US4186172A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Monolithic catalytic muffler having nondeposit welds
Assignee: Audi AG
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Filing: 1978-05-05
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Granted: 1980-01-29
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Expires: 1998-05-05
Abstract
Abstract A catalytic muffler is formed by winding together a pair of relatively thin catalytically active foils one of which is corrugated. The wound-together foils are secured together by nondeposit welding to form a rigid insert having longitudinally throughgoing gas passages. This insert is then fitted into a cylindrical housing and welded to the housing once again using a beam-type welder.
Inventors
- 👤 Rainer Scholz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:36
CPC Classifications
F; F01; F01N; F01N3/00; F01N3/08; F01N3/10; F01N3/24; F01N3/28; F01N3/2803; F01N3/2807; F01N3/281; F01N3/2839; F01N3/2842; F01N2330/00; F01N2330/02; F01N2330/04; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49345
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
86 words
A catalytic muffler comprising: a first metal foil; a second metal foil wrapped with said first foil and forming therewith a plurality of throughgoing gas passages, said foils contacting each other at a multiplicity of locations, at least one of said foils being catalytically active; nondeposit welds between said foils at a plurality of said locations uniting said foils into a monolithic and rigid insert; a housing snugly surrounding and contacting said insert; and nondeposit welds between said housing and said insert fixing same rigidly together.
Claim 2
Dependent Claim
86 words
A catalytic muffler comprising: a first metal foil; a second metal foil wrapped with said first foil and forming therewith a plurality of throughgoing gas passages, said foils contacting each other at a multiplicity of locations, at least one of said foils being catalytically active; nondeposit welds between said foils at a plurality of said locations uniting said foils into a monolithic and rigid insert; a housing snugly surrounding and contacting said insert; and nondeposit welds between said housing and said insert fixing same rigidly together.
Claim 3
Dependent Claim
24 words
The muffler defined in claim 1 wherein one of said foils is corrugated with its corrugations extending in line with and defining said passages.
Claim 4
Dependent Claim
14 words
The muffler defined in claim 2 wherein the other of said foils is flat.
Claim 5
Dependent Claim
22 words
The muffler defined in claim 2 wherein both of said foils are catalytically active and have thicknesses of at most 100 microns.
Claim 6
Independent Claim
85 words
A method of making a catalytic muffler comprising the steps of: wrapping together a pair of catalytically active metal foils into a body having a plurality of throughgoing gas passages with said foils in contact with each other between said passages at a multiplicity of locations; nondeposit welding together said foils at a plurality of said locations to form same body into a rigid insert by advancing said foils adjacent a fixed-beam welder; and fitting said insert into a housing and rigidly securing same therein.
Claim 7
Independent Claim
85 words
A method of making a catalytic muffler comprising the steps of: wrapping together a pair of catalytically active metal foils into a body having a plurality of throughgoing gas passages with said foils in contact with each other between said passages at a multiplicity of locations; nondeposit welding together said foils at a plurality of said locations to form same body into a rigid insert by advancing said foils adjacent a fixed-beam welder; and fitting said insert into a housing and rigidly securing same therein.
Claim 8
Dependent Claim
17 words
The method defined in claim 5 wherein said foils are welded together as they are wrapped together.
Claim 9
Dependent Claim
32 words
The method defined in claim 5 wherein said insert is welded along a generally spiral seam to said housing by rotating and advancing said insert and housing past a fixed beam welder.
Claim 10
Dependent Claim
25 words
The method defined in claim 5 wherein said insert is generally cylindrical and said foils are welded together along at least one generally diametral plane.
Claim 11
Dependent Claim
27 words
The method defined in claim 5 wherein one of said foils is corrugated and the other foil is generally flat and said foils are wound together spiral-fashion.
Claim 12
Dependent Claim
45 words
The method defined in claim 5, further comprising the step of nondeposit welding said insert to said housing after fitting of said insert therein to rigidly secure said insert and housing together by means of a beam welder directed into the end of said housing.
Claim 13
Dependent Claim
16 words
The method defined in claim 10 wherein said welding is carried out with a laser beam.
Claim 14
Dependent Claim
16 words
The method defined in claim 10 wherein said welding is carried out with an electron beam.
Claim 15
Dependent Claim
17 words
The method defined in claim 10 wherein said foils are welded together as they are wrapped together.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-01-28 | 1983-07-30 | 1984-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-01-28 | 1987-07-30 | 1988-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-01-28 | 1991-07-30 | 1992-01-29 | $7700.00 | Window Closed / Lapsed |