US3399398A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Combustible gas monitoring system
Assignee: MSA Safety Inc
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Filing: 1965-07-27
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Granted: 1968-08-27
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Expires: 1985-07-27
Abstract
No abstract record available.
Inventors
- 👤 Becker Earl Matthew
- 👤 Mcinnes Alexander Crawford
- 👤 Heller Herbert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:55
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/04; G01N27/14; G01N27/16; G08; G08B; G08B17/00; G08B17/10; G08B17/117
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
193 words
A MONITORING AND ALARM SYSTEM FOR COMBUSTIBLE GASES COMPRISING IN COMBINATION: MEANS FOR PROVIDING A DC VOLTLAGE; MAGNETIC AMPLIFIER MEANS COUPLED TO SAID MEANS FOR PROFIDING A DC VOLTAGE AND BEING PROWERED THEREBY; A COMBUSTIBLE GAS DETECTOR CIRCUIT COUPLED TO SAID MAGNETIC AMPLIFIER MEANS AND SAID MEANS FOR PROVIDING A DC VOLTAGE AND HAVING AN ELECTRICAL BRIDGE CIRCUIT WHICH IS RESPONSIVE TO THE PRESENCE OF A COMBUSTIBLE GAS FOR GENERATING A SIGNAL WHICH IS TRANSLATED TO SAID MAGNETIC AMPLIFIER MEANS WHICH IN TURN GENERATES A PULSATING OUTPUT SIGNAL AS LONG AS SAID BRIDGE CIRCUIT SENSES SAID COMBUSTIBLE GAS OF A FIRST PREDETERMINED LEVEL OF CONCENTRATION BUT GENERATES A STEADY STATE OUTPUT SIGNAL FOR A SECOND LEVEL OF CONCENTRATION; AN ALARM CIRCUIT BEING RESPONSIVE TO SAID PULSATING AND STEADY STATE OUTPUT SIGNAL COUPLED TO SAID MAGNETIC AMPLIFIER MENS, AND INCLUDING MEANS FOR SHUTTING DOWN AN APPARATUS UNDER CONTROL WHEN SAID COMBUSTIBLE GAS OF SAID SECOND PREDETERMINED LEVEL PERSISTS FOR A PRESET PERIOD OF TIME AND DELAYS THE POSSIBLE SUBSEQUENT TURNING ON OF SAID APPARTUS UNDER CONTROL FOR STILL ANOTHER PRESET PERIOD OF TIME AFTER SAID OUTPUT SIGNAL CEASES SIGNIFYING A SAFE CONDITION FOR OPERATION.
Claim 2
Dependent Claim
193 words
A MONITORING AND ALARM SYSTEM FOR COMBUSTIBLE GASES COMPRISING IN COMBINATION: MEANS FOR PROVIDING A DC VOLTLAGE; MAGNETIC AMPLIFIER MEANS COUPLED TO SAID MEANS FOR PROFIDING A DC VOLTAGE AND BEING PROWERED THEREBY; A COMBUSTIBLE GAS DETECTOR CIRCUIT COUPLED TO SAID MAGNETIC AMPLIFIER MEANS AND SAID MEANS FOR PROVIDING A DC VOLTAGE AND HAVING AN ELECTRICAL BRIDGE CIRCUIT WHICH IS RESPONSIVE TO THE PRESENCE OF A COMBUSTIBLE GAS FOR GENERATING A SIGNAL WHICH IS TRANSLATED TO SAID MAGNETIC AMPLIFIER MEANS WHICH IN TURN GENERATES A PULSATING OUTPUT SIGNAL AS LONG AS SAID BRIDGE CIRCUIT SENSES SAID COMBUSTIBLE GAS OF A FIRST PREDETERMINED LEVEL OF CONCENTRATION BUT GENERATES A STEADY STATE OUTPUT SIGNAL FOR A SECOND LEVEL OF CONCENTRATION; AN ALARM CIRCUIT BEING RESPONSIVE TO SAID PULSATING AND STEADY STATE OUTPUT SIGNAL COUPLED TO SAID MAGNETIC AMPLIFIER MENS, AND INCLUDING MEANS FOR SHUTTING DOWN AN APPARATUS UNDER CONTROL WHEN SAID COMBUSTIBLE GAS OF SAID SECOND PREDETERMINED LEVEL PERSISTS FOR A PRESET PERIOD OF TIME AND DELAYS THE POSSIBLE SUBSEQUENT TURNING ON OF SAID APPARTUS UNDER CONTROL FOR STILL ANOTHER PRESET PERIOD OF TIME AFTER SAID OUTPUT SIGNAL CEASES SIGNIFYING A SAFE CONDITION FOR OPERATION.
References Cited (Backward Citations)
US2499806A
Cited
US3147465A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1971-08-27 | 1972-02-26 | 1972-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-08-27 | 1976-02-26 | 1976-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-08-27 | 1980-02-26 | 1980-08-27 | $7700.00 | Window Closed / Lapsed |