WHILE WORKING ON A SCREW CONVEYOR, EE GOT HIS LEFT FOOT WEDGED BETWEEN THE SCREW BLADE AND THE SCREW HOUSING. EE AND THREE OTHERS WERE CLEANING THE SCREW WITHOUT LOCKING OUT THE CONVEYOR SYSTE M. EE WAS TREATED AT HOSPITAL FOR AN ABRASION OFTHE LEFT ANKLE AND RELEASED TO LIGHT DUTY. THE SCREW CONVEYOR SWITCH HAD BEEN TURNED ON ACCIDENTLY.