US2640169A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heated cathode electron multiplier
Assignee: Farnsworth Research Corp
•
Filing: 1950-06-19
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Granted: 1953-05-26
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Expires: 1970-06-19
Abstract
No abstract record available.
Inventors
- 👤 Nevin Scott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:07
CPC Classifications
H; H01; H01J; H01J43/00; H01J43/04; H01J43/06; H01J43/16
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
42 words
AN ELECTRON TUBE COMPRISING, AN ELECTRON TUBE ENVELOPE, A SECONDARY ELECTRON EMISSIVE TARGET ELECTRODE, A HEATED TYPE PRIMARY ELECTRON EMISSIVE CATHODE ELECTRODE, AND A COLLECTOR ELECTRODE POSITIONED WITHIN SAID ENVOLOPE, SAID CATHODE ELECTRODE COMPRISING A TANTALUM BASE COATED WITH AN EMISSIVE OXIDE.
Claim 2
Dependent Claim
42 words
AN ELECTRON TUBE COMPRISING, AN ELECTRON TUBE ENVELOPE, A SECONDARY ELECTRON EMISSIVE TARGET ELECTRODE, A HEATED TYPE PRIMARY ELECTRON EMISSIVE CATHODE ELECTRODE, AND A COLLECTOR ELECTRODE POSITIONED WITHIN SAID ENVOLOPE, SAID CATHODE ELECTRODE COMPRISING A TANTALUM BASE COATED WITH AN EMISSIVE OXIDE.
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) | 1956-05-25 | 1956-11-24 | 1957-05-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-05-25 | 1960-11-24 | 1961-05-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-05-25 | 1964-11-24 | 1965-05-26 | $7700.00 | Window Closed / Lapsed |