Patent US2836101A successfully refreshed from Google Patents.
US2836101A
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US
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Optical elements
Assignee: DE SWART DEVELOPMENT Co
•
Filing: 1955-09-01
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Granted: 1958-05-27
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Expires: 1975-09-01
Abstract
No abstract record available.
Inventors
- 👤 Swart Jan De
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:52
CPC Classifications
G; G02; G02B; G02B3/00; G02B3/12; G02B3/14
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
GB191106534A
Cited
US1241738A
Cited
GB101260A
Cited
GB258325A
Cited
GB386721A
Cited
DE628774C
Cited
US2269905A
Cited
FR859877A
Cited
US2300251A
Cited
US2525921A
Cited
FR972995A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-05-26 | 1961-11-25 | 1962-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-05-26 | 1965-11-25 | 1966-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-05-26 | 1969-11-25 | 1970-05-27 | $7700.00 | Window Closed / Lapsed |