US3328677A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermistor detector
Assignee: J E WATKINS CO
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Filing: 1964-04-16
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Granted: 1967-06-27
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Expires: 1984-04-16
Abstract
No abstract record available.
Inventors
- 👤 Robert A Naegele
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:30
CPC Classifications
G; G05; G05D; G05D9/00; G05D9/12; Y; Y10; Y10T; Y10T137/00; Y10T137/7287; Y10T137/7306
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
150 words
IN A SYSTEM FOR DETECTING CHANGES IN CONDITION OF A SURROUNDING MEDIUM, INCLUDING MEANS FOR ENERGIZING A THERMOELECTRIC HEATING ELEMENT AND MEANS FOR DETECTING CHANGES IN RESISTANCE OF A NEGATIVE TEMPERATURE COEFFICIENT THERMOELECTRIC RESISTANCE ELEMENT, BOTH SAID ELEMENTS BEING DISPOSED (I) IN HEAT TRANSFER PROXIMITY TO EACH OTHER AND (II) IN SAID SURROUNDING MEDIUM, THE IMPROVEMENT WHEREBY THE HEAT OUTPUT OF SAID HEATING ELEMENT IS SELFLIMITED TO THEREBY AVOID DAMAGE BY EXCESSIVE HEAT, WHICH COMPRISES A PROBE FOR SAID SYSTEM INCLUDING: (A) A NEGATIVE TEMPERATURE COEFFICIENT THERMISTOR AS SAID RESISTANCE ELEMENT, SAID THERMISTOR HAVING A CHARACTERISTIC OF RAPIDLY DECREASING RESISTANCE WITH INCREASING TEMPERATURE, AND (B) A POSITIVE TEMPERATURE COEFFICIENT THERMISTOR AS SAID HEATING ELEMENT, SAID THERMISTOR HAVING A CHARACTERISTIC OF SUBSTANTIALLY CONSTANT RESISTANCE BELOW A SWITCHING POINT TEMPERATURE AND A RAPIDLY INCREASING RESISTANCE WITH INCREASING TEMPERATURE ABOVE A SWITCHING POINT TEMPERATURE WHEREBY THE HEAT OUTPUT OF SAID THERMISTOR IS SELF-LIMITED.
Claim 2
Dependent Claim
150 words
IN A SYSTEM FOR DETECTING CHANGES IN CONDITION OF A SURROUNDING MEDIUM, INCLUDING MEANS FOR ENERGIZING A THERMOELECTRIC HEATING ELEMENT AND MEANS FOR DETECTING CHANGES IN RESISTANCE OF A NEGATIVE TEMPERATURE COEFFICIENT THERMOELECTRIC RESISTANCE ELEMENT, BOTH SAID ELEMENTS BEING DISPOSED (I) IN HEAT TRANSFER PROXIMITY TO EACH OTHER AND (II) IN SAID SURROUNDING MEDIUM, THE IMPROVEMENT WHEREBY THE HEAT OUTPUT OF SAID HEATING ELEMENT IS SELFLIMITED TO THEREBY AVOID DAMAGE BY EXCESSIVE HEAT, WHICH COMPRISES A PROBE FOR SAID SYSTEM INCLUDING: (A) A NEGATIVE TEMPERATURE COEFFICIENT THERMISTOR AS SAID RESISTANCE ELEMENT, SAID THERMISTOR HAVING A CHARACTERISTIC OF RAPIDLY DECREASING RESISTANCE WITH INCREASING TEMPERATURE, AND (B) A POSITIVE TEMPERATURE COEFFICIENT THERMISTOR AS SAID HEATING ELEMENT, SAID THERMISTOR HAVING A CHARACTERISTIC OF SUBSTANTIALLY CONSTANT RESISTANCE BELOW A SWITCHING POINT TEMPERATURE AND A RAPIDLY INCREASING RESISTANCE WITH INCREASING TEMPERATURE ABOVE A SWITCHING POINT TEMPERATURE WHEREBY THE HEAT OUTPUT OF SAID THERMISTOR IS SELF-LIMITED.
References Cited (Backward Citations)
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US2926299A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-06-26 | 1970-12-26 | 1971-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-06-26 | 1974-12-26 | 1975-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-06-26 | 1978-12-26 | 1979-06-27 | $7700.00 | Window Closed / Lapsed |