Patent US2879142A successfully refreshed from Google Patents.
US2879142A
Expired / Lapsed
US
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Combustible gas detector
Assignee: MSA Safety Inc
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Filing: 1955-09-21
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Granted: 1959-03-24
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Expires: 1975-09-21
Abstract
No abstract record available.
Inventors
- 👤 Clarence I Jones
- 👤 Robert A Morris
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:14
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/04; G01N27/14; G01N27/16
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
132 words
COMBUSTIBLE GAS TESTING APPARATUS COMPRISING A DETECTOR FILAMENT AND A SUBSTANTIALLY IDENTICAL COMPENSATOR FILAMENT, EACH ADAPTED TO BE BROUGHT INTO CONTACT SIMULTANEOUSLY WITH A SAMPLE OF THE GAS TO BE TESTED, BUT THE DETECTOR FILAMENT ALONE BEING ADAPTED TO CAUSE OXIDATION OF COMBUSTIBLE CONSTITUENTS THEREIN, A WHEATSTONE BRIDGE CIRCUIT INCLUDING IN ONE BRANCH THE DETECTOR AND COMPENSATOR FILAMENTS CONNECTED IN SERIES AND IN THE OTHER BRANCH FIXED RESISTANCES CONNECTED IN SERIES, A SINGLE SOURCE OF ELECTRIC POWER CONNECTED TO THE BRIDGE CIRCUIT, SERVO MEANS CONNECTED ACROSS THE DETECTOR FILAMENT AND RESPONSIVE TO CHANGES IN THE RESISTANCE OF THAT FILAMENT, THE SERVO MEANS BEING ALSO CONNECTED TO SAID POWER SOURCE AND ADAPTED TO VARY THE POWER INPUT TO THE BRIDGE CIRCUIT TO MAINTAIN THE RESISTANCE OF THE DETECTOR FILAMENT AT A PREDETERMINED VALUE.
Claim 2
Dependent Claim
132 words
COMBUSTIBLE GAS TESTING APPARATUS COMPRISING A DETECTOR FILAMENT AND A SUBSTANTIALLY IDENTICAL COMPENSATOR FILAMENT, EACH ADAPTED TO BE BROUGHT INTO CONTACT SIMULTANEOUSLY WITH A SAMPLE OF THE GAS TO BE TESTED, BUT THE DETECTOR FILAMENT ALONE BEING ADAPTED TO CAUSE OXIDATION OF COMBUSTIBLE CONSTITUENTS THEREIN, A WHEATSTONE BRIDGE CIRCUIT INCLUDING IN ONE BRANCH THE DETECTOR AND COMPENSATOR FILAMENTS CONNECTED IN SERIES AND IN THE OTHER BRANCH FIXED RESISTANCES CONNECTED IN SERIES, A SINGLE SOURCE OF ELECTRIC POWER CONNECTED TO THE BRIDGE CIRCUIT, SERVO MEANS CONNECTED ACROSS THE DETECTOR FILAMENT AND RESPONSIVE TO CHANGES IN THE RESISTANCE OF THAT FILAMENT, THE SERVO MEANS BEING ALSO CONNECTED TO SAID POWER SOURCE AND ADAPTED TO VARY THE POWER INPUT TO THE BRIDGE CIRCUIT TO MAINTAIN THE RESISTANCE OF THE DETECTOR FILAMENT AT A PREDETERMINED VALUE.
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) | 1962-03-23 | 1962-09-22 | 1963-03-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-03-23 | 1966-09-22 | 1967-03-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-03-23 | 1970-09-22 | 1971-03-24 | $7700.00 | Window Closed / Lapsed |