Patent US2437931A successfully refreshed from Google Patents.
US2437931A
Expired / Lapsed
US
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Process of indurating boards of fibrous materials
Assignee: Individual
•
Filing: 1944-11-22
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Granted: 1948-03-16
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Expires: 1964-11-22
Abstract
No abstract record available.
Inventors
- 👤 Bergstrom Hilding Olof Vidar
- 👤 Heijmer Gustaf Bristol
- 👤 Trobeck Karl Gustaf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:21
CPC Classifications
C; C08; C08L; C08L91/00; D; D21; D21J; D21J1/00; D21J1/08
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) | 1951-03-16 | 1951-09-15 | 1952-03-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-03-16 | 1955-09-15 | 1956-03-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-03-16 | 1959-09-15 | 1960-03-16 | $7700.00 | Window Closed / Lapsed |