Patent US2792991A successfully refreshed from Google Patents.
US2792991A
Expired / Lapsed
US
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Electronic commutator for calculators
Assignee: International Business Machines Corp
•
Filing: 1953-11-23
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Granted: 1957-05-21
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Expires: 1973-11-23
Abstract
No abstract record available.
Inventors
- 👤 Cambio Edmond P Di
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 20:10
CPC Classifications
G; G06; G06F; G06F9/00; G06F9/06; G06F9/30
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2442428A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-05-20 | 1960-11-19 | 1961-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-05-20 | 1964-11-19 | 1965-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-05-20 | 1968-11-19 | 1969-05-21 | $7700.00 | Window Closed / Lapsed |