US2420023A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Changeable lens and filter structure for copy cameras
Assignee: Sun Chemical Corp
•
Filing: 1943-04-29
•
Granted: 1947-05-06
•
Expires: 1963-04-29
Abstract
No abstract record available.
Inventors
- 👤 Stephen N Wekeman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:12
CPC Classifications
G; G03; G03B; G03B27/00; G03B27/32; G03B27/323
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US403476A
Cited
US547855A
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US666856A
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US1945481A
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US2117727A
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US2205179A
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US2236069A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1950-05-05 | 1950-11-04 | 1951-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1954-05-05 | 1954-11-04 | 1955-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1958-05-05 | 1958-11-04 | 1959-05-06 | $7700.00 | Window Closed / Lapsed |