Abstract:
The present invention provides a bracket, which can be easily installed to a vibrato device having a string bar with projecting string pins. The bracket facilitates re-stringing the strings through slots which are conveniently placed and readily accessible to the installer.

Description:
This is a Non-Provisional Patent Application. 
     FIELD OF THE INVENTION 
     This invention relates to vibrato devices for guitars, and more particularly to adjunct equipment relative thereto, and most particularly to apparatuses that facilitate re-stringing relative thereto. 
     BACKGROUND OF THE INVENTION 
     The strings of a guitar are anchored near the lowermost end of the guitar body by a tailpiece. Occasionally, this tailpiece function is served by a vibrato, or tremolo, which is a piece of equipment designed to produce a unique sound effect similar to a singer&#39;s vibrato. 
     Vibrato mechanisms provide a means for changing the tension on all the strings of a guitar simultaneously. Changing the tension creates a pitch change in each vibrating string. This is accomplished by a moving tailpiece which pivots about an axis substantially perpendicular to the strings. A handle is provided to facilitate a pulse-like pivoting of the tailpiece while simultaneously playing the instrument. 
     There are numerous examples of vibrato devices and like mechanisms in the prior art. Three of these, which characterize the genre, are U.S. Pat. No. 4,497,236 to Rose, U.S. Pat. No. 4,632,005 to Steinberger, and U.S. Pat. No. 3,457,821 to McCarty et al. The latter patent is progenitor to what is now known as the Bigsby® family of vibrato devices, arguably the preferred choice for both after-market and factory-installed devices of this type. 
     Bigsby vibrato devices are installed on top of the guitar in an original equipment installation, or after removing an existing tailpiece in an after-market installation. The installation procedure is to string the strings over a pivoting metal bar, called the string bar, which is a component of the vibrato mechanism. Pins project from the string bar to connect with the strings by threading through a hole in the ball-end of each string. The pins, however, are oriented at a downward and forward angle, such that the wires have to be bent approximately 315° around the string bar. The pins must be in this attitude in order to prevent the strings from slipping off the pins when the bar is pivoted to lighten the string tension and create the desired pitch change. Assembling the strings, however, can be an awkward process. The pin is approached from a blind side and from underneath the bar, below which a minimal clearance for finger manipulation is afforded. As a result, the installer must grope in tight space to pin a tiny hole, and often the process is hit or miss. A simplified means for connecting the strings would shorten the installation time and save frustration on the part of the installer. It would also make it easier for a musician having to change a string. 
     The range of pitch change is limited both by the radius of rotation of a vibrato device and the degree of articulation about its axis of rotation. Because a Bigsby vibrato mounts to the surface, and does not require the routing of a nesting location in the body of a guitar, its profile is relatively shallow. As a consequence, the range of a Bigsby is essentially limited by the radius of the string bar. This characteristic suits musicians who prefer slow, subtle, or extended blends, but even these musicians would benefit from a broader range, preferred by other musicians, for a choice to increase the sound dynamic. 
     The present invention improves upon the widely-used Bigsby vibrato design. It to addresses the aforementioned deficiencies, namely finicky installation and limited range, by providing a novel, universal and inexpensive bracket as an adjunct piece of equipment. 
     SUMMARY OF THE INVENTION 
     It is accordingly an object of the present invention to provide a simplified means to assemble guitar strings to a Bigsby vibrato device. It is a further object to extend the rotational radius of the string bar of a Bigsby device, and therefore broaden the tonal range, by leveraging the string anchor points. It is a further object to accomplish the above two objectives by providing an easy-to-install and inexpensive bracket. It is a further object to make said bracket universal for all presently-marketed Bigsby vibrato products. 
     These objectives, and others to be discovered through further disclosure herein, and through practice of the invention, are embodied in a string attachment bracket for a vibrato unit having a string bar with string pins mounted to a guitar with a plurality of strings. The string attachment bracket comprises a shaped plate having distal and proximal ends. The proximal end has a concave form to wrap, at least partially, around the string bar to reach the string pins. The distal end is positioned for enabling quick string connections thereto. The string attachment bracket further comprises one or more apertures through the proximal end adapted for receiving the string pins. Additionally, the bracket comprises a plurality of slots at the distal end, the plurality of slots being to equal or greater than the number of strings. The slots are adapted for slidingly receiving each string in a slot and for capturing a bulbous end of the string therein. When tension is applied to the strings connected at the distal end, with the shaped plate is biased against the string bar by the string pins at the proximal end, the strings are caused to be anchored in the balance of forces. 
     All Bigsby vibrato units, as elements of design, have the recited string bar and projecting string pins. The distal end of the shaped plate relocates the anchor point of the strings from the string pins to a location free from intervening structures, such as the string bar. The slots in the distal end allow for simplified and quick assembly of the strings to the vibrato device. 
     As this is not intended to be an exhaustive recitation, other embodiments may be learned from practicing the invention or may otherwise become apparent to those skilled in the art. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       Various other objects, features and attendant advantages of the present invention will become fully appreciated as the same becomes better understood through the accompanying drawings and the following detailed description, in which like reference characters designate the same or similar parts throughout the several views, and wherein: 
         FIG. 1  is a perspective view of the string attachment bracket of the present invention installed with a vibrato device on a guitar; 
         FIG. 2  is a perspective view of several of the constituent parts of a vibrato installation, including a Bigsby B5 vibrato, an alternate Bigsby B7 vibrato, the guitar strings with ball-end finials, and the string attachment bracket; 
         FIG. 3  is a perspective view of the string attachment bracket; 
         FIG. 4  is a section view of the string attachment bracket taken along the lines  4 - 4  in  FIG. 3 ; 
         FIG. 5A  is a plan view of the string attachment bracket; 
         FIG. 5B  is a plan view the string attachment bracket positioned on a Bigsby B5 vibrato device; 
         FIG. 6  is a section view taken along the lines  6 - 6  in  FIG. 5B ; and 
         FIG. 7  is a partial perspective view of strings being assembled to a Bigsby B3 vibrato unit mounted on a guitar. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG. 1  shows a string attachment bracket  10  installed on vibrato device  20  with the vibrato device  20  mounted on a guitar  1 . A plurality of strings  3  are terminated at the string attachment bracket  10  after passing over a bridge  2 . Because the strings  3  are caused to bend over the bridge  2 , the bridge effectively determines the vibrating length of the string. The string attachment bracket  10  facilitates the re-stringing of the strings  3 , which may follow from routine maintenance on the strings, or which otherwise may be necessitated by an after-market installation of a vibrato device. 
       FIG. 2  shows two of the vibrato devices  20  compatible with string attachment bracket  10 : A Bigsby B5 vibrato  100  and a Bigsby B7 vibrato  101 . The conventional re-stringing procedure for these devices involves connecting a pin hole  5  in a ball end  4  of the string  3  to a string pin  22 . The ball end  4  is essentially bulbous in character. The string pins  22  project at a downward angle of approximately 45° from the string bar  21 . The angle is critical to prevent the ball ends  4  from slipping off the string pins  22  when the string bar  21  is rotated in a vibrato manipulation. As a consequence of the string pin angle, the strings  3  must be bent around the string bar  21 , circumscribing an angle of approximately 315°, to reach the string pins  22  from underneath the string bar  21 . The space underneath is narrow and little room is afforded near the pins for working the strings. Further, the strings can be stiff, particularly near the ball ends where the string thickens, and they do not easily yield to the near 90° secondary bend required to thread the pin. As a consequence, re-stringing the strings in a conventional manner can be a pains-taking process, possibly involving multiple hit-or-miss tries, not to mention a quotient of patience, if not frustration. 
     The novel design of the string attachment bracket  10  remedies this inconvenient process, while also providing other beneficial features. As best shown in  FIGS. 2-4  and  5 A, the string attachment bracket  10  is comprised of a shaped plate  11  having a proximal end  12  and a distal end  13 . The shaped plate  11  can also be described as a “lever arm”, reflecting a capacity to leverage a rotational displacement. The string attachment bracket  10  can be easily assembled to the vibrato device  20  by slipping the proximal end  12  underneath the string bar  21 . A concave-shaped form  14  of the proximal end  12  positions apertures  15  in location to receive therein the string pins  22 . With the string pins  22  positioned in the apertures  15 , the distal end  13  of the string attachment bracket  10  is presented in an easily accessible location.  FIGS. 5B and 6  show the string attachment bracket  10  mounted to the Bigsby B5 vibrato  100 . 
     The distal end  13  of the shaped plate  11  conveniently receives the strings  3  in slots  16 , wherein they slide to a seated position. At the seated position, the ball ends  4  are held captive by interfering geometries. Ample free space is provided above the distal end  13  for handling and inserting the strings  3 , and little bending of the strings, if any, is required to engage the slots  16 . The slots  16  may be tapered down from a broad opening to assist with guiding the strings into position. A portion of the shaped plate  11  at the extremis of the distal end  13  may be bent upwardly to avoid bending the strings  3  at a sharp angle when tension is applied thereto. The slots  16  are of a plurality equal to or greater than the number of strings  3 , which is, typically, six.  FIG. 7  shows the engagement of strings  3  in the slots  16  on the string attachment bracket  10  placed on a Bigsby B3 vibrato  102 . 
     The Bigsby B5 vibrato  100  is fitted with a string hold down bar  25  ( FIG. 2 ). During installation, the strings  3  are threaded beneath the hold down bar  25 , the purpose of which is to maintain the bend of the strings over the bridge  2 . Not all Bigsby vibrato devices, however, have a hold down bar  25 . As a functional requirement, in the case of the absence of a hold down bar  25 , the distal end  13  must never raise the strings  3  to an elevation that would essentially eliminate the bend or compromise contact with the bridge  2 . 
     Tensioning the strings on a guitar involves method and means well known in the musical arts. When tension is reapplied to the strings  3  after engagement to the string attachment bracket  10 , the force at the distal end  13  is counter-balanced by the string pins  22  at the proximal end  12  acting about a fulcrum at the string bar  21 . The string bar  21 , and therefore the string pins  22 , are biased against rotation in the direction of string tension by a vibrato spring  26  ( FIG. 2 ). The balance of forces keeps the string pins  22 , and the strings  3 , in continuous contact with the string attachment bracket  10  throughout operational use, including rotation of the string bar  21  during play of the vibrato, providing tension is maintained in the strings. 
     When the strings  3  are engaged in tension on the string attachment bracket  10  mounted on the vibrato device  20 , the string ends are caused to move, when the string bar  21  is pivoted, in an arc defined by the radial distance from the axis of rotation  24  (see  FIG. 2 ). Because the radial distance is greater than in the case of a conventional mounting of the strings  3  about the string bar  21 , the greater arc subtended by a common angle will cause a wider fluctuation of tension and, thereby, of pitch. Consequently, the string attachment bracket  10 , by repositioning the string ends away from the string pins, produces the beneficial effect of broadening the range of vibrato effect. 
     The novel string attachment bracket  10  has been configured for compatibility with a multiplicity of Bigsby vibratos, including original series models B3, B5, B6, B7, B11, B12 and B16; licensed series models B30, B50, B60 and B70; and import series models B500 and B700. As a result of the universality comprehended in the design, the longitudinal span of the apertures  15 , and any webs inboard or outboard thereto, anticipate all of the pin spacing&#39;s in this model group. Furthermore, the widths of the slots  16  accommodate variable thickness of strings and ball end profiles. In the preferred embodiment, the apertures  15  are enlarged to facilitate “fishing” for the string pins  22  from beneath the string bar  21 . 
     In the preferred embodiment, the string attachment bracket  10  is fabricated from metal plate by die-stamping or machining The plate must have sufficient modulus to avoid bending in the force ranges typical for taut musical strings. The preferred metals are stainless steel or aluminum. The preferred thickness for stainless steel is 0.060″. 
     It is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the preceding description or illustrated in the drawings. For example, the slots may be replaced by pins, or some other feature of connection. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of the description and should not be regarded as limiting.