US4301890A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sound-absorbing panel
Assignee: UNITED MCGILL Corp A CORP OF OH
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Filing: 1979-12-06
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Granted: 1981-11-24
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Expires: 1999-12-06
Abstract
Abstract A non-porous, sound-absorbing panel which can be readily cleaned and which is intended for use in high humidity, sanitary environments. The panel comprises two non-porous membranes or panels bonded to opposite sides of a honeycomb structure. At least one membrane is formed of sound-absorbing material with the membrane natural frequency, the membrane/honeycomb cavity natural frequency and the standing wave natural frequency of the honeycomb cavities being closely matched. In a preferred embodiment of the invention, the membrane comprises a polyurethane panel; while the honeycomb structure is formed from phenolic impregnated paper.
Inventors
- 👤 John M. Zalas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 09:35
CPC Classifications
B; B32; B32B; B32B3/00; B32B3/10; B32B3/12; B32B27/00; B32B27/06; B32B27/10; B32B27/40; B32B7/00; B32B7/04; B32B7/12; E; E04; E04B; E04B1/00; E04B1/62; E04B1/74; E04B1/82; E04B1/84; E04B1/86; E04C; E04C2/00; E04C2/30; E04C2/34; E04C2/36; B32B2307/00; B32B2307/10; B32B2307/102; B32B2375/00; B32B2607/00; E04B2001/742; E04B2001/747; E04B2001/748; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24149
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
76 words
A sound-absorbing panel comprising a honeycomb core having cavities formed therein and having bonded to its opposite sides non-porous panels, at least one of said panels which is subjected to acoustic vibrations being formed from a flexible membrane whose natural frequency of vibration is substantially the same as both the natural frequency of vibration of the membrane in combination with a cavity in the honeycomb core and the standing wave natural frequency of the cavity itself.
Claim 2
Dependent Claim
76 words
A sound-absorbing panel comprising a honeycomb core having cavities formed therein and having bonded to its opposite sides non-porous panels, at least one of said panels which is subjected to acoustic vibrations being formed from a flexible membrane whose natural frequency of vibration is substantially the same as both the natural frequency of vibration of the membrane in combination with a cavity in the honeycomb core and the standing wave natural frequency of the cavity itself.
Claim 3
Dependent Claim
52 words
The sound-absorbing panel of claim 1 wherein said flexible membrane comprises a film of polyurethane having a thickness of about 3.8×10 -5 meters, an elastic modulus of about 10 9 Newtons per square meter, a membrane density of about 1.24×10 3 kilograms per cubic meter, and a Poisson's ratio of about 0.4.
Claim 4
Dependent Claim
26 words
The sound-absorbing panel of claim 1 including a frame surrounding the periphery of the panel and bonded thereto so as to completely encapsulate said honeycomb core.
Claim 5
Dependent Claim
15 words
The sound-absorbing panel of claim 1 wherein one of said panels comprises a rigid backing.
Claim 6
Dependent Claim
53 words
A sound-absorbing panel comprising a honeycomb core having cavities formed therein and having bonded to its opposite sides non-porous panels, at least one of said panels which is subjected to acoustic vibrations being formed from a flexible membrane which absorbs acoustic vibrations from the hysteretic damping associated with flexing of the membrane itself.
Claim 7
Dependent Claim
53 words
A sound-absorbing panel comprising a honeycomb core having cavities formed therein and having bonded to its opposite sides non-porous panels, at least one of said panels which is subjected to acoustic vibrations being formed from a flexible membrane which absorbs acoustic vibrations from the hysteretic damping associated with flexing of the membrane itself.
Claim 8
Dependent Claim
42 words
The sound-absorbing panel of claim 5 wherein said one panel subjected to acoustic vibrations is formed from a plastic material having a density between 49 lb/ft 3 and 107 lb/ft 3 and an elastic modulus between 1000 psi and 25×10 5 psi.
Claim 9
Dependent Claim
18 words
The sound-absorbing panel of claim 6 wherein said plastic material has a loss tangent between 0.01 and 1.0.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-11-23 | 1985-05-25 | 1985-11-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-11-23 | 1989-05-25 | 1989-11-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-11-23 | 1993-05-25 | 1993-11-24 | $7700.00 | Window Closed / Lapsed |