Abstract: A spiral conveyor for positively driving a conveyor belt along a helical path. The spiral conveyor includes a rotating cylindrical tower with parallel drive members extending from the bottom to the top of the tower on its periphery. Each drive member includes an outwardly protruding ridge that varies in height from the bottom to the top of the tower. The variations in height facilitate the belt's entry onto and exit from the tower and robust, positive driving engagement with the inside edge of the belt along the majority of its path along the tower.

Abstract: A spiral conveyor having a self-stacking conveyor belt positively driven on a helical path up or down a drive drum. Stacker supports at opposite sides of the belt support the tiers above. Locking structure on the outer stacker supports interlock consecutive tiers. Drive members on the drive drum have a belt entrance segment and a positive-drive segment. The positive-drive segment has ridges that engage the inner side of the belt without slip. The entrance segment provides a smooth reduction in drum diameter without drive ridges to multiple belt tiers entering the helical path.

Abstract: A spiral conveyor for positively driving a conveyor belt along a helical path. The spiral conveyor includes a rotating cylindrical tower with parallel drive members extending from the bottom to the top of the tower on its periphery. Each drive member includes an outwardly protruding ridge that varies in height from the bottom to the top of the tower. The variations in height facilitate the belt's entry onto and exit from the tower and robust, positive driving engagement with the inside edge of the belt along the majority of its path along the tower.

Abstract: A spiral conveyor having a self-stacking conveyor belt positively driven on a helical path up or down a drive drum. Stacker supports at opposite sides of the belt support the tiers above. Locking structure on the outer stacker supports interlock consecutive tiers. Drive members on the drive drum have a belt entrance segment and a positive-drive segment. The positive-drive segment has ridges that engage the inner side of the belt without slip. The entrance segment provides a smooth reduction in drum diameter without drive ridges to multiple belt tiers entering the helical path.

Abstract: A spiral conveyor for positively driving a conveyor belt along a helical path. The spiral conveyor includes a rotating cylindrical tower with parallel drive members extending from the bottom to the top of the tower on its periphery. Each drive member includes an outwardly protruding ridge that varies in height from the bottom to the top of the tower. The variations in height facilitate the belt's entry onto and exit from the tower and robust, positive driving engagement with the inside edge of the belt along the majority of its path along the tower.

Abstract: A spiral conveyor for positively driving a conveyor belt along a helical path. The spiral conveyor includes a rotating cylindrical tower with parallel drive members extending from the bottom to the top of the tower on its periphery. Each drive member includes an outwardly protruding ridge that varies in height from the bottom to the top of the tower. The variations in height facilitate the belt's entry onto and exit from the tower and robust, positive driving engagement with the inside edge of the belt along the majority of its path along the tower.

Abstract: A spiral conveyor for positively driving a conveyor belt along a helical path. The spiral conveyor includes a rotating cylindrical tower with parallel drive members extending from the bottom to the top of the tower on its periphery. Each drive member includes an outwardly protruding ridge that varies in height from the bottom to the top of the tower. The variations in height facilitate the belt's entry onto and exit from the tower and robust, positive driving engagement with the inside edge of the belt along the majority of its path along the tower.

Abstract: A spiral conveyor and methods for positively driving a conveyor belt along a helical path. The spiral conveyor includes a rotating cylindrical tower with parallel drive members extending from the bottom to the top of the tower on its periphery. Each drive member includes an outwardly protruding ridge that varies in height from the bottom to the top of the tower. The variations in height facilitate the belt's entry onto and exit from the tower and robust, positive driving engagement with the inside edge of the belt along the majority of its path along the tower.

Abstract: A spiral conveyor and methods for positively driving a conveyor belt along a helical path. The spiral conveyor includes a rotating cylindrical tower with parallel drive members extending from the bottom to the top of the tower on its periphery. Each drive member includes an outwardly protruding ridge that varies in height from the bottom to the top of the tower. The variations in height facilitate the belt's entry onto and exit from the tower and robust, positive driving engagement with the inside edge of the belt along the majority of its path along the tower.

Abstract: A spiral conveyor for positively driving a conveyor belt along a helical path. The spiral conveyor includes a rotating cylindrical tower with parallel drive members extending from the bottom to the top of the tower on its periphery. Each drive member includes an outwardly protruding ridge that varies in height from the bottom to the top of the tower. The variations in height facilitate the belt's entry onto and exit from the tower and robust, positive driving engagement with the inside edge of the belt along the majority of its path along the tower.

Abstract: A spiral conveyor for positively driving a conveyor belt along a helical path. The spiral conveyor includes a rotating cylindrical tower with parallel drive members extending from the bottom to the top of the tower on its periphery. Each drive member includes an outwardly protruding ridge that varies in height from the bottom to the top of the tower. The variations in height facilitate the belt's entry onto and exit from the tower and robust, positive driving engagement with the inside edge of the belt along the majority of its path along the tower.

Abstract: A spiral conveyor for positively driving a conveyor belt along a helical path. The spiral conveyor includes a rotating cylindrical tower with parallel drive members extending from the bottom to the top of the tower on its periphery. Each drive member includes an outwardly protruding ridge that varies in height from the bottom to the top of the tower. The variations in height facilitate the belt's entry onto and exit from the tower and robust, positive driving engagement with the inside edge of the belt along the majority of its path along the tower.

Abstract: A spiral conveyor for positively driving a conveyor belt along a helical path. The spiral conveyor includes a rotating cylindrical tower with parallel drive members extending from the bottom to the top of the tower on its periphery. Each drive member includes an outwardly protruding ridge that varies in height from the bottom to the top of the tower. The variations in height facilitate the belt's entry onto and exit from the tower and robust, positive driving engagement with the inside edge of the belt along the majority of its path along the tower.

Abstract: A spiral conveyor for positively driving a conveyor belt along a helical path. The spiral conveyor includes a rotating cylindrical tower with parallel drive members extending from the bottom to the top of the tower on its periphery. Each drive member includes an outwardly protruding ridge that varies in height from the bottom to the top of the tower. The variations in height facilitate the belt's entry onto and exit from the tower and robust, positive driving engagement with the inside edge of the belt along the majority of its path along the tower.

Abstract: A spiral conveyor for positively driving a conveyor belt along a helical path. The spiral conveyor includes a rotating cylindrical tower with parallel drive members extending from the bottom to the top of the tower on its periphery. Each drive member includes an outwardly protruding ridge that varies in height from the bottom to the top of the tower. The variations in height facilitate the belt's entry onto and exit from the tower and robust, positive driving engagement with the inside edge of the belt along the majority of its path along the tower.

Abstract: A spiral conveyor for positively driving a conveyor belt along a helical path. The spiral conveyor includes a rotating cylindrical tower with parallel drive members extending from the bottom to the top of the tower on its periphery. Each drive member includes an outwardly protruding ridge that varies in height from the bottom to the top of the tower. The variations in height facilitate the belt's entry onto and exit from the tower and robust, positive driving engagement with the inside edge of the belt along the majority of its path along the tower.

Abstract: A spiral conveyor for positively driving a conveyor belt (20) along a helical path. The spiral conveyor includes a rotating cylindrical tower (10) with parallel drive members (14) extending from the bottom to the top of the tower on its periphery. Each drive member includes an outwardly protruding ridge (28) that varies in height from the bottom to the top of the tower. The variations in height facilitate the belt's entry onto and exit from the tower and robust, positive driving engagement with the inside edge of the belt along the majority of its path along the tower. In another version, a conveyor belt has teeth (62) with guide surfaces (78, 79) at the inside edge of the belt. The teeth guide the drive members between belt rows into driving engagement with drive faces at the inside edge of the belt.

Abstract: A spiral conveyor for positively driving a hinged, modular conveyor belt along a helical path. The spiral conveyor includes a rotating cylindrical tower with parallel drive members extending from the bottom to the top of the tower on its periphery. Each drive member includes an outwardly protruding ridge extending from the bottom to the top of the tower for engaging the inside edges of the belt. In one version, the ridges at the entrance end of the spiral are movable to provide a gradually decreasing spacing between consecutive ridges as the belt enters the spiral. In another version, alignment elements at the entrance end align belt-edge structure with the tip ends of associated ridges to help engagement. In another version, the ridges at a discharge end of the tower are retractable between an extended position driving the belt and a retracted position.

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.