US2936732A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of optical filters
Assignee: National Research Development Corp UK
•
Filing: 1955-07-15
•
Granted: 1960-05-17
•
Expires: 1975-07-15
Abstract
No abstract record available.
Inventors
- 👤 Ring James
- 👤 Henry J J Braddick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:26
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/20; G02B5/28; G02B5/285; C; C23; C23C; C23C14/00; C23C14/06; C23C14/22; C23C14/54; C23C14/542; C23C14/545; C23C14/547
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2166824A
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US2338234A
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US2439373A
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US2604528A
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US2666267A
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US2725487A
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US2629283A
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US2745773A
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US2726173A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-05-17 | 1963-11-16 | 1964-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-05-17 | 1967-11-16 | 1968-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-05-17 | 1971-11-16 | 1972-05-17 | $7700.00 | Window Closed / Lapsed |