EE WAS ATTEMPTING TO CLEAR A CLOD FROM FEED HOPPER IN PUG MILL TUNNEL. BELT WAS AT STOP & THE TRIP CABLE WAS PULLED LOCKING BELT OUT. THE EE WASHITTING SIDE OF CHUTE WITH SLEDGE HAMMER. AS HE SWUNG THE HAMMER THE LONG HANDLE HUNG ON AN I-BEAM CAUSING HIM TO MISS AND HIT THE ADJUSTING RODHANDLE WITH HIS RIGHT INDEX FINGER.