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Patent US2456643A successfully refreshed from Google Patents.
US2456643A
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Lightweight material and its preparation
Assignee: F E Schundler & Co Inc
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Filing: 1943-06-12
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Granted: 1948-12-21
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Expires: 1963-06-12
Abstract
No abstract record available.
Inventors
- 👤 Napier Henry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 10:34
CPC Classifications
C; C04; C04B; C04B28/00; C04B28/02; C04B28/04
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1226779A
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US1520893A
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US1574363A
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US1770767A
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US1755502A
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US2023511A
Cited
US1932971A
Cited
GB501024A
Cited
US2156311A
Cited
US2339041A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1951-12-21 | 1952-06-21 | 1952-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-12-21 | 1956-06-21 | 1956-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-12-21 | 1960-06-21 | 1960-12-21 | $7700.00 | Window Closed / Lapsed |