Lockable drill chuck

Abstract

A drill chuck has a chuck body centered on and adapted to be rotated about a longitudinal axis and formed with a plurality of forwardly open angled guides angularly spaced about the axis, respective jaws displaceable along the guides in the chuck body and each formed with a row of teeth, and a tightening collar rotatably surrounding the body, formed internally with a screwthread meshing with the teeth of the jaws, and forming with the chuck body an annular space axially forward of the screwthread so that rotation of the collar in one direction moves the jaws radially together and opposite rotation moves them radially apart. A locking element axially displaceable in the space and nonrotatable on the chuck body is biased backward into axial engagement with the tightening collar to brake rotation of same. This locking element is a ring coaxial with the chuck body and interengaging formations on the ring and on the chuck body rotationally couple same together while permitting same to move axially relative to each other. At least one spring is braced axially between the ring and the body.

Dependencies are inferred from the claim text.