Abstract:
An improved roller assembly that, when installed on a BIGSBY vibrato system, causes the roller to be raised, which reduces the angle of the strings. This reduces the tension on the strings, which improves the performance of the device and reduces or eliminates the instability in tuning. Two versions of the device are disclosed that can be used with both BIGSBY and BIGSBY LICENSE model vibratos.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     Not Applicable 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT 
     Not Applicable 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to guitar vibrato devices and particularly to guitar vibrato stabilizing devices. 
     2. Description of the Prior Art 
     Modern electric and modified acoustic guitars often use a vibrato device (often mistakenly called a “tremolo” “tremolo bar”) for enhanced musical performance. Although many such devices are used, the vibratos predominant used are produced by the Bigsby company as the BIGSBY vibrato tailpiece. Popular models include the “B5”, “B7” and “B12 and” “BIGSBY LICENSED” Brand models “B50”, “B70” and “B700” vibrato systems. The difference between them being that BIGSBY LICENSED devices are produced overseas. 
     As shown in  FIGS. 1-6  (prior art), the Bigsby models “B5”, “B7” and “B12” have the same basic components. The difference between them has to do with the type of guitar on which the vibrato is installed. A BIGSBY model “B5” is designed for flattop, solid body guitars. A model “B7” is designed for thin electric guitars and has more downward pressure and the model “B12” is designed for large acoustic and arch-topped guitars.  FIGS. 1 and 2  show a BIGSBY type “B5” model without strings, as prior art. This device has a frame  100  that has a formed tailpiece  101  that is used to secure the ends of the strings, as discussed below. At the front of the frame  100  is a roller  102  that is used to carry the strings and allows the strings to move when the vibrato is being used. A handle  103  (commonly called a “whammy bar”) is attached to a spring  104  that is positioned under an extension  105  as shown. Note that the extension is rotatably installed on the frame. 
       FIGS. 3 and 4  show a BIGSBY type model “B7” or “B12 model without strings, as prior art. These models are similar to the “B5” in that they have a frame  110  that has a formed tailpiece  111  that is used to secure the ends of the strings. Note that for the “B7” or “B12 models, the frame  110  extends rearward as shown. At the front of the frame  110  is a roller  112  that is used to carry the strings and allows the strings to move when the vibrato is being used. A handle  113  (commonly called a “whammy bar”) is attached to a spring  114  that is positioned under an extension  115  as shown. Note that the extension is rotatably installed on the frame. 
       FIG. 5  is a side view of a BIGSBY model “B7” or “B12” with strings, as prior art, showing a reduced angle of the strings passing under the front roller. Here, the strings  120  pass over a bridge  121  that has a saddle  122  on it. The saddle  122  has a number of grooves formed on it to receive the strings, which helps to hold them in place and anchors them to the bridge. The bridge is placed on to of the guitar body  123 . Note that the guitar neck (not shown is to the left of the figure). Note too that the strings pass under the front roller  112  and then up and over the tailpiece  111 . The roller  112  provides a certain amount of required downward string tension on the bridge  122  of guitar to keep the strings  120  from falling out of the grooves of bridge saddle  122  while playing. Normally, when playing the strings remain in a fixed position, axially with respect to the longitudinal axis of the guitar. When the whammy bar is depressed and released (the spring  114  pushed the handle back upwards), the strings are pushed and pulled slightly axially, as indicated by the arrows. This produces the vibrato sounds that the device is designed to achieve. 
       FIG. 6  is a side view of a BIGSBY model “B7” or “B12” with strings, as prior art, showing an increased angle of the strings passing under the front roller because of the closer bridge placement. In this figure, the bridge  122  is positioned near the front of the frame  110  (within 2 inches). Note the angle made by the strings  120  passing over the saddle  122  and under the roller  112 . The extreme angle created by the strings passing under roller  112  creates too much tension on the roller  112  causing impediment to optimum rolling as strings  120  move during typical vibrato operation, thus causing instability in tuning. 
     BRIEF DESCRIPTION OF THE INVENTION 
     The instant invention overcomes these difficulties. It is an improved roller assembly that, when installed on a BIGSBY vibrato system, causes the roller to be raised, which reduces the angle of the strings. This reduces the tension on the strings, which improves the performance of the device and reduces or eliminates the instability in tuning. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of a BIGSBY type “B5” model without strings, as prior art. 
         FIG. 2  is a top view of a BIGSBY type “B5” model without strings, as prior art. 
         FIG. 3  is a side view of a BIGSBY model “B7” or “B12” without strings, as prior art. 
         FIG. 4  is a top view of a BIGSBY model “B7” or “B12” without strings, as prior art. 
         FIG. 5  is a side view of a BIGSBY model “B7” or “B12” with strings, as prior art, showing a reduced angle of the strings passing under the front roller. 
         FIG. 6  is a side view of a BIGSBY model “B7” or “B12” with strings, as prior art, showing an increased angle of the strings passing under the front roller because of the closer bridge placement. 
         FIG. 7  is a front view of the roller system of the instant invention for the BIGSBY type “B5”, “B7” or “B12” model. 
         FIG. 8  is a right side view of the roller system of the instant invention for the BIGSBY type “B5”, “B7” or “B12” model. 
         FIG. 9  is an exploded view of the components of the roller system of the instant invention for a BIGSBY type “B5”, “B7” OR “B12” models. 
         FIG. 10  is a side view of a BIGSBY type “B5”, “B7” or B12 model with the roller system of the instant invention installed, showing the improved string angle with a closely positioned bridge. 
         FIG. 11  is a front view of the roller system of the instant invention for use with a BIGSBY LICENSED” brand model “B50”, “B70” or “B700 model. 
         FIG. 12  is a right side view of the roller system of the instant invention for use with a BIGSBY LICENSED” brand model “B50”, “B70” or “B700 model. 
         FIG. 13  is an exploded view of the components of the roller system of the instant invention for a BIGSBY LICENSED” brand model “B50”, “B70” or “B700 model. 
         FIG. 14  is a detail view of a vibrato with the original roller removed, ready for the installation of the roller system of the instant invention. 
         FIG. 15  is a detail view of the roller system of the instant invention being installed. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to  FIG. 7 , a front view of the roller system of the instant invention for the BIGSBY type “B5”, “B7” or “B12” models. The invention  10  attaches to the existing roller axle frame  100  on the B5, and 110 on the B7 &amp; B12 models) once the existing roller  112  is removed. Referring now to  FIGS. 7, 8 and 9 , the invention  10  is a pair of cylinders. The first is a roller  11  and the second is an axle  12  that sits within the roller  11 . Sealed bearings  13  (see  FIG. 9 ) are positioned between two end posts  14  as shown.  FIG. 8  shows and end view of the device. Here, one of the end posts  14  is shown. Although the end post here is shown having a figure “8” shape, it is not important to the operation of the device. The important factor is that there are two holes formed on the end post  14 . The hole at the top  14   a  is used to secure the axle  12  and its components to the end post. This is done with threads, as described below. The hole  14   b , located in the lower portion of the end post  14 , is used to connect the new roller device to the axle frame of the vibrato device. This hole is threaded to accept an 8-32×½ inch screw (not shown). This screw is used to attach the device to the existing vibrato, as discussed below. 
     The relationship of the two holes is important in that the spacing defines the amount of height that the roller  11  of the device is raised, which produces less tension. With less tension on the new roller, tuning stability increases. The unit is designed so that the axle  12  allows the roller  11  to move on the bearings.  FIG. 9  is an exploded view of the invention  10 . Here, the roller  11  is shown with the axle  12 . 
     In the preferred embodiment, the axle  12  is a cylinder ¼ inch in diameter and is 56.62 mm in length. The ends  12   a  of the axle have ¼-28 NF threads formed on them. The roller  11  has an inside diameter of ⅜ inch and an outside diameter of 7/16 inches. The roller  11  has a length of 53.10 mm. The sealed bearings  13  have and inside diameter of ¼ inch, an outside diameter of ⅜ inch and a thickness of ⅛ inch. The end post, as noted above, has a top hole  14   a  that has a ¼-28 NF tapered thread to receive the axle  12 . The end post has a height of 18.45 mm and is 1.35 mm thick. The bottom hole  14   b  is 13/64 inches in diameter, and as noted, is threaded with 8-32 NF tapered threads. When assembled, the device has an overall length of 56 mm and an overall height of 19.45 mm. 
     The device is assembled by first inserting the axle  12  into the roller  11 . Pressing the sealed bearings  13  into each end of the roller such that the threaded ends of the axle  12  extend out from the roller. Then each end post is screwed onto the ends of the axle  11  until the unit is secure. Then, the device can be installed into the vibrato device, as discussed below. 
       FIG. 10  is a side view of a BIGSBY type “B7” of “B12”, model with the roller system of the instant invention installed, showing the improved string angle with a closely positioned bridge. In this figure, the vibrato device  100  has the same components as described above, including the tailpiece  110 , the whammy bar  103 , the spring  104 , the bridge  121  and the saddle  122 . Unlike the prior art model, this figure shows that the roller  10  is the instant invention. Note how the raised position of the roller  10  makes the angle of the strings  120  less severe, as compared to that of  FIG. 6 . This reduced angle helps keep the strings in tune making playing a lot better. 
     The improved roller system is modified to be compatible with the BIGSBY LICENSED” brand model “B50”, “B70” or “B700 models, as discussed below. 
     Referring now to  FIGS. 11, 12, and 13 , details of the roller system of the instant invention for use with a BIGSBY LICENSED” brand model “B50”, “B70” or “B700 models are shown.  FIG. 11  is a front view of the assembled (but not installed) device  20 . As before, this version has a roller  21 , an axle  22 , sealed bearings  23  and end posts  24 . In addition to those components, nylon bushings  25  and hex key screws  26  are used to install the device into the existing vibrato body, as discussed below. 
       FIG. 12  is a right side view of the roller system of the instant invention for use with a BIGSBY LICENSED” brand model “B50”, “B70” or “B700 model. In this figure, the end post  24  is shown. As before, the end post  24  has a top hole  24   a  that has tapered threads to accept the axle  22 . The lower hole  24   b  is also threaded to accept the hex screw  26 . 
       FIG. 13  is an exploded view of the components of the roller system of the instant invention for a BIGSBY LICENSED” brand model “B50”, “B70” or “B700 model. Note that in the preferred embodiment, the roller  21  I 55.10 mm long and has an inside diameter of ⅜ inch and an outside diameter of 7/16 inch. The axle  22  has a length of 58.62 mm and a diameter of ¼ inch with ¼-28 NF threads cut on both ends. The sealed bearings  23  have an inside diameter if 1.4 inch and an outside diameter of ⅜ inch and a width off ⅛ inch. Each end post  24  is 1.25 mm thick and has a height if 17.10 mm. The top hole  24   a  has ¼-28 NF tapered threads. The bottom hole  14   b  has 8-32 NC tapered threads. Also in the preferred embodiment, the nylon bushings  25  are ⅜ inch× 3/316 in ×¼ inch nylon and hex key screws  26  are 8-32 NC×½ inch 9/64 inch stainless steel hex key screws. When assembled, the roller and end posts have an overall length of 58 mm and a height of 17.10 mm. The nylon bushings and screws extend beyond these dimensions, 
       FIG. 14  is a detail view of a vibrato device of the BIGSBY LICENSED” brand model  110 , as shown in  FIG. 4  with the original roller  112  removed, ready for the installation of the roller system of the instant invention. Note the opening  112   a  and the open portions  112   b  of the vibrato arms that are ready to receive the device  20 . 
       FIG. 15  is a detail view of the roller system of the instant invention being installed in the vibrato of  FIG. 14 . First, the existing axle, roller and nylon bushings must be removed. Note that in this top view, the roller  21  is shown in the space  112   a  (see  FIG. 14 ). Note the end plates  24  are positioned as shown. Note too that the lower holes  24   b  (not visible) are aligned with the open portions  112   b . Note too the bushings  25  and the hex key screws  26 , which are positioned on the outside of the vibrato device. The bushings are pushed into the holes  112   b  and the screws then engage the holes  24   b  in the end plates to secure the device in place. 
     Similarly, for the installation of the device  10  into a BIGSBY type “B5”, “B7” or “B12” model, the device is positioned between the arms of the vibrato device and screws are used to attach the device using the 8-32×½ inch screws mentioned above. 
     One feature of the new roller is that when it attached to existing roller axle location the entire device has the ability to pivot during typical tremolo operation. This further reduces string movement and any restriction at new roller location, which adds additional tuning stability. 
     The present disclosure should not be construed in any limited sense other than that limited by the scope of the claims having regard to the teachings herein and the prior art being apparent with the preferred form of the invention disclosed herein and which reveals details of structure of a preferred form necessary for a better understanding of the invention and may be subject to change by skilled persons within the scope of the invention without departing from the concept thereof.