Abstract: This invention is directed to a vibration damping soundproof sheet for use in vehicles, in which the surface of the soundproof layer is made flat irrespective of the or uneven configuration at the surface of a vehicle. The soundproof layer-forming material comprises a formed rubber blend in which a foaming agent and other rubber blending agents are blended with a rubber type polymer in which the soundproof layer-forming material contains from 15 to 85% by weight of 1,2-polybutadiene ingredient.

Abstract: A foamed metal which has an apparent specific gravity of from 0.2 to 0.8 and comprises an aggregate of polygonal closed cells of from 2 to 10 mm in average diameter. The foamed metal is not only light in weight, free of directionality and structurally strong but also excellent in sound-absorbing and electromagnetic shielding properties, and is useful as constructional, structural or functional material. A method for producing the foamed material comprises adding calcium as a thickening agent to molten aluminum or alloy thereof in an amount of from 0.2 to 8% by weight, followed by agitating to adjust the viscosity of the melet, then adding from 1 to 3% by weight of powdered titanium hydride as a foaming agent to the melt, and agitating the melt to effect foaming.

Abstract: A sound-damping composite panel with elastic properties is provided by disposing a prefabricated porous core made from rubber granules or scrap, e.g. rubber tire scrap, between a pair of metal layers or sheets, e.g. of aluminum, and adhesively bonding the metal layers to the core under heat and pressure.

Abstract: A sound insulation part for surfaces with known source-sink distribution, in particular in passenger spaces of motor vehicles, is provided, which is designed as a mass-spring system with discontinuities incorporated therein for the purpose of converting sources into sinks. In order to achieve a particularly effective sound insulation with low mass or light weight, the sound insulation part contains, over limited parts of its surface, closed cells (1) embedded in the spring (foam 3) and encased in coils (2). These cells (1) can be directed towards the heavy layer (4) or the panel (8) which the part adjoins, or can be wholly or partly in the intermediate region. The cells (1) can be gas- or air-filled. The foils (2) advantageously have masses of about 25 to 150 g/m.sup.2 of surface.

Abstract: The pasty damping medium is used to damp mechanical and/or acoustic oscillations. The agent contains as a minimum compound a solid finely divided substance or a mixture of solid finely divided substances, as a liquid phase, a silicone oil, a polyglycol, a mineral oil and/or a saturated aliphatic or aromatic aliphatic carboxylic acid ester, an agent for increasing the interfacial surface activity or a surfactant, a finely divided magnesium and/or aluminium silicate and/or a silicon dioxide finely divided as a viscosity stabilizer and possibly a small quantity of an antioxidant. The invention concerns also a method for producing the pasty damping medium and the use of the pasty damping medium in different hydraulic damping devices or for industrial shock absorber or industrial vibration damper.

Abstract: A co-oscillating, volume-changing resonator in the form of a silencer, includes a lens-shaped housing formed of a material having a given flexural stiffness, the housing being arched defining an evacuated cup-shaped cavity formed therein, and a coating layer completely surrounding the housing, the coating layer being formed of a material having a flexural stiffness being at most one-third of the given flexural stiffness of the material of the housing.

Abstract: Composite laminates such as metal plate/vibration damper/metal plate, metal plate/vibration damper/metal plate/vibration damper, metal plate/vibration damper/metal plate/vibration damper/metal plate are disclosed. The vibration damper is composed of ethylene-(meth)acrylic acid salt copolymers or its modified products having a specific melting point and a particular heat of fusion. The composite laminate having at least one vibration damper exhibits excellent vibration damping performance, particularly at high temperatures.

Abstract: The present invention relates to a composite material comprising a porous lead alloy containing from 0.7 to 1.0% silver or 0.1 to 1.0% calcium or 0.7 to 1.0% silver and 0.1 to 1.0% calcium and having its pores filled by a resin such as epoxy resin. The product has utility as a battery electrode and as a sound absorbing material.

Abstract: This is a sound barrier fence adapted to reduce the noise level in a yard which is adjacent a freeway for example. The fence includes two spaced apart upright panels of a dense material such as concrete. The space between the panels which may be three to four inches in width, for example, is filled with a foam insulation material. Posts are provided to hold the upright members in place and rail caps and post caps are provided to keep water out of the interior of the fence.

Abstract: A neutrally buoyant, wide frequency range underwater acoustic baffle suite for extended depth operation comprising a laminated structure including a rigid inner separator sheet having a plurality of uniformly distributed cavities sandwiched between two flexible outer cover sheets and surrounded along its edges with a waterproof seal to completely encapsulate the separator sheet within the cover sheets and waterproof seal. Entrapped air within the air cavities offers a low effective acoustic impedance compared to water, and the rigid inner separator sheet maintains constant separation between the flexible cover sheets, and therefore low acoustic impedance, even under high hydrostatic pressures.

Abstract: A method of producing an open, triaxial woven, acoustic face sheet useful in acoustic energy absorbing panels for aircraft engines or the like. The composite face sheet is formed from carbon fibers in an epoxy resin matrix and has about 25 to 33% open area. This face sheet has lower weight and superior and more uniform strength and stiffness than biaxial composite face sheets. The face sheet is made by first weaving carbon fiber tows at warp angles of +30.degree. and -30.degree. and a fill angle of 90.degree.. The woven sheet is impregnated with epoxy as other resins in a manner which produces no rich or starved areas and no blocked openings. The resulting prepreg material may be stored for extended periods at reduced temperatures. The prepreg material is shaped on a suitable mold surface and the resin is fully cured, preferably in a vacuum bag assembly in an autoclave. The resulting sheet has very light weight, an excellent percentage of openings and high strength and stiffness.

Abstract: A composite board having an excellent vibration-suppressing sound-shielding performance can be obtained by joining a plurality of board materials with each other by the intermediary of a tacky adhesive. This tacky adhesive contains, as its principal components, one or more kinds of polymers selected from the group consisting of natural rubber, synthetic rubbers, various resins (acrylic resin, silicone resin, etc.). A sheet-like base material such as a paper sheet can be used in association with the tacky adhesive layer in the composite board, and such type of composite boards have an excellent vibration-suppressing sound-shielding performance as compared to the composite boards in which the tacky adhesive layer is not associated with a sheet-like material.

Abstract: A sound dampening panel comprises a corrugated center barrier sandwiched between fibrous sound dampening material which is covered with fabric. The fibrous material fills the spaces between corrugations and forms a layer over the corrugations. In one form of panel the fibrous material is thermally fused under pressure such that it is rigidly formed with a relatively low density in the spaces between the corrugations and with a relatively high density in the layer over the corrugations. The fibrous material is also thermally bonded to the center barrier. In another form of panel, inserts of one density are placed in the spaces between corrugatins and those inserts are covered by a layer of greater density which is glued to ridges of the corrugations.

Abstract: A panel having a cellular core and an acoustically semi-transparent facing is provided. The core, which may be a honeycomb, has cells opening to a face of the core. The facing is bonded to the face of the core such that pillow-like portions of the facing extend into the open cells of the core to provide a mechanical interlock between the facing and the core and to improve the absorption of acoustic energy directed upon the panel. The panel may include a layer bonded to the core opposite the facing for reducing the transmission of acoustic energy through the panel or for increasing its strength and rigidity. Preferably, the facing is non-homogeneous such that the density of the pillow-like portions is less than the portions of the facing adjacent the structure of the core. The panel may be formed by heating and compressing an uncured fibrous element of relatively uniform thickness and density against a cellular core. A heated platen may be used to produce a relatively flat, hardened outer surface of the panel.

Abstract: A tackable acoustical structure comprising a tack pin retaining layer, a sound absorptive layer, and a metal foil septum separating the tack pin retaining layer and the sound absorptive layer. The structure can be formed into wall panels having a flame spread index which qualifies them as a Class A rated building materials.

Abstract: A loudspeaker system employing a diaphragm type loudspeaker mounted in an opening in one of a plurality of walls of a hollow enclosure, the walls of the enclosure consisting of a plurality of layers disposed between surfaces thereof, the layers comprising a plurality of elongated strands of wood in a mass of solid resin, the axes of elongation of the strands in layers adjacent to the surfaces being generally parallel to a common plane and generally parallel to each other, the strands in adjacent layers being oriented with the axes of elongation of the strands in one layer normal to the axes of elongation of the strands in the adjacent layer. The enclosure has an axis of elongation and a transverse axis, and the strands in layers adjacent to the surfaces of the walls are generally parallel to the axis of elongation.

Abstract: A sound-insulated flow duct is provided with walls made up of a composite of an elastic thermoplastic, predominantly closed-cell foam material as the outer layer and an open-cell, elastic soft foam material as the inner layer.

Abstract: The present invention is an acoustic panel having a porous layer and a generally rigid layer affixed to each other. The generally rigid layer includes at least one passageway opening on one side of the rigid layer and extending through the rigid layer to the porous layer. The porous layer is a fibrous material. The rigid layer is a concrete-type material, such as vermiculite-cement plaster. This acoustic panel further comprises a generally rigid planar surface positioned adjacent to the porous layer. This generally rigid planar surface can comprise an insulating layer affixed to the other side of the porous layer and a structural layer fastened to the insulating layer. The insulating layer is a polyurethane foam board. The structural layer is a particle board.

Abstract: A device having a high sound absorption ability and intended for use as floor, wall and/or ceiling facing in so-called echo-free rooms (10), i.e. in acoustic measuring rooms designed according to international standard, ISO-3745, in picture and sound recording studios, in sound laboratories etc., in which a sound propagation as in a free field is desired. The new device is based on sound absorbents in the form of plates (16, 20) forming a substrate support (16) and units (20) projecting obliquely from this which are so placed that they have a wave-like cross-section. The size and reciprocal angular conditions of the sound absorbents (20) projecting from the substrate support (16) are chosen so that at least double reflection is always obtained before a sound wave deriving from a measuring object (12) is directed from the device. The sound absorption ability is further increased by utilizing a low-frequency cavity resonance between the projecting sound absorbents (20) and the substrate support (16).

Abstract: A multidirectional sound absorber which is adapted to be mounted on an exterior surface of a wall and includes a substantially flat base made of a relatively low density, sound absorbing material, and an outer layer made of a relatively high density, sound absorbing material attached to the base and shaped to form a plurality of channels which, together with the base, form enclosed hollow chambers. A substantially flexible sheet of acoustically transparent material covers the outer face of the outer layer, and upper and lower track members which enclose the ends of the base and outer layer and are adapted to attach the assembly to an exterior surface of a wall. The base and outer layer preferably are made of fiber glass insulation material. Also in a preferred embodiment, a woven mat of fiber glass material is attached to the outer face of the outer layer, and the sheet is attached to the mat.

Abstract: This invention relates to the field of sound control equipment, and particularly to an acoustical panel for absorbing sound generated by equipment in a sterile environment such as a clean room, kitchen, food processing plant or drug manufacturing facility. The acoustical panel is comprised of an inner core made of loosely woven fibrous material, at least one middle layer on at least one side of the inner core which enhances durability without significantly reducing the sound absorption characteristics of the inner core; and an outer layer fabricated of a durable plastic material capable of being heat shrunk.

Abstract: The present invention relates to a sound absorbing member comprising a fiber grid insert disposed between and bonded to two open cell foam panels.

Abstract: In order to subject sound-emitting surfaces of motor vehicles to localized interference with the sound field, for example, sound obstruction and attenuation, it is already known to insulate the region of the sound sources against noise by cladding the passenger space from within at the relevant point of the wall to be insulated by application of a heavy layer and of a resilient layer which, if necessary, is impregnated with a sound-attenuating material. However, limits are imposed on a sound-insulating cladding of this kind even when further sound-reducing materials are applied, as the transmission of sound energy to the interior space of the motor vehicle then takes place in other ways.In order to remedy this, at least one sound sink is subjected to intensified sound absorption by providing on the wall (2,3) a sound-insulating cladding (6/7). Specifically this cladding comprises a resilient layer (6) preferably made of foam material or fleece which is covered by a heavy layer (7).

Abstract: This invention relates to the field of sound control equipment, and particularly to an acoustical panel for absorbing sound generated by equipment in a sterile environment such as a clean room, kitchen, food processing plant or drug manufacturing facility. The acoustical panel is comprised of an inner core made of loosely woven fibrous material, at least one middle layer on at least one side of the inner core which enhances durability without significantly reducing the sound absorption characteristics of the inner core; edge support means; and an outer layer fabricated of a durable plastic material capable of being heat shrunk.

Abstract: A co-oscillating, volume-changing resonator in the form of a silencer, includes a lens-shaped housing formed of a material having a given flexural stiffness, the housing being arched defining an evacuated cup-shaped cavity formed therein, and a coating layer completely surrounding the housing, the coating layer being formed of a material having a flexural stiffness being at most one-third of the given flexural stiffness of the material of the housing.

Abstract: Fiberizable basalt compositions are disclosed. The fibers are produced from natural basalt rock modified with alkaline earth metal oxides. The fibers can be used to make low density composites for ceiling tile or boards.

Abstract: In sound absorbing lining, conduits (4) are provided, filled with a viscous damping fluid, and are in contact by their ends facing towards the rigid supporting wall (1) to which the lining is applied with flexible cells containing a gas and forming a readily compressible material, for example foam rubber (6). Said conduits are separated from the ambient medium (2) by a separating membrane (3) which is permeable to acoustic waves. Lining is applied to absorbing acoustic waves underwater.

Abstract: An acoustic enclosure (10) has interconnected sound reducing panels forming a substantially rectangular structure which is configured to house a computer printer. Each side (12,14) panel is a multiple strata panel having an outer polymeric stratum (26), a multiple channel intermediate thermoplastic stratum (28) and an inner open celled acoustic material stratum (30). The rear and bottom panels (16, 18) are multiple stratum panels, having multiple channel intermediate thermoplastic stratum (46) which is sandwiched between inner and outer polyurethane foam strata (44,48). An adhesive material (42) is provided for bonding the outer stratum to the intermediate stratum and the intermediate stratum to the inner stratum for each of the panels. An angle member (62) affixed to the intermediate stratum is provided for joining adjacent panels of the enclosure. A rigid thermoplastic hinged cover (22) having a uniform bend (52) is provided for closing the enclosure.

Abstract: An improved ceiling panel especially useful in mobile residential or commercial structures is provided wherein said ceiling panel has on one surface (usually the back surface) a moisture barrier comprising a cured coating of an aqueous emulsion of slack wax, an emulsifier of triethanolamine and stearic acid, and silicone.

Abstract: A board having improved thermal and/or acoustical properties is disclosed, together with a method and apparatus for producing same. The board is of finite thickness and has a graduated density, the two opposing major surfaces have the greatest density and the intermediate portion has the least density with the board density gradually decreasing in the region between the major surfaces toward the intermediate portion thereof. The board is produced by a molding process, wherein blankets of loosely gathered fibers and containing a suitable binder, are utilized to form the board. The blankets are preferably high compressible and have interposed therebetween an initially relatively highly incompressible air filled member. These laminates are pressed together between a pair of heated mold halves. As the temperature of the laminate increases, the interposed member softens and is rapidly reduced in thickness due to the escape of air as it softens and melts.

Abstract: Two pelts of fiberglass are bonded together to form a sound absorption panel. One pelt is deformed to a sawtooth shape and the teeth of the sawtooth pelts are bonded into grooves in the other pelt which is essentially flat except for the grooves.

Abstract: A panel having a cellular core and an acoustically semi-transparent facing is provided. The core, which may be a honeycomb, has cells opening to a face of the core. The facing is bonded to the face of the core such that pillow-like portions of the facing extend into the open cells of the core to provide a mechanical interlock between the facing and the core and to improve the absorption of acoustic energy directed upon the panel. The panel may include a layer bonded to the core opposite the facing for reducing the transmission of acoustic energy through the panel or for increasing its strength and rigidity. Preferably, the facing is non-homogeneous such that the density of the pillow-like portions is less than the portions of the facing adjacent the structure of the core. The panel may be formed by heating and compressing an uncured fibrous element of relatively uniform thickness and density against a cellular core. A heated platen may be used to produce a relatively flat, hardened outer surface of the panel.

Abstract: The pasty damping medium is used to damp mechanical and/or acoustic osciallations. The agent contains as a minimum compound a solid finely divided substance or a mixture of solid finely divided substances, as a liquid phase, a silicone oil, a polyglycol, a mineral oil and/or a saturated aliphatic or aromatic aliphatic carboxylic acid ester, an agent for increasing the interfacial surface activity or a surfactant, a finely divided magnesium and/or aluminium silicate and/or a silicon dioxide finely divided as a viscosity stabilizer and possibly a small quantity of an antioxidant. The invention concerns also a method for producing the pasty damping medium and the use of the pasty damping medium in different hydraulic damping devices or for industrial shock absorber or industrial vibration damper.

Abstract: This invention relates to vacuum-tight tubular enclosures, made of plastic material and designed for making up insulating panels. Each vacuum cell is composed of a rigid plastic tube (1), both ends of which are closed by perforated plugs (3). This tube is placed in a thin flexible sheath (6) of highly impervious plastic material, preferably polyvinylidene or a derivative of polyvinylidic alcohol. This sheath extends beyond both ends of the rigid tube and is sealed by welding after the rigid tube has been evacuated to a high vacuum, namely less than 10.sup.-3 mm Hg. The extensions of the sheath are flattened and joined together by seams in a grid pattern so as to form offset rows of alveoles (11) for effectively preventing air leaks into the evacuated tube.This invention also relates to thermal and/or acoustic insulating panels in which evacuated cells (18, FIG. 9) of the above design are inserted, preferably in overlapping layers.

Abstract: A sound absorption panel in which a honeycomb core exhibiting cell end planes has bonded to those planes a porous fiberglass pelt, a layer of thermoplastic material intermediate the core and the porous fiberglass pelt having been subjected to pressure and heated to the point of liquification providing the bond between the porous fiberglass pelt and the cell end plane of the honeycomb core. The thermoplastic in its melted state penetrates the fibers of the porous fiberglass pelt and flows around the edges of the cell end plane of the honeycomb core.

Abstract: A foam-barrier-foam-facing acoustical composite is disclosed having improved acoustical and flame retardant properties. The acoustical composite is a multilayered laminated fabric composed of: (a) a flame retardant polyvinyl fluoride facing layer; (b) a fire resistant acrylic adhesive layer bonded to the polyvinyl fluoride facing layer; (c) a first polyimide open cell foam layer bonded to the adhesive layer; (d) a noise barrier layer bonded to the first polyimide open cell foam layer, and (e) a second polyimide open cell foam layer bonded to the noise barrier layer.

Abstract: A structure for absorbing wave energy, particularly acoustic wave energy, which includes a first essentially planar surface against which wave energy is directed and a second essentially planar surface generally parallel to and spaced from the first surface. Wedge-shaped elements of sound-absorbing material are disposed between the planar surfaces. All of the wedge-shaped elements, which may be of triangular cross section or pyramidal, have generally flat base portions which form said first planar surface against which wave energy is directed. The apex portions of the wedge-shaped elements are in substantial abutment with the second planar surface. The invention has utility in anechoic applications; however, in contrast to prior art structures of this type, the apex portions of the sound-absorbing material face away from incident wave energy rather than facing toward it.

Abstract: It should be possible to manufacture, in a simple manner, a sound-absorbing wall-lining (3) consisting of a material to be applied to the wall which needs lining, and a resilient layer (4, 5) of foam, e.g. foam rubber, felt, or similar material, having locally distinctive sound-absorbing capacities, and whose thickness will possibly remain uniform, provided the resilient layer (4, 5) contains a filler with locally distinctive degrees of cross-linking--corresponding to distinctive sound-absorbing capacities.

Abstract: A noise-shielding panel comprises a flat section spacedly disposed from the surface of an engine body and formed of a fibrous composite, and a contacting section integral with the flat section and formed of the same fibrous composite as in the flat section. The contacting section is in direct contact with the engine body surface and lower in density of the fibrous composite than the flat section, thereby facilitating production thereof and exhibiting a high noise-shielding effect.

Abstract: A shaped sound barrier component comprising a thermoplastic member highly loaded with barium sulfate (more than 200 to about 400 parts) and zinc oxide (1 to 500 parts). Preferably the thermoplastic contains 20 to 50 parts of chopped fibers per 100 parts of said thermoplastic although larger amounts can be used, for instance a 100 parts where the usage is severe.

Abstract: Soundproof lining for a gas pipe, in particular for a turbojet fan jet, of the type including a multiplicity of thin, perforated panels juxtaposed by tiling, as well as an intermediate layer between the wall of the pipe and each of said panels to delimit with said perforated panel a multiplicity of resonant acoustical cavities in which the acoustical vents consist of the ports in the perforated panel. According to the invention, in order to make the tubular vents, each perforated panel has a short, tubular sleeve at right angles to each port and located on its face opposite the wall of the pipe.

Abstract: A plate-component (1) which can be used for airborne-sound insulation has chambers (5, 6) filled with a pulverulent or granular, e.g. metallic material, whose chamber walls (2, 3, 4) at least partly are formed by a flexible material. Chambers (5, 6) are small in the vertical direction, but in the horizontal direction can form long channels. This construction not only leads to an increase in the sound insulation of a board joined to component 1 corresponding to an increase in the weight per unit area, but it is also possible to prevent coincidence breakdowns in the range 100-3000 Hz.

Abstract: An acoustical wall panel includes an elongated sound absorbent board faced with a needle-punched non-woven fabric provided with a woven scrim backing and having linear ribs extending longitudinally of the panel. Such panels are mounted by generally H-shaped splines concealed by the panels. The lofted texture of the fabric and the linear ribs help conceal a seam between two panels.

Abstract: A noise reducing cover for an internal combustion engine, comprising a layer formed of a material which is high in damping capacity, and metal fibers contained in the high damping capacity material, thereby effectively preventing engine noise emission, maintaining good heat conductivity therethrough.

Abstract: A sound-absorbing building component for indoor paneling consisting of at least two superimposed sheets, preferably made of a synthetic resin. At least one of the sheets is provided with cup-shaped indentations lying side-by-side in the manner of a grid, the bottom surfaces of these indentations being excitable to lossy vibrations upon the incidence of sound. The upper rims of the cup-shaped indentations are all covered by a further planar sheet which is likewise capable of vibrations. This further sheet seals off the air volumes contained in the individual cup-shaped indentations in an airtight fashion. Small lumpy or irregularly-sized bodies can be provided on the bottom surfaces of the cup-shaped indentations.

Abstract: Beam dampers comprising a stiff, lightweight, elongate beam and layer of viscoelastic material located along an attachment flange of the beam are disclosed. The flanges of the beam is attached by the layer of viscoelastic material to the skin of a structure whose skin vibrations are to be damped. While a beam having a cross-sectional I-shape is preferred, other cross-sectional shapes can be used, such as L, Z, U and T-shapes. Regardless of their shapes, the beam acts as a constraining element for the viscoelastic attachment layer. The beam is oriented such that it is stiff in a plane transverse to the plane of the skin, resulting in thickness deformation of the layer of viscoelastic material (rather than shear deformation) converting vibration energy into heat.

Abstract: Multiple membranes which are transparent, translucent, opaque or otherwise limit electromagnetic radiation are employed in an easily manufactured and transported roll which can be unrolled, cut to length, expanded, erected and sealed, thereby creating a thermally and acoustically insulating electromagnetic wave-limiting panel with separate dead air space separated by said multiple tensioned membranes.

Abstract: A panel for sound insulation of vehicles or other devices is described which is constructed of a fabric of autogenously and chemically bonded, matted polyester fibers having fine surface pores. The fabric is shaped by compression so that it has a thickness of 1 to 3 mm. and exhibits an acoustical impedance of about 30 to about 100 Rayl.

Abstract: The present invention relates to a paste-like damping medium for damping mechanical and/or acoustical vibrations, based on silicone oil, polyglycol, mineral oil and/or a thermally-stable aliphatic or aromatic carboxylic acid ester, finely divided solid material, an agent for reducing the surface tension and an agent for increasing the intrinsic viscosity.

Abstract: The invention is directed to a wallboard structure which is first composed of a base sheet having a dense upper surface region. Over the dense surface region there is placed a vinyl sheet. Perforations are placed through the vinyl sheet and through the dense surface region and partly into the base region so there is formed an acoustical vinyl faced wallboard.