US2293351A - Sound absorbing construction - Google Patents

Description

Aug. 1s, 1942.

Filed Dec L ,16. 19:59

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` raminous unit which Patented Aug. 18,

UNITED sTAT ES J4PATmi OFFICE.

` SOUND AnsonniNG CoNsTltUo'roN Richard N. Meginnity,

The Celotex Corpora poration of Delaware Chicago, Ille.; assignor to tion, Chicago, Ill., a cor- 1Application December-16, 1939,` seriaiNa 309,583 Y Y y A l n 4 clame.` (o1.`2o 4) VThis `invention relatesfto improvements in constructions, particularly" sound absorbing 4material is These materialsare notusually used in'their loose, fbrousyor granular condition because they are inconvenient to handleand because thel soundr absorption characteristics of these` ma.; terials when in `this condition are Also, if they are used in this loose `condition,- the fibres or o granules tend to lter `throughthe openings in Vthe foraminous construction 4into theroom lbelow. To overcome these objectidnf t 2o not uniform. t

able features,` thematerials for the absorption units are usually fabricatedinto preformed units by felting or bondinglwith a` suitablefadhesive'` as is disclosed in the prior art, as forexample in the patent to"Norris 2,172,771 tember 12,` 1939, and February 14; 1939.` y w n It has been also found that in order to obtain satisfactory sound absorption characteristics of a foraminous unit and its sound absorption pad grantedSepthat the sound absorption pad should be suitably spaced from the surface` of theforaminous sheet l pan" unity ManyA forms `of forming the metal` o supports have been previously used; but, these are generally rather costly to form and install, and they usually are not satisfactory in V`that Weiss o 2,147,276 granted openings inthe surface `of the metal pan unit may therebyfbecome covered causing anon-uniform breathing across the surfaceof the foresults in` leaving unsightly dirt streaks and the like on the face" unit.

It is; therefore, e prmeipe-l objectV ef meintentionto. provides4 novel sound absorbingunitas-, sembly in which the Vobjectionable features of"` the prior sound absorptiongunit assemblies" are overcome and to form a sound absorption pad support which'is substantiallyffooliproof hither` :on erection,` which may 'be speedily installedgand which is inexpensive, n t

` of the A isuu further object ef the invention( is te provide `annovel sound absorption pad. support p o which is adapted for various lengths of sound absorption pads and` Afurthermore may be adapted either for application longitudinally or transversely of the pad.. f Without `referring" in detail to n the construction of the sound absorption lpad and support therefor; the inventionrelates to a body of `sound 'absorbing material `which `is enclosed in ajsuitable wrapper, wherein the material of the sound absorption pad is (":onilned by thewrapf per against the `escape of the dine particles therefrom, while the Wrapper is of such `a character that the sourd absorbing characteristics of the material forming the pad is not appreciably modified bythe wrapper or sheath therefor.` The wrapper or sheath should, however,

be preferably a thin flexible sheet material which may besubstantia-lly impervious to thepassage such a material thatit functionsI as adiaphragmffor transferring any of the "sound f waves impinging thereon to the sound absorpof air but is of tion material. In" combination with the novel soundabsorption pad formed in this mannerrit' is preferred to use a novel pad support which may be readily aiiixed to the pad and is. adapted to space the sound absorption pad from the metal `pan unit or other suitable foraminous surfacing `sheet without injuring the wrapper for thesound absorption pad. Y Y

Further objects, features, and advantages of the invention will become apparentfrom the following detailed description of the preferred embodiment and modifications ,thereof Vof the invention, as'` illustrated'in4 the accompanying drawing, wherein like reference characters indicate similar parts:

Figure 1 is a sectional view in-elevation il# n lustratingthe sound absorption pad assembled .inplace in a metal pan u'nit'and supported from bythe novel sound absorption pad support; f l Y Figure 2 isa plane view of a metal pan unit partly broken away and illustrating the manner in which the novel soun a face thereof Figure 3 iste view musa-ating `the jfermed sound `absorptionmpad support in its retracted position; and, a

Figure l` is a modified form of the sound ab- 1 sorption pad Vsupport as illustrated in Figure 3.`

Referring to n Figure construction comprises a facing I0 which is preferably in the form of a foraminous sheet metal o d absorption p ad support o n is affixed to a soundabsorption pad; l

j1, the soundabsorbing` 4fastened to the wall or ceiling II pan and is supported in spaced relation from the ceiling II, and between the facing and the ceiling, there are positioned sound absorbing units I2. The perforated metal pans I are preferably supported from the ceiling by means of furring strips I3 which are as illustrated substantially T shaped in cross section and are suitably by any suitable securing means, as the screws. I4. The :furring strips have downwardly extending leg portions I5 and are provided with outwardly formed longitudinal beads I6 adapted to resiliently grip complementally formed beads Il on the upturned flanges I8 of the metal pans. In erecting the metal pan units in position, the upturned flanges I8 or marginal portions of the metal pan units are inserted between the leg portions I5 of the furring strips with the of being engaged by the'complementally formed portions I6 of the furring strips whereby, as the furring strips resiliently engage the upturned flange portions of the metal pans, the metal pans are rigidly affixed in position and are adapted to be assembled or retracted from their position. Y The metal pan construction and the supports therefor are only disclosed as being illustrative of a suitable wall surfacing construction adapted for acoustical construction inconnection with which the novel sound absorption material and support therefor are to be further described in detail.

Although the sound absorption unit I2 maybe supported in direct contact with the interior surface of the perforated facing or metal pan members I0, it is preferred, however, to space the sound absorbing unit I2 a substantial distance from the inner face of the facing member. Referring to Figures 1, 2, and 3, Vpad supporting members I8 space the sound absorption pad I2 from the inner face of the metal pan units I0. The pad support I9l is originally formed preferably as a tightly coiled spring, as illustrated in Figure 3, having hooked shaped end portions 20 having inturned ends 2I thereof preferably pointed for piercing the sheath or wrapper 22. It is preferred that the hooked shaped end portions 20 shall be transversely positioned with respect to the axis of the coiled pad support I9 so that the lower edge of the coiled member shall beaded portions II there- I be contiguous to the sheath or wrapper 22 of the Y pad support, as illustrated in Figure 1,Y although it is to be understood that it is'within the scope of this invention that the hooked shaped end portion 20 may have the '1n-turned ends 2I thereof substantially in alignment with the axis of the coiled pad support.

Although the pad support I9 is preferably a coiled and resiliently formed member, it is obvious that it may -be coiled as indicated in its extended position, Figure 1, without making the absorption pad support adapted to have the coils thereof close upon themselves when removed to return to the shape as illustrated in Figure 3. However, for convenience in packaging, it is preferred that the pad support shall be made in the form of a resilient coiled springwhich is adapted to be extended, as illustrated in Figure 1, and alsoadapted to be extended for various length or widths of pads I2 without the necessity of providing various size sof the sound absorption pad support for different sizes of sound absorption units. It is preferred to form the sound absorption pad supports so that when they are extended from the shape illustrated in Figure 3, which is substantially a full size illustration of the pad support, it will be adapted to fit a sound absorption pad which is substantially 24" long,

the usual size of the sound absorption pads being such that they will fit a metal pan unit substantially 12" x 24" in length.

It is obvious from the construction illustrated in Figures l and 2 that three pad supports I9 are sufficient to satisfactorily support the sound absorption pad in position in the metal pan unit. A particular advantage of this form of sound absorption pad support is that these pad supports may be applied as the sound absorption pads are being erected in position or they may be applied to the sound absorption pads I2 and the pads and support therefor mounted within the metal pan to be shipped as a completelunit ready for erection in the wall facing which is adapted for accoustical correction. Although the pad supports I9 have been illustrated as being applied longitudinally with respect to the sound absorption pad I2, as illustrated in Figure 2, it is obvi-` ous that these pad supports may be suitably applied transverse with respect'to the sound absorption pad without departing from the scope of the invention. v

As the prongs 2I readily pierce the wrapper 22 and extend into the soundabsorption material forming the pad, it is obvious that the sound absorption supports are firmly aflixed in place forming a sound absorption pad which may be considered as having the supports directly affixed thereto or which may be readily separated therefrom or affixed thereto, depending upon whether the pad and support are to be fabricated as a unit or whether they are to be applied as the construction is erected in place.

It is preferred that the wire from which the sound absorption pad support is formed shall be of suflicient gauge to Aform a substantially stiff support for the pad when the support is in an extended position, as in Figure 1, and that the support when removed from the pad shall, because of the resiliency of the material of which it is formed, return to its original condition as indicated in Figure 3. Althoughthis is the preferred form, it is obvious that a material may be used for forming the pad support and coiled as in Figure 3, which, upon being extended'to fit the pad support, will not return toits original shape because the material will not have been 'g It is preferred to fabricate the coiled wire support I9 so that it will have anoutside diameter substantially to 1/2" and a length of approximatelyA 11A as coiled, as illustrated in Figure 3, the length of the hooks 20 at each end being additional. wire support when it is extended to a length of substantially 24" becomes substantially 15;". It is preferred that the prongs 2I shall be pointed a suillcient amount to readily penetrate the wrapper 22. wire from which the material is formed is substantially 0.025", and it is also preferred that the finished coiled wire support I9 shall be galvanized as a safeguard against rusting. Although it is preferred that these coiled pad supports shall be galvanized, it is obvious that any other suitable form of coating which will prevent corrosion is .satisfactory and within the scope' of this invention.

As previously described, it is preferred in forming the coiled wire supports that the hooks shall lie substantially in the same plane to pre- The diameter of the coiled The preferred diameter of the folded and arranged as illustrated in x4ent any warping tendency of the installed support so thatat alll times thehpad supportshall` directly abut` the face of` thefsound absorption pad to which itis applied,withoutcausing,warping of the` pad awayfrom` the support. ,'Ifhe tension of the coiled," support preferably shall be `such that the coiled support, when it is erected in position, will not ,cause thesound absorption pad Vtokbuckle out, the tension being onlysuffif` cient to maintain the coiled supportin place.`

When the pad supports are `used inconjun'ction with yielding pads, it is` preferred ,tofform the supports from` materialwhich after it is formed into thecoiled supports may beformfed into its,

extended position `by stretching Vthe coiled` suping the` "supportfbeyond itsl ,elastic limitso that its elongated positionis retained. However, with a rigid.`form of absorption pad, the coiled pad support" may. be formed from material which,

port.` substantially .theV lengthlof theel padwhich length is suicient ,to stress the materialform-` after ithas been extended for use may returnto.`

its original shape. f i

Figures illustrates a modified form z3 of the coiled sound` absorption pad,` support` I9 il1us. trated inEigure 3.` In the modified lformillush trated in Figurefijit is preferred that the `ends of the pad support shall be substantially L `pens to be too great, to tear the wrapper 22 at the point to which the pad support is applied. It

copper, aluminum, and other metals and alloys,

asbestos paper andflm forming materials. such` as cellulose, acetates, esters, and ethers. n Papers `of various kinds and Athicknesses maybe em`` ployed but a thinflexible :paper in .which the fibres areirregularly arranged is preferred with the paper being substantially`-0025" in, thick-V ness.` The metal foil, if used as a wrapper, is preferably substantially 0.003- inthickness. r

It isobvious there ,has been disclosed anovel Y l sound absorbing pad support `and a combination` thereof `with a pad support, and particularly,a

t is obvious that the modified form z3 ofthe coiIed pad support may be coiled fomrthe lsame size wire to the same diameter and length of coil as the preferred form, illustrated in Figure 3, and that it may also be suitably `coated to prevent corrosion as has been previously described, without departing from lthe scope of the invention.

The sound absorption unit I2 to which `the novel pad support is affixed preferably comprises a body of porous, fibrous, granular, or ceramic material 21 enclosed in the envelope 22 of thin flexibleV sheet material. The sound absorption unit may also be in the form of a flexible pad of felted fibres such as hair felt, or a semi-rigid tile` of woodbres, mineral, or glass wool, or a rigid tile of porous ceramic substance, or it may be a body of loose fibrous or granular material such as wood fibres, mineral wool,` crushed pumice, coke, slag or the like materials.

It is preferred that the wrapper 22 maybe u Figure 2 with the folded portions joined to the body portionsV by means of a suitable adhesive to form a unit which is convenient to fabricate and `to handle. It is also preferred that the overlapping portions may be adhesively ailixed together in such a manner as to seal the sound absorption material 21 `within the wrapper 22 so that no loose particles will escape from thewrapper. The prongs 2| or 25 of the modified pad support as they are affixed to the sound absorption pad such `as disclosed ln Weiss 2,147,276, granted l February 141939, mayl serve to substantially seal the opening formed by the prongs thus preventing any of the material from `within the pad from escaping. p

Suitable sheet materials which may be used in combination with the novel pad support may be sound absorption padsupport which is inexpensive tomanufacture. and which is `light in weight; and in. connection with which because of its small size, thepackaging andshipp ing, costs thereofare reduced to a minimum. Other advantages of the novel pad support areithat the supports, when applied "to a sound absorption pad, cannot shift their `relative `position with` re`. spect to the `sound absorptionpad or to `a lretal 'pan unit;" and, as the pad support is formed from coiled wire having no` flat surfaces, there `is no tendency `of the perforations of theforaminous metal pan which would reduce the efficiency-.of `the sound absorption unit. Furthermore, breathing through all the perforations of the foraminousunit is substantially uniform so that any air borne dust or dirt is deposited substantially'u'niformly on `the exposed ceiling without leaving any objectionable streaks. t Q

Although the coiled sound absorption pad support `has preferably been described as being adapted to be affixed tothe sound absorption pad, it is also obvious that it is within the scope of the invention, as `an equivalent construction, that the coiled pad `support may be welded or otherwise secured to the inner face of the metal pan unit or otherwise 'suitably incorported in the `assembled construction, as by hooking the support to perforations inthe metal pan Without departing from the scope of the invention.

It will, of course; be understood that 4various combinations of the features of the invention. other than the` combinations illustrated and described, 'will be obvious to those skilled in the art and are therefore entirely Within the scope of the invention :as defined by the appended claims. The same applies to various modifications and minor departuresfrom the specific formof sound absorption pad support per se and combinations with a sound absorption pad or unit of the pad support and foraminousv metal pan unit as well as the method of and means for forming the sound absorption pad support,` herein illustrated and described, which is used forspacing a sound absorption pad from its contiguous facing unit in t material, a wrapper of sheet material enclosing Y said body and a plurality of helically formed sized or unsized paper, metal foil, such as zinc,

means spacing the sound absorbn'g unit from the foraminous member, each of said spaced means comprising a coil spring extending across the face" the pad support to'blanket` any lof` of said unit and spacing the unit from the foraminous meinberand means for piercing the opposite edges of the sound absorbing unit, whereby the coil spring means are aflixed to the sound absorbing body and said means and body may be utilized as a unit.

2. In combination with the interior surface of a room, a foraminous member mounted in spaced relation with respect to a'portion of the interior surface thereof and a sound absorbing unit positioned between said interior surface and said (oraminous member, said sound absorbing unit' comprising a sheet form pad of porous sound absorbing material, slender wire form material helically shaped and interposed between a face of the foraminous member and contiguous face of a sheet formed pad, the helically shaped member resting on the foraminous member and contacting the surface thereof at pitch points along a line extending axially along the helically shaped member and the pad supported on the helically shaped member along a line of pitch points substantially diametrically opposite butv longitudinally displaced with respect to the points of contact with the face of the foraminous member.

3. In combination in a sound absorbing assembly, a pan form perforated facing portion,V a sheet form pad of. sound absorbing material carried therein and spacing means interposed between the sound absorbing pad and foraminous face, the spacing means comprising an elongated, wire form, helically formed member contacting each of the opposed faces of the foraminous face por-` tion of the pan member and the sound absorbing.

pad at points along the helically shaped member respectively spaced, a distance apart, equal to the pitch thereof.

4. In combination in a sound absorbing assembly a pan form perforated facing portion, a sheet form pad of sound Vabsorbing material carriedY therein and spacing means interposed between the sound absorbing pad and foraminous face.

RICHARD N. MEGINNITY.

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