US2741155A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable magnification optical systems
Assignee: W Watson and Sons Ltd
•
Filing: 1952-09-10
•
Granted: 1956-04-10
•
Expires: 1972-09-10
Abstract
No abstract record available.
Inventors
- 👤 Hopkins Harold Horace
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:12
CPC Classifications
G; G02; G02B; G02B15/00; G02B15/14; G02B15/143; G02B15/1431; G02B15/143105
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
GB440397A
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US2130347A
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US2235364A
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US2159394A
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US2165341A
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GB536706A
Cited
US2353565A
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US2454686A
Cited
US2496069A
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US2514239A
Cited
US2515104A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-04-10 | 1959-10-10 | 1960-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-04-10 | 1963-10-10 | 1964-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-04-10 | 1967-10-10 | 1968-04-10 | $7700.00 | Window Closed / Lapsed |