Abstract:
A musical instrument soundboard including a resonant layer affixed to a base layer by a non-dampening acoustic coupling layer. The resonant layer can be sheets, plates, flakes, granules and powders formed of metal, crystal, glass, and ceramic. A protective layer is positioned atop the resonant layer. When formed into a musical instrument, the soundboard is highly resonant so as to provide the musical instrument with excellent tone.

Description:
CONTINUING APPLICATION DATA  
       [0001]     This application is a continuation of U.S. patent application, Ser. No. 10/845,347, filed on May 14, 2004, now abandoned. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates generally to musical instruments and, more particularly, to body details thereof.  
       BACKGROUND OF THE INVENTION  
       [0003]     For centuries the makers of violins, pianos and other musical instruments have attempted to enhance the quality of the sound emitted from their instruments. These attempts have included changes in: instrument designs, construction techniques, building materials, and coatings. While many of these changes have resulted in the production of excellent musical instruments in terms of appearance and sound quality, it remains exceedingly difficult, even for the best instrument makers, to produce instruments with optimal tonal qualities. As costs of materials and labor continue to increase, only the wealthiest can expect to own the best looking and sounding musical instruments. This need not be the case, however.  
       SUMMARY OF THE INVENTION  
       [0004]     In light of the problems associated with producing musical instruments of the highest quality, it is a principal object of the invention to provide a musical instrument soundboard with both an attractive appearance and a high resonance. The soundboard responds readily to external periodic driving forces or oscillations such as those caused by vibrating strings attached to the soundboard. The soundboard increases the amplitude of the oscillations thereby producing a resonant characteristic that is pleasant to listeners.  
         [0005]     It is another object of the invention to provide a soundboard of the type described having an attractive and durable finish.  
         [0006]     It is a further object of the invention to provide a soundboard of the type described that can be incorporated into musical instruments of many types including, by way of example only: violins, guitars, pianos, trumpets, oboes, drums, cymbals and dulcimers.  
         [0007]     It is an object of the invention to provide improved elements and arrangements thereof in a musical instrument soundboard for the purposes described that is lightweight in construction, inexpensive to manufacture, durable, and dependable in use.  
         [0008]     Briefly, the musical instrument soundboard in accordance with this invention achieves the intended objects by featuring a resonant layer affixed to a base layer by an acoustic coupling layer. The resonant layer can comprise sheets, plates, flakes, granules and powders formed of metal, crystal, glass, and ceramic. A protective layer is positioned atop the resonant layer to prevent marring of the protective layer and the resulting diminution of the resonance of the soundboard.  
         [0009]     The foregoing and other objects, features and advantages of the present invention will become readily apparent upon further review of the following detailed description of the preferred embodiment as illustrated in the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0010]     The present invention may be more readily described with reference to the accompanying drawing that is a perspective view of a musical instrument having a soundboard in accordance with the present invention, the musical instrument having a portion thereof removed and enlarged to reveal details thereof. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0011]     Referring now to the drawing, a musical instrument in the form of a guitar  10  is shown to have a soundboard  12  in accordance with the present invention. Soundboard  12  includes a resonant layer  14  affixed to a base layer  16  by an acoustic coupling layer  18 . A protective layer  20  is positioned atop resonant layer  14 . When incorporated into musical instrument  10 , soundboard  12  provides instrument  10  with optimal sound production capabilities.  
         [0012]     Base layer  16  can be formed from any material known in the art for constructing a musical instrument. Such materials can include, by way of example: wood, metal, fiberglass, plastic, carbon fiber composite, bone, and animal hide. These materials can be used singly or can be laminated or otherwise pieced together as a manufacturer may desire. Furthermore, the dimensions of base layer  16  are a matter of design choice. Thus, base layer  16  can be a planar piece of spruce with two bouts connected by a narrow waist for use as the top of musical instrument  10  or it could be the coiled metallic tube that is the body of a trumpet (not shown). The possibilities are limitless.  
         [0013]     Should wood be employed to construct base layer  16 , it is preferably dried to limit subsequent shrinking, checking and cracking. Wood can be quickly dried in a kiln or more slowly dried by prolonged exposure to air. The application of supercritical fluids, such as carbon dioxide, to wood can also have a dehydrating effect. Of course, the use of these or any other dehydrants is within the discretion of the musical instrument manufacturer.  
         [0014]     Acoustic coupling layer  18  is applied by brushing, spraying, pouring, or otherwise positioning it upon base layer  16 . Although acoustic coupling layer  18  is shown positioned atop base layer  16  in the drawing, this is for the sake of convenience only as coupling layer  18  can be applied to any and all sides of base layer  16 . Preferably, acoustic coupling layer  18  comprises an oil or comprises an acoustic coupling gel that is compatible with base layer  16 . Alternatively, acoustic coupling layer  18  can comprise adhesive cement. Acoustic coupling layer  18  can, in terms of phase, be a solid, semi-solid or liquid in the completed soundboard  12 , such being a matter of design choice.  
         [0015]     Resonant layer  14  is positioned atop acoustic coupling layer  18  and is bonded by acoustic coupling layer  18  to base layer  16  so that layers  14 ,  16  and  18  oscillate in response to external periodic driving forces. Resonant layer  14  can be formed from a variety of solid materials including, but not limited to: metals (crystal, single crystal, glassy, and amorphous) like magnesium, aluminum or bell bronze; crystals like garnet; glass; leaded glass; mixed glass; and ceramics. Combinations of these materials can also be formed so that resonant layer  14  comprises: metals with ceramics or glassy metals with ceramics or amorphous metals with ceramics or metals with crystals or glassy metals with crystals or amorphous metals with crystals or metals with single crystals or ceramics with single crystals or glassy metals with single crystals. The materials from which resonant layer  14  is formed can be in the form of: sheets, plates, flakes, and finely divided aggregates and powders of varying particle size. For ease in applying a resonant layer  14  comprising small particles atop acoustic coupling layer  18 , the particles can be applied as a suspension in an evaporative liquid analogous to the liquid component of paint.  
         [0016]     Protective layer  20  is positioned atop resonant layer  14  to prevent the marring of resonant layer  14 . Preferably, protective layer  20  is a coating of varnish or other material compatible with base layer  16 , acoustic coupling layer  18  and resonant layer  14 . It is anticipated that protective layer  20 , will be thin, on the order of a few thousandths of an inch, so as to not appreciably reduce the resonance of soundboard  12 . If resonant layer  14  is sufficiently durable in its initial construction, as might be the case if resonant layer  14  comprises a glass plate or a metallic sheet, protective layer  20  can be omitted from soundboard  12 .  
         [0017]     From the foregoing, it should be appreciated that soundboard  12  is uncomplicated to construct and can be readily incorporated into the manufacture of numerous types of musical instruments. For example, in the construction of musical instrument  10 , base layer  16  is a thin sheet of spruce. Upon the top of spruce sheet  16  is sprayed a liquid adhesive cement, i.e., acoustic coupling layer  18 , upon which is positioned, before the cement has cured, resonant layer  14  comprising aluminum powder. After the adhesive comprising acoustic coupling layer  18  has set and the aluminum powder comprising resonant layer  14  is affixed to the spruce sheet comprising base layer  16 , protective layer  20  of varnish is sprayed. Once the varnish comprising protective layer  20  has set, and strings  22  capable of applying external periodic driving forces or oscillations are attached to soundboard  12 , strings  22  are plucked to oscillate them. Soundboard  12  increases the amplitude of the oscillations of strings  10  producing a resonant characteristic in air that is pleasant to nearby listeners. The resonance and tonal characteristics of soundboard  12  will be noted to be markedly better than an instrument  10  constructed in a conventional manner.  
         [0018]     While the invention has been described with a high degree of particularity, it will be appreciated by those skilled in the art that modifications may be made thereto. For example, it may be possible to incorporate more than one acoustic coupling layer  18  and resonant layer  14  into soundboard  12 , stacking them in the manner of a layer cake, to further enhance the resonant qualities of a soundboard. Therefore, it is to be understood that the present invention is not limited to the sole embodiment described above, but encompasses any and all embodiments within the scope of the following claims.