US Patent 10027201 Reciprocating tool

A reciprocating tool includes a motor, a reciprocating member, and a crank mechanism. The motor is disposed in a housing. The reciprocating member projects from the housing. The crank mechanism converts rotation of a rotation shaft of the motor into reciprocation of the reciprocating member. The crank mechanism rotates around an axis ma lateral direction by rotation transmission from the rotation, shaft, and the crank, mechanism includes a crank member having an eccentric pin, a connecting rod coupling the eccentric pin to the reciprocating member, and a balancer coupled to the eccentric pin, and the balancer is supported by the eccentric pin alone in the housing.