Abstract: A direct-drive spiral conveyor and a method for operating a spiral conveyor in which a sideflexing conveyor belt is positively driven in a helical path about the periphery of a rotating cylindrical drive drum. Parallel drive members extend in length along the periphery from the top to the bottom of the drive drum. The drive members engage drive faces on the inside edge of the conveyor belt and positively drive the inside edges along the helical path. The helical path is steeper at the entrance end—the bottom in an upgoing spiral, the top in a downgoing spiral—than at the opposite exit end and along a majority of the path.

Abstract: Overlapping cage-bar caps in a spiral belt conveyor. The cage bars of a spiral-conveyor cage are covered along the majority of their length by a main cage-bar cap fastened to the cage bar at the exit of the belt from the spiral. At the belt's entrance to the spiral, an entrance cage-bar cap overlaps a portion of the main cage-bar cap and the cage bar. The overlap is great enough to prevent a gap from forming along the length of the cage bar between the main cage-bar cap and the entrance cage-bar cap.

Abstract: Overlapping cage-bar caps in a spiral belt conveyor. The cage bars of a spiral-conveyor cage are covered along the majority of their length by a main cage-bar cap fastened to the cage bar at the exit of the belt from the spiral. At the belt's entrance to the spiral, an entrance cage-bar cap overlaps a portion of the main cage-bar cap and the cage bar. The overlap is great enough to prevent a gap from forming along the length of the cage bar between the main cage-bar cap and the entrance cage-bar cap.