EE WAS INSTALLING GEAR BOX ON DRILL USING AN OVERHEAD CRANE TO LIFT GEAR BOX. AS GEAR BOX CONTACTED DRILL MAST, THE CHAIN WENT SLACK AND GEAR BOX TOPPLED OVER. AS IT FELL, IT PUT WEIGHT BACK O N CHAIN AND EE''S FINGERS WERE CAUGHT BETWEEN CHAIN AND GEAR BOX. PARTIAL AMPUTATION OF RING AND SMALL FINGER OF LEFT HAND.