Speaker vent

In a woodwind instrument, the improvement comprising a speaker vent extending from inside to outside of the instrument, said speaker vent being characterized by an internal volume in the range of 200 mm.sup.3 to 285 mm.sup.3.

CROSS REFERENCE TO RELATED APPLICATION 
This is a continuation-in-part application of International Patent 
Application No, PCT/CA91/00136 filed on Apr. 23, 1991 (pending). 
FIELD OF THE INVENTION 
This invention relates in general to woodwind instruments, and more 
particularly to an improved clarinet speaker vent for providing a better 
"throat" B.music-flat.. 
BACKGROUND OF THE INVENTION 
The speaker vent is a small tube in a clarinet that assists the player in 
changing from the low register to the next higher register. More 
particularly, the vent serves the function of breaking the vibrating 
column of air within the bore of the clarinet into further acoustical 
segments. 
The small speaker vent also acts as a musical note called "throat" tone 
B.music-flat.. In existing clarinets, the sound of this note is weak and 
fuzzy. Many attempts have been made at correcting the weakness of the 
"throat" B.music-flat. tone with mechanisms that switch from the speaker 
vent to a lower alternative tone hole for B.music-flat.. Most of these 
prior art solutions necessitated added mechanisms. 
For example, U.S. Pat. No. 2,508,550 (Stubbins) teaches a speaker vent 
located at a node in the low register of a clarinet for producing upper 
register tones. A separate "resonance" hole is spaced circumferentially 
downstream from the register hole for producing, when opened with the 
speaker vent and the A key, a better B.music-flat.. 
U.S. Pat. No. 2,951,414 (Christensen) teaches a mechanism associated with 
the register vent key by which an outlet of a size smaller than the 
conventional size of a register key may be opened to function exclusively 
when the tones A, A#, B and C just above the staff are produced, to sound 
these tones in correct pitch. 
U.S. Pat. No. 706,557 (Heckel) teaches two separate holes on opposite sides 
of the clarinet at the approximate location of the normal vent, and added 
mechanisms for opening and closing the separate holes simultaneously 
U.S. Pat. No. 2,226,536 (Selmer) discloses a woodwind instrument, such as a 
clarinet, in which the speaker vent inside the clarinet is surrounded by a 
tubular cap or body, forming a resonant space opened freely toward the 
inside of the clarinet. The resonant space or chamber around the vent tube 
is said to provide for musical notes of enhanced timbre, purity and 
intensity. 
U.S. Pat. No. 2,867,146 (Mazzeo) teaches the use of the lower side 
"B.music-flat." hole with a mechanism that utilizes a different fingering 
from the usual clarinet fingering, and a cancellation mechanism which can 
revert to the standard clarinet fingering utilizing the prior vent 
B.music-flat.. 
According to an aspect of the present invention, a speaker vent is provided 
having larger tube volume than hitherto provided, resulting in the 
sounding of a strong and better B.music-flat.. There is no added mechanism 
or change of fingering. 
According to the preferred embodiment, the larger volume speaker vent 
incorporates an intermediate chamber in the middle of the vent tube to 
provide the required volume. This combined tube and chamber serve the dual 
purpose of speaker vent and throat B.music-flat..

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Turning to FIG. 1, a cross-sectional view of a portion of a clarinet 1 is 
shown having a bore 2 and a stock 3 for connection to a further section of 
the clarinet. A speaker vent 4 is provided in the usual position and size, 
characterized by an internal volume in the order of 99 cubic millimeters. 
In FIG. 2, the speaker vent 5 is shown more than twice as long as the prior 
art vent 4, and is characterized by an inside diameter that is larger, 
thereby providing an increased volume of air within the tube, resulting in 
a stronger B.music-flat. tone than prior art clarinets. The vent 5 
protrudes from the body of the clarinet in the illustrated embodiment. 
Turning to the preferred embodiment of FIGS. 3, 4 and 5, the length of the 
speaker vent 5 is reduced from the embodiment of FIG. 2 to a little more 
than the length of the conventional speaker vent 4 shown in FIG. 1. An 
intermediate chamber 6 is introduced in the tube 7 to compensate for the 
volume of the shortened portion tube as compared with the embodiment shown 
in FIG. 2. This shortened tube 7 and chamber 6 act both as the speaker 
vent and as a throat B.music-flat. note. The inner chamber 6 functions to 
lower the pressure from inside the clarinet bore 2 to outside of the 
clarinet, thereby rendering smooth and unobstructed emission of the 
clarinet register. 
Furthermore, in order to compensate for lost flow resistance by enlarging 
the tube at 6, impedance has been introduced by cutting threads 8 into the 
chamber 6, as shown in FIGS. 4 and 5. More particularly, upper and lower 
sections 9 and 10 of the vent 7, are connected together by means of 
cooperating outer threads 8a on top section 9 and inner threads 8b on 
bottom section 10, while inner threads 8c on bottom section 10 function to 
provide the necessary flow impedance. 
Through experimentation, it has been discovered that the internal volume of 
the vent tubes in the embodiments of FIGS. 2-6 is in the vicinity of 
200-285 mm.sup.3 as compared to approximately 99 m.sup.3 in the prior art. 
Thus, in a successful prototype of the embodiment of FIG. 2, the tube 5 was 
characterized by a length of 26-28 mm and an inner diameter in the range 
of 3 mm to 4 mm. In a successful prototype of the preferred embodiment in 
FIGS. 3-5, the inner operative chamber 6 was characterized by a length in 
the range of 2-3 mm and inner diameter in the range of 7-9 mm, whereas the 
two sections of tube 7 on either side of chamber 6 were characterized by 
an inner diameter in the range of 2.8 mm to 3.8 mm and a combined length 
of in the range of 12 mm to 13 mm. The total length of the vent is 17-19 
mm. 
In summary, it has been found that the transition from the low register to 
the clarinet register is accomplished using the principle of the present 
invention, with much more ease than hitherto experienced. Transitions 
between notes have been found to be very smooth and the "clarinet" 
register rendered more 
The "throat" B.music-flat. has been vastly improved and flexible. The 
"throat" B.music-flat. has been vastly improved and strengthened over 
small tube vents of prior art clarinets. There is no added mechanisms or 
change of fingering. 
Another embodiment of the invention is illustrated in FIGS. 6a-6d. The 
entire vent of the embodiment is between 17-19 mm long. The vent comprises 
a tube 11 that is between 12-13 mm long with an inside diameter of between 
2.7-3.5 mm wide, leading to a chamber 12 that is between 5-7 mm long with 
an inside diameter of between 5-7 mm. 
The inside of the chamber 12 is lined with a sleeve 14 that has 
perforations as in number 14a (FIG. 6c) or a sleeve that has grooves 14b 
as shown in FIG. 6d. The sleeve 14 can have other different topographic 
features such as indentations, threads or a combination of shapes. Each 
such shape or combination thereof offers a different tone quality. 
The top of the chamber 12 is covered with a cap 13 that has an opening of 
between 3.5-5 mm in diameter. The cap may be screwed or soldered to the 
top of chamber 12. 
Other embodiments or variations are possible within the sphere and scope of 
the present invention. 
For example, as an alternative to lengthening the vent tube outside the 
bore of the clarinet itself, one alternative comprises disposing the tube 
at an oblique angle 15, with the entrance in the bore 2 being located at 
the same place as prior art vents and the opening outside the clarinet 
being lower and closer to the "throat G" tone hole (see FIG. 7). 
Furthermore, the principles of the present invention is equally applicable 
to the high register vent of a clarinet. 
For example, the first finger hole for the left hand, the F-C hole, is used 
as a vent for the high register of the clarinet (i.e. the altissimo 
register). 
When most notes in the high register are played, this tone hole is left 
open. The tone hole is of a small size and in a location which enables it 
to act as a high register vent. 
There was an innovation by Adolphe Sax, in the last century, to improve 
this vent by covering the first finger hole with a perforated plate such 
that the plate would be closed and a smaller hole would be left open when 
the left hand first finger is raised. This principle is presently applied 
to bass clarinets and other such lower sounding clarinets. 
U.S. Pat. No. 3,844,193 (Marchi) discloses a high register vent which is 
situated almost as high as the top of the barrel of the clarinet. The 
purpose of the Marchi vent is to create a new harmonic series starting 
from middle B (third line of the stave). 
The alternative embodiment of FIG. 8 is an improvement on the prior art 
high register vent (i.e. the hole 16 controlled by the first finger of the 
left hand). According to the illustrated embodiment, a further small hole 
17 is drilled obliquely from inside the left hand first finger tone hole 
16, towards the top of the instrument, opening into the bore 2, 
approximately opposite the location where the throat G tone hole is 
located. 
When the first finger of the left hand is raised, this new oblique hole 17 
allows the high notes to sound smoothly and, makes it easier to slur to 
and from the clarinet register to the higher altissimo notes. 
With reference to FIG. 9, an alternative embodiment of the invention is 
shown which operates using a similar principle to the embodiment of FIG. 
2. Specifically, a speaker vent is provided having two portions 5' and 5" 
disposed on opposite sides of the bore 2 of the clarinet 1. The speaker 
vent portion 5' is open at both ends, whereas the speaker vent portion 5" 
is open to the bore 2 but capped at 5'" on the outside of the clarinet 
stock. The combined volume of speaker vent portions 5' and 5" is in the 
preferred range of from 200 mm.sup.3 to 285 mm.sup.3. 
Finally, although the disclosed embodiments all relate to clarinet 
implementations of the invention, the principles of the invention are 
equally applicable to the entire clarinet, saxophone and oboe family 
(soprano, alto, bass, etc.), and are not limited to the clarinet 
embodiment disclosed herein. 
All such embodiments or variations are believed to be within the sphere and 
scope of the claims appended hereto.