US3928837A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ceramic oxide resistor element
Assignee: Robert Bosch GmbH
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Filing: 1974-09-06
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Granted: 1975-12-23
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Expires: 1994-09-06
Abstract
Abstract A ceramic oxide thermistor having a negative temperature coefficient at elevated temperatures comprising about 30% to 100% Fe2O3 and 0% to 70% Al2O3. It preferably also contains MnO. The invention also includes a process for manufacturing said thermistor.
Inventors
- 👤 Friedrich J Esper
- 👤 Karl-Hermann Friese
- 👤 Rudolf Pollner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:22
CPC Classifications
H; H01; H01C; H01C7/00; H01C7/04; H01C7/042; H01C7/043; H01C7/046
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
43 words
A CERAMIC OXIDE RESISTANCE ELEMENT HAVING A NEGATIVE TEMPERATURE COEFFICIENT AT TEMPERATURES ABOVE ABOUT 200*C COMPRISING A SHAPED BODY COMPRISING FE2O3 ABOUT 50% BY WEIGHT OF AL2O3 AND MNO IN WEIGHT PERCENT BASED ON THE TOTAL FE2O3 AND AL2O3 WITHIN THE RANGE OF
Claim 2
Dependent Claim
43 words
A CERAMIC OXIDE RESISTANCE ELEMENT HAVING A NEGATIVE TEMPERATURE COEFFICIENT AT TEMPERATURES ABOVE ABOUT 200*C COMPRISING A SHAPED BODY COMPRISING FE2O3 ABOUT 50% BY WEIGHT OF AL2O3 AND MNO IN WEIGHT PERCENT BASED ON THE TOTAL FE2O3 AND AL2O3 WITHIN THE RANGE OF
Claim 3
Dependent Claim
13 words
The resistance element of claim 1 wherein said electrical conductors are platinum conductors.
Claim 4
Dependent Claim
13 words
The resistance element of claim 1 wherein said electrical conductors are gold conductors.
Claim 5
Dependent Claim
13 words
The resistance element of claim 1 wherein said electrical conductors are silver conductors.
Claim 6
Dependent Claim
13 words
The resistance element of claim 1 wherein X is from 0.9 to 4.5.
Claim 7
Dependent Claim
23 words
The resistance element of claim 1 wherein said shaped body comprises about 50% Al2O3, between 0.1 and 2% MnO, and the balance Fe2O3.
Claim 8
Dependent Claim
18 words
The resistance element of claim 6 wherein said shaped body contains about 0.1% MnO and about 49.9% Fe2O3.
Claim 9
Dependent Claim
18 words
The resistance element of claim 6 wherein said shaped body contains about 0.2% MnO and about 49.8% Fe2O3.
Claim 10
Dependent Claim
18 words
The resistance element of claim 6 wherein said shaped body contains about 0.4% MnO and about 49.6% Fe2O3.
Claim 11
Dependent Claim
18 words
The resistance element of claim 6 wherein said shaped body contains about 2% MnO and about 48% Fe2O3.
References Cited (Backward Citations)
US2258646A
Cited
US2616859A
Cited
US2674583A
Cited
US2626445A
Cited
US2720573A
Cited
US3359632A
Cited
US3477055A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-22 | 1979-06-23 | 1979-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-22 | 1983-06-23 | 1983-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-22 | 1987-06-23 | 1987-12-23 | $7700.00 | Window Closed / Lapsed |