US4581284A
Expired / Lapsed
US
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Fiber compound material
Assignee: Dornier GmbH
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Filing: 1984-02-28
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Granted: 1986-04-08
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Expires: 2004-02-28
Abstract
Abstract A fiber compound material of individual layers of superposed fiber plies such as glass fiber prepregs which are joined together by a matrix of a resin and a hardener and act as a load carrying structure to absorb electromagnetic waves. Radar beam-absorbing fillers, for instance iron powder or soot, are included, in concentrations varying from the outside to the inside, in the individual plies of the fiber compound material.
Inventors
- 👤 Klaus Eggert
- 👤 Manfred Flemming
- 👤 Siegfried Roth
- 👤 Horst Schneider
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 00:57
CPC Classifications
H; H01; H01Q; H01Q17/00; H01Q17/002; Y; Y10; Y10S; Y10S428/00; Y10S428/902; Y10S428/919; Y10T; Y10T428/00; Y10T428/25; Y10T428/256; Y10T428/29; Y10T428/2982; Y10T442/00; Y10T442/60; Y10T442/659; Y10T442/67
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
73 words
In a fiber compound material composed of individual layers of superposed directed fiber plies which are joined by a matrix of a resin and a hardener, to act as a load carrying structure to absorb electromagnetic waves, the improvement which comprises the inclusion of at least one radar beam-absorbing filler (10) in the individual plies of the fiber compound material (7) in a concentration varying from the exterior side toward the interior side.
Claim 2
Dependent Claim
73 words
In a fiber compound material composed of individual layers of superposed directed fiber plies which are joined by a matrix of a resin and a hardener, to act as a load carrying structure to absorb electromagnetic waves, the improvement which comprises the inclusion of at least one radar beam-absorbing filler (10) in the individual plies of the fiber compound material (7) in a concentration varying from the exterior side toward the interior side.
Claim 3
Dependent Claim
31 words
A fiber compound material according to claim 1, in which the concentration of the filler (10) in the fiber compound material (7) increases from the exterior side toward the interior side.
Claim 4
Dependent Claim
36 words
A fiber compound material according to claim 1, in which the concentration of the filler (10) is higher in the central region of the fiber compound material (7) than at the interior side or exterior side.
Claim 5
Dependent Claim
64 words
A fiber compound material according to claim 1, in which the first ply (1) facing the incident electromagnetic waves (8) in the fiber compound material (7) is transparent or only slightly absorbing with respect to the electromagnetic waves (8), one or more of the following plies (2, 3, 4, or 5) is or are absorbing, and a subsequent ply (6) is reflecting or absorbent.
Claim 6
Dependent Claim
32 words
A fiber compound material according to claim 1, in which only minor reflection of the electromagnetic waves (8) occurs at the filler (10) and at the ply boundary surfaces of the compound.
Claim 7
Dependent Claim
40 words
A fiber compound material according to claim 1, in which at least the first ply (1) facing the electromagnetic waves (8) is transparent with respect thereto and the last ply (6) facing away from the waves (8) may be reflecting.
Claim 8
Dependent Claim
65 words
A fiber compound material according to claim 1, in which the first ply (1) is composed of an Aramid fiber of high transmission for the waves (8) or of special fibers, for instance quartz-glass fibers or of e, r, and d type fibers, and in that the last ply (6) is composed for instance of strongly reflecting metallized carbon fibers or of a metal foil.
Claim 9
Dependent Claim
29 words
A fiber compound material according to claim 1, in which the filler (10) is composed of several components, for instance graphite, pulverized carbon, ferrite, plastic-ceramic powder, or combinations thereof.
Claim 10
Dependent Claim
36 words
A fiber compound material according to claim 1, in which the filler (10) provides absorption for the electromagnetic waves (8) in the frequency range from about 2 to 60 GHz, preferably from 6 to 18 GHz.
Claim 11
Dependent Claim
39 words
A fiber compound material according to claim 1, in which the filler (10) can be excited by electrical and/or magnetic fields, for instance in the frequency bands between 2 and 60 GHz and thereby act in an absorbing manner.
Claim 12
Dependent Claim
32 words
A fiber compound material according to claim 1, in which the thickness (d 1 ) of the individual plies (1, 2, 3, 4, 5, 6) may vary with respect to each other.
Claim 13
Dependent Claim
18 words
A fiber compound material according to claim 1, in which the filler (10) is iron powder or soot.
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) | 1989-04-07 | 1989-10-07 | 1990-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-07 | 1993-10-07 | 1994-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-07 | 1997-10-07 | 1998-04-08 | $7700.00 | Window Closed / Lapsed |