US3520357A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Open core sandwich-structure
Assignee: Boeing North American Inc
•
Filing: 1967-07-03
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Granted: 1970-07-14
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Expires: 1987-07-03
Abstract
No abstract record available.
Inventors
- 👤 Ralph C Bruner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:43
CPC Classifications
F; F28; F28F; F28F3/00; F28F3/02; E; E04; E04C; E04C2/00; E04C2/30; E04C2/34; E04C2/3405; F28F3/12; E04C2002/3411; E04C2002/3427; E04C2002/3472; Y; Y10; Y10S; Y10S165/00; Y10S165/355; Y10S165/356; Y10S165/393
Claims Analysis
Total Claims: 0
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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) | 1973-07-13 | 1974-01-12 | 1974-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-07-13 | 1978-01-12 | 1978-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-07-13 | 1982-01-12 | 1982-07-14 | $7700.00 | Window Closed / Lapsed |