US2710270A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coated filaments and their production
Assignee: Duro Test Corp
•
Filing: 1954-02-09
•
Granted: 1955-06-07
•
Expires: 1974-02-09
Abstract
No abstract record available.
Inventors
- 👤 James L Cox
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:59
CPC Classifications
H; H01; H01K; H01K1/00; H01K1/52; H01K1/54; H01K1/56; H01J; H01J61/00; H01J61/02; H01J61/24; H01J61/26; H01J9/00; H01J9/02; H01J9/04; H01J9/06; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12535; Y10T428/12771; Y10T428/12806; Y10T428/12812; Y10T428/12986
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
118 words
THE METHOD OF PREPARING AN ELECTRON EMISSIVE FILAMENT COMPRISING PROVIDING A ZIRCONIUM SOURCE AND MAKING IT PART OF A RESISTOR IN AN ELECTRIC CIRCUIT, ENCLOSING SAID ZIRCONIUM SOURCE IN AN ENCLOSED SPACE, ALSO ENCLOSING IN SAID SPACE A PLURALITY OF METAL HEATER FILAMENTS ON WHICH IT IS DESIRED TO DEPOSIT ZIRCONIUM, EVACUATING SAID SPACE TO A HIGH DEGREE OF VACUUM, AND PASSING ELECTRIC CURRENT THROUGH SAID ZIRCONIUM SOURCE SUFFICIENT TO HEAT IT TO EVAPORATION TEMPERATURE, THEREBY TO GENERATE ZIRCONIUM VAPOR IN SAID EVACUATED SPACE AND TO CONDENSE A THIN LAYER OF ZIRCONIUM ON SAID METAL HEATER FILAMENTS IN SAID ENCLOSED SPACE, AGITATING SAID FILAMENT DURING SAID EVAPORATION, AND THEREAFTER COATING SAID METAL HEATER FILAMENTS WITH ELECTRON EMISSIVE MATERIAL.
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) | 1958-06-06 | 1958-12-06 | 1959-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1962-06-06 | 1962-12-06 | 1963-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1966-06-06 | 1966-12-06 | 1967-06-07 | $7700.00 | Window Closed / Lapsed |