GB2301220A

GB2301220A - Musical instument

Info

Publication number: GB2301220A
Application number: GB9510618A
Authority: GB
Inventors: Daniel Hugh Bangham
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-05-25
Filing date: 1995-05-25
Publication date: 1996-11-27
Anticipated expiration: 2015-05-25
Also published as: GB9510618D0; GB2301220B

Abstract

An insertion element for a wind instrument 12 having a vent aperture is provided, the insertion element 20, being made from a water absorbent material so that in use the insertion element is situated in the vent aperture 16, and water condensate is drawn into the water absorbent material so as to prevent closure of the aperture by water during the playing of the instrument. The insertion element acts to provide an octave hole so that in use the frequency alteration obtained by the octave hole is constant. The water absorbent material is substantially impermeable to air, with a water porosity of 0.1% to 5%.

Description

Title: Musical Instrument Field of the invention The invention relates to musical instruments, in particular wind instruments.

Backaround to the invention Wind instruments, in particular those based on an open pipe system, typically have a number of tone holes and one or more vent holes. The tone holes along the body of the instrument act to change the sounding length of the open pipe and hence alter the pitch of the note produced. Typically the end of tne instrument into which the musician blows acts as a node with the area beyond the last closed tone hole acting to provide an antinode. This produces waves of a fundamental frequency fo.

The vent holes introduce a new antinode into the standing wave set up when a tone hole is covered and thus act to double the frequency of the note produced to 2fc.

The vent holes typically have octave bushes inserted into them to restrict the hole opening and ensure that the antinode is formed. The bushes are typically made of metal and while the instrument is being played condensation is found to collect in the bushes. This effectively closes the opening and prevents the formation of an antinode, and only the lower frequency fo will sound.

Summary of the invention According to a first aspect of the invention there is provided an insertion element for a wind instrument having a vent aperture, wherein the insertion element is made from a water absorbent material so that in use the insertion element is situated in the vent aperture, and water condensate is drawn into the water absorbant material so as to prevent closure of the aperture by water during the playing of the instrument.

Preferably the insertion element acts to provide an octave hole so that in use the frequency alteration obtained by the octave hole is constant.

The instrument may have two or more vent apertures each having an insertion element. Alternatively a common insertIon element may be for two or more vent apertures.

Preferably a water absorbent material is selected that is substantially impermeable to air, so that on insertion into the vent aperture of the instrument, a seal to the atmosphere is formed where the vent aperture and insertion element make contact, so that the aperture size is determined by the insertion element. This allows the lower registers of the instrument to be played.

Preferably the material has a water porosity of 0.1% to 5%.

In use, the insertion element absorbs any condensation that collects on it and thereby prevents the restricted aperture provided by the insertion element becoming closed. Whilst the instrument is not being played, absorbed water evaporates from the insertion element through its upper surface.

The absorbent material is preferably machinable for example by means of a lathe.

A preferred material for the insertion element is a ceramic such as pyrophyllite.

Preferably this is heat treated to 800-1000 C before being machined.

According to a second aspect of the invention in a musical wind instrument having vent holes, the latter are provided with water absorbing insertion elements in the vent holes, the insertion elements being formed from water absorbent material so as to prevent the build up of moisture and closure of the aperture while the instrument is being played.

A method of modifying a musical instrument having a vent aperture is also provided, comprising the step of securing an insert of water absorbent material into the vent aperture so as to absorb water condensation when the instrument is played.

The invention will now be described by way of example with reference to the following drawings in which: Figure 1 shows a schematic diagram of an oboe with an insertion element according to the invention; Figure 2 shows a detailed cross-section through the upper end of the oboe; and Figure 3 shows a cross-section through the insertion element.

Description Figure 1 shows a schematic diagram of an oboe 10. The conical oboe body 12 has a series of tone holes 14 and two vent holes 16, 18. To ensure that the vent holes 16, 18 are of the required diameter, insertion elements 20, 22 are inserted into them so as to provide an octave hole. The octave hole typically has a diameter of 0.7 millimetres. The upper end of the oboe is provided with a reed 24.

During use, a musician blows through the reed 24 so as to create standing waves of a particular frequency within the open pipe structure of the oboe body 12. The tone holes 14 are typically 3 millimetres in diameter and when covered change the soundIng length of the body of the oboe. This affects the pitch of the note produced. The octave holes cause antinodes within the body of the oboe. This alters the frequency of the note played and where one antinode is present acts to double the frequency of the note played from the fundamental frequency of an open pipe f0 to that of an open pipe with an antinode, le. 2f0.

The insertion elements 20, 22 may be known as octave bushes.

Prior art octave bushes have been typically made from nickel silver or sterling silver. When playing the instrument, condensation collects in the piece of the oboe tube below the metal octave bush. This condensation eventually closes the small hole provided by the octave bush. This removes the antinode so provided and prevents the required alteration in frequency. The player must then blow out the octave holes by mouth so as to restore the antinode. This is undesirable during musical performances.

A cross-section of the oboe 10 and the vent hole 16 with octave bush 20 is shown in Figure 2. The octave bush 20 is provided with a screw thread 26 which engages with a corresponding thread 28 of the vent hole 16. The use of a water absorbent material for the octave bushes 20, 22 as provided in the invention, ensures that during play, any water that condenses below the octave bush is absorbed and is not allowed to close the octave bush hole.

A detailed cross-sectional view of the octave bush is shown in Figure 3. The cross-section of the octave bush 20 shows the screw thread 26 which engages with the corresponding screw thread 28 in the vent hole. The centre aperture 30 is typically of 0.7 millimetre diameter and this provides the opening which results in the frequency alteration. The material used for the insertion element or octave bush 20 is preferably pyrophyllite, a naturally occurring alumino-silicate material.

The pyrophyllite is preferably heat treated to 800-10000C. The heat treatment is typically carried out in a mufle furnace, with the material being heated at a rate of 50-100 C per hour up to 000C and then at nct more than 160c per hour to the required temperature. The heat treated material is allowed to furnace cool. The resulting heated material has a typical water porosity of 0.1% to 5%. As the oboe is played, water is absorbed by the pyrophyllite, preventing closure of the octave hole and so avoiding removal of the antinode.The material is sufficiently impermeable to air for the octave bush to orm the necessary seal to the atmosphere so that the 0.7 millimetre diameter aperture in the bush represents the true aperture size to air. The use of pyrophyllite provides an easily machinable material that is as dimensionally stable as metal bushes and may be inserted into vent holes that exist in existing oboes.

Alternatively the octave bush may have the screw thread 25 replaced by an alternative securing means such as a mastic washer.

When the instrument is not in use, water that has been absorbed into the octave bush evaporates. Over time it may be necessary to clean the octave bushes 20, 22 so as to remove deposits of sugar etc that have resulted from saliva. As the bushes 20, 22 are readily detachable, this is readily achieved by simply washing the octave bushes in alcohol or other such suitable solvents.

The use of the water absorbent material pyrophyllite is of use in instruments where the collection of water in apertures detrimental to the performance of the instrument.

Claims

1. An insertion element for a wind instrument having a vent aperture, wherein the insertion element is made from a water absorbent material so that in use the insertion element is situated in the vent aperture, and water condensate is drawn into the water absorbent material so as to prevent closure of the aperture by water during the playing of the instrument.

2. An insertion element according to claim 1, wherein the insertion element acts to provide an octave hole so that in use the frequency alteration obtained by the octave hole is constant.

3. An insertion element according to claim 1 or claim 2, wherein the water absorbent material is substantially impermeable to air, so that on insertion into the vent aperture of the instrument, a seal to the atmosphere is formed where the vent aperture and insertion element make contact, so that the aperture size is determined by the insertion element.

4. An insertion element according to any of the preceding claims, wherein the water absorbent material has a water porosity of 0.1% to 5%.

5. An insertion element according to any of the preceding claims, wherein the water absorbent material is machinable.

6. An insertion element according to any of the preceding claims, wherein the water absorbant material is a ceramic.

7. An insertion element according to claim 6, wherein the ceramic is heat treated to 800-10000C before being machined to make the insertion element.

8. A musical wind instrument having vent holes, the latter being provided with insertion elements in the vent holes, wherein the insertion elements are formed from water absorbent material so that in use the build up of moisture and closure of the aperture while the instrument is being played is prevented.

9. A method of modifying a musical instrument having a vent aperture, comprising the step of securing an insert of water absorbent material into the vent aperture so as to absorb water condensation when the instrument is played.

10. An insertion element for a musical instrument substantially as herein particularly described.