I can't think of a direct example of a permanent magnet axial from the early era. The early permanent magnet stuff was radial. I suppose we could just about get Pixii into this category PM axial.

The early axial machines of Feranti, Mordey, Siemens etc were electromagnet. A clever patent would just say magnet and cover the lot. Not sure how much of the early stuff was patented anyway.

It does bother me that anything pre 1950 seems to have been totally forgotten and the world just seems to reinvent it rather than build on what has been done before.

The people that run the patent offices are pretty clueless and would never realise that there is nothing new in this.

Universities are particularly bad at reinventing the wheel, I suppose that if you are going for a PhD on something done a few years ago you might as well go for a patent.

while looking for another book on power electronics, i came across a google excerpted section of the book that was also copied into the text of a patent application as if it were the original work of the guy applying for the patent.

i really wonder how many of these patents would hold up to court review?

wouldn't surprise me to see a new patent on a "wheel" come up in  a google search.

not much new under the sun it would seem.

notice in the OP link, the reference to a stator with toroid coils?
hmmmm, sounds like my old torogen design to me,, and even my old torogen was designed on the shoulders of a design from the 50's, which was probably built on a design from even earlier in the century.

i wonder if those that get these patents, ever make a dime for their effort?