US3087795A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hot wire gas detector and indicator
Assignee: MSA Safety Inc
•
Filing: 1962-02-26
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Granted: 1963-04-30
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Expires: 1982-02-26
Abstract
No abstract record available.
Inventors
- 👤 Edward J Ross
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 10:06
CPC Classifications
G; G01; G01N; G01N25/00; G01N25/20; G01N25/22; G01N25/28; G01N25/34; G01N25/36
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
158 words
FOR USE WITH A COMBUSTIBLE GAS DETECTOR OF KNOWN TYPE THAT INCLUDES A PAIR OF HEAT EXPANDABLE ELECTRICAL RESISTANCE MEMBERS HAVING EQUAL THERMAL EXPANSION CHARACTERISTICS, IN WHICH THE FIRST OF SAID RESISTANCE MEMBERS ALONE INCLUDES A CATALYST TO PROMOTE THE OXIDATION OF COMBUSTIBLE GAS AT THE SURFACE OF SAID MEMBER, AND THAT INCLUDES MEANS FOR MEASURING DIFFERENTIAL LINEAR EXPANSION BETWEEN THE FIRST AND SECOND RESISTANCE MEMBERS, THE IMPROVEMENT THAT COMPRISES: A RESISTOR CONNECTED IN SERIES WITH THE FIRST RESISTANCE MEMBER; A SOURCE OF ELECTRICAL CURRENT CONNECTED IN PARALLEL ACROSS (1) THE FIRST RESISTANCE MEMBER AND THE RESISTOR AND (2) THE SECOND RESISTANCE MEMBER; SAID RESISTOR BEING EFFECTIVE TO REDUCE THE CURRENT FLOWING THROUGH THE FIRST RESISTANCE MEMBER BY AN AMOUNT PROPORTIONAL TO THE HEAT OF COMBUSTION OF THE COMBUSTIBLE GAS AT A DEFINED CRITICAL CONCENTRATION AT THE SURFACE OF SAID MEMBER, WHEREBY AT SAID CRITICAL CONCENTRATION THE FIRST AND SECOND RESISTANCE MEMBERS WILL BE AT THE SAME TEMPERATURE.
Claim 2
Dependent Claim
158 words
FOR USE WITH A COMBUSTIBLE GAS DETECTOR OF KNOWN TYPE THAT INCLUDES A PAIR OF HEAT EXPANDABLE ELECTRICAL RESISTANCE MEMBERS HAVING EQUAL THERMAL EXPANSION CHARACTERISTICS, IN WHICH THE FIRST OF SAID RESISTANCE MEMBERS ALONE INCLUDES A CATALYST TO PROMOTE THE OXIDATION OF COMBUSTIBLE GAS AT THE SURFACE OF SAID MEMBER, AND THAT INCLUDES MEANS FOR MEASURING DIFFERENTIAL LINEAR EXPANSION BETWEEN THE FIRST AND SECOND RESISTANCE MEMBERS, THE IMPROVEMENT THAT COMPRISES: A RESISTOR CONNECTED IN SERIES WITH THE FIRST RESISTANCE MEMBER; A SOURCE OF ELECTRICAL CURRENT CONNECTED IN PARALLEL ACROSS (1) THE FIRST RESISTANCE MEMBER AND THE RESISTOR AND (2) THE SECOND RESISTANCE MEMBER; SAID RESISTOR BEING EFFECTIVE TO REDUCE THE CURRENT FLOWING THROUGH THE FIRST RESISTANCE MEMBER BY AN AMOUNT PROPORTIONAL TO THE HEAT OF COMBUSTION OF THE COMBUSTIBLE GAS AT A DEFINED CRITICAL CONCENTRATION AT THE SURFACE OF SAID MEMBER, WHEREBY AT SAID CRITICAL CONCENTRATION THE FIRST AND SECOND RESISTANCE MEMBERS WILL BE AT THE SAME TEMPERATURE.
References Cited (Backward Citations)
US2645564A
Cited
US2745721A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1966-04-29 | 1966-10-29 | 1967-04-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1970-04-29 | 1970-10-29 | 1971-04-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1974-04-29 | 1974-10-29 | 1975-04-30 | $7700.00 | Window Closed / Lapsed |