The 1890s pedals by Ramsey and Diebel have the cage below the pedal axle axis, so it's not quite the same, though I consider them to be the same basic concept. .However, there was a French pedal in the 1950s called the Sanasax (translates to without spindle)which placed the cage top in line with the pedal axle axis, just like the Hi-E and Shimano AX pedals.The concept was revived about 10 years with a clipless version called the SMp Side Mount pedal). What we would consider the pedal body is actually a cleat that clips onto a sealed cartridge bearing with axle! This makes the float plate completely independent of the cleat retention. I've never seen one in person but they are out there. It only goes to show that great ideas never die, though market acceptance can be problematic!