US4184100A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Indirectly-heated cathode device for electron tubes
Assignee: Toshiba Corp
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Filing: 1978-03-22
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Granted: 1980-01-15
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Expires: 1998-03-22
Abstract
Abstract An indirectly-heated cathode device for electron tubes, comprising a hollow cathode sleeve of thin wall, a base metal mounted to one end of the sleeve and having the surface coated with an electron-emitting material, and a heater mounted within the sleeve. The sleeve is made of Ni-Cr alloy containing 2 to 35% by weight of Cr and predetermined amounts of additives including Co, W, Mo and/or Fe.
Inventors
- 👤 Yukio Takanashi
- 👤 Sakae Kimura
- 👤 Takashi Kuse
- 👤 Toshiharu Matsuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:58
CPC Classifications
C; C22; C22C; C22C19/00; C22C19/03; C22C19/05; H; H01; H01J; H01J1/00; H01J1/02; H01J1/13; H01J1/20; H01J1/26; H01J29/00; H01J29/02; H01J29/04
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
122 words
An indirectly-heated cathode device for electron tubes comprising a hollow cathode sleeve having a thin wall; a base metal having a layer of electron-emitting materials formed on the surface thereof and provided at one end of the sleeve; and a heater disposed within the sleeve for heating the sleeve, the sleeve being made of an alloy consisting essentially of 2 to 35% by weight of chromium, an additive metal selected from the group consisting of cobalt, tungsten, molybdenum, and mixtures thereof, and the balance of nickel, the cobalt content when present ranging from 3 to 30% by weight, the tungsten content when present ranging from 0.5 to 15% by weight, the molybdenum content when present ranging from 0.5 to 15% by weight.
Claim 2
Dependent Claim
122 words
An indirectly-heated cathode device for electron tubes comprising a hollow cathode sleeve having a thin wall; a base metal having a layer of electron-emitting materials formed on the surface thereof and provided at one end of the sleeve; and a heater disposed within the sleeve for heating the sleeve, the sleeve being made of an alloy consisting essentially of 2 to 35% by weight of chromium, an additive metal selected from the group consisting of cobalt, tungsten, molybdenum, and mixtures thereof, and the balance of nickel, the cobalt content when present ranging from 3 to 30% by weight, the tungsten content when present ranging from 0.5 to 15% by weight, the molybdenum content when present ranging from 0.5 to 15% by weight.
Claim 3
Dependent Claim
18 words
The cathode device according to claim 1, wherein the chromium content ranges from 15 to 25% by weight.
Claim 4
Dependent Claim
13 words
The cathode device according to claim 1, wherein the additive metal is cobalt.
Claim 5
Dependent Claim
18 words
The cathode device according to claim 3, wherein the cobalt content ranges from 10 to 20% by weight.
Claim 6
Dependent Claim
13 words
The cathode device according to claim 1, wherein the additive metal is tungsten.
Claim 7
Dependent Claim
18 words
The cathode device according to claim 5, wherein the tungsten content ranges from 3 to 10% by weight.
Claim 8
Dependent Claim
13 words
The cathode device according to claim 1, wherein the additive metal is molybdenum.
Claim 9
Dependent Claim
18 words
The cathode device according to claim 7, wherein the molybdenum content ranges from 3 to 10% by weight.
Claim 10
Dependent Claim
39 words
The cathode device according to claim 1, wherein the alloy consists essentially of 15 to 25% by weight of chromium, 3 to 10% by weight of tungsten, 5 to 12% by weight of molybdenum and the balance of nickel.
Claim 11
Dependent Claim
22 words
The cathode device according to claim 1, wherein the cathode sleeve is covered with a black layer consisting essentially of chromium oxide.
Claim 12
Dependent Claim
20 words
The cathode device according to claim 10, wherein the black layer is formed by heating under a wet hydrogen atmosphere.
Claim 13
Dependent Claim
24 words
The cathode device according to claim 1, wherein the base metal is inserted in and welded to one edge portion of the cathode sleeve.
Claim 14
Dependent Claim
25 words
The cathode device according to claim 1, wherein the base metal is of a cup shape and houses one edge portion of the cathode sleeve.
Claim 15
Dependent Claim
28 words
The cathode device according to claim 1, wherein one edge portion of the cathode sleeve is folded inward and the base metal is supported by the folded portion.
Claim 16
Dependent Claim
28 words
The cathode sleeve according to claim 1, wherein one edge portion of the cathode sleeve is folded outward and the base metal is supported by the folded portion.
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) | 1983-01-14 | 1983-07-16 | 1984-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-01-14 | 1987-07-16 | 1988-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-01-14 | 1991-07-16 | 1992-01-15 | $7700.00 | Window Closed / Lapsed |