Abstract:
Disclosed is a tool for finishing a work piece where the tool includes multiple pieces of abrasive material (sandpaper) mounted to a cylindrical housing and carrying a shank for mounting the tool to a portable electric drill or drill press or bench motor. The drill is powered to rotate the shank and housing in a first direction and the sheets of abrasive material are mounted at spaced locations around the periphery of the housing and wrapped in an opposite direction to the direction of rotation of the shank and housing, The sheet of abrasive material is cut from the end opposite to the attached end to form a plurality of finger-like projections which are not secured but tend to move outward when the housing is rotated. The fingers provide a yieldable abrasive surface which can adapt to the contours of the work piece and allow for finishing an irregular work piece.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of Invention 
         [0002]    The present invention relates to a tool for finishing a work piece. More particularly, the present invention related to a tool which carries abrasive material and is rotated to remove burrs (or similar imperfections) from a work piece, such as a wooden spindle, dowel or similar member. 
         [0003]    2. Background Art 
         [0004]    Various sanding and burr-removal tools are known in the trade. Some are self-contained machinery (such as a grinding machine or a belt sander) and others are mounted on a large machine (such as a floor-mounted grinder, a bench motor or a drill press). Unfortunately, neither of these types of tools is suitable for a home shop or a small operation where the worker may prefer to have something which is relatively inexpensive and attaches to a hand-held rotating tool which he already has (such as a portable electric drill). 
         [0005]    Examples of some of such tools for working on a work piece may be seen, inter alia, in U.S. Pat. Nos. 5,752,876; 6,190,246; 6,506,100; and 6,001,009. 
         [0006]    Some of these systems are large and costly and others require specialized machinery which may not be available to a worker in a home shop or small scale operation. 
         [0007]    Accordingly, it will be seen that these prior art systems for removing imperfections in a work piece have undesirable features and limitations. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention overcomes some of the disadvantages and limitations of the prior art systems and tools while providing a simple, yet effective, tool for removing burrs and irregularities from a work piece. Such a work piece might be made from wood in some applications and other material, such as metals, alloys or plastics, in other applications. Think of a wooden dowel or spindle as one work piece which might be cut roughly from a blank and have resulting burrs and imperfections along its exposed surface, which may be curved, have corners, or have other features which make removing the burrs and/or imperfections difficult and/or time-consuming for a hobbyist or a worker in his home shop. Despite the curves, corners or other geometric shapes, it is desired to have a smooth surface on the work piece, so a sanding function is desired. Hand sanding is slow, tedious and expensive, but using a machine can damage the work piece and/or remove desired features of the work piece. 
         [0009]    The present invention is a sanding tool which can be attached, in one embodiment, to the chuck assembly of a conventional portable drill, the kind that any home shop might have. This sanding tool has a shank which is of conventional size and shape for attachment to a conventional drill (the size of the shank may be ¼ inch or ⅜ inch, for example, a size which would fit into most conventional home-use portable drills and be rotated by the motor within the drill). This tool can be easily inserted into the drill, as desired, and removed from the drill when the work piece has been finished to the desired smoothness. The tool can be moved easily when assembled into the drill into a desired location and orientation with respect to the work piece by the operator and moved along a length of the work piece, if desired. 
         [0010]    This tool includes a plurality of small finger-like projecting pieces of sandpaper which tend to fly out as the tool is rotated in the direction opposite to the direction of mounting of the sandpaper, creating an appearance of the sandpaper fingers flapping, so this device has been called a “sand flap”. That is, the sheet(s) of sandpaper has been wrapped around a cylindrical core in a clockwise direction, then the assembly is rotated in a counterclockwise direction for use of the tool. 
         [0011]    The present tool has a rounded body mounted to the shaft and aligned generally with the shank for mounting it to the drill and carries a piece of sandpaper which has been cut into a plurality of elongated segments which are generally rectangular and extend outwardly from the rounded body as it rotates. The elongated segments may be only partially separated from a sheet of sandpaper which has been mounted to the rounded body. The piece of sandpaper is mounted to the rounded body in one direction (for example, clockwise) with respect to the axis of the rounded body, then is rotated in the opposite direction (in this example, counterclockwise) with respect to the rounded body by the drill in order to cause the segments to tend to move away from the body due to the centrifugal force from the rotation of the body. As the segments move away from the rounded body, they are brought into contact with the work piece in order to provide a yielding contact between the sandpaper and the work piece and remove burrs and imperfections. 
         [0012]    Of course, many variations and adaptations are possible to the preferred embodiment of the present invention, and some of the features of the present invention may be used without the corresponding use of other features. Accordingly, the present document seeks to describe a preferred embodiment of the present invention with some particularity and some alternatives which are thought to be within the scope of the present invention and allow those of ordinary skill in the present art to make additional changes and adaptations to the invention as they might envision. Based upon the teachings of this invention many changes can be made to the present invention without departing from its spirit. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a perspective view of the sand flap tool of the present invention; 
           [0014]      FIG. 2  is an end view of the sand flap tool of  FIG. 1 ; 
           [0015]      FIG. 3  is an end view of the sand flap tool of  FIG. 2  in a time-lapse photographic representation of the tool of  FIG. 2  as it is rotated; and 
           [0016]      FIG. 4  is a perspective view of a sand flap tool of the present invention working on a work piece. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0017]    As shown in  FIG. 1 , the sand flap tool  10  of the present invention includes a housing  20  mounted to a shank  30 . The housing  20  preferably has a cylindrical shape and includes a sheet of sandpaper  40  mounted to it. The sheet of abrasive material (which may be thought of as sandpaper or a similar material)  40  has a rectangular shape to start, then one end of the sheet is attached to the round external surface of the cylindrical housing  20  and an opposite end of the sheet is cut to define a plurality of finger-like projections  42  extending from the sheet  40  at the other end from the end secured to the housing. In one embodiment, each of the finger-like projections  42  is approximately the same width, or about 3/16 of an inch, and each finger is defined by short (perhaps 1.25 inches) cut that extends generally parallel to each other and aligned generally with a transverse edge (of the rectangular sheet  40 ) that connects the end which is attached to the surface and the opposite end with the finger-like projections  42 . 
         [0018]    The rectangular sheet of sandpaper  40  with the finger-like projections  42  is secured at one end to the housing  20  and is wound in a first direction (shown by arrow A1) around the housing  20 , forming a generally spiral side view of the abrasive material. In one configuration of the present invention, the cylindrical housing  20  (and the mounted piece of sandpaper) has a length of approximately 3 inches and the sheet of sandpaper is divided into 16 finger-like projections of approximately the same width of 3/16 of an inch, although the fingers could be of somewhat greater or lesser size. While a single sheet of sandpaper  40  could be used, an assembly having a plurality of sheets of sandpaper  40  mounted spaced around the circumference of the cylinder could also be used to advantage. For example, if eighteen pieces of sandpaper are used, then one piece of sandpaper is mounted every 20 degrees around the circumference of the cylindrical housing  20 , allowing the process of finishing or sanding to progress faster. 
         [0019]    The shank  30  is a conventional tool shank of the type conventionally used to secure working tools within a chuck of a rotating tool such as a convention electric portable hand drill (not shown) or a drill press or similar rotating tool. Although many of such electric hand drills are known which operate to rotate a tool in a forward direction or a reverse direction, the preferred rotation for the drill or similar tool is shown by a second arrow A2, a direction which is oppose to the direction which each sheet of sandpaper  40  has been mounted to the cylindrical housing  20 . In this way, the ends  44  of the finger-like projections  42  are urged outwardly by centrifugal force of the rotating housing when the tool (e.g., the portable hand drill, not shown) is operated to rotate the housing  20  in the direction of the arrow A2. 
         [0020]      FIG. 2  is an end view of the sand flap tool  10  discussed in connection with  FIG. 1  above, taken from the right hand side of the tool in  FIG. 1 . This view shows the several pieces of sandpaper are spiraled around the housing  20 . These piece of sandpaper or abrasive material are represented by the reference numerals  40   a ,  40   b ,  40   c ,  40   d , . . .  40   q  and  40   r . The exact number of these pieces of sandpaper is somewhat a matter of design choice (it is believed that the present invention would work, albeit slowly, with a single sheet of sandpaper). In any event, each sheet of abrasive material is secured to the housing at one end and the other end is free. Thus, the piece of abrasive material  40   a  has a free end  42   a  and an opposed end  46   a  which is secured to the housing  20 . Because this is an end view, one cannot see the plurality of cuts along the length of the sheet or the individual finger-like projections created by the plurality of cuts. 
         [0021]      FIG. 3  is another end view of the sand flap tool  10  of the present invention, in an orientation similar to that of  FIG. 2  but including some representations of “time-lapse” photography as the tool  10  is rotate, e.g., by a user&#39;s electric drill, not shown in its preferred direction of rotation shown by the arrows A2. One such sheet of abrasive material is represented by the reference numeral  40   a   1  at a given point in time. The location of that same sheet at three previous times is represented by the reference numerals  40   a   2 ,  40   a   3  and  40   a   4 . Other sheets have similar representations, with the current position of a second sheet  40   b   1  also showing the location of that sheet at three previous times as well, by the reference numerals  40   b   2 ,  40   b   3  and  40   b   4 . 
         [0022]      FIG. 4  shows the use of the sand flap tool  10  of the present invention to work on a work piece  50 . An end surface  52  of the work piece  50  may have burrs or other imperfections s. In some applications, the work piece  50  may be made from wood and the process which formed the work piece—whether sawing, milling or other processing, may leave imperfections such as burrs which might snag or otherwise be disadvantageous. The sand flap tool  10  is rotated in the direction of the arrow A2 by a suitable drive (such as a portable electric drill, not shown, held by an operator). This rotation of the tool  10  cases the finger-like projections (the end of the sheet farthest away from the attachment of the sheet to the housing  30 ) to fan out due to centrifugal force on the ends of the sheet. However, where the work piece is brought into contact with the sand flap tool  10 , those ends are compressed and provide a polishing or sanding action on the end surface  52  of the work piece  50 . The force of the work piece  50  on a section of the sand tool  10  causes those finger-like projections  42  to compress and adds to the force applied by the abrasive sheet onto the work piece. Typically there is relative movement of the work piece  50  with respect to the sand flap tool  10 , a movement which is shown by the arrow F indicating that the work piece  50  is moved toward the tool  10 ; it will be appreciated that a similar arrangement can be obtained by moving the tool  10  into the work piece  50 , as might be the case where the work piece  50  is held in a vice or other suitable jig and the tool is moved by moving the portable electric drill (not shown) which is rotating the sand flap tool  10 . 
         [0023]    The present design uses the abrasive action of sheets of sandpaper, but it will be appreciated that much of the work (the abrading) will be accomplished with the outer portions of the sandpaper, and the amount of sanding or polishing will decrease as one moves inwardly from the outer edge of the sandpaper sheet, so that there will be little to no use of the sandpaper located well in from the outer edge. For this reason—and to obtain additional use from a given amount of sandpaper—it may be desirable to remove the outer edges of the sandpaper after the tool has been used for some time and the grit on the outer edges has become worn and less effective. Accordingly, the user may cut off the outer most ends of the finger-like projections at this point and continue to use the shortened pieces of sandpaper with a better supply of abrasive material. In some cases, it may be desirable to score such sandpaper to facilitate the remove of the leading edge of the sheet and expose an end which has better supply of abrasive. 
         [0024]    Of course, many modifications and adaptations of the preferred embodiment shown in the accompanying drawings and described above are possible without departing from the spirit of the present invention which is defined solely by the claims which follow. For example, while a cylindrical housing is desirable in some applications, another shape (such as an oval shaped housing, or a housing with a contour chosen to match the contour of a work piece to be worked) could be used to advantage in some situations. Also, for some work pieces, it might be desirable to have multiple cylindrical housings of different diameters attached together, for example, to work on a work piece with a larger portion and a smaller portion. While the finger-like projections might be formed with slits which are general parallel with each other and spaced equal distant from the adjoining projection, the present design does not require that the finger-like projections all be of similar size or shape, and in some cases it may be desirable to have thinner projections in one portion of the tool for finer polishing and a wider projection in other portions for coarser working of the work piece. Further, it may be desirable to use some of the features of the present invention without the corresponding use of other features. In some cases, it may be desirable to use a shank which is bent or flexible to allow the working on a work piece to occur with an orientation which is not an extension of the shank. Accordingly, it will be apparent that the present invention may be altered in many ways without departing from the spirit of the invention.