Abstract: A sound attenuating device is provided for attenuating noise in an exhaust system. The attenuating device includes an inlet end, an outlet end and a constricted portion therebetween. In use, the attenuating device may be disposed in a tubular housing or may be an integral portion of a tail pipe, connecting pipe, or muffler. Further, a sound suppressing system is described including one or more attenuating regions including attenuating devices. The attenuating regions are spaced to attenuate desired frequencies. Expansion chambers formed between attenuating regions contribute to sound suppression.

Abstract: A compact, sound-attenuating muffler for an internal combustion engine or the like. The muffler has a divergently tapered partition located near the inlet of the muffler for dividing the exhaust gases into two pulse streams with similar sound frequencies to achieve sound attenuation when the streams are converged back together. The diverging partition creates a low-pressure volume or region on the partition's downstream side where unignited fuels may accumulate. The partition is formed with a passageway to provide communication of live fire from the inlet of the muffler to the low-pressure volume for ignition of any unignited fuel. A method of communication of live fire from the inlet of the muffler to the low-pressure volume on the downstream side of the diverging partition in the muffler also is described.

Abstract: A light-weight and tough muffler having a high noise deadening effect characterized in that the outer barrel (I) of the muffler is made of a thermotropic liquid crystal polymer. An example of said polymer is a wholly polyester having monomer units represented by general formula (I): ##STR1## This polymer may contain 10 to 60 wt. % of inorganic additives such as glass fibers or carbon fibers.

Abstract: A low restriction exhaust treatment apparatus having a hollow outer shell into which a means for treating exhaust gas emitted from an internal combustion engine is disposed, end portions disposed at each end of the outer shell to sealingly close the inner portion of the shell, and end tubes inserted into apertures formed in the sealing end portions for facilitating exhaust flow into and out of the apparatus. The end tubes each have a plurality of axially extending, radially inwardly angled serrations formed about one end thereof to form a lead-in portion of a reduced diameter for ease of insertion of the tubes into the apertures of the end portions without creation of undesirable exhaust system back pressure.

Abstract: A muffler includes an outer box fitted over and attached to an exhaust pipe. The muffler also has a connecting member of a noncircular cross section fixed to said exhaust pipe and interposed between the exhaust pipe and the outer box.

Abstract: A compressor bleed air passageway includes a duct having an upstream section (48) which terminates in a baffle (44) and a downstream duct section (54) having a forward portion (56) which surrounds the baffle (44). Bleed air flow through openings (58) in the baffle wall (52). This reduces velocity of the bleed air stream at the duct discharge port to a value equal to or less than Mach 1.0. The baffle (44) has virtually no effect on a low-velocity, low-pressure air stream. The downstream duct section (54) may be perforated and surrounded by outer wall (64) to form sound-absorbing chambers (66).

Abstract: Sound muffling devices for marine engines for installation on the external portion of the transom of a marine vessel are attached in such a manner that any breakdown within the silencer causes no discharge of exhaust gases or cooling fluids into the interior of the vessel and the gases and cooling fluid continue to be discharged overboard. The silencer is designed to reduce, substantially, the noise level emitted by the engine under operation by the efficient mixture of gases and water through a series of baffles, with low resistance to gas flow that does not diminish engine efficiency. The gases and odors are emitted from the vessel at the centerline with distance and direction such as to reduce, substantially, emissions into the air environment. The device receives exhaust gas and cooling water from an exhaust pipe passing through the transom at the side of the boat and directs the gas athwart the boat to the center where it is exhausted.

Abstract: A charge air system for an internal combustion engine includes a compressor wheel which is rotated to draw ambient air into a housing, compress the air, and to force the air through a discharge conduit into the the intake manifold of an internal combustion engine. The silencers may be placed in the inlet conduit or the outlet conduit to attenuate pressure fluctuations in the conduits, which are a source of significant noise.

Abstract: A muffler device for reducing the noise level of an internal combustion engine as exhaust gases and sound waves produced by the operation of the engine are expelled into the atmosphere is disclosed. The device is placed in the exhaust system, being disposed within the exhaust pipe or pipes as close to the exhaust manifold as possible. The device has a sound chamber for attenuating sound waves entering the chamber by deflection of the sound waves back toward their source and a venturi for drawing exhaust gases through the device and expelling them to the atmosphere.

Abstract: A silencer for the exhaust gas of motor vehicle internal combustion engines is proposed comprising an outer wall having in its upper part a deformable zone, preferably in the form of a transverse indentation, which provides preferential deformation under impact, and if a rear impact occurs prevents the silencer from rigidly striking the most inner structure of the vehicle floor and the fuel tank.

Abstract: A muffler includes a cylindrical body, a gas passage pipe insertedly mounted within the cylindrical body, and a sound absorber mounted upon the gas passage pipe in an encircling manner. Gas is discharged from the gas passage pipe through the cylindrical body and sound absorber. The cylindrical body has a disk-like partitioning wall axially dividing the interior space thereof. The gas passage pipe has an outer flange and a plurality of pawls cooperating with the flange so as to clamp the partitioning wall therebetween.

Abstract: The invention relates to an exhaust gas muffler for a two-stroke engine of a portable handheld tool such as a chain saw. The exhaust gas muffler includes a catalyzer wherein high exhaust gas temperatures are developed because of the exothermal reaction which takes place therein. The catalyzer is located in the forward portion of a gas-tight hollow body mounted in the housing of the muffler. The hollow body has a tapered portion which extends out of the housing in the direction of the exhaust gas flow. In this way, the surface temperature of the muffler housing is reduced.

Abstract: An exhaust system is provided for internal combustion engines which relatively improves the performance of such engines. The system comprises a plurality of approximately equal length exhaust pipes which are operably flow connected to exhaust ports of the engine at one end thereof and to a collection chamber at an opposite end thereof. The system further includes discharge pipes which communicate between ambient atmosphere and the collection chamber. The exhaust pipes are grouped in sets such that each of the pipes in the set is generally axially aligned with one of the discharge pipes. The collection chamber has a cross-sectional area which is greater than the cross-sectional area of the exhaust pipes where they are attached thereto and converges to a smaller cross section at the opposite end thereof where the discharge pipes are attached thereto. The discharge pipes diverge away from the collection chamber and include a silencing device in the discharge ends thereof.

Abstract: A combination air inlet - engine noise silencer consists of a shell-type housing of large volume having a small volume air inlet tube at one end and an outlet of restricted area at another portion at right angles to the inlet for direct passage into the engine induction system, the air inlet tube containing a conical-like insert coaxially mounted with its apex facing upstream to provide a base portion at right angles to the axis of the inlet tube whereby engine acoustical waves passing from the engine towards the inlet are reflected against the base portion of the cone back into the expansion chamber to be dissipated and broken-up thereby reducing the engine noise, the cone concurrently increasing the velocity of the air flow into the engine proper to increase operating efficiency.

Abstract: An exhaust dissipator device for a rocket exhaust has an inlet for connection to the exhaust and a plurality of smaller exhaust orifices spaced around its surface to dissipate the flow into a plurality of smaller jets. A deflector surface in the direction of exhaust flow into the container acts to further dissipate the flow and deflect it out of its original path. This may comprise an internal surface of the container, or a separate deflector plate spaced from the container surface.

Abstract: An exhaust silencer has an inlet opening and an outlet opening spaced axially from the inlet opening and includes a cylindrical shell. A core inside the shell defines at least one axial passage and has at least one helical baffle defining a helical flow passage around the axial flow passage within the shell. The axial flow passage has a barrier at its downstream end and has an upstream opening aligned with the silencer inlet opening. It also has an outlet axially spaced from the axial passage inlet opening, the said outlet being directed transversely outwardly into the downstream half of the helical flow passage, at a region upstream from the barrier.

Abstract: A muffler capable of suppressing the shockwave generated by an internal combustion engine forming a housing having an inlet and an outlet and a center rectifier section extending between the inlet and the outlet, the center rectifier section having a transverse cross-sectional area substantially the same as or greater than the transverse cross-sectional area of either the inlet or the outlet, and having a small dimension and a large dimension, the large dimension being several magnitudes of order greater than the small dimension.

Abstract: To reduce the speed of air being sucked towards a compressor turbine wheel, typically an exhaust gas supercharger turbine for an internal combustion engine, guide vanes (18) are located in the path of air being supplied to an inlet (3) of the compressor (1) which are positioned to impart a rotating component of motion to the air stream of air column being supplied to the compressor, the guide vanes extending essentially perpendicularly to the plane of radially positioned damping elements (14), while being inclined with respect to a radial line (19) passing through the axis of rotation of the compressor and, typically, of the housing (8) which has an air-pervious circumferential wall (8). The speed of air being supplied to the turbine thus can be reduced below Mach 1, thereby increasing the efficiency of operation of the turbine while substantially reducing its noise level.

Abstract: A fluid control valve assembly having a threaded bore within which is located a spool having an end bluff surface and a threaded peripheral surface, the valve has a body with an entry passage communicating with a tapered chamber which delivers fluid to the bore by means of cage passages, said chamber, cage passages and bore all being tuned to frequencies well above the range of the human ear.

Abstract: Exhaust device wherein the exhaust gas from the engine is not directly exhausted to the ambient air. The free end of the exhaust pipe is closed and openings are arranged in the mantle of the pipe in the area of the free end. The openings are directed to the road side. Openings are also provided in the exhaust pipe within the housing of the exhaust device. Additional filters are mounted in the container to purify the exhaust gas. The container is provided with an inner wall or coating along the mantle surface to improve sound damping. The simple construction of the proposed exhaust device makes its manufacture inexpensive. Furthermore, its contribution to the protection of the environment is considerable.

Abstract: A fluid discharge silencer for steam or other vapors or gases (with or without entrained solids or liquids) has an expansion chamber into which the fluid is passed through an inlet duct which discharges the fluid over an extended region of the chamber, flow deflector means in the chamber gradually redirecting the flow of gas from the inlet duct to change the direction of flow and to permit the gas phase components of the fluid to expand; the expansion chamber has an outlet which in use is connected to a silencer such as a parallel splitter silencer for further attenuating noise in the discharge flow. The inlet duct can be an elongated pipe having a longitudinal discharge aperture arrangement discharging the fluid into a trough-like redirecting structure which removes entrained components and redirects the flow.

Abstract: An improved induction system silencing device for an outboard motor having an engine and a surrounding protective cowling comprising a baffle plate positioned within the protective cowling for forming a resonance chamber.

Abstract: Acoustic pulsations in fluid transmission systems such as gas pipelines, engine exhaust systems and compressed air networks are suppressed by an acoustic filter comprising an enlarged pressure vessel with inlet and outlet conduits arranged such that conduit inlet and outlet openings are at the pressure node of standing pressure waves of the pressure vessel length resonant frequency and odd or even harmonics of the fundamental frequency. The inlet and outlet conduit openings are arranged such that the direction of convection flow and acoustic pulsation modulating flow is transverse to the instantaneous particle velocity of fluid resulting from acoustic pulsations existing in or excitable in the pressure vessel. Inlet and outlet conduits preferably open into the pressure vessel in a generally radial direction with respect to the central longitudinal axis of the vessel.

Abstract: A connection block or adapter for joining up pneumatic components is made with an exhaust muffler to let off air from components into the outside atmosphere. The muffler is composed of a chamber inside the connection block and has a porous wall. The wall may be made in one piece with the connection block or bonded to it as a separate part. Preferred materials are load bearing foam resin for the connection block and metal frit for the wall of the muffler.

Abstract: An element of a sound arresting device has a cylinder and a blade integrally formed in the cylinder and helically twisted along the longitudinal direction of the cylinder. A plurality of elements are coupled to each other along their longitudinal direction and are fitted in a pipe. The ends of the two adjacent blades are perpendicular to each other. The pipe is covered with a sound insulating material. The elements and the pipe are made of a porous metal material, a porous plastic material or a porous ceramic material. When the sound arresting device is used as an automobile muffler, acoustic waves propagating in the gas are repeatedly mixed, interfere with each other and are absorbed by the apertures and the sound insulating material, thereby decreasing noise from the engine. Dust in the exhaust gas is captured by the apertures of the elements and the pipe, and is removed from the exhaust gas.

Abstract: A replacement muffler which can replace original equipment mufflers with substantially no modifications thereto, and methods for producing the same are disclosed. The replacement muffler is provided with a muffler body which only approximates the body of the original equipment muffler and a pair of replacement muffler nipples secured to the muffler body, having diameters substantially equal to the corresponding nipple diameters of the original equipment muffler and having lengths adapted to produce a nipple-to-nipple length substantially equal to the corresponding length of the original equipment muffler. The replacement muffler may be produced with a six to seven fold increase in production line efficiency by customizing only the nipple portions of the replacement muffler.

Abstract: A valve includes a diffuser for the recovery of static pressure energy. The point of flow separation is stabilized by introducing, into the region where the flow separation point can occur, a volume of the working medium from a portion of the valve having a higher pressure than such region. By stabilizing the flow separation point against vibration, resulting noise is minimized.

Abstract: A pulsation dampener and acoustic attenuator for hydraulic systems is designed to be inserted into a liquid flow line. The dampener is a flow-through device with a pressurized bladder restrained within a perforated sleeve. The arrangement of inlet/outlet ports, the bladder, and the screen provides means for dampening flow pulsations in the supply system to effect a more uniform flow and to attenuate acoustic noises reverberating within the system. The dampener provides for self-cleaning due to the flow of the liquid and is thus suitable for sanitary applications. Further, the bladder may be readily removed through one end of the dampener without otherwise removing the dampener from the pipeline in order to examine or replace the bladder.

Abstract: Sound damping apparatus for internal combustion engines, especially for public works or agricultural machines, and machines provided with such an apparatus.This sound damping device is intended for machines or engines mounted within a bonnet (1) and provided with a blower (3) discharging cooling air to the outside through a radiator (4). It is constituted by a sound damping element (9, 21) such as a block of expanded foam material having one or more central openings (14) oriented in the direction of flow of the air discharged by the blower and peripheral openings (16) inclined or specially shaped so as to direct the air towards the central flow passing through the central opening or openings downstream of the device. Means are provided for forming an expansion chamber (13) between the radiator and the sound damping element.

Abstract: An exhaust assembly for a tractor having a pivotal or slidable engine hood that must be moved out of the way to permit an operator complete access into the engine compartment. The exhaust assembly includes a tubular housing positioned within the engine compartment below the top surface of the engine hood. The tubular housing has a cylindrically shaped inlet conduit adapted to be connected to the exhaust manifold of the tractor engine. Exhaust gases are forced vertically into the inlet conduit and then directed in a horizontal swirling fashion through the tubular housing by apertures and baffles along the length of the inlet conduit. The tubular housing further includes a cylindrically shaped outlet conduit having an open conical discharge end which is in close proximity to the lower end of an elongated exhaust tube that is attached to the engine hood.

Abstract: A muffler of the Helmholtz resonator type has a housing surrounding a main gas flow conduit, the gas flow conduit having an apertured zone within the housing wherein apertures extend through the conduit wall, the shape of the conduit wall at the apertured zone being so varied that gas flows through the apertures into or out of the housing, the flow inhibiting the development of whistle noises.

Abstract: A muffler of the expansion type comprises an inlet pipe and an outlet pipe connected with each other through a main body. Minimization of pressure pulsation is achieved by a variety of means including appropriately-located apertures in those portions of the walls of said pipes within said main body, an apertured partition within said main body so located that exhaust gas passes through said partition, and appropriate tapering of said pipes. A foamed, heat-resistant material may be positioned over said apertures in said walls of said pipes. Pipe constructions suitable for mass production and pipe-to-main body constructions free of the danger of separation during prolonged use are shown.

Abstract: A muffler construction comprising an outer body, and a pair of end walls extend transversely across the body to define an internal chamber. An inlet conduit is located in one of the end walls, while an outlet conduit is in the other end wall. In one embodiment, the inlet conduit is disposed axially of the body to excite symmetric higher order modes and the outlet is offset radially from the axis of the body and is located on a nodal circle of the transverse pressure distribution. In a second embodiment, the inlet is offset from the axis of the body causing excitation of asymmetric higher order modes and the outlet is located on a nodal line of the transverse pressure distribution. The construction of the invention maximizes attenuation of high order modes in mufflers.

Abstract: An exhaust silencer for use with small vehicles which use low speed engines and have minimal space available for the silencer while still requiring a long exhaust path to silence the low frequency engine pulsations. The silencer includes a silencer chamber with an axis, and an exhaust pipe with a U-shape, one arm of which extends axially into the chamber, and the other arm of which extends parallel to the axis outside of the chamber, both for a substantial part of the length of the chamber. At least the bight of the U-shaped pipe is double-walled to minimize the emission of pulsations from that portion of the exhaust pipe.

Abstract: An exhaust gas silencing system wherein standing waves are utilized in a silencing chamber to reduce low frequency components of noise, and a downstream muffler is utilized to reduce the high frequency components of noise. An expansion chamber can be utilized further to reduce the pressure of the sound waves.

Abstract: An internal combustion engine air cleaner assembly has a lower supporting tray wall, a top cover or enclosure wall, and a side wall, together defining a hollow air expansion chamber containing a filter element; the chamber has an air inlet and an outlet opening to the engine that lies in the plane of the lower wall, the outlet being part of an angled outlet orifice cowl asymmetrically positioned with respect to the centerline of the surrounding side and top walls and surrounding the outlet and having an inlet that is in a plane inclined to the planes of the top and side walls to reduce noise.

Abstract: A silencer construction for connection to the intake side of a compressor comprises an assembly of axially spaced annular sound damping elements which form air in-flow passages therebetween. The sound damping assembly is located in a radially outer annular chamber of the silencer housing and the radially inner circumference of each of the sound damping elements merges into a curvilinear air guiding element which functions to deflect the partial air flows leaving the passages between the damping elements in the direction of the main air flow into a convergent intake manifold of the compressor.

Abstract: A muffler having a sealed diffusion chamber provided at its front end with an inlet port of a cross section smaller than that of the diffusion chamber. Within the diffusion chamber there is an outlet pipe having a closed front end disposed a fixed distance from the inlet port. The rear end of the outlet pipe communicates with the atmosphere. The walls of the outlet pipe are perforated to permit communication between the diffusion chamber and the interior of the outlet pipe.

Abstract: A combination muffler and air filter is provided having a central tubular member with spaced longitudinally disposed elongated slots. A disposable canister on the central tubular member is removably held in position by retainer caps engaged on the ends of the central tubular member. One of the retainer caps is adapted for connection to the exhaust conductor from a pneumatically operated device. The disposable canister has a perforated cylinder encasing a series of stacked annular members having both muffling and filtering properties. A perforated sleeve in the disposable canister supportively engages the inner periphery of the stacked annular members. A closure disc, fixed on each end of the perforated cylinder, holds the stacked annular members in a compact and compressed condition.

Abstract: A noise suppressor for internal combustion engine exhaust, adapted for marine use wherein water coolant is discharged into the chamber of a single-walled riser and partially vaporized by the exhaust gases directed into the dome thereof for downward redirection and discharge from the lower portion of the riser chamber through a muffler element, and preferably through the hull chest and/or cover of a jet pump drive acting as the final noise barrier to atmosphere.

Abstract: An exhaust muffler intended for noise dampening of, for instance, pneumatic tools, comprising a variable flow restricting passage, an attenuation chamber and a non-variable flow restricting passage. A valve body is arranged to control said variable flow restricting passage in response to the actual exhaust gas pressure. A movement dampening chamber, partly defined by the valve body, communicates with the atmosphere through a restriction opening to prevent resonance vibration of the valve body.

Abstract: An exhaust gas silencing system wherein standing waves are utilized in a silencing chamber to reduce low frequency components of noise, and a downstream muffler is utilized to reduce the high frequency components of noise. An expansion chamber can be utilized further to reduce the pressure of the sound waves.

Abstract: A multi-effect passive detonation trap utilizes a manifold having a rectalarly shaped cross sectional area with oppositely disposed off-set pipeline fixedly connected thereto to attenuate an upstream detonation wave. The detonation wave is arrested by providing for maximum containment and self relief of the energy produced, directional control of the reaction, and a manifold configuration which assures extinction of the detonation wave.

Abstract: There is disclosed a muffler for an internal combustion engine, particularly an automobile engine, which includes a heavy steel outer casing formed from a section of cylindrical tubing together with an internal baffle structure of two sections of smaller diameter cylindrical steel tubing at least one of which is perforated to create a plurality of louvered openings extending along and around the tubing section. Each of the tubing sections has an end that is offset by reason of a pair of opposite-direction bends in the tubing, and the offset ends of the two sections of tubing are overlapped and joined together by welding or other suitable means to produce an extended baffle structure of approximately the same length as the outer casing. The offset ends of the sections of tubing which are joined together are preferably flattened on the sides adjacent to each other to reduce the maximum dimension of the baffle structure along the portion thereof where the two tube sections overlap.

Abstract: Core noise, a low frequency noise component believed to be partly caused by the combustion processes within the engine, and turbine noise, a higher frequency noise component caused by the interaction of high velocity gases with the engine's turbine, are attenuated by noise absorbing structures that are disposed within the engine's nozzle and that in part define the physical geometry of the nozzle duct. The nozzle is formed of an outer sleeve and an inner generally bulb-shaped plug which are coaxially arranged to define an annular nozzle duct that channels the flow of gases rearwardly from the outlet of the engine's turbine. The plug has a hollow interior that is partitioned into a plurality of cavities that communicate with the nozzle duct via perforations provided in an outer wall of the plug.

Abstract: A muffler comprising: an upper case provided at the opposite ends with semi-cylindrical inlet and outlet sections respectively and having an outwardly raised central portion and an integral flange-like edge portion; a lower case joined at a flange-like edge portion to that of said upper case and substantially symmetrical with said upper case with respect to the underside thereof; an exhaust inlet tube forming member having at least a semi-cylindrical inlet section inserted in a cylindrical inlet formed by the inlet sections of said upper and lower cases joined together and a gutter-like guide section connected to said inlet section and being joined to said upper case, lower case or both of them, said forming member being provided adjacent to an end thereof with a perforated portion; and an exhaust outlet tube forming member having at least a semi-cylindrical outlet section fitted in a cylindrical outlet formed by the outlet sections of said upper and lower cases and a gutter-like guide section connected to sa

Abstract: The acoustic silencer functions as a pulsation dampener to minimize noise generated in liquid and/or gaseous fluids inherently present in fluid conveying systems which embody pumps, compressors, engines and the like. The device includes a shell divided into first and second compartments by a partition supporting a central tube placing the compartments in communication with each other. The tube passage itself is provided with internal diametrically oppositely positioned vanes forming an acute angle with the axis of the tube to impart a rotational component to fluid flow through the tube. A polar or rotational inertence is thus provided in addition to linear inertence to the fluid flow thereby enabling shorter tubes to be utilized with a subsequent simplication in the manufacture and an increased reliability in the structural integrity of the silencer.

Abstract: A silencer which may be arranged in place in an exhaust system of an internal combustion engine includes walls forming the main body of the silencer; a first separator supported by the walls to define a rear chamber therebetween; a second separator supported by the walls to define a first intermediate chamber between the walls and the first and second separators; a flame-extinguishing device supported by the walls to define a second intermediate chamber in combination with the walls, the second separator and the flame-extinguishing device as well as to define a front chamber between the walls and the flame-extinguishing device; an inlet pipe in fluid communication with the front chamber whereby an exhaust gas may flow from the inlet pipe into the front chamber; an outlet pipe in fluid communication with the first intermediate chamber whereby the exhaust gas may flow out of the first intermediate chamber through the outlet pipe; and an inner pipe having a plurality of apertures formed therein.

Abstract: A muffler for a motor vehicle which serves as a reactor for oxidizing or re-burning unburned constituents in engine exhaust gases. The muffler comprises a heat insulated inner shell in which a chamber is provided with a silencing unit and is kept at a high temperature sufficient to oxidize the unburned constituents, an outer shell covering the heat insulated inner shell, and means for absorbing the thermal expansion of the inner shell provided in a supporting device of the inner shell. An exhaust pipe extends into the inner shell and has one end provided with a collector. The collector has a guide opening to pass engine exhaust gases into the inner shell while achieving mixing of the exhaust gases in the collector thereby to promote oxidizing reaction of the exhaust gases.

Abstract: The exhaust of an internal-combustion engine comprises a muffler of malleable aluminum or aluminum alloy with a heat-resistant inner layer extending at least along a wall portion confronting an inlet for the hot exhaust gases. The heat-resistant layer may be a refractory coating, e.g. alumina, beryllia or zirconia particles in a matrix of Teflon or silicone rubber, or a metallic liner separated from the outer wall by an airspace possibly occupied by rock wool or the like.