US4235303A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Combination bulk absorber-honeycomb acoustic panels
Assignee: Boeing Co
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Filing: 1978-11-20
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Granted: 1980-11-25
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Expires: 1998-11-20
Abstract
Abstract Combination bulk absorber-honeycomb acoustic panels particularly adapted for use in the inlet and fan air duct of a fan jet engine are disclosed. Each panel comprises a broadband noise-suppressing bulk absorber layer mounted between a back sheet and a perforated septum; and, a narrow band noise-suppressing honeycomb layer mounted between the septum and a perforated face sheet. The panels are mounted in an engine such that the perforated face sheet interfaces with airflow in the inlet or the fan air duct, as the case may be, whereby the face sheet, honeycomb layer and septum protect the bulk absorber from deterioration by isolating the high speed inlet and fan air duct airflows from the bulk absorber layer.
Inventors
- 👤 Louis G. Dhoore
- 👤 William H. Schultz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:17
CPC Classifications
B; B64; B64D; B64D33/00; B64D33/02; F; F02; F02C; F02C7/00; F02C7/04; F02C7/045; F04; F04D; F04D29/00; F04D29/66; F04D29/661; F04D29/663; B64D2033/0206; F05; F05D; F05D2250/00; F05D2250/20; F05D2250/28; F05D2250/283; Y; Y02; Y02T; Y02T50/00; Y02T50/60; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24149
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
49 words
A combination bulk absorber-honeycomb acoustic panel comprising: an impervious back sheet; a perforated septum sheet; a broadband noise-suppressing bulk absorber layer mounted between said back sheet and said septum sheet; a perforated face sheet; and a rigid noise-suppressing honeycomb layer mounted between said septum sheet and said face sheet.
Claim 2
Dependent Claim
49 words
A combination bulk absorber-honeycomb acoustic panel comprising: an impervious back sheet; a perforated septum sheet; a broadband noise-suppressing bulk absorber layer mounted between said back sheet and said septum sheet; a perforated face sheet; and a rigid noise-suppressing honeycomb layer mounted between said septum sheet and said face sheet.
Claim 3
Dependent Claim
26 words
The acoustic panel claimed in claim 1 wherein the thickness of said honeycomb layer lies in the range between about 0.125 inch and about 0.75 inch.
Claim 4
Dependent Claim
26 words
The acoustic panel claimed in claim 2 wherein the percent open area of said perforated septum lies in the range between about 10% and about 20%.
Claim 5
Dependent Claim
40 words
The acoustic panel claimed in claim 3 wherein the density of said bulk absorber layer lies in the range between about 6 and 9 pounds per cubic foot, and the thickness of said bulk absorber is greater than 0.45 inch.
Claim 6
Dependent Claim
21 words
The acoustic panel claimed in claim 4 wherein the percent open area of said perforated face sheet is greater than 19%.
Claim 7
Dependent Claim
26 words
The acoustic panel claimed in claim 1 wherein the percent open area of said perforated septum lies in the range between about 10% and about 20%.
Claim 8
Dependent Claim
40 words
The acoustic panel claimed in claim 6 wherein the density of said bulk absorber layer lies in the range between about 6 and 9 pounds per cubic foot, and the thickness of said bulk absorber is greater than 0.45 inch.
Claim 9
Dependent Claim
21 words
The acoustic panel claimed in claim 7 wherein the percent open area of said perforated face sheet is greater than 19%.
Claim 10
Dependent Claim
40 words
The acoustic panel claimed in claim 1 wherein the density of said bulk absorber layer lies in the range between about 6 and 9 pounds per cubic foot, and the thickness of said bulk absorber is greater than 0.45 inch.
Claim 11
Dependent Claim
21 words
The acoustic panel claimed in claim 9 wherein the percent open area of said perforated face sheet is greater than 19%.
Claim 12
Dependent Claim
21 words
The acoustic panel claimed in claim 1 wherein the percent open area of said perforated face sheet is greater than 19%.
Claim 13
Dependent Claim
158 words
In a fan jet engine having a fan and ducting for directing air past said fan, said ducting defined by an inlet wall located forward of said fan and fan air duct outer and inner walls located aft of said fan, the improvement comprising: combination bulk absorber-honeycomb acoustic panels forming at least a portion of, said inlet wall and/or said fan air duct outer and inner walls for attenuating noise produced by said jet engine including buzz saw noise, forward radiated fan noise and aft radiated fan noise, each of said combination bulk absorber-honeycomb acoustic panels comprising: an impervious back sheet; a perforated septum sheet; a broadband noise-suppressing bulk absorber layer mounted between said back sheet and said septum sheet; a perforated face sheet; and a rigid noise-suppressing honeycomb layer mounted between said septum sheet and said face sheet, said face sheet being substantially flush with said inlet wall and said fan air duct outer and inner walls.
Claim 14
Dependent Claim
158 words
In a fan jet engine having a fan and ducting for directing air past said fan, said ducting defined by an inlet wall located forward of said fan and fan air duct outer and inner walls located aft of said fan, the improvement comprising: combination bulk absorber-honeycomb acoustic panels forming at least a portion of, said inlet wall and/or said fan air duct outer and inner walls for attenuating noise produced by said jet engine including buzz saw noise, forward radiated fan noise and aft radiated fan noise, each of said combination bulk absorber-honeycomb acoustic panels comprising: an impervious back sheet; a perforated septum sheet; a broadband noise-suppressing bulk absorber layer mounted between said back sheet and said septum sheet; a perforated face sheet; and a rigid noise-suppressing honeycomb layer mounted between said septum sheet and said face sheet, said face sheet being substantially flush with said inlet wall and said fan air duct outer and inner walls.
Claim 15
Dependent Claim
25 words
The improvement claimed in claim 12 wherein the thickness of said honeycomb layer lies in the range between about 0.125 inch and about 0.75 inch.
Claim 16
Dependent Claim
25 words
The improvement claimed in claim 13 wherein the percent open area of said perforated septum lies in the range between about 10% to about 20%.
Claim 17
Dependent Claim
39 words
The improvement claimed in claim 14 wherein the density of said bulk absorber layer lies in the range between about 6 and 9 pounds per cubic foot, and the thickness of said bulk absorber is greater than 0.45 inch.
Claim 18
Dependent Claim
19 words
The improvement claimed in claim 15 wherein the open area of said perforated face sheet is greater than 19%.
Claim 19
Dependent Claim
25 words
The improvement claimed in claim 12 wherein the percent open area of said perforated septum lies in the range between about 10% to about 20%.
Claim 20
Dependent Claim
39 words
The improvement claimed in claim 17 wherein the density of said bulk absorber layer lies in the range between about 6 and 9 pounds per cubic foot, and the thickness of said bulk absorber is greater than 0.45 inch.
Claim 21
Dependent Claim
19 words
The improvement claimed in claim 18 wherein the open area of said perforated face sheet is greater than 19%.
Claim 22
Dependent Claim
40 words
The improvement claimed in claim 12 wherein the density of said bulk absorber layer lies in the range of between about 6 and 9 pounds per cubic foot, and the thickness of said bulk absorber is greater than 0.45 inch.
Claim 23
Dependent Claim
19 words
The improvement claimed in claim 20 wherein the open area of said perforated face sheet is greater than 19%.
Claim 24
Dependent Claim
19 words
The improvement claimed in claim 12 wherein the open area of said perforated face sheet is greater than 19%.
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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) | 1983-11-25 | 1984-05-26 | 1984-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-25 | 1988-05-26 | 1988-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-25 | 1992-05-26 | 1992-11-25 | $7700.00 | Window Closed / Lapsed |