Abstract: The invention relates to a drilling apparatus that can position a drill at the precise center between two overlapping flanges and clamp at that position while a self feeding drill drills a hole.

Abstract: A peck feed drilling machine incorporates a pneumatically operated vane motor and peck feed components. The vane motor drives a conventional drill bit through a speed reducing gear train. The peck feed assembly includes a plurality of multi-state shuttle valves which cooperate with a drilling feed piston, a peck piston and a clutch assembly to incrementally advance and fully retract the drill bit to peck drill an aperture. The drilling machine also includes a dashpot which adjusts the feed rate of the drill bit, a second dashpot for slowing the drill bit as it breaks through the workpiece and countersinks, a threaded mechanism for adjusting the depth of drilling and a spring mechanism for slowing the advance of the drill bit just before it engages the workpiece.