Patent US2939977A successfully refreshed from Google Patents.
US2939977A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical brush
Assignee: IIT Research Institute
•
Filing: 1955-07-14
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Granted: 1960-06-07
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Expires: 1975-07-14
Abstract
No abstract record available.
Inventors
- 👤 George A Forster
- 👤 Cord H Sump
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 14:49
CPC Classifications
H; H01; H01R; H01R39/00; H01R39/02; H01R39/38; H01R39/41
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US556176A
Cited
US589162A
Cited
US1002648A
Cited
GB191127621A
Cited
US1396948A
Cited
US1494927A
Cited
US2449078A
Cited
US2696570A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-06-07 | 1963-12-07 | 1964-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-06-07 | 1967-12-07 | 1968-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-06-07 | 1971-12-07 | 1972-06-07 | $7700.00 | Window Closed / Lapsed |