US3708385A
Expired / Lapsed
US
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Sandwich panel construction
Assignee: Ethyl Corp
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Filing: 1971-06-21
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Granted: 1973-01-02
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Expires: 1991-06-21
Abstract
Abstract A SANDWICH PANEL CONSTRUCTION COMPRISING TWO INDEPENDENT OUTER LAYERS ATTACHED TO OPPOSITE SIDES OF A FOAMED METAL CORE, SAID CORE HAVING REINFORCING ELEMENTS THEREIN. COMPARED TO SANDWICH PANEL CONSTRUCTION HAVING NO REINFORCING ELEMENTS, THE PRESENT CONSTRUCTION HAS SUBSTANTIALLY IMPROVED RESISTANCE TO DEFORMATION.
Inventors
- 👤 P Immethun
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 03:51
CPC Classifications
B; B32; B32B; B32B15/00; B32B15/04; B32B15/046; E; E04; E04C; E04C2/00; E04C2/02; E04C2/26; E04C2/284; B32B15/18; B32B15/20; B32B17/00; B32B17/06; B32B17/066; B32B21/00; B32B21/04; B32B21/047; B32B27/00; B32B27/06; B32B27/065; B32B5/00; B32B5/18; E04C2/296; B32B2266/00; B32B2266/04; B32B2266/045; B32B2607/00; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24174; Y10T428/249921; Y10T428/249953; Y10T428/249967; Y10T428/24997
Claims Analysis
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References Cited (Backward Citations)
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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) | 1976-01-02 | 1976-07-03 | 1977-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-02 | 1980-07-03 | 1981-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-02 | 1984-07-03 | 1985-01-02 | $7700.00 | Window Closed / Lapsed |