EMPLOYEE WAS CALLED TO ""MUD ROOM"" TO REPAIR V BELT THAT HAD COME OFF THE HEAD ROLLER PULLEY ON THE DISCHARGE BELT FROM THE MIXER. NO ONE WAS AWARE HE CAME IN AND STARTED REPAIRS. HE BEGAN TO R EPAIR V BELT WHEN MIXER OPERATOR ENGAGED BELT TRAPPING HIS HAND BETWEEN PULLEY AND BELT. THE DOCTOR TRIED TO SAVE HIS FINGER BUT LATER AMPUTATEDTHE RIGHT INDEX TO 1ST JOINT.