Patent US5740649A successfully refreshed from Google Patents.
US5740649A
Expired / Lapsed
US
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False ceiling
Assignee: Fraunhofer-Gesellschaft zur Förderung der Angewandten Forschung eV
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Filing: 1994-04-20
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Granted: 1998-04-21
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Expires: 2014-04-20
Abstract
Abstract A false ceiling for buildings designed to absorb acoustic waves has perfoed plates. One or several suspended plates (1, 6) are provided which are so hard that they cannot vibrate. The plates have a plurality of regularly or irregularly arranged holes (4, 7) with 0.2-3 mm diameter, the surface of the holes being less than 4% of the total surface. The air in the holes (4, 7) forms with the overlying cavities (11) a dampening active mass system of the foil absorber type.
Inventors
- 👤 Helmut Fuchs
- 👤 Dietmar Eckoldt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:42
CPC Classifications
E; E04; E04B; E04B1/00; E04B1/62; E04B1/74; E04B1/82; E04B1/84; E04B1/86; E04B9/00; E04B9/001; E04B2001/8263; E04B2001/8281; E04B2001/8423; E04B2001/8433; E04B2001/8442; E04B2001/8457; E04B2001/8476; E04B2001/848; E04B2001/8495
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
96 words
A false ceiling for rooms in buildings, which is designed to absorb soundwaves, comprising a perforated panel having sufficient construction so that sound waves in the building do not excite vibrations in the panel and having a multiplicity of holes having a diameter d of 0.2-3 mm and a hole to surface portion of less than 4%, and suspensions or subconstructions for attaching the perforated panel to the buildings, wherein air in said holes forming with air in hollow spaces situated thereabove a spring-mass system and wherein additional porous or fibrous damping material is not included.
Claim 2
Dependent Claim
96 words
A false ceiling for rooms in buildings, which is designed to absorb soundwaves, comprising a perforated panel having sufficient construction so that sound waves in the building do not excite vibrations in the panel and having a multiplicity of holes having a diameter d of 0.2-3 mm and a hole to surface portion of less than 4%, and suspensions or subconstructions for attaching the perforated panel to the buildings, wherein air in said holes forming with air in hollow spaces situated thereabove a spring-mass system and wherein additional porous or fibrous damping material is not included.
Claim 3
Dependent Claim
20 words
A false ceiling according to claim 1, wherein said holes have a hole to surface portion of less than 2%.
Claim 4
Dependent Claim
27 words
A false ceiling according to claim 1, wherein multiple panels are provided and said panels are disposed at an increasing distance D in relation to the ceiling.
Claim 5
Dependent Claim
17 words
A false ceiling according to claim 1, wherein said panels are composed of plastic, composites or metal.
Claim 6
Dependent Claim
18 words
A false ceiling according to claim 1, further comprising reinforcements in order to prevent sagging of said panels.
Claim 7
Dependent Claim
25 words
A false ceiling according to claim 1, wherein said panels are attached to a lateral frame and a plane rear wall designed as a module.
Claim 8
Dependent Claim
17 words
A false ceiling according to claim 1, wherein said hole to surface portion is 0.5 to 3%.
Claim 9
Dependent Claim
16 words
A false ceiling according to claim 2, wherein said holes have a diameter of 0.2-0.8 mm.
Claim 10
Dependent Claim
16 words
A false ceiling according to claim 2, wherein said holes have a diameter of 0.4-0.8 mm.
Claim 11
Dependent Claim
16 words
A false ceiling according to claim 7, wherein said holes have a diameter of 0.4-0.8 mm.
Claim 12
Dependent Claim
15 words
A false ceiling according to claim 1, wherein said perforated panel has a downward curvature.
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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) | 2001-04-20 | 2001-10-20 | 2002-04-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-04-20 | 2005-10-20 | 2006-04-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-04-20 | 2009-10-20 | 2010-04-21 | $7700.00 | Window Closed / Lapsed |