Patent US2139731A successfully refreshed from Google Patents.
US2139731A
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Asymmetric electrode system
Assignee: Koninklijke Philips NV
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Filing: 1936-05-23
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Granted: 1938-12-13
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Expires: 1956-05-23
Abstract
No abstract record available.
Inventors
- 👤 Boer Jan Hendrik De
- 👤 Willem Christiaan Van Geel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:31
CPC Classifications
H; H10; H10D; H10D48/00; H10D48/01; H10D48/04; H10D48/043; H10D48/046; H10D48/044
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1941-12-12 | 1942-06-13 | 1942-12-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1945-12-12 | 1946-06-13 | 1946-12-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1949-12-12 | 1950-06-13 | 1950-12-13 | $7700.00 | Window Closed / Lapsed |