Patent US1921869A successfully refreshed from Google Patents.
US1921869A
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Method of and means for making coils possessing accurate inductance
Assignee: Telefunken AG
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Filing: 1930-09-19
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Granted: 1933-08-08
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Expires: 1950-09-19
Abstract
No abstract record available.
Inventors
- 👤 Wolfgang F Ewald
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:51
CPC Classifications
H; H01; H01F; H01F41/00; H01F41/02; H01F41/04; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49071
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) | 1936-08-07 | 1937-02-06 | 1937-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1940-08-07 | 1941-02-06 | 1941-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1944-08-07 | 1945-02-06 | 1945-08-08 | $7700.00 | Window Closed / Lapsed |