Patent Publication Number: US-8119892-B2

Title: Latch for travel guitar with hinged neck

Description:
TECHNICAL FIELD 
     The invention relates to a latch for locking the neck of a hinged neck traveling guitar in place. 
     CROSS REFERENCE TO RELATED APPLICATIONS 
     (Not applicable) 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     (Not applicable) 
     BACKGROUND OF THE INVENTION 
     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. 
     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. 
     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.). 
     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 varieties, in a wide range of musical genres including blues, bluegrass, and so forth. 
     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. 
     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. 
     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 U.S. 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. 
     In order for a hinged neck traveling guitar to be used, one must employ a latch to hold the neck in the playing position after the neck has been moved from the travel or storage position to the playing position by rotation of the neck about the hinge. This latch should be easy to use and at the same time positively lock the neck in the proper position, or the acoustics of the guitar will be degraded. 
     SUMMARY OF THE INVENTION 
     In accordance with the invention, a latch is provided which is easy to use, requiring only that the user insert a ball-terminated arms in a catch and rotate a lever. 
     The inventive folding guitar comprises a guitar body and guitar neck. A hinge connects the guitar body to the guitar neck. The hinge is disposed on one side of the guitar body and guitar neck. A latch plate is secured to the other side of one of the guitar body or guitar neck. A catch member is secured to the other side of the other one of the guitar body or guitar neck. The catch member defines a catch member catch surface. A latch arm is pivotally mounted to the latch plate. A hitch arm is pivotally mounted to the latch arm. 
     A securement member mounted on the hitch arm, the securement member think configured to engage the catch member catch surface. The latch arm, hitch arm and latch plate are configured to vary the distance between the securement member and the catch member catch surface. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The operation of the invention will become apparent from the following description taken in conjunction with the drawings, in which: 
         FIG. 1  is a side view generally illustrating a general implementation of the latch of the present invention; 
         FIG. 2  is a view similar to  FIG. 1 , but illustrating hidden portions of parts in phantom lines; 
         FIG. 3  is an exploded side plan view of the principal components of the inventive latch; 
         FIG. 4  is a diagrammatic side view of the components of the inventive latch similar to  FIG. 2 , superimposed over each other in position, but not using any hidden lines; 
         FIG. 5  illustrates operation of the inventive latch; 
         FIG. 6  illustrates another embodiment of the hinge of the present disclosure in exploded perspective; 
         FIG. 7  is a top view of a latch plate of the hinge of  FIG. 6 ; 
         FIG. 8  is a side view of the latch plate of  FIG. 7 ; 
         FIG. 9  is a bottom view of the latch plate of  FIG. 7 ; 
         FIG. 10  is a perspective view of the latch plate of  FIG. 7 ; 
         FIG. 11  is a side view of the latch arm of the hinge of  FIG. 6 ; 
         FIG. 12  is a perspective view of the latch arm of the hinge of  FIG. 6 ; 
         FIG. 13  is a perspective view of the hitch body of the hinge of  FIG. 6 ; 
         FIG. 14  is a side view of a hitch arm of the hinge of  FIG. 6 ; 
         FIG. 15  is a perspective view of a hitch arm of the hinge of  FIG. 6 ; 
         FIG. 16  is a perspective view of the guide of the hinge of  FIG. 6 ; 
         FIG. 17  is a plan view of a guide of the hinge of  FIG. 6 ; 
         FIG. 18  is a perspective of the heel catch plate of the hinge of  FIG. 6 ; 
         FIG. 19  is a side plan view of the heel catch plate of the hinge of  FIG. 6 ; 
         FIG. 20  is a side plan view of the heel catch plate of the hinge of  FIG. 6 ; 
         FIG. 21  is a top plan view of the heel catch plate of the hinge of  FIG. 6 ; 
         FIG. 22  is a top plan view of a third embodiment of the inventive hinge; 
         FIG. 23  is a perspective view of the hinge of  FIG. 22  with the latch arm in the unlocked position; 
         FIG. 24  is a bottom plan view of the hinge of  FIG. 22 ; and 
         FIG. 25  is a detail of the hinge of  FIG. 22 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to  FIGS. 1-5 , and in particular initially to  FIG. 1 , a latch  10 , constructed in accordance with the present invention is illustrated. Latch  10  comprises a guitar body base plate  12  which is secured to the body  14  of a guitar ( FIG. 5 ) by screws  19 , which are secured in holes in guitar body  14 . Base plate  12  includes integral upstanding walls  16 . Walls  16  include holes  18  which support short pivot pins or screws  20 . Screws  20  screw into the threaded holes  18 , and fit into holes  24 . Latch arm  22  rotates on the end of screws  20 . Thus, latch arm  22  (which includes holes  24  which receive screws  20 ) is rotatably mounted on pivot pin  20 . 
     A hitch arm  26  comprises a base  28  which defines a hole  30 . A pin  32  is mounted in hole  30  in hitch arm  26  and hole  34 s in latch arm  22 . This allows for rotational movement between hitch arm  26  and latch arm  22 . 
     The distance by which the ball  36  is positioned with respect to the end of base  28  is adjusted by screw arm  38 , by rotation of screw arm  38  which is screwed into a tapped hole  40  in base or hitch body  28 . The rotary position of screw arm  38  may be locked by rotation of nut  42 . Nut  42  rotates on threads  43 . It is noted that threads  43  also mate with tapped hole  40 . 
     Ball  36  engages a socket  44  in heel catch plate  46  at an arc shaped engagement surface  48 . The structure of the hinge is completed by a spring  50  which is mounted in tension between a hook  52  on hitch arm  26 , and a hook  54  on guitar body base plate  12 . 
     The operation of the inventive latch may be understood from  FIG. 5 . In the locking position, latch  10  takes the position illustrated in the solid lines, with heel catch plate  46  mounted in folding guitar neck  56  by screws  57 . If it is desired to put the guitar in the travel position, it is folded about hinge  58  in the direction of arrow  60 . In order to do this, it is necessary to release latch  10 . This is done by pulling latch arm  22  to the position illustrated in phantom lines in  FIG. 5 . This is facilitated by tapered surface  62  which allows the user to insert a fingernail to pull latch arm  22  out in the direction of arrow  64 . This also allows ball  36  to be moved in the direction of arrow  64  and exit heel catch plate  46 . 
     The operation of latch  10  is much like a Visegrips brand locking pliers. More particularly, in the position illustrated in broken lines in  FIG. 5 , pin  32  is relatively far from arc-shaped engagement surface  48 . When the center of pin  32  passes over the center line  66  of screw  20 , pin  32  is closer to engagement surface  48 . It is then so close to engagement surface  48  that significant pressure is exerted between ball  36  and engagement surface  48 . As pin  32  continues to the position shown in solid lines in  FIG. 5 , this pressure is somewhat reduced as the distance between pin  32  becomes somewhat larger again. Thus, the latch securely joins neck  56  to body  14 , and is held in that position because the tension acting on screw arm  38  tends to pull neck  56  toward body  14 . 
     Referring now to  FIGS. 6-21 , another embodiment of the hinge is illustrated. This embodiment operates much the same way as the embodiment of  FIGS. 1-5 , and analogous or corresponding parts are labeled with numbers 100 higher than the numbers of the corresponding or analogous parts in the embodiment of  FIGS. 1-5 . 
     More particularly, latch  110  comprises a latch arm  122  mounted for rotation on screws  120  which pass through tapped holes  118  in latch plate  112 . The ends of screws  120  extend into holes  124  in latch arm  122  to support latch arm  122  for rotation with respect to latch plate  112 . 
     Pin  132  is jam fitted into hole  130 . The ends of pin  132  extend into and are loosely fitted to holes  134  in latch arm  122 . A pair of balls  168  are received within hole  170  at opposite ends of hole  170 . A coil spring  172  is held in compression between balls  168 . In the position where latch arm  122  is parallel to latch plate  112  and flush with latch plate  112 , balls  168  are driven toward holes  124 , thus positively locking latch arm  122  in place. 
     A leaf spring  150  is secured to hitch body  128  by a bolt  152 , which screws into hole  174  in hitch body  128 . When latch arm  122  is pulled from the guitar neck to allow the guitar neck to be folded, leaf spring  150  urges ball  136  away from latch arm  122 , facilitating folding of the guitar neck. 
     Hitch arm  138  passes through hole  177  in hitch body  128 . Rubber washer  145 , washer  143  and locking nut  142  are mounted on the end  176  of hitch arm  138 . When latch arm  122  is flush with latch plate  112 , latch arm  122  pulls the end  176  of hitch arm  138  together with rubber washer  145 , washer  143  and locking nut  142  toward heel catch plate  146 . Rubber washer  144  acts like a spring to apply a locking force. This results in an exertion of force without applying that force to the wood surrounding the screws which are used to secure the latch to the guitar body and neck. More particularly, screws, not illustrated, pass through holes  178  in heel catch plate  146 , and holes  180  in latch plate  112 . 
     Excess movement of hitch arm  138  is limited by skirt  182 . The movement of hitch arm  138  is limited by locking cap nut  142 , which when the latch is opened, is caused to bear against spring pin  184 , which is mounted in holes  186  in perpendicular extensions  188  of latch plate  112 . 
     When latch arm  122  is fully extended, holes  190  are in engagement with balls  168 . 
     A guide  191  includes a guide surface  192  which guides the exit of hitch arm  138  from heel catch plate  146  during folding of the guitar neck. Holes  193  receive the same screws as holes  180  illustrated in  FIG. 6 . If desired, guide  191  and heel catch plate  146  may be cast as a single part. 
     Yet another embodiment of the invention is illustrated in  FIGS. 22 through 25 . In this embodiment, corresponding and analogous parts have been given numbers 100 higher than corresponding and analogous parts of the embodiment of  FIG. 6-21 . 
     Latch  210  comprises a latch arm  222  mounted in a latch plate  212 . A ball  236  mounts in a heel catch plate  246 . A sliding latch lock  294  is mounted in a slot  295 , within which it slides. In the position illustrated in  FIG. 22 , latch lock  294  overlies latch arm  222 , thus positively retaining latch arm  222  in the locked position. Rivet  296  is secured to lock  294  and maintained in slot  295  by a washer  297 . This allows the end  298  of lock  294  to be driven against the force of spring  299  in the direction of arrow  301  over the edge  300  of heel catch plate  246 . This allows latch arm  222  to be rotated into the unlocked position analogous to the position illustrated in broken lines in  FIG. 5 , thus allowing the guitar neck to be folded over the body. 
     While illustrative embodiments of the invention have been described, it is noted that various modifications will be apparent to those of ordinary skill in the art in view of the above description and drawings. Such modifications are within the scope of the invention which is limited and defined only by the following claims.