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US2430253A
Expired / Lapsed
US
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Photoelectric exposure and contrast control for enlargers
Assignee: Simmon Brothers Inc
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Filing: 1946-06-21
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Granted: 1947-11-04
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Expires: 1966-06-21
Abstract
No abstract record available.
Inventors
- 👤 Simmon Alfred
- 👤 Louis L Weisglass
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:35
CPC Classifications
G; G01; G01J; G01J1/00; G01J1/42; G01J1/4209; G01J1/4219
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2183217A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1950-11-03 | 1951-05-05 | 1951-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1954-11-03 | 1955-05-05 | 1955-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1958-11-03 | 1959-05-05 | 1959-11-04 | $7700.00 | Window Closed / Lapsed |