Abstract:
A brush for a car wash has radial arrays of fingers cut from flat sheets of closed cell foam. The finger arrays are stacked atop each other with interposed spacer discs, bonded together to form sections of the brush. A top brush has a center section core formed by the spacer discs of a larger diameter than two smaller core diameter ends to provide a larger diameter center section core caused to roll when encountering a vehicle surface to pass over the some without damage, and smaller core diameter end sections able to accommodate antennas with less bending. The fingers of the scrubbing section of the brush are short, no longer than and are held sufficiently stiffly to support the brush on the side rails of pickup cargo beds at a high enough height as to avoid finger contact with the cargo bed bottom surfaces.

Description:
BACKGROUND OF THE INVENTION 
   This invention concerns car wash brushes and more particularly horizontal top brushes which extend across the top of a car or vertical side brushes which are positioned on each side of the car body. These brushes are rotated as they pass over the upper or side surfaces of a car body as it transmits through the car wash tunnel to effect cleaning of these surfaces. The top brush is mounted on a counterweighted frame which pivots to allow the rotating top brush to move up and down as the brush contacts the various vehicle surfaces, with a preset contact pressure exerted by an adjustment of the counterweighting. Such top and side brushes have in the past used closed cell foam fingers which are long and flaccid. Washing is achieved by a scrubbing action carried out by the tips of the fingers which are held extended by rotation of the brush core at a relatively high speed, i.e., in excess of 100 rpm, with the long length and speed of rotation creating sufficient centrifugal force to hold the tips out stiffly to create adequate scrubbing pressure without folding of the fingers. 
   The tips must be held extended out to develop proper scrubbing pressure, since if the fingers bend over, scrubbing pressure is substantially compromised. Thus, a high speed rotation and a large brush diameter (50 inches or larger) is required to create the level of centrifugal force acting on the fingers necessary to achieve this result. 
   In prior designs, such top brushes have had a constant diameter core from which the foam brush fingers extend radially. The brush core in the prior top brush designs were of a relatively small diameter, i.e., 10 inches, since car antennas would be bent too far when the brush passes over the same if the cores were of a substantially greater diameter. The long flaccid fingers which are extended by rotation at a relatively high speed, define a space for the antenna to pass through without excessive bending of the antenna. 
   The prior top brushes sometimes create difficulties when the small diameter core encounters a sharply vertical surface vehicle when the brush is not rotating as when a vehicle is driven through the wash tunnel without the equipment operating or when the brush is not rotating because of an equipment failure since the small diameter core will often wedge against such a surface, stopping the vehicle or breaking the brush or frame. 
   The high speed rotation of the fingers in both the top and side brushes create the possibility of vehicle damage by the fingers snagging some feature on a washed vehicle exterior. 
   Another difficulty concerns the possibility of the brush fingers of a top brush descending completely down into the bed of a pickup, kicking up debris collecting in the bed as the long fingers held out by centrifugal force reach down into every crevice of the bed. The long fingers straddle the side rails and allow the brush to descend to create contact with the bed bottom. 
   It is the object of the present invention to provide a car wash brush construction for both top and side brushes which does not require rotation at high speed. 
   It is another object to provide a top brush which avoids jamming of a top brush core when encountering a vertical or sharply inclined surface of a vehicle being washed when the brush is not rotated, and also does not contact the bottoms of pickup truck beds. 
   SUMMARY OF THE INVENTION 
   The above objects and others which will become apparent upon a reading of the following specification and claims are accomplished by a stepped diameter core top brush construction or a constant diameter side brush in which relatively stiff fingers are mounted on a core. The top brush also has a smaller overall diameter than prior top brush designs, i.e., on the order of 40 inches. Both the top and side brushes are rotated at a substantially lower speed (100 rpm or less) while still developing sufficient finger tip stiffness to achieve effective scrubbing action. 
   The top brush core has a stepped diameter, and an inner core of the main center section of a larger diameter than prior art top brushes, i.e., on the order of 20 inches, such that it will have a much greater tendency to roll over vertically inclined surfaces on a car if the brush is not rotating, thus usually avoiding vehicle or equipment damage in such situations. 
   The top brush also has an overall smaller diameter when rotating on the order of 40 inches than prior top brush designs with the foam fingers still being held stiff enough to achieve effective scrubbing action. 
   The top brush core is of a stepped diameter, with a smaller diameter section at each end (i.e., ≈10 inches), which enables passage over an antenna without creating excessive bending of the antenna. The foam fingers  48  are aligned in rows on the end sections to create openness further reducing the changes of antenna damage. 
   In both the top and side brushes, the brush construction consists of sets of closed cell foam fingers of a tapering shape wider and shorter than the diameter of the core to be stiffer than prior art brush fingers. The core spacer discs are also constructed of closed cell foam sheet material stacked and bonded together into brush sections, with fewer gaps or crevices in which an antenna could be snagged. 
   The core discs each have aligned square openings which are fitted onto a square drive shaft to establish a driving connection to the brush and to maintain a predetermined alignment of the brush segments. 
   The foam fingers of the top brush center section are staggered with respect to adjacent fingers to maintain a denser finger pattern in the brush center section for maximizing scrubbing effectiveness. 

   
     DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a side elevational view of a car wash top brush mechanism incorporating a top brush according to the invention. 
       FIG. 2  is a plan view of the top brush included in the mechanism shown in  FIG. 1 . 
       FIG. 3  is an end view of an outboard section of the brush shown in  FIG. 2 . 
       FIG. 4  is an end view of the center section of the top brush shown in  FIG. 2 . 
       FIG. 5  is a perspective endwise view of the top brush showing the finger arrangements. 
       FIG. 6  is a perspective view of a car wash side brush mechanism incorporating a brush according to the present invention. 
       FIG. 7  is a plan view of the side brush mechanism shown in  FIG. 6 . 
       FIG. 8  is a front elevational view of the side brush mechanism shown in  FIGS. 6 and 7 . 
       FIG. 9  is a side elevational view of the side brush mechanism shown in FIGS.  6 – 8 . 
       FIG. 10  is a perspective view of another side brush configuration according to the invention. 
       FIG. 11  is a perspective view of yet another side brush configuration according to the invention. 
   

   DETAILED DESCRIPTION 
   In the following detailed description, certain specific terminology will be employed for the sake of clarity and a particular embodiment described in accordance with the requirements of 35 USC 112, but it is to be understood that the same is not intended to be limiting and should not be so construed inasmuch as the invention is capable of taking many forms and variations within the scope of the appended claims. 
   Referring to the drawings,  FIG. 1  shows a top brush mechanism  10 , of a generally conventional design, including a pair of swing arms  12  pivoted atop respective stanchions  14  having bottom plates  40  fixed to a floor surface on either side of a car wash tunnel. Bearing supports  18  allow swinging movement of the arms  12  and corresponding movement of a top brush  20  supported to the outermost ends of the arms  12 . 
   A square center shaft  22  passes through the corresponding square core of the top brush  20  to establish a driven connection therewith. Stub ends of the center shaft  22  are supported in corresponding bearings  24 . A hydraulic motor  26  is connected via a torque plate  28  to rotate the shaft  22  and brush  20 . A set of counterweights  30  are secured to an overhang section  34  of the arm to counterbalance the weight of the brush  20 , leaving a net downward force on the order of 15 to 20 pounds on a vehicle passing along the car wash tunnel  50  with the arms  12  released. 
   A power cylinder  32  is connected between each overhang section  34  and a respective stanchion  14  to allow the brush to be raised. The power cylinders  32  may be also be operated to drive the brush down on trailing surfaces of the vehicle particularly when the car wash is being operated at a high rate. 
   When the cylinders  32  are unpressurized, the brush  20  slowly descends to a lowered position at which it engages the vehicle and follows its contour as it moves through the wash tunnel  50 . 
   A pair of shock absorbers  36  are likewise mounted to prevent bouncing as the top brush  20  moves up or down. A stabilizer bar (not shown) extending between the arms also may be installed. 
   A pair of down stops  38  and up stops  40  are also provided. 
   This arrangement with the associated hydraulic and electrical circuitry is well known and will not be described here in further detail. 
   The top brush mechanism  10  is preferably constructed of stainless steel to be able to operate in the wet environment of a car wash without being excessively corroded. 
   The top brush  20  is uniquely configured to have a stepped diameter core  42 , having smaller diameter (≈10 inches) end sections  44 , and a larger diameter (≈20 inches) scrubbing center section  46 . The larger diameter core  42  of the scrubbing center section  46  will roll much more readily than the prior art 10 inch diameter cores when encountering a vertically inclined surface on a vehicle, causing the core to roll over and past the vehicle contours, rather than wedging against the same as with the brushes having a smaller diameter core. At the same time, the smaller diameter end sections  44  create sufficient clearance with the antennas to avoid breakage. 
   A radial array comprised of sets of foam sheet fingers  48  lying flat in a common radial plane project radially from the core  45  of end sections  44  and sets of shorter form fingers  52  lying flat in a common radial plane project radially from the core  42  of the center section  46  so that the outside diameter (≈40 inches) is substantially uniform, as seen in  FIG. 2 , and substantially smaller than prior foam finger top brushes which were 50–54 inches in diameter. This smaller outside diameter is allowed because of a stiffer shorter finger design. 
   That is, the length of fingers  52  projecting from the core  42   45  are no longer and preferably shorter than the diameter of the core  42 . 
   The center section core  42  is constructed of segments  56 A each several inches in length. Each segment in the center section  46  is constructed of glued together radial arrays of the foam cell fingers  52  with foam cell spacer discs  58  interposed. 
   The center section core  42  is constructed of segments  56 A,  56 B, each several inches in length. Each segment in the center section  46  is constructed of glued together radial arrays of the foam cell fingers  52  with foam cell spacer discs  58  interposed. 
   The fingers  52  may be die cut from ⅜″ thick sheets of closed cell foam to comprise flat pieces with the fingers  52  in each set lying flat in a common radial plane, and have mutually interlocking projecting portions extending between adjacent fingers resisting relative movement to prevent pull out of any individual finger  52  ( FIG. 3 ). 
   The discs  58  are formed with a square opening  60  to be received over the square shaft  22 . A center disc  62  occupies the space defined within the inner ends of the fingers  52 . 
   The end sections  44  are also constructed with sets of closed foam cell fingers  48  and foam spacer discs  64  each having a square opening  66 , forming segments  56 B glued together in alternating layers. The fingers  48  are longer than the fingers  52  to create the uniform outside diameter of the brush  20 . The end section fingers  48  do not have to be short since they do not perform significant scrubbing action. 
   The end section fingers  48  are aligned in rows so to create intervening spaces to lessen the chance of snagging an antenna. The center section fingers  52  on the other hand are staggered to create a more uniform distributed pattern of the tips of the fingers  52  across the outside of the center section  46 .  FIG. 5  shows this arrangement. 
   As noted, the main center section foam fingers  52  are configured to be relatively short (equal to or preferably less than the core diameter, ≈10 inches projecting from the core  42 ) and thus stiff compared to conventional foam fingers, with a tapering shape much wider at their inner root ends projecting from the core  42 . This root width would be on the order of 2¾ inches and top width on the order of ½ inch for a ⅜ inch thick finger, projecting from the core a distance of about 10–12 inches when constructed of closed cell foam material. 
   The closed cell foam material used to construct the fingers  52  and  48  and discs  62 ,  64 ,  58 , is widely available under the trademarks CELL FLEX and MINICELL and is well known to those skilled in the art. As noted, the fingers  48 ,  52  can be die cut from a foam sheet ⅜ inch thick. 
   A particular type of closed cell foam material designated as 380 DVA low density closed cell available from DER-TEX Corporation of Saco, Me., has been successfully used to construct brushes according to the invention. An odd number of fingers  52  in the center section  46  are preferably provided to allow staggered assembly and a more uniform distribution of the finger tips to create a more complete scrubbing coverage of the vehicle surfaces. As seen in  FIGS. 3 and 4 , more washer fingers  52  may also be provided in each center section set than the number of washer fingers  78  in each end section set. 
   The segments  56 A,  56 B are assembled onto the square shaft  22 . 
   The top brush  20  so formed is able to be rotated at a slower rate, i.e., in the approximate range of 70–100 rpm, due to the increased finger stiffness, while still producing effective scrubbing action. The smaller diameter end sections  44  prevent extreme bending of car antennas as the top brush  20  moves over the same. The solid stacked construction without crevices avoids snagging antennas. At the same time, the larger center section core  42  will not jam against vertically inclined surfaces on a vehicle moving against the brush  20 . 
   The center section core  42  will roll along the side rails of pickup beds without descending therein to a degree that would allow contact of the tips of the relatively short fingers  52  to contact the bed bottom. 
   It is noted that top brushes are normally operated only with soap foam from a generator or pump applied to the washed vehicle prior to moving into contact with the brush. 
     FIGS. 6–9  show a side brush mechanism  70  including a vertically oriented side brush  72  supported on a support arm  74  for swinging motion in the well known manner. A spring-shock absorber assembly controls swinging movement of the arm  74  on bearings  82  on stanchion  78  in the well known manner. 
   A hydraulic motor  80  is utilized to rotate the brush  22  as with the top brush mechanism  20 . Similar to the top brush, the side brush  72  is constructed of flat fingers  82  made of closed cell foam sheet material, of a tapering shape, with radial arrays of fingers and interposed discs  84  of closed cell foam material. Stacked together to form a core, and bonded into shorter sections. The sections are assembled onto a square shaft to create a driving connection for rotating the same, as in the top brush. 
   The fingers  82  are of the same shorter stiffer construction described above to allow a smaller overall diameter D, i.e., on the order of 44 inches. The core  86  is preferably of relative large diameter (i.e., ≈20 inches) as in the top brush to avoid jam conditions. The fingers  82  are offset to create a staggered relationship of the fingers  82  along the length of the brush  72 . 
     FIG. 10  shows another stepped outer diameter side brush configuration  90  having a core diameter D C  of 20 inches and outside diameters D 0     1    and D 0     2    ranging from 45 inches to 55 inches. The projecting finger length thus ranges from 12½ to 17½ inches, less than the core diameter D C . 
     FIG. 11  is yet another stepped outer diameter side brush  88  having a core diameter of 18 inches and an overall diameter D 0     1    on the order of 42 inches at the bottom and DO 2  53 inches at the top, the projecting finger length ranging from about 13–17½ inches in length, thus being less than the core diameter D C . D 0     2