Dynamically balanced apparatus having reciprocating member

Abstract

A dynamically balanced apparatus having a reciprocating member includes an eccentric shaft operatively connected to a motor output shaft, and a drive member operatively connecting the eccentric shaft to the reciprocating member for driving the reciprocating member upon rotation of the eccentric shaft. An eccentric flyweight is mounted on the output shaft to be rotatable therewith for canceling the vibration or inertia force developed by the motion of the reciprocating member. Also included in the apparatus is a vibrator also driven by the eccentric shaft to vibrate in a direction perpendicular to the reciprocating direction. For eliminating the vibration inherently arising from the rotation of the eccentric shaft and acting in the direction perpendicular to the reciprocating direction, at least one counterweight is carried on the vibrator to be movable therewith for canceling such inherent vibration in the direction questioned. A novel feature of the present invention resides in that the counterweight is disposed at a location spaced longitudinally outwardly of the drive member to be in substantially longitudinal alignment with the drive member and the eccentric flyweight. Consequently, the counterweight can be conveniently received in longitudinal end of the apparatus housing without requiring any additional space on the lateral side of the apparatus housing, while providing dynamic balancing of all moving parts to effectively cancel unpleasant vibrations in all directions.