A chuck includes a generally cylindrical body constructed of aluminum and a plurality of jaws moveably disposed with respect to the body in communication with the body's axial bore. A generally cylindrical sleeve is rotatably mounted about the body in operative communication with the jaws so rotation of the sleeve in a closing direction moves the jaws towards the axis of the axial bore and rotation of the sleeve in an opening direction moves the jaws away from the axis. A bearing has a first race adjacent the body, a second race adjacent the sleeve and at least one bearing element disposed between the first race and the second race. One of the first race and the second race defines a ratchet. The other of the first race and the second race defines a pawl biased toward the ratchet. The ratchet and the pawl are configured so that when the pawl engages the ratchet, the ratchet and pawl prevent the second race from rotating in the opening direction with respect to the first race.
1. A chuck for use with a manual or powered driver having a rotatable drive shaft, said chuck comprising:
a generally cylindrical body comprised of aluminum, said body having a nose section and a tail section, said tail section being configured to rotate with said drive shaft and said nose section having an axial bore formed therein;
a plurality of jaws movably disposed with respect to said body in communication with said axial bore;
a sleeve rotatably mounted about said body in operative communication with said jaws so that rotation of said sleeve in a closing direction moves said jaws toward the axis of said axial bore and rotation of said sleeve in an opening direction moves said jaws away from said axis; and
a bearing having a first race adjacent said body, a second race adjacent said sleeve and at least one bearing element disposed between said first race and said second race, wherein one of said first race and said second race defines a ratchet, wherein the other of said first race and said second race defines a pawl biased toward said ratchet and wherein said ratchet and said pawl are configured so that when said chuck is in first state, said first race and said second race are rotatable about said body, and when said chuck is in a second state in which said pawl engages said ratchet, said ratchet and pawl prevent said second race from rotating in said opening direction with respect to said first race.
2. The chuck as in claim 1 , wherein said sleeve includes a first sleeve and a second sleeve and wherein said first sleeve rotationally drives said second sleeve but is movable with respect to said second sleeve between a first position and a second position.
3. The chuck as in claim 2 , wherein said first sleeve defines a cam surface disposed with respect to said pawl so that said cam surface disengages said pawl from said ratchet when said first sleeve is in said first position with respect to said second sleeve and releases said pawl to engage said ratchet when said first sleeve is in said second position with respect to said second sleeve.
4. The chuck as in claim 1 , wherein said sleeve is an annular nut having threads formed thereon in engagement with threads on said jaws so that rotation of said nut about said body moves said jaws toward or away from said axis.
5. The chuck as in claim 4 , wherein said pawl is deflectable and wherein said pawl and said ratchet are configured so that when said pawl engages said ratchet, said pawl and ratchet permit said second race to rotate in said closing direction with respect to said first race but prevent said second race from rotating in said opening direction with respect to said first race.
6. The chuck as in claim 4 , including an outer sleeve in operative communication with said nut so that said outer sleeve rotationally drives said nut but is rotatable with respect to said nut between a first rotational position and a second rotational position, wherein said outer sleeve defines a cam surface disposed with respect to said pawl so that said cam surface disengages said pawl from said ratchet when said outer sleeve is in said first position with respect to said nut and releases said pawl to engage said ratchet when said outer sleeve is in said second position with respect to said nut.
7. A chuck for use with a manual or powered driver having a rotatable drive shaft, said chuck comprising: a generally cylindrical body comprised of aluminum, said body having a nose section and a tail section, said tail section being configured to rotate with said drive shaft and said nose section having an axial bore formed therein and a plurality of passageways formed therethrough and intersecting said axial bore; a plurality of jaws movably disposed in said passageways; a generally cylindrical sleeve rotatably mounted about said body; a nut rotatably mounted about said body and in operative communication with said jaws so that rotation of said nut in a closing direction moves said jaws toward the axis of said axial bore and rotation of said nut in an opening direction moves said jaws away from said axis; and a bearing having a first race adjacent said body, a second race adjacent said nut and a plurality of bearing elements disposed between said first race and said second race, wherein said first race defines a ratchet, wherein said second race defines a deflectable first pawl biased toward said ratchet and wherein said ratchet and said first pawl are configured so that when said chuck is in a first state, said first race and said second race are rotatable about said body, and when said chuck is in a second state in which said first pawl engages said ratchet, said ratchet and first pawl permit said second race to rotate in said closing direction with respect to said first race but prevent said second race from rotating in said opening direction with respect to said first race, wherein said sleeve is in operative communication with said nut so that said sleeve rotationally drives said nut but is rotatable with respect to said nut between a first rotational position and a second rotational position, and wherein said sleeve defines a cam surface disposed with respect to said first pawl so that said cam surface disengages said first pawl from said ratchet when said sleeve is in said first position with respect to said nut and releases said first pawl to engage said ratchet when said sleeve is in said second position with respect to said nut.
8. The chuck as in claim 7 , wherein said second race is rotationally fixed to said nut.
9. The chuck as in claim 8 , wherein said second race includes a dog extending therefrom into a corresponding groove in said nut.
10. The chuck as in claim 8 , wherein said sleeve rotationally drives said nut through said second race.
11. The chuck as in claim 10 , wherein said second race includes a second deflectable pawl, wherein said second pawl is biased toward an inner circumferential surface of said sleeve and wherein said inner circumferential surface defines two recesses disposed with respect to said second race so that said second pawl is received by a first said recess when said sleeve is in said first position and so that said second pawl is received by a second said recess when said sleeve is in said second position.
12. The chuck as in claim 11 , wherein said inner circumferential surface defines said cam surface and defines a third recess disposed adjacent said cam surface and with respect to said first pawl so that said first pawl engages said cam surface when said sleeve is in said first position and so that said first pawl is received by said third recess when said sleeve is in said second position.
13. The chuck as in claim 7 , wherein an inner circumferential surface of said sleeve defines said cam surface and defines a recess disposed adjacent said cam surface and with respect to said first pawl so that said first pawl engages said cam surface when said sleeve is in said first position and so that said first pawl is received by said recess when said sleeve is in said second position.
14. The chuck as in claim 7 , including a plurality of said first pawls and a corresponding plurality of said cam surfaces.
15. A chuck for use with a manual or powered driver having a rotatable drive shaft, said chuck comprising: a generally cylindrical body comprised of aluminum, said body having a nose section and a tail section, said tail section being configured to rotate with said drive shaft and said nose section having an axial bore formed therein and a plurality of passageways formed therethrough and intersecting said axial bore; a plurality of jaws movably disposed in said passageways; a generally cylindrical sleeve rotatably mounted about said body; a nut rotatably mounted about said body and in operative communication with said jaws so that rotation of said nut in a closing direction moves said jaws toward the axis of said axial bore and rotation of said nut in an opening direction moves said jaws away from said axis; and a bearing having a first race rotationally fixed to said body, a second race rotationally fixed to said nut and a plurality of bearing elements disposed between said first race and said second race, wherein said first race defines a ratchet, wherein said second race defines a deflectable first pawl biased toward said ratchet and wherein said ratchet and said first pawl are configured so that when said chuck is in a first state, said first race and said second race are rotatable about said body, and when said chuck is in a second state in which said first pawl engages said ratchet, said ratchet and first pawl permit said second race to rotate in said closing direction with respect to said first race but prevent said second race from rotating in said opening direction with respect to said first race, wherein said sleeve is in operative communication with said nut so that said sleeve rotationally drives said nut but is rotatable with respect to said nut between a first rotational position and a second rotational position, and wherein said sleeve defines a cam surface disposed with respect to said first pawl so that said cam surface disengages said first pawl from said ratchet when said sleeve is in said first position with respect to said nut and releases said first pawl to engage said ratchet when said sleeve is in said second position with respect to said nut.
16. The chuck as in claim 15 , wherein said first race includes a second deflectable pawl, wherein said second pawl is biased toward an inner circumferential surface of said sleeve and wherein said inner circumferential surface defines two recesses disposed with respect to said first race so that said second pawl is received by a first said recess when said sleeve is in said first position and so that said second pawl is received by a second said recess when said sleeve is in said second position.
17. The chuck as in claim 16 , including a plurality of said first pawls, said second pawls, said cam surfaces and said recesses.