A power tool includes a housing, a motor, and a drive mechanism. The drive mechanism includes a driven gear that is rotated by the motor. The driven gear is vertically-oriented within the housing and has an upper portion and a lower portion. The drive mechanism also includes a connecting rod coupled to the driven gear to translate rotary motion of the driven gear into reciprocating motion, and an output shaft coupled to the connecting rod to reciprocate relative to the housing through a cutting stroke and a return stroke. The drive mechanism further includes a counterweight coupled to the driven gear for rotation with the driven gear. The counterweight moves through the upper portion of the driven gear during the cutting stroke of the output shaft, and moves through the lower portion of the driven gear during a return stroke of the output shaft.

A power tool includes a housing, a motor, and a drive mechanism. The drive mechanism includes a driven gear that is rotated by the motor. The driven gear is vertically-oriented within the housing and has an upper portion and a lower portion. The drive mechanism also includes a connecting rod coupled to the driven gear to translate rotary motion of the driven gear into reciprocating motion, and an output shaft coupled to the connecting rod to reciprocate relative to the housing through a cutting stroke and a return stroke. The drive mechanism further includes a counterweight coupled to the driven gear for rotation with the driven gear. The counterweight moves through the upper portion of the driven gear during the cutting stroke of the output shaft, and moves through the lower portion of the driven gear during a return stroke of the output shaft.

A piston includes a piston cap and a piston rod with the piston cap being removable from the piston rod body. The piston cap includes a cap body and a socket extending into the cap body. A mounting portion of the piston rod body extends into the socket of the cap body to connect the piston rod body to the piston cap. A wear sleeve is mounted on the piston rod.

A piston includes a piston cap and a piston rod with the piston cap being removable from the piston rod body. The piston cap includes a cap body and a socket extending into the cap body. A mounting portion of the piston rod body extends into the socket of the cap body to connect the piston rod body to the piston cap. A wear sleeve is mounted on the piston rod.

A crank mechanism for the use in an in-line boxer engine has at least two diametrically opposed cylinders, that has a crankshaft and the respective pistons as well as connecting rods for each cylinder of the in-line boxer engine, with the connecting rods cooperatively connecting the pistons with the crankshaft. Each of the connecting rods encompasses a respective piston connecting portion, at one end having bushings accepting a gudgeon pin. At the other end, the central connecting rod has a one-piece crankshaft bearing portion for the crankpin whereas the forked connecting rod has a crankshaft bearing portion with two spaced limbs resultant in bifurcated crankshaft bearing portions for the crankpin. The crankshaft possesses a cylindrical central middle crankpin, that is eccentric towards the crankshaft, onto which a cylindrical outer crank pin is immediately attached at each side without crank webs.

A piston assembly is provided with a piston head retaining structure. The piston assembly includes a piston shaft and a piston head disposed around the piston shaft and providing a piston head face that faces a cylinder wall. The piston assembly further includes a piston head mount element arranged adjacent to the piston head and mounted around the piston shaft and a tensioning device that generates an axial tension between the piston shaft and the piston head.

A piston assembly is provided with a piston head retaining structure. The piston assembly includes a piston shaft and a piston head disposed around the piston shaft and providing a piston head face that faces a cylinder wall. The piston assembly further includes a piston head mount element arranged adjacent to the piston head and mounted around the piston shaft and a tensioning device that generates an axial tension between the piston shaft and the piston head.

The invention relates to a method for producing a piston rod unit, or a shaft, in light-weight construction, with a rod which is hollowly-drilled by means of a deep bore into the rod shank, and the resulting rod opening is closed subsequently by means of a forging process.

The invention relates to a method for producing a piston rod unit, or a shaft, in light-weight construction, with a rod which is hollowly-drilled by means of a deep bore into the rod shank, and the resulting rod opening is closed subsequently by means of a forging process.

A reciprocating saw includes a housing, a motor, and a drive mechanism. The motor includes an output gear rotatable about a motor axis. The drive mechanism includes a driven gear that engages the output gear and is rotated by the motor. The driven gear has a circumference and is vertically-oriented within the housing. The drive mechanism also includes an output shaft coupled to the driven gear and configured to reciprocate relative to the housing. The drive mechanism further includes a single counterweight fixed relative to the driven gear and rotating with the driven gear through a path and in a same direction. As the counterweight moves through a rearward half of the path, the counterweight generally moves in an upward direction, and as the counterweight moves through a forward half of the path, the counterweight generally moves in a downward direction.