US2987957A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light-sensitive exposure meters
Assignee: Daystrom Inc
•
Filing: 1957-03-18
•
Granted: 1961-06-13
•
Expires: 1977-03-18
Abstract
No abstract record available.
Inventors
- 👤 Lovegrove Henry Joseph
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:22
CPC Classifications
G; G01; G01J; G01J1/00; G01J1/42; G01J1/4209; G01J1/4214
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
GB335179A
Cited
US2472381A
Cited
US2501547A
Cited
US2542299A
Cited
US2651963A
Cited
US2745021A
Cited
US2897720A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-06-12 | 1964-12-12 | 1965-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-06-12 | 1968-12-12 | 1969-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-06-12 | 1972-12-12 | 1973-06-13 | $7700.00 | Window Closed / Lapsed |