Abstract: A gearbox is provided for a handheld power tool. The gearbox includes a housing including a recess having a wall section, a main gear disposed within the recess and including a plurality of gear teeth, and a drive gear engaged with the main gear for driving the main gear. The gearbox also includes means for retaining lubricant within the housing for improved retention of the lubricant on the main gear. The means for retaining is configured to create a localized pressure reduction within the housing during operation of the power tool. In one example, a portion of the wall section curves towards the main gear, and a localized pressure reduction is formed proximate the minimum distance between the curving wall section and the main gear during operation of the power tool.

Abstract: A gearbox for a handheld power tool is provided, including a housing, a main gear disposed within the housing and including a plurality of cams attached thereto. A drive gear is engaged with the main gear for driving the main gear. The gearbox also includes a plurality of cutting members configured to engage the plurality of cams. Rotation of the main gear causes rotation of the cams to thereby cause the cutting members to move in a reciprocal manner. The gearbox also includes a separator plate attached to the housing. A portion of the separator plate is disposed between the plurality of cutting members to inhibit contact between the cutting members. In one example, the separator plate includes a leg section configured to be secured to a portion of the power tool.

Abstract: A power tool includes a braking system that minimizes a stopping time for a cutting blade of the power tool. The braking system includes a roller bearing clutch mechanism combined with a positive stop pin. The stop pin is provided at an end portion of a cable assembly. The cable assembly is coupled to a trigger through a lever on one end, with the stop pin and a return spring inserted into a gear box on the other end. When the trigger is in a released position, the stop pin fully engages into a positive stop on a bearing cage at a top portion of the drive assembly. The coiled return spring keeps the stop pin in position. When the trigger is pulled, the cable pulls the stop pin out of the positive stop.

Abstract: An oil ring and coiled expander spring assembly in which the groove for the expander spring is of unique configuration and possesses a unique relationship with the expander spring.

Abstract: A means maintaining compressive force in a seal assembly to assure seal reliability. The valve cover is fastened to the engine head with a shoulder bolt which carries Belleville washers compressively positioned between the bolt head and valve cover. The gasket load and deflection is determined by the compressive force or gasket loading of the Belleville washers on the unthreaded length of the shoulder bolt. The resilience of the Belleville washers maintains a continuous force on the gasket for the life of the sealed assembly.

Abstract: An inner peripheral seal ring on the inner periphery of a wear sleeve to seal axial flow of oil and permit heat radially transferred through the wear sleeve for cooler operation of the seal on the wear sleeve.

Abstract: An engine balancer for a four cylinder in-line internal combustion engine. The balancer is mounted centrally under the crankshaft and driven by a drive gear adjacent the nodal point of torsional vibrations on the crankshaft. The balancer is for secondary forces on the engine and the drive reduces feed of torsional vibrations to the engine balancer from the crankshaft.

Abstract: An intercooler mounted on the cylinder head with an intake manifold of an internal combustion engine. The intake manifold and cylinder head are adapted for fastening together for operation with or without the intercooler mounted between the manifold and the cylinder head. The use of a sandwich type intercooler arrangement permits use of standard components of the manifold or engine head with the optional use of the intercooler as a turbocharged engine or without as a naturally aspirated engine.