Abstract: A muffler assembly, comprising an outer muffler assembly comprising a plurality of fiberglass discs and a plurality of reactive plates, and an inner muffler assembly comprising a plurality of fiberglass discs and a plurality of reactive plates the inner muffler assembly generally surrounded by the outer muffler assembly and defining therebetween a gas flow gap.

Abstract: Exemplary methods, devices and/or system for reducing noise produced by a turbine, such as, a turbocharger turbine. An exemplary exhaust conduit employs material to absorb exhaust-borne noise and/or structure-borne noise. Another exemplary exhaust conduit employs features that dampen wall vibration.

Abstract: A method is employed to attenuate ultrasonic noise propagating in a flow stream of a fluid flow system. In particular, the method attenuates the noise propagating between a noise source and a reference point in the flow stream (wherein the reference point and the noise source are positioned in the flow stream in direct acoustic line of sight relation). The method includes positioning an absorbent element in the flow stream between the noise source and the reference point. Then, the ultrasonic noise is directed past vicinity of the absorbent element such that indirect ultrasonic noise is absorbed by the absorbent element. Preferably, the method also includes deflecting the ultrasonic noise to convert direct noise to indirect noise prior to directing the ultrasonic noise past the vicinity of the absorbent material in the flow stream. Such a method may be employed to attenuate ultrasonic noise by up to about 20 dB to 45 dB.

Abstract: An exhaust gas muffler of multi-chamber construction includes an outer housing having an upper and lower half shell, an inner shell, and an inner exhaust gas duct through the exhaust gas muffler. The inner exhaust gas duct has at lease one curved outlet pipe that has a first curved section and a straight outlet end runs flush with the outer housing. The invention also covers a method for the production of the multi-chamber exhaust gas muffler.

Abstract: A noise muffler for the exhaust of waste gases from apparatus such as an oxygen concentrator, including a muffler core with an inlet to receive the waste gases and a plurality of bores in the core first to direct the waste gases through a filter material and a cap enclosing the filter material and forming a plurality of outlets to direct the waste gases out of the muffler, the bores and outlets positioned to cause the waste gases to change their direction of flow multiple times before exiting the muffler.

Abstract: Duct units for delivery of air to an air supply fan and for connecting this fan to an air heater unit are disclosed. The duct unit for delivering air in one version has a narrow first section, a second, transition-type section and a wide sound attenuating, third section with these three sections extending generally vertically. Spaced apart splitters containing sound attenuating material and having side walls of perforated metal are mounted in the third section. The splitters include a central splitter and outer splitters with the latter converging inwardly towards a central axis of the third section. This duct unit also has an elbow-shaped duct section connected to the third section at its upstream end and connectible to the fan at its downstream end. In another version, the duct unit has a single, elongate splitter that extends longitudinally along at least a major portion of a second duct section and that bends through a smooth curve.

Abstract: A trim panel insulator is provided for a vehicle. The insulator includes a nonlaminate acoustical and thermal insulating layer of polymer fiber. The insulator may include a relatively high density, nonlaminate skin of polymer fiber and/or one or more facing layers constructed from various materials.

Abstract: A compressed air muffler comprises a rear attachment section, a compressed air muffler section adjoining it in the longitudinal direction with a compressed air muffler body of a porous compressed air muffler material and an outlet duct extending in the length direction as far as a front outlet opening, such outlet duct having in the muffler section, a form tapering toward the outlet opening. The muffler body has a bare outer peripheral face, its outer periphery face constituting an outlet face for the compressed air flowing through its wall athwart the longitudinal direction. The duct section extending through the attachment section, of the outlet duct merges steplessly with the duct section running in the muffler section.

Abstract: A noise reduction system for significantly reducing the noise generated by an air turbine used to create suction for automatic cutting tables. The system employs one or more baffles mounted within a closed main housing including noise reduction foam and an exhaust housing lined with noise reduction foam mounted around the baffle exhaust. The direction of the exhaust air is changed 180 degrees and is utilized for cooling the air turbine and electric motor.

Abstract: An improved exhaust system for an internal combustion engine generally comprises two expanding megaphones, separated by a dual core annular flow silencing section. The two or split megaphone design facilitates broadening of the time of the negative pressure wave to provide a desirable broad range power output while substantially reducing obnoxious sound output.

Abstract: This engine muffler has a sound absorbing material interposed between an internal tube and an external tube which is formed with a projection projecting toward the sound absorbing material along almost its entire periphery. When interposing the sound absorbing material between the internal tube and the external tube and drawing the end of the external tube for manufacturing the muffler, the projection projecting toward the sound absorbing material is formed on the external tube almost along its entire periphery after inserting the sound absorbing material between the internal tube and the external tube but before drawing the end of the external tube.

Abstract: A sound attenuating duct unit suitable for connection to an outlet of a gas turbine and an improved heat recovery apparatus for use with such a turbine are disclosed. The former unit includes a duct housing having exterior sides, an air inlet at one end and first and second air outlets. Interior walls define a main airflow passageway extending from the air inlet to both of the outlets. Sound absorbing and heat insulation material is arranged between these walls and the exterior sides. Sound attenuating members are mounted in the passageway and a diverter damper is mounted in the housing and is able to direct air flow to either one of the air outlets. The sound attenuating members are mounted between the diverter damper and the air inlet. The heat recovery apparatus includes a series of aerodynamic diffusers mounted in a housing adjacent an air flow inlet connectable to the gas turbine.

Abstract: A tuning cable assembly comprising a reinforced tube, a tuning cable placed within said reinforced tube, where the tuning cable is comprised of a thermoset material or a cross-linked thermoplastic material, and a narrow annular cavity formed between the inner surface of the reinforced tube and the outer surface of the tuning cable. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. This abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Abstract: An exhaust muffler for an internal combustion engine included in a motorcycle includes a perforated inner pipe (32), an outer pipe (31) coaxially surrounding the inner pipe (32), and a glass wool mat (33) packed in a space between the inner pipe (32) and the outer pipe (31). A three-layer protective structure is formed by winding an inner stainless steel wire mesh (34) wound around the inner pipe (32), winding a stainless steel wool mat (35) around the inner stainless steel wire mesh (934), and winding an outer stainless steel wire mesh (36) around the stainless steel wool mat (35). The glass wool mat (33) is wound around the three-layer structure. The three-layer structure extends the life of the glass wool mat (33) even if the temperature and pressure of the exhaust gas discharged by the internal combustion engine increase.

Abstract: A gas expansion silencer comprising an endpiece for being connected to a source of gas under pressure, and a low-pressure stage comprising two cylindrical portions respectively of smaller diameter and of larger diameter, the smaller-diameter portion being connected to the endpiece and the larger-diameter portion having gas outlet orifices, the low-pressure stage being entirely filled with a porous metal packing.

Abstract: A permeable port constituted by an aperture and a porous member for covering the aperture is provided in a part of an intake air passageway portion of an air intake apparatus. The permeable port is disposed in at least a part of a region between the central position of the whole length of an air intake duct and the central position of the whole length of the intake air passageway portion.

Abstract: An absorptive and reactive muffler includes an annular flow path for the gas with the center of the annulus having a plurality of resonators which are in open communication with the downstream end of the annular flow path and make up the reactive portion of the muffler. The flow path is at least partially lined by an absorptive material overlain by a perforate material and makes up the absorptive portion of the muffler.

Abstract: A high-performance exhaust silencer in which a shell wall includes a shell outer plate, a shell inner plate, and a damping material to be inserted therebetween. A space between the shell outer plate and shell inner plate of the exhaust silencer is narrowed and the shell outer plate and the shell inner plate will not interfere with each other. An outer shape of the exhaust silencer is small but the expansion chambers are large by providing an air space between the shell outer plate and the shell inner plate. For the above-mentioned damping material, a material obtained by stretchably weaving metal wire into mesh is used.

Abstract: In the engine muffler including a first expansion chamber 12 of the exhaust gas having an exhaust gas inlet aperture 11 connecting to an exhaust gas outlet of the engine, a second expansion chamber 14 having an exhaust gas outlet aperture 13, at least one first exhaust gas purifier 15 coated wit a catalyst to purify the exhaust gas purifier provided with innumerable numbers of small holes, a wall side of said second expansion chamber 14 to which the engine is not installed is formed to a double-wall construction of walls 14a and 14b with a predetermined distance, further, the double-wall is packed with a heat insulating material to improve the purification efficiency, heat insulation and sound elimination. Heated muffler wall is decreased. It is also possible by applying a detachable construction to take out the first exhaust gas purifier outside the wall for replacement or cleaning.

Abstract: An improved exhaust system for an internal combustion engine generally comprises two expanding megaphones, separated by a dual core annular flow silencing section. The two or split megaphone design facilitates broadening of the time of the negative pressure wave to provide a desirable broad range power output while substantially reducing obnoxious sound output.

Abstract: The present invention provides a noise attenuation assembly having at least one noise prevention pad disposed within an annular gap formed between a gas passage tube and an overlap tube. The noise prevention pad prevents the two tubes from becoming in contact during thermal expansion of the tubes, and allows the tubes to contract without causing “Tick and Ping” noise, during a cool down.

Abstract: A silencer is provided that is intended to be connected to a gas flow with pressure fluctuations, such as for example downstream a combustion engine, the silencer comprising a housing provided with an envelope surface and two side surfaces and an inlet opening and an outlet opening arranged in the envelope surface.

Abstract: A sound attenuation system for a compressor of a direct fuel injected engine of an outboard motor comprises a discharge sound attenuator connected in fluid communication with an air distribution manifold outlet and a suction sound attenuator connected in fluid communication with the suction port of a compressor. In a typical application of the present invention, the air distribution manifold is connected in fluid communication with a discharge port of the compressor. Both the discharge sound attenuator and the suction sound attenuator can further include filter media disposed within their internal cavities.

Abstract: A method is employed to attenuate ultrasonic noise propagating in a flow stream of a fluid flow system. In particular, the method attenuates the noise propagating between a noise source and a reference point in the flow stream (wherein the reference point and the noise source are positioned in the flow stream in direct acoustic line of sight relation). The method includes positioning an absorbent element in the flow stream between the noise source and the reference point. Then, the ultrasonic noise is directed past vicinity of the absorbent element such that indirect ultrasonic noise is absorbed by the absorbent element. Preferably, the method also includes deflecting the ultrasonic noise to convert direct noise to indirect noise prior to directing the ultrasonic noise past the vicinity of the absorbent material in the flow stream. Such a method may be employed to attenuate ultrasonic noise by up to about 20 dB to 45 dB.

Abstract: An improved inlet silencer/filter for an oxygen concentrator includes a HEPA filter and an adjoining chamber for receiving air flow from the HEPA filter. The chamber is surrounded on one face by the HEPA filter, and by sound absorbing padding on at least 4 other faces. Air is forced from the HEPA filter, through the open chamber and then through the sound absorbing padding by a flow restrictor plate. Air flows from here through air channels and into an open chamber leading to an outlet from the air silencer/filter.

Abstract: An exhaust muffler for a fuel-operated heating device has upper and lower housing half shells, an exhaust gas through-duct and absorption and reflection chambers. The exhaust muffler is connectable to an exhaust pipe of the heating device. The exhaust gas through-duct has an inlet pipe of a single absorption chamber and a single following reflection chamber that are separated by a partially perforated partition, with double reversal of the exhaust gas flow, and an outlet pipe; the inlet pipe being perforated on the outer surface side, with an S-shaped curved section and a straight end section, and the outlet pipe being a straight outlet pipe, closed on the outer surface side, and the straight section of the inlet pipe runs parallel to, and at a spacing from, an inlet section of the outlet pipe.

Abstract: A multi-duct diffusion exhaust device for a turbomachine. The exhaust device including an annular inlet, an outer casing shaped symmetrically overall with respect to an axis, one or more internal partitions defining several roughly concentric ducts for an exhaust stream to flow through, and an absorbent coating capable of absorbing some of the acoustic energy generated by the flow. The absorbent coating being provided on at least one of a surface of one internal partition and an interior surface of the outer casing. The absorbent coating having a thickness that is tailored along a length of the exhaust device to optimize the flow in the ducts by maintaining progressive diffusion and avoiding detachment near stationary surfaces.

Abstract: A bumper/muffler assembly is provided comprising a bumper; and a muffler having an outer shell. The outer shell may be formed from a non-high impact resistant material, such as a thin metal or a composite material. The muffler may comprise a separate element from the bumper, which is coupled thereto, or is formed as an integral part of the bumper.

Abstract: A muffler is provided for use in a pneumatic hand tool having a handle with an exhaust passage. The muffler includes an inner tube, an outer tube, an upper plate, and an end cap. The inner tube is located within the outer tube, with one or more openings being provided in each. The upper plate is located near the inner tube and is provided to close off the exhaust passage so that a majority of the exhaust air is directed into the inner tube during use. The end cap attaches to the handle for closing off the exhaust passage, but for one or more exit openings. During use, exhaust air enters the inner tube, flows out its penguins, flows out the outer tube openings, and flows out the exit opening in the end cap. The tortuous path slows the exhaust air and assists in dampening exhaust noise.

Abstract: The invention relates to a device in a silencer unit of an automotive vehicle, for suppressing unwanted noise originating from an exhaust gas flow from the vehicle engine, said silencer unit being terminated by an end pipe, through which said exhaust gas flow is conveyed to the surroundings. The invention is characterized by the end pipe comprising at least one perforated section having a predetermined extension (L2) in the longitudinal direction of the end pipe, and being positioned downstream of a point (L3) along the end pipe where there is substantially no turbulence in the exhaust flow. Through the invention, an improved silencer unit is provided, with which predetermined requirements for comfort directed low-frequency suppression of the exhaust flow noise, as well as statutory requirements for high-frequency absorption of the noise, are fulfilled.

Abstract: A process is provided for filling a muffler shell with fibrous material. It comprises the step of providing a muffler shell comprising one or more muffler shell outer parts which define an internal cavity and an internal structure adapted to extend at least part way through the shell internal cavity and having one or more openings adapted to communicate with the shell internal cavity. The process further comprises the step of providing a bag filled with fibrous material. The bag has a first side with one or more first perforations defining a first side total open area and a second side with either no perforations or one or more second perforations defining a second side total open area. The first open area is greater than the second open area.

Abstract: An insert assembly for a muffler of a high-performance motor cycle, having an insert with a filling of compressed heat-resistant, sound-absorbing material mounted on a removable hollow tube having an inside diameter greater than the outside diameter of the perforated core of the muffler. The filling includes a bulked-up continuous filamentary material. Once the insert has been introduced into the muffler by sliding the tube along the core, the tube is then withdrawn leaving the insert behind in the muffler. Removal of the tube allows the filling to relax towards its intended density. The first subsequent exposure to hot exhaust gases causes certain portions of the insert to degrade, allowing further relaxation of the filling to assume its intended density. Further, the tube precludes potential damage to the insert during its introduction into the muffler.

Abstract: A process is provided for filling a muffler shell with fibrous material. The process involves providing a muffler shell comprising first and second muffler shell outer parts which define an internal cavity when coupled together and an internal structure adapted to extend at least part way through the shell internal cavity and having one or more openings communicating with the shell internal cavity.

Abstract: A reciprocating piston compressor having a suction muffler and a pair of discharge mufflers to attenuate noise created by the primary pumping frequency in the primary pumping pulse. The suction muffler is disposed along a suction tube extending between the motor cap and the cylinder head of the compressor. The discharge mufflers are positioned in series within the compressor to receive discharge gases from the compression mechanism and are spaced one quarter of a wavelength from each other so as to sequentially diminish the problematic or noisy frequencies created during compressor operation. The motor/compressor assembly including the motor and compression mechanism is mounted to the interior surface of the compressor housing by spring mounts. These mounted are secured to the housing to define the position of the nodes and anti-nodes of the frequency created in the housing to reduce noise produced by natural frequencies during compressor operation.

Abstract: A multiple layer fiber filled sound absorber and method of manufacturing the absorber are disclosed. The sound absorber includes an outer housing, a porous or perforated inner tube or housing defining a passageway through which a gas may flow, and two layers of sound absorbing material, such as fiberglass wool, is positioned between the housings. The sound absorbing material adjacent the inner housing is selected to be more heat resistant than the material farther away from the inner housing. The sound absorber is filled with the sound absorbing materials using a direct fill process in which continuous fibers are injected into the sound absorber. In preparation for filling, a partition is positioned between the housings to define two chambers. Each chamber is filled with one of the sound absorbing materials. The partition may then be removed from the sound absorber, or may be left in place (in which case the partition is preferably porous or perforated).

Abstract: A process is provided for filling a muffler shell with fibrous material. It comprises the step of providing a muffler shell comprising one or more muffler shell outer parts which define an internal cavity and an internal structure adapted to extend at least part way through the shell internal cavity and having one or more openings adapted to communicate with the shell internal cavity. The process further comprises the step of providing a bag filled with fibrous material. The bag has a first side with one or more first perforations defining a first side total open area and a second side with either no perforations or one or more second perforations defining a second side total open area. The first open area is greater than the second open area.

Abstract: A process is provided for filling a muffler shell with fibrous material. The process involves providing a muffler shell comprising first and second muffler shell outer parts which define an internal cavity when coupled together and an internal structure adapted to extend at least part way through the shell internal cavity and having one or more openings communicating with the shell internal cavity.

Abstract: An exhaust pipe includes an outer pipe and an inner pipe firmly fitted in the outer pipe. An air intake pipe and an outlet pipe having a comparatively small diameter are positioned respectively at two opposite ends of the outer pipe and respectively communicating with the front and the rear end of the inner pipe. Besides, a great number of through holes are bored around the wall of the inner pipe. Then an intermediate pipe having numerous through holes around the wall is fitted around the inner pipe, with a plurality of gaps formed between both the pipes. The muffling cotton is filled in a space between the outer pipe and the intermediate pipe. Thus, the intermediate pipe is easy to assemble, kept secured firmly for a long time and achieving effectual muffling.

Abstract: A device for silencing a flow includes at least one acoustic chamber through-flowed by gas, e.g., exhaust gas, at least one inlet pipe and at least one pipe or passage interconnecting two chambers or a chamber and an exterior environment or chamber and is designed with such cross-sectional area transitions, between passages and the chambers that the sound attenuation achieved by the device is high while the pressure drop across the silencer is low and that high attenuation at low characteristic frequencies of flow systems are obtained. The device may contain at least one of diffusers, monolithic bodies and catalysts. The passages may be curved or helical so as to allow for a low natural frequency. Embodiments with resonance chambers attenuating at selected frequencies are disclosed. A method for operating a vehicle including a combustion engine and a silencing system is disclosed.

Abstract: An exhaust muffler for an internal combustion engine included in a motorcycle includes a perforated inner pipe (32), an outer pipe (31) coaxially surrounding the inner pipe (32), and a glass wool mat (33) packed in a space between the inner pipe (32) and the outer pipe (31). A three-layer protective structure is formed by winding an inner stainless steel wire mesh (34) wound around the inner pipe (32), winding a stainless steel wool mat (35) around the inner stainless steel wire mesh (934), and winding an outer stainless steel wire mesh (36) around the stainless steel wool mat (35). The glass wool mat (33) is wound around the three-layer structure. The three-layer structure extends the life of the glass wool mat (33) even if the temperature and pressure of the exhaust gas discharged by the internal combustion engine increase.

Abstract: A submuffler for a vehicle muffler system which comprises a housing, a pressure-reducing conduit disposed within said housing, said pressure-reducing conduit containing a plurality of apertures disposed on the surface thereof, an eddy-generating member disposed within the pressure-reducing conduit along a substantial length thereof, and pipe means connected to an inlet side and an exit side of the housing for introducing exhaust gas thereto and exiting exhaust gas therefrom.

Abstract: In order to provide a sound absorbing material superior in acid resistance, alkali resistance and sound absorbing quality and a sound absorbing layer using this sound absorbing material, multiple pieces of basalt yarn obtained by dissolving basalt to be continuous fibers are bundled by a fiber bundling agent to acquire a bundled material, and the bundled material is fibrillated to obtain a bulky sound absorbing material. Moreover, the sound absorbing material is arranged on the outer periphery of a perforated pipe constituting a muffler to form a sound absorbing layer.

Abstract: An engine muffler and spark arrestor includes an outer tube extending along an axis and having an inlet end and an outlet end. A plurality of substantially identical nested discs are disposed coaxially adjacent the outlet end of the outer tube. Each of the discs has a centrally located aperture. Each of the discs also has at least one slot extending therethrough. An end cap is disposed on a distal end of the set of discs. The end cap has a solid central portion which forces at least a portion of an exhaust gas flowing from an internal combustion to which the muffler is connected to flow radially outwardly along interstitial spaces defined between each pair of discs and then flow axially in a direction approximately parallel to a longitudinal axis of the muffler.

Abstract: A sound attenuating device including a sound insulating structure and a windband. The sound insulating structure is constructed and arranged to receive vented air from an exhaust vent. The windband is affixed to the sound insulating structure and is constructed and arranged to prevent water from entering the sound insulating structure. The windband also provides a structure for attenuating sound.

Abstract: The present invention discloses an improved structure of a muffler at the rear end of an exhaust pipe, mainly comprising a tapered inner pipe inside a tapered conical outer pipe, and a plurality of silencing holes being disposed on the wall of the inner pipe, and a silencing cotton wrappers around and covers the external rim of the inner pipe, and a sleeve being disposed in the inner pipe proximate to the rear end of the inner pipe. The front end of such sleeve is a tapered conical pipe, and the rear end slight extends to the outside of the rear end of the external pipe. A decorative lid covers the rear end surface of the external pipe, and a gas-receiving pipe having a French connector being soldered to the front end of the external pipe, and an n-shaped fixing bracket having a fixing hole on it being soldered to an appropriate position on the external surface of the external pipe proximate to the rear end.

Abstract: A process is provided for filling a muffler shell with fibrous material. The process comprises the steps of: providing a muffler shell comprising first and second muffler shell outer parts which define an internal cavity when coupled together and an internal structure adapted to extend at least part way through the shell internal cavity for defining at least one channel having one or more openings communicating with the shell internal cavity; placing a form over at least one of the internal structure and the first muffler shell part; drawing a partial vacuum through a first end of the channel; feeding fibrous material into the form while drawing a partial vacuum through the channel; removing the form after the fibrous material feeding step; and positioning the second muffler shell part over at least one of the internal structure and the first muffler shell part.

Abstract: A process is provided for filling a muffler shell with fibrous material. The process comprises the steps of: providing a muffler shell comprising first and second muffler shell outer parts which define an internal cavity when coupled together and an internal structure adapted to extend at least part way through the shell internal cavity for defining at least one channel having one or more openings communicating with the shell internal cavity; placing a form over at least one of the internal structure and the first muffler shell part; drawing a partial vacuum through a first end of the channel; feeding fibrous material into the form while drawing a partial vacuum through the channel; removing the form after the fibrous material feeding step; and positioning the second muffler shell part over at least one of the internal structure and the first muffler shell part.

Abstract: A motor vehicle muffler having a muffler loop installed in a casing in the exhaust pipe of a motor vehicle, the muffler loop formed of three muffler tubes and two connecting tubes, the muffler tubes being arranged at different elevations in the casing and crossed by one another at the same point, the connecting tubes being arranged in parallel outside the casing to connect the muffler tubes in series.

Abstract: This invention relates to a muffler to be used in the exhaust system of an engine for automobiles, specifically to a muffler including a sound absorbing material interposed between the external tube and the internal tube, and a method of manufacturing the same. There are provided a durable and easy-to-manufacture engine muffler in which the sound absorbing material is reliably secured during use and during manufacturing process, and a method of manufacturing the same. The engine muffler comprising a sound absorbing material interposed between an internal tube and an external tube is formed with a projection projecting toward the sound absorbing material on the external tube along almost entire periphery thereof.

Abstract: A process is provided for filling a muffler with fibrous material as well as a muffler filled with fibrous material. The process includes a first step of providing a muffler comprising a closed outer shell having an inner cavity and a perforated pipe. The perforated pipe has a first end portion with at least one fill opening. A second step comprises feeding fibrous material into the outer shell inner cavity through the at least one fill opening in the perforated pipe to form a fibrous product in the outer shell.