Abstract:
A cleaning apparatus is disclosed for extracting a liquid from a surface. The apparatus includes at least one extraction head that has at least one aperture that is facing the surface to be cleaned. The vacuum cleaner includes a vacuum pathway situated between the at least one extraction head and a riser that is connected to a vacuum motor. The internal surfaces of the vacuum pathway are smooth and the vacuum pathway has certain dimensions and orientations that optimize the extraction of a liquid from a surface.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application No. 61/535,684 entitled “VACUUM PATHWAY IN A ROTARY HEAD CLEANER” and filed on Sep. 16, 2011 for Edward E. Durrant et al., which is incorporated herein by reference. 
     
    
     FIELD 
       [0002]    This disclosure relates to floor cleaning devices and more particularly relates to vacuum pathways of cleaning devices. 
       BACKGROUND 
       [0003]    The cleaning of carpet, to remove stains, dirt, etc., is achieved using various different methods, including dry-cleaning techniques, wet-cleaning techniques, and vacuuming. Wet-cleaning, or steam cleaning as it is commonly known, is a technique that involves spraying heated water onto carpet, agitation of the carpet, and extraction of the heated water. The extraction step may require several passes with a cleaning tool to extract water from the carpet before allowing the carpet to air-dry. 
         [0004]    Unfortunately, many of the conventional cleaning tools used to extract water from the carpet are bulky, cumbersome and inefficient. Thus, even after several passes with the cleaning tool, a substantial amount of water remains in/on the carpet and the carpet must be left to air-dry for many hours. Furthermore, motors that provide the vacuum suction to the cleaning tool are often located remotely, and therefore suffer from a loss of suction power over the length of the suction hose. 
       SUMMARY 
       [0005]    From the foregoing discussion, it should be apparent that a need exists for an apparatus that extracts a greater amount of water from surfaces than conventional vacuum cleaning systems. Beneficially, such an apparatus would include a vacuum pathway optimized for efficiently extracting a liquid. 
         [0006]    The subject matter of the present application has been developed in response to the present state of the art, and in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available cleaning systems. Accordingly, the present disclosure has been developed to provide an apparatus for cleaning surfaces that overcome many or all of the above-discussed shortcomings in the art. 
         [0007]    The present disclosure relates to a vacuum cleaner that includes at least one extraction head that has at least one aperture that is facing the surface to be cleaned. The vacuum cleaner includes a vacuum pathway situated between the at least one extraction head and a riser that is connected to a vacuum motor. The vacuum pathway may have a cross-sectional area in the range of between about 0.8 square inches and 7.0 square inches. 
         [0008]    In one embodiment, the length of the vacuum pathway is in the range of between about 0.25 and 3.0 feet. In another embodiment, the length of the vacuum pathway is in the range of between about 0.75 feet and 2.0 feet. In yet another embodiment, the length of the vacuum pathway is about 1 foot. The internal surfaces of the vacuum pathway may be smooth and the pathway may include at most two 90 degree bends. 
         [0009]    The vacuum pathway may also include a tube that is coupled with and disposed between the extraction head(s) and a vacuum chamber. The vacuum chamber is connected with a plenum chamber, which is in turn connected with the riser. The ratio of the cross-sectional area of the vacuum pathway in the plenum chamber to the summed cross-sectional area of all the apertures in the at least one extraction head is about 5 to 1. In another implementation, the ratio of the cross-sectional area of the vacuum pathway in the plenum chamber to one of the cross-sectional areas of the tube, vacuum chamber, or riser is in the range of between about 1.7 and 1 to 1. The vacuum cleaner may also include a rotary head that includes multiple extraction heads. The vacuum cleaner may also include an evacuation tank where the extracted liquids are temporarily contained. 
         [0010]    Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present disclosure should be or are in any single embodiment of the invention. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the subject matter disclosed herein. Thus, discussion of the features and advantages, and similar language, throughout this specification may, but do not necessarily, refer to the same embodiment. 
         [0011]    Furthermore, the described features, advantages, and characteristics of the disclosure may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize that the subject matter of the present application may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the disclosure. 
         [0012]    These features and advantages of the present disclosure will become more fully apparent from the following description and appended claims, or may be learned by the practice of the disclosure as set forth hereinafter. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    In order that the advantages of the disclosure will be readily understood, a more particular description of the disclosure briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the disclosure and are not therefore to be considered to be limiting of its scope, the disclosure will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which: 
           [0014]      FIG. 1  is a diagram illustrating one embodiment of a rotary head cleaning machine; 
           [0015]      FIG. 2  is a perspective view diagram illustrating one embodiment of the rotary head; 
           [0016]      FIG. 3  is a perspective view diagram illustrating one embodiment of the extraction head; 
           [0017]      FIG. 4  is a perspective view diagram illustrating another embodiment of the rotary head; 
           [0018]      FIG. 5  is a perspective view diagram illustrating one embodiment of a vacuum path of the machine; 
           [0019]      FIG. 6  is a side view diagram illustrating another embodiment of the vacuum path; and 
           [0020]      FIG. 7  is a side view diagram illustrating yet another embodiment of the vacuum path. 
       
    
    
     DETAILED DESCRIPTION 
       [0021]    Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment. 
         [0022]    Furthermore, the described features, structures, or characteristics of the disclosure may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments of the disclosure. One skilled in the relevant art will recognize, however, that the disclosure may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the disclosure. 
         [0023]      FIG. 1  is a diagram illustrating one embodiment of a rotary head cleaning machine  100  (hereinafter “machine  100 ”). The machine  100 , in one embodiment, includes a housing  102  that forms a supportive base for a rotary motor, a vacuum motor, an evacuation tank  108 , and an evacuation pump. A pair of wheels  110  and a handle  112  may also be connected to the housing  102 . The housing  102 , in a further embodiment, is configured having a bell shape to form a protective cover around a rotary head which will be described in greater detail below with reference to  FIGS. 2-3 . 
         [0024]    The housing  102  is formed of a rigid material capable of supporting the rotary motor, vacuum motor, evacuation tank, wheels  110 , and handle  112 . Examples of a rigid material capable of use in the present disclosure include, but are not limited to, aluminum, aluminum alloys, steel alloys, other metal alloys, and rigid plastics. The rotary motor, in one embodiment, is an electrical motor capable of generating a force sufficient to turn the rotary head. In one embodiment, the rotary motor is a ¾ hp motor. The rotary motor  104  may be connected with a gearbox that transfers the rotary force of the rotary motor through a driveshaft to the rotary head. 
         [0025]    The evacuation tank  108  is a storage tank for holding liquid that is extracted from flooring via the extraction heads. The evacuation tank  108  may be formed as an integral piece of the housing  102 , or alternatively as a separate component that is attached to the housing  102 . 
         [0026]    The machine  100  may be powered via an electrical cord for accessing 110 V or 220 V electricity on the premises. Additionally, the machine  100  may be powered by a generator that may be moveable to the premises or which may be located on the truck. 
         [0027]    In one embodiment, the electrical characteristics of the machine  100  are selected to keep the electricity usage from exceeding an amount that might exceed the capacity of the power supply. For instance, the rotary motor and the vacuum motor are preferably selected to have a combined current usage within a selected threshold level. In a further embodiment, the evacuation pump is also selected to combine with the rotary motor and the vacuum motor to maintain a current usage within the selected threshold. 
         [0028]    In one embodiment, the selected threshold is within the range of between about 10 and about 22 amps. In a further embodiment, the selected threshold is within the range of between about 12 and about 18 amps. In a more specific embodiment, the selected threshold is about 15 amps. 
         [0029]    In order to stay within the threshold current usage, power saving configurations may be used. For instance, the heads  201  may be made of a low friction material. In one embodiment, the friction reducing material is polytetraflouroethylene. 
         [0030]    In a further embodiment, the machine  100  may be powered by multiple power cords for plugging into different phases of the power source. An indicator  114  positioned on the handle may identify when the multiple power cords are plugged into different phases or electrical circuits. 
         [0031]      FIG. 2  is a perspective view diagram illustrating one embodiment of the rotary head  200 . As described above, the rotary head  200  is coupled with extraction heads  201 . The depicted embodiment demonstrates a rotary head  200  having five extraction heads  201 . Alternatively, the rotary head  200  may include more or less extraction heads  201  depending on the type of flooring to be cleaned. 
         [0032]    The rotary head  200 , in one embodiment, includes at least one spray nozzle  202 . Alternatively, the rotary head  200  may be configured with multiple spray nozzles  202 , each fluidly coupled with a cleaning solution source. The cleaning solution may be a pressurized liquid such as water or a mixture of water and a cleaning agent. The cleaning solution is delivered via a conduit that passes through a hollow driveshaft that connects a gearbox with rotary head  200 . The hollow driveshaft will be discussed in greater detail below with reference to  FIG. 4 . 
         [0033]    Concentric with the hollow driveshaft  204  is a vacuum chamber  206  having a plurality of inlets  208 . The vacuum chamber  206 , in one embodiment, may be sub-divided into smaller chambers. The smaller chambers are each fluidly coupled with the inlets  208 . Alternatively, the vacuum chamber  206  may be configured as a single chamber having multiple inlets  208 . Each inlet  208  is connected via a hose (not shown) with an outlet  210  of an extraction head  201 . The hoses are not depicted here so as to not obstruct the perspective view of the rotary head  200 . 
         [0034]      FIG. 3  is a perspective view diagram illustrating one embodiment of the extraction head  201 . The extraction head  201 , or vacuum head, is shown here for removing liquid from fabric such as carpet. The extraction head includes a base plate  302  with one or more openings which function as extraction nozzles  304  to remove the liquid from the fabric. The base plate  302  is elongated and may be coated with an anti-friction coating to more easily move through a carpeted surface. Examples of coatings suitable for use in the present disclosure include, but are not limited to, polytetraflouroethylene (PTFE). In a further embodiment, various components of the extraction head  201  may be formed of PTFE other low-friction polymers, metals, or composites. 
         [0035]    Extending from the base plate  302  is a guide bar  306 . The guide bar  306  extends “forward” from the base plate  302  to guide the extraction head  201  over objects in the carpeted surface. For example, because the guide bar  306  extends outward in front of the base plate  302 , the guide bar will make contact with objects in the carpeted surface before the base plate  302  as the extraction head  201  moves through a carpeted surface. As depicted, the guide bar  306  is configured with a leading bar  308  positioned above the plane of the base plate  302 . As such, as the leading bar  308  encounters a carpet transition bar, for example, the incline of the guide bar  306  will “ride” up the carpet transition bar and consequently lift the base plate  302  over the carpet transition bar. In other words, the guide bar  306  protects the base plate  302  and prevents the extraction head  201  from catching on objects in the carpeted surface. 
         [0036]    As discussed above, the extraction head  201  also includes the outlet  210 . The outlet  210  is fluidly coupled with the plurality of extraction nozzles  304 , and configured to attach with a hose that connects with the vacuum chamber described above with reference to  FIG. 2 . Also depicted here is a mounting point  310  for connecting the extraction head  201  with the rotary head of  FIG. 2 . The mounting point  310 , in one embodiment, is an aperture through which a bolt or other fastening device may pass to secure the extraction head  201  to the rotary head. 
         [0037]      FIG. 4  is a perspective view diagram illustrating another embodiment of the rotary head  200 . The rotary head  200  is driven by a hollow driveshaft disposed between the gearbox and the rotary head  200 . The driveshaft transfers the rotary force from the rotary motor, via the gearbox, to the rotary head  200  so that the rotary head  200  rotates about the driveshaft. The driveshaft connects to the rotary head  200  at the center of the hub  402 . 
         [0038]    The hub  402  includes, in this embodiment, multiple vacuum chambers  404  positioned radially around a center channel  406 . Each of the vacuum chambers  404  is fluidly coupled with an inlet  408  and the evacuation tank  108  of  FIG. 1 . As such, a partial vacuum applied to the evacuation tank  108  causes a partial vacuum in the vacuum chambers  404  which thereby draws liquid through a hose connecting the inlet  408  to the outlet  410  of an extraction head  412 . 
         [0039]    Referring jointly now to  FIGS. 5 and 6 ,  FIG. 5  is a perspective view diagram illustrating one embodiment of a vacuum path of the machine  500 , and  FIG. 6  is a side view diagram illustrating another embodiment of the vacuum path. As used herein, the term “vacuum path” refers to the pathway along which air and extracted fluid move under when a partial vacuum is introduced in the evacuation tank. The vacuum path, as described above with reference to the rotary head, starts at the extraction heads which are coupled with vacuum chambers  501  in the rotary head.  FIG. 5  illustrates a plenum  502  coupled with the top of the rotary head and the vacuum riser  504 . The plenum  502  forms a channel through which air and extracted fluid may pass. The plenum  502  is formed having smooth surfaces and rounded edges to minimize disruptions to the flow of air and extracted fluid. 
         [0040]    The plenum  502  may be formed of a cast metal so that the interior surfaces that form the vacuum pathway are very smooth, as opposed to a machined part that may have ridges resulting from a milling process. Alternatively, the plenum may be formed of a smooth composite or rigid polymer material. 
         [0041]    The vacuum path  604 , as depicted in  FIG. 6 , rises from the extraction heads  201  to the vacuum chambers, up through the plenum  502 , over to the vacuum riser  504 , and then to the evacuation tank. In one embodiment, the length of the vacuum path  604  is in the range of between about 0.25 and 3 feet. In a further embodiment, the length of the vacuum path  604  is in the range of between about 0.75 and 2 feet. In yet another embodiment, the length of the vacuum path is in the range of between about 0.8 feet and 1 foot. The total height the extracted fluid is lifted via vacuum, therefore, is minimized and therefore less power is required to extract fluid from the floor, and extracted fluid performance increases. 
         [0042]    The extraction capability of the machine  500  is increased by minimizing the length of the vacuum path  604 , and the number of turns or obstacles in the vacuum path  604 . As depicted, starting at the vacuum chamber  501 , the vacuum path  604  includes two “turns”  606 . As used herein, the term “turn” refers to a change in direction of the vacuum path  604 . Therefore, the depicted vacuum path has a turn from a vertical to a horizontal path when entering the plenum  502 , and a turn  606  from the plenum  502  to the vacuum riser  504 . Beveled or sloped edges at the turns  606  will further reduce obstructions and improve air and extracted fluid flow. In other words, smoothing out the vacuum path  604  improves air and extracted fluid flow. As such the machine  500  is capable of extracting substantial amounts of cleaning solution from the floor. This greatly reduces the drying time of the floor. 
         [0043]      FIG. 7  is a side view diagram illustrating one embodiment of the vacuum path  700 . The flow of air and liquid, as induced by the vacuum motor, is generally indicated here by arrows  702 . For clarity, a single extraction head  704  is depicted, however, it is to be understood that multiple extraction heads  704  may be used. As described above, the extraction head  704  has multiple openings or nozzles in the floor facing surface of the extraction head for extracting liquid from the floor. In one example, the extraction head  704  includes 10 nozzles or openings, and the machine  100  includes 5 extraction heads  704 . Each opening or aperture may have a diameter of about 5/32 inch. Alternatively, the size of the opening may be in the range of between about 1/32 and 11/32 inch. 
         [0044]    Under the above example of a 5/32 inch opening, the total cross-sectional area for extracting fluid of 50 openings (10 openings per extraction head  704 , and 5 extraction heads coupled with the rotating head of  FIG. 2 ) is about 0.958 square inches. The fluid pathway length (or the distance fluid travels through the extraction head) is about 2.5 inches. 
         [0045]    The extraction head  704  is fluidly coupled with an inlet tube  706  and the hub or rotating vacuum chamber  708 . The inlet tube  706 , in one example, is a smooth flexible tube with minimized obstructions. In other words, the inlet tube  706 , in one embodiment, is not reinforced with ribbings that perturb and disrupt the air/liquid flow  702 . In one embodiment, the cross-sectional area of all inlet tubes  706  is in the range of between about 2.5 and 3.5 square inches. In a further embodiment, the total cross-sectional area of the inlet tubes  706  is about 3.041 square inches. The fluid pathway length of each inlet tube  704  is about 5.5 inches. 
         [0046]    The hub  708 , as described above, transfers rotating power from a motor to the rotating head and also operates to transfer fluid from the floor to the waste tank. The hub  708  has a chamber that fluidly connects the inlet tubes  706  with the plenum. The chamber of the hub  708 , in one embodiment, has a cross-sectional area in the range of between about 3.0 and 4.5 square inches. In a further embodiment, the cross-sectional area of the hub  708  is about 3.675 square inches. The fluid pathway length of the hub  708  is about 2.25 inches. 
         [0047]    The plenum  710  fluidly connects the hub  708  to the riser  712  of standpipe. The plenum  710 , in one embodiment is formed with an interior passageway having smooth interior surfaces so as to not disrupt or perturb the flow of air and liquid through the plenum  710 . The cross-sectional surface area of the interior passageway of the plenum  710  is, in one example, in the range of between about 4.5 and 5.5 square inches. In a further example, the cross-sectional area of the interior passageway of the plenum  710  is about 5.089 square inches. The fluid pathway length of the plenum  710  is about 4.5 inches. 
         [0048]    The riser  712  fluidly connects the plenum  710  with the waste tank described above with reference to  FIG. 1 . The riser  712  may be a hollow pipe having a diameter in the range of between about 2 and 3 inches. In a further example the riser  712  has a diameter of about 2.5 inches, and subsequently, an interior cross-sectional area of about 4.430 square inches. The riser  712  has a fluid pathway length of about 9.5 inches. 
         [0049]    The total length of the fluid pathway or vacuum pathway  702  across the extraction head  704 , inlet tube  706 , hub  708 , plenum  710 , and riser  712  is about 24 inches. As described above, after the fluid enters the hub  708 , the vacuum pathway has only two “turns” before reaching the waste tank. The first turn is a substantially 90 degree turn from the hub to the plenum  710 . The second turn is a substantially 90 degree turn from the plenum to the riser  712 . Therefore, the fluid is changes direction a maximum of about 180 degrees. This feature decreases the disruption of the fluid flow because turns or obstructions function to disrupt fluid flow and therefore decrease efficiency. 
         [0050]    The ratio of cross-sectional area between the plenum  710  and the total cross-sectional areas of nozzles is about 5:1, while the ratios of the plenum  710  with the remaining components is in the range of between about 1.7 and 1. By maintaining a ratio between 1.7 and 1 between the plenum  710  and either the inlet tubes  706 , hub  708 , and riser  712  the fluid flow disruption is minimized because fluid is not being forced through substantially smaller pathways as it travels to the waste tank. 
         [0051]    The present disclosure may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the disclosure is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.