[varispeed]

This always grinds my gears. For some people "discoveries" are so obvious, they don't bother writing a paper let alone patenting it. Then someone goes and patents it...

[dotancohen]

Examples?

[varispeed]

https://ppubs.uspto.gov/pubwebapp/static/pages/ppubsbasic.ht...

Have a look. For instance in the search box enter "categories".

[dotancohen]

  > Search results
  > Results for query "(Categories).pn."

  > No records found

[varispeed]

I am sorry for not being precise. You should enter "Categories" in "For" input. (in the "Or" section)