Classifications

• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
  • E04B1/00—Constructions in general; Structures which are not restricted either to walls, e.g. partitions, or floors or ceilings or roofs
  • E04B1/62—Insulation or other protection; Elements or use of specified material therefor
  • E04B1/74—Heat, sound or noise insulation, absorption, or reflection; Other building methods affording favourable thermal or acoustical conditions, e.g. accumulating of heat within walls
  • E04B1/82—Heat, sound or noise insulation, absorption, or reflection; Other building methods affording favourable thermal or acoustical conditions, e.g. accumulating of heat within walls specifically with respect to sound only
  • E04B1/84—Sound-absorbing elements
  • E04B1/86—Sound-absorbing elements slab-shaped
• • G—PHYSICS
  • G10—MUSICAL INSTRUMENTS; ACOUSTICS
  • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
  • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
  • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
  • G10K11/172—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using resonance effects
• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
  • E04B1/00—Constructions in general; Structures which are not restricted either to walls, e.g. partitions, or floors or ceilings or roofs
  • E04B1/62—Insulation or other protection; Elements or use of specified material therefor
  • E04B1/74—Heat, sound or noise insulation, absorption, or reflection; Other building methods affording favourable thermal or acoustical conditions, e.g. accumulating of heat within walls
  • E04B1/82—Heat, sound or noise insulation, absorption, or reflection; Other building methods affording favourable thermal or acoustical conditions, e.g. accumulating of heat within walls specifically with respect to sound only
  • E04B2001/8263—Mounting of acoustical elements on supporting structure, e.g. framework or wall surface
  • E04B2001/8272—Resiliently mounted wall cladding acting as a diaphragmatic sound damper
• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
  • E04B1/00—Constructions in general; Structures which are not restricted either to walls, e.g. partitions, or floors or ceilings or roofs
  • E04B1/62—Insulation or other protection; Elements or use of specified material therefor
  • E04B1/74—Heat, sound or noise insulation, absorption, or reflection; Other building methods affording favourable thermal or acoustical conditions, e.g. accumulating of heat within walls
  • E04B1/82—Heat, sound or noise insulation, absorption, or reflection; Other building methods affording favourable thermal or acoustical conditions, e.g. accumulating of heat within walls specifically with respect to sound only
  • E04B1/84—Sound-absorbing elements
  • E04B2001/8423—Tray or frame type panels or blocks, with or without acoustical filling
  • E04B2001/8452—Tray or frame type panels or blocks, with or without acoustical filling with peripheral frame members

Definitions

• This invention relates to acoustic damping devices and installations, in particular, acoustic damping devices utilizing microperforated polymeric films.
• Acoustic damping devices sometimes referred to as sound absorbers, are in widespread use in a number of different applications.
• one common sound absorber design utilizes one or more layers of fibrous material to dissipate sound wave energy.
• fiber-based absorbers may include, for example, fiberglass strands, open-cell polymeric foams, fibrous spray-on materials such as polyurethanes, and acoustic tiles (agglomerated fibrous and/or particulate matter). These materials permit the frictional dissipation of sound energy within the interstitial voids of the sound absorbing material.
• fiber-based absorbers are advantageous in that they are effective over a broad acoustic spectrum, they have inherent disadvantages. For instance, these sound absorbers can release particulate matter, degrading the surrounding air quality.
• some fiber-based sound absorbers do not possess sufficient resistance to heat or fire. They are therefore often limited in application or, alternatively, must undergo additional and sometimes costly treatment to provide desirable heat/flame resistance.
• Another type of sound absorber utilizes perforated sheets, such as relatively thick metal having perforations of large diameter. These sheets may be used alone with a reflective surface to provide narrow band sound absorption for relatively tonal sounds. Alternatively, these perforated sheets may be used as a facing overlying a fibrous sound absorber to improve sound absorption over a wider acoustic spectrum. In addition to their own absorbing properties, the perforated sheets also serve to protect the fiber-material. However, these "two-piece" sound absorbers are limited in application due to their cost and relative complexity.
• Conventional perforated, sheet-based sound absorbers may use either relatively thick (e.g., greater than 2 mm) and stiff perforated sheets of metal or glass or thinner perforated sheets which are externally supported or stiffened with reinforcing strips to eliminate vibration of the sheet when subject to incident sound waves.
• US Patent No. 5,700,527 (Fuchs), for example, teaches a sound absorber using relatively thick and stiff perforated sheets of 2 to 20 mm thick glass or synthetic glass. Fuchs suggests using thinner sheets (e.g., 0.2 mm thick) of relatively stiff synthetic glass provided that the sheets are reinforced with thickening or glued-on strips in such a manner that incident sound cannot cause the sheets to vibrate. In this case, the thin, reinforced sheet is positioned away from an underlying reflective surface.
• US Patent No. 6,598,701 (Wood et al.) discloses shaped microperforated polymeric film sound absorbers.
• the invention provides acoustic damping devices, in particular, acoustic damping devices that are well suited for use in rooms.
• acoustic damping devices of the invention comprise (1) a shell having a cavity, i.e., an acoustic active cavity or Helmholtz cavity, and having at least one first opening that communicates with the cavity and (2) an acoustic film attached to the shell and substantially spanning the opening.
• the acoustic film has an array of through holes, sometimes referred to as
• the device When installed in accordance with the invention, the device functions as a Helmholtz resonator, providing desired acoustic damping.
• Acoustic damping devices of the invention can be made in a variety of configurations and are well suited for providing effective damping or absorption of sound in the frequency range of voices.
• Devices of the invention can provide superior acoustic damping in a myriad of installation applications, including, for example, offices, class rooms, hallways, auditoriums, museums, conference rooms, great halls, cubicles, etc.
• devices as described herein may be installed on ceilings, walls, doors, floors, partitions, and other supporting surfaces in rooms.
• Fig. 1 is a perspective view of the front of an illustrative embodiment of an acoustic damping device of the invention
• Fig. 2 is a perspective view of the rear of the device shown in Fig. 1 ;
• Figs. 3a and 3b are plan views of an illustrative embodiment of a clip that can be used to mount devices of the invention on a surface;
• Fig. 4a is a plan view of another embodiment of an acoustic damping device of the invention
• Fig. 4b is a plan view of the rear of device shown in Fig. 4a;
• Fig. 5a is a perspective view of the front of the shell of still another embodiment of an acoustic damping device of the invention
• Fig. 5b is a perspective view of the front of still another embodiment of an acoustic damping device of the invention
• Fig. 6 is a plan view of an array of four of the acoustic damping devices shown in Figs. 1 and 2;
• Fig. 7 is a plan view of an array of nine of the acoustic damping devices shown in Figs. 1 and 2;
• Fig. 8 is a plan view of the acoustic film of a portion of another illustrative embodiment of an acoustic damping device of the invention.
• Fig. 9 is a side view of the acoustic damping device shown in Fig. 8.
• Fig. 10 is a cross-sectional view of another illustrative embodiment of an acoustic damping device of the invention.
• Fig. 1 1 is a plan view of the front face of an illustrative acoustic damping device of the invention configured as a wall hanging;
• Fig. 12 is a plan view of the front face of the acoustic damping device shown in Fig. 1 1 with the fascia removed;
• Fig. 13 is a plan view of the back side of the device shown in Fig. 1 1 ;
• Fig. 14 is a plan view of a side of the device shown in Fig. 1 1 ;
• Fig. 15 is a plan view of a frame or casing of an illustrative acoustic device of the invention. These figures are not to scale and are intended to be merely illustrative and not limiting.
• an acoustic damping device of the invention comprises (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 first 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.
• a acoustic damping device 10 comprising shell 12 and acoustic film 14 is shown.
• Shell 12 has a cavity 16 and an opening 18; acoustic film 14 spans opening 18.
• first opening refers to an opening in the shell that communicates with the cavity and which, in accordance with the invention, will be substantially spanned or covered by an acoustic film as described herein.
• first opening will typically be oriented to face broadly the directions from which sound energy whose attenuation is desired will be incident from.
• second opening refers to an opening in the shell that communicates with the cavity but which is not a "first opening”.
• the second opening(s) will typically be oriented toward a supporting surface, e.g., a wall.
• shell 12 has a hexagonal shape with six, substantially equal length sides.
• Devices of the invention can be made in a myriad of other regular and irregular geometric shapes as desired. Illustrative examples include circles, ovals, and right triangles such as shown in Figs. 4a, 4b, 5a, and 5b, squares, rectangles, octagons, etc. Selection of the shape will be dependent in part upon resultant visual appearance of the device, manufacturing ease, etc.
• the portion of shell 12 around the first opening 18 has lip or flange extending therefrom to provide a surface to which acoustic film 14 can be readily secured.
• the acoustic film is preferably sealed to the shell substantially continuously around the first opening.
• the film can be bonded to the lip using suitable adhesive, mechanical attachment, e.g., clips, screws, staples, etc.
• the acoustic film is secured under tension to avoid bagging and oil canning which affects acoustic performance in the use of the device.
• the fabric or printable layer should be securely attached for appearance as well as acoustic performance overlaying the perforated film.
• the shell will substantially completely close about the cavity but for the first opening, which is substantially completely spanned by the acoustic film.
• acoustic energy in the form of pressure waves in the air when incident to the acoustic film will pass through the through holes therein into the cavity where they will resonate off the inner surfaces of the shell and acoustic film, until dissipating, resulting in damping of the acoustic energy in the room.
• Figs. 4a and 4b show in another embodiment in which device 1 10 has a triangular configuration in which shell 1 12 has third side walls defining first opening 1 18 which is spanned by acoustic film 114 and second opening 120.
• second opening 120 will be covered by the surface to which device 1 10 is mounted, e.g., a wall, partition, door, or other surface.
• acoustic energy in the form of pressure waves in the air when incident to the acoustic film will pass through the through holes therein into the cavity where they will resonate off the inner surfaces of the shell and acoustic film, and the surface of the wall, ceiling, partition, etc. to which the device is mounted, until dissipating, resulting in damping of the acoustic energy in the room.
• the first opening is substantially planar, e.g., as shown in Figs. 1, 4a, 5a, and 5b; in other embodiments it may be of more complex configuration.
• the active cavity should be completely surrounded. In some embodiments, this is achieved with the shell being substantially continuous but for the first opening which is spanned by the acoustic film.
• the shell has one or more second openings, such as second opening 20 in Fig. 2 and second opening 120 in Fig. 4b
• the device is configured such that the one or more second openings are seated against the surface or support (not shown) on which the device is mounted, e.g., a wall or ceiling, such that the cavity 16 in Fig. 2 and cavity 116 in Fig. 4b is completely closed or surrounded by the shell, the acoustic film, and the surface.
• the device is configured such that the acoustic film is positioned at a distance about 0.5 to about 3 inches from the rear surface of the shell in instances where the shell is fully closed or from the surface of the support on which the device is mounted in instances where the shell has one or more second openings that communicate with the cavity.
• first opening is of planar configuration, it may be oriented to be substantially parallel to the rear surface of the shell or support surface, respectively, or it may be oriented at an angle thereto.
• first opening 18 and acoustic film 14 are substantially parallel to second opening 20.
• the device 10 will be mounted on a support surface (not shown) so as to cover second opening 20, resulting in acoustic film 14 being substantially parallel thereto.
• the planes of acoustic films (not shown in Fig. 5a, 314 in Fig. 5b) will be positioned at an angle to the plane of the respective support surfaces because the height of the side walls of the shells are varied in the z-axis.
• dimension zi is less than dimension z 2 .
• the shell is preferably constructed such that device will be dimensionally stable in use, i.e., maintaining its desired configuration and shape.
• the shell can be molded, e.g., via injection molding, of suitable plastic such as acrylonitrile-butadiene-styrene, or other suitable material which can be readily selected by one skilled in the art.
• microperforated, polymeric films, and methods for producing such films described in US Patent No. 6,598,701 (Wood et al.) are well suited for use in the present invention.
• the acoustic film has a bending stiffness of about 10 7 dyne-cm or less.
• the acoustic film has a thickness between about 9 and about 35 mils. In some embodiments, the portion of the acoustic film that spans the first opening will be of substantially uniform thickness.
• the through holes or perforations have a diameter which varies between the first major surface and the second major surface. In some instances, the through holes have a narrowest diameter that is less than the film thickness. In some embodiments, the through holes have a maximum diameter of from about 2.0 to about 6.0 mils. In some instances, a majority of the plurality of microperf orations are tapered between the first and second major surfaces of the polymeric film. In some embodiments, a majority of the plurality of microperf orations are tapered between the first and second major surfaces of the polymeric film, and wherein each of the tapered microperforations has a narrowest diameter less than a thickness of the polymeric film at its thickest portion.
• the plurality of microperforations are arranged in a pattern comprising a density of about 100 to about 4000 per square inch., and in some embodiments, the film has an average of between about 800 and about 1 100 through holes per inch 2
• Devices of the invention can be made in range of sizes.
• the active cavity has a volume of from about 10 inch 3 to about 200 inch 3 .
• devices of the invention may further comprise a fascia disposed in front of or over at least a portion of the acoustic film.
• a fabric sheet of selected appearance may be mounted in front of or over the acoustic film, e.g., preferably obscuring all of the acoustic film.
• the fascia is preferably acoustically transparent so as to achieve desired visual appearance without impacting the acoustic damping performance of the device.
• the front face of the acoustic film may have desired visual matter formed thereon, e.g., by printing. Such means facilitate location of devices of the invention in optimum position without undesirably impairing use of the space.
• devices may be configured with fascia and used as visually pleasing backdrops or decoration.
• the fascia may be provided with information thereon such that the devices or an array of a plurality thereof concurrently functions as a sign, e.g., presenting explanatory for an item in a museum.
• the fascia should be sufficiently open to acoustic energy so as to not unduly interfere with the desired acoustic damping function of the device.
• the fascia (which may be monolayer, multilayer, or composite) will be breathable, e.g., have a rayls value of from about 50 to at least about 1500.
• the fascia may essentially serve only to provide desired visual appearance or other non-acoustic effect.
• the fascia may have an image or pattern provided thereon.
• the fascia may be selected to be capable of engaging with mechanical fasteners, e.g., hook- and-loop fasteners.
• the fascia may be selected to provide other desired performance, e.g., to filter or entrap dirt and other air-borne particles. So as to not interfere undesirably with the overall acoustic performance of the device, if the components and construction of the fascia will be selected to be breathable.
• adhesive and other layers therein such as supporting scrims may have pores formed therein, may be discontinuously coated, be bonded or unbounded non-wovens, etc. to provide desired breathability.
• the fascia may be selected to alter the acoustic damping properties of the device as desired.
• the device will constructed such that the fascia can be removed as desired, e.g., to be replaced with a fascia having a different appearance, or in the case of dirt trapping embodiments for cleaning or replacement with a clean member to maintain desired acoustic performance.
• the fascia may be a single layer component selected for desired purposes or may itself be of multilayer construction to impart a desired combination of performance attributes to the resultant acoustic damping device, e.g., receptivity to printing or other imaging techniques, compatibility with hook-and- loop fastening devices, dirt and particulate capture, etc.
• Some illustrative features that can be provided or enhanced by incorporation of a fascia include thermal insulation, dirt and particulate entrapment, enhanced structural strength and dimensional stability, visual appearance, protection from impact and abrasion, etc.
• the fascia if any, will sometimes be attached to the acoustic damping device with releasable measures, e.g., screws, clips, hook-and-loop fasteners, etc. to permit the fascia or portions thereof to be removed for cleaning, refreshing, and replacement.
• the fascia may be attached with other measures such as nails, staples, clips, etc.
• fascia layers of devices of the invention include knit, woven, and nonwoven materials.
• materials that may be used in fascia layers of devices of the invention include knit, woven, and nonwoven materials.
• fiberglass or other fiber batt foam, recycled bonded fiber batts ("shoddy"), blown fibers mats such as THINSULATETM insulation and other such materials.
• the fascia should not undesirably impede transmission of the acoustic energy from the room through the fascia to and through the acoustic film.
• components of the fascia may be secured to other components of the fascia or to the acoustic film.
• the adhesive should be in a discontinuous coat, stripes, dots, etc. such that the resultant adhesive construction is at least semi-permeable so as to permit desired transmission of acoustic energy to the acoustic film.
• acoustic devices of the invention will have one or more second openings and be mounted on a wall, door, partition, or other vertical surface such that the vertical surface completes the desired acoustic cavity.
• Fig. 1 a typical embodiment of an acoustic damping device 1 1 10 with fascia 1 140 is shown.
• Fig. 12 is a plan view of the front face of the acoustic damping device 1 1 10 shown with the fascia removed to reveal acoustic film 1 1 14 and shell 1 1 12.
• the shell is made from wood members attached together to form an array of four active cavities attached in a row.
• FIG. 14 is a plan view of a side of the device.
• device 1 1 10 is 4 feet long, 1.5 feet wide, and about 2 inches in depth.
• the wood members selected for shell 1 1 12 have a depth of about 2 inches, width of about 0.75 inch and length chosen accordingly.
• Fig. 15 is a plan view of a shell or frame 1512 of an acoustic device 1510 comprising an array of three cavities by four cavities.
• a shell or frame 1512 of an acoustic device 1510 comprising an array of three cavities by four cavities.
• other configura5triopns can be made in accordance with the invention.
• the active cavity have lateral dimensions of from about 1 to about 1.5 feet and that the ratio of longest width to narrowest width be less than about 2: 1.
• arrays of a plurality of acoustic devices of the invention will be mounted on a support.
• Fig. 6 shows an illustrative array 60 of four hexagonal shaped devices 10 of the invention arranged in a loosely packed arrangement.
• Fig. 7 shows another illustrative array 70 of nine hexagonal devices 10 of the invention in closely packed arrangement.
• an array may comprise devices which are arranged in a spaced arrangement from one another, though this will tend to lessen the acoustic damping performance which may be attained per unit area, and arrays comprising devices of varied shape may be used.
• devices of the invention will be mounted on a room such surface such as a wall, ceiling, furniture panel, room divider, floor, etc.
• the device(s) are mounted removably to facilitate reconfiguration, cleaning, repair, etc.
• a device of the invention can be adhered to the surface, e.g., with double sided tape, adhesive, etc. applied to the back or a side of the shell, suspended by wire or string, etc.
• the device should be mounted so that the shell seats against the surface preferably substantially completely covering the second opening(s). As shown in Figs.
• the device 10 may comprise slotted openings 22 which can engage, preferably releasably, with clips 24 which are adapted to mount to the surface, e.g., via use of hook and loop closures (not shown), adhesive (not shown) such as 3MTM CommandTM Bonding Strips.
• the clips 24 are configured to engage with slotted openings 22 such that the foot surface 26 of clips 24 will not protrude beyond the bottom edge of shell 12, 1 12 so that shell 12, 1 12 will seat against the surface (not shown) to provide the desired fully closed active cavity.
• the shell will completely enclose the cavity but for the first opening. In other embodiments, the shell will completely enclose the cavity but for the first opening to which the acoustic film is provided, and one or more second openings. In such embodiments, the shell completely separates the one or more first openings from the one or more second openings.
• the device of claim 1 wherein the shell is substantially closed about the cavity but for the first opening and at least one second opening, wherein the shell separates the first opening and the at least one second opening.
• the engagement may be substantially closed, i.e., the edges of the one or more second openings are substantially in contact with the surface.
• the device may not be positioned in such close proximity to the surface, i.e., a substantial gap may exist between the surface and the device.
• Such mounting arrangements may provide desired acoustic damping benefits in accordance with the invention provided that the mounting arrangement results in sufficient constraint on air flow through the gaps between the surface and the devise such that the cavity defined by the acoustic film, shell, and portion of the surface can provide Helmholtz resonance.
• devices of the invention may be mounted on a surface in the same manner as conventional wall hangings, e.g., by picture hook(s), suspended from a ceiling or elevated rack, etc.
• the portion of the acoustic film spanning the first opening is substantially planar in configuration.
• the portion of acoustic film spanning the first opening is configured so as to have two or more planar portions.
• Such configurations may be used to impart desired visual appearance or to provide improved acoustic damping potential orienting portions of the acoustic film in varied directions.
• An illustrative example of such an embodiment is shown in Figs. 8 and 9.
• Device 810 has shell 812 defining two active cavities each substantially completely spanned by an acoustic film 814a, 814b, respectively.
• the acoustic films are configured to have four planar portions each, namely two triangles 830a, 830b and 832a, 832b, respectively and two trapezoids 834a, 836a, and 834b, 836b, respectively.
• acoustic damping devices of the invention will comprise two or more active cavities oriented in different directions.
• acoustic damping devices may be assembled in arrays of two or more active chambers per array, each active chamber having an acoustic film as described herein, which are oriented in opposing directions.
• An illustrative example of such an embodiment is shown in Fig. 10 where device 1010 comprises two active cavities 1002 and 1004 oriented toward location A and two active cavities 1006 and 1008 oriented toward location B.
• each of the active cavities is enclosed in part by acoustic film 1014a, 1014b, 1014c, and 1014d, and shell 1012a, 1012b.
• Device 1010 further comprises panel 1020 to which shells 1012a, 1012b are mounted.
• panel 1020 be sufficiently strong to support the arrays of active cavities so during installation in a room and during use.
• panel 1020 may be sufficiently strong to permit it to be mounted on the top edge of a workspace cubicle partition.
• the active chambers may be arranged in closely nested fashion, e.g., similar to the array shown in Fig. 7, to maximize acoustic damping performance, or they may be arranged with gaps between active cavities, e.g., such as the array shown in Fig. 6.
• panel 1020 may, if desired, be open or light transmissive in the areas between active cavities to facilitate light flow or visibility between opposing sides of the device, such as between adjacent cubicles, or it may be closed in those areas, e.g., to provide additional privacy between opposing sides of the device.

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• Physics & Mathematics (AREA)
• Acoustics & Sound (AREA)
• Engineering & Computer Science (AREA)
• Architecture (AREA)
• Multimedia (AREA)
• Electromagnetism (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Building Environments (AREA)
• Soundproofing, Sound Blocking, And Sound Damping (AREA)

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• 2013
  • 2013-05-07 TW TW102116296A patent/TW201404985A/zh unknown
  • 2013-05-07 WO PCT/US2013/039962 patent/WO2013169788A2/fr not_active Ceased

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