Abstract: A controllable muffler system is sued for use with an engine that produces a power by burning fuel. The system comprises a first passage section extending from the engine for having an exhaust gas of the engine flow therethrough. The first passage section has a catalytic converter mounted thereon. The system further comprises a dual passage section including second and third passage sections which extend separately from an end of the first passage section. The second passage has a control valve for controlling the flow rate of the exhaust gas flowing therethrough. The system further comprises a fourth passage section extending from respective ends of the second and third passage sections to the open air. The fourth passage section has a rear muffler mounted thereon. The system further comprises a control unit which controls the control valve of the second passage section in accordance with an operation condition of the engine.

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

Abstract: An exhaust pipe is branched into a right side connecting portion and a connecting portion. The right side connecting portion is connected to a first muffler while the connecting portion is connected to a second muffler through a space under a boundary between a driver's seat and a passenger's seat. It is possible to eliminate the need for reducing the thickness of a portion, corresponding to each of the driver's seat and the passenger's seat, of a cushioning material of the seat and to ensure a sufficient range of vertical movement of a rear wheel. The aforementioned arrangement permits the weight of the exhaust system to be reduced without sacrificing the cushioning characteristic of the seat and the range of vertical movement of the rear wheel.

Abstract: A device for noise configuration in a motor vehicle has a hollow body which is divided into at least two spaces. One space is connected to a gas-carrying part of an internal combustion engine arranged in the motor vehicle, and the other space is coupled acoustically to an interior and/or to an engine space of the motor vehicle and/or to the space surrounding the motor vehicle. The hollow body is divided into the two spaces by an essentially acoustically inactive wall. A vibrational element, which extends into both spaces, is arranged within the hollow body.

Abstract: An exhaust system features first and second exhaust conduits fluidly coupled to first and second cylinder banks of an associated internal combustion engine. The first and second conduits cross over each other downstream of the engine and are coupled together by a common chamber. The common chamber allows pressure pulses in the first and second conduits flowing past the chamber in opposite directions to at least partially cancel each other, thereby reducing low frequency exhaust noise.

Abstract: A method and system for attenuating noise including arranging a plurality of accumulators (210, 310) to form a transmittance path for compressible flow mass and noise between a noise source (212, 312) and the external environment (218, 318), and selectively accumulating and confining compressible flow mass and noise within at least one of the plurality of accumulators, and attenuating noise confined within the at least one accumulator by ringdown. The system may include a plurality of interruptors/valves (220, 320) which are operated at respective timings for periodically accumulating and confining compressible flow mass and noise in at least one of the plurality of accumulators.

Abstract: A method and system for attenuating noise including arranging a plurality of accumulators (210, 310) to form a transmittance path for compressible flow mass and noise between a noise source (212, 312) and the external environment (218, 318), and selectively accumulating and confining compressible flow mass and noise within at least one of the plurality of accumulators, and attenuating noise confined within the at least one accumulator by ringdown. The system may include a plurality of interruptors/valves (220, 320) which are operated at respective timings for periodically accumulating and confining compressible flow mass and noise in at least one of the plurality of accumulators.

Abstract: A controllable muffler system is sued for use with an engine that produces a power by burning fuel. The system comprises a first passage section extending from the engine for having an exhaust gas of the engine flow therethrough. The first passage section has a catalytic converter mounted thereon. The system further comprises a dual passage section including second and third passage sections which extend separately from an end of the first passage section. The second passage has a control valve for controlling the flow rate of the exhaust gas flowing therethrough. The system further comprises a fourth passage section extending from respective ends of the second and third passage sections to the open air. The fourth passage section has a rear muffler mounted thereon. The system further comprises a control unit which controls the control valve of the second passage section in accordance with an operation condition of the engine.

Abstract: An energy attenuation device for a conduit conveying a liquid under pressure, a system incorporating same, and a method for attenuating energy in a conduit, are provided. The device includes a conduit, a restrictor disposed in the conduit and dividing the interior thereof into an inlet chamber and an outlet chamber, and a first tube disposed in one of the chambers, wherein an annular space is formed between the inner peripheral surface of the conduit and an outer peripheral surface of the tube. One end of the tube is connected to and in fluid communication with the restrictor or with the inlet or outlet end of the one chamber, and the other, free end of the tube is spaced by an open gap from the inlet or the outlet end of the one chamber or from the restrictor. The tube has at least one aperture in the free end and/or on the peripheral surface thereof for providing fluid communication between the tube and the one chamber.

Abstract: An exhaust system for a jet propulsion boat and a jet propulsion boat including the exhaust system. The exhaust system includes a muffler connected to the boat's engine by an exhaust pipe, and an auxiliary muffler connected to the muffler by a first connecting portion of a connecting pipe, A second connecting portion of the connecting pipe connects the auxiliary muffler to a tail pipe, through which exhaust gases travel to be exhausted into the water through a nozzle of a jet propulsion device. The auxiliary muffler is elevated with respect to the connecting pipe, which prevents the entry of water into the auxiliary muffler and a corresponding degradation of its sound reduction capability.

Abstract: A device and a method for achieving sound reduction within a frequency band in a transport system for gaseous medium, the transport system being arranged between an inlet, which is connected to a sound source, and an outlet. The transport system comprises with a plurality of interconnected channel parts (1-7) and exhibits at least one module (8, 9) comprising at least one reflection attenuator (4) with a resistive length (a2, b2) and at least one reactive attenuator (3) with a reactive length (a1, a3, b1, b3). The resistive length is brought to constitute a quarter of a wavelength of the center frequency of the frequency band and the reactive length is brought to constitute a quarter of a wavelength of a frequency between, respectively, the lower and upper limit frequencies of the frequency band.

Abstract: An energy attenuation device for a conduit conveying liquid under pressure, a system incorporating same, and a method for attenuating energy in a conduit, are provided. The device includes a conduit that is disposed in or is part of the liquid-conveying conduit, wherein a chamber having an inlet end and an outlet end is formed in the conduit. Two separate tubes are disposed in the chamber of the conduit such that a respective annular space is provided between an inner peripheral surface of the conduit and an outer peripheral surface of each of the tubes, wherein at least one of the tubes has at least one hole in the outer peripheral surface thereof to allow communication between the interior of the tube and the chamber.

Abstract: An exhaust system structure and method comprising two or more silencers which are placed in series and are each provided with a tubular section, the edges of which are in each case attached to a transverse plate which marks the end of the section in question, and each tubular section is provided with sound-damping internal parts, two tubular sections with different cross-sections being mounted one behind the other, making use of a transverse plate, the external dimensions of which are related to the cross-sectional dimensions of the tubular section with the largest cross-section and provided with an opening, the dimensions of which are related to the cross-sectional dimensions of the tubular section with the smallest cross-section, in which exhaust system the transverse plate is attached to the edges of the two tubular sections by means of seamed roll joints.

Abstract: A vehicle exhaust device including a rear silencer disposed at the rear portion of a vehicle, a large-capacity silencer having a capacity larger than that of the rear silencer and disposed below a passenger compartment of the vehicle, and an intermediate silencer disposed substantially at the middle of an exhaust tube interconnecting the rear silencer and the large-capacity silencer. With the vehicle exhaust device thus arranged, exhaust noises can be attenuated at a position near an engine forming a noise source, i.e., at the early stage of transmission and with substantially reduced length-dependent resonance of the exhaust tube.

Abstract: A device for sound suppression in a channel system for flowing gases or air, particularly an exhaust system or intake system in an internal combustion engine, includes at least one channel which is in communication with two volumes or apertures, wherein standing sound waves arise in the channel. One of the two volumes or apertures can be in the form of a main silencer or a filter housing while the other volume of aperture is in the form of a smaller silencer or an inlet pipe. The pipe, which may be in the form of a volume space, has one end, an inlet opening, in acoustical communication with the channel, while an opposite end is wholly or partly closed against the environment. The pipe is located outside the channel and an acoustic permeable filter is provided in the region near the inlet opening of the pipe. The filter has a flow resistance within the interval 5 Ns/m.sup.3 -2000 Ns/m.sup.3, preferably within the interval 30-300 Ns/m.sup.3.

Abstract: An improved muffler for silencing the exhaust emitted from a water cooled marine engine employing a first housing encompassing a second housing which is partitioned by an angularly disposed inner planar baffle further having an inlet for exhaust gas and cooling water to fluidly communicate into an inlet chamber of the second housing resulting in a diminution in flow velocity so as to attenuate the exhaust noise, the exhaust gas and cooling water exiting the inlet chamber through an aperture fluidly communicated therewith into a silencing volume formed by an area between the first and second housing and forced through an aperture into an outlet chamber of said second housing. The outlet chamber acting as a back flow preventor.

Abstract: An apparatus for modifying an exhaust stream of a diesel engine is provided. The apparatus includes a muffler arrangement having an exhaust inlet and an exhaust outlet in construct and arrange for sound attenuation therein. The apparatus also includes a catalytic converter arrangement positioned within the muffler arrangement. During operation, the exhaust flow is directed both through the muffler arrangement and the catalytic converter arrangement, to advantage.

Abstract: An apparatus for purifying air which may act downstream supplement to a catalytic converter of an internal combustion engine for further reducing the hydrocarbon and carbon monoxide gases which the catalytic converter failed to remove. The apparatus comprises a housing filled with volcanic ash over which is directed a turbulent stream of exhaust gases for chemical reaction with the volcanic ash.

Abstract: An apparatus for modifying an exhaust stream of a diesel engine is provided. The apparatus includes a muffler arrangement having an exhaust inlet and an exhaust outlet in construct and arrange for sound attenuation therein. The apparatus also includes a catalytic converter arrangement positioned within the muffler arrangement between the exhaust inlet and exhaust outlet. During operation, the exhaust flow is directed both through the muffler arrangement and the catalytic converter arrangement, to advantage.

Abstract: An improved muffler for silencing the exhaust emitted from a water cooled marine engine employing a first housing encompassing a second housing which is partitioned by an angularly disposed inner planar baffle further having an inlet for exhaust gas and cooling water to fluidly communicate into an inlet chamber of the second housing resulting in a diminution in flow velocity so as to attenuate the exhaust noise, the exhaust gas and cooling water exiting the inlet chamber through an aperture fluidly communicated therewith into a silencing volume formed by an area between the first and second housing and forced through an aperture into an outlet chamber of said second housing. The outlet chamber acting as a back flow preventor.

Abstract: This invention relates to a muffler and in particular to one including a high frequency chamber, a first exhaust pipe connected between an engine and the high frequency chamber, a second exhaust pipe disposed within said high frequency, an intermediate frequency chamber connected with the other end of the second exhaust chamber, a third exhaust pipe disposed within the intermediate frequency chamber, a low frequency chamber connected with the other end of the third exhaust pipe, and a tubular pipe disposed within the low frequency chamber, whereby the noise will be effectively suppressed without decreasing the flow rate of the exhaust gas and the output power of the engine.

Abstract: A muffler with a catalyst A muffler closure is detachably attached to the muffler body of the muffler. A thermal insulation acoustic material layer and a catalyst layer are mounted to an inner surface of muffler closure through a porous holding plate along exhaust gas passage.

Abstract: An aquarium pump includes an air-delivery silencer connected with an air-pumping device encased in two covers mounted on a base portion having a silencing box provided with a plurality of sinuous air passages in the box for reducing a sound transmission speed and pressure of sound wave caused by the operating pump for greatly reducing its noise, and a metal plate embedded in a bottom plate formed in the base portion having a plurality of spring-like cushioning supporting legs secured under the bottom plate for further reducing vibrations caused by the operating pump for preventing noise pollution from an aquarium pump.

Abstract: The invention relates to a combination power and heat unit with a bedplate (1), flanged-together machines (2, 3), a noise suppressor (8), an exhaust-gas heat exchanger (9), a cooling-water heat exchanger (19) as well as the associated auxiliary apparatus and piping, wherein the bedplate (1) shelters the noise suppressor (8) and the exhaust-gas heat exchanger (9) along its opposite longitudinal sides below the machines (2, 3), which are elastically supported on the bedplate (1).

Abstract: A marine engine exhaust system and method utilizes first and second enclosed, generally tubular chambers having generally parallel lengthwise dimensions and internal intermediatae exhaust passageways spaced along the lengthwise dimension of the second chamber for circulating the exhaust gases through the first chamber, laterally through the intermediate exhaust passageways into the second chamber, along the lengthwise dimension of the second chamber and thence out of an outlet exhaust passageway which passes through the second chamber wall and may also extend through a cooling water-collecting portion of the first chamber to achieve maximum muffling of the exhaust gas noise.

Abstract: There is provided a new and useful combined muffler and catalytic converter exhaust unit for the exhaust stream from an internal combustion engine, the combined unit comprising a housing having an inlet and an outlet, first and second chambers within the housing, an oxidation/reduction catalyst within the first chamber, noise muffling means within the second chamber, and wherein the first chamber has an inlet leading to the inlet of the housing and an outlet leading to an inlet of the second chamber, and the second chamber has an outlet leading to the outlet of the housing.

Abstract: Disclosed is an engine-control apparatus in which an exhaust passageway of the engine is provided with plural sound deadening passages. A portion of the plural sound deadening passages is designed to be opened or closed by a shift valve on the basis of a predetermined switching characteristic, and the pressure of the exhaust gases is changed upon the switching of the shift valve. In order to prevent torque shock to the driven wheels which may occur attendant upon operation of the shift valve to open or close or in order to reduce probability that torque shock would occur, there is provided a torque regulating apparatus which permits an adjustment of torque generator by the engine, of a transmission efficiency of power to the driven wheel, or of a switching speed at which the shift valve is switched to open or close, or a change in the switching characteristic.

Abstract: A power thermo-coupling unit with muffler (4, 5) and exhaust gas heat exchanger (6, 7) avoids the requirement of a disproportionately large space for component removal at the front end of the power thermo-coupling unit. The muffler (4, 5) and the exhaust gas heat exchanger (6, 7) each have two separate components, the lengths of which are shorter than the distances between the center column (8) and the end walls of the unit support (1).

Abstract: A stamp formed exhaust muffler for mounting on a vehicle is provided. The muffler comprises a plurality of plates secured in juxtaposed relationship and stamp formed to define an array of tubes therebetween. At least one external shell is secured to the internal plates to define at least one chamber which communicates with the array of tubes. The external shell includes at least one conformal area which permits the muffler to conform to the shape of a structure on the vehicle. The conformal area may be an area of generally arcuate concavity when viewed from the exterior of the muffler or may define an internal corner on the muffler. Thus, a plane or line connecting two locations on the conformal area of the external shell will pass through the interference zone of a structure on the vehicle. The conformal area may be disposed where peripheral edges of the formed components are joined.

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: A stamp formed exhaust muffler for mounting on a vehicle is provided. The muffler comprises a plurality of plates secured in juxtaposed relationship and stamp formed to define an array of tubes therebetween. At least one external shell is secured to the internal plates to define at least one chamber which communicates with the array of tubes. The external shell includes a conformal area which permits the muffler to conform to the shape of a structure on the vehicle. The conformal area may be an area of generally arcuate concavity when viewed from the exterior of the muffler or may define an internal corner on the muffler. Thus, a plane or line connecting two locations on the conformal area of the external shell will pass through the interference zone of a structure on the vehicle.

Abstract: An exhaust passage has an upstream end connected to an engine combustion chamber and a downstream end open to the atmosphere. A device substantially equalizes natural frequencies of the exhaust passage respectively corresponding to third-degree and fourth-degree modes of standing pressure waves developing in the exhaust passage. A pressure damper is connected to a point of the exhaust passage at which an antinode of the third-degree or fourth-degree mode lies.

Abstract: A silencing system for exhaust gases from internal combustion engines, comprising an intermediate silencing device for connection to the exhaust manifold of an internal combustion engine, and a final silencing device series connected to the intermediate silencing device, in which the final silencing device comprises, within an envelope, a number of spaced annular members, intersected by radial partition walls, forming series of chambers of different size, which occupy the peripheral portion of the envelope and open towards the axial portion of this latter, leaving this axial portion substantially free for passage of the flow of exhaust gases, and an idle fan is provided for acting onto the passage for the exhaust gases and onto a passage for additional air, which passages join downstream the fan into an exhaust nosepiece. Some annular members are made of a catalytically active material in order to exert a purifying action on the exhaust gases.

Abstract: A combination acoustical muffler and exhaust converter for use with internal combustion engines, comprising an elongated hollow cylinder adapted to be connected to a source of exhaust gas, screen means positioned at a plurality of longitudinally spaced locations within said cylinder for partitioning the cylinder into a plurality of chambers arranged in series flow relation with each other and with respect to the flow of exhaust gas through said cylinder, the screens having a silencing action on said exhaust gas, magnet means in one of said chambers for exerting a magnetic pressure on the gas passing therethrough to serve to separate ferrous particles from the exhaust gas stream, a packing material of mineral material, such as mineral wool, in another of said chambers for condensing moisture in said exhaust gas and for removing hydrocarbon therefrom, and a material such as a ceramic material of an extremely fine porous nature, in still another of said chambers for removing carbon monoxide from said exhaust gas

Abstract: An exhaust system for an engine of a motorcycle is disclosed having catalytic and silencing mufflers arranged in adjacent side-by-side series flow relationship, the catalytic muffler extending rearwardly of the motorcycle, and, adjacent its rear end, being interconnected with the silencing muffler, the silencing muffler including plural expansion chambers which are interconnected in flow reversal relationship for gases to be exhausted rearwardly of the motorcycle.

Abstract: The invention relates to a muffler, which is suitable for large-scale production and which at a maintained or reduced sound level reduces the pressure drop of the exhaust gases as compared to known mufflers. The muffler comprises an insert of sheet metal cones with their apices directed toward the outlet thereof with the cones having one or a small number of relatively large size gas flow passages. Adjacent cones of the insert are disposed at such a distance relative to one another that the apex of the rear cone, as viewed in the direction of the gas flow, lies downstream of a plane perpendicular to the direction of the axis through the abutment surface to the envelope of the front cone.

Abstract: An apparatus and method is provided for venting high pressure gas to a lower pressure region with a minimum of noise. A high pressure vent valve controls egress from a high pressure gas source. In order to limit the generation of noise downstream of the vent valve, at least one control orifice is provided which is configured to have a flow velocity through a throat section thereof of the speed of sound, and with a pressure downstream of the throat being the same as the throat pressure. In this manner, the pressure is reduced by about half at each control orifice, with no or little noise generation. Downstream of these sonic velocity control orifices, sound attenuating means including radially extended passages lined with sound-baffling structure are provided to reduce any residual noise in the flowing gas as it passes into the region of lower pressure.

Abstract: An `in-line` unit for use in compressor station piping, arranged to reduce the level of noise generated when the blowdown valves of the station piping are opened in an emergency to vent the high pressure gas therein to atmosphere, the unit comprising a pipe section having a plurality of orifice plates the number and hole area of which is designed to ensure sub-sonic flow through each plate. The unit is preferably used in combination with a modified form of silencer element connected `in-line` downstream thereof.