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US2554201A
Expired / Lapsed
US
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Key-sending automatic telephone signaling system
Assignee: Telefonaktiebolaget LM Ericsson AB
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Filing: 1947-06-05
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Granted: 1951-05-22
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Expires: 1967-06-05
Abstract
No abstract record available.
Inventors
- 👤 Lundkvist Karl Axel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:35
CPC Classifications
H; H04; H04Q; H04Q3/00; H04Q3/42; H04M; H04M1/00; H04M1/26; H04M1/30; H04M1/50
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1337715A
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US1541367A
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US2228113A
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US2164335A
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US2244500A
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US2308637A
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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) | 1954-05-21 | 1954-11-20 | 1955-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-05-21 | 1958-11-20 | 1959-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-05-21 | 1962-11-20 | 1963-05-22 | $7700.00 | Window Closed / Lapsed |