Patent US1820240A successfully refreshed from Google Patents.
US1820240A
Expired / Lapsed
US
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Coil
Assignee: Individual
•
Filing: 1929-03-30
•
Granted: 1931-08-25
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Expires: 1949-03-30
Abstract
No abstract record available.
Inventors
- 👤 Philip A Michell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:50
CPC Classifications
H; H01; H01F; H01F41/00; H01F41/02; H01F41/04; H01F41/041; H01F17/00; H01F17/0006; H01F2017/004; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/4998; Y10T29/49982
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) | 1934-08-24 | 1935-02-23 | 1935-08-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1938-08-24 | 1939-02-23 | 1939-08-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1942-08-24 | 1943-02-23 | 1943-08-25 | $7700.00 | Window Closed / Lapsed |