Patents Assigned to Walbro Corporation
  • Patent number: 6457460
    Abstract: A fuel system for a marine engine has a recirculation cooler which receives a portion of fuel discharged from a fuel pump, cools that fuel, and then returns the cooled fuel to the inlet of the fuel pump to reduce fuel vapor formation and to cool the pump as the cooled fuel flows through the pump. The recirculation cooler is preferably formed of a material of high thermal conductivity and has a water passage adjacent to the fuel passage to reduce the temperature of the fuel that flows through the recirculation cooler. The recirculation cooler is preferably used in high heat applications or with a speed controlled fuel pump, with a pulse width modulated drive, for example. In these applications, during at least some fuel flow conditions, the flow of fuel through the fuel pump may be insufficient to cool the fuel pump motor and may cause increased fuel vapor formation.
    Type: Grant
    Filed: November 13, 2000
    Date of Patent: October 1, 2002
    Assignee: Walbro Corporation
    Inventors: Kirk D. Doane, Jason D. Hatton, Edward J. Talaski
  • Patent number: 6454246
    Abstract: A carburetor has an upper body and a lower separate nozzle post member that extends into the fuel chamber of a lower fuel bowl. The nozzle post member has a main nozzle mixing passage leading from a main fuel jet inlet to a nozzle. An annular air passage and an annular idle fuel passage surround the mixing passage. The nozzle post member also has integrally formed brackets to pivotally mount the fuel float.
    Type: Grant
    Filed: November 17, 2000
    Date of Patent: September 24, 2002
    Assignee: Walbro Corporation
    Inventors: Timothy K. Grifka, Terry O. Hendrick, Kevin L. Israelson, Eric L. King, Albert L. Sayers, John C. Woody
  • Patent number: 6446939
    Abstract: A modular diaphragm carburetor is provided which has a plurality of plates each with generally planar faces adapted to be mated and releasably connected together to facilitate manufacturing and assembling the carburetor and to permit various plates and components of the carburetor to be used in carburetors designed for use with different engine families. By providing a plurality of mated together plates, the machining of the passages through the carburetor is made dramatically easier when compared to the machining of a carburetor having a single body with end caps. Still further, the modular diaphragm design permits different plates and/or components of the carburetor to be used with other components to provide a carburetor having different performance characteristics and suitable for use with a different engine family.
    Type: Grant
    Filed: August 29, 2000
    Date of Patent: September 10, 2002
    Assignee: Walbro Corporation
    Inventors: Jeffrey C. Hoppe, Ronald H. Roche, Kevin L. Williams
  • Patent number: 6447270
    Abstract: A liquid pump with a brushless motor constructed to be received within a liquid reservoir of a cooling system to deliver liquid coolant under pressure to a manifold assembly through which the coolant is discharged onto various electronic components to cool them. The pump has a pumping assembly, a rotor, a stator and an electronic control circuit which controls the operation of the pump and each of which is immersed in liquid coolant in the pump housing to cool them as the coolant flows through the pump. Further, because each component within the pump can be exposed to the liquid in the pump, no sealed enclosures are needed for the pump as a whole or for any component therein and the pump can be received directly in the reservoir.
    Type: Grant
    Filed: September 16, 1999
    Date of Patent: September 10, 2002
    Assignees: Walbro Corporation, Isothermal Systems Research, Inc.
    Inventors: Robert A. Schmidt, Bruce A. Smetana, Thomas T. Weir
  • Patent number: 6439547
    Abstract: A carburetor throttle and choke control mechanism incorporating a choke-throttle cold-start fast idle setting latch mechanism having, in a first embodiment, a blade of a fast idle lever specially contoured for creating upon interengagement with a tang on a throttle lever initial torque resistance to co-rotation of the fast idle lever toward latched condition and then effecting force reversal for creating aiding torque to accelerate the fast idle lever relative to choke lever and thereby open a gap in the push coupling that remains in the latched position of the choke and throttle valves. The choke lever has a relatively rigid pusher leg portion adapted for abutment in push relation with a fast idle lever tang. In a second embodiment an extension of the leg portion in the form of a generally U-shaped resilient spring hook portion is adapted to overlap the tang and releasably hook engage the same when the leg portion is brought into full push abutment with said tang.
    Type: Grant
    Filed: March 5, 2001
    Date of Patent: August 27, 2002
    Assignee: Walbro Corporation
    Inventors: Eric L. King, George M. Pattullo
  • Patent number: 6439546
    Abstract: A carburetor having a plurality of restricted fluid flow paths upstream of a fuel and air mixing passage to inhibit the passage of large fuel vapor bubbles through the fuel paths and to the fuel and air mixing passage. Desirably, the restricted flow paths constrain large volume vapor bubbles and clusters of bubbles from passing therethrough undistributed in the fuel to prevent an inconsistent or overly lean fuel and air mixture from being delivered to the engine. At least two restrictive flow paths diffuse, separate, and/or break up the large vapor bubbles and clusters into a plurality of smaller vapor bubbles which are more uniformly distributed within the liquid fuel flowing through the carburetor to provide a more consistent flow of fuel to the engine.
    Type: Grant
    Filed: August 29, 2000
    Date of Patent: August 27, 2002
    Assignee: Walbro Corporation
    Inventor: William E. Galka
  • Patent number: 6431527
    Abstract: A rotary throttle valve carburetor for a two cycle engine reroutes a portion of intake air and introduces the air around the circumference of a fuel feed tube. A rotary throttle, rotatable and vertically moveable, fits into a cylindrical chamber intersecting an air intake channel through a carburetor body. A needle supported by the rotary throttle fits into the fuel feed tube which extends from a fuel metering chamber within the carburetor body into a throttling bore extending laterally through the rotary throttle. An intake portion of the air intake channel expands conically toward an upstream side. An air guide tube is aligned co-axially and radially outward from a fuel feed tube forming an air passageway there between. The intake air portion flows through the air passage from the intake portion of the air intake channel and into a bottom space of the cylindrical chamber beneath the rotary throttle.
    Type: Grant
    Filed: November 2, 2000
    Date of Patent: August 13, 2002
    Assignee: Walbro Corporation
    Inventors: Masao Suzuki, Tamio Aihara
  • Patent number: 6427646
    Abstract: A fuel injection system for a two-stroke small engine has a charge forming device with an injector mixing passage which forms a rich fuel and air mixture supplied to a tuned injector tube connected adjacent one end through a port to the engine cylinder and adjacent the other end to the engine crankcase. The charge forming device has a high speed fuel circuit which supplies at least a majority of the fuel to the mixing passage under wide open throttle operating conditions and preferably a minor portion of the fuel is also supplied by an idle fuel circuit which under engine idle conditions preferably supplies essentially all of the fuel to the engine. A separate inlet air flow passage of the charge forming device also supplies primarily air to the crankcase of the engine for transfer to the cylinder.
    Type: Grant
    Filed: January 18, 2001
    Date of Patent: August 6, 2002
    Assignee: Walbro Corporation
    Inventors: William E. Galka, Anthony M. Kueffner, Dale P. Kus, Kevin L. Williams
  • Patent number: 6427647
    Abstract: A two stroke combustion engine, equipped with fuel injection apparatus and ignition timing controlled by throttle position, has a charge forming device which delivers a rich fuel mixture from an integral float-type fuel chamber. The fuel injection apparatus typically comprises a tuned injector tube that communicates between a crankcase injector port and a cylinder injector port. The vast majority of fuel mixes with air in an injector mixing passage of the charge forming device where it is subsequently delivered to the tuned injector tube which directly injects the rich fuel mixture into a cylinder of the engine. The rich fuel mixture supplied by the charge forming device injects into the combustion chamber through the cylinder injector port via a reflected pressure wave generated from the previous combustion cycle.
    Type: Grant
    Filed: October 11, 2001
    Date of Patent: August 6, 2002
    Assignee: Walbro Corporation
    Inventors: William E. Galka, Ronald H. Roche
  • Patent number: 6428739
    Abstract: A parison handling device has a pair of opposed arms with each arm having at least a pair of grippers to selectively engage an extruded parison and transfer it to a second location such as to a mold of a blow molding machine. At least one gripper on each arm is both slidably and generally pivotally movable relative to the arm to facilitate initially engaging and gripping the parison and subsequent closing and stretching of a gripped end of the parison to more efficiently distribute the material of the parison such that after blow molding of the parison, the molded product has a substantially uniform wall thickness throughout. Preferably, a follower attached to each movable gripper is responsive to a profile or contour of a cam carried by each arm to guide the movement of the gripper corresponding to the profile of the cam.
    Type: Grant
    Filed: October 13, 2000
    Date of Patent: August 6, 2002
    Assignee: Walbro Corporation
    Inventors: Vladimir Franjo, John F. Kenyon, Laszlo Papp
  • Patent number: 6425733
    Abstract: An electric motor turbine-type fuel pump having a pair of substantially separate fuel pumping channels on opposed faces of an impeller which has a plurality of circumferentially spaced vanes disposed about the periphery of the impeller. The tip portion of each vane is generally arcuate or curved such that a radially outermost edge of the tip is forward or leads the corresponding radially innermost edge of its base relative to the direction of rotation of the impeller. Preferably, each vane is defined between a pair of radially, axially, and circumferentially extending pockets formed in the impeller, with one set of vanes opening to each of a pair of opposed side faces of the impeller. An axially centered, circumferentially extending rib extends to the radially outermost portion of the vanes and separates the vanes on one face of the impeller from the vanes on the opposed face of the impeller.
    Type: Grant
    Filed: September 11, 2000
    Date of Patent: July 30, 2002
    Assignee: Walbro Corporation
    Inventor: Joseph M. Ross
  • Patent number: 6408820
    Abstract: A capacitor discharge engine ignition system includes an ignition coil having a primary winding and a secondary winding for coupling to an engine ignition spark plug. A first electronic switch has primary current conducting electrodes in circuit with an ignition charge storage capacitor and the primary winding of the ignition coil, and a control electrode responsive to-trigger signals for operatively connecting the ignition charge storage capacitor to discharge through the primary winding of the, ignition coil. A charge/trigger coil arrangement generates periodic signals in synchronism with operation of the engine. The charge coil generates a charge signal to charge the ignition charge storage capacitor, while the trigger coil generates a trigger signal for triggering discharge of the capacitor through the ignition coil.
    Type: Grant
    Filed: August 2, 2000
    Date of Patent: June 25, 2002
    Assignee: Walbro Corporation
    Inventor: Gerald L. LaMarr, Jr.
  • Patent number: 6401685
    Abstract: A fuel shut off solenoid device of a carburetor has a solenoid chamber which typically fills with fuel. When the solenoid device is energized, fuel flows from a fuel chamber into a mixing passage of the carburetor to mix with air. During the energized state, heat from the solenoid tends to vaporize the fuel within the solenoid chamber. Also when energized, the solenoid device is held in a retracted position whereby a head at a distal end of the shaft mates with or seals to a washer which in turn seals to an upward face of the encasement of the fuel shut off solenoid device. Thus the potential migration of large vapor bubbles from the solenoid chamber to the mixing passage of the carburetor is eliminated, providing a smoother idling or running engine at light loads.
    Type: Grant
    Filed: February 2, 2001
    Date of Patent: June 11, 2002
    Assignee: Walbro Corporation
    Inventor: Donald W. Warner
  • Patent number: 6402125
    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.
    Type: Grant
    Filed: March 2, 2001
    Date of Patent: June 11, 2002
    Assignee: Walbro Corporation
    Inventors: Michael P. Burns, Gary U. Gliniecki, George M. Pattullo, James E. VanAllen
  • Patent number: 6402124
    Abstract: A carburetor fuel mixture adjustment assembly including a threaded cylindrical needle valve receptacle formed in a carburetor main body and intersecting a fuel passage. A needle valve body is threaded into the needle valve receptacle and includes a needle that extends into an axially-aligned needle seat orifice portion of the fuel passage. The needle is axially movable within the needle seat orifice by rotation of the needle valve body to control how much of the orifice is open to fuel flow. A valve spring disposed between a head of the needle valve body and the carburetor main body biases the head away from the carburetor main body. A needle stabilizer engages and cooperates with the valve spring in laterally biasing the needle into one position relative to the needle seat orifice. The lateral bias assures constant fuel flow through the orifice by resisting needle movement.
    Type: Grant
    Filed: March 29, 2000
    Date of Patent: June 11, 2002
    Assignee: Walbro Corporation
    Inventors: George M. Pattullo, Donald C. Ross, David L. Speirs
  • Patent number: 6394426
    Abstract: An engine fuel apparatus has a fuel and air mixing passage through which a rich fuel and air mixture is provided to an engine to support the operation of the engine at idle and low speed, low load engine operation, and a pressurized fuel delivery passage provides liquid fuel to a downstream fuel injector for operation of the engine at high load, high speed and wide open throttle engine operating conditions. A shut-off valve prevents the flow of fuel to the mixing passage when a throttle valve therein, which controls engine operation, is opened a predetermined amount from idle to prevent the flow of the fuel into the mixing passage at high load and/or high speed engine operation. Another shut-off valve prevents the flow of pressurized fuel to the downstream fuel injector device when the throttle valve is between idle and a predetermined position off of idle to prevent the flow of pressurized fuel to the fuel injector device under low speed, low load engine operation.
    Type: Grant
    Filed: July 7, 2000
    Date of Patent: May 28, 2002
    Assignee: Walbro Corporation
    Inventors: William E. Galka, Joseph M. Graham, Anthony M. Kueffner, Peter P. Kuperus, Ronald H. Roche
  • Patent number: 6394424
    Abstract: For a four-stroke engine, a carburetor with a fuel pump diaphragm which defines a fuel pump chamber on one side and a pressure pulse chamber on its other side in communication with the engine to receive pressure pulses which actuate the fuel pump diaphragm to draw fuel into the carburetor and to discharge fuel under pressure to a downstream fuel metering assembly. An air passage communicates an air supply with the pressure pulse chamber to provide an air flow within the pressure pulse chamber which sweeps away, dries out or aerates and removes any liquid fuel within the pressure pulse chamber to avoid puddling of liquid fuel therein. In one form, a throttle valve carried by the carburetor body for movement between idle and wide open positions also actuates a valve which controls the flow of fluid through the air passage as a function of the position of the throttle valve.
    Type: Grant
    Filed: June 4, 2001
    Date of Patent: May 28, 2002
    Assignee: Walbro Corporation
    Inventors: George M. Pattullo, Thomas L. Schmidt
  • Patent number: 6388445
    Abstract: A capacitor discharge engine ignition system that includes an ignition coil having a primary winding and a secondary winding for coupling to an engine ignition spark plug. A first electronic switch has primary current conducting electrodes in circuit with an ignition charge storage capacitor and the primary winding of the ignition coil, and a control electrode responsive to trigger signals for operatively connecting the ignition charge storage capacitor to discharge through the primary winding of the ignition coil. A charge/trigger coil arrangement generates periodic signals in synchronism with operation of the engine. The charge coil generates a charge signal to charge the ignition charge storage capacitor, while the trigger coil generates a trigger signal for triggering discharge of the capacitor through the ignition coil.
    Type: Grant
    Filed: April 13, 2000
    Date of Patent: May 14, 2002
    Assignee: Walbro Corporation
    Inventor: Martin N. Andersson
  • Patent number: 6378846
    Abstract: A throttle valve lever for controlling the rate of fuel flow in a rotary throttle valve type carburetor is proposed, wherein the throttle valve lever has increased stiffness to help prevent structural deformation due to excessive force exerted and applied to the lever over time. The throttle valve lever basically includes an oblong structure comprising synthetic resin and an oblong reinforcement plate comprising metal. The resin structure has a hole defined therethrough, which is capable of fitting around the shaft of a throttle valve of a carburetor, and also has a lever portion at one end of the resin structure. The metal plate has a hole defined therethrough, which is capable of fitting around the shaft of a throttle valve of a carburetor, and also has a lever portion at one end of the metal plate.
    Type: Grant
    Filed: June 12, 2000
    Date of Patent: April 30, 2002
    Assignee: Walbro Corporation
    Inventors: Hitoshi Terakado, Shinichi Ohgane, Teruhiko Tobinai
  • Patent number: 6374810
    Abstract: A method of reducing gaseous phase presence in the liquid fuel metering chamber of a diaphragm by providing a “High-Point Pick Up” hole positioned in the optimal metering chamber location (highest) to assure maximum purge evacuation of air and/or other gases prior to engine start-up and during running. This optimal location is dependent upon first determining, in advance of carburetor fuel feed circuitry and/or air purge system design, the orientation of the carburetor as mounted on the engine in its primary operator usage position, or so-called “standard operating position” (SOP). This SOP in turn is determined in the first instance by the engine manufacturer and/or the manufacturer of the portable engine-driven handheld appliance on which the engine is mounted.
    Type: Grant
    Filed: January 13, 2000
    Date of Patent: April 23, 2002
    Assignee: Walbro Corporation
    Inventor: George M. Pattullo