Abstract: A self-colleting drill that includes a pair of parallel output shafts arranged to drive a pair of drill bits and means for retaining the work piece against a foot member of the drill so that the holes will be spaced therein in accordance with the spacing between the drill bits or shafts. A plurality of drill guide members having varying hole spacings therein, provide a variety of center distances between the shafts that extend therethrough. A plurality of foot members are also provided that have mating hole spacings to the drill bushings providing for the variable drill bit spacing.

Abstract: The improved locking means includes a pair of shaft mounted gears that are in mesh with the thread on the exterior of the feed screw mounted in the housing of a positive feed drill. On the opposite ends of the shafts are mounted gears which rotate with the shafts. When the drill tool holder is not to be advanced, the gears and shafts rotate as the feed screw is being rotated and thus do not cause axial movement of the feed screw as the feed screw rotates. A rack gear is located in the housing adjacent the spur gears. A pressure actuated piston is provided to move the rack gear into engagement with the spur gears to lock the spur gears and shafts against rotation. When this occurs, the gears in mesh with the thread on the feed screw act as a fulcrum so that the feed screw and tool holder are moved axially as the feed screw rotates.