Abstract: A machine for labeling or delabeling vessels is disclosed. The machine has a turret with a series of work stations and input and output transfer stations for supplying and removing vessels to and from the turret. Input and output star wheel assemblies are respectively positioned at the input and out stations. A supply conveyor is provided for transporting vessels to the input star wheel assembly. The supply conveyor includes a variable pitch feed screw opposite a pair of spring biased input guide rails. The input guide rails each have guide and a jam relief positions. An exit conveyor delineates an exit path of vessel travel downstream from the output star wheel assembly including an exit guide rail having an input end pivotally mounted at a location near the output star wheel assembly. The exit guide rail has a normal position adjacent the exit path and a jam relief position.