US1119543A - Wall and ceiling of auditoriums and the like. - Google Patents

Description

W. G. SABINE & R. GU'ASTAVINO. WALL AND CEILING OF AUDITORIUMS AND THE LIKE. APPLICATION FILED PEB.17, 1913.

1,1 19,543. Patented Dec. 1,1914.

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UNITED "STATES OFFICE.

.WALLAGE CLEMENT SABINE, OF BOSTON, MASSACHUSETTS, ALE) RAFAEL GUASTAVINO, OF BROOKLYN, NEW YORK.

.WALL AND CEILING OF AUDITOBIUMS AND THE LIKE.

Specification of Letters Patent.

- Application filed February 17, 1913. Serial No. 748,943.

To'all'whom it may concern:

Be it known thatwe, WALLAonCmMEN SABINE, a citizen of the United States, residing-in Boston, in the county of Sufiolk and State of Massachusetts, and RAFAEL GUASTAVINO, a citizen of the United States, residing in Brooklyn, in the county of Queens and State of New York, have invented a new and useful Improvement in Walls and Ceilings of Auditoriums and the like. The object of our invention is to provide walls and ceilings in auditoriums and the like which shall correct certain types of acoustical difliculties by the prevention, when properly used, of excessive reverberation and echo, and injurious focusing of sound.

This invention is'the result of a request from architects for structural walls and ceilings, which shall'be at the same time finished in appearance and acoustically corrective.

In 1900, Wallace Clement Sabine, one of thev applicants herein, published in The- Ameflcan Architect the result of personal investigations showing that certaintypes of acoustical difliculties in auditoriums could be corrected by the use of fabrics, such as felt, uncovered or covered with denim, burlap, or the ,like. From that time to the present manyof the acoustical difficulties in auditoriums have been corrected by this method. All structural walls and ceilings heretofore in use, such asbrick, tile, wood sheathing, plaster on wood or wire lath, and plaster applied directly to a solid support, are practically impervious to sound waves, and the diminution of incident sound is almost wholly due to the flexibility of such 'strii'ctures, and such flexibility is so slight that for the purpose of correcting acoustical difliculties they are practically non-absorbent. All such previously known structural walls and ceilings reflect at least ninety per centum of the incident sound, and in the great majority of cases more than ninety- .five per centum, the loss of the remaining sound being due almost wholly to the yieldoctaves above middle C. Although the funpitch of themale speakmgvoice is below middle O, the characteristic sounds j whlch distinguish articulate speech he mainly within this range.

' Accordingly, the invention pnimarily-consists in a porous artificial masonry material capable of absorbing sound waves to a very high degree, and hence being specially adapted for the interior exposed face of the iryliills and ceilings of auditoriums and the Also, the invention contemplates a novel wall or ceiling structure embodying the improved material as the inner exposed layer thereof.

. Further objects and advantages of the invention, in its aforesaid several aspects, will more readily appear as the description thereof proceeds, and in the accompanyingillustrative drawings.

Figure 1 is a diagram plotting the power for absorbing sounds by the structure which is the result of this invention, in contrast with the sound-absorbing power of typical standard masonry structures, simple and compound. Figs. 2 and 3 are sectional views of walls constructed in accordance with our invention. Fig. 4 shows a section of a wall arch constructed 1n accordance with our mvention.

First referring to these illustrations, it

but like brick, is practically non-absorbent through porosity. Curve 3 shows the absorbing power of a plaster on lath wall, in which the resonance for the 'lower notes is apparent. Curve 4 shows the superior acoustic eifect actually obtained by using the construction described in this invention.

In Fig. 2 we have shown a structural wall jl, to which is secured-a layer of hollow Patented Dec. 1, 1914.

Suchtile is a little more yielding than brick,

blocksB by means of cement or other suitnot porous, in the sense in which the word able binding material. To the interior surface of the hollow blocks is secured, by

means of cement or other suitable binding materlal, our porous sound-absorbing material 2, which forms the interior exposed surface of the wall.

In Fig. 4 we have shown a structural vaulted ceiling 1, to which is secured, by a suitable binding material such as cement, our porous sound-absorbing material'2.

' From the foregoing it will be seen that in the adaptation of our improved'porous material to a Wall or ceiling structure, the inner layer, directly exposed to the sound, is of masonryQhighly and peculiarly porous, in such a manner as to make it absorbent of sound, and the outer layer ofwhich is designed for heavy pressure and structural support.

We pfovideone innerlayer ofmasonry material structurally 'rigid in its own interior formation, and structurally-a part of the walk It may have a finished and-decoratire surface, and must be suitable for interior exposure, suitability for such direct interior exposure being necessary to the present invention. The outer layer may be either solid masonry or hollow-for heat and moisture insulation. Its primary purpose is that of supporting the superstructure.

. It is not sufficient for the. purposes of this invention that the peculiar porosity of the inner layer above referred to consist merely of lnclosed air spaces. Suchstructure is in reality cellular and :without value'for. thepurpose ofthis invention. The air spaces may beconnecting --and mustconstitute channels traversing the rigid structure of the porous-layer, and reaching to and penetrating the interior surface. It is desirable that these channels be irregular in form, ex-

panding and contracting in cross-sectiomlso that their action will be .like the mufiiin-g action ofa muflier on; an engine exhaust. Also, it is essential that the pores intercommumcate and openly penetrate the exposed face or faces of the body and shall be of such.

.proportional and variant dimensions'that said bodyshall possess the property of absorbmg in excess of ten per centum of sounds lying 1n pitch a between middle 0 and the third octave above'middle 0. Hence, the

body of material, generally stated, is sponge-' like insstructure;

Thus, by porosity we do not mean the vcellular structure that exists in the commercialrporousblock used for insulating for heat and sound. It is essential to this'invention that the sound penetrate thematerial. Any structure which is useful minsulation must be impervious to air, and therefore unsuitable toythis invention. The porousrblock used :forasouad mid heat insurlation, 1s, 1ntheony and. iniacneellulals and is here use n I The new material hereindescribed may be made in different ways, but for illustrative purposes one practical method formaking such material is given in the following description: Clay, flux, such as feldspar, anda vegetable bearing earth, in a slightly moist condition, are pulverized and thoroughly mixed. \Ve have found that the proportionate size or dimensions of the I pores and their consequent power to absorb sounds differing in pitch may be varied and determined according .to the degree of pulverization. In this powdered and slightly moistcondition the material is then screened with a screen about sixteen meshes to an inch. The powdered material is then placed in' molds of suitable form and subjected. to sufficient pressure to cause the-particles. to cohere The blanks are then dried, after which they are placed in a suitable kiln,

the temperature of which. is slowly raised of the .tile whenit is incorporated into the wall of a structure'or upon the.upper.face of the material! as it lies in the mold.

We have found in our experience that the blanks cannot be satisfactorily formed in a press from which the material is ex.- uded, as the rubbing of thematerials against the walls of the dies tends to close the'surface-pores, which renders the finished material entirely unsuitable forour. purposes. a We have found thatthe best ratioin which the three-components should beused varies somewhat with the kind of claysand .earthusedi With our particular materials the followingratios give very satisfactory results.v Clav 25%, vegetable bearing earth 65% and feldspar 10%.

The advantages of a wall constructed in accordance with-our invention are that the desired absorption of sound and the correction of acoustical difficulties is obtained by its use, while at the same time it is'stru'ctural in its nature, and forms a permanent fireproof wall or ceiling, which has to the eye the appearance of solid masonry or "stone, and which may be readily cleaned Wedaim:

1; A sound absorbing wall or ceiling, iiieluding a ceramic material whose body has an exposed finished face and is provided throughout with intercommunicating pores which openly penetrate said exposed finished face.

2. A sound absorbing wall or ceiling, in cluding a ceramic material whose body has an exposed finished face and is provided throughout with irregular intercommunieating pores of variant dimensions which openly penetrate said exposed finished face, the said material possessing the property of absorbing in excess of ten percentum of sounds lying in pitch between middle C and the third octave above middle C.

3. A wall or ceiling for auditoriums and the like, having in combination, a supporting masonry structure, and attached thereto an exposed inner layer of finished masonry sponge-like in structure, the latter having pores which have rigid walls and are intercommunicating throughout the mass and openly penetrate the exposed finished surface, the saidcpores being of such proportional and variant dimensions that said inner masonry material possesses the property of absorbing in excess of ten percentum of sounds lyingin pitch between middle C and the third octave above middle C.

4. A sound absorbing ceramic material having a finished surface which when in place forms the finished exposed Wall or ceiling surface, such material being spongelike in structure and provided with irregular pores which intercommunicate and openly penetrate the exposed finished face or faces of such material and permit the transmission of sound into the interior of such material and provide means for the absorption thereof.

Signed at New York in the county of New York and State of New York this 7th day of February, A. D. 1913.

WALLACE CLEMENT SABINE. ,RAFAEL GUASTAVINO. Witnesses:

T. M. TrrUs, VIOLA E. HUGHES.

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