A patent has to be on something original or something that has never been done before. When I look at the Tab, I don't see that it's shape is any different than many of the old time campers that have been built for years so it probably wasn't patentable by the company that produces it. You can always go to the Patent Office online and do a search, if there is any patent on it, you should be able to find it. I think it is more likely that some of the components might have a patent, but not the whole trailer. Patents are expensive and time consuming so many people and businesses don't bother to get them.