Abstract: A power-driven reciprocating tool may include a transmission mechanism that converts rotational force from a motor to linear force to be output by a reciprocating mechanism coupled thereto, and a counterbalancing mechanism coupled to the transmission mechanism to counter-balance forces generated by the reciprocating mechanism. The transmission mechanism may include a planetary gear assembly including a sun gear in meshed engagement with at least one planet gear. In response to a force converted by and transmitted from the transmission mechanism, the reciprocating mechanism may move in a first linear direction, and the counterbalancing mechanism may move in a second linear direction, opposite the first linear direction. The opposite linear movement of the reciprocating mechanism and the counterbalancing mechanism may counteract forces generated by the reciprocating motion of the reciprocating mechanism, thus reducing vibration output by the tool.

Abstract: A force and moment canceling reciprocating mechanism for a power-driven tool may include a transmission including an input gear assembly and an output gear assembly, coupled to a reciprocating mechanism. The input gear assembly may include a first input gear coaxially aligned with a second input gear. The output gear assembly may include a first output gear coaxially arranged with a second output gear. The reciprocating mechanism may be coupled to the output gear assembly, to convert rotational motion to linear motion, for output to an output accessory of the tool. One or both of the first and second input gears may include counterweights, or counterweight masses, and one or both of the first and second output gears may include counterweights, or counterweight masses. The counterweighting of the input and output gear assemblies may provide for the cancelation of forces and moments generated by the operation of the motor and the transmission, and the reciprocal motion of the reciprocating mechanism.

Abstract: A power-driven reciprocating tool may include a transmission mechanism that converts rotational force from a motor to linear force to be output by a reciprocating mechanism coupled thereto, and a counterbalancing mechanism coupled to the transmission mechanism to counter-balance forces generated by the reciprocating mechanism. The transmission mechanism may include a planetary gear assembly including a sun gear in meshed engagement with at least one planet gear. In response to a force converted by and transmitted from the transmission mechanism, the reciprocating mechanism may move in a first linear direction, and the counterbalancing mechanism may move in a second linear direction, opposite the first linear direction. The opposite linear movement of the reciprocating mechanism and the counterbalancing mechanism may counteract forces generated by the reciprocating motion of the reciprocating mechanism, thus reducing vibration output by the tool.

Abstract: A force and moment canceling reciprocating mechanism for a power-driven tool may include a transmission including an input gear assembly and an output gear assembly, coupled to a reciprocating mechanism. The input gear assembly may include a first input gear coaxially aligned with a second input gear. The output gear assembly may include a first output gear coaxially arranged with a second output gear. The reciprocating mechanism may be coupled to the output gear assembly, to convert rotational motion to linear motion, for output to an output accessory of the tool. One or both of the first and second input gears may include counterweights, or counterweight masses, and one or both of the first and second output gears may include counterweights, or counterweight masses. The counterweighting of the input and output gear assemblies may provide for the cancelation of forces and moments generated by the operation of the motor and the transmission, and the reciprocal motion of the reciprocating mechanism.