WO2017138826A1

WO2017138826A1 - Acoustic guitar

Info

Publication number: WO2017138826A1
Application number: PCT/RU2016/000056
Authority: WO
Inventors: Алексей Федорович ЧУНАРЕВ
Original assignee: Алексей Федорович ЧУНАРЕВ
Priority date: 2016-02-09
Filing date: 2016-02-09
Publication date: 2017-08-17

Abstract

The claimed invention relates to the field of plucked musical instruments, and specifically to the design of acoustic guitars. An acoustic guitar contains a fretboard, strings and a body with a soundboard. A bridge with a base is installed on the outer surface of the soundboard, a tailpiece is installed on the inner surface of the soundboard, and through-holes for the strings are provided in the soundboard outside of the base, the strings being secured in the tailpiece. The claimed implementation of an acoustic guitar allows for achieving a higher power of outputted sound and also simpler manufacturing while simultaneously enhancing the reliability and operational characteristics of the instrument.

Description

Acoustic guitar

The invention relates to the field of plucked musical instruments, namely the design of acoustic guitars.

The main purpose of any musical instrument, including the guitar, is its ability to reproduce sound waves with given acoustic characteristics, such as: dynamic range (loudness), attack speed, timbre. The most important characteristic of the guitar, as a complex oscillatory system is the quality factor. The problem of creating instruments with the best acoustic characteristics has attracted the attention of the best craftsmen in the world for centuries. The disadvantages of the known designs include:

- low volume of instruments. By some estimates, it is (5-8)% of the energy of vibrations of the strings. Many famous musicians and composers complained about the insufficiently loud sound of a classical guitar;

- most of the instruments have valid claims to such characteristics as attack speed, uneven frequency response, low Q-value of the oscillating system.

The acoustic guitar is well-known, consisting of a neck with an upper nut and frets, a neck head with pegs located on it, a body consisting of a shell, an upper and lower deck, a stand holder with strings attached to it, which transmit vibrations the strings of the upper deck when playing (see O. Puchol "School of playing the six-string guitar" Moscow, All-Union Publishing House "Soviet Composer" 1983)

The design feature of the well-known solution is a rigid, direct connection between the tailpiece (hole system) and the nut, through the base of the stand. One end of the string is attached to the tailpiece and rests on the lower support of the stand, the other end rests on the upper support, located on the neck of the guitar and fixed by a system of pin mechanisms located in the neck of the neck and allowing you to adjust the tension of the string. The traditional stand (base) is, in fact, a foreign part that has a large mass and area that has a negative impact on the sound of the guitar. However it is impossible to significantly reduce its area, since it is necessary to ensure a significant area of its glue joint with the deck, otherwise there is a threat of partial or complete detachment of the stand (base) due to the tension force of the strings.

Studies of the characteristics of acoustic guitars using the methods outlined in my patent RU 2416128 “The method of tuning and measuring the dynamic characteristics of stringed musical instruments and the device for its implementation” showed that these shortcomings are largely due to the design of the stand holder placed in the center of the big oval of the upper deck . The inventor of the stand is considered to be Dionisio Aguado (04/08/1784 - 12/20/1849) - Spanish virtuoso guitarist, composer, teacher. The stand of Aguado has not undergone significant changes for more than 170 years and consists of a base having a significant area (for a classical guitar more than 10% of the effectively emitted surface of the large oval of the upper deck) the tailpiece formed on it and the lower threshold resting on the base.

For the best transmission of vibrations of strings, the supports of master guitars are made, as a rule, from rosewood, a very hard and dense material, and their average weight is about 35 grams or more, which often exceeds 30–40% of the most efficiently vibrating mass of the upper deck located in the central parts of a large oval, mainly forming the main acoustic characteristics of the instrument. The placement of the known stand design, which has a significant mass and area in the center of the antrum of the main mode of the upper guitar deck, inevitably has a damping effect on the propagation of elastic oscillations in the resonator (body) of the guitar, resulting in a lowering of the quality factor of the oscillatory system, deterioration of all acoustic characteristics.

A known construction of a classical guitar, in which the tailpiece, made with the base of the lower nut as a whole, is divided into three separate parts in the central part, proportional to the number of strings placed on them, each part being separately attached to a glue-threaded deck connection at a distance from each other, preserving the overall geometric shape of the tailpiece (application for invention PCT7UA2013 / 000126). This constructive solution is designed to increase the amount of string energy transmitted to the deck, by using the energy of the parallel component of the string vibrations. It is known that the axis of the string, when it is excited, rotates along a curve close to an ellipse. In the case when the string oscillates perpendicular to the plane of the deck, its oscillations (with the existing stand design) are best transmitted to the deck. In the case when the string oscillates parallel to the plane of the deck, the oscillations are practically not transmitted, since the base has a considerable length, it is “clamped” by the neighboring strings, as a result of which this component of the oscillations is damped. Cutting the base, according to the idea of the author of the application PCT / UA2013 / 000126, should increase the mobility of the three bases obtained in this plane of oscillation. The proposed technical solution affects the acoustic properties of the instrument for the following reason.

The stand (base), in a well-known construction, besides the function of fastening the strings and transmitting vibrations to the deck, is also a transverse spring that increases the elastic properties of the upper deck, and thus partially compensates for the negative effect of increasing mass. When separating the stand (base), its spring function is eliminated and it will only act as an additional weighting agent for the deck, which will inevitably lead to a further decrease in the quality factor of the oscillating system and other characteristics than was the case with the classical design.

The technical result of the present invention is to improve the acoustic characteristics of an acoustic guitar, increasing the radiated sound power. In addition, the production is simplified, the reliability and performance of the instrument is increased, in particular, the possibility of the tailpiece being torn off by the string tension is eliminated.

The technical result is achieved in an acoustic guitar containing a neck, strings, body with top deck. On the outer surface of the upper deck set the lower threshold with the base. Cereals with base can be made separate. On the inner surface of the upper deck mounted tailpiece, the top Deck, outside the base, made through holes for the strings (buttons) fixed in the tailpiece. The base rests on the upper deck throughout the length or at least two points. The tailpiece is made in the form of a bar (otherwise, a footer or spring, in the form of a wooden bar, the shape of which is related to the acoustic properties of the instrument), in which through holes for strings (buttons) are made. The strings are fastened in the tailpiece with a spike or button, or a knot made at the end of the string, and a button. Through holes in the upper deck can be located at equal distances or at different distances from the lower threshold. The lower threshold with the base is divided into parts that do not touch each other, each part rests on the deck throughout its length, or, each part rests on the deck, at least two points. On the outer surface of the upper deck, over the tailpiece, there is a pad with through holes for the strings (buttons).

The invention is illustrated by drawings that do not cover and, moreover, do not limit the entire scope of the claims of this technical solution, but are merely illustrative materials of a particular case of performance, where:

- figure 1 shows a view of the proposed construction of an acoustic guitar;

- figure 2 - shows a longitudinal section aa, indicated in figure 1 explaining the fastening of the string in the tailpiece using the button and the node performed on the string;

-Fig.Z - shows an embodiment of the acoustic guitar design, different from Fig. 1, with different distances between the lower threshold and the fixing point of the string end on the upper deck;

- figure 4 - shows a variant of the base of the lower nut, based on the upper deck two points;

- figure 5 - shows a variant of the base of the lower nut, which is an integral part of the lower nut;

-fig.6 shows an embodiment of the construction of an acoustic guitar, which differs from Fig. 1 in that the lower threshold is structurally divided into equal parts non-touching with each other, in proportion to the number of strings supported on it;

- in FIG. 7 shows a variant of fastening the end of a nylon string with the help of a clamp of the “spinek” or “button” type. An acoustic guitar consists of a neck 1, with an upper nut 2 installed on it, a fret 3, a neck head 4, with pegs 5 on it, a body 6 consisting of a shell 7, an upper deck 8, a lower deck 9. On the outer surface of the upper deck 8 installed the lower threshold 10 with the base 11. On the upper and lower thresholds 2, 10 strings 15 are supported.

The base And can be an integral part of the lower nut 10, with which it rests on the upper deck 8, that is, the lower threshold 10 with the base 11 is made in the form of a single, indivisible piece, made for example of a single piece of plastic or bone (Fig. 5). In addition, the bottom blade 10 with the base 11 can be made separate (as shown in the figures), while the bottom wheel 10 can be installed in the groove made at the base 11. The separate implementation allows you to replace the bottom wheel 10 during operation of the guitar.

The base 11 rests on the upper deck 8 over the entire length (Fig. 1, 3) or at least two points (Fig. 4). The pillars of the base 11 may be more than two, for example, three, four, etc.

On the inner surface of the upper deck 8 there is a tailpiece 12. In the upper deck 8, outside the base 11, there are holes 14 for the strings 15, buttons 17 fixed in the tailpiece 12. The tailpiece 12 is made in the form of a bar (otherwise, a footer or spring, wooden bar, whose shape is associated with the acoustic properties of the instrument). Under the footer or spring are meant strips of wood glued to the inner surface of the upper deck 8, which serve, inter alia, to strengthen the structure of the upper deck 8 in the loaded places. The location, material, thickness, shape of the tailpiece 12 can be very different. It is only important that in the area of fastening of the strings 15, the thickness of the tailpiece 12 is sufficient (about 6 mm) so that the string 15 is securely fixed, for example, buttons 17 do not fall out. representing a thin plate (2- 2.5 mm). In order to balance the pressure force of the strings 15, springs (wooden slats) and a footer are glued to the bottom of the upper deck 8, the location of which can be anything. Springs and footer provide unique to each Guitar distribution of oscillations. In order to obtain the best Q-factors, the upper deck 8 with springs and a footer must have the smallest mass, at the same time providing the necessary rigidity of the structure and the maximum amplitude of propagation of vibrations. The purpose of the tailpiece 12 is to distribute the pressure of the strings 15 over the entire area of the top deck 8.

Lower sill 10 with base 11 can be divided into parts that do not touch each other (Fig. 6), for example, into equal parts, in proportion to the number of strings that rest on it. At the same time, each part rests on the upper deck 8 throughout its length , or, each part rests on the upper deck 8, at least two points. The separation of the base 11, unlike the solution for PCT / UA2013 / 000126, does not impair the acoustic characteristics of the instrument, since this design has a small area and weight, and the tailpiece 12 is completely identical to the conventional spring (footer) design placed on the inside of the upper deck 8.

On the outer surface of the top deck 8, above the tailpiece 12, a cover plate 13 with through holes 14 for the strings 15, buttons 17 can be installed. The cover plate 13 prevents the top deck 8 from being jammed with strings 15. The upper deck 8 is usually made of soft wood, lining 13 is made of harder wood.

The strings 15 are secured in the tailpiece 12 with a locking element 18, for example, with a pin or button. At the same time, small diameter through holes 14 are made in the tailpiece 12, through which the strings 15 can be passed. The locking element 18 is mounted on the string 15 by pulling it out, through the resonator opening of the top deck 8. The strings 15 can be fixed in the tailpiece 12 by the node 16 and button 17, at the same time, the through holes 14 are larger diameter corresponding to the diameter of the button 17 inserted into them.

Through holes 14 in the upper deck 8 can be located at equal distances (Fig. 1) or at different distances (Fig. 3) from the lower threshold 10, depending on the wavelength generated by the string 15. Change distance from the lower nut 10 changes the length of the applied force arm. For better excitation of low frequencies, the shoulder should be longer and vice versa.

In the proposed technical solution, the problem of detachment of the stand by the force of tension of the strings is solved automatically: there is no stand, no problem. The tension force of the strings acts on the bar (footer, spring) glued to the inside of the upper deck and this force presses it to the deck, and does not tear off the base of the stand, as it is implemented in the traditional design.

The invention reduces production costs by reducing the consumption of expensive materials such as rosewood, due to the fact that the base 11 in the proposed design has much smaller dimensions in comparison with the traditional stand.

Due to the fact that the tailpiece 12 is “hidden” inside the body of the guitar, and the tension force of the strings 15 presses it to the top deck 8, the material for the manufacture of the tailpiece 12 (footer), its shape, size, location, location of the springs, can be chosen in this way that these factors will ensure a reduction in the mass of the central (most significant for acoustics) region of the large oval of the upper deck 8 several times. Hesitating, the strings 15 do the work of “transferring” the mass of the upper deck 8, the smaller its mass, the less energy is expended for each period, the higher the quality factor of the system, and the longer the duration of the oscillations.

The dimensions of the traditional base of the stand are (180 x 30) mm. Thus, its area is equal to 5400 square meters. mm Vibrations of the strings transmitted through the lower threshold to the upper deck are initially distributed over a considerable area of the base, as a result, the effect on the upper deck, leading to its elastic deformation, is insignificant. In the proposed invention, the area of the base And the lower nut 10 may be (80 x 10) mm = 800 square meters. mm in the event that it relies on the upper deck for the entire length. Thus, the ratio of the areas of support of the lower nut 10 in the traditional and the proposed version will be 5400/800 = 6.75 times. In the case where the base 11, the nut 10, rests on the top deck 8, by several points, this ratio will be even greater. Oscillations of the strings 15 in the present invention, by reducing the area of the base, will directly affect the top deck 8 and the strength of these fluctuations increases significantly. In connection with the increase in the strength of the vibrations of the strings 15 transmitted to the upper deck 8, the magnitude of its deformation increases, and, accordingly, the elastic force returning the upper deck 8 to the initial state. As the magnitudes of these two forces increase, the amplitude of the flexural elastic mechanical vibrations generated in the upper deck increases, which in turn leads to an increase in the volume of the instrument.

Due to the fact that the threshold 10 with the base 11, responsible for the transmission of oscillations of the strings 15 has decreased several times, both in area and in mass, the inertia of the system as a whole has decreased. As a result, the parallel body vibrations of the strings 15 will be transmitted to the deck much better, thereby improving all the acoustic characteristics of the guitar.

The proposed invention extends the experimental possibilities in the direction of creating instruments with the best sound characteristics. Thus, it becomes possible to change the length of the arm of application of force, depending on the wavelength of the concrete string being excited, by changing the distance between the lower threshold 10 and the fixing point of the end of the string 15 on the upper deck 8. The change in the number of support points of the base 11, their area, in combination with different arrangements of the springs, makes it possible to achieve the best transmission of all the harmonic components of the vibrations of the strings 15 of the upper deck 8.

In the manufacture of the instrument, the guitar master at the stage of manufacturing parts of the body, such as the upper deck 8, the lower deck 9, makes resonant frequency settings. After building the case 6 by grinding the upper and lower deck 8, 9, this work can be continued. The purpose of these settings is to achieve the best sound settings. After gluing the traditional stand, the frequency characteristics of the instrument change in an unpredictable way, due to the addition of a node of considerable size and weight to the oscillatory system. Considering that sticking a stand in the technological cycle of making a guitar is practically the last operation, to introduce some frequency adjustments to the finished tool - very problematic. In the proposed design, the installation of the bottom nut 10 with the base 11, due to the small mass and area does not affect the acoustic characteristics of the instrument, resulting in much easier to achieve the planned acoustic parameters on the finished tool. Exciting forces of vibrations of the strings are applied to the upper deck 8 on both sides, which contributes to a more efficient, less inertial, occurrence of bending elastic vibrations.

All known stand designs include a hole system, which is part of their base through which the strings are passed. The consequence of such a constructive solution is a common problem of the detachment of the base of the stand from the top deck, the tension force of the strings during operation. The operation of gluing the stand is one of the most difficult and time consuming. Achieving a reliable glue joint can only be ensured by an ideal fit of the glued surfaces. Considering the considerable area of the base of the stand, it is technologically difficult to achieve this, especially if the surface of the upper deck has a convex dome shape. Some manufacturers are trying to solve this problem using screws, screws and nuts. But, even if the stand externally "firmly" rests on the upper deck, but the adhesive bond is broken, it will inevitably act as a damper load, which degrades the acoustic characteristics of the instrument. In addition, the use of "foreign" metal parts, often leads to the appearance of cracks in the places of their contact with wood. In the proposed invention, the system of holes 14 for fastening the strings 15 is located separately from the base 11, and the tailpiece 12 (footer, spring) is placed on the inner side of the upper deck 8, and its separation by the tension force of the strings 15 is completely excluded. Due to the fact that the base 11 of the nut 10, has a small area, and during operation is pressed against the upper deck 8 by the tension of the strings 15, the technology of its gluing is extremely simple, and does not have any special requirements for the strength of adhesive bonding.

Claims

CLAIM

1. Acoustic guitar containing fingerboard, strings, body with upper deck, lower gate with base is installed on outer surface of upper deck, tailpiece is installed on inner surface of upper deck, through holes are made in upper deck, outside of base, fixed in string holder .

2. Acoustic guitar according to claim 1, characterized in that the threshold with the base are made separate.

3. Acoustic guitar according to claim 1, characterized in that the base rests on the upper deck for the entire length.

4. Acoustic guitar according to claim 1, characterized in that the base rests on the upper deck, at least two points.

5. Acoustic guitar according to claim 1, characterized by the fact that the tailpiece is made in the form of a bar in which through holes for the strings are made.

6. Acoustic guitar according to claim 1, characterized in that the through holes in the upper deck are located at equal distances from the lower threshold.

7. Acoustic guitar according to claim 1, characterized in that the through holes in the upper deck are located at different distances from the lower nut.

8. Acoustic guitar according to claim 1, characterized by the fact that the lower threshold with the base is divided into parts that are not in contact with each other, each part rests on the deck throughout its length.

9. Acoustic guitar according to claim 1, characterized by the fact that the lower threshold with the base is divided into parts that are not in contact with each other, each part rests on the deck with at least two points.

10. Acoustic guitar according to claim 5, characterized by the fact that the strings are secured in the tailpiece with a pin or button.

1 1. Acoustic guitar according to claim 5, characterized by the fact that the strings are fixed in the tailpiece node and button.

12. Acoustic guitar according to claim 1, characterized in that on the outer surface of the top deck, over the tailpiece, a pad with through holes for strings is installed