Drill chuck for smooth- and hex-shank bits

摘要

A drill chuck has a chuck body centered on an axis and forming an axially forwardly open bit-receiving recess, an axially forwardly open polygonal-section seat at a base of the recess, and a plurality of jaws spaced angularly around the seat. The jaws can be displaced radially inward and outward to grip a bit in the recess. An element can move in the base of the recess between a blocking position in front of the polygonal-section seat and preventing entry of a bit thereinto and a freeing position clear of the seat and permitting entry of a bit thereinto. This element can be actuated for movement between the blocking and freeing positions either manually or automatically.