Automatic impact device

Abstract

An impact tool for use in surgical procedures is provided. The invented tool is useful for performing such surgical functions as freeing cement, implanting pins, setting guides, and inserting surgical staples. The tool comprises a body that has an impact force calibrating member coupled to a first end and a chuck in a second end. The chuck includes a rod that extends into a channel in the body. An impact inducing assembly is retained in the channel. The assembly causes a surgical implement retained in the chuck to deliver an impact with a calibrated force to a desired object. The impact inducing assembly comprises a piston, a spring interposed between the piston and calibrating member, and an actuation mechanism to engage the rod. An antirotation assembly may optionally be provided to prevent the implement from rotating relative to the body, as the rod is propelled along the channel. An object is impacted by applying pressure to the implement with the tool. The rod is urged into the channel until the impact inducing assembly disengages the rod. The impact assembly then strikes and propels the rod along the channel, until the implement impacts the object. After impact, the piston is drawn toward the first end of the body by the calibrating member and impact inducing assembly to an initial position, for enabling the implement to deliver subsequent impacts to the object.