Patent US420934A successfully refreshed from Google Patents.
Patent US4644783A successfully refreshed from Google Patents.
US4644783A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Active control of acoustic instability in combustion chambers
Assignee: Noise Cancellation Technologies Inc
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Filing: 1985-07-15
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Granted: 1987-02-24
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Expires: 2005-07-15
Abstract
Abstract A combustion chamber subject to the build-up of acoustic vibrations may have the vibrations inhibited by an electrode system which can be modulated to produce anti-noise. Sound is sensed by a microphone which may be mounted remotely to produce a control signal coupled to a voltage generator feeding the electrode system.
Inventors
- 👤 John P. Roberts
- 👤 Maxime L. Vuillermoz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 17:45
CPC Classifications
F; F23; F23N; F23N5/00; F23N5/16
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
89 words
A combustion system comprising: at least one chamber for the combustion of gaseous or vaporized reactants, sensing means responsive to acoustic noise within said chamber to produce an electrical signal dependent on the amplitude, frequency and phase of said acoustic noise, control circuit means connected to said sensing means to produce an electrical control signal and transducer means to receive said control signal and to generate therefrom an acoustic signal in anti-phase with said acoustic noise, said transducer comprising an electrical arc struck between electrodes within the combustion chamber.
Claim 2
Dependent Claim
89 words
A combustion system comprising: at least one chamber for the combustion of gaseous or vaporized reactants, sensing means responsive to acoustic noise within said chamber to produce an electrical signal dependent on the amplitude, frequency and phase of said acoustic noise, control circuit means connected to said sensing means to produce an electrical control signal and transducer means to receive said control signal and to generate therefrom an acoustic signal in anti-phase with said acoustic noise, said transducer comprising an electrical arc struck between electrodes within the combustion chamber.
Claim 3
Dependent Claim
44 words
A combustion system as claimed in claim 1 incorporating means for sensing acoustic noise sensitive to predetermined frequencies and transducer means to generate anti-phase acoustic signals at further predetermined critical frequencies in response to control signals produced by said means for sensing acoustic noise.
Claim 4
Dependent Claim
42 words
A combustion system as claimed in claim 1 in which the combustion chamber is adapted to resonate at a predetermined frequency and the control circuit means and transducer means are adapted to produce an acoustic signal in anti-phase at said predetermined frequency.
Claim 5
Dependent Claim
28 words
A combustion system as claimed in claim 1 wherein the sensing means comprises a microphone together with conduct means for conducting the acoustic noise from its source thereto.
Claim 6
Dependent Claim
121 words
A combustion system comprising: at least one chamber for the combustion of gaseous or vaporized reactants, sensing means responsive to acoustic noise within said chamber to produce an electrical signal dependent on the amplitude, frequency and phase of said acoustic noise, control circuit means connected to said sensing means to produce an electrical control signal and transducer means to receive said control signal and to generate therefrom an acoustic signal in anti-phase with said acoustic noise, wherein the sensing means comprises a microphone together with conduit means for conducting the acoustic noise from its source thereto, wherein said means for conducting the acoustic noise comprises a tube having an open end adjacent to a region of generation of said acoustic noise.
Claim 7
Dependent Claim
121 words
A combustion system comprising: at least one chamber for the combustion of gaseous or vaporized reactants, sensing means responsive to acoustic noise within said chamber to produce an electrical signal dependent on the amplitude, frequency and phase of said acoustic noise, control circuit means connected to said sensing means to produce an electrical control signal and transducer means to receive said control signal and to generate therefrom an acoustic signal in anti-phase with said acoustic noise, wherein the sensing means comprises a microphone together with conduit means for conducting the acoustic noise from its source thereto, wherein said means for conducting the acoustic noise comprises a tube having an open end adjacent to a region of generation of said acoustic noise.
Claim 8
Dependent Claim
15 words
A combustion system as claimed in claim 5 wherein said tube extends beyond said microphone.
References Cited (Backward Citations)
US2951473A
Cited
US3601985A
Cited
US3602331A
Cited
US3620013A
Cited
US4025724A
Cited
GB1495015A
Cited
EP0040774A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-02-23 | 1990-08-25 | 1991-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-02-23 | 1994-08-25 | 1995-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-02-23 | 1998-08-25 | 1999-02-24 | $7700.00 | Window Closed / Lapsed |