US4439774A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Antenna reflector with triangulated cellular back structure
Assignee: ITT Inc
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Filing: 1980-12-23
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Granted: 1984-03-27
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Expires: 2000-12-23
Abstract
Abstract A triangulated rib structure including first, second and third sets of "egg-crate" interlocking ribs. The first set is oriented in a predetermined direction such as the horizontal or vertical coordinate, and the second and third sets are oriented at angles of first and second senses, respectively, thereby forming triangulated spaces which are inherently rigid. The individual ribs have edges falling adjacent to a desired overall reflector surface, each of these being precut before assembly to provide the required line of curvature as a function of the individual ribs placement. Each rib is itself a planar piece, and the "egg-crate" interlocking slot joints may be stabilized with one or more seam welds. A conductive mesh forming the actual contoured reflector surface is conformed to the desired contoured shape and affixed as by tack-welding to the edges of the ribs adjacent the contoured surface.
Inventors
- 👤 Robert E. Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 17:49
CPC Classifications
H; H01; H01Q; H01Q15/00; H01Q15/14; H01Q15/16; H01Q15/168
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
195 words
A structure for a radar reflector in which an accurately contoured reflection surface is provided, comprising: a first set of elongated, parallel, spaced structural ribs each having a first edge adjacent to and shaped to said contoured reflection surface and each having a first dimension generally normal to said reflection surface, said first dimension being greater than a second dimension which is the thickness of said ribs in a direction substantially tangent to said contoured reflection surface; second and third sets of elongated, parallel, spaced structural ribs intersecting the ribs of said first set generally diagonally and meshing therewith by means of interlocking slots in said ribs at the points of intersection, said second and third rib sets intersecting said first set ribs in diagonally opposite senses such that a plurality of generally triangular included spaces are generated; and a relatively thin conductive surface affixed at a plurality of points to said rib edges thereby forming said reflection surface, said ribs of said first, second and third sets being shaped along their first edges according to their respective positions and orientations within said structure to make said first edges congruent with said contoured reflection surface.
Claim 2
Dependent Claim
195 words
A structure for a radar reflector in which an accurately contoured reflection surface is provided, comprising: a first set of elongated, parallel, spaced structural ribs each having a first edge adjacent to and shaped to said contoured reflection surface and each having a first dimension generally normal to said reflection surface, said first dimension being greater than a second dimension which is the thickness of said ribs in a direction substantially tangent to said contoured reflection surface; second and third sets of elongated, parallel, spaced structural ribs intersecting the ribs of said first set generally diagonally and meshing therewith by means of interlocking slots in said ribs at the points of intersection, said second and third rib sets intersecting said first set ribs in diagonally opposite senses such that a plurality of generally triangular included spaces are generated; and a relatively thin conductive surface affixed at a plurality of points to said rib edges thereby forming said reflection surface, said ribs of said first, second and third sets being shaped along their first edges according to their respective positions and orientations within said structure to make said first edges congruent with said contoured reflection surface.
Claim 3
Dependent Claim
33 words
Apparatus according to claim 1 in which said first dimension of said ribs is at least half of the average dimension of the sides of said triangular space lying along said contoured surface.
Claim 4
Dependent Claim
35 words
Apparatus according to claim 1 in which an outside rib of said first set is of greater thickness as compared to the other ribs of said first set, to provide a suitably rigid mounting surface.
Claim 5
Dependent Claim
75 words
Apparatus according to claim 1 in which said ribs are all of substantially the same first dimension and said interlocking slots are through substantially two-thirds of the first dimension of said ribs of said second and third sets and said slots are two in numbers and extend one from each edge of the ribs of said first set to a depth of substantially one-third of said first dimension of said ribs of said first set.
Claim 6
Dependent Claim
22 words
Apparatus according to claim 2 in which said first dimensions of said first, second and third rib sets are all substantially equal.
Claim 7
Dependent Claim
33 words
Apparatus according to claim 5 in which said first dimension of said ribs is at least half of the average dimension of the sides of said triangular space lying along said contoured surface.
Claim 8
Dependent Claim
27 words
Apparatus according to claim 6 in which said first dimensions of said ribs are substantially the same as said triangular space sides lying along said contoured surface.
References Cited (Backward Citations)
US2423648A
Cited
US3964071A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-03-27 | 1987-09-26 | 1988-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-27 | 1991-09-26 | 1992-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-27 | 1995-09-26 | 1996-03-27 | $7700.00 | Window Closed / Lapsed |