Patent US4523662A successfully refreshed from Google Patents.
US4523662A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Muffler for exhaust gas from an internal combustion engine
Assignee: Mitsubishi Electric Corp
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Filing: 1982-11-05
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Granted: 1985-06-18
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Expires: 2002-11-05
Abstract
Abstract A muffler of the absorption type for the exhaust gas of an internal combustion engine including a cylindrical porous sound-absorbing body 1, and a film 5 of a metal or other material formed cylindrically on the inner surface of the porous body 1. The film prevents clogging of the pores in the porous body and enables the absorption of the sound in a wide frequency range.
Inventors
- 👤 Hideharu Tanaka
- 👤 Mutsuo Sekiya
- 👤 Fusaoki Uchikawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:42
CPC Classifications
F; F01; F01N; F01N1/00; F01N1/24; C; C09; C09D; C09D5/00; C09D5/18; D; D01; D01D; D01D5/00; D01D5/24; F01N2310/00; F01N2310/04; F02; F02B; F02B1/00; F02B1/02; F02B1/04
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
126 words
A muffler for the exhaust gas of an internal combustion engine, comprising: a casing, a perforated sleeve disposed in said casing, said perforated sleeve having an interior through which the exhaust gas flows and a wall having a plurality of openings, a cylindrical porous sound-absorbing body arranged coaxially with said perforated sleeve on an outer periphery of said perforated sleeve, a cylindrical thin film made of metal, said cylindrical thin film being intimately interposed between said perforated sleeve said cylindrical porous sound-absorbing body, a space defined between an inner periphery of said casing and an outer periphery of said cylindrical porous sound-absorbing body, and at least one communication passage means for providing a pressure balancing communication between the interior of said perforated sleeve and said space.
Claim 2
Dependent Claim
126 words
A muffler for the exhaust gas of an internal combustion engine, comprising: a casing, a perforated sleeve disposed in said casing, said perforated sleeve having an interior through which the exhaust gas flows and a wall having a plurality of openings, a cylindrical porous sound-absorbing body arranged coaxially with said perforated sleeve on an outer periphery of said perforated sleeve, a cylindrical thin film made of metal, said cylindrical thin film being intimately interposed between said perforated sleeve said cylindrical porous sound-absorbing body, a space defined between an inner periphery of said casing and an outer periphery of said cylindrical porous sound-absorbing body, and at least one communication passage means for providing a pressure balancing communication between the interior of said perforated sleeve and said space.
Claim 3
Dependent Claim
24 words
A muffler as set forth in claim 1, wherein said sound-absorbing body and said thin metal film are smaller in length than said casing.
Claim 4
Dependent Claim
37 words
A muffler as set forth in claim 1, wherein said thin metal film, which surrounds a passage for the exhaust gas, has a smaller thickness in the upstream portion of said passage than in its downstream portion.
Claim 5
Dependent Claim
24 words
A muffler as set forth in claim 6, wherein said thin metal film is welded or fused to the surface of said porous metal.
Claim 6
Dependent Claim
22 words
A muffler as set forth in claim 6, wherein said porous metal has a surface ground to form said thin metal film.
Claim 7
Dependent Claim
15 words
A muffler as claimed in claim 1 wherein said sound-absorbing body is a porous metal.
Claim 8
Dependent Claim
20 words
A muffler as claimed in claim 1 wherein said thin metal film has a thickness of less than 50 micrometers.
Claim 9
Dependent Claim
16 words
A muffler as claimed in claim 1 wherein said sound-absorbing body is a porous nickel-chromium alloy.
Claim 10
Dependent Claim
17 words
A muffler as claimed in claim 1 wherein said thin metal film is a nickel-chromium alloy film.
Claim 11
Dependent Claim
26 words
A muffler as claimed in claim 1 wherein said sound-absorbing body is divided into sections longitudinally of said muffler and said sections are separated by partitions.
Claim 12
Dependent Claim
107 words
A muffler as claimed in claim 1 wherein said sound-absorbing body and said thin metal film are smaller lengthwise than the length of said casing so that said sound-absorbing body and thin metal film do not reach either end of said casing, said sound-absorbing body being positioned inside said casing so as to leave an air space between the wall of said casing and said body, and partition means extending from said casing wall to said thin metal film for separating said body and said air space into segments longitudinally of said muffler, said partition means having openings therein to permit communication between said segmented air spaces.
Claim 13
Dependent Claim
16 words
A muffler as claimed in claim 11 wherein said sound-absorbing body is a porous nickel-chromium alloy.
Claim 14
Dependent Claim
17 words
A muffler as claimed in claim 12 wherein said thin metal film is a nickel-chromium alloy film.
Claim 15
Dependent Claim
32 words
A muffler as claimed in claim 1 wherein said communication passage means is constituted by at least one opening in said perforated sleeve which is not blocked by said cylindrical thin film.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-06-17 | 1988-12-17 | 1989-06-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-06-17 | 1992-12-17 | 1993-06-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-06-17 | 1996-12-17 | 1997-06-18 | $7700.00 | Window Closed / Lapsed |