Patent Document

TECHNICAL FIELD 
       [0001]    The present invention relates to a tremolo device for a stringed musical instrument and more particularly to an electric guitar. The electric guitar equipped with tremolo device and double locking allows smooth pitch increase and decrease of the tone without that resulting later in strings coming out of tune. The present tremolo device can be used also on electric guitars adapted for a non-locking tremolo device. 
       BACKGROUND ART 
       [0002]    A known tremolo device for stringed musical instrument [1] comprises a base plate, on the upper surface of which saddle assemblies are independently mounted corresponding to the number of the strings, each assembly including a front and a rear string saddle. The saddles have asymmetrically projecting arms movably connected to each other via a saddle assembly shaft, located perpendicularly to the corresponding string. To each saddle assembly means are provided for their fixing on the base plate, for fine tuning, intonation adjustment and string locking. In the front string saddle a slot is formed housing a saddle mounting screw mounted in a threaded opening in the base plate, and at the back portion of the rear string saddle a rear slot is formed, housing a fine tuning screw mounted in a threaded opening in the base plate. In the front portion of the rear string saddle a string receiving recess is formed extending to the front slot, which axis is parallel to the axis of the slot in the front string saddle and to the axis of the rear slot. In the front slot a string lock insert is mounted. From the front slot to the back wall of the rear string saddle a lower threaded opening is extended in which a string lock screw is mounted and which is screwed up to the front slot and to the string lock insert mounted in it. From the rear slot to the back wall of the rear string saddle an upper threaded opening is formed, in which an adjustment screw is disposed contacting with the fine tuning screw head. The axes of the slot in the front string saddle and the rear slot in the rear string saddle are parallel and displaced with respect to the axis of the corresponding string. The string lock insert is formed by a head and a cylindrical body. In the lower portion of the string lock insert a slot is formed reaching the rear part of the string lock screw. The string lock insert is mounted so that the slot is at the height of the string lock screw. The base plate abuts against a pivot assembly, each one including a pivot stud and a pivot insert. To the base plate front end circular recesses are provided, conically beveled at the upper and lower surface of the base plate so that with each circular slot a knife edge is formed engaged with a double conical recess below the head of each pivot stud. To the lower surface of the base plate a sustain block is mounted by means of block mounting screws. In one side of the sustain block an opening with arm bush is formed in which a tremolo arm is mounted. It is fixed by a screw and passes through an opening in the base plate. To the lower side of the sustain block a balancing mechanism is mounted, inserted in a cavity provided on the lower side of the instrument body, including a number of springs which ends are fixed to the spring claw, the other ends are immovably fixed to the sustain block by means of hooks and spring fix screws. The adjustment screw is mounted in the upper threaded opening of the rear string saddle contacting the fine tuning spring which axis is perpendicular to the axis of the saddle assembly shaft, the axes being at some distance from each other. The fine tuning spring is disposed in a recess provided in the sustain block upper side and passes through an opening in the base plate reaching the lower surface of the corresponding rear string saddle, the spring axis being perpendicular to and intersecting the string axis. 
         [0003]    A disadvantage of the known tremolo device for stringed musical instrument is its complicated construction and difficult usage at unsatisfactory sustain. 
       SUMMARY OF THE INVENTION 
       [0004]    The object of the present invention is to provide a tremolo device for a stringed musical instrument with simplified construction allowing easier usage and improved sustain. 
         [0005]    This object is accomplished by a tremolo device for a stringed musical instrument comprising a base plate, on the upper surface of which are independently mounted saddle assemblies corresponding to the number of the strings, each assembly including a front and a rear string saddle with asymmetrically projecting arms movably connected to each other via a saddle assembly shaft located perpendicularly to the corresponding string. To each saddle assembly means are provided for their fixing on the base plate, for fine tuning, intonation adjustment and string locking. In the front string saddle a slot is formed housing a saddle mounting screw mounted in a threaded opening in the base plate. In the back portion of the rear string saddle a rear slot is formed housing a fine tuning screw mounted in a threaded opening in the base plate. In the front portion of the rear string saddle a string receiving recess is formed extending to the front slot, which axis is parallel to the axis of the slot in the front string saddle and to the axis of the rear slot. In the front slot a string lock insert is mounted. From the front slot to the back wall of the rear string saddle a lower threaded opening is extended, in which a string lock screw is mounted and screwed up to the front slot and to the string lock insert mounted in it. From the rear slot to the back wall of the rear string saddle an upper threaded opening is formed, in which an adjustment screw is disposed, contacting with the fine tuning screw head. The axes of the slot in the front string saddle and the rear slot in the rear string saddle are parallel and displaced with respect to the axis of the corresponding string. The string lock insert is formed by a cylindrical body wherein in the lower portion of the string lock insert a slot is formed reaching the rear part of the string lock screw. The string lock insert is mounted so that the slot is at the height of the string lock screw. The base plate abuts against a pivot assembly, each one including a pivot stud and a pivot insert. To the base plate front end circular recesses are provided, conically beveled at the upper and lower surface of the base plate so that with each circular slot a knife edge is formed engaged with a double conical recess below the head of each pivot stud. To the lower surface of the base plate a sustain block is mounted by means of block mounting screws. In one side of the sustain block a two step opening with an arm bush is formed, through which a tremolo arm passes. To the lower side of the sustain block a balancing mechanism is mounted, inserted in a cavity provided on the lower side of the instrument body, including a number of springs which ends are fixed to the spring claw, the other ends are immovably fixed to the sustain block by means of hooks and spring fix screws. The adjustment screw is mounted in the upper threaded opening of the rear string saddle. The rear string saddle reaches the fine tuning spring which axis is perpendicular to the axis of the saddle assembly shaft and the axes are at some distance from each other. The tremolo device according to the present invention wherein in the front portion of the rear string saddle an opening is formed, which axis is nonparallel to and does not intersect the saddle assembly shaft axis and also the string axis. In the opening the fine tuning spring is disposed reaching the opening bottom with one end and with the other—the back wall of the front string saddle. 
         [0006]    An advantage of the tremolo device for a stringed musical instrument according to the present invention is its simplified construction allowing easier usage and improved sustain. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0007]    The tremolo device for a stringed musical instrument according to the invention is clarified by the following brief description of the presently preferred embodiment, illustrated by the attached figures, wherein, 
           [0008]      FIG. 1  is a top view of an electric guitar, equipped with a tremolo device and a top lock unit; 
           [0009]      FIG. 2  is an exploded perspective view of the tremolo device; 
           [0010]      FIG. 3  is a perspective view; 
           [0011]      FIG. 4  is a perspective view from the lower side of the device; 
           [0012]      FIG. 5  is a side view of the saddle assembly; 
           [0013]      FIG. 6  is a top view of the saddle assembly; 
           [0014]      FIG. 7  is a partial sectional view taken along line A-A of  FIG. 5 ; 
           [0015]      FIG. 8  is a partial sectional view taken along line B-B of  FIG. 6 ; 
           [0016]      FIG. 9  is a partial sectional view taken along line C-C of  FIG. 6 ; 
           [0017]      FIG. 10  is a partial sectional view taken along line D-D of  FIG. 1 ; 
           [0018]      FIG. 11  is a side sectional view taken along line C-C of  FIG. 6  with illustration of the fine tuning spring force F and the perpendicular distance r from the rotation axis. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0019]    A tremolo device  1  for a stringed musical instrument ( FIG. 1  and  FIG. 2 ) according to the present invention comprises a base plate  2 , on the upper surface of which are independently mounted saddle assemblies  3 , corresponding to the number of the strings  29 . Each assembly  3  ( FIG. 5  and  FIG. 6 ) including a front  4  and a rear  5  string saddle with asymmetrically projecting arms movably connected to each other via a saddle assembly shaft  7  located perpendicularly to the corresponding string  29 . To each saddle assembly  3  means are provided for their fixing on the base plate  2 , for fine tuning, intonation adjustment and string locking. In the front  4  string saddle ( FIG. 7 ) a slot  4   a  is formed housing a saddle mounting screw  9  mounted in a threaded opening in the base plate  2 . In the back portion of the rear  5  string saddle ( FIG. 7 ) a rear slot  5   a  is formed housing a fine tuning screw mounted in a threaded opening in the base plate  2 . In the screw  9  head ( FIG. 3 ) crossed slots  9   a  are formed, allowing fine tuning of the string  29  by guitar pick  33  or nail. In the front portion of the rear saddle  5  ( FIG. 6 ) a string receiving recess  5   b  is formed extending to the front slot  5   c,  which axis is parallel to the axis of slot  4   a  in the front  4  string saddle and to the axis of the rear slot  5   a.  In the front slot  5   c  a string lock insert  10  is mounted. From the front slot  5   c  ( FIG. 8 ) to the back wall of the rear string saddle  5  a lower threaded opening  5   e  is extended, in which a string lock screw  11  is mounted and screwed up to the front slot  5   c  and to the string lock insert  10  mounted in it. From the rear slot  5   a  ( FIG. 9 ) to the back wall of the rear string saddle  5  an upper threaded opening  5   d  is formed, in which an adjustment screw  12  is disposed, contacting with the fine tuning screw  9  head. The axes of the slot  4   a  in the front string saddle  4  ( FIG. 6 ) and the rear slot  5   a  in the rear string saddle  5  are parallel and displaced with respect to the axis of the corresponding string  29 . The string lock insert  10  ( FIG. 2 ) is formed by a cylindrical body. In the lower portion of the string lock insert  10  a slot  10   a  is formed ( FIG. 8 ), reaching the rear part of the string lock screw  11 . The string lock insert  10  mounted so that the slot  10   a  is at the height of the string lock screw  11 . The base plate  2  ( FIG. 3  and  FIG. 10 ) abuts against a pivot assembly  13 , each one including a pivot stud  14  and a pivot insert  15 . In the base plate  2  front end circular recesses are provided, conically beveled at the upper and lower surface of the base plate  2 , so that with each circular slot a knife edge is formed engaged with a double conical recess below the head of each pivot stud  14 . To the lower surface of the base plate  2  ( FIG. 4  and  FIG. 9 ) a sustain block  17  is mounted by means of block mounting screws  16 . In one side of the sustain block  17  ( FIG. 2 ) a two step opening  17   a  with an arm bush  19  is formed, through which a tremolo arm  18  passes with thread in its lower end, corresponding to that of the lower end of the opening  17   a.  Under the arm bush  19  ( FIG. 10 ), an arm washer  20  and an arm spring  21  are consecutively disposed. In the base plate  2  ( FIG. 4 ) a second opening for the tremolo arm  18  is formed symmetrically to the mid distance between the pivot assemblies  13 . To the lower side of the sustain block  17  a balancing mechanism  22  is mounted, inserted in a cavity provided on the lower side of the instrument body, including a number of springs which ends are fixed to the spring claw  25 , the other ends are immovably fixed to the sustain block  17  by means of hooks  23   a  and spring fix screws  24 . The adjustment screw  12  ( FIG. 9 ) is mounted in the upper threaded opening  5   d  of the rear string saddle  5 . The rear string saddle  5  reaching the fine tuning spring  6 , which axis is perpendicular to the axis of the saddle assembly shaft  7  and the axes are at some distance from each other. In the front portion of the rear string saddle  5  an opening  5   f  is formed, which axis is nonparallel to and does not intersect the saddle assembly shaft  7  axis and also the string  29  axis. In the opening  5   f  the fine tuning spring  6  is disposed reaching the opening bottom with one end and with the other—the back wall of the front string saddle  4 . 
       OPERATION OF THE INVENTION 
       [0020]    The tremolo device  1  ( FIG. 1  and  FIG. 10 ) is movably mounted in a preliminary prepared cavity in the body  28  of the instrument  27  via a pair of pivot studs  14  and pivot inserts  15  fixed in the body  28  and balances by being pulled in one direction by the tensile force in the strings  29 , and in the other direction—by the force of springs  23  of the balancing mechanism  22 . Controlled by spring claw screws  26 , regulating the tension in springs  23 , these two forces are balanced so that the tremolo surface is parallel to the plane of the body  28  of the instrument. The strings  29  are tightly fixed in the top lock device  32  or in the machine heads  30 , as well as in the tremolo device  1 . 
         [0021]    When the arm  18  is pressed to the body  28  of the instrument, the tremolo device  1  gets rotated around the pivot points axis in one direction so that the tensile force in the strings  29  decreases, causing lowering of strings  29  tone pitch. 
         [0022]    When the arm  18  is pulled in the opposite direction—the tensile force in the strings  29  gets increased, causing increase of strings  29  tone pitch. 
         [0023]    The designation of the fine tuning spring  6  ( FIG. 11 ) is to create a torque around the saddle assembly shaft  7  axis through the force F and the perpendicular distance r from the rotation axis, so that the rear string saddle  5  surface located under the fine tuning screw  9  head, should always touch the surface of the lower side of the fine tuning screw  9  head, even in the cases when the arm  18  is pressed and the strings  29  are completely loose. 
         [0024]    The functions of the tremolo device according to the invention are as follows: locking one end of the strings  29  to the body  28  of the instrument; adjusting the strings  29  height; adjusting the strings  29  intonation; fine tuning of the strings  29 ; smooth decrease or increase of the played tone by using the arm  18 . 
         [0025]    The advantage of the tremolo device for a stringed musical instrument  1  according to the invention is its simplified construction, finding expression in simplification of the sustain block and the base plate by forming a fine tuning spring opening  5   f  in the front portion of the rear string saddles  5 . 
         [0026]    The easier usage of the device is achieved in the device assembly and maintenance due to the decreased number of parts and units. It is also expressed in dropping out of a number of free fine tuning springs. 
         [0027]    The improved sustain is achieved by elimination of a number of openings and recesses in the sustain block and base plate. Thus the sustain block increases its mass, resulting in improved sustain. 
       CITED LITERATURE 
       [0028]    1. WO2012/162764A1

Technology Category: 3