Patent ID: 8246280

Claim:
A chuck for holding a tool or workpiece having a tapered mounting collar, the chuck comprising: a tubular spindle centered on and rotatable about an axis, the collar fittable in a front end of the spindle; a holding sleeve axially fixed in the tubular spindle and having a frustoconical inner surface; radially shiftable jaws in the spindle grippingly engageable with the collar fitted to the spindle and radially outwardly engageable with the holding sleeve; a rod axially shiftable in the spindle between a front releasing position and a rear holding position and having at a front end a tapered head that is stepped back toward the pull-back rod at a back-facing shoulder; a chuck head on the rod engageable with the jaws for spreading same and gripping the collar of the tool or workpiece with the jaws; and a gripper in the spindle having a wedge ring with an inner surface engaging the rod and a front-facing shoulder for engagement with the back-facing shoulder of the tapered head, the gripper being constructed to spread and pass the back-facing shoulder with the front-facing shoulder in the axial region of the frustoconical inner surface of the holding sleeve.