Abstract: An exhaust system for vehicles and other devices with internal combustion engines such as boats, airplanes, lawnmowers, tractors, and the like, includes a sound attenuating chamber having a single, common opening in an imperforate container providing access for exhaust gases both to and from the container while attenuating the exhaust sound thereof. The system maintains low back pressure during operation. Resonator tubes and optional sound absorbing material may be used in the chamber to control exhaust sounds. An optional, remote-operated, sound control valve upstream of the chamber allows individualized control of the exhaust sound by the vehicle driver. An optional baffle in the exhaust outlet and/or an optional helical insert in the exhaust pipe further deadens the sound. In a preferred form, the system is attached downstream of a catalytic converter and includes dual sound attenuating chambers and dual exhaust outlets at the opposite vehicle sides between the front and rear wheels.

Abstract: A sound absorbing muffler used to attenuate noise carried by the exhaust gases of an internal combustion engine includes a straight-through flow tube of cross-section having no baffles or flow reversals. The muffler utilizes both reactive and dissipative components and includes an outer annular resonating chamber and an inner sound absorbing chamber. The muffler's configuration produces effective broad band noise attenuation even at lower frequencies, yet low backpressure.

Abstract: An exhaust muffler for an internal combustion engine including an outer shell containing two halves made of synthetic resin material, a metallic inner pipe extending through the parting plane between the two halves via a tubular extension extending integrally from the two halves, and an outer sleeve which is fitted onto the tubular extension, preferably by using a bayonet mount structure, for securely joining the two halves at its one end and forming an air-tight seal in cooperation with the part of the inner pipe extending out of the tubular extension at its other end. An arrangement is provided for accommodating a relative displacement between the other end of the outer sleeve and the inner pipe for avoiding the generation of thermal stress due to the difference in the coefficient of thermal expansion between the outer shell and the inner pipe made of different materials.

Abstract: A car silencer includes an outer pipe having a front expansion chamber defined in a front portion of the outer pipe connected with a connecting tube which is connected to an engine manifold for directing waste gas as discharged from a car engine, an inner pipe detachably inserted in a rear expansion chamber in the outer pipe at a rear portion of the front expansion chamber, an absorbing and filtering medium filled in the inner pipe, and a perforated tail pipe inserted in the absorbing and filtering medium, wherein an engine exhaust gas will be reduced its sound in the front and rear expansion chambers and a plurality of pollutants laden in the exhaust gas will be absorbed, filtered and removed in the absorbing and filtering medium for preventing air pollution caused by an engine waste gas.

Abstract: A double-wall hollow body comprises an inner hollow body and a cooperating outer hollow body. The outer hollow body is frictionally attached to the inner hollow body, and is radially spaced from the inner body so that an annular space is formed between the two bodies. Acoustic-damping insulating material is contained within the annular space, and forms an interlayer between the inner and outer bodies. An end of the double-wall hollow body is formed by respective ends of the inner and outer hollow bodies that rest directly against each other without insulating material. The inner hollow body is separated over an entire circumference from the outer hollow body by the insulating interlayer. Various methods of manufacturing the foregoing double-wall hollow body are also described. For instance, to apply the insulating material to the inner hollow body, such body may be heated and then rolled into the insulating material.

Abstract: This invention relates to sound attenuating mufflers, and more particularly to sound attenuating mufflers for dampening sound waves of various frequencies above a pre-selected cut-off frequency. Specially positioned acoustical insulation is provided to partially attenuate sound waves of a relatively low frequency. The insulation is carried in a chamber having one dimension of sound wave travel on the order of one-tenth the wavelength of a preselected cutoff frequency above which sound attenuation is desired. An adjacent chamber substantially free of insulation has one dimension of sound wave travel on the order of one-quarter wavelength of the cutoff frequency.

Abstract: An engine-exhaust gas driven turbo compressor has a controllable diaphragm valve (13, 15) in a flow path (20, 24) between a compressor delivery port (6) and an atmospheric inlet port (4), this valve being controllable to regulate gas flow via the compressor wheel member (2) to avoid compressor surging when the demand is low and a compressed torroidal wire mesh element (23) is accomodated in an annular region (22) of the compressor housing between the valve (13, 15) and the inlet port to suppress noise resultant upon operation of the valve.

Abstract: The silencer includes a tubular envelope supported by an end piece for fixture to a gas supply source in which the pressure is to be reduced. A perforated plate and a disk close off the ends of the envelope which is drilled with escape apertures in the region of the disk. According to the invention, the gas flows at sonic speed through the plate to enter the envelope which is completely filled with a packing consisting of a tightly wound roll of wire mesh. The packing absorbs the shock waves developed by the supersonic flow of the gas in the packing. The latter maintains a subsonic flow with a low noise level upstream of the silencer. Application to the treatment of a surface by blasting of a gas flow is also described.

Abstract: A mounting assembly for an exhaust gas catalyst includes a metallic exhaust gas catalyst carrier body and a tubular jacket in which the catalyst carrier body is disposed. The catalyst carrier body is fastened to the tubular jacket while permitting lengthwise expansion of the catalyst carrier body, through the use of beads encircling at least part of the catalyst carrier body and corresponding formations formed in the tubular jacket into which the beads protrude in the form of slots and keys. The catalyst carrier body and the beads are disposed at axial and radial distances from the tubular jacket and the formations.

Abstract: A silencer is provided for reducing noise from exhaust gases from an internal combustion engine. The silencer is of the type having an outer cylindrical cover and a coaxial inner cylindrical tube which define between them an annular cylindrical chamber into which the exhaust gases which enter the silencer are admitted. The inner tube is a perforated tube, a first open end of which forms the sole admission orifice for the gases into the silencer and the other opposite end of which is closed. The inside wall of the outer cover is lined with a layer of absorbent material mounted about the inner tube along substantially the entire perforated length of the inner tube.

Abstract: Sound absorptive fiberglass pads within a silencer device for a centrifugal compressor are precompressed while installing the device in a containing frame mounted in the discharge pipe by a process including the steps of establishing the transverse dimension of the frame as a function of the transverse thickness of the device, precompressing one end of the device to a thickness which allows its insertion into the frame, and then forcing the entire device into the cavity in a wedgelike manner to thereby precompress the entire device, to thereby precompress the absorptive pad to a desired degree for purposes of erosion prevention.

Abstract: An exhaust processor is provided for filtering particulate matter from a combustion product. The exhaust processor includes a housing providing a main passageway having a substrate mounted therein for solid particle filtration. The housing also provides an auxiliary passageway containing a muffler for attenuating noise of combustion product. Combustion product is diverted through the auxiliary passageway after the substrate collects a predetermined amount of solid particles from combustion product to permit regeneration of the substrate by a burner.

Abstract: In a process for the manufacture of an exhaust silencer for motor vehicles, the advantages derived from employing mineral fiber mouldings are extensively retained while at the same time greatly reducing expenditure on shape-stabilization and transportation. To this end the silencer casing itself is divided in the meridian plane and the mineral wool is supplied and inserted directly into the original silencer casing in the form of precisely dimensioned prefabricated elements which have been impregnated with a suitable fluid, for example pretreated with synthetic resin, but not cured. This enables fast and reliable positioning of the impregnated and manually compressed prefabricated elements around the periphery of the exhaust pipe and the internal component containing the exhaust pipe inside the original silencer casing; once the silencer casing has been closed, the silencer is ready for installation. Curing, hardening or some other time consuming method of shape-stabilization is not necessary.

Abstract: An engine exhaust including a silencer which has a cylindrical shell, a front and a rear end plate which are provided to close both ends of the cylindrical shell, and at least three partition walls to divide an inside space of the silencer into a plurality of chambers, i.e. at least a first chamber, a second chamber, a third chamber and a fourth chamber. An inlet pipe which bypasses at least the first and the second chambers, and connects the front end and the third chamber. The inlet pipe has a plurality of small holes which face toward the first and the second chambers. The small holes facing the second chamber are surrounded by a sound absorber. An outlet pipe bypasses at least the second, the third and the fourth chambers and connects the first chamber and the rear end plate. The outlet pipe has a plurality of small holes which face toward the third and the fourth chambers. The small holes facing the fourth chamber are surrounded by a sound absorber.

Abstract: A sound depressing exhaust means for a pneumatic power tool with a substantially cylindrical housing (10) and a vane motor (11) with exhaust port means (23), has an annular casing (41) surrounding a portion of the housing (10), and four expansion chambers (31-32, 34, 36, 39) arranged in series and combined with four flow restrictions (33, 37, 30, 35) and a sound trap (38). All of the expansion chambers are annular and located concentrically relative to the tool housing (10), and one of the flow restrictions has an annular screen (37) separating two of these chambers (34, 36). The last two of the expansion chambers (36, 39) in the exhaust flow direction contain high frequency absorbing elements (43, 44) of foamed plastic.

Abstract: A tubular sock made of fibrous material is placed over a louver patch formed in an exhaust flow tube mounted in a muffler to attenuate engine exhaust noise. A slip tube is provided for preventing the tubular sock from becoming entangled on the louver patch as it is being placed on the exhaust flow tube.

Abstract: The invention provides a pressure-fluctuation and noise suppressor having low flow resistance and high effectiveness. It is especially useful as a suppressor for an oil-injection inlet system of a positive-displacement air compressor. It has a cylinderical housing separated into ante- and main chambers by a partition. A tubular suppressing element is fixed through the partition eccentrically of the axis of the housing. The inlet of the suppressing element is in the form of a nozzle in the ante-chamber that widens away from the partition. In the main chamber, the wall of the suppressing element is perforated and the end of the suppressing element in the main chamber is closed by a conical member. An outlet tube is situated on a side wall of the housing in a plane perpendicular to the axis of the housing on an axis transecting the axes of the chambers and the suppressing element. An inlet extends into the ante-chamber diagonally from the nozzle of the suppressing element.

Abstract: An exhaust muffler for use with an internal combustion engine has at least one internal suppression chamber, at least one inlet pipe for receiving exhaust gases from the internal combustion engine, and at least one outlet pipe vented to atmosphere. The exhaust muffler comprises a plurailty of component units connected in series with each other and each having the internal suppression chamber. Each of the component units has a casing having an inner layer of a sound-absorbing material which defines the internal suppression chamber, and a connector pipe connected to and extending through the casing, the connector pipe having upstream and downstream ends projecting out of the casing, the connector pipe having at least one opening which opens into the internal suppression chamber.

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: A fireplace provided with a sound reducer is shown. The sound reducer eliminates ambient noise feeding back to the indoor through the flue system of the fireplace.

Abstract: An exhaust muffler for an internal combustion engine, comprising a hollow casing defining a plurality of chambers which are communicated with each other by way of small holes, an exhaust inlet tube fixedly attached to an exhaust port of an internal combustion engine at its one end and fitted into the casing from a hole provided therein for communication with one of the chambers at its other end, and an exhaust outlet passage communicating another one of the chambers to the atmosphere. The internal end of the exhaust inlet tube and an opposing casing wall are joined by a threaded fastener while the exhaust inlet tube is provided with an annular shoulder surface which fits into the hole of the casing in an air tight fashion, so that the mounting of the muffler can be accomplished simply by fitting the casing of the muffler onto the exhaust inlet tube which is typically attached to a cylinder head of an internal combustion engine in advance and tightening the threaded fastener.

Abstract: A sound attenuating muffler for motor vehicle exhaust systems contains a fibrous glass cartridge with a binder-hardened outer shell surrounding a soft fibrous core through which a gas flow tube extends.

Abstract: A unique vacuum loader is provided with a special silencer base to quietly, efficiently, and effectively remove particulate matter, debris and waste from industrial plants and other locations. The silencer base comprises a muffler and sound abatement control assembly with a composite sound attenuating chamber. The sound attenuating chamber has a zigzag channel to decrease and dampen operational noises to safe and comfortable levels. The silencer base has a top plate to support and dampen vibrations of the vacuum pump and motor.

Abstract: A silencer to be mounted on the air intake of a cooling fan of an electric motor in a vacuum cleaning system. The silencer comprises a cylindrical housing closed at one end and opened at the other end. The housing is provided with perforations around its periphery adjacent the closed end. A sleeve made of sound absorbing material lines the inside of the housing without obstructing the perforations.

Abstract: Muffler for hermetic compressor formed by a first portion for attenuating the pulsations and for separating the oil and by a second portion provided with means for damping the gas pulsations transmitted outwardly. A little tube permits the discharge of the oil separated from the refrigerating gas from the first or second portion.

Abstract: An exhaust silencer for internal combustion engines, particularly as used on motor vehicles including tractors. A front pipe, a plurality of core tubes and a tail pipe have successive inner flow channels of equal section areas. The plurality of core tubes are integrally connected to the larger end of a trumpet pipe. The walls of the core tubes are punched with flanged holes forming converging passages. Flow-dividing plates are provided in the tail pipe. The exhaust flow divides into smaller substreams on passing through the front pipe and the core tubes, thus raising the ratio of expansion, leading to a decrease in noise level and exhaust back pressure, while reducing engine output loss. The noise level of a vehicle can be reduced to 80-83 dB(A), while oil consumption is reduced by 6-8.8%.

Abstract: A muffler for exhaust gases of an internal combustion engine. The muffler is a hybrid consisting of gas expansion chambers defined by partitions in a muffler casing, and a sound-absorbing body. The sound-absorbing body includes a perforated pipe surrounded by a porous sound-absorbing material with a thin metal film sandwiched therebetween.

Abstract: The exhaust muffler comprises a body (12) of ceramic material which is enclosed within a metal case (1) defining an inlet chamber (16) and an outlet chamber (18) for the exhaust gases. A blanket (20, 22) of refractory fibres resisting high temperatures, assembled with a very small amount of binder and substantially without water of constitution, is highly compressed between the body (12) and the case. A sealing element (24) surrounding the body (12) is interposed between the blanket and the gas outlet chamber (18).

Abstract: An internal combustion engine exhaust gas catalytic converter has coaxial inner and outer louvered tubes which define an annular catalyst bed. An outer shell coaxial with the inner and outer louvered tubes define a portion of a gas flow path downstream from the catalytic bed. The downstream flow portion has an annular outlet of smaller cross sectional area than the cross-sectional area of the inlet end of an upstream portion of the flow path. Heat expandable means maintain a constant density of catalyst beads within the catalytic bed. These heat expandable means preferably comprise a composition of ceramic fibers, vermiculite and a binder.

Abstract: A high performance vehicular muffler is provided. The muffler includes a centrally disposed outlet tube, an inlet tube and a transfer tube. Internal baffles define a low frequency tuning chamber with which the inlet tube and transfer tube communicate. A high frequency tuning chamber surrounds the portion of the outlet tube between the internal baffles. The high frequency tuning chamber is packed with an absorbant. The opposed end caps of the muffler are provided with outwardly bowed portions to achieve a more laminar flow of exhaust gases and to minimize back pressure.

Abstract: A vacuum cleaner apparatus having separate passages for outgoing air from the blower and for cooling air for the blower motor, and having a number of turns in each of said passages, each of said passages having a plurality of variations in cross-sectional area, the passages being provided with sound-absorbent linings.

Abstract: A muffler for use on an internal combustion engine includes an enclosure generally cylindrical and having end plates for closing the internal volume of the enclosure, at least one partition plate for dividing the internal volume of the enclosure into at least two chambers, an inlet tube, supported by one of said end plates and at least one partition plate, for conducting combustion gases supplied from the engine to one of the chambers; an outlet tube, supported by the other of the end plates and at least one partition plate, for blowing out the gases from remaining one of the chambers; and a connecting tube supported by said at least one partition plate for interconnecting the volume of adjacent ones of the chambers. At least two of the inlet, outlet and connecting tubes are integrally made of a single sheet of metal shaped to form a combination tube including the at least two tubes. A method of manufacturing such a combination tube is also provided.

Abstract: A noise converter according to this invention is provided with gas conducting spiral passages defined between spirally twisted outer and inner tubes polygonal in cross-section. A gaseous body generating noise flows through the gas conducting passages from one end to the other. Since noise is generated by masses of particles of gaseous body having energy, particles of less energy move forward along a course near the center of each spiral passage whereas those of more energy along the other course near the outside of the passage due to centrifugal force, thereby dispersion and attenuation of energy being performed.

Abstract: A composite sound and heat insulating board comprising a base layer consisting of a compacted mat of filaments, and an additional layer of a material which differs in hardness than the compacted mat, wherein one surface of the base layer is securely attached to one surface of the additional layer. The compacted fiber mat may be composed of filaments of an organic composition, filaments of an inorganic composition, or partially of filaments of an organic composition and partially of filaments of an inorganic composition. The additional layer of the composite board is constructed of a naturally occurring or synthetic resin such as, for example, a relatively hard thermosetting or thermoplastic synthetic resin, or a relatively soft material which is lower in hardness than the compacted fiber mat. The composite board is advantageous when used in association with a source of heat and noise such as, for example, an internal combustion engine of a power driven vehicle.

Abstract: A muffler for exhaust gases of an internal combustion engine. The muffler is a hybrid consisting of gas expansion chambers defined by partitions in a muffler casing, and a sound-absorbing body. The sound-absorbing body includes a perforated pipe surrounded by a porous sound-absorbing material with a thin metal film sandwiched therebetween.

Abstract: A muffler of the absorption type for the exhaust gas of an internal combustion engine including a cylindrical porous sound-absorbing body 1, and a film 5 of the metal or other material formed cylindrically on the inner surface of the porous body 1. The film prevents clogging of the pores in the porous body and enables the absorption of the sound in a wide frequency range.

Abstract: A muffler of the absorption type for the exhaust gas of an internal combustion engine including a fibrous sound-absorbing body, and a film of paint on the inner surface of the fibrous body. The film prevents clogging of the pores in the porous body and enables the absorption of the sound in a wide frequency range.

Abstract: A sound insulating apparatus. Heretofore, the sound insulating apparatus to be installed in a ventilator, etc. of an architecture requires a long duct, and becomes large in its size and heavy in its weight, and is not sufficient in its sound absorbing performance.The sound insulating apparatus according to the present invention comprises a closed container including a first opening and a second opening, and having a sound absorbing member at its internal surface. The first opening is provided with a sound converging means for converging a sound wave coming into the closed container through the first opening to a predetermined place within the closed container. The second opening is formed in a place away from the predetermined place.

Abstract: An exhaust silencing system for an automotive engine comprises a sound absorbing tube formed of a gas permeable porous material and connected at its one end with a tailpipe of an exhaust system of the engine, thereby effectively attenuating exhaust noise, particularly in a high frequency range.

Abstract: A muffler for an internal combustion engine for effectively damping noise over a wide frequency range, from low frequency noise to high frequency noise. An absorber packed type muffler adapted to absorb noise by a sound absorbing material is inserted in and fixed to a housing which has a bore or bores thereinside, thereby forming one of a pipe inserted type muffler, a resonance type muffler and an interference type muffler to attain combined characteristics of both the types of mufflers.

Abstract: A muffler for an internal combustion engine includes an outer box composed of a plurality of separate bodies made of a formed sound insulation material and having portions joined by an adhesive, the outer box having an inlet for introducing an exhaust gas from the internal combustion engine and an outlet for discharging the exhaust gas, and a reinforcing member mounted on the joined portions to seal and reinforce the same. The muffler is simple in construction, has a good sound insulation capability, is lightweight, and sufficiently mechanically strong.

Abstract: A muffler connected to an exhaust system of an automotive or like internal combustion engine for damping noise, which accompanies engine exhaust, using a sound absorbing member. An intertwined meshwork in a tubular configuration serves as means for covering and firmly retaining the sound absorbing member, which is wound around a perforated pipe, on the outer periphery of the perforated pipe. The tubular meshwork is produced by intertwining in a desired density strings each of which is made up of a number of strands.

Abstract: An acoustic capacitor of minimum size and minimum susceptability to temperature-induced internal pressure change. The capacitor comprises an insulated container having an internal member of high heat capacity material surrounded by a porous thermally conductive material; the member acts as a heat sink, slowing the rate of change of pressure due to change in ambient temperature. The internal pressure that is built up due to temperature change is bled off by the same orifice that equilibrates the internal pressure to ambient atmospheric pressure.

Abstract: A muffler for internal combustion engine houses a catalyst for exhaust gas purification and is provided with an exhaust gas inlet pipe through which exhaust gas from the engine is fed to the upstream side of the catalyst. The exhaust gas inlet pipe includes an inlet pipe section provided therein with a venturi section through which atmospheric air as secondary air is inducted into the exhaust gas inlet pipe. The inlet pipe section is extended in the direction of exhaust gas flow to form an extension pipe section which has a length of at least two times the inner diameter of the extension pipe section, thereby suppressing cutoff frequency at lower levels.

Abstract: A muffler for use with various instruments and furnished with a spark arresting function. An inlet pipe for receiving exhaust gases from the instrument and an outlet pipe for discharging the exhaust gases to the atmosphere are arranged in an expansion chamber of a housing with their one end open to the latter. The expansion chamber is divided into two compartments by a partition having a wire net therewith. An intermediate pipe for providing fluid communication between the two compartments is mounted on the partition. The air flow area of the wire net and the cross-sectional area of the intermediate pipe are selected such that the quantity of the gases flowing through the wire net is larger than that of the gases flowing through the intermediate pipe. The outlet pipe is formed with an exhaust gas inlet through its side wall portion which is larger in area than the open one end and covered with a wire net.

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: A noise suppression device is provided for a vacuum cylinder having a conl head which is used in high speed paper converting machines and which includes a sound attenuator which is integral with the vacuum cylinder. The sound attenuator incorporates a plurality of attenuation chambers within the vacuum cylinder which are interconnected by tubes arranged in an offset manner to overlap each other in the projection. Air passages are also provided in the side of the vacuum cylinder opposite the control head to connect the last attenuation chamber to the atmosphere.

Abstract: An internal combustion engine powering a motor vehicle is provided with a separate exhaust casing which is located within an engine compartment developed into a sound-insulating capsule, and is designed as a roof-type cover without a bottom shielding at least those parts of the exhaust system close to the cylinder head of the engine. This cover is connected with an outlet opening in an outer wall of the vehicle, which opening is positioned in an area where the heated air rises from the exhaust system, such that ventilation of the capsule and the exhaust system is ensured even after the engine has been turned off.

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 muffler of the absorption type for the exhaust gas of an internal combustion engine including a cylindrical porous sound-absorbing body 1, and a film 5 of a metal or other material formed cylindrically on the inner surface of the porous body 1. The film prevents clogging of the pores in the porous body and enables the absorption of the sound in a wide frequency range.