Patent Publication Number: US-2003224705-A1

Title: Diamond abrasive tonehole file for woodwind musical instruments

Description:
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OF DEVELOPMENT  
       [0001] Not Applicable  
       REFERENCE TO MICROFICHE APPENDIX  
       [0002] Not Applicable  
       BACKGROUND OF THE INVENTION  
       [0003] Steel files, stone lapping tools and abrasives attached to cloth or paper have been used to abrade and level the rims of musical wind instrument toneholes.  
       BRIEF SUMMARY OF THE INVENTION  
       [0004] The present invention uses diamonds as an abrasive to cut down and level the uneven rims of musical instrument toneholes so that the rims present a flat planar surface to the corresponding pads.  
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0005]FIG. 1 is a bottom view of a tonehole file and pilot.  
     [0006]FIG. 2 is a cross sectional side view of a tonehole file, pilot and tonehole.  
     [0007]FIG. 3 is a cross sectional side view of a tonehole file, pilot and tonehole showing diamond abrasive on the front and back side of the disc.  
     [0008]FIG. 4 is a cross sectional side view of a tonehole file, pilot and tonehole showing a layer of diamond abrasive that has been bonded to a disc with an adhesive.  
     [0009]FIG. 5 is a cross sectional side view of a tonehole file, pilot and tonehole showing a diamond abrasive on the front and/or back side of a disc that has an upward angled or curved outer edge.  
     [0010]FIG. 6 is a cross sectional side view of a tonehole file, pilot and tonehole showing a diamond abrasive on the front and/or back side of a disc that has a downward angled or curved outer edge.  
    
    
     DETAILED DESCRIPTION OF THE PRESENT INVENTION  
     [0011] The present invention is a disc  1  or combination of discs that have a diamond abrasive  2  on the surface of the disc. An additional pilot disc of a smaller diameter  3  may be attached to a larger disc  1  with the diamond abrasive  2  so that the pilot is inserted into the tonehole  4  and acts as a guide to keep the diamond faced/surfaced disc aligned and centrally located with the tonehole  4  of a musical wind instrument. The tonehole file assembly is then rotated so that it abraids the tonehole rim, bringing down the high spots so that it becomes flat. Musical wind instruments have toneholes that are covered or uncovered with pads. It is important that the rim of the tonehole be evenly flat or flat in plane so that the pad can form a good seal on the tonehole rim, Tonehole rims that are not flat are more likely to have unwanted leaks and are more difficult to correct when repairmen attempt to level the pad so that it makes a good closing seal all the way around the circumference of the tonehole.  
     [0012] The diamonds can be any reasonable grit or micron size and can be attached to any surface of the file/disc. For example the diamonds may be attached to the front and back surfaces so that either side can be used to abrade the rim of the tonehole as shown is FIG. 3. The discs can be of any practical thickness. They need not be round and can have any number of sides on the periphery.  
     [0013] A bolt or screw  5  is provided in the center of the disc so that a wrench or other driver can be used to turn the diamond faced disc and pilot assembly. The bolt can be a common hex head bolt, or screw driver head, or allen head/cap screw. The rotary file can be driven by hand, by an automotive type ratchet or an electric drill or similar motor. One embodiment of the invention is to use an Allen head/cap screw and turn it with a T handled driver. The Allen wrench can have a ball end so that the wrench will tilt to some degree without rocking the rotary file out of plane with the tonehole rim. The ball end Allen wrench makes it easier to form a perfectly flat tonehole rim. The bolt or screw  5  is threaded into the center of the disc/pilot  1  so that various size diamond faced discs/pilots can be attached to each other to fit various size toneholes  4 . The disc can be made of any metal, plastic or other stiff material. Diamond faced discs can also serve as pilots when attached to diamond faced discs of a larger size. Or the pilot can be a disc without the diamond abrasive. The pilot may be made of plastic so that the interior of the tonehole is not damaged or marked when rubbed against by the turning pilot disc.  
     [0014] A disc with diamond abrasive may have an upward or downward angled or curved outer edge as shown in FIGS. 5 and 6. The angle or curve makes it possible to chamfer or de-burr the inner and outer corners of the tonehole rim to remove any sharp edge that might damage a pad that comes into contact with the tonehole rim.  
     [0015] Steel files have a tendency to chatter on the tonehole, thus leaving an undesirable rough finish. Sandpaper abrasives such as silicone carbide wear out much too quickly and are thus unsatisfactory. Diamonds are the hardest material know. They provide the best abrasion because they stay sharp and are extremely resistant to wear. Diamond abrasives are widely used in the machine tool industry and diamond/cutting tools are known for their excellent durability. They cut fast and smooth and do a better job than any other abrasive. Another super abrasive that could be used in substitution for diamonds is Cubic Boron Nitride.  
     [0016] The diamonds may be attached to a thin metal sheet by adhesive, plating or other bonding process and then the thin metal sheet can be bonded to the disc by adhesive, solder, brazing, welding or other method. The preferred method is to first machine the surface of the disc so that it is flat and then bond or embed the diamonds directly to the disc surface. One way to attach the diamonds directly to the disc is to apply diamonds to the disc surface and then electroplate the surface with nickel or other metal so that the plating grabs or partially surrounds the diamonds and holds them fast to the disc surface. This diamond/electro-plating method is commonly used in the diamond tool industry.  
     [0017] The diamonds may be attached to a non-metallic sheet  6  and the sheet can then be attached to a rigid disc  1  by an adhesive or bonding process as shown in FIG. 4. Diamond abrasives that are first attached to a paper, mat or other material before being attached to a rigid disc will also work well but the abrasive surface may not be as perfectly dimensioned because of irregularities in the paper, mat or the adhesive layer that is used to bond the abrasive to the rigid disc. For the tonehole file to work well, the abrasive should have an excellent planar flatness so that the rim of the tonehole is abraded perfectly flat. Using a mat, paper layer or other non-metallic substrate between the diamonds and the rigid disc is usually not as durable or desirable and may be subject to premature failure. There are several methods of attaching diamond abrasives to rigid discs and some will provide better service than others. The present invention includes all of these methods whether or not they are specifically mentioned.