Patent US4123825A successfully refreshed from Google Patents.
Patent US3597891A successfully refreshed from Google Patents.
US3597891A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Interior absorptive panel
Assignee: McDonnell Douglas Corp
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Filing: 1969-10-02
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Granted: 1971-08-10
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Expires: 1989-10-02
Abstract
Abstract Perforated blankets of fiberglass material are fitted on each side of a double-dimpled core material having perforations therethrough. A backing sheet and face sheet of panel material is bonded to the outer surfaces of the dimples. Sound passing through the face sheet material enters the panel and is dissipated in the fiberglass material in the core. The panel has no resonant frequency and has a high coefficient of absorption over a broad band of frequencies in the speech frequency range.
Inventors
- 👤 Flyodd A Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:25
CPC Classifications
E; E04; E04B; E04B1/00; E04B1/62; E04B1/74; E04B1/82; E04B1/84; E04B1/8409; B; B62; B62D; B62D29/00; B62D29/04; B64; B64C; B64C1/00; B64C1/40; E04C; E04C2/00; E04C2/30; E04C2/34; E04C2/3405; E04B2001/8423; E04B2001/8428; E04B2001/8457; E04B2001/8461; E04B2001/8471; E04B2001/8476; E04C2002/3411; E04C2002/3427; E04C2002/3433; E04C2002/3438; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24628; Y10T428/24661
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
159 words
A panel having a high coefficient of absorption over a broad band of frequencies comprising: an inner double-dimple core having alternate upwardly and downwardly extending indentations terminating in nodes on both sides with truncated conical walls interconnecting opposing nodes, elongated apertures in said truncated conical walls, said core defining a plane between said nodes, said nodes having flat surfaces with apertures therein, said walls extending in the same direction forming a saddle in said plane, a first layer of acoustic material having apertures therein and of a thickness substantially equal to the space between said saddle and said nodes, said layer being positioned over said core with apertures in said layer being adapted to fit over said indentations and thereby exposing said nodes, a second layer of acoustic material similar to said first layer and applied to the other side of said core, said indentations defining unfilled cavities within said truncated walls between said nodes and said core plane.
Claim 2
Dependent Claim
159 words
A panel having a high coefficient of absorption over a broad band of frequencies comprising: an inner double-dimple core having alternate upwardly and downwardly extending indentations terminating in nodes on both sides with truncated conical walls interconnecting opposing nodes, elongated apertures in said truncated conical walls, said core defining a plane between said nodes, said nodes having flat surfaces with apertures therein, said walls extending in the same direction forming a saddle in said plane, a first layer of acoustic material having apertures therein and of a thickness substantially equal to the space between said saddle and said nodes, said layer being positioned over said core with apertures in said layer being adapted to fit over said indentations and thereby exposing said nodes, a second layer of acoustic material similar to said first layer and applied to the other side of said core, said indentations defining unfilled cavities within said truncated walls between said nodes and said core plane.
Claim 3
Dependent Claim
55 words
A panel as set forth in claim 1 wherein said first layer loosely fills space between said saddle and said nodes for absorbing high frequency components of noise in the speech frequency range, and said second layer is more dense closely packed to absorb the lower frequency components of noise in the speech frequency range.
Claim 4
Dependent Claim
22 words
A panel as set forth in claim 1, and an open weave material affixed to said nodes to retain said layers thereover.
References Cited (Backward Citations)
US1961374A
Cited
GB424620A
Cited
FR1024889A
Cited
US3013641A
Cited
DE1180504B
Cited
US3231454A
Cited
US3430405A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-08-09 | 1975-02-08 | 1975-08-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-09 | 1979-02-08 | 1979-08-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-09 | 1983-02-08 | 1983-08-10 | $7700.00 | Window Closed / Lapsed |