Hammer-drill chuck

A drill chuck comprising:

• a chuck body rotatable about a chuck axis and provided centered on the axis with an annular array of teeth each having a steep flank and a shallow flank;
• a plurality of jaws angularly spaced on the body about the axis and radially displaceable relative to the body between inner and outer positions;
• a tightening ring axially fixed but rotatable about the axis on the body in a tightening direction and in an opposite loosening direction;
• means including a pair of screwthread formations between the tightening ring and the jaws for moving the jaws radially together on rotation of the tightening ring in the tightening direction and for moving the jaws radially apart on rotation of the tightening ring in the loosening direction;
• a locking member engageable with the teeth and angularly fixed on the tightening ring, the member being radially displaceable between a locking position engaging the teeth and preventing rotation of the body relative to the tightening ring in the loosening direction and a freeing position permitting free rotation of the body relative to the tightening ring in both directions;
• a setting ring axially fixed but angularly displaceable on the tightening ring and formed with a pair of angularly spaced and radially open seats;
• means including a pair of angularly spaced abutments between the setting ring and the tightening ring for limiting angular movement of the sleeve on the ring to movement between a pair of end positions of the sleeve on the ring;
• means including a cam on the setting ring engageable with the locking member for displacing the locking member into the locking position when the setting ring is in one of its end positions and for displacing the locking member into the freeing position when the setting ring is in the other of its end positions;
• latch means including a latch member angularly fixed on the tightening ring and engageable in the seats of the setting ring for releasably retaining the setting ring in its end positions;
• and
• a common spring extending angularly along and fixed angularly in the tightening ring and urging the latch member into the seats and the locking member into the freeing position.