Abstract: A ceiling baffle includes a glass cloth faced fibrous glass board, grooved and folded to provide a double thickness of board. End caps for the folded board are each provided with blade portions extending between the two thicknesses of board and with a hole in an upper wall portion for receiving a barb portion of a suspension clip attachable to an inverted T-bar of a ceiling grid system for mounting ceiling panels.

Abstract: A fibrous glass board is longitudinally grooved on one side adjacent the center for folding. The folded board is provided with a pair of plastic end caps respectively on opposite ends. The exposed surfaces of the folded board are provided with a decorative facing material, preferably glass cloth. Means are provided for suspending the completed baffle by the end caps from a gridwork of inverted T-bars.

Abstract: A heat and sound insulating panel assembly for wall, ceiling or floor construction consists of a plurality of interlocking vacuum-chambered panel elements fabricated from a relatively hard, low thermally-conductive, fire-resistant or fireproof material with heat-reflective, moisture-restraining coatings on its inner and outer surfaces. Abutting surfaces may be provided with sound-cushioning pads, and vacuum-chambered spacer column elements may be employed, interlocked between panel elements, for uniform increased panel wall thickness.

Abstract: A vertically suspended foil structure for sound muffling and light scattering false ceilings comprises a grid of U-shaped metal crossbeams, resting on longitudinal stringers, and foils attached to one another by a crossbeam engaging device having a spring biassed head for insertion in a hole through a metal plate and a prismatic body whereto a foil is affixed rigidly, each crossbeam having holes through the upper side thereof and mating notches in its wing portions adapted to engage the head in the hole and concurrently snap engage two opposite corners of the crossbeam engaging device in the wing portions.

Abstract: A damper for sound conducted or propagating in solids is constructed to ecially damp oscillations or vibrations of the bending type particularly in plates, housings, girders, rails, rods, etc. The damper is connected to the structural member to be damped in such a manner that the damping force is taken up by the structure member itself. For this purpose a damping element having a high rigidity against bending is secured longitudinally to a structural member to be damped. The structural member and the element form the damping unit. Due to the high flexural rigidity, the damping element behaves like a solid platform or a fixed point, such that vibrations of the structural member cause a relative motion between the structural member and the damping element. This relative motion provides excellent damping characteristics which may even be improved by placing a viscous damping material between the structural member and the element.

Abstract: Electromagnetic wave-absorbing wall comprising ferrimagnetic plates arranged at some intervals in the direction of the electric field of the electromagnetic wave said ferrimagnetic plates being plates of ferrite having the following general formula:MFe.sub.2 O.sub.4wherein M is a bivalent metal such as Mn, Ni, Co, Mg, Cu, Zn and Cd, or plates of a mixture of ferrite powders or carbonyl iron with organic high molecular weight compounds, and said plates having a specified thickness according to the interval.

Abstract: A multi layered sound-proofing structure comprises: a first layer comprising a light aggregate and a binder and having a bulk density of from 0.1 to 2.0 g/cm.sup.3 and void fraction as continuous void of from 15 to 60%; a second layer of a material having a quality to insulate relatively high frequency sounds and penetrate relatively low frequency sounds; a third layer comprising a light aggregate and a binder, the same as or different from those of the first layer and having a bulk density of from 0.1 to 2.0 g/cm.sup.3 and void fraction as continuous void of from 15 to 60%, the first and second layers each overlying the third layer; and a fourth layer of a material having a high sound-insulating ability and covering all surfaces of a layered structure of said first, second and third layers except for the sound incident surface of said first layer. A perforated plate may be provided over the sound incident surface of the first layer with an air space therebetween.

Abstract: A sound barrier and sound-absorption panel preferably of a transparent nature so as not to interfere with vision of and light for the machine or other noise-emitting device, to be shielded or enclosed by one or more of the panels. The panel is formed of transparent sound-reflecting material and sound-absorbing material so arranged relatively that the sound waves are received by the panel and deflected into the sound-absorbing material. The reflecting material and sound-absorbing material are arranged to provide one or more sound-receiving pockets or cavities each of which has an outwardly-diverging sound-reflecting wall surface which faces toward the sound-emitter. The sound-absorbing material is in the form of an outwardly-extending member so located in the pocket or cavity as to absorb sound waves which are received in the pocket or cavity and are deflected into the sound-absorbing member by the sound-reflecting wall surface.

Abstract: The edge of a ceiling tile adjacent the fissured or embossed face of the ceiling tile is provided with a powder coating. The ceiling tile is formed from a fibrous board which has an open pore structure, and powder is dusted on the edge of the ceiling tile and is mechanically held in the open pore structure of the ceiling tile. The powder coating covers the upper edge of the ceiling tile with a coating so as to eliminate the dark edge effect secured when two ceiling tiles are in position with their front planar surfaces not quite in the same plane.

Abstract: In combination, a composite construction comprising a load-bearing substrate, an impermeable liner, and disposed therebetween a circulatory system defined by a network of cells having side walls which are generally in lateral orientation to the liner and the load-bearing substrate, at least some of said side walls having apertures therein whereby at least some adjacent cells are in communication with each other, and means for circulating a fluid through said circulatory system.

Abstract: An arrangement for silencing or damping sound by resonators having space elements with closed air chambers. The resonators have openings in the outside wall facing the air stream, and air in the chambers constitutes a spring. The air in the openings constitutes an element of mass. The combination is caused to oscillate by the sonic energy of the flowing air, thus forming a vibrating system which absorbs the sonic energy.

Abstract: A structural panel of the skin-stiffener type, commonly used in aircraft construction, having significantly reduced vibration response, noise radiation and increased acoustic fatigue life, has a skin supported by uniformly spaced stiffeners which are located such that the fundamental natural frequencies of stiffener segments are equal to the fundamental natural frequency of skin sub-panels between the stiffener segments. The physical and geometric properties of the skin and stringers and the spacing of the stringers in various disclosed embodiments depend upon the trace velocity of the excitation field, loading conditions to which the panel is subjected, and end-conditions of the sub-panels and stiffeners.

Abstract: An enclosure for isolating noise sources composed of four walls and a ceiling, in which some or all of the sides and top consist of a muffler barrier including one or more air paths transverse to the principal direction of sound transmission through the structure. Various types of component muffler barriers are illustrated which include double leaf structures lined with sound absorbing material where the two leaves are disposed in spaced apart relation and include oppositely disposed air intakes and air exhausts to provide the intervening air paths. In one embodiment, components comprise corrugated panels of sound absorbing material disposed in face-to-face relation to provide multiple air channels.

Abstract: A sound attenuating wall comprises a skeleton frame, surface layers secured thereto, skeleton frame members, and an insulation provided between the skeleton frame members and the surface layers, respectively. The skeleton frame members are formed by two elements which in point of strength act separately of each other and are interconnected by portions of material which are weak or slender in the direction of the plane of the wall. The insulation disposed in the wall fills out only part of the space therein.

Abstract: A sound insulation wall having good sound reflection and/or sound absorption properties, high resistance to weathering, resistance to stress, can be easily assembled and has a relatively low weight per unit area can be made in boards 5 to 20 cm in thickness from composite rubber materials comprising rubber shavings having a volume of which is mostly 1 to 20 cm.sup.3 incorporated with a binder of reactive resin.

Abstract: A number of modular office screens are assembled to provide movable sound-absorbing partitions for offices and the like. Each office screen includes a modular sound-absorbing panel comprised of a rigid sound-reflecting core, a separate compressible layer of fibrous material on each side of the core for absorbing and dissipating sound energy coming from opposite sides of the core, and a channel-shaped frame extending around the perimeter of the panel. The sound-absorbing panel is slidably mounted in the channel-shaped frame and releasably held in the frame without the aid of tools or fasteners. A number of such screens are interconnected in various floor plan configurations also without requiring tools or fasteners, by releasably mounting the bottom portions of the frames in fixed upright channel-shaped base members adapted to rest on the floor and arranged in the desired floor plan configuration for each junction of two or more screens.