US3978563A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing an electric discharge tube having an oxide cathode
Assignee: US Philips Corp
•
Filing: 1974-11-26
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Granted: 1976-09-07
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Expires: 1994-11-26
Abstract
Abstract A method of manufacturing an electric discharge tube having an oxide cathode, wherein a suspension is made containing a carbonate mixture, a solution of nitrocellulose as a first binder and a second binder selected from the group of polyimides, highly molecular acrylate resins, and nylon types, a cathode support is coated with the suspension and dried, whereupon the cathode is mounted in the tube and, upon evacuation of the tube, is activated at 1200°C.
Inventors
- 👤 Klaas Schol
- 👤 Johannes Maria Azalina Antonius Compen
- 👤 Reinier Maria VAN DEN Heuvel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 12:39
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/02; H01J9/04; H01J9/042
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
131 words
A method of manufacturing an electric discharge tube having an envelope of a volume of at least 2 liters, and an oxide cathode, comprising the steps of: preparing a suspension containing a mixture of carbonates; a first binder including nitrocellulose; a second binder including at least one substance selected from the group consisting of polyimides, highly molecular acrylic resins and nylon types, said second binder having a higher resistance than said first binder to withstand impacts of water droplets and resist temperatures up to 450°C for at least a few minutes; coating a cathode support with said suspension, drying the coating at a temperature below 450°C; mounting the cathode in said envelope and evacuating said envelope; and activating the cathode at a temperature above 450°C to convert the carbonates into oxides.
Claim 2
Independent Claim
131 words
A method of manufacturing an electric discharge tube having an envelope of a volume of at least 2 liters, and an oxide cathode, comprising the steps of: preparing a suspension containing a mixture of carbonates; a first binder including nitrocellulose; a second binder including at least one substance selected from the group consisting of polyimides, highly molecular acrylic resins and nylon types, said second binder having a higher resistance than said first binder to withstand impacts of water droplets and resist temperatures up to 450°C for at least a few minutes; coating a cathode support with said suspension, drying the coating at a temperature below 450°C; mounting the cathode in said envelope and evacuating said envelope; and activating the cathode at a temperature above 450°C to convert the carbonates into oxides.
Claim 3
Dependent Claim
33 words
A method as claimed in claim 1,wherein a solution of the said second binder is mixed with the said mixture of carbonates and is then suspended in a solution of the first binder.
Claim 4
Dependent Claim
32 words
A method as claimed in claim 1, wherein a solution of the second binder is mixed with a solution of the first binder in which the mixture of carbonates is then suspended.
Claim 5
Dependent Claim
37 words
A method as claimed in claim 1, wherein the mixture of carbonates is mixed with a solution of the said second binder and is filtered off, then dried and suspended in a solution of the first binder.
Claim 6
Dependent Claim
65 words
A method as claimed in claim 1, wherein the said mixture of carbonates is suspended in a solution of the first binder after which at least one layer is formed from the formed suspension and at least one layer is also formed from a solution of the second binder, which layers are provided one on top of the other and together constitute the said coating.
Claim 7
Dependent Claim
15 words
A method as claimed in claim 1, wherein the said coating is formed by spraying.
Claim 8
Dependent Claim
27 words
A method as claimed in claim 6, wherein after the spraying, the coating is dried and hardened at a temperature of approximately 300°C for approximately 1 minute.
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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) | 1979-09-07 | 1980-03-08 | 1980-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-09-07 | 1984-03-08 | 1984-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-09-07 | 1988-03-08 | 1988-09-07 | $7700.00 | Window Closed / Lapsed |