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US4149612A
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US
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Noise reducing resonator apparatus
Assignee: Airbus Defence and Space GmbH
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Filing: 1977-07-05
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Granted: 1979-04-17
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Expires: 1997-07-05
Abstract
Abstract The present noise reducing apparatus includes resonators which have a small and variable volume as well as a high admittance. For this purpose the resonators constitute vibrating systems having at least one volume wherein the pressure is reduced below atmospheric pressure to provide a reduced volume stiffness. The volume is confined by wall elements having a very small or a negative spring rate under reduced pressure inside said volume.
Inventors
- 👤 Oskar Bschorr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:57
CPC Classifications
G; G10; G10K; G10K11/00; G10K11/16; G10K11/172
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
78 words
A noise reducing apparatus comprising resonator means having a variable, sealed volume and wall means defining said variable, sealed volume, a reduced pressure confined in said volume, said reduced pressure being below atmospheric pressure, said wall means having a spring rate ranging from small positive values to negative values in response to said reduced pressure inside said sealed volume, whereby a high admittance is achieved, and wherein said sealed volume confining wall means comprise so-called Belleville spring means.
Claim 2
Dependent Claim
78 words
A noise reducing apparatus comprising resonator means having a variable, sealed volume and wall means defining said variable, sealed volume, a reduced pressure confined in said volume, said reduced pressure being below atmospheric pressure, said wall means having a spring rate ranging from small positive values to negative values in response to said reduced pressure inside said sealed volume, whereby a high admittance is achieved, and wherein said sealed volume confining wall means comprise so-called Belleville spring means.
Claim 3
Dependent Claim
38 words
The apparatus of claim 1, wherein said volume confining Belleville spring means are constructed to convey shearing forces, said resonator means comprising an inner volume of prismatic shape and of an oval cross-section confined by said wall means.
Claim 4
Dependent Claim
40 words
The apparatus of claim 1, wherein said Belleville spring means comprise spring members of which at least two spring members are arranged adjacent to each other, said apparatus further comprising junction means operatively connecting adjacent spring members to each other.
Claim 5
Dependent Claim
56 words
The apparatus of claim 1, wherein said resonator means comprise a plurality of individual resonator members tuned to different frequencies and arranged in sets at the location where noise is to be reduced, whereby the noise reduction is accomplished over a wide band of frequencies as determined by the total frequency range of said resonator members.
Claim 6
Dependent Claim
15 words
The apparatus of claim 4, wherein the individual resonator members are arranged in a row.
Claim 7
Dependent Claim
22 words
The apparatus of claim 6, wherein the individual resonator members are arranged to cover a surface to form a noise reducing curtain.
Claim 8
Dependent Claim
15 words
The apparatus of claim 7, further comprising sound absorbing material surrounding said individual resonator members.
Claim 9
Dependent Claim
60 words
The apparatus of claim 1, wherein said resonator means comprise a plurality of individual resonator members all of which are tuned to the same frequency, said resonator members being spaced from each other at intervals corresponding in length to the wave length of the noise to be reduced whereby the directional distribution of the noise or sound may be varied.
Claim 10
Dependent Claim
82 words
A noise reducing apparatus comprising resonator means having a variable, sealed volume and wall means defining said variable, sealed volume, a reduced pressure confined in said volume, said reduced pressure being below atmospheric pressure, said wall means having a spring rate ranging from small positive values to negative values in response to said reduced pressure inside said sealed volume, whereby a high admittance is achieved, and wherein said sealed volume confining wall means comprise a plurality of Euler type buckling strip means.
Claim 11
Dependent Claim
82 words
A noise reducing apparatus comprising resonator means having a variable, sealed volume and wall means defining said variable, sealed volume, a reduced pressure confined in said volume, said reduced pressure being below atmospheric pressure, said wall means having a spring rate ranging from small positive values to negative values in response to said reduced pressure inside said sealed volume, whereby a high admittance is achieved, and wherein said sealed volume confining wall means comprise a plurality of Euler type buckling strip means.
Claim 12
Dependent Claim
39 words
The apparatus of claim 9, wherein said volume confining Euler type buckling strips are constructed to convey shearing forces, said resonator means comprising an inner volume of prismatic shape and of an oval cross-section confined by said wall means.
Claim 13
Dependent Claim
56 words
The apparatus of claim 9, wherein said resonator means comprise a plurality of individual resonator members tuned to different frequencies and arranged in sets at the location where noise is to be reduced, whereby the noise reduction is accomplished over a wide band of frequencies as determined by the total frequency range of said resonator members.
Claim 14
Dependent Claim
15 words
The apparatus of claim 11, wherein the individual resonator members are arranged in a row.
Claim 15
Dependent Claim
22 words
The apparatus of claim 11, wherein the individual resonator members are arranged to cover a surface to form a noise reducing curtain.
Claim 16
Dependent Claim
15 words
The apparatus of claim 11, further comprising sound absorbing material surrounding said individual resonator members.
Claim 17
Dependent Claim
60 words
The apparatus of claim 9, wherein said resonator means comprise a plurality of individual resonator members all of which are tuned to the same frequency, said resonator members being spaced from each other at intervals corresponding in length to the wave length of the noise to be reduced whereby the directional distribution of the noise or sound may be varied.
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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) | 1982-04-16 | 1982-10-16 | 1983-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-04-16 | 1986-10-16 | 1987-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-04-16 | 1990-10-16 | 1991-04-17 | $7700.00 | Window Closed / Lapsed |