Patent US4035536A successfully refreshed from Google Patents.
US4035536A
Expired / Lapsed
US
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Sandwich panel core
Assignee: McDonnell Douglas Corp
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Filing: 1975-03-03
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Granted: 1977-07-12
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Expires: 1995-03-03
Abstract
Abstract A core having a repetitive pattern for ribbing comprising triangles and hexagons where each side of any given hexagon is extended pinwheel fashion toward the appropriate side extensions of each of the six adjoining hexagons, all of the hexagons having sides extending to form pinwheels having the same sense, i.e., clockwise or counterclockwise. The triangles are defined by the extensions and are located between the hexagons. Panels using this core are stiff about all axes and do not have an angle of inherent weakness. The core may be stamped, rolled or vacuum-formed out of many materials including paper, cardboard, sheets of various metals and reinforced or thermosetting plastic.
Inventors
- 👤 Hadley F. Morrison
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 13:42
CPC Classifications
E; E04; E04C; E04C2/00; E04C2/30; E04C2/34; E04C2/3405; B; B32; B32B; B32B3/00; B32B3/10; B32B3/12; E04C2002/3411; E04C2002/3422; F; F01; F01N; F01N2330/00; F01N2330/30; F01N2330/34; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/1234; Y10T428/24; Y10T428/24149; Y10T428/24165; Y10T428/24628; Y10T428/24661; Y10T428/24669; Y10T428/24678
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
65 words
A flat sandwich panel core deformed from a single flat sheet of material, said core having channel-shaped ribs in a repetitive pattern of triangles and hexagons, each hexagon having six equilateral triangles positioned therearound, and wherein each side of the hexagon is extended to a side of another hexagon, forming a triangle leg inbetween, said triangle leg being longer than the side of the hexagon.
Claim 2
Dependent Claim
65 words
A flat sandwich panel core deformed from a single flat sheet of material, said core having channel-shaped ribs in a repetitive pattern of triangles and hexagons, each hexagon having six equilateral triangles positioned therearound, and wherein each side of the hexagon is extended to a side of another hexagon, forming a triangle leg inbetween, said triangle leg being longer than the side of the hexagon.
Claim 3
Dependent Claim
22 words
A sandwich panel core as in claim 1 wherein said triangles are defined by extensions of and are located between said hexagons.
Claim 4
Dependent Claim
20 words
A sandwich panel core as in claim 1 wherein each side of said hexagon is extended in one direction only.
Claim 5
Dependent Claim
26 words
A sandwich panel core as in claim 1 wherein triangular portions of material are removed to provide a greater weight to strength ratio of said core.
Claim 6
Dependent Claim
28 words
A sandwich panel core as in claim 1 wherein triangular and hexagonal portions of material are removed to provide a greater weight to strength ratio of said core.
Claim 7
Dependent Claim
30 words
A sandwich panel core as in claim 1 wherein the sides of each triangle terminate at each end with a side of a hexagon and becomes an aligned extension thereof.
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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) | 1980-07-11 | 1981-01-10 | 1981-07-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-11 | 1985-01-10 | 1985-07-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-11 | 1989-01-10 | 1989-07-12 | $7700.00 | Window Closed / Lapsed |