For the safety sake of the user/purchaser as well as your financial well-being I think it would be prudent to at least have your inventions checked by an Engineer or a consultant to a safety association. In Canada we have CSA approvals, they test products and give it an approval. This does not negate court action towards you. In all seriousness have you considered just how impossible personaly injury is? I was being serious when I said what I said about the act that may follow if one side let loose.