Abstract: In a vehicle with an engine, an engine air flow system for attenuating engine noise comprising: a first flow path of air intake through which a first gas flow is substantially into the engine; a second flow path of engine exhaust in which a second gas flow is substantially out of the engine; and at least one duct in flow contact with at least one of the first and second flow paths, wherein the duct comprises: a tubular fluid flow passage; at least one open end connecting the tubular fluid flow passage to the at least one of the first and second flow paths; a support structure preventing radial collapse of the duct during occurrences of a negative pressures, caused by the engine, within the duct; and a pliant material attached to the support structure forming a gas-tight tubular duct wall for the tubular fluid flow passage, wherein the pliant material forms, on the support structure, a series of loosely pliant panels that freely move radially outwardly and inwardly, wherein during engine operation sound genera

Abstract: A muffler including an offshoot path, one end of which is connected to a middle of a ventilation path so as to diverge from the ventilation path, and another end of which is closed. One portion of the offshoot path and another portion thereof are communicated through a communicating portion. Accordingly, sound waves entering the offshoot path are propagated in a direction of a closed portion, and are also propagated via the communicating portion from the one portion to the other portion.

Abstract: The invention relates to a sound-damping arrangement in a passageway system or pipe system for flowing gases, in particular in an exhaust system for internal combustion engines. The arrangement comprising at least one pipe which communicates with at least two chambers or openings, for example in a form of a muffler and/or a passageway/pipe-outlet, in such a manner that multiples of standing waves can arise in the pipe between both the chambers or openings. At least one tube is arranged in the pipe, with one end of the tube serving as in inlet while the other end of the tube is totally or partially closed. The inlet of the tube is arranged in, or in the vicinity of, one of the maximum sound-pressure regions of the pipe so as to dampen at least one maximum sound pressure.

Abstract: A device for cancelling annoying sounds caused by operation of an internal combustion engine. An intake sound of the engine, and also a rotational speed of the engine, are obtained. The phase difference between the present intake sound and a desired intake sound is obtained using map data. The map data depends on the rotational speed of the engine and is specifically calculated so that at least the (n+0.5) harmonics (n integer.gtoreq.0) are cancelled. The phase data is used to drive a ceramic speaker or two oppositely directed ceramic speakers, to appropriately compensate the input sound.

Abstract: An exhaust muffler for outboard motors which is fastened to the rear end of the propeller hub and directs the motor's exhaust back into the hub of the propeller and out through the front of the propeller and the by-pass exhaust ports of the motor. The muffler includes an elastomeric member and a blocking member with the blocking member having pressure relief mechanism therein.

Abstract: This invention relates to a detachable filter and muffler device used in an exhaust system, wherein the filter and muffler device is easily detachable so that the maintenance of the exhaust system is simplified, and the cost of maintenance is reduced.

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

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

Abstract: 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 muffler for use on the exhaust system of the motor vehicle. The muffler has a central pipe which is surrounded by an outer pipe which leaves an annular space between the two. The outer pipe is open at both ends and the annular space is filled with a sound deadening material. The central pipe has openings which pass to the annular space and a perforated sound deadening member is affixed to the inner surface of the central pipe. Preferably, the outer pipe is outwardly flared at its upstream end, and the perforated sound deadening member is conical in shape.

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 system is provided for orienting two engaged exhaust pipes or conduits and maintaining a proper orientation between those pipes after engagement to provide a proper alignment between the pipes. The system includes a tab formed on one of the pipes and a tab-receiving notch formed on the other of the pipes.

Abstract: A connecting device connects a tailpipe to an exhaust pipe of an internal combustion engine for a vehicle. The tailpipe includes a smaller diameter section and a larger diameter section, and the free end of the exhaust pipe is received by the larger diameter section of the tailpipe. An annular space separates the larger diameter section of the tailpipe and the free end of the exhaust pipe. Screw threads are formed on the free end of the exhaust pipe. A connecting spring is configured as a conical helical spring, the larger diameter end of which is fixed to the tailpipe. The other end of the spring has coils configured as screw threads which screwed onto the screw threads which are formed on the free end of the exhaust pipe. The spring is relatively soft in a direction parallel to an axis of the tailpipe, and is relatively stiff in a direction transverse to an axis of the tailpipe. The spring absorbs vibrations of the engine and centers the pipes with respect to each other.

Abstract: To reduce noise, an automotive exhaust tailpipe has a convoluted surface at or near its outlet to generate pairs of counterrotating axial vortices within the exhaust gases just before or just as the gases exit the tailpipe. The convoluted surface may be the internal surface of the tailpipe, or a thin-walled convoluted member may be disposed within the tailpipe near its outlet end.

Abstract: There is disclosed a method of fabricating a double pipe capable of attenuating vibration. The pipe can be used in an automobile exhaust system. The method is initiated with forming a coating either on the outer surface of an inner pipe or on the inner surface of the outer pipe. The coating is made from an epoxy resin, an acrylic resin, or other resin. The inner pipe is inserted into the outer pipe, and then they are brought into intimate contact with each other via the coating to couple them together. The coupled pipes are heated beyond 400.degree. C.

Abstract: A muffler is provided with a pair of plates formed to define an array of tubes therebetween. At least one external shell is secured to at least one of the plates to surround selected portions of the tubes. The shell is formed to define a plurality of chambers separated from one another by a baffle crease. The baffle crease is parallel to and abutting a selected tube of the muffler to simplify the draw of metal material in the vicinity of the baffle crease and to thereby save metal. The baffle crease is of substantially uniform depth along a major portion of its length and is free of pockets that could conceivably retain corrosive fluids.

Abstract: Attachment means for connecting an insulated pipe to an element, such as the manifold, in the exhaust system of a vehicle. The attachment means includes a conduit which extends into the end of the insulated pipe. A transverse lug or a helical flange on the conduit engages the spiral corrugations of the inner diameter of the pipe to allow the conduit to be threaded into the pipe. The end of the pipe is received in an end cap slidably mounted on the conduit. When the cap hits a stop on the conduit during threading of the conduit into the pipe the lug or helical flange pulls the pipe against the cap, tightening the connection to the pipe.

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

Abstract: A stamp formed muffler includes upper and lower internal plates and upper and lower external shells secured to the respective internal plates. The internal plates are formed to include arrays of channels that are placed in register with one another to define an array of tubes. The external shells are formed to define chambers that surround selected tubes formed by the internal plates. The upper internal plate includes at least one pair of aligned channels disposed in spaced apart end-to-end relationship and in register with a continuous channel in the lower internal plate. The chambers of the external shells are separated from one another by baffle creases. The baffle crease of the upper external shell is disposed in registration with the spaced apart aligned channels of the upper external shell. As a result, the baffle crease of the upper external shell is substantially free of pockets that conceivably could trap foreign materials.

Abstract: A muffler has a muffler body within which is located an intermediate duct pipe colinear with the exhaust and tail pipes, so that exhaust gas from the exhaust duct pipe can pass through a main flow route in the intermediate duct pipe in a substantially straight line without reflecting. An inner or by-pass pipe forms a gas by-pass and has gas flow restriction elements.

Abstract: For the purpose of muffling low-frequency sound waves such as occur in components of fluid-flow engines, the muffler proposed here consists of a feed pipe (1) through which (3) and around which (4) a medium flows. At its end in the direction of flow, the feed pipe (1) has a row of muffling bore holes (2) distributed over the periphery, via which the medium (4) flowing around the feed pipe (1) flows into the interior of the feed pipe (1). The effective length L of the feed pipe (1), the cross-sectional area A of the feed pipe (1) and the total cross-sectional area B of the muffling bore holes form the geometric parameters for calculating an optimum muffling of the low-frequency sound waves.

Abstract: A gas silencing system for controlled sound attenuation of the exhaust gas in a motor vehicle comprises a sound attenuation muffler for exhaust gases. The system also includes means providing a bypass passage for gas to flow around at least part of the muffler. Bypass control valve is provided to allow selective regulation of the flow of exhaust through the muffler and the pass-pipe. The bypass control valve is responsive to a modulated pressure signal controlled by the driver of the vehicle. The invention also includes circuits for visually indicating the amount of bypass flow and the sound level of gas leaving the system.

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: A light weight exhaust muffler is provided comprising a pair of formed external shells and a pair of pipes disposed therein. The external shells are formed to include peripheral portions and chambers extending from the peripheral portions. The chambers are separated from one another by baffle creases unitary with the respective external shells. Portions of the baffle creases of one external shell are secured in face-to-face contact with corresponding portions of the baffle creases in the other external shell. The baffle creases comprise arcuate portions corresponding to the shape of the pipes passing between the chambers separated by the baffle creases.

Abstract: A light weight exhaust muffler is provided comprising a pair of formed external shells and a pair of pipes disposed therein. The external shells are formed to include peripheral portions and chambers extending from the peripheral portions. The chambers are separated from one another by baffle creases unitary with the respective external shells. Portions of the baffle creases of one external shell are secured in face-to-face contact with corresponding portions of the baffle creases in the other external shell. The baffle creases comprise arcuate portions corresponding to the shape of the pipes passing between the chambers separated by the baffle creases.

Abstract: A system of stamp formed mufflers is provided. Each muffler in the system includes a pair of plates formed to define an array of tubes therebetween. At least one external shell is securely affixed to at least one of the plates to surround the tube. The mufflers in the system have generally the same pattern of tubes therein. However selected mufflers in the system have portions which are different from other mufflers in the system depending upon the acoustical requirements of the particular muffler in the system.

Abstract: The invention is directed to an exhaust gas muffler for a two-cycle engine, especially for a handheld portable tool, such as a chain saw. In exhaust gas mufflers equipped with a catalyzer, the formation of flame from the fuel-containing exhaust gases exiting from the muffler must be prevented. These exhaust gases are intensely overheated because of the exothermal process in the catalyzer. The muffler according to the invention includes a catalyzer which establishes a connection between separate component chambers of the muffler housing. The muffler can be mounted directly on the motor outlet.

Abstract: A muffler construction having improved sound attenuation characteristics. A tapered tubular metal screen is disposed within the outlet conduit of a muffler and has a axis concentric with the axis of the conduit. The screen has a closed end preferably facing in a downstream direction with respect to gas flow, and the opposite open end of the screen is attached to the conduit. The screen acts to reduce the sound levels without increasing the overall size of the muffler and with a minimum increase of weight.

Abstract: A flat, box-like muffler formed of metal upper and lower housing sections and internal gas passage defining plates has drainage holes to allow liquid that collects on the top of the muffler or on the bottom of the lower section inside the housing to drain out of the muffler. A special sound attenuation structure comprising passages pressed in the plates and support channels in the housing sections is shown.

Abstract: A stamp formed muffler is provided with a nonplanar array of tubes. The tubes are defined by at least one pair of nested formed members. The nested members include at least one external shell having a nonplanar portion and at least one internal plate having a nonplanar portion, with the respective nonplanar portions being configured to be placed in generally nested face-to-face relationship. The nonplanar configuration comprises an array of channels, such that an array of tubes is defined by the channels when the components are placed in nested relationship to one another. One or more chambers of the muffler are defined adjacent the nested formed members. The chambers may be defined by a single plate placed in register with the nested components or by a second pair of nested members. The nested pairs of formed members is effective in dampening shell noise attributable to vibration of the formed members.

Abstract: A tail pipe structure of a control type muffler having a first outlet pipe and a second outlet pipe provided with a control valve inserted therein, wherein the first outlet pipe is in communication with the downstream side of the control valve of the second outlet pipe. The mechanism of the muffler is such that when the control valve is opened, the exhaust gases flow into the atmosphere from the first and second outlet pipes. Further, even when the control valve is closed, the exhaust gases in the first outlet pipe flow into the atmosphere therethrough while a part of the exhaust gases flow into the second outlet pipe from the first outlet pipe through the communication pipe and is then discharged into the atmosphere.

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: The invention relates to an exhaust system for a multicylinder internal combustion engine comprising at least a manifold formed by individual exhaust ducts connected to the engine's cylinders, connector pipes, into which groups of individual ducts come together, a common exhaust pipe into which the said connector pipes join each other, the silencer mufflers, wherein the system is characterized in that the said silencer mufflers are positioned in correspondence of at least an end of said common exhaust pipe.

Abstract: A silencing device for an internal combustion engine includes an expansion chamber which may be implemented with a prechamber, a muffler or the like installed in an exhaust system of the engine. An exhaust pipe connected to the expansion chamber is provided with a double-layer structure consisting of an inner conduit through which exhaust gases flow and an outer conduit which surrounds the inner conduit. An air gap defined between the inner and outer conduits is opened into the expansion chamber at one end and closed at the other end so as to serve as a resonance chamber.

Abstract: An exhaust muffler is provided. The muffler may be formed from a pair of internal plates that are secured in registration with one another and are formed to define an array of tubes through which the exhaust gages may travel. Selected portions of the tubes in the internal plates may be formed to include perforations. The muffler may further include at least one external shell formed to define at least one chamber which may at least partly surround the perforations in the internal plates. At least one inlet or outlet may lie on the seam between the formed plate members. However, at least one inlet or outlet may also be provided through a portion of the muffler spaced from the seams. The inlet and/or the outlet may be angularly aligned to the longitudinal axis of the muffler and may further be angularly aligned to one another.

Abstract: An exhaust silencing device comprises an outer tube that is pinched down to form a series of annular chambers around a coaxial inner gas flow tube and has openings connecting the chambers to provide for some secondary gas flow parallel to primary flow through the tube. The device and is shown in conjunction with a catalytic converter to provide an exhaust system that has a sporty sound.

Abstract: Disclosed is a simple steam trap muffler. It is comprised of two comentric pipes which are both welded at their first ends to the exhaust pipe of a steam trap. The steam and condensate flows into the inner pipe from the exhaust pipe. The inner pipe has its opposite end capped so that the steam and condensate can not flow to the atmosphere through this inner pipe. However, the inner pipe does have orifices in its circumferential side through which this fluid can flow into the annular space between the first and second concentric pipes. There is no cap on the second end of the outer pipe. Thus the fluid flows along this annular space and out of the muffler through this open end of the outer pipe.

Abstract: A rope ladder of the type having a series of ladder steps and two spaced-apart pairs of ropes. Each step has a metal step frame about which is molded a hard elastomer body. Each step has a rope-receiving opening therethrough shaped and sized for closely confining a pair of ropes. Each step has a pair of horizontal transverse openings therethrough parallel to each other on each side of each rope-receiving opening. Before molding, nylon tubes are inserted in each end of each transverse opening and held during molding by slug bolts. After molding, the steps are each cut, on one side only, to provide a main step portion and two separate gripping portions, one for each rope-receiving opening, and each incorporating a portion of the frame and a portion of the body, the gripping portions including a portion of each transverse opening. A bolt is inserted through each pair of aligned nylong tubes, extending through both the main step portion and each gripping portion. A nut is loosely placed on each bolt.

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: An exhaust system for a vehicle is made sufficiently long and yet allows the muffler to be located relatively close to the engine by curving the exhaust pipe about a cooling fan provided for the engine. The arrangement also facilitates mounting of the exhaust system to the engine and vehicle bodies at a fewer number of support points.

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

Abstract: An improved exhaust system (24) uses the entire length of the system in which to perform the essential functions of muffling noise and converting unburned hydrocarbons. The improved exhaust system (24) performs these functions with a relatively uniform minimum diameter along its length. The exhaust system (24) includes a uniform outer diameter pipe (26) and elements (44) of porous material (46) forming a plurality of filters (50) through which the exhaust gas flows and which attenuates sonic frequency sound waves in the exhaust. The elements (44) are preferably elongate strips which may be folded into rectangular filters (60) or elliptical filters (90). The rectangular filters can be folded sufficiently to form squares and the elliptical filters to form circles. The rectangular filters define passageways (62-68) between the edges of the filters and inner wall (70) of the pipe (26) which further attenuates exhaust noise through imbalances in the gas flow.

Abstract: Various universal muffler assemblies are disclosed which allow one or more muffler nipples to be secured to a selected muffler body at the time of installation.

Abstract: A technique for threadedly securing muffler nipples to a muffler body is disclosed. The muffler nipples are provided with a threaded portion which is adapted to be inserted into a bushing attached to the muffler body, threadedly secured thereto, and tightened with a predetermined torque designed to prevent the nipples from unthreading or loosening within the muffler body.

Abstract: This invention relates to a tractor muffler structure that is mounted in an upright position and operates to keep moisture and foreign particles from entering the internal workings of a tractor cab engine. The tractor muffler structure includes (1) an inlet pipe member connectable to an exhaust pipe from an engine; (2) a basic housing assembly secured to the inlet pipe; (3) an outlet pipe member secured to the basic housing assembly to convey gases therefrom; and (4) a fluid control assembly mounted within the basic housing assembly and connected to the inlet pipe member and the outlet pipe member. The basic housing assembly resembles a canister having the inlet pipe member extended through a bottom wall and the outlet pipe member extended through a top wall. The bottom wall has a drainage hole therein to allow fluids to pass therethrough.

Abstract: An exhaust device for a 2-cycle engine including an exhaust pipe having an expanded portion, and a curved outlet pipe inserted in the exhaust pipe in such a manner that its one end opening is disposed in a position in the expanded portion in which the output power loss of the expanded portion can be decreased and its the other end opening is disposed at one side of the exhaust pipe. The use of a curved pipe as an outlet pipe enables the outlet pipe to be positioned such that its one end opening is disposed in a suitable position in the expanded portion while its the other end opening is disposed at one side of the exhaust pipe, thereby allowing the outlet pipe to have a suitable length and the volume of the resonance chamber in the exhaust pipe to be increased.

Abstract: A motor cycle includes a frame, a front and rear wheel, and an engine mounted to the frame which has at least two exhaust pipes. A muffler is mounted to the frame beneath the engine, and both exhaust pipes discharge into the muffler. At least one tailpipe exhausts from the muffler. The silencing volume of the muffler can enable a shorter-than-usual tailpipe to be used, which need not interfere with access to the rear wheel axle.

Abstract: From the exhaust tube of automobiles the power source sounds and travelling sounds are radiated as noises. A heat-resistant intermediate layer is disposed partly around the inner tube of dual metal tubing and achieves decreases in the radiated noise from the exhaust pipe due to the vibration damping of the inner and outer tubes.

Abstract: A motor cycle includes a frame, a front and rear wheel, and an engine mounted to the frame which has at least two exhaust pipes. A muffler is mounted to the frame beneath the engine, and both exhaust pipes discharge into the muffler. At least one tailpipe exhausts from the muffler. The silencing volume of the muffler can enable a shorter-than-usual tailpipe to be used, which need not interfere with access to the rear wheel axle.