FWIW, having looked at the patent in question (Gillette, 1988), I have to say it's pretty trick. The helical honing wheels lets them use the opposing wheels to stabilize the blade during the honing operation in much the same way that the old straight razor dual-wheel grinding setups did, and by varying the diameter and grit along the helical surface they pull off both a smoothly rounded bevel and fast coarse honing and fine finish honing all in one smooth hat trick. I'm impressed.