Abstract: The current invention is device for lowering the air velocity and inherent noise of high-speed air released from a closed system, comprising a straight pipe module with an outer tube and a concentric inner tube creating an annular space therebetween. The inner tube has interior fins at the inlet, which initiate rotation in an airflow directed therethrough, and interior fins at the outlet, which arrest the airflow rotation. Perforations along the length of the inner tube, from inlet fins to outlet fins, permit the release of a turbulent outer zone of the airflow, permitting the high velocity core of the airflow to expand and slow, reducing the noise of the airflow.

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 muffler including a long outlet pipe 20 having an exhaust gas inlet pipe portion 21, a return pipe portion 22, an exhaust gas outlet pipe portion 23, and two turnaround pipes 24, 25 for connecting the three pipe portions 21, 22, 23 together in series. These pipe portions 21, 22, 23 are arranged in parallel with one another along a longitudinal direction of a shell 2, and in such a manner that longitudinal axes 21L, 22L, 23L of the pipe portions are positioned at respective vertices of a triangle.

Abstract: A muffler has an elongated generally cylindrical casing having inlet and outlet ends, an elongated generally frustroconical baffle in the casing adjacent the inlet end with the smaller diameter portion being spaced from the inlet end. The peripheral wall of the baffle has closely spaced perforations over the major portion of its axial length and is spaced from the shell to provide a chamber thereabout. A generally cylindrical baffle has one end extending over the smaller diameter portion of the frustroconical baffle and has its peripheral wall spaced from the casing to provide a chamber thereabout. The peripheral wall of the cylindrical baffle has closely spaced perforations over most of its length. Exhaust gases enter the frustroconical baffle and exit through the perforations therein, move axially in the casing thereabout, and then pass through the apertures into the cylindrical baffle.

Abstract: A modular muffler that is quickly and easily adapted for use with a wide variety engines is disclosed. The muffler has a dimensionally standardized body member with end portions that may receive any of a number of adaptor end plates provided with various inlet and outlet configurations. The adaptor end plates are inwardly and outwardly adjustable relative to the body member end portions in order to vary the body member internal volume.

Abstract: A muffler for use with high performance powerboats to reduce exhaust noise to below 90 decibels without significantly reducing horsepower is described. The muffler includes a cylindrical outer housing with an interior cavity that is divided into first and second chambers by parallel intake and discharge cylinders. The intake cylinder has intake and discharge ends, and inwardly directed louvers toward the intake cylinder discharge end. The abutting discharge cylinder has inner and discharge ends, with inwardly directed louvers toward the discharge cylinder inner end. A first plate extends across the interior cavity of the housing, blocking the inner end of the discharge cylinder, with the intake end of the intake cylinder extending through a hole in the first plate. A second plate extends across the interior cavity of the housing, and includes a hole in communication with the discharge end of the discharge cylinder.

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: A muffler in which in order to reduce a harsh high-frequency component exhaust noise as exhaust noise of a vehicle, and relieve a feeling of discomfort due to the exhaust noise, on at least one of an inner plate and an outer plate, a plurality of dot-shaped convex portions 15 and dot-shaped concave portions 16 are provided, and the convex portions 15 and concave portions 16 are alternately arranged to be surrounded with each other. Furthermore, the convex portion 15 is connected to the concave portion 16 by a curved surface.

Abstract: To provide a muffler structure capable of lowering muffler cost. A muffler structure is provided in which a sound absorbing material is laid on the inside surface of an outer tube. The sound absorbing material is retained by an inner tube made of a metal that is punched with a plurality of holes. The inner tube is divided into a plurality of expansion chambers. Exhaust gas from an engine is led into the fiat expansion chamber by an inlet pipe. The exhaust gas is discharged out after being supplied to the second and third expansion chambers in succession through the connecting pipes. In the muffler structure, the inner tube is made of an approximately flat metal that is punched with a plurality of holes by bending the metal into circular form until its opposite edges are butted to each other, and is fitted in the outer tube, with the butt portions not jointed, so that the butt portions will come behind the connecting pipe when viewed from the inlet pipe side.

Abstract: A silencer, for silencing and purification of exhaust gases, comprises an air-tight casing (1) connected to an exhaust inlet pipe (2) and to an exhaust outlet pipe (3) and contains at least two acoustic compartments (4i, 4ii) and one or more monolithic bodies (5) such as catalysers or particle filters through which exhaust gases flow in a flow direction in longitudinal channels or porosities, and one or more pipes or channels (6, 7), at least one pipe or channel penetrating one or more of the monolithic bodies (5) and guiding exhaust gases in a flow direction which is opposite to the flow direction in the channels or porosities of the monolithic body (5), and at least one of the pipes or channels (6, 7) connecting the at least two acoustic compartments (4i, 4ii). The general flow direction is preferably reversed substantially immediately upstream of a penetrated monolithic body (5) and substantially immediately downstream of either the same monolithic body (5) or of another penetrated monolithic body.

Abstract: A compact muffler has a straight through inner cylindrical casing surrounded by an outer cylindrical casing defining a closed ended sound attenuating chamber therebetween. Within the outer chamber a plurality of axially extending, radially overlying, cylindrical intermediate casings form a plurality of annular sound attenuating passages. The sound passages are configured to have entrances in fluid communication either with an especially configured slot in the inner casing or between certain passages to define a plurality of discrete sound paths, with each sound path having a set length sufficient to generate a reflection wave for attenuating a sound wave having a frequency correlated to the distance of the sound path.

Abstract: There is disclosed a muffler structure in which a valve opened/closed in accordance with exhaust gas pressure in a pipe is prevented from chattering by an inlet pipe provided with a first side hole and an outlet pipe provided with a second side hole with a valve biased by a spring to simultaneously close both the first and second side holes when the pressure is relatively low. When the pressure of the exhaust gas is relatively high, the pressure exerted on the valve by the exhaust gas in the inlet pipe is sufficient to open the valve and the exhaust gas introduced to the inlet pipe flows out to a second chamber via the first side hole, flows into the outlet pipe via the second side hole, and is exhausted to the outside of the muffler via the downstream outlet opening.

Abstract: A semi-active muffler for an internal combustion engine comprising a case defining a closed space with a predetermined capacity, the case being partitioned into first, second, and third chambers, a first bypass pipe for communicating the first chamber with the third chamber, a second bypass pipe for communicating the second chamber with the third chamber, an inlet pipe for introducing exhaust gas into the first and second chambers, an outlet pipe for exhausting the exhaust gas introduced into the third chamber from the first and second chambers respectively through the first and second bypass pipes, a valve for selectively opening a downstream end of the second bypass pipe according to a pressure level within the second chamber, and buffer means for reducing an impact and noise when the valve is opened and closed, wherein the buffer means comprises a gap kept between the valve and the downstream end of the second bypass pipe even when the valve is in a completely closed position.

Abstract: An expansion chamber, and first and second volume chambers on either side of said expansion chamber, are formed inside a muffler housing. Engine exhaust is led by an inlet tube to the first volume chamber, and an opening facing the expansion chamber is formed in an intermediate part of the inlet tube. Exhaust in the second volume chamber is discharged outside by a tail tube, and an opening is formed facing the expansion chamber in an intermediate part of the tail tube. A valve is provided for leading exhaust from the first volume chamber to the second volume chamber according to a pressure difference between the chambers. This forms two exhaust flowpaths. A resonance system with two degrees of freedom is thereby formed with respect to exhaust discharged via the two openings and the expansion chamber, and a high noise silencing efficiency is obtained.

Abstract: In a muffler, a first exhaust outlet pipe has an opening-closing device, and a second exhaust outlet pipe is connected or joined to the first exhaust outlet pipe at a downstream portion of the opening-closing device. An overall length of the second exhaust outlet pipe is greater than the distance between the above joint portion, at which the second exhaust outlet pipe is connected to the first exhaust outlet pipe, and an exhaust inlet end of the first exhaust outlet pipe, and the overall length of the second exhaust outlet pipe is shorter than or generally equal to an overall length of the first exhaust outlet pipe. With this construction, in a low engine revolution speed range, the production of abnormal sounds in the second exhaust outlet pipe is prevented.

Abstract: A muffler including paraboloid steel baffle chambers which may contain a continuously encased vacuum. These chambers can be shaped out of steel paraboloids. The exhaust of the engine (or noise source) can flow into the space between chambers and out of the muffler with high efficiency. The paraboloids are designed so that the noise is reflected to maximize a sound wave's path and minimize its intensity.

Abstract: A double U shaped exhaust pipe having varying internal pipe diameters for increasing horsepower, designed within internal combustion engine vehicle racing or other rules that limit such features as overall size. A first stage portion of the exhaust pipe produces a first periodic flow of exhaust, with a vacuum pulse created where the pipe internal diameter increases upon the exhaust reaching a second stage portion. A third stage portion of the exhaust pipe produces a third stage periodic flow of exhaust upon the exhaust reaching an increased pipe internal diameter at a fourth stage portion. These periodic pulsed flows are matched to the opening of the intake and exhaust valves of the engine for a selected engine speed range. The matching of a vacuum pulse to the opening exhaust valve improves engine performance by drawing exhaust gases from the engine.

Abstract: The inner area of a muffler of an engine is partitioned into an expansion chamber, a first volume chamber and a second volume chamber. An inlet tube and the first volume chamber are connected by a first passage. The first volume chamber and a second volume chamber are connected by a second passage, and the second volume chamber and expansion chamber are connected by a third passage. The flow of exhaust gas reaching the expansion chamber via the first passage, second passage and third passage is blocked by a valve which opens according to a pressure rise of the exhaust gas. One of the two acoustic paths formed when the valve is open functions as a resonator having two degrees of freedom relative to the other path so that a high muffling effect is obtained.

Abstract: In a muffler for internal combustion engine which is provided with a valve capable of closing and opening an open end of by-pass inner pipe, the opening and closing operation of the valve is performed via the exhaust gas pressure, without being affected by external factors. Also, the structure is simple and easy to be assembled. On a fixed shaft (36) supported in the vicinity of an open end (28a) of a by-pass inner pipe (28) is a valve (32) rotatably mounted. The valve (32) is urged against the open end (28a) by a coil spring (42), and when fitted in a flange part (38), it closes the open end (28a). When the revolving speed of the internal combustion engine is low, the pressure inside the by-pass inner pipe (28) is smaller than the operative force which is an addition of the urging force by the coil spring (42) and the external pressure. The open end (28a) is therefore closed.

Abstract: This invention relates to an exhaust gas muffler assembly for internal combustion engines which is operable in both a muffled or unmuffled mode. In exterior appearance, the bypass muffler of this invention looks like a conventional muffler having a shell and end caps which enclose the interior components, an inlet for entry of the exhaust gas from the engine, and two outlets for exit of the exhaust gas to atmosphere. A first outlet is preferably positioned opposite to the exhaust gas inlet and connected directly to the inlet by means of a pipe. This pipe is not provided with silencing means. Within the interior of the muffler are silencing means employing a center pipe and an exhaust gas outlet pipe, each of which are provided with silencing means such as apertures in the walls of each pipe. Flow diverting means are removably placed within the first outlet.

Abstract: A compact muffler has a straight through inner cylindrical casing surrounded by an outer cylindrical casing defining a closed ended sound attenuating chamber therebetween. Within the outer chamber a plurality of axially extending, radially overlying, cylindrical intermediate casings form a plurality of annular sound attenuating passages. The sound passages are configured to have entrances in fluid communication either with an especially configured slot in the inner casing or between certain passages to define a plurality of discrete sound paths, with each sound path having a set length sufficient to generate a reflection wave for attenuating a sound wave having a frequency correlated to the distance of the sound path.

Abstract: A small-sized muffler having porous partition walls includes a first expansion chamber, a second expansion chamber, a third expansion chamber and a fourth expansion chamber. A first porous partition wall is longitudinally arranged within the third expansion chamber so as to define a fifth expansion chamber. Similarly, a second porous partition wall is longitudinally arranged within the first expansion chamber so as to define the sixth expansion chamber. The first porous partition wall and the second porous partition wall are provided with small holes over their entire surface. The first porous partition wall and the second porous partition wall are each formed as a convexly curved surface curved toward the center of the muffler around the first feeding pipe and the second feeding pipe, respectively.

Abstract: A muffler having a movable valve disk, with the help of which at least one of the tubes in the muffler housing can be opened and closed. The actuation organ for the valve disk is a corrugated tube, the fixed end of which is placed into an opening in the housing and the interior of which is connected to the atmosphere. As a result, the total pressure loss of the muffler is available as an actuation force.

Abstract: In an exhaust silencing device having inner tubes which are connected to an exhaust pipe connected to an engine and provided with a plurality of through holes, and an outer tube which covers the inner tubes. The occurrence of a whistling sound is prevented while avoiding the use of a sound absorbing material. Recesses or indentations, are provided on the inner surface of the inner tube, which, together with the outer tube, form an annular expansion chamber.

Abstract: A muffler for reducing acoustic noise contained in a gas flow, such as created by internal combustion engines, air compressors, and blower manifolds. The muffler consists of a conventional sheet metal casing which has an inlet and an outlet at opposite ends thereof. A flow of gas containing acoustic noise flows from inlet to outlet. A plurality of spiral acoustic traps, each of which extend from bottom to top of the casing, have a central axis positioned perpendicular to the gas flow. An opening in each spiral acoustic trap extends into the gas flow to divert some gas into the trap, wherein the gas flows in a circular path so as to degrade and randomize the sound waves into heat, by utilizing a circular mixing process with increased gas retention time.

Abstract: In a muffler for an internal combustion engine which is provided with a valve capable of closing and opening an open end of a by-pass inner pipe, the opening and closing operation of the valve is performed by means of the exhaust gas pressure, without being affected by external factors. Also, the structure is simple and easy to be assembled. On a fixed shaft (36) supported proximate an open end (28a) of a by-pass inner pipe (28) is a valve (32), rotatably mounted. The valve (32) is urged against the open end (28a) by a coil spring (42), and when fitted in a flange part (38), it closes the open end (28a). When the revolving speed of internal combustion engine is low, the pressure inside the by-pass inner pipe (28) is smaller than the operative force which is an addition of the urging force by the coil spring (42) and the external pressure. The open end (28a) is therefore closed.

Abstract: A double throat tuner including a second conduit concentric to a first conduit which connects the gas flow to a first volume tuning chamber having a first effective volume. The radial difference between the first and second conduits and the length of overlap of the first and second conduits in combination with the effective volume of the first tuning chamber attenuates a preselective frequency of sound. This attenuation is for a specific frequency range in addition to the overall attenuation of the complete system including a plurality of conduits serially connected by a respective chamber.

Abstract: A first and second noise suppressing mechanism are provided inside the muffler. Each mechanism is provided with a discharge pipe for discharging exhaust gas to outside the muffler. The first noise suppressing mechanism reduces exhaust noise in the low engine speed region. The second noise suppressing mechanism reduces noise in the medium and high engine speed regions. A valve is provided that connects the first noise suppressing mechanism and second noise suppressing mechanism according to the engine exhaust pressure. In the low speed region, the valve is closed and exhaust gas is discharged via the first noise suppressing mechanism where mainly low frequency noise is eliminated. In the medium and high speed regions, the valve is opened and exhaust gas is also discharged via the second noise suppressing mechanism where high frequency noise specific in these regions is also eliminated.

Abstract: An exhaust system in an internal combustion engine includes a flow rate regulating valve which is positioned in an intermediate portion of an exhaust gas flow passage. The flow rate regulating valve has a rotary shaft rotatably supported in a valve housing, and a rotationally biasing spring mounted between the rotary shaft and the valve housing which provides a spring force to rotationally bias the rotary shaft. In the exhaust system, an axially biasing spring is mounted separately from the rotationally biasing spring between the valve housing and the rotary shaft for biasing the rotary shaft in an axial direction. The rotary shaft is provided with an abutment surface which faces in the one axial direction, and the valve housing is provided with a limiting portion which abuts against the abutment surface to limit the axial movement of the rotary shaft.

Abstract: An inlet tube leads exhaust gas from an automobile engine to an expansion chamber inside a muffler housing. Exhaust gas from the expansion chamber is discharged to the atmosphere via a first tail tube. A dead space chamber and volume chamber are disposed on either side of the expansion chamber in the housing, and a first internal tube connects the volume chamber and expansion chamber. A second internal tube having a valve which opens under pressure of the exhaust gas connects the volume chamber and dead space chamber. Exhaust gas from the dead space chamber is discharged to the atmosphere via a second tail tube. As the dead space chamber and volume chamber are not adjacent, pressure waves in the volume chamber do not cause a volume change of the dead space chamber, and emission noise from the second tail tube due to excitation of a resonance system comprising the dead space chamber, is reduced.

Abstract: In an exhaust silencing device having inner tubes which are connected to an exhaust pipe connected to an engine and provided with a plurality of through holes, and an outer tube which covers the inner tubes. The occurrence of a whistling sound is prevented while avoiding the use of a sound absorbing material. Recesses are provided on the inner surface of the inner tube, which, together with the outer tube, form an annular expansion chamber.

Abstract: A device for deadening sound in pipelines comprising a chamber (1) positioned on the pipeline (2, 7) with a discontinuous pipeline section (3) projecting inwards at the chamber inlet and a discontinuous section (7) of the pipeline connected at the chamber outlet. Disposed within the chamber (1) opposite the opening of the pipeline section (3) there is a cover cap (4), in the form of a pipe resonator, whose side wall encloses the pipeline section (3) on one part of its length so that an annular channel (5) remains between the side wall and the pipe section (3). This permits the attainment of a very efficient sound deadening under certain geometric conditions.

Abstract: A sound attenuating muffler useful with an internal combustion engine, preferably for marine applications, contains an insert comprising an arrangement of annular sound reflecting surfaces defining an inner chamber into which engine exhaust gases flow in a first direction and one or more directors to divert the axial flow of gases and sound waves in a second direction past these sound reflecting surfaces. As the sound waves are reflected off of these surfaces back into the muffler interior, attenuation of the sound is achieved. One or more additional inserts may be placed downstream from the first insert for additional sound attenuation. Each of the inserts may be in the form of discrete sound reflector rings or as a continuous helix. A method of assembling the component parts of the insert is also described.

Abstract: An improved muffler for silencing the exhaust emitted from a marine engine employing a reverse entry inlet conduit, an attenuation chamber and an outlet conduit whereby exhaust gas and liquid is communicated through the inlet conduit and into the attenuation chamber against the direction of the outlet stream. Upon entering the attenuation chamber exhaust gases and liquids reflect off the inner walls of the chamber and incoming exhaust thereby attenuating exhaust noise until they are finally forced out of the attenuation chamber through the outlet conduit. The reverse entry design of the muffler provides protection against backwardly flowing water that commonly enters a marine exhaust system by orienting the direction of inlet flow at an angle which is greater than 0 degrees but less than 90 degrees relative to the direction of output flow from the muffler.

Abstract: A first and second noise suppressing mechanism are provided inside the muffler. Each mechanism is provided with a discharge pipe for discharging exhaust gas to outside the muffler. The first noise suppressing mechanism reduces exhaust noise in the low engine speed region. The second noise suppressing mechanism reduces noise in the medium and high engine speed regions. A valve is provided that connects the first noise suppressing mechanism and second noise suppressing mechanism according to the engine exhaust pressure. In the low speed region, the valve is closed and exhaust gas is discharged via the first noise suppressing mechanism where mainly low frequency noise is eliminated. In the medium and high speed regions, the valve is opened and exhaust gas is also discharged via the second noise suppressing mechanism where high frequency noise specific in these regions is also eliminated.

Abstract: A muffler having an inner shell of two deep-drawn inner sheet metal plates laid one atop the other and a housing shell of at least two deep-drawn outer sheet metal plates laid one atop the other. The inner shell has an encircling edge while the housing shell has an encircling housing flange with a lock seam connection which seals the housing shell. The edge of the inner shell is designed so that it barely touches the wall of the housing shell and is held in a spring-like fashion only between clamping creases of the housing shell.

Abstract: A muffler designed at least about the exterior surface by a barrel with end plates. An inlet tube and an exhaust pipe are associated with the end plates, respectively. The external joints are formed by locked seamed roll joints and S-shaped deformed joints to avoid welding at the exterior of the muffler. Tubes extending between baffle plates may also employ the S-shaped deformed joints. Joint tubes having some ability to telescope axially with the other internal components provide thermal stress relief.

Abstract: An open path low back pressure muffler for reciprocating air motor pulsing exhaust providing an increased area inlet orifice, double flow path reversal with directional flow assistance and a turnable sound absorbing lined duct exit.

Abstract: A turbine sound reducer for reducing high frequency noise generated by a bleed air discharge from a paint spraying equipment turbine for operation with a non-bleeder gun. The sound reducer includes an enclosure containing inlet and outlet tubes in a spaced, opposed parallel relationship. The enclosure may be part of the turbine housing or it may be an independent closed body. In one embodiment, the inlet and outlet tubes are integrally molded with the enclosure, and a bifurcated, molded barbed fitting is provided to connect turbine bleed air to the sound reducer.

Abstract: A muffler for coupling to an exhaust port of an internal combustion engine includes a housing, a first hollow body within the housing, a catalyzer within the first hollow body, and a second hollow body within the housing. The first hollow body has an inner surface defining a first chamber and an inlet adjacent the exhaust port to admit the exhaust gas into the first chamber. The exhaust gas is exothermally treated as it flows through the catalyst in the first chamber in a direction away from the engine and passes through an outlet of the first hollow body to a second chamber. The second chamber is formed by an inner surface of the second hollow body and an outer surface of the first hollow body. The treated exhaust gas flows through the second chamber in a direction toward the engine over the outer surface of the first hollow body where a thermal reaction takes place and/or further emission reduction takes place by a catalytic coating on the outer surface of the first hollow body.

Abstract: A muffler for a two-stroke internal combustion engine having a housing and a partition wall which cooperate to define a first chamber adjacent an engine exhaust port and a second chamber remote from the engine. A catalyzer element is housed within the second chamber. A discharge pipe extends from an outlet of the catalyzer element and through the first chamber to atmosphere. An outer pipe surrounds a portion of the discharge pipe within the first chamber and cooperates therewith to define a passage whereby exhaust gas within the first chamber is directed through the partition wall and into the second chamber. Heat from the treated exhaust gas flowing through the discharge pipe is transferred to the exhaust gas flowing through the passage to preheat the exhaust gas prior to reaching the catalyzer element, thereby reducing the time required to bring the catalyzer element to an operating temperature following engine start-up.

Abstract: An exhaust muffler includes first and second internal plates formed to define channels and chambers. The plates are secured in face-to-face relationship, such that the channels define tubes. The tubes include an inlet tube, a return tube and an outlet tube each of which extends to or from a reversing chamber. A separate pipe extends through the return tube and into the outlet tube. The pipe and the return tube are dimensioned to permit a flow of exhaust gas therebetween.

Abstract: A sound attenuating muffler useful with an internal combustion engine, preferably for marine applications, contains an insert comprising an arrangement of annular sound reflecting surfaces defining an inner chamber into which engine exhaust gases flow in a first direction and one or more directors to divert the axial flow of gases and sound waves in a second direction past these sound reflecting surfaces. As the sound waves are reflected off of these surfaces back into the muffler interior, attenuation of the sound is achieved. The gases exit the muffler to the atmosphere through an outer chamber surrounding the inner chamber. A method of assembling the component parts of the insert is also described.

Abstract: A muffler arrangement includes a muffler with an essentially cylindrical housing having a face end with a central entrance opening and at least one exit opening arranged other than centrally on the face end. Baffles are disposed within the housing, the baffles being concentrically arranged pipe cylinders which extend alternatingly into one another and are closed at one end, for effecting a multiple deflection of gases traveling from the central entrance opening to the at least one exit opening. A coupling structure is secured to the muffler housing, for carrying the muffler in an operating position. The coupling structure has a central passage for connecting the muffler to an exhaust outlet of a machine, and has an other than central channel, surrounding the central passage, for connection to an exhaust gas output conduit for outputting exhaust gases from the muffler arrangement.

Abstract: A device for restricting flow of fluids and reducing noise that minimizes filling losses and muffles the vent noise, for example, while gravity filling cryogenic cylinders from a storage tank. The filling loss reducer part of this device is comprised of valve body, rotor, valve seat, o-ring, springs, and ball bearings. The noise muffler is comprised of a cylinder with tubes inside it. The loss reducer and muffler are assembled together to form the device. In operation, when filling cryogenic cylinders, for example, the device is screwed on to the vent valve of the cryogenic cylinder being filled. During the fill process, vent gases from the cryogenic cylinder pass through an orifice in the device. The size of the orifice can be changed to any one of the multiple discrete sizes by manually turning the rotor. This manipulation of the orifice size changes the pressure difference between the storage tank and the cryogenic cylinder.

Abstract: The noise generated by onrushing air which is produced by an air blower for use in conjunction with pneumatic conveying equipment is substantially reduced by directing the air flow through an enclosed housing from an air inlet opening to an air outlet opening mainly via hollow tubular members made of air pervious material shaped in a snake-like or serpentine fashion between the air inlet and the air outlet openings.

Abstract: A muffler for muffling engine operating sounds and including a cylindrical shell closed at opposite ends by double-walled closure caps. The space within the shell is partitioned into three axially contiguous chambers. A gas charging pipe projects through one end of the shell and axially within the shell, and has two pairs of facing discharge elbows for discharging gas from the charging pipe at locations in the first of the chambers. A first pair of gas transfer pipes extends from the first chamber into the central chamber to points of opposed gas discharge. A second pair of gas transfer pipes extends from the central chamber into the third or discharge chamber, and from this location, the gas passes out of the muffler via a discharge pipe.

Abstract: An improved automotive exhaust system comprises a flared expansion chamber having two inlet ports at its narrow end and three outlet ports at its wide end. The inlet ports extend a predetermined distance into the chamber to form therein a pair of lips that function as dams against migration of reversion pulses back up the exhaust pipes. The total area provided by the outlet ports is greater than that provided by the inlet ports. Exhaust gases fed to the chamber can thereby expand as they traverse the length of the chamber and can pass freely from the chamber through the outlet ports. Reversion pulses, which tend to migrate toward the inlet ports along the interior surface of the chamber, encounter and are reflected by the reversion dams and thus are inhibited from migrating back up the exhaust pipes to the engine. Engine performance and usable power is thereby enhanced.

Abstract: A muffler of the type used to attenuate exhaust gas noise in exhaust systems of automobiles, trucks, or the like, particularly characterized by a gas flow conduit which is axially slotted and laterally flattened to form a closure and a pair of openings axially inward of the closure, wherein the end walls of the shell are pressed into engagement with the conduit ends to close the conduit and support the conduit.

Abstract: A sound muffling device for use in lawnmowers includes a hollow body containing an aperture plate, a plurality of serpentine configured pipes, a plurality of fans, a double net having a bundle of wires, and a microporous plate, an adaptor having a sound inlet disposed on the exterior of the front end of the hollow body, and a sound outlet of the exterior of a rear end of the hollow body.