US2588397A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spaced-pulse impulse sender
Assignee: AT&T Inc
•
Filing: 1948-06-29
•
Granted: 1952-03-11
•
Expires: 1968-06-29
Abstract
No abstract record available.
Inventors
- 👤 Clarence A Lovell
- 👤 David B Parkinson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:41
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/26; H04M1/27; H04M1/272
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1972289A
Cited
US1834934A
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US2004114A
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US2097577A
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US2323019A
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US2199443A
Cited
US2423096A
Cited
US2459858A
Cited
US2475553A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1955-03-11 | 1955-09-10 | 1956-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-03-11 | 1959-09-10 | 1960-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-03-11 | 1963-09-10 | 1964-03-11 | $7700.00 | Window Closed / Lapsed |