TITLE

TREMOLO MEANS

DESCRIPTION Technical field

The present invention relates to a tremolo at string instruments, such as in particular guitars.

Background of the invention Tones created with a string instrument develop by bringing the string or strings in swing, which strings being operated to tension in the instrument, by strumming with the fingers on the string or strings. When the string swings sound waves are created which are received differently depending on the frequency at which the string swings. Within music the frequency is named in given steps so called tones. The tone created by the string is partly dependent on the tension of the string, partly of the thickness of the string, partly of the material of which the string is made, and partly of the length of the string.

The strings of a guitar are fastened to a tuning device, which normally consists of six tuning screws attached to the head of the neck of the guitar. The strings run from the tuning screws over a neck nut down over the neck or grip and over pick-up elements to a bridge attached to the body of the guitar into which the other ends of the strings are attached. By using the tuning screws the guitar is tuned, i.e., the tension of each string is adjusted and is locked when the desired tone has been achieved. When the tension of a string is increased the tone height is increased and lowered, respectively, when the tension is reduced. Present on the guitar body is controls to adjust volume, tone and select pick-up. (FIG. 1 ).

When the guitar player plays the guitar different tones are created by shortening or lengthening the string by holding the string against the neck, fret board, or the frets, and simultaneously strumming the string. One of the more simple methods to play the guitar is to hold a group of strings against the fret board or the frets using one hand and strum the strings using the other hand. The shorter the strings are swinging at a maintained tension, the higher are the tones created, and vice verse.

A tool the guitar player may use, for example to create more feeling and expression by means of his instrument is to use a tremolo system. Using a tremolo the guitar player can create a vibrato. A vibrato is a wave shaped change of the tone, by rapidly changing the tone position. Using a conventional tremolo the tone level is changed synchronously on all

strings, so called synchronous tremolo effect, by interchangeably straining and/or loosening the tension of the strings. The change of the tensions raises or lowers the pitch synchronously. (It can be noted that the term tremolo is false as the effect obtained is a vibrato, while a tremolo is a change of the volume, not the tone).

A tremolo replaces the traditional stationary bridge on the guitar. A tremolo can be regarded as a movable "block" into which the strings are attached. On the tremolo there are bridge nuts, one for each string over which the strings run over the neck nut to the tuning screws. The bridge nuts or saddle can be raised or lowered to adjust the string height based upon the design of the guitar and its components. The bridge nuts can also be moved in a longitudinal direction with the string to individually fine tune the length of the strings using the tuning screws on the tremolo. Another way of raising or lowering the strings is to adjust the attachment screws of the tremolo into the guitar body. By using these all strings are raised or lowered simultaneously.

The block can be moved in a pivoting movement at the front edge of the bridge over the attachment screws of the tremolo. The pivotal movement is controlled by the tremolo arm or actuator being attached to the block. The tremolo is pivoted upwards by pressing the arm downwards, the tensions of the strings are reduced and the tone position is lowered synchronously, or is raised if the tremolo is pivoted downwards by drawing the arm upwards, for stretching the strings, alternatively.

The horizontal force of the strings is balanced by springs being attached within the guitar body. Generally, the bridge is balanced at site on knife edges against to two screws by the power balance between springs and strings (FIG. 2). The knife edge suspension provides for a low friction which is required when the bridge shall return to its original position after a pivotal movement. The bridge can also be attached using more screws, but then it is only possible to create a small vibrato by the tremolo. When suspending the tremolo using a number of screws then it is generally possible to create synchronous tone lowering only.

If the bridge should not return exactly to its original position the guitar will become untuned.

There is a number of known tremolo systems disclosed in the patent literature such as US 2,741 ,146, US 3,250,167, US 4,171 ,661 , US 4,782,732, US 4,044,208, US 5,194,679, US 5,419,227, US 6,710,235, and US 6,384,311. Common to these systems are that the strings are attached to the same movable part which leads to the fact that if one string is actuated all strings attached to the tremolo will become actuated. These will, as a

consequence, lead to a number of undesired effects when using the tremolo system of the guitar.

WO 00/08629 invention relates generally to stringed musical instruments and specifically to devices designed to harmonically, melodically or modally bend any combination of strings without changing the initial tuning of the instrument, such as guitars. It further relates to above described devices that can be easily operated by use of a remote activator such as foot pedal. When an arm (17) is touched, a shaft (22) is rotated which leads to that a system (20, 39, 38) is swung up and down around a second shaft (33). The bridges (34) onto which the string runs over can be rotated around a third shaft (32). The string force draws the bridge forward but is stopped by a spring system (FIG. 6) to an equilibrium point. This point of equilibrium may be adjusted by the spring system. In order to influence the tension of the strings using the arm the bridge (34) has to be able to be brought to and fro. When the bridge is moved forward the tuning is lowered and vice verse. The transfer of force from the arm to the bridges is provided by a plug (36) via means (38, 20, 19, 22) which plug runs in the groove (38) and is downwardly spring loaded.

However, in order to provide equilibrium in the system according to the shown embodiments the spring force need to be 10 times greater than the string force, i.e., the spring constant should be around c = 200 N/mm, and then the pressure spring will be impressed about 3 mm, which according to the figures it can not be, as the movement then will become to large. It is more possible that the spring constant is 400 N/mm. Such a spring is available but it has a diameter of about 25 mm, but this spring will not fit into any guitar in the number requested.

Normal spring constant in the tremolo of the present invention is 4 N/mm, which shows how unrealistic the construction of the said disclosure is.

In order to tension the string the arm (17) downward which means that the plug (36) is moved backward and downward into the groove which in turn leads to that the bridge (34) is pressed backward and the tension of the string increases. When the arm (17) is released the force of the string make the plug to slide upward in the groove and impress the spring (35) and the spring (53) shall take the system back into equilibrium. In an orderly analysis of the document this is impossible.

To slacken the string the arm (17) is withdrawn which pivots the means (38) around the second shaft (33), which leads to that the plug (36) and the pressure springs (44) are

moved forward (the transfer of force between the means (38) and the springs (44) is not shown, but has to be present in order to provide a possibility of the system to slacken the string) and provides for that the bridge (34) can be pivoted around the shaft (32) thereby lowering the tuning. When the arm is released the springs (44 and 53) presses the system back into an equilibrium position.

Using the disclosed system one or more strings can be slackened or tightened. How much the strings shall become slackened or tightened can be adjusted relative each other. However, there is no possibility to slacken one string, and tighten another one.

FR 2780542 discloses an attachment that consists of a vibrato lever (8) and a housing (1 ) with a spindle (2) lying parallel to the instrument's surface and perpendicular to its strings (5). Bars (4) pivoted about the spindle have the strings attached to one end and balancing springs (6) at the other, and are equipped with sliders (11 ). In the engaged position the sliders make contact on either side with synchronised cams (15, 16) linked to the lever. The cams have specific profiles for each of the strings and are mounted on pivoted plates linked by a transmission bar.

The strings are attached in a bridge (4) which is pivotable over a knife edge (3) or a shaft (2) in equilibrium between a spring (6 or 8) and the string force (5). The springs are adjustable. The system can be locked at its rear end, i.e., provide for a fixed system. Each bridge can be locked individually. The bridges can not, however, be influenced individually by pressing on them, as the means for the arm hinders this and locks the bridges in place. Thus it is not possible to raise a tone of one string, and lower the one of another string. When the arm is influenced the rear edge of the bridges are elevated by means of oval surfaces, non-centred wheels, and thereby a simultaneous tremolo effect will be obtained. If one string is broken this will influence all the other strings by the linking system of the arm, if it is not be released, i.e., is locked at its rear end. The bridges to become influenced are controlled in that the arm can be controlled via a control (29 or 31). Vibrations from one bridge to another bridge are transferred via the link system of the arm, which means that the tones will not become pure.

When studying the figures 4 and 5 of the said document it looks like the system will always become fixed, as the string that moves the bridges downward into a locked position has to be tight if a desired effect shall be obtained when one switches the "knob" over for fixed bridge. The string will catch the movement and the bridges can not be moved.

In a tremolo the vibrations from the strummed strings e.g., at normal guitar play are transmitted to the remaining strings. The vibrations influence the other strings, which mean that the string does not create completely pure tones.

When using a tremolo and the playing technique of "bending" a dissonance is achieved leading a reduced control of the tone for the player as a consequence. The dissonance is created when several strings are strummed simultaneously in e.g., a chord, and when one of the strings is bended i.e., one of the strings moves upward (is bent upward) or downward (is bent downward), respectively, using the fingers which tensions the strings and creates a soft tone raise. The result of the bending is that the remaining strings strummed have been lowered as to tone position and create a dissonance which in turn leads to a reduced control of the tones by the player.

Another known effect created when using a tremolo is that the guitar becomes unplayable if one string is cut off. The consequence when one string is cut off is that the guitar becomes totally untuned and thereby unplayable, which may have devastating consequences, in particular at live concerts. The reason why the guitar becomes untuned when one string is cut off is that the constant force of the springs is divided over 5 strings in stead of 6 strings which provide for an increased tension of the strings giving an uneven raise of the tones of the remaining strings.

After a broken string has been replaced with a new one, all the strings have to be tuned again and this process takes a long period of time because not only the new string but also the remaining strings are required to be tuned. The tuning is complicated when it comes to a conventional tremolo bridge. This because when one string has obtained correct tuning it has influenced the other strings and thereby the remaining strings have to be re-tuned. When the following string has been correctly tuned, once again the force distribution between the strings has been changed and the already tuned string has become untuned. This means a lot of manipulation to tune the guitar by means of a number of re-tunings of each string, which is extremely time consuming.

Guitars provided with conventional tremolo systems do not maintain tuning as well as guitars without a tremolo system. This is due to the fact that after some time in use the tremolo will not return to the correct original position. This means that the power balance has been influenced and the tensions of the strings are not the same as after tuning, which

will create dissonant tones. The reason why the tremolo doesn't return to its original position is normally that the friction of the pivoting movement has increased.

Tremolo systems provided with several attachment screws does not maintain tuning well at all, due to the great friction between the bridge and the screws. A knife edge attachment provides for a lower friction but is often not low enough. The edge become dull after some time in use which increases the friction and thereby a greater risk for not maintaining tuning. There is also a possibility that a raw edge is formed on the edge which in turn leads to an increased friction followed by an untuned instrument.

Thus a considerable drawback of the tremolo means marketed today is their inability of maintaining tuning. Thus, it is quite common that a guitar has to be re-tuned quite often during a concert due to loss of tuning.

Meanwhile, there have arisen demands for guitars capable of effecting a wide range of adjustment of string tension for a freer, more sophisticated, and novel playing effects.

Summary of the invention

In view of such shortcomings of the prior art stringed instruments and recent demands for more versatile devices for adjusting string tension of stringed musical instruments, a primary object of the present invention is to provide a device for adjusting string tension of stringed musical instruments which offers a hitherto unavailable freedom in producing vibrato effects.

The present invention relates to a tremolo used at string instruments, in particular guitars, such as electrical guitars, which tremolo maintains tuning, each string can be influenced individually, and which tremolo maintains tuning on each string even after a cut off of one or more strings, thus solving the problems of the prior art tremolos.

Thus one object of the present invention is to provide a device for adjusting string tension of stringed musical instruments which, even when one of the strings is broken, can keep at least some of the remaining strings in tune.

A second object of the present invention is to provide a device for adjusting string tension of stringed musical instruments which is simple in structure but can offer much freedom in producing vibrato effects.

A third object of the present invention is to provide a device for adjusting string tension of stringed musical instruments which can offer much freedom in producing vibrato effects and, if desired, can be used in the same way as a conventional device.

A fourth object of the present invention is to provide a device for adjusting string tension of stringed musical instruments which will increase play control.

A fifth object of the present invention is to provide a device maintaining tuning in a better way.

A sixth object of the present invention is to provide a device providing a more pure and longer ring.

A seventh object of the present invention is to provide a device, which enables development of a new playing technique and thereby a new sound.

Detailed description of the present invention

In particular the present invention relates to a tremolo, which comprises a number of rockable bridges to which guitar strings are attached, characterized in that i) the bridges are operated via a common shaft to which they are individually journalled with a bearing to said shaft; ii) the bridges are separated from each other by friction reducing washers; iii) the common shaft is journalled in a rigid frame surrounding the bridges and being arranged to become attached to a guitar body; and iv) the bridges are spring biased to said frame.

A preferred embodiment of the guitar tremolo, wherein the tremolo further comprises a connection between the bridges to allow for a common actuating means.

A preferred embodiment of the guitar tremolo, wherein each bridge is operated to be actuated individually.

A preferred embodiment of the guitar tremolo wherein the bearing is a needle bearing.

A preferred embodiment of the guitar tremolo, wherein the bearing is a ball bearing.

A preferred embodiment of the guitar tremolo, wherein the bearing is a toroidal bearing.

A preferred embodiment of the guitar tremolo, wherein the bearing is a slide bearing.

A preferred embodiment of the guitar tremolo, wherein the bridges are further provided with a common locking block (80) to provide for a synchronous tremolo effect.

A preferred embodiment of the guitar tremolo, wherein the frame to which the bridges are attached via their common shaft is mounted to slide lengthwise in order to provide for a synchronous, as well as individual tremolo effect.

A preferred embodiment of the guitar tremolo, wherein the rear side of the tremolo bridges is provided with a track (90) to receive a second shaft (91) mounted to lock the system by locking the bridges, whereby the shaft (91) is moved into the track (90) by means of a tremolo arm (92), and when the tremolo arm (92) is turned the shaft is brought into the said track (90) of the bridges (89), e.g., by means of a concentric wheel.

A further aspect of the invention relates to a guitar being provided with a tremolo according to above, whereby in a preferred embodiment thereof the guitar is provided with pickup elements.

A preferred embodiment of the guitar, the guitar is an acoustic guitar.

A preferred embodiment of the guitar tremolo, the guitar is an electrical guitar.

A preferred embodiment of the guitar tremolo, the guitar is a bass guitar.

The invention will be described in the following with reference to the accompanying drawing showing some preferred embodiments of the invention, however, without being limited thereto. In the drawing FIG. 1 shows a guitar provided a conventional tremolo, seen from above;

FIG. 2 shows a conventional tremolo having a knife edge;

FIG. 3 shows a guitar seen from above comprising a tremolo of the present invention;

FIG. 4 shows a cross-section in longitudinal direction with regard to the guitar length of a tremolo of FIG. 3; FIG. 5 shows a tremolo of the invention seen from below;

FIG. 6 shows a perspective view of another embodiment of the tremolo having an integrated spring beam;

FIG. 7 shows a string saver to be used in a tremolo of the present invention;

FIG. 8 shows a device for string elevation;

FIG. 9 shows an embodiment to provide a synchronous tremolo effect with the tremolo of the present invention; FIG. 10 shows the embodiment of FIG. 9 in side view;

FIG. 11 shows a perspective view of a second embodiment to provide a synchronous tremolo effect with the tremolo of the present invention;

FIG. 12 shows a perspective view of a detail of the second embodiment of FIG. 11 to provide a synchronous tremolo effect with the tremolo of the present invention; FIG. 13 shows a perspective view of a detail of a third embodiment to provide a synchronous tremolo effect with the tremolo of the present invention;

FIG. 14 shows a perspective view of a detail of a fourth embodiment to provide a synchronous tremolo effect with the tremolo of the present invention;

FIG. 15 shows a perspective view of a detail of a fifth embodiment to provide a synchronous tremolo effect with the tremolo of the present invention;

FIG. 16 shows a side view of the embodiment of FIG. 15;

FIG. 17 shows a perspective view of an eighth embodiment to provide a synchronous tremolo effect with the tremolo of the present invention;

FIGs. 18-36 show different graphs of comparative tests made; and FIGs 37-40 show different designs of the individual bridges of the invention, and in particular their rearward, manually touchable ends.

I denotes a general guitar body provided with at its one end a fret board or neck 2, which neck 2 at its distal end receives a tuning device 3 comprising six screws 9 to which strings 4 can be attached and locked. At the opposite end the strings 4 are attached to a tremolo

I 1 after having passed over the fret board 2 and its frets 5. Further, in this case, the strings have passed over two pick-up means 6 operated to transmit any tone to an amplifier (not shown, not part of the invention). The guitar may be provided with volume control 7 and pick-up control 8 or pick-up selector, as well.

The tremolo 11 comprises a number of rocker arms 12, corresponding to the number of strings 4 to be attached to the guitar 1. The strings 4 are each attached to its rocker arm 12 by means of a connector 13 being either an integral part of the rocker arm 12, or being an added on connector 13 having been screwed onto the arm 12. The connector 13 contains means for holding and locking a string therein, such as clamping means locked by one or more screws. It should be understood that the attachment will have such a quality that the

string does not move out of attachment. The connector 13, or bridge nut or saddle, should allow adjustment of the string height and the string length, individually.

The rocker arms 12 are journalled to a shaft 14, the rocker arm shaft, and the rocker arms can be pivoted downwards or upwards around said shaft 14 at the forward edge of the rocker arms 12. As the bridge nut 13 is rotated eccentrically to the shaft 14 a downward pivotal movement will stretch the string, i.e., will increase the tension of the string 4, and an upward pivotal movement will loosen the string, i.e., will reduce the tension of the string 4.

The rocker arms 12 are each journalled in each their bearings 15 to the shaft 14. The bearings can be of different type depending on the space available. However, different suitable bearings are selected from the group of needle bearings, ball bearings, toroidal bearings and slide bearings. By means of these bearings the rocker arms 12 will become isolated from each other, and from a frame. Each rocker arm 12 is thus individually mounted in a bearing 15.

The rocker arms 12 may take different designs at their rearward end as shown in FIGs. 37 to 40. The rocker arm shown in FIGs. 37A-B is an arm being fairly in line with the longitudinal axis of the guitar and having a first and a second "break" of the arm forming a final touch end. FIGs. 38A-B show an arm being fairly in line with the longitudinal axis of the guitar and being arcuate bent from a lower position to an upper final touch end position. The rocker arm shown in FIGs. 39A-D is designed with a laterally bent rearward end in relation to the longitudinal axis of the guitar, when seeing the guitar from above, and where the rear end is arcuate bent. The rocker arm shown in FIGs. 40A-D is designed with a laterally bent rearward end in relation to the longitudinal axis of the guitar, when seeing the guitar from above, and where the rear end is straight bent.

The rocker arm shaft 14 is mounted in a framework 16 operated to be fixedly secured to a guitar body 1. The frame work 16 is arranged at least on each side of the rocker arms 12 assembly forming two side covers 16A, 16B, which side covers provide a large abutment surface against the guitar body 1 increasing the length of the ring. The frame work 16 is fixed to the guitar in the same place conventional bridges are mounted to a guitar body. The strings are attached to the rocker arms and run over the bridge nuts up to the tuning screws 3. The horizontal force from the strings is counterbalanced by springs 17, one spring 17 for each rocker arm 12 balancing the rocker arms. This design having each rocker arm 12 made individualized by means of its separate suspension on the shaft 14

and the separate balancing of the rocker arm 12 creates an individualized suspension of each string 4.

As the strings of a guitar have different thicknesses and shall emit different tones, the tension of the strings will not be equal. This means that the rocker arms 12 will not be present at the same level, in the same plane, when the guitar has been tuned. In order to compensate for this variation of tensions the springs 17 being fixed to a spring rail 18 can be adjusted lengthwise. If one rocker arm 12 is situated too high its spring 17 can be shortened, which in turn leads to that the rocker arm 12 will be drawn back to the level of the others.

The springs 17 can be affixed to a separate spring rail 18 to be separately mounted to the guitar body (FIG. 4, 5), or can be mounted to a spring rail 18 being a connecting beam between the two frame sides (FIG. 6). Further, the springs 17 may take any design such as helical or blade like, as well as they can be drawing as well as pressing.

Alternative solutions to counteract the power of the strings are, e.g., to have a mounting over the rocker arms 12 wherein springs or a spring providing material, e.g., leaf springs are attached to. Another embodiment to counteract the power of the strings onto the rocker arms, is to use a turning spring being mounted to the front edge of the rocker arm above the rocker arm shaft.

Another solution to solve the string height is to influence the whole rocker arm shaft 14 as to its height position. The adjustment of the string height using the rocker arm shaft can e.g., be made by having the rocker arm shaft mounted in a movable block. The block is then attached to guide grooves in the framework 16. The block can be adjusted using screws. When the screws are drawn the shaft is raised and vice verse.

The individualization releases the strings 4 from each other which results in that one string 4 can be affected without affecting any other string by this. This gives, as different from conventional tremolo systems that a string can be cut off without the guitar becoming untuned and unplayable. The guitar player can still use the tuned strings present and can play the tune to an end before having to replace the cut off string 4.

This has been shown in a test which will be described in the following:

Tests of a conventional tremolo system and a system according to the present invention herein called TremoLogic.

Test guitars:

• Yamaha RGX 612S - Floating tremolo system using knife edge suspension and locking of strings at neck bridge and tremolo

• Dinosour, provided with a tremolo of the present invention, herein called TremoLogic Test equipment:

• Fluke 199 Scope Meter

• Fluke view Scope Meter software, SW90W

• BOSS Chromatic tuner TU-12H

Basic facts

When a string is brought out of its equilibrium and is released it starts to swing with a number of different frequencies. The lowest oscillation is called the basic tone, followed by higher part tones being multiples of the basic tone. If the lowest tone should be 110 Hz the second part tone is 220 Hz, the third one is 330 Hz etc. The basic tone for a stricken A - 110 Hz is the same for all music instruments while the composition of and the strength of overtones contribute to the particular timbre of the instrument.

Basic tones of the guitar Frequency e 329.6 Hz

B 246.92 Hz

G 196 Hz

D 148.8 Hz

A 110 Hz

E 82.4 Hz

Questions to be answered by the tests

1. TremoLogic keeps tuning better than a guitar having a conventional tremolo system?

2. Having a TremoLogic mounted the guitar will not become unplayable if a string becomes cut off?

3. Using TremoLogic a chord can be struck and strings can be bended without influencing the chord, as such?

1. TremoLogic keeps tuning better than a guitar provided with a conventional tremolo system?

FIGs. 18-22 Actions

1. The guitars are tuned using BOSS Chromatic tuner TU-12H

2. Strums the E-string [A] 3. Muffles the E-string

4. Strums the E-string and lowers the tone level until the string becomes completely loose by means of the tremolo, releases the tremolo so that the bridge returns to original position [B]

5. Muffles E-string 6. Strummeds the E-string [C]

7. Muffles E-string

8. Reads the frequencies (frequency = 1/T T = dX ) at A and C.

9. Checks the deviations

Conclusions based on the graphs of FIGs. 18-22

On the Yamaha guitar and the TremoLogic the frequency before affecting it using the tremolo systems with the tremolo arm are 1/0,012 = 83,33 Hz [A] (Sensitivity is on one decimal for the time on Fluke 199, the reason for non correct tuning). After affection the frequencies are 80,65 Hz and 83,33 Hz, respectively, [C]. Using TremoLogic there will be no change of the frequency after influence on the strings. Tuning will be better maintained when using TremoLogic.

2. Using a mounted TremoLogic the guitar will not become unplayable if a string should be cut off?

FIGs. 23-31

1. The guitars are tuned using BOSS Chromatic tuner TU-12H

2. Strums the E-string [A]

3. Muffles the E-string 4. Strums an A-string [B]

5. Muffles the A-string

6. Tunes down the E-string until the string hits the pick-up, which simulates a broken/cut off string [C]

7. Strums an E-string [D]

8. Muffles E-string 9. Strums the A-string [E]

10. Muffles A-string

11. Reads the frequencies at A, B, D and E.

12. Checks the deviations

Conclusions based on the graphs of FIGs. 23-31 :

On the Yamaha guitar and the TremoLogic guitar the frequency is 83,33 Hz [A] of the E- string and 113,63 Hz [B] of the A-string, respectively, before simulation of cut off string [C]. The frequencies of the E-strings of the guitars are then impossible to define [D]. The frequencies of the A-strings are 125 Hz and 113,63 Hz, respectively [E]. The tuning of the Yamaha guitar has been changed as to tone level while the TremoLogic is unchanged. Using the TremoLogic the guitar will not become unplayable if a string should become cut off.

3. Using TremoLogic a chord can be strummed and strings can be bended without affecting the chord by the bending?

FIGs. 32-36

1. The guitars are tuned using BOSS Chromatic tuner TU-12H

2. Strums an A-string and lets it ring for about 2 s [A]

3. Bends the D-string by moving it 1.5 cm from the A-string without influencing the A- string, which continues to ring. [B]

4. Checks if the frequency of the A-string has been affected during the bending of the D-string.

Conclusions based on the graphs of FIGs. 32-36: On the Yamaha guitar and the TremoLogic the frequency is 108.7 Hz [A] of the A-string before bending. During the bending of the D-string the frequencies are 104.16 Hz and 108.7 Hz respectively of the A-string [B]. Using the TremoLogic will not affect a struck string, if another string should be bent.

When replacing a broken string/strings or change of strings the tuning process will be rapid and simple due to the individualization of the strings. Using the invention one string can be attached to the guitar and be tuned to the desired tone without any reflection concerning

what might happen when another string is attached and tuned. The result of the individualization is that there is only need for tuning each string once and then the guitar will become tuned, as different from the time consuming manipulation needed in order to get a conventional tremolo tuned.

Due to the individualization of the strings using the invention a guitar player can bend a string without causing any slackening of the other strummed strings, and will not cause any dissonance which happens when using conventional tremolo systems. The guitar player can play a chord, bend one string still having control over the tones without creating dissonance.

The individualization of the strings will also lead to that each rocker arm can be influenced individually. This means that each string can be influenced by the user in a quite new way by pressing down or pulling the rocker arms and thereby creates quite new sounds and effects. The user may for example strum a chord and simultaneously lower one or more tones of the strings or raise a tone of a string and lower the tone of another string, alternatively.

The use of a needle, roller, toroidal or ball bearing isolates the strings from each other. The isolation releases each string so that the vibrations will not transmit between the strings. The isolation of the strings provides for the fact that vibrations from a single string do not transmit to the remaining strings which results in that the strings emit more pure and distinct tones.

Having the bearings means that the rocker arms will return to their original location with a better precision than when using the knife edge suspension of the prior art. This in turn means that the guitar holds the tone better and need not be tuned that frequently as those of the prior art. This is due to the fact that in the knife edge suspension the knife edges and screws will become worn after some time of use and will then not return into their original position after having used the tremolo by the tremolo arm, which results in dissonance and an untuned guitar.

Using individualized strings the tuning will be better maintained than when using conventional tremolo means. This is because when one string becomes untuned in a conventional system this will influence all strings which will also become untuned, which means that the knowledge of which string that first become untuned will be lost and thus all strings need to be tuned again. Having an individualized bridge only one string will be

influenced. When a string becomes untuned such as due to natural elongation thereof due to its material properties only this string will become untuned and need to be tuned, all other strings maintaining their tuning without need for tuning.

When using the invention a synchronous tremolo effect can be obtained, as well, in a similar manner as obtained at conventional systems by simply pressing or drawing all rocker arms using the whole hand.

FIGs. 9 and 10 show a method for obtaining a synchronous tremolo system by locking the rocker arms 89 by utilizing a shaft 91 for obtaining a locking. In this case there is a track 90 into which the shaft 91 can be pushed. The pushing of the shaft into the track 90 is controlled by a tremolo arm 92. When the tremolo arm is not in use, the arm hangs downward and the rocker arms can be pivoted freely, i.e., an individual tremolo effect can be obtained. When the tremolo arm 92 is turned upwards the shaft is brought into the track 90 of the rocker arms 89 e.g., by means of a concentric wheel, and locks the rocker arms into a unit. The frame 93, into which the locking shaft and the tremolo arm with its introducing mechanism are being mounted on, is pivoted around the same shaft 94 as the rocker arms are suspended to.

When the tremolo arm has been brought up and the locking shaft has been pushed into the rocker arms an influence of the tremolo arm will give a synchronous change of the tones. The functions of synchronous and individual tremolo effect are separated in time and cannot be used simultaneously.

Another solution, FIGs. 11-14 for creating a synchronous tremolo effect is to lock the rocker arms 79. This can be made by designing a block 80. In the block 80 there are apertures or throughgoing holes 81 having the same inner form as the outer form of the ends of the rocker arms 79 in order to fit snugly. When the block is slipped onto the ends of the rocker amrs 79 all rocker arms become locked together to one unit. To the block 80 there is a tremolo arm 84 attached, by means of which the tremolo effect is controlled. The apertures or holes 81 of the block may have different designs. For example as shown in FIG. 13, the apertures or holes 81 of the block 82 may be irregularly placed. This irregularity of the placement of the apertures or holes results in the fact that the guitar can be tuned, in a simple manner, down to e.g., an open G with a simple handling. The apertures or holes 81 of the block 80 may also be adjustable with regard to their level or height above the guitar body, cf. FIG. 14. Here this is solved by providing detachable holders 87 present in the block, into which holders 87 the rocker arms 79 are applied. The holders slide, respectively,

in grooves (not shown) and are adjusted as to their levels using e.g., screws 88. This design makes it possible to influence the key into which the guitar is tuned, and a possibility to adjust finely the same.

When the tremolo arm is influenced the whole unit becomes pivoted, which results in that the pitch of the strings is synchronously affected, just as when using the conventional systems.

In this case the block can be designed to lock all the bridges in all directions, as well. Thus by applying a counter piece on the underside of the block 80 which abuts the guitar body any bending downward, tension of the strings, is hindered. By applying side arms abutting the frame work of the tremolo any upward movement, i.e., loosening of the string tension, will be hindered. A combination of the two will hinder any use of the tremolo, i.e., the guitar is played as a common guitar.

In order to be able to use the invention as the traditional bridges, i.e., being able to influence all strings synchronously by means of a tremolo arm this can be made by moving the rocker shaft along a linear path in the direction of the elongation of strings. FIGs. 15-16 show different embodiment of such a solution. A synchronous tremolo effect can be obtained using the tremolo arm 10 by moving the rocker shaft linearly with the strings 101. The rocker shaft is mounted in a frame 102 e.g., in the same way as according to the basic function of the present invention. The frame 102 is mounted in a linear bearing 103. This linear bearing in turn is mounted in the guitar body 104. The design provides for that the whole tremolo (frame, rocker shaft, rocker arms 50) can be moved longitudinally along with the strings of the guitar. In order to control the movement linearly using the tremolo arm, the chord of a circle sector can be used. The circle movement needed to utilize the chord of the cicle sector is obtained by a pivoting movement. When the tremolo arm is pressed downward the tremolo block 105 is pivoted around a second shaft 106. This shaft 106 is mounted in a block 107 which in turn is mounted to the guitar body 104. Wen the tremolo arm is being pivoted the tremolo block 105 will pivot as well and will create the linear movement. The linear movement created moves the tremolo forward via a linkage 108, which is partly articulated in its mounting point 109 of the tremolo, partly is articulated in the mounting point 110 of the tremolo block 105. When the tremolo is moved forward the strings will become loosened and a synchronous lowering of the tones will be obtained. When the tremolo arm is, on the other hand, drawn upward the whole tremolo will be moved backward and a synchronous increase in pitch will be obtained.

The tension of the strings will be counterbalanced by rocker springs 111 being mounted to the rocker arms. The balance between the tension of the strings and the rocker springs cr4eates a floating suspension of the rocker arms. The rocker arms can be adjusted lengthwise by means of a second set of springs 112. The rocker springs 111 are mounted in a spring block 113 which in turn is mounted in the guitar body by screws 114.

The force of the strings 51 and the rocker springs 111 will draw the whole tremolo forward in the linear movement. This force is counterbalanced by e.g., springs or another similar spring element.

When the tremolo arm is influenced the whole system will move linearly, which results in that the tension of the strings is changed synchronously. The synchronous change of the tension creates a synchronous change of the pitch, as the one obtained using the tremolo arm at conventional tremolo systems. Simultaneously, however, each rocker arm can be affected, which provide an individual change of the pitch. The design provides for a tremolo where individual as well as synchronous tremolo effects can be created simultaneously.

FIG. 17 shows an embodiment where the invention can work as a conventional tremolo by moving the mounting point of the rocker springs 112, the spring block 116 linearly with the strings. The spring block 116 is hereby movably mounted in an opening in the side frame 118, which opening 1 15 has a longitudinal extension. When the spring block 116 is moved linearly, the rocker springs 112 influence the rocker arms 50 synchronously. When the rocker arms 50 are influenced synchronously, the rocker arms will pivot, which creates a synchronous change of the pitch. The linear movement of the spring block 116 is controlled by the frame 118 in said opening 115, or e.g., in a linear bearing. The linear movement needed to move the spring block 116 may be created by using the chord of a cicle sector. The circular movement, to utilize the chord of the cicle sector, is created by a pivot 119, which is controlled by the tremolo arm 120. When the tremolo arm 120 is affected the pivot will pivot. The linear movement created by the tremolo arm is transferred to the spring block 116 by means of link arms 120, which are partly articulated in the spring block, partly articulated in a second pivot 121.

The rocker springs 112 are mounted in the spring block 116 which rocker springs 112 can be adjusted in length by means of spring screws 124 in order to compensate for the different tensions present in the springs. In the spring block a third set of springs 123 are mounted as well. Their function is to compensate or counterbalance the force of the strings which will move the spring block 116 forward.

When the tremolo arm is influenced the spring block will move and all rocker arms will become pivoted. Simultaneously herewith each rocker arm can be influenced as well. Thus the embodiment provides for a tremolo where individual as well as synchronous tremolo effects can be created simultaneously. The set of rocker arms can be locked as such, to get a guitar behaving as a "normal" guitar, i.e., without allowing a tremolo to be carried out.