TW201404985A - Acoustic dampening device and installation - Google Patents

Abstract

An acoustic dampening device comprising at least one (1) a shell having a cavity and having a first opening that communicates with the cavity and (2) an acoustic film attached to the shell and substantially spanning the opening, wherein the acoustic film has an array of through holes therein, the shell and acoustic film defining in at least part an active cavity and wherein the device is adapted to be mounted to a support.

Description

Acoustic wave damping device and equipment

The present invention relates to acoustic wave damper devices and apparatus, and more particularly to acoustic wave damper devices utilizing microperforated polymer membranes.

Many chambers (eg, rooms in buildings where people live, work, and gather for other reasons) have less desirable sonic properties. Frequently, ambient sounds (especially when there are many sources) cause louder than desired environmental conditions, resulting in discomfort, fatigue, reduced productivity, and the like.

Acoustic wave damping devices (sometimes referred to as sound absorbers) are widely used in several different applications.

While various configurations are known, a common sound absorber design utilizes one or more layers of fibrous material to dissipate sonic energy. Such fiber-based absorbers may include, for example, glass fiber bundles, open cell polymeric foams, fiber spray materials such as polyurethanes, and acoustical tiles (coagulated fibers and/or granules) substance). These materials permit frictional dissipation of acoustic energy within the interstitial void of the sound absorbing material. While such fiber based absorbers are advantageous (which is advantageous in that they are effective over a wide sound spectrum), they have inherent disadvantages. For example, such sound absorbers can release particulate matter, thereby degrading ambient air quality. In addition, some fiber-based sound absorbers do not possess sufficient heat resistance or fire resistance. It is therefore often limited in application or must undergo additional and sometimes expensive processing to provide the desired heat/fire resistance.

Another type of sound absorbing device utilizes a perforated sheet, such as a perforated phase having a large diameter. For thick metal. These sheets can be used with a reflective surface to provide narrow band sound absorption for relatively tonal sound. Alternatively, such perforated sheets can be used as a cover for covering fiber optic dampers to improve sound absorption over a wider sound spectrum. In addition to its own absorbent properties, perforated sheets are also used to protect the fibrous material. However, such "two-piece" sound absorbers are limited in application due to their cost and relative complexity.

Perforated sheet-based sound absorbers have also been proposed for sound absorption. Conventional perforated sheet-based sound absorbing devices may use relatively thick (eg, greater than 2 mm) and rigid metal or glass perforated sheets or thinner perforated sheets that are externally supported or stiffened by reinforcing strips. The vibration of the sheet is eliminated when subjected to incident sound waves. For example, U.S. Patent No. 5,700,527 (Fuchs) teaches the use of a relatively thick and rigid 2 to 20 mm thick glass or synthetic glass perforated sheet. Fuchs proposes to use a relatively thin sheet of relatively rigid synthetic glass (e.g., 0.2 mm thick) with the proviso that the sheet is reinforced by thickening or adhesive tape so that the incident sound does not cause the sheet to vibrate. In this case, the thin reinforcing sheet is positioned away from the underlying reflective surface.

U.S. Patent No. 6,598,701 (Wood et al.) discloses a shaped microperforated polymer film absorber.

There is a need for improved sonic dampers and equipment.

The present invention provides an acoustic wave dampening device, and in particular, provides an acoustic wave dampening device suitable for use in a room.

Briefly, the acoustic wave damping device of the present invention comprises: (1) a casing having a cavity and having a first opening in communication with the cavity; and (2) an acoustic wave film attached thereto The outer casing and substantially spans the opening. As described herein, the acoustic film has an array of through holes (sometimes referred to as microperforations). The outer casing, together with the acoustic film, or in some embodiments, the outer casing, the acoustic film, and the surface on which the device is mounted together define an active cavity. When installed in accordance with the present invention, the device acts as a Helmholtz resonator to provide the desired Sound wave damping.

The acoustic wave dampening device of the present invention can be made in a variety of configurations and is adapted to provide effective damping or absorption of sound in the frequency range of speech. The device of the present invention provides excellent sonic damping in a wide variety of equipment applications including, for example, offices, classrooms, foyers, town halls, museums, conference rooms, halls, cabs, and the like. In accordance with the present invention, the device as described herein can be mounted to ceilings, walls, doors, floors, partitions, and other support surfaces in a room.

10‧‧‧Sonic damper

12‧‧‧ Shell

14‧‧‧Sonic film

16‧‧‧ cavity

18‧‧‧ first opening

20‧‧‧second opening

22‧‧‧ slotted opening

24‧‧‧ clip

26‧‧‧Foot press surface

60‧‧‧Array

70‧‧‧Array

110‧‧‧ device

112‧‧‧Shell

114‧‧‧Sonic film

120‧‧‧second opening

314‧‧‧Sonic film

810‧‧‧ device

812‧‧‧Shell

814a‧‧‧Sonic film

814b‧‧‧Sonic film

830a‧‧‧ triangle

830b‧‧‧ triangle

832a‧‧‧ triangle

832b‧‧‧ triangle

834a‧‧‧Ladder

834b‧‧‧Ladder

836a‧‧‧Ladder

836b‧‧‧Ladder

1010‧‧‧ device

1012a‧‧‧ Shell

1012b‧‧‧ Shell

1014a‧‧‧Sonic film

1014b‧‧‧Sonic film

1014c‧‧‧Sonic film

1014d‧‧‧Sonic film

1020‧‧‧ panels

The invention is further explained with reference to the drawings, wherein: Figure 1 is a front perspective view of an illustrative embodiment of the acoustic wave dampening device of the present invention; Figure 2 is a perspective view of the back of the device shown in Figure 1; Figure 3a and Figure 3b is a plan view of an illustrative embodiment of a clip that can be used to mount the device of the present invention on a surface; FIG. 4a is a plan view of another embodiment of the acoustic wave dampening device of the present invention; FIG. 4b is a device shown in FIG. 4a Figure 5a is a perspective view of the front side of the outer casing of the acoustic wave damping device of the present invention; Figure 5b is a front perspective view of another embodiment of the acoustic wave damping device of the present invention; A plan view of an array of four acoustic wave damper devices shown in FIGS. 1 and 2; FIG. 7 is a plan view of an array having nine acoustic wave damper devices shown in FIGS. 1 and 2; FIG. 8 is a sound wave of the present invention. A plan view of an acoustic wave film of a portion of another illustrative embodiment of the damping device; FIG. 9 is a side view of the acoustic wave damping device shown in FIG. 8; and FIG. 10 is another illustrative embodiment of the acoustic wave damping device of the present invention of Sectional view.

The figures are not necessarily to scale, and are intended to be illustrative and not limiting.

In general, the acoustic wave damping device of the present invention comprises: (1) a housing having a cavity and having a first opening in communication with the cavity; and (2) an acoustical film attached to the housing And substantially across the first opening, wherein the acoustic film has an array of through holes, the outer casing and the acoustic film at least partially defining an active cavity. Turning to Figures 1 and 2, an illustrative acoustic wave dampening device 10 including a housing 12 and an acoustic diaphragm 14 is shown. The outer casing 12 has a cavity 16 and an opening 18; the acoustic wave film 14 spans the opening 18.

In the embodiment shown in Figures 1 and 2, the outer casing 12 has a hexagonal shape with six substantially equal length sides. The apparatus of the present invention can be fabricated in a wide variety of other rules and irregular geometries as desired. Illustrative examples include circular, elliptical, and right triangles, squares, rectangles, octagons, and the like, such as shown in Figures 4a, 4b, 5a, and 5b. The choice of shape will depend in part on the resulting visual appearance, ease of manufacture, and the like of the device.

In the illustrated embodiment, the portion of the outer casing 12 around the first opening 18 has a lip or flange extending therefrom to provide a surface to which the acoustic wave film 14 can be easily secured. The acoustic film is preferably sealed to a substantially continuous outer casing around the first opening. The film can be bonded to the lip using a suitable adhesive, mechanical attachment (eg, clips, screws, etc.).

In some embodiments of the invention, the outer casing will be substantially completely enclosed around the cavity except for the first opening, which is substantially completely spanned by the acoustical membrane. When installed in a room (for example, mounted on a wall, ceiling, partition, etc.), acoustic energy in the form of a pressure wave in the air will pass through the through hole therein to the cavity when incident on the acoustic film. At the cavity, the acoustic energy will resonate away from the inner surface of the outer casing and the acoustic film until dissipated, resulting in damping of the acoustic energy in the room.

4a and 4b show another embodiment in which the device 110 has a triangular configuration in which the outer casing 112 has three side walls that define a first opening 118 and a second opening 120 that are spanned by the acoustic wave film 114. The second opening 120 will be illuminated by the device 110 when installed for use. Cover the surface to which it is mounted (for example, walls, partitions, doors, or other surfaces). Once installed in a room, the acoustic energy in the form of a pressure wave in the air will pass through the through hole into the cavity when it is incident on the acoustic film. At the cavity, the acoustic energy will resonate away from the outer casing and the acoustic film. The inner surface and the surface to which the device is mounted to the wall, ceiling, partition, etc., until dissipated, results in damping of the acoustic energy in the room.

In some embodiments, the first opening is substantially planar, such as shown in Figures 1, 4a, 5a, and 5b; in other embodiments, it can have a more complex configuration.

For best performance (ie maximum damping effect), the active cavity should be completely surrounded. In some embodiments, this is achieved by the outer casing being substantially continuous (except for the first opening spanned by the acoustic film). In embodiments where the outer casing has one or more second openings, such as the second opening 20 in FIG. 2 and the second opening 120 in FIG. 4b, the device is configured such that one or more second openings are above The surface on which the device is mounted or the support (not shown) (e.g., wall or ceiling) is offset such that the cavity 16 of Figure 2 and the cavity 116 of Figure 4b are completely enclosed or surrounded by the outer casing, the acoustic film, and the surface.

In many embodiments, the device is configured such that the acoustical film is positioned at a distance of from about 0.5 吋 to about 3 距 from the rear surface of the outer casing in the case where the outer casing is completely closed or has one or more of the outer casing connected to the cavity In the example of the second opening, it is positioned at a distance of from about 0.5 吋 to about 3 。 from the surface of the support on which the device is mounted.

If the first opening has a planar configuration, it can be oriented to be substantially parallel to the rear surface of the outer casing or the surface of the support, or it can be oriented at an angle to the surface. In the embodiment shown in FIGS. 1 and 2, the first opening 18 and the acoustic wave film 14 are substantially parallel to the second opening 20. In this embodiment, the device 10 will be mounted on a support surface (not shown) to cover the second opening 20, resulting in the acoustic film 14 being substantially parallel to the support surface. In the embodiment shown in Figures 5a and 5b, the plane of the acoustic film (not shown in Figure 5a, 314 in Figure 5b) will be positioned at an angle to the plane of the respective support surface, due to the outer casing The height of the side walls varies on the z-axis. In Figure 5b, the dimension z _{1 is} smaller than the dimension z ₂ .

The outer casing is preferably constructed such that the device will be dimensionally stable in use, i.e., maintain its desired configuration and shape. In many embodiments, the outer casing can be molded, for example, by injection molding from a suitable plastic such as acrylonitrile butadiene styrene, or other suitable material that can be readily selected by those skilled in the art. .

The microperforated polymer films described in U.S. Patent No. 6,598,701 (Wood et al.) and the methods for producing such films are suitable for use in the present invention.

In general, the acoustic film has a bending stiffness of about 10 ⁷ dyne or less.

In many embodiments, the acoustic film has a thickness of between about 9 and about 35 mils. In some embodiments, the portion of the acoustic film that spans the first opening will have a substantially uniform thickness.

In some embodiments, the through hole or perforation has a diameter that varies between the first major surface and the second major surface. In some examples, the via has a narrowest diameter that is less than the thickness of the film. In some embodiments, the through holes have a maximum diameter of from about 2.0 mils to about 6.0 mils. In some examples, a majority of the plurality of microperforations are wedged between the first major surface and the second major surface of the polymeric film. In some embodiments, a majority of the plurality of microperforations are wedged between the first major surface and the second major surface of the polymeric film, and wherein each of the wedge shaped microperforations has less than a polymeric film therein The narrowest diameter of the thickness at the thickest part.

In some embodiments, the plurality of microperforations are configured to include a pattern having a density of from about 100 to about 4000 per square inch, and in some embodiments, the film has between about 800 and about 1100 vias per square inch. average value.

The apparatus of the present invention can be fabricated in a range of sizes. Typically, the active cavity has a volume of from about 10 cubic feet to about 200 cubic feet.

In order to obtain an improved visual appearance, the apparatus of the present invention may further comprise a sash disposed in front of at least a portion of the acoustical film. For example, a fabric sheet having a selected appearance can be mounted in front of the sonic film. The sash is preferably transparent on the sound waves to achieve the desired visual appearance without affecting the sonic damping performance of the device. Or, the front side of the sonic film can be A visual substance is formed thereon (for example, by printing). These means facilitate the positioning of the device of the present invention in an optimal position without adversely damaging the use of the space. For example, the device can be configured with a sash and used as a visually pleasing back curtain or decoration. In other examples, the sash may have information such that the device or array of devices simultaneously acts as a token, such as presenting an interpretation of a project in the museum.

The sash is fully open to the sound so that it does not unduly interfere with the desired sonic damping function of the device. Typically, the sash (which may be a single layer, multiple layers or composite) will be ventable, for example having a rayls value of from about 100 to at least about 1000.

In some embodiments, the sash may be used substantially only to provide a desired visual appearance or other non-sonic effect. For example, an image or pattern can be provided on the sash. In some cases, the sash may be selected to be engageable with a mechanical fastener (eg, a hook and loop fastener). The sash can be selected to provide other desired properties, such as filtering or trapping dust and other air bearing particles. In order not to adversely interfere with the overall acoustic performance of the device, the composition and construction of the sash will need to be selected to be ventilated. For example, the binder and other layers thereof (such as a support scrim) may be formed with small holes therein, may be coated without reading, may be bonded or unbonded non-woven, etc. to provide desired ventilation Sex.

However, in other embodiments, the sash may be selected to modify the acoustic damping properties of the device as desired.

Typically, the device will be constructed such that the sash can be removed as desired, for example, by a sash having a different appearance, or in the case of a dust-trapping embodiment, for cleaning or replacement by a cleaning component to maintain the desired Sound wave performance.

In a typical application, an array of the present invention having a plurality of acoustic wave devices will be mounted on a support. Figure 6 shows an illustrative array 60 having four hexagonal devices 10 of the present invention configured in a loose configuration. Figure 7 shows another illustrative array 70 having nine hexagonal devices 10 of the present invention in a dense configuration. If desired, the array may include devices configured in spaced apart configurations, but this will tend to reduce the acoustic damping effect available per unit area An array of devices comprising varying shapes can be used.

In a typical application, the device of the present invention will be mounted on a room surface such as a wall, ceiling, furniture panel, room divider, floor, and the like. In a preferred embodiment, the device is removably mounted to facilitate reconfiguration, cleaning, repair, and the like.

The manner in which the device is mounted on the surface will be selected depending in part on the application; suitable components can be easily selected. In the case where the outer casing does not have the second opening, the apparatus of the present invention can be attached to the surface, for example, by a double-sided tape, an adhesive or the like applied to the back or one side of the outer casing, and suspended by a wire or a string or the like. In the example where the outer casing has one or more second openings, as discussed above, the device should be mounted such that the outer casing abuts the surface, preferably substantially completely covering the second opening. As shown in Figures 2, 3a and 3b, the device 10 can include a slotted opening 22 that can be releasably engaged with the clip 24, the clip 24 being adapted, for example, via the use of a hook and loop loops thereof (not shown), such as 3M ^TM Command ^TM binding of adhesive tape (not shown) mounted to a surface. Preferably, the clip 24 is configured to engage the slotted opening 22 such that the presser foot surface 26 of the clip 24 will not protrude beyond the bottom edge of the outer casing 12, 112 such that the outer casing 12, 112 will be surfaced (not shown ) to provide the desired fully enclosed active cavity.

As discussed above, in some embodiments, the outer casing will completely enclose the cavity except for the first opening. In other embodiments, the outer casing will completely enclose the cavity except that the acoustical membrane is provided to the first opening and one or more second openings. In such embodiments, the outer casing completely separates the one or more first openings from the one or more second openings. The device of claim 1 wherein the outer casing is substantially enclosed about the cavity except for the first opening and the at least one second opening, wherein the outer casing separates the first opening from the at least one second opening. When installed in accordance with the present invention (e.g., mounted on a surface of a room such as a wall, partition, or ceiling), one or more second openings will engage the surface. Generally, to maximize the resulting acoustic wave damping effect, preferably, the engagement can be substantially closed, i.e., the edges of the one or more second openings are substantially in contact with the surface. However, in other embodiments, the device may not be positioned so close to the surface, That is, a substantial gap may exist between the surface and the device. In accordance with the present invention, such mounting configurations provide the desired acoustic wave damping benefits, with the constraint that the mounting configuration results in sufficient restraint of the airflow through the gap between the surface and the device such that the cavity defined by the acoustic film, the outer casing and portions of the surface The body can provide Helmholtz resonance. Thus, the apparatus of the present invention can be mounted to a surface, suspended from a ceiling or overhead bracket, etc., in the same manner as conventional wall mounts (e.g., by image hooks).

In some embodiments, for example, as in the illustrative embodiment illustrated in Figures 1, 4a, and 5, the configuration of the portion of the acoustical membrane that spans the first opening is substantially planar.

However, in other embodiments, it may be desirable for the portion of the acoustic film that spans the first opening to be configured to have two or more planar portions. Such configurations may be used to impart a desired visual appearance or to provide an improved acoustically damped potential directional portion of the acoustic film in a changing direction. An illustrative example of this embodiment is shown in Figures 8 and 9. Device 810 has a housing 812 that defines two active cavities, each cavity being substantially traversed substantially entirely by sonic membranes 814a, 814b. The acoustic wave membranes are configured to each have four planar portions, i.e., have two triangles 830a, 830b and 832a, 832b, respectively, and have two trapezoids 834a, 836a and 834b, 836b, respectively.

In some embodiments, the acoustic wave dampening device of the present invention will comprise two or more active cavities oriented in different directions. For example, the acoustic wave dampening device can be assembled into an array having two or more active chambers per array, each active chamber having an acoustic wave membrane as described herein, the chambers being oriented in opposite directions. An illustrative example of this embodiment is shown in FIG. 10, in which device 1010 includes two active cavities 1002 and 1004 oriented toward position A and two active cavities 1006 and 1008 oriented toward position B. In accordance with the present invention, each of the active cavities is partially enclosed by acoustical membranes 1014a, 1014b, 1014c, and 1014d and outer casings 1012a, 1012b. Device 1010 further includes a panel 1020 to which housings 1012a, 1012b are mounted.

In addition to closing the respective active cavities in accordance with the present invention, each cavity will exhibit Helmhol In addition to resonance, it is generally preferred that the panel 1020 be sufficiently strong to support an array of active cavities during installation and during use. For example, the panel 1020 can be strong enough to permit it to be mounted on the top edge of the workspace compartment partition. In some embodiments, the active chambers may be configured in a tight fit (eg, similar to the array shown in FIG. 7) to maximize acoustic damping performance, or they may be configured with gaps between the active chambers (eg, , the array shown in Figure 6). In the latter case, panels 1020 may be open or light transmissive in the region between the active cavities to facilitate light flow or visibility between opposing sides of the device (such as between adjacent cells), as desired. The slate, or panel 1020, may be closed in such areas, for example, to provide additional privacy between opposing sides of the device.

The entire disclosures of the patents, patent documents, and publications herein are hereby incorporated by reference in their entirety in their entirety in their entirety herein

Although the present invention has been fully described in connection with the preferred embodiments of the present invention, it will be understood that Such changes and modifications are to be understood as included within the scope of the invention as defined by the appended claims.

10‧‧‧Sonic damper

12‧‧‧ Shell

14‧‧‧Sonic film

18‧‧‧ first opening

Claims (30)

An acoustic wave damping device comprising: (1) a housing having a cavity and having a first opening in communication with the cavity; and (2) an acoustical membrane attached to the housing and substantially complete Across the opening, wherein the acoustic film has an array of through holes, the outer casing and the acoustic film at least partially defining an active cavity, and wherein the device is adapted to be mounted to a support. The device of claim 1, wherein the first opening is substantially planar. The device of claim 1 wherein the outer casing is substantially enclosed about the cavity except for the first opening. The device of claim 1, wherein the outer casing is substantially enclosed around the cavity except for (1) the first opening and (2) one or more second openings, the one or more second openings The cavity is in communication and positioned such that it faces the support when the device is mounted to the support. The device of claim 1 wherein the film is substantially continuously sealed to the outer casing about the first opening. The device of claim 1, wherein the acoustic film has a bending stiffness of about 10 ⁷ dyne or less. The device of claim 1 wherein the acoustic film has a thickness between about 9 mils and about 35 mils. The device of claim 1, wherein at least a portion of the acoustic film that spans the first opening has a substantially uniform thickness. The device of claim 1, wherein the acoustic film has an auditory depth of from about 0.5 吋 to about 3 。. The device of claim 1, wherein one or more of the plurality of microperforations have a diameter that varies between the first major surface and the second major surface. The device of claim 10, wherein the through holes have a narrowest diameter that is less than one of the film thicknesses. The device of claim 1 wherein the through holes have a maximum diameter of from about 2.0 mils to about 6.0 mils. The device of claim 1, wherein at least one of the plurality of microperforations has a narrowest diameter that is less than a thickness of one of the polymer film at its thickest portion. The device of claim 1, wherein a majority of the plurality of microperforations are wedged between the first major surface and the second major surface of the polymeric film. The device of claim 1, wherein a majority of the plurality of microperforations are wedged between the first major surface and the second major surface of the polymeric film, and wherein each of the wedge shaped microperforations The person has a narrowest diameter that is less than the thickness of the polymer film at one of its thickest portions. The device of claim 1, wherein the microperforations comprise one of the narrowest diameters of about 20 mils or less. The device of claim 1, wherein the plurality of microperforations are configured to comprise a pattern having a density of from about 100 to about 4000 per square inch. The device of claim 1, wherein the film comprises an average between about 800 vias per square inch and about 1100 vias. The device of claim 1, wherein the active cavity has a volume of from about 10 cubic feet to about 200 cubic feet. The device of claim 1, wherein the outer casing is adapted to be removably mounted to a surface. The device of claim 1 further comprising a lacing disposed in front of at least a portion of the acoustical film. The device of claim 1 is mounted on a wall of a room. An array of devices of claim 1 mounted on a wall of a room. The device of claim 1, wherein the outer casing is substantially enclosed about the cavity except for the first opening and the at least one second opening, wherein the outer casing separates the first opening from the at least one second opening. The device of claim 24 is mounted on a surface of a room such that the device can have a Helmholtz resonance effect. The device of claim 1, wherein the portion of the acoustic film that spans the first opening is in a substantially planar configuration. The device of claim 1, wherein the portion of the acoustic film that spans the first opening is configured in one of two or more different planar portions. The device of claim 27, wherein the outer casing is substantially enclosed except for the first opening. A device as claimed in claim 1, comprising two or more active cavities oriented in different directions. The device of claim 29, comprising a panel having a first major side and a second major side, the first side having: (a) at least one (1) outer casing having a cavity and having communication with the cavity a first opening; and (2) an acoustical membrane attached to the outer casing and substantially completely spanning the opening, wherein the acoustical membrane has an array of through holes therein, the outer casing and the acoustic film being at least partially defined An active cavity; and (b) at least one (1) outer casing having a cavity and having a first opening in communication with the cavity; and (2) an acoustical membrane attached to the outer casing and substantially The opening is completely across the opening, wherein the acoustic film has an array of through holes therein, the outer casing and the acoustic film at least partially defining an active cavity.