US4530418A — Automotive exhaust system

Claim 1

Independent Claim 167 words

An exhaust system for exhausting gases from an internal combustion engine having an exhaust manifold on a vehicle, the engine being capable of conventional muffling by at least one muffler section positioned along the length of an exhaust pipe extending from the exhaust manifold to the atmosphere, the muffler section having a larger diameter than the diameter of the exhaust pipe, comprising: a uniform diameter pipe having a diameter approximately that of the exhaust pipe for conventional muffling extending from the engine exhaust manifold to an opening to the atmosphere, the pipe carrying the exhaust gases from the engine to the atmosphere; and a plurality of expanded, porous material filters positioned within the pipe along its length to muffle the noise of the exhaust, said filters being formed of at least one element of porous material, said element being folded at preselected positions along the length of said element to form individual filters between the folds with each filter spaced a predetermined distance from the proximate filters.

Claim 2

Dependent Claim 167 words

An exhaust system for exhausting gases from an internal combustion engine having an exhaust manifold on a vehicle, the engine being capable of conventional muffling by at least one muffler section positioned along the length of an exhaust pipe extending from the exhaust manifold to the atmosphere, the muffler section having a larger diameter than the diameter of the exhaust pipe, comprising: a uniform diameter pipe having a diameter approximately that of the exhaust pipe for conventional muffling extending from the engine exhaust manifold to an opening to the atmosphere, the pipe carrying the exhaust gases from the engine to the atmosphere; and a plurality of expanded, porous material filters positioned within the pipe along its length to muffle the noise of the exhaust, said filters being formed of at least one element of porous material, said element being folded at preselected positions along the length of said element to form individual filters between the folds with each filter spaced a predetermined distance from the proximate filters.

Claim 3

Dependent Claim 33 words

The exhaust system of claim 1 wherein the predetermined distance between proximate filters varies along the length of said pipe to enhance muffling of a range of sonic frequencies in the exhaust system.

Claim 4

Dependent Claim 41 words

The exhaust system of claim 1 wherein said pipe includes at least one section along its length without filters to form a mixing chamber where portions of sonic frequency shock waves that have been subdivided by previous filters cancel one another.

Claim 5

Dependent Claim 45 words

The exhaust system of claim 1 wherein said filters have a rectangular cross section, forming four arcuate channels along the length of said pipe between the inner wall thereof and the edges of said filters to assist in dissipation of the sonic frequency shock waves.

Claim 6

Dependent Claim 33 words

The exhaust system of claim 1 wherein said filters have an elliptical cross section to permit said filters to contact the inner wall of said pipe about the entire circumference of said filter.

Claim 7

Dependent Claim 47 words

The exhaust system of claim 1 wherein said at least one element comprises a strip of porous material having a uniform width equal to the inner diameter of said pipe, said element being twisted into a spiral shape for placement within said pipe to form said filters.

Claim 8

Dependent Claim 26 words

The exhaust system of claim 1 wherein said porous material is formed from a material selected from a group comprising metal, ceramics and high temperature plastics.

Claim 9

Dependent Claim 21 words

The exhaust system of claim 1 wherein said porous material is an expanded steel having openings approximately 1/4 by 1/8 inch.

Claim 10

Dependent Claim 27 words

The exhaust system of claim 1 wherein said porous material includes webbing having an airfoil shape for altering the gas flow to attenuate sonic frequency shock waves.

Claim 11

Dependent Claim 25 words

The exhaust system of claim 1 wherein said uniform diameter pipe is a continuous length from the exhaust manifold to the opening into the atmosphere.

Claim 12

Dependent Claim 31 words

The exhaust system of claim 1 wherein the openings in said porous material vary in size along the length of said pipe to attenuate a range of sonic frequency shock waves.

Claim 13

Dependent Claim 30 words

The exhaust system of claim 1 wherein said porous material includes webbing having alumina and a platinum group metal plated thereon to form a catalytic converter within the exhaust system.

Claim 14

Dependent Claim 26 words

The exhaust system of claim 1 wherein said porous material is plated with a substance selected from the group comprising alumina and a platinum group metal.

Claim 15

Dependent Claim 208 words

An exhaust system for exhausting gases from an internal combustion engine having an exhaust manifold on a vehicle, the engine being capable of conventional muffling by at least one muffler section positioned along the length of an exhaust pipe extending from the exhaust manifold to the atmosphere, the muffler section having a larger diameter that the diameter of the exhaust pipe, comprising: a uniform diameter pipe having a diameter approximately that of the exhaust pipe for conventional muffling extending from the engine exhaust manifold to an opening to the atmosphere, the pipe carrying the exhaust gases from the engine to the atmosphere; and a plurality of porous material filters having openings therethrough positioned within the pipe along its length to muffle the noise of the exhaust, said material filters being formed of at least one element of porous material, said element being folded at preselected positions along the length of said element to form individual filters between adjacent folds with each of said filters spaced a predetermined distance from the filters formed on either side thereof sharing a common fold, portions of said porous material being coated with alumina and a platinum group metal to form a catalytic converter section for oxidizing unburned hydrocarbons in the exhaust gases.

Claim 16

Dependent Claim 208 words

An exhaust system for exhausting gases from an internal combustion engine having an exhaust manifold on a vehicle, the engine being capable of conventional muffling by at least one muffler section positioned along the length of an exhaust pipe extending from the exhaust manifold to the atmosphere, the muffler section having a larger diameter that the diameter of the exhaust pipe, comprising: a uniform diameter pipe having a diameter approximately that of the exhaust pipe for conventional muffling extending from the engine exhaust manifold to an opening to the atmosphere, the pipe carrying the exhaust gases from the engine to the atmosphere; and a plurality of porous material filters having openings therethrough positioned within the pipe along its length to muffle the noise of the exhaust, said material filters being formed of at least one element of porous material, said element being folded at preselected positions along the length of said element to form individual filters between adjacent folds with each of said filters spaced a predetermined distance from the filters formed on either side thereof sharing a common fold, portions of said porous material being coated with alumina and a platinum group metal to form a catalytic converter section for oxidizing unburned hydrocarbons in the exhaust gases.

Claim 17

Dependent Claim 28 words

The exhaust system of claim 14 wherein the predetermined distances between filters varies to enhance muffling of a range of sonic frequency shock waves in the exhaust system.

Claim 18

Dependent Claim 39 words

The exhaust system of claim 14 wherein the interior of at least one portion of said pipe is not provided with filters to form an empty mixing chamber for mixing and cancellation of separated portions of shock waves therein.

Claim 19

Dependent Claim 75 words

The exhaust system of claim 14 wherein said element has a generally uniform width and is folded at folds an angle not exceeding 180° to form rectangular cross section filters, said element forming four arcuate channels between the edges of each filter and the inner wall of said pipe to permit exhaust gases to flow therethrough, the pressure and imbalances between the flow through said filters and said channels further attenuating sonic frequency shock waves.

Claim 20

Dependent Claim 44 words

The exhaust system of claim 14 wherein the width of said element varies to form elliptical cross-sectional filters with varying angles of the fold so that the edges of each of said filters contacts the inner wall of said pipe along an elliptical curve.

Claim 21

Dependent Claim 25 words

The exhaust system of claim 14 wherein said element has a uniform width and is twisted to form a spiral for inclusion within said pipe.

Claim 22

Dependent Claim 24 words

The exhaust system of claim 14 wherein said porous material is selected from the group of materials comprising metal, ceramics and high temperature plastics.

Claim 23

Dependent Claim 40 words

The exhaust system of claim 14 wherein said filters are formed by webbing, the webbing forming said filters having an airfoil cross section exposed to the gas flow for altering the gas flow to further attenuate sonic frequency shock waves.

Claim 24

Dependent Claim 28 words

The exhaust system of claim 14 wherein said expanded material is formed of expanded steel, the openings in said expanded steel having dimensions approximately 1/4 by 1/8 inch.

Claim 25

Dependent Claim 25 words

The exhaust system of claim 14 wherein said uniform diameter pipe is a continuous length from the exhaust manifold to the opening into the atmosphere.

Claim 26

Dependent Claim 34 words

The exhaust system of claim 14 wherein the openings in said porous material vary in size along the length of said pipe to attenuate target frequencies across a range of sonic frequency shock waves.

Claim 27

Dependent Claim 37 words

The exhaust system of claim 14 wherein said pipe comprises at least two sections, a first section being predominantly for muffling the exhaust and the second section being predominantly for reducing the hydrocarbons in the exhaust gases.

Claim 28

Dependent Claim 17 words

The exhaust system of claim 17 wherein said element is folded to form square cross section filters.

Claim 29

Dependent Claim 17 words

The exhaust system of claim 18 wherein said element is folded to form circular cross section filters.

Claim 30

Dependent Claim 241 words

An exhaust system for exhausting gases from an internal combustion engine having an exhaust manifold on a vehicle, the engine being capable of conventional muffling by at least one muffler section positioned along the length of an exhaust pipe extending from the exhaust manifold to the atmosphere, the muffler section having a larger diameter than the diameter of the exhaust pipe, comprising: a uniform diameter pipe having a diameter approximately that of the exhaust pipe for conventional muffling extending from the engine exhaust manifold to an opening to the atmosphere, the pipe carrying within exhaust gases from the engine to the atmosphere; and a plurality of porous metal filters having a webbing and openings therebetween positioned within the pipe along its length to muffle the noise of the exhaust, said filters being formed of at least one elongate strip element of expanded metal, said element being folded at preselected positions along its length to form individual filters between the folds, adjacent filters being separated by the folds, selected ones of said filters having webbing coated with alumina and a platinum group metal to perform a catalytic conversion function, said element being of uniform width and defining filters of rectangular cross section upon folding to form four arcuate channels between the inner wall of said pipe and edges of said filters to further attenuate sonic frequency shock waves, the openings between the webbing of said filters being approximately 1/4 by 1/8 inch.

Claim 31

Dependent Claim 241 words

An exhaust system for exhausting gases from an internal combustion engine having an exhaust manifold on a vehicle, the engine being capable of conventional muffling by at least one muffler section positioned along the length of an exhaust pipe extending from the exhaust manifold to the atmosphere, the muffler section having a larger diameter than the diameter of the exhaust pipe, comprising: a uniform diameter pipe having a diameter approximately that of the exhaust pipe for conventional muffling extending from the engine exhaust manifold to an opening to the atmosphere, the pipe carrying within exhaust gases from the engine to the atmosphere; and a plurality of porous metal filters having a webbing and openings therebetween positioned within the pipe along its length to muffle the noise of the exhaust, said filters being formed of at least one elongate strip element of expanded metal, said element being folded at preselected positions along its length to form individual filters between the folds, adjacent filters being separated by the folds, selected ones of said filters having webbing coated with alumina and a platinum group metal to perform a catalytic conversion function, said element being of uniform width and defining filters of rectangular cross section upon folding to form four arcuate channels between the inner wall of said pipe and edges of said filters to further attenuate sonic frequency shock waves, the openings between the webbing of said filters being approximately 1/4 by 1/8 inch.

Claim 32

Dependent Claim 201 words

An exhaust system for exhausting gases from an internal combustion engine having an exhaust manifold on a vehicle, the engine being capable of conventional muffling by at least one muffler section positioned along the length of a conventional exhaust pipe extending from the exhaust manifold to the atmosphere, the muffler section having a larger diameter than the diameter of the exhaust pipe, the vehicle being specifically constructed to mount an exhaust pipe of said diameter, comprising: a uniform diameter single walled pipe having a diameter no greater than approximately that of the conventional exhaust pipe, said uniform diameter pipe extending from the engine exhaust manifold to an opening to the atmosphere, the uniform diameter pipe carrying within exhaust gases; muffling means within the uniform diameter pipe for muffling the exhaust, the muffling means extending continuously along the entire length of the uniform diameter pipe so that the entire length of the uniform diameter pipe has a muffling effect on the exhaust; and the single walled uniform diameter pipe being sized to fit in the vehicle without redesign of the vehicle configuration as a result of the uniformity between the outer diameter of the uniform diameter pipe and the conventional exhaust pipe.

Claim 33

Dependent Claim 201 words

An exhaust system for exhausting gases from an internal combustion engine having an exhaust manifold on a vehicle, the engine being capable of conventional muffling by at least one muffler section positioned along the length of a conventional exhaust pipe extending from the exhaust manifold to the atmosphere, the muffler section having a larger diameter than the diameter of the exhaust pipe, the vehicle being specifically constructed to mount an exhaust pipe of said diameter, comprising: a uniform diameter single walled pipe having a diameter no greater than approximately that of the conventional exhaust pipe, said uniform diameter pipe extending from the engine exhaust manifold to an opening to the atmosphere, the uniform diameter pipe carrying within exhaust gases; muffling means within the uniform diameter pipe for muffling the exhaust, the muffling means extending continuously along the entire length of the uniform diameter pipe so that the entire length of the uniform diameter pipe has a muffling effect on the exhaust; and the single walled uniform diameter pipe being sized to fit in the vehicle without redesign of the vehicle configuration as a result of the uniformity between the outer diameter of the uniform diameter pipe and the conventional exhaust pipe.

Claim 34

Dependent Claim 55 words

The exhaust system of claim 29 wherein said muffling means comprises a woven wire fabric, the wire in said woven wire fabric varying in diamater in cross section to attenuate a range of sonic frequency shock waves, the openings between wires also being varied in size to attenuate a range of sonic frequency shock waves.

Claim 35

Dependent Claim 19 words

The exhaust system of claim 29 wherein said muffling means is coated with alumina and a platinum group metal.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1988-07-22	1989-01-21	1989-07-23	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1992-07-22	1993-01-21	1993-07-23	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1996-07-22	1997-01-21	1997-07-23	$7700.00	Window Closed / Lapsed

Automotive exhaust system

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