Abstract: A portable, operator-carried power tool having an implement supported on an operator-carried frame, and a lightweight, four-stroke, internal combustion engine drivably connected to the implement and supported by the frame. The engine has a crankshaft situated in a crankshaft housing and a cylinder block secured to the crankshaft housing, the crankshaft being provided with a crankcase ventilation passage extending between the crankcase and an outlet end in communication with an air/fuel induction passage. A passage establishes communication between the interior of the crankcase and the valve chamber through a cam and cam gear region of the cylinder block. An oil mist generator is connected drivably to the crankshaft for agitating liquid oil in the crankcase to establish a lubricating oil mist. The crankcase, the cam region and the valve chamber form a closed oil mist containment whereby lubricating oil mist is distributed throughout the engine during operation regardless of angular orientation of the engine.

Abstract: An engine powered hand-held power tool and engine lubrication method is provided, the power tool being intended to be carried by an operator during use. The power tool has a frame, including a handle to be grasped by the operator, an implement affixed to the frame having a rotary input member, and a small four-cycle, lightweight, internal combustion engine attached to the frame for driving the implement. The four-cycle engine has a lightweight aluminum alloy engine block having a cylindrical bore and an enclosed oil reservoir formed therein. A crankshaft is rotatably mounted in the engine block for rotation about a crankshaft axis. A piston reciprocates within the bore and is connected to the crankshaft by a connecting rod. An oil splasher driven by the crankshaft intermittently engages the oil within the enclosed oil reservoir to splash-lubricate the engine.

Abstract: A hand held powered tool is provided which is intended to be carried by an operator during use. The power tool has a frame, including a handle to be grasped by the operator, an implement affixed to the frame having a rotary input member and a small four-cycle lightweight internal combustion engine attached to the frame for driving the implement. The four-cycle engine is made up of a lightweight aluminum engine block having a cylindrical bore and an oil reservoir. A crankshaft is journaled to the engine block for rotation about a crankshaft axis. A piston reciprocates within the bore and is connected to the crankshaft by a connecting rod having an oil splasher formed thereon for intermittently engaging the oil within the enclosed oil reservoir to splash lubricate the engine. The engine is provided with a cylinder head assembly defining a compact combustion chamber having a pair of overhead intake exhaust ports cooperating intake and exhaust valves.

Abstract: An adjustment mechanism is provided for positioning a fence assembly along a guide rail of a bench top woodworking tool. The device includes a body member having a guide way portion which is linearly slidable along the guide rail and lockable at various positions. The barrel's body is provided with an elongated axial bore parallel to the guide rail. An elongated barrel extends through the bore and the body of the barrel is relatively rotatable thereto. An attachment member connects the elongated barrel to the fence assembly so that relative rotation of the elongated barrel and the body member causes the attachment member and fence assembly to move linearly relative to the body. The body member is provided with a locking mechanism so that the body member can be secured to the guide rail at various positions to facilitate precise adjustments of the fence relative to a woodworking tool cutter.

Abstract: A portable, hand-held snow thrower comprising a power unit and an attachment removably securable to the power unit. The attachment includes an impeller having a first pulley and a flexible drive shaft. A first end of the drive shaft is connected to the power unit, and a second end of the drive shaft is drivably connected to a second pulley lying substantially in a plane with the first pulley. A lower portion of the drive shaft is curved and extends through an impeller housing. The second pulley is operably connected to the first pulley to provide a gear ratio therebetween resulting in a desired rotational speed of the impeller.

Abstract: A small four cycle internal combustion engine is disclosed having a cylinder head assembly which comprises a cylinder head cooperating with a cylinder block of the engine, and a rocker box connected to the cylinder head so as to define an air passage therebetween through which air may pass. The cylinder head has cooling fins projecting into the air passage between the cylinder head and the rocker box and aligned generally transversely to a line extending between the axes of the intake and exhaust valves. The air passage preferably extends between an intake port and an exhaust port of the engine, and above an exhaust gas recirculation port extending between the intake and exhaust ports. A pair of push rod tubes are integral with the rocker box and extend between the rocker box and a crankcase of the engine externally of the cylinder block. The engine of the present invention also includes a cam tower assembly comprising a base member and a pair of parallel shafts extending from the base member.

Abstract: A hand held powered tool is provided which is intended to be carried by an operator during use. The power tool has a frame, including a handle to be grasped by the operator, an implement affixed to the frame having a rotary input member and a small four-cycle lightweight internal combustion engine attached to the frame for driving the implement. The four-cycle engine is made up of a lightweight aluminum engine block having a cylindrical bore and an enclosed oil reservoir formed therein. A crankshaft is journaled to the engine block for rotation about a crankshaft axis. A piston reciprocates within the bore and is connected to the crankshaft by a connecting rod having oil splasher formed thereon for intermittently engaging the oil within the enclosed oil reservoir to splash lubricate the engine. The engine is provided with a cylinder head assembly defining a compact combustion chamber having a pair of overhead intake exhaust ports cooperating intake and exhaust valves.

Abstract: A hand held power tool is disclosed comprising an internal combustion engine, a workpiece driven by the engine, a boom extending between the engine and the workpiece, and an actuator for a kill switch of the engine. The actuator includes a collar disposed around the boom, a fingerpiece connected to the collar and movable with the collar between a first position and a second position, and an extension depending from the collar. Preferably, the fingerpiece and the kill switch are disposed on opposite sides a horizontal plane bisecting the boom. The extension engages the kill switch such that when the fingerpiece is moved to the second position, the kill switch interrupts the flow of electricity to the spark plug. Preferably, the collar, fingerpiece and extension being formed as a unitary piece.

Abstract: An angle gear drive for a portable lawn care implement including first and second housing portions molded to net shape. First and second housing portions support an input shaft having a bevel gear and an output shaft having a mating bevel gear. The assembled housing portions include annular ribs for locating and restraining the input and output shafts so that the bevel gears are securely enclosed in a sealed gear cavity. The gear cavity is sealed by an anaerobic sealant. Grease is supplied to the sealed gear cavity through an axial lubrication bore formed in the input shaft along the axis of the input shaft. The method of making an angle gear drive is also disclosed.

Abstract: A camshaft assembly comprising a shaft, a lobe, a gear, and a boss portion is disclosed. The lobe includes a first powdered metal and has a first density, while the gear includes a second powdered metal and has a second density. The boss portion is formed on one of the lobe or gear, and has an aperture sized to cooperate with the shaft and a periphery cooperating with the other of the lobe or gear to fix the lobe against rotation relative to the gear. The boss portion has a third density less than the density of the lobe or gear on which the boss portion is formed. A method of making a camshaft component is also disclosed.

Abstract: A trigger retainer assembly for a portable power tool such as a line trimmer has an internal combustion engine and a workpiece driven by the engine. The trigger retainer assembly includes a housing grippable by an operator, a trigger disposed at least partially in the housing, a throttle cable connected between the engine and the trigger for operating the engine, ignition wires forming at least part of an electrical circuit including the engine and a kill switch, and a molded plastic trigger retainer. The trigger retainer is fastened with a single screw to a lower half of the housing and retains the throttle cable, trigger, ignition wires and kill switch in the housing.

Abstract: A small four cycle internal combustion engine is disclosed having a cylinder head assembly which comprises a cylinder head cooperating with a cylinder block of the engine, and a rocker box connected to the cylinder head so as to define an air passage therebetween through which air may pass. The cylinder head has cooling fins projecting into the air passage between the cylinder head and the rocker box and aligned generally transversely to a line extending between the axes of the intake and exhaust valves. The air passage preferably extends between an intake port and an exhaust port of the engine, and above an exhaust gas recirculation port extending between the intake and exhaust ports. A pair of push rod tubes are integral with the rocker box and extend between the rocker box and a crankcase of the engine externally of the cylinder block. The engine of the present invention also includes a cam tower assembly comprising a base member and a pair of parallel shafts extending from the base member.

Abstract: A motor housing for a string trimmer having a vibration damper disposed between the housing member and the motor. The motor housing has transverse motor support ribs fixedly supporting the motor. A damper chamber is formed in the housing between and end face and an adjacent transverse motor support rib. Stiffner ribs disposed between the end face and the adjacent transverse motor support rib form radial seats on diametrically opposite sides of the motor. A resilient linear vibration damper member is compressively received in each of the damper chambers between the electric motor and the radial seats.

Abstract: A hand held power tool is disclosed comprising an internal combustion engine, a workpiece driven by the engine, a boom extending between the engine and the workpiece, a clutch housing, a starter module, and an isolator. The clutch housing, the starter module and the isolator are disposed in a rearward section of the power tool housing the boom. The isolator is preferably formed of thermoplastic rubber, and is disposed between the clutch housing and the starter module. The clutch housing and the starter module are connected by fasteners extending therebetween, but the fasteners do not penetrate the isolator. Because the isolator is soft mounted, the isolator effectively dampens engine vibration forces to the operator and avoids local stresses which might otherwise lead to premature failure.

Abstract: An angle gear drive for a portable lawn care implement including first and second housing portions molded to net shape. First and second housing portions support an input shaft having a bevel gear and an output shaft having a mating bevel gear. The assembled housing portions include annular ribs for locating and restraining the input and output shafts so that the bevel gears are securely enclosed in a sealed gear cavity. The gear cavity is sealed by an anaerobic sealant. Grease is supplied to the sealed gear cavity through an axial lubrication bore formed in the input shaft along the axis of the input shaft.