Abstract: A muffler has an integrated SCR catalytic converter for an exhaust line of an internal combustion engine, in particular in a motor vehicle The muffler includes a housing which has an intake trumpet on the intake end and an exhaust pipe on the output end. Catalytic converter elements are arranged in the housing with one inlet end in an inlet chamber and with an outlet end in an outlet chamber. An outlet end of the intake trumpet communicates with the inlet chamber. To improve the efficiency of the SCR catalytic converter the inlet chamber is sealed off from the outside and with respect to the intake trumpet and the catalytic converter elements to the extent that in operation of the internal combustion engine with exhaust gas loaded with urea, passing through the intake trumpet into the inlet chamber, the exhaust gas leaves the inlet chamber only through the catalytic converter elements.

Abstract: An object of the present invention is to provide a construction for exhaust emission control, which can prevent thermal deterioration in a catalyst and can heat exhaust gas to a catalyst activation temperature. In the present invention, an electrically heated catalyst portion 10 is provided in a separator 12a in a silencer 3 located at a distance from an engine. This electrically heated catalyst portion 10 heats low-temperature exhaust gas to a catalyst activation temperature. The exhaust pipe 11a branches into three pipes 22a, 22b and 22c in the silencer 3. The electrically heated catalyst portion 10 has a shape surrounding the each outer peripheral surface of pipe 22a, 22b and 22c of an exhaust pipe 11a. Exhaust gas is warmed to a temperature close to the catalyst activation temperature when it flows in the pipes 22a, 22b and 22c, and flows out of the pipe 22a, 22b and 22c.

Abstract: A pneumatic tool includes a shell with a chamber defined therein, a first passage communicated with the chamber and a second passage communicated with the chamber. A rotor is installed in the chamber for rotation when driven by pressurized air flowing into the chamber through the first passage. A shaft extends to the exterior of the shell from the rotor. A trigger is installed on the shell. A control device is put in the first passage and connected with the trigger for controlling the first passage. A muffler is put in the second passage. The muffler includes a plurality of balls.

Abstract: In an exhaust emission control system for an engine, comprising an exhaust emission control catalyst disposed in an exhaust muffler whose inside is divided into a plurality of chambers, at least a portion of the inside of the exhaust muffler is divided into a first chamber for converting mainly NOx in exhaust gas and a second chamber for converting HC and CO in the exhaust gas. The exhaust muffler comprises: a partition wall having a conduit for guiding the exhaust gas from the first chamber to the second chamber; an exhaust gas inlet for introducing the exhaust gas into the first chamber; an external-air suction means for sucking external air into the second chamber; and a discharge pipe for discharging the external air and the exhaust gas flowing through the second chamber.

Abstract: An exhaust apparatus for a vehicle includes a spark arrester having a tubular spark arrester body assembled on a rear portion of a muffler connected to an exhaust pipe. A tail pipe is inserted in the spark arrester body and is mounted on the spark arrester such that exhaust gas flowing through the muffler is discharged into the atmospheric air from the tail pipe through the spark arrester, to carry out, expansion and contraction of exhaust gas in the spark arrester occurs to augment the sound reduction performance. An annular partition plate cooperates with an inner face of a spark arrester body to form a throttle path therebetween that is securely mounted on a tail pipe wherein a plurality of expansion chambers that communicate with each other through the throttle path are formed between the tail pipe and the spark arrester body with the annular partition plate disposed therebetween.

Abstract: An exhaust muffler system for use on a motorcycle or four-wheeled vehicle provides for operation in either of two modes, a regular configuration that provides a high degree of noise reduction, or a racing specification that provides for a freer-flowing exhaust. Without changing the main body of the muffler, an operator can choose between a quieter, public road setting or a louder, high performance setting. The muffler is provided with two interchangeable spark arresters, and a main body having multiple expansion chambers therein, defined by bulkheads. When a regular spark arrester is installed, exhaust gas passes through one bulkhead three times, greatly reducing the noise produced. With the spark arrester removed, the exhaust gas passes straight through to the open air, enhancing performance. A seal is provided between the bulkheads and the spark arrester, which provides for extension or retraction in the lengthwise direction of the tail pipe.

Abstract: A silencer for a vacuum cleaner is provided and includes at least one hermetic expansion chamber mounted in an exhaust channel of the vacuum cleaner and allowing an exhaust airflow from the vacuum cleaner to pass through. The expansion chamber at its two sides has an inlet and an outlet connected to the exhaust channel. A silencing board is mounted in the expansion chamber, separating the inlet from the outlet. Pores are distributed throughout in the silencing board. The silencer integrates several different silencing structures together, and, when mounted to the exhaust port of the vacuum cleaner, can considerably diminish the noise generated by the vacuum cleaner in operation.

Abstract: A noise-reducing engine enclosure for an engine includes first and second members removably mounted to one another in cooperating relation to define an engine receiving space therebetween. The first and second members each include a noise-reducing layer of material to reduce noise transmission to the atmosphere outside of the engine enclosure during operation. The first and second members are movable between (1) an engine accessing position, wherein the first and second members are positioned to allow access to the engine during operation and (2) an engine enclosing position, wherein the first and second members cooperate to define the engine receiving space to receive and enclose the engine therein such that noise transmission to the atmosphere during operation is reduced.

Abstract: In order to provide a silencer (100), in particular an exhaust silencer, for an internal combustion engine, comprising a first housing (12) with an inlet aperture (E) and an outlet aperture (A), wherein an exhaust stream flowing into the inlet aperture (E) and escaping from the outlet aperture (A) is fed via a catalytic converter element (K), which silencer can be variably used for various internal combustion engines of different engine displacement, which silencer achieves low final temperature values, low sound values, and small pressure fluctuations and in addition allows a space-saving exhaust-flow guide arrangement through the silencer, it is proposed that a calming chamber (10) be provided between an outlet area (30) of the catalytic converter element (K) and the outlet aperture (A) of the first housing (12).

Abstract: A muffler includes a tubular body having an interior surface extending between a first end and an opposing second end, the interior surface bounding a chamber. An exhaust cap is disposed on the second end of the tubular body, the exhaust cap having an interior surface bounding a channel that communicates with the chamber. An inlet cap is disposed on the first end of the tubular body. A perf tube is longitudinally disposed within the chamber of the tubular body. A spark arrestor includes a tubular neck advanced within the channel of the exhaust cap toward the body. A spark barrier is mounted on an end of the tubular neck so as to be at least partially disposed within the perf tube, the spark barrier being comprised of a sheet of mesh or porous material.

Abstract: The invention relates to a suction muffler for a hermetically enclosed compressor, with a housing having a first part with an outlet channel and a second part with an inlet channel, flow conducting means being arranged between the outlet channel and the inlet channel, said means forming, together with the inlet channel and the outlet channel, a flow path, and a filter being arranged in the outlet channel. Further improvements of the noise damping are endeavored. For this purpose, the filter has a sieve-like embodiment and that the flow path comprises at least one second filter with a sieve-like embodiment.

Abstract: An improved inlet silencer/filter for an oxygen concentrator includes a HEPA filter and an adjoining chamber for receiving air flow from the HEPA filter. The chamber is surrounded on one face by the HEPA filter, and by sound absorbing padding on at least 4 other faces. Air is forced from the HEPA filter, through the open chamber and then through the sound absorbing padding by a flow restrictor plate. Air flows from here through air channels and into an open chamber leading to an outlet from the air silencer/filter.

Abstract: The invention concerns a suction apparatus with noise reduction means (7, 8) in one or more airflow passages (2, 3, 4) for reducing noise emission from an airflow generator (1) or the like, wherein at least one airflow passage (2, 3, 4) is provided with at least one indentation (7) with a predetermined depth (D) extending substantially perpendicularly to the general direction of the noise in the passage. By the invention, a suction apparatus with noise reduction means is provided which is simple and efficient at reducing noise and also inexpensive to manufacture.

Abstract: A container device having both a silencer chamber and an air filter chamber disposed within it and inlet and outlet conduits to each chamber and the two chambers compliment each other by the filter chamber providing acoustic qualities for the silencer chamber and the silencer chamber providing harmonic vibration to the filter chamber for filter cleaning assistance.

Abstract: A silencer for silencing exhaust gases includes an acoustic resonator chamber that serves as a spark arrester to trap burning carbon particles and prevent them passing to the atmosphere. The silencer has an exhaust gas inlet and an exhaust gas outlet. Exhaust gases pass from the inlet to the outlet through a first passage and into a first chamber. The first chamber communicates with an acoustic resonator chamber by means of a connecting passage. The connecting passage is positioned adjacent the first passage so that sparks in the exhaust enter the acoustic resonator chamber where they are trapped. The silencer thus avoids the need for a separate spark arrester, as required by prior art silencers.

Abstract: An exhaust apparatus for a vehicle includes a spark arrester having a tubular spark arrester body assembled on a rear portion of a muffler connected to an exhaust pipe. A tail pipe is inserted in the spark arrester body and is mounted on the spark arrester such that exhaust gas flowing through the muffler is discharged into the atmospheric air from the tail pipe through the spark arrester, to carry out, expansion and contraction of exhaust gas in the spark arrester occurs to augment the sound reduction performance. An annular partition plate cooperates with an inner face of a spark arrester body to form a throttle path therebetween that is securely mounted on a tail pipe wherein a plurality of expansion chambers that communicate with each other through the throttle path are formed between the tail pipe and the spark arrester body with the annular partition plate disposed therebetween.

Abstract: A screen-type spark arrestor (34) may be efficiently and compactly mounted in a muffler (10). A tubular screen is coaxial with an exhaust pipe (24) and has a first end (36) axially spaced from the pipe and star-crimped closed, and a second end (38) axially overlapping the pipe in concentric relation and crimped thereto by a crimp ring (40). The combination is mounted as a modular component by a flange (22) closing the muffler housing (12).

Abstract: An exhaust processor includes a housing formed to include an interior region and a partition or first spark arrester that partitions the interior region into chambers and includes a wool filter formed to include an opening. The wool filter is positioned to filter unburned carbon particles from combustion product generated by a vehicle engine. The exhaust processor further includes an outer conduit that extends through the opening formed in the wool filter and is formed to include a passage and an inner conduit that extends into the passage and is formed to include an opening through which unburned carbon particles flow from inside the inner conduit to impinge against the outer conduit so that the outer and inner conduits operate as a second spark arrester.

Abstract: An engine muffler and spark arrestor includes an outer tube extending along an axis and having an inlet end and an outlet end. A plurality of substantially identical nested discs are disposed coaxially adjacent the outlet end of the outer tube. Each of the discs has a centrally located aperture. Each of the discs also has at least one slot extending therethrough. An end cap is disposed on a distal end of the set of discs. The end cap has a solid central portion which forces at least a portion of an exhaust gas flowing from an internal combustion to which the muffler is connected to flow radially outwardly along interstitial spaces defined between each pair of discs and then flow axially in a direction approximately parallel to a longitudinal axis of the muffler.

Abstract: An engine muffler and spark arrestor includes an outer tube extending along an axis and having an inlet end and an outlet end. A plurality of substantially identical nested discs are disposed coaxially adjacent the outlet end of the outer tube. Each of the discs has a centrally located aperture. Each of the discs also has at least one slot extending therethrough. An end cap is disposed on a distal end of the set of discs. The end cap has a solid central portion which forces at least a portion of an exhaust gas flowing from an internal combustion to which the muffler is connected to flow radially outwardly along interstitial spaces defined between each pair of discs and then flow axially in a direction approximately parallel to a longitudinal axis of the muffler.

Abstract: An exhaust gas muffler is provided for an internal combustion engine, especially for two-stroke engines of manually guided implements such as power chain saws, brush cutters or the like. The muffler has a housing that includes two shells. One of the shells is provided with at least one outlet opening for exhaust gas. A cover is provided that guides the exhaust gas, and the cover has at least one discharge opening for the discharge of exhaust gas to the surrounding air. An exhaust gas chamber is formed within the cover. A screen element is disposed in the vicinity of the at least one discharge opening such that the exhaust gas stream is guided through the screen element.

Abstract: A muffler is described with a housing having an input and an output. At least one plate is disposed within the housing to divide it into at least a first and a second internal expansion chamber. At least one tube is disposed through the plate, the tube having first and second ends with a bend therebetween, the bend altering an orientation of the second end of the tube so that the second end faces an interior surface of the housing. The housing, the plate and the tube establish a path for the exhaust between the input and the output. In addition, the first and second internal expansion chambers cooperate to attenuate sound, and the tube assists in sound attenuation and/or affects the path of the exhaust to arrest the discharge of sparks from the output.

Abstract: The invention relates to an exhaust-gas muffler on an internal combustion engine in a motor chain saw. The exhaust-gas muffler includes a housing (1) which is assembled of two housing shells (2, 3). The one housing shell (2) has an exhaust-gas inlet (4) and the other housing shell (3) has an exhaust-gas outlet (5). An inner wall (8) as well as a catalytic converting element (7) are provided in the inner space (6) of the muffler housing (1). The catalytic converting element (7) is mounted between the exhaust-gas inlet (4) and the exhaust-gas outlet (5). In order to ensure an adequate catalytic converting treatment of the exhaust gas at low gas counterpressure, it is provided to divide the entering exhaust-gas flow (10) and to conduct at least one of these component flows (23) in contact with the catalytic converting element (7). The component flows (22, 23) are brought together and mixed with other before exiting from the muffler housing (1).

Abstract: A muffler for the exhaust gas of an internal combustion engine is provided. The muffler has a housing with an inlet opening and an outlet, and surrounds a muffling chamber. In the flow path of the exhaust gas a spark arrestor screen, and on the side of the inlet opening an exhaust gas diffuser, are provided. The muffling chamber is divided by a partition into a first and second partial chamber. The volume of the second partial chamber corresponds at least approximately to the volume of the first partial chamber. The spark arrestor screen is disposed in the partition.

Abstract: An exhaust gas muffler for an internal combustion engine has a housing having an inlet and an outlet for engine exhaust gas. The housing has walls defining the interior of the housing. The housing has a first housing shell having a first connecting flange and a second housing shell having a second connecting flange, wherein the first and second connecting flanges are fastened to one another in a common flange plane. Each housing shell has a bottom. A partition is mounted in the housing and divides the interior of the housing into two compartments. The two compartments are connected by flow connections allowing passage of the engine exhaust gas between the two compartments. The partition has opposed ends supported respectively on the bottoms of the housing shells. The partition has two wall portions curved outwardly in opposite directions relative to a plane of the partition and has multiple openings.

Abstract: A muffler for an internal combustion engine has a vertically elongated expansion chamber into which an exhaust gas from the exhaust port of internal combustion engine is introduced. The expansion chamber is separated level-wise into a first expansion chamber and a second expansion chamber by a partition plate. An exhaust emission purifier formed of an oxidation catalyst is attached to the partition plate, thereby allowing the exhaust gas ejected from the exhaust port to be introduced into the second expansion chamber from the first expansion chamber via the exhaust emission purifier. The exhaust emission purifier is spaced apart from the exhaust port by a predetermined distance in a direction orthogonal to an ejecting direction of the exhaust gas.

Abstract: A suction cleaner comprising a motor which operates a blower in such a manner that the blower blows a flow of air out into a motor chamber that delimits a volume which extends at least radially around the motor, and then out through outlet openings arranged in said motor chamber, and wherein the motor chamber is provided with a silencer element made of a silencing material, such as foamed plastics, said silencer element enclosing the motor radially and forming a silencing chamber around the same, and wherein the silencer element is provided with flow passages which substantially constitute the flow connection from said silencing chamber to the outflow openings in the motor chamber. The fact that the flow passages in the silencer element according to the invention extend axially along the motor in substantially the entire length thereof provides an optimum silencing effect.

Abstract: An integral filter and resonator apparatus includes filter elements positioned upstream of a Helmholtz resonator. The first embodiment includes filter elements positioned side by side within the housing. Other embodiments include a filter element with a tube which curves slightly downstream from the element. Another embodiment includes coupled chambers for attenuating the noise.

Abstract: A muffler for small general-purpose engine includes a case comprising a pair of case halves coupled together and divided into a first chamber and a second chamber by a partition plate. An inlet of the exhaust gas is provided closer to a first end portion of the case in a first case half. An outlet of the exhaust gas is provided closer to a second end portion of the case in a second case half. A recess projecting from the first chamber toward the second chamber guiding the exhaust gas from the inlet toward the second end portion is provided in the partition plate opposite the inlet. A communication orifice is formed in the partition plate at a location offset from the recess and closer to the first end portion than the inlet.

Abstract: A muffler for a two-stroke internal combustion engine has a housing enclosing a hollow space and having an exhaust gas inlet and an exhaust gas outlet. Shaped sheet metal members are mounted in the housing and define an exhaust gas flow channel. The flow channel extends at least over a portion of its length in a plane of the sheet metal members. A first one of the sheet metal members has a projecting portion projecting from the plane of the sheet metal members and forming a connector of the flow channel. The connector communicates with the exhaust gas inlet. A second one of the sheet metal members has a projecting portion projecting from the plane of the sheet metal members and forming an end portion of the flow channel opening into the hollow space of the housing.

Abstract: An exhaust system for a vehicle includes a muffler connected to an exhaust pipe, which is in turn connected to an engine. A spark arrester is provided with a tail pipe and connected to the rear end of the muffler, and is capable of discharging an exhaust gas flowing through the muffler through the tail pipe of the spark arrester into the atmosphere. The interior of the muffler can be divided into a plurality of expansion chambers connected by restricting passages by attaching the spark arrester to the muffler to enhance the sound attenuating effect. The interior of the muffler is divided into the plurality of expansion chambers by separators disposed in the muffler and a spark arrester combined with the muffler.

Abstract: The invention relates to an exhaust-gas muffler for a two-stroke engine in a portable handheld work apparatus such as a motor-driven chain saw. The muffler housing includes an outer shell and an inner shell and also includes an exhaust-gas inlet and an exhaust-gas outlet. A fire-protective screen is arranged in the exhaust-gas flow of the muffler. With the invention, a high service life of the fire-protective screen is achieved together with an easier exchangeability. This is achieved in that the fire-protective screen can be inserted from outside of the housing into the interior of the muffler. The screen covers the exhaust-gas inlet into an inlet chamber of the muffler. At this location, the temperature of the exhaust gas is high so that coking of the screen is very slight.

Abstract: An electric fan comprises: a radial impeller for expelling the air trapped therein out of the impeller; a diffuser having a multiplicity of air passages separated by air guides, the air passages adapted to receive the air expelled from the impeller; a fan case for covering the impeller and the air guides; at least one throughhole which is formed in the fan case for each of the air passages; and a silencer equipped with a multiplicity of silencer cavities each having a predetermined volume and communicating with a corresponding one of the air passages, the silencer covering the fan case. The silencer is provided either on top of or beneath the fan case. Because the volumes of these silencer cavities may be chosen arbitrarily such that the silencer cavities may absorb noise caused by the interference between the impeller and the air passages, even audible noise may be suppressed sufficiently.

Abstract: A muffling device for a combustion engine of a hand-guided working tool has at least one housing member with at least one outlet opening for exhaust gas. An elongate cover member is positioned above the outlet opening for deflecting the exhaust gas into a main flow direction. The cover member has a longitudinal extension in the main flow direction. The cover member has a first end face with a main exhaust gas opening in the main flow direction through which a main exhaust gas stream exits into the surrounding atmosphere. The cover member has at least one lateral wall with at least one auxiliary exhaust gas opening through which a partial or auxiliary exhaust gas stream exits.

Abstract: Muffler (1) for portable working tools, preferably chain saws (2), whereby the muffler is mounted directly onto the cylinder's (16) exhaust gas outlet (3). The muffler's (1) exhaust gas outlet (4) is positioned on an upper side (5) of the muffler, i.e. a side which is turned in the same direction as the cylinder's (16) upper side, and the muffler's exhaust gas outlet (4) is equipped with a deflecting device (6), for instance a bent tube, which deflects the exhaust gas flow (7), so that this leaves the muffler in a plane which is parallel to the muffler's upper side (5). The figure shows the chain saw schematically, without protective covers, guide bar and chain. Its cooling fan (19) blows cooling air (20) over the cylinder and the muffler. The positioning and the design of the exhaust gas outlet facilitate a very favorable dilution of the exhaust gases with the cooling air.

Abstract: An engine muffler and spark arrester includes an oval shaped outer tube extending along an axis and having an inlet end and an outlet end. A plurality of substantially identical nested oval shaped disks are disposed coaxially adjacent the outlet end. Each of the disks has an oval shaped centrally located aperture. An inner tube is disposed coaxially within the outer tube. The inner tube has a circular inlet end and an oval-shaped outlet end. An oval end cap is disposed adjacent the disks. A sound absorbent material can be disposed in a cavity defined between the inner tube and the outer tube. An oval-shaped inlet cap is secured to the inlet end of the outer tube with the inlet cap having a circular centrally located aperture extending therethrough. An oval-shaped outlet cap is secured to the outlet end of the outer tube. The outlet cap has an oval-shaped centrally located aperture extending therethrough.

Abstract: Muffler with catalytic converter (1) essentially arranged in direct connection with a combustion engine's exhaust port and mainly intended for portable working tools such as chain saws. A spark arrester screen (3), i.e. a structure (3) which at least partly contains a wire mesh (4) and a net (4), usually made of metallic material, is located in the exhaust gas flow downstream a converter element (5). In connection with the spark arrester screen (3), upstream or downstream the screen, flow dividers (8, 13, 9) are arranged.

Abstract: In integral filter and resonator apparatus includes filter elements positioned upstream of a Helmholtz resonator. The first embodiment includes filter elements positioned side by side within the housing. Other embodiments include a filter element with a tube which curves slightly downstream from the element. Another embodiment includes coupled chambers for attenuating the noise.

Abstract: A modular filter for removing particulate matter from gases or liquids is disclosed. The filter includes at least two porous ceramic or ceramic composite modules and a heater structure for regenerating the modules by heating which is integral with the modules. The regenerating structure may also be a ceramic structure. The filter modules may be manufactured using micropyretic synthesis and manufactured to have interconnected porosity. The filter may be used to remove particulates from the exhaust of engines such as engines of land and water vehicles.

Abstract: Muffler with catalytic converter (1) composed of a muffler housing (2) and a lid (3) which seals the muffler housing. A catalytic converter element is mounted in the lid and an exhaust pipe (5) leads from this element out of the muffler (1). The exhaust gas pipe (5) is located entirely in the lid, so that the exhaust gases are released via the lid (3).

Abstract: A compact filter structure is provided having a cylindrical body disposed in the expansion chamber of a muffler. A tail pipe is inserted into the filter. The diameter of the filter is greater than that of the tail pipe. The filtering function of the body and the noise reducing function of the tail pipe are separated from each other. The filter structure can be formed in a compact construction which provides a large filtering capacity.

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-cycle internal combustion engine used to power lawn and garden equipment includes two mating shells and two plates, sandwiching a spark arrestor screen, are disposed between the shells to form first and second expansion chambers between each plate and the adjacent shell. The first chamber includes an opening for coupling to the exhaust port of the engine. Within one plate is stamped a first depression, a baffle within that depression, and an elongated depression separate from the first depression. In the other plate is stamped a second depression that is punched with an air passage. When mated, an attenuating tube having an entrance in the second of the two expansion chambers and an exit into the atmosphere is formed. The first and second depressions cooperate to expose a large area of the spark arrestor screen to a flow of exhaust gas from the first chamber, through the baffle and into the second chamber.

Abstract: A noise attenuating air cleaner assembly for an internal combustion engines or the like operating in a dusty environment. The air cleaner assembly having a silencer assembly arranged concentric inside an air filter cartridge assembly and a noise attenuating end wall assembly closing an end of the air filter cartridge assembly attenuating air cleaner assembly to provide a source of clean air to the engine and to reduce transmitted induction noise.

Abstract: A muffler for internal combustion engines is formed of vertically separable body sections so that the sound absorbing and filter members may be accessed easily for replacement and/or cleaning.

Abstract: A combination muffler and catalytic converter for an exhaust system of a small internal combustion engine. The catalytic converter is mounted within a chamber formed inside the muffler which functions not only to contain the catalytic converter but also to provide sound attenuation. The combination muffler/catalytic converter also includes an assembly for introducing secondary air into the interior of the muffler body containing the catalytic converter so that harmful uncombusted components such as hydrocarbons, carbon monoxide and nitrous oxides contained in the exhaust gases are further combusted prior to exiting the muffler. The secondary air supply assembly includes an opening formed in the muffler body which communicates between the interior of the muffler body and atmosphere, and a reed valve mounted directly on the muffler body adjacent this opening.

Abstract: A spark arrester is mounted in a tail pipe of an exhaust pipe of an engine, in particular a 2-strokecycle engine, and prevents sparks from being emitted. The spark arrester includes a sack-like member of a wire mesh and a cylindrical member secured to open end of the sack-like member. The cylindrical member received in the tail pipe is retained therein by a resilient retainer in a groove formed in the inner peripheral wall of the tail pipe.

Abstract: A high performance exhaust muffler which improves engine power and economy as well as providing a smoother engine performance. The muffler comprises an exhaust gas expansion section and a tubular baffle section closed or partially blocked at one end, its open end being attached within a smaller end of the exhaust gas expansion section to allow gas to pass directly into the exhaust gas expansion section and some to pass into the baffle section causing a weak back pressure to pulse back along the baffle tube.

Abstract: An external spark arrestor assembly attached directly to the outer shell of a muffler of an internal combustion engine. The assembly includes a spark arresting screen disposed over the exhaust port of the muffler and forming a first exhaust-receiving conduit between the screen and the muffler; an outer perforated cover disposed over the screen and forming a second exhaust-receiving conduit between the screen and the outer cover; and a single centrally located fastener for removably fastening the screen and outer cover to the muffler shell.

Abstract: A blower cover is provided so as to surround an electric driven blower. The blower cover comprises an upper blower cover and a lower blower cover. An exhaust air duct as a silencer mechanism is provided on the upper blower cover and is disposed between a blower receiving chamber and a cord receiving chamber. The exhaust air duct comprising an outer peripheral wall portion and a side wall portion. The outer peripheral wall portion has a partitioning rib and a curved guiding rib. The exhaust air duct forms a U-shaped exhaust air flow passage. An expansion chamber is disposed air flow passage. An expansion chamber is disposed at a down stream of the exhaust air duct. The exhaust air from an intake port of the exhaust air duct flows the U-shaped flow passage and is led to the expansion chamber. The suctioned air is expanded in the blower receiving chamber. The exhaust air is compressed in the exhaust air duct and is expanded again in the expansion chamber.