That's simple and very effective. I'm calling the patent office on Monday and get a patent on that. Then you can come work for me.
BUT, you might want to consider getting a patent on it. I've never seen a product like it and it looks like it will work great. I'm with Richard. The wing nut will come loose. The type of lock down nut he pictured would be the best thing to use. Good luck with it. I do think you should send it in for patenting.