US3578105A

US3578105A - Acoustical tile

Info

Publication number: US3578105A
Application number: US30919A
Authority: US
Inventors: Allan L Griff
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-04-22
Filing date: 1970-04-22
Publication date: 1971-05-11
Anticipated expiration: 1988-05-11

Abstract

An acoustical tile has a base panel, which may be flat or curved, adapted to be connected with a wall or ceiling, a large plurality of flexible elongated members, and thin planar leaflike resonance members attached at the ends of each of the elongated members. For use on a ceiling, preferably the elongated members are springs or thread or threadlike material and the leaflike resonance members overlap and move separately from each other. For use on a wall, the elongated members are springs.

Description

United States Patent Allan L. Griff 70 Riverside Drive, New York, N.Y. 10024 [21] Appl'. No. 30,919

[72] lnventor [22] Filed Apr. 22, 1970 [45] Patented May 11, 1971 [54] ACOUSTICAL TILE 9 Chins, 8 Drawing Figs.

[52] US. Cl 181/33, 181/30 [51] Int. Cl .L E041 1/86 [50] Field olSearch l8l/33,30, 33.1, 33.14

[56] References Cited UNITED STATES PATENTS 2,502,016 3/1950 Olson l8l/33(.l4)

3,483,944 12/1969 Handy 18l/33(.1) FOREIGN PATENTS 1,108,046 8/1955 France 181/33(.l)

625,660 7/1949 Great Britain 181 /33(. 14)

Primary Examiner-Robert S. Ward, Jr. Attorney-Eliot S. Gerber ABSTRACT: An acoustical tile has a base panel, which may be flat or curved, adapted to be connected with a wall or ceiling, a large plurality of flexible elongated members, and thin planar leaflike resonance members attached at the ends of ACOUSTICAL TILE The present invention relates to building construction and more particularly to an acoustical surface.

At the present time most acoustical members are flat tiles consisting of 'apanel having sound absorbent qualities. The sound absorption is provided by a large number of cavities, either regularly or irregularly spaced on the surface of the panel facing the room. It has been sought to provide an aesthetic appearance with such panels by having either the holes or raised portions form a design. Various other types of acoustical materials have been suggested, for example, loudspeakerlike diaphragms connected to the ceiling or a lattice or rough or textured materials which could be attached to the ceiling or wall. Many of these suggestions, however, have not been acceptable because the surface did not present a pleasing appearance, the units were excessively fragile, they had poor sound absorption, they collected dust, or because of factors of cost of production or of installation.

It has been recognized that a sound absorber may be made on the principle of resonance; for example, it has been'suggestedthat a perforated front panel be mounted some distance from a solid backwall and a layer of porous absorbing material applied between the two layers. The theory of such construction is that vibrations of the volume of air between the front panel and the backwall are obstructed by the absorbing material. One difficulty which has been envisioned with that suggestion is that a relatively large volume of absorbing material would be required to absorb low-frequency noise.

It is the objective of the present invention to provide a sound absorbing surface which is effective to acoustically dampen a room and which may be applied either to the ceiling or to walls of the room.

It is a further objective of the present invention to provide such a sound absorbing surface in the form of modular panels which may be readily adhered to existing structural ceilings and walls and which may be replaced for repair and cleaning.

It is a further'objective of the present invention to provide an acoustical ceiling or wall surface which presents an interesting and pleasing aesthetic appearance.

In accordance with the present invention, an acoustical surface is provided having sound absorbing properties and presenting an interesting and novel appearance. The surface may be formed of members which are tiles (modular units); for example, the squares may be from 6X6 inches to 24x24 inches large. Alternatively, the members may be curved. Each modular unit consists of a base panel adapted to form, or be adhered to, a ceiling or wall. For example, the back of the panel may have adhesive material covered by a removable paper, or it may have a surface adapted to receive an adhesive, or its edges may be adapted to interlock with each other and with a metal, plastic or wooden support grid. A large number of thin elongated flexible support members are attached to the base panel. For example, in the case of a ceiling tile, the support members may be elongated thin springs, threads or threadlike plastic members, or electric current carrying wires. In the case of wall tile, the elongated members are metal or plastic elastic springs. Each of the elongated members carries, at its free end, a planar leaflike resonance members which may be of a curved, irregular, circular, square, or other shape. Preferably the large number of resonance members overlap each other (when viewed from below in the case of a ceiling tile) and may move separately because of gaps between the overlapping portions or because they lightly touch. Consequently, each of the resonance leaflike members is free to vibrate at its natural frequency and to dampen sound. Preferably, the leaflike resonance members are of different sizes and weights to effectively dampen the frequencies of sound over a wide range. The overlapping resonance members present generally a plane or surface which has an air space between its top surface and the bottom surface of the base panel, which-air space acts as a cavity to further dampen sound.

Other objectives of the present invention will be apparent from the detailed description provided below, taken in conjunction with the accompanying drawings. In the drawings:

FIG. 1 is a bottom plan view of the first embodiment of a ceiling member;

FIG. 2 is a side plan view of the member of FIG. 1;

FIG. 3 is a perspective view of one form of the elongated support member and its attached leaflike resonance member;

FIG. 4 is a second form of elongated support member and its attached leaflike resonance member;

FIG. Sis a side plan view ofa portion ofa wall panel;

FIG. 6 is a side plan view of an alternative ceiling tile;

FIG. 7 is a side plan view of another alternative ceiling tile; and

FIG. 8 is a perspective view of the elongated support member and its attached leaflike resonance member as used in the tile of FIG. 7.

As shown in the drawings, the ceiling acoustical member of FIG. 1 presents generally, from below, the appearance 'of an irregular surface. The surface consists of a plurality of acoustically resonant planar

leaflike members

1, 2, 3, 4, etc. In an acoustical tile of the present invention, in the size of 9X9 inches square, there may be, for example, from 30 to of such planar leaflike resonance members. For example, a tile l2 inches X 12 inches would have about 50 resonance leaves. Preferably each of the resonance members is differently shaped in plane outline, although their thickness may be uniform. The average size of each of the resonance members 1-4 is preferably 2 to 8 square inches, with 6 square inches average being preferred, although some are smaller than others, for example, the range being 1 to 9 square inches.

A suitable leaflike resonance member may be cut from foamed sheet material of 4080 mils in thickness of polystyrene or polyurethane material. The material may also be a foam-paper laminate or may be electroluminescent. For simplicity of manufacture, only five or six differently shaped sizes need be used, as long as they are relatively randomly dispersed.

As shown in FIG. 2, each of the planar leaflike resonance members 1--4 is attached to a flexible elongated support member, respectively 5, 6, 7 and 8. The elongated support member, in the case of a ceiling tile, may be cotton thread or elongated filament plastic members. The thread may also be elastic, or an electric wire. As shown in FIG. 4, each of the elongated support members, in the case of a wall tile, is a flexible and elastic spring, for example, a flat or round in cross section spring capable of supporting the weight of the resonant members to which it is attached. Such springs may also be used for the ceiling tile. Those springs 9, 10, 11 and 12 may flex in any direction if they are round in cross section.

In both the case of the wall tile and the ceiling tile, the elongated support members' 5 through 8 and 9 through 11 are attached to respective base panels 12 and 13. The base panels preferably are rigid panels which are adapted to be connected to either the ceiling or to a wall. The base panels may be flat or curved, depending upon the surface to which they would be attached. For example, the back of the panels may have an adhesive covered by a removable cover sheet. Alternatively, the base panels, as in conventional ceilings tiles, may have protruding lips adapted to interlock and be stapled or other wise attached to a ceiling.

As shown in FIG. 3, each of the leaflike resonant members may be integrally molded with its attached elongated support member. The flat portion 14 and its integral support portion 15 terminate in a ball-like knob 16 at the top of the elongated support portion. Any of the inexpensive and somewhat rigid plastics may be used in molding the integral member of FIG. 3; for example, the member may be molded of high molecular weight polyethylene or nylon and may be molded in different colors to provide an interesting appearance. The integral member of FIG. 3, if the elongated support portion 15 is made of sufiicient thickness, may be self-supporting and consequently used in the wall unit shown in FIG. 5. The alternative resonant member 17, as shown in FIG. 4, is die-cut as a regular circular disc from foamed polystyrene or polyurethane sheet. The elongated support member is a cotton or nylon thread 18 which is adhered to the back of the planar resonant member 17 by a spot of adhesive glue 19.

A method of manufacture of the leaflike resonant member shown in FIG. 4 would be to jam the thread through the foam piece 17 using a sewing-machinelike device. The glue can then be added, in a subsequent stage, by machine.

Other methods of manufacture of the acoustical member are possible, for example, the integral member of FIG. 3 may be formed on a mold consisting of a solid metal cylinder having a central tube. Small runners from the tube lead to the surface of the cylinder with the form of the leaflike resonant member 14 as a cavity in the surface of the cylinder. The

cylinder is inserted into a tube, the hot molten plastic resin injected and the leaflike resonant member 14 formed. After such formation, the enclosing cylinder is removed and the leaf ejected or pulled out from the cylinder. The string (elongated filament support member 15) may be automatically formed as the plastic in the central tube would be sufficiently hot for separation. An elongated member three inches long, for example, may be formed using that process.

Preferably each of the back panel, elongated support and leaflike members is formed having antistatic materials therein so as to decrease their attraction to dust.

In another method of manufacture, a plastic thread may be punched through resonant members of plastic resin foam leaves. The thread would be prevented from going beyond the leaves by a heated metal plate. The thread, made of nylon, would ballup at its tip due to the heat, thereby preventing the leaf from coming off the thread. Alternatively, a knot may be formed by using sewing machine techniques, at one or at both opposite sides of the leaves.

The spacing between the general plane formed by the leaflike resonance members and the backing panel may be from 2-6 inches, depending upon the weight and size of the resonance members and the type of sound desired to be absorbed.

As an alternative method of manufacture, the planar leaflike resonance members may be integrally molded as elongated suppott members, as shown in FIG. 3, and placed on a fiat fixture panel having an adhesive to temporarily hold them in place. The fixture panel can then be inverted and the free ends of all the elongated support members 15 placed against a hot plate, causing the ends to ballup and forming balls 16. The balls 16 will lie in a common plane. The balls 16 can then be placed in a frame (molding apparatus) and either a foam plastic resin or liquid plastic resin poured in the frame. The foam or liquid plastic resin will harden, forming a base panel for the acoustical tile in which each of the balls 16 will be firmly held. The temporary adhesive holding the faces of the resonance members 14 to the fixture panel can then be removed. Preferably the members 14 will be formed in a flat arrangement on a larger frame, for example 12 inches X 12 inches, with their integral supports 15 bent inward to form a smaller base panel, for example, 9 inches X 9 inches. Upon release of the temporarily held position, the flat resonant members will tend to overlap each other and form a unit of about 9 inches X 9 inches.

In theembodiments of FIGS. 1, 2, 3 and 4, the elongated support member (thread or integral string) is attached to the leaflike resonance member preferably at the exact center of gravity of the leaflike member, so that its bottom surface lies approximately parallel with the bottom surface of the ceiling. In the alternative embodiment of FIG. 6, each of the

leaflike resonance members

20,21 is attached by two elongated members 22,23 and 24,25 to the base panel 26.

In the embodiment of FIG. 7, each of the

leaflike resonance members

27,28 is connected by three short string members to a central elongated support member. Leaf 27 is connected by the

short strings

29, 30 and 31 to the elongated support member 32 which is connected to the base panel 33. Similarly, leaflike member 28 has three strings connected to the single elongated support string 34. By using the proper lengths of the short strings, it is possible to avoid finding the exact center of gravity of each of the leaflike resonance members. It is important in all cases, however, that the bottoms of the leaflike resonance members lie more or less parallel with the ceiling or floor.

The description of the preferred embodiment set'forth above is in terms of relatively thin leaflike resonance members. However, if additional weight is desired, or for an alternative appearance, thick and irregularly shaped members may be used.' For example, the resonance members may be cubes or balls.

I claim:

1. An acoustical member comprising:

a back panel adapted to be secured to a wall or ceiling,

a plurality of elongated flexible support members each connected at its first end to the said panel,

a plurality of resonance members each connected to the second end of said elongated support members,

said resonance members forming a plane which is separated by an air gap from the said back panel.

2. An acoustical member as in claim I wherein said air gap is from 2 to 6 inches.

3. An acoustical member as in claim 1 wherein each resonance member is a planar leaflike sheet member of foamed plastic.

4. An acoustical member as in claim 3 wherein each resonance member is 40 to mils in thickness.

5 An acoustical member as in claim I wherein each resonance member is a planar sheet member molded of plastic resin and integral with its connected elongated support member also of plastic resin.

6. A acoustical member as in claim 1 wherein the resonance members are of leaflike sheet form and overlap each other, when viewed in plan view, and wherein the overlapping portions of the said resonance members are separated from each other.

7. An acoustical member as in claim 1 adapted as a wall tile wherein each of the elongated support members is an elastic spring of sufficient strength to support its attached resonance member in a horizontal position relative to the ground.

8. An acoustical member as in claim I wherein most of the resonance members are leaflike sheets having noncircular curved outlines when viewed in plan view.

9. An acoustical member as in claim I wherein each of the resonance members is a planar disc.

Claims

1. An acoustical member comprising: a back panel adapted to be secured to a wall or ceiling, a plurality of elongated flexible support members each connected at its first end to the said panel, a plurality of resonance members each connected to the second end of said elongated support members, said resonance members forming a plane which is separated by an air gap from the said back panel.

2. An acoustical member as in claim 1 wherein said air gap is from 2 to 6 inches.

4. An acoustical member as in claim 3 wherein each resonance member is 40 to 80 mils in thickness. 5 An acoustical member as in claim 1 wherein each resonance member is a planar sheet member molded of plastic resin and integral with its connected elongated support member also of plastic resin.

8. An acoustical member as in claim 1 wherein most of the resonance members are leaflike sheets having noncircular curved outlines when viewed in plan view.

9. An acoustical member as in claim 1 wherein each Of the resonance members is a planar disc.