Abstract:
A musical instrument of the chordophone family is provided that has reduced stresses and strains, and is easily assembled. A braceless system both reduces the stresses and allows for the elimination of bracing. As a consequence, a binding and kerfing unit is used, further increasing the ease of construction. Additionally, the instrument is provided with an offset headstock to allow the strings to be normal to the bridge, still further reducing the stresses and strains in the instrument. A method of constructing the instrument is also provided.

Description:
FIELD 
       [0001]    The present technology is directed to a string instrument in which the stresses and strains on the soundboard are reduced through the implementation of a braceless system and an offset headstock. More specifically, the present technology is directed to a guitar having the braceless system and an offset headstock. 
       BACKGROUND 
       [0002]    Acoustic string instruments are subjected to high stresses and strains caused by the strings. As the instrument is tuned, the strings are tightened, leading to force developing between the neck and the soundbox. The direct recipient of the force is the bridge. The force is then indirectly exerted on the soundboard. This may lead to damage to both the bridge and the soundboard. In extreme cases, the neck can also be affected by damaging the joint between the neck and the soundbox of the instrument. 
         [0003]    The inner surfaces of the soundboard and back of guitars are provided with bracing to counteract the force. A complex pattern of bracing is used on the inner surface of the back. During construction of the instrument, a luthier spends a significant amount of time shaping the bracing in order to tune the instrument. In order to reduce the work, Griffiths (U.S. Pat. No. 6,333,454) provides a bracing system that combines kerfing, binding and bracing. One unit is for use with the soundboard and a second unit is for use with the back. 
         [0004]    In U.S. Pat. No. 7,462,767, a bracing system is used to counter balance the force by using an additional string or cable, preferably made of Kevlar, carbon fiber or a similar non-elastic material, that is attached to the bridge and the neck of the guitar within the soundbox. A bracket is located inside the soundbox of the instrument and attached to the bottom of the bridge of the instrument. It is connected to an adjustable brace by a non-elastic string. The adjustable brace may adjust the tension placed upon the string to control the amount of counter-balancing tension. This system does not alleviate the force, but rather, simply counter balances the force. 
         [0005]    Another cause of stress to the instrument arises because the strings are not aligned between the headstock and the bridge such that they are normal to the bridge. The strings therefore exert a twisting force on the bridge and soundbox. 
         [0006]    Despite the fact that many instruments are damaged by the two forces, those of the force on the bridge and soundboard and the force on the neck and the soundbox, the string instrument industry is reluctant to make change to reduce the forces exerted, preferring to retain the “look” of the instrument in preference to the health of the instrument. 
       SUMMARY 
       [0007]    The present technology provides a system for reducing the forces exerted on instruments in the chordophone family by the strings. The braceless system reduces the tension on the soundboard and the span thereby allowing the top to resonate freely without bracing for strength, as much of the tension is relieved. A further reduction in stresses and strains on the instrument can be provided by an offset headstock. This allows for the strings to remain normal to the span, as the offset side has two tuning keys and the side opposite to the offset has four tuning keys. 
         [0008]    An additional advantage of the braceless system is the saving in construction time. As the name suggests, there is no need for bracing. Consequently, there is no need for the luthier to spend hours tuning the soundboard by carefully carving away bracing in order to achieve the desired tone. 
         [0009]    The technology further provides a universal binding and kerfing unit. The unit is universal in that it can be used interchangeably for connecting the soundboard to the sides and the back to the sides. This allows for easy and quick assembly of the string instrument. 
     
    
     
       FIGURES 
         [0010]      FIG. 1  is a perspective view of the guitar of the present technology. 
           [0011]      FIG. 2  is a longitudinal section view of the guitar of  FIG. 1 . 
           [0012]      FIG. 3  is a view of the binding and kerfing unit of the present technology. 
           [0013]      FIG. 4  is a plan view of the floating bridge region of the braceless system of the present technology. 
           [0014]      FIG. 5  is a perspective view with cutaway of the guitar of the present technology. 
           [0015]      FIG. 6  is an exploded view of the neck region of the braceless system. 
           [0016]      FIG. 7  is a longitudinal section view of the floating bridge. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    A guitar, generally referred to as  10  is shown in  FIG. 1 . The guitar has a headstock  12  and a neck  14  extending therefrom. The neck  14  is connected to a soundbox, generally referred to as  16  at a proximal end  18  of the neck  14 . The soundbox  16  has a soundboard  20  forming the top of the soundbox  16 . A sound hole  22  is located centrally in the soundboard  20 . Binding  28  can be seen between the soundboard  20  and the sides  26 . As can be seen in  FIG. 2 , binding  28  can is also between the back  30  of the guitar  10  and the sides  26 . The binding  28  is provided as a binding and kerfing unit  39 . 
         [0018]    Referring still to  FIG. 2 , it can be seen that the soundbox  16  is defined by the inner surface  32  of the soundboard  20 , the inner surface  32  of the sides  26  and the inner surface  36  of the back  30 . The binding and kerfing unit  39 , runs the perimeter of the joints between the sides  26  and both the soundboard  20  and the back  30  on the side inner surfaces  32 ,  36  and distal inner surface  34 , and provides structural support for the soundbox  16 . As can be seen in FIG.  3 , the binding and kerfing unit  39  is universal in that it can be used interchangeably for connecting the soundboard  20  to the sides  26  and the back  30  to the sides  26 . Returning to  FIG. 2 , a neckblock  40  is located in the soundbox  16  proximate the neck  14 . 
         [0019]    Returning to  FIG. 1 , the headstock  12  is provided with tuning keys  42 . In the prior art, the headstock is symmetrical and there are an equal number of tuning keys  42  on either side of the headstock  12 . In contrast the headstock  12  of the present technology has an offset  44 . There are two tuning keys  42  located on the same side as the offset  44  and four tuning keys  42  located on the side opposite to the offset  44 . This allows the strings  46  to extend in a parallel manner between the headstock  12  and the span  48  and to be normal to the span  48 . 
         [0020]    As shown in  FIG. 2 , the strings  46  do not terminate at pins that are engaged with the bridge as occurs in the guitar prior art or the tail piece as occurs in the violin prior art, but rather continue to a floating bridge, generally referred to as  62 . The floating bridge  62  is part of a braceless system, generally referred to as  50 . As shown in  FIG. 4 , the floating bridge  62  consists of a span  48 , and a member  64  that includes a series of fingers  66 , a series of bodies  68  and a series of connectors  70 . As shown in  FIG. 5 , the bodies  68  are in engagement with the span  48  by means of the fingers  66  and the connector  70  to create a pivot point  84 . The pivot point  84  should be aligned in the same plane as the strings  46 . The combination of the fingers and connectors both allows for adjusting intonation of each string  46  and relieves tensions that would normally be present on the bridge and top of a conventional guitar. This allows the soundboard  20  to function solely as a resonant membrane rather than a structural support and resonant membrane. 
         [0021]    In one embodiment a threaded ball  71  functions as the connector  70 . Each finger  66  terminates in a ball  71  that is located in a socket  72  on a distal side  74  of the span  48 . This allows for rotational movement of the fingers  66 . The fingers  66  are threaded  61  and are therefore in adjustable engagement with the bodies  68 . A spring  76  surrounds each finger  66  and extends between the proximal side  78  of the span  48  and each body  68 . As shown in  FIG. 2 , each body  68  has a wedge-shaped opening  80  at a proximal end  81  to engage the strings  46 . The strings pass through the wedge-shapes openings  80  and terminate in individual keyholes  82  in the soundboard  20  of the guitar  10 . 
         [0022]    In another embodiment, the connector is integral with the finger  66  and the unit is constructed of a material, such as a plastic polymer, that permits flexing between these components. In all embodiments, in order to reduce stresses on the soundboard  20 , it is preferable that the circular movement of the strings  46  when strummed is accommodated by resultant movement of the bodies  68  in at least two planes (up and down and side to side) and preferably in a circle, therefore in all embodiments the connector, whether integral or not is selected to provide such movement (referred to as “substantially rotatable”). This differs from a conventional guitar as the pins of a conventional guitar only accommodate up and down movement of the strings  46 , again resulting in torsional stress on the soundboard. 
         [0023]    As shown in  FIG. 5 , the floating bridge  62  is attached to a strut  90  by means of two adjustable posts  92 , for example, bolts. More specifically, the posts  92  slot into keyways  94  in the proximal side  78  of the span  48 , pass through floating bridge apertures  96  in the soundboard  20 , and are threadably attached to a T  98 , which in turn is attached to the strut  90 . 
         [0024]    As shown in  FIG. 6 , it can be seen that a soundbox aperture  100  is provided in the soundbox  16  for receiving the neck  14 , neckblock  40  and strut  90 , with the T  98  attached. These can be assembled and then introduced as a unit. Returning to  FIG. 2 , the strut  90  abuts the distal inner surface  34 , and is adjustably affixed to the distal inner surface  34  by a bolt  102  or by the strap peg. Further adjustment can be made by tightening or loosening the posts  92 . These adjustments alter the effective length of the strut. Effective length in this context is measured as the distance between the inner surface  36  of the back  30  and the neckblock  40 . 
         [0025]    As shown in  FIG. 7 , the bodies  68  are preferably each provided with transducers  104  or musical instrument digital interface (MIDI), located in the vicinity of the bottom  65  of the bodies  64 . This allows for individual processing of each string. 
         [0026]    The guitar of the present technology can be assembled very quickly as follows: 
       1. Construction of the Body of the Guitar: 
       [0027]    The binding and kerfing unit  39  is used to attach the sides  26  to the soundboard  20  and back  30  of the guitar  10 . 
       2. Introduction of the Braceless System: 
       [0028]    The neck  14 , neckblock  40  and strut  90 , with the T  98  attached are slid into the soundbox  16  of the guitar  10  as a unit, through the soundbox aperture  100 . The strut  90  abuts the distal inner surface  34 , and is adjustably affixed to the distal inner surface  34  by a bolt  102  or by the strap peg. The braceless system  50  is then assembled by placing the floating bridge  62  comprising the span  48 , the series of fingers  66  and the series of bodies  68  on the soundboard  20 , slotting posts  92  into the keyways  94  in the proximal side  78  of the span  48 , passing the posts  92  through apertures  96  in the soundboard  20  and attaching them to the T  98 . Further adjustment can be made by tightening or loosening the posts  92 , allowing for intonating the guitar  10 . The pivot point  84  should be aligned in the same plane as the strings  46 . 
       3. Adjustment of the Braceless System: 
       [0029]    Adjustments are made by tightening or loosening the posts  92  and/or the bolt  102 . This in turn adjusts the force exerted on the floating bridge  62 . 
       4. Stringing the Instrument: 
       [0030]    The instrument is strung by securing each string  46  in the wedge-shaped opening  80  and through the soundboard  20  via the keyholes  82 . It is important that the string pull comes from the wedge-shaped opening  80 . The strings  46  are wound onto the tuning keys  42 , noting that the alignment of the strings  46  is kept normal to the span  48  by the offset  44 . 
         [0031]    The foregoing is a description of an embodiment of the technology. As would be known to one skilled in the art, variations that do not alter the scope of the technology are contemplated. For example, the instrument may have more or less than six strings and need not be a guitar, but any instrument in the chordophone family, for example but not limited to a violin, a ukulele, lute or mandolin. Regardless of the plurality of strings, the offset will allow for an uneven distribution of the tuning keys between the sides of the headstock, thereby allowing for the strings to be normal to the span. Further, more than one set of strings can be used, for example, the instrument could have a six string and twelve strings embodiment, wherein two braceless systems would be used having a total of four struts, or a combination wherein three struts were employed. A bolt  86  or other connector, such as a screw, could adjustably attach each finger  66  to the span  48 , with a rubber bushing  88  separating the finger  66  from the span  48 . The thickness and tensile strength of the components would be selected to permit flexing. The braceless system can be constructed in a number of ways. For example, the neck and strut could be a unit body construction, the strut could be a solid member, or could be a truss, and the floating bridge could be a variety of shapes, the constraints being that the torsional stress on the soundboard is reduced or eliminated by providing a connector that is substantially rotatably attached to the span and is substantially parallel to the strut, such that the force of the string pull is directed to the floating bridge and not to the soundboard of the instrument. The binding and kerfing unit may be constructed of a number of materials, including but not limited to a plastic polymer, aluminum, titanium, graphite, carbon fibre or brass.
       comprises attaching two strings to the tuning keys in the vicinity of the offset and four strings to the tuning keys opposite the offset.