Abstract: A portable information terminal device has a plurality of casings providing a front surface and a rear surface, respectively. The casings have walls defining spaces in which speakers are housed and thicker than walls thereof that define a space in which a component including an internal circuit is housed. The walls defining the spaces in which speakers are housed are prevented from causing resonance due to vibrations of the speakers. The walls that define the space in which the component including the internal circuit is housed may be of a minimum thickness required irrespective of resonance caused by vibrations of the speakers. With the above arrangement, the portable information terminal device is small in size and weight.

Abstract: The present invention is a system and method to significantly reduce noise associated with air-moving devices such as an axial flow fan using a fan shroud and barrel combination with built in silencers such as Helmholtz resonators. The invention can be applied to a variety of applications such as a thermal management system for a fuel cell powered vehicle. The resonator can be a hollow cavity in networks attached to an outer or inner barrel or shroud and tuned to reduce noise at predetermined noise frequency ranges within the airflow. The invention can also attach stator members on the inner surface of the outer barrel to further reduce noise. Additional sound absorbing material, such as steel wool, can be disposed within the resonator cavity.

Abstract: A speaker box is covered with a buffer material exclusive of a portion where an acoustic output is derived from a speaker unit. The speaker box covered with the buffer material is attached to the surface of a wall member such as an interior member of a vehicle body or a side plate outside the vehicle body in a manner the speaker box is pressed by a holding member, which is a part of the interior member or designed member, and secured by bolts. Even when the surface of the speaker box is vibrated, the buffer material prevents an acoustic output due to the vibration from being generated so that no unnecessary acoustic signal is generated.

Abstract: The present invention relates to an improved structure for quick-assembly cabinet; and comprises a cabinet with a loudspeaker provided thereon. The first side of cabinet is provided with a loudspeaker holder and the second side opposite to the loudspeaker holder is provided with a screw hole. Loudspeaker stand is provided with an expansion plate larger than the foregoing loudspeaker holder; and the back of magnetic loop is provided with a pair of screw holes that allow screw to penetrate from behind the box to fix the loudspeaker. The loudspeaker holder and loudspeaker stand are provided with joints and openings, respectively. Thus the sound box can be assembled faster and no screws are needed on the front side of loudspeaker and, therefore, the production efficiency is significantly improved and the cabinet looks more attractive than conventional cabinets.

Abstract: This invention has been made to provide a speaker system capable of miniaturization and presenting a good sound quality. A speaker 15 is mounted on a printed circuit board 21 arranged inside a telephone body enclosure 12. Acoustic waves of positive phase produced by vibration of a diaphragm 23 of the speaker 15 are output through front acoustic apertures 28 and a front air chamber 37 to the exterior from an enclosure acoustic aperture 13. On the other hand, the acoustic waves of opposite phase enter a rear air chamber 35 through rear acoustic apertures 29, reach an enclosure internal space 36 through an opposite-phase opening 34 provided by cutting away a part of a rear sealing member 32, and transmit to a card slot 14, then being output to the exterior.

Abstract: In an arrangement comprising a motor/pump unit and a sound-deadening cover, the sound-deadening cover absorbs the airborne noise emitted by the motor/pump unit. On the other hand, the sound-deadening cover acts like the diaphragm of a loudspeaker for the structureborne noise emanating from the motor/pump unit. In order to absorb the structureborne noise as well, the sound-deadening cover is constructed as a sound-deadening hood, and is placed over the motor/pump unit in the operating condition, without touching it. During transportation, the sound-deadening hood and the motor/pump unit are supported on one another. The arrangement is used to absorb sound from units comprising a pump and a motor driving the latter.

Abstract: An engine cover has a cover body having a through hole penetrating both sides of the cover body in an area opposed to a resonant space in which resonant sounds are generated. An opening of the through hole is covered with the sound absorbing member layer. Because a part of the resonant space is open, resonant sounds generated in the resonance space are decreased.

Abstract: An air compressor unit having an enclosure that permits adequate cooling air flow, and reduces the amount of noise that emanates from the air compressor unit. The enclosure has a partition that separates the interior of the enclosure into two compartments: a discharge compartment and a component compartment. A discharge aperture is in fluid flow communication with the discharge compartment. A compressor and motor are contained in the component compartment. The component compartment may be separated in a first compartment and a second compartment. Inlets allow cooling air to enter the enclosure, and a discharge aperture permits the cooling air to exit the enclosure. A blower draws cooling air into the enclosure through the inlets. An aftercooler is located between the compressor and the discharge aperture. The enclosure and compartments are configured to reduce the amount of direct “line of sight” noise that emanates from the air compressor unit.

Abstract: A speaker assembly is provided for enclosure within a structural pole. The speaker assembly includes a sub-plate adapted to be affixed adjacent to an internal cavity formed in a fixed end of the structural pole. A speaker is mounted to the sub-plate and oriented such that acoustical vibrations provided by the speaker are directed toward an underlying support surface of the structural pole. A resonating chamber member is oriented within the structural pole internal cavity and has an open end mounted adjacent to the speaker. The resonating chamber member is sized to match the speaker.

Abstract: A device and a method for reducing or muffling sound from kitchen appliances such as coffee grinders. The sound reducing or muffling device can be left on the appliance even when not in use, providing a decoration to the kitchen in a style appropriate to it's surroundings. Using the muffling device, a person can enjoy fresh-ground coffee at any time with the assurance that the sound from the coffee grinder is well insulated. The device is particularly easy to deploy and use, requires no moving parts, and is flexible enough to work with the majority of coffee grinder products currently on the market. Other embodiments can be used with other forms of kitchen appliances.

Abstract: Speaker system for a display including a cover frame integrated type speaker 1 having a cover frame 101 with screw holes 106 for assembly with a rear cover 2 at top and bottom thereof and a speaker 100 for emitting sound integrated with the cover frame 101, a rear cover 2 fastened to a rear of the cover frame integrated type speaker 1 having a vibration attenuation member mounting unit 200 provided on top and bottom thereof, and vibration attenuation means disposed between the cover frame integrated type speaker 1 and the cabinet for attenuating a system vibration to prevent transmission of the system vibration to the cabinet 4, whereby saving cost, improving a productivity, preventing a pressure loss of a sound directed forward caused by a leaked sound directed backward, and attenuating a system vibration from the speaker so as not to reach to the cabinet, to provide a speaker of a high sound quality and a low howling.

Abstract: A speaker system and related method for making the same include a rigid, cylindrically shaped body member with opposite ends and a hollow interior which defines a sound chamber. A base is connected with one end of the body member to support the speaker system within a building room. A high-range speaker is mounted in the sound chamber, with a diaphragm portion located within a first radial opening in the body member to direct high-range sound radially toward the listener. A bass port is mounted in a second radial opening in the body member opposite the high-range speaker, and directs low-range sound in the sound chamber radially toward the listener. A head is mounted on the end of the body member opposite the base member, and includes a mid-bass speaker with a diaphragm oriented axially outwardly, so that sound emitted therefrom is directed axially onto the surfaces of the room to naturally equalize the output of the speaker system.

Abstract: An air introduction system (10) provides an active noise control system which includes a speaker assembly (28) in which the speaker support ring (36) is mounted to a speaker housing (32) without fasteners. In one speaker assembly, the speaker housing includes a plurality of extensions (40) which extend radially from an outer periphery of the speaker housing (32). The speaker support ring includes an edge (42) which at least partially surrounds the extensions (40). In another speaker assembly, the speaker support ring (50) includes a plurality of apertures (52) through a flange (54) which closely fits a speaker housing (32). The housing edge (54) and the speaker protection cone edge (56) are heated to a melting point of the material and the speaker support ring (50) is sandwiched therebetween. Heated material from the housing edge and the speaker protection cone edge pass through the apertures (52) to provide an effective bond therebetween.

Abstract: The speaker assembly includes a speaker housing having a closed top wall and an opposed open end. The speaker assembly further includes a first sound source having a cone with an interior surface and an exterior surface. The first sound source is mounted within the speaker housing such that the interior surface of the cone faces the closed top wall and the exterior surface substantially faces the opposed open end. A portion of the exterior surface of the cone is covered, thereby, revealing an exposed portion which defines the directionality of the first sound source. The speaker assembly also includes a second sound source having a cone with an interior surface and an exterior surface. The second sound source is mounted within the speaker housing such that the interior surface of the cone faces the closed top wall and the exterior surface substantially faces the opposed open end.

Abstract: A speaker enclosure (10) comprising a speaker box (12) having an opening (27) and adapted for mounting within a wall (20) upon a wall stud (22); a compressible gasket (14) affixed about the box opening (27); a faceplate (16); and a plurality of independently adjustable coupling mechanisms (18) for coupling the faceplate (16) with the box (12). The protruding, uncompressed gasket (14) is compressed by the faceplate (16) and the coupling mechanisms (18), which may be independently adjusted to provide an optimum and substantially uniform degree of separation between faceplate (16) and wall (20), thereby reducing distortion, vibration, and damage due to undesirable contact therebetween. A spring (160) is provided to prevent over-compression of the gasket (14) due to heavy or low frequency speakers, thereby facilitating maintaining the uniform degree of separation; and a spacer (162) is provided to maintain the spring (160) in its operating position.

Abstract: An improved heat shield offers both a thermal insulation and reduced noise transmission for vehicular engine components, including exhaust manifolds, for example. The structure has three layers: an outer structural metal layer, a center insulation layer to isolate heat and dampen noise, and an inner metal layer directly adjacent the shielded component for reflecting heat back to the shielded component. As disclosed, the heat shield includes at least one bolt aperture for attachment of the shield to a shielded component, such as an exhaust manifold in the described embodiment. The aperture is circumferentially bordered by at least one non-planar undulation defining a protuberance. The protuberance is spaced circumferentially about the aperture. As the bolted connection of the heat shield to the manifold is a major source of vibration transmittal from the manifold into the shield, the protuberance is effective to dampen the vibration, and hence noise associated with the vibration.

Abstract: A directional speaker system includes an enclosure having an inner surface, an outer surface, an open end, and a closed end, a speaker driver directed toward the open end and mounted near the closed end of the enclosure, an in-line phase plug mounted in front of the speaker driver for manipulating the wavefront of sound waves produced by the speaker driver, and a preferably frustoconical shaped wave guide provided between the speaker driver and the open end of the speaker enclosure. A preferably annular space is provided between the enclosure and the wave guide and a plurality of openings are provided between the enclosure at the open end of the enclosure. Out-of-phase sound waves produced by the speaker driver travel into the space and exit the speaker system through the openings.

Abstract: A shielding enclosure, for example an appliance sound enclosure comprises a base, a front shield and a top shield. The base is fixed onto a surface and has a back wall and pair of sidewalls connected to the back wall. The front shield is adapted to be rotatably mounted onto the base and is slidingly connected to the top shield by a pin-in-slot connection. The top shield is adapted to be rotatably mounted onto the base and is slidingly connected to the front shield by a pin-in-slot connection. The front and top shields have arcuate panels that, in combination with the rotation around the base, provide for an enclosure around an appliance.

Abstract: An improved structure of speaker cabinet comprising a housing opened on one side thereof, and comprising a front panel, wherein, a plurality of intermediate speakers can be held firm and get increased connecting strength when the front panel is integrally connected with the housing to thereby offset the frontward and rearward thrusts of the speakers. Moreover, a plurality of hollow posts located at the positions in correspondence with those of the connecting areas of the speakers to the cabinet can be filled therein with vibration absorbing material in order to reduce vibration at the earliest time. Such a design not only can reduce volume and weight of the cabinet, but also can improve sound quality and provide a hidden port to improve beauty and waterproofing effect of the cabinet.

Abstract: The present invention provides an exterior structure for an electronic keyboard instrument which has excellence in an outward appearance and which can be produced easily without detracting acoustic characteristics. In the present invention, a recess groove 9 extending in a direction in which keyboards 3 are arranged is formed at an upper portion of a back panel 4 of the electronic keyboard instrument 1, a locking edge 8a formed at an upper edge of a speaker cover 8 is fitted into the recess groove 9, and a lower edge of the speaker cover 8 is fixed to a lower portion of the back panel 4 by a screw 11. A lower portion of the back panel 4 is provided with a positioning stopper 4d which abuts against a back surface of a keybed 12 of the electronic keyboard instrument 1, and a fixing piece 4e which abuts against a lower surface of the keybed 12. A thick plate 14 having rigidness is provided around the periphery of the speaker-mounting hole 6.

Abstract: An improved structure of speaker cabinet comprising a housing opened on one side thereof, and comprising a front panel, wherein, a plurality of intermediate speakers can be held firm and get increased connecting strength when the front panel is integrally connected with the housing to thereby offset the frontward and rearward thrusts of the speakers. Moreover, a plurality of hollow posts located at the positions in correspondence with those of the connecting areas of the speakers to the cabinet can be filled therein with vibration absorbing material in order to reduce vibration at the earliest time. Such a design not only can reduce volume and weight of the cabinet, but also can improve sound quality and provide a hidden port to improve beauty and waterproofing effect of the cabinet.

Abstract: A woofer that is capable of producing a flashing light show depending upon the volume and frequency of the sounds emitted thereby. The woofer includes at least one light emitting diode and a control circuit that are conveniently mounted on a printed circuit board at the center of the woofer at an inconspicuous location below a transparent dust cover so as to achieve a compact configuration without effecting the aesthetic appearance of the woofer. The woofer also includes a magnetic structure having at least one permanent magnet and at least one electromagnetic voice coil that is adapted to move in first and opposite directions towards and away from the permanent magnet depending upon the changing polarities of an alternating current that is supplied to the electromagnetic voice coil.

Abstract: This invention simply quiets down the sound of the operation of the Oxygen Concentrator so the user can sleep.

Abstract: A speaker box is comprising a hollow enclosure having opposing open ends, a molded plastic end cap acoustically sealing each of the open ends of the enclosure, and each end cap having at least one lengthwise reinforcement rib formed across a surface thereof to thereby substantially prevent the end cap from flexing under acoustic pressure. Each end cap preferably has a pair of reinforcement ribs formed on an inner surface of the end cap. The reinforcement ribs preferably intersect one another and taper upward toward the center of the end cap. The reinforcement ribs preferably extend substantially perpendicularly from the end cap. The end caps preferably have a recessed portion that recesses toward an inner surface of the end cap. An outer lip of the recessed portion provides additional rigidity to the end cap.

Abstract: A modularized loudspeaker enclosure having an open-ended enclosure body, a loudspeaker support at one open end and an end structure at the other end. The enclosure body can be modified to alter the volume of the enclosure. A finally assembled enclosure can be sealed or ported. In one embodiment, the enclosure body includes a cylindrical tube cut to a length that provides a desired volume. In another embodiment the enclosure comprises standard corner, wall and end structures that constitute a component set for a constant length enclosure that can have different cross section areas.

Abstract: Apparatus for reducing noise emitted from an appliance having a cabinet that supports at least one component that emits at least one acoustic pressure wave therefrom. In a preferred form, the apparatus comprises at least one diffuser having at least one deflection surface. The diffuser is coupled to the cabinet and positioned relative to the one component such that the acoustic pressure wave emitted from the component is deflected by the one deflection surface in a predetermined direction. The diffuser can be used to deflect acoustic pressure waves such that they collide with each other. The apparatus may further include at least one absorber. The diffuser is strategically located to deflect acoustic pressure waves being emitted from the component into the absorber to reduce the noise emitted from the appliance.

Abstract: An economical and compact dual-chamber loudspeaker includes a small driver received within a partition extending between, and in acoustical and pneumatic communication with, both a front and a back chamber, each of which has a relatively small volume. An elongated vent is in acoustical and pneumatic communication between the front and back chamber at a substantially planar opening in the partition. The drone cone is in acoustical and pneumatic communication between the front chamber and the outside environment at a substantially planar opening in the housing. The two openings are spaced apart and generally parallel to each other. In a preferred embodiment, the volume of the chambers is minimized by securing an elongated concentric vent around the vent extending between the front and back chambers.

Abstract: This invention provides a speaker enclosure that minimizes or defuses standing waves and minimizes resonance within the operating frequency range of its transducers. To minimize standing waves, the speaker enclosure has no two surfaces that are parallel to each other thus preventing the propagation of standing waves. The interior surface of the speaker enclosure may have ribs spaced apart on any surface that is prone to resonate so that the surface is strengthened such that it resonates at a predetermined frequency that is typically outside of the operating frequency range of the transducers.

Abstract: An apparatus attenuates noise from a cabinet that houses computer equipment. The apparatus includes a frame, a set of positioning members to position the frame relative to the cabinet, and lateral noise absorption members that are supported by the frame. The lateral noise absorption members define surfaces that form sides of airflow channels through the apparatus. The surfaces are substantially non-parallel to a direction of an airflow pathway through the cabinet when the set of positioning members positions the frame relative to the cabinet. The lateral noise absorption members absorb sound energy emanating from the cabinet (e.g., from a fan assembly within the cabinet). The lateral noise absorption members transform some of the sound energy into low level heat which can be dissipated into the air stream. Additionally, some of the sound energy is reflected back into the cabinet toward the source.

Abstract: A rigging system for flying a vertical stack of loudspeakers includes left and right rigging side frames (15, 17). Each rigging side frame includes a frame structure having a top end (43), a bottom end (45), and rear and front corners (51, 53, 55, 57) which is mountable to the side of a correspondingly sized loudspeaker (13). Each rigging side frame further includes a rear link (59) for pivotally linking the rear corner of a rigging frame of one loudspeaker to the rear corner of the same side rigging frame of another loudspeaker placed in stacked relation therewith, and a cam plate link (61) pivotally attached to a cam pivot point (85) at one of the top or bottom ends of the frame structure in displaced relation to the cam link. Two or more link openings (143) are provided in the cam plate link at different angles about the cam plate link pivot point and at different radial distances from the cam plate pivot point.

Abstract: A personal care apparatus (1) with a housing (2) and with apparatus parts (6) for treating body parts of a person, which apparatus parts (6) are provided in a head region (5) of the personal care apparatus (1), is fitted in its head region (5) with a noise protection cap (9) which is designed with a closed circumference and which has a cap edge (12) which can be placed on the skin of a person during operation of the personal care apparatus (1) in order to fulfill a noise protection function.

Abstract: A cable reel comprises a cable enclosure having a rubbing face, and a flat cable provided on the rubbing face. A noise-absorbing material is then fixed, without using adhesives, on the rubbing face on which the flat cable moves. The noise-absorbing material is prepared integrally by superposing a highly-slidable noise-absorbing sheet on a support plate, and is formed into a torus shape. The cable enclosure has an outer circular wall and an inner circular wall. The outer circular wall and/or the inner circular wall includes a plurality of holding tabs which are integrally provided in the circumferential direction with substantially a same distance and at a position corresponding to where the noise-absorbing material is mounted. The holding tabs hold the external circular rim and/or the internal circular rim of a highly-slidable noise-absorbing sheet, whereby the noise-absorbing material is immobilized.

Abstract: An acoustic absorber includes an enclosure having a front opening and having a chamber communicating with the front opening for receiving an acoustic absorbing member which includes a housing having a number of apertures for receiving and dissipating noises. The housing may include a circular cross section or the other cross sections, and may include a casing having a number of apertures for receiving and dissipating the noises. The housing may be detachably secured to the enclosure with one or more catches which may engage with the lock grooves of the enclosure.

Abstract: A soundproof cover to be mounted on the engine of an automobile is provided. The soundproof cover includes a foam material having a mixed cell structure of open cells and closed cells and a water absorption coefficient of 0.01 g/cm3 or more and less than 0.5 g/cm3. The foam material is provided along the circumferential rim of a cover main body surface facing an engine, and projects to the engine side by a predetermined height such that the foam material closes the gap with respect to the engine at the time it is mounted on the engine.

Abstract: A fuel tank with a baffle disposed therein is disposed at an intermediate place between the two ends of the tank is provided for preventing noise caused when fuel shifts in the fuel tank from one end to the other. In a preferred embodiment, the baffle is constructed of a fiberglass filter media material. Also in a preferred embodiment, the baffle is collapsible so that it can be inserted into an opening in the top of a plastic fuel tank and then allowed to return to its original larger height whereby it will be held by a biasing pressure in a desired position within the tank.

Abstract: A speaker system includes two cylindrical tubular cabinets. Each cabinet has a vertical longitudinal axis and defines a cylindrical cabinet cavity therein. At least one speaker element is located in each cavity. Preferably, there are upper and lower speaker elements mounted within each cavity, and dividing the cavity into upper, middle and lower speaker cavity portions. The speaker system is particularly constructed for reproduction of the very low frequency audio data below 200 Hz, and preferably below 60 Hz, which is associated with modern high fidelity sound sources such as those using a Dolby®5.1 format.

Abstract: A speaker cabinet has front and back walls and side walls defining a sound chamber, and a location for supporting at least one speaker in one of the walls. Thin metallic stress elements extend between and are connected to selected pairs of walls, and are loaded undertensile stress so as to tune them to desired resonant frequencies. The tuned stress elements vibrate in response to excitation by sound waves emitted from the speaker, thus producing additional sound which enhances the sound from the speaker. Tensioning means provide for selectively adjusting the tensile stress and resonant frequencies of the stress elements and, consequently, the character of the sound produced by vibration of the stress elements.

Abstract: A speaker system suppresses standing waves generated in the system and reproduces clear and dynamic bass sound. The system includes a cabinet formed of acoustic isolation walls, and at least one partition wall situated inside the cabinet to form a space by surrounding the space. The partition wall suppresses the standing waves generated inside the cabinet and is formed of a material having high internal loss. The space has a total capacity more than one tenth of a capacity of the cabinet, wherein a closed end of the partition wall is located between one-half and four-fifths of a distance from one end to the other end, and an opening area of the same partition wall is located at a side opposite to the closed end in a longitudinal direction of the cabinet. The opening area is located between four-fifths and five fifths of a distance from one end to the other end.

Abstract: Speaker apparatus for use in a vehicle having a passenger compartment and a trunk. The speaker apparatus comprises a spare wheel carrying a tire that is disposed in the trunk. An enclosure is secured to the spare wheel. A speaker disposed in the interior of the enclosure. A vent hose couples the interior of the enclosure to the passenger compartment. In another embodiment, the enclosure comprises front and rear sections that are secured together and sandwich the spare wheel. In another embodiment, the enclosure is sealed, and two vent hoses are used to couple rear and front waves emanating from the speaker into the passenger compartment.

Abstract: An acoustic waveguide loudspeaker system has an electroacoustical transducer having a vibratile surface. An acoustic waveguide has a first end open and a second end adjacent to the vibratile surface and an effective length corresponding substantially to a quarter wavelength at the lowest frequency of pressure wave energy to be transmitted between the first and second ends. Damping material in the waveguide near the vibratile surface is positioned so as to negligibly attenuate bass frequency energy while of sufficient volume to damp peaks at higher frequencies above the range of the bass frequency energy.

Abstract: A cladding element having sound-absorbent properties is provided for screening an engine and/or exhaust system of a motor vehicle, for example as an underbody cover panel for same, in the form of a substantially plate-shaped, self-supporting stiff component of thermoplastic material formed at least in part as a hollow body, which at least partially accommodates a sound-absorbent filling of foamed thermoplastic material.

Abstract: A reduced-noise relay has an inside housing and an outside housing. Inside terminals are connected to outside terminals via stranded conductors. An additional intermediate cap of elastomer is plugged over the inside housing with the stranded conductors in the interspace between the inside housing and the outside housing. Together with a damping frame and a damping plate, the intermediate cap effects a sound decoupling of the relay from the outside.

Abstract: An apparatus for protecting equipment in an outdoor communication structure from adverse weather conditions, vibration, and vandalism includes a housing that possesses hidden lip door edges and is assembled such that no screws, nuts, hinges, etc. are left exposed. Also, any speakers and/or microphones are largely isolated from potential vibration by surrounding them with vibration dampeners such as foam or other padding or insulation. Heat, dust intake, vibration, and electricity usage are reduced by providing convection venting wherein the internal cavity of the housing narrows at a top region of the housing. Vents in the top region of the housing allow air from the narrowed internal cavity to escape as it heats and expands. As hot air is displaced from the narrowed internal cavity, cooler ambient air is drawn into the internal cavity through bottom vents in a bottom region of the housing.

Abstract: The television having a device for preventing vibration of speaker comprises a speaker. The speaker is fixed on one wall toward a hollow portion formed in an enclosure, and an opening for emitting sound is formed on the enclosure. A vibration plate faces the speaker to be positioned in the opening at a predetermined interval from the speaker. And, a mounting means for mounting the vibration plate on the enclosure is provided. Therefore, vibration of speaker emitting medium/low bandwidth sound outside and vibration of cabinet in which the speaker is mounted is minimized so that quality of sound becomes high and sound having high power is emitted outside.

Abstract: A sandwich composite panel (2) provides a load bearing structural member as well as noise protection, especially for a helicopter fuselage cell or cabin. The panel (2) includes an inner honey-comb core (6) made up of hollow cell bodies (4) extending trans-versely and sandwiched between first and second cover skins (8, 10) of fiber composite material. In order to achieve a low weight, a simple manufacturing, and good noise absorption, at least one of the cover skins (8) adapted to face the main source of noise (H) is made up of an open mesh fiber composite net (12) and a flexible cover film (16) applied on the outer surface of this fiber composite net (12). The net (12) has a smaller mesh size than the inner cross-sectional size of the hollow cell bodies (4).

Abstract: A hydraulic pump-motor having an end shield which deadens the sound generated by the pump-motor do thereby result in a quieter unit. The present invention provides a conventional hydraulic pump-motor having an electric motor coupled to a pumping mechanism wherein the motor includes an improved sound attenuating end shield design. Through the use of acoustically deadening materials such as cast iron and polypropylene plastic, the end plates of the present invention deaden the sounds stemming from the vibration of the pump-motor. In addition, the present invention provides an end shield design which allows the stator to be secured to the motor housing and the air gap between the rotor and the stator to be precisely measured prior to the installation of the end shield. The present invention therefore results in not only a quieter pump-motor but also a pump-motor with higher machining tolerances, improved efficiency, and lower production and maintenance costs.

Abstract: In an aircraft turbine, an assembly consisting of an air inlet structure, a air blower housing (22) and a connecting part (36), is fitted in such a way as to reduce noise including in the junction area between the structure and the housing. The connecting part (36) is fastened onto a rear section (20'), not provided with a honeycomb core, of the internal wall (20) of the air inlet structure. A honeycomb structure (44) is fitted inside the air blower housing (22). The space inside the rear section (20') houses a forward extension (44') of the honeycomb structure (44), or a different honeycomb structure.

Abstract: An acoustic testing device is relatively small enough and light enough to be transported from business to business and room to room, and yet still has acoustic characteristics sufficient to characterize a test item's noise profile in a relatively short period of time. The device preferably achieves this result by providing inner and outer housings coupled through noise and vibration isolation, the inner housing having at least some mutually non-orthogonal walls, and the sound detection apparatus comprising spatially translating microphones.

Abstract: Disclosed a thermal- and sound-insulating container having a chamber, which is defined by multilayer wall structure including vacuum layers therein. The chamber is made as small as possible the surface area thereof to achieve the high insulating effectiveness. The thermal- and sound-insulating container is comprised of the multilayer wall structure with vacuum layers therein, which constitutes the chamber defined in a hollow cylinder partially having a flat secant face, the hollow cylinder having a cross section of a circle or an ellipse that closely resembles the circle. The multilayer wall structure is composed of a pair of confronting frames arranged spaced away from each other, surface panels attached to the frames to define an empty space between the confronting frames, and sealing members arranged between the frames and the peripheries of the surface panels so as to keep the space at vacuum.

Abstract: A window-type air conditioner housing includes a backboard and two parietal sideboards of polystyrene. Each sideboard has a steel plate implant and a coaxial bracing hole for supporting a motor and an associated air conditioner fan bearing components, respectively, to thereby maintain vibration and noise at reduced levels. Preferably each steel plate implant is dimpled in the area surrounding each coaxial bracing hole to strengthen and stiffen the sideboard in that area for supporting the motor and fan assembly.