US3738448A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sound silencing method and apparatus
Assignee: RTX BBN Technologies Corp
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Filing: 1971-12-13
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Granted: 1973-06-12
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Expires: 1991-12-13
Abstract
Abstract This disclosure deals with a novel sound muffler for gas turbine engines and the like employing in the same duct section both longitudinal baffles and outwardly transversely extending sidebranch cavities.
Inventors
- 👤 I Ver
- 👤 U Kurze
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:06
CPC Classifications
G; G10; G10K; G10K11/00; G10K11/16; G10K11/172; F; F02; F02K; F02K1/00; F02K1/78; F02K1/82; F02K1/827; F16; F16L; F16L55/00; F16L55/02; F16L55/033; F16L55/0336
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
150 words
Apparatus for attenuating sound of relatively low and high frequencies accompanying the flow of a fluid medium, having, in combination, longitudinally extending duct means provided with an inlet for receiving the said fluid medium and an outlet for exiting the same, a plurality of substantially parallel longitudinal sound-absorbing baffle means extending along the duct means between the inlet and outlet and transversely spaced from one another between the sides of the duct means so as to provide a plurality of longitudinal fluid flow paths between the inlet and the outlet, the said duct means sides opening into transverse side branches extending transversely outward and longitudinally along the duct means and defining cavity means faced with flow resistive layer means and communicating through the same with the duct means, the cavities having terminating walls spaced from said layer means, and said duct means having transverse fluid flow paths between said sides.
Claim 2
Dependent Claim
150 words
Apparatus for attenuating sound of relatively low and high frequencies accompanying the flow of a fluid medium, having, in combination, longitudinally extending duct means provided with an inlet for receiving the said fluid medium and an outlet for exiting the same, a plurality of substantially parallel longitudinal sound-absorbing baffle means extending along the duct means between the inlet and outlet and transversely spaced from one another between the sides of the duct means so as to provide a plurality of longitudinal fluid flow paths between the inlet and the outlet, the said duct means sides opening into transverse side branches extending transversely outward and longitudinally along the duct means and defining cavity means faced with flow resistive layer means and communicating through the same with the duct means, the cavities having terminating walls spaced from said layer means, and said duct means having transverse fluid flow paths between said sides.
Claim 3
Dependent Claim
40 words
Apparatus as claimed in claim 1 and in which the flow resistive layer means and the baffle means are substantially co-extensive and the said cavity means contain sound-impervious septum means for preventing low-frequency sound propagation longitudinally along the cavity means.
Claim 4
Dependent Claim
38 words
Apparatus as claimed in claim 1 and in which the transverse spacing between the baffle means and the longitudinal length of said baffle means are respectively small and large compared to the wave lengths of said sound frequencies.
Claim 5
Dependent Claim
28 words
Apparatus as claimed in claim 1 and in which the said substantially parallel baffle means are disposed substantially parallel to the said side branch flow resistive layer means.
Claim 6
Dependent Claim
28 words
Apparatus as claimed in claim 1 and in which the said substantially parallel baffle means are disposed substantially perpendicular to the said side branch flow resistive layer means.
Claim 7
Independent Claim
79 words
A method of attenuating sound of relatively low and high frequencies accompanying the flow of a fluid medium, that comprises flowing the sound-carrying fluid medium longitudinally along a predetermined duct region, transversely dividing said region into a plurality of longitudinally extending sub-regions, absorbing the high frequencies along a plurality of sides of each of said sub-regions, and forcing the low frequencies to travel transversely across said region and transversely outwardly therefrom while resonantly absorbing the same during such travel.
Claim 8
Independent Claim
79 words
A method of attenuating sound of relatively low and high frequencies accompanying the flow of a fluid medium, that comprises flowing the sound-carrying fluid medium longitudinally along a predetermined duct region, transversely dividing said region into a plurality of longitudinally extending sub-regions, absorbing the high frequencies along a plurality of sides of each of said sub-regions, and forcing the low frequencies to travel transversely across said region and transversely outwardly therefrom while resonantly absorbing the same during such travel.
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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) | 1976-06-11 | 1976-12-11 | 1977-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-11 | 1980-12-11 | 1981-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-11 | 1984-12-11 | 1985-06-12 | $7700.00 | Window Closed / Lapsed |