Abstract: The present invention provides composite muffler systems formed of a long fiber thermoplastic. Long fiber thermoplastic technology allows the fibers, to maintain a length sufficient to provide structural strength at lower fiber loading. The long fiber thermoplastic material for forming composite muffler systems also provides increased impact strength and creep resistance as well as chemical and thermal resistance. Mufflers molded with long fiber thermoplastics demonstrate improved dimensional stability as compared to known short fiber based moldings. One suitable muffler structure is a multi-piece muffler assembly including at least one long fiber thermoplastic shell section. In accordance with the present invention, the long fiber thermoplastic material and moldings may also be combined with over-molding of preforms of unidirectional or woven inlays, which provide local structural performance.

Abstract: An exhaust gas exhausted from a fuel cell is sent to a silencer through an exhaust pipe. The silencer is provided with a conductive noise absorbing material, and is fixed to a vehicle body through a metallic fixing jig. Thus, the noise absorbing material is earthed to the vehicle body so that it is possible to prevent static electricity from being generated in the use of the fuel cell vehicle such as in a low humidity environment.

Abstract: A muffler insulating element comprises a mat of interconnected fibers. The mat has a constant density and at least two sections of different thicknesses. A muffler having such an insulating element and a method of producing a muffler are furthermore described.

Abstract: Methods and devices for increasing the sound attenuation properties of a noise suppression device are provided. Various embodiments include sound-attenuating cavities with improved sound capturing openings. In some embodiments, the sound capturing openings include holes surrounded by projections. In other embodiments, the sound capturing openings include angled slats. Embodiments also include sound capturing devices that include the improved sound capturing openings, such as silencers, vent hoods, barrier walls, air exchanges, and air intake and exhaust ducts.

Abstract: A passive noise attenuation device and system is provided having a reticulated open-cell porous structure configured to acts as a passive control device in order to mitigate combustion noise and instability problems in combustion systems. A porous inert media structure is placed downstream of the reaction zone of a combustion chamber to dissipate noise and/or instability generated upstream in the flame. The porous inert media also limits and/or disintegrates vortical structures in the flame to produce a homogeneous flow field to facilitate distributed reaction zones.

Abstract: An air induction silencer assembly includes an acoustic interference member disposed within a conduit. The acoustic interference member is tuned to acoustically cancel a selected noise energy frequency. An acoustic absorbing member is also disposed within the conduit. The acoustic absorbing member converts noise energy within the conduit into heat energy to attenuate noise energy within the air induction silencer assembly. The air induction silencer assembly connects to a flexible conduit that includes an inlet portion, an outlet portion, and a flexible joint that connects the inlet portion and the outlet portion together. The flexible joint includes a rolling lobe and a rolling surface. The rolling lobe moves along the rolling surface when the inlet portion moves relative to the outlet portion.

Abstract: A mat member includes inorganic fibers, a first surface and a second surface opposite to the first surface. The first surface has a plurality of needle penetration marks and/or a plurality of needle protrusion marks. The second surface has a plurality of needle protrusion marks and/or a plurality of needle penetration marks. A plurality of needle marks are formed in the mat member by needle punching and extend from the needle penetration mark to the needle protrusion mark. An inorganic fiber bundle which includes a plurality of the inorganic fibers oriented in a closed loop configuration is formed at the needle protrusion mark.

Abstract: A system for separating contaminants from an air stream entering a sealed case through a vent fitting communicating to the interior cavity of the case includes a contaminant separator having a housing enclosing a chamber, an inlet and outlet communicating with the chamber, a baffle located in the chamber and producing a constricted fluid flow passageway between the inlet and the outlet.

Abstract: A system and method for dissipating at least one pressure wave in an exhaust gas flow is disclosed. A vehicular exhaust system directs the exhaust gas flow through a plurality of coaxial and perforated generally cylindrical tubes contained within an insulated canister towards a perforated partition plate. Through a series of apertures in the tubes and plate, the at least one pressure wave is dissipated such that sound attenuation is achieved without output loss from the engine.

Abstract: An exhaust system for a straddle-type vehicle that achieves miniaturization while meeting a demand for noise reducing characteristics. The exhaust system is connectable to an engine, and includes an exhaust pipe connectable to the engine and a silencer. The exhaust system further comprises a tail pipe inserted into the silencer 10. The silencer comprises an outer housing and an inner core accommodated in the outer housing. An air space is provided between the tail pipe and the inner core.

Abstract: An environmental control system muffler including a thin wall polyetherether ketone (PEEK) cover tube, an open cell polymer attenuator tube slip fit there into and polymer end fitting securing the two tubes together and cooperating to form a pneumatic seal with the cover tube. The method of making the muffler apparatus includes the selection of tubing constructed of such PEEK corrugated construction and the open cell polymer noise attenuation construction, telescoping the tubes together and securing the end fittings thereto.

Abstract: A catcher, in combination with a firearm having an ejection port, for receiving and retaining expended magnetically attracted shell casings through the ejection port as the firearm is discharged. The catcher includes a hollow housing having a plurality of rigid walls, and retainers. One of the walls has an opening in communication with the ejection port when the catcher is mounted to the firearm for receiving the shell casings. A seal is attached to the housing at the opening and surrounding the opening and provides controlled release of pressurized ejection port gas from inside the housing as the firearm is discharged such that noise and flash as a result of escape of the pressurized ejection port gas is reduced or eliminated.

Abstract: An exhaust deflector is attachable to a muffler. The exhaust deflector includes a single-piece housing having a flange that defines an inlet aperture, an outlet wall that defines an outlet aperture, and an intermediate wall that interconnects the flange and the outlet wall. A mesh is in contact with the flange and is positioned to cover the inlet aperture. A perforated member is sandwiched between the mesh and the intermediate wall such that the perforated member and the intermediate wall cooperate to define a space. A low-density material is disposed within the space.

Abstract: An exhaust deflector is attachable to a muffler. The exhaust deflector includes a housing having a flange that is attachable to the muffler, and an outer wall extending from the flange. The outer wall defines an aperture. A single piece mesh is in contact with the flange and cooperates with the housing to define a space. A low-density material is disposed within the space.

Abstract: A mat material includes inorganic fibers, a first surface, and a second surface opposite to the first surface. The mat material has plural needle traces formed by performing a needling treatment. The needle traces extend from the first surface toward the second surface and from the second surface toward the first surface. There is no depth in the mat material that the needle traces do not reach. There is substantially no protrusion of a bundle of the inorganic fibers at a position on the second surface that lies on a line extending from each of the needle traces extending from the first surface. There is substantially no protrusion of a bundle of the inorganic fibers at a position on the first surface that lies on a line extending from each of the needle traces extending from the second surface.

Abstract: A mat member includes a base member and a sheet member. The base member includes inorganic fibers and has first and second main surfaces. The sheet member is disposed on at least one of the first and the second main surface. The sheet member has an openings provided on at least a part of a surface of the sheet member.

Abstract: An absorption muffler includes a metallic exhaust pipe including a plurality of perforations, a polymeric housing carried by the exhaust pipe and enclosing the plurality of perforations, and including axially opposed ends. Thermal insulation is carried radially between the exhaust pipe and the polymeric housing and axially between the axially opposed ends inclusive thereof. Acoustic insulation is carried between the thermal insulation and the polymeric housing.

Abstract: A compressor has first and second enmeshed rotors rotating about first and second axes to pump refrigerant to a discharge plenum. The compressor includes a muffler system comprising a sound absorbing first element and a sound absorbing second element. The second element at least partially surrounds the first element and defines a generally annular flow path portion between the first element and the second element At least one of the first and second elements comprises an expanded bead material.

Abstract: A compressor has first and second enmeshed rotors: rotating about first and second axes. The first rotor is supported by a bearing system carried by a bearing case. The bearing case has at least a first port to a discharge plenum. A first sound-absorbing material is positioned within the first port.

Abstract: A vehicular exhaust resonator features an exhaust inlet conduit which narrows down in a manner such as to define a venturi effect region. Air entrainment apertures in the housing of the resonator provide fluid communication between outside cooling air and an air inlet chamber in the resonator. A further air inlet aperture in an outlet conduit section of the resonator is in fluid communication with the air inlet chamber. Due to the venturi effect inside the inlet conduit, a pressure drop is created to pull air from the outside into the air inlet chamber and then into an outlet conduit of the resonator for mixing with the exhaust gas to provide cooling thereof.

Abstract: The present invention provides composite muffler systems formed of a long fiber thermoplastic. Long fiber thermoplastic technology allows the fibers, to maintain a length sufficient to provide structural strength at lower fiber loading. The long fiber thermoplastic material for forming composite muffler systems also provides increased impact strength and creep resistance as well as chemical and thermal resistance. Mufflers molded with long fiber thermoplastics demonstrate improved dimensional stability as compared to known short fiber based moldings. One suitable muffler structure is a multi-piece muffler assembly including at least one long fiber thermoplastic shell section. In accordance with the present invention, the long fiber thermoplastic material and moldings may also be combined with over-molding of preforms of unidirectional or woven inlays, which provide local structural performance.

Abstract: An engine muffling system includes a Helmholtz tuning chamber to meet the changing acoustic muffling requirements associated with multiple applications. The engine muffling system in one embodiment includes at least one chamber configured as a plenum device, typically filled with an aggregate material or acoustic absorbing particulate material(s) in order to produce a tortuous path through the at least one chamber.

Abstract: An exhaust pipe comprises a pipe body formed therein with a silence chamber and an expansion chamber. A U-shaped gas inlet tube and a discharge tube are settled in the pipe body. The exhaust pipe facilitates smoothening waste gas discharge, generating appropriate exhaust back pressure and decreasing exhaust noise.

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: An automotive muffler includes an external tube consisting of a first widened portion, a first tapering portion, and a first narrow portion, the first widened section having a sealing wall with a through hole at the front end thereof; an internal tube consisting of a second widened portion, a second tapering portion, and a second narrow portion, the internal tube being disposed within the external tube, a plurality of vent holes being formed in the wall of the second widened portion; an internal guide tube consisting of a third widened portion, a third tapering portion, and a third narrow portion, the internal guide tube being disposed within the internal tube, a plurality of vent holes being formed in the wall of the third widened section that is disposed within the internal pipe; and a plurality of partitions interposed between the first widened section and the second widened section as well as between the second widened section and the third widened section.

Abstract: The present invention provides a composite muffler for use with an auxiliary power unit. The composite muffler comprises a composite outer can, an annular baffle, an acoustic liner, and a thermal barrier. The composite outer can is disposed substantially symmetrically about a longitudinal axis and has an inner peripheral surface defining a cavity. The annular baffle is disposed within the composite outer can cavity, has an opening formed therein, and extends radially outwardly from the opening toward the composite outer can inner peripheral surface. The acoustic liner extends through the annular baffle opening. The thermal barrier is coupled between the annular baffle and the outer can inner peripheral surface.

Abstract: A muffler for a motorcycle, the muffler including an outer tube and an inner tube disposed substantially within the outer tube. The inner tube includes a first end adapted to receive the exhaust gases from the engine, a second end opposite the first end adapted to release the exhaust gases to the environment, and first and second apertures positioned between the ends. The muffler also includes a mesh tube disposed between the outer tube and the inner tube. The mesh tube defines a chamber between the inner tube and the mesh tube such that the exhaust gases exit the inner tube through the first aperture into the chamber, and exit the chamber into the inner tube through the second aperture. The muffler also includes a noise attenuating material disposed between the mesh tube and the outer tube.

Abstract: A muffling apparatus (100) is provided for placement within an oil separator of refrigeration or cooling system, wherein the apparatus has a non-straight shape and a lumen (160) defined therein to allow for noise-creating pressure pulsations/waves to come into contact with absorbing material (110) of the muffling apparatus in order to attenuate the energy of the pressure waves/pulsations into heat and thus reduce oil separator vibrations caused thereby.

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: An exhaust system includes a tubular inner shell for passing therethrough exhaust gases from a combustion engine, and a tubular outer shell enclosing the tubular inner shell and cooperating therewith to define a sound silencing chamber into which the exhaust gases are introduced. The tubular inner shell forms an inner peripheral wall of the sound silencing chamber, and an upstream portion of the inner peripheral wall is formed with a perforated wall area having a plurality of communicating perforations for communicating between an interior of the tubular inner shell and the sound silencing chamber, and a downstream portion of the inner peripheral wall has a non-perforated wall area having no communicating perforation defined therein.

Abstract: A sheet member includes inorganic fiber; and a first surface and a second surface that are substantially perpendicular with respect to a thickness direction of the sheet member. The first surface includes a first sheet portion having a first volume density. The second surface includes a second sheet portion having a second volume density that is higher than the first volume density.

Abstract: An aero acoustic fan assembly is provided and generally includes a fan wheel, a frame, and first and second air outlet diffusing structures. The fan wheel generally, and typically includes an axial air inlet delimited by an air inlet cone, an annular air outlet, a back plate, and front plate opposite the back plate. The frame within supports the fan wheel for rotation about a central axis thereof. The first air outlet diffusing structure is supported by a portion of the frame, adjacent the back plate of the fan wheel and includes a peripheral region. The second air outlet diffusing structure is similarly supported by a portion of the frame, adjacent the front plate of the fan wheel, and also includes a peripheral region, air exiting the annular air outlet of the fan wheel passing between the peripheral regions of the diffusing structures.

Abstract: One embodiment of the invention includes a product including a fuel-cell exhaust diffuser; an air funnel; and at least two exhaust tubes attached to the diffuser.

Abstract: In a method of forming a silencer preform from fibers of a fiberizable material, the fibers are fed into a mold, and a low temperature cure binder is applied to the fibers. The binder is cured at a low temperature to bond together the fibers, thereby forming a preform having generally the shape of the mold. The preform is removed from the mold. The preform is structured for insertion into a silencer. A silencer preform includes fibers of a fiberizable material and a low temperature cure binder bonding together the fibers.

Abstract: An exhaust chamber system having a rotatable propeller type blade assembly at the entry to an expansion chamber which creates a vortex that swirls exhaust gas towards the outlet. The resultant action within the exhaust chamber aids in scavenging internal combustion engine exhaust gases, and in reducing system back pressure. The exhaust chamber maintains the sound level of the exhaust within acceptable limits while delivering improved horsepower, torque, and/or fuel efficiency over other known conventional mufflers.

Abstract: The present invention describes an automobile exhaust pipes, and more particularly to an exhaust pipe capable of producing appropriate pressure to assist engine torque output when the engine is running at a low speed and expediting the waste gas to be discharged from an automobile when the engine is running at a high speed, so as to enhance the operating performance of automobile engines.

Abstract: The present invention provides an exhaust chamber system, comprising a stationary propeller type blade assembly with a nose cone within or adjacent to an expansion chamber, to create a vortex that swirls exhaust gas towards the outlet. The resultant vacuum within the exhaust chamber aids in scavenging an internal combustion engines exhaust gases, and in reducing system back pressure The exhaust chamber maintains the sound level of the exhaust within acceptable limits, while delivering improved horsepower, torque, and/or fuel efficiency over standard and other performance mufflers.

Abstract: The present invention includes a power booster pipe suitable for attenuating sound associated with the intake or exhaust of an internal combustion engine and reducing pressure drop associated with movement of gases during operation of the engine. Generally, a diffuser portion is combined with an attenuation portion. One or more tubes of perforated material, such as steel and perforated flutes running the length of the tube increases the surface area of sound attenuating material exposed to combustion gases and the accompanying noise. The perforated flutes and tube can be encircled with sound reducing infill material. A low pressure drop design can be incorporated which includes a gradually increasing diameter tube utilized to route the combustion gases.

Abstract: There is disclosed a silencer for attenuating sound waves produced in a fluid that circulates through a fluid conveyer. The silencer comprises an expansion chamber that is in fluid communication with the fluid conveyer, and which carries sound waves there through; a sound wave dissipater provided with the expansion chamber and arranged to absorb sound waves traveling there through; a resonator operatively associated with the sound wave dissipater and constructed and arranged to cause attenuation and reflection of the sound waves back and forth towards the sound wave dissipater; the expansion chamber having a chamber: conveyer cross-sectional area ratio and chamber length characteristics allowing maximum transmission loss for a given frequency. The expansion chamber has an exit to allow fluid containing attenuated sound waves to escape therefrom.

Abstract: An exhaust deflector is attachable to a muffler. The exhaust deflector includes a housing having a flange that is attachable to the muffler, and an outer wall extending from the flange. The outer wall defines an aperture. A single piece mesh is in contact with the flange and cooperates with the housing to define a space. A low-density material is disposed within the space.

Abstract: A tubular sound/heat insulating tubular structure which may serve as a muffler packing for internal combustion engine exhaust mufflers comprises in one embodiment an inner layer of solely stainless steel wire mesh formed into a continuous length tube. An intermediate structure in that embodiment comprises a flattened tubular structure which is wrapped into two overlying layers of coknitted basalt or other continuous length non-metallic fibers and preferably stainless steel wire. The flattened juxtaposed layers are wrapped about the inner layer at least once by feeding both structures through a cone and forming at least two or more layers of coknitted wire mesh and basalt fibers. In this embodiment, an outer layer of solely stainless steel wire mesh is then knitted about the overlying concentric tubular structures fed from the cone into and through a knitting machine.

Abstract: The invention relates to an exhaust silencer or muffler for an internal combustion engine, in particular a silencer with the damping characteristics of a resonator with the absorptive characteristics of a dissipative silencer. The silencer of the present invention provides an improved silencer or muffler for use with an internal combustion engine that incorporates both a dissipative silencer and a resonator in a single muffler assembly suitable for use with standard automotive construction techniques.

Abstract: An acoustic filter is provided with a single flow chamber for exposure of a flexible rubber layer to liquid undergoing flow through the flow chamber with noise producing acoustic energy therein. The flexible rubber layer is supported on a cylindrical drum with slanted holes therein through which the exposure to the liquid in the flow chamber is effected. An axially sectioned drum with dimensionally different diameters, radial thicknesses and slanted holes therein is positioned over the rubber layer within an outer casing to establish a plurality of gas-filled cavities of different axial lengths and separated from each other along the axial length of the liquid flow chamber which is connected at its opposite axial ends by pipe sections to a piping system from which the liquid within the flow chamber is derived.

Abstract: An exhaust muffler includes upper and lower external shells that are formed from metal material. A heat shield is disposed in the muffler adjacent the upper external shell. The heat shield is formed from a high-density fiber insulation pad configured to nest with the concave inner surface of the upper external shell.

Abstract: The present invention relates to a muffler for an exhaust system of an internal combustion engine, including a housing having at least one absorption chamber which is filled with an absorbent material that has an absorbent effect for airborne sound, a straight-through pipe that carries exhaust gas during operation of the muffler and passes through the housing, and at least one blind pipe that is connected at one end laterally to the straight-through pipe and is sealed at the other end. The blind pipe has a wall that is acoustically transmissive for airborne sound in an area running in the absorption chamber.

Abstract: The exhaust created from the operation of pneumatic tools can create a considerable amount of noise. The present disclosure includes a detachable muffler apparatus used to reduce the sound during the operation of a pneumatic tool. The muffler apparatus includes a flexible outer housing that defines a muffler passage extending between a muffler inlet and a muffler outlet. The flexible outer housing includes an attachment end that defines the muffler inlet and a distal end that defines the muffler outlet. The attachment end can be removably attached to a pneumatic tool body by a fastener. Tool exhaust is forced through and around folds within at least one sheet of permeable material positioned within the muffler passage.

Abstract: A pneumatic tool (610) and a muffler assembly (600) therefor, for quieting the operation of the pneumatic tool, are disclosed. In one embodiment, the muffler assembly (600) is slidably disposed within the exhaust passage (616) and includes a tube member (602) having a proximal flange (604), an intermediate tubular portion (606) with apertures (608), and a distal receptacle (620). The tubular portion may include a blocking plate (618) therein. A porous, sound-deadening panel (622) is disposed about the tubular portion, and a diffuser panel (630) is disposed in the distal receptacle. A perforated end cap (624) holds the muffler assembly in place. In operation, the exhaust enters the tube member, is directed transversely through apertures in the tubular portion and through the porous panel, then back into the distal portion of the tube member, through the diffuser panel, and exits through the end cap.

Abstract: A noise reducing device for a pressurized fluid stream, i.e., a gas, includes a housing. An inlet end and an outlet end of the housing each have at least one orifice for passing a fluid therethrough. The inlet end orifice includes an inlet face and an outlet face and the inlet end orifice is configured for maintaining a backpressure upstream of the inlet end orifice. A diffusing pack material is disposed within the housing. One or more stiffeners may be disposed within the diffusing pack material to ensure that the diffusing pack material maintains contact with the outlet face of the inlet end orifice and/or to prevent the migration of the diffusing pack material within the housing, thereby maintaining a homogeneous distribution of the pack material.

Abstract: A method for containing fibrous material within muffler comprises the initial step of providing an internal assembly of a muffler. In the next method step, a sheet is placed about the internal assembly to form an enclosure about a compartment. In the next method step, the compartment is filled with a fibrous material. A muffler according to the invention comprises a muffler having an outer shell having an internal cavity and outer edges. An internal assembly is inserted within the internal cavity. The internal assembly comprises partitions and a sheet about the internal assembly and extending between the partitions from an enclosure between the partitions. The enclosure is filled with fibrous material. End plates are joined to the outer edges of the outer shell.

Abstract: A filter assembly configured for acoustic dampening for use with compressor assemblies such as oxygen concentrators including a compartmented housing member having an inlet opening, an outlet opening, a filter member, and a plurality of noise attenuating members positioned and located therewithin. The configuration of the compartmented housing member in conjunction with the positioning and location of the filter member and the noise attenuating members therewithin all contribute to absorb and dissipate any sound waves generated within the housing member due to air flow movement therethrough. This substantially reduces and minimizes noise associated with the present filter assembly.