FR2488019A1 - Stringed musical instrument e.g. guitar - has elastic relaxation device deflecting strings at cross-member to rear of bridge - Google Patents

Abstract

The stringed musical instrument, particularly a guitar, has a cross-piece supporting the bridge and secured by its base to the sounding board. To the rear of the bridge are holders for the strings. An elastic relaxation device (21) extends from the body of the instrument to the cross-member (20) at the rear of the bridge (23,24). The cross-member deflects the strings (18) w.r.t. the connecting surface between the cross-member and the sounding board.

Description

 The invention relates to stringed instruments, in particular guitars, comprising a spacer carrying the bridge, fixed by its base surface to the soundboard and which, at the rear of the bridge relative to the fingerboard and at some distance from the bridge , has rope retaining arrangements.

 In conventional stringed instruments of this kind, the strings are fixed at one end to these retaining arrangements, then pass over the bridge and go from the bridge to the arrangements for tensioning the strings on the neck pin. This mode of string guidance determines the characteristic sound of string instruments of this kind, because, due to the arrangement of the bridge and the restraining arrangements, the transverse oscillations which prevail on the affected string are converted into relaxation oscillations of the spacer. , around its longitudinal axis placed transversely to the strings, and these relaxation oscillations are transmitted to the soundboard. The longitudinal oscillations6 also generated in the string when it is touched are converted, on the spacer, into oscillations which occur parallel to the soundboard, essentially around a centerline of the spacer. This second kind of oscillation of the spacer is also transmitted to the soundboard, since the spacer is integral with its base surface.

 However, in conventional stringed instruments of this kind, the transmission of these oscillations to the body of the instrument is hampered by the fact that the spacer, the soundboard and the connection between them must withstand the prevailing tensile stress. on the ropes. For this purpose, it is necessary that inside the soundboard is provided a sufficiently strong bracing provided by stiffening strips. This stiffening and this bracing of the soundboard normally causes a significant damping of the oscillations generated on the table, in particular in the domain of the fundamental mode.

We have already proposed, in the utility model
DE 79 18 617.7, to ensure an amplification of the vibrations emitted by such stringed instruments, in particular, also, in the field of fundamental mode, by giving the spacer the form of a frame surrounding at least one eleven. However, it has appeared in practice that, by this structure, one can only obtain a limited amplification of the vibrations emitted by the instrument, because, if it is true that the shape of the frame giving the spacer allows appreciable widening, this is without significantly expanding the vibration behavior of the soundboard in the region of the sntretois-. However, the arrangement of an oufe inside the frame formed by the spacer signifies a significant weakening of the table in the region of the spacer and therefore requires, as previously, the provision of stiffenings and reinforcements below Table.

 Relative to this, the invention aims to save at least partially, at the soundboard and in particular at the connection surface between this and the spacer, the tensile stress to transmit strings, by intermediate of the spacer, to the body or to the table.

 According to the invention, this problem is solved thanks to the fact that the instrument comprises an elastic device for relaxing constraints extending from the body to the spacer, at the rear of the bridge relative to the fingerboard and which, in the region of the spacer, is designed as a deflection, acting for at least part of the tensile stress of the strings to be transmitted to the body, relative to the bonding surface between the spacer and the soundboard.

 Thanks to this, the tensile stress of the strings or, at least, a significant part of this stress is spared the connection surface between the spacer and the table and is transmitted elastically to the body, avoiding this connection surface, by through the stress relief device. Thus, the bonding surface of the spacer, relieved to a large extent of the tensile stress of the strings, is able to transmit to the soundboard, practically without preload, the relaxation oscillations of the spacer as well as the lontitudinal oscillations of the strings. The soundboard no longer needs, in the region of the spacer, than a noticeably less stiffening and reinforcement than before.

 In one embodiment of the invention, in order to form the stress relief device, the arrangement for retaining the cords provided on the spacer is in the form of a cords return element and the cords, in passing by this return element, go to a tailpiece separate from the spacer, which tends them and which is fixed to the edge of the body opposite the spacer. In this way, the essential longitudinal component of the tension of the strings is absorbed by the tailpiece located at the edge of the body. As a result of the strings being guided by the bridge and the string return element, the spacer only experiences a couple of forces, the size of which varies according to the transverse oscillations of the affected string. apply with appreciable friction on the bridge and in the deflection element, there is also a transmission of the longitudinal oscillations of the strings to the spacer and from this to the soundboard.

 It is true that, for bowed string instruments, it is known to bring the strings, passing through the bridge, to a tailpiece placed at the edge of the body. However, in bowed stringed instruments, the transmission of the oscillations of the strings is practically carried out only by the pressure exerted by the bridge on the soundboard, in combination with a soul placed inside the body, in the vicinity easel.

 However, in this first embodiment of the invention, there is a preferential transmission and a particularly large amplification of the low oscillation frequencies, in particular of the fundamental modes of the strings, while the higher frequency oscillations, in particular the longitudinal string oscillations and higher order harmonics are transmitted less efficiently and less amplified.

This causes the sound to change, in that the fundamental modes and lower order harmonics are felt more strongly in the sound impression, to the detriment of higher order harmonics.

 If, on the other hand, we want to keep as much as possible unchanged the classic sound of string instruments of this kind, it is particularly advantageous to adopt a second embodiment of the invention in which the strings are fixed in one of the classic ways, by one end, to the strings retaining arrangement of the strut and in which the strain relief device is formed by at least one elastic counter-tension element which extends from the strut to a tension device fixed to the edge of the body opposite the spacer. This counter-tensioning element or a group of elements of this kind constitute, for the tension constraint of the strings to be transmitted to the body of the instrument, a derivation just as effective as the method of guiding the strings themselves, such as it is provided in the first embodiment.

However, by attaching the ends of the strings to the strut retaining arrangement, it is ensured that the longitudinal oscillations of the strings are transmitted fully effectively to the strut and from the strut to the table of harmony. Thanks to the arrangement of the elastic counter-tensioning element or of a group of such elements, it is possible, without difficulty, to act fully on the couple of forces described above to generate the relaxation oscillations by virtue of the transverse oscillations of the rope.

 According to a development and a particularly advantageous complement to the second embodiment of the invention, the tensioning device can be adjustable in order to establish the desired tension on the elastic back-tensioning element or the group of elements of this kind. By adjusting the tension on the contretension element or group of elements of this kind, one can influence in a desired and reproducible way the sound of the instrument.

 In order to adjust the desired tension on the elastic counter-tension element (s), other tensioning devices may be provided in the tensioning device, conical plugs which are extremely suitable, in particular when the counter-element (s) tension are formed of elastic material in the form of thread or cord. Since, normally, the adjustment of the desired tension on the counter-tensioning element (s) should only be carried out at long time intervals, anchors are preferably used which have an actuating groove allowing insert the edge of a coin.

 The relaxation of the constraints of the spacer, provided according to the invention, can be combined, according to the invention, with a view to development and an advantageous complement, with the arrangement of one or more openings in the region of the spacer. For this purpose, the spacer can also form a frame which surrounds at least one hood arranged in the soundboard. This arrangement of louvers in the region of the spacer can between provided instead of the conventional eleven or in addition to glue. In a particularly advantageous embodiment, on either side of the central region of the spacer, a hole may be provided at each end of the bridge or the spacer may be surrounded by a number of ouSes . Iwans another mode of execution, an additional yes or a certain number of gills can between provided along the bridge.

One can also use, in combination with the invention, in the central region of the spacer, the arrangement of louvers known by the utility model DE 79 18 617.7 already cited or a similar arrangement.

 The passage of the frame-shaped part of the spacer is preferably adapted to the edge of the hearing in question. However, one can also provide, on the passage of the spacer, an ornamental covering, for example of the kind of a sculpture and, inside this part in the form of a frame of the spacer, multiple passages can be formed over the hearing provided in the soundboard. The ouSes can have the most diverse section shape, for example a square or rectangular section, a rosette section, a circular section or an elongated hole section. The cross-sectional shape of ltouSe is suitable for influencing the spectrum of sound emitted by the body of the instrument, which is why we will adapt the outline of the stock exchange arrangement provided in the region between the spacers to the desired sound spectrum in each case .

Exemplary embodiments of the invention are explained more precisely below, with reference to the accompanying drawings, in which
Figure 1 shows in plan a guitar designed according to the invention
Figure 2 is a section along line 2-2 of Figure 1, showing the spacer and the rope fixing device;
Figure 3 is a plan of the bridge and the hearing of the guitar according to Figure 1
Figure 4 is a section along line 4-4 of Figure 3, showing the spacer region of the guitar according to Figure 1
Figure 5 is a schematic view of the forces and conditions of oscillation that crop on the spacer in the guitar according to Figure 1
Figure 6 is a plan of a second embodiment of a guitar designed according to the invention
Figure 7 is a section along line 7-7 of Figure 6, showing the bridge and the counter-tensioning device
Figure 8 is an enlarged section of the spacer of the guitar according to Figure 6
FIG. 9 is a schematic representation of the conditions of forces and oscillations on the spacer of a guitar according to the figure *
FIG. 10 is a plan of the device for tensioning the counter-tension elements of a guitar according to FIG. 6.

 In the examples shown, these are guitars 10, whose neck 12 connected to the body of the instrument is provided with a nut 13. The finger length of the guitar 10 is therefore established from the nut 13 to the bridge 24 The easel 24 is arranged, in the two exemplary embodiments, on a trestle-shaped easel 23, which is itself formed in a spacer 20. The spacer 20 has, at a point spaced at the rear of the bridge 24 (relative to the key length), a string retaining arrangement 25. Correspondingly, the strings 18 are stretched from the peg of the neck 12 of the guitar to the string retaining arrangement passing through the bridge 24 .

 In the example of FIGS. 1 to 5, the strings 18 pass through one end through passage perforations 26 of the rod-shaped cord retention arrangement and are fixed in an additional tailpiece 30 disposed at the edge 14 of the body. , opposite the spacer 20. As can be seen in FIG. 2, the attachment of the string ends is ensured by a string attachment rod 31, which, in the example shown, is formed inside. of a mounting element 32. One could also imagine mounting the string fixing rod on the outside of the mounting element 32, but this could be less advisable, given the smooth surface that one wishes to give to the mounting element 32.

 The tailpiece 30 is fixedly disposed on the edge 14 of the body or on the splint 19, for example by gluing. The tailpiece 30 has a support of strings in the shape of a cap 33 which protrudes above the soundboard 15 to such an extent that it practically agrees with the level of the oscillating strings 18 or the height of the bridge 24.

 Each string 18, coming from the bridge 24, passes through a passage perforation 26 of the string retaining arrangement 25 serving as a string return element and then arrives on the support of strings in the shape of a cap 33 of the tailpiece 30. As a result, each string undergoes a double return between the bridge 24 and the support of strings in the shape of a cap 33. As shown in FIG. 5, it follows that the tensile stress prevailing on the strings 18 is well absorbed essentially by the tailpiece 30, but generates on the spacer 20 a couple of forces 41, which is transmitted to the soundboard 15, at the location of the connecting surface 22 between the latter and the spacer 20. By the transverse oscillation of a cord -18 touched, on this couple of forces are superimposed the oscillation forces indicated in 42 and, because of these, to the rhythm of the oscillation of the cord, the couple of forces becomes asymmetrical in one direction and in the other, thus causing oscillations of relaxatio n of ltentretoise 20, which are transmitted, via the connecting surface 22, to the soundboard 15. In this embodiment of the guitar, the longitudinal oscillations which also occur in a string 18 affected are transmitted to a certain extent, by the ends of strings, to tailpiece 30. However, the strings 18 placed with tension present on the bridge 24 and in the perforation of passage 26 a significant friction, so that the longitudinal oscillations generate also on the spacer 20 of the oscillation forces in the longitudinal direction of the strings 18, as indicated at 43 in FIG. 5.

As a result of these longitudinal oscillation forces 43, oscillations of the spacer 20 in the longitudinal direction of the strings 18 also occur and the transmission of these oscillations to the soundboard 15.

 As shown in Figure 3, the central region 27 of the spacer 20 is kept free of section interruptions. On either side of this central region 27, the spacer has in its terminal regions 28 a form of frame. Each of these frame-shaped regions 28 surrounds a louver 17. The frame-shaped regions 28 of the spacer 20 have - as shown in FIG. 4 - a thickness that is significantly less than the central region 27.

 However, analogously to what is known by the utility model DE 79 18 617 already cited, it is also possible to imagine giving a form of frame to the central region 27 of the spacer and of having a tool within this region. In addition, one can also imagine having wadding on the back of the spacer, however, it can then ensure that the propagation of the oscillations transmitted from the spacer 20 to the soundboard 15 is not hampered.

 In the example of FIGS. 6 to 10, to form the counter-tension device 21, there are provided elastic counter-tension elements in the form of a wire, more precisely three of these elements 34, one of which is applies in the middle and the other two, symmetrically around it, in the lateral regions of the spacer 20. For this purpose, the baguette-shaped bridge foot 23 is provided with through perforations 26, while the string retaining arrangement 25 has, as in the example in FIGS. 1 to 5, the passage perforations 26 intended to allow the strings to pass through. At the top, the string retaining arrangement 25 forms a support strip 29 which has practically the same height as the easel 24.

As shown in Figure 8, the support strip 29 can be coated do tale or synthetic material on the domed upper side. Unlike the example of FIGS. 1 to 5, the strings 18 which pass through the perforations 26 are fixed at 18 '(FIG. 8), at the rear of the string retaining arrangement 25. The elements counter-tension 34, coming from the support strip 29, pass through the perforations 26 'of the easel stand 23-and are fixed in 34' to the anterior side of the easel stand 23. Since the passage perforations 26 and 26 'are arranged substantially at the same height in the bottom region of the string retainer 25 and the bridge foot 23, the strings 18 and the tensioning members 34 intersect, however, since the counter-tensioning elements 34 are arranged between the cords 18, the parts which intersect remain spaced laterally.

 The counter-tensioning elements 34 go, over the curvature of the support strip 29, to a tensioning device 35 disposed on the edge 14 of the body.

This tensioning device has a mounting element 36 disposed on the splice 19 of the body 11, projecting from the harmony table 15 upwards and carrying in this place a support strip 37. In the example shown, the strip support 37 is disposed at approximately the same height as the support strip 39 and the bridge 24, so that the counter-tension elements 34, between the two support strips 29 and 37, are located approximately in line with the strings of the instrument. The counter-tensioning elements are brought to a desired tension by means of conical dowels 38. The conical dowels 38 mounted in the mounting element 36 are each provided with an actuating groove in which the edge of a workpiece can be inserted. currency. In this way, the tension of the elastic counter-tensioning elements 34 can be adjusted after the fact at any time. The conditions which result from this embodiment of the invention are clearly indicated in FIG. 9. The constraint of traction 40 applied to the strings 18, when the instrument is tuned, is transformed, by the upper edge of the bridge 24 and the string retention arrangement 25, into a couple of forces 41. On the other hand, the stress of traction 40 ', applied to the contretensioning elements 34 by the support strip 29 and the foot of the bridge 23, is converted into a couple of forces 41t.

Depending on the tensile stress 40 'set on the counter-tensioning elements 34, the force couple 41 coming from the tension stress 40 of the strings 18 is partially compensated (representation of FIG. 9) or completely or even overcompensated. According to the representation of FIG. 9, in the planned adjustment of the tensile stress 40 ′ of the counter-tensioning elements 34, there remains a torque of resulting forces 41a which is notably less than the torque 41. Then, when a cord 18 is touched, the transverse oscillation forces indicated at 42 are converted by the bridge 24 and the string retention arrangement 25 into oscillation force components 42 ′, which are superimposed on the resulting force torque 41a. The comparison with FIG. 5 shows that these oscillation force components 42 ′ have a significantly greater magnitude, relative to the resulting couple of forces 41a to be absorbed by the soundboard 15, than in the embodiment of FIGS. 1 to 5. This means that a significantly amplified relaxation oscillation of the spacer 20 can be transmitted to the soundboard and that, on the other hand, the stiffening of the soundboard 15, shown in Figure 8, can be maintained significantly less than in the first example of execution.

 The longitudinal oscillation forces 43 generated on the rope 18, when touched, are almost completely absorbed by the spacer and, essentially, by the string retaining arrangement 25. The transmission of the longitudinal oscillation forces 43 is indicated in Figure 9, at 43 'and 43 ".

It is assumed that a smaller component 43 'is transmitted to the bridge 23, 24 by virtue of the friction of the string stretched over the upper edge of the bridge 24, while the larger component 43 "is transmitted to the arrangement for retaining ropes 25 because of the rigid attachment of the end of the rope. In any case, an effective transmission of the longitudinal oscillation forces 43 takes place at the spacer and from the latter through the surface of link 22, to the soundboard 15.

 The construction of the oules, in the example of FIGS. 6 to 10, is of a conventional nature, that is to say that a conventional circular hem 16 is provided in the soundboard 15. However, one can also imagine to apply the possibilities of constitution of wadding provided in the embodiment of Figures 1 to 5 to the embodiment of Figures 6 to tO, instead of the conventional hem 16 or in addition to that- this.

 The arrangement of the ovules, their arrangement and their outline have a notable influence on the oscillation behavior of the body 1 of the instrument and therefore on its technical, that is to say acoustic, properties. Thanks to the construction of the spacer 20 according to the invention, it is possible to combine the most diverse arrangements, arrangements and contours of ouzos with the stress relieving device 21 according to the invention, to give the instrument properties. desired acoustics. It is envisaged, in particular, for this purpose, arrangements of gills of the most diverse nature in the vicinity or in the region of the spacer 20. The shape of the oules can be for example square, rectangular, in rosette, circular or in elongated hole.

 The dome can also be completely open or even be provided with a partial covering, for example a sculpted covering having multiple passages having the most diverse contours.

Claims (17)

 1.- Stringed instrument, in particular guitar, comprising a spacer carrying the bridge, fixed by its base surface to the harmony table and which, at the rear of the bridge relative to the fingerboard and at some distance from the bridge, presents arrangements for retaining the strings, instrument characterized in that it comprises an elastic stress relieving device (21) extending from the body (11) to the spacer (20), behind the bridge (23, 24 ) relative to the fingerboard and which, in the region of the spacer (20), is designed in the manner of a deflection, acting for at least part of the tensile stress of the strings (18) to be transmitted to the body ( 11), relative to the connecting surface (22) between the spacer (20) and the soundboard (15).  2. An instrument according to claim 1, characterized in that, to form the stress relieving device (21), the arrangement for retaining the strings (25) provided on the spacer (20) is in the form of a rope return element and the ropes (18), passing through this return element, go to a tailpiece (30) separate from the spacer (20), which tightens them and which is fixed to the edge ( 14) of the body opposite the spacer (20).  3.- Instrument according to claim 2, characterized in that the tailpiece (30) is provided with a string support (33) practically directed parallel to the bridge (23, 24) and the length of which, relative to the harmony table (15 ), is harmonized with that of the easel (23, 24), preferably equal to it.  4.- Instrument according to one of claims 2 and 3, characterized in that the support of strings (33) of the tailpiece (30) has the shape of an elongated cap whose height is practically harmonized with the level of oscillating parts of the strings (18).  5.- Instrument according to one of claims 2 to 5, characterized in that a string fixing rod (31) is formed in a mounting element (32) of the tailpiece (30).  6.- Instrument according to claim 1, characterized in that the strings are conventionally fixed by one end to the string retaining arrangement (25) of the spacer (30) and that, to form the device tension release (11), at least one elastic counter-tension element (34) extends from the spacer (20) to a tension device (35) fixed to the edge (14) of the body, opposite the 'spacer (20).  7.- Instrument according to one of claims 2 and 6, characterized in that the string retention arrangement (25) is in the form of a rod practically parallel to the bridge (23, 24), provided with through perforations (26), and that these passage perforations (26) are practically parallel to the direction of tension of the strings (18) and are arranged, above the disharmony table (15), at a height significantly less than the surface d support of the bridge (23, 24), the ends of the cord being able, as desired, to be fixed to these passage perforations (26) or the cords being able to be drawn, through the passage perforations (26), up to a tailpiece (30) separate from the spacer (20).  8. An instrument according to claim 6, characterized in that the tensioning device (35) has a mounting element (36) in the form of a plate, which is applied against the splint (19) of the body (11), receiving the tensioning devices proper and that the lateral part of the mounting element (36-), projecting relative to the harmony table (15), carries a convex support strip (37) which returns the counter element (s) -tension (34) in a plane practically parallel to the splint (19).  9.- Instrument according to one of claims 6 and 8, characterized in that the one or more counter-tension elements (34) are arranged practically in the extension of the string surface of the instrument.  10.- Instrument according to claim 9, characterized in that the arrangement for retaining strings (25) of the spacer (20) is in the form of a rope retaining rod which carries a rod at the top convex support (29) practically located at the same level as the support surface of the bridge (23, 24) and intended for the element or the counter-tensioning elements (34).  11.- Instrument according to rev.endication 10, characterized in that a foot strip (23), the bridge (24), formed on the spacer (20), as well as the string retaining strip ( 25, 29) have passage perforations (26, 26 ') for fixing the ends of ropes or counter-tensioning elements and that these passage perforations (26, 261) are practically at the same height relative to the table harmony (15).  12.- Instrument according to one of claims 6 to 11, characterized in that the tensioning device (35) is adjustable to allow the desired tension to be established on the counter-tensioning element (s) (34).  13.- Instrument according to one of claims 6 to 12, characterized in that the one or more counter-tension elements (34) are in the form of wire or rope and formed of elastic material, for example of hose, synthetic material or metal.  14.- Instrument according to one of claims 1 to 13, characterized in that 11 spacer (20) further forms a frame which surrounds at least one hole (17) formed in the soundboard (15) of the body (11).  15.- Instrument according to one of claims 1 to 14, characterized in that at least on both sides, next to ltentretoise (20), wadding is practiced in the soundboard (15) of the body ( 11).  16.- Instrument according to one of claims 1 to 15, characterized in that the or the perforations of the region (28) of the lrentretoise (20) which surrounds a wadding (17) have an outer contour adapted to the shape of the corresponding hearing and that inside the surface of the hearing (17), this region has an ornamental covering forming multiple passages.  17.- Instrument according to one of claims 1 to 16, characterized in that the spacer (20) is integral with the foot (23) of the bridge and that 11 arrangement of retaining strings (25) is formed d1un wood hard, preferably rosewood, whose wire is transverse to that of the soundboard.