Electroacoustic driver housing element

Abstract

The present invention provides for a woven mesh element for an electroacoustic driver enclosure, and to an electroacoustic driver enclosure including such an element, wherein the element includes a plurality of mesh layers, and wherein the plurality of layers includes a layer of Dutch weave mesh preferably including a layer of Dutch Twill weave mesh, and in particular wherein the element includes plural layers of cross woven wire mesh and a layer of Dutch weave wire mesh.

Claims

1. A woven mesh element for an enclosure for an electroacoustic driver, the woven mesh element comprising: a plurality of mesh layers sintered together, wherein said plurality of mesh layers includes a layer of Dutch weave mesh, and wherein the plurality of mesh layers includes a plurality of wire mesh layers and only a single layer of Dutch weave mesh.

2. The woven mesh element as claimed in claim 1, wherein said layer of Dutch weave mesh comprises a layer of Dutch Twill weave mesh.

3. The woven mesh element as claimed in claim 1, wherein said plurality of mesh layers comprises woven wire mesh layers.

4. The woven mesh element as claimed in claim 1, wherein the Dutch weave mesh comprises a metal mesh.

5. The woven mesh element as claimed in claim 1, wherein the plurality of mesh layers includes a layer of cross woven mesh.

6. The woven mesh element as claimed in claim 5, wherein the plurality of mesh layers includes a plurality of layers of cross weave mesh.

7. The woven mesh element as claimed in claim 6, wherein the plurality of mesh layers includes a single layer of Dutch weave mesh.

8. The woven mesh element as claimed in claim 1, wherein the layer of Dutch weave comprises an outer layer of the woven mesh element.

9. The woven mesh element as claimed in claim 1, wherein the layer of Dutch weave comprises an inner layer of the woven mesh element.

10. The woven mesh element as claimed in claim 1, further comprising a flame arrester.

11. The enclosure for the electroacoustic driver, wherein the enclosure includes the woven mesh element as claimed in claim 1.

12. The enclosure as claimed in claim 11, wherein the enclosure is flame-proof and/or explosion-proof.

13. A loudspeaker or sounder including the enclosure as claimed in claim 11.

14. An element of an enclosure of an electroacoustic driver comprising: a plurality of mesh layers sintered together, wherein said plurality of mesh layers includes a layer of Dutch weave mesh, and wherein the plurality of mesh layers includes a plurality of wire mesh layers and only a single layer of Dutch weave mesh.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is described further hereinafter, by way of example only, with reference to the accompanying drawings in which:

(2) FIG. 1 is a schematic sectional view of an explosion-proof loudspeaker according to an embodiment of the present invention;

(3) FIG. 2 is a schematic sectional view of one example of a sintered housing element such as employed in the loudspeaker of FIG. 1, and according to an embodiment of the present invention; and

(4) FIG. 3 is a schematic sectional view of another example of a sintered housing element such as employed in the loudspeaker of FIG. 1, and according to another embodiment of the present invention

DETAILED DESCRIPTION

(5) Turning first to FIG. 1, there is illustrated a sounder/speaker assembly 10 comprising a housing 12 enclosing an internal volume 14 in which there is located an electroacoustic driver 16 comprising a relatively large permanent magnetic 18, a voice coil 20 mounted to a diaphragm 22. The driver and diaphragm are arranged to supply, in response to an audio signal at the positive/negative terminals 23, audible sound waves arranged to exit the housing 12 by way of an opening 24. Beyond the opening 24 on the outside of the housing 12 is a frusto-conical outer horn 26 serving to acoustically couple the output audible signal.

(6) In order to provide sufficient sealing of the housing 12, so as to effectively isolate it from the external environment and so prevent any internal explosion event within the internal volume 14 from travelling to the external environment, a flat disk-like sintered metal element 28 is provided and serving to close the opening 24 and offer the required isolation between the enclosure internal volume 14 and the hazardous environment external to the housing 12. In particular, the sintered metal element 28 is provided to quench a flame of an internal explosion and comprises a metal mesh sinter.

(7) The sound waves created by the driver 16 can however pass through this sintered element 28 and onward via the outer horn 26 although a degree of attenuation occurs at the sintered element 28. Such attenuation can, to some extent, be compensated for by an overly large and expensive driver 16 and associated magnet 18.

(8) Within the illustrated example of FIG. 1, the sintered element 28 comprises a plurality of layers of wire mesh 28A sintered together so as to form the sintered element 28 and, as required by the present invention, employing as one of the layers, a layer of Dutch weave mesh.

(9) Further details of the sintered element 28 of the present invention according to the embodiment of FIG. 1 are illustrated with reference to FIGS. 2 and 3.

(10) Turning therefore to FIG. 2, there is provided a sectional view of the sintered element 28 employed within the housing 12 of FIG. 1 and which, as noted, comprises a plurality of wire mesh layers 28A sintered together.

(11) Although in no way limited to the present invention, within the illustrated embodiment the multi-layered sintered element 28 includes a single layer 30 of Dutch weave mesh which in the illustrated example comprises a single layer of industry standard Dutch twill weave 30×250 uM mesh, 0.0075′ wire diameter, which can also be referred to as micromesh. The remaining (9 in the illustrated example) layers are each formed of industry standard cross weave wire mesh, which in the illustrated example can comprise 60×60 uM mesh, 0.0075′ wire diameter.

(12) As illustrated with reference to FIG. 2, in this particular example, the layer of Dutch twill weave mesh is provided within the body, and generally within a central region, of the multi-layered sintered element 28.

(13) However, other locations for the layer of Dutch twill weave mesh are available such as illustrated with reference to FIG. 3.

(14) Here, it can be seen that the single layer 32 of Dutch twill weave mesh is provided on, and forming part of, an outer surface of the sintered element 28.

(15) As will be appreciated from reference to the illustrated examples of the present invention in particular, the element of the present invention proves advantageous insofar as it can prevent the ingress of dust due to the presence of the layer of Dutch twill weave mesh thereby meeting the required standards for explosive dust hazardous areas. However, insofar as the remainder of the sinter element is provided by layers of industry standard cross weave wire mesh the overall porosity to sound of the sintered element 28 is limited only to a minor, and readily acceptable, degree.

(16) The overall layered structure therefore acts an effective flame arrester for explosive gas atmospheres, while being sufficiently porous to sound, but with the added feature of preventing the ingress of dust as noted above.

(17) The combination of mesh types as employed within the present invention therefore provides for a sintered element offering sufficient porosity to sound along with effective flame arrester capabilities and while preventing the ingress of dust when located in explosive dust environments.

(18) It should be appreciated that the embodiments illustrated with reference to the accompanying Figures are only some of the possible examples of the present invention and which is therefore not limited to the details of the illustrated embodiments. For example, the sintered element can be formed of any required number of layers of mesh material which could comprise two or more different types of mesh. Also, if required, more than one layer of Dutch twill woven mesh could be provided within the sintered element 28 and the overall shape and configuration of the sintered element is in no way restricted to that as illustrated in the accompanying drawings.

(19) Also, reference to a loudspeaker and sounder are intended to encompass an electroacoustic transducer-based device for outputting any form of audible sound wave or signal.