A chuck including a body having a tail section and a nose section defining an axial bore. A plurality of jaws are movably disposed with respect to the axial bore and a nut is in threaded engagement with the jaws. A sleeve engages the nut so that rotation of the sleeve moves the jaws. A first ring defines a plurality of teeth and a second ring is rotatable relative to the nut over a limited arc and defines at least one pawl. In a first state, the second ring is non-rotatable relative to the first ring in both the opening and closing directions, and in a second state the first and second rings are rotatable about the body, and the second ring is rotatable relative to the first ring in the closing direction.
1. A chuck for securing a tool with a shank to a manual or powered driver having a drive shaft, the chuck comprising:
a. a body having a nose section and a tail section, the nose section having an axial bore formed therein;
b. a plurality of jaws movably disposed with respect to the body in communication with the axial bore, the jaws defining a first plurality of threads thereon;
c. a nut defining a plurality of threads on an inner circumference thereof, the nut being in threaded engagement with the jaws;
d. a sleeve rotatably mounted about the body and in driving engagement with the nut so that rotation of the sleeve moves the jaws;
e. a planar first ring having a front face, a rear face and a plurality of teeth disposed about a periphery thereof; and
f. a second ring that is rotatable relative to the nut over a limited arc, the second ring defining at least one tab thereon, the at least one tab continuously engaging the plurality of teeth so that,
when the chuck is in a first state, the planar first ring and the second ring are rotationally coupled to each other so that the first ring and the second ring are rotatable about the body, and
when the chuck is in a second state in which the jaws clamp onto the shank of the tool, the second ring is rotatable relative to the planar first ring in a closing direction so that the at least one tab is biased radially outwardly from an innermost first position to an outermost second position by each tooth as the second ring rotates in the closing direction relative to the first ring.
2. The chuck as in claim 1 , wherein the second ring further comprises at least one positioning element extending radially inwardly from the second ring, the at least one positioning element abutting the front face of the first ring.
3. The chuck as in claim 2 , wherein the at least one positioning element extends from a front edge of the second ring.