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US2813807A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of making a dispenser cathode

Assignee: US Philips Corp
•
Filing: 1954-07-19
•
Granted: 1957-11-19
•
Expires: 1974-07-19
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Abstract

No abstract record available.

Inventors

  • 👤 Levi Roberto

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 19:59
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/02; H01J9/04; H01J9/042; H01J9/047

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 88 words
A METHOD OF MANUFACTURING A THERMIONIC CATHODE ADAPTED TO OPERATE AT ELEVATED TEMPERATURES WHICH COMPRISES FORMING A POROUS BODY OF SINTERED REFRACTORY METAL, IMPREGNATING IN AN INERT ATMOSPHERE THE PORES OF SAID BODY WITH A MOLTEN MIXTURE OF BARIUM OXIDE AND AN OXIDE SELECTED FROM THE GROUP CONSISTING OF ALUMINUM OXIDE, SILICON DIOXIDE, BORIC OXIDE, BERYLLIUM OXIDE, NEODYMIUM OXIDE, LANTHANUM OXIDE AND PRASEODYMIUM OXIDE, A MAJORCOOLING PROPORTION OF THE OXIDES BEING BARIUM OXIDE, AND COOLING SAID IMPREGNATED BODY TO DULL RED HEAT IN LESS THAN ABOUT ONE MINUTE.
Claim 2
Independent Claim 88 words
A METHOD OF MANUFACTURING A THERMIONIC CATHODE ADAPTED TO OPERATE AT ELEVATED TEMPERATURES WHICH COMPRISES FORMING A POROUS BODY OF SINTERED REFRACTORY METAL, IMPREGNATING IN AN INERT ATMOSPHERE THE PORES OF SAID BODY WITH A MOLTEN MIXTURE OF BARIUM OXIDE AND AN OXIDE SELECTED FROM THE GROUP CONSISTING OF ALUMINUM OXIDE, SILICON DIOXIDE, BORIC OXIDE, BERYLLIUM OXIDE, NEODYMIUM OXIDE, LANTHANUM OXIDE AND PRASEODYMIUM OXIDE, A MAJORCOOLING PROPORTION OF THE OXIDES BEING BARIUM OXIDE, AND COOLING SAID IMPREGNATED BODY TO DULL RED HEAT IN LESS THAN ABOUT ONE MINUTE.

References Cited (Backward Citations)

US1794298A Cited
US2677623A Cited
US2686735A Cited
US2700000A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1960-11-18 1961-05-20 1961-11-19 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1964-11-18 1965-05-20 1965-11-19 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1968-11-18 1969-05-20 1969-11-19 $7700.00 Window Closed / Lapsed

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