Abstract: A fuel metering system for a combustion engine carburetor utilizes a non-convoluted, planar, flexible diaphragm which does not require a molding process to form a traditional convolution. The diaphragm defines in part a pressure controlled fuel metering chamber on one side and a reference chamber at atmospheric pressure on the other side. During operation of the engine, sub-atmospheric pressure within a fuel and air mixing passage draws fuel from the metering chamber to mix with air for combustion within the engine. As pressure within the metering chamber thus decreases, the diaphragm flexes into metering chamber. The displacement of the diaphragm actuates a flow control valve of the metering system which flows pressurized make-up fuel into the metering chamber until the diaphragm returns to its datum position.

Abstract: A carburetor with a valve assembly having a plastic cam body connected to a plastic shaft which extends into the carburetor body and a valve head press-fit into a slot formed through the plastic shaft. Desirably, the valve assembly eliminates the use of threaded fasteners and the need to swage or otherwise deform any of the components to connect them together. Desirably, the shaft and cam body are constructed and arranged to prevent relative rotation between them. This permits accurate location of the cam body on the shaft and facilitates calibration of the throttle valve assembly between its idle and wide open throttle positions. Further, the characteristics of the throttle valve assembly can be changed by simply providing a cam body having a different shape or construction with the shaft and/or valve disc being the same for a wide range of carburetors.

Abstract: An injection molded component having at least one structural layer of material and at least one fuel vapor barrier layer carried by the structural layer, and a method of making it utilizing separately injection molded structural and fuel vapor barrier layers. The vapor barrier layer may be trapped between two other interconnected layers, or may be bonded to a structural layer by an adhesive. In one form, a fuel vapor barrier layer and a structural layer are separately molded onto a preformed adhesive layer. Desirably, the heat generated during the steps of molding both the vapor barrier layer and the structural layer onto the adhesive layer is sufficient to activate the adhesive and bond the layers together. In another form, a fuel vapor barrier layer is bonded to a layer comprised of a blend of structural and adhesive materials. In yet another form, a fuel vapor barrier layer is disposed and captured between two interconnected structural layers.

Abstract: A fuel evaporative emission control apparatus in a carburetor which prevents diurnal evaporation to the atmosphere of fuel from a remote fuel tank through a fuel bowl or fuel chamber of a float-type carburetor. One or more shut-off valves in the carburetor are yieldably biased to a shut-off position. Only upon engine operation or user intervention will the fuel shut-off valve move to an open or on position. In this way, reliance upon the engine user is not required to reduce evaporative emissions.

Abstract: A high flow rate fuel vapor vent and rollover valve assembly with a float valve that provides a progressive closing of a vapor outlet to control the venting of fuel vapors from a fuel tank and the addition of liquid fuel to the tank. The float closes a portion of the vapor outlet in response to liquid fuel at a first level in a vehicle fuel tank. A body completely closes the vapor outlet in response to rollover attitudes of the vehicle. One or more separate baffles are constructed and arranged to prevent the escape of liquid fuel through the vapor outlet.

Abstract: A carburetor having a first valve to control the application of pressure pulses to a fuel metering assembly of the carburetor through a first flow path and a second valve which controls at least a second flow path to provide an enriched fuel and air mixture to the engine to facilitate starting the engine and warming it up. The pressure pulses are preferably applied to a fuel metering diaphragm to actuate the diaphragm and cause a richer than normal fuel and air mixture to be delivered to the engine. Desirably, a maximum enrichment of the fuel and air mixture is obtained when at least one valve is open to facilitate starting the engine, and a lesser enrichment of the mixture may be obtained by closing a valve to facilitate warming the engine up after it is initially started.

Abstract: A fuel pressure regulation system for an internal combustion engine to regulate fuel pressure using a two-state pressure switch. In addition to the pressure switch, the system includes a control circuit, a current sensor, and a fuel pressure control device such as a fuel pump. The control circuit uses the pressure switch to sense whether the downstream fuel pressure is above or below a desired reference pressure. When below the reference pressure, the control circuit drives the fuel pump at full on to increase the fuel line pressure to the reference pressure. Once the fuel pressure rises and increases to or past the reference pressure, the pressure switch changes state, at which point the current sensor is used to sample and record the magnitude of the electric current supplied to the fuel pump at the moment the switch state changes.

Abstract: Method of and mechanism for regulating fuel feed from a rotary valve type carburetor to an associated engine. A carburetor bypass air passage variably communicates the throttle valve hole with a bypass air source at engine idle setting of the throttle valve. The bypass air passage outlet is closed by movement of the throttle valve out of idle setting toward high speed. At an initial carburetor-to-engine set-up and calibration, a bypass regulating valve is maintained open while the engine is running at idle speed. Then the fuel-regulating needle is adjusted to maximum fuel to air (F/A) mixture ratio permitted by applicable engine exhaust quality regulations, and then is permanently set and sealed. During subsequent end user operation of the engine, the bypass valve is closed only when preparing to crank the engine for starting to thereby provide an enriched fuel-to-air mixture for starting of the engine. When the engine is running under its own power the bypass valve is maintained open.

Abstract: A fuel level sensor for use with a vehicle fuel tank includes a magnet carrying float assembly that rises and falls with the fuel level to open and close various magnetically activated reed-switches located at different axial positions along a vertically extending electrical circuit. Activating a reed-switch located at a particular vertical position along the electrical circuit causes the overall resistance of the circuit to depend upon the position of the float assembly. The float assembly is capable of freely rotating about the vertical axis of the electrical circuit and carries magnets producing a horizontal magnetic field that can activate a reed-switch from any angular orientation of the float assembly. Thus, assuming the fuel level sensor is provided with a constant voltage source, the sensor is able to determine the fuel level by the amount of electrical current flowing through the circuit.

Abstract: A carburetor having a throttle valve co-rotatable with a small diameter throttle shaft having a free end protruding from an exterior side surface of the associated carburetor body. A throttle lever detent arm is co-rotatable on and with the throttle shaft free end adjacent each body surface. Interengageable detents on the detent arm and body surface are spaced radially away from the throttle shaft rotational axis by a distance, for example, of about three times the shaft diameter. The arm and body detents are releasably engageable with one another for thereby yieldably holding the detent arm and hence the throttle shaft and associated throttle valve in any one of a plurality of selected angular settings.

Abstract: A carburetor with a manual priming pump having an integrated fuel drain which provides both the engine manufacturer and end user with an easy way to drain fuel from a fuel chamber of the carburetor. The priming pump has a pump chamber defined by a resilient priming bulb. The pump chamber generally communicates between the fuel chamber and a fuel-and-air mixing passage of the carburetor body and is preferably positioned above the fuel chamber. The dual function of the manual priming pump, prime or drain, is switched by a valve with a rotatable selector member received between a seat and the resilient priming bulb of the pump. The selector member moves between a drain position and a priming position thus enabling draining of the fuel chamber or priming of the carburetor via successive manual depressions of the priming bulb.

Abstract: A glass-sealed electrical fitting for an automotive fuel tank is mounted on a flange which supports an internal fuel pump and fuel level sensor within the fuel tank. In one form, the glass seal surrounds a plurality of pins longitudinally disposed within an elongated housing which penetrates a fuel tank wall. An outer surface of the housing engages rigidly to the flange, and an inner surface of the housing engages to the glass seal. In another form each pin is sealed to a housing by a separate glass seal.

Abstract: A regenerative type electric motor fuel pump has a vapor vent passage disposed outside of a fuel pumping channel and communicating the fuel pumping channel with the exterior of the fuel pump to vent fuel vapor from the fuel pumping channel. The vapor vent passage extends through one of a pair of end plates between which a pump impeller is received for rotation. Preferably, the vapor vent passage communicates with the fuel-pumping channel through a connecting slot in the end plate.

Abstract: A shield structure for reducing radio frequency interference (RFI) from an electric motor situated within a fuel pump housing having an end with a fuel inlet and another end with a fuel outlet. The shield structure includes, first of all, an electrically insulative and hollow cup-like outer cover mountable on an end of the fuel pump housing adjacent the brushes and commutator of the electric motor. The outer cover has an inner surface, an outer surface, and preferably a fuel outlet opening defined therethrough. In addition, the shield structure includes an electrically conductive outer coat layer formed on substantially all of the outer surface of the outer cover. Lastly, the shield structure includes means for electrically grounding the outer coat layer to the electric motor of the fuel pump housing.

Abstract: A fuel needle valve assembly of a carburetor has a retainer which yieldingly restrains the rotational fuel flow setting capability of the needle valve. The retainer engages a shank of the needle valve and a parallel shaft, both of which project from the carburetor body. The retainer exerts a force which laterally displaces the projecting shank with respect to the shaft. The retainer has sufficient strength to ensure the factory set rotational setting of the fuel needle valve does not alter when a limiter cap is press fitted to a distal head of the needle. Furthermore, wherein the shaft is also a shank of a second needle valve, the same retainer laterally displaces the projecting shanks of both needle valves.

Abstract: A carburetor preferably of a diaphragm type for an internal combustion engine has a low speed circuit for starting and idling of a cold engine. An air bleed line of the low speed circuit communicates between an inlet of a fuel and air mixing passage of the carburetor and an emulsifying chamber of the low speed circuit. Fuel flows to the emulsifying chamber from a fuel metering chamber and is regulated by a low speed idling adjustment needle screw. The bleed air and the fuel mixes within the emulsifying chamber and flows into the mixing passage between the throttle valve and the outlet of the mixing passage. Promoting this flow is a high vacuum produced by cranking and idling of the engine and accentuated by the substantially closed throttle valve. The fuel-and-air mixture is rich during cold idling as a result of the closed air bleed line. When the engine warms up, the air bleed line is opened via the restrictor valve.

Abstract: A carburetor for a small internal combustion engine has a manual priming fuel pump with a resilient valve for allowing fuel flow in a first direction and for preventing fuel flow in a second direction. The resilient valve is reinforced with longitudinally extending ribs to prevent recirculation of fuel through an outlet orifice of the valve in a running engine. The outlet orifice is defined by a distal end of a tubular portion of the valve press fitted and projecting into an outlet passage that communicates with a pump chamber defined by a resilient domed cap. The ribs project laterally outward from the tubular portion within the outlet passage. Integral with an opposite end of the resilient valve is a head which flexes outward to open an inlet passage which then communicates with the pump chamber.

Abstract: A flange seal assembly for a multi-layered plastic fuel tank having a wall with a permeation barrier layer encapsulated by inner and outer layers. The wall is blow molded about a ring so that the outer layer alone is in actual contact with the ring. The permeation barrier layer is exposed and engaged by a resilient seal. A locking member is located outboard of a flange which engages the seal. Engagement of the locking member with the ring produces a force compressing the seal against the flange and the permeation barrier layer.

Abstract: A carburetor having a first valve to control the application of pressure pulses to a fuel metering assembly of the carburetor through a first flow path and a second valve which controls application of pressure pulses to the fuel metering assembly through at least a second flow path to provide an enriched fuel and air mixture to the engine to facilitate starting the engine and warming it up. The pressure pulses are preferably applied to a fuel metering diaphragm to actuate the diaphragm and cause a richer than normal fuel and air mixture to be delivered to the engine. Desirably, a maximum enrichment of the fuel and air mixture is obtained when both valves are open to facilitate starting the engine, and a lesser enrichment of the mixture may be obtained when only one valve is open to facilitate warming the engine up after it is initially started.

Abstract: A diaphragm type carburetor which has a purge system to remove air and fuel vapor from the carburetor and to fill it with liquid fuel prior to starting an engine fed by the carburetor. The purge system has a primer valve actuated by moving a choke valve of the carburetor to its closed position to inject a small volume of liquid fuel into a throttle bore to provide a richer fuel and air mixture to the engine to facilitate starting it. Desirably, the small volume of liquid fuel is injected into the throttle bore in response to closing of the choke valve without requiring any additional steps such as depressing a button on the carburetor, to do so. Preferably, the choke valve is carried on a shaft which has at least one detent formed therein to provide a camming surface which actuates the primer valve as the choke valve is rotated from its open position to its closed position. Preferably, the choke valve shaft has a pair of detents.