US2784907A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic adding devices
Assignee: National Research Development Corp UK
•
Filing: 1952-04-30
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Granted: 1957-03-12
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Expires: 1972-04-30
Abstract
No abstract record available.
Inventors
- 👤 Williams Frederic Calland
- 👤 Kilburn Tom
- 👤 Gibbings Dennis Lawrenc Harold
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:19
CPC Classifications
G; G06; G06J; G06J1/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2401779A
Cited
US2429227A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-03-11 | 1960-09-10 | 1961-03-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-03-11 | 1964-09-10 | 1965-03-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-03-11 | 1968-09-10 | 1969-03-12 | $7700.00 | Window Closed / Lapsed |