Power drill

A power drill comprising:

• a power-unit housing;
• a drill spindle extending from the housing and rotatable about and centered on an axis;
• a chuck body rotationally fixed to the drill spindle;
• a jaw guide carried on the chuck body and rotatable relative thereto about the axis;
• jaws carried in the chuck body;
• a pusher element rotatable about the axis in the chuck body and fixed to and bearing axially on the jaws;
• screwthreads between the pusher element and the drill spindle effective to move the jaws radially together on rotation of the spindle about the axis in a tightening direction relative to the guide and radially apart on opposite rotation of the spindle about the axis in a loosening direction;
• a coupling sleeve rotationally fixed to the jaw guide and movable between a tightening position rotationally fixed to the housing for movement of the jaws by the pusher element on rotation of the spindle and a drilling position rotationally fixed to the spindle and rotatable relative to the guide for joint rotation of the guide, jaws, and spindle.