Drill jig assembly having hydraulic chuck and drill guide with pilot bore

摘要

A drill jig assembly for accurately supporting a drill relative to a workpiece is provided that includes a drill having a cylindrical shank, a chuck having a cylindrical exterior, and a hydraulically-operated collet for detachably gripping the drill shank, a housing tube for slidably and rotatably supporting the cylindrical exterior of the chuck, and a drill guide mounted on the distal end of the housing tube. The drill guide is formed from a carbide bushing having a pilot bore for rotatably receiving the cylindrical shank of the drill and maintaining a pilot concentric alignment between the bushing and the shank during a drilling operation. The use of hydraulic chuck in combination with the pilot bore of the carbide bushing allows the drill to accurately bore holes in a workpiece to very tight tolerances in a one-step, extend and retract drilling operation.