EE WAS USING A CHAIN RATCHET TO REMOVE A CABLE TRAY OFF OF OLD STAGE LOADER IN OLD PULLOUT AREA WHEN CHAIN RATCHET CAME LOOSE STRIKING HIM IN THE MOUTH, CAUSING A LACERATION REQUIRING 4 SUTURES. THIS WAS EE'S LAST SHIFT BEFORE STARTING HIS ALREADY-SCHEDULED VACATION. HE RETURNED TO WORK ON NEXT SCHEDULED SHIFT.