US4390584A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for making a perforated rigid sheet material for sound absorbing composite cellular structure
Assignee: Airbus Group SAS
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Filing: 1981-01-21
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Granted: 1983-06-28
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Expires: 2001-01-21
Abstract
Abstract A composite structure for absorbing sound energy, comprising an outer porous layer covering a cellular layer, wherein said porous layer is made by forming a supple loose fabric from slivers each constituted by a plurality of relatively free mineral or synthetic fibres, substantially parallel to one another and shaping said supple fabric to its final form and rendering it rigid by means of a hardenable resin, while being subjected to pressure so as to become a thin, rigid lattice, with wide crossed lines, virtually uniformly smooth on at least its face opposite said cellular layer.
Inventors
- 👤 Guy Briens
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 03:02
CPC Classifications
B; B32; B32B; B32B3/00; B32B3/10; B32B3/12; B29; B29D; B29D24/00; B29D24/002; B29D24/005; B32B3/26; E; E04; E04B; E04B1/00; E04B1/62; E04B1/74; E04B1/82; E04B1/84; E04B1/86; G; G10; G10K; G10K11/00; G10K11/16; G10K11/172; B32B2262/00; B32B2262/10; B32B2262/106; B32B2305/00; B32B2305/38; B32B2307/00; B32B2307/10; E04B2001/742; E04B2001/748; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24149
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
174 words
A process for making a light, perforated, electrically conducting rigid sheet material suitable for use as the outer surface in a sound absorbing composite cellular structure comprising the steps of: providing a supple loosely woven fabric comprising a plurality of spaced parallel warp slivers and a plurality of spaced parallel transverse weft slivers interlaced therewith, said warp and weft slivers defining openings corresponding to a porosity greater than that desired in said rigid sheet, each of said slivers comprising a plurality of substantially straight parallel and unconnected fibers, and a pair of electrically conducting wires arranged respectively at the opposite margins of said sliver, the marginal wires in said slivers being electrically interconnected to form an electrically conducting grid; impregnating said fabric with a hardenable resin; applying controlled pressure to opposite faces of said impregnated fabric to create lateral expansion of said slivers sufficient to reduce the porosity to that desired in said sheet; and hardening said resin while maintaining said pressure, to produce a thin rigid electrically conducting sheet having said desired porosity.
Claim 2
Dependent Claim
174 words
A process for making a light, perforated, electrically conducting rigid sheet material suitable for use as the outer surface in a sound absorbing composite cellular structure comprising the steps of: providing a supple loosely woven fabric comprising a plurality of spaced parallel warp slivers and a plurality of spaced parallel transverse weft slivers interlaced therewith, said warp and weft slivers defining openings corresponding to a porosity greater than that desired in said rigid sheet, each of said slivers comprising a plurality of substantially straight parallel and unconnected fibers, and a pair of electrically conducting wires arranged respectively at the opposite margins of said sliver, the marginal wires in said slivers being electrically interconnected to form an electrically conducting grid; impregnating said fabric with a hardenable resin; applying controlled pressure to opposite faces of said impregnated fabric to create lateral expansion of said slivers sufficient to reduce the porosity to that desired in said sheet; and hardening said resin while maintaining said pressure, to produce a thin rigid electrically conducting sheet having said desired porosity.
Claim 3
Dependent Claim
27 words
The process of claim 1 wherein said pressure is applied by means which produces a substantially uniformly smooth surface on at least one face of said sheet.
Claim 4
Dependent Claim
25 words
The process of claim 1 wherein the porosity of said supple fabric is about 25-35% and the porosity of said rigid sheet is about 5-15%.
Claim 5
Dependent Claim
42 words
The process of claim 1 wherein, in said supple fabric, said warp slivers and said weft slivers are positioned at right angles to each other and define square openings whose sides have a length substantially equal to the width of said slivers.
Claim 6
Dependent Claim
11 words
The process of claim 1 wherein said fibers comprise carbon filaments.
Claim 7
Dependent Claim
30 words
The process of claim 5 wherein said warp and weft slivers in said supple fabric are about 2 mm wide and define square openings having sides about 2 mm long.
Claim 8
Dependent Claim
12 words
The process of claim 1 wherein said wires are made of bronze.
Claim 9
Dependent Claim
14 words
A perforated rigid sheet material made in accordance with the process of claim 1.
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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) | 1986-06-27 | 1986-12-27 | 1987-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-06-27 | 1990-12-27 | 1991-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-06-27 | 1994-12-27 | 1995-06-28 | $7700.00 | Window Closed / Lapsed |