Spring actuated chuck

Claim 1

In a chuck of the type wherein a holder has a socket to receive the shank of a flanged tool mounting member and a pair of keys secured by screw means to said holder to axially interfit slots in the flange of said member, the improvement which comprises a nut having threaded engagement with said holder and having an opening for passage of said flange therethrough; said nut having radially inwardly extending clamping lugs to engage the axially outer face of said flange upon rotation and axial inward movement of said nut thus to clamp said member in said holder; spring means acting on said nut to rotate said nut as aforesaid; and latch means actuated upon insertion of said shank into said socket to release said nut for rotation by said spring means; said latch means comprising a latch member pivotally mounted on one of said screw means and having an inner portion actuated radially outward by said shank to move an outer portion thereof radially inward out of engagement with a notch in said nut thus to release said nut for rotation by said spring means; and another spring means acting on said latch member to re-engage said outer portion with said notch upon manual rotation of said nut in the opposite direction against said spring means and upon withdrawal movement of said shank from said socket.