Abstract: An apparatus for providing a reciprocating motion. The apparatus has a housing block that contains two movable arms in spaced apart relationship to one another. The movable arms are each controlled by independently attached fluid driven actuator cylinders that are mounted externally of the housing block. Tools for the altering of a workpiece may be attached to one or both ends of the movable arms. An embodiment utilizes a rack and pinion gear arrangement to immobilize any imbalance in forces that may exist when the movable arms are biased against a workpiece.

Abstract: An apparatus for providing a reciprocating motion. The apparatus has a housing block that contains two movable arms in spaced apart relationship to one another. The movable arms each contain a rack gear connected to a common pinion gear. One movable arm is driven by a fluid actuated cylinder. The driven movable arm then produces an equal and opposite motion in the other arm because of the interconnection of the pinion gear. Tools for altering of a workpiece may be attached to one or both ends of the movable arms. An embodiment utilizes the rotation of the pinion gear shaft to cause a translation of the entire apparatus away from a workpiece.