Chuck with one-way lock

Abstract

A chuck includes a generally elongated body having a tail section configured to rotate with the drive shaft and a nose section having an axial bore formed therein. A plurality of jaws are movably disposed with respect to the body to and away from the axial bore. A collar in axially driving engagement with the jaws is axially movably disposed with respect to the body so that movement in a first axial direction drives the jaws toward the axis and movement in the opposite direction moves the jaws away from the axis. The collar is configured to receive at least one of the body and a shaft and defines a first surface that faces a second surface defined by the body or the shaft when the same is received by the collar. The first surface is tapered in the axial direction from a first end to a second end of the fist surface so that a first radial distance between the second surface and the first end is less than a second radial distance between the second surface and the second end. A rolling element is disposed between the first and second surfaces and defines a diameter greater than the first radial distance and less than the second radial distance. When an axial force is applied to the collar in the second axial direction, the rolling element wedges between the first and second surfaces.