Patent ID: 8522960

Claim:
A spiral belt conveyor comprising: an upwardly extending central frame structure having an upper end and a lower end; a helical track concentrically disposed around the central frame structure, the helical track defining an inner helical path and an outer helical path, the inner helical path having a smaller radius than the outer helical path, the inner and outer helical paths each having an upper end and a lower end, the upper ends meeting at the upper end of the central frame structure; a first linear track segment leading to the helical track at the lower end of the inner helical path; a second linear track segment leading to the helical track at the lower end of the outer helical path, wherein the first and second linear track segments are collinear in a vertical projection; at least one conveyor belt mounted on the helical track and the first and second linear track segments; at least one drive unit disposed in line with the first and second linear track segments and driving the conveyor belt upward or downward on the inner helical path and oppositely on the outer helical path.