A ROLL OF BELT 24"" WAS BEING INSTALLED ON CONVEYER WHEN IT BECAME LODGED AGAINST CHAIN, WHEN EMPLOYEE PULLED SIDEWAYS ON BELT CHAIN CAME UNHOOKED. BELT FELL STRIKING EMPLOYEE IN SHOULDER, DISLOCATING SHOULDER TOOK FOR MEDICAL TREATMENT MISSED MONDAY RETURNED FOR WORK TUES MORN 6:30.