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Patent US3398481A successfully refreshed from Google Patents.
US3398481A
Expired / Lapsed
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Method and apparatus for controlling carbon dioxide concentrations in greenhouses
Assignee: National Research Development Corp UK
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Filing: 1966-05-20
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Granted: 1968-08-27
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Expires: 1986-05-20
Abstract
No abstract record available.
Inventors
- 👤 John V Lake
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 20:58
CPC Classifications
A; A01; A01G; A01G9/00; A01G9/18; A01G7/00; A01G7/02
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2686754A
Cited
US2996429A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1971-08-27 | 1972-02-26 | 1972-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-08-27 | 1976-02-26 | 1976-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-08-27 | 1980-02-26 | 1980-08-27 | $7700.00 | Window Closed / Lapsed |