Patent US4197922A successfully refreshed from Google Patents.
US4197922A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air intake pipe for an internal combustion engine
Assignee: Volkswagen AG
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Filing: 1978-02-27
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Granted: 1980-04-15
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Expires: 1998-02-27
Abstract
Abstract An air intake pipe, for mounting to the air filter of an internal combustion engine has two air flow channels having different lengths. A duct is provided between the air flow channels connecting them over their entire length. The duct is dimensioned to provide both sound attenuation and acoustic wave interference between intake noises in the two channels. Thus, the intake pipe acts as an intake noise silencer.
Inventors
- 👤 Otto Weber
- 👤 Volkmar Keck
- 👤 Rolf Engelking
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:20
CPC Classifications
F; F02; F02M; F02M35/00; F02M35/10; F02M35/10006; F02M35/10013; F02M35/10091; F02M35/10118; F02M35/12; F02M35/1205; F02M35/1227; F02M35/1244; Y; Y10; Y10S; Y10S138/00; Y10S138/11; Y10S55/00; Y10S55/21
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
73 words
An air filter housing assembly for an internal combustion engine comprising an air filter housing and an air intake pipe mounted on said filter housing including first and second air-flow channels having different lengths each of said channels including a continuous opening extending longitudinally substantially along the entire length of each channel, and a duct interconnecting the openings in the channels throughout substantially their entire length, whereby said duct suppresses engine intake noise.
Claim 2
Dependent Claim
73 words
An air filter housing assembly for an internal combustion engine comprising an air filter housing and an air intake pipe mounted on said filter housing including first and second air-flow channels having different lengths each of said channels including a continuous opening extending longitudinally substantially along the entire length of each channel, and a duct interconnecting the openings in the channels throughout substantially their entire length, whereby said duct suppresses engine intake noise.
Claim 3
Dependent Claim
18 words
An air intake pipe as specified in claim 1 wherein said air-flow channels have different average cross-sectional areas.
Claim 4
Dependent Claim
21 words
An air intake pipe as specified in claim 1 wherein at least the longest channel extends into said air filter housing.
Claim 5
Dependent Claim
27 words
An air intake pipe as specified in claim 1 wherein said second air-flow channel is at least 3 cm. greater in length than said first air-flow channel.
Claim 6
Dependent Claim
21 words
An air intake pipe as specified in claim 1 wherein said duct has a width of between 1 and 2 mm.
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) | 1983-04-15 | 1983-10-15 | 1984-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-04-15 | 1987-10-15 | 1988-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-04-15 | 1991-10-15 | 1992-04-15 | $7700.00 | Window Closed / Lapsed |