US3537771A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Viewing system employing a fresnel lens
Assignee: Kollsman Instrument Corp
•
Filing: 1967-12-07
•
Granted: 1970-11-03
•
Expires: 1987-12-07
Abstract
No abstract record available.
Inventors
- 👤 Doric Trufanoff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:05
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/01; G02B27/0101; G02B3/00; G02B3/02; G02B3/08; G02B2027/0118
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1505878A
Cited
US2589014A
Cited
US2963942A
Cited
US3003387A
Cited
US3171879A
Cited
US2952180A
Cited
FR1344385A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-11-02 | 1974-05-04 | 1974-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-11-02 | 1978-05-04 | 1978-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-11-02 | 1982-05-04 | 1982-11-03 | $7700.00 | Window Closed / Lapsed |