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USRE27993E Expired / Lapsed US ⏱️ 0.0 years remaining

Exhaust recirculation control for an engine

Assignee: —
•
Filing: 1972-04-20
•
Granted: 1974-04-30
•
Expires: 1992-04-20
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Abstract

Abstract THIS INVENTION PERTAINS TO A DEVICE TO CONTROL RECIRCULATION OF SOME OF THE EXHAUST GASES CARBURETED IN A FOUR STROKE CYCLE INTERNAL COMBUSTION ENGINE DURING SOME SELECTED DRIVING CYCLES BUT NOT ALL TO REDUCE THE NITROGEN OXIDES IN THE EXHAUST. NITROGEN OXIDES ARE PRODUCED IN THE COMBUSTION CHAMBER OF AN ENGINE WHEN THE TEMPERATURES OF COMBUSTION ARE HIGH AND THE MIXTURE IS LEAN. THEY ARE USUALLY LOWER AND WITHIN THE PRESENT AND CONTEMPLATED FUTURE LIMITS OF CONTROL WHEN (1) THE ENGINE IS IDLING AND ON VERY LOW POWER AT LOWER SPEEDS (2) AT HIGH POWER WHEN THE POWER VALVE ENRICHES THE MIXTURE OVER THE LEVEL CRUISE MIXTURE AS NITROGEN OXIDES ARE NOT PRESENT IN AS LARGE A PERCENT WITH A RICH OR SUBSTANTIALLY RICHER THAN LEAN MIXTURE.

Inventors

No inventors recorded.

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 14:01
CPC Classifications
F; F02; F02D; F02D21/00; F02D21/06; F02D21/08; F02M; F02M26/00; F02M26/13; F02M26/42; F02M26/44

Claims Analysis

Total Claims: 0
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References Cited (Backward Citations)

No citation records indexed.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1977-04-29 1977-10-29 1978-04-30 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1981-04-29 1981-10-29 1982-04-30 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1985-04-29 1985-10-29 1986-04-30 $7700.00 Window Closed / Lapsed

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