I’ll buy that. I don’t claim to be an expert. But I do know that if you prohibit what is commonly known as a switchblade, you have tied yourself to the common definition.
Unless your law then says, “and all other spring-assisted knives.”
Understand, the ordnances are written by legislators with consultation by lawyers. They are written very loosely so they can be used in a variety of circumstances. If the law was written as tightly as you are alleging with your switchblade argument, you’d have to have a law for every conceivable situation and circumstance.
Again, I’m not arguing with your position, It is a VERY POORLY written law. Probably something was was thrown together because a previous case was lost on just such a technicality.