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US3645833A
Expired / Lapsed
US
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Article and method of quasi-isotropic core filaments
Assignee: United States Department of the Army
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Filing: 1970-05-20
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Granted: 1972-02-29
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Expires: 1990-05-20
Abstract
Abstract A quasi-isotropic sandwich-type structural core filament winding made by a jig on which the fiber filaments are interwoven in a manner where each fiber lays on top of the preceding fiber so that when the winding is completed, a core is produced which consists of a series of tetrahedrons, half of which point upwards and half point downwards. The completed winding is then coated with an epoxy resin and cured, when removed from the jig. The jig may be of varied shapes so that the core is flat, cylindrical, air foil or other irregular shapes.
Inventors
- 👤 Irving E Figge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 00:42
CPC Classifications
E; E04; E04C; E04C2/00; E04C2/30; E04C2/32; B; B29; B29C; B29C53/00; B29C53/56; B29C53/58; B29C53/583; B29C53/587; B29C53/80; B29C53/82; B29C53/821; B29D; B29D24/00; B29D24/002; B29D24/005; B29D28/00; B29D28/005; E04C2/34; Y; Y10; Y10S; Y10S52/00; Y10S52/10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24058; Y10T428/24074; Y10T428/24149; Y10T428/24273; Y10T428/24298; Y10T428/29; Y10T428/2913; Y10T428/2933; Y10T428/2964; Y10T428/2967; Y10T428/2969; Y10T428/31504; Y10T428/31511
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
23 words
An article of manufacture as set forth in claim 1 wherein one-half of said tetrahedRons point upwards and the other half point downwards.
Claim 2
Dependent Claim
17 words
An article of manufacture as set forth in claim 1 wherein said core is a flat sheet.
Claim 3
Dependent Claim
15 words
An article of manufacture as set forth in claim 1 wherein said core is cylindrical.
Claim 4
Dependent Claim
17 words
An article of manufacture as set forth in claim 1 wherein said core is of airfoil shape.
Claim 5
Independent Claim
71 words
A method for making a structural core of longitudinal rows of tetrahedrons which comprises interweaving a plurality of rows of fibrous filaments upon each other over an offsetting jig whereby the filament rows mounted on top of each other are each offset from the preceding row to form biased surfaces that intersect to define a plurality of tetrahedrons, coating said interwoven filaments with a resin and curing the resin coated filaments.
Claim 6
Dependent Claim
16 words
A method as set forth in claim 6 wherein said filaments are composed of polyester fibers.
Claim 7
Dependent Claim
32 words
A method as set forth in claim 6 wherein the formed structural core is a cylinder and the jig is a circular mandrel having a sheet of offset tetrahedronal molds mounted thereon.
Claim 8
Dependent Claim
35 words
A method as set forth in claim 8 wherein said cylindrical structure is separated from the jig by removing the mandrel and extracting the sheet of tetrahedron molds from the inside of the structural core.
Claim 9
Dependent Claim
17 words
A method as set forth in claim 6 wherein said tetrahedrons formed by said method are symmetrical.
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) | 1975-02-28 | 1975-08-30 | 1976-02-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-28 | 1979-08-30 | 1980-02-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-28 | 1983-08-30 | 1984-02-29 | $7700.00 | Window Closed / Lapsed |