Tremolo unit for string instrument

#The present invention relates to a tremolo unit for string instruments.

#Tremolo units for string instruments are widely known and often installed in electric guitars. A tremolo unit increases and decreases the tension of the strings of a string instrument to make the sound of the instrument impressive. FIG. 11 illustrates a typical prior art tremolo unit 110 applied to a guitar. The tremolo unit 110 includes a base plate 111, string supports (bridge saddles) 121, a tremolo body (bridge) 120, a tremolo arm 125, and springs 130. The string supports 121 are pivotally attached to a body B of the guitar and support strings S at the top surface of the base plate 111. The tremolo body 120 has a tremolo block 122 extending inward of the body B below the base plate 111. The tremolo arm 125 is attached to the tremolo body 120 to pivot the tremolo body 120. The springs 130 are located between the tremolo block 122 and the body B. In cooperation with the tension of the strings S, the springs 130 keep the tremolo body 120 at an equilibrium position. The base plate 111 has knife edges 112 at one end. Stud bolts 115, each having a groove, are fixed to the body B. Each stud bolt 115 pivotally supports the corresponding knife edge 112 at the groove. Spring engaging member 135, to which the springs 130 are hooked, is fixed to the body B. The urging force of the springs 130 is adjusted by the spring bolts 135.

#The tremolo unit 110 is constructed such that the tremolo body 120 is kept in equilibrium by the tension of the strings S and the urging force of the springs 130, which acts against the tension of the strings S. When the tremolo body 120 is pivoted by manipulation of the tremolo arm 125, the tension of the strings S is increased or decreased, which raises or lowers the pitch of each string S. When the arm 125 is released, the tremolo 120 returns to the equilibrium position and the pitch of each string S returns to the original pitch.

#The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which:

#FIG. 1 is a perspective view illustrating an electric guitar equipped with a tremolo unit according to the present invention;

#FIG. 2 is a plan view showing the tremolo unit of FIG. 1;

#A preferred embodiment of the present invention will now be described with reference to the drawings.

#FIG. 1 shows a string instrument, which is an electric guitar G in this embodiment. The guitar G includes a neck N, a body B, and six strings S. A head H is located at the top end of the neck N. Tuning posts Nb are provided on the head H. One end of each string S is held by one of the tuning posts Nb. A tremolo unit 1 is located in the body B. The tremolo unit 1 forms a bridge and functions as a string tuning device and a pitch changing device. One end of each string S that is opposite from the end held at the head H is held by the tremolo unit 1. A nut Na is located at the front end of the neck N to support a section of the strings S at the end of the neck N connected to the head H. Tuning pegs Nc are provided at the head H. The tuning pegs Nc are connected to the tuning posts Nb and are used for tuning the strings S.

#As shown in FIGS. 2 to 6, the tremolo unit 1 includes a tremolo body 10, a tremolo arm K, and a back mechanism 60. The tremolo arm K is detachably connected to the tremolo body 10 and is used for manipulating the tremolo body 10. The back mechanism 60 forms a tremolo body returning mechanism, which returns the tremolo body 10 to an equilibrium position after the tremolo body 10 is pivoted. The back mechanism 60 is located in a recess Bb formed in a back portion of the body B.