AU2004101069B4

AU2004101069B4 - Communication apparatus and helmet

Info

Publication number: AU2004101069B4
Application number: AU2004101069A
Authority: AU
Inventors: Stephen Alfred Miranda
Original assignee: Innotech Pty Ltd
Current assignee: Innotech Pty Ltd
Priority date: 2002-09-11
Filing date: 2004-12-21
Publication date: 2005-08-18
Anticipated expiration: 2011-04-23
Also published as: AU2004101069A4

Description

COMMUNICATION APPARATUS AND HELMET FIELD OF THE INVENTION The present invention is concerned with improved means for facilitating communication by workers in noisy and hazardous environments. In particular, this invention relates to a communication apparatus and a helmet that incorporates a communication apparatus.

BACKGROUND TO THE INVENTION A problem that is particularly faced by workers, such as fire-fighters, in noisy and often hazardous environments, is that it is difficult to communicate clearly with fellow workers and other parties when wearing apparatus such as helmets and breathing masks. Several approaches to this problem are described in the prior art. For example. in Japanese Patent Application publication No. JP 11215581-A to Temco Japan Co. Ltd, there is described a bone conduction headset suitable for mounting under a helmet. The bone conduction microphone is mounted on the top of the head. Such an apparatus is believed to be potentially dangerous. If a load falls upon a wearer of the apparatus the bone conduction microphone may depress the wearer's skull. Other approaches to facilitating communication have involved the use of headphones which cover the ears. While such an approach allows the wearer readily to hear sound from the headphones, it prevents the wearer from hearing ambient noise and engaging in direct communication with those nearby.

Where personnel operate in high ambient noise environments there may be a need for hearing protection to be used. However, the use of hearing protection typically interferes with the provision of clear communication.

A further problem that is faced in providing a communication means for

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ofirefighters is that the communication means may be damaged by water used by the firefighters in the course of their work.

o It is an objective of the present invention to provide means for addressing the above described problems.

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SUMMARY OF THE INVENTION oAccording to a first aspect of the invention, there is provided a communication apparatus that includes oa bone-based vibration conduction microphone that is mountable on a strap of an article of headgear such that when the article is worn, the microphone bears against a side of a wearer's head; and a bone-based sound conduction assembly having a vibration conduction means that is mountable on the strap and is configured to cause sound conduction through bone, the sound conduction assembly being mountable on the strap such that when the headgear is worn, the vibration conduction means bears against a side of a wearer's head.

Both the sound conduction assembly and the microphone may have a housing that defines openings that are configured to permit the strap to be threaded through the openings According to a second aspect of the invention, there is provided a communication apparatus that includes a bone-based vibration conduction microphone that is mountable on a strap of an article of headgear such that when the headgear is worn, the microphone bears against a side of a user's head; and a bone-based sound conduction assembly that is mounted on the strap, the sound conduction assembly including a housing, a speaker mounted in the housing and an acoustically transparent cover mounted on the housing to cover the speaker, the cover being oriented to bear against the side of the user's head, spaced from the user's ear, when the headgear is worn.

The vibration conduction microphone may include a transducer mounted in the 0 ohousing.

-4 According to a third aspect of the invention there is provided a vibration oconduction microphone that includes: a transducer; an acoustic isolator disposed about the transducer; and a housing.

SPreferably the acoustic isolator includes a visco-elastic material. Preferably the 0 o acoustic isolator further includes a holder for holding the visco-elastic material.

In a preferred embodiment the transducer comprises an accelerometer.

In one embodiment the housing is a flexible body of, for example, urethane, configured to receive the accelerometer, acoustic isolator and holder.

The housing may include a mounting means. The mounting means may be configured to receive a strap, belt or the like.

According to a fourth aspect of the present invention there is provided a helmet mounting, including transducing means consisting of a vibration conduction microphone and/or a sound conduction assembly; wherein the transducing means is mounted on a component of the helmet so that in use the transducing means makes contact with a wearer's head, below a crown of the wearer's head.

Preferably the helmet mounting includes both the vibration conduction microphone and the sound conduction assembly.

The transducing means may be conveniently mounted to, or suspended from, an internal headband or nape strap of the helmet.

The helmet mounting may be provided in combination with a helmet or 0 oalternatively it may be provided separately for retrofitting to a helmet.

According to a fifth aspect of the invention, there is provided a bone-based osound conduction assembly that includes a housing; and a vibration conduction means arranged on the housing, the housing o 10 being mountable on a strap of an article of headgear such that, when the oheadgear is worn, the vibration conduction means bears against a side of a wearer's head.

0 The sound conduction assembly may include a housing disposed about a speaker, the housing defining at least one opening. A resilient diaphragm may be attached to the housing for making contact with the side of the wearer's head. A membrane may seal the at least one opening thereby shielding the speaker from water.

The housing may define first and second openings. The resilient diaphragm may seal the first opening for contact with the head of the wearer and the second opening may be sealed by the waterproof membrane.

Preferably the second opening is protected by an acoustically transparent cover.

A speaker may be positioned in the housing. A cone of the speaker may face the membrane and the acoustically transparent cover.

The housing may be dimensioned so that energy transfer from the speaker to the wearer via the resilient diaphragm is maximised.

An electrical cable is typically coupled to the speaker.

o Preferably the housing includes an aperture and the electrical cable passes through the aperture. It is desirable that the aperture be filled with a sealant.

Preferably the sealant provides strain relief to the electrical cable.

A transducer may be located inside the housing adjacent to the resilient diaphragm so that the assembly can be used to pick-up vibrations from a wearer as well as to transfer vibrations to the wearer. Preferably the transducer ois an accelerometer.

0 oThe accelerometer is preferably acoustically insulated, for example by means of a visco-elastic layer. A spacer may be attached between the visco-elastic layer and the speaker.

According to a sixth aspect of the invention, there is provided a bone-based sound conduction assembly that includes a speaker assembly that is mountable on a strap of an article of headgear, the speaker assembly including a housing, a speaker mounted on the housing and an acoustically transparent cover mounted on the housing to cover the speaker, the cover being oriented also to bear against the side of the user's head, spaced from the user's ear, when the headgear is worn.

According to a seventh aspect of the invention, there is provided a helmet that includes a protective shell; straps in the shell for engaging a wearer's head; a bone-based vibration conduction microphone mounted on one of the straps such that when the helmet is worn the microphone bears against a side of a user's head; and a bone-based sound conduction assembly having a vibration conduction means and mounted on one of the straps such that when the helmet is worn the vibration conduction means bears against a side of a wearer's head.

0 o Both the vibration conduction microphone and the sound conduction assembly may be waterproof.

oOther preferred features of the invention will be apparent from the following detailed description wherein the invention will be explained in relation to a number of exemplary drawings.

Va In order that this invention may be more readily understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate typical preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a first perspective view of a sound conduction assembly according to an embodiment of an aspect of the invention.

Figure 2 is a second perspective view of the sound conduction assembly of Figure 1.

Figure 3 is a plan view of the assembly of Figures 1 and 2.

Figure 3A is a cross-sectional view of the assembly of Figures 1 and 2.

Figure 4 is a perspective view of a sound conduction assembly according to a further embodiment of the invention.

Figure 5 is a plan view of the assembly of Figure 4 Figure 5A is a cross-sectional view of the assembly of Figures 4 and Figure 6 is a first perspective view of a vibration conduction microphone according to an embodiment of another aspect of the present invention.

Figure 7 is a second perspective view of the vibration conduction microphone of Figure 6.

Figure 8 is a plan view of the vibration conduction microphone of Figures 6 and 7.

Figure 8A is a cross-sectional view of the vibration conduction microphone of Figures 6 and 7.

Figure 9 depicts a use of the assembly of Figure 1 and the vibration conduction microphone of Figure 6.

Figure 10 is a front perspective view of a communication apparatus according to a further aspect of the invention.

Figure 11 is a rear perspective view of the communication apparatus of Figure Figure 12 is a plan view of the communication apparatus of Figure Figure 12A is a cross-sectional view of a sound conduction assembly of the communication apparatus of Figure Figure 12B is a cross-sectional view of a vibration conduction microphone of the communication apparatus of Figure Figure 13 is an external view of a helmet, in accordance with the invention.

Figure 14 is an interior view of the helmet showing the position of the communication apparatus of Figure DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Figure 1 is a perspective view of a first side of a sound conduction assembly according to a preferred embodiment of the present invention. The assembly includes a housing 2 which incorporates a mounting means in the form of slots 3 arranged for securing the assembly 50 to a component of a helmet such as a belt, strap or the like. A cover in the form of a grill 4 covers one end of the housing 2. The grill 4 is acoustically transparent due to a number of perforations that allow the escape of sound from a speaker located in the housing 2. A cable 6 protrudes through a port 7 formed in the housing 2. The cable 6 is connected to the speaker located in the housing 2 as explained below.

Figure 2 is a further perspective view of the assembly 50 showing a diaphragm 8 which is incorporated into the housing 2 opposite the grill 4. Figure 3A is a cross-section through the assembly 50 showing an internally located speaker 9 with a cone 10 facing the grill 4 as shown. A waterproof membrane 11 is located between the cone 10 and the grill 4. The port 7 is sealed with a waterproof sealant 12 which surrounds the cable 6 and provides strain relief to the cable 6.

It will be realised that the inside of the assembly 50 is waterproofed by virtue of the membrane 11, the diaphragm 8 and the sealant 12.

In use, the assembly 50 is mounted to the side of a head of a wearer, by means of a band or strap through the slots 3, so that the diaphragm 8 is brought into contact with the side of the head but preferably not over the ear. An electrical signal from some communication source, for example a walkie-talkie radio, is applied by means of the cable 6 to the speaker 9. In response, the speaker cone 10 vibrates so that sound may be heard emanating from the grill 4.

Simultaneously, the diaphragm 8 vibrates against the side of the head thereby causing sound conduction through the skull and allowing the wearer to perceive communication. The depth of the housing 2, indicated by dimension D in Figure 3A, is tuned to maximise the coupling of energy from the speaker 9 into the wearer's head via the diaphragm 8.

Figure 4 is a perspective view of a sound conduction assembly 52 according to a further embodiment of the invention. With reference to figures 1 to 3A, like reference numerals refer to like parts, unless otherwise specified.

Figure 5A is a cross-section of the assembly 52. An acoustic isolator 13, which preferably includes a visco-elastic material such as Sorbothane@, surrounds a transducer in the form of an accelerometer 14. A preferred accelerometer is the Knowles Corporation's 1771 single axis accelerometer. The acoustic isolator 13 further includes a transducer cup 15 which anchors the visco-elastic material and which is secured to the rear of a speaker 16. A cable 17 from the accelerometer 14 runs out through a port 18 along with the cable 17 from the speaker 16. A resilient diaphragm 19 forms part of the housing 2, as before. In use, the resilient diaphragm 19 is placed against a wearer's head. In order to transmit a voice signal to the wearer, the speaker 16 is appropriately energised.

Vibrations from the speaker 16 are transmitted via the resilient diaphragm 19 into the head of the wearer thereby causing the person to perceive the voice signal via bone-based sound conduction. Sound waves generated by the speaker 16 also emanate out through a membrane 20 and a grill 21 and are heard by the wearer in the normal way. Conversely when the wearer speaks vibrations pass through the resilient diaphragm 19, are picked up by the accelerometer 14 and transduced into an electrical signal that is conveyed by the cable 17 for further processing. The accelerometer 14 is prevented from picking-up spurious external sounds by the acoustic isolator 13.

Figure 6 is a perspective view of a bone-based vibration conduction microphone 54 according to a preferred embodiment of a further aspect of the present invention. Figure 7 is a second perspective view of the vibration conduction microphone 54, Figure 8A is a cross-sectional view of the vibration conduction microphone 54.

A housing 22 has slots 23 for receiving a strap or belt fdr mounting the microphone 54 to the head of a wearer. The housing 22 also incorporates a diaphragm 24. Preferably the housing 22 is a flexible body of, for example, urethane. The housing 22 defines a recess 26.

An acoustic isolator 25 which includes a visco-elastic material such as Sorbothane, surrounds a transducer in the form of an accelerometer 27. A preferred accelerometer is the Knowles Corporation's 1771 single axis accelerometer. The acoustic isolator 25 is a transducer holder in the form of a cup 28 which is secured into the recess 26 by means of waterproof sealant (not shown). A cable 29 protrudes through a port 30 formed in the housing 22. The cable 29 is connected to the accelerometer 27 for conveying electrical signals generated by the accelerometer 27 during use for processing. A flexible waterproof sealant 31 seals the port 30. It will be realised that the inside of the housing 22 is waterproofed by virtue of diaphragm 24 and sealant 31.

In use, the vibration conduction microphone 54 is secured to the head of a wearer by threading a belt or strap through slots 23 and securing it with the diaphragm 24 against the wearer's head. As the wearer speaks, vibrations corresponding to the speech are produced and these are conveyed to the accelerometer 27 which converts them into electrical signals that are conveyed by the cable 29 for processing by suitable electronic circuitry.

Figure 9 shows a person 32 wearing a typical breathing apparatus mask 33 that includes a number of straps 34 and 35. Attached to the strap 34 is a vibration conduction microphone 36, similar to that of Figure 6. Attached to the strap is a sound conduction assembly 38 similar to that of Figure A cable 37 from the microphone 54 and the assembly 38 is connected to suitable electronic communication modules.

The communication modules may include signal-conditioning circuitry such as filters to improve the clarity of the communications. It will be noted that the wearer's ear 39 is not covered by the assembly 38 so that the wearer may readily hear ambient sound or wear hearing protection in areas of high ambient noise.

Figure 10 is a first perspective view of a communication apparatus 56 in accordance with a further aspect of the present invention. Figure 11 is a second perspective view of the communication apparatus 56. Figure 12A is a crosssectional view of a sound conduction assembly 43 of the apparatus 56. The assembly 43 is similar to the assembly 50. Figure 12B is a cross-sectional view of a vibration conduction microphone 42 of the apparatus 56. The vibration conduction microphone 42 is similar to the microphone 54. It follows that, with reference to Figures 1 to 9, like reference numerals refer to like parts, unless otherwise specified.

The communication apparatus 56 includes a support structure 41 (shown as a helmet mount in Figure 14). As can be seen in Figures 10 to 12, the assembly 43 and the microphone 42 are positioned in the support structure 41.

Figure 13 is an external view of a helmet 58, also in accordance with the invention, suitable for use by, for example, fire fighters. Figure 14 is a view of the interior of the helmet 58 showing a position of the communication apparatus 56 of Figure The communication apparatus 56 is suspended from a strap 40 of the helmet 58. The support structure 41 is configured to be connected to the strap 40. The assembly 43 and the microphone 42 are positioned on the support structure 41 so that the diaphragm 24 of the vibration conduction microphone 42 and the diaphragm 8 of the assembly 43 make contact with the wearer's head.

The inventors have discovered that the vibration conduction microphone and/or the sound conduction assembly may be located away from the top of the head.

As discussed previously, this location is in contrast to prior art approaches which mount bone conduction transducers at the top of the head which is a potentially dangerous position. As is also the case with the arrangement depicted in Figure 14, the wearer's ear is not covered by the sound conduction assembly so that the wearer may readily hear ambient sound or wear hearing protection in areas of high ambient noise. The inventors have discovered that a sound conduction assembly and/or bone conduction microphone according to the invention works well when mounted on a strap of a helmet.

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o The embodiments of the invention described herein are provided for purposes o of explaining the principles thereof, and are not to be considered as limiting or restricting the invention since many modifications may be made by the exercise of skill in the art without departing from the scope of the invention.

Claims

2. A communication apparatus as claimed in claim 1, in which both the sound conduction assembly and the microphone have housings that define openings that are configured to permit the strap to be threaded through the openings.
3. A communication apparatus that includes a bone-based vibration conduction microphone that is mountable on a strap of an article of headgear such that when the headgear is worn, the microphone bears against a side of a user's head; and a bone-based sound conduction assembly that is mountable on the strap, the sound conduction assembly including a housing, a speaker mounted in the housing, an acoustically transparent cover mounted on the housing to cover the speaker and a protective element interposed between the cover and the speaker to protect the speaker, the cover being oriented also to bear against the side of the user's head, spaced from the user's ear, when the headgear is worn.
4. A bone-based sound conduction assembly that includes a bone-based sound conduction assembly that is mountable on a strap of an article of headgear, the sound conduction assembly including a housing, a O speaker mounted on the housing, an acoustically transparent cover mounted on N the housing to cover the speaker and a protective element interposed between S the cover and the speaker to protect the speaker, the cover being oriented to bear against the side of the user's head, spaced from the user's ear, when the headgear is worn. A helmet that includes 0 Sa protective shell; 0 Sa headband mounted in the shell; o 10 a bone-based vibration conduction microphone mounted on the 0 'N headband; and a bone-based sound conduction assembly having a vibration conduction means for bone-based sound conduction mounted on the headband. Dated this 4 th day of July 2005 Innotech Pty Ltd By my attorneys Eagar Buck