DE2604156A1 - Stringed musical instrument wood resonance production - involving subjection to additional structurally deforming mechanical stresses - Google Patents

Abstract

Resonant wood, pref. in the form in which it is to be used, is subjected to additional stresses, esp. deforming it in structure, apart from the normally resulting mechanical stresses. These can act on points in the wood (10) where primarily generated tonal vibrations are transmitted to the wood. Device incorporates a yore (12,14,20) with two retainers for the instrument, and form-locked adjacent cross-arm (32), piezoelectric gauge (30), spring (28), clamping plate (26) and vibrator. The clamping plate may be adjustable by a setscrew (34). A musical instrument with improved fullness and quality of tone can be produced.

Description

. 6051 Ober-Roderv via Offenbach / M.

Patent and tax lender 'Ludwlg-Uhland-StraBe 25

Telephone: Office Urborudi 06074/3577

the 2. 2ο76

Method and device for improving the resonance properties of resonance woods, especially that of

Musical instruments

It is known to improve the resonance of wood by compressing it into one another in length and width. It has also become known to compress resonance wood only in its grain direction. In this way it is possible _{to improve the wood 1} of flat panels with regard to its acoustic properties. (German patents 34-3 109, 363187,536598)

With the implementation of these measures, however, such woods do not yet take the desirable and permanent ones Properties that they should have on the finished musical instrument, because the wood is due to the storage as well processing and processing are still subject to changes in its microstructure.

The change takes place in these known methods the resonance properties of the raw wood, which is still unformed or unprocessed for the intended purpose in certain, predetermined directions, taking the shape of the soundboards of musical instruments, such as string instruments and the course of the vibrations caused by the sound in the resonance wood is not taken into account.

Accordingly, the present invention is based on the creation of resonance woods for, for example, musical instruments

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the special ones in their natural, i.e. grown Properties, after shaping, are treated and influenced in such a way that a musical instrument with in the tone quality and richness of clay with refined properties.

■ s
Based on a method and a device for improving the properties of woods, in particular 'the resonance woods of musical instruments, such as string instruments, by mechanical stress, the invention consists in that the resonance wood, preferably in the Porm used in use, to the normally existing static mechanical stresses are temporarily subjected to additional stresses that deform the resonance material, especially in the structure

The temporarily applied additional mechanical stresses at points of the resonance hole have an advantageous effect one in which the sound vibrations primarily generated in the use of the musical instrument affect the resonance wood be transmitted"

the temporarily applied additional mechanical Stresses can be static or dynamic mechanical stresses, but they can also be separately, beneficial but at the same time can act on the sesonance wood. v

The resonance wood is advantageous as dynamic stresses Mains frequency oscillations, such as 50 or 60 Hz, are imposed. The use of vibrations is also advantageous, which correspond approximately to the mean value of the frequencies occurring in the use of the musical instrument.

The present invention is based on the knowledge that pores and structural irregularities containing, especially inhomogeneous materials such as KoIz, acoustic Appearances are transmitted more evenly and better when they are exposed to mechanical stress, through which the material structure an equalization

or experiences equalization. This can be due to mechanical stress, such as compression or compression or

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done by stretching. According to the invention, this can also be achieved by a combination of these types of stress Material happen. Here, the neighboring microstructure particles become more intimate and solid with one another Brought into contact and thereby the transition or the propagation of acoustic phenomena becomes less Opposite resistance than before the treatment according to the invention.

This is roughly comparable to the change in state of the Structural structure of seasoned wood, which after fresh wood z, B. was cut into boards and still "lived" or "worked", subject to distortions, a change in length, in particular a change in width was, experienced a natural partial consolidation of its structure over time »

It is assumed that the material of the resonance wood in the treatment according to the invention undergoes similar, but he forced structural changes that result in an equalization of the transmission of acoustic phenomena, in particular of sound vibrations, over the paths of the vibrations, in such a way that disadvantageous and, if necessary, unsymmetrical reflections and partial or full cancellations, similar to those that occur during remote reception of amplitude-modulated high-frequency transmissions, avoided. The acoustic annihilation phenomena can, particularly in the case of the harmonics, which strongly influence the sound character of the musical instrument, on »

When using string instruments, for example, this is the resonance wood not only the mechanical stresses caused by the mechanical tension of the strings or exposed to the mechanical forces that make the resonance wood of the musical instrument static when at rest burden. Rather, this static mechanical stress caused by the tension of the strings is the When playing the musical instrument, the resonance wood is still changed by the fact that it is usually pushed over the bridge Mechanical stress transmitted to resonance wood as a result of the acoustic vibrations superimposed on it

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rhytmi scne ^undergoes changes «These increase and decrease the static stress on the soundboard according to the tone vibrations of the tones excited by the strings in time with the frequency of the acting tones. This means that the static mechanical load on the resonance wood is superimposed by the mechanical vibrations caused by the use of the instrument.

Over the course of time and the static-mechanical stresses that are usually present when the instrument is not in use the resonance wood as well as during the playing of the musical instrument to this static load Additional alternating stresses of a dynamic nature, the resonance wood is correspondingly more mechanically stressed and, as mentioned, caused the structural manifestations.

It is still significant that with this combination of static and dynamic mechanical loads, the run straight in or in the directions of the soundboard or soundboard that are in use of the musical instrument, especially the parts of the resonance material and the path mechanically influenced affecting the properties of the sound are important. In particular these, despite the use of seasoned and selected resonance wood existing irregularities in the structure are made by the treatment according to the invention Compression, stretching and shaking to refine the acoustic properties of the instrument are equalized and homogenized.

This process of equalizing the structure or artificial aging, regardless of whether it is only static, only dynamic or combined static-dynamic caused, can be compared with the vibration processes that occur in technology can be used, for example, to compress or compact bulk material, be it by compacting into containers or bulk material filled with bags on a vibrating table, be it the compaction of loose soil Vibration shakers or be it homogenization and the setting of, for example, concrete masses in their shapes or their formwork in the manufacture of concrete structures or individual concrete objects

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Further features of the invention are evident from the description, the claims and the drawings «

The invention is shown in Figures 1 to 8, for example shown.

In the figures show:

1 shows a side view and FIG. 2 shows a plan view of a treatment device according to the invention Violin,

FIG. 3 shows two views of the pressure part used to achieve and adjust the treatment pressure, Figures 5 and 6 show two views of a further embodiment a treatment device according to the "invention, wherein FIG. 5 is a side view and FIG. 6 is a plan view represent,

FIG. 7 shows two views of the clamping arrangement for the device according to Figures 5 and 6 and

FIG. 8 shows the unit of FIG. 5 acting on the resonance wood.

In the figures, 10 denotes a stringed instrument, for example a violin, from which the strings and the bridge have been omitted. The violin is at the neck end and the Saifcenhalterende each with a yoke 12, 14 in connection with which the violin body 10 at these ends of holding projections 16, 18 is encompassed. The upper yoke part is formed by a rigid rod 20, the ends of which pass through openings 22 in the yoke parts 12, 14.

Between the middle yoke part 20 and the resonance cover 24 are a pressure plate 26, a spring 28, advantageously a disk spring, a pressure load cell $ 0 and a web 32 intended.

A set screw 34, which is in a thread 36 of the middle Yoke part 20 sits rotatably, it enables the parts 26, 28, 30, 32, which, as shown, one above the other, are arranged one above the other, against the soundboard 24

32 of the instrument 10 to press. The bridge lies on the points of the soundboard 24 on which normally the bridge supporting the strings (not shown) stands

It is made possible by the use of the pressure cell 30

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the pressure on the instrument set by screw 34 10 or the resonance ceiling 24 to set values that mechanical damage to the instrument 13 * exclude »

When applying pressure to the instrument 10, the The sound post remain in the instrument * but it can also be removed beforehand. It is more beneficial to use the sound post to leave it in the instrument because of the practical mechanical stresses occurring during use can be more clearly imitated »

In order to shorten the mechanical stress and the deformation of the soundboard 24 in terms of time, the loading act according to a further feature of the invention in an atmosphere that makes a wood more malleable Medium, such as moisture or steam, is saturated »The degree of saturation is selected so that the instrument not impaired in its structure, in particular its gluing will ο

The treatment according to the invention in an atmosphere that makes the wood more malleable and one carried out afterwards "Setting" in a dry and possibly warmed atmosphere only guarantees a negligibly small amount Degree of deformation towards the original state.

For treatment in a humid atmosphere, for example, the instrument 10 with the yoke parts η 12, 14, 20 and the other devices 26. 28. 30. 32 of a dash-dotted line indicated housing 38 surrounded.

The purpose of the interposed disc spring 28 is that when the resonance ceiling 24 is deformed when it yields by the pressure exerted, which is indicated by the drop in the loading pressure measured by the load cell 30 will. In this way, on the one hand, the degree of deformation of the soundboard 24 can be better observed while on the other hand, inadmissible overloading of the treated body 24 can be avoided. With sufficient deformation, which are beneficial only in a number of small ones

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ok

Steps is completed, the treatment pressure is increased step by step using the adjusting screw 3 ^ =

In order to make the pressure adjustment as fine as possible, the screw 34 and the thread 36 of the yoke part 20 are provided with a slight pitch, for example one of 0 _s 2 mm.

Instead of using the spring 28, the mifctle-;

re yoke part 20 be resilient .. j

The treatment is advantageously carried out in such a way that the measured pressure values are plotted against time. ^: From the resulting characteristic curve, for example with adjusting screw 34 adjusted at regular intervals to a specific treatment pressure, the pressure differences determined can be used to identify the deformation or deflection or structural change of the resonance ceiling 24 and whether the final deformation and structural equalization can finally be detected has been ο

Once this state has been reached, the housing 38;

the moist and possibly warmed treatment atmosphere

sphere withdrawn and, if the load persists j

of the instrument or the resonance cover, the normal, re— j

relatively dry atmosphere admitted, possibly j

can also be hypothermic. ;

Due to the existing permanent pressure or stress |

state of the resonance ceiling 24 it can be determined whether j

the wood the changes in shape made by the treatment— tion or structural equalization or homogenization is maintained or not. Changes are an indication of this state of affairs the pressure state of the arrangement measured by the pressure cell 30 and displayed by a measuring device (not shown). This measurement is also an indication of the result of the treatment.

The pressure plate 26 used here is shown in the figure 3 shown together with the adjusting screw 34. The pressure plate has a recess 40 into which the

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OBIQlMAL INSPECTED

spherically shaped end 42 of the pressure screw 34 protrudes.

For holding the adjusting screw 34 on the pressure plate 26 is a holding plate 44. It has a slot 46 for receiving the tapered part 48 of the adjusting screw 34 and is attached to the pressure plate 54 by screws 50 held.

As FIG. 4 shows, the disk spring 28 is a disk spring with an outer edge 52 and a support surface 54.

The execution of sound refinements on musical instruments with the device according to FIGS. 1 and 2 according to FIG The present invention is particularly suitable for instruments that have already been completed.

In the case of new musical instruments to be manufactured, it is more advantageous to use the device shown in FIGS. 5 and 6 use. Here the soundboard 24 of the musical instrument is treated separately.

It is of course also possible and also more advantageous to detach the soundboard 24 from a finished musical instrument and to be treated in the device according to Figures 5 and 6 «,

It contains a rigid base plate 56 on which the resonance ceiling 24 using clips 58 is held clamped in various places.

As Figure 7 shows, the brackets 58 are with a Edge of the soundboard 24 provided little overarching approach. One screwed into the base plate 56, through a slot 29 of the bracket 58 leading screw 32 is used with the interposition of a disk 33 for securing the so pivotable and displaceable in its longitudinal direction Brackets 58.

The base plate 56 carries two yoke parts 60, 62, in which in openings 22, similar to i ^ connection with figure 1 described, a middle yoke is used.

Here, too, as in FIG. 1, there is a pressure plate 26 between the adjusting screw 34 and the resmnanzdeckel a plate spring 28, a pressure load cell 30 and a Ste # g

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intended. The latter becomes, similarly, in connection with Figures 1 and 2 described, attached to the points of the soundboard 24, at which normally the Strings supporting bridge rests.

The treatment of the soundboard 24 is carried out in a manner similar to that described in connection with FIGS. 1 and 2 »You is also carried out here within a closed treatment room (not shown) in which practically only the device with the sound box to be treated 24 is included, which with a wood atmospheres that make it more vivid, e.g. containing water vapor and heated air is filled, if necessary. Treatment can be done in the same way as in conjunction is described with Figures 1 and 2 «

Another essential feature of the invention is in that the soundboard 24, as already indicated is not only statically mechanically stressed, but that the stress is caused by pure mechanical stresses takes place or that a combination of static and dynamic loads is applied.

For this purpose, in the frictional series arrangement of pressure plate 26, spring 28, pressure load cell 50 and Bridge 32 a vibrating device, e.g. a technical one Vibrator attached.

This arrangement can then be seen from FIG A vibrator 64 is arranged on the pressure plate 26. Any kind of technical vibrator can be used as a vibrator Find use.

There is no need to pay special attention to these vibrators, v / cil these are known as electromagnetic and electrodynamic as well as unbalance vibrators.

The vibrator 64 is used in the arrangement that in the non-energized state of the vibrator 64 the pressure over the set pressure screw 54 a certain lower Value assumes »Wipd the vibrator 64 is excited, then the static load set by SbellscrewN the mechanical oscillations of the vibrator 64 superimposed and thus transferred to the soundboard 24

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OBlQINAL INSPECTED

As a result, the resonance ceiling 24 is not subject to static stress exposed to mechanical alternating stresses.

It is supported by this measure of alternating stress Structural changes in the resonance ceiling are possible better and faster, e.g. through a moist atmosphere and that for an easy response of the instrument with great power, fullness and softness of the tone to achieve favorable properties that are equivalent to artificial aging »

The vibrator 64 can be operated at the mains frequency, for example 50 or 60 Hz, but it can also be operated at an increased frequency, such as a sound frequency of 800 Hz, for example, in particular the average tonal frequency of the instrument can be used for alternating stress on the resonance wood. If an audio frequency is used to generate the alternating stress, it is advantageous to use a moving- coil vibrator, the construction of which generally corresponds to that of a moving-coil microphone or a _{moving-coil loudspeaker β}

It is also possible to operate the vibrator with an alternating voltage of sliding frequency, which is advantageous about the The range of the instrument corresponds to that for which the resonance wood is intended. »The feed is advantageous here Variable output frequency via a solid-state frequency converter.

ITm the amplitude of the mechanical alternating stress on the resonance wood for the purpose of changing the strength of the to be able to vary mechanical vibration shocks, takes place the energization of the vibrator 64 at a variable voltage. The frequency converter (not shown) for supply of the vibrator 64 is therefore designed so that it "a variable alternating voltage at a variable frequency o · * ·

The variable tension makes it possible during the treatment of resonance woods with a low oscillation amplitude, i.e., there is less mechanical stress -, begin and gradually increase to higher values.

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iüinllciie conditions arise when feeding the Vibrator 64- at a sliding frequency.

By observing the mechanical stress on deis The value given by the load cell and read on a measuring device (not shown) can be used to determine the progress of the Treatment according to the invention observed, in particular but also the observance of load values that are still harmless for the resonance wood are monitored.

The invention thus enables simple, factory-made musical instruments, such as string instruments, Although selected and seasoned sesonance wood does not have a satisfactory sound quality, sound and tone richness so too influence that they experience a lasting sound refinement. But it also enables it from the start Musical instruments manufactured using simple processes using the present finishing process have a high Elang quality, Brilliant sound and full tone with easy responsiveness and to give softness to the 'tone.

The invention is not limited to stringed instruments, but is general to all musical instruments. can be used where a sound or resonance body is provided is""

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Claims (1)

6051 Ober-Roden above Offenbach / M. / Ludwlg-Uhland-StraSa 25 Patent · and ZMIlngwiiaur. Famruf: Office Urbarach 06074 / 8S77 ... η 2.2.76 Claims ■ ■ ■. 1. Method and device for improving the properties of woods, especially the resonance woods of musical instruments such as stringed instruments, by: ■ mechanical stress ·, characterized in that the resonance wood, preferably in the one used in use Form, temporarily additional to the normally existing static mechanical stresses the resonance material especially in the structure is subjected to deformed stresses. 2. The method according to claim 1, characterized in that da8 the temporarily applied additional mechanical stresses at points of the resonance wood (10,24) have an effect on those in the use of the musical instrument primarily generated sound vibrations on the Resonance wood are transferred. 3. The method according to claims 1 and 2, characterized in that ' that the temporarily used? additional: _, mechanical stresses static stresses are. 4. The method according to claims 1 and 2, characterized gekennzsich- ^ net that the temporarily applied, additional Stresses are alternating stresses. 5. The method according to claims 1, 2 and 4, characterized in that " draws that the i.Vechse Ibe claims of the conventional Mains frequency of 50 or 60 Hz. 6. The method according to claims 1, 2, 4 and 5 »marked - ''" 'draws, that the alternating stress on et v / a the middle »It is generated in the use of the musical instrument Corresponds to fundamental frequencies. 709832/0415 copy 260A156 S, 7. The method according to claims 1-6, characterized in that that the Besonanzholz (10, 24--) before and / or subjected to an influence on the physical properties of the wood during the vibration treatment will. 8. The method according to claims 1-7 »characterized in that da3 influencing the Holzoig-jn-: ^ a Shafts by storing the wood and / or performing the method in one with one of the wood absorbed medium, such as! moisture or ./water vapor, saturated atmosphere takes place. 9. The method according to claims 1-8, characterized ^ that the wood shafts are influenced by the fact that the resonance wood "(24)" or the musical instrument (10) exposed to a vacuum ii and then in a with moisture or The like. Saturated atmosphere is brought. 10. Vtfi-iahren according to claims 1-9 »characterized in that that the mechanical load on the resonance wood (24-) or the musical instrument (10) and Effects of this on the resonance wood (24) or I "musical instrument (10) during the treatment Measurement of the treatment pressure is monitored. 11. Apparatus for performing the method according to claims 1-10, characterized in that a yoke (12, 14, 20) is provided, which two with the sesonance wood (24) or musical instrument (10) or with a deflection strip a resonance wood (24) or a musical instrument (10) receiving support plate (56) has connected holders (60, 62), while between an upper yoke part (20) and the resonance wood (24) or the musical instrument (10) force-fit against one another a oteg (52), a pressure cell (30), each (28), a clamping plate (26) and optionally a '; Vibrator (64) arranged are. 709832/0415 12. The device according to claim 11, characterized in that the clamping plate (20) for setting the on the Resonance wood (10, 24 ·) acting mechanical load with an adjusting screw that is screwed into the upper yoke part (20) and presses against the clamping plate (26) (34-) is in connection. 13. Device according to claims 11 12, characterized in that that the Zviii.-ehenfeder (28) is a disc spring is. 14. Device according to claims 11-13, characterized in that that the Srregersystem- of the vibrator (64) is a voice pulse system. 15 · Device according to claims 11-14, characterized in that that the vibrator (64), the pressure cell (30), the! spring (28) and the pressure plate (26) are a unit form. ^ oaV> ^Λ · * - » t-> us r» i ί λ V »<s ν-» Λ Λ _ "IC draws, da.3 the vibrator (64) from an alternating current variable frenzy is aroused. Ό * 17 · Device according to claims 11-16, characterized by the fact that the foodstroin from a l ^? Estkörperumrichter, in particular variable iünplitude and / or frequency is supplied. 18. Device according to claims 11 - I7, characterized in that da3 is the amplitude of the Y / echsel excitation voltage of the vibrator (64) is adjustable. 19. Device according to claims 11-18, characterized thereby, draws that the treatment device (Fig. 1j 2; Fig. 5 »6) within a housing (38) can also be changed rer atmosphere is arranged. 709832/041 5