Abstract: A system for measuring air flow rate in a duct includes an air flow sensor and an air flow conditioning device for collecting and accelerating a portion of the total air stream to the sensor, which may be means as known in the art. The conditioning device includes two opposed converging walls defining a nozzle, preferably a venturi, the sensor being disposed in the throat of the nozzle. The surfaces of the venturi walls are textured to trip the boundary layer near the wall surface into turbulence to maintain attachment of flowing air to the walls even when the angle of attack of the air is significantly non-axial. The wall texturing may be random or may be an organized pattern. A further embodiment includes a second flow conditioner/sensor in parallel with the first whereby an averaged flow measurement is taken for a more accurate reading.

Abstract: A bi-directional mass air flow sensing device for measuring air flow, comprising a bridge circuit coupled across a voltage potential, wherein the bridge circuit comprises a first side including first and second temperature dependent sensor resistors connected in series and disposed on a thermally insulative substrate window in line with an air flow and arranged such that relative to a first direction of air flow, the first sensor resistor is upstream of the second sensor resistor, and a second side in parallel with the first side and including third and fourth temperature dependent sensor resistors connected in series and disposed on the thermally insulative substrate in line with the air flow such that relative to the first direction of air flow, the third sensor resistor is upstream of the fourth sensor resistor, and a temperature dependent balance resistor connected between the first and second temperature dependent sensor resistors on the first side of the bridge circuit.

Abstract: A bi-directional mass air flow sensing device for measuring air flow, comprising a bridge circuit coupled across a voltage potential, wherein the bridge circuit comprises a first side including first and second temperature dependent sensor resistors connected in series and disposed on a thermally insulative substrate window in line with an air flow and arranged such that relative to a first direction of air flow, the first sensor resistor is upstream of the second sensor resistor, and a second side in parallel with the first side and including third and fourth temperature dependent sensor resistors connected in series and disposed on the thermally insulative substrate in line with the air flow such that relative to the first direction of air flow, the third sensor resistor is upstream of the fourth sensor resistor, and a temperature dependent balance resistor connected between the first and second temperature dependent sensor resistors on the first side of the bridge circuit.

Abstract: A modular fuel sender in a fuel tank of a motor vehicle includes a reservoir, a fuel pump in the reservoir, a low pressure conduit conducting hot return fuel back to the reservoir, a secondary pump in the reservoir for pumping new fuel from the tank into the reservoir, and a control which effects a recirculation mode of secondary pump operation when the new fuel level in the fuel tank is above a predetermined low level and a scavenge mode of secondary pump operation when the new fuel level in the reservoir is below the predetermined low level. In the recirculation mode, the secondary pump recirculates reservoir fuel to avoid overflowing hot fuel into the fuel tank. In the scavenge mode, the secondary pump continuously maintains a partial vacuum in a screen in the fuel tank regardless of the fuel level in the reservoir to maximize new fuel scavenged from the fuel tank before fuel starvation occurs.

Abstract: In a fuel delivery apparatus including a canister in an automobile fuel tank, an electric fuel pump in the canister having two rotating elements from which three stages of pump operation are derived. A housing of the fuel pump has two cavities in which the two rotating elements are disposed. A first element has a web which divides the corresponding cavity into first and second stage pump chambers. The second element in the second cavity cooperates therewith in defining a third stage pump chamber. When the motor is on, vane pockets on one side of the web in the first pump chamber pump fuel from the fuel tank into the canister. Vane pockets on the other side of the web in the second pump chamber pump fuel from the canister to the third stage pump chamber. The second pump element pumps fuel into the interior of the fuel pump at a high pressure compatible with the requirements of internal combustion engine fuel injection systems. Vapor is separated from the fuel in the second stage pump chamber.

Abstract: An automotive fuel system including a reservoir having upper and lower chambers on opposite sides of a partition in the reservoir, a high pressure fuel pump having an inlet connected to the lower chamber, a low pressure fuel overage return pipe returning overage fuel directly to the lower chamber, and a low pressure pump transferring fuel from the tank directly to the upper chamber. A drain in the partition conducts gravity induced fuel flow from the upper chamber to the lower chamber at a rate equal to the difference between the rate at which the high pressure pump withdraws fuel from the lower chamber and the rate at which overage is returned to the lower chamber through the overage return pipe.