Abstract:
A tire and wheel washing apparatus for cleaning exterior surfaces of tire and wheel combinations of a vehicle as the vehicle is conveyed past the apparatus. The tire washing apparatus preferably includes a longitudinally-extending cleaning element rotating about a shaft having a longitudinal axis extending generally parallel to the conveyed direction of the vehicle. The cleaning element is adapted to clean the exterior surfaces of tire and wheel combinations of the vehicle, and preferably has an undulating cleaning surface with a repeating pattern of a peak portion followed by a valley portion. Preferably, an intermediate portion located between the peak and valley portions has a substantially curvilinear edge surface.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The invention relates to an improved vehicle washing apparatus for use in automatic car washes which clean the outside of the vehicle wheels and tires, and rocker panels. 
         [0002]    In the context of automatic car washes, various vehicle wheel and/or tire washing devices are known. (Here reference to the “tire” is to the rubber portion of the wheel/tire combination, while reference to the “wheel” is to the metal “rim” portion mounted to the vehicle axle. The tire is usually attached to the wheel in typical fashion using a bead sealer.) One known device for washing the exterior surfaces of the wheel and tire combination employs a stationary frame  19  which may be bolted to the ground, pivotably attached to moveable frame members  22  connected to a rotating brush frame  16 . Rotating brush frame supports brush axis  14  about which rotating brushes  12  spin. Brush axis  14  has a longitudinal axis aligned with the vehicle length, as shown in  FIGS. 1-1A . As the vehicle to be washed is conveyed past the rotating brush, with tires  20  in conveyor track  26 , cleaning fluid from hose  18  may be discharged onto the outside of its wheels/tires and/or the rotating brush, and the rotating brush then contacts and cleans the outside surfaces of the tire  20  and wheel  23 . Larger diameter rotating brushes may also clean the rocker panels of vehicles, as well. (When reference to tire and wheel cleaning is made here, it is understood that cleaning of the rocker panel, where applicable, is also meant to be included.) Upper portions of the vehicle may be washed with overhanging equipment carried by frame  27 , for example. 
         [0003]    Still referring to  FIGS. 1  and IA, shock absorber  17  attached to support  22  may be used to absorb contact of the wheel and tire against the brush rotating on longitudinal axis  14  carried by frame  16 . Support  22  may be permitted to pivot relative to frame  16  to enable rotating brushes  12  to be moved into pressurized contact with wheels and tires of cars having various “stances” or widths between the tires. Known devices accomplish this motion either through inclined surfaces and gravity movement, pneumatics, or through the use of biasing springs which urge support  22  toward the wheel and tire; surface inclination (in the case of gravity movement) or the force of the springs or pneumatics may be manipulated as desired depending upon the preference of the owner or manufacturer. 
         [0004]    Given the length of the rotating brush (a typical length is 8 feet, for example), the speed of the conveyor and the tire diameter, typical conveyor car washes should enable one complete tire revolution or more during the wash. This means the rotating brush will only have relatively limited and brief contact with each tire portion to be cleaned. 
         [0005]    Known rotating brushes are either entirely uniform in diameter along their length, or they are “poodle” type brushes. Poodle brushes have a repeating pattern of a squared-off, brush portion length with a constant diameter followed by a squared-off, brush portion length in which shorter brush bristles or filaments (or cloth or foam) are present, as shown in  FIGS. 1-5 . There are disadvantages with either type of known rotating brush, as now discussed. 
         [0006]    Known uniform-diameter rotating brushes do not effectively clean the exterior surfaces of both wheels and tires. The reason is that modern wheels/tires include wheels with largely varying inward slopes and crevices, and may also have wheels with large distance variations between the vertical wheel surface and a fixed interior tire point such as its true center or centroid, in the case of a concave wheel. In other words, some wheels slope so that when viewed from the side, the wheel cannot be seen. Conversely, some wheels slope outwardly. Examples of different wheel types are shown in  FIGS. 11-15 . A uniform-width rotating brush whose axis is aligned with the vehicle length cannot effectively clean substantially all exterior wheel/tire portions for wheels/tires of different vehicles, because the cleaning portions of the rotating brush either do not touch all such portions, or do not contact them with sufficient force/cleaning penetration. 
         [0007]    “Poodle”-type rotating brushes such as shown in prior art  FIGS. 1-5  provide better cleaning than uniform-width rotating brushes, but still suffer from disadvantages. Known poodle brushes have filament ends that are squared off, not curvilinear. The valley diameter range for these brushes is believed to have been about 6-8 inches, while the peak diameter range is believed to have been about 11-13 inches. Further, this squared-off shape has been found less effective in cleaning, particularly in cleaning the exterior surfaces of wheels that inwardly slope and/or have significant crevices. Further, past stationary, rotating brushes, whether uniform-width or poodle type, have employed filaments (or cloth or foam elements) that are either too short to provide proper cleaning penetration and/or have an insufficient density providing insufficient cleaning penetration and/or apply insufficient force to be cleaned to provide satisfactory cleaning. 
       SUMMARY OF THE INVENTION 
       [0008]    The objects mentioned above, as well as other objects are solved by the present invention, which overcomes disadvantages of prior rotating brushes for cleaning the outside surfaces of tires/wheels, while providing new advantages not believed associated with such known brushes. 
         [0009]    In a preferred embodiment of the present invention, a tire washing apparatus is provided for cleaning exterior surfaces of tire and wheel combinations of a vehicle as the vehicle is conveyed past the apparatus. The tire washing apparatus preferably includes a cleaning elements, such as a brush made of filaments, cloth or foam, rotating about a shaft having a longitudinal axis extending generally parallel to the conveyed direction of the vehicle. The cleaning elements are adapted to clean the exterior surfaces of tire and wheel combinations of the vehicle, and preferably includes an undulating cleaning surface with a repeating pattern of a peak portion followed by a valley portion, with an intermediate portion located between the peak and valley portions having a substantially curvilinear edge surface. In a particularly preferred embodiment, a preferred range for the diameter of the peak portion is about 14-18 inches, while a preferred range for the diameter of the valley portion is about 9-14 inches. 
         [0010]    In alternative embodiments, undulating cleaning element may be made of filaments, cloth fingers or closed cell foam, or combinations thereof In one preferred embodiment, the undulating surface employs filaments having a density range of about one-half pound/per linear inch. A preferred shaft diameter is about 1½-2½ inches, a particularly preferred shaft diameter is 1⅞ inches, and a preferred shaft rotational speed is about 100-175 RPMs. The filaments are preferably made of polyethylene, and are preferably generally X-shaped in cross-section, with a preferred specific gravity of between about 0.90-0.93. The filaments preferably have a thickness in the range of about 15-50 thousandths of an inch. 
         [0011]    The undulating cleaning element may be a rotating brush with either separate parallel strips, or a spiral wound strip. 
         [0012]    In one preferred embodiment, the undulating cleaning elements exert a force of about 15-40 pounds of force over about an 8-foot long brush length on the tire and wheel combinations being cleaned. 
       DEFINITION OF CLAIM TERMS 
       [0013]    The following terms are used in the claims of the patent as filed and are intended to have their broadest meaning consistent with the requirements of law. Where alternative meanings are possible, the broadest meaning is intended. All words used in the claims are intended to be used in the normal, customary usage of grammar and the English language. 
         [0014]    “Undulating” means a cleaning element, such as a rotating filament-filled brush, or a brush made of other materials such as cloth or closed cell foam, that is generally wave-shaped. The general wave shape may be sinusoidal-shaped or generally so, sawtooth-shaped or generally so, or generally sinusoidal-shaped or generally sawtooth-shaped with flattened wave peaks, etc., provided that the brush diameter has a repeating pattern of a peak portion with a substantial diameter followed by a valley portion having a smaller diameter. Preferably, an intermediate edge between the peak and valley portions is curvilinear, not squared-off, in shape. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    The novel features which are characteristic of the invention are set forth in the appended claims. The invention itself, however, together with further objects and attendant advantages thereof, can be better understood by reference to the following description taken in connection with the accompanying drawings, in which: 
           [0016]      FIG. 1  is a side and top perspective view of a prior art, stationary machine frame supporting a longitudinally-extending, poodle-type brush rotating about its longitudinal axis, for cleaning the outer surface and rim of a tire; 
           [0017]      FIG. 1A  is an enlarged view of a portion of the device shown in FIGS.  1  and  2 - 5 ; 
           [0018]      FIG. 2  is a perspective view of a portion of the prior art rotating, poodle-type brush of  FIG. 1A ; 
           [0019]      FIG. 3  is a top schematic view of a portion of the prior art rotating brush shown in  FIG. 1A , along reference line  3 - 3 ; 
           [0020]      FIG. 4  is a sectional view taken along reference line  4 - 4  of  FIG. 3 ; 
           [0021]      FIG. 5  is a side view of the rotating brush shown in  FIG. 1A ; 
           [0022]      FIG. 6  is a perspective view of one preferred embodiment of the rotating brush of the present invention; 
           [0023]      FIGS. 7-9  are partial side views of various preferred embodiments of the rotating brush of the present invention; 
           [0024]      FIGS. 10A-10E  are side, schematic views of various tire/rim sizes; 
           [0025]      FIG. 11  is a top and side perspective view of a conventional tire and wheel; 
           [0026]      FIG. 11A  is a sectional view along reference line  11 A- 11 A of  FIG. 11 ; and 
           [0027]      FIGS. 12-15  are top and side perspective views of various conventional tires with fitted rims, showing a planar view of wheel contact with the rotating brush of the present invention. 
       
    
    
       [0028]    The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention. In the drawings, like reference numerals designate corresponding parts throughout the several views. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0029]    Set forth below is a description of what are believed to be the preferred embodiments and/or best examples of the invention claimed. Future and present alternatives and modifications to this preferred embodiment are contemplated. Any alternatives or modifications which make insubstantial changes in function, in purpose, in structure, or in result are intended to be covered by the claims of this patent. 
         [0030]    Referring now to  FIGS. 6-9 , the subject of the present invention is the “undulating” brush  24 . Undulating brush  24  may be effectively used in a device such as shown in  FIGS. 1-2 . In contrast to known prior art rotating brushes, undulating brush  24  includes a repeating pattern of a “peak” portion  24 A, and a “valley” portion  24 B, in which the peak and valley portions preferably have dimensional ranges as specified here for cleaning the (automobile and small truck) tire sizes addressed here. (In order to clean larger tire sizes than those mentioned here, this will of course require undulating brushes with larger dimensions.) 
         [0031]    Using an “undulating” rotating brush as described here, it was surprisingly discovered that superior cleaning characteristics were obtained, as opposed to prior known rotating brushes as described above. (It is noted that satisfactory cleaning also requires the use of an appropriate chemical formulation that is properly applied to the entire outside surface of the outside tire portion and wheel surfaces to be cleaned.) 
         [0032]    It was found that the use of an undulating rotating brush with a curvilinear intermediate edge between the peak and valley portions works particularly well. It appears that rotating brushes with squared-off intermediate portions do not clean as well. 
         [0033]    It was also found that the density of the cleaning elements of the undulating rotating brush, as well as the pressure they apply on the surfaces to be cleaned, also facilitate superior cleaning, as described below. 
         [0034]    Referring to  FIGS. 10A-10E , typical tire OD/IDs (in inches) are shown, of: 24/16 ( FIG. 10A ); 25/20 ( FIG. 10B ); 16/8 ( FIG. 10C ); 28.5/16.5 ( FIG. 10D ); and 32/19 ( FIG. 10E ). For wheels in this size range, it was found that the following diameter ranges for a brush diameter measured at the peak and valley portions of the undulating brush  24  of the present invention are preferred: for tire sizes for automobiles and small trucks in the tire outside diameter range of 24-32 inches, preferred diameter ranges for diameter Dp (see  FIG. 7 ) measured at peak portion  24 A are about 14-18 inches, while preferred diameter ranges for diameter Dv (see  FIG. 7 ) measured at valley portion  24 B are about 9-14 inches. (If Dp is 14, Dv is preferably about 9; if Dp is 18, Dv is preferably about 14; other corresponding Dp and Dv numbers may be proportionally derived.) 
         [0035]    The undulating brush of the present invention may take various shapes and sizes, such as sinusoidal ( FIG. 7 ) or modified sinusoidal waves, flattened sine waves ( FIG. 8 ), sawtooth waves ( FIG. 9 ), etc., provided that there is an “undulating” characteristic to the brush length (i.e., peak portions followed by valley portions). The common characteristic of these undulating brush shapes is that the cleaning element peak and valley diameters and lengths should be sufficient to provide desirable cleaning. 
         [0036]    The cleaning surface of the rotating brush may be made of filaments, cloth, or closed cell foam. If filaments are used, they may be “X-shaped” in cross-section, have a thickness in the range of about 15-50 thousandths of an inch, and are made of low density polyethylene. (Polypropylene or nylon could be used, but these are harder materials which may scratch the vehicle exterior and nylon may not be economical to use.) 
         [0037]    The shaft carrying the rotating brush preferably has a smaller diameter conventional such shafts (about 1½-1⅞ inches, for example, instead of 2¼-2½ inches). (As the shaft diameter decreases, longer filaments may be used for the same outside brush diameter.) The present invention is currently believed to preferably use a filament density of about one-half pound/linear inch of length measured at the core/shaft, whereas prior art brushes are believed to employ lower filament densities of roughly about one-half or three-quarters of this preferred density. In other words, for an  8 -foot long brush, the undulating brush of the present invention may have about  48  pounds of polyethylene filament. This density may vary depending upon the type of material and the length of cleaning elements (e.g., filaments) selected. 
         [0038]    Sufficient force must also be exerted on surfaces to be cleaned by the rotating brush to provide sufficient penetration into the surfaces of the tire and wheel to be cleaned. This force is a function of the distances of the shaft from the wheel/tire to be cleaned, as well as the shaft RPM. A faster shaft RPM actually results in less brush penetration into the surfaces to be cleaned. A preferred range is currently believed to be about 100-175 RPMs, with about 15-40 pounds of force exerted over the (e.g.) 8-foot rotating brush length. Shaft rotational speed and overall brush diameter can substantially influence the distance between the brush cleaning element ends and the surfaces to be cleaned. (The higher the RPM or the larger the overall brush diameter, the greater the force needed, i.e., the brush can be “tuned” by varying the shaft distance and/or the RPMs for best cleaning results.) 
         [0039]    Referring to  FIG. 7 , in a particularly preferred embodiment, it was found that satisfactory cleaning was achieved when using about 15-50 thousandths of an inch, X-shaped polyethylene filaments with a peak wave diameter Dp at peak  24 A of about 18 inches and a valley height diameter Dv at valley  24 B of about 14 inches, that exerted about 15-35 pounds of force exerted on the 96-inch long brush as measured by a Grainger push-pull gauge scale. Based on visual observation, assuming adequate cleaning chemical coverage, satisfactory cleaning was achieved over roughly 90-99 percent of the exterior surfaces of the tire and wheel, as compared to about 70 percent for a comparable uniform-width brush and about 80 percent for a comparable poodle brush. 
         [0040]    Referring to  FIG. 8 , in a particularly preferred embodiment, the length of the peak portion Lp is preferably longer than the length of the valley portion Lv, such as in about a 1-2:1 ratio. In alternative, less-preferred embodiments, Lv may be about equal to or less than Lp. 
         [0041]    While the preferred embodiment of the invention has been discussed above with regard to undulating, rotating brush elements made of filaments, those of ordinary skill in the art will appreciate that the foregoing inventive principles may be applied with brush elements made of cloth or closed cell foam, as is well known in the art to be used. It will also be understood that the undulating, rotating brush of the present invention may include parallel strips, or a spiral wound strip, and may include individually drawn brush elements or tufts, or stapled brush elements. 
         [0042]    The above description is not intended to limit the meaning of the words used in the following claims that define the invention. Persons of ordinary skill in the art will understand that a variety of other designs still falling within the scope of the following claims may be envisioned and used. It is contemplated that future modifications in structure, function, or result will exist that are not substantial changes and that all such insubstantial changes in what is claimed are intended to be covered by the claims.