Patent US2520899A successfully refreshed from Google Patents.
US2520899A
Expired / Lapsed
US
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Electrical instrument
Assignee: Productive Inventions Inc
•
Filing: 1946-04-22
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Granted: 1950-08-29
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Expires: 1966-04-22
Abstract
No abstract record available.
Inventors
- 👤 Theodore J Smulski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:14
CPC Classifications
G; G01; G01R; G01R5/00; G01R5/22; G01R5/26
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1885052A
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USRE21527E
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US2211773A
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US2213339A
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US2004421A
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US2006608A
Cited
US2022441A
Cited
US2107560A
Cited
US2133077A
Cited
US2353155A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-08-28 | 1954-02-27 | 1954-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-08-28 | 1958-02-27 | 1958-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-08-28 | 1962-02-27 | 1962-08-29 | $7700.00 | Window Closed / Lapsed |