US3895249A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Instant warm-up heater cathode
Assignee: International Standard Electric Corp
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Filing: 1973-11-23
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Granted: 1975-07-15
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Expires: 1993-11-23
Abstract
Abstract A fast warm-up cathode for an electron tube is provided by having the major portion of the coiled heater element close to the emitting layer end within the cathode tubing. The heater is also coated with a dark layer of insulation, the inner cathode tubing around the heater is made non-reflective and the outer surface of the cathode is roughened and/or provided with a dark color coating to concentrate the heat at the end.
Inventors
- 👤 Wolfram Andre
- 👤 Eberhard Nill
- 👤 Peter Schmidt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 01:05
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/02; H01J29/04
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
134 words
A fast warm-up cathode for an electron tube comprising a hollow tubular enclosure having a closed end, an electron emissive layer on the outer surface of said end, a coiled heater element extending within said enclosure adjacent said end so that the ratio of the length of the tubular enclosure to the effective length of the coiled portion of the heater is at least 2:1, a supporting disc, a holding element securing said tubular enclosure to said disc, said tubular enclosure being mounted within said holding element and disc and an insulating coating of a layer of dark colored material on said heater, the inner and outer surfaces adjacent said end of said tubular enclosure around said heating element being substantially non-reflective and the entire said outer surface of said tubular enclosure being roughened.
Claim 2
Dependent Claim
134 words
A fast warm-up cathode for an electron tube comprising a hollow tubular enclosure having a closed end, an electron emissive layer on the outer surface of said end, a coiled heater element extending within said enclosure adjacent said end so that the ratio of the length of the tubular enclosure to the effective length of the coiled portion of the heater is at least 2:1, a supporting disc, a holding element securing said tubular enclosure to said disc, said tubular enclosure being mounted within said holding element and disc and an insulating coating of a layer of dark colored material on said heater, the inner and outer surfaces adjacent said end of said tubular enclosure around said heating element being substantially non-reflective and the entire said outer surface of said tubular enclosure being roughened.
Claim 3
Dependent Claim
20 words
The device of claim 1 wherein the entire said outer surface of said tubular enclosure has a dark colored coating.
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) | 1978-07-14 | 1979-01-13 | 1979-07-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-14 | 1983-01-13 | 1983-07-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-14 | 1987-01-13 | 1987-07-15 | $7700.00 | Window Closed / Lapsed |