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US 4,044,738 AGranted
Pollution control arrangements for engines
AssigneeThe Lucas Electrical Company Limited
InventorsMalcolm Williams, Christopher Robin Jones
Life of this patent
Estimating the term…
Abstract
An engine exhaust recirculating valve is operated by a solenoid. The valve is normally open, but has an electronic control circuit, including an engine speed transducer, which energizes the solenoid to close the valve when the engine speed is above a predetermined level.
Claims6
A pollution control arrangement for an engine including a valve by way of which exhaust gases can be recirculated, a solenoid which when energized closes said valve, and electronic control means energizing said solenoid when the engine speed is above a predetermined level, said control means comprising:
- an engine speed transducer for producing an a.c. signal of frequency proportional to the engine speed;
- and
- means sensitive to said frequency of said a.c. signal for continuously energizing said solenoid when the frequency of said signal is above a predetermined level.
Dependencies are inferred from the claim text.