Patent Publication Number: US-11019915-B1

Title: Infinity brush

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a Divisional of U.S. patent application Ser. No. 15/161,378 filed May 23, 2016 and granted as U.S. Pat. No. 10,251,472 on Apr. 9, 2019. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention pertains generally to brushing, scrubbing, and general cleaning, and more particularly to an improved bristles and brushes that enhance the brushing and cleaning experience. 
     2. Description of the Related Art 
     Brushing is an age-old technique that is used for many purposes, including but not limited to cleaning, shaping, texturing, polishing, and even ice melting such as performed in the sport of curling. The vast majority of brushing applications rely upon contact between a surface being treated and the ends of a plurality of longitudinally extensive bristles. The bristle ends will form an abrupt edge, and the bodies of the bristles will be slightly spring-loaded, thereby ensuring that the bristle ends stay in contact with a surface, even if the surface is slightly irregular. 
     These bristles are often provided in a plurality of individually bound groups or clusters. Many modern brushes are formed by transversely cutting a plurality of parallel strands into relatively shorter segments, and then folding or crimping this cluster of strands in half. The folded or crimped cluster is then pressed into a brush body hole, or molded into the body in one way or another. The clusters of bristles are often located in relation to adjacent groups or clusters of brush bristles by the brush body, a holder, or the like. As a result, while the outer bristles are exposed fully along their length, the majority of bristles are instead primarily only exposed adjacent to their ends. When the brush bristles are then pressed against and moved relative to a surface, the abrupt edge of the bristle ends is then pressed into contact with the surface, generating quite high forces in the relatively small surface area points of contact. This is very useful to dislodge debris from a surface when cleaning the surface, or to create enough very local heat to provide limited ice melting such as in the sport of curling. In addition, the many individual bristles will move through a viscous fluid with very limited fluid displacement adjacent the bristle ends, while the displaced fluid elevates with respect to the surrounding fluid. As a result, this process creates a surface texture that is simply known as a “brushed finish”. 
     Unfortunately, with either or both of age and excessive brushing force, the outer bristles will tend to deform away from the clusters, tending to flatten. This can also happen temporarily and reversibly during use, when the force applied to the brush is sufficiently great to exceed the stiffness of the plurality of bristles. In other words, at some sufficient force, the individual strands that form the brush bristles will flex, and the brush will flatten. Once this occurs, these deformed bristles become much less useful and productive. This is because the point of contact changes when the brush flattens from the abrupt transition formed by the transverse cut at the ends of the bristles to the long smooth side of the bristle. 
     In addition to permanent flattening or deformation of the brush bristles, another sometimes challenging or alternatively sometimes beneficial feature of the brush is the fact that the brush will typically be pressed and drawn in such a way that the cut end of each bristle will follow in a line parallel to that defined by other bristles. This is a primary benefit in surface texturing, such as the “brush finish” described herein above, since the lines of texture will follow the direction the brush is moved. A person may then easily control the pattern of the brushed finish, simply by controlling the direction of movement of the brush. This is also of benefit in moving debris in a common direction to a collection location, where the debris may then be scooped up or otherwise handled. 
     However, when cleaning a surface it is of great benefit to be able to contact the surface from different directions. When debris is adhered to a surface, contacting the debris from at least two different directions is of special benefit, leading to much greater debris removal. A small ridge will cause the bristle to lift and snap over the top of the of the ridge, leaving a shadow of debris parallel to and in the lee of the small ridge. When a bristle then comes from a perpendicular direction, and particularly when the bristle hits the shadow of debris before the ridge, then the shadow of debris will more likely be removed. Similar effect can occur with depressions in a surface, and with movement of bristles over tightly adhered debris, and in each case, a substantially perpendicular direction travel of bristles or even an opposed direction is highly beneficial. 
     Recognizing the benefit of moving bristles in different directions over a surface, a number of artisans have designed brushes that include brush blocks that rotate or move. The following US patents, the teachings and contents of each which are incorporated herein by reference, are exemplary: U.S. Pat. No. 2,140,307 by Belaschk et al, entitled “Electrically operated combination set for the dressing table”; U.S. Pat. No. 4,084,280 by May, entitled “Tooth brush”; U.S. Pat. No. 4,156,620 by Clemens, entitled “Apparatus and method for cleaning teeth”; U.S. Pat. No. 4,344,202 by Hayat, entitled “Electric toothbrush”; U.S. Pat. No. 6,799,346 by Jeng et al, entitled “Toothbrush with oppositely reciprocating brush heads”; U.S. Pat. No. 7,954,192 by Gatzemeyer et al, entitled “Powered toothbrush with rotating sections”; U.S. Pat. No. 8,250,694 by Gatzemeyer et al, entitled “Powered toothbrush with rotating sections”; U.S. Pat. No. 8,584,291 by Thompson, entitled “Whole mouth toothbrush”; U.S. Pat. No. 8,677,542 by Whillock, entitled “Interchangeable tooth brush system and associated method for promoting oral health”; and U.S. Pat. No. 8,683,639 by Khudoley, entitled “Mechanical toothbrush and drive mechanism therefor (embodiments)”. While these work admirably for many applications, they are not without limitations. As but one example, where the brush blocks rotate, this ensures complex movement of the bristles over a surface. This is highly desirable for many applications. However, along edges the bristles will in fact only move substantially in a single direction, running parallel to the edge. 
     Again, for many applications, this is of little or no consequence. However, in more critical applications, such as in the case of tooth brushing for patients with afflictions such as gingivitis, it may be critical to remove as much of the debris as possible from the tooth surface and within the gingival pockets. For such an application, having bristles moving in more than one direction is of great benefit. For those situations, the counter-rotating bristle blocks are highly beneficial, such as illustrated by Belaschk et al; Clemens; Jeng et al; and several others incorporated herein above. While these brushes offer substantial improvement over many of the prior brushing apparatus, once again along an edge there is only minimal contact. In other words, as the brush traverses across the tooth, with the brush in contact with the gingival tissue, only a few of the bristles located about the outer diameter are in contact with the tooth along this edge. For exemplary purposes, only ten or fifteen degrees of the 360 degrees of outer diameter bristles in a circular bristle block may be in contact with an edge. The exact angle of bristles in contact will depend upon a number of variables, but it should be apparent that just a small part of the diameter of the brush head is active adjacent the edge. In contrast, at a distance form the edge defined by half the diameter of the brush block, the entire diameter of bristles are active. In other words, the brushing at one-half the diameter of the bristle block is many times more intense and thorough than along the gingival tissue. Unfortunately, for patients with gingivitis, this creates a dilemma. Either they must spend many times the amount of time brushing, or tolerate the less thorough cleaning of debris along the gingival tissue. Neither option is particularly desirable. 
     Other US patents, the teachings and contents of each which are incorporated herein by reference, illustrate endless belt brushes, including: U.S. Pat. No. 997,113 by Campbell, entitled “Shoe polishing machine”; U.S. Pat. No. 2,247,440 by Hempel, entitled “Scalp massaging device”; U.S. Pat. No. 3,252,175 by Pedersen, entitled “Electrically operated hair brush”; and U.S. Pat. No. 6,272,711 by Ignacio, entitled “Multifunction surface engaging apparatus that is particularly suited in removing snow and ice”. Additional US patents, the teachings and contents of each which are incorporated herein by reference, illustrate endless belt brushes with specially noted brush belt drives: U.S. Pat. No. 582,509 by Seufert, entitled “Can washing machine”; U.S. Pat. No. 878,748 by Scanlan, entitled “Brush”; U.S. Pat. No. 1,180,172 by Mitchell, entitled “Brushing machine”; U.S. Pat. No. 2,181,676 by Wheeler, entitled “Shoe polishing machine”; U.S. Pat. No. 3,686,699 by Knestele, entitled “Device for cleaning carpeted floors”. Endless belts are particularly beneficial where an even distribution of bristle contact across an area is desired. Consequently, many of these patents are equally effective adjacent an edge as they are in the center of the brush. However, these apparatus also generally lose the benefit of contacting a surface from many directions, and instead the contact is primarily linear along a single axis. 
     One US patent, the teachings and contents of each which are incorporated herein by reference, illustrates both rotary, linear reciprocating, and endless belt brushes: U.S. Pat. No. 6,032,313 by Tsang, entitled “Household appliance having plural coaxially rotatable or parallel linearly movable heads or tools”. 
     Two additional patents of general interest, the teachings and contents of each which are incorporated herein by reference, include: U.S. Pat. No. 827,965 by Engel, entitled “Tooth brush”; and U.S. Pat. No. 8,636,677 by Van Der Rijt et al, entitled “Intraoral appliance for cleaning teeth”. 
     In addition to the aforementioned patents, Webster&#39;s New Universal Unabridged Dictionary, Second Edition copyright 1983, is incorporated herein by reference in entirety for the definitions of words and terms used herein. 
     SUMMARY OF THE INVENTION 
     In a first manifestation, the invention is a brush bristle. The brush bristle has a longitudinal shaft having a first end and a second end longitudinally distal to the first end. An edge exists at the juncture between the longitudinal shaft and first end. At least one diameter transition is provided between the said first and second ends. 
     In a second manifestation, the invention is a bristle belt. The belt has a flaccid endless loop. A plurality of brush segments are securely carried by the loop. 
     In a third manifestation, the invention is a brush. The brush has a flaccid belt configured to define a lemniscate. A plurality of work-contacting segments protrude from and are carried by the flaccid belt. A mechanical drive rotates the flaccid belt. 
     OBJECTS OF THE INVENTION 
     Exemplary embodiments of the present invention solve inadequacies of the prior art by providing improved non-cylindrical brush bristles, bristle belts formed from a loop and provided with a half-twist to form a shape resembling an infinity sign, and brushes incorporating a drive apparatus and various combinations of non-cylindrical brush bristles and bristle belts. 
     The present invention and the preferred and alternative embodiments have been developed with a number of objectives in mind. While not all of these objectives are found in every embodiment, these objectives nevertheless provide a sense of the general intent and the many possible benefits that are available from embodiments of the present invention. 
     A first object of the invention is to provide improved bristles and brushes that enhance the brushing and cleaning experience. A second object of the invention is to provide an improved brush bristle that does not significantly lose efficacy with age or application of extraordinary forces thereto. Another object of the present invention is to provide an improved brush bristle belt that moves brush bristles in a lemniscate pattern. A further object of the invention is to provide a brush that may incorporate these improved brush bristles and brush bristle belts while also being readily configured for a variety of functions, including but not limited to cleaning, shaping, texturing, polishing, and even ice melting such as performed in the sport of curling. Yet another object of the present invention is to provide both full lemniscate geometries and optional simulated lemniscates. In some embodiments, another object of the invention is to provide equal and opposed forces from a plurality of brush bristles. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing and other objects, advantages, and novel features of the present invention can be understood and appreciated by reference to the following detailed description of the invention, taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  illustrates a preferred embodiment bristle designed in accord with the teachings of the present invention from a side elevational view. 
         FIG. 2  illustrates a first alternative embodiment bristle designed in accord with the teachings of the present invention from a side elevational view. 
         FIG. 3  illustrates a preferred embodiment bristle belt arranged in an infinity loop designed in accord with the teachings of the present invention from a top plan view. 
         FIG. 4  illustrates a first alternative embodiment bristle belt arranged in a double parallel and counter-rotating infinity loop designed in accord with the teachings of the present invention from a top plan view. 
         FIG. 5  illustrates a second alternative embodiment bristle belt arranged in a double perpendicular infinity loop designed in accord with the teachings of the present invention from a top plan view. 
         FIG. 6  illustrates a segment of a third alternative embodiment bristle belt designed in accord with the teachings of the present invention from a top plan view. 
         FIG. 7  illustrates the third alternative embodiment bristle belt segment of  FIG. 6  by sectional view taken along section line  7 ′ of  FIG. 6 . 
         FIG. 8  illustrates a segment of a fourth alternative embodiment bristle belt designed in accord with the teachings of the present invention from a projected and partially sectioned view. 
         FIG. 9  illustrates a preferred embodiment brush designed in accord with the teachings of the present invention from a top plan view. 
         FIG. 10  illustrates the preferred embodiment brush of  FIG. 9  from a side elevational view. 
         FIG. 11  illustrates a preferred brush belt tensioning apparatus used in the preferred embodiment brush of  FIG. 9  from a simplified top plan view. 
         FIG. 12  illustrates a first alternative embodiment brush designed in accord with the teachings of the present invention from a simplified projected view. 
         FIG. 13  illustrates a second alternative embodiment brush designed in accord with the teachings of the present invention from a simplified projected view. 
         FIG. 14  illustrates a third alternative embodiment brush designed in accord with the teachings of the present invention from a simplified projected view. 
         FIGS. 15 and 16  illustrates a fourth alternative embodiment brush designed in accord with the teachings of the present invention from a simplified top plan view and a simplified side elevational view. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Manifested in the preferred and alternative embodiments, the present invention provides an infinity brush that provides novel bristle construction and movement with respect to an object or work surface being brushed, swabbed, massaged, or otherwise contacted. 
       FIG. 1  illustrates a preferred embodiment bristle  10  that provides a typical transversely cut end  11  defining an edge  13  that is defined by longitudinal shaft  12 . However, and as noted herein above, with prior art bristles, overt time the bristle will soften and flex, and edge  13  may contact the surface from an angle or orientation that follows the outer periphery of shaft  12 , rather than presenting a sharp edge and point of contact along edge  13 . Said another way, as a bristle ages and tends to flatten, contact changes from adjacent transverse cut edge  11  to the outer diameter of shaft  12 , along the outer cylindrical geometry. As may immediately be recognized or understood, this will spread the contact area over a much larger surface area, and the lack of sudden discontinuity means that debris will not likely be displaced by this gentle rubbing of shaft  12 . However, in the case of bristle  10 , one or more narrowed segments  14  that define a diameter transition are provided, that each define sharp edges  15  in shaft  12 . Consequently, when bristle  10  flattens, either due to age or to large force being applied to bristle  10 , then sharp edges  15  will become active and will assist in the brushing action. While two of these narrowed segments  14  are illustrated, there may be any number from one to many of these narrowed segments  14 . They may be very close to transverse cut edge  11 , or spaced therefrom. They may also be equidistantly spaced, or may be clustered adjacent to transverse cut edge  11 . 
       FIG. 2  illustrates a first alternative embodiment bristle  20  designed in accord with the teachings of the present invention. Bristle  20  has a transverse cut  21  defining one end of the bristle, and an edge  23  at the juncture between transverse cut  21  and shaft  22  which defines the usually active sharp transition that contacts surfaces and displaces or removes debris. Instead of narrowed segments  14 , bristle  20  incorporates ribs  24  that are of larger diameter than shaft  22 . This also defines additional sharp edges  25  that, like sharp edges  15 , will become active any time bristle  20  is pressed against an object or work surface onto the outer diameter of shaft  22 , rather than along edge  23 . Like narrowed segments  14 , at least one but many ribs  24  may be provided at any suitable locations and spacings. 
     While a sharp edge  15 ,  25  is illustrated and preferred, it will be understood herein that more gentle transitions may in an alternative embodiment also be provided. In one alternative, bristle  20  may be configured to resemble a ringed nail. Furthermore, in various additional alternative embodiments, other means to provide a textured surface to shafts  12 ,  22  are also contemplated, including roughening the exterior of the shaft or other suitable technique. In addition, while cylindrical shafts  12 ,  22  are illustrated, any cross-sectional geometry may also be used, including for exemplary and non-limiting purpose, strips having more rectangular cross-section or the like. 
       FIG. 3  illustrates a preferred embodiment bristle belt  30  arranged in an infinity loop, also referred to as a “ FIG. 8 ” or a lemniscate. As described herein above, one challenge with brushes is providing a brushing motion from different directions, particularly in restricted spaces. Bristle belt  30  overcomes this challenge by providing a flaccid and reasonably durable belt  32  having a plurality of brush segments  34 ,  36  secured to move with belt  32 . Exemplary motion is shown by the arrows in  FIG. 3 , and as may be apparent then, the left portion of the loop moves in a generally clockwise manner, while the right portion of the loop moves in a generally counter-clockwise manner. In a crowded location, such as in the lower or upper jaw adjacent to the gums, electric toothbrushes of the prior art will only move in one direction with respect thereto, or only very slightly oscillate as in the case of the Van Der Rijt et al patent. In the few instances where round bristle blocks are provided that counter-rotate, the point of contact adjacent the gum line will be exactly that, a point at the top of the circular brush block. In contrast, bristle belt  30  will provide not only the benefit of movement in different and complex directions, including both rotary and more nearly linear movement, it will also provide an extended track adjacent an edge or boundary, such as along the gum line within a mouth, which will move in multiple directions along that edge or boundary. 
     Another challenge with rotary brush blocks, particularly those having just one block or several that all rotate in the same direction, is that if less than the entire brush is in contact with a surface, or if the cut ends of the bristles are not loaded to be parallel to the plane of the work surface, the bristles will then tend to push or move the brush around. In the case of the lemniscate configuration of  FIG. 3 , if an edge is adjacent either the top or bottom of the lemniscate as viewed in  FIG. 3 , then even if bristle belt  30  is titled towards the top or bottom the left and right loops will counteract each other, and bristle belt  30  will not tend to walk or drive across a surface. 
     Belt  32  may for exemplary purposes comprise a mono- or multi-filament strand formed into a continuous loop. Exemplary materials might include various polymers such as nylon, polyester, and other polymers, but might also include other materials such as steel and other metals, or natural fibers such as cotton, jute, hemp, or the like. To form a lemniscate, or infinity symbol geometry from a simple circle, the belt  32  may be wrapped about a pulley and extended therefrom. Then the free half of the endless loop is given a one-half turn, making the top of the belt the bottom in that rotated half. This preserves the endless belt movement, but causes the familiar overlap of a lemniscate midway on the belt. 
     Bristle belt  30  may be provided with any of a wide variety of brush segments  34 ,  36 . For exemplary purposes only, and not solely limiting the invention thereto, these segments may comprise small oval beads as illustrated, round beads, cylindrical beads, brush blocks, or even discs similar to those found on candy necklaces. In fact, any known geometry that a designer may find acceptable for a particular application will be understood to be incorporated herein. Likewise, many different materials may also be used. Silicone is one preferred material, particularly where oval beads such as illustrated in  FIGS. 3-5  are used. Nevertheless, the invention is not so limited, and a wide variety of materials ranging from brushes to brush balls, soft cloth balls, or pads are contemplated herein, again depending entirely upon the object to be treated. Again for exemplary and non-limiting purposes, it is contemplated herein that brush segments  34 ,  36  might be comprised by a soft and absorbent material such as wool or cotton that may then be used to buff or polish diverse surfaces including but not limited to plastics, glass, and various metals. 
     In an even further embodiment, brush segments  34 ,  36  may be of different sizes or geometries. For exemplary purposes, brush segment  34  might be of a first diameter, while brush segment  36  might be of a second larger diameter. In such case, then bristle belt  30  as it move over a surface will alternate between larger brush segments  36  and smaller brush segments  34 . This varying geometry may be used advantageously to create a pulsating effect of slightly greater contact forces with brush segments  36  and slightly lesser contact forces with brush segments  34 . With different compositions, the characteristics may vary. Once again, for exemplary and non-limiting purpose, brush segments  34  might be more absorbent and so may transport more liquid, including cleaning liquids or pastes, while brush segments  36  might be moisture impervious, and so remove any moisture including cleaning fluids. This alternating contact with a surface can be designed and configured for particular purposes to have many benefits. 
       FIG. 4  illustrates preferred embodiment bristle belt  30  in further combination with a second bristle belt  40 . In this arrangement, the two bristle belts  30 ,  40  counter-rotate with respect to each other, thereby even further improving the coverage provided by these belts. In addition, the counter-rotation of belt  40  tends to cancel the forces that might otherwise lead to a brush pulling or “walking” across a surface or object. As described above with reference to  FIG. 3 , tilting toward the top or bottom of bristle belt  30  will lead to fully canceled forces. However, tilting to either the right or left as illustrated in  FIG. 3  will lead to an unbalanced force that will either drive bristle belt  30  down if tilted to the left, or up if tilted to the right. In contrast, the counter-rotation of bristle belt  40  will tend to cancel this motion. More complete cancellation may be achieved by either driving belt  40  faster than belt  30 , such as by using a larger drive sprocket or cogged wheel, or alternatively by providing either more or wider clusters of bristles, to increase the surface contact area of the bristles of bristle belt  40  with respect to bristle belt  30 . 
       FIG. 5  illustrates an alternative embodiment arrangement where the two bristle belts  30 ,  40  are arranged in infinity loops perpendicular to each other. Brush segments  44 , securely driven by flaccid and reasonably durable belt  42 , may be of like composition and geometry to brush segments  34 ,  36 , or may alternatively be of either or both of different composition and geometry. 
     While  FIGS. 4 and 5  are described and illustrated as comprising two distinct bristle belts  30 ,  40 , it will be understood that the provision of extra appropriately positioned half-turns will permit the fabrication of these dual lemniscate arrangements from a single bristle belt as well. 
       FIGS. 6 and 7  illustrate a segment of a third alternative embodiment bristle belt  60 . A softer brush belt  61  may be provided, and have a plurality of bristles  64  inserted into and passing through. A potentially harder drive belt  62  may be securely laminated thereto. In one embodiment, drive belt  62  may first be fabricated, having conical openings therein. Next, bristles  64  may be placed therein, and brush belt  61  may be molded, simultaneously forming both belt  61  and conical plugs  63 . In an alternative embodiment, bristles  64  may be preformed with and molded into slightly conical plugs  63 , which are in turn inserted or molded into drive belt  62 . In either case, this slightly conical geometry helps to ensure that bristles  64  do not pull out of harder drive belt  62 . To facilitate driving belt  60  from a side face, perpendicular to bristles  64 , additional features may be provided such as small dimples  65  or any other features known in the art of drive belts to assist in the engagement and driving by a sheave other belt drive mechanism. 
     To form a lemniscate, or infinity symbol geometry from a simple circle, bristle belt  60  must be formed already in the geometry, or preferably by forming the belt with half the bristles pointing up, and the other half down. Then, when bristle belt  60  is wrapped about a pulley and extended therefrom, and then the free half of the endless loop given a one-half turn, making the top of the belt the bottom in that rotated half, the half with the bristles pointing down will thereby be returned to an upward position. This preserves the endless belt movement, and aligns all bristles up, but also causes the familiar overlap of a lemniscate midway on the belt. 
       FIG. 8  illustrates a segment of a fourth alternative embodiment bristle belt  80 . In this embodiment, bristles  84  are secured between to belts  81 ,  82 . Belts  81 ,  82  may each have geometry similar to a standard drive belt or rubber band, but the two are laminated together. At the time of lamination, bristle clusters  84  are inserted there between, and in the process of bonding, vulcanizing, or other suitable technique, bristle clusters  84  are permanently secured therein. As with belt  60 , one half of the bristles must be oriented downward, and the other half upward, if the belt is formed in a circle, to permit the half twist required to form the lemniscate. 
       FIG. 9  illustrates a preferred embodiment brush  100  designed in accord with the teachings of the present invention from a top plan view. As illustrated therein, a brush body  110  supports a pair of drive pulleys  140 . Each drive pulley may optionally be configured to include to drive belts, by incorporating a smaller diameter top  144  and a larger diameter lower portion  142 , in the manner of a layer cake. In this case, each drive pulley  140  will engage with two belts  80 ,  90 . Each of the belts is then coupled to an associated idler roller  124 ,  134 . As may be apparent, belts  80 ,  90  are configured in the general geometry of a tear drop shape. This does not define a full lemniscate geometry. However, and as may have been apparent form the illustrations of  FIGS. 3-5 , a full lemniscate requires an intersection between the two half loops. With the oval beads of  FIGS. 3-5 , this is possible without severe detriment. There will be slight “bumps” in the drive force required as brush segments  34 ,  36 ,  44  pass over the vertex or point of intersection between the two loops, but with appropriate design and materials, this would still function properly. However, when more severe edges are provided, such as with cylindrical beads, or with brushes extending transversely in an abrupt manner from the belts, this distinct overlap of a true and complete lemniscate is not practically possible. Consequently, and as illustrated in  FIG. 9 , the pair of tear drop shaped belt arrangements provides a very close simulation to a full lemniscate, while avoiding the actual overlap at the vertex. 
     In addition, and as discussed herein above with respect to  FIG. 4 , the dual lemniscate as illustrated in  FIG. 9  with counter-rotating bristle belts  80 ,  90 , helps to provide equal and opposed forces from a plurality of brush bristles, to prevent the generation of unbalanced forces that might otherwise cause the entire brush to be driven across a work surface. 
     A belt tensioning apparatus  150  is provided, which, as will be described herein below with regard to  FIG. 11 , may be used to ensure tension in belts  80 ,  90 . In addition, and while not illustrated, a mechanical drive such as is known from the prior art incorporated by reference herein above will be provided to turn drive pulleys  140 . Noteworthy here, and throughout the various preferred and alternative embodiments illustrated, is that the preferred bristle belts and bristles are omni-directional. This means that the drive direction may be reversed. Consequently, while arrows are provided in the illustration for a particular drive direction, it is further contemplated herein that the drive arrows could all be reversed, if the drive motor were reversed. 
       FIG. 10  illustrates the preferred embodiment brush of  FIG. 9 , but in a simplified form only illustrating a single bristle belt  80 . Visible therein are drive features  145  formed within drive pulleys  144 . These drive features  145  are illustrated as simple grooves cut into pulleys  144 , though they may also take the form of full notches, defining the tops of pulleys  144  as castellations, similar to the top of a rook piece from a chess game, or as notches, cogs, or sprockets. The particular geometry of features  145  is not critical, and several alternatives are illustrated in the present figures. Nevertheless, these features may interact with either brush segments such as  34 ,  36 ,  44 , or with small dimples  65  of bristle belt  60  to provide more powerful drive with less chance of belt slippage. 
     In  FIG. 10 , belts  80  adjacent to idler rollers  132 ,  134  may be lowered slightly relative to drive pulleys  144 . This optional feature de-emphasizes the bristle force in the center of the lemniscate, thereby diminishing the less than perfect portion of the lemniscate simulation. 
       FIG. 11  illustrates the preferred brush belt tensioning apparatus used in the preferred embodiment brush  100  of  FIG. 9 . As shown therein, an extension spring  152  is shown extending between an anchor in the handle of brush  100  and plate  151 . Plate  151  in turn couples securely to cables  154 ,  156 . Cable  156  directly connects to linkage  155 , which links to idler roller  124 . While only shown linking to idler roller  124 , it will be understood that idler roller  134  may also be engaged by linkage  155 , or may alternatively be provided with a separate cable and linkage. Spring  152  is pulling these idler rollers  124 ,  134  towards spring  152 , and thereby tensioning the associated belts  80 ,  90 . Likewise, cable  154  is coupled to linkage  153 , and from there to idler roller  122  (and optionally  132 ). However, idler rollers  122 ,  132  need pulled in the opposite direction, s a reversing pulley  157  is provided that reverses the direction fo force to pull idler rollers  122 ,  132  away from spring  152 . Guide slots  158 ,  159  are one of many exemplary ways to provide proper tracks to ensure that the idler rollers move linearly to tension the belts while still maintaining the respective generally tear drop or half-lemniscate geometries. 
     Various embodiments of brushes designed in accord with the present invention have been illustrated in the various  FIGS. 10-16 . The embodiments are distinguished by the hundreds digit, and various components within each embodiment designated by the ones and tens digits. However, many of the components are alike or similar between embodiments, so numbering of the ones and tens digits have been maintained wherever possible, such that identical, like or similar functions may more readily be identified between the embodiments. If not otherwise expressed, those skilled in the art will readily recognize the similarities and understand that in many cases like numbered ones and tens digit components may be substituted from one embodiment to another in accord with the present teachings, except where such substitution would otherwise destroy operation of the embodiment. Consequently, those skilled in the art will readily determine the function and operation of many of the components illustrated herein without unnecessary additional description. 
       FIG. 12  illustrates a first alternative embodiment brush designed in accord with the teachings of the present invention from a simplified projected view. In this case, a modified lemniscate is illustrated, wherein pulley  242  has an axis of rotation  246  that is offset from the axis of rotation  248  of pulley  244 . This angular offset permits bristle belt  280  to move in a generally lemniscate pattern when viewed from a top plan view, but which in fact displaces the two directions of belt travel so that bristles  284  will not interfere with belt  280  while belt  280  rotates. As visible therein, a plurality of cogs may optionally be provided about each of pulleys  242 ,  244 . 
       FIG. 13  illustrates a second alternative embodiment brush  200  very similar to brush  200  of  FIG. 12 , including like pulleys  242 ,  244 , but with bristle belt  280  replaced with a bristle belt  232  having large balls  234  affixed thereon. In this case, the angle of rotational axes  246 ,  248  may be more similar or more nearly parallel, since the balls  234  do not extend as far transversely from belt  232 . 
       FIG. 14  illustrates a third alternative embodiment brush  300  designed in accord with the teachings of the present invention. Similar to brush  200  of  FIGS. 12 and 13 , brush  300  incorporates offset axis pulleys. However, pulleys  342 ,  344  have no features permitting access to brush segments  332 ,  334 , meaning brush  300  is only active in the region of bristle belt  332  between pulleys. 
       FIGS. 15 and 16  illustrates a fourth alternative embodiment brush  400  designed in accord with the teachings of the present invention. In this embodiment, brush  400  includes pulleys  442 ,  444  having indentations  443  to assist in positive engagement with brush segments  434 , thereby increasing the drive torque before belt slippage. In addition rollers  433  and  435  are provided to guide belt  432  down in one direction adjacent to what would otherwise be the vertex, to avoid interference at the vertex. 
     As may be apparent then, there are a wide range of brush bristles, bristle belts, pulleys, and geometries that have been illustrated herein. While these have been illustrated in particular combinations, it should also be apparent that these components are generally adapted to be used alternatively among the various designs. So for exemplary purposes only, a number of different bristle belts have been illustrated, and could be used interchangeably across most of the brushes. Nevertheless, the bristles  64 ,  84 ,  284  are not universal, and so can only be used on some of the illustrated brushes. Such opportunities for substitution, and limitations preventing universal substitution, will be apparent to one reasonably skilled in the art upon review of the present disclosure. 
     Consequently, while the foregoing details what is felt to be the preferred embodiment of the invention, no material limitations to the scope of the claimed invention are intended. Further, features and design alternatives that would be obvious to one of ordinary skill in the art are considered to be incorporated herein. The scope of the invention is set forth and particularly described in the claims herein below.