US2029441A - Acoustical structure - Google Patents

Acoustical structure Download PDF

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Publication number
US2029441A
US2029441A US701962A US70196233A US2029441A US 2029441 A US2029441 A US 2029441A US 701962 A US701962 A US 701962A US 70196233 A US70196233 A US 70196233A US 2029441 A US2029441 A US 2029441A
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US
United States
Prior art keywords
sound
facing member
vibration
vibratile
impermeable
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US701962A
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English (en)
Inventor
John S Parkinson
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Johns Manville Corp
Johns Manville
Original Assignee
Johns Manville
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to NL42287D priority Critical patent/NL42287C/xx
Application filed by Johns Manville filed Critical Johns Manville
Priority to US701962A priority patent/US2029441A/en
Priority to FR785234D priority patent/FR785234A/fr
Application granted granted Critical
Publication of US2029441A publication Critical patent/US2029441A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • 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
    • G10K11/162—Selection of materials
    • G10K11/168—Plural layers of different materials, e.g. sandwiches
    • 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
    • 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
    • E04B2001/8281—Flat elements mounted parallel to a supporting surface with an acoustically active air gap between the elements and the mounting surface
    • 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 an acoustical stmoture and particularly to one that is adapted for use in the absorption of sound of low frequency, such, for example as that emitted by an airplane motor.
  • Airplane motors give a very large amount of sound of a frequency of about 250 to 400 cycles per second.
  • the commonly used acoustical materials show a maximum absorption eiliciency for sounds of frequency considerably above this range.
  • To absorb a satisfactory proportion of sound of the frequency given by the motors would require such a thickness of material or type of construction, with certain conventional sound absorbents, as to increase undesirably the weight of the installation.
  • a further object is to provide such a structure having a face that is non-porous, not susceptible to penetration by dirt or dust, and that may be decorated or washed without appreciable injury.
  • Another object is to provide a non-fragile acoustical structure that is resistant to permanent deformation.
  • Fig. 1 shows a perspective view, in part broken away for clearness of illustration, of a structure made in accordance with the present invention
  • Fig. 2 shows a cross sectional view of a structure similar to that of Fig. 1 in which a felt backing is continuously adhered to the non-porous facing member or diaphragm;
  • Fig. 3 shows a cross sectional View of a similar structure in which the continuous backing member is replaced by several small units of such material adhered to the diaphragm in selected localized areas;
  • Fig. 4 shows a structure adaptable for certain purposes in which the backing material is eliminated, the structure being otherwise similar to that shown in Fig. 1;
  • Fig. 5 shows graphically the results obtained in absorbing sound of several frequencies for various spacings of the diaphragm from the rigid base member or wall.
  • a facing member I there is shown a facing member I, a backing material 2, a supporting frame 4, and a base material in the form of the sheet 5.
  • the facing member is in contact with the backing material and is secured, as by the tacks 3, to the frame and supported thereby in spaced relationship to the base material.
  • the sheet 5 is illustrative of a structural material, as, for example, the air-impermeable metal sheet of an airplane cabin.
  • 'Ihe frame I may be of wood or other rigid material.
  • the various elements of the frame may consist of struts, bracings, or other reenforcing or supporting elements in an airplane or the like.
  • the Supporting framework may serve solely the purpose of holding the facing element and the material adhered thereto, or it may serve also to reenforce the member 5 and enclose the air space 6.
  • the facing member l should be non-permeable and readily vibratile under the inuence of incident sound, that is, in the absence of the material 2, and is suitably a woven textile fabric coated with an impermeable film that is vibratile in the finished member.
  • a strong silk fabric or, preferably, airplane linen there may be used.
  • the fabric is moderately stretched and secured to rigid supports, such as the sides of the frame 4, and then is provided with a coating of the type obtained by doping and allowing the volatile solvents therein to evaporate. The fabric is thus made taut. The tension thereon is maintained by the frame support l.
  • the member When tapped with the finger, for example, the member emits a noise that is more or less drumlike.
  • the doped facing member is adapted to vibrate or to resonate under the iniluence of incident sound.
  • the resonance frequency of the member in the structure should be in the range of frequency of the sound that is to be absorbed. It will be understood that the resonance frequency of a vibratile membrane of this type depends largely upon its mass and tautness, and that one skilled in the art may produce membranes adapted to resonate at the frequency desired, within the considerable range that is allowable.
  • the material 2 disposed behind the facing member should be lightweight, yet not so light as to absorb no appreciable energy in being moved, yieldable, non-vibratile, and adapted to damp vibration of the facing member.
  • amaterial is a fibrous felt of hair, wool, or the like.
  • thickness of layerof the material 2 may vary over a substantial range, one-fourth inch being a satisfactory thickness.
  • damping member is said to be non-vibratile in the'sense that the member alone is not susceptible to vibration, although it may move, in certain parts at least, in periodic manner under the influence of an adhered vibrating element.
  • the vibration-damping material is adhered to the vibratile facing member at an internodal position thereon, that is, at a position substantially removed from the places of support of the said member upon a frame.
  • These positions of support as illustrated in Figs. 1, 2, and 3, are necessarily nodal positions.
  • the adhesive 'I that may be used to adhere the material 2 to the facing member I may consist of any suitable composition. While sodium silicate may be used, the adhesive is preferably one that, in the form of the nal film, is durable and firmly adherent to both the felt and the fabric l.
  • the adhesive lm may consist largely of a resin, such as pontianak, or other material that is compatible with and adherent to the dope or coating on the facing member as well as to the felt.
  • the sound of 256 cycles frequency has a complete Wave length slightly greater than 4 feet and the maximum absorption of sound of that frequency is obtained when the diaphragm is spaced slightly more than 6 inches from the base 5, 6 inches being one-eighth of 4 feet.
  • the optimum results with sound of 512 cycles is obtained when the spacing is approximately 3 inches.
  • a spacing of the diaphragm I approximately 2 to 6 inches from the base 5 is desirable.
  • sound absorption as here used includes sound deadening. That is, any sound absorption in the usual sense may be supplemented by the deadening of sound,l
  • any small amount of sound generated by the vibrating member I is absorbed, in part, by the member 2.
  • the air between the facing member and the air-impermeable base may contribute to the damping effect, by the small amount of work done upon the air by alternate slight compression and rarefaction.
  • Permeability refers to permeability to airborne sound waves.
  • the resonance frequency of the facing member in the structure is affected by factors other than the properties of the facing member itself and that the term resonance frequency, as applied to the facing member, refers to the resonance frequency of the member in the finished, complete structure.
  • a sound-absorbing structure comprising a facing member maintained under tension and adapted to be set in vibration by incident sound and lightweight, yieldable, non-vibratile. vibration-damping material disposed behind and in contact with the said facing member at an internodal position thereon.
  • a sound-absorbing structure comprising an impermeable member adapted to be set in vibration by incident sound and lightweight, yieldable, non-vibratile, vibration-damping material disposed in contact with the said member at an internodal position thereon.
  • a sound-absorbing structure comprising an impermeable facing member adapted to be set in vibration by incident sound, and lightweight, non-vibratile, yieldable, sound-absorbing material secured to the back of the facing member at an internodal position thereon.
  • a structure, adapted to absorb incident sound, comprising a readily vibratile facing member of resonance frequency in the range of the frequency of the incident sound and lightweight, yieldable, non-vibratile, vibration-damping material disposed in contact with the facing member at an internodal position thereon.
  • a structure, adapted to absorb incident sound, comprising a readily vibratile facing member including a taut, coated, impermeable fabric of resonance frequency in the range of the frequency of the incident sound and lightweight, yieldable, non-vibratile, vibration-damping material disposed in contact with the facing member.
  • a sound-absorbing structure comprising a readily vibratile facing member including a taut, impermeable, coated fabric adapted to be set in vibration by incident sound and lightweight, yieldable, non-vibratile, felted fibrous material disposed in contact with the facing member.
  • a sound-absorbing structure comprising an air-impermeable support, a lightweight, yieldable, vibration-damping material disposed in spaced relationship to the support, and an impermeable facing element, adapted to be set in vibration by incident sound, adhered at an internodal position to the side of the vibration-damping material remote from the said support.
  • a sound-absorbing structure comprising an air-impermeable support, a lightweight, yieldable, vibration-damping material disposed in spaced relationship to the support, at a distance of the order of two to six inches, and an impermeable facing member, adapted to be set in vibration by incident sound, adhered at an internodal position to the side of the vibration-damping material remote from the said support.
  • a sound-absorbing structure comprising an air-impermeable support, a lightweight, yieldable, vibration-.damping material disposed in spaced relationship to the support, and an impermeable facing member, adapted to be set in vibration by incident sound, adhered at an internodal position to the vibration-damping material.
  • a structure adapted to absorb incident sound comprising an air-impermeable, rigid support, a taut readily vibratile facing member maintained in spaced relationship to the support, and means enclosing the space between the said member and support, whereby circulation of air between the space and the outside is restricted.
  • a structure adapted to absorb incident sound comprising an air-impermeable, rigid support and a facing member maintained in spaced relationship to the support, at a distance therefrom approximately equal to one-eighth of the predominant or average wave length of the incident sound.
  • a structure adapted to absorb incident sound comprising an air-impermeable, rigid support and a facing member maintained in spaced relationship to the support, at a distance therefrom approximately equal to one-eighth of the predominant or average wave length of the incident sound, the facing member in the structure having a resonance frequency in the range of the frequency of the incident sound.
  • a structure adapted to absorb incident sound comprising an air-impermeable, rigid support and an impermeable facing member maintained in spaced relationship to the support, at a distance therefrom of approximately 2 to 6 inches.

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  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Architecture (AREA)
  • Electromagnetism (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Building Environments (AREA)
US701962A 1933-12-12 1933-12-12 Acoustical structure Expired - Lifetime US2029441A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
NL42287D NL42287C (fr) 1933-12-12
US701962A US2029441A (en) 1933-12-12 1933-12-12 Acoustical structure
FR785234D FR785234A (fr) 1933-12-12 1934-12-11 Perfectionnements aux éléments de construction acoustique

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US701962A US2029441A (en) 1933-12-12 1933-12-12 Acoustical structure

Publications (1)

Publication Number Publication Date
US2029441A true US2029441A (en) 1936-02-04

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Family Applications (1)

Application Number Title Priority Date Filing Date
US701962A Expired - Lifetime US2029441A (en) 1933-12-12 1933-12-12 Acoustical structure

Country Status (3)

Country Link
US (1) US2029441A (fr)
FR (1) FR785234A (fr)
NL (1) NL42287C (fr)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2459121A (en) * 1943-09-17 1949-01-11 United States Gypsum Co Acoustical tile
US2488555A (en) * 1944-01-27 1949-11-22 Rca Corp Diffraction type sound absorber with fibrous walls
US2502018A (en) * 1944-03-30 1950-03-28 Rca Corp Diffraction type sound absorber covered by a membrane
US2541159A (en) * 1946-01-22 1951-02-13 Paul H Geiger Sound deadener for vibratory bodies
US2600236A (en) * 1948-11-16 1952-06-10 Esther Larsen Muffler with a plurality of passages
US2802764A (en) * 1952-10-08 1957-08-13 Owens Corning Fiberglass Corp Acoustical material
US3115948A (en) * 1960-12-14 1963-12-31 Koppers Co Inc Panel for the reduction of sound transmission
US3202561A (en) * 1961-03-30 1965-08-24 Johns Manville Method for making acoustical tile with thermoplastic film covering
EP0046559A2 (fr) * 1980-08-27 1982-03-03 Hoechst Aktiengesellschaft Elément résonnant absorbant le son
FR2712325A1 (fr) * 1993-11-09 1995-05-19 Newmat Sa Procédé de fabrication de dalles notamment pour plafonds suspendus.
US20070157535A1 (en) * 2005-11-03 2007-07-12 Etienne Cousin Fabric support frame section
WO2013156739A1 (fr) * 2012-04-20 2013-10-24 Aircelle Panneau mince d'absorption d'ondes acoustiques émises par un turboréacteur de nacelle d'aéronef, et nacelle équipée d'un tel panneau

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2459121A (en) * 1943-09-17 1949-01-11 United States Gypsum Co Acoustical tile
US2488555A (en) * 1944-01-27 1949-11-22 Rca Corp Diffraction type sound absorber with fibrous walls
US2502018A (en) * 1944-03-30 1950-03-28 Rca Corp Diffraction type sound absorber covered by a membrane
US2541159A (en) * 1946-01-22 1951-02-13 Paul H Geiger Sound deadener for vibratory bodies
US2600236A (en) * 1948-11-16 1952-06-10 Esther Larsen Muffler with a plurality of passages
US2802764A (en) * 1952-10-08 1957-08-13 Owens Corning Fiberglass Corp Acoustical material
US3115948A (en) * 1960-12-14 1963-12-31 Koppers Co Inc Panel for the reduction of sound transmission
US3202561A (en) * 1961-03-30 1965-08-24 Johns Manville Method for making acoustical tile with thermoplastic film covering
EP0046559A2 (fr) * 1980-08-27 1982-03-03 Hoechst Aktiengesellschaft Elément résonnant absorbant le son
EP0046559A3 (en) * 1980-08-27 1982-11-03 Hoechst Aktiengesellschaft Resonant sound-absorbing element
FR2712325A1 (fr) * 1993-11-09 1995-05-19 Newmat Sa Procédé de fabrication de dalles notamment pour plafonds suspendus.
US20070157535A1 (en) * 2005-11-03 2007-07-12 Etienne Cousin Fabric support frame section
US7685786B2 (en) * 2005-11-03 2010-03-30 Etienne Cousin Fabric support frame section
WO2013156739A1 (fr) * 2012-04-20 2013-10-24 Aircelle Panneau mince d'absorption d'ondes acoustiques émises par un turboréacteur de nacelle d'aéronef, et nacelle équipée d'un tel panneau
FR2989814A1 (fr) * 2012-04-20 2013-10-25 Aircelle Sa Panneau mince d'absorption d'ondes acoustiques emises par un turboreacteur de nacelle d'aeronef, et nacelle equipee d'un tel panneau

Also Published As

Publication number Publication date
FR785234A (fr) 1935-08-05
NL42287C (fr)

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