A chuck has a chuck body formed centered on an axis with a rearwardly open hole adapted to receive a drill spindle and with a plurality of axially forwardly and axially rearwardly open guide passages, an adjustment ring axially fixed but rotatable about the axis on the chuck body and formed with an internal...http://www.google.es/patents/US5927914?utm_source=gb-gplus-sharePatente US5927914 - Compact chuck assembly for a power drill
