US2867742A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dispenser cathode
Assignee: US Philips Corp
•
Filing: 1954-02-18
•
Granted: 1959-01-06
•
Expires: 1974-02-18
Abstract
No abstract record available.
Inventors
- 👤 Lemmens Hendrikus Johannes
- 👤 Jansen Marinus Jacobus
- 👤 Haayman Pieter Willem
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:06
CPC Classifications
H; H01; H01J; H01J1/00; H01J1/02; H01J1/13; H01J1/20; H01J1/28; H01J9/00; H01J9/02; H01J9/04; H01J9/042; H01J9/047
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
106 words
IN THE METHOD OF MANUFACTURING A DISPENSER CATHODE COMPRISING A BODY OF REFRACTORY METAL HAVING AN INTERNAL CAVITY AND AT LEAST ONE EMISSIVE SURFACE PORTION, ONE WALL PORTION SURROUNDING SAID CAVITY BEING POROUS, THE PORES OF SAID LATTER WALL PORTION CONSTITUTING THE LARGEST PASSAGEWAYS CONNECTING THE CAVITY TO SAID SURFACE, THE STEPS OF FORMING A MIXTURE OF ALKALINE EARTH CARBONATES, SINTERING SAID MIXTURE IN A NON-REACTIVE ATMOSPHERE TO CONVERT THE SAME TO A COHERENT BODY OF ALKALINE EARTH OXIDES SUBSTANTIALLY IMPERVIOUS TO REACTIVE GASES, AND CLOSING SAID CAVITY AFTER PLACING THE SINTERED BODY THEREIN WHEREBY SAID CATHODE CAN BE ACTIVATED SUBSTANTIALLY WITHOUT THE RELEASE OF GASES.
Claim 2
Dependent Claim
106 words
IN THE METHOD OF MANUFACTURING A DISPENSER CATHODE COMPRISING A BODY OF REFRACTORY METAL HAVING AN INTERNAL CAVITY AND AT LEAST ONE EMISSIVE SURFACE PORTION, ONE WALL PORTION SURROUNDING SAID CAVITY BEING POROUS, THE PORES OF SAID LATTER WALL PORTION CONSTITUTING THE LARGEST PASSAGEWAYS CONNECTING THE CAVITY TO SAID SURFACE, THE STEPS OF FORMING A MIXTURE OF ALKALINE EARTH CARBONATES, SINTERING SAID MIXTURE IN A NON-REACTIVE ATMOSPHERE TO CONVERT THE SAME TO A COHERENT BODY OF ALKALINE EARTH OXIDES SUBSTANTIALLY IMPERVIOUS TO REACTIVE GASES, AND CLOSING SAID CAVITY AFTER PLACING THE SINTERED BODY THEREIN WHEREBY SAID CATHODE CAN BE ACTIVATED SUBSTANTIALLY WITHOUT THE RELEASE OF GASES.
References Cited (Backward Citations)
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Cited
US2175345A
Cited
US2171238A
Cited
US2492142A
Cited
US2543728A
Cited
US2721372A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1962-01-05 | 1962-07-07 | 1963-01-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-01-05 | 1966-07-07 | 1967-01-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-01-05 | 1970-07-07 | 1971-01-06 | $7700.00 | Window Closed / Lapsed |