Abstract: Integrated, multi-cylinder opposed engine constructions include a unitary support structure to which cylinder liners are removeably mounted and sealed and on which crankshafts are rotatably supported. The engine constructions include a cooled piston with a resiliently deformable joint connecting crown and skirt and a cooled cylinder liner with wipers to manage lubricant in the cylindrical interstice between the cylinder bore and the piston skirts.

Abstract: A self-propelled mower with blade and ground speed controls. The mower includes a motor with an output shaft and a rotatable cutting blade mounted on a blade shaft. The motor may be an internal combustion engine. A torque transmitting mechanism such as a variable diameter pulley defines a rotational speed ratio between the output shaft and the blade shaft. A transmission is coupled to the output shaft. Sensors provide an electronic control unit with the blade speed, ground speed and engine speed. The ECU may be used to maintain either a desired blade speed or a desired ground speed. To maintain a desired blade speed, the ECU monitors the blade speed and, when the blade speed diverges from the desired speed, adjusts either the rotational speed ratio of the output shaft and blade shaft or the ground speed of the mower to maintain the desired blade speed.

Abstract: An evaporative emissions control system for small internal combustion engines includes a control valve associated with a fuel line and with a vent line which each connect the fuel tank to the carburetor. When the engine is not running, the control valve automatically closes the vent line and the fuel line, thereby trapping fuel vapors within the fuel tank and vent line and preventing the supply of liquid fuel to the carburetor. Upon engine start up, actuation of a bail assembly or vacuum produced within the carburetor causes the control valve to open the vent line and the fuel line, venting fuel vapors from the fuel tank through the fuel line to the carburetor for consumption by the engine, and opening the supply of liquid fuel from the fuel tank to the carburetor.

Abstract: An evaporative emissions control system for small internal combustion engines. A control valve assembly includes a pair of control valves which are respectively associated with a fuel line and with a vent line which each connect the fuel tank and the carburetor of the engine. The control valve assembly is automatically operable responsive to the rotation of a rotatable member of the engine drive train, such as the crankshaft, camshaft, flywheel, governor assembly, or other rotatable member. In one embodiment, for example, the control valve assembly is driven from the flywheel. When the engine is not running, the flywheel is stationary and does not rotate, and the control valves automatically closes the vent line and the fuel line, thereby trapping fuel vapors within the fuel tank and blocking the supply of liquid fuel to the carburetor.

Abstract: An engine control system for maintaining the operator-commanded speed setting of an internal combustion engine over a range of engine loads and for easy starting and improved efficiency over a range of ambient and engine operating temperatures. The engine control system includes a governor assembly driven by the engine, the governor assembly supplying an output to a sensor assembly through a mechanical coupling member operator. The sensor assembly provides an engine speed control signal which corresponds to operator commanded engine speed and actual engine speed. The engine speed control signal is provided to a throttle actuator to control actual engine speed is controlled to correspond with the operator-commanded engine speed regardless of loads imposed on the engine.

Abstract: A priming system for the carburetor of a small internal combustion engine which is used with a lawnmower, for example, in which the priming system is remotely actuated. The priming system includes a priming feature for supplying an amount of liquid fuel to the carburetor throat to aid in starting the engine, and an enrichment feature for providing an enriched fuel supply to the engine during a warm-up period. In one embodiment, the priming system includes an automatic primer disabling feature which is operative when the engine is warm to block the supply of priming fuel to the carburetor throat and thereby prevent priming during a warm engine re-start. In another embodiment, the priming system includes a primer reduction feature, which is operative when the engine is warm to provide a reduced amount of priming fuel to the carburetor throat during a warm engine re-start, with respect to the amount of fuel which is supplied during a cold engine start.

Abstract: A self-propelled mower with blade and ground speed controls. The mower includes a motor with an output shaft and a rotatable cutting blade mounted on a blade shaft. The motor may be an internal combustion engine. A torque transmitting mechanism such as a variable diameter pulley defines a rotational speed ratio between the output shaft and the blade shaft. A transmission is coupled to the output shaft. Sensors provide an electronic control unit with the blade speed, ground speed and engine speed. The ECU may be used to maintain either a desired blade speed or a desired ground speed. To maintain a desired blade speed, the ECU monitors the blade speed and, when the blade speed diverges from the desired speed, adjusts either the rotational speed ratio of the output shaft and blade shaft or the ground speed of the mower to maintain the desired blade speed.

Abstract: A fuel injector including a piezoelectric actuator directly attached to a metering rod wherein when the actuator is distorted in proportion to an input voltage, the metering rod moves to vary the size of a discharge spray orifice. The input voltage, and therefore the distortion of the actuator, may be varied in accordance with the readings from a throttle position sensor or an oxygen sensor, for example. A dual actuator type of fuel injector is also provided which has an injector body in engagement with the combustion chamber and a fuel chamber therein to receive low pressure fuel. A piezoelectric actuator moves a piston to close the fuel chamber inlet and pressurize the fuel therein. A second piezoelectric actuator moves the metering rod to open the discharge orifice. The amount of distortion of the respective actuators effects proportional movement of the piston or the metering rod.

Abstract: A self-propelled mower with blade and ground speed controls. The mower includes a motor with an output shaft and a rotatable cutting blade mounted on a blade shaft. The motor may be an internal combustion engine. A torque transmitting mechanism such as a variable diameter pulley defines a rotational speed ratio between the output shaft and the blade shaft. A transmission is coupled to the output shaft. Sensors provide an electronic control unit with the blade speed, ground speed and engine speed. The ECU may be used to maintain either a desired blade speed or a desired ground speed. To maintain a desired blade speed, the ECU monitors the blade speed and, when the blade speed diverges from the desired speed, adjusts either the rotational speed ratio of the output shaft and blade shaft or the ground speed of the mower to maintain the desired blade speed.

Abstract: A priming system for a carburetor for small internal combustion engines, wherein the priming system is remotely actuated and includes an automatic primer disabling feature operative when the engine is in a warm condition to prevent the supply of an overly rich fuel/air mixture to the engine intake system during warm re-starts, for example.

Abstract: An evaporative emissions control system for small internal combustion engines includes a control valve associated with a fuel line and with a vent line which each connect the fuel tank to the carburetor. When the engine is not running, the control valve automatically closes the vent line and the fuel line, thereby trapping fuel vapors within the fuel tank and vent line and preventing the supply of liquid fuel to the carburetor. Upon engine start up, actuation of a bail assembly or vacuum produced within the carburetor causes the control valve to open the vent line and the fuel line, venting fuel vapors from the fuel tank through the fuel line to the carburetor for consumption by the engine, and opening the supply of liquid fuel from the fuel tank to the carburetor.

Abstract: An engine control system for maintaining the operator-commanded speed setting of an internal combustion engine over a range of engine loads and for easy starting and improved efficiency over a range of ambient and engine operating temperatures. The engine control system includes a governor assembly driven by the engine, the governor assembly supplying an output to a sensor assembly through a mechanical coupling member operator. The sensor assembly provides an engine speed control signal which corresponds to operator commanded engine speed and actual engine speed. The engine speed control signal is provided to a throttle actuator and/or a fuel control device in a manner in which the actual engine speed is controlled to correspond with the operator-commanded engine speed regardless of loads imposed on the engine. The fuel control device may include, for example, a fuel pump driven by a variable speed electric motor or a solenoid controlled variable fuel pressure regulator.

Abstract: A priming system for the carburetor of a small internal combustion engine which is used with a lawnmower, for example, in which the priming system is remotely actuated. The priming system includes a priming feature for supplying an amount of liquid fuel to the carburetor throat to aid in starting the engine, and an enrichment feature for providing an enriched fuel supply to the engine during a warm-up period. In one embodiment, the priming system includes an automatic primer disabling feature which is operative when the engine is warm to block the supply of priming fuel to the carburetor throat and thereby prevent priming during a warm engine re-start. In another embodiment, the priming system includes a primer reduction feature, which is operative when the engine is warm to provide a reduced amount of priming fuel to the carburetor throat during a warm engine re-start, with respect to the amount of fuel which is supplied during a cold engine start.

Abstract: A priming system for a carburetor for small internal combustion engines, wherein the priming system is remotely actuated and includes an automatic primer disabling feature operative when the engine is in a warm condition to prevent the supply of an overly rich fuel/air mixture to the engine intake system during warm re-starts, for example.

Abstract: An engine having a piezoelectric device attached thereto for production of electrical power to be used by the engine. The piezoelectric device extends from the engine to the mass in a direction transverse to the direction of piston travel. The piezoelectric device has a mass attached at an extremity thereof, which oscillates during engine operation to produce a natural frequency coincident with the operating speed of the engine. The resultant attenuation will maximize the power output from the piezoelectric generating device.

Abstract: A fuel injector including a piezoelectric actuator directly attached to a metering rod wherein when the actuator is distorted in proportion to an input voltage, the metering rod moves to vary the size of a discharge spray orifice. The input voltage, and therefore the distortion of the actuator, may be varied in accordance with the readings from a throttle position sensor or an oxygen sensor, for example. A dual actuator type of fuel injector is also provided which has an injector body in engagement with the combustion chamber and a fuel chamber therein to receive low pressure fuel. A piezoelectric actuator moves a piston to close the fuel chamber inlet and pressurize the fuel therein. A second piezoelectric actuator moves the metering rod to open the discharge orifice. The amount of distortion of the respective actuators effects proportional movement of the piston or the metering rod.

Abstract: A piezoelectric valve actuation system for an internal combustion engine includes a piezoelectric driver in the form of a pre-stressed wafer or strip including a layer of piezoceramic material such as lead zirconate titanate (PZT). The driver has a central portion which includes an aperture for direct engagement with a valve stem so that the valve is moved between open and closed positions directly by the piezoelectric driver. The piezoelectric driver can have end portions which attach to the engine cylinder head proximate the valve location. The piezoelectric actuator is driven by an electronic control module (ECM) providing electrical signals to control valve operation based various engine parameters along with user input.

Abstract: A four-stroke internal combustion engine includes a cylinder block including a cylinder therein and having a piston reciprocally disposed within the cylinder. A piston is operably engaged with a crankshaft. At least one intake valve is reciprocally driven by a camshaft. At least one exhaust valve is reciprocally driven by the camshaft. A vacuum release mechanism includes an operating member reciprocally supported within the camshaft for translation along an axis. A centrifugally actuated flyweight member is engaged with the operating member, wherein rotation of the camshaft above engine cranking speeds causes the flyweight member to move the operating member from a first position to a second position. A vacuum release member is movably supported within the camshaft and is in engagement with the operating member wherein translational movement of the operating member causes movement of the vacuum release member.

Abstract: A four-stroke internal combustion engine includes a cylinder block including a cylinder therein and having a piston reciprocally disposed within the cylinder. A piston is operably engaged with a crankshaft. At least one intake valve is reciprocally driven by a camshaft. At least one exhaust valve is reciprocally driven by the camshaft. A vacuum release mechanism includes an operating member reciprocally supported within the camshaft for translation along an axis. A centrifugally actuated flyweight member is engaged with the operating member, wherein rotation of the camshaft above engine cranking speeds causes the flyweight member to move the operating member from a first position to a second position. A vacuum release member is movably supported within the camshaft and is in engagement with the operating member wherein translational movement of the operating member causes movement of the vacuum release member.

Abstract: A four-stroke internal combustion engine includes a cylinder block having a cylinder therein and a piston reciprocally disposed within the cylinder. The piston is operably engaged with a crankshaft. At least one intake valve and one exhaust valve is reciprocally driven by a camshaft. A vacuum release mechanism includes an operating member rotationally supported by the camshaft and has an operator disposed thereon. A centrifugally actuated flyweight member is attached to the operating member, wherein rotation of the camshaft above engine cranking speeds causes the flyweight member to rotate the operating member. A vacuum release member is reciprocally supported by the camshaft and in engagement with the operator wherein rotational movement of the operating member causes radial translation of the vacuum release member through the operator.