US2914402A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making sintered cathodes
Assignee: AT&T Inc
•
Filing: 1957-02-26
•
Granted: 1959-11-24
•
Expires: 1977-02-26
Abstract
No abstract record available.
Inventors
- 👤 Edward J Becker
- 👤 Hugh M Cleveland
- 👤 Pat R Pondy
- 👤 Harold J Robinson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 05:38
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/02; H01J9/04; H01J9/042; H01J23/00; H01J23/02; H01J23/04; H01J23/05; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12014; Y10T428/12028; Y10T428/12063; Y10T428/12069
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
124 words
A METHOD OF MAKING A CATHODE FOR AN ELECTRON TUBE COMPRISING MAKING A POWDER MIXTURE COMPRISING FROM 5 TO 15 PERCENT BY WEIGHT OF A COMPOUND OF AN ALKALI EARTH METAL WHICH WILL DECOMPOSE THERMALLY TO PRODUCE THE CORRESPONDING OXIDE OF THE ALKALI EARTH METAL, REMAINDER A REFRACTORY MATERIAL CONTAINING AT LEAST 25 PERCENT BY WEIGHT OF AN ELEMENT SELECTED FROM THE GROUP CONSISTING OF MOLYBENUM AND TUNGSTEN, PRESSING THE RESULTANT MIXTURE UNDER PRESSURE OF AT LEAST SEVERAL TONS PER SQUARE INCH, FIRING THE PRESSED MIXTURE IN A REDUCING ATMOSPHERE AT A TEMPERATURE OF FROM 700 TO 750*C. FOR AT LEAST 15 MINUTES AND FIRONG IN AN INERT ATMOSPHERE AT A TEMPERATURE OF AT LEAST 1300*C. FOR A PERIOD OF AT LEAST 15 MINUTES.
Claim 2
Independent Claim
124 words
A METHOD OF MAKING A CATHODE FOR AN ELECTRON TUBE COMPRISING MAKING A POWDER MIXTURE COMPRISING FROM 5 TO 15 PERCENT BY WEIGHT OF A COMPOUND OF AN ALKALI EARTH METAL WHICH WILL DECOMPOSE THERMALLY TO PRODUCE THE CORRESPONDING OXIDE OF THE ALKALI EARTH METAL, REMAINDER A REFRACTORY MATERIAL CONTAINING AT LEAST 25 PERCENT BY WEIGHT OF AN ELEMENT SELECTED FROM THE GROUP CONSISTING OF MOLYBENUM AND TUNGSTEN, PRESSING THE RESULTANT MIXTURE UNDER PRESSURE OF AT LEAST SEVERAL TONS PER SQUARE INCH, FIRING THE PRESSED MIXTURE IN A REDUCING ATMOSPHERE AT A TEMPERATURE OF FROM 700 TO 750*C. FOR AT LEAST 15 MINUTES AND FIRONG IN AN INERT ATMOSPHERE AT A TEMPERATURE OF AT LEAST 1300*C. FOR A PERIOD OF AT LEAST 15 MINUTES.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1962-11-23 | 1963-05-25 | 1963-11-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-11-23 | 1967-05-25 | 1967-11-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-11-23 | 1971-05-25 | 1971-11-24 | $7700.00 | Window Closed / Lapsed |