Centerless grinding machine with ferris wheel arrangement

In a centerless grinding machine for grinding the inner surface of a cylindrical, tubular workpiece concentric with the outer surface, the combination of a rotatable ferris wheel means having multiple, circumferentially-spaced, workpiece-receiving pockets, a workpiece feed means at a first loading position adjacent the circumference of said ferris wheel means, a stationary workpiece alignment shoe means at a second grinding position adjacent the outer circumference of said ferris wheel means and a workpiece discharge means at a third unloading position adjacent the circumference of said ferris wheel means, indexer means for incrementally rotating said ferris wheel means to place each pocket thereof successively at the loading, grinding and unloading position, said ferris wheel means having workpiece alignment shoe means located in each of said pockets such that said stationary shoe means and the respective pocket shoe means support and align the outer workpiece surface when the respective pocket is at the grinding position and retain the workpiece substantially inside said respective pocket at the grinding position, a grinding wheel means on one side of said ferris wheel means movable axially inside the workpiece in said pocket in the grinding position and movable radially outward toward said stationary shoe means into engagement with the inner workpiece surface to grind said inner surface while said outer surface is aligned by said stationary shoe means and pocket shoe means, and a workpiece driver means on the other side of said ferris wheel means for rotating the workpiece in the pocket in the grinding position.