US2568823A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Loud-speaking telephone set
Assignee: AT&T Inc
•
Filing: 1948-08-11
•
Granted: 1951-09-25
•
Expires: 1968-08-11
Abstract
No abstract record available.
Inventors
- 👤 Ralph K Potter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 07:21
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/60; H04M1/6033
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US544732A
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US580872A
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US837196A
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US1683316A
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US1828151A
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US2157140A
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US2277907A
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US2343115A
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US2461344A
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US2495426A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-09-24 | 1955-03-26 | 1955-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-09-24 | 1959-03-26 | 1959-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-09-24 | 1963-03-26 | 1963-09-25 | $7700.00 | Window Closed / Lapsed |