Patent US4497334A successfully refreshed from Google Patents.
US1990482A
Expired / Lapsed
US
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Demountable screen grid tube
Assignee: Individual
•
Filing: 1933-04-17
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Granted: 1935-02-12
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Expires: 1953-04-17
Abstract
No abstract record available.
Inventors
- 👤 Louis A Gebhard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:08
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/50; H01J2893/00; H01J2893/0072; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/82
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) | 1938-02-11 | 1938-08-13 | 1939-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1942-02-11 | 1942-08-13 | 1943-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1946-02-11 | 1946-08-13 | 1947-02-12 | $7700.00 | Window Closed / Lapsed |