US3625759A
Expired / Lapsed
US
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Process for making oxide cathodes having improved thermal emissivity
Assignee: Varian Medical Systems Inc
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Filing: 1969-08-27
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Granted: 1971-12-07
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Expires: 1989-08-27
Abstract
Abstract A process for making an oxide cathode having metallic powders finely and evenly interspersed with alkaline earth oxides. An alkaline earth carbonate is dispersed in an aqueous solution having a soluble metal salt dissolved therein. The water is evaporated leaving carbonate crystals coated with the metal salt. The coated crystals are then dispersed in a lacquer which in turn is coated onto a cathode base.
Inventors
- 👤 Paul D Williams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 08:24
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/02; H01J9/04; H01J9/042
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
30 words
The process of claim 1 wherein said soluble metal salt is selected from the group consisting of nickel salt, tungsten salt, cobalt salt, platinum salt, iron salt and rhodium salt.
Claim 2
Dependent Claim
26 words
The process of claim 1 wherein step A said alkaline earth carbonate is selected from the group consisting of calcium carbonate, barium carbonate and strontium carbonate.
Claim 3
Dependent Claim
21 words
The process of claim 1 wherein step A said alkaline earth carbonate is dispersed in said aqueous solution by ball-milling action.
Claim 4
Dependent Claim
20 words
The process of claim 1 wherein step C the coated crystals are dispersed in the organic lacquer by ball-milling action.
Claim 5
Dependent Claim
24 words
The process of claim 1 wherein step B is accomplished by heating the aqueous solution in an air atmosphere oven at approximately 90* C.
Claim 6
Dependent Claim
18 words
The process of claim 1 wherein step C is accomplished by mixing the crystals with a nitrocellulose lacquer.
Claim 7
Dependent Claim
22 words
The process of claim 1 wherein step C is accomplished by ball-milling a butyl methacrylate lacquer having said coated crystals suspended therein.
Claim 8
Dependent Claim
19 words
The process of claim 1 wherein step A said aqueous solution has barium carbonate and strontium carbonate suspended therein.
Claim 9
Dependent Claim
21 words
The process of claim 9 wherein said barium carbonate and said strontium carbonate are present in substantially equal proportions by weight.
Claim 10
Dependent Claim
14 words
The process of claim 1 wherein said soluble metal salt is a nickel salt.
Claim 11
Dependent Claim
39 words
The process of claim 11 wherein the nickel of said nickel salt and said alkaline earth carbonate are present in the respective proportional ranges by weight of 1/4 to 10 percent nickel and 99- 3/4 to 90 percent carbonate.
Claim 12
Dependent Claim
30 words
The process of claim 11 wherein the nickel of said nickel salt and said alkaline earth carbonate are present in the approximate proportions by weight of 25 to 975 respectively.
Claim 13
Dependent Claim
23 words
The process of claim 11 wherein step A said nickel salt is dissolved in said aqueous solution by mixing nickel acetate with water.
Claim 14
Dependent Claim
27 words
The process of claim 14 wherein said nickel acetate and said alkaline earth carbonate are present in the approximate proportions by weight of 1 to 10 respectively.
References Cited (Backward Citations)
US3563797A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-12-06 | 1975-06-07 | 1975-12-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-06 | 1979-06-07 | 1979-12-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-06 | 1983-06-07 | 1983-12-07 | $7700.00 | Window Closed / Lapsed |