I spent four years developing a patent-able idea, but there already is a U.S. patent that claims to produce exactly the same result but has a critical flaw that renders it inoperable.
Any person skilled in the art following the the outlined claims and interpreting the terms in said claims with an authoritative english dictionary, or even constructing it according to the specification, will quickly realise that the entire construction can amount to nothing but a very complex paperweight because something that is mentioned explicitly makes it non-working.
Obviously either the inventor meant something and had the right idea, but the patent clerk wrote something else down, or the inventor didn't fully understand what they were talking about but patented a gut feeling.
What I mean to say with this is, if I were to produce and sell a working product that fulfils 99% of the claims, and were to be sued, I am certain I would win.
However, my question is, how likely can I patent my version of the widget?
99% of the claims would be verbatim, except for one word, which is similar, but critically different. The specification and drawings however would differ substantially.
would they call it an obvious correction and not really a novelty? can a patent that cannot work be considered prior art?
will I get a patent or will the whole thing become effective public domain?