Abstract:
A system for anchoring a guitar string comprising a guitar top, a bridge fixed to the guitar top, and at least one aperture extending through the bridge and top for receiving an end of a string with a ball attached thereto. A bridge pin has a body that is insertable into the aperture. The body has two spaced-apart legs forming a space therebetween wide enough to accommodate the string but not the ball. A rear side of the legs has matching anchoring surfaces that are constructed and arranged to receive and retain the ball when the string is in tension.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to musical instruments. More particularly, the invention relates to stringed instruments, like guitars. More particularly still, the invention relates to an anchoring system for guitar strings. 
     2. Description of the Related Art 
       FIG. 1  is a plan view of a 6 string guitar showing the strings  1  anchored at a first end at a head stock  5  where they are tightened with tuners  10  and anchored at a second end at a bridge  15  with bridge pins  20 . Traditionally, the strings on fretted instruments are either single core wires or in the case of larger diameter strings, a core wire with another wire wrapped around it. In either case, a cylindrical “ball” is attached to one end of the string to facilitate anchoring the string to the instrument. The body of the string is secured to the anchoring ball by wrapping the string around the ball and back onto itself where it is twisted, thereby forming a loop which captures the cylindrical ball. This arrangement creates an extra stiff area near the end of the string with a larger diameter than the body of the string and the extra stiff area increases in length with the diameter of the string.  FIG. 2  is a partial section view of a prior art anchoring arrangement. Visible in the Figure are a guitar top  25 , a reinforcing member  30  below the top, a bridge  35  affixed to the top and an aperture  40  extending through the bridge, top and reinforcing member into an interior of the instrument. A string  1  is supported by a saddle  55  and has an enlarged diameter portion  2  terminating in a ball  3  on its end. The string is inserted through the aperture and held at a front side of the aperture by a pin  45 . In the example shown in  FIG. 2 , the section of the string extending through the aperture is housed in a vertical slot  50  formed in the bridge, top and reinforcing member in a manner whereby it conjoins the aperture. In another example (not shown), the slot is formed in the pin rather than in the aperture. In either case, the string  1  is held between the pin  45  and the aperture  40  and the pin must be precisely sized to fit in the aperture in a manner that retains the string while it is being tensioned and played. 
     This conventional arrangement of the mounting hole, mounting pin, and saddle, create geometry that can force the string into an undesirably small radius bend made worse by the stiffened end condition affected by the anchoring ball&#39;s retaining wrap. In extreme cases, when the string is of very large diameter, such as those found on a bass guitar, or in cases where the components of the bridge are exceptionally small or in close proximity, the radius of the string&#39;s bend over the saddle cannot be accomplished, leading to improper functioning of the instrument. Additionally, the arrangement can cause the large diameter area of the string to contact the saddle, thereby preventing the string from “sounding” properly. What is needed is an improved anchoring system for a string, in particular one that can be utilized in instances of large diameter strings and/or instruments having limited space for anchoring components. 
     SUMMARY OF THE INVENTION 
     The present invention generally includes a system for anchoring a guitar string comprising a guitar top, a bridge fixed to the guitar top, and at least one aperture extending through the bridge and top for receiving an end of a string with a ball attached thereto. A bridge pin has a body that is insertable into the aperture. The body has two spaced-apart legs forming a space therebetween wide enough to accommodate the string but not the ball. A rear side of the legs has matching anchoring surfaces that are constructed and arranged to receive and retain the ball when the string is in tension. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments. 
         FIG. 1  is a plan view of a guitar. 
         FIG. 2  is a partial section view of a prior art mounting arrangement. 
         FIG. 3  is a perspective view of a bridge pin according to one aspect of the invention. 
         FIG. 4  is a side view of the pin of  FIG. 3 . 
         FIG. 5  is a rear view of the pin illustrating anchoring surfaces formed in the legs of the pin. 
         FIG. 6  is a section view taken along a line  6 - 6  of  FIG. 5 . 
         FIG. 7  is a partial section view of an instrument showing a top, bridge, saddle, pin and a string extending through an aperture in the bridge and top. 
         FIG. 8  is a partial section view showing a string prior to tensioning and 
         FIG. 9  is a rear view thereof. 
         FIG. 10  is a partial section view showing the string retained after tensioning and 
         FIG. 11  is a rear view thereof. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 3  is a perspective view of a bridge pin  100  according to one aspect of the invention. In the embodiment shown the pin has a top portion  110  and an enlarged diameter portion  115  therebelow. The pin includes a body  120  having two legs  121 ,  122  that are separated to create a space  125  therebetween for accommodating a string as will be explained herein. Considering  FIGS. 3-6  together, the legs  121 ,  122  include an anchoring arrangement made up of matching anchoring surfaces  130   a ,  130   b  formed at a rear and inside surface of each leg  121 ,  122 . The surfaces are designed to retain a ball end of a string as the string is tensioned and pulled against the surfaces. In  FIG. 4  the surfaces  130   a ,  130   b  appear as a profile.  FIGS. 3 and 5  illustrate the surfaces  130   a ,  130   b  as matching, angled surfaces formed in an inside, rear edge of each leg in a manner wherein they appear as a single tear drop shape best appreciated in  FIG. 5 . The angle  131  created by the surfaces is shown in  FIG. 6 , a section view taken along a line  6 - 6  of  FIG. 5 . In the embodiment of  FIG. 6 , angle  131  is about 45 degrees although the exact angle can vary based upon a number of factors including the size of the ball and the length of the pin legs that extend below the top of the instrument. 
       FIG. 7  is a partial section view of an instrument showing the various portions of the anchoring system prior to installation of the pin  100  and tensioning of a string  200 . A typical string is shown with a first diameter  210  and a larger diameter  220  portion having a cylindrical ball  225  attached at an end. Shown in section is an instrument top  140 , a bridge  150  attached the top and a saddle  155  installed in the bridge. The saddle&#39;s purpose is to provide an end point for the string&#39;s vibration at the correct location for proper intonation and to transfer the vibrations through the bridge into the top wood of the guitar. For this reason it is necessary that the ball end of the string transitions to the smaller diameter  210  prior to contact with the bridge. An aperture  160  extends through the bridge and top and the string  200  is shown inserted through the aperture in a manner wherein the ball is housed in the body of the instrument. Rather than a vertical slot, the aperture includes an angled opening  161  in the form of a slot or notch in the direction of the saddle to reduce bending of the tensioned string as it moves from an interior of the instrument to the saddle  155 . A pin  100  as described in reference to  FIGS. 3-6  is shown above the aperture  160 . While not shown in  FIG. 7 , an optional bridge reinforcement plate can be utilized in a way that sandwiches the top between the bridge and an additional piece of strong hardwood glued to the underside of the top. 
       FIG. 8  is a partial section view of the anchoring system showing a string  200  prior to tensioning and  FIG. 9  is a rear view thereof. The string is shown inserted through the aperture  160  in the bridge and top and the pin is shown inserted in the aperture in a manner whereby the string runs along the angled portion  161  of the aperture and extends through space  125  formed between the legs  121 ,  122  of the pin  100 . Anchoring surface  130   b  of the pin is visible and the ball  225  is shown adjacent that surface. Arrow  165  illustrates the direction of the string  200  as it is tightened from an opposite end and tension is applied. In  FIGS. 8 and 9  the ball is not in compression contact with the surfaces  130   a ,  130   b  of the pin legs and the legs have not been deformed due to forces between the pin and the ball. However, the tear drop shape of the surfaces, with their exaggerated length in the downward direction, serves as a guide to the ball  225  as the string  200  is initially tightened. 
       FIG. 10  is a partial section view of the anchoring system showing the string  200  retained after tensioning.  FIG. 11  is a rear view. The string  200  is shown in a tensioned condition and forces developed in the anchoring system are shown with arrows  168 ,  170 ,  172 . For example, the tensioning action has pulled the ball  225  into the pin  100  via surfaces  130   a ,  130   b  ( 130   b  visible in  FIG. 8 ). Those forces are shown with arrows  168 ,  170  and have also caused the ball to be firmly in contact with a lower surface  141  of top  140 . The same forces serve to create a downward force (arrow  172 ) on the pin  100 , thereby seating the enlarged diameter portion  115  of the pin firmly on the upper surface of the bridge  150 . Considering  FIG. 11 , the force between the ball and the anchoring surfaces of the pin has deformed the legs in the area of the ball and surfaces and enlarged the space between the legs as shown by distance  175 . In this manner, the pin, and with it the string is further anchored in the aperture. 
     In operation, one embodiment of the anchoring system includes the following steps: A ball-end of a string is inserted through an aperture and into the body of an instrument, like a guitar. Typically, the aperture is formed in a bridge and top of the guitar and includes an angled slot. A pin like the one described herein is then inserted into the aperture in a manner whereby the string is straddled by two spaced-apart legs of the pin whereby the string enters the front of the pin and exists the rear of the pin. Thereafter, the string is tightened and put into tension and the ball is urged into contact with anchoring surfaces at the rear of the legs of the pin. The surfaces, along with an underside of the guitar top, serve to anchor the ball end of the string in the instrument. In doing so, room is provided for the thickened end of the string prior to the string crossing a saddle. 
     While simultaneously anchoring the string, the slot in which the string passes through alleviates severely tight radius bends in the string, allowing a more relaxed end condition and the elimination of distortion of the string, critical to accurate musical function. Additionally, this arrangement provides clearance for the increased diameter of the doubly wrapped end of the string, and provides a more stable anchoring for the string overall which improves tuning stability of the complete instrument, enhanced clarity of the notes, and improves sustain of the string&#39;s vibration. 
     Unlike conventional string mounting, the present invention utilizes a straight sided installation hole serving to anchor the string under the top and bridge at a point furthest from the saddle, with a space formed through the pin through which the string passes. The bridge features a clearance slot on the forward side of the hole. The bridge pin features a straight sided profile which mates to the straight sided, cylindrical hole. By utilizing a straight sided pin and matching straight sided bore, as well as a clearance ramp located entirely in the bridge, accurate manufacturing is greatly facilitated. 
     While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. For example, the invention as described presumes a bridge on an instrument top and an aperture that extends through both the bridge and top. It will be understood that these components can be combined or the invention can be used without a bridge. While the invention might typically be used with a 6 string guitar it is equally useful with a base guitar having fewer strings of a mandolin, 12 string guitar or any stringed instrument utilizing a ball that requires anchoring at one end.