US3883767A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heater for fast warmup cathode
Assignee: GTE Sylvania Inc
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Filing: 1974-02-08
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Granted: 1975-05-13
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Expires: 1994-02-08
Abstract
Abstract Heat loss from a fast warmup cathode heater is minimized by keeping the coiled body portion of the heater small in relation to the length of the heater legs and by increasing the thickness of the insulating coating on the legs by a factor of about 400% over that on the coils.
Inventors
- 👤 William E Buescher
- 👤 Donald R Kerstetter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:37
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/02; H01J29/04; H01J1/00; H01J1/02; H01J1/13; H01J1/20; H01J1/22
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
81 words
A heater for a fast warmup cathode comprising: a metallic, electrically conductive core; and an electrically insulating coating surrounding said core; said heater being formed to provide a coiled body having a pair of legs extending therefrom, the height of said coiled body being small compared with the length of said legs; the insulating coating on said pair of legs having a thickness about 400% greater than the thickness of the insulating coating on the coils of said coiled body portion.
Claim 2
Dependent Claim
81 words
A heater for a fast warmup cathode comprising: a metallic, electrically conductive core; and an electrically insulating coating surrounding said core; said heater being formed to provide a coiled body having a pair of legs extending therefrom, the height of said coiled body being small compared with the length of said legs; the insulating coating on said pair of legs having a thickness about 400% greater than the thickness of the insulating coating on the coils of said coiled body portion.
Claim 3
Dependent Claim
11 words
The heater of claim 1 wherein said insulating coating is alumina.
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) | 1978-05-12 | 1978-11-11 | 1979-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-12 | 1982-11-11 | 1983-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-12 | 1986-11-11 | 1987-05-13 | $7700.00 | Window Closed / Lapsed |