Patent US2720367A successfully refreshed from Google Patents.
US2590893A
Expired / Lapsed
US
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Insulator
Assignee: Individual
•
Filing: 1949-09-20
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Granted: 1952-04-01
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Expires: 1969-09-20
Abstract
No abstract record available.
Inventors
- 👤 Paul H Sanborn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 04:08
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; H; H01; H01B; H01B1/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
64 words
AN ELECTRICAL INSULATOR COMPRISING, IN COMBINATION, A CERAMIC BODY AND AN APPLIED COATING OF SEMI-CONDUCTING MATERIAL UPON PREDETERMINED PORTIONS OF THE CERAMIC BODY THE SEMI-CONDUCTING COATING COMPOSED OF FROM 1% TO 40% BY WEIGHT OF TITANIUM DIOXIDE AND FROM 60% TO 99% BY WEIGHT OF IRON OXIDE AND THE APPLIED COATING BEING FIRED AT TEMPERATURES ABOVE PYROMETRIC CONE 8 AND NOT OVER CONE 13.
Claim 2
Dependent Claim
64 words
AN ELECTRICAL INSULATOR COMPRISING, IN COMBINATION, A CERAMIC BODY AND AN APPLIED COATING OF SEMI-CONDUCTING MATERIAL UPON PREDETERMINED PORTIONS OF THE CERAMIC BODY THE SEMI-CONDUCTING COATING COMPOSED OF FROM 1% TO 40% BY WEIGHT OF TITANIUM DIOXIDE AND FROM 60% TO 99% BY WEIGHT OF IRON OXIDE AND THE APPLIED COATING BEING FIRED AT TEMPERATURES ABOVE PYROMETRIC CONE 8 AND NOT OVER CONE 13.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1955-04-01 | 1955-10-01 | 1956-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-04-01 | 1959-10-01 | 1960-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-04-01 | 1963-10-01 | 1964-04-01 | $7700.00 | Window Closed / Lapsed |