US4164266A — Exhaust gas muffler

Claim 1

Independent Claim 146 words

In a muffler for dampening exhaust noise composed of sound waves having various frequencies: an axially extending tube adapted to be connected to an exhaust pipe, a casing surrounding said tube, and being devoid of dampening material, first axial wall means extending longitudinally of said tube to subdivide said casing into at least two mutually separate spaces, second transverse wall means extending radially from said tube to subdivide at least one of said spaces into at least two mutually separate chambers, and openings in the wall of said tube for individually communicating the interior of said tube with said at least one sub-divided space and said two chambers, the openings communicating said tube with said at least one sub-divided space being located along part of the axial extension of said tube, to form said space into a resonator compatible with the lowest frequency to be dampened.

Claim 2

Dependent Claim 146 words

In a muffler for dampening exhaust noise composed of sound waves having various frequencies: an axially extending tube adapted to be connected to an exhaust pipe, a casing surrounding said tube, and being devoid of dampening material, first axial wall means extending longitudinally of said tube to subdivide said casing into at least two mutually separate spaces, second transverse wall means extending radially from said tube to subdivide at least one of said spaces into at least two mutually separate chambers, and openings in the wall of said tube for individually communicating the interior of said tube with said at least one sub-divided space and said two chambers, the openings communicating said tube with said at least one sub-divided space being located along part of the axial extension of said tube, to form said space into a resonator compatible with the lowest frequency to be dampened.

Claim 3

Dependent Claim 103 words

In an exhaust gas muffler a first portion including an inner, perforated tube attachable to an exhaust pipe, a casing devoid of dampening material, enclosing said inner tube and wall means subdividing said casing axially as well as transversely into a number of separate chambers, a second portion including dampening material, a common outer housing defined by a shell plate and two end plates enclosing said first and said second portions, an inlet to and an outlet from said muffler located at one of said end plates, and an internal return chamber for conducting gas from said first portion to said second portion.

Claim 4

Dependent Claim 103 words

In an exhaust gas muffler a first portion including an inner, perforated tube attachable to an exhaust pipe, a casing devoid of dampening material, enclosing said inner tube and wall means subdividing said casing axially as well as transversely into a number of separate chambers, a second portion including dampening material, a common outer housing defined by a shell plate and two end plates enclosing said first and said second portions, an inlet to and an outlet from said muffler located at one of said end plates, and an internal return chamber for conducting gas from said first portion to said second portion.

Claim 5

Dependent Claim 18 words

The muffler according to claim 2, in which the return chamber means is formed as a radial diffusor.

Claim 6

Dependent Claim 37 words

The muffler according to claim 3, in which said radial diffusor is inwardly defined by the half shell of a toroid body and outwardly by an outer-quarter shell of a toroid body combined with an abutment plate.

Claim 7

Dependent Claim 56 words

The muffler according to claim 4, in which said abutment plate, at least partly, is formed as a conical shell, the generating line of which is selected so as to maintain a substantially constant cross sectional area during the first 90° of the deflection of the gas pass, and thereafter causes an expansion of the area.

Claim 8

Dependent Claim 38 words

The muffler according to claim 2, in which said second portion is located concentrically around said first portion, said return chamber means communicating with a return flow passage, being inwardly defined by the casing of said first portion.

Claim 9

Dependent Claim 27 words

The muffler according to claim 6, in which the cross sectional area of said return passage is at least 50% bigger than that of said inner tube.

Claim 10

Dependent Claim 16 words

The muffler according to claim 6 further including a perforated plate, outwardly defining said return passage.

Claim 11

Dependent Claim 17 words

The muffler according to claim 8, in which said perforated plate is provided with outwardly tapering perforations.

Claim 12

Dependent Claim 35 words

The muffler according to claim 8 further including a wire mesh concentrically arranged with respect to said perforated plate for maintaining the dampening material of said second portion at a distance from said perforated plate.

Claim 13

Dependent Claim 21 words

The muffler according to claim 8 further including guide walls for subdividing said return passage into a number of parallel ducts.

Claim 14

Dependent Claim 59 words

The muffler according to claim 11 having an outlet connected radially to its shell, in which said guide walls, adjacent to said outlet are bent in relation to the longitudinal axis of the casing, the cross sectional areas within said ducts being maintained substantially uniform by an increase of the radial distance between said casing and said perforated plate.

Claim 15

Dependent Claim 50 words

The muffler according to claim 2, comprising a first low frequency dampening portion and a second high frequency dampening portion arranged axially with respect to each other, and having substantially the same cross sectional area, and having said inlet and said outlet arranged concentrically in one of said end plates.

Claim 16

Dependent Claim 29 words

The muffler according to claim 13, in which the second portion, as well as the surrounding part of the return flow passage tapers in the direction towards said outlet.

Claim 17

Dependent Claim 29 words

The muffler according to claim 13, in which the return flow passage extends through said second portion and within said second portion tapers in the direction towards said outlet.

Claim 18

Dependent Claim 187 words

In an exhaust gas muffler a first portion including an inner part perforated tube attachable to an exhaust pipe, a casing enclosing said inner tube and wall means subdividing said casing axially as well as transversely into a number of separate chambers, a second portion forming an annular chamber surrounding the first portion, a common outer housing defined by a shell plate and two end plates enclosing said first and said second portions, an inlet to said first portion axially connected to one of said end plates and an outlet from said second portion directed radially outwards from said shell adjacent to said one end plate, means for mounting dampening material within said second portion and within at least one of the chambers in said first portion located outside of an unperforated part of said inner tube, openings in said inner tube for communicating the interior of said inner tube with those compartments in said first portion being devoid of dampening material and further openings in said casing for communicating said second portions with said at least one chamber in said first portion supplied with dampening material.

Claim 19

Dependent Claim 187 words

In an exhaust gas muffler a first portion including an inner part perforated tube attachable to an exhaust pipe, a casing enclosing said inner tube and wall means subdividing said casing axially as well as transversely into a number of separate chambers, a second portion forming an annular chamber surrounding the first portion, a common outer housing defined by a shell plate and two end plates enclosing said first and said second portions, an inlet to said first portion axially connected to one of said end plates and an outlet from said second portion directed radially outwards from said shell adjacent to said one end plate, means for mounting dampening material within said second portion and within at least one of the chambers in said first portion located outside of an unperforated part of said inner tube, openings in said inner tube for communicating the interior of said inner tube with those compartments in said first portion being devoid of dampening material and further openings in said casing for communicating said second portions with said at least one chamber in said first portion supplied with dampening material.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1982-08-13	1983-02-12	1983-08-14	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1986-08-13	1987-02-12	1987-08-14	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1990-08-13	1991-02-12	1991-08-14	$7700.00	Window Closed / Lapsed

Exhaust gas muffler

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