Reciprocating power tool having a counterbalance device

A reciprocating saw comprising:

• a housing;
• a motor supported by the housing and having an output shaft, the motor operable to rotate the output shaft;
• a drive system coupled to the output shaft of the motor, the drive system including,
• a driving gear coupled to the output shaft for rotation with the output shaft,
• a first driven gear having a spindle counterbalance weight, the first driven gear coupled to the driving gear such that the first driven gear is configured to rotate about an axis of rotation in a first direction in response to rotation of the driving gear by the motor,
• a second driven gear having a spindle counterbalance weight, the second driven gear coupled to the driving gear such that the second driven gear is configured to rotate about the axis of rotation in a second direction that is opposite the first direction in response to rotation of the driving gear by the motor,
• a spindle having a first end, a second end, and a longitudinal axis that extends through the first end and the second end;
• a blade clamp coupled to the first end of the spindle, the blade clamp configured to couple a saw blade to the spindle;
• and
• a yoke coupled to the second end of the spindle,
• wherein the drive system further includes a pin coupled to one of the first driven gear and the second driven gear for rotation with the one of the first driven gear and the second driven gear,
• wherein the pin extends into the yoke to reciprocate the spindle with respect to the housing along the longitudinal axis of the spindle in response to operation of the motor,
• wherein the spindle counterbalance weights of the first and the second driven gears rotate with the first and the second driven gears, respectively, between an upper position, a forward position, a lower position opposite the upper position, and a rearward position opposite the forward position,
• wherein the spindle reciprocates between an extended position and a retracted position,
• wherein a plurality of intermediate positions are defined between the extended position and the retracted position,
• wherein when the spindle is in the extended position, the spindle counterbalance weights of the first and the second driven gears are in the rearward positions,
• wherein when the spindle is in the retracted position, the spindle counterbalance weights of the first and the second driven gears are in the forward positions, and
• wherein when the spindle is in the plurality of intermediate positions, at least a portion of the spindle counterbalance weight of one of the first and the second driven gears is above the counterbalance weight of the other of the first and the second driven gears.