Abstract:
A self aligning folding guitar comprises a neck portion, and a body portion. They hinge it is mounted to the neck portion and the body portion. A first alignment member is secured to the neck portion. The second alignment member is secured to the body portion, the second alignment member meeting with the first alignment member at a substantially fixed position. A securement member secures the first alignment member to the second alignment member.

Description:
TECHNICAL FIELD 
       [0001]    The invention relates to a folding guitar with a position locking mechanism. 
       BACKGROUND OF THE INVENTION 
       [0002]    The manufacture of note producing musical instruments began as a search for the mechanical equivalent of the human voice. This in fact remained the standard through the Middle Ages and into the Renaissance and the early modern period. 
         [0003]    Stringed instruments have been known since ancient times. These included such instruments as the lute, a guitar-like instrument with a sound box and fingerboard. A New Kingdom (ancient Egypt, 1380 BC) bronze in the collection of the Metropolitan Museum of Art depicts a dancing Nubian raised on his toes with one knee cocked, left hand high working a fingerboard and right hand plucking the strings in a pose which might be illustrative of a modern rock musician. 
         [0004]    But the lute has a much more ancient history, perhaps originating with West Semitic nomadic people who brought the instrument to Mesopotamia, where the archaeological record includes representations dating back to the Akkadian period (2350 to 2170 B.C.), being introduced to the Egyptians, perhaps at the end of the Middle Kingdom Hyksos dynasties (XV to XVII dynasty, 1730 to 1580 B.C.). 
         [0005]    In more recent times, stringed lute-like musical instruments continue to be among the most popular instruments. Folk artists throughout the United States have used the guitar, sometimes one of the homemade variety, in a wide range of musical genres including blues, bluegrass, and so forth. 
         [0006]    In contrast to percussive instrumentation, the need for amplification of the relatively weak sounds of strings, reeds, and vibrating human lips presented challenges to early musical instrument manufacturers. These challenges were met primarily by resonant systems that mechanically concentrate, and output musical sound. There is a demanding standard in the stability of the instrument if high-quality sound is to be produced. 
         [0007]    Moreover, over the years, artists playing acoustic stringed instruments have introduced a wide variety of playing techniques into the music surrounding these instruments. While, perhaps, the ancients only plucked the strings of the lute to achieve a musical tone which gradually decayed, later artists used the bow to produce notes of relatively constant and somewhat controllable amplitude. Modern artists employ a variety of techniques in their performances. Acoustic blues performers may rap their instruments with fingertips, palms or knuckles. Certain violin compositions, typically played by having a horsehair bundle slide across the strings, also call for the strings to be plucked. This results in yet greater demands being put on the mechanical stability of the instrument. 
         [0008]    Given the popularity of stringed musical instruments, especially the guitar, people often take them along when traveling. However, they are bulky and poorly suited to convenient transport. They are unlikely to fit into airlines stowaway spaces or under airline seats. In response to this need, guitars with folding necks have been proposed. See for example my earlier United States Design Pat. No. 516,114, and my earlier pending U.S. patent application Ser. No. 11/640,095, filed Dec. 15, 2006. While this instrument is effective, it is difficult to make requiring significant handwork and fine tuning. 
         [0009]    Accordingly, there is a need for a stringed instrument which may be a guitar, violin or the like and which is easy to use during a performance, consistent, and rigorous in its transduction of artistic interpretations into an acoustic or other performance and easily transportable. It is believed that the structure disclosed herein is a most effective solution in providing for a highly mobile instrument which may be accommodated to a range of user preferences. 
         [0010]    This invention also relates to hinges and particularly what is commonly known as invisible hinges for the use in connection with doors and other swinging articles and the invention described here is an improvement on previous designs for the specific use where a very narrow surface is available for the hinge mechanism and the hinge must be able to support a proportionally much longer perpendicular surface. Also significant to this invention is the method used to locate and install the hinges. 
         [0011]    In this type of hinge the hinge parts are connected by pivoted linkages hinged on a hinge pin and sliding on sliding pins, the linkages being within pockets or compartments within the hinge parts, that is the hinge plates or butt plates. An early version of such hinges is a hinge design created by Joseph Soss and bearing his name. It is illustrated in several patents including U.S. Pat. Nos. 1,030,936, 1,484,093, 1,688,996, 1,984,092, and 2,178,271 among others. A hinge of this sort is employed in the above referenced design patent. 
         [0012]    These hinges are designed to be invisible when in the closed position and allow for the focal point of the hinge to be below the surface when in the closed position and then extend beyond the surface to allow for a full 180 degree opening. Two basic versions of the hinge are common, the first having a long narrow body with two attachment screws, one located at each end. This style is of a shape requiring a multi-level mortise cut for installation, the second is a cylinder or barrel hinge with a side mounted screw as a means of attachment and requiring a hole to be bored for installation. 
         [0013]    These previous designs are of a similar nature but either lacks the clearance necessary, have methods of attachment that are either insufficient or impractical in a guitar with a folding neck and also require a complex process to create the openings for the hinge butt plates or cylinders. 
         [0014]    Furthermore, while a version of the previous design has been proven capable of supporting this application to some extent in above United States Design Pat. No. D516,114, it has been found lacking in several areas with regard to effective production beyond the small, hand assembly shop. 
         [0015]    First, these hinges, known as “barrel hinges,” require a final outer surface, an example being a fretboard on musical instruments, to be attached out of sequence with normal production procedure and require holes to be bored extremely close to the surface of the fretboard weakening this vital structural member. 
         [0016]    Second, these hinges are very difficult to set accurately with respect to depth and alignment. The other version of Soss hinge has better means of securement and greater location and depth control. However, its design only allows for a single hinge to fit in the required area which lacks the structural integrity for this application and lacks sufficient capability to adequately align the two hinged parts. Furthermore, the location of the securement screws is too close to the outer edges of the members, which in this application creates problems because of the lack of material for the screws to properly secure themselves. Currently available versions also lack the opening clearance needed for guitar hinge application. Finally, the means required to cut the mortises is very time consuming and difficult to consistently achieve. 
         [0017]    In my copending patent application, U.S. patent application Ser. No. 11/640,095, I proposed an improved hinge for use in a folding guitar. 
       SUMMARY OF THE INVENTION 
       [0018]    In accordance with the invention, the improved alignment provided by that improved hinge is still further improved by the self-aligning locking mechanism provided in accordance with the present invention. Such mechanism may be a screw or a bayonet type engagement. 
         [0019]    In accordance with the invention, a self aligning folding guitar comprises a neck portion, and a body portion. The hinge it is mounted to the neck portion and the body portion. A first alignment member is secured to the neck portion. The second alignment member is secured to the body portion, the second alignment member meeting with the first alignment member at a substantially fixed position. A securement member secures the first alignment member to the second alignment member. 
         [0020]    The first alignment member may include a conical surface. 
         [0021]    The first and second alignment members may define surfaces which fit to each other. 
         [0022]    The securement member is a threaded member. 
         [0023]    The securement member may be a bolt or a bayonet. 
         [0024]    Advantageously, the first alignment member may define an elongated bore for receiving the securement member. 
         [0000]    The first alignment member may comprise a pipe like member with an internal thread and a frustroconical stud which screws into the pipe like member. 
         [0025]    The second alignment member may comprise a solid body with a receiving volume which mates with the frustroconical stud, and further defines a threaded bore for receiving the securement member. 
     
    
     
       BRIEF DESCRIPTION THE DRAWINGS 
         [0026]    The operation of the invention will become apparent from the following description taken in conjunction with the drawings, in which: 
           [0027]      FIG. 1  is schematic side view illustrating the male member of the self-aligning mechanism of the present invention; 
           [0028]      FIG. 2  is a plan view of the bolt-receiving hole in the member of  FIG. 1 ; 
           [0029]      FIG. 3  illustrates the locking screw used in accordance with the present invention; 
           [0030]      FIG. 4  illustrates the female member of the self-aligning mechanism of the present invention; 
           [0031]      FIG. 5  illustrates the male and female members installed on a guitar or other string instrument in the open configuration; 
           [0032]      FIG. 6  is a side view similar to  FIG. 5  illustrating the alignment operation; 
           [0033]      FIG. 7  is a side view similar to  FIG. 6 , showing the guitar neck in the playing position; and 
           [0034]      FIG. 8  is a view similar to  FIG. 7  showing the guitar neck locked in the playing position; 
           [0035]      FIG. 9  illustrates an alternative locking member; 
           [0036]      FIG. 10  illustrates an alternative embodiment of a female member in accordance with the present invention for receiving the alternative locking member of  FIG. 9 ; 
           [0037]      FIG. 11  is a along lines  11 - 11  of  FIG. 10 ; 
           [0038]      FIG. 12  illustrates the alternative embodiment of the female member of the present invention in the locking position; 
           [0039]      FIG. 13  illustrates the inventive locking mechanism installed in a guitar; 
           [0040]      FIG. 14  is a perspective view of an improved hinge useful with the locking mechanism of the present invention; 
           [0041]      FIG. 15  is a perspective view of the hinge of  FIG. 9  in the closed position from the bottom; 
           [0042]      FIG. 16  is a perspective view of the hinge of  FIG. 9  from the top; 
           [0043]      FIG. 17  is a view similar to  FIG. 9  of another alternative hinge design; 
           [0044]      FIG. 18  is a view similar to  FIG. 10  of the hinge illustrated in  FIG. 12 ; and 
           [0045]      FIG. 19  illustrates the hinge of  FIGS. 12 and 13  in use. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0046]    Referring to  FIG. 1 , the neck  12  of a folding guitar is provided with a male alignment member  15 . An alignment member  15  comprises a docking member  17  which screws into the threaded bore  19 . Docking member  17  includes they had  21  and an integral threaded tubular member  23 . 
         [0047]    Alignment member  15  further comprises elongated tube  25  which includes a top flange  27 . Flange  27  defines an elongated hole  29 . Hole  29  receives a bolt  31  ( FIG. 2 ) which includes a fictionally engaged retainer washer  33 , as is described in detail below. 
         [0048]    A mating female member  35 , as illustrated in  FIG. 4  is mounted in the body  14  of the guitar, passing through bout  26  support block  50 . A bolt  37  passes through block that to mate with female member  35 . Female member  35  includes a receiving cone  39 , which receives and mates with head  21 , to securely lock neck  12  with respect to body  14  of the guitar. 
         [0049]    As shown in  FIG. 5 , neck  12  is mounted to the body  14  of the guitar by a hinge  48 . During use, neck  14  is pivoted toward body  12  from the position illustrated in  FIG. 5  to the position illustrated in  FIG. 6 . Due to wear or normal tolerances in hinge  48 , there may be some misalignment, as is illustrated in  FIG. 6 . Such misalignment is addressed by the engagement of surface  41  by surface  43  during the advancement of neck  12  from the position illustrated in  FIG. 5  to the position illustrated in  FIG. 6  and on to the position illustrated in  FIG. 7 . 
         [0050]    Misalignment does not affect the ability to screw bolt  31  into bore  49  because elongated hole  29  allows proper alignment of bolt  31  with bore  49   
         [0051]    Once the guitar has been put in the configuration illustrated in  FIG. 7 , both  31  may be tightened to take the position illustrated in  FIG. 8 . 
         [0052]    Referring to  FIG. 9 , a bayonet  131  with a retainer washer  133  and an arm  134  may be used instead of bolt  31 . As shown in  FIG. 10 , a ramp  136  is engaged by the arm  138  of bayonet  131 . Ramp  136  as a shallow side  140  and a high side  142 . During use arm  138  engages shallow side  140  after passing through notch  144 , and is rotated to high side  142  to securely be locked in position, as illustrated in  FIG. 12 . 
         [0053]    Referring to  FIG. 13 , a musical instrument constructed in accordance with the present invention is illustrated in which the self alignment structures of the present invention all our employed. While the invention may be employed in connection with acoustic or electrical guitars, violins, violas, bases, banjos or other stringed instruments, for purposes of illustration an acoustical guitar  10  is illustrated. 
         [0054]    Generally, guitar  10  comprises a large hollow body  12 , secured to the inventive neck  14 . Neck  14  comprises a head  16 , which accommodates tuning screws  18  in a conventional manner. 
         [0055]    Body  12  comprises top plate  20  which defines a sound hole  22 . Bottom plate  24  is secured to top plate  20  by bouts  26  and  28  which together form a guitar sound box sidewall having U-shaped upper and lower ends at the heel and tail ends of the body  12 , and a curved central bout  30  and curved central bout  32  (not illustrated) which form the waist of the instrument. 
         [0056]    Neck  14  supports a neck fretboard  34 , which is glued to neck  14 . Neck fretboard  34  supports a plurality of frets  36 . Neck base  38  supports a neck base fretboard  40 , which is glued to neck base  38 . Neck base fretboard  40  supports a plurality of frets  42 , against which strings  44  are played. For purposes of clarity of illustration, strings  44 , which are supported by bridge  46  are illustrated partially and in phantom lines. Guitar neck  14  may be folded by rotation in the direction of arrow  47 . 
         [0057]    A preferred embodiment of a hinge  448  for use with the self aligning mechanism of the present invention is illustrated in  FIGS. 14-16 . Hinge  448  comprises Soss link assemblies  449 , which comprise hinge links  468 , hinge pins  470 , hinge pins  472  and pins  478 . The operation of this hinge is similar to other Soss hinges. However, advantages are provided by the placement of screw hole  476 , which because it is proximate side  477  of hinge  448  supports a screw which is driven into the, for example, neck at a point where there is sufficient wood on all of the sides of the screw to provide excellent support. At the same time, sidewalls  479  have a relatively small thickness  481  which promotes making available added thickness for Soss link assemblies  449 . Slanted tracks  474  cooperate in providing the requisite configuration to allow use of the hinge in a guitar with a hinged neck. 
         [0058]    In addition, compactness and strength is provided by thin receiving recesses  481 , which allow the relatively large heads of robust pins  470  to be seated. 
         [0059]    In accordance with a particularly preferred embodiment of the invention, it has been discovered that a short version of the hinge, as illustrated in  FIGS. 17-18  is relatively advantageous. Hinge  548  is similar in construction otherwise to hinge  448 . Part of the advantage of this construction may be seen from  FIG. 19 , where the shallower hinge butt results in a shorter lever arm acting through screw  583  to reduce the integrity of hole  585  in which screw  583  is seated, thus promoting the long-term stability of the guitar body  512  and guitar neck  514 . 
         [0060]    In accordance with a preferred embodiment, hinge  548  includes sidewalls  579  having a thickness  585  of approximately 0.25 cm. The thickness  587  of the links  568  is also 0.25 cm. The sidewalls  579  have a height  589  of 2 cm and a length  591  of 2 cm. Sidewalls  579  have a length  593  of 2 cm. Likewise, in accordance with a preferred embodiment, hinge  548  has a width  595  of 4 cm. 
         [0061]    While illustrative embodiments of the invention have been described, it is, of course, understood that various modifications will be obvious to those of ordinary skill in the art. Such modifications are within the spirit and scope of the invention as illustrated and defined only by the appended claims.