US2671735A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical resistors and methods of making them
Assignee: AT&T Inc
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Filing: 1950-07-07
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Granted: 1954-03-09
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Expires: 1970-07-07
Abstract
No abstract record available.
Inventors
- 👤 Richard O Grisdale
- 👤 Anthony C Pfister
- 👤 Gordon K Teal
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:08
CPC Classifications
H; H01; H01B; H01B1/00; H01B1/20; H01B1/24; Y; Y10; Y10T; Y10T428/00; Y10T428/30
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
99 words
AN ELECTRICAL RESISTOR HAVING A TEMPERATURE COEFFICIENT OF RESISTANCE NOT GREATER THAN 150 PARTS PER MILLION PER DEGREE CENTRGRADE COMPRISING A CERAMIC CORE HAVING ON ITS SURFACE AN ADHERENT, CONTINUOUS, HOMOGENEOUS FILM OF CARBON CONTAINING BETWEEN 0.35 PER CENT AND 20 PER CENT BY WEIGHT OF BORON, DEPOSITED AT A TEMPERATURE BETWEEN 1000* C. AND 130 *. FROM A GAS CONTAINING BORON IN THE FORM OF A COMPOUND SELECTED FROM THE GROUP CONSISTING OF BORON HYDRIDES, BORON HALIDES AND BORON HYDROHALIDES AND CARBON IN THE FORM OF A COMPOUND SELECTED FROM THE GROUP CONSISTING OF HYDROCARBONS AND HALOGENATED HYDROCARBONS.
Claim 2
Dependent Claim
99 words
AN ELECTRICAL RESISTOR HAVING A TEMPERATURE COEFFICIENT OF RESISTANCE NOT GREATER THAN 150 PARTS PER MILLION PER DEGREE CENTRGRADE COMPRISING A CERAMIC CORE HAVING ON ITS SURFACE AN ADHERENT, CONTINUOUS, HOMOGENEOUS FILM OF CARBON CONTAINING BETWEEN 0.35 PER CENT AND 20 PER CENT BY WEIGHT OF BORON, DEPOSITED AT A TEMPERATURE BETWEEN 1000* C. AND 130 *. FROM A GAS CONTAINING BORON IN THE FORM OF A COMPOUND SELECTED FROM THE GROUP CONSISTING OF BORON HYDRIDES, BORON HALIDES AND BORON HYDROHALIDES AND CARBON IN THE FORM OF A COMPOUND SELECTED FROM THE GROUP CONSISTING OF HYDROCARBONS AND HALOGENATED HYDROCARBONS.
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) | 1957-03-08 | 1957-09-07 | 1958-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-03-08 | 1961-09-07 | 1962-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-03-08 | 1965-09-07 | 1966-03-09 | $7700.00 | Window Closed / Lapsed |