Again, I am not a Patent Lawyer, but that is exactly why it is worth having one to word your patent very carefully indeed using exact definitions.
In theory everything mechanical is some form of wheel or lever, so theoretically nothing mechanical since their invention is "new". A gear wheel is a wheel with levers around its circumference.
Often a mechanical invention combines familiar parts arranged in novel ways or with a new purpose or concept in mind. A turbine existed before the steam turbine, which in turn existed before turbo jet. A compressor pre-existed in the form of a piston in a cylinder.
So to the extent of my knowledge a patent can be granted if familiar elements are arranged in a novel way and/or for a novel purpose.
So it comes down to LEGAL definitions of novel, and a Legal decision is not necessarily the right one!
It is getting much harder to Patent mechanical inventions; I am not discussing electronic, chemical or other inventions because they are not my area of work. Over the years I have gleaned enough to re-state with some confidence what I said earlier about the US (and some other) Patent Offices at the time of the Wright brothers, indeed I believe that internationally the USPO became notorious and eventually had to act to reduce corruption, partisanship and vested interests. I do NOT mean to insult Americans, just to state what I believe is a matter of record. I cannot be sure yet, but I have reason to believe that one or more of the Wright Brothers' patents would probably not have been granted elsewhere.
I must admit that I had heard of some controversy over the Wrights long before this thread, but I had always accepted them as "the First", and I also accepted that they invented the Wind Tunnel and 3 Axis control. Now I am starting to wonder if Legal Definitions have decreed their priority at least as much as some of the facts. For instance, I now know that they did not invent the wind tunnel and were not the first to use it for aeronautical research.
I still do not agree with much of Simplex's words, but I enjoy the debate that they have started.
And I still have great respect for the Wright Brothers; whatever the facts, personalities and Legal niceties, they worked hard, studied, practicesd, achieved a lot and were true pioneers.