Patent US4446404A successfully refreshed from Google Patents.
US4446404A
Expired / Lapsed
US
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Directly heated oxide cathode and production thereof
Assignee: Hitachi Ltd
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Filing: 1980-09-12
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Granted: 1984-05-01
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Expires: 2000-09-12
Abstract
Abstract A directly heated type oxide cathode comprising a base made of an alloy containing Ni as a major component and Zr as a reducing agent, a coating of Co powders or a mixture of Ni powders and Co powders wherein the average particle size of the Co powders is smaller than that of Ni powders formed on the base, and an electron emissive alkaline earth oxide layer formed on the coating of Co powders or the mixture of Ni powders and Co powders does not show deformation of the base or peeling of the oxide layer during the production procedure or operation of electron tubes and the like.
Inventors
- 👤 Masaharu Kumada
- 👤 Akira Misumi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:04
CPC Classifications
H; H01; H01J; H01J1/00; H01J1/02; H01J1/13; H01J1/14
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
116 words
A directly heated type oxide cathode comprising a base made of an alloy containing Ni as a major component and Zr as a reducing agent, a coating of Co powders or Co-Ni alloy powders containing Co in the amount of 80% by weight or more, or a coating of a mixture of Ni powders or Ni alloy powders and Co powders wherein the average particle size of the Co powders is smaller than that of the Ni or Ni alloy powders, formed on the base and an electron emissive alkaline earth oxide layer formed on the coating of Co powders or Co-Ni alloy powders or the mixture of Ni or Ni alloy powders and Co powders.
Claim 2
Dependent Claim
116 words
A directly heated type oxide cathode comprising a base made of an alloy containing Ni as a major component and Zr as a reducing agent, a coating of Co powders or Co-Ni alloy powders containing Co in the amount of 80% by weight or more, or a coating of a mixture of Ni powders or Ni alloy powders and Co powders wherein the average particle size of the Co powders is smaller than that of the Ni or Ni alloy powders, formed on the base and an electron emissive alkaline earth oxide layer formed on the coating of Co powders or Co-Ni alloy powders or the mixture of Ni or Ni alloy powders and Co powders.
Claim 3
Dependent Claim
49 words
A directly heated type oxide cathode comprising a base made of an alloy containing Ni as a major compenent and Zr as a reducing agent, a coating of Co powders formed on the base and an electron emissive alkaline earth oxide layer formed on the coating of Co powders.
Claim 4
Dependent Claim
49 words
A directly heated type oxide cathode comprising a base made of an alloy containing Ni as a major compenent and Zr as a reducing agent, a coating of Co powders formed on the base and an electron emissive alkaline earth oxide layer formed on the coating of Co powders.
Claim 5
Dependent Claim
88 words
A directly heated type oxide cathode comprising a base made of an alloy containing Ni as a major component and Zr as a reducing agent, a coating of a mixture of Ni powders or Ni alloy powders and Co powders wherein the average particle size of the Co powders is smaller than that of the Ni or Ni alloy powders formed on the base and an electron emissive alkaline earth oxide layer formed on the coating of the mixture of Ni or Ni alloy powders and Co powders.
Claim 6
Dependent Claim
88 words
A directly heated type oxide cathode comprising a base made of an alloy containing Ni as a major component and Zr as a reducing agent, a coating of a mixture of Ni powders or Ni alloy powders and Co powders wherein the average particle size of the Co powders is smaller than that of the Ni or Ni alloy powders formed on the base and an electron emissive alkaline earth oxide layer formed on the coating of the mixture of Ni or Ni alloy powders and Co powders.
Claim 7
Dependent Claim
37 words
A cathode according to claim 1, 2 or 3, wherein the base is made of an alloy containing 15 to 30% by weight of W, 0.02 to 5% by weight of Zr and the remainder being Ni.
Claim 8
Dependent Claim
37 words
A cathode according to claim 1, 2 or 3, wherein the base is made of an alloy containing 10 to 22% by weight of Mo, 0.02 to 5% by weight of Zr and the remainder being Ni.
Claim 9
Dependent Claim
44 words
A cathode according to claim 1, 2 or 3, wherein the base is made of an alloy containing 1 to 8% by weight of W, 10 to 22% by weight of Mo, 0.02 to 5% by weight of Zr and the remainder being Ni.
Claim 10
Dependent Claim
40 words
A cathode according to claim 1, 2 or 3, wherein the base is made of an alloy containing W and/or Mo and Re as a high-melting point metal, 0.02 to 5% by weight of Zr and the remainder being Ni.
Claim 11
Dependent Claim
42 words
A cathode according to claim 1, wherein the coating amount of the Co powders or Co-Ni alloy powders containing Co in an amount of 80% by weight or more on the surface of the base is 0.1 to 5 mg/cm 2 .
Claim 12
Dependent Claim
40 words
A cathode according to claim 1 or 3, wherein the average particle size of Co powders in the mixture of Co powders and Ni or Ni alloy powders is 50% or less of that of Ni or Ni alloy powders.
Claim 13
Dependent Claim
154 words
A process for producing a directly heated type oxide cathode which comprises coating Co powders or Co-Ni alloy powders containing Co in an amount of 80% by weight or more on the surface of a base made of an alloy containing Ni as a major component and Zr as a reducing agent, in an amount of 0.1 to 5 mg/cm 2 , or coating Ni powders or Ni alloy powders in an amount of 0.1 to 5 mg/cm 2 and Co powders the average particle size of which is smaller than the Ni or Ni alloy powders in an amount of 0.01 to 5 mg/cm 2 on the surface of the base at the same time, baking the Co powders or Co-Ni alloy powders, or simultaneously coated Ni and Co powders at 700° to 1100° C. in vacuum or under hydrogen, and coating electron emissive alkaline earth carbonates thereon and baking them in vacuum.
Claim 14
Dependent Claim
154 words
A process for producing a directly heated type oxide cathode which comprises coating Co powders or Co-Ni alloy powders containing Co in an amount of 80% by weight or more on the surface of a base made of an alloy containing Ni as a major component and Zr as a reducing agent, in an amount of 0.1 to 5 mg/cm 2 , or coating Ni powders or Ni alloy powders in an amount of 0.1 to 5 mg/cm 2 and Co powders the average particle size of which is smaller than the Ni or Ni alloy powders in an amount of 0.01 to 5 mg/cm 2 on the surface of the base at the same time, baking the Co powders or Co-Ni alloy powders, or simultaneously coated Ni and Co powders at 700° to 1100° C. in vacuum or under hydrogen, and coating electron emissive alkaline earth carbonates thereon and baking them in vacuum.
Claim 15
Dependent Claim
62 words
A directly heated type oxide cathode comprising a base made of an alloy containing Ni as a major component and Zr as a reducing agent, a coating of Co-Ni alloy powders containing Co in an amount of 80% by weight or more formed on the base and an electron emissive alkaline earth oxide layer formed on the coating of Co-Ni alloy powders.
Claim 16
Dependent Claim
62 words
A directly heated type oxide cathode comprising a base made of an alloy containing Ni as a major component and Zr as a reducing agent, a coating of Co-Ni alloy powders containing Co in an amount of 80% by weight or more formed on the base and an electron emissive alkaline earth oxide layer formed on the coating of Co-Ni alloy powders.
Claim 17
Dependent Claim
39 words
A cathode according to claim 11, wherein the coating amount of the Co-Ni alloy powders containing Co in an amount of 80% by weight or more on the surface of the base is 0.1 to 5 mg/cm 2 .
Claim 18
Dependent Claim
27 words
A cathode according to claim 2, wherein the coating amount of the Co powders on the surface of the base is 0.1 to 5 mg/cm 2 .
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) | 1987-05-01 | 1987-10-31 | 1988-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-01 | 1991-10-31 | 1992-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-01 | 1995-10-31 | 1996-05-01 | $7700.00 | Window Closed / Lapsed |