US2820846A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Telephone recording pickups
Assignee: PERMOFLUX Corp
•
Filing: 1951-05-04
•
Granted: 1958-01-21
•
Expires: 1971-05-04
Abstract
No abstract record available.
Inventors
- 👤 Jr Ernest E Hansen
- 👤 Lawrence M Heineman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 17:03
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/02; H04M1/21; H04M1/215
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1842190A
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US2005973A
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US1928669A
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US2160829A
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US2204529A
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US2268665A
Cited
US2500264A
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US2554834A
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US2479806A
Cited
US2501212A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-01-20 | 1961-07-22 | 1962-01-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-01-20 | 1965-07-22 | 1966-01-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-01-20 | 1969-07-22 | 1970-01-21 | $7700.00 | Window Closed / Lapsed |