Patent ID: 8056906

Claim:
A drill chuck comprising: a chuck body centered on and rotatable about an axis; a jaw holder element rotatable on the body and formed with a plurality of angularly spaced guides; a sleeve element surrounding the holder element and body; respective jaws in the guides between the sleeve element and the body; means for shifting the jaws in the guides forward and together on rotation of the holder element in a tightening direction relative to the body and for opposite shifting of the jaws on rotation of the holder element relative to the body in an opposite loosening direction; interengaging formations on the sleeve element and on the jaw holder element limiting relative angular movement of the sleeve element on the jaw holder element between a pair of angularly offset end positions; latch means releasably retaining the sleeve element in the end positions; an annular array of teeth rotationally fixed to the body; a pawl angularly fixed on the holder element and having a tooth engageable with the teeth, the pawl tooth and the array of teeth being oriented such that when the pawl tooth is in a locking position engaged with the array of teeth the holder element can rotate relative to the body in the tightening direction but not in the loosening direction and when in a freeing position disengaged from the teeth the holder element can rotate freely in either direction relative to the body; spring means for urging the pawl into the locking position; cam means between the sleeve element and the pawl for displacing the pawl into the locking position in one of the end positions of the sleeve element and for displacing the pawl into the freeing position in the other end position of the sleeve element; and a plastic release ring rotatable on the body rearward of the sleeve element and rotationally coupled to one of the elements for operating same, for joint rotation therewith, and for loosening and tightening the chuck, the release ring being formed with at least one radially outwardly open blind hole lined with metal and adapted to receive a tool.