Abstract: An assembly useful in reducing aircraft engine noise such as turbofan engine noise (730) comprises: (1) at least one tube “H-Q” having an inlet end (738), an outlet end (740) and a central tube portion therebetween; an (ii) at least one actuator operatively interconnected to at least one tube, wherein the actuator is capable of causing dynamic response by the tube. The assembly of this invention may be used in a method for reducing noise, the method comprising: (a) providing means for generating non-uniform noise energy about an inner surface and within a disclosure having at least an inlet; (b) providing an assembly for reducing noise comprising; (i) at least one tube having an inlet end, an outlet end and a central tube portion therebetween, and (ii) at least one actuator operatively interconnected to at least one tube, wherein the actuator is capable of causing dynamic response by the tube; and (c) directing at least a portion of the non-uniform noise into the assembly.

Abstract: Methods and apparatus are provided for an exhaust duct having an externally replaceable acoustic liner. The exhaust duct includes a forward section that is configured to be axially coupled with a bulkhead collar on the aircraft, a body section that is coupled to the forward section and a stinger cap that includes the replaceable acoustic liner. The replaceable acoustic liner is configured to be slideably received by the body section.

Abstract: A repositionable attenuator for a terminal unit in a heating, ventilation, and air conditioning system is disclosed. The attenuator is positionable between at least a first and a second position. This enables the attenuator to be attached to and shipped with the terminal unit prior to installation of the terminal unit.

Abstract: The exhaust created from the operation of pneumatic tools can create a considerable amount of noise. The present disclosure includes a detachable muffler apparatus used to reduce the sound during the operation of a pneumatic tool. The muffler apparatus includes a flexible outer housing that defines a muffler passage extending between a muffler inlet and a muffler outlet. The flexible outer housing includes an attachment end that defines the muffler inlet and a distal end that defines the muffler outlet. The attachment end can be removably attached to a pneumatic tool body by a fastener. Tool exhaust is forced through and around folds within at least one sheet of permeable material positioned within the muffler passage.

Abstract: Sound and power are an important part of the motorcycling experience. From the early days people have been attempting to get it “right” and have tried numerous ways to achieve the best of both worlds. Generally one had to be sacrificed to some degree to get the other. Tuning the exhaust rather than tuning the carburetor or increasing cubic inches is a less expensive and more efficient way to get both the sound and midrange power that motorcyclists are looking for. With the exhaust enhancement device of the present invention, exhaust pipes can be tuned for sound and increased midrange power very simply and easily by installing them in the exit end of an aftermarket straight type pipe using various combinations to achieve a desired sound and not sacrifice power.

Abstract: A serviceable muffler (20) has an end plate (34) releasably clamped (36) to an open end (30) of a muffler body (26) and permitting access to an internal catalytic or filter element (28) for removal and replacement. An apertured flange (44) has an outer border with flared rounded portion (46) complemental to flared rounded portions (40 and 42) of each of the end plate (34) and the open end (30) of the body (26), and having an inner border defined by an aperture (48) through which the element (28) is removed and replaced. Servicing and manufacturing methods are provided.

Abstract: An assembly useful in reducing aircraft engine noise such as turbofan engine noise (730) comprises: (i) at least one tube “H-Q” having an inlet end (738), an outlet end (740) and a central tube portion therebetween; and (ii) at least one actuator operatively interconnected to at least one tube, wherein the actuator is capable of causing dynamic response by the tube. The assembly of this invention may be used in a method for reducing noise, the method comprising: (a) providing means for generating non-uniform noise energy about an inner surface and within a disclosure having at least an inlet; (b) providing an assembly for reducing noise comprising; (i) at least one having an inlet end, an outlet end and a central tube portion therebetween, and (ii) at least one actuator operatively interconnected to at least one tube, wherein the actuator is capable of causing dynamic response by the tube; and (c) directing at least a portion of the non-uniform noise into the assembly.

Abstract: Exhaust system assemblies employ wire bushings for thermal compensation to minimize noise due to “stick-slip” while the system cools. In a preferred embodiment, the wire bushings are formed of at least one strand of wire coiled about male end portions of pipe sections used in the system, each of which male end portions are inserted into a female end portion and held therein by an interference fit. The strand of wire is spot welded at spaced locations to the male end portions to provide bearing surfaces between the spot welds that move slightly as the exhaust system heats and cools to relieve thermal stress in small, substantially inaudible increments.

Abstract: A motorcycle exhaust control system for covering exhaust cross-over pipes is comprised of an elongate tubular crossover block-off member having a side wall. The crossover block-off member side wall has a slit extending the length thereof. The crossover block-off member forms the springed structure capable of placement in a motorcycle exhaust pipe. The crossover block-off member is capable of self-detainment in the motorcycle exhaust pipe. The crossover block-off member is capable of blocking the motorcycle exhaust pipe crossover.

Abstract: A sonic nozzle is disclosed that is positioned between an evaporator and compressor in an air conditioning system. The sonic nozzle limits refrigerant flow rate to that allowed by sonic velocity at a throat area of the sonic nozzle. The sonic nozzle may have a by-pass flow area that allows for less pressure drop at lower flow rates where the by-pass flow area is sealed off at a predetermined pressure drop to force all flow through the sonic nozzle. Another embodiment that is disclosed features a thermally actuated suction throttling valve that is attached to a sonic nozzle. A power element of the throttling valve contains thermally active fluid, such as water, when frozen activates a piston member into the throat portion of the sonic nozzle to restrict fluid flow.

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: An exhaust gas system for an internal combustion engine, in particular, of a motor vehicle has two mufflers through which the exhaust gas is able to flow in a parallel fashion. A switching unit makes it possible to selectively convey the exhaust gas flow of the internal combustion engine only or almost exclusively through the first muffler, or only or almost exclusively through the second muffler, or through both mufflers in a parallel fashion. The two mufflers are realized differently with respect to their muffling effect and/or flow resistance.

Abstract: A device for noise structuring in a motor vehicle has a plurality of gas-carrying lines connected to an internal combustion engine. At least two of the gas-carrying lines are acoustically linked together by at least one connection.

Abstract: An exhaust processor comprises a Helmholtz resonance chamber with a variable tuning throat. The tuning frequency of the exhaust processor changes as the outlet opening from the variable tuning throat into the Helmholtz resonance chamber changes.

Abstract: An exhaust processor has an exhaust tube and a cover mounted for rotation at least partially around the exhaust tube to adjust the tuning frequency of the exhaust processor. A method of operating the exhaust processor is also disclosed.

Abstract: Sound and power are an important part of the motorcycling experience. From the early days people have been attempting to get it “right” and have tried numerous ways to achieve the best of both worlds. Generally one had to be sacrificed to some degree to get the other. Tuning the exhaust rather than tuning the carburetor or increasing cubic inches is a less expensive and more efficient way to get both the sound and midrange power that motorcyclists are looking for. With the Exhaust Enhancement exhaust pipes can be tuned for sound and increased midrange power very simply and easily by installing them in the exit end of an aftermarket straight type pipe using various combinations to achieve a desired sound and not sacrifice power.

Abstract: A muffler includes a housing having a side wall defining a chamber. The housing includes a first section and a removable second section. A selectively removable insert is received in the chamber of the housing. A coupling is provided for selectively attaching the housing first section to the housing second section.

Abstract: A vertical mount muffler (40) has an external water trap (52) in an exhaust pipe (48) and drains water from a point between the muffler housing upper outlet (46) and the terminal end (50) of the exhaust pipe. The water trap (52) is laterally adjacent to the muffler housing (42) and below the housing upper outlet (46) and traps and drains water entering the exhaust pipe (48) from the terminal end (50).

Abstract: A muffler includes a housing having an inlet, an outlet, and at least one variable resonance chamber defined by a slidable member. The slidable member may be actuated by the pressure of exhaust gas flowing through the housing. Actuation of the slidable member changes the length of the resonance chamber, which alters the resonance and/or the flow path of the exhaust to provide varying tuning for acoustic damping.

Abstract: An exhaust processor comprises a Helmholtz resonance chamber with a variable tuning throat. The tuning frequency of the exhaust processor changes as the outlet opening from the variable tuning throat into the Helmholtz resonance chamber changes.

Abstract: A sound level adjustable muffler has a pop-up mechanism working in parallel pairs used for lifting the tabletop part of a piece of furniture has a pair of cantilever arms joined together by an upper oblong member and a lower oblong member, both said upper oblong member and lower oblong member being parallel relative to each other and each being rotationally attached to opposite ends of said pair of cantilever arms.

Abstract: An exhaust processor comprises a Helmholtz resonance chamber with a variable tuning throat. The tuning frequency of the exhaust processor changes as the outlet opening from the variable tuning throat into the Helmholtz resonance chamber changes.

Abstract: An assembly useful in reducing aircraft engine noise such as turbofan engine noise (730) comprises: (i) at least one tube “H-Q” having an inlet end (738), an outlet end (740) and a central tube portion therebetween; and (ii) at least one actuator operatively interconnected to at least one tube, wherein the actuator is capable of causing dynamic response by the tube. The assembly of this invention may be used in a method for reducing noise, the method comprising: (a) providing means for generating non-uniform noise energy about an inner surface and within a disclosure having at least an inlet; (b) providing an assembly for reducing noise comprising; (i) at least one having an inlet end, an outlet end and a central tube portion therebetween, and (ii) at least one actuator operatively interconnected to at least one tube, wherein the actuator is capable of causing dynamic response by the tube; and (c) directing at least a portion of the non-uniform noise into the assembly.

Abstract: A variable tuned telescoping resonator which militates against the emission of noise energy caused by intake air in a vehicle wherein the connector length and the volume of the resonator are varied as a function of engine speed simultaneously to provide attenuation of noise energy over a wide frequency range.

Abstract: An apparatus for damping acoustic vibrations in a combustor as well as a corresponding combustor arrangement with the apparatus. The apparatus includes a Helmholtz resonator (4) that can be connected via a connecting channel (2) with a combustor (1). The Helmholtz resonator (4) contains a hollow body (6) the volume of which can be changed by adding or draining a fluid via a supply line (5), or is located adjacent to such a hollow body in such a way that the resonance volume (3) of the Helmholtz resonator (4) is changed when the volume of the hollow body (6) is changed. This apparatus makes it possible to adjust the resonance frequency of a Helmholtz resonator arranged inside a pressure container in accordance with the respective current operating point of the combustor to be damped, without having to pass movable components through the pressure container.

Abstract: An apparatus for controlling exhaust noise in an internal combustion engine uses the length difference between the exhaust pipe and the bypass pipe. The apparatus includes an exhaust pipe for outwardly releasing exhaust gas from the engine; a bypass pipe variable in length which diverges from said exhaust pipe with a distance and has U-shaped and reverse U-shaped sections formed alternately; an actuator having an actuating rod connected to the bypass pipe to vary the length of the bypass pipe; and a control unit for controlling the actuator. The bypass pipe has the U-shaped and reverse U-shaped sections arranged alternately so that the variable length of the bypass pipe can be extended while minimizing the space for installing the bypass pipe, and thereby noise in the low frequency band can be suitably reduced. Also, the exhaust pipe is additionally provided with a device for adjusting the length to increase the length difference with the bypass pipe so that noise in a wider band can be controlled.

Abstract: A duct or conduit section (10) for installation, in particular, in an air intake system of an internal combustion engine, in which the duct section is composed of two shells (14) which are joined by a snap connection (15). Openings located in the parting seam or joint (16) between the shells (14) are produced by recesses in the half shells. These openings each have a cross-sectional area of less than 7 mm2 and are useful for suppressing noise resulting from the air intake. As a result of the openings, vibration-inducing forces exerted on adjacent components in the engine compartment due to pulsations in the intake tube, can be minimized or avoided. Also, the quantity of additional air drawn in from the engine compartment, which is undesired because it is too warm, is decreased.

Abstract: An adjustable muffler system for a combustible engine including a muffler adapted for connection with an exhaust pipe of an engine, a blocking tube configured to be removably inserted within the muffler, and latch means adapted to removably secure the blocking tube within the muffler. In other embodiments, the blocking tube can include various holes or slots and may be telescoping or fabricated from multiple pieces.

Abstract: A gear pump for the power steering of a motor vehicle is integrated into the housing of the drive unit and is surrounded by both the discharge space and the intake space, which extend over the entire length of the housing Ribs are provided in the discharge space for pulsation damping and for stabilization of the pressure field. A filter space is provided between the cover and a filter cap.

Abstract: A sound adjustable tail pipe structure includes an adjuster secured in a rear section of a tail pipe which defines a first oblong slot. The adjuster includes a tube having a first end provided with a first positioning base and a second end provided with a second positioning base, and an adjusting base rotatably mounted in the second positioning base. The first positioning base defines a first through hole connecting to the tube and has a wall defining a plurality of first guide holes. The second positioning base defines a second through hole connecting to the tube and has a wall defining a plurality of second guide holes, and a peripheral wall defining a second oblong slot. The adjusting base defines a third through hole connecting to the second through hole and has a wall defining a plurality of third guide holes aligning with each of the second guide holes, and a peripheral wall defining a screw hole.

Abstract: An adjustable muffler system for a combustible engine including a muffler adapted for connection with an exhaust pipe of an engine, a blocking tube configured to be removably inserted within the muffler, and latch means adapted to removably secure the blocking tube within the muffler. In other embodiments, the blocking tube can include various holes or slots and may be telescoping or fabricated from multiple pieces.

Abstract: An engine exhaust silencer arrangement with a variable geometry, which is controlled by control elements in dependence of engine data. The increased exhaust noise occurring during engine operation under differing engine stroke modes is suppressed by the different geometry of the silencer arrangement.

Abstract: An exhaust passage control valve has a valve element of a spiral shape mounted on a valve seat portion of a housing through which exhaust gases from an engine pass. The valve element is urged by a valve spring in a direction of closing the valve. A spring constant of the valve spring is kept low without enlarging the valve spring, and there can be obtained opening and closing characteristics in that the valve opens at a stretch when an exhaust-gas pressure has reached a predetermined value. As the valve spring, a helical torsion spring having a coiled cylindrical body portion is used. Arm portions on both ends of a coiled cylindrical body portion are engaged with a pair of spring receiving members. The spring receiving members are disposed in the housing on circumferentially opposite sides of the valve seat portions. The arm portion are engaged with the spring receiving members so as to be slidable in a longitudinal direction of the arm portions.

Abstract: The present invention relates to an apparatus for damping acoustic vibrations in a combustor as well as a corresponding combustor arrangement with the apparatus. The apparatus comprises a Helmholtz resonator (4) that can be connected via a connecting channel (2) with a combustor (1). The Helmholtz resonator (4) contains a hollow body (6) the volume of which can be changed by adding or draining a fluid via a supply line (5), or is located adjacent to such a hollow body in such a way that the resonance volume (3) of the Helmholtz resonator (4) is changed when the volume of the hollow body (6) is changed. This apparatus makes it possible to adjust the resonance frequency of a Helmholtz resonator arranged inside a pressure container in accordance with the respective current operating point of the combustor to be damped, without having to pass movable components through the pressure container.

Abstract: An exhaust assembly for use with a motor vehicle having a combustion engine. The exhaust assembly includes an exhaust and a muffler having first and second gas flow routes. A control device controls the damping characteristic of the exhaust assembly by selectively dividing the gas flow by different amounts between the different gas flow routes. The control device, which may include a valve or a sliceable sleeve, is selectively operable by a user manually or electronically while the combustion engine is operating.

Abstract: Pipe section running along a curve, intended for use in a muffler, comprising two hollow-formed molded parts which are mirror-symmetrical in relation to the radial plane of the curve and which have connected thereto a flat outside edge running in the radial plane along the outside of the curve, which flat outside edges are placed on each other so that the molded parts together form the pipe section, a third flat part being placed at the position of the radial plane between the two molded parts in such a way that a curved edge of said third flat part is situated between the two flat outside edges of the molded parts and is fastened to said outside edges.

Abstract: A motor vehicle muffler mounted with a plurality of baffles, the muffler comprising a variable control unit constructed such that at least one baffle in the muffler is moved to vary volumes of chambers according to a depression of an accelerator pedal, to obtain an optimum noise attenuation effect and to increase exhaust efficiency.

Abstract: A muffler includes a housing and one or more tubes secured in the housing. A valve member is engaged in each of the tubes for adjusting an opening size of the tube and for adjusting the pressure that may be generated in the housing such that the mufflers may be secured to various kinds of engines. The valve member includes a ball rotatably engaged in the tube and having an orifice for adjusting the opening size of the bore when the ball is rotated. A filter material is engaged in the housing and may be squeezed for adjusting the output noise of the muffler.

Abstract: A device (8) for modifying the height of the discharge end (5) of an exhaust silencer (1) of a motorcycle from the ground is provided. The silencer (1) is connected at one end (6) to the terminal part (7A) of the exhaust pipe (7) of the motorcycle engine. The device (8) comprises cylindrical elements (10, 11) connected respectively to the end (6) of the silencer (1) and to the terminal part (7A) of the exhaust pipe (7), said elements (10, 11) being able to be fitted together in socket manner and being rotatable relative to each other so as to enable the discharge end (5) of the silencer (1) to be set to the desired height and to be locked in that position to the motorcycle frame.

Abstract: A retrofittable muffler to reduce noise associated with air-operated hand tools and other working devices provides a housing with an inner expansion chamber and an outer expansion chamber so that at least a portion of spent pneumatic fluid passes from the pneumatic device, through the internal expansion chamber, and through the outer expansion chamber prior to discharge to atmosphere through exhaust ports in the housing.

Abstract: Pulses are sensed at the inlet and outlet of a two-chamber reflective muffler and responsive thereto the cavities are tuned to the frequency of the pulses. Specifically, chamber walls are moved to have them located at spacings corresponding, respectively, to one half and one quarter of the wavelength of the pulses.

Abstract: A muffler for an exhaust system of an outboard engine is constructed in two parts, one being longer than the other with the longer portion being of standard length for various engine applications, while the shorter length muffler section is constructed to have variable lengths to accommodate various engine and propulsion unit applications. The lower muffler section is resiliently mounted to reduce transmittal of vibrations to the engine housing and associated structure. By constructing one of the muffler sections of a standard length for all engine applications, molding costs for various applications are reduced.

Abstract: A resonator type silencer in which the resonance frequency is variable in accordance with engine speed of an automotive engine. The silencer is comprised of a casing connected through a neck section to a duct through which intake air or exhaust gas flows. A cylindrical rotatable member is disposed in the casing and rotatably supported on a rotatable shaft, forming an annular space between it and the inner peripheral surface of the casing. A stationary partition wall is fixedly disposed inside the cylindrical rotatable member and extends radially. A movable partition wall is disposed in the casing and extends from the rotatable shaft to the cylindrical rotatable member. The movable partition wall defines, in cooperation with the stationary partition wall, a tuning chamber inside the cylindrical movable member. A movable blocking wall is disposed in the casing to block the annular space thereby to define a peripheral passage in communication with the neck section.

Abstract: The vehicular muffler assembly of this invention includes a muffler which has a elongated shell. An inlet communicates with the interior of the shell to provide a port for entry of exhaust gases from an internal combustion engine to the interior of the shell. An outlet communicates with the interior of the shell to allow exhaust gases to leave the shell. A heat shield is mounted on the exterior of the shell. The heat shield is symmetrical and has an outer wall. The outer wall has a weld skirt which is integral with the outer wall. A plurality of discreet welds spaced along the weld skirt fixes the outer wall to the shell. A slot opening is formed in the weld skirt between adjacent discreet welds.

Abstract: A dynamically variable exhaust system provides for maximum efficiency of an internal combustion engine (30) by including an exhaust control device (35) which is operated by a control mechanism (33) and managed by a control unit (32). The length and cross-sectional area of the exhaust header section (36) can be varied by transversely displacing the effective exhaust passage within control device (35) while maintaining a streamlined profile of the effective passage throughout a predetermined range of displacement. The control unit (32) can be influenced by numerous operational inputs including control device position potentiometer (40), engine speed input (41), engine load input (42), vehicle braking sensor (43), exhaust emission and temperature sensor (44), and engine management system input (45).

Abstract: A triple cone exhaust wave and flow tuner for controlling the flow of exhaust gases and altering the resonant wave frequency generated by thee exhaust pulses including a reverse cone megaphone shaped enclosure, a perforated guide sleeve, and a rotatable, slidable perforated tuning pipe having a conical end.

Abstract: The invention is directed to a seal arranged between two housing parts of a muffler. The seal is configured essentially as a frame and made of sheet steel and has at least two layers. The first layer is defined by the frame itself and the second layer is defined by lugs which are folded over and are configured so as to be integral with the frame.

Abstract: An exhaust pipe shield for motorcycles or the like comprises curved shield member having a generally constant radius greater than that of a cylindrically shaped exhaust pipe. A plurality of spacer blocks are interposed between the shield inner surface and the outer surface of the exhaust pipe. The spacer blocks are secured to the shield. A clamping mechanism is coupled to the spacer blocks for securing the shield to the exhaust pipe.

Abstract: A fluid friction controller that includes an outer member having a first friction control surface and an inner member having a second friction control surface. The control surfaces coact to define an elongated orifice that diverges from its entrance toward its exit. The length of the orifice is related to the angle of divergence so that the flow of a fluid passing therethrough remains attached to the control surfaces and the dynamic pressure in the flow does not exceed the static pressure at any point along the length of the orifice.