IMPEDANCE VARIATOR FOR A WIND INSTRUMENT

Abstract

An impedance variator for suppressing the parasitic harmonics of a wind musical instrument, the impedance variator including at least one permanent magnet, the impedance variator including at least two brass bearing plates separated from each other by a brass tube, the tube including a manner for setting the distance between the two plates, and each of the two plates being intended to bear respectively against two wall portions of the wind instrument extending substantially parallel to one another.

Claims

1-20. (canceled)

21. An impedance variator for limiting or suppressing the parasitic harmonics of a wind musical instrument, comprising: at least two bearing plates separated from each other by a tube, said tube including a means for setting the distance between the two plates, each of the two plates is configured to bear, respectively, against two wall portions of the wind instrument extending substantially parallel to one another, wherein: the bearing plates and the tube are made of brass, the impedance variator comprises a brass spar fastened to an end of the tube, one of said support plates being fastened on said spar, and a permanent magnet is fixedly mounted between the spar and the means for sitting the distance between the plates.

22. The impedance variator according to claim 21, wherein the impedance variator comprises three brass bearing plates, two of said bearing plates being fastened to said spar whereas the last bearing plate is fastened to the free end of said tube.

23. The impedance variator according to claim 21, wherein the means for setting the distance between the bearing plates is a threaded spindle mounted in the brass tube and a setting knob mounted free in rotation on the threaded spindle for this distance, and the knob is made of brass.

24. The impedance variator according to claim 21, wherein the permanent magnet has a cylinder shape and is fixed against or on said spar.

25. The impedance variator according to claim 22, wherein the permanent magnet is fixedly mounted between said brass spar and the means for setting the distance between the bearing plates.

26. The impedance variator according to claim 21, wherein the bearing plates include, on their faces bearing against a portion of the instrument, a non-metallic lining, preferably this lining is made of cork.

27. The impedance variator according to claim 21, wherein the outer surface of the brass plates, of the brass tube, are varnished or platinised or plated with silver or gold, the silver or gold plating having a thickness of 6 microns.

28. The impedance variator according to claim 21, wherein the permanent magnet has an external diameter between 12 and 18 mm.

29. A wind instrument, comprising a trumpet or a horn, having an impedance variator according to claim 21, fixed between two wall portions of said wind instrument, extending substantially parallel to one another.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0042] Other advantages and features of the invention will appear more clearly upon reading the description of a following preferred embodiment, with reference to the appended drawings, made as indicative and non-limiting examples and wherein:

[0043] FIG. 1 is a schematic illustration of an embodiment of an impedance variator according to the invention when the latter is in the low position, the setting knob being in contact with the permanent magnet.

[0044] FIG. 2 is a profile view of the impedance variator shown in FIG. 1.

[0045] FIG. 3 is a top view of the impedance variator shown in FIG. 1.

[0046] FIG. 4 is a schematic illustration of an embodiment of the impedance variator shown in FIGS. 1 to 3 when the latter is in the high position.

[0047] FIG. 5 is a profile view of the impedance variator shown in FIG. 4.

[0048] FIG. 6 is an exploded view of the impedance variator according to the invention depicted in the appended figures showing all of the elements that compose it or it comprises.

[0049] FIG. 7 is a schematic view of a trumpet on which an impedance variator according to the invention is mounted or fastened.

[0050] FIG. 8 is a schematic view of a horn on which an impedance variator according to the invention is mounted or fastened.

DESCRIPTION OF THE EMBODIMENTS

[0051] The impedance variator 1 comprises a brass tube 2 at the two ends of which two plates 3, 3 are fastened, the brass tube 2 accommodating a means 5, 6 for setting the spacing distance between the two plates 3, 3.

[0052] In this case, the impedance variator 1 includes a brass spar 10 on which two plates 3, 3 are fastened, instead of one single plate.

[0053] Each of the three plates 3, 3, 3 has identical shape and dimensions. A plate 3, 3 or 3 is intended to bear against a wall portion of a wind instrument, this is why their shapes are adapted to that of the wall portion on which they are brought to come into contact. Thus, a plate 3, 3 or 3 has a substantially semi-cylindrical shape with a central portion wider than the end portions.

[0054] According to one embodiment, a plate 3, 3 or 3 has a length of 18 mm (millimetres) for a maximum width of 12 mm. The height of a plate 3, 3 or 3, i.e. when it is placed for example on a flat or horizontal support, is greater than 3 mm, more specifically equal to 3.3 mm.

[0055] As indicated before, the internal face of the plates 3, 3, 3, namely the face intended to come into contact with a portion of the instrument, is fitted or provided with a non-metallic lining 11, preferably made of cork. According to the embodiment chosen to illustrate the invention, this lining 11 has a thickness of 1.5 mm. Of course, it is possible to consider a material other than corksuch as, for example, a plastic material, rubber or elastomerbut cork has the advantage of facilitating bearing of the plates 3, 3 and 3 without damaging the instrument, while being aesthetic.

[0056] According to one embodiment, the brass tube 2 has a length of 15 mm and an outer diameter of 5 mm bored at 4 mm (inner diameter). This tube 2 being hollow by nature, it accommodates a threaded spindle 5, fastened to the brass spar 10, having an outer diameter of 4 mm so as to cooperate with the inner diameter of the brass tube 2. Still according to an embodiment, this threaded spindle 5 has a length of 24 mm.

[0057] According to one embodiment, the means 5, 6 for setting the distance between the two end plates 3 and 3 or 3 and 3 consists of a rotary (or freely rotating) knob 6 allowing raising or lowering the brass tube 2 away from the permanent magnet 8 or on the contrary against the permanent magnet 8 so as to make the distance separating these two plates 3 and 3 or 3 and 3 vary, more specifically the pair of plates 3, 3 fastened on the spar 10 and the plate 3 fastened directly to an end of the brass tube 2.

[0058] In FIGS. 1 and 2, the setting knob 6 is in contact with the permanent magnet 8, and therefore proximate to the spar 10, so that the distance between the pair of plates 3, 3 under the spar 10 and the plate 3 on the end of the brass tube 2 is minimum, in this case 25 mm. In FIGS. 4 and 5, the setting knob 6 is at a distance from the permanent magnet 8, and therefore from the spar 10, the maximum distance between the pair of plates 3, 3 and the plate 3 at the opposite end of the brass tube 2 being 45 mm. Of course, such a spacing between the minimum and maximum distance, i.e. between 25 mm and 45 mm, allows mounting and fastening the impedance variator 1 in or on most wind instruments provided with at least two portions facing one another substantially parallel to one another, but it is possible to provide for a larger or on the contrary smaller distance. This variable distance 25 mm to 45 mm adapts in particular to trumpets 20 or horns 30.

[0059] In one embodiment, the brass spar 10, on which or under which two plates 3, 3 are fastened is in the form of a parallelepiped with a length of 44 mm, a width of 7 mm and a thickness of 2 mm. The permanent magnet 8 and the threaded spindle 5 are fastened on the spar 10 so that the brass tube 2 extends along an axis perpendicular to the plane (along the direction defining the length and the direction defining the width) or to the axis of extension (in the lengthwise direction) of the brass spar 10.

[0060] Advantageously, the permanent magnet 8 is fastened on the brass spar 10 and has, in the embodiment chosen to illustrate the invention, the following dimensions: [0061] an inner diameter of 5.5 mm, [0062] an outer diameter of 15 mm, [0063] a thickness of 6 mm.

[0064] Advantageously, the permanent magnet 8 is a neodymium magnet. The permanent magnet 8 has an inner bore to let the threaded spindle 5 pass throughout the magnet 8.

[0065] Fastening of the elements to one another, in particular fastening of the brass tube 2 on a brass plate 3, 3 or 3, fastening of the permanent magnet 8 on the brass spar 10 and fastening of the pair of plates 3, 3 under the spar 10 is done according to methods and means well-known to a person skilled in the art, for example by welding, crimping or by gluing; the fastening modes may of course vary to fasten two types of the aforementioned elements.

[0066] The dimensions of the aforementioned elementsin the specific embodiment or in their more general or wide rangeare advantageous to achieve the main effect of the impedance variator 1, namely the limitation and possibly the suppression of parasitic sounds. Of course, these dimensions are primarily important for the plates 3, 3, 3, the brass tube 2 and the permanent magnet 8 and then advantageously for the brass spar 10.

[0067] According to another variant, the impedance variator 1 consists of two brass plates-namely two bearing plates 3, 3 or 3, 3 located at the two opposite ends of the tube-connected by a micrometric screw elevator (the means 5, 6 for setting the distance between these two plates 3, 3 or 3, 3), namely the threaded spindle 5 and the brass tube 2. Thus, the musician places the impedance variator 1 by putting a first bearing point on the beginning of a branch of a horn 30, and a second bearing point on the same branch after the first bend 31 (FIG. 8). Thanks to its adjustability, the impedance variator 1 according to the invention can be positioned where the musician desires and with the adapted pressure on the two branches of the horn 30.

[0068] On the trumpet 20 visible in FIG. 7, the impedance variator 1 is fastened in the same manner, namely with a first bearing point (via a bearing plate 3 or a pair of bearing plates 3, 3) on a branch and a second bearing point (again via a bearing plate 3 or a pair of bearing plates 3, 3) on the bell portion of the instrument 20, as shown in this figure.

[0069] As indicated before, the impedance variator 1 may have a colour that is suitable or aesthetic with regards to the wind instrument 20 or 30, or in particular thanks to varnishing or platinising or plating with silver or gold, preferably with a thickness of 6 microns.

[0070] All of the indicated elements 2, 3, 3, 3, 10 are made of brass, namely of an alloy essentially of copper and zinc, at variable proportions. Preferably, all these elements 2, 3, 3, 3, 10 consist of the same brass, i.e. a brass having exactly the same components in the same relative amounts.

[0071] Amongst the three categories of brass, namely simple brasses or binary alloy brasses containing only copper and zinc, lead brasses containing from 1 to 3% by weight of lead and special brasses comprising in particular one or more of the elements selected from among tin, aluminium, arsenic, magnesium, nickel, iron, silicon, etc., the brass elements 2, 3, 3, 3, 10 in the impedance variator 1 according to the invention preferably consists of simple or binary alloy brasses.

[0072] Although the invention has been described in connection with several particular embodiments, it is obvious that it is in no way limited thereto and that it comprises all of the technical equivalents of the described means as well as their combinations if these fall within the scope of the invention.

[0073] The arrangement of the different elements and/or of the means and/or steps of the invention, in the above-described embodiments, should not be understood as requiring such an arrangement in all implementations. In any case, it should be understood that various modifications could be made to these elements and/or means and/or steps, without departing from the spirit and the scope of the invention. In particular: [0074] the shape and the number of brass plates 3, 3, 3; [0075] the making of the means 5, 6 for setting the distance between the plates 3 and 3 or 3 located opposite one another, namely on two bearing points opposite one another on the wind instrument 20 or 30, the setting means 5, 6 which may consist of a different assembly of mechanical elements or of electromechanical means such as, for example, a worm screw driven using an electric motor or at least one small hydraulic cylinder; [0076] the permanent magnet 8 may consist of any ferromagnetic material other than a neodymium magnet and may be fastened on the brass tube 2 or directly on a plate 3, 3 or 3, it being understood that the impedance variator 1 according to the invention may have a plurality of permanent magnets 8, possibly or advantageously having different dimensions.

[0077] The use of the verb include, comprise or contain and of its conjugated forms does not exclude the presence of other elements or other steps than those set out in a claim.

[0078] In the claims, any reference sign between brackets should not be interpreted as a limitation of the claim.