US3504218A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dual cathode for fluorescent lamps
Assignee: Duro Test Corp
•
Filing: 1969-01-03
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Granted: 1970-03-31
•
Expires: 1989-01-03
Abstract
No abstract record available.
Inventors
- 👤 Thomas J Emidy
- 👤 Walter H Simson
- 👤 Luke Thorington
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:51
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/02; H01J61/04; H01J61/06; H01J61/067; H01J61/0672; H01J61/54; H01J61/545
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) | 1973-03-30 | 1973-09-29 | 1974-03-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-03-30 | 1977-09-29 | 1978-03-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-03-30 | 1981-09-29 | 1982-03-31 | $7700.00 | Window Closed / Lapsed |