Patent US6920318B2 successfully refreshed from Google Patents.
US5119902A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Active muffler transducer arrangement
Assignee: Visteon Global Technologies Inc
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Filing: 1990-04-25
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Granted: 1992-06-09
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Expires: 2010-04-25
Abstract
Abstract An active muffler for use in motor vehicles comprises a sensor, an electronic control responsive to the signal generated by the sensor for producing a drive signal delivered to a transducer which emits cancellation pulses phased 180° from the sound pressure pulses passing through a conduit, where both front and rear sides of the transducer are acoustically coupled to the conduit to improve the efficiency of the transducer operation. Preferably, the acoustic coupling comprises an enclosed chamber including a port for communicating with the conduit which can be tuned to resonate at predetermined frequencies. When both sides of the transducer are so coupled to the conduit, the transducer has increased efficiency over a broad band of frequencies, and the frequency band can be broadened at the low end as required to accommodate the frequencies generated by a source of noise. The transducer mounting arrangement according to the present invention is particularly suitable for use in adapting noise cancellation techniques to replace passive mufflers on motor vehicles.
Inventors
- 👤 Earl R. Geddes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:25
CPC Classifications
F; F01; F01N; F01N1/00; F01N1/06; F01N1/065; G; G10; G10K; G10K11/00; G10K11/16; G10K11/175; G10K11/178; G10K11/1785; G10K11/17855; G10K11/17857; G10K11/1787; G10K11/17873; G10K2210/00; G10K2210/10; G10K2210/112; G10K2210/128; G10K2210/1282; G10K2210/12822; G10K2210/30; G10K2210/301; G10K2210/3045; G10K2210/321; G10K2210/3227; G10K2210/32272
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
99 words
An active, noise cancellation apparatus for a conduit comprising: a sensor for generating a sensor signal representative of an input pulse train; a transducer having a front side and a rear side; means for mounting said transducer adjacent to the conduit; electronic control means for driving said transducer in response to said sensor signal and producing an output pulse train having a phase opposite to said input pulse train at a predetermined point; and means for acoustically separating said front side from said rear side and acoustically coupling said front and rear sides of said transducer with said conduit.
Claim 2
Dependent Claim
99 words
An active, noise cancellation apparatus for a conduit comprising: a sensor for generating a sensor signal representative of an input pulse train; a transducer having a front side and a rear side; means for mounting said transducer adjacent to the conduit; electronic control means for driving said transducer in response to said sensor signal and producing an output pulse train having a phase opposite to said input pulse train at a predetermined point; and means for acoustically separating said front side from said rear side and acoustically coupling said front and rear sides of said transducer with said conduit.
Claim 3
Dependent Claim
37 words
The invention as defined in claim 1 wherein said means for acoustically separating and coupling comprises a chamber on one of said front and rear sides of said transducer including a port in communication with the conduit.
Claim 4
Dependent Claim
39 words
The invention as defined in claim 2 wherein said means for acoustically separating and coupling comprises a chamber on each of said front and rear sides of said transducer each chamber including a port in communication with the conduit.
Claim 5
Dependent Claim
16 words
The invention as defined in claim 3 wherein said ports are longitudinally spaced along the duct.
Claim 6
Dependent Claim
44 words
The invention as defined in claim 4 wherein the noise signal has a range of pulse train frequencies and the length of said spacing between the ports is less than the wavelength of the highest frequency pulse train to be transmitted through said conduit.
Claim 7
Dependent Claim
110 words
An active muffler for a motor vehicle exhaust conduit comprising: a sensor for generating a sensor signal representative of pressure pulses in the conduit; at least one transducer positioned for inducing pressure pulses in said conduit at least one location along said conduit; electronic control means for driving said transducer to produce cancellation signals of opposite phase to said generated signal at a predetermined point; wherein said transducer has a first side and an opposite second side adapted to generate pulses of opposite phase; and means for acoustically separating said first side from said second side and acoustically coupling said first and second sides of said transducer to said conduit.
Claim 8
Dependent Claim
110 words
An active muffler for a motor vehicle exhaust conduit comprising: a sensor for generating a sensor signal representative of pressure pulses in the conduit; at least one transducer positioned for inducing pressure pulses in said conduit at least one location along said conduit; electronic control means for driving said transducer to produce cancellation signals of opposite phase to said generated signal at a predetermined point; wherein said transducer has a first side and an opposite second side adapted to generate pulses of opposite phase; and means for acoustically separating said first side from said second side and acoustically coupling said first and second sides of said transducer to said conduit.
Claim 9
Dependent Claim
22 words
The invention as defined in claim 6 wherein said means for acoustically separating and coupling comprises a peripheral wall of said conduit.
Claim 10
Dependent Claim
55 words
The invention as defined in claim 6 wherein said means for acoustically separating and coupling comprise a first chamber enclosing said first side, a second chamber enclosing said second side, a first port in communication with said conduit and said first chamber and a second port in communication with said conduit and said second chamber.
References Cited (Backward Citations)
US1969704A
Cited
FR768373A
Cited
US4153815A
Cited
US4473906A
Cited
US4480333A
Cited
US4549631A
Cited
US4669122A
Cited
US4677677A
Cited
US4665549A
Cited
US4783817A
Cited
US4677676A
Cited
US4876722A
Cited
GB2191063A
Cited
US4736431A
Cited
US4805733A
Cited
US4815139A
Cited
US4837834A
Cited
US4878188A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-06-09 | 1995-12-09 | 1996-06-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-06-09 | 1999-12-09 | 2000-06-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-06-09 | 2003-12-09 | 2004-06-09 | $7700.00 | Window Closed / Lapsed |