Abstract: An automotive type carburetor has a choke plate or valve that falls by gravity or is moved by airflow from a closed engine cranking position to a variable number of cold engine running partially closed positions as a function of the differential force between a bimetallic coiled spring and a modulating spring, the positions being independent of engine intake manifold vacuum.

Abstract: The carburetor fuel bowl has a vapor vent hole closed by a manifold vacuum opened valve to prevent fuel spillage during vehicle rollover. During engine operation with low vacuum, the accelerator pump mechanically inhibits closure of the vent valve.

Abstract: An automotive type internal combustion engine has a positive crankcase ventilation (PCV) valve metering the flow of engine blow-by gases and fumes from the engine crankcase to the intake manifold, the valve having a sonic flow passage providing flow over the entire part throttle operating range of the vehicle to provide a precise flow and predictable calibration of the flow.

Abstract: A carburetor has a manually adjustable control to simultaneously change fuel flow rates from the power valve and accelerator pump circuits to compensate for altitude changes varying the air density and thereby the air/fuel ratio of the mixture flowing from the carburetor.

Abstract: The carburetor has a conventional automatic choke construction heating a bimetallic coil by engine exhaust stove heat to slowly open the choke valve during cold weather starts; supplemental heat is provided by an electrically controlled positive temperature coefficient heater device operable above a predetermined ambient temperature to move the choke valve open faster, to reduce emissions.

Abstract: The carburetor has a conventional automatic choke construction heating a bimetallic coil by engine exhaust stove heat to slowly open the choke valve during cold weather starts; supplemental heat is provided by an electrically controlled positive temperature coefficient heater device operable above a predetermined ambient temperature to move the choke valve open faster, to reduce emissions.

Abstract: An internal combustion engine provided with an exhaust gas recirculating (EGR) system containing a vacuum/electric switch assembly activated in response to a non-movement type malfunction of the EGR valve to energize a warning light.

Abstract: A downdraft type carburetor having essentially conventional idle speed and main fuel metering systems has a throttle body or plug movable within a fixed area venturi to provide sonic flow at idle and part throttle operations; the plug is slidably mounted on a fuel tube extension of a centrally located main fuel discharge snout, and discharges fuel into a high velocity constricted area or throat formed between the plug and fixed area venturi.

Abstract: A sonic flow, plug type carburetor has an annular fuel induction slot in the periphery of the plug connected to an air/fuel mixture supply in the plug, and fuel distribution means in the plug in the form of an air turbine located adjacent the slot and in a position to receive liquid fuel from the air/fuel mixture to centrifuge the fuel globules outwardly and thinly spread the fuel as a film uniformally around the annulus of the induction slot for a uniform entry into the air stream.

Abstract: A sonic flow, plug type carburetor has an annular fuel induction slot in the outer periphery of the plug connected to an air/fuel mixture supply in the plug, and fuel distribution means in the plug in the form of a vortex chamber located adjacent the slot and receiving liquid fuel therein to centrifuge the fuel outwardly towards the slot in a thin film uniformly around the annulus of the slot.

Abstract: A multi-stage carburetor has a primary throttle bore that is extended into the intake manifold in close proximity to the exhaust gas heated manifold floor, and a secondary bore that surrounds a portion of the primary bore and terminates at the inlet to the intake manifold so as to avoid a restriction to flow of secondary air into the manifold and past the primary passage.

Abstract: A sonic flow-type carburetor having a variable area venturi defined by a conical air nozzle receiving axially within a movable matching conically-shaped plug to define a constricted annular variable area or zone between through which air flows at sonic velocity over a large portion of the operating range of the engine, the plug shape defining a diffuserless nozzle to locate the point of maximum flow velocity at the manifold edge of the plug for better atomization of the fuel and uniform distribution into the air stream for flow into the manifold, the plug having an annular fuel induction port opening into the zone and connected by conduit means to an induction-type fuel supply slot by an overlapping christmas tree-shaped slot, air also being variably supplied to the conduit means as a function of engine operation to vary the fuel induction signal and, therefore, the overall air/fuel ratio of the mixture flow to the engine.

Abstract: An engine has an air injection system injecting air into the exhaust system to reduce emissions. The injection is scheduled by a bypass valve that normally permits injection, but bypasses or dumps the air as a function of a carburetor ported vacuum signal that is also used to control exhaust gas recirculation. A control is provided to maintain air injection for a short period during certain engine idle conditions, but dumping of the air after this period. An engine deceleration override is provided to dump the air when this condition exists, to prevent backfire. A cold engine vacuum lock-out also is provided.

Abstract: A motor vehicle type engine has an exhaust gas crossover passage connecting exhaust gases to the intake manifold below the carburetor and past a selectively operable, valve type sonic flow metering control that provides very accurate and reproducible measurements of the exhaust gas flow at all times, the control comprising a variable area convergent-divergent nozzle that is so designed and constructed as to provide sonic flow of the gases through the metering area over essentially the entire operating range of the engine manifold vacuum regardless of the change in metering area, thereby providing a constant flow rate for each changed area of the nozzle, with variances in the flow rate being in direct proportion to the change in metering area.

Abstract: A carburetor has a choke apparatus including a pulldown servo to crack open the choke valve a predetermined amount once the engine has attained a running condition, to lean the air/fuel mixture. The conventional bimetallic spring is included to slowly open the choke valve wider. A locking lever is provided to lock the choke valve against return to a more closed position than that attained by the pulldown servo, to prevent stalls due to cold engine loading and loss of vacuum; the lever, however, freely permitting opening of the choke valve and also including means to reset the locking lever so that the engine can be restarted with a closed choke valve.

Abstract: A carburetor has a cold engine fuel enrichment apparatus including a single vacuum servo to progressively first crack open the choke valve a predetermined amount once the engine has attained a running condition, to lean the air/fuel mixture, and then pull the fast idle cam off the high cam step, to decrease the mixture flow to the engine, the apparatus including a slide rail cam connected to the servo and progressively engagable with cam follower surfaces on the choke valve operating linkage and the fast idle cam to accomplish the above-desired functions in an automatic manner.

Abstract: A carburetor has a vacuum servo that actuates a rotatable cam member to automatically rotate the fast idle cam off its high cam step engagement with the throttle valve adjustable idle stop screw while at the same time opening the choke valve to both lean the mixture and reduce mixture volume, for better emission control than when manually controlled as in conventional constructions.

Abstract: A fluid flow shut-off device has a number of valves which upon lateral tilting movement of the device selectively move to block flow, regardless of the direction of tilting movement.

Abstract: A four barrel carburetor is provided with apparatus that operates automatically during predetermined engine deceleration operating conditions to crack open the secondary induction passage throttle valve to supply a quantity of fuel and air to the engine that is supplemental to that being supplied through the primary induction system, to decrease the output of harmful emissions by causing a cleaner burn.

Abstract: A valve located in an engine intake manifold vacuum line is operated by differential vacuum forces to temporarily open an air bleed during engine deceleration high manifold vacuums to apply atmospheric pressure to a vacuum controlled unit that then bypasses air away from a catalytic converter and the engine to protect the converter and prevent backfire.