Image Number 7 for United States Patent #6863134.
A rotary tool, such as an impact wrench, includes a housing having a forward end and supporting a motor. The motor has a motor shaft extending axially through the housing and defining an axis. The rotary tool further includes a frame coupled to the motor shaft and rotatable relative to the housing about the axis in response to rotation of the motor shaft. The frame defines an interior space. The rotary tool also includes a piston supported by the frame and moveable axially in the interior space and an output shaft supported in the forward end of the housing and rotatable about the axis. The output shaft has a plurality of cams. The piston is engageable with the plurality of cams to intermittently hammer the output shaft.