Patent US2457530A successfully refreshed from Google Patents.
US2457530A
Expired / Lapsed
US
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Electron gun for mass spectrometers
Assignee: Gulf Research and Development Co
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Filing: 1946-08-06
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Granted: 1948-12-28
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Expires: 1966-08-06
Abstract
No abstract record available.
Inventors
- 👤 Norman D Coggeshall
- 👤 Nathan F Kerr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 10:55
CPC Classifications
H; H01; H01J; H01J49/00; H01J49/02; H01J49/10; H01J49/14; H01J49/147
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USRE21907E
Cited
US1961703A
Cited
US2181720A
Cited
US2240713A
Cited
US2149080A
Cited
US2373151A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1951-12-28 | 1952-06-28 | 1952-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-12-28 | 1956-06-28 | 1956-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-12-28 | 1960-06-28 | 1960-12-28 | $7700.00 | Window Closed / Lapsed |