US3223875A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric heating tube in which enlarged convolutions of filament coil act as filament supports
Assignee: Individual
•
Filing: 1959-12-15
•
Granted: 1965-12-14
•
Expires: 1979-12-15
Abstract
No abstract record available.
Inventors
- 👤 Eggers Reinhold
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:19
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/40; H05B3/42; H05B3/44; H01; H01K; H01K1/00; H01K1/18; H01K1/24; H05B3/0033; H05B3/0038; H05B3/0057; H05B3/0071; H05B3/0076
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
98 words
ELECTRIC HEAT-GENERATING DEVICE COMPRISING A HERMETICALLY SEALED TUBULAR ENCLOSURE HAVING TWO ENDS, AN INSIDE WALL, AND AN INSIDE DIAMETER, TWO CONDUCTORS SEALED THROUGH SAID ENDS, AND AN INTEGRAL COILED FILAMENT EXTENDING APPROXIMATELY CENTRALLY WITHIN SAID ENCLOSURE AND BEING CONNECTED AT ITS ENDS TO SAID CONDUCTORS, SAID COILED FILAMENT INCLUDING A MAIN PORTION OF SMALLER CONVOLUTIONS AND AT LEAST A SINGLE LARGER CONVOLUTION, SAID MAIN PORTION HAVING A SUBSTANTIALLY CYLINDRICAL SHAPE AND AN OUTSIDE DIAMETER SMALLER THAN SAID INSIDE DIAMETER, SAID SINGLE LARGER CONVOLUTION BEING SHAPED TO PROVIDE POINT-CONTACTS WITH SAID INSIDE WALL AND THUS TO POSITION SAID FILAMENT.
Claim 2
Dependent Claim
98 words
ELECTRIC HEAT-GENERATING DEVICE COMPRISING A HERMETICALLY SEALED TUBULAR ENCLOSURE HAVING TWO ENDS, AN INSIDE WALL, AND AN INSIDE DIAMETER, TWO CONDUCTORS SEALED THROUGH SAID ENDS, AND AN INTEGRAL COILED FILAMENT EXTENDING APPROXIMATELY CENTRALLY WITHIN SAID ENCLOSURE AND BEING CONNECTED AT ITS ENDS TO SAID CONDUCTORS, SAID COILED FILAMENT INCLUDING A MAIN PORTION OF SMALLER CONVOLUTIONS AND AT LEAST A SINGLE LARGER CONVOLUTION, SAID MAIN PORTION HAVING A SUBSTANTIALLY CYLINDRICAL SHAPE AND AN OUTSIDE DIAMETER SMALLER THAN SAID INSIDE DIAMETER, SAID SINGLE LARGER CONVOLUTION BEING SHAPED TO PROVIDE POINT-CONTACTS WITH SAID INSIDE WALL AND THUS TO POSITION SAID FILAMENT.
References Cited (Backward Citations)
US2342044A
Cited
US2523033A
Cited
US2859368A
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US2864025A
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US2883571A
Cited
US2957154A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-12-13 | 1969-06-14 | 1969-12-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-12-13 | 1973-06-14 | 1973-12-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-12-13 | 1977-06-14 | 1977-12-14 | $7700.00 | Window Closed / Lapsed |