US2744987A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical resistance heating elements
Assignee: Commonwealth Engineering Company of Ohio
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Filing: 1954-03-18
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Granted: 1956-05-08
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Expires: 1974-03-18
Abstract
No abstract record available.
Inventors
- 👤 Philip R Marvin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 14:04
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/20; H05B3/22; H05B3/26
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
50 words
AN ELECTRICAL RESISTOR COMPRISING A BASE OF ELECTRICAL INSULATING MATERIAL HAVING A SPIRAL GROOVE THEREIN, THE BASE ALSO HAVING AN OPENING THERETHROUGH TRANSVERSELY TO THE GROOVE COINCIDING WITH ONE END OF THE GROOVE, AND A FILM OF METAL IN THE GROOVE AND ALSO IN THE OPENING ON THE SIDES THEREOF.
Claim 2
Dependent Claim
50 words
AN ELECTRICAL RESISTOR COMPRISING A BASE OF ELECTRICAL INSULATING MATERIAL HAVING A SPIRAL GROOVE THEREIN, THE BASE ALSO HAVING AN OPENING THERETHROUGH TRANSVERSELY TO THE GROOVE COINCIDING WITH ONE END OF THE GROOVE, AND A FILM OF METAL IN THE GROOVE AND ALSO IN THE OPENING ON THE SIDES THEREOF.
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) | 1959-05-08 | 1959-11-07 | 1960-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-05-08 | 1963-11-07 | 1964-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-05-08 | 1967-11-07 | 1968-05-08 | $7700.00 | Window Closed / Lapsed |