Self-actuating keyless chuck

A chuck for use with a powered driver having a drive shaft comprising generally cylindrical body means including a body member having a nose section and a tail section and a circumferential groove formed therein intermediate said nose and tail sections, said tail section having an axial bore formed therein to mate with said drive shaft of said powered driver and said nose section having an axial bore formed therein and a plurality of angularly disposed passageways formed therethrough and intersecting said axial bore and said circumferential groove, a plurality of jaw pieces slidably positioned in each of said angularly disposed passageways, each of said jaw pieces having a jaw face formed on one side thereof and threads formed on the opposite side thereof, split nut means rotatably mounted in said circumferential groove and in engagement with said threads of said jaw pieces, said split nut means including a split nut, a collar surrounding and securing said split nut, and at least one first impact dog, sleeve means rotatably mounted on said body member, said sleeve means including an impact ring and at least one second impact dog and spring means interposed between said split nut means and said sleeve means and adapted to bias said second impact dog into juxtaposition with said first impact dog.