A plunger assembly (30) is disposed on the access side of a conveyor (20). The conveyor (20) has a conveying surface upon which it transports articles by moving the conveying surface in a direction of flow (F). The plunger assembly (30) is mounted overhead vertically with respect to the conveying surface of the conveyor (20) such that sufficient clearance below the plunger assembly (30) is maintained to provide an access space through which the conveyor (20) and mechanisms and elements thereof can be accessed. Further, the plunger assembly (30) may be mounted both above and at least partially offset horizontally from the conveyor surface of the conveyor (20), such that no operative portion of the plunger assembly (30) breaks the plane (C) of the conveyor surface.