Patent US2825837A successfully refreshed from Google Patents.
US2825837A
Expired / Lapsed
US
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Electrostatic focusing system
Assignee: Hazeltine Research Inc
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Filing: 1955-03-01
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Granted: 1958-03-04
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Expires: 1975-03-01
Abstract
No abstract record available.
Inventors
- 👤 Dudley Michael Duke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 03:24
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/46; H01J29/48; H01J29/488; H01J29/58; H01J29/62; H01J29/622; H01J29/624
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-03-03 | 1961-09-02 | 1962-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-03-03 | 1965-09-02 | 1966-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-03-03 | 1969-09-02 | 1970-03-04 | $7700.00 | Window Closed / Lapsed |