GB2431508A

GB2431508A - Whistle with airway that can be variably tapered

Info

Publication number: GB2431508A
Application number: GB0606534A
Authority: GB
Inventors: Isao Kubota
Original assignee: RAZA V Ltd
Current assignee: RAZA V Ltd
Priority date: 2005-10-24
Filing date: 2006-03-31
Publication date: 2007-04-25
Anticipated expiration: 2026-03-31
Also published as: JP2007114638A; GB0606534D0; GB2431508B; JP4398418B2

Abstract

A whistle 1 includes a main body 10 and a mouthpiece 20. The main body 10 has a resonating chamber 11 and an air release opening 12 connecting the resonating chamber 11 with an outside. The mouthpiece 20 has an airway 21 for feeding air to the resonating chamber 11. The airway 21 has 0.3-1.0 mm height at an outlet 23 communicating with the resonating chamber 11 and 0.8-3.5mm height at an inlet 22, and a height of the airway 21 becomes gradually smaller from the inlet 22 to the outlet 23. The inclination of the tapered airway can be altered by way of a sliding part to one of the walls of the airway.

Description

WHISTLE

FIELD OF THE INVENTION

This invention relates to a whistle, and more particularly to a whistle suitable for calling emergency rescue.

BACKGROUND OF THE INVENTION

Generally, a whistle makes a sound by using air that is blown and forced to flow from an air supply opening to an air release opening through an airway and while impacting an edge of the air release opening to flow out from the air release opening. One conventional whistle with this typical structure is known from Japanese Laid-open Patent Application No. H09212171 (see FIGS. 1 and 2), in which a mouthpiece has an elongated airway having a substantially rectangular vertical cross section, and a resonating chamber connected to the airway has a blow-off opening at one wall portion thereof. In this typical kind of whistles, the airway is usually more or less 3 mm in height, and the height is constant throughout the airway.

However, such a conventional whistle requires a large amount of air to make a sound because the height of the airway is large.

Namely, it is not until a user blows air strongly from the air supply opening that he can make a sound with the whistle.

Recently, disaster prevention has been paid attention as disaster such as earthquake and flood damage comes into particular prominent. To use a whistle is particularly advantageous for calling rescue from collapsed buildings. The conventional whistle, however, needs blowing with a strong blowing force, so an elderly person or small child who cannot blow air strongly cannot make a sufficiently loud sound.

In order to overcome this problem, there has been suggested a whistle with which a user can readily make a sound even with a weak blowing force. In this whistle, the airway is set, for example, for 1 mm height.

However, if the height is set for 1mm throughout the airway, there is aproblemin thatauser cannot make a sound when he strongly blows the whistle. Under such circumstance that one meets with a disaster and is confused, he may inadvertently blow the whistle more strongly than necessary. In this instance, blown air does not flow smoothly in the airway, so that he cannot make a sound with the whistle.

By the way, it is preferable for whistles used for calling emergency rescue to produce a loud and high-pitched sound because such a sound can reach farther and help rescue crews to find out victims.

The whistle disclosed in the above Japanese Laid-open Patent Application No. H09-212l7l can produce a sound with a frequency of about 3.0-3.5 kHz at the peak intensity. The conventional whistle whose airway is 1 mm in height can also produce a sound with a frequency of about 3.0 kHz at the peak intensity.

With the foregoing drawbacks of the conventional whistles in view, the present invention seeks to provide a whistle which is less subject to the blowing force for blowing the whistle and produces a loud and highpitched sound, and which is suitable for calling emergency rescue.

SUMMARY OF THE INVENTION

According to the present invention, there is provided a whistle, which comprises a main body having a resonating chamber and an air release opening connecting the resonating chamber with an outside, and a mouthpiece having an airway for feeding air to the resonating chamber. The airway has 0.3-1.0 mm height at an outlet communicating with the resonating chamber and 0.8-3.5 mm height at an inlet, and the height of the airway becomes gradually smaller from the inlet to the outlet. The height of the inlet is preferably 1.0-3.0 mm.

In this whistle, the height of the airway is made smaller to the extent of 0.3-1.0 mm at the outlet. Therefore, even if a user blows air with a weak blowing force, a flow of air having sufficiently fast flow velocity is generated at the airway, thereby enabling the whistle to make a sound. Meanwhile, even if the user blows air with a strong blowing force, the blown air can smoothly flow through the airway as the inlet of the airway is wider than the outlet, so that air is fed from the outlet of the airway to the resonating chamber at high speed. As the result, the whistle can produce an extremely loud and high-pitched sound. If the user uses this whistle for calling help at an emergency, it is possible to inform others over a long distance about the existence of the user.

In a preferred embodiment of the present invention, at least one of an upper wall and a lower wall which form a part of the airway is movable so as to vary an inclination of the airway.

With this structure of the whistle, the inclination of the wall of the airway extending from the inlet to the outlet (inclination of the airway) can be set for a large angle when the user prefers a loud sound to call help. In a normal use, however, the inclination of the airway can be set for a small angle or the angle formed by the upper and lower walls can be set parallel so as to adjust the volume or the tone of the sound. Therefore, it is possible to produce an appropriate sound in accordance with the use situations.

Other objects and advantages will become apparent from the following description taken in conjunction with the accompanying drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a whistle according to one embodiment of the present invention; FIG. 2A is a perspective view of a movable lower wall member; FIG. 2B is a sectional view of a main body part, in which the drawing corresponds to a sectional view taken along the line X-X of FIG. 1; FIG. 3A is a sectional view taken along the line X-X of FIG. 1 and illustrates a normal use; FIG. 3B is a sectional view taken along the line X-X of FIG. 1 and illustrates an emergency use; FIG. 4 explainsa firstmodificationof thepresent invention, in which the drawing corresponds to a sectional view taken along the line X-X of FIG. 1; FIGS. 5A and 5B explain a second modification of the present invention and each of the drawings corresponds to a sectional view taken along the line X-X of FIG. 1, in which FIG. 5A illustrates a state where the inlet of the airway is set narrow, and FIG. 5B illustrates a state where the inlet of the airway is set wide; FIGS. 6A and 6B explain a third modification of the present invention and each of the drawings corresponds to a sectional view taken along the line X-X of FIG. 1, in which FIG. 6A illustrates a state where the inlet of the airway is set narrow, and FIG. 6B illustrates a state where the inlet of the airway is set wide; and FIG. 7 is a graph showing the results of an example.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to the accompanying drawings, preferred embodiments of the present invention will be described.

As shown in FIG. 1, a whistle 1 includes a main body 10 having a resonating chamber 11, and a mouthpiece 20 connected to the main body 10. The mouthpiece 20 is provided with an airway 21, which opens at one end (inlet 22) to the outside of the mouthpiece 20 and communicates at the other end (outlet 23) with the resonating chamber 11. The whistle 1 according to this embodiment is divided into the main body 10 and the mouthpiece 20 in terms of function.

However, considering the component parts, the whistle 1 consists of two parts as shown in FIGS. 2A and 2B, that is, a main body part 15 and a movable lower wall member 25. As shown in FIG. 2B, the main body part 15 is molded by resin and integrates the main body 10 and the upper part of the mouthpiece 20. Throughout the description, the terms "upper" and "lower" are defined with reference to those directions of FIG. 1. As shown in FIG. 2A, the movable lower wall member 25 forms the lower part of the mouthpiece 20. Thewayof dividing the whistle 1 is not important in the present invention, and the whistle 1 can be assembled by a desired number of component parts. Material which forms the whistle 1 is not limited to resin, and metal, ceramic and wood may also be used as needed.

The main body 10 has an air release opening 12 for discharging air that is fed to the resonating chamber 11. The air release opening 12 has an edge 12a to which blown air fed from the airway 21 impacts and produces a sound. The edge 12a is arranged in a direction extending toward the outlet 23 of the airway 21.

The airway 21 has a substantially rectangular vertical cross section and extends from the inlet 22 to the outlet 23. Although the airway 21 has a substantially plate-like outer profile, the shape of the passage can be changed by the operation of the movable lower wall member 25 as described later. The edge 12a of the air release opening 12 forms an edge line along the flat direction of the airway 21, that is, the width direction of the airway 21.

A small strap hole 13 is formed at a rear end portion (far side of FIG. 1) of the main body 10. The strap hole 13 extends through the rear end portion in the vertical direction so that if a strap or chain is passed through the strap hole 13 and hooked in a key holder or a mobile phone, a user can bring the whistle 1 at any time. This is advantageous because he can call rescue at any time of an emergency.

As shown in FIG. 2A, the movable lower wall member 25 is substantially wedge shaped such that the front side thereof (near side of FIG. 2A) becomes thinner while the vertical section thereof as viewed from side is substantially constant at any section in its width direction. Provided at both side walls of the movable lower wall member 25 are a rotational shaft 25a in the shape of a columnar protrusion. Further, two small protrusions 25b are formed on the upper surface of the movable lower wall member 25, that is, the lower wall 27 of the airway 21. Moreover, a small protrusion 25c is formed on both side walls of the movable lower wall member 25 in a position adjacent to the rotational shaft 25a.

At the upper rear end of the movable lower wall member 25, there is formed a recessed curved surface 25d facing to the air release opening 12 of the main body 10. The recessed curved surface 25d directs the flow of air toward the air release opening 12 when the air in the resonating chamber 11 is released from the air release opening 12, thereby preventing disruption of sound.

As best seen in FIG. 2B, the main body part 15 has a shaft supporting hole 17 in the shape of a columnar recess at each inner side wall 16 thereof in a position corresponding to the rotational shaft 25a of the movable lower wall member 25. When the rotational shafts 25a are fitted into the corresponding shaft supporting holes 17, the movable lower wall member 25 becomes rotatable around the rotational shafts 25a. Formedjneachinnersidewall 16 extending from the shaft supporting hole 17 is a guide groove 18, the depth of which is slightly shallower than the shaft supporting hole 17.

The guide grooves 18 function to guide the rotational shafts 25a when the rotational shafts 25a are fitted into the corresponding shaft supporting holes 17. The protrusions 25c formed on the side walls of the movable lower wall member 25 are arranged such that they are positioned in the corresponding guide grooves 18 when the movable lower wall member 25 is assembled with the main body part 15.

According to the above structured parts, the positional relation of the main body part 15 and the movable lower wall member when assembled is shown by FIGS. 3A and 3B.

In a normal use such as shown in FIG. 3A, the front end (left side of FIG. 3A) of the movable lower wall member 25 is lifted up so that the inlet 22 of the airway 21 becomes narrow. In this position, the protrusions 25b abut on the upper wall 26 of the airway 21, thereby restricting the height of the airway 21 at the inlet 22. For example, if the height of the protrusions 25b is set for 1. 0 mm, the height of the inlet 22 upon closing the movable lower wall member 25, which is denoted by H2 in the figure, is also set for 1.0 mm.

Meanwhile, in an emergency use such as shown in FIG. 3B, the movable lower wall member 25 is rotated such that the front end thereof is lifted down, so that the inlet 22 of the airway 21 becomes wide. In this position, each of the protrusions 25c of the movable lower wall member 25 positioned in the corresponding guide groove 18 abuts on the wall 18a of each guide groove 18, which is a stepped portion formed between the inner side wall 16 and the guide groove 18, thereby restricting the height of the airway2iattheinlet22. Forexample, position of theprotrusions 25c can be set such that the height of the inlet 22 at the fully open position of the movable lower wall member 25, which is denoted by H2 in the figure, is set for 3.0 mm.

Height of the airway 21 at the outlet 23, which is denoted by Hi, is set in the range of 0.3-1.0 mm. Setting the height Hi greaterthanO.3mmallowsa sufficientamountofairtoflowthrough the airway 21 and to produce a loud and high-pitched sound. Also, setting the height Hi smaller than 1.0 mm allows air to flow in the airway 21 at high flow velocities and to produce a loud and high-pitched sound.

Height of the airway 21 at the inlet 22, which is denoted by H2, is set such that the movable lower wall member 25 is movable at least in the range of 0.8-3.5 mm, and preferably in the range of 1.0-3.0 mm. Setting the height H2 greater than 0.8 mm allows a sufficient amount of air to be fed in the resonating chamber ii, and setting the height H2 smaller than 3.5 mm can prevent the flow of air flowing through the airway 21 from being disrupted, thereby producing a stable sound. Preferably, when the movable lower wall member 25 is rotated to the lowermost position, the height H2 is set in the above range (0.8-3.5 mm or 1.0-3.0 mm) This is particularly advantageous because the airway 21 suitable for the emergency use can be ensured by a simple operation at an emergency such as to open or rotate the movable lower wall member to the fully open position. Further, it is preferable that the height of the airway 21 is gradually smaller from the inlet 22 to the outlet 23 when the movable lower wall member 25 is opened.

Width of the airway 21 is not so important. However, if the width is too small, a user cannot make a loud sound. On the contrary, ifthewidthis toolarge, theuserhas toblowthewhistle 1 with a strong blowing force. Usually, the width of the airway 21 is set arbitrarily in the range of 5-15 mm in accordance with the height of the airway 21.

Operation of the above structured whistle 1 will be described below.

As best seen in FIG. 3A, in the normal use of the whistle 1, the movable lower wall member 25 is closed with the front end thereof lifted up so that the protrusions 25b abut on the upper wall 26 of the airway 21. Therefore, the airway 21 is set to have a constant height from the inlet 22 to the outlet 23, for example, for 1.0mm. If a user blows air from the inlet 22 while the movable lower wall member 25 is set in this position, he can make a sound evenwithaweakblowingforce. Whencomparedwiththeconventional - 10 - typical whistle, the whistle 1 produces a sound of which loudness is slightly greater than the conventional whistle and of which pitchisalmost sameastheconventionalwhistle. Therefore, sound of the whistle 1 is not offensive to the ear, and it is possible to use the whistle 1 in a general use such as gymnastics lesson and club activities.

As best seen in FIG. 3B, in the emergency use of the whistle 1, the movable lower wall member 25 is opened with the front end thereof lifted down so that the protrusions 25c abut on the walls 18a of the guide grooves 18. Therefore, for example, the height H2 (inlet height of the airway 21) is set for 3.0mm and the height Hl (outlet height of the airway 21) is set for 1.0 mm. As shown in FIGS. 3A and 3B, if the rotational shafts 25a are arranged near the position substantially right below the outlet 23, that is in the lower vertical direction relative to the surface of the upper wall 26, it is possible to keep the height of the outlet 23 substantially constant even with the operation of the movable lower wall member 25.

If the user blows air from the inlet 22 while the movable lower wall member 25 is set in this position, the air flows through the airway 21 with low resistance and is fed into the resonating chamber 11 rapidly from this narrowly restricted outlet 23.

Therefore, the whistle 1 produces a loud and high-pitched sound.

When the user blows the whistle 1 with a weak blowing force, the whistle 1 produces a sound because the outlet 23 is restricted.

When the user blows the whistle 1 with a strong blowing force, - 11 - the whistle 1 produces a loud sound because the inlet 22 opens wide and the airway 21 becomes gradually narrower toward the outlet 23 so as to allow a smooth flow of air.

Further, because the recessed curved surface 25d positions facing to the air release opening 12, air that is flowed into the resonating chamber 11 is smoothly discharged from the outlet 12, which can prevent the whistle 1 from producing an intermittent sound.

As previously described, the whistle 1 according to this embodiment can produce a stable sound even if the user blows the whistle 1 with a strong blowing force or a weak blowing force.

Further, when the inlet 22 of the airway 21 is opened to set the opening area of the inlet 22 wide, the whistle 1 can produce a loud and highpitched sound and is suitable for calling emergency rescue. For example, the whistle 1 can produce a sound as high frequency as 5 kHz at the peak intensity.

While the present invention has been described with reference to a preferred embodiment thereof, it is to be understood that the invention is not limited thereto, and various changes and modifications may be made without departing from the spirit of the invention.

According to the above described embodiment, the inclination angle of the lower wall of the airway 21 to the upper wall of the airway 21 can be varied by the rotative movement of the movable lower wall member 25. However, as shown in FIG. 4, the inclination angle of the airway 21 may be fixed to a constant angle with a - 12 - lower wall member 27' being integral with the main body 10. Even in this embodiment, if the airway 21 having a substantially rectangular vertical cross section is made such that the height of the inlet 22 (height H2) and the height of the outlet 23 (height Hi) are set in the predetermined range to be defined in the present invention, it is possible to obtain the same advantages of the present invention in that the whistle 1' can produce a sound even with a weak blowing force of the user and also produce a loud and high-pitched sound. As a whistle dedicated for calling emergency rescue, the user can bring the whistle 1' and call a help at an emergency.

Structure for restricting the operation of the movable lower wall member 25 is not limited to the above described embodiment.

For example, as a modified embodiment of FIGS. 5A and 5B, a predetermined number of protrusions 126 may be provided at the rear end of the movable lower wall member 125, while the main body may be provided with a groove 116 for accommodating the protrusions 126 at a position facing to the protrusions 126. In this embodiment, if the whistle is designed such that the protrusions 126 of the movable lower wall member 125 abut on the walls of the groove 116 provided in the main body 115 at a position where the movable lower wall member 125 is fully closed and at a position where the movable lower wall member 125 is fully open, it is possible to appropriately set the rotation range of the movable lower wall member 125.

Further, according to the above described embodiment, the - 13 - lower wall 27 of the airway 21 is movable. However, as seen in FIGS. 6A and 6B, the whistle may be designed such that a lower wall 227 is stationary relative to a main body 215 while an upper wall 226 is rotatable around rotational shafts 226a. Even inthis embodiment, protrusions 226b provided on the upper wall 226 can restrict the position where the upper wall 226 is fully closed as with the above embodiment. To restrict the position where the upper wall 226 is fully open, a protrusion 216 for the abutment with a rear portion of the upper wall 226 may be provided at an inner wall of the resonating chamber 11. In the cases where the upper wall 226 is movable, it is preferable that the air release opening 12 moves integrally with the upper wall 226 such as illustrated in FIGS. 6A and 6B so as to prevent a change in the tone of the sound as well as to prevent an intermittent sound due to manufacturing errors.

It is also possible to combine the movable lower wall member as shown in FIGS. 2A and 2B and the movable upper wall 226 as shown in FIGS. 6A and 6B, so that both of the upper wall and the lower wall can be movable.

Example

Description will be given to an example for verifying operational advantages of the whistle according to the present invention.

With respect to a whistle similar to that described in the above embodiment and having an elongated airway whose vertical - 14 - cross section is substantially rectangular to have a plate-like outer profile, the inlet height and the outlet height of the airway are varied and frequency of the sound produced by the whistle was measured. SoundanalyzerTEs-l358Awasusedtomeasure frequency.

In each test, the frequency corresponding to the peak intensity was plotted in the graph. In this example, width of the airway was set for 10 mm.

FIG. 7 is a graph showing the results of the example, in which the outlet height was set for 0.2 mm, 0.3 mm, 0.5 mm, 1.0 mm, 1.2 mmand 1.5mm, respectively. Thewhistleproduceda stable sound when the outlet height was set in the range of 0.3-1.0 mm.

However, in the cases where the outlet height was 0.2 mm, 1.2 mm and 1.5 mm, the whistle could not produce a sufficiently loud and high-pitched sound.

Further, pluralities of tests were conducted by changing the inlet height in the range of 0.5-4.0 mm. The whistle produced a sound as high as 3 kHz or more when the inlet height was set in the range of 0.8-3.5 mm. Particularly, the whistle produced a loud and high-pitched sound that is greater than 3 kHz when the inlet height was set in the range of 1.0-3.0 mm.

To produce a high-pitched sound that is even higher than 3.5 kHz, for example, it became apparent that the inlet height was set in the range of 2.0-3.0 mm.

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Claims

1. A whistle comprising a main body having a resonating chamber and an air release opening connecting the resonating chamber with an outside, and a mouthpiece having an airway for feeding air to the resonating chamber, whereby the airway has 0.3-1.0 mm height at an outlet communicating with the resonating chamber and 0.8-3.5 mm height at an inlet, and a height of the airway becomes gradually smaller from the inlet to the outlet.

2. A whistle according to claim 1, wherein at least one of an upper wall and a lower wall which form a part of the airway is movable so as to vary an inclination of the airway.

3. A whistle substantially as herein described with reference to FIGS. 1 to 3B of the accompanying drawings or when modified substantially in accordance with FIGS. 4 to 6B of the accompanying drawings.

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