US2897908A - Sound absorbing unit and bundle thereof - Google Patents

Description

Aug. 4, 1959 BARSHEFSKY 2,897,908

SOUND ABSORBING UNIT AND BUNDLE THEREOF Filed 00"). 4, 1956 United States Patent SOUND ABSORBING UNIT AND BUNDLE THEREOF Gustave Barshefsky, Chicago, Ill., assignor to The Celotex Corporation, Chicago, Ill., a corporation of Delaware Application October 4, 1956, Serial No. 613,935

2 Claims. (Cl. 181-33) The invention hereof is with respect to a new and novel sound absorbing unit constructed in a novel manner and is with respect to a most novel manner of packaging such units.

The unit hereof is of such construction that it is extremely light in weight so that the shipment of such units in the normal manner is to all intents and purposes prohibitive in cost due to the fact that a truck load or freight carload would Weigh but a relatively few pounds.

The unit hereof is so constructed that for shipment it may be so bundled or packaged that the volume thereof when prepared for shipment is appreciably decreased as compared with the usual volume of the unit, and consequently shipping costs can be materially reduced.

The sound absorbing unit hereof is of the type sometimes referred to as an acoustic sink, a functional sound absorber, or, in some cases, as sound absorbing baflles. These unitsare ordinarily installed individually, that is, each unit is usually independently mounted or suspended spaced from other such units comprising the over-all installation. Of course, at times they may be mounted in individual rows, that is, in spaced rows but with the ends of the units in or substantially in contact. This particular unit, as mentioned, is adapted to be suspended from a ceiling or overhead supporting member, but it is immaterial whether it is mounted in any particular manner.

The unit may be suspended from suitable supporting members either horizontally or vertically with its faces parallel to the floor or ceiling, or angularly or diagonally with respect thereto. The unit may even be suspended from one corner or in some areas the unit may be, for example, suspended of its lengthwise axis running in one direction and in another area with its axis running in a different direction.

The unit as herein particularly disclosed and described comprises a sheet metal casing and suitable sound absorbing material in combination. It is to be understood, however, that the specific showing and description is not by way of limitation, and that the casing instead of being of metal may be of carboard-like material, or substantially any sheet material which may be folded. The invention comprehends the combination of such casing and sound absorbing filler which is of unit form and combined with the casing in a specific manner. Here again, however, while the preferred material, and that which will be specifically referred to herein, is a very light weight glass wool block, it is to be understood that other equivalent light weight sound absorbing materials may be substituted therefor, as, for example, light weight resilient plastic foam having the requisite light weight and sound absorbing property, or light weight elements comprised of other fibrous materials so felted or constructed as to be of light weight and having the requisite sound absorption.

The procedures for the packaging or bundling of these units for economic shipment and handling will not be referred to at this point other than most generally. The otherwise fabricated but not formed units are compacted ice for shipment by stacking a plurality thereof followed by compression of the stack to a higher unit density, whereupon the such compressed stack is suitably banded or the like to retain it in such compressed state. In such compressed state the individual units are much safer against damage in shipment and, particularly, due to the increased density, the units may be shipped much more economically than can be the completed or formed but uncompressed units.

The particular objects of the invention hereof are the provision of a functional type sound absorber unit which is simple to make, which has very low-unit weight, high absorption and the like, and is economical to manufacture.

A further object of the invention is the provision of a bundle or package of functional type sound absorber elements where, by compression, the density has been appreciably increased with the consequence that there results considerable economy in the shipment and handling, and particularly whereby the units so bundled or packaged are less susceptible to damage in shipment.

In the accompanying drawings, wherein exemplifications of the inventions are illustrated, Figure 1 is a perspective of a functional sound absorber hereof;

Figure 2 is a top plan view of the unit as it is manufactured before formation into the finished unit;

Figure 3 is an end elevation of the unit of Figure 2;

Figure 4 is a diagrammatic illustration showing the manner in which two of the units, as manufactured, may be nested;

Figure 5 is a diagrammatic showing of two of the units actually nested;

Figure 6 is a diagrammatic illustration of two such nested units which have been somewhat compressed; and

Figure 7 is a diagrammatic showing of the bundle or bale of units as prepared for shipment.

In the drawings the complete fabricated unit is identified by the numeral 10, such being shown with suspending wires or straps 11 by means of which it may be suspended from any suitable overhead structure. In connection with the attachment of suspending elements 11, it will be understood, of course, that a suspending member 11 or a plurality thereof may be suitably attached to the unit 10 whereby it may be suspended in almost any position.

For example, if only two suspending members 11 are used, attached as shown on one edge of unit 10, then the unit will, of course, be suspended with its faces diagonal with respect to the normal ceiling or like horizontal structural member from which it is suspended. In like manner the unit may be suspended by suspending members 11 secured at an end thereof, or it may even be suspended by a suspending member suitably secured thereto at one corner. It is to be understood that the specific manner or position in which the unit 10 is suspended will in most cases be immaterial and dictated only by circumstances or expediency, or possibly by personal preference.

The functional sound absorber hereof is made up of a fiat sheet 12 of thin metal or the like. This thin metal sheet is, of course, of dimensions of the developed exterior surface of the unit 10 whereby, as is evident, the flat sheet comprises a body portion of dimensions of the length of unit 10 by the sum of the width of four sides of the unit or four times the width of a side of the unit. To such body sheet there are integrally attached two end pieces of the dimensions of an end of the unit which are positioned such that when the body sheet is folded to square form, they may be folded up to constitute end closures thereof. The such end closure portion of the body sheet need not necessarily be integral therewith,

3 but if desired may be separate sheets or members which can be inserted in the ends of the body portion and secured therein after the body portion has been folded into the finished unit form.

To such body sheet 12 there are secured blocks of sound absorbing material of the nature above referred to which are identified by the numeral 20. Each of these sound absorbing block members 20 is of a length equal to the length of unit 10, of a width equal to the width of a side of unit 10, and of a height one-half of such width whereby the height of two blocks 20 is equal to the width of a side of unit 10. The sound absorbing blocks 20 being of the dimensions just referred to, it follows that when the body sheet 12 has been folded to its finished or unit form, the two blocks will constitute a volume which is the internal volume of the body sheet 12 when so formed. These two sound absorbing blocks 23 of a unit are mounted on those portions of the body sheet 12 which, when such sheet is folded, comprise opposite surfaces of the finished unit 10, and with the blocks 20 so mounted and secured by suitable adhesive the mere procedure of folding the body sheet 12 will result in the formation of the desired functional sound absorber in complete form and comprising an outside casing with a filling of sound absorbing material.

For the purpose of allowing access of impinging sound waves into the interior of the sound absorber, body sheet 12 is provided with suitable perforations which may comprise small, closely spaced circular perforations, such as 13, or small slots such as are indicated at 130. The size, spacing and number of such perforations for the purpose for which they are provided being well known and understood by those skilled in the art of sound absorption, no specific dimensions or number therefor will be given, but as an example thereof, reference may be had to the patent to Norris, No. 1,726,500.

While the body sheet or housing 12 may be secured in any manner desired, as representative of securing means therefor there have been shown small tongues 14 formed integral with body sheet 12, and registering,

slots 15 whereby, when the body sheet 12 is folded to unit form, the tongues 14 may be entered into slots 15 and bent over to secure the body or housing in its final assembled form.

As above referred to, due to the extremely light weight of the units as above described, it is advantageous, in connection with the shipping and storing thereof, that in some manner the unit density be increased or volume occupied by a unit be reduced. In this connection the fabricated unit, as above described, while still in fiat form, that is, before the sections thereof are folded to constitute the complete unit, admirably lends itself to procedures whereby the volume occupied by a unit may be very appreciably reduced with consequent advantage in shipping and storing the material.

The procedure of reducing the volume of the units for the advantage derived therefrom in connection with shipping and storing the same, will be referred to as packaging of the units. In packaging the units, they are packaged in pairs, such referring to two of the complete units in fiat form, as clearly illustrated in Figure 2 of the drawings. The two units making up a unit-package are reversed, one with respect to the other, so that the fiber blocks thereon will intermesh, as is clearly apparent in Figure 4 of the drawings and from which it is apparent that when the respective blocks 20 of the two units are intermeshed that there is comprised a solid package which is only one-half the thickness of the cross sectional dimension of the completed unit 10, as shown in Figure l.

The fiber blocks 20 which constitute the filling of unit 10 are preferably, as before mentioned, light weight resilient glass fiber blocks or blankets, the fibers of which are bonded at points of contact by suitable adhesive. Such glass wool material is available on the market having weight of from approximately three-fourths to one pound per cubic foot, but which material is quite resilient and will stand considerable compression without undue compaction.

For forming a bale of the units for shipment and storage, a suitable number of pairs of the units are made into packages, as referred to, and such are assembled one on the other to the desired height, whereupon pressure normal to the fiat faces of the packages is applied to compress the pile of packages to at least the extent of onehalf of the initial height of the pile. Depending somewhat on the physical properties of the blocks 20 used, the amount of compression which can be accomplished may vary somewhat, but in general the pile of packages can be compressed to one-third of the original height of the stacked packages, or at least to the extent of onehalf of such height. After the pile of packages has been compressed, as just referred to, slats 25 may be placed therearound and bands 26 applied to retain the bale in compressed condition. It, of course, follows that when compressed to one-half the initial height, at least twice as many units can be stored in any given space, and that twice the number may be shipped in a car or on a truck. Or, if compressed to one-third of the original height that likewise three units when so compressed occupy no more space than would a single unit uncompressed. This is of great importance economically in connection with the storing and shipping of the units, which is otherwise quite expensive due to the very light weight of a unit.

In connection with the specific construction of a unit 10, it may in some cases be desirable to apply a sheet of tissue-like paper 21 to the interior surface of the casing sheet 12, such sheet being securely adhered thereto. In adhering tissue sheet 21 to the casing 12, it is to be understood that it will be necessary to apply the adhesive to the casing sheet 12 and then to apply the tissue sheet 21 thereto, since while it is desired that the tissue sheet 21 be securely adhered to the casing sheet, that the portion of the tissue sheet which covers the perforations in the casing sheet should not have glue or adhesive thereon which would tend to or would block the natural porosity of the tissue sheet. It is necessary, to obtain the advantage of the incorporation of such tissue sheet, that the portion of the sheet overlying the perforations, such as 13, should be porous to air whereby pressure waves impacting thereon may pass therethrough without hindrance other than that resulting from the resistance of the porous tissue sheet to the passage of air therethrough.

The inventions hereof having been described in detail, I claim:

1. An acoustical correction unit comprising a parallelepiped space enclosing casing comprised of a shape retaining sheet forming a plurality of the sides of the easing and mounted on the interior surface thereof blocks of sound absorbing material, such blocks of sound absorbing material substantially co-extensive with and mounted on the interior surface of two of said sides of the casing contiguous to a third side thereof, each of such blocks of sound absorbing material of a thickness substantially one-half the width of said third side of the casing.

2. An acoustical correction unit comprising a parallelepiped space enclosing casing comprised of a sheet of form-retaining material forming the walls thereof, the casing sheet perforated for the passage of sound waves thereinto, an air porous tissue sheet firmly adhered to the interior surfaces of the enclosing casing and sound absorbing glass fiber blocks of density of about threefourths to one pound per cubic foot mounted to the tissue sheet on two of the walls of the parallelepiped space enclosing casing contiguous to a third wall there of, each said block of a thickness substantially one-half of the width of said third wall and together occupying substantially the entire interior cavity of the casing.

(References on following page) References Cited in the file of this patent UNITED STATES PATENTS Donahue July 25, 1944 6 Pare Nov. 22, 1949 Olson Mar. 28, 1950 Olson Mar. 28, 1950 Kjaer Dec. 2, 1952 Bourgeois Mar. 9, 1954

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