US Patent 10960474 Power tool

An electric tool includes a rotary wheel driven to rotate around a central axis thereof, an action member configured to bear a cutter of the electric tool, and a counterweight. The rotary wheel drives the action member such that it reciprocates linearly in a first direction. The rotary wheel simultaneously drives the counterweight such that it not only reciprocates linearly in the first direction in an opposite manner to the action member, but also performs reciprocating swinging movement in a plane perpendicular to the central axis. The first direction is parallel to the plane.