided for driving agitator  33  so that the lower portion of the agitator moves from back to front relative to device  100 .  
         [0050]    As seen in FIG. 3, agitator  33  comprises a substantially cylindrical spindle  35  and a plurality of flexible loops or fins  34 . Spindle  35  is adapted to rotate around a central axis. Loops  34  are preferably made of a flexible material, such as nylon or other synthetic materials that allow the loops to absorb impacts with hard objects. Loops may be a continuous fiber that is sewn into spindle  35 . In the preferred embodiment, two helical rows of loops  34  are attached to spindle  35 . However, a greater or lesser number of rows may be used and the rows may be straight. Alternatively, loops  34  may have a solid center portion  116 . Thus, loops  34  may be substantially planar fins. Loops  34  with solid center portion  116  may have the advantage that they are less expensive to manufacture and are more wear resistant.  
         [0051]    Flexible loops  34  are a significant improvement over prior art agitating brushes because the loops will not tear or damage the fibers in carpets as brushes tend to do. Carpets are made up of tufts of fibers that are bond to a carpet backing. As the bristles of brushes move over a carpet, they are inserted into and pass through the tufts of fibers in a rake-like action. This action tends to tear and separate the fibers in the tufts. Brushes also force the fibers flat against the carpet backing. This applies stress to the fiber ends that may cause fibers to separate from the backing.  
         [0052]    Loops  34  do not suffer from these problems because the loops move past the tufts and do not penetrate the tufts. Loops  34  comprise a leading edge that is wider than the leading edge of brush bristles. Loops  34  also have a rounded profile that does not catch on carpet fiber loops. These characteristics allow loops  34  to message tufts rather than rake the tufts.  
         [0053]    Loops  34  are also self-cleaning. Brushes tend to get clogged with hair, carpet fibers, and other debris, especially when the carpet is wet. Flexible loops  34 , on the other hand, have less surface area upon which debris may rest. Consequently, loops  34  seldom become clogged or bound by debris.  
         [0054]    The present invention does not require a height adjustment mechanism to adjust the height of the agitator as is required with brush agitators. The height of brush agitators must be adjusted to prevent deep penetration of carpet tufts. If the height is not properly adjusted, a brush agitator will quickly destroy a carpet by ripping fibers out of the backing. Loops  34  of agitator  33  go through carpets without penetrating the tufts of the carpet fibers. Therefore, agitator  33  will not destroy the carpet if it is not adjusted to a proper height.  
         [0055]    The agitator of the present invention is also very effective at cleaning chemical laden carpets. Many carpet cleaning devices use excessive amounts of cleaning chemicals or they use chemicals that leave a heavy residue. After several cleanings with these chemicals, a crusty layer of hardened chemicals tends to accumulate in the backing and fibers of the carpet. Unlike brush agitators, agitator  33  of the present invention provides enough rigidity to break up and loosen the hardened chemicals without damaging the carpet.  
         [0056]    Another advantage of agitator  33  is that it is not required to rotate at high speeds. In the preferred embodiment, agitator  33  rotates at 850 revolutions per minute. This is substantially slower than many prior art brush agitators. The slower speed helps prevent damage to materials and does not require a large drive mechanism. A smaller drive mechanism allows device  100  to be smaller, lighter, and less expensive than prior art devices.  
         [0057]    As seen in FIG. 4A, flexible loops  34  may be attached to spindle  35  at an angle to the direction of rotation  52 . In other words, the mounting angle or angular orientation of each loop  34  may not be in line with the direction of rotation. This angular orientation produces a greater agitating action in fibers of carpet  50  as the tufts of fibers are forced to move along the side of each loop  34 . In addition, each row of loops may have a different angular orientation. For example, a first row of loops  54  may be angled to the left of direction of rotation  52  and a second row of loops  56  may be angled to the right of direction of rotation  52 . This alternating angular orientation further enhances the agitating action of agitator  33  as the fibers in the carpet are vibrated in two directions. Alternatively, as seen in FIG. 4B, first row of loops  54  may be aligned with the direction of rotation  52  with no angular orientation and second row of loops  56  may have an angular orientation.  
         [0058]    Returning to FIG. 3, a plurality of squeegee elements  37  may also be provided on spindle  35  for squeezing water and soil out of material  50  as agitator  33  rotates. This allows device  100  to remove more wastewater more quickly than prior art agitating devices. Having less liquid in material  50  allows the material to dry more quickly.  
         [0059]    Agitator  33  may also be used on a variety of cleaning equipment. Carpet cleaning devices, vacuums, and other devices utilize agitators. These devices may be easily adapted to utilize agitator  33  of the present invention to benefit from its many advantages.  
         [0060]    It has been found that prior art agitators have a tendency to become wound or entangled with large amounts of hair, animal fur, and other fibers that decrease the efficiency of the agitators. Returning to FIGS. 1 and 2, the present invention reduces this problem by providing a blade  102  in close relative proximity to agitator  33 . Blade  102  comprises a sharp edge that cuts long fibers as agitator  33  rotates. Preferably, blade  102  is substantially ⅛ th  of an inch away from agitator loops  34  to prevent impacts between the loops and the blade. Blade  102  preferably has a serrated edge but a smooth edge may also be used.  
         [0061]    The present invention also includes side rails  108  that are located on each side of agitator  33 . Side rails  108  slide on top of carpet  50  and maintain agitator  33  a predetermined height above the floor. This prevents agitator  33  from being damaged by hard objects that are below the predetermined height.  
         [0062]    An inlet duct  101  is provided for removing wastewater, soil, and debris. A rear lip  39  of the opening of duct  101  is preferably  20  thousandths of an inch above the floor and a front lip  60  of the opening of duct  101  is in contact with the floor. A negative pressure is created by vacuum motor  7  which draws water and debris out of carpet  50  upwards through duct  101 .  
         [0063]    Carpet cleaning devices often encounter heavy suds or foam that are caused by the residue of prior carpet cleaning operations. Many prior art carpet cleaning devices use excessive amounts of cleaning chemicals or they use poor quality cleaning chemicals. This can leave a chemical residue in carpets. When the residue is loosened and dissolved, heavy suds may form in carpet cleaning devices. Heavy suds reduce the efficiency of vacuum motors and may lead to clogging and overheating.  
         [0064]    Most prior art carpet cleaning devices require an operator of the device to manually spray de-foaming chemicals into the ducts and tanks of the device. The present invention solves the excessive suds problem by utilizing an automatic de-foaming device. When suds reach electrodes  9  and  10 , electricity is conducted between the electrodes that activates a solid state relay switch  26 . Switch  26  controls a solenoid valve  21  that is connected to a de-foaming chemical tank  22 . When valve  21  is open, the negative pressure created by vacuum motor  7  in inlet vacuum chamber  1  draws the de-foaming chemical through tube  121 , and nozzle  120 . Thus, suds are dissolved before going into basket  11  and tank  38 .  
         [0065]    This de-foaming design is simpler, less expensive to manufacturer, and requires less maintenance because no pump is needed to dispense the de-foaming chemical. The design is also automatic which eliminates the need for the operator to activate the de-foaming device. This reduces the risk of an inattentive operator damaging device  100  from an overload of suds and it also provides more efficient use of de-foaming chemicals as only enough is dispensed to eliminate the suds present in duct  101 .  
         [0066]    As wastewater and debris are vacuumed up duct  101 , they are drawn into a basket  11  with a disposable bag  23 . Bag  23  comprises a plastic mesh or nylon that strains the wastewater and collects large debris. This prevents larger objects from falling into tank  38  where the objects may be ingested by a wastewater pump  20 . Basket  11  is perforated with holes  104  on the lower surfaces of basket  11  to allow water to drain from basket  11 . A plurality of holes  106  are provided in the upper surfaces of basket  11  to allow air to be vacuumed from basket  11 . The design of basket  11  provides an efficient means for separating air, wastewater and debris. The overall efficiency of device  100  is increased by efficiently separating and controlling the air, wastewater, and debris.  
         [0067]    Preferably, basket  11  and may be removed from device  100  to enable an operator to remove and replace bag  23 . This is accomplished by pivoting basket  11  around a detachable hinge  114 . However, it is important that an adequate seal be provided when basket  11  is in place to prevent substantial loss of vacuum pressure.  
         [0068]    Once wastewater filters through bag  23  and basket  11 , it drains into tank  38 . Tank  38  is provided with electrodes  24  and  61 . When the water level in tank  38  contacts both electrodes  24  and  61 , an electrical circuit is completed which signals solid state relay switch  25  to activate wastewater pump  20 . The wastewater pump  20  pumps wastewater out through wastewater line  19 .  
         [0069]    Once the water level in tank  38  looses contact with electrodes  24  and  61 , relay switch  25  deactivates wastewater pump  20 . A logic circuit may be provided for allowing pump  20  to operate for a predetermined interval before it is deactivated. This allows pump  20  to remove most of the water in tank  38 .  
         [0070]    When pump  20  is deactivated, some amount of wastewater is preferably allowed to flow backwards through the pump to clear the pump of sand and other debris that could otherwise accumulate. This is an advance over prior art carpet cleaning devices that allow debris to accumulate in wastewater pumps. The accumulated debris causes wear that reduces efficiency and eventually causes the pump to fail. In the present invention, back flushing is accomplished by allowing gravity and vacuum pressure to pull some amount of wastewater back through pump  20 .  
         [0071]    Once air has been vacuumed through basket  11  it passes through screen  62 , return vacuum chamber  12 , and return air tube  67 . The air is then forced through vacuum motor  7  and channeled down exhaust duct  110  towards duct  69 . A gap is provided between ducts  110  and  69  to allow air circulation. It has been found that gaps between ducts  69  and  110  induce turbulence and a negative pressure that draws air from the internal cavity of device  100 . This creates air circulation that cools the motors and electrical components.  
         [0072]    In the preferred embodiment, skids  112  are provided on the rear surface of device  100 . Skids  112  provide structural rigidity that supports the rear surface of device  100  when subjected to vacuum pressure. Skids  112  also provide a surface upon which device  100  may slide when being pulled over a step.  
       SUMMARY  
       [0073]    It may now be seen from the above description that the present invention provides a novel carpet cleaning device. The device comprises a number of components and features that provide a number of advantages and improvements over the prior art. For example, the present invention is smaller, lighter, and less expensive to manufacture than prior art carpet cleaning devices. The present invention is also less destructive to carpets and material, uses less water, and is able to remove more soil than prior art devices.  
         [0074]    Although the description above contains many specifications, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. Thus, the scope of the invention should be determined by the appended claims and their legal equivalents rather than by the examples given.