Collet-type drill

An improved collet-type drill including a drill motor, a drill bit rotatably driven by the motor and feed means for moving the bit toward and away from a workpiece having a pre-formed collet hole therein and in which holes are to be drilled, the improvement comprising clamping means including:

• a pressure foot member engageable with the work piece and arranged for connection with the drill motor and with the feed means;
• collet means operably connected to and movable relative to said foot member;
• a clamp bushing having one end pivotally connected with said collet means and having an annular end portion, said end portion having an inner periphery and having an annular groove formed in said inner periphery;
• a cylindrical sleeve forming part of said feed means extending through said clamp bushing and connected to said pressure foot member, said sleeve having a transverse slot extending therethrough;
• a clamping piston including an elongated clamping rod movably disposed in said sleeve, said rod having a transverse hole extending therethrough;
• and,
• a connecting pin disposed in said transverse hole and projecting through said transverse slot into the annular groove in said clamp bushing whereby said bushing, collet holder, collet and rod are movable together upon movement of said clamping piston to engage said collet means with the workpiece to secure said drill to the workpiece.