FR2518292A1 - Wind instrument with adjustable fibre - has space of variable length between mouthpiece and tube controlled by vernier - Google Patents

Abstract

The musical instrument has a wave generator (11) mouthpiece and a pipe (3) for standing waves. Between the two is a space (1). This space is cylindrical and of variable length, controlled by threaded sections (17,18), forming a vernier (20). The adjustment is fixed by a locking ring (19). The mouthpiece is fitted on a support (2) with a ferule (6) sliding in the outer tube and extending around upstream of the outer tube (4). The mouthpiece support is fixed to a threaded (18) adjusting ring (16) around the threaded (17) outer tube.

Description

Wind instrument with adjustable timbre.

 , invention relates to wind instruments, of the type comprising upstream n wave generator device, such as trumpet mouthpiece, simple clarinet reed or saxop @ onc, oboe double reed, bevel, etc., followed by downstream of a standing wave development pipe and having a different name depending on the instruments concerned.

The physics of these instruments is the subject of continuous study of great complexity, given the number and the indefinite nature of the factors which enter into I @ in the establishment and reception of a sound.
Thus, in the structure of musical instruments at @@ beuch @ such as the trumpet, sensitive parameters, that is to say having an influence on the ratio of frequencies (trueness) and on the radiated spectrum (timbre ) are as follows: 1 - Total length @ of the main circuit 2 - Length of the roof 3 - Degree of taper of the roof 4 - Starting diameter of the roof 5 - Profile of the roof curve 6 - Diameter of the bore 7 - Radius of curvature of the cranes 8 - Cylindrical or conical profile of the tuning crane 9 - Relative length of the piston slides compared
port to the main circuit 10- Starting diameter of the mouth branch 11- Relative length of the mouth branch by
compared to the main circuit 12- Degree of taper and profile of the nozzle branch
chure 13- Volume of the cavity (pocket) which separates the end of the
tail of the mouth of the start of the branch of em mouth.

14 - Ratio of the volume of the mouthpiece bowl to
the surface of the "grain" of the mouth
15 - Grain length from the mouth 16 - Ratio of the grain diameter to the taper rate
of the inner cone of the mouth
17 - Length of the inner cone of the mouthpiece
18 - Profile of the internal cone of the mouth
19 - Nature of the roetal constituting the instrument.

To this non-exhaustive list of parameters linked to the construction of the instrument, the following random parameters are added: 20 - Air pressure supplied by the lungs of the
tant 21 - Physiology of the performer and in particular tone
and ability to re-oxygenate the muscles of his
lips 22 - Room acoustics 23 - Peròrmances of the auditory system, faculties of inte
gration and musicaia culture of the listener.

 The construction of an instrument, which must combine accuracy and quality of timbre, strives to make the most of all or part of these parameters.

We can refer to this subject in the work "Musical Acoustics" by EARLE L. KENT published in 1977 by
DOWDEN, HUTCHINSON & ROSS, INC., STROUDSBURG, Pennsylvania, USA, and also to U.S. Patents 3,307,181 and 2,987,950.

 However, the documents cited offer solutions of a definitive and non-modular nature (apart from the classic correctness correction by backstage agreement). Now the element of randomness - determining which constitutes the physiology of the performer poses a permanent problem with the instrumental invoice and it was advisable to seek a system which makes it possible to grant the instrument to the instrumentalist.

 This system had to be convenient to operate by the musician, simple to manufacture and therefore of an acceptable cost price.

 These are the aims of the invention.

 These aims are achieved, in accordance with the invention, by the fact that the instrument comprises, between the wave generator device and the pipe, a cavity with variable volume. In the particular case of the trumpet, this variable-volume cavity is located between the tail of the mouthpiece and the start of the mouthpiece branch.

 Numerous researches carried out by the Applicant, it appears that, among the parameters related to the invoice of Itínstrument, only the possibility of varying the volume of a cavity which separates the tail of the mouth from the departure of the branch of mouth proves to be satisfactory, acting a great deal on the timbre and in a negligible way on the correctness. Variations of 1 order of 5 microns a'e ll length of the cylindrical cavity feels clearly perceptible to the ear at the timbre.

 the artist can thus tune the impedance of the resonator that constitutes the instrument on the impedance that delivers the coupling lips-mouths by variation of the volume of the cavity playing a role in the selection of the harmonics highlighted by the continuation of this memory.

In other words, an instrument according to the invention allows the musician 1) to choose the timbre that pleases him 2) to freely choose a type of mouthpiece con
shape its anatomy 3) to adapt its sound to particular conditions
musical, room or play acoustics
in the open air 4) to obtain a given energy potential
optimal sound.

 The effect obtained by the variation in accordance with the invention of the volume of the cavity is all the more surprising since hitherto the expected effects of an evolution of this factor concerned more the accuracy than the timbre. This is how KENT, in its US patent 2,987,950, studies and notes the impact of the volume of this cavity on the effective length of the instrument, that is to say on its accuracy. It should be noted in passing that, quite obviously, KENT does not propose or suggest in any way to make the volume of this cavity variable on an instrument, but simply proposes to take into account, among other multiple factors, the volume of this cavity in the preliminary evaluation of the effective length of the instrument to be constructed; instrument which he wishes to see follow as closely as possible the notes of the temperate scale.

 Now the Applicant has discovered that very small variations in the volume of the cavity act considerably on the timbre and insensitively on the accuracy. Without being bound in any way by a scientific explanation, the Applicant thinks that it can be understood by the fact that, during a small increase in the volume of the cavity, for example, there is an elongation of the column d air which tends to lower the note, but which, at the same time, an increase in the intensity of the higher harmonics tends to raise the note, whence it results in compensation for the correctness of the latter, while the timbre is significantly changed by the new sound spectrum.

In order to allow fine variations in the volume of the cavity, the latter is advantageously designed in the form of a cylindrical cavity, the length of which varies thanks to a threaded assembly means with fine pitch and preferably having a fine graduation. as well as a device for maintaining the adjustment
The invention will be better understood on reading the description which follows, made with reference to the drawings on which
- Figure 1 shows in section a first embodiment of the variable cavity in a pette tram
- Figure 2 shows a second embodiment of the variable cavity in a trumpet
- Figures 3 and 4 show two available siti @ s for adjusting the volume of the cavity;
- Figure 5 shows in section an embodiment of the variable cavity in a clear clari or @n saxophone;
Figure @ shows in section an embodiment of @@ variable cavity in an oboe ;;
- Figures 7 and 8 show respective
ment the @@ gespe @ és graphs of frequencies and intensities recorded @@@ @ @ l '@@ ission of a ut 4 by a trumpet of the i enti @ for a cavity of 25/100 mm compared to a cavity @@ lle on the one hand, and a cavity of 275/100 mm relative to a null cavity, on the other hand.

 Figure 1 is a sectional view of the upstream organs of a trumpet @@@ form of the invention (except mouthpiece), proport @ @@ @ xagéré to be more readable.

 FIG. 1 shows a cylindrical cavity 1, of variable length, formed between the mouthpiece support (plug) 2, @@ starting from the mouthpiece branch 3. and the outer tube 4 surrounding the mouthpiece branch.

 The start of the conical mouth branch 3 is centered and fixed in the outer tube 4 by means of a ring 5 welded to the mouth branch.

 The outer tube 4 is extended upstream from the start of the mouth branch of a cylindrical part 6 in which the downstream end of the mouth support 2 can slide.

 The mouthpiece support 2 has in its central part 7 an external thread 8 cooperating with a thread 9 at the end of the external tube 4.

A flange 10 terminates the mouthpiece support 2, the collar 10 having the same outside diameter as the outside tube 4.

 The mouthpiece support 2 comprises an inner cane 11 into which the outer cone of a conventional mouthpiece not shown is fitted, flush with the downstream end of the mouthpiece support and contributing to the formation of the cavity.

 The rotation of the mouthpiece support 2 relative to the rest of the instrument makes it possible to vary the volume of the cavity l and to adjust the timbre of the horn.

 A blocking in the adjustment position can be carried out around the upstream part of the tube.

outside 4 by a clamp 12 (fig.3), or by providing a cone and thread clamp, as shown in fig. 4 where a threaded clamping ring 13 rotates on a threaded boss 14, a conical part of the ring 13 pressing with more or less force according to its angular position on a complementary part of the boss, made deformable by the production of three slots 15 to 120 on the periphery, and thus allowing tightening.

 Figure 2 shows a preferred embodiment of the invention. The bodies common to Figures 1 and 2 bear the same references.

 The chamber or cavity l, of variable length a, is formed under the same conditions as in the previous embodiment.

 The outer tube 4 is extended and ends upstream of the start of the mouth branch 3 by the cylindrical part 6 in which the downstream end of the mouth support 2 slides.

 The mouthpiece support 2 is welded. to an adjustment ring 16 surrounding an end portion of the outer tube 4. The outer tube 4 carries on its periphery an external thread 17 cooperating with a thread 18 of the adjustment ring. The threads have a diameter of 14 min and not 0.5 mm and allow fine adjustment of the volume of the cavity 1.

 At the ring 16 is welded a braking ring 19 adjusted with friction on the outer tube 4 t making it possible to maintain the chosen setting in position without, however, preventing it from being intentionally moved by turning the adjusting ring 16.

 A graduation 20 of the "Palmer" type is provided on the outer tube and on the ring 16-19 so as to pinpoint the length a of the chamber and therefore the stamp hçisi.

 Experiments were carried out to show the importance of the changes in the sound spectrum as a function of the adjustment of the volume of the cavity. Figures 7 and 8 illustrate two extreme positions of these experiments.

 ne trumpet according to the invention plays a C 4 (523 Hz) whose sound spectrum is represented, via a spectrograph and a plotter, on the graphs of Figures 7 and 8 graduated in k Hz on the abscissa and dB on the ordinate . The temperature is kept constant at 200C.

 In FIG. 7, the curve in dotted lines shows the sound spectrum obtained with a nonexistent cavity, that is to say for a = 0 while the curve in solid line shows the sound spectrum obtained for a 1 25/100 mm The graph shows that the frequency of the fundamental 21 (harmonic I) is not appreciably affected by the opening of the cavity, that the second harmonic 22 is slightly less powerful and the third harmonic 23 slightly more powerful, etc. when the cavity is open. It can be seen that the differences increase with the high harmonics. This graphic visualizes a modification of the timbre sensitive to the ear and identifiable for the musician, the accuracy of the note being, for its part, not noticeably affected by the ear.

 By modifying the opening of the cavity l in very fine steps, for example of 25 / lOOmm, we perceive extremely varied timbres-s in color, and the graphic recordings show sound spectra modifying without the appearance of laws governing these modifications and, in any case, without linearity, with respect to the adjustment of the volume of the chamber 1.

 FIG. 8 shows a graph similar to that of FIG. 7 with, in dotted line the sound spectrum of C 4 for a a O and in solid line the sound spectrum for a = 275/100 mm. There is a marked strengthening of the fundamental 21, a weakening of the second harmonic 22, a relative stability of the following four harmonics. The very high frequencies show extraordinary reinforcement. Again the timbre of the instrument takes on a particular color.

 The invention is obviously not limited to mouthpieces.

Thus, Figure 5 shows a beak 30 of clarinet or saxophone (the reed is not shown) in which a cylindrical cavity 31 of variable length has been provided upstream of the bore 35 of the beak and just
downstream of the chamber 34 of the spout; the variation of vo
lume of the cavity 31 is possible thanks to a thread
32 provided on the spout support 33 and the spout 30.

 As in the case of the trumpet, the variation in the volume of the cavity 31 gives rise to notable changes in the timbre of the instrument.

 FIG. 6 shows the application of the invention to an oboe, the top of the body 40 of which comprises, in the extension of the part 41, a cylindrical and tapped receiving sleeve 42 capable of receiving a reed support 43 thread @ tee in which engages the cork 44, now, with the brass tab 45, the double reed reed 46 of the oboe, The chamber 47 of variable length d is reserved between the bottom of the reed support 43 and the bottom of the douil 42. The thread 48 makes it possible to modify the @imbre of the oboe.

Claims (12)

1. Wind instrument, of the type comprising, upstream, a wave generating device such as mouthpiece, single reed, double reed, bevel, etc. followed downstream of a standing wave development pipe, characterized in that it comprises, between the wave generating device and the pipe (3,33,41), a cavity. (1,31,47) variable volume. 2. Instrument according to claim 1, characterized in that the cavity is cylindrical (1,31,47) of variable length. 3. Instrument according to claim 2, characterized in that the length (a) of the cavity (1,31,47) is made variable by means of a threaded assembly (8-9, 17-18, 32, 48) . 4. Instrument according to claim 3, characterized in that the threaded assembly 17-18) is associated with a fine graduation (20). 5. Instrument according to any one of claims 1 to 4, characterized in that it comprises a device for maintaining the adjustment (12, 13-15, 19). 6. Instrument according to any one of claims 1 to 5, of the trumpet type, characterized in that the cavity (1) is located between the tail of the mouthpiece and the start of the mouthpiece branch ( 3) .. 7. Instrument according to claim 5, characterized in that the tail of the mouthpiece is inserted into an adjustable mouthpiece support (2) comprising a sliding part in the outer tube (6,4) surrounding and extending upstream the branch mouth (3), said part delimiting, with the departure of the mouth branch and the upstream of the outer tube (4), the cavity (1) with variable volume, the mouth support (2) comprising by elsewhere a threaded zone (8,18) cooperating with a threaded zone (9,17) of the outer tube (4). 8. Instrument according to claim 7, characterized in that the mouthpiece support (2) is integral with an adjusting ring (16) threaded (18) surrounding the outer tube (4) itself threaded (17). 9. Instrument according to claim 8, characterized in that tail the adjustment ring (16) is provided with a brake f19) rubbing on the outer tube (4). 10. Instrument according to one of claims 8 to 9, characterized in that the adjustment ring (16,19) and the outer tube (4) carry a g-raduation (20) type "Palmer". 11. Instrument according to any one of claims 1 to 5, of the clarinet or saxophone type, characterized in that the cavity (31) is bonded just upstream of the bore (35) of the spout (30) and just downstream from the @@ amber (34) of the beak. 12. Instrument according to any one of claims 1 to 5, of the oboe type, characterized in that the cavity (47) is located between the bottom of the reed support (43), which is threaded, and a receiving socket. (47), also threaded, provided at the top of the body of the hamburger (40).