US2820089A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rhythmic telegraph system
Assignee: US Philips Corp
•
Filing: 1955-09-08
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Granted: 1958-01-14
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Expires: 1975-09-08
Abstract
No abstract record available.
Inventors
- 👤 Schouten Gerrit Hilbertus
- 👤 Hendrik Cornelis Anthon Duuren
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:42
CPC Classifications
H; H04; H04L; H04L1/00; H04L1/12; H04L1/16
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-01-13 | 1961-07-15 | 1962-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-01-13 | 1965-07-15 | 1966-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-01-13 | 1969-07-15 | 1970-01-14 | $7700.00 | Window Closed / Lapsed |