US2839601A
Expired / Lapsed
US
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Methods of and apparatus for rendering visible magnetic and electric field patterns
Assignee: JULIUS CATO VREDENBURG INGLESB
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Filing: 1951-09-24
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Granted: 1958-06-17
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Expires: 1971-09-24
Abstract
No abstract record available.
Inventors
- 👤 Fries Gustav
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:07
CPC Classifications
H; H01; H01J; H01J31/00; H01J31/08; H01J31/50; H01J31/503
Claims Analysis
Total Claims: 0
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-06-16 | 1961-12-16 | 1962-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-06-16 | 1965-12-16 | 1966-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-06-16 | 1969-12-16 | 1970-06-17 | $7700.00 | Window Closed / Lapsed |