Lawn Mower Blade Sharpening Tool

I generally sharpen the blades for my 60 inch cut mower 5 sets per session.  The mower uses 3 blades, so that's 15 blades.  I use a Bench grinder but holding them while sharpening is a tiring, difficult job.   I thought, "There must be a better way of doing this."  I made this tool which consists of a pair of Vice Grips welded to an adjustable bracket that slides back and forth on a long rod mounted on the front of the bench, below the grinder.  It really works good.  Sorry I cannot furnish photos of it's construction, but I would be glad to take some more detailed photos of it if anyone is interested.