Abstract:
An apparatus for polishing a surface comprising: a polishing head comprising a plurality of flap assemblies; and a shaft attached to the plurality of flap assemblies for rotatably driving the polishing head.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 61/029,059, filed on Feb. 15, 2008, and U.S. Provisional Application No. 61/048,019, filed on Apr. 25, 2008, which are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present application relates to a rotary tool for polishing a surface. 
       BACKGROUND OF THE INVENTION 
       [0003]    Rotary polishing tools are available for polishing various surfaces. Such tools commonly have a substantially uniform size and shape making it difficult for a single polishing head to polish surfaces having varying sizes and shapes. For example, U.S. Pat. No. 7,203,989 B2, discloses a buffing and polishing ball made of a compressible polymeric foam material is formed by slitting a body of foam material in a substantially uncompressed state (1) from an outside surface of the body in a direction generally perpendicular to the rotational axis and (2) on circumferentially spaced planes that extend generally radially from the outside surface of the body to define a plurality of foam fingers. A fastening system is used to compress and hold a center portion of the foam body in a direction along the rotational axis such that the uncompressed outer ends of the finger assume a generally spherical ball. 
         [0004]    In addition, U.S. Pat. No. 5,560,744 discloses a buffing apparatus including a buffing assembly including a stack of buffing wheels with or without spacers between the rings, compressed under high pressure. Each wheel includes a clinch ring which in turn secures an annulus of fabric extending radially therefrom. Each spacer includes a ring; they may be the remnants of used buffing wheels. The wheels and spacers, if any, are contiguous forming an inner cylindrical surface of the rings. Steel straps extend axially along this inner surface, the straps being secured by metal inert-gas welding to the rings at the ends of the stack. The pressure between the buffing wheels and any spacers of the stacks is so high as to suppress any tendency of the wheels or spacers to slip circumferentially with respect to each other when the stack is under high tangential force in use. The straps serve to be engaged by the keys of a drive shaft to drive the buffing apparatus. 
         [0005]    Such shapes are not generally suitable for polishing small cavities as well as large substantially flat surfaces. 
       SUMMARY OF THE INVENTION 
       [0006]    In one embodiment, the present invention provides an apparatus for polishing a surface comprising: a polishing head comprising a plurality of flap assemblies; and a shaft attached to the plurality of flap assemblies for rotatably driving the polishing head. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    For a detailed understanding of embodiments of the present invention, reference is made to the following detailed description of example embodiments, taken in conjunction with the accompanying drawings, in which like elements have been given like numerals, wherein: 
           [0008]      FIG. 1  is a view of an example embodiment of a polishing tool for polishing a surface; 
           [0009]      FIG. 2  is a view of another example embodiment of a polishing tool for polishing a surface; 
           [0010]      FIG. 3A  is a view of an example of a polishing head; 
           [0011]      FIG. 3B  is a cross-section of the polishing head of  FIG. 3A ; 
           [0012]      FIG. 4  is an exploded view of an example of upper and lower material layers with at least one stiffener element between the upper and lower material layers; 
           [0013]      FIG. 5  is a cross-section of a flap assembly showing upper and lower material layers with stiffener elements; 
           [0014]      FIG. 6  is a cross-section of a plurality of stacked flap assemblies; 
           [0015]      FIG. 7  is a view of another shape for a material layer; 
           [0016]      FIG. 8A  is a view of an example of a material layer having a substantially circular bulbous tip; 
           [0017]      FIG. 8B  is a view of substantially elliptical bulbous tip; 
           [0018]      FIG. 9A  is an exploded view of one example of a flap assembly; 
           [0019]      FIG. 9B  is a view of the assembled flap assembly of  FIG. 9A ; 
           [0020]      FIG. 10  is a view of another flap assembly; 
           [0021]      FIG. 11  is a view of one example of a flap material layer having a textured surface; and 
           [0022]      FIG. 12  is a view of another example of a flap material layer having a textured surface. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0023]    Referring to  FIG. 1 , in one example embodiment, a polishing tool  10  comprises a polishing head  20  coupled to a handle assembly  30 . Polishing tool  10  may be coupled to a rotary power device  40  to rotate polishing head  20 . In one example embodiment, polishing head  20  comprises a plurality of flap assemblies  21  attached to a shaft  22  extending at least partially upward through the center of polishing head  20 . 
         [0024]    In the example embodiment shown in  FIG. 1 , shaft  22  extends through an axial bore (not shown) in housing  31 , and protrudes out of the bottom of housing  31 . The bore in housing  31  acts to support and guide shaft  22  during rotary motion of shaft  22 . The protruding portion of shaft  22  may be coupled to chuck  41  of rotary power device  40 . In one example, rotary power device  40  is a cordless portable drill. Alternatively, corded electric drills or air driven rotary devices may be used. Folding handle  32  is pivotally attached to housing  31  by a pin  33 . As shown, handle  32  may be folded around housing  31  in position  32 ′, or may be extended as shown. When extended, handle  32  may provide better support and control of the polishing tool as the polishing head interacts with a surface to be polished. 
         [0025]    Housing  31  may be made of a plastic material, a metal material, or a combination of a plastic material and a metal material. Likewise, shaft  22  may be made from a plastic material, a metal material, or a combination of a plastic material and a metal material. Suitable plastic materials may comprise polyethylenes, polycarbonates, nylons, polypropylenes, polyvinylcarbonates, polyurethanes, and polyethylene terephthalate (PET). Suitable metal materials may comprise steel, aluminum, aluminum alloys, brass, and bronze. 
         [0026]    In another embodiment, see  FIG. 2 , polishing tool  110  comprises a polishing head  120  coupled to a handle assembly  130 . Polishing head  120  comprises a plurality of flap assemblies  21  attached to shaft  122 . Shaft  122  extends below polishing head  120  and is sized to attach to handle assembly  130  at coupling  27 . Coupling  27  connects shaft  122  to handle shaft  28 . Handle shaft  28  extends through an axial bore (not shown) in housing  31 . Handle shaft  28  may be attached to rotary power device  40  by chuck  41 . Shaft  122  and handle shaft  28  may be made from plastic materials, metal materials, and combinations thereof as previously described. Folding handle  32  is pivotally attached to housing  31  by a pin  33 . As shown, handle  32  may be folded around housing  31  in position  32 ′, or may be extended as shown. When extended, handle  32  may provide better support and control of the polishing tool as the polishing head interacts with a surface to be polished. 
         [0027]      FIG. 3A  shows a view of polishing head  20 . It will be appreciated that the difference between polishing head  20  and polishing head  120  is the difference in length of shafts  22  and  122 . The following description of the arrangement and construction of the plurality of flap assemblies  21  applies to both polishing head  20  and polishing head  120 . Referring also to  FIGS. 3B-5 , each flap assembly  21  may comprise an upper material layer  51  and a lower material layer  53  with two stiffener elements  52  located between upper material layer  51  and lower material layer  53 . In one embodiment, the width W of upper material layer  51  and lower material layer  53  is in the range of about 4.5 inches (114 mm) to about 5 inches (127 mm).  FIG. 4  shows an exploded partial view of one example of the construction of flap assembly  21 .  FIG. 5  is a cross-section of a flap assembly showing upper and lower material layers with stiffener elements. In  FIG. 4 , only one stiffener element  52  and a cutaway upper material layer  51  are shown for clarity above a full lower material layer  53 . Upper material layer  51  and lower material layer  53  may comprise a cloth material and/or a foam material. In one embodiment upper material layer  51  and lower material layer  53  comprise a polyester and polyamide microfiber fabric. Alternatively, natural fiber materials may be used, including felt, wool, mohair, cotton, and linen. In one example, stiffener element  52  may be made of an elastomer or plastic foam material having a stiffness greater than the stiffness of upper material layer  51  and lower material layer  53 . Stiffener element  52  provides sufficient rigidity to force upper material layer  51  and lower material layer  53  of flap assembly  21  to extend substantially radially outward from shaft  22  during rotation of polishing head  20 . Alternatively, at least one unstiffened material layer (not shown) may be interleaved between flap assemblies  21 . 
         [0028]    In one embodiment, upper material layer  51  and lower material layer  53  may be attached to stiffener  52  by any suitable technique, for example, by an adhesive, by stitching, or a combination of adhesive and stitching. As shown in  FIGS. 4 and 5 , stiffener element  52  is located inboard from the edge of material layers  51  and  53 , such that a predetermined length L of unsupported material makes first contact with the workpiece surface. The flexible, unsupported material may enhance the polishing action of the material when the material interacts with the workpiece surface. There is a gap H between the stiffeners  52  in each flap assembly. Gap H provides access for stitching multiple layers together as shown in  FIG. 3B  and  FIG. 6 , where a plurality of flap assemblies  21  are stacked and stitched together along stitch lines A and B that may extend along the length of upper material layer  51  and lower material layer  53 . The stitched stack allows for insertion of shaft  22  between two flap assemblies  21 , see  FIG. 3B . The attached flap assemblies may be attached to shaft  22 , for example, using an adhesive. In other embodiments, upper material layer  51  and lower material layer  53  may comprise multiple layers of material attached together by adhesive and/or stitching. 
         [0029]    The upper and lower material layers  51  and  53  may be shaped having varying widths such that both small and large workpiece features may be polished using the same polishing head. For example,  FIG. 4  shows a substantially bullet shaped layer having a large relatively constant width section P 1  for polishing relatively flat surfaces, and a smaller tapered width section P 2  for polishing smaller surfaces and/or cavities. In use on automotive surfaces, for example, the large relatively constant width section P 1  may be used for polishing, for example, fenders, hoods, and trunk lids. The smaller tapered width section P 2  may be more useful for polishing, for example, around door handles and/or within wheel spokes. 
         [0030]      FIG. 7  presents another example shape for a material layer  60  for the polishing head wherein the edges S 1  and S 2  taper substantially linearly from a relatively small width at each end to a relatively large width W near the center of each side. 
         [0031]      FIG. 8A  shows another example shape for a material layer  70  for the polishing head. Layer  70  comprises a main section  71  for polishing large surfaces, and a bulbous tip  72  for polishing small areas and openings. In the example embodiment shown, there are at least three polishing areas S 3 , S 4 , and S 5  of differing shapes for polishing a variety of different surfaces on a workpiece. In  FIG. 8A , bulbous tip  72  is substantially round having a radius R. In one embodiment, the radius R is about 0.5 inch (13 mm). In another embodiment, see  FIG. 8B , a bulbous tip  75  may have an elliptical shape. 
         [0032]      FIGS. 9A and 9B  show another example embodiment of a flap assembly  110  that may be used with polishing heads  20  and/or  120 , described previously. Flap assembly  110  may comprise an upper material layer  90  and a lower material layer  91  with stiffener elements  95  located between upper material layer  90  and lower material layer  91 . In one example, material layers  90  and  91  may comprise a polyester and polyamide microfiber fabric, a felt material, a wool material, a mohair material, a cotton material, a linen material, and combinations thereof. Stiffener elements  95  may comprise an elastomer or a plastic foam material having a stiffness greater than the stiffness of upper material layer  90  and lower material layer  91 . In one example, upper material layer  90  and lower material layer  91  may comprise a textured pattern  98 . For example, textured pattern  98  may be formed into the material. Textured pattern  98  may comprise a hexagonal pattern, as shown. Alternatively, textured pattern  98  may comprise any suitable geometric pattern. 
         [0033]    Upper material layer  90  and lower material layer  91  may be attached to stiffeners  95  by any suitable technique, for example, by an adhesive, by stitching, or a combination of an adhesive and stitching. A plurality of flap assemblies  110  may be assembled together using the techniques described previously with reference to  FIG. 3B  and  FIG. 6 . The assembled flap assemblies may be attached to shaft  22  or shaft  122  as described previously. 
         [0034]    In another example, referring to  FIG. 10 , a flap assembly  121  may have a cutout  96  located on one side of a centerline  94  of an upper material layer  93  such that a foam stiffener element  95  is accessible through cutout  96 . The placement of cutout  96  on one side allows the foam stiffener element material to be accessed for polishing a surface when the rotary power device is driven in a first direction, and the material layer is accessible for buffing when the rotary power device is driven in an opposite second direction. Any number of such cutout flap assemblies  121  may be assembled together, as described previously. In one example, stiffener element  95  may comprise an open cell plastic foam material that holds a polishing compound, for example a polishing wax, during the polishing process. It will be understood that a similar cutout may be formed in lower material layer  91 . 
         [0035]      FIG. 11  shows one example of material layers  90  or  91  having a textured pattern, for example, a textured pattern  98  formed in the material layer. In the example shown, a hexagonal pattern may be formed in the material layer. In one example, an outline perimeter  97  may be raised with respect to a hexagonal surface  99 . Alternatively, hexagonal surface  99  may be raised with respect to outline perimeter  97 . The portion that is not raised, that is the lower feature, may provide a collection area for dirt and/or used polishing compound collected on the material layers during the polishing and/or buffing process. As indicated previously, any suitable textured geometric pattern may be used. 
         [0036]      FIG. 12  shows an example of an upper or lower material layer  100  that has an internally arched lower edge  102  that may provide for increased hand clearance when used in an assembled polishing head, for example polishing heads  20  and  120 , described previously. 
         [0037]    The foregoing description is intended for illustration and should not be construed as limiting the scope of the invention in any way. Those skilled in the art will recognize many variations that may be made without departing from the scope of the disclosed invention.