Patent US2679181A successfully refreshed from Google Patents.
US2679181A
Expired / Lapsed
US
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Optical plummet
Assignee: Keuffel and Esser Co
•
Filing: 1949-07-28
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Granted: 1954-05-25
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Expires: 1969-07-28
Abstract
No abstract record available.
Inventors
- 👤 Carl W Keuffel
- 👤 Kissam Philip
- 👤 Allister L Baker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:27
CPC Classifications
G; G01; G01C; G01C1/00; G01C1/02; G12; G12B; G12B5/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1722209A
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US2485558A
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US928477A
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US940329A
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US973062A
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US1121309A
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US1028224A
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GB141850A
Cited
US1891641A
Cited
US2088262A
Cited
US2399014A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-05-24 | 1957-11-23 | 1958-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-05-24 | 1961-11-23 | 1962-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-05-24 | 1965-11-23 | 1966-05-25 | $7700.00 | Window Closed / Lapsed |