WHILE INSTALLING A RESIN GROUTED ROOF BOLT, THE INDIVIDUAL WAS RAISING THE DRILL BOX UP WITH A CHUCK WRENCH IN DRIL CHUCK. THIS WAS TO PUSH AND SPIN THE ROOF BOLT INTO HOLE. AS THE CHUCK WRENC H CONTACTED THE OF THE ROOF BOLT, THE JOINT MOVED AND PINNED INDIVIDUALS THUMB BETWEEN CHUCK WRENCH AND DRILL GUIDE BRACKET, CAUSING A 1/4"" CUT ON RIGHT THUMB NEEDING 2 STITCHES TO CLOSE.